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Sample records for kill biofilm-associated amoebae

  1. Pseudomonas aeruginosa uses type III secretion system to kill biofilm-associated amoebae

    Matz, Carsten; Moreno, Ana Maria; Alhede, Morten

    2008-01-01

    Bacteria and protozoa coexist in a wide range of biofilm communities of natural, technical and medical importance. Generally, this interaction is characterized by the extensive grazing activity of protozoa on bacterial prey populations. We hypothesized that the close spatial coexistence in biofilms...... suggest that conserved virulence pathways and specifically the T3SS play a central role in bacteria- protozoa interactions in biofilms and may be instrumental for the environmental persistence and evolution of opportunistic bacterial pathogens....

  2. Characterization of Acinetobacter baumannii biofilm associated components

    Brossard, Kari A.

    Acinetobacter baumannii is a Gram-negative aerobic coccobaccillus that is a major cause of nosocomial infections worldwide. Infected individuals may develop pneumonia, urinary tract, wound, and other infections that are associated with the use of indwelling medical devices such as catheters and mechanical ventilation. Treatment is difficult because many A. baumannii isolates have developed multi-drug resistance and the bacterium can persist on abiotic surfaces. Persistence and resistance may be due to formation of biofilms, which leads to long-term colonization, evasion of the host immune system and resistance to treatment with antibiotics and disinfectants. While biofilms are complex multifaceted structures, two bacterial components that have been shown to be important in formation and stability are exopolysaccharides (EPS) and the biofilm-associated protein (Bap). An EPS, poly-beta-1,6-N-acetylglucosamine, PNAG, has been described for E. coli and S. epidermidis. PNAG acts as an intercellular adhesin. Production of this adhesin is dependent on the pga/icaABCD locus. We have identified a homologous locus in A. baumannii 307-0294 that is involved in production of an exopolysaccharide, recognized by an anti-PNAG antibody. We hypothesized that the A. baumannii pgaABCD locus plays a role in biofilm formation, and protection against host innate defenses and disinfectants suggesting that PNAG is a possible virulence factor for the organism. The first aim of this thesis will define the pgaABCD locus. We have previously identified Bap, a protein with similarity to those described for S. aureus and we have demonstrated that this protein is involved in maintaining the stability of biofilms on glass. We hypothesized that A. baumannii Bap plays a role in persistence and pathogenesis and is regulated by quorum sensing. In our second aim we will examine the role of Bap in attachment and biofilm formation on medically relevant surfaces and also determine if Bap is involved in

  3. Towards diagnostic guidelines for biofilm-associated infections

    Hall-Stoodley, Luanne; Stoodley, Paul; Kathju, Sandeep

    2012-01-01

    Biofilms associated with the human body, particularly in typically sterile locations, are difficult to diagnose and treat effectively because of their recalcitrance to conventional antibiotic therapy and host immune responses. The study of biofilms in medicine today requires a translational appro...

  4. Microsensor and transcriptomic signatures of oxygen depletion in biofilms associated with chronic wounds: Biofilms and oxygen

    James, Garth A. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Ge Zhao, Alice [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Usui, Marcia [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Underwood, Robert A. [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Nguyen, Hung [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; Beyenal, Haluk [The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman Washington; deLancey Pulcini, Elinor [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Agostinho Hunt, Alessandra [Department of Microbiology and Molecular Genetics, 5180 Biomedical and Physical Sciences, Michigan State University, East Lansing Michigan; Bernstein, Hans C. [Pacific Northwest National Laboratory, Chemical and Biological Signature Science, Richland Washington; Fleckman, Philip [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Olerud, John [Division of Dermatology, Department of Medicine, University of Washington, Seattle Washington; Williamson, Kerry S. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Franklin, Michael J. [Center for Biofilm Engineering, Montana State University, Bozeman Montana; Stewart, Philip S. [Center for Biofilm Engineering, Montana State University, Bozeman Montana

    2016-02-16

    Polymicrobial biofilms have been implicated in delayed wound healing, although the mechanisms by which biofilms impair wound healing are poorly understood. Many species of bacteria produce exotoxins and exoenzymes that may inhibit healing. In addition, oxygen consumption by biofilms may impede wound healing. In this study, we used oxygen microsensors to measure oxygen transects through in vitro-cultured biofilms, biofilms formed in vivo in a diabetic (db/db) mouse model, and ex vivo human chronic wound specimens. The results show that oxygen levels within both euthanized and live mouse wounds had steep gradients that reached minima ranging from 19 to 61% oxygen partial pressure, compared to atmospheric oxygen levels. The oxygen gradients in the mouse wounds were similar to those observed for clinical isolates cultured in vitro and for human ex vivo scabs. No oxygen gradients were observed for heat-killed scabs, suggesting that active metabolism by the viable bacteria contributed to the reduced oxygen partial pressure of the wounds. To characterize the metabolic activities of the bacteria in the mouse wounds, we performed transcriptomics analyses of Pseudomonas aeruginosa biofilms associated with the db/db mice wounds using Affymetrix microarrays. The results demonstrated that the bacteria expressed genes for metabolic activities associated with cell growth. Interestingly, the transcriptome results indicated that the bacteria within the wounds also experienced oxygen-limitation stress. Among the bacterial genes that were expressed in vivo were genes associated with the Anr-mediated hypoxia-stress response. Other bacterial stress response genes highly expressed in vivo were genes associated with stationary-phase growth, osmotic stress, and RpoH-mediated heat shock stress. Overall, the results support the hypothesis that the metabolic activities of bacteria in biofilms act as oxygen sinks in chronic wounds and that the depletion of oxygen contributes to the

  5. Sensitivity of planktonic and biofilm-associated Aeromonas spp. to ionizing radiation

    Nagar, Vandan; Bandekar, J.R.

    2015-01-01

    Genus Aeromonas has emerged as an important human pathogen because it causes a variety of diseases including gastroenteritis and extra-intestinal infections. Aeromonas have the ability to adhere and form biofilms on food surfaces and food contact surfaces. Biofilm formation on foods and food contact surfaces is the major reason for contamination, cross contamination and post-processing contamination of the final food product leading to food spoilage, product rejection, economic losses and food-borne diseases. Biofilms have shown high resistance to heat, desiccation, acidic condition, high salt concentration, antibiotics and other food preservatives. Earlier studies in our laboratory have shown that ionizing radiation effectively inactivates Aeromonas in different food products. However, the relative efficacy of this process against biofilm associated cells versus free-living planktonic cells of Aeromonas is not well documented. Therefore, the dose of gamma radiation required to reduce the population by 90% (D10) was calculated for planktonic and biofilm-associated A. salmonicida Y567 and A. hydrophila A331 cells. Both A. hydrophila A331 and A. salmonicida Y567 expressed significant ability to attach and grow on glass surface following incubation at 30℃ in TSB. Ionizing radiation effectively reduced the populations of both planktonic and biofilm-associated cells for both the strains. Mean cell counts of survivors and surviving fraction of planktonic and biofilm-associated cells decreased with increased irradiation doses. The D10 values of planktonic cells and biofilm cells for A. salmonicida (Y567) were 232.65 Gy and 248.41 Gy, respectively; whereas, the D10 values of planktonic cells and biofilm cells for A. hydrophila (A331) were 249.2 Gy and 240.2 Gy respectively. No significant difference in the D10 values of planktonic and biofilm associated Aeromonas was observed. The influence of the cultured state of the organism, i.e., planktonic versus biofilm associated

  6. Evaluation of the Enterococcus faecalis Biofilm-Associated Virulence Factors AhrC and Eep in Rat Foreign Body Osteomyelitis and In Vitro Biofilm-Associated Antimicrobial Resistance.

    Kristi L Frank

    Full Text Available Enterococcus faecalis can cause healthcare-associated biofilm infections, including those of orthopedic devices. Treatment of enterococcal prosthetic joint infection is difficult, in part, due to biofilm-associated antimicrobial resistance. We previously showed that the E. faecalis OG1RF genes ahrC and eep are in vitro biofilm determinants and virulence factors in animal models of endocarditis and catheter-associated urinary tract infection. In this study, we evaluated the role of these genes in a rat acute foreign body osteomyelitis model and in in vitro biofilm-associated antimicrobial resistance. Osteomyelitis was established for one week following the implantation of stainless steel orthopedic wires inoculated with E. faecalis strains OG1RF, ΩahrC, and ∆eep into the proximal tibiae of rats. The median bacterial loads recovered from bones and wires did not differ significantly between the strains at multiple inoculum concentrations. We hypothesize that factors present at the infection site that affect biofilm formation, such as the presence or absence of shear force, may account for the differences in attenuation in the various animal models we have used to study the ΩahrC and ∆eep strains. No differences among the three strains were observed in the planktonic and biofilm antimicrobial susceptibilities to ampicillin, vancomycin, daptomycin, linezolid, and tetracycline. These findings suggest that neither ahrC nor eep directly contribute to E. faecalis biofilm-associated antimicrobial resistance. Notably, the experimental evidence that the biofilm attachment mutant ΩahrC displays biofilm-associated antimicrobial resistance suggests that surface colonization alone is sufficient for E. faecalis cells to acquire the biofilm antimicrobial resistance phenotype.

  7. The Killing

    Agger, Gunhild

    2013-01-01

    This article tracks the uncanny locations of The Killing (2007–2012), relating them to place, space and atmosphere, putting bits and pieces from the topographic puzzle together with cues from the symbolic space in order to see how they fit into the overall pattern of Nordic Noir. In The Killing......, the abstract level of space and atmosphere meets the concrete level of place, both influencing the notion of location. This meeting, I suggest, has contributed towards the simultaneous domestic and international appeal of The Killing....

  8. Killing Range

    Asal, Victor; Rethemeyer, R. Karl; Horgan, John

    2015-01-01

    This paper presents an analysis of the Provisional Irish Republican Army's (PIRA) brigade level behavior during the Northern Ireland Conflict (1970-1998) and identifies the organizational factors that impact a brigade's lethality as measured via terrorist attacks. Key independent variables include levels of technical expertise, cadre age, counter-terrorism policies experienced, brigade size, and IED components and delivery methods. We find that technical expertise within a brigade allows for careful IED usage, which significantly minimizes civilian casualties (a specific strategic goal of PIRA) while increasing the ability to kill more high value targets with IEDs. Lethal counter-terrorism events also significantly affect a brigade's likelihood of killing both civilians and high-value targets but in different ways. Killing PIRA members significantly decreases IED fatalities but also significantly decreases the possibility of zero civilian IED-related deaths in a given year. Killing innocent Catholics in a Brigade's county significantly increases total and civilian IED fatalities. Together the results suggest the necessity to analyze dynamic situational variables that impact terrorist group behavior at the sub-unit level. PMID:25838603

  9. Anti-virulence approaches and novel peptidomimetics for combating resistant and biofilm associated bacteria

    Liu, Yang

    Anti-virulence approaches and novel peptidomimetics for combating resistant and biofilm associated bacteria The misuse and overuse of antibiotics has a broad impact on the environment. Antibiotic resistance has become a major threat for modern medical treatment of infectious diseases. There are m......Anti-virulence approaches and novel peptidomimetics for combating resistant and biofilm associated bacteria The misuse and overuse of antibiotics has a broad impact on the environment. Antibiotic resistance has become a major threat for modern medical treatment of infectious diseases...... consisting of microcolonies embedded in self-produced extracellular polymer substances (EPS). EPS can contribute to cell-cell adhesion and restrict antibiotic penetration. Biofilm cells show much greater resistance to stressful conditions than their free-living counterparts. Conventional treatment strategies...

  10. Inhalable Antimicrobials for Treatment of Bacterial Biofilm-Associated Sinusitis in Cystic Fibrosis Patients

    Klodzinska, Sylvia Natalie; Priemel, Petra Alexandra; Rades, Thomas

    2016-01-01

    Bacterial biofilm-associated chronic sinusitis in cystic fibrosis (CF) patients caused by Pseudomonas aeruginosa infections and the lack of available treatments for such infections constitute a critical aspect of CF disease management. Currently, inhalation therapies to combat P. aeruginosa infec...... and management of biofilm infections caused by P. aeruginosa and discusses critical issues related to novel antimicrobial drug formulation design approaches.......Bacterial biofilm-associated chronic sinusitis in cystic fibrosis (CF) patients caused by Pseudomonas aeruginosa infections and the lack of available treatments for such infections constitute a critical aspect of CF disease management. Currently, inhalation therapies to combat P. aeruginosa....... aeruginosa from the respiratory tract after a first infection has been shown to delay chronic pulmonary infection with the bacteria for up to two years. The challenges with providing a suitable treatment for bacterial sinusitis include: (i) identifying a suitable antimicrobial compound; (ii) selecting...

  11. Killing tensors and conformal Killing tensors from conformal Killing vectors

    Rani, Raffaele; Edgar, S Brian; Barnes, Alan

    2003-01-01

    Koutras has proposed some methods to construct reducible proper conformal Killing tensors and Killing tensors (which are, in general, irreducible) when a pair of orthogonal conformal Killing vectors exist in a given space. We give the completely general result demonstrating that this severe restriction of orthogonality is unnecessary. In addition, we correct and extend some results concerning Killing tensors constructed from a single conformal Killing vector. A number of examples demonstrate that it is possible to construct a much larger class of reducible proper conformal Killing tensors and Killing tensors than permitted by the Koutras algorithms. In particular, by showing that all conformal Killing tensors are reducible in conformally flat spaces, we have a method of constructing all conformal Killing tensors, and hence all the Killing tensors (which will in general be irreducible) of conformally flat spaces using their conformal Killing vectors

  12. Infection and Proliferation of Giant Viruses in Amoeba Cells.

    Takemura, Masaharu

    2016-01-01

    Acanthamoeba polyphaga mimivirus, the first discovered giant virus with genome size and particle size much larger than previously discovered viruses, possesses several genes for translation and CRISPER Cas system-like defense mechanism against virophages, which co-infect amoeba cells with the giant virus and which inhibit giant virus proliferation. Mimiviruses infect amoeba cells by phagocytosis and release their DNA into amoeba cytoplasm through their stargate structure. After infection, giant virion factories (VFs) form in amoeba cytoplasm, followed by DNA replication and particle formation at peripheral regions of VF. Marseilleviruses, the smallest giant viruses, infect amoeba cells by phagocytosis or endocytosis, form larger VF than Mimivirus's VF in amoeba cytoplasm, and replicate their particles. Pandoraviruses found in 2013 have the largest genome size and particle size among all viruses ever found. Pandoraviruses infect amoeba cells by phagocytosis and release their DNA into amoeba cytoplasm through their mouth-like apical pores. The proliferation of Pandoraviruses occurs along with nucleus disruption. New virions form at the periphery of the region formerly occupied by the amoeba cell nucleus.

  13. Revised Parameters for the AMOEBA Polarizable Atomic Multipole Water Model

    Pande, Vijay S.; Head-Gordon, Teresa; Ponder, Jay W.

    2016-01-01

    A set of improved parameters for the AMOEBA polarizable atomic multipole water model is developed. The protocol uses an automated procedure, ForceBalance, to adjust model parameters to enforce agreement with ab initio-derived results for water clusters and experimentally obtained data for a variety of liquid phase properties across a broad temperature range. The values reported here for the new AMOEBA14 water model represent a substantial improvement over the previous AMOEBA03 model. The new AMOEBA14 water model accurately predicts the temperature of maximum density and qualitatively matches the experimental density curve across temperatures ranging from 249 K to 373 K. Excellent agreement is observed for the AMOEBA14 model in comparison to a variety of experimental properties as a function of temperature, including the 2nd virial coefficient, enthalpy of vaporization, isothermal compressibility, thermal expansion coefficient and dielectric constant. The viscosity, self-diffusion constant and surface tension are also well reproduced. In comparison to high-level ab initio results for clusters of 2 to 20 water molecules, the AMOEBA14 model yields results similar to the AMOEBA03 and the direct polarization iAMOEBA models. With advances in computing power, calibration data, and optimization techniques, we recommend the use of the AMOEBA14 water model for future studies employing a polarizable water model. PMID:25683601

  14. Biofilm-Associated Gene Expression in Staphylococcus pseudintermedius on a Variety of Implant Materials.

    Crawford, Evan C; Singh, Ameet; Gibson, Thomas W G; Scott Weese, J

    2016-05-01

    To evaluate the expression of biofilm-associated genes in Staphylococcus pseudintermedius on multiple clinically relevant surfaces. In vitro experimental study. Two strains of methicillin-resistant S. pseudintermedius isolated from clinical infections representing the most common international isolates. A quantitative polymerase chain reaction (qPCR) assay for expression of genes related to biofilm initial adhesion, formation/maturation, antimicrobial resistance, and intracellular communication was developed and validated. S. pseudintermedius biofilms were grown on 8 clinically relevant surfaces (polymethylmethacrylate, stainless steel, titanium, latex, silicone, polydioxanone, polystyrene, and glass) and samples of logarithmic and stationary growth phases were collected. Gene expression in samples was measured by qPCR. Significant differences in gene expression were identified between surfaces and between bacterial strains for most gene/strain/surface combinations studied. Expression of genes responsible for production of extracellular matrix were increased in biofilms. Expression of genes responsible for initial adhesion and intracellular communication was markedly variable. Antimicrobial resistance gene expression was increased on multiple surfaces, including stainless steel and titanium. A method for evaluation of expression of multiple biofilm-associated genes in S. pseudintermedius was successfully developed and applied to the study of biofilms on multiple surfaces. Variations in expression of these genes have a bearing on understanding the development and treatment of implant-associated biofilm infections and will inform future clinical research. © Copyright 2016 by The American College of Veterinary Surgeons.

  15. Amoeba: a distributed operating system for the 1990s

    Mullender, Sape J.; van Rossum, Guido; Tanenbaum, Andrew S.; van Renesse, Robbert; van Staveren, Hans

    A description is given of the Amoeba distributed operating system, which appears to users as a centralized system but has the speed, fault tolerance, security safeguards, and flexibility required for the 1990s. The Amoeba software is based on objects. Objects are managed by server processes and

  16. Culture growth of testate amoebae under different silicon concentrations.

    Wanner, Manfred; Seidl-Lampa, Barbara; Höhn, Axel; Puppe, Daniel; Meisterfeld, Ralf; Sommer, Michael

    2016-10-01

    Testate amoebae with self-secreted siliceous shell platelets ("idiosomes") play an important role in terrestrial silicon (Si) cycles. In this context, Si-dependent culture growth dynamics of idiosomic testate amoebae are of interest. Clonal cultures of idiosomic testate amoebae were analyzed under three different Si concentrations: low (50μmolL -1 ), moderate/site-specific (150μmolL -1 ) and high Si supply (500μmolL -1 ). Food (Saccharomyces cerevisiae) was provided in surplus. (i) Shell size of four different clones of idiosomic testate amoebae either decreased (Trinema galeata, Euglypha filifera cf.), increased (E. rotunda cf.), or did not change (E. rotunda) under the lowest Si concentration (50μmolSiL -1 ). (ii) Culture growth of idiosomic Euglypha rotunda was dependent on Si concentration. The more Si available in the culture medium, the earlier the entry into exponential growth phase. (iii) Culture growth of idiosomic Euglypha rotunda was dependent on origin of inoculum. Amoebae previously cultured under a moderate Si concentration revealed highest sustainability in consecutive cultures. Amoebae derived from cultures with high Si concentrations showed rapid culture growth which finished early in consecutive cultures. (iv) Si (diluted in the culture medium) was absorbed by amoebae and fixed in the amoeba shells resulting in decreased Si concentrations. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Amoeba: A Distributed Operating System for the 1990s

    Mullender, S.J.; van Rossum, G.; Tanenbaum, A.S.; van Renesse, R.; van Staveren, H.

    1990-01-01

    A description is given of the Amoeba distributed operating system, which appears to users as a centralized system but has the speed, fault tolerance, security safeguards, and flexibility required for the 1990s. The Amoeba software is based on objects. Objects are managed by server processes and

  18. Buse_Francisella and free-living amoebae data sets

    U.S. Environmental Protection Agency — Co-infection data in the form of colony forming units and amoeba cell counts. This dataset is associated with the following publication: Buse , H., F. Schaefer, and...

  19. An electronic implementation of amoeba anticipation

    Ziegler, Martin; Ochs, Karlheinz; Hansen, Mirko; Kohlstedt, Hermann

    2014-02-01

    In nature, the capability of memorizing environmental changes and recalling past events can be observed in unicellular organisms like amoebas. Pershin and Di Ventra have shown that such learning behavior can be mimicked in a simple memristive circuit model consisting of an LC (inductance capacitance) contour and a memristive device. Here, we implement this model experimentally by using an Ag/TiO2- x /Al memristive device. A theoretical analysis of the circuit is used to gain insight into the functionality of this model and to give advice for the circuit implementation. In this respect, the transfer function, resonant frequency, and damping behavior for a varying resistance of the memristive device are discussed in detail.

  20. Identification of biofilm-associated cluster (bac in Pseudomonas aeruginosa involved in biofilm formation and virulence.

    Camille Macé

    Full Text Available Biofilms are prevalent in diseases caused by Pseudomonas aeruginosa, an opportunistic and nosocomial pathogen. By a proteomic approach, we previously identified a hypothetical protein of P. aeruginosa (coded by the gene pA3731 that was accumulated by biofilm cells. We report here that a Delta pA3731 mutant is highly biofilm-defective as compared with the wild-type strain. Using a mouse model of lung infection, we show that the mutation also induces a defect in bacterial growth during the acute phase of infection and an attenuation of the virulence. The pA3731 gene is found to control positively the ability to swarm and to produce extracellular rhamnolipids, and belongs to a cluster of 4 genes (pA3729-pA3732 not previously described in P. aeruginosa. Though the protein PA3731 has a predicted secondary structure similar to that of the Phage Shock Protein, some obvious differences are observed compared to already described psp systems, e.g., this unknown cluster is monocistronic and no homology is found between the other proteins constituting this locus and psp proteins. As E. coli PspA, the amount of the protein PA3731 is enlarged by an osmotic shock, however, not affected by a heat shock. We consequently named this locus bac for biofilm-associated cluster.

  1. Palaeoecology of testate amoebae in a tropical peatland.

    Swindles, Graeme T; Lamentowicz, Mariusz; Reczuga, Monika; Galloway, Jennifer M

    2016-09-01

    We present the first detailed analysis of subfossil testate amoebae from a tropical peatland. Testate amoebae were analysed in a 4-m peat core from western Amazonia (Peru) and a transfer function developed from the site was applied to reconstruct changes in water table over the past ca. 8,000 years. Testate amoebae were in very low abundance in the core, especially in the lower 125cm, due to a combination of poor preservation and obscuration by other organic matter. A modified preparation method enabled at least 50 testate amoebae to be counted in each core sample. The most abundant taxa preserved include Centropyxis aculeata, Hyalosphenia subflava, Phryganella acropodia and Trigonopyxis arcula. Centropyxis aculeata, an unambiguous wet indicator, is variably present and indicates several phases of near-surface water table. Our work shows that even degraded, low-abundance assemblages of testate amoebae can provide useful information regarding the long-term ecohydrological developmental history of tropical peatlands. Copyright © 2015 Elsevier GmbH. All rights reserved.

  2. Parasitic amoebae found in water bodies of Ukraine.

    Patsyuk, Marina

    2017-12-01

    Two parasitic amoebian species are found in mollusks of the water bodies of Ukraine. Vahlkampfia sp. is found in hepatopankreas of Unio conus Spengler, 1793, and Acanthamoeba sp. is observed in mantle cavity of Viviparus viviparus Linnaeus, 1758. For these protist species, the mollusks are shown to be intermediate hosts where amoebae feed and reproduce. An experimental infection with Vahlkampfia sp. and Acanthamoeba sp. was not successful, no pathological changes in mollusks were observed. These amoebae are successfully cultured in fresh water and agar medium, hence we can safely consider them free-living. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Cloning, killing, and identity.

    McMahan, J

    1999-01-01

    One potentially valuable use of cloning is to provide a source of tissues or organs for transplantation. The most important objection to this use of cloning is that a human clone would be the sort of entity that it would be seriously wrong to kill. I argue that entities of the sort that you and I essentially are do not begin to exist until around the seventh month of fetal gestation. Therefore to kill a clone prior to that would not be to kill someone like you or me but would be only to prevent one of us from existing. And even after one of us begins to exist, the objections to killing it remain comparatively weak until its psychological capacities reach a certain level of maturation. These claims support the permissibility of killing a clone during the early stages of its development in order to use its organs for transplantation. PMID:10226909

  4. Amoeba/amoebal symbiont genetic transfers: lessons from giant virus neighbours.

    Thomas, Vincent; Greub, Gilbert

    2010-01-01

    Free-living amoebae serve as hosts for a variety of amoebae-resisting microorganisms, including giant viruses and certain bacteria. The latter include symbiotic bacteria as well as bacteria exhibiting a pathogenic phenotype towards amoebae. Amoebae-resisting bacteria have been shown to be widespread in water and to use the amoebae as a reservoir, a replication niche, a protective armour as well as a training ground to select virulence traits allowing survival in the face of microbicidal effects of macrophages, the first line of defense against invading pathogens. More importantly, amoebae play a significant role as a melting pot for genetic exchanges. These ecological and evolutionary roles of amoebae might also be at play for giant viruses and knowledge derived from the study of amoebae-resisting bacteria is useful for the study and understanding of interactions between amoebae and giant viruses. This is especially important since some genes have spread in all domains of life and the exponential availability of eukaryotic genomes and metagenomic sequences will allow researchers to explore these genetic exchanges in a more comprehensive way, thus completely changing our perception of the evolutionary history of organisms. Thus, a large part of this review is dedicated to report current known gene exchanges between the different amoebae-resisting organisms and between amoebae and the internalized bacteria. Copyright 2010 S. Karger AG, Basel.

  5. The Evolution of a distributed operating system (Amoeba)

    van Renesse, Robbert; Tanenbaum, Andrew S.; Mullender, Sape J.

    1989-01-01

    AMOEBA is a research project to build a true distributed operating system using the object model. Under the COST11-ter MANDIS project this work was extended to cover wide-area networks. Besides describing the system, this paper discusses the successive versions in the implementation of its model,

  6. Checklist, diversity and distribution of testate amoebae in Chile.

    Fernández, Leonardo D; Lara, Enrique; Mitchell, Edward A D

    2015-10-01

    Bringing together more than 170 years of data, this study represents the first attempt to construct a species checklist and analyze the diversity and distribution of testate amoebae in Chile, a country that encompasses the southwestern region of South America, countless islands and part of the Antarctic. In Chile, known diversity includes 416 testate amoeba taxa (64 genera, 352 infrageneric taxa), 24 of which are here reported for the first time. Species-accumulation plots show that in Chile, the number of testate amoeba species reported has been continually increasing since the mid-19th century without leveling off. Testate amoebae have been recorded in 37 different habitats, though they are more diverse in peatlands and rainforest soils. Only 11% of species are widespread in continental Chile, while the remaining 89% of the species exhibit medium or short latitudinal distribution ranges. Also, species composition of insular Chile and the Chilean Antarctic territory is a depauperated subset of that found in continental Chile. Nearly, the 10% of the species reported here are endemic to Chile and many of them are distributed only within the so-called Chilean biodiversity hotspot (ca. 25° S-47° S). These findings are here thoroughly discussed in a biogeographical and evolutionary context. Copyright © 2015 Elsevier GmbH. All rights reserved.

  7. Counting Legionella cells within single amoeba host cells

    Here we present the first attempt to quantify L. pneumophila cell numbers within individual amoebae hosts that may be released into engineered water systems. The maximum numbers of culturable L. pneumophila cells grown within Acanthamoeba polyphaga and Naegleria fowleri were 134...

  8. The genome of the social amoeba Dictyostelium discoideum

    Eichinger, L; Pachebat, J A; Glöckner, G

    2005-01-01

    The social amoebae are exceptional in their ability to alternate between unicellular and multicellular forms. Here we describe the genome of the best-studied member of this group, Dictyostelium discoideum. The gene-dense chromosomes of this organism encode approximately 12,500 predicted proteins,...

  9. Advances in the knowledge of amphizoic amoebae infecting fish

    Dyková, Iva; Lom, Jiří

    2004-01-01

    Roč. 51, 2/3 (2004), s. 81-97 ISSN 0015-5683 R&D Projects: GA AV ČR IAA6022202 Institutional research plan: CEZ:AV0Z6022909 Keywords : amphizoic amoebae * fish hosts * review Subject RIV: EA - Cell Biology Impact factor: 0.837, year: 2004

  10. Surveillance of parasitic Legionella in surface waters by using immunomagnetic separation and amoebae enrichment.

    Hsu, Tsui-Kang; Wu, Shu-Fen; Hsu, Bing-Mu; Kao, Po-Min; Tao, Chi-Wei; Shen, Shu-Min; Ji, Wen-Tsai; Huang, Wen-Chien; Fan, Cheng-Wei

    2015-01-01

    Free-living amoebae (FLA) are potential reservoirs of Legionella in aquatic environments. However, the parasitic relationship between various Legionella and amoebae remains unclear. In this study, surface water samples were gathered from two rivers for evaluating parasitic Legionella. Warmer water temperature is critical to the existence of Legionella. This result suggests that amoebae may be helpful in maintaining Legionella in natural environments because warmer temperatures could enhance parasitisation of Legionella in amoebae. We next used immunomagnetic separation (IMS) to identify extracellular Legionella and remove most free Legionella before detecting the parasitic ones in selectively enriched amoebae. Legionella pneumophila was detected in all the approaches, confirming that the pathogen is a facultative amoebae parasite. By contrast, two obligate amoebae parasites, Legionella-like amoebal pathogens (LLAPs) 8 and 9, were detected only in enriched amoebae. However, several uncultured Legionella were detected only in the extracellular samples. Because the presence of potential hosts, namely Vermamoeba vermiformis, Acanthamoeba spp. and Naegleria gruberi, was confirmed in the samples that contained intracellular Legionella, uncultured Legionella may survive independently of amoebae. Immunomagnetic separation and amoebae enrichment may have referential value for detecting parasitic Legionella in surface waters.

  11. Raman spectroscopic study on the excystation process in a single unicellular organism amoeba (Acanthamoeba polyphaga)

    Lin, Yu-Chung; Perevedentseva, Elena; Cheng, Chia-Liang

    2015-05-01

    An in vivo Raman spectroscopic study of amoeba (Acanthamoeba polyphaga) is presented. The changes of the spectra during the amoeba cyst activation and excystation are analyzed. The spectra show the changes of the relative intensities of bands corresponding to protein, lipid, and carotenoid components during cyst activation. The presence of carotenoids in the amoeba is observed via characteristic Raman bands. These signals in the Raman spectra are intense in cysts but decrease in intensity with cyst activation and exhibit a correlation with the life cycle of amoeba. This work demonstrates the feasibility of using Raman spectroscopy for the detection of single amoeba microorganisms in vivo and for the analysis of the amoeba life activity. The information obtained may have implications for the estimation of epidemiological situations and for the diagnostics and prognosis of the development of amoebic inflammations.

  12. Kin discrimination increases with genetic distance in a social amoeba.

    Ostrowski, Elizabeth A; Katoh, Mariko; Shaulsky, Gad; Queller, David C; Strassmann, Joan E

    2008-11-25

    In the social amoeba Dictyostelium discoideum, thousands of cells aggregate upon starvation to form a multicellular fruiting body, and approximately 20% of them die to form a stalk that benefits the others. The aggregative nature of multicellular development makes the cells vulnerable to exploitation by cheaters, and the potential for cheating is indeed high. Cells might avoid being victimized if they can discriminate among individuals and avoid those that are genetically different. We tested how widely social amoebae cooperate by mixing isolates from different localities that cover most of their natural range. We show here that different isolates partially exclude one another during aggregation, and there is a positive relationship between the extent of this exclusion and the genetic distance between strains. Our findings demonstrate that D. discoideum cells co-aggregate more with genetically similar than dissimilar individuals, suggesting the existence of a mechanism that discerns the degree of genetic similarity between individuals in this social microorganism.

  13. Theriocide: Naming Animal Killing

    Piers Beirne

    2014-08-01

    Full Text Available In this essay I recommend ‘theriocide’ as the name for those diverse human actions that cause the deaths of animals. Like the killing of one human by another, theriocide may be socially acceptable or unacceptable, legal or illegal. It may be intentional or unintentional and may involve active maltreatment or passive neglect. Theriocide may occur one-on-one, in small groups or in large-scale social institutions. The numerous and sometimes intersecting sites of theriocide include intensive rearing regimes; hunting and fishing; trafficking; vivisection; militarism; pollution; and human-induced climate change. If the killing of animals by humans is as harmful to them as homicide is to humans, then the proper naming of such deaths offers a remedy, however small, to the extensive privileging of human lives over those of other animals. Inevitably, the essay leads to a shocking question: Is theriocide murder?

  14. Oil is killing Africa

    Paris, H.

    2007-09-01

    Sub-Saharan Africa, with its mining and petroleum resources, is still the object of covetous desires from developed countries. The Gulf of Guinea is a promising area and probably the future battlefield of the 21. century. The fighters of this war are the African people and the big powers, the USA and China at the head, who call upon mercenaries to get their share of this fabulous treasure. Oil was a chance for Africa, but now oil is killing it

  15. Analysing the Wrongness of Killing

    Di Nucci, Ezio

    2014-01-01

    This article provides an in-depth analysis of the wrongness of killing by comparing different versions of three influential views: the traditional view that killing is always wrong; the liberal view that killing is wrong if and only if the victim does not want to be killed; and Don Marquis‟ future...... of value account of the wrongness of killing. In particular, I illustrate the advantages that a basic version of the liberal view and a basic version of the future of value account have over competing alternatives. Still, ultimately none of the views analysed here are satisfactory; but the different...

  16. Detection and Identification of Free-living Amoeba from Environmental Water in Taiwan by PCR Method

    Tsai, H. F.; Hsu, B. M.; Huang, K. H.; She, C. Y.; Kao, P. M.; Shen, S. M.; Tseng, S. F.; Chen, J. S.

    2012-04-01

    Acanthamoeba, Naegleria, Balamuthia and Hartmannella all belong to free-living amoebae that are present ubiquitously in the environment including water, soil, and air. Free-living amoebae are parasites which can infect humans and can lead to serious illness and even death. The aim of this study is to investigate the presence of free-living amoebae in aquatic environment in Taiwan, and to compare the differences between Acanthamoeba and Naegleria in diverse cultivation methods and conditions. In this study, we used molecular method by PCR amplification with specific primers to analyze the occurrence of free-living amoebae. We collected 176 samples from environmental water including drinking water treatment plants, stream water, and hot spring recreational areas in Taiwan. Based on the results of PCR, 43 water samples (24.4%) were detected positive for free-living amoebae. The most common Acanthamoeba genotype isolated from samples including T2, T4, T5, T12, and T15. N. australiensis and N. lovaniensis were also identified by molecular biology techniques. Furthermore, we found that both Acanthamoeba and Naegleria can be cultured by PYG in 30° C, but not all free-living amoebae can be isolated and enriched by using storage-cultivation method. Because of the widespread presence of Acanthamoeba and Naegleria in aquatic environments, the water quality and safety of aquatic environments should be more conscious in Taiwan and worldwide. Keywords: free-living amoebae; Acanthamoeba; Naegleria; Balamuthia; Hartmannella; PCR

  17. How to kill creativity.

    Amabile, T M

    1998-01-01

    In today's knowledge economy, creativity is more important than ever. But many companies unwittingly employ managerial practices that kill it. How? By crushing their employees' intrinsic motivation--the strong internal desire to do something based on interests and passions. Managers don't kill creativity on purpose. Yet in the pursuit of productivity, efficiency, and control--all worthy business imperatives--they undermine creativity. It doesn't have to be that way, says Teresa Amabile. Business imperatives can comfortably coexist with creativity. But managers will have to change their thinking first. Specifically, managers will need to understand that creativity has three parts: expertise, the ability to think flexibly and imaginatively, and motivation. Managers can influence the first two, but doing so is costly and slow. It would be far more effective to increase employees' intrinsic motivation. To that end, managers have five levers to pull: the amount of challenge they give employees, the degree of freedom they grant around process, the way they design work groups, the level of encouragement they give, and the nature of organizational support. Take challenge as an example. Intrinsic motivation is high when employees feel challenged but not overwhelmed by their work. The task for managers, therefore, becomes matching people to the right assignments. Consider also freedom. Intrinsic motivation--and thus creativity--soars when managers let people decide how to achieve goals, not what goals to achieve. Managers can make a difference when it comes to employee creativity. The result can be truly innovative companies in which creativity doesn't just survive but actually thrives.

  18. Contrasting species-environment relationships in communities of testate amoebae, bryophytes and vascular plants along the fen-bog gradient.

    Lamentowicz, Mariusz; Lamentowicz, Lukasz; van der Knaap, Willem O; Gabka, Maciej; Mitchell, Edward A D

    2010-04-01

    We studied the vegetation, testate amoebae and abiotic variables (depth of the water table, pH, electrical conductivity, Ca and Mg concentrations of water extracted from mosses) along the bog to extremely rich fen gradient in sub-alpine peatlands of the Upper Engadine (Swiss Alps). Testate amoeba diversity was correlated to that of mosses but not of vascular plants. Diversity peaked in rich fen for testate amoebae and in extremely rich fen for mosses, while for testate amoebae and mosses it was lowest in bog but for vascular plants in extremely rich fen. Multiple factor and redundancy analyses (RDA) revealed a stronger correlation of testate amoebae than of vegetation to water table and hydrochemical variables and relatively strong correlation between testate amoeba and moss community data. In RDA, hydrochemical variables explained a higher proportion of the testate amoeba and moss data than water table depth. Abiotic variables explained a higher percentage of the species data for testate amoebae (30.3% or 19.5% for binary data) than for mosses (13.4%) and vascular plants (10%). These results show that (1) vascular plant, moss and testate amoeba communities respond differently to ecological gradients in peatlands and (2) testate amoebae are more strongly related than vascular plants to the abiotic factors at the mire surface. These differences are related to vertical trophic gradients and associated niche differentiation.

  19. Amoebae and other protozoa in material samples from moisture-damaged buildings

    Yli-Pirilae, T.; Kusnetsov, Jaana; Haatainen, Susanna; Haenninen, Marja; Jalava, Pasi; Reiman, Marjut; Seuri, Markku; Hirvonen, Maija-Riitta; Nevalainen, Aino

    2004-01-01

    Mold growth in buildings has been shown to be associated with adverse health effects. The fungal and bacterial growth on moistened building materials has been studied, but little attention has been paid to the other organisms spawning in the damaged materials. We examined moist building materials for protozoa, concentrating on amoebae. Material samples (n=124) from moisture-damaged buildings were analyzed for amoebae, fungi, and bacteria. Amoebae were detected in 22% of the samples, and they were found to favor cooccurrence with bacteria and the fungi Acremonium spp., Aspergillus versicolor, Chaetomium spp., and Trichoderma spp. In addition, 11 seriously damaged samples were screened for other protozoa. Ciliates and flagellates were found in almost every sample analyzed. Amoebae are known to host pathogenic bacteria, such as chlamydiae, legionellae, and mycobacteria and they may have a role in the complex of exposure that contributes to the health effects associated with moisture damage in buildings

  20. Occurrence of Infected Free-Living Amoebae in Cooling Towers of Southern Brazil.

    Soares, Scheila S; Souza, Thamires K; Berté, Francisco K; Cantarelli, Vlademir V; Rott, Marilise B

    2017-12-01

    This study determined the occurrence of potentially pathogenic free-living amoebae (FLA) and bacteria associated with amoebae in air-conditioning cooling towers in southern Brazil. Water samples were collected from 36 cooling systems from air-conditioning in the state of Rio Grande do Sul, Brazil. The organisms were identified using polymerase chain reaction (PCR) and sequencing automated. The results showed that these aquatic environments, with variable temperature, are potential "hot spots" for emerging human pathogens like free-living amoebae and bacteria associated. In total, 92% of the cooling-tower samples analyzed were positive for FLA, and Acanthamoeba was the dominant genus by culture and PCR. Amoebal isolates revealed intracellular bacteria in 39.3% of them and all were confirmed as members of the genus Pseudomonas. The results obtained show the important role of cooling towers as a source of amoebae-associated pathogens.

  1. Giant Viruses of Amoebae: A Journey Through Innovative Research and Paradigm Changes.

    Colson, Philippe; La Scola, Bernard; Raoult, Didier

    2017-09-29

    Giant viruses of amoebae were discovered serendipitously in 2003; they are visible via optical microscopy, making them bona fide microbes. Their lifestyle, structure, and genomes break the mold of classical viruses. Giant viruses of amoebae are complex microorganisms. Their genomes harbor between 444 and 2,544 genes, including many that are unique to viruses, and encode translation components; their virions contain >100 proteins as well as mRNAs. Mimiviruses have a specific mobilome, including virophages, provirophages, and transpovirons, and can resist virophages through a system known as MIMIVIRE (mimivirus virophage resistance element). Giant viruses of amoebae bring upheaval to the definition of viruses and tend to separate the current virosphere into two categories: very simple viruses and viruses with complexity similar to that of other microbes. This new paradigm is propitious for enhanced detection and characterization of giant viruses of amoebae, and a particular focus on their role in humans is warranted.

  2. Archivists Killed for Political Reasons

    de Baets, Antoon

    2015-01-01

    This essay, Archivists Killed for Political Reasons, offers an overview of archivists who were killed for political reasons through the ages. After determining the criteria for inclusion, sixteen such political murders of archivists are briefly discussed. These cases were distributed over six

  3. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward; Carrivick, Jonathan L.; Woulds, Clare; Raby, Cassandra; Mullan, Donal; Roland, Thomas P.; Galloway, Jennifer M.; Parry, Lauren; Kokfelt, Ulla; Garneau, Michelle; Charman, Dan J.; Holden, Joseph

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (~ 200 km north of the Arctic Circle). Multivariate statistical analysis confirms that water-table depth and moisture content are the dominant controls on the distribution of testate amoebae, corroborating the results from studies in mid-latitude peatlands. We present a ne...

  4. "The Killing Fields" of Innovation

    Ingerslev, Karen

    2014-01-01

    to clustering of ideas, a design strategy which seemed to kill unique ideas. The reframing of innovation as a radical endeavor killed learning from others for being not innovative. The findings of this paper supplement theories of deliberate killing of ideas by suggesting framing, design and facilitation......This paper points to seemingly contradicted processes of framing innovation, idea generation and killing ideas. It reports from a yearlong innovation project, where health care professionals explored problems and tested ideas for solutions, regarding a future downsizing of the case hospital....... Theories in various ways describe the opening and closing phases of innovation. Exploration and idea generation opens a field of interest, which is then closed by making choices of ideas to further explore in the next opening phase. These choices deliberately kill a lot of ideas. In the innovation project...

  5. Amoeba-related health risk in drinking water systems: could monitoring of amoebae be a complementary approach to current quality control strategies?

    Codony, Francesc; Pérez, Leonardo Martín; Adrados, Bárbara; Agustí, Gemma; Fittipaldi, Mariana; Morató, Jordi

    2012-01-01

    Culture-based methods for fecal indicator microorganisms are the standard protocol to assess potential health risk from drinking water systems. However, these traditional fecal indicators are inappropriate surrogates for disinfection-resistant fecal pathogens and the indigenous pathogens that grow in drinking water systems. There is now a range of molecular-based methods, such as quantitative PCR, which allow detection of a variety of pathogens and alternative indicators. Hence, in addition to targeting total Escherichia coli (i.e., dead and alive) for the detection of fecal pollution, various amoebae may be suitable to indicate the potential presence of pathogenic amoeba-resisting microorganisms, such as Legionellae. Therefore, monitoring amoeba levels by quantitative PCR could be a useful tool for directly and indirectly evaluating health risk and could also be a complementary approach to current microbial quality control strategies for drinking water systems.

  6. AMOEBA Polarizable Force Field Parameters of the Heme Cofactor in Its Ferrous and Ferric Forms.

    Wu, Xiaojing; Clavaguera, Carine; Lagardère, Louis; Piquemal, Jean-Philip; de la Lande, Aurélien

    2018-04-16

    We report the first parameters of the heme redox cofactors for the polarizable AMOEBA force field in both the ferric and ferrous forms. We consider two types of complexes, one with two histidine side chains as axial ligands and one with a histidine and a methionine side chain as ligands. We have derived permanent multipoles from second-order Møller-Plesset perturbation theory (MP2). The sets of parameters have been validated in a first step by comparison of AMOEBA interaction energies of heme and a collection of biologically relevant molecules with MP2 and Density Functional Theory (DFT) calculations. In a second validation step, we consider interaction energies with large aggregates comprising around 80 H 2 O molecules. These calculations are repeated for 30 structures extracted from semiempirical PM7 DM simulations. Very encouraging agreement is found between DFT and the AMOEBA force field, which results from an accurate treatment of electrostatic interactions. We finally report long (10 ns) MD simulations of cytochromes in two redox states with AMOEBA testing both the 2003 and 2014 AMOEBA water models. These simulations have been carried out with the TINKER-HP (High Performance) program. In conclusion, owing to their ubiquity in biology, we think the present work opens a wide array of applications of the polarizable AMOEBA force field on hemeproteins.

  7. Diversity and community ecology of forest epiphyte testate amoebae from European Russia.

    Payne, Richard J; Belyakova, Olga; Mazei, Yuri

    2015-10-01

    Testate amoebae are an abundant group of microorganisms which make a significant contribution to the diversity of protist life. Most of the world's potential habitats for testate amoebae have been barely studied and when such places are investigated they frequently reveal novel communities and species. Here we consider the testate amoeba communities associated with boreal forest epiphytes (mosses and lichens); an environment which we argue has been under-researched. We present a dataset of 165 samples from four regions of western Russia and analyse these data in relation to micro-habitat position and selected environmental data. The testate amoebae of epiphytes are abundant but dominated by ubiquitous species. We show that there are trends toward a lower species richness and test concentration with greater elevation on the trunk and in lichens compared to mosses. There are considerable differences in community composition between sampling regions. Of all measured environmental variables only moisture content showed a significant relationship with testate amoeba community structure. Our data highlight how little is known about testate amoeba communities of this habitat and call for greater research efforts, particularly in less-studied regions and biomes. Copyright © 2015 Elsevier GmbH. All rights reserved.

  8. Behavioural differentiation induced by environmental variation when crossing a toxic zone in an amoeba

    Kunita, Itsuki; Kuroda, Shigeru; Nakagaki, Toshiyuki; Ueda, Kei-Ichi; Akita, Dai

    2017-01-01

    Organisms choose from among various courses of action in response to a wide variety of environmental conditions and the mechanism by which various behaviours are induced is an open question. Interesting behaviour was recently reported: that a unicellular organism of slime mold Physarum polycephalum known as an amoeba had multiple responses (crossing, returning, etc) when the amoeba encounters a zone with toxic levels of quinine, even under carefully controlled conditions. We here examined this elegant example in more detail to obtain insight into behavioural differentiation. We found that the statistical distribution of passage times across a quinine zone switch from unimodal to bimodal (with peaks corresponding to fast crossing and no crossing) when a periodic light stimulation to modulate a biorhythm in amoeba is applied homogeneously across the space, even under the same level of chemical stimuli. Based on a mathematical model for cell movement in amoeba, we successfully reproduced the stimulation-induced differentiation, which was observed experimentally. These dynamics may be explained by a saddle structure around a canard solution. Our results imply that the differentiation of behavioural types in amoeba is modified step-by-step via the compounding of stimulation inputs. The complex behaviour like the differentiation in amoeba may provide a basis for understanding the mechanism of behaviour selection in higher animals from an ethological perspective. (paper)

  9. Behavioural differentiation induced by environmental variation when crossing a toxic zone in an amoeba

    Kunita, Itsuki; Ueda, Kei-Ichi; Akita, Dai; Kuroda, Shigeru; Nakagaki, Toshiyuki

    2017-09-01

    Organisms choose from among various courses of action in response to a wide variety of environmental conditions and the mechanism by which various behaviours are induced is an open question. Interesting behaviour was recently reported: that a unicellular organism of slime mold Physarum polycephalum known as an amoeba had multiple responses (crossing, returning, etc) when the amoeba encounters a zone with toxic levels of quinine, even under carefully controlled conditions. We here examined this elegant example in more detail to obtain insight into behavioural differentiation. We found that the statistical distribution of passage times across a quinine zone switch from unimodal to bimodal (with peaks corresponding to fast crossing and no crossing) when a periodic light stimulation to modulate a biorhythm in amoeba is applied homogeneously across the space, even under the same level of chemical stimuli. Based on a mathematical model for cell movement in amoeba, we successfully reproduced the stimulation-induced differentiation, which was observed experimentally. These dynamics may be explained by a saddle structure around a canard solution. Our results imply that the differentiation of behavioural types in amoeba is modified step-by-step via the compounding of stimulation inputs. The complex behaviour like the differentiation in amoeba may provide a basis for understanding the mechanism of behaviour selection in higher animals from an ethological perspective.

  10. A study of nucleo-cytoplasmic large DNA viruses: detection and characterization of viruses in environmental amoeba

    Fugas, Mariana Costa

    2012-01-01

    Tese de mestrado. Biologia (Biologia Molecular e Genética). Universidade de Lisboa, Faculdade de Ciências, 2012 Amoeba associated microorganisms (ARMs) are bacteria or viruses that share a symbiotic relationship with amoebas. Many ARMs are associated with human diseases and it has been reported the acquisition of resistance inside their host. These facts highlight the importance of finding and characterizing ARMs in a public health’s perspective. In the present work, amoebas from environme...

  11. Notes on super Killing tensors

    Howe, P.S. [Department of Mathematics, King’s College London,The Strand, London WC2R 2LS (United Kingdom); Lindström, University [Department of Physics and Astronomy, Theoretical Physics, Uppsala University,SE-751 20 Uppsala (Sweden); Theoretical Physics, Imperial College London,Prince Consort Road, London SW7 2AZ (United Kingdom)

    2016-03-14

    The notion of a Killing tensor is generalised to a superspace setting. Conserved quantities associated with these are defined for superparticles and Poisson brackets are used to define a supersymmetric version of the even Schouten-Nijenhuis bracket. Superconformal Killing tensors in flat superspaces are studied for spacetime dimensions 3,4,5,6 and 10. These tensors are also presented in analytic superspaces and super-twistor spaces for 3,4 and 6 dimensions. Algebraic structures associated with superconformal Killing tensors are also briefly discussed.

  12. Killing Horizons as Equipotential Hypersurfaces

    Smolić, Ivica

    2012-01-01

    In this note we present a new proof that Killing horizons are equipotential hypersurfaces for the electric and the magnetic scalar potential, that makes no use of gravitational field equations or the assumption about the existence of bifurcation surface.

  13. Phantom metrics with Killing spinors

    W.A. Sabra

    2015-11-01

    Full Text Available We study metric solutions of Einstein–anti-Maxwell theory admitting Killing spinors. The analogue of the IWP metric which admits a space-like Killing vector is found and is expressed in terms of a complex function satisfying the wave equation in flat (2+1-dimensional space–time. As examples, electric and magnetic Kasner spaces are constructed by allowing the solution to depend only on the time coordinate. Euclidean solutions are also presented.

  14. Spacetimes foliated by Killing horizons

    Pawlowski, Tomasz; Lewandowski, Jerzy; Jezierski, Jacek

    2004-01-01

    It seems to be expected that a horizon of a quasi-local type, such as a Killing or an isolated horizon, by analogy with a globally defined event horizon, should be unique in some open neighbourhood in the spacetime, provided the vacuum Einstein or the Einstein-Maxwell equations are satisfied. The aim of our paper is to verify whether that intuition is correct. If one can extend a so-called Kundt metric, in such a way that its null, shear-free surfaces have spherical spacetime sections, the resulting spacetime is foliated by so-called non-expanding horizons. The obstacle is Kundt's constraint induced at the surfaces by the Einstein or the Einstein-Maxwell equations, and the requirement that a solution be globally defined on the sphere. We derived a transformation (reflection) that creates a solution to Kundt's constraint out of data defining an extremal isolated horizon. Using that transformation, we derived a class of exact solutions to the Einstein or Einstein-Maxwell equations of very special properties. Each spacetime we construct is foliated by a family of the Killing horizons. Moreover, it admits another, transversal Killing horizon. The intrinsic and extrinsic geometries of the transversal Killing horizon coincide with the one defined on the event horizon of the extremal Kerr-Newman solution. However, the Killing horizon in our example admits yet another Killing vector tangent to and null at it. The geometries of the leaves are given by the reflection

  15. Detection and identification of free-living amoeba from aquatic environment in Taiwan

    Jiun Tzeng, Kai; Che Tung, Min; Hsu, Bing Mu; Tsai, Hsiu Feng; Huang, Po Hsiang; Hao Huang, Kuan; Kao, Po Min; Shen, Shu Min; Chen, Jung Sheng

    2013-04-01

    Free-living amoebae including Acanthamoeba, Naegleria, Balamuthia and Hartmannella are widely distributed in water, soil, and air. They can infect humans and can lead to serious illness even death. The aim of this study is to investigate the presence of free-living amoebae from aquatic environment in Taiwan, and to compare the differences between Acanthamoeba and Naegleria in different cultivation methods and conditions. In this study, we used molecular method with specific primers by Polymerase Chain Reaction (PCR) to amplify and to analyze the occurrence of free-living amoebae in aquatic environment. We collected 92 samples from environmental water in Taiwan. The results show that 33 water samples (35.9%) and 11 water samples (12.0%) were detected positive for Acanthamoeba and Naegleria, respectively. Furthermore, both Acanthamoeba and Naegleria can be cultured by PYG in 30° C, but not all free-living amoebae can be enriched and isolated by using storage-cultivation method. Due to the presence of Acanthamoeba and Naegleria in aquatic environment, the water quality monitoring should be more conscious. Keywords: free-living amoebae; Acanthamoeba; Naegleria; Balamuthia; Hartmannella; PCR

  16. Origin and diversity of testate amoebae shell composition: Example of Bullinularia indica living in Sphagnum capillifolium.

    Delaine, Maxence; Bernard, Nadine; Gilbert, Daniel; Recourt, Philippe; Armynot du Châtelet, Eric

    2017-06-01

    Testate amoebae are free-living shelled protists that build a wide range of shells with various sizes, shapes, and compositions. Recent studies showed that xenosomic testate amoebae shells could be indicators of atmospheric particulate matter (PM) deposition. However, no study has yet been conducted to assess the intra-specific mineral, organic, and biologic grain diversity of a single xenosomic species in a natural undisturbed environment. This study aims at providing new information about grain selection to develop the potential use of xenosomic testate amoebae shells as bioindicators of the multiple-origin mineral/organic diversity of their proximal environment. To fulfil these objectives, we analysed the shell content of 38 Bullinularia indica individuals, a single xenosomic testate amoeba species living in Sphagnum capillifolium, by scanning electron microscope (SEM) coupled with X-ray spectroscopy. The shells exhibited high diversities of mineral, organic, and biomineral grains, which confirms their capability to recycle xenosomes. Mineral grain diversity and size of B. indica matched those of the atmospheric natural mineral PM deposited in the peatbog. Calculation of grain size sorting revealed a discrete selection of grains agglutinated by B. indica. These results are a first step towards understanding the mechanisms of particle selection by xenosomic testate amoebae in natural conditions. Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. Burkholderia bacteria infectiously induce the proto-farming symbiosis of Dictyostelium amoebae and food bacteria.

    DiSalvo, Susanne; Haselkorn, Tamara S; Bashir, Usman; Jimenez, Daniela; Brock, Debra A; Queller, David C; Strassmann, Joan E

    2015-09-08

    Symbiotic associations can allow an organism to acquire novel traits by accessing the genetic repertoire of its partner. In the Dictyostelium discoideum farming symbiosis, certain amoebas (termed "farmers") stably associate with bacterial partners. Farmers can suffer a reproductive cost but also gain beneficial capabilities, such as carriage of bacterial food (proto-farming) and defense against competitors. Farming status previously has been attributed to amoeba genotype, but the role of bacterial partners in its induction has not been examined. Here, we explore the role of bacterial associates in the initiation, maintenance, and phenotypic effects of the farming symbiosis. We demonstrate that two clades of farmer-associated Burkholderia isolates colonize D. discoideum nonfarmers and infectiously endow them with farmer-like characteristics, indicating that Burkholderia symbionts are a major driver of the farming phenomenon. Under food-rich conditions, Burkholderia-colonized amoebas produce fewer spores than uncolonized counterparts, with the severity of this reduction being dependent on the Burkholderia colonizer. However, the induction of food carriage by Burkholderia colonization may be considered a conditionally adaptive trait because it can confer an advantage to the amoeba host when grown in food-limiting conditions. We observed Burkholderia inside and outside colonized D. discoideum spores after fruiting body formation; this observation, together with the ability of Burkholderia to colonize new amoebas, suggests a mixed mode of symbiont transmission. These results change our understanding of the D. discoideum farming symbiosis by establishing that the bacterial partner, Burkholderia, is an important causative agent of the farming phenomenon.

  18. Review: Occurrence of the pathogenic amoeba Naegleria fowleri in groundwater

    Bright, Kelly R.; Gerba, Charles P.

    2017-06-01

    Naegleria fowleri is a thermophilic free-living amoeba found worldwide in soils and warm freshwater. It is the causative agent of primary amebic meningoencephalitis, a nearly always fatal disease afflicting mainly children and young adults. Humans are exposed to the organism via swimming, bathing, or other recreational activity during which water is forcefully inhaled into the upper nasal passages. Although many studies have looked at the occurrence of N. fowleri in surface waters, limited information is available regarding its occurrence in groundwater and geothermally heated natural waters such as hot springs. This paper reviews the current literature related to the occurrence of N. fowleri in these waters and the methods employed for its detection. Case reports of potential groundwater exposures are also included. Despite increased interest in N. fowleri in recent years due to well-publicized cases linked to drinking water, many questions still remain unanswered. For instance, why the organism persists in some water sources and not in others is not well understood. The role of biofilms in groundwater wells and plumbing in individual buildings, and the potential for warming due to climate change to expand the occurrence of the organism into new regions, are still unclear. Additional research is needed to address these questions in order to better understand the ecology of N. fowleri and the conditions that result in greater risks to bathers.

  19. Paramecium species ingest and kill the cells of the human pathogenic fungus Cryptococcus neoformans.

    Frager, Shalom Z; Chrisman, Cara J; Shakked, Rachel; Casadevall, Arturo

    2010-08-01

    A fundamental question in the field of medical mycology is the origin of virulence in those fungal pathogens acquired directly from the environment. In recent years, it was proposed that the virulence of certain environmental animal-pathogenic microbes, such as Cryptococcus neoformans, originated from selection pressures caused by species-specific predation. In this study, we analyzed the interaction of C. neoformans with three Paramecium spp., all of which are ciliated mobile protists. In contrast to the interaction with amoebae, some Paramecium spp. rapidly ingested C. neoformans and killed the fungus. This study establishes yet another type of protist-fungal interaction supporting the notion that animal-pathogenic fungi in the environment are under constant selection by predation.

  20. Killing, letting die and euthanasia.

    Husak, D N

    1979-12-01

    Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible.

  1. Killing, letting die and euthanasia.

    Husak, D N

    1979-01-01

    Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible. PMID:541821

  2. "Guns do not kill, people do!"

    Lemche, Niels Peter

    2011-01-01

    The Bible does not kill, but many people who have read the Bible (in their way) have killed, virtually or in real.......The Bible does not kill, but many people who have read the Bible (in their way) have killed, virtually or in real....

  3. Late Holocene palaeohydrological changes in a Sphagnum peat bog from NW Romania based on testate amoebae

    Andrei-Cosmin Diaconu

    2016-04-01

    Full Text Available This paper investigates the possibility of reconstructing the palaeohydrological changes in an active Sphagnum peat bog from north-western Romania using testate amoebae fauna and organic matter content determined by loss on ignition (LOI. In total 28 taxa of testate amoebae were identified of which 11 were frequent enough to present a remarkable ecological significance. Based on the relative abundance of these taxa nine zones were identified, crossing from very wet to dry climate conditions. The wet periods identified are characterized by taxa like Centropyxis cassis, Amphitrema flavum and Hyalosphenia papilio, while in the dry periods Difflugia pulex and Nebela militaris thrive. We showed that combining qualitative information regarding hydrological preferences with the quantitative percentage data from the fossil record it is possible to obtain information regarding major surface moisture changes from the peat bog surface. Furthermore we identified a link between distribution of testate amoebae assemblages, organic matter variation and minerogenic material.

  4. Free energy simulations with the AMOEBA polarizable force field and metadynamics on GPU platform.

    Peng, Xiangda; Zhang, Yuebin; Chu, Huiying; Li, Guohui

    2016-03-05

    The free energy calculation library PLUMED has been incorporated into the OpenMM simulation toolkit, with the purpose to perform enhanced sampling MD simulations using the AMOEBA polarizable force field on GPU platform. Two examples, (I) the free energy profile of water pair separation (II) alanine dipeptide dihedral angle free energy surface in explicit solvent, are provided here to demonstrate the accuracy and efficiency of our implementation. The converged free energy profiles could be obtained within an affordable MD simulation time when the AMOEBA polarizable force field is employed. Moreover, the free energy surfaces estimated using the AMOEBA polarizable force field are in agreement with those calculated from experimental data and ab initio methods. Hence, the implementation in this work is reliable and would be utilized to study more complicated biological phenomena in both an accurate and efficient way. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  5. [Nitrogen input altered testate amoebae community in peatland of Sanjiang Plain, Northeast China].

    Song, Li-hong; Yan, Xiu-min; Wang, Ke-hong; Zhu, Xiao-yan; Wu, Dong-hu

    2015-02-01

    In the present study, an in situ control experiment was carried out to explore the response of testate amoebae to exogenous nitrogen addition in peatland of Sanjiang Plain. The results showed that nitrogen addition increased the biomass of testate amoebae at lower levels (6 g N · m(-2)), while decreased it at higher levels (> 12 g N · m(-2)). At genus level, nitrogen addition significantly increased the biomass of Arcella and Phryganella, decreased the biomass of Euglypha. Only lower nitrogen addition significantly increased the biomass of Centropyxis. At species level, nitrogen addition significantly decreased the biomass of Euglypha rotunda, while the biomass of either Centropyxis cassis or Phryganella acropodia was increased by a lower nitrogen addition treatment. This study suggested that the response of peatland testate amoebae to nitrogen addition was species specific, which could potentially be used as an indicator for the environment of peatlands.

  6. Amoeba Management System Transformation in the Light of Organisational Change Literature

    Urban Wieslaw

    2017-03-01

    Full Text Available The object of this study is the system of amoebas founded originally in Japanese Kyocera. The study aims to identify milestones of the transformation in a company organisational system to the Amoeba Management System (AMS. The study takes a conceptual research approach. It starts from the analysis of available sources on the AMS, identifies the most challenging points of this system, and afterwards, based on organisational change literature, formulates the main steps of transformation towards AMS. The following milestones of AMS implementation emerge from organisational change theories: (1 the preparation for AMS, (2 the change of organisational structure, (3 the design and introduction of a new accounting system, (4 the introduction of inner prices between amoebas, and (5 the transformation of the organisational culture. At the end of the study, the most important issues for future research are listed.

  7. Short communication: Effects of lactose and milk on the expression of biofilm-associated genes in Staphylococcus aureus strains isolated from a dairy cow with mastitis.

    Xue, Ting; Chen, Xiaolin; Shang, Fei

    2014-10-01

    Staphylococcus aureus is the main etiological organism responsible for bovine mastitis. The ability of S. aureus to form biofilms plays an important role in the pathogenesis of mastitis. Biofilm formation in S. aureus is associated with the production of polysaccharide intercellular adhesin (PIA) protein and several other proteins. Several environmental factors, including glucose, osmolarity, oleic acid, temperature, and anaerobiosis, have been reported to affect biofilm formation in S. aureus. This study investigated the influence of lactose and milk on the biofilm formation capacity of 2 clinical bovine isolates of S. aureus. We found that lactose increased biofilm formation predominantly by inducing PIA production, whereas milk increased biofilm formation through PIA as well as by increasing the production of other biofilm-associated proteins, which might be mediated by the transcriptional regulators intercellular adhesion regulator (icaR) and repressor of biofilm (rbf). Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. [The role of the floodplain gradient in structuring of testate amoebae communities in the Ilych River].

    Mazeĭ, Iu A; Malysheva, E A; Lapteva, E M; Komarov, A A; Taskaeva, A A

    2012-01-01

    Forty-two testate amoebae taxa were identified in alluvial soils of floodplain islands in the Ilych River. Among the pedo- and eurybionts, there were aquatic rhizopods. Along the floodplain transect (willow --> meadow --> deciduous forest --> coniferous forest), the testate amoebae community changed directly. There are spatially homogeneous (low beta-diversity) testacean communities but species rich on the local level (high alpha-diversity) within forests. Within willows and meadows, communities are characterized by low alpha-diversity and high heterogeneity that leads to high gamma-diversity.

  9. political killings in South Africa

    mainly occurred in KwaZulu-Natal, with a much smaller number occurring in Mpumalanga and ... Though the problem is concentrated in specific provinces it is likely to impact on political life ... killings that are the focus of the article, including.

  10. To kill a mockingbird robot

    Bartneck, C.; Verbunt, M.N.C.; Mubin, O.; Al Mahmud, A.

    2007-01-01

    Robots are being introduced in our society but their social status is still unclear. A critical issue is if the robot's exhibition of intelligent life-like behavior leads to the users' perception of animacy. The ultimate test for the life-likeness of a robot is to kill it. We therefore conducted an

  11. Killing horizons as equipotential hypersurfaces

    Smolić, Ivica

    2012-01-01

    In this note we present a new proof that Killing horizons are equipotential hypersurfaces for the electric and the magnetic scalar potential, which makes no use of gravitational field equations or the assumption about the existence of a bifurcation surface. (note)

  12. Amoebae as potential environmental hosts for Mycobacterium ulcerans and other mycobacteria, but doubtful actors in Buruli ulcer epidemiology.

    Sophie Gryseels

    Full Text Available The reservoir and mode of transmission of Mycobacterium ulcerans, the causative agent of Buruli ulcer, remain unknown. Ecological, genetic and epidemiological information nonetheless suggests that M. ulcerans may reside in aquatic protozoa.We experimentally infected Acanthamoeba polyphaga with M. ulcerans and found that the bacilli were phagocytised, not digested and remained viable for the duration of the experiment. Furthermore, we collected 13 water, 90 biofilm and 45 detritus samples in both Buruli ulcer endemic and non-endemic communities in Ghana, from which we cultivated amoeboid protozoa and mycobacteria. M. ulcerans was not isolated, but other mycobacteria were as frequently isolated from intracellular as from extracellular sources, suggesting that they commonly infect amoebae in nature. We screened the samples as well as the amoeba cultures for the M. ulcerans markers IS2404, IS2606 and KR-B. IS2404 was detected in 2% of the environmental samples and in 4% of the amoeba cultures. The IS2404 positive amoeba cultures included up to 5 different protozoan species, and originated both from Buruli ulcer endemic and non-endemic communities.This is the first report of experimental infection of amoebae with M. ulcerans and of the detection of the marker IS2404 in amoeba cultures isolated from the environment. We conclude that amoeba are potential natural hosts for M. ulcerans, yet remain sceptical about their implication in the transmission of M. ulcerans to humans and their importance in the epidemiology of Buruli ulcer.

  13. Seasonal changes in Sphagnum peatland testate amoeba communities along a hydrological gradient.

    Marcisz, Katarzyna; Lamentowicz, Lukasz; Słowińska, Sandra; Słowiński, Michał; Muszak, Witold; Lamentowicz, Mariusz

    2014-10-01

    Testate amoebae are an abundant and functionally important group of protists in peatlands, but little is known about the seasonal patterns of their communities. We investigated the relationships between testate amoeba diversity and community structure and water table depth and light conditions (shading vs. insolation) in a Sphagnum peatland in Northern Poland (Linje mire) in spring and summer 2010. We monitored the water table at five sites across the peatland and collected Sphagnum samples in lawn and hummock micro-sites around each piezometer, in spring (3 May) and mid-summer (6 August) 2010. Water table differed significantly between micro-sites and seasons (Kruskal-Wallis test, p=0.001). The community structure of testate amoebae differed significantly between spring and summer in both hummock and lawn micro-sites. We recorded a small, but significant drop in Shannon diversity, between spring and summer (1.76 vs. 1.72). Strongest correlations were found between testate amoeba communities and water table lowering and light conditions. The relative abundance of mixotrophic species Hyalosphenia papilio, Archerella flavum and of Euglypha ciliata was higher in the summer. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (similar to 200 km north of the Arctic Circle). Multivariate statistical ...

  15. Mimivirus: leading the way in the discovery of giant viruses of amoebae.

    Colson, Philippe; La Scola, Bernard; Levasseur, Anthony; Caetano-Anollés, Gustavo; Raoult, Didier

    2017-04-01

    The accidental discovery of the giant virus of amoeba - Acanthamoeba polyphaga mimivirus (APMV; more commonly known as mimivirus) - in 2003 changed the field of virology. Viruses were previously defined by their submicroscopic size, which probably prevented the search for giant viruses, which are visible by light microscopy. Extended studies of giant viruses of amoebae revealed that they have genetic, proteomic and structural complexities that were not thought to exist among viruses and that are comparable to those of bacteria, archaea and small eukaryotes. The giant virus particles contain mRNA and more than 100 proteins, they have gene repertoires that are broader than those of other viruses and, notably, some encode translation components. The infection cycles of giant viruses of amoebae involve virus entry by amoebal phagocytosis and replication in viral factories. In addition, mimiviruses are infected by virophages, defend against them through the mimivirus virophage resistance element (MIMIVIRE) system and have a unique mobilome. Overall, giant viruses of amoebae, including mimiviruses, marseilleviruses, pandoraviruses, pithoviruses, faustoviruses and molliviruses, challenge the definition and classification of viruses, and have increasingly been detected in humans.

  16. Exposure to synthetic greywater inhibits amoebae encystation and alters expression of Legionella pneumophila virulence genes

    Water conservation efforts have focused on greywater (GW) usage, especially for applications that do not require potable water quality. However, there is a need to better understand environmental pathogens and their free-living amoebae (FLA) hosts within GW. Using synthetic gre...

  17. Presence of rotavirus and free-living amoebae in the water supplies of Karachi, Pakistan

    Yousuf, Farzana Abubakar; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2017-01-01

    ABSTRACT Rotavirus and pathogenic free-living amoebae are causative agents of important health problems, especially for developing countries like Pakistan where the population has limited access to clean water supplies. Here, we evaluated the prevalence of rotavirus and free-living amoebae (Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri) in drinking water supplies of Karachi, Pakistan. Six water filtration plants that supply drinking water to the population of Karachi were investigated. Additionally, drinking water samples from households were analyzed for the presence of rotavirus and free-living amoebae. Rotavirus was present in 35% of the water samples collected from water filtration plants; however, domestic tap water samples had a prevalence of only 5%. Out of 20 water samples from filtration plants, 13 (65%) were positive for Acanthamoeba spp., and one (5%) was positive for B. mandrillaris. Out of 20 drinking water samples collected from different areas of Karachi, 35% were positive for Acanthamoeba spp. Rotavirus was detected in 5% of the drinking water samples tested. Overall, these findings showed for the first time the presence of rotavirus, in addition to pathogenic free-living amoebae in drinking water supplies of Karachi that could be an important public health risk for the affected population. PMID:28591260

  18. Presence of rotavirus and free-living amoebae in the water supplies of Karachi, Pakistan

    Farzana Abubakar Yousuf

    Full Text Available ABSTRACT Rotavirus and pathogenic free-living amoebae are causative agents of important health problems, especially for developing countries like Pakistan where the population has limited access to clean water supplies. Here, we evaluated the prevalence of rotavirus and free-living amoebae (Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri in drinking water supplies of Karachi, Pakistan. Six water filtration plants that supply drinking water to the population of Karachi were investigated. Additionally, drinking water samples from households were analyzed for the presence of rotavirus and free-living amoebae. Rotavirus was present in 35% of the water samples collected from water filtration plants; however, domestic tap water samples had a prevalence of only 5%. Out of 20 water samples from filtration plants, 13 (65% were positive for Acanthamoeba spp., and one (5% was positive for B. mandrillaris. Out of 20 drinking water samples collected from different areas of Karachi, 35% were positive for Acanthamoeba spp. Rotavirus was detected in 5% of the drinking water samples tested. Overall, these findings showed for the first time the presence of rotavirus, in addition to pathogenic free-living amoebae in drinking water supplies of Karachi that could be an important public health risk for the affected population.

  19. Quadrulella texcalense sp nov from a Mexican desert: An unexpected new environment for hyalospheniid testate amoebae

    Perez-Juarez, H.; Serrano-Vazquez, A.; Kosakyan, Anush; Mitchell, E.A.D.; Rivera Aguilar, V. M.; Lahr, D. J. G.; Hernandez Moreno, M. M.; Macías Cuellar, H.; Eguiarte, L. E.; Lara, E.

    2017-01-01

    Roč. 61, 17 July (2017), s. 253-264 ISSN 0932-4739 Institutional support: RVO:60077344 Keywords : Adaptation * Biological soil crust desert * Protist * Tehuacain-Cuicatlain Biosphere Reserve * Testate amoebae Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 2.581, year: 2016

  20. Long-Term Hydrological Reconstruction From a Beaver Meadow Using Testate Amoebae

    Von Ness, K.; Loisel, J.; Karran, D. J.; Westbrook, C.; Kohlmeyer, C.

    2016-12-01

    Beaver ponds contribute up to 0.8 Tg/yr of atmospheric methane (CH4) globally (Whitfield et al., 2014) and were found to be the largest CH4 emitters among all the wetland types in boreal environments (Roulet et al., 1992). However, the sources and underlying mechanisms of carbon emission and sequestration in beaver ponds requires further elucidation. Here we present the historical development of a beaver meadow located in the Sibbald Research Wetland in the Rocky Mountains of Kananaskis Provincial Park, Alberta, Canada. We use a combination of testate amoebae, plant macrofossils, and other geochemical proxies to provide high-resolution reconstructions along three peat cores extracted in hydrologically distinct portions of the meadow. To our knowledge, this is the first attempt at reconstructing long-term hydrological conditions in these systems. Testate amoebae (Protozoa: Rhizopoda) are single-celled organisms that inhabit moist substrates and produce a decay-resistant test. As each taxon generally occupies a discrete ecological niche related to soil moisture and pH, testate amoebae are good indicators of past and ongoing hydrological change. Preliminary analysis of testate amoebae assemblages downcore suggests that this proxy is suitable to reconstruct hydrological changes in meadows, with wetter and drier communities being in good agreement with wetter and drier plant macrofossil assemblages. The nitrogen isotopic signature of peat samples (ongoing) will be used as a proxy for changes in nutrient input; it could become a proxy for past beaver activity.

  1. Seasonal abundances of naked amoebae in biofilms on shells of zebra mussels (Dreissena polymorpha) with comparative data from rock scrapings.

    Bischoff, Paul J; Wetmore, Scott

    2009-01-01

    In North America, zebra mussels (Dreissena polymorpha) are notoriously known as invasive species. The abundance of naked amoebae sampled from the shells of zebra mussels was compared with abundances from rock scrapings at approximately monthly intervals for 1 year. The sites were 2 km apart along the same shoreline. No significant difference in abundance of naked amoebae (F = 1.44; P amoebae in winter, followed by peaks in early spring. The percent encysted increased from a low of 1% in the summer to 80% in early winter.

  2. WOMEN'S RIGHTS VIOLATION: HONOUR KILLINGS

    CRISTINA OTOVESCU FRASIE

    2011-04-01

    Full Text Available In this study I have presented the domestic violence concept and the situation regarding the observing of woman’s rights in Syria. We have also evidenced the juridical aspects regarding the honor killing directed against women after the modification of the article 548 from the Penal Code changed by the President al-Asad on July the 1st 2009. The data offered by NGOs have been of great help for the elaboration of the study as also the statistic data presented in Thara E-Magazine regarding the cities where had been done the honor killings and their number, the instrument of the murder, the age of the victim, and the motives for the murders. It must be noticed that, lately, the Government fought for the observing of the woman’s rights and promoted he gender equality by appointing women in leading positions, including the vice-president one.

  3. Evolution equations for Killing fields

    Coll, B.

    1977-01-01

    The problem of finding necessary and sufficient conditions on the Cauchy data for Einstein equations which insure the existence of Killing fields in a neighborhood of an initial hypersurface has been considered recently by Berezdivin, Coll, and Moncrief. Nevertheless, it can be shown that the evolution equations obtained in all these cases are of nonstrictly hyperbolic type, and, thus, the Cauchy data must belong to a special class of functions. We prove here that, for the vacuum and Einstein--Maxwell space--times and in a coordinate independent way, one can always choose, as evolution equations for the Killing fields, a strictly hyperbolic system: The above theorems can be thus extended to all Cauchy data for which the Einstein evolution problem has been proved to be well set

  4. Wind power and bird kills

    Raynolds, M.

    1998-01-01

    The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy

  5. Wind power and bird kills

    Raynolds, M.

    1998-12-01

    The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy.

  6. Isolated Horizon, Killing Horizon and Event Horizon

    Date, G.

    2001-01-01

    We consider space-times which in addition to admitting an isolated horizon also admit Killing horizons with or without an event horizon. We show that an isolated horizon is a Killing horizon provided either (1) it admits a stationary neighbourhood or (2) it admits a neighbourhood with two independent, commuting Killing vectors. A Killing horizon is always an isolated horizon. For the case when an event horizon is definable, all conceivable relative locations of isolated horizon and event hori...

  7. 33 CFR 117.801 - Newtown Creek, Dutch Kills, English Kills and their tributaries.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117.801 Section 117.801 Navigation and Navigable Waters COAST GUARD....801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a) The following requirements...

  8. Killing-Yano tensors and Nambu mechanics

    Baleanu, D.

    1998-01-01

    Killing-Yano tensors were introduced in 1952 by Kentaro-Yano from mathematical point of view. The physical interpretation of Killing-Yano tensors of rank higher than two was unclear. We found that all Killing-Yano tensors η i 1 i 2 . .. i n with covariant derivative zero are Nambu tensors. We found that in the case of flat space case all Killing-Yano tensors are Nambu tensors. In the case of Taub-NUT and Kerr-Newmann metric Killing-Yano tensors of order two generate Nambu tensors of rank 3

  9. Evidence of test detachment in Astrorhiza limicola and two consequential synonyms: Amoeba gigantea and Megamoebomyxa argillobia (Foraminiferida)

    Cedhagen, Tomas; Tendal, Ole S.

    1989-01-01

    Laboratory observations and experiments demonstrate that the naked rhizopods Amoeba gigantea SANDAHL, 1857 and Megamoebomyxa argillo~ia NYHOLM, 1950, and the foraminifers Astrorhiza arenifera STSCHEDRlNA, 1946, A. sabulifera STSCHEDRINA, 1946 and A. arctlca STSCHEDRINA, 1958 are synonyms of Astro......Laboratory observations and experiments demonstrate that the naked rhizopods Amoeba gigantea SANDAHL, 1857 and Megamoebomyxa argillo~ia NYHOLM, 1950, and the foraminifers Astrorhiza arenifera STSCHEDRlNA, 1946, A. sabulifera STSCHEDRINA, 1946 and A. arctlca STSCHEDRINA, 1958 are synonyms...

  10. Detection and identification of free-living amoeba from aquatic environment in different seasons in Taiwan

    Tzeng, K.; Hsu, B.; Tsai, H.; Huang, P.; Tsai, J.; Kao, P.; Huang, K.; Chen, J.

    2013-12-01

    Free-living amoeba includes Acanthamoeba and Naegleria, which are widely distributed in water and soil. Human infection with free-living amoeba leads to serious illness, even lethal. For example, central nervous system infection will cause amoebic meningoencephalitis, and infections will cause amoebic keratitis. The presence of free-living amoeba in environment water can be used as a water quality indicator in ecosystem assessment. In Taiwan, reservoirs are indispensable because of the water source are limited by the steep terrain and the short river flow. Therefore, we need to pay more attention in the quality control of reservoirs water. The aims of this study are to investigate the presence of free-living amoeba in Taiwan reservoirs, and to compare the differences among seasons. At last, the identification and genotyping of Acanthamoeba and Naegleria are investigated. In this study, we use polymerase chain reaction with specific primers to analyze the presence of free-living amoeba in aquatic environment. We collected total 60 samples from reservoirs in Taiwan. The water samples are divided into two parts for both direct concentration method and culture method. The results show the different detection rates among seasons. For Acanthamoeba, the detection rates were 28.3% (17 of 60 water samples), 21.7% (13 of 60 water samples) and 8.3% (5 of 60 water samples) in autumn, winter and spring, respectively. For Naegleria, the detection rates were 6.7% (4 of 60 water samples), 0% (0 of 60 water samples) and 0% (0 of 60 water samples) were detected positive in autumn, winter and spring, respectively. Sequence analysis showed that the major genotypes in Acanthamoeba were T3, T4, T10 and T11 in autumn, T2, T4 and T10 in winter, T4 in spring. Due to the presences of Acanthamoeba and Naegleria in reservoirs, we should pay more attention in water quality monitoring to prevent the potential risks of diseases. Keywords: free-living amoeba, Acanthamoeba, Naegleria, polymerase

  11. Platyamoeba pseudovannellida n. sp., a naked amoeba with wide salt tolerance isolated from the Salton Sea, California.

    Hauer, G; Rogerson, A; Anderson, O R

    2001-01-01

    A new species of naked amoeba, Platyamoeba pseudovannellida n.sp., is described on the basis of light microscopic and fine structural features. The amoeba was isolated from the Salton Sea, California, from water at a salinity of ca. 44%. Locomotive amoebae occasionally had a spatulate outline and floating cells had radiating pseudopodia, sometimes with pointed tips. Both these features are reminiscent of the genus Vannella. However, the surface coat (glycocalyx) as revealed by TEM indicates that this is a species of Platyamoeba. Although salinity was not used as a diagnostic feature, this species was found to have remarkable tolerance to fluctuating salinity levels, even when changes were rapid. Amoebae survived over the range 0 per thousand to 150 per thousand salt and grew within the range 0 per thousand to 138 per thousand salt. The generation time of cells averaged 29 h and was not markedly affected by salt concentration. This is longer than expected for an amoeba of this size and suggests a high energetic cost of coping with salinity changes. The morphology of cells changed with increasing salinity: at 0 per thousand cells were flattened and active and at the other extreme (138 per thousand) amoebae were wrinkled and domed and cell movement was very slow. At the ultrastructural level, the cytoplasm of cells grown at high salinity (98 per thousand was considerably denser than that of cells reared at 0 per thousand.

  12. Engineering an artificial amoeba propelled by nanoparticle-triggered actin polymerization

    Yi Jinsoo; Schmidt, Jacob; Chien Aichi; Montemagno, Carlo D [Department of Bioengineering, University of California Los Angeles, 420 Westwood Plaza, 7523 Boelter Hall, Los Angeles, CA 90095-1600 (United States)], E-mail: montemcd@ucmail.uc.edu

    2009-02-25

    We have engineered an amoeba system combining nanofabricated inorganic materials with biological components, capable of propelling itself via actin polymerization. The nanofabricated materials have a mechanism similar to the locomotion of the Listeria monocytogenes, food poisoning bacteria. The propulsive force generation utilizes nanoparticles made from nickel and gold functionalized with the Listeria monocytogenes transmembrane protein, ActA. These Listeria-mimic nanoparticles were in concert with actin, actin binding proteins, ATP (adenosine triphosphate) and encapsulated within a lipid vesicle. This system is an artificial cell, such as a vesicle, where artificial nanobacteria and actin polymerization machinery are used in driving force generators inside the cell. The assembled structure was observed to crawl on a glass surface analogously to an amoeba, with the speed of the movement dependent on the amount of actin monomers and ATP present.

  13. Ecology of Testate Amoebae in the Komořany Ponds in the Vltava Basin

    Burdíková, Zuzana; Čapek, Martin; Švindrych, Zdeněk; Gryndler, M.; Kubínová, Lucie; Holcová, K.

    2012-01-01

    Roč. 64, č. 1 (2012), s. 117-130 ISSN 0095-3628 R&D Projects: GA MŠk(CZ) LC06063; GA ČR(CZ) GAP108/11/0794 Institutional research plan: CEZ:AV0Z50110509 Keywords : ecology * freshwater ecosystem * testate amoebae * seasonal variability Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.277, year: 2012

  14. Interactions Between Testate Amoebae and Saprotrophic Microfungi in a Scots Pine Litter Microcosm

    Vohník, Martin; Burdíková, Zuzana; Vyhnal, Aleš; Koukol, O.

    2011-01-01

    Roč. 61, č. 3 (2011), s. 660-668 ISSN 0095-3628 R&D Projects: GA ČR GP206/09/P340; GA ČR(CZ) GD204/09/H084 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z60050516 Keywords : testate amoebae * saprotrophic fungi * litter Subject RIV: EF - Botanics Impact factor: 2.912, year: 2011

  15. Brain-Eating Amoebae: Predilection Sites in the Brain and Disease Outcome

    Ong, Timothy Yu Yee; Khan, Naveed Ahmed; Siddiqui, Ruqaiyyah

    2017-01-01

    Acanthamoeba spp. and Balamuthia mandrillaris are causative agents of granulomatous amoebic encephalitis (GAE), while Naegleria fowleri causes primary amoebic meningoencephalitis (PAM). PAM is an acute infection that lasts a few days, while GAE is a chronic to subacute infection that can last up to several months. Here, we present a literature review of 86 case reports from 1968 to 2016, in order to explore the affinity of these amoebae for particular sites of the brain, diagnostic modalities...

  16. Environmental Free-Living Amoebae Isolated from Soil in Khon Kaen, Thailand, Antagonize Burkholderia pseudomallei.

    Parumon Noinarin

    Full Text Available Presence of Burkholderia pseudomallei in soil and water is correlated with endemicity of melioidosis in Southeast Asia and northern Australia. Several biological and physico-chemical factors have been shown to influence persistence of B. pseudomallei in the environment of endemic areas. This study was the first to evaluate the interaction of B. pseudomallei with soil amoebae isolated from B. pseudomallei-positive soil site in Khon Kaen, Thailand. Four species of amoebae, Paravahlkampfia ustiana, Acanthamoeba sp., Naegleria pagei, and isolate A-ST39-E1, were isolated, cultured and identified based on morphology, movement and 18S rRNA gene sequence. Co-cultivation combined with a kanamycin-protection assay of B. pseudomallei with these amoebae at MOI 20 at 30°C were evaluated during 0-6 h using the plate count technique on Ashdown's agar. The fate of intracellular B. pseudomallei in these amoebae was also monitored by confocal laser scanning microscopy (CLSM observation of the CellTracker™ Orange-B. pseudomallei stained cells. The results demonstrated the ability of P. ustiana, Acanthamoeba sp. and isolate A-ST39-E1 to graze B. pseudomallei. However, the number of internalized B. pseudomallei substantially decreased and the bacterial cells disappeared during the observation period, suggesting they had been digested. We found that B. pseudomallei promoted the growth of Acanthamoeba sp. and isolate A-ST39-E1 in co-cultures at MOI 100 at 30°C, 24 h. These findings indicated that P. ustiana, Acanthamoeba sp. and isolate A-ST39-E1 may prey upon B. pseudomallei rather than representing potential environmental reservoirs in which the bacteria can persist.

  17. Response of testate amoebae to a late Holocene ecosystem shift in an Amazonian peatland.

    Swindles, Graeme T; Kelly, Thomas J; Roucoux, Katherine H; Lawson, Ian T

    2018-03-15

    To date there have only been two studies using testate amoebae as palaeoecological indicators in tropical peatlands. Here we present a new ∼500-year testate amoeba record from San Jorge, a domed peatland in Peruvian Amazonia, which has a well-constrained vegetation history based on pollen analysis. We observe a major shift from Hyalosphenia subflava to Cryptodifflugia oviformis-dominated communities at ∼50 cm depth (c. AD 1760), which suggests a change to drier conditions in the peatland. The application of a statistical transfer function also suggests a deepening of the water table at this time. The transition in the microbial assemblage occurs at a time when pollen and geochemical data indicate drier conditions (reduced influence of river flooding), leading to an ecosystem switch to more ombrotrophic-like conditions in the peatland. Our work illustrates the potential of testate amoebae as important tools in tropical peatland palaeoecology, and the power of multiproxy approaches for understanding the long-term development of tropical peatlands. Copyright © 2018 Elsevier GmbH. All rights reserved.

  18. What is the optimum sample size for the study of peatland testate amoeba assemblages?

    Mazei, Yuri A; Tsyganov, Andrey N; Esaulov, Anton S; Tychkov, Alexander Yu; Payne, Richard J

    2017-10-01

    Testate amoebae are widely used in ecological and palaeoecological studies of peatlands, particularly as indicators of surface wetness. To ensure data are robust and comparable it is important to consider methodological factors which may affect results. One significant question which has not been directly addressed in previous studies is how sample size (expressed here as number of Sphagnum stems) affects data quality. In three contrasting locations in a Russian peatland we extracted samples of differing size, analysed testate amoebae and calculated a number of widely-used indices: species richness, Simpson diversity, compositional dissimilarity from the largest sample and transfer function predictions of water table depth. We found that there was a trend for larger samples to contain more species across the range of commonly-used sample sizes in ecological studies. Smaller samples sometimes failed to produce counts of testate amoebae often considered minimally adequate. It seems likely that analyses based on samples of different sizes may not produce consistent data. Decisions about sample size need to reflect trade-offs between logistics, data quality, spatial resolution and the disturbance involved in sample extraction. For most common ecological applications we suggest that samples of more than eight Sphagnum stems are likely to be desirable. Copyright © 2017 Elsevier GmbH. All rights reserved.

  19. Ecological niche models reveal the importance of climate variability for the biogeography of protosteloid amoebae.

    Aguilar, María; Lado, Carlos

    2012-08-01

    Habitat availability and environmental preferences of species are among the most important factors in determining the success of dispersal processes and therefore in shaping the distribution of protists. We explored the differences in fundamental niches and potential distributions of an ecological guild of slime moulds-protosteloid amoebae-in the Iberian Peninsula. A large set of samples collected in a north-east to south-west transect of approximately 1000 km along the peninsula was used to test the hypothesis that, together with the existence of suitable microhabitats, climate conditions may determine the probability of survival of species. Although protosteloid amoebae share similar morphologies and life history strategies, canonical correspondence analyses showed that they have varied ecological optima, and that climate conditions have an important effect in niche differentiation. Maxent environmental niche models provided consistent predictions of the probability of presence of the species based on climate data, and they were used to generate maps of potential distribution in an 'everything is everywhere' scenario. The most important climatic factors were, in both analyses, variables that measure changes in conditions throughout the year, confirming that the alternation of fruiting bodies, cysts and amoeboid stages in the life cycles of protosteloid amoebae constitutes an advantage for surviving in a changing environment. Microhabitat affinity seems to be influenced by climatic conditions, which suggests that the micro-environment may vary at a local scale and change together with the external climate at a larger scale.

  20. Pathogenic waterborne free-living amoebae: An update from selected Southeast Asian countries

    Abdul Majid, Mohamad Azlan; Mahboob, Tooba; Mong, Brandon G. J.; Jaturas, Narong; Richard, Reena Leeba; Tian-Chye, Tan; Phimphila, Anusorn; Mahaphonh, Panomphanh; Aye, Kyaw Nyein; Aung, Wai Lynn; Chuah, Joon; Ziegler, Alan D.; Yasiri, Atipat; Sawangjaroen, Nongyao; Lim, Yvonne A. L.; Nissapatorn, Veeranoot

    2017-01-01

    Data on the distribution of free-living amoebae is still lacking especially in Southeast Asian region. The aquatic environment revealed a high occurrence of free-living amoebae (FLA) due to its suitable condition and availability of food source, which subsequently causes infection to humans. A total of 94 water samples consisted of both treated and untreated from Laos (31), Myanmar (42), and Singapore (21) were investigated for the presence of pathogenic FLA. Each water sample was filtered and cultured onto non-nutrient agar seeded with live suspension of Escherichia coli and incubated at room temperature. Morphological identification was conducted for both trophozoites and cysts via microscopic stains (Giemsa and immunofluorescence). The presence of Naegleria-like structures was the most frequently encountered in both treated and untreated water samples, followed by Acanthamoeba-like and Vermamoeba-like features. To identify the pathogenic isolates, species-specific primer sets were applied for molecular identification of Acanthamoeba, Naegleria, and Vermamoeba. The pathogenic species of Acanthamoeba lenticulata and A. triangularis were detected from untreated water samples, while Vermamoeba vermiformis was found in both treated and untreated water samples. Our results suggested that poor water quality as well as inadequate maintenance and treatment might be the cause of this alarming problem since chlorine disinfection is ineffective in eradicating these amoebas in treated water samples. Regular monitoring and examination of water qualities are necessary in order to control the growth, hence, further preventing the widespread of FLA infections among the public. PMID:28212409

  1. Real-time PCR systems targeting giant viruses of amoebae and their virophages.

    Ngounga, Tatsiana; Pagnier, Isabelle; Reteno, Dorine-Gaelle Ikanga; Raoult, Didier; La Scola, Bernard; Colson, Philippe

    2013-01-01

    Giant viruses that infect amoebae, including mimiviruses and marseilleviruses, were first described in 2003. Virophages were subsequently described that infect mimiviruses. Culture isolation with Acanthamoeba spp. and metagenomic studies have shown that these giant viruses are common inhabitants of our biosphere and have enabled the recent detection of these viruses in human samples. However, the genomes of these viruses display substantial genetic diversity, making it a challenge to examine their presence in environmental and clinical samples using conventional and real-time PCR. We designed and evaluated the performance of PCR systems capable of detecting all currently isolated mimiviruses, marseilleviruses and virophages to assess their prevalence in various samples. Our real-time PCR assays accurately detected all or most of the members of the currently delineated lineages of giant viruses infecting acanthamoebae as well as the mimivirus virophages, and enabled accurate classification of the mimiviruses of amoebae in lineages A, B or C. We were able to detect four new mimiviruses directly from environmental samples and correctly classified these viruses within mimivirus lineage C. This was subsequently confirmed by culture on amoebae followed by partial Sanger sequencing. PCR systems such as those implemented here may contribute to an improved understanding of the prevalence of mimiviruses, their virophages and marseilleviruses in humans.

  2. Potential influence of birds on soil testate amoebae in the Arctic

    Mazei, Yuri A.; Lebedeva, Natalia V.; Taskaeva, Anastasia A.; Ivanovsky, Alexander A.; Chernyshov, Viktor A.; Tsyganov, Andrey N.; Payne, Richard J.

    2018-06-01

    Birds can be an important agent of environmental change in High Arctic ecosystems, particularly due to the role of seabirds as a vector transferring nutrients from the marine to terrestrial realms. The soils of bird nesting sites are known to host distinct plant communities but the consequences of bird modification for microorganisms are much less clear. Our focus here is testate amoebae: a widely-distributed group of protists with significant roles in many aspects of ecosystem functioning. We compared the testate amoeba assemblages of a site on Spitsbergen (Svalbard archipelago) affected by nesting birds, with nearby control sites. We found differences in assemblage between sites, typified by reduced relative abundance of Phryganella acropodia and Centropyxis aerophila in bird-modified soils. These changes may reflect a reduced availability of fungal food sources. We found no evidence for differences in assemblage diversity or test concentration between bird-modified and control soils. Our dataset is small but results provide the first evidence for the potential effect of bird modification of soils on testate amoebae in the Arctic. Results show only limited similarity to experimental studies of nutrient addition, implying that response mechanisms may be more complicated than simply additional nutrient supply.

  3. [CHROMATIN ORGANIZATION IN CELL CYCLE OF AMOEBA PROTEUS ACCORDING TO OPTICAL TOMOGRAPHY DATA].

    Demin, S Yu; Berdieva, M A; Podlipaeva, Yu I; Yudin, A L; Goodkov, A V

    2015-01-01

    For the first time the nuclear cycle of large freshwater amoeba Amoeba proteus was studied by the method of optical tomography. The nuclei were fixed in situ in the cells of synchronized culture, stained by DAPI and examined by confocal laser scanning microscope. 3D-images of intranuclear chromatin were studied in details at different stages of nuclear cycle. The obtained data, together with literary ones allow represent the dynamics of structural organization of the nucleus in Amoeba proteus cell cycle in a new fashion. It was concluded that in this species the two-stage interphase takes place, as well as mitosis of peculiar type which does not correspond to any known type of mitosis according to classification existing now. It is presumed that in the course of nuclear cycle the chromosomes and/or their fragments are amplified, this presumption being in a good correspondence with the data about nuclear DNA hyperreplication in the cell cycle of A. proteus. As a result of chromosomes amplification their number may vary at different stages of cell cycle, and it allows to explain the contradictory data concerning the exact number of chromosomes in this species. The elimination of extra-DNA occurs mainly at the stage between prophase and prometaphase. We presume the majority of chromosomes, or may be even all of them to be referred to cholocentric type according to their behaviour during the mitosis.

  4. Timelike Killing spinors in seven dimensions

    Cariglia, Marco; Conamhna, Oisin A.P. Mac

    2004-01-01

    We employ the G-structure formalism to study supersymmetric solutions of minimal and SU(2) gauged supergravities in seven dimensions admitting Killing spinors with an associated timelike Killing vector. The most general such Killing spinor defines a SU(3) structure. We deduce necessary and sufficient conditions for the existence of a timelike Killing spinor on the bosonic fields of the theories, and find that such configurations generically preserve one out of 16 supersymmetries. Using our general supersymmetric ansatz we obtain numerous new solutions, including squashed or deformed anti-de Sitter solutions of the gauged theory, and a large class of Goedel-like solutions with closed timelike curves

  5. Evaluation of Honour Killings in Turkey

    Celbis, Osman; Ozdemir, Bora; Oruc, Mucahit; Dogan, Mustafa; Egri, Mucahit

    2013-01-01

    Honour killings are still pervasive in many societies.  The aim of this study is to reveal the characteristics of the victims of honour killings and honour killers in Malatya province between 2000 and 2004, and to review the concept of honour killings in Turkey.  Data are collected from the records of Malatya Higher Criminal Court.  The results are discussed in the light of the data obtained from Turkish Republic Ministry of Justice.  There were 36 honour killings in Malatya between 2000 and ...

  6. The potential influence of short-term environmental variability on the composition of testate amoeba communities in Sphagnum peatlands.

    Sullivan, Maura E; Booth, Robert K

    2011-07-01

    Testate amoebae are a group of moisture-sensitive, shell-producing protozoa that have been widely used as indicators of changes in mean water-table depth within oligotrophic peatlands. However, short-term environmental variability (i.e., sub-annual) also probably influences community composition. The objective of this study was to assess the potential influence of short-term environmental variability on the composition of testate amoeba communities in Sphagnum-dominated peatlands. Testate amoebae and environmental conditions, including hourly measurements of relative humidity within the upper centimeter of the peatland surface, were examined throughout the 2008 growing season at 72 microsites within 11 peatlands of Pennsylvania and Wisconsin, USA. Relationships among testate amoeba communities, vegetation, depth to water table, pH, and an index of short-term environmental variability (EVI), were examined using nonmetric multidimensional scaling and correlation analysis. Results suggest that EVI influences testate amoeba communities, with some taxa more abundant under highly variable conditions (e.g., Arcella discoides, Difflugia pulex, and Hyalosphenia subflava) and others more abundant when environmental conditions at the peatland surface were relatively stable (e.g., Archerella flavum and Bullinularia indica). The magnitude of environmental variability experienced at the peatland surface appears to be primarily controlled by vegetation composition and density. In particular, sites with dense Sphagnum cover had lower EVI values than sites with loose-growing Sphagnum or vegetation dominated by vascular plants and/or non-Sphagnum bryophytes. Our results suggest that more environmental information may be inferred from testate amoebae than previously recognized. Knowledge of relationships between testate amoebae and short-term environmental variability should lead to more detailed and refined environmental inferences.

  7. On integrability of the Killing equation

    Houri, Tsuyoshi; Tomoda, Kentaro; Yasui, Yukinori

    2018-04-01

    Killing tensor fields have been thought of as describing the hidden symmetry of space(-time) since they are in one-to-one correspondence with polynomial first integrals of geodesic equations. Since many problems in classical mechanics can be formulated as geodesic problems in curved space and spacetime, solving the defining equation for Killing tensor fields (the Killing equation) is a powerful way to integrate equations of motion. Thus it has been desirable to formulate the integrability conditions of the Killing equation, which serve to determine the number of linearly independent solutions and also to restrict the possible forms of solutions tightly. In this paper, we show the prolongation for the Killing equation in a manner that uses Young symmetrizers. Using the prolonged equations, we provide the integrability conditions explicitly.

  8. Antibacterial surface design - Contact kill

    Kaur, Rajbir; Liu, Song

    2016-08-01

    Designing antibacterial surfaces has become extremely important to minimize Healthcare Associated Infections which are a major cause of mortality worldwide. A previous biocide-releasing approach is based on leaching of encapsulated biocides such as silver and triclosan which exerts negative impacts on the environment and potentially contributes to the development of bacterial resistance. This drawback of leachable compounds led to the shift of interest towards a more sustainable and environmentally friendly approach: contact-killing surfaces. Biocides that can be bound onto surfaces to give the substrates contact-active antibacterial activity include quaternary ammonium compounds (QACs), quaternary phosphoniums (QPs), carbon nanotubes, antibacterial peptides, and N-chloramines. Among the above, QACs and N-chloramines are the most researched contact-active biocides. We review the engineering of contact-active surfaces using QACs or N-chloramines, the modes of actions as well as the test methods. The charge-density threshold of cationic surfaces for desired antibacterial efficacy and attempts to combine various biocides for the generation of new contact-active surfaces are discussed in detail. Surface positive charge density is identified as a key parameter to define antibacterial efficacy. We expect that this research field will continue to attract more research interest in view of the potential impact of self-disinfective surfaces on healthcare-associated infections, food safety and corrosion/fouling resistance required on industrial surfaces such as oil pipes and ship hulls.

  9. Germ killing by ultraviolet radiation

    Wawrik, O.

    1975-01-01

    Short-wave UV radiation, in particular the range about 250 nm, has a high germ reducing effect. Corresponding UV burners which above all emit radiation at the line of 254 nm can therefore be used effectively in all cases where the least possible content of germs in the air is aimed at. Apart from this it is also possible to reduce by this process the germs on surfaces and liquids. Especially in the most various ranges of pharmaceutical production one is steadily striving for efficient and last not least economic procedures by which it is possible to reduce the germs present in the air of a room. Numerous scientific investigations have sufficiently proved that short-wave UV radiation is extremely well appropriate for such purposes. Absolutely germ-free air in a room can only be obtained under laboratory conditions. In practice, however, the aim is not to achieve a 100 per cent killing of the germs present in a room but to make sure that the germ rate in certain rooms is constantly reduced to the lowest possible level. If in this connection it is referred to a germ reduction of 100 or 99 per cent this is but theory. (orig.) [de

  10. Control of Branchionus sp. and Amoeba sp. in cultures of Arthrospira sp. Control de Branchionus sp. y Amoeba sp. en cultivos de Arthrospira sp.

    Carlos Méndez

    2012-09-01

    Full Text Available Cultivation of cyanobacterium Arthrospira sp. has been developed in many countries for the production of proteins, pigments and other compounds. Outdoor mass cultures are often affected by biological contamination, drastically reducing productivity as far as bringing death. This study evaluates the control of Branchionus sp. and Amoeba sp. with two chemical compounds: urea (U and ammonium bicarbonate (AB, in laboratory conditions and outdoor mass culture of Arthrospira sp. The lethal concentration 100 (LC100 at 24 h for Branchionus sp. and Amoeba sp. determined was of 60-80 mg L-1 (U and 100-150 mg L-1 (AB. The average effective inhibition concentration for 50% of the population (IC50 in Arthrospira sp., after 72 h, was 80 mg L-1 (U and 150 mg L-1 (AB. The application of doses of 60 mg L-1 (U or 100 mg L-1 (AB in the outdoor mass culture of this contaminated microalga, completely inhibited grazing and did not affect the growth of Arthrospira sp. but rather promoted rapid recovery of algal density at levels prior to infestation. These compounds provided an economical and effective control of predators in cultures of Arthrospira sp.El cultivo de la cianobacteria Arthrospira sp. ha sido desarrollado en muchos países para la obtención de proteínas, pigmentos y otros compuestos. Cultivo que a nivel industrial se ve afectado frecuentemente por contaminación biológica, reduciendo drásticamente la productividad hasta causar la muerte. Este estudio evalúa el control de Branchionus sp. y de Amoeba sp. con dos compuestos químicos, la urea (U y bicarbonato de amonio (AB en cultivos de Arthrospira sp. La concentración letal 100 (LC100 determinada a las 24 h para Branchionus sp. y Amoeba sp. fue de 60-80 mg L-1 (U y 100-150 mg L-1 (AB. La concentración media de inhibición efectiva, después de 72 h, para el 50% de la población (IC50 en Arthrospira fue de 80 mg L-1 (U y 150 mg L-1 (AB. La aplicación de dosis de 60 mg L-1 (U ó 100 mg L-1 (AB en

  11. Testate amoebae communities sensitive to surface moisture conditions in Patagonian peatlands

    Loisel, J.; Booth, R.; Charman, D.; van Bellen, S.; Yu, Z.

    2017-12-01

    Here we examine moss surface samples that were collected during three field campaigns (2005, 2010, 2014) across southern Patagonian peatlands to assess the potential use of testate amoebae and 13C isotope data as proxy indicators of soil moisture. These proxies have been widely tested across North America, but their use as paleoecological tools remains sparse in the southern hemisphere. Samples were collected along a hydrological gradient spanning a range of water table depth from 0cm in wet hollows to over 85cm in dry hummocks. Moss moisture content was measured in the field. Over 25 taxa were identified, with many of them not found in North America. Ordinations indicate statistically significant and dominant effects of soil moisture and water table depth on testate assemblages, though interestingly 13C is even more strongly correlated with testates amoebae than direct soil conditions. It is possible that moss 13C signature constitutes a compound indicator that represents seasonal soil moisture better than opportunistic sampling during field campaigns. There is no significant effect of year or site across the dataset. In addition to providing a training set that translates testate amoebae moisture tolerance range into water tabel depth for Patagonian peatlands, we also compare our results with those from the North American training set to show that, despite 'novel' Patagonian taxa, the robustness of international training sets is probably sufficient to quantify most changes in soil moisture from any site around the world. We also identify key indicator species that are shown to be of universal value in peat-based hydrological reconstructions.

  12. Honor Killing: Where Pride Defeats Reason.

    Kanchan, Tanuj; Tandon, Abhishek; Krishan, Kewal

    2016-12-01

    Honor killings are graceless and ferocious murders by chauvinists with an antediluvian mind. These are categorized separately because these killings are committed for the prime reason of satisfying the ego of the people whom the victim trusts and always looks up to for support and protection. It is for this sole reason that honor killings demand strict and stern punishment, not only for the person who committed the murder but also for any person who contributed or was party to the act. A positive change can occur with stricter legislation and changes in the ethos of the society we live in today.

  13. Some basic properties of Killing spinors

    Hacyan, S.; Plebanski, J.

    1976-01-01

    The concept of Killing spinor is analyzed in a general way by using the spinorial formalism. It is shown, among other things, that higher derivatives of Killing spinors can be expressed in terms of lower order derivatives. Conformal Killing vectors are studied in some detail in the light of spinorial analysis: Classical results are formulated in terms of spinors. A theorem on Lie derivatives of Debever--Penrose vectors is proved, and it is shown that conformal motion in vacuum with zero cosmological constant must be homothetic, unless the conformal tensor vanishes or is of type N. Our results are valid for either real or complex space--time manifolds

  14. Brain-Eating Amoebae: Predilection Sites in the Brain and Disease Outcome

    Ong, Timothy Yu Yee; Siddiqui, Ruqaiyyah

    2017-01-01

    ABSTRACT Acanthamoeba spp. and Balamuthia mandrillaris are causative agents of granulomatous amoebic encephalitis (GAE), while Naegleria fowleri causes primary amoebic meningoencephalitis (PAM). PAM is an acute infection that lasts a few days, while GAE is a chronic to subacute infection that can last up to several months. Here, we present a literature review of 86 case reports from 1968 to 2016, in order to explore the affinity of these amoebae for particular sites of the brain, diagnostic modalities, treatment options, and disease outcomes in a comparative manner. PMID:28404683

  15. Homefucking is Killing Prostitution / Taavi Eelmaa

    Eelmaa, Taavi, 1971-

    2008-01-01

    Mis jääb vaatajale teatrietendusest meelde? Ilmus Kris Moori raamat "Homefucking is Killing Prostitution". Raamat sisaldab tekste ja Erki Lauri fotosid Von Krahli Teatri samanimelisest etendusest, mida kordagi ei mängitud

  16. KILLING, VIEWED FROM A CONFLICT RESOLUTION PERSPECTIVE

    DODO

    2017-07-01

    Jul 1, 2017 ... ... million people were killed as part of the industrial policy of Belgium's ..... the seeds of hate and further conspiracies against others, the entire .... International Commission On Intervention and State Sovereignty (ICISS) 2001.

  17. Cryptococcus neoformans modulates extracellular killing by neutrophils

    Asfia eQureshi

    2011-09-01

    Full Text Available We recently established a key role for host sphingomyelin synthase (SMS in the regulation of the killing activity of neutrophils against Cryptococcus neoformans. In this work, we studied the effect of C. neoformans on the killing activity of neutrophils and whether SMS would still be a player against C. neoformans in immunocompromised mice lacking T and NK cells (Tgε26 mice. To this end, we analyzed whether C. neoformans would have any effect on neutrophil survival and killing in vitro and in vivo. We show that unlike C. albicans, neither the presence nor the capsule size of C. neoformans cells have any effect on neutrophil viability. Interestingly, melanized C. neoformans cells totally abrogated the killing activity of neutrophils. Next, we monitored how exposure of neutrophils to C. neoformans cells would interfere with any further killing activity of the medium and found that pre-incubation with live but not heat-killed fungal cells significantly inhibits further killing activity of the medium. We next studied whether activation of SMS at the site of C. neoformans infection is dependent on T and NK cells. Using matrix-assisted laser desorption-ionization (MALDI tissue imaging in infected lung we found that similarly to previous observations in the isogenic wild type CBA/J mice, SM 16:0 levels are significantly elevated at the site of infection in mice lacking T and NK cells but only at early time points. This study highlights that C. neoformans may negatively regulate the killing activity of neutrophils and that SMS activation in neutrophils appears to be partially independent of T and/or NK cells.

  18. Targeted Killings in Bangladesh: Diversity at Stake

    Syed, Jawad

    2016-01-01

    Since 2013, Bangladesh has repeatedly been in headline news across the world due to systematic and incessant targeted killings. In the mainstream media, both in South Asia and the West, the focus has been generally on high profile murders of secular and progressive bloggers. This includes the recent worldwide broad coverage on the tragic murder of Xulhaz Mannan, editor of Bangladesh's first LGBT rights magazine. However, not many know that these killings are only one part of the story. Secula...

  19. Contagion in Mass Killings and School Shootings

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    Background Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Methods Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent dat...

  20. Dirac operators and Killing spinors with torsion

    Becker-Bender, Julia

    2012-01-01

    On a Riemannian spin manifold with parallel skew torsion, we use the twistor operator to obtain an eigenvalue estimate for the Dirac operator with torsion. We consider the equality case in dimensions four and six. In odd dimensions we describe Sasaki manifolds on which equality in the estimate is realized by Killing spinors with torsion. In dimension five we characterize all Killing spinors with torsion and obtain certain naturally reductive spaces as exceptional cases.

  1. Technical Aspects of Cyber Kill Chain

    Yadav, Tarun; Mallari, Rao Arvind

    2016-01-01

    Recent trends in targeted cyber-attacks has increased the interest of research in the field of cyber security. Such attacks have massive disruptive effects on rganizations, enterprises and governments. Cyber kill chain is a model to describe cyber-attacks so as to develop incident response and analysis capabilities. Cyber kill chain in simple terms is an attack chain, the path that an intruder takes to penetrate information systems over time to execute an attack on the target. This paper broa...

  2. Killing-Yano tensors, rank-2 Killing tensors, and conserved quantities in higher dimensions

    Krtous, Pavel [Institute of Theoretical Physics, Charles University, V Holesovickach 2, Prague (Czech Republic); Kubiznak, David [Institute of Theoretical Physics, Charles University, V Holesovickach 2, Prague (Czech Republic); Page, Don N. [Theoretical Physics Institute, University of Alberta, Edmonton T6G 2G7, Alberta (Canada); Frolov, Valeri P. [Theoretical Physics Institute, University of Alberta, Edmonton T6G 2G7, Alberta (Canada)

    2007-02-15

    From the metric and one Killing-Yano tensor of rank D-2 in any D-dimensional spacetime with such a principal Killing-Yano tensor, we show how to generate k = [(D+1)/2] Killing-Yano tensors, of rank D-2j for all 0 {<=} j {<=} k-1, and k rank-2 Killing tensors, giving k constants of geodesic motion that are in involution. For the example of the Kerr-NUT-AdS spacetime (hep-th/0604125) with its principal Killing-Yano tensor (gr-qc/0610144), these constants and the constants from the k Killing vectors give D independent constants in involution, making the geodesic motion completely integrable (hep-th/0611083). The constants of motion are also related to the constants recently obtained in the separation of the Hamilton-Jacobi and Klein-Gordon equations (hep-th/0611245)

  3. Killing-Yano tensors, rank-2 Killing tensors, and conserved quantities in higher dimensions

    Krtous, Pavel; Kubiznak, David; Page, Don N.; Frolov, Valeri P.

    2007-01-01

    From the metric and one Killing-Yano tensor of rank D-2 in any D-dimensional spacetime with such a principal Killing-Yano tensor, we show how to generate k = [(D+1)/2] Killing-Yano tensors, of rank D-2j for all 0 ≤ j ≤ k-1, and k rank-2 Killing tensors, giving k constants of geodesic motion that are in involution. For the example of the Kerr-NUT-AdS spacetime (hep-th/0604125) with its principal Killing-Yano tensor (gr-qc/0610144), these constants and the constants from the k Killing vectors give D independent constants in involution, making the geodesic motion completely integrable (hep-th/0611083). The constants of motion are also related to the constants recently obtained in the separation of the Hamilton-Jacobi and Klein-Gordon equations (hep-th/0611245)

  4. PESAN MORAL DALAM FILM TO KILL A MOCKINGBIRD (ANALISIS SEMIOTIKA PADA FILM TO KILL A MOCKINGBIRD

    RENYOET, JAQUILINE MELISSA

    2014-01-01

    2014 JAQUILINE MELISSA RENYOET. Pesan Moral Dalam Film To Kill A Mockingbird (Analisis Semiotika Pada Film To Kill A Mockingbird). (Dibimbing oleh Muh. Nadjib dan Alem Febri Sonni). Tujuan Penelitian ini adalah mengidentifikasi bentuk pesan moral dan memahami makna pesan moral dalam film To Kill A Mockingbird. Penelitian ini dilakukan selama kurang lebih 2 bulan yaitu Maret ??? Mei 2014. Metode yang digunakan untuk penelitian ini adalah metode penelitian kualitatif den...

  5. Old lineages in a new ecosystem: diversification of arcellinid amoebae (Amoebozoa and peatland mosses.

    Omar Fiz-Palacios

    Full Text Available Arcellinid testate amoebae (Amoebozoa form a group of free-living microbial eukaryotes with one of the oldest fossil records known, yet several aspects of their evolutionary history remain poorly understood. Arcellinids occur in a range of terrestrial, freshwater and even brackish habitats; however, many arcellinid morphospecies such as Hyalosphenia papilio are particularly abundant in Sphagnum-dominated peatlands, a relatively new ecosystem that appeared during the diversification of Sphagnum species in the Miocene (5-20 Myr ago. Here, we reconstruct divergence times in arcellinid testate amoebae after selecting several fossils for clock calibrations and then infer whether or not arcellinids followed a pattern of diversification that parallels the pattern described for Sphagnum. We found that the diversification of core arcellinids occurred during the Phanerozoic, which is congruent with most arcellinid fossils but not with the oldest known amoebozoan fossil (i.e. at ca. 662 or ca. 750 Myr. Overall, Sphagnum and the Hyalospheniidae exhibit different patterns of diversification. However, an extensive molecular phylogenetic analysis of distinct clades within H. papilio species complex demonstrated a correlation between the recent diversification of H. papilio, the recent diversification of Sphagnum mosses, and the establishment of peatlands.

  6. Tinker-OpenMM: Absolute and relative alchemical free energies using AMOEBA on GPUs.

    Harger, Matthew; Li, Daniel; Wang, Zhi; Dalby, Kevin; Lagardère, Louis; Piquemal, Jean-Philip; Ponder, Jay; Ren, Pengyu

    2017-09-05

    The capabilities of the polarizable force fields for alchemical free energy calculations have been limited by the high computational cost and complexity of the underlying potential energy functions. In this work, we present a GPU-based general alchemical free energy simulation platform for polarizable potential AMOEBA. Tinker-OpenMM, the OpenMM implementation of the AMOEBA simulation engine has been modified to enable both absolute and relative alchemical simulations on GPUs, which leads to a ∼200-fold improvement in simulation speed over a single CPU core. We show that free energy values calculated using this platform agree with the results of Tinker simulations for the hydration of organic compounds and binding of host-guest systems within the statistical errors. In addition to absolute binding, we designed a relative alchemical approach for computing relative binding affinities of ligands to the same host, where a special path was applied to avoid numerical instability due to polarization between the different ligands that bind to the same site. This scheme is general and does not require ligands to have similar scaffolds. We show that relative hydration and binding free energy calculated using this approach match those computed from the absolute free energy approach. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Two distinct sensing pathways allow recognition of Klebsiella pneumoniae by Dictyostelium amoebae.

    Lima, Wanessa C; Balestrino, Damien; Forestier, Christiane; Cosson, Pierre

    2014-03-01

    Recognition of bacteria by metazoans is mediated by receptors that recognize different types of microorganisms and elicit specific cellular responses. The soil amoebae Dictyostelium discoideum feeds upon a variable mixture of environmental bacteria, and it is expected to recognize and adapt to various food sources. To date, however, no bacteria-sensing mechanisms have been described. In this study, we isolated a Dictyostelium mutant (fspA KO) unable to grow in the presence of non-capsulated Klebsiella pneumoniae bacteria, but growing as efficiently as wild-type cells in the presence of other bacteria, such as Bacillus subtilis. fspA KO cells were also unable to respond to K. pneumoniae and more specifically to bacterially secreted folate in a chemokinetic assay, while they responded readily to B. subtilis. Remarkably, both WT and fspA KO cells were able to grow in the presence of capsulated LM21 K. pneumoniae, and responded to purified capsule, indicating that capsule recognition may represent an alternative, FspA-independent mechanism for K. pneumoniae sensing. When LM21 capsule synthesis genes were deleted, growth and chemokinetic response were lost for fspA KO cells, but not for WT cells. Altogether, these results indicate that Dictyostelium amoebae use specific recognition mechanisms to respond to different K. pneumoniae elements. © 2013 John Wiley & Sons Ltd.

  8. Preferential feeding in Naegleria fowleri; intracellular bacteria isolated from amoebae in operational drinking water distribution systems.

    Miller, Haylea C; Morgan, Matthew J; Walsh, Tom; Wylie, Jason T; Kaksonen, Anna H; Puzon, Geoffrey J

    2018-05-06

    The amoeba Naegleria fowleri is the causative agent of the highly fatal disease, primary amoebic meningoencephalitis, and estimated to cause 16 deaths per year in the United States alone. Colonisation of drinking water distribution systems (DWDSs) by the N. fowleri is a significant public health issue. Understanding the factors which enable this pathogen to colonise and thrive in DWDSs is critical for proper management. The microbial ecology within DWDSs may influence the ability of N. fowleri to colonise DWDSs by facilitating the availability of an appropriate food source. Using biofilm samples obtained from operational DWDSs, 16S rRNA amplicon metabarcoding was combined with genus-specific PCR and Sanger sequencing of intracellular associated bacteria from isolated amoeba and their parental biofilms to identify Meiothermus chliarophilus as a potential food source for N. fowleri. Meiothermus was confirmed as a food source for N. fowleri following successful serial culturing of axenic N. fowleri with M. chliarophilus or M. ruber as the sole food source. The ability to identify environmental and ecological conditions favourable to N. fowleri colonisation, including the detection of appropriate food sources such as Meiothermus, could provide water utilities with a predictive tool for managing N. fowleri colonisation within the DWDS. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Evidence of parasexual activity in "asexual amoebae" Cochliopodium spp. (Amoebozoa): extensive cellular and nuclear fusion.

    Tekle, Yonas I; Anderson, O Roger; Lecky, Ariel F

    2014-09-01

    The majority of microbial eukaryotes have long been considered asexual, though new evidence indicates sex, or sexual-like (parasexual) behaviors that deviate from the usual union of two gametes, among other variant aspects. Over a dozen amoebozoans are implicated to have sexual stages. However, the exact mechanism by which sex occurs in these lineages remains elusive. This is mainly due to the diverse quality and cryptic nature of their life cycle. In this study we present evidence of some previously unreported aspects of the life cycle of an amoeba, Cochliopodium, that undergoes unusual intraspecific interactions using light microscopy and immunocytochemistry. Similar to other amoebozoans, Cochliopodium, is considered asexual with no published reports of sex or parasexuality. We also investigated environmental conditions that govern the observed intraspecific interactions. Both light microscopic and immunocytochemistry evidence demonstrates Cochliopodium undergoes cellular fusion (plasmogamy) and nuclear fusion (karyogamy). Large plasmodia eventually undergo karyogamy and contain large fused, polyploid, nuclei. These are observed to fragment, subsequently, by karyotomy (nuclear fission) and cytoplasmic fission to yield uninucleated amoebae. This process could lead to a non-meiotic, parasexual exchange of chromosomes in Cochliopodium. These findings strongly suggest that Cochliopodium is involved in parasexual activity and should no longer be considered strictly asexual. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Differential growth of Legionella pneumophila strains within a range of amoebae at various temperatures associated with in-premise plumbing

    The potential effect of in-premise plumbing temperatures (24, 32, 37 and 41 °C) on the growth of five different L. pneumophila strains within free-living amoebae (Acanthamoeba polyphaga, Hartmannella vermiformis and Naegleria fowleri) was examined. Compared to controls only fed E...

  11. Contrasting diversity of testate amoebae communities in Sphagnum and brown-moss dominated patches in relation to shell counts.

    Lizoňová, Zuzana; Horsák, Michal

    2017-04-01

    Ecological studies of peatland testate amoebae are generally based on totals of 150 individuals per sample. However, the suitability of this standard has never been assessed for alkaline habitats such as spring fens. We explored the differences in testate amoeba diversity between Sphagnum and brown-moss microhabitats at a mire site with a highly diversified moss layer which reflects the small-scale heterogeneity in groundwater chemistry. Relationships between sampling efficiency and sample completeness were explored using individual-based species accumulation curves and the effort required to gain an extra species was assessed. Testate amoeba diversity differed substantially between microhabitats, with brown mosses hosting on average twice as many species and requiring greater shell totals to reach comparable sample analysis efficiency as for Sphagnum. Thus, for samples from alkaline conditions an increase in shell totals would be required and even an overall doubling up to 300 individuals might be considered for reliable community description. Our small-scale data are likely not robust enough to provide an ultimate solution for the optimization of shell totals. However, the results proved that testate amoebae communities from acidic and alkaline environments differ sharply in both species richness and composition and they might call for different methodological approaches. Copyright © 2017 Elsevier GmbH. All rights reserved.

  12. SSU rRNA reveals a sequential increase in shell complexity among the euglyphid testate amoebae (Rhizaria: Euglyphida)

    Lara, Enrique; Heger, Thierry J; Mitchell, Edward A D

    2007-01-01

    The existing data on the molecular phylogeny of filose testate amoebae from order Euglyphida has revealed contradictions between traditional morphological classification and SSU rRNA phylogeny and, moreover, the position of several important genera remained unknown. We therefore carried out a stu...

  13. A free-living amoeba with unusual pattern of mitochondrial structure isolated from Atlantic salmon, Salmo salar L

    Dyková, Iva; Veverková, Marie; Fiala, Ivan; Macháčková, Blanka

    2002-01-01

    Roč. 41, - (2002), s. 415-419 ISSN 0065-1583 R&D Projects: GA AV ČR IAA6022202 Institutional research plan: CEZ:AV0Z6022909 Keywords : free-living amoeba * mitochondrial cristae * Salmo salar Subject RIV: EA - Cell Biology Impact factor: 0.446, year: 2002

  14. Chemically enhanced sunlight for killing bacteria

    Block, S.S.; Goswami, D.Y.

    1995-01-01

    Solar ultraviolet (UV) photocatalyzed oxidation of chemicals with titanium dioxide (TiO 2 ) has received considerable attention. Much less recognized, however, is the ability of the same system to destroy bacteria. This study examined this phenomenon and the conditions that affect it. Bacteria in aqueous solution were given solar exposure with titanium dioxide and their survival with time was determined. Lamps with a predominantly solar ultraviolet spectrum were also used in the experiments. Without exposure to UV light, TiO 2 had no deleterious effect on the bacteria. However, several common bacteria on solar exposure in the presence of TiO 2 were killed in just a few minutes, whereas without TiO 2 it took over an hour to destroy them. A concentration of 0.01% TiO 2 was most effective in killing bacteria and 10-fold concentrations lower or higher were successively less effective. Inorganic and organic compounds in solution, even in small amounts, interfered with the efficiency of killing. Alkaline solution also reduced the bactericidal activity. Circulation and agitation provided by stirring to keep the TiO 2 particles suspended reduced the time necessary to kill the bacteria. Time-intensity curves for killing bacteria were the same general shape with or without TiO 2 , indicating that TiO 2 served merely as a catalyst to increase the rate of the reaction but that the mechanism of action was not changed. The shape of the curves show that the organisms are sensitized with a minimum intensity of radiation and that an increase doesn't greatly increase the rate of kill. Below this critical intensity, however, the time required for killing markedly increases as the intensity is decreased

  15. Effect of UV irradiation (253.7 nm) on free Legionella and Legionella associated with its amoebae hosts.

    Cervero-Aragó, Sílvia; Sommer, Regina; Araujo, Rosa M

    2014-12-15

    Water systems are the primary reservoir for Legionella spp., where the bacteria live in association with other microorganisms, such as free-living amoebae. A wide range of disinfection treatments have been studied to control and prevent Legionella colonization but few of them were performed considering its relation with protozoa. In this study, the effectiveness of UV irradiation (253.7 nm) using low-pressure lamps was investigated as a disinfection method for Legionella and amoebae under controlled laboratory conditions. UV treatments were applied to 5 strains of Legionella spp., 4 strains of free-living amoeba of the genera Acanthamoeba and Vermamoeba, treating separately trophozoites and cysts, and to two different co-cultures of Legionella pneumophila with the Acanthamoeba strains. No significant differences in the UV inactivation behavior were observed among Legionella strains tested which were 3 logs reduced for fluences around 45 J/m(2). UV irradiation was less effective against free-living amoebae; which in some cases required up to 990 J/m(2) to obtain the same population reduction. UV treatment was more effective against trophozoites compared to cysts; moreover, inactivation patterns were clearly different between the genus Acanthamoeba and Vermamoeba. For the first time data about Vermamoeba vermiformis UV inactivation has been reported in a study. Finally, the results showed that the association of L. pneumophila with free-living amoebae decreases the effectiveness of UV irradiation against the bacteria in a range of 1.5-2 fold. That fact demonstrates that the relations established between different microorganisms in the water systems can modify the effectiveness of the UV treatments applied. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Killing superalgebras for Lorentzian four-manifolds

    Medeiros, Paul de; Figueroa-O’Farrill, José; Santi, Andrea

    2016-01-01

    We determine the Killing superalgebras underpinning field theories with rigid unextended supersymmetry on Lorentzian four-manifolds by re-interpreting them as filtered deformations of ℤ-graded subalgebras with maximum odd dimension of the N=1 Poincaré superalgebra in four dimensions. Part of this calculation involves computing a Spencer cohomology group which, by analogy with a similar result in eleven dimensions, prescribes a notion of Killing spinor, which we identify with the defining condition for bosonic supersymmetric backgrounds of minimal off-shell supergravity in four dimensions. We prove that such Killing spinors always generate a Lie superalgebra, and that this Lie superalgebra is a filtered deformation of a subalgebra of the N=1 Poincaré superalgebra in four dimensions. Demanding the flatness of the connection defining the Killing spinors, we obtain equations satisfied by the maximally supersymmetric backgrounds. We solve these equations, arriving at the classification of maximally supersymmetric backgrounds whose associated Killing superalgebras are precisely the filtered deformations we classify in this paper.

  17. Killing superalgebras for Lorentzian four-manifolds

    Medeiros, Paul de [Department of Mathematics and Natural Sciences, University of Stavanger,4036 Stavanger (Norway); Figueroa-O’Farrill, José; Santi, Andrea [Maxwell Institute and School of Mathematics, The University of Edinburgh,James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD, Scotland (United Kingdom)

    2016-06-20

    We determine the Killing superalgebras underpinning field theories with rigid unextended supersymmetry on Lorentzian four-manifolds by re-interpreting them as filtered deformations of ℤ-graded subalgebras with maximum odd dimension of the N=1 Poincaré superalgebra in four dimensions. Part of this calculation involves computing a Spencer cohomology group which, by analogy with a similar result in eleven dimensions, prescribes a notion of Killing spinor, which we identify with the defining condition for bosonic supersymmetric backgrounds of minimal off-shell supergravity in four dimensions. We prove that such Killing spinors always generate a Lie superalgebra, and that this Lie superalgebra is a filtered deformation of a subalgebra of the N=1 Poincaré superalgebra in four dimensions. Demanding the flatness of the connection defining the Killing spinors, we obtain equations satisfied by the maximally supersymmetric backgrounds. We solve these equations, arriving at the classification of maximally supersymmetric backgrounds whose associated Killing superalgebras are precisely the filtered deformations we classify in this paper.

  18. Female serial killing: review and case report.

    Frei, Andreas; Völlm, Birgit; Graf, Marc; Dittmann, Volker

    2006-01-01

    Single homicide committed by women is rare. Serial killing is very infrequent, and the perpetrators are usually white, intelligent males with sadistic tendencies. Serial killing by women has, however, also been described. To conduct a review of published literature on female serial killers and consider its usefulness in assessing a presenting case. A literature review was conducted, after searching EMBASE, MEDLINE and PsycINFO. The presenting clinical case is described in detail in the context of the literature findings. Results The literature search revealed few relevant publications. Attempts to categorize the phenomenon of female serial killing according to patterns of and motives for the homicides have been made by some authors. The most common motive identified was material gain or similar extrinsic gratification while the 'hedonistic' sadistic or sexual serial killer seems to be extremely rare in women. There is no consistent theory of serial killing by women, but psychopathic personality traits and abusive childhood experiences have consistently been observed. The authors' case did not fit the description of a 'typical' female serial killer. In such unusual circumstances as serial killing by a woman, detailed individual case formulation is required to make sense of the psychopathology in each case. Publication of cases in scientific journals should be encouraged to advance our understanding of this phenomenon. Copyright (c) 2006 John Wiley & Sons, Ltd.

  19. 75 FR 62469 - Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their...

    2010-10-12

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 [Docket No. USCG-2010-0907] Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their Tributaries, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander...

  20. 75 FR 30299 - Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their...

    2010-06-01

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 [Docket No. USCG-2010-0355] Drawbridge Operation Regulations; Newtown Creek, Dutch Kills, English Kills, and Their Tributaries, NY, Maintenance AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander...

  1. 9 CFR 113.206 - Wart Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Wart Vaccine, Killed Virus. 113.206... AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart Vaccine, Killed Virus. Wart Vaccine, Killed Virus, shall be prepared...

  2. 9 CFR 113.213 - Pseudorabies Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Pseudorabies Vaccine, Killed Virus..., DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.213 Pseudorabies Vaccine, Killed Virus. Pseudorabies Vaccine, Killed...

  3. 9 CFR 113.209 - Rabies Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Rabies Vaccine, Killed Virus. 113.209... Killed Virus Vaccines § 113.209 Rabies Vaccine, Killed Virus. Rabies Vaccine (Killed Virus) shall be prepared from virus-bearing cell cultures or nerve tissues obtained from animals that have developed rabies...

  4. Conformal Killing horizons and their thermodynamics

    Nielsen, Alex B.; Shoom, Andrey A.

    2018-05-01

    Certain dynamical black hole solutions can be mapped to static spacetimes by conformal metric transformations. This mapping provides a physical link between the conformal Killing horizon of the dynamical black hole and the Killing horizon of the static spacetime. Using the Vaidya spacetime as an example, we show how this conformal relation can be used to derive thermodynamic properties of such dynamical black holes. Although these horizons are defined quasi-locally and can be located by local experiments, they are distinct from other popular notions of quasi-local horizons such as apparent horizons. Thus in the dynamical Vaidya spacetime describing constant accretion of null dust, the conformal Killing horizon, which is null by construction, is the natural horizon to describe the black hole.

  5. "Drone Killings in Principle and in Practice"

    Dige, Morten

    2017-01-01

    to argue that what we see in the real world cases of drone killings is not merely an accidental or contingent use of drone technology. The real life use reflects to a large extent features that are inherent of the dominant drone systems that has been developed to date. What is being imagined "in principle......" is thus to a large extent drone killings in dreamland. I use an historic example as a point of reference and departure: the debate over the lawfulness of nuclear weapons....

  6. Bioaccumulation of pathogenic bacteria and amoeba by zebra mussels and their presence in watercourses.

    Mosteo, R; Goñi, P; Miguel, N; Abadías, J; Valero, P; Ormad, M P

    2016-01-01

    Dreissena polymorpha (the zebra mussel) has been invading freshwater bodies in Europe since the beginning of the nineteenth century. Filter-feeding organisms can accumulate and concentrate both chemical and biological contaminants in their tissues. Therefore, zebra mussels are recognized as indicators of freshwater quality. In this work, the capacity of the zebra mussel to accumulate human pathogenic bacteria and protozoa has been evaluated and the sanitary risk associated with their presence in surface water has also been assessed. The results show a good correlation between the pathogenic bacteria concentration in zebra mussels and in watercourses. Zebra mussels could therefore be used as an indicator of biological contamination. The bacteria (Escherichia coli, Enterococcus spp., Pseudomonas spp., and Salmonella spp.) and parasites (Cryptosporidium oocysts and free-living amoebae) detected in these mussels reflect a potential sanitary risk in water.

  7. Spontaneous emergence of large-scale cell cycle synchronization in amoeba colonies

    Segota, Igor; Boulet, Laurent; Franck, David; Franck, Carl

    2014-01-01

    Unicellular eukaryotic amoebae Dictyostelium discoideum are generally believed to grow in their vegetative state as single cells until starvation, when their collective aspect emerges and they differentiate to form a multicellular slime mold. While major efforts continue to be aimed at their starvation-induced social aspect, our understanding of population dynamics and cell cycle in the vegetative growth phase has remained incomplete. Here we show that cell populations grown on a substrate spontaneously synchronize their cell cycles within several hours. These collective population-wide cell cycle oscillations span millimeter length scales and can be completely suppressed by washing away putative cell-secreted signals, implying signaling by means of a diffusible growth factor or mitogen. These observations give strong evidence for collective proliferation behavior in the vegetative state. (paper)

  8. Amoeba-like self-oscillating polymeric fluids with autonomous sol-gel transition.

    Onoda, Michika; Ueki, Takeshi; Tamate, Ryota; Shibayama, Mitsuhiro; Yoshida, Ryo

    2017-07-13

    In the field of polymer science, many kinds of polymeric material systems that show a sol-gel transition have been created. However, most systems are unidirectional stimuli-responsive systems that require physical signals such as a change in temperature. Here, we report on the design of a block copolymer solution that undergoes autonomous and periodic sol-gel transition under constant conditions without any on-off switching through external stimuli. The amplitude of this self-oscillation of the viscosity is about 2,000 mPa s. We also demonstrate an intermittent forward motion of a droplet of the polymer solution synchronized with the autonomous sol-gel transition. This polymer solution bears the potential to become the base for a type of slime-like soft robot that can transform its shape kaleidoscopically and move autonomously, which is associated with the living amoeba that moves forward by a repeated sol-gel transition.

  9. Giants among larges: how gigantism impacts giant virus entry into amoebae.

    Rodrigues, Rodrigo Araújo Lima; Abrahão, Jônatas Santos; Drumond, Betânia Paiva; Kroon, Erna Geessien

    2016-06-01

    The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host cells, developing various strategies to penetrate them. Mimiviruses and other giant viruses enter cells through phagocytosis, while Marseillevirus and other large viruses explore endocytosis and macropinocytosis. These differing strategies might reflect the evolution of those viruses. Various scenarios have been proposed for the origin and evolution of these viruses, presenting one of the most enigmatic issues to surround these microorganisms. In this context, we believe that giant viruses evolved independently by massive gene/size gain, exploring the phagocytic pathway of entry into amoebas. In response to gigantism, hosts developed mechanisms to evade these parasites. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Reaching an entrepreneurial management system of amoebas. A qualitative insight into the European experiences

    Urban Wiesław

    2016-03-01

    Full Text Available The aim of the study is an assessment of the Amoeba Management System (AMS introduction advancements in some European companies. The study takes the practically focused research approach. The approaches, achievements and phases whilst introducing the AMS principles by companies are observed and critically assessed. First insight into the challenges of AMS introduction is taken basing on critical study of the literature output. The scientific studies and managerial publications are taken into consideration. The empirical part of the study is based on the qualitative approach. A multiple case study methodology is employed. The research objects are three companies, one of them operates in Sweden, the next two in Poland. Each of them have different experiences in AMS implementation, they also manifest different management styles and habits. The study demonstrates that AMS is a very prospective management methodology which can support companies in employees commitment during their journey towards operational excellence. The analysis results show different motivations for AMS introduction as well as different development paths, these are harmonized with different management styles in companies and culture occurring in countries. The study is particularly valuable because this is one of the first empirical investigations of AMS implementation in European companies. In the field of theory the study proposes the four level scale for amoebas system maturity. This scale allows to classify companies following AMS principles and, at the same time, this scale is also the kind of path of AMS implementation. The study points out basic tools for companies which support AMS implementation. These tools are already known in management literature, but experience of investigated companies shows that they are fundamental for successful AMS implementation.

  11. Check-list of microscopic protosteloid amoebae from the Southwest of Europe

    Aguilar, María

    2012-12-01

    Full Text Available A biodiversity survey for protosteloid amoebae was carried out in Spain, Portugal and France between 2005 and 2010. Samples were collected from three different microhabitats – aerial litter, ground litter, and bark of living plants – in a total of 97 localities. As result 26 to 28 species out of the 33 species of microscopic protosteloid amoebae described to date were recorded. An annotated list that comprises all available data about these organisms from this part of the world, a key to the species, comments on the morphology of the sporocarps and the trophic stages is presented. Photomicrographs of the fruiting bodies of most species, and distribution maps are also included.

    Se ha realizado un estudio de la biodiversidad de las amebas protos - teloides en España, Portugal y Francia entre 2005 y 2010. Las muestras se recolectaron en tres microhábitats diferentes –hojarasca aérea, hojarasca del suelo y corteza de plantas vivas– en un total de 97 localidades. Como resultado se encontraron entre 26 y 28 especies de las 33 especies de amebas protosteloides microscópicas descritas. Se presenta una lista comentada que contiene todos los datos disponibles sobre estos organismos en esta parte del mundo, una clave de las especies y comentarios sobre la morfología de los esporocarpos y de los estados tróficos. También se incluyen fotomicrografías de los cuerpos fructíferos de la mayoría de las especies y mapas de distribución.

  12. Killing Hitler: A Writer's Journey and Angst.

    Thaler, Paul

    2002-01-01

    Describes the author's experiences in preparing a talk that "evokes the specter" of Adolf Hitler and in writing an historical account of a British plot to kill Hitler. Address the question of why the British allowed him to live that final year of the war. Muses on why scholars write, and the impact of violence and terrorism. (SG)

  13. Integrating Poetry and "To Kill a Mockingbird."

    Jolley, Susan Arpajian

    2002-01-01

    Outlines a method of teaching "To Kill a Mockingbird" along with the study of poetry. Notes that this method allows students to consider the themes of courage and developing compassion. Concludes that teaching such a multigenre unit allows students to look for connections among fact and fiction, the past and present, their own lives and…

  14. School Shootings; Standards Kill Students and Society

    Angert, Betsy L.

    2008-01-01

    School shootings have been in the news of late. People ponder what occurs in classrooms today. Why would a young person wish to take a life? Within educational institutions, the killings are a concern. In our dire attempt to teach the children and ensure student success, it seems many of our offspring are lost. Some students feel separate from…

  15. Mass killings and detection of impacts

    McLaren, Digby J.

    Highly energetic bolide impacts occur and their flux is known. For larger bodies the energy release is greater than for any other short-term global phenomenon. Such impacts produce or release a large variety of shock induced changes including major atmospheric, sedimentologic, seismic and volcanic events. These events must necessarily leave a variety of records in the stratigraphic column, including mass killings resulting in major changes in population density and reduction or extinction of many taxonomic groups, followed by characteristic patterns of faunal and flora replacement. Of these effects, mass killings, marked by large-scale loss of biomass, are the most easily detected evidence in the field but must be manifest on a near-global scale. Such mass killings that appear to be approximately synchronous and involve disappearance of biomass at a bedding plane in many sedimentologically independent sections globally suggest a common cause and probable synchroneity. Mass killings identify an horizon which may be examined for evidence of cause. Geochemical markers may be ephemeral and absence may not be significant. There appears to be no reason why ongoing phenomena such as climate and sea-level changes are primary causes of anomolous episodic events.

  16. Holocene environmental changes in southern Kamchatka, Far Eastern Russia, inferred from a pollen and testate amoebae peat succession record

    Klimaschewski, A.; Barnekow, L.; Bennett, K. D.; Andreev, A. A.; Andrén, E.; Bobrov, A. A.; Hammarlund, D.

    2015-11-01

    High resolution palaeoenvironmental records in Far-Eastern Russia are rare, and the Kamchatka Peninsula is among the least studied areas of the region. This paper describes a record spanning the last ca. 11,000 yr, obtained from a bog in the southern part of Kamchatka. The radiocarbon dated core was analysed for pollen, testate amoebae, charcoal and loss-on-ignition (LOI). The vegetation during the early Holocene was dominated by grasses (Poaceae), birch (Betula) and heath (Ericaceae p. p.). Around 10,300 cal yr BP there was a substantial change in the vegetation cover to shrub alder (Alnus viridis s.l.) stands with sedges and ferns (Polypodiophyta) as well as herbs such as meadow rue (Thalictrum) in the understory. In the surroundings of Utka peatlands started to form. The variations in the vegetation cover were most probably caused by climatic changes. At the beginning of sediment accumulation, before 10,300 cal yr BP, the composition of the vegetation points to cooler summers and/or decreased annual precipitation. Around 10,300 cal yr BP, changes in vegetation occurred due to rising temperatures and/or changed water regimes. Increased abundancies of dry indicating testate amoebae after 9100 cal yr BP point to intermediate to dry soil conditions. Between 8600 and 7700 cal yr BP tree alder (Alnus incana) was widely spread at the site which probably indicates optimal environmental conditions. The tephra layer at 381-384.5 cm (ca. 8500 cal yr BP) produces a strong impact on the testate amoebae assemblages. At 7700 cal yr BP there was a sudden drop of A. incana in the local vegetation. From this time on, A. incana and also A. viridis decrease continuously whereas Betula gradually increases. The upper part of the sequence (after 6300 cal yr BP) shows higher abundancies of meadowsweet (Filipendula) and sweet gale (Myrica) pollen. After 6300 cal yr BP, changes in testate amoebae demonstrate variable soil moisture conditions at the site. Between 3700 and 1800 cal yr BP

  17. Contagion in Mass Killings and School Shootings.

    Sherry Towers

    Full Text Available Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts.Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed. We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event.We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015. We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001. All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

  18. Contagion in Mass Killings and School Shootings.

    Towers, Sherry; Gomez-Lievano, Andres; Khan, Maryam; Mubayi, Anuj; Castillo-Chavez, Carlos

    2015-01-01

    Several past studies have found that media reports of suicides and homicides appear to subsequently increase the incidence of similar events in the community, apparently due to the coverage planting the seeds of ideation in at-risk individuals to commit similar acts. Here we explore whether or not contagion is evident in more high-profile incidents, such as school shootings and mass killings (incidents with four or more people killed). We fit a contagion model to recent data sets related to such incidents in the US, with terms that take into account the fact that a school shooting or mass murder may temporarily increase the probability of a similar event in the immediate future, by assuming an exponential decay in contagiousness after an event. We find significant evidence that mass killings involving firearms are incented by similar events in the immediate past. On average, this temporary increase in probability lasts 13 days, and each incident incites at least 0.30 new incidents (p = 0.0015). We also find significant evidence of contagion in school shootings, for which an incident is contagious for an average of 13 days, and incites an average of at least 0.22 new incidents (p = 0.0001). All p-values are assessed based on a likelihood ratio test comparing the likelihood of a contagion model to that of a null model with no contagion. On average, mass killings involving firearms occur approximately every two weeks in the US, while school shootings occur on average monthly. We find that state prevalence of firearm ownership is significantly associated with the state incidence of mass killings with firearms, school shootings, and mass shootings.

  19. Dirac operators and Killing spinors with torsion; Dirac-Operatoren und Killing-Spinoren mit Torsion

    Becker-Bender, Julia

    2012-12-17

    On a Riemannian spin manifold with parallel skew torsion, we use the twistor operator to obtain an eigenvalue estimate for the Dirac operator with torsion. We consider the equality case in dimensions four and six. In odd dimensions we describe Sasaki manifolds on which equality in the estimate is realized by Killing spinors with torsion. In dimension five we characterize all Killing spinors with torsion and obtain certain naturally reductive spaces as exceptional cases.

  20. Distribution of Legionella pneumophila bacteria and Naegleria and Hartmannella amoebae in thermal saline baths used in balneotherapy.

    Zbikowska, Elżbieta; Walczak, Maciej; Krawiec, Arkadiusz

    2013-01-01

    The present study was aimed at investigating the coexistence and interactions between free living amoebae of Naegleria and Hartmannella genera and pathogenic Legionella pneumophila bacteria in thermal saline baths used in balneotherapy in central Poland. Water samples were collected from November 2010 to May 2011 at intervals longer than 1 month. The microorganisms were detected with the use of a very sensitive fluorescence in situ hybridisation method. In addition, the morphology of the amoebae was studied. Despite relatively high salinity level, ranging from 1.5 to 5.0 %, L. pneumophila were found in all investigated baths, although their number never exceeded 10(6) cells dm(-3). Hartmannella were not detected, while Naegleria fowleri were found in one bath. The observation that N. fowleri and L. pneumophila may coexist in thermal saline baths is the first observation emphasising potential threat from these microorganisms in balneotherapy.

  1. Growth regulation of Legionella Pneumophila in biofilms and amoebae; Wachstumsregulation von Legionella Pneumophila in Biofilmen und Amoeben

    Hilbi, H.

    2006-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of studies made on the regulation of the growth of Legionella Pneumophila bacteria in biofilms and amoebae. In a first project, the formation of biofilms by Legionella Pneumophila bacteria was analysed in static and dynamic systems using a complex growth medium. Under static and dynamic clinical and environmental conditions, the adherence of the biofilms on polystyrene tissue was studied. This was also examined under dynamic flow conditions. In a second part of the project, the regulation of growth of Legionella Pneumophila in amoebae was examined in that changes were made to the genome of the bacteria. The importance of the work for the de-activation of Legionella Pneumophila bacteria in biofilms is noted in the conclusions of the report.

  2. Growth-supporting activity for Legionella pneumophila in tap water cultures and implication of hartmannellid amoebae as growth factors.

    Wadowsky, R M; Butler, L J; Cook, M K; Verma, S M; Paul, M A; Fields, B S; Keleti, G; Sykora, J L; Yee, R B

    1988-11-01

    Photosynthetic cyanobacteria, heterotrophic bacteria, free-living amoebae, and ciliated protozoa may support growth of Legionella pneumophila. Studies were done with two tap water cultures (WS1 and WS2) containing L. pneumophila and associated microbiota to characterize growth-supporting activity and assess the relative importance of the microbiota in supporting multiplication of L. pneumophila. The water cultures were incubated in the dark at 35 degrees C. The growth-supporting factor(s) was separated from each culture by filtration through 1-micron-pore-size membrane filters. The retentate was then suspended in sterile tap water. Multiplication of L. pneumophila occurred when both the retentate suspension and the filtrate from either culture were inoculated into sterile tap water. L. pneumophila did not multiply in tap water inoculated with only the filtrate, even though filtration did not reduce the concentration of L. pneumophila or heterotrophic bacteria in either culture. Growth-supporting activity of the retentate suspension from WS1 was inactivated at 60 degrees C but unaffected at 0, 25, and 45 degrees C after 30-min incubations. Filtration experiments indicated that the growth-supporting factor(s) in WS1 was 2 to 5 micron in diameter. Ciliated protozoa were not detected in either culture. Hartmannellid amoebae were conclusively demonstrated in WS2 but not in WS1. L. pneumophila multiplied in tap water inoculated with the amoebae (10(3)/ml) and the 1-micron filtrate of WS2. No multiplication occurred in tap water inoculated with the filtrate only. Growth-supporting activity for L. pneumophila may be present in plumbing systems; hartmannellid amoebae appear to be important determinants of multiplication of L. pneumophila in some tap water cultures.

  3. The Phanerozoic diversification of silica-cycling testate amoebae and its possible links to changes in terrestrial ecosystems

    Bosak, Tanja; Lara, Enrique; Mitchell, Edward A.D.

    2015-01-01

    The terrestrial cycling of Si is thought to have a large influence on the terrestrial and marine primary production, as well as the coupled biogeochemical cycles of Si and C. Biomineralization of silica is widespread among terrestrial eukaryotes such as plants, soil diatoms, freshwater sponges, silicifying flagellates and testate amoebae. Two major groups of testate (shelled) amoebae, arcellinids and euglyphids, produce their own silica particles to construct shells. The two are unrelated phylogenetically and acquired biomineralizing capabilities independently. Hyalosphenids, a group within arcellinids, are predators of euglyphids. We demonstrate that hyalosphenids can construct shells using silica scales mineralized by the euglyphids. Parsimony analyses of the current hyalosphenid phylogeny indicate that the ability to “steal” euglyphid scales is most likely ancestral in hyalosphenids, implying that euglyphids should be older than hyalosphenids. However, exactly when euglyphids arose is uncertain. Current fossil record contains unambiguous euglyphid fossils that are as old as 50 million years, but older fossils are scarce and difficult to interpret. Poor taxon sampling of euglyphids has also prevented the development of molecular clocks. Here, we present a novel molecular clock reconstruction for arcellinids and consider the uncertainties due to various previously used calibration points. The new molecular clock puts the origin of hyalosphenids in the early Carboniferous (∼370 mya). Notably, this estimate coincides with the widespread colonization of land by Si-accumulating plants, suggesting possible links between the evolution of Arcellinid testate amoebae and the expansion of terrestrial habitats rich in organic matter and bioavailable Si. PMID:26734499

  4. An analysis of hereditary increase in frequency of cell mortality induced by external factors (Experiments on nuclear transplantation in amoebae)

    Bychkovskaya, I.B.; Ochinskaya, G.K.; Yudin, A.L.; AN SSSR, Leningrad. Inst. Tsitologii)

    1980-01-01

    By using nuclear transplantations in Amoeba proteus a study was made of a peculiar heritable effect, a stable increase in the frequency of cell mortality incuced by comparatively low doses of x radiation (50 Gy) or slight heating (29 0 C during 6 to 7 h). This effect differs qualitatively from the known radiation effects (reproductive death, lethal sectoring) by its being non-specific for radiation. In addition, the effect is saltatory appearing in 100% of the treated cells and the extent of its expression is not dependent on the dose of an inducing factor (at supra-threshold doses) and the period of time after treatment. It was found that (1) the hereditary changes in amoebae, unlike those resulting in reproductive death, are transmitted during intercellular transplantations both by the nucleus and cytoplasm of an altered cell; (2) the transfer of the character under test is accomplished by means of a certiin factor capable of shuttling between the nucleus and cytoplasm, (3) the effect is not necessarily a consequence of primary injury of nuclear structures and it may be induced by treatment of the cytoplasm of an enucleated cell renucleated then by the nucleus of a normal amoeba. In this respect, the effect under test differs also from the known types of hereditary post-radiation lethal effects which are commonly suggested to involve primary injury of the nucleus. Possible mechanisms of genetic control over the character tested are discussed. (author)

  5. Potentially pathogenic free-living amoebae in some flood-affected areas during 2011 Chiang Mai flood.

    Wannasan, Anchalee; Uparanukraw, Pichart; Songsangchun, Apichart; Morakote, Nimit

    2013-01-01

    The survey was carried out to investigate the presence of potentially pathogenic free-living amoebae (FLA) during flood in Chiang Mai, Thailand in 2011. From different crisis flood areas, seven water samples were collected and tested for the presence of amoebae using culture and molecular methods. By monoxenic culture, FLA were detected from all samples at 37 °C incubation. The FLA growing at 37 °C were morphologically identified as Acanthamoeba spp., Naegleria spp. and some unidentified amoebae. Only three samples (42.8%), defined as thermotolerant FLA, continued to grow at 42 °C. By molecular methods, two non-thermotolerant FlA were shown to have 99% identity to Acanthamoeba sp. and 98% identity to Hartmannella vermiformis while the two thermotolerant FLA were identified as Echinamoeba exundans (100% identity) and Hartmannella sp. (99% identity). This first report of the occurrence of FLA in water during the flood disaster will provide information to the public to be aware of potentially pathogenic FLA.

  6. Pathogenic free-living amoebae in a closed-loop power plant; risk assessment and risk management

    Cabanes, P.; Pernin, P.

    1998-01-01

    Since 1980, the water used for cooling in French power plants has been tested for pathogenic amoebae, especially Naegleria fowleri, the causative agent of Primary Amoebic Meningoencephalitis (PAM), a rapid fatal disease of the central nervous system. The replacement of brass condensers by stainless steel condensers resulted in increased Naegleria fowleri development, to a density of as much as 3000 l -1 in the Dampierre power plant cooling water. Downstream from Dampierre, the maximum detected density of this amoeba during the summer of 1995 was 80 l -1 , at low river flow. The replacement of a second condenser in 1996 at the same power plant was expected to double the amoebae concentration in the river. The hypothetical PAM risk for swimmers was then predicted to be 10 -4 per swim. To reduce the risk continuous chlorination of the closed-loop cooling system was implemented at a free residual chlorine level in the range of 0.3-0.5 mg.l -1 . Naegleria fowleri concentrations decreased immediately and thereafter remained under 4 l -1 . Total residual chlorine and chlorinated organic compounds were also monitored in the evaluation of the environmental impact of this preventive action. (authors)

  7. Bacterial Killing by Dry Metallic Copper Surfaces▿

    Santo, Christophe Espírito; Lam, Ee Wen; Elowsky, Christian G.; Quaranta, Davide; Domaille, Dylan W.; Chang, Christopher J.; Grass, Gregor

    2010-01-01

    Metallic copper surfaces rapidly and efficiently kill bacteria. Cells exposed to copper surfaces accumulated large amounts of copper ions, and this copper uptake was faster from dry copper than from moist copper. Cells suffered extensive membrane damage within minutes of exposure to dry copper. Further, cells removed from copper showed loss of cell integrity. Acute contact with metallic copper surfaces did not result in increased mutation rates or DNA lesions. These findings are important fir...

  8. It's not just conflict that motivates killing of orangutans.

    Jacqueline T Davis

    Full Text Available We investigated why orangutans are being killed in Kalimantan, Indonesia, and the role of conflict in these killings. Based on an analysis of interview data from over 5,000 respondents in over 450 villages, we also assessed the socio-ecological factors associated with conflict and non-conflict killings. Most respondents never kill orangutans. Those who reported having personally killed an orangutan primarily did so for non-conflict reasons; for example, 56% of these respondents said that the reason they had killed an orangutan was to eat it. Of the conflict-related reasons for killing, the most common reasons orangutans were killed was fear of orangutans or in self-defence. A similar pattern was evident among reports of orangutan killing by other people in the villages. Regression analyses indicated that religion and the percentage of intact forest around villages were the strongest socio-ecological predictors of whether orangutans were killed for conflict or non-conflict related reasons. Our data indicate that between 44,170 and 66,570 orangutans were killed in Kalimantan within the respondents' active hunting lifetimes: between 12,690 and 29,024 for conflict reasons (95%CI and between 26,361 and 41,688 for non-conflict reasons (95% CI. These findings confirm that habitat protection alone will not ensure the survival of orangutans in Indonesian Borneo, and that effective reduction of orangutan killings is urgently needed.

  9. It's not just conflict that motivates killing of orangutans.

    Davis, Jacqueline T; Mengersen, Kerrie; Abram, Nicola K; Ancrenaz, Marc; Wells, Jessie A; Meijaard, Erik

    2013-01-01

    We investigated why orangutans are being killed in Kalimantan, Indonesia, and the role of conflict in these killings. Based on an analysis of interview data from over 5,000 respondents in over 450 villages, we also assessed the socio-ecological factors associated with conflict and non-conflict killings. Most respondents never kill orangutans. Those who reported having personally killed an orangutan primarily did so for non-conflict reasons; for example, 56% of these respondents said that the reason they had killed an orangutan was to eat it. Of the conflict-related reasons for killing, the most common reasons orangutans were killed was fear of orangutans or in self-defence. A similar pattern was evident among reports of orangutan killing by other people in the villages. Regression analyses indicated that religion and the percentage of intact forest around villages were the strongest socio-ecological predictors of whether orangutans were killed for conflict or non-conflict related reasons. Our data indicate that between 44,170 and 66,570 orangutans were killed in Kalimantan within the respondents' active hunting lifetimes: between 12,690 and 29,024 for conflict reasons (95%CI) and between 26,361 and 41,688 for non-conflict reasons (95% CI). These findings confirm that habitat protection alone will not ensure the survival of orangutans in Indonesian Borneo, and that effective reduction of orangutan killings is urgently needed.

  10. 9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Canine Distemper Vaccine, Killed Virus... REQUIREMENTS Killed Virus Vaccines § 113.201 Canine Distemper Vaccine, Killed Virus. Canine Distemper Vaccine... canine distemper susceptible dogs (20 vaccinates and 5 controls) shall be used as test animals. Blood...

  11. 9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.

    2010-01-01

    ..., Killed Virus. 113.208 Section 113.208 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian Encephalomyelitis Vaccine, Killed Virus. Avian...

  12. 9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Mink Enteritis Vaccine, Killed Virus..., DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204 Mink Enteritis Vaccine, Killed Virus. Mink Enteritis Vaccine...

  13. 9 CFR 113.212 - Bursal Disease Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Bursal Disease Vaccine, Killed Virus..., DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.212 Bursal Disease Vaccine, Killed Virus. Bursal Disease Vaccine...

  14. Road-Killed Animals as Resources for Ecological Studies.

    Adams, Clark E.

    1983-01-01

    Summarizes 19 literature sources identifying road-killed vertebrates and frequency of kill by numbers. Examples of how these animals can be incorporated into curricula (integrating biology, society, people, and values) are given, followed by an illustrated example of how a road-killed raccoon's skull demonstrated a human/wildlife interaction prior…

  15. Killing vectors in empty space algebraically special metrics. II

    Held, A.

    1976-01-01

    Empty space algebraically special metrics possessing an expanding degenerate principal null vector and Killing vectors are investigated. Attention is centered on that class of Killing vector (called nonpreferred) which is necessarily spacelike in the asymptotic region. A detailed analysis of the relationship between the Petrov--Penrose classification and these Killing vectors is carried out

  16. Flourish or flush: effects of simulated extreme rainfall events on Sphagnum-dwelling testate amoebae in a subarctic bog (Abisko, Sweden).

    Tsyganov, Andrey N; Keuper, Frida; Aerts, Rien; Beyens, Louis

    2013-01-01

    Extreme precipitation events are recognised as important drivers of ecosystem responses to climate change and can considerably affect high-latitude ombrotrophic bogs. Therefore, understanding the relationships between increased rainfall and the biotic components of these ecosystems is necessary for an estimation of climate change impacts. We studied overall effects of increased magnitude, intensity and frequency of rainfall on assemblages of Sphagnum-dwelling testate amoebae in a field climate manipulation experiment located in a relatively dry subarctic bog (Abisko, Sweden). The effects of the treatment were estimated using abundance, species diversity and structure of living and empty shell assemblages of testate amoebae in living and decaying layers of Sphagnum. Our results show that increased rainfall reduced the mean abundance and species richness of living testate amoebae. Besides, the treatment affected species structure of both living and empty shell assemblages, reducing proportions of hydrophilous species. The effects are counterintuitive as increased precipitation-related substrate moisture was expected to have opposite effects on testate amoeba assemblages in relatively dry biotopes. Therefore, we conclude that other rainfall-related factors such as increased infiltration rates and frequency of environmental disturbances can also affect testate amoeba assemblages in Sphagnum and that hydrophilous species are particularly sensitive to variation in these environmental variables.

  17. Hydroecology of Amazonian lacustrine Arcellinida (testate amoebae): A case study from Lake Quistococha, Peru.

    Patterson, R Timothy; Huckerby, Gail; Kelly, Thomas J; Swindles, Graeme T; Nasser, Nawaf A

    2015-10-01

    Organic rich sediments were obtained from seven core tops taken in Lake Quistococha, near the city of Iquitos in the Peruvian Amazon. Subsamples from 0 to 4cm depth in each core were analyzed under dissecting light microscopy to carry out the first investigation of Arcellinida (testate lobose amoebae) from a lacustrine environment in this ecologically important region. The fauna was characterized by a low diversity, low abundance community dominated by centropyxids. This fauna is similar to 'stressed' assemblages reported from temperate latitudes, except that test concentrations were two orders of magnitude lower than typical in temperate lakes. Principle arcellinidan stressors in Lake Quistococha likely include the low pH 4 conditions in the lake, and a general lack of suitable minerogenic material to construct tests in the organic rich lake substrate. The low pH conditions are the result of runoff and seepage of water high in dissolved organic carbon from the adjacent similarly low pH 4 terrestrial peatland. The dearth of minerogenic material is the result of the lake being isolated from riverine input for the past ∼2000 years, even during flooding events. Other limiting factors contributing to depressed arcellinidan populations may include nutrient supply, predation pressure, competition, and post-mortem taphonomic factors. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Lateral gene exchanges shape the genomes of amoeba-resisting microorganisms

    Claire eBertelli

    2012-08-01

    Full Text Available Based on Darwin’s concept of the tree of life, vertical inheritance was thought to be dominant, and mutations, deletions and duplication were streaming the genomes of living organisms. In the current genomic era, increasing data indicated that both vertical and lateral gene inheritance interact in space and time to trigger genome evolution, particularly among microorganisms sharing a given ecological niche. As a paradigm to their diversity and their survival in a variety of cell types, intracellular microorganisms, and notably intracellular bacteria, were considered as less prone to lateral genetic exchanges. Such specialized microorganisms generally have a smaller gene repertoire because they do rely on their host’s factors for some basic regulatory and metabolic functions. Here we review events of lateral gene transfer (LGT that illustrate the genetic exchanges among intra-amoebal microorganisms or between the microorganism and its amoebal host. We tentatively investigate the functions of laterally transferred genes in the light of the interaction with their host as they should confer a selective advantage and success to the amoeba-resisting microorganisms.

  19. Quadrulella texcalense sp. nov. from a Mexican desert: An unexpected new environment for hyalospheniid testate amoebae.

    Pérez-Juárez, Horacio; Serrano-Vázquez, Angélica; Kosakyan, Anush; Mitchell, Edward A D; Rivera Aguilar, Víctor M; Lahr, Daniel J G; Hernández Moreno, Mayra M; Cuellar, Humberto Macías; Eguiarte, Luis E; Lara, Enrique

    2017-10-01

    Quadrulella (Amoebozoa, Arcellinida, Hyalospheniidae) is a genus of testate amoebae with unmistakable morphology, which secretes characteristic square plates to reinforce the test. They are mainly known from fens and freshwater habitats and have never been documented in deserts. We describe a new species, Quadrulella texcalense, from biological soil crusts in the intertropical desert of Tehuacán (state of Puebla, Mexico). Quadrulella texcalense occurred only at altitudes between 2140 and 2221m.a.s.l., together with the bryophyte genera Pseudocrossidium, Weissia, Bryum, Didymodon, Neohyophyla and Aloina. The soil was extremely dry (moisture of 1.97-2.6%), which contrasts sharply with previous reports for the Quadrulella genus. Single cell mitochondrial cytochrome oxidase I (COI) barcoding of thirteen isolated cells showed an important morphological variability despite having all the same COI barcode sequence. Quadrulella texcalense was placed in a tree containing other Hyalsopheniidae, including a newly barcoded South African species, Q. elegans. Q. texcalense unambiguously branched within genus Quadrulella in a compact clade but with a long branch, suggesting accelerated evolution due to a transition towards a new environment and/or under-sampling. Copyright © 2017 Elsevier GmbH. All rights reserved.

  20. Influence of climate and geography on the occurrence of Legionella and amoebae in composting facilities.

    Conza, Lisa; Casati Pagani, Simona; Gaia, Valeria

    2014-11-24

    The incidence of Legionnaires' disease (LD) in southern Switzerland is three times higher than in northern Switzerland. Climatic and geographic factors may be potential causes for this difference.We studied the prevalence of Legionella and free-living amoebae (FLA) in compost and bioaerosol in two Swiss regions to understand the role of climate and geography in the transmission of LD. We also tried to investigate whether or not compost storage duration would influence the composition of Legionella and FLA communities. A larger proportion of compost heaps in facilities from southern Switzerland harbor more diverse Legionella compared to the north (P=0.0146). FLA were isolated from composts in northern facilities at slightly higher rates (88.2% vs. 69.2%) and at lower rates from bioaerosols (6.3% vs. 13%) than in southern Switzerland. The diversity of FLA was higher in northern than in southern Switzerland (80% vs. 65%). A general decrease in the presence and variety of species was observed with decreasing compost storage time length. A discriminant model showed that values of vapour pressure, relative humidity and temperature distinguish the two regions, which were also characterised by different contamination rates by FLA and Legionella. The duration of outdoor storage may favour contamination of the compost by Legionella, and may increase the number and isolation of Legionella naturally occurring in compost. The climate in the south seems to favour higher Legionella contamination of compost heaps: this could explain the higher incidence of LD in southern Switzerland.

  1. Myosin-II sets the optimal response time scale of chemotactic amoeba

    Hsu, Hsin-Fang; Westendorf, Christian; Tarantola, Marco; Bodenschatz, Eberhard; Beta, Carsten

    2014-03-01

    The response dynamics of the actin cytoskeleton to external chemical stimuli plays a fundamental role in numerous cellular functions. One of the key players that governs the dynamics of the actin network is the motor protein myosin-II. Here we investigate the role of myosin-II in the response of the actin system to external stimuli. We used a microfluidic device in combination with a photoactivatable chemoattractant to apply stimuli to individual cells with high temporal resolution. We directly compare the actin dynamics in Dictyostelium discodelium wild type (WT) cells to a knockout mutant that is deficient in myosin-II (MNL). Similar to the WT a small population of MNL cells showed self-sustained oscillations even in absence of external stimuli. The actin response of MNL cells to a short pulse of chemoattractant resembles WT during the first 15 sec but is significantly delayed afterward. The amplitude of the dominant peak in the power spectrum from the response time series of MNL cells to periodic stimuli with varying period showed a clear resonance peak at a forcing period of 36 sec, which is significantly delayed as compared to the resonance at 20 sec found for the WT. This shift indicates an important role of myosin-II in setting the response time scale of motile amoeba. Institute of Physics und Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany.

  2. The rate and effects of spontaneous mutation on fitness traits in the social amoeba, Dictyostelium discoideum.

    Hall, David W; Fox, Sara; Kuzdzal-Fick, Jennie J; Strassmann, Joan E; Queller, David C

    2013-07-08

    We performed a mutation accumulation (MA) experiment in the social amoeba Dictyostelium discoideum to estimate the rate and distribution of effects of spontaneous mutations affecting eight putative fitness traits. We found that the per-generation mutation rate for most fitness components is 0.0019 mutations per haploid genome per generation or larger. This rate is an order of magnitude higher than estimates for fitness components in the unicellular eukaryote Saccharomyces cerevisiae, even though the base-pair substitution rate is two orders of magnitude lower. The high rate of fitness-altering mutations observed in this species may be partially explained by a large mutational target relative to S. cerevisiae. Fitness-altering mutations also may occur primarily at simple sequence repeats, which are common throughout the genome, including in coding regions, and may represent a target that is particularly likely to give fitness effects upon mutation. The majority of mutations had deleterious effects on fitness, but there was evidence for a substantial fraction, up to 40%, being beneficial for some of the putative fitness traits. Competitive ability within the multicellular slug appears to be under weak directional selection, perhaps reflecting the fact that slugs are sometimes, but not often, comprised of multiple clones in nature. Evidence for pleiotropy among fitness components across MA lines was absent, suggesting that mutations tend to act on single fitness components.

  3. Roman Lyariev, How to Skin Your Kill

    Gedeeva, Darina; Ubushieva, Bamba; Babaev, Andrei

    2016-01-01

    Roman explains how to skin a fox. First, one needs to prepare the ground by trampling it. Skinning should be done with a small sharp knife. A freshly killed fox skins easily. Then one needs to treat the skin with an anti-flea spray. At home the skin should be stretched on a triangular wooden panel called in Russian pravilka and left in a dry room for up to five days. People usually go hunting when foxes are on heat and are busy fighting with each other for females. When the wind is strong, fo...

  4. Micro-sociology of mass rampage killings.

    Collins, Randall

    2014-01-01

    Spectacular but very rare violent events such as mass killings by habitual non-criminals cannot be explained by factors which are very widespread, such as possession of firearms, being a victim of bullying, an introvert, or a career failure. A stronger clue is clandestine preparation of attack by one or two individuals, against randomly chosen representatives of a hated collective identity. Mass killers develop a deep back-stage, obsessed with planning their attack, overcoming social inferiority and isolation by an emotion of clandestine excitement.

  5. Designing Antibacterial Peptides with Enhanced Killing Kinetics

    Faiza H. Waghu

    2018-02-01

    Full Text Available Antimicrobial peptides (AMPs are gaining attention as substitutes for antibiotics in order to combat the risk posed by multi-drug resistant pathogens. Several research groups are engaged in design of potent anti-infective agents using natural AMPs as templates. In this study, a library of peptides with high sequence similarity to Myeloid Antimicrobial Peptide (MAP family were screened using popular online prediction algorithms. These peptide variants were designed in a manner to retain the conserved residues within the MAP family. The prediction algorithms were found to effectively classify peptides based on their antimicrobial nature. In order to improve the activity of the identified peptides, molecular dynamics (MD simulations, using bilayer and micellar systems could be used to design and predict effect of residue substitution on membranes of microbial and mammalian cells. The inference from MD simulation studies well corroborated with the wet-lab observations indicating that MD-guided rational design could lead to discovery of potent AMPs. The effect of the residue substitution on membrane activity was studied in greater detail using killing kinetic analysis. Killing kinetics studies on Gram-positive, negative and human erythrocytes indicated that a single residue change has a drastic effect on the potency of AMPs. An interesting outcome was a switch from monophasic to biphasic death rate constant of Staphylococcus aureus due to a single residue mutation in the peptide.

  6. The 1990 Arthur Kill oil spills

    Astor, P.H.

    1990-01-01

    On January 1-2, 1990, Exxon discharged 567,000 gallons of No. 2 heating oil in the Arthur Kill, the strait separating Staten Island, New York from New Jersey. Lawsuits against Exxon were filed by the State of New Jersey, New York City, and the City of Elizabeth. They seek to force Exxon to reimburse the municipalities and the state for cleanup costs and to restore damaged wetlands and other natural resources. The three plaintiffs, joined by New York State and the federal government, initiated a three-tiered natural resource damage assessment study (Tier II), currently underway, includes sampling and chemical analysis of sediments and benthic invertebrates, mapping of impacted wetlands and measurement of direct impacts on water birds and their prey. The purposes of the study are to quantify the damages and determine the presence of Exxon's oil in the sediments. Since the Exxon spill, there have been two major spills and an intermediate-size spill. During the first size months of 1990, over one million gallons of petroleum products have been discharged into the Arthur Kill and nearby waters. This paper reports that a review of these incidents provides lessons for the prevention, investigation, and cleanup of spills in urban estuaries

  7. Where and How Wolves (Canis lupus Kill Beavers (Castor canadensis.

    Thomas D Gable

    Full Text Available Beavers (Castor canadensis can be a significant prey item for wolves (Canis lupus in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. We identified 22 sites where wolves from 4 different packs killed beavers. We classified these kill sites into 8 categories based on the beaver-habitat type near which each kill occurred. Seasonal variation existed in types of kill sites as 7 of 12 (58% kills in the spring occurred at sites below dams and on shorelines, and 8 of 10 (80% kills in the fall occurred near feeding trails and canals. From these kill sites we deduced that the typical hunting strategy has 3 components: 1 waiting near areas of high beaver use (e.g., feeding trails until a beaver comes near shore or ashore, 2 using vegetation, the dam, or other habitat features for concealment, and 3 immediately attacking the beaver, or ambushing the beaver by cutting off access to water. By identifying kill sites and inferring hunting behavior we have provided the most complete description available of how and where wolves hunt and kill beavers.

  8. Ecology of testate amoebae in an Amazonian peatland and development of a transfer function for palaeohydrological reconstruction.

    Swindles, Graeme T; Reczuga, Monika; Lamentowicz, Mariusz; Raby, Cassandra L; Turner, T Edward; Charman, Dan J; Gallego-Sala, Angela; Valderrama, Elvis; Williams, Christopher; Draper, Frederick; Honorio Coronado, Euridice N; Roucoux, Katherine H; Baker, Tim; Mullan, Donal J

    2014-08-01

    Tropical peatlands represent globally important carbon sinks with a unique biodiversity and are currently threatened by climate change and human activities. It is now imperative that proxy methods are developed to understand the ecohydrological dynamics of these systems and for testing peatland development models. Testate amoebae have been used as environmental indicators in ecological and palaeoecological studies of peatlands, primarily in ombrotrophic Sphagnum-dominated peatlands in the mid- and high-latitudes. We present the first ecological analysis of testate amoebae in a tropical peatland, a nutrient-poor domed bog in western (Peruvian) Amazonia. Litter samples were collected from different hydrological microforms (hummock to pool) along a transect from the edge to the interior of the peatland. We recorded 47 taxa from 21 genera. The most common taxa are Cryptodifflugia oviformis, Euglypha rotunda type, Phryganella acropodia, Pseudodifflugia fulva type and Trinema lineare. One species found only in the southern hemisphere, Argynnia spicata, is present. Arcella spp., Centropyxis aculeata and Lesqueresia spiralis are indicators of pools containing standing water. Canonical correspondence analysis and non-metric multidimensional scaling illustrate that water table depth is a significant control on the distribution of testate amoebae, similar to the results from mid- and high-latitude peatlands. A transfer function model for water table based on weighted averaging partial least-squares (WAPLS) regression is presented and performs well under cross-validation (r(2)(apparent)= 0.76, RMSE = 4.29; r(2)(jack)= 0.68, RMSEP =5.18). The transfer function was applied to a 1-m peat core, and sample-specific reconstruction errors were generated using bootstrapping. The reconstruction generally suggests near-surface water tables over the last 3,000 years, with a shift to drier conditions at c. cal. 1218-1273 AD.

  9. Heterosigma bloom and associated fish kill

    Hershberger, P.K.; Rensel, J.E.; Postel, J.R.; Taub, F.B.

    1997-01-01

    A bloom of the harmful marine phytoplankton, Heterosigma carterae occurred in upper Case Inlet, south Puget Sound, Washington in late September, 1994, correlating with the presence of at least 35 dead salmon. This marks the first time that this alga has been closely correlated with a wild fish kill; in the past it was thought to be associated with kills of penned fish at fish farms only. We were informed of the presence of a possible harmful algal bloom and dead salinois Ilear the town of Allyn on 27 September and a team was formed to investigate. We arrived at the Allyn waterfront at 17:30 hours the same day. Prior to our arrival, state agency personnel walked approximatcly two miles of shoreline from the powerlines north of the dock, to the mouth of Sherwood Creek and conducted the only official count of dead fish present along the shore consisting of 12 coho salmon (Oncorhynchus kisutch), 11 chum salmon (Oncorhynchus keta), 12 chinook salmon (Oncorhynchus tschawytscha), one flat fish, and one sculpin on the morning of 9/27. Since previous harmful blooms of Heterosigma have resultedin the majority of net penreared salmon sinking to the bottom of pens, and only approximately two miles of shoreline were sampled, it is suspected that many more exposed fish may have succumbed than were counted. Witnesses who explored the east side of the bay reported seeing many dead salmon there as well, but no counts were made. State agency personnel who observed the fish kill reported seeing “dying fish coming to the beach, gulping at the surface, trying to get out of the water” Scavengers were seen consuming the salmon carcasses; these included two harbor seals, a house cat, and Hymenopteran insects. None suffered any noticeable acute ill effects. Although precise cause of death has not been ascertained, visual inspection of the reproductive organs from a deceased male chum salmon found on the shore at Allyn confirmed that the fish was not yet reproductively mature and

  10. Arcellacea (testate amoebae) as bio-indicators of road salt contamination in lakes.

    Roe, Helen M; Patterson, R Timothy

    2014-08-01

    Winter deicing operations occur extensively in mid- to high-latitude metropolitan regions around the world and result in a significant reduction in road accidents. Deicing salts can, however, pose a major threat to water quality and aquatic organisms. In this paper, we examine the utility of Arcellacea (testate amoebae) for monitoring lakes that have become contaminated by winter deicing salts, particularly sodium chloride. We analysed 50 sediment samples and salt-related water property variables (chloride concentrations; conductivity) from 15 lakes in the Greater Toronto Area and adjacent areas of southern Ontario, Canada. The sampled lakes included lakes in proximity to major highways and suburban roads and control lakes in forested settings away from road influences. Samples from the most contaminated lakes, with chloride concentrations in excess of 400 mg/l and conductivities of >800 μS/cm, were dominated by species typically found in brackish and/or inhospitable lake environments and by lower faunal diversities (lowest Shannon diversity index values) than samples with lower readings. Q-R-mode cluster analysis and detrended correspondence analysis (DCA) resulted in the recognition of four assemblage groupings. These reflect varying levels of salt contamination in the study lakes, along with other local influences, including nutrient loading. The response to nutrients can, however, be isolated if the planktic eutrophic indicator species Cucurbitella tricuspis is removed from the counts. The findings show that the group has considerable potential for biomonitoring in salt-contaminated lakes, and their presence in lake sediment cores may provide significant insights into long-term benthic community health, which is integral for remedial efforts.

  11. Presence of Legionella and Free-Living Amoebae in Composts and Bioaerosols from Composting Facilities

    Conza, Lisa; Pagani, Simona Casati; Gaia, Valeria

    2013-01-01

    Several species of Legionella cause Legionnaires’ disease (LD). Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA) that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture) and FLA (by culture) in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila) were detected in 69.3% (61/88) of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba) in 92.0% (81/88). L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88) of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012) than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47) were positive for FLA and 10.6% (5/47) for L. pneumophila. Composts (62.8%) were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents. PMID:23844174

  12. Lamarckian evolution of the giant Mimivirus in allopatric laboratory culture on amoebae.

    Colson, Philippe; Raoult, Didier

    2012-01-01

    Acanthamoeba polyphaga Mimivirus has been subcultured 150 times on germ-free amoebae. This allopatric niche is very different from that found in the natural environment, where the virus is in competition with many other organisms. In this experiment, substantial gene variability and loss occurred concurrently with the emergence of phenotypically different viruses. We sought to quantify the respective roles of Lamarckian and Darwinian evolution during this experiment. We postulated that the Mimivirus genes that were down-regulated at the beginning of the allopatric laboratory culture and inactivated after 150 passages experienced Lamarckian evolution because phenotypic modifications preceded genotypic modifications, whereas we considered that genes that were highly transcribed in the new niche but were later inactivated obeyed Darwinian rules. We used the total transcript abundances and sequences described for the genes of Mimivirus at the beginning of its laboratory life and after 150 passages in allopatric culture on Acanthamoeba spp. We found a statistically significant positive correlation between the level of gene expression at the beginning of the culture and gene inactivation during the 150 passages. In particular, the mean transcript abundance at baseline was significantly lower for inactivated genes than for unchanged genes (165 ± 589 vs. 470 ± 1,625; p allopatric laboratory culture if they were encoded by variable genes than if they were encoded by conserved genes (9 vs. 15%; p = 0.062). Finally, Lamarckian evolution represented the evolutionary process encountered by 63% of the inactivated genes. Such observations may be explained by the lower level of DNA repair of useless genes.

  13. Presence of Legionella and free-living Amoebae in composts and bioaerosols from composting facilities.

    Lisa Conza

    Full Text Available Several species of Legionella cause Legionnaires' disease (LD. Infection may occur through inhalation of Legionella or amoebal vesicles. The reservoirs of Legionella are water, soil, potting soil and compost. Some species of free-living amoebae (FLA that are naturally present in water and soil were described as hosts for Legionella. This study aimed to understand whether or not the composting facilities could be sources of community-acquired Legionella infections after development of bioaerosols containing Legionella or FLA. We looked for the presence of Legionella (by co-culture and FLA (by culture in composts and bioaerosols collected at four composting facilities located in southern Switzerland. We investigated the association between the presence of Legionella and compost and air parameters and presence of FLA. Legionella spp. (including L. pneumophila were detected in 69.3% (61/88 of the composts and FLA (mainly Acanthamoeba, Vermamoeba, Naegleria and Stenamoeba in 92.0% (81/88. L. pneumophila and L. bozemanii were most frequently isolated. FLA as potential host for Legionella spp. were isolated from 40.9% (36/88 of the composts in all facilities. In Legionella-positive samples the temperature of compost was significantly lower (P = 0.012 than in Legionella-negative samples. Of 47 bioaerosol samples, 19.1% (9/47 were positive for FLA and 10.6% (5/47 for L. pneumophila. Composts (62.8% were positive for Legionella and FLA contemporaneously, but both microorganisms were never detected simultaneously in bioaerosols. Compost can release bioaerosol containing FLA or Legionella and could represent a source of infection of community-acquired Legionella infections for workers and nearby residents.

  14. Conformal Killing vectors in Robertson-Walker spacetimes

    Maartens, R.; Maharaj, S.d.

    1986-01-01

    It is well known that Robertson-Walker spacetimes admit a conformal Killingl vector normal to the spacelike homogeneous hypersurfaces. Because these spacetimes are conformally flat, there are a further eight conformal Killing vectors, which are neither normal nor tangent to the homogeneous hypersurfaces. The authors find these further conformal Killing vectors and the Lie algebra of the full G 15 of conformal motions. Conditions on the metric scale factor are determined which reduce some of the conformal Killing vectors to homothetic Killing vectors or Killing vectors, allowing one to regain in a unified way the known special geometries. The non-normal conformal Killing vectors provide a counter-example to show that conformal motions do not, in general, map a fluid flow conformally. These non-normal vectors are also used to find the general solution of the null geodesic equation and photon Liouville equation. (author)

  15. The eyeball killer: serial killings with postmortem globe enucleation.

    Coyle, Julie; Ross, Karen F; Barnard, Jeffrey J; Peacock, Elizabeth; Linch, Charles A; Prahlow, Joseph A

    2015-05-01

    Although serial killings are relatively rare, they can be the cause of a great deal of anxiety while the killer remains at-large. Despite the fact that the motivations for serial killings are typically quite complex, the psychological analysis of a serial killer can provide valuable insight into how and why certain individuals become serial killers. Such knowledge may be instrumental in preventing future serial killings or in solving ongoing cases. In certain serial killings, the various incidents have a variety of similar features. Identification of similarities between separate homicidal incidents is necessary to recognize that a serial killer may be actively killing. In this report, the authors present a group of serial killings involving three prostitutes who were shot to death over a 3-month period. Scene and autopsy findings, including the unusual finding of postmortem enucleation of the eyes, led investigators to recognize the serial nature of the homicides. © 2015 American Academy of Forensic Sciences.

  16. Monoclonal TCR-redirected tumor cell killing.

    Liddy, Nathaniel; Bossi, Giovanna; Adams, Katherine J; Lissina, Anna; Mahon, Tara M; Hassan, Namir J; Gavarret, Jessie; Bianchi, Frayne C; Pumphrey, Nicholas J; Ladell, Kristin; Gostick, Emma; Sewell, Andrew K; Lissin, Nikolai M; Harwood, Naomi E; Molloy, Peter E; Li, Yi; Cameron, Brian J; Sami, Malkit; Baston, Emma E; Todorov, Penio T; Paston, Samantha J; Dennis, Rebecca E; Harper, Jane V; Dunn, Steve M; Ashfield, Rebecca; Johnson, Andy; McGrath, Yvonne; Plesa, Gabriela; June, Carl H; Kalos, Michael; Price, David A; Vuidepot, Annelise; Williams, Daniel D; Sutton, Deborah H; Jakobsen, Bent K

    2012-06-01

    T cell immunity can potentially eradicate malignant cells and lead to clinical remission in a minority of patients with cancer. In the majority of these individuals, however, there is a failure of the specific T cell receptor (TCR)–mediated immune recognition and activation process. Here we describe the engineering and characterization of new reagents termed immune-mobilizing monoclonal TCRs against cancer (ImmTACs). Four such ImmTACs, each comprising a distinct tumor-associated epitope-specific monoclonal TCR with picomolar affinity fused to a humanized cluster of differentiation 3 (CD3)-specific single-chain antibody fragment (scFv), effectively redirected T cells to kill cancer cells expressing extremely low surface epitope densities. Furthermore, these reagents potently suppressed tumor growth in vivo. Thus, ImmTACs overcome immune tolerance to cancer and represent a new approach to tumor immunotherapy.

  17. Killing vectors in algebraically special space-times

    Torres del Castillo, G.F.

    1984-01-01

    The form of the isometric, homothetic, and conformal Killing vectors for algebraically special metrics which admit a shear-free congruence of null geodesics is obtained by considering their complexification, using the existence of a congruence of null strings. The Killing equations are partially integrated and the reasons which permit this reduction are exhibited. In the case where the congruence of null strings has a vanishing expansion, the Killing equations are reduced to a single master equation

  18. Spacelike conformal Killing vectors and spacelike congruences

    Mason, D.P.; Tsamparlis, M.

    1985-01-01

    Necessary and sufficient conditions are derived for space-time to admit a spacelike conformal motion with symmetry vector parallel to a unit spacelike vector field n/sup a/. These conditions are expressed in terms of the shear and expansion of the spacelike congruence generated by n/sup a/ and in terms of the four-velocity of the observer employed at any given point of the congruence. It is shown that either the expansion or the rotation of this spacelike congruence must vanish if Dn/sup a//dp = 0, where p denotes arc length measured along the integral curves of n/sup a/, and also that there exist no proper spacelike homothetic motions with constant expansion. Propagation equations for the projection tensor and the rotation tensor are derived and it is proved that every isometric spacelike congruence is rigid. Fluid space-times are studied in detail. A relation is established between spacelike conformal motions and material curves in the fluid: if a fluid space-time admits a spacelike conformal Killing vector parallel to n/sup a/ and n/sub a/u/sup a/ = 0, where u/sup a/ is the fluid four-velocity, then the integral curves of n/sup a/ are material curves in an irrotational fluid, while if the fluid vorticity is nonzero, then the integral curves of n/sup a/ are material curves if and only if they are vortex lines. An alternative derivation, based on the theory of spacelike congruences, of some of the results of Collins [J. Math. Phys. 25, 995 (1984)] on conformal Killing vectors parallel to the local vorticity vector in shear-free perfect fluids with zero magnetic Weyl tensor is given

  19. Antibacterial activity of silver-killed bacteria: the "zombies" effect

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

    2015-04-01

    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  20. Killing spinors as a characterisation of rotating black hole spacetimes

    Cole, Michael J; Kroon, Juan A Valiente

    2016-01-01

    We investigate the implications of the existence of Killing spinors in a spacetime. In particular, we show that in vacuum and electrovacuum a Killing spinor, along with some assumptions on the associated Killing vector in an asymptotic region, guarantees that the spacetime is locally isometric to the Kerr or Kerr–Newman solutions. We show that the characterisation of these spacetimes in terms of Killing spinors is an alternative expression of characterisation results of Mars (Kerr) and Wong (Kerr–Newman) involving restrictions on the Weyl curvature and matter content. (paper)

  1. The reconstruction of late Holocene depth-to-water-table based on testate amoebae in an eastern Australian mire

    Zheng, X.; Money, S.; Hope, G.

    2017-12-01

    There are relatively few quantitative palaeo-hydrological records available in eastern Australia, and those that are available, for example from dendroclimatology and the reconstruction of lake level, are often relatively short or have a relatively coarse temporal resolution (e.g. Wilkins et al. 2013; Palmer et al. 2015). Testate amoebae, a widely used hydrological proxy in the Northern Hemisphere, were used here to reconstruct depth to water table (DWT) at Snowy Flat, which is a Sphagnum-Richea-Empodismahigh altitude (1618 m asl) shrub bog in the Australian Capital Territory, Australia. Testate amoebae were quantified in a Snowy Flat core representing 4,200 cal Y BP and the community composition was used to reconstruct DWT based on our recently established transfer functions. Results from three different types of transfer functions (Fig. 1) consistently show there was a decreasing DWT (wetter) period centred on about 3350 cal Y BP, a trend towards increased dryness from about 3300 to 2200 cal Y BP and a distinctly drier period 850 to 700 cal Y BP which was immediately followed by a wetter period from 700 to 500 cal Y BP. We discuss these episodes and trends in relation to the drivers of climatic variability in this region and in particular, by comparing our results with other south-eastern Australia records, comment on the history of the southern annular mode.

  2. Folic acid is a potent chemoattractant of free-living amoebae in a new and amazing species of protist, Vahlkampfia sp.

    Maeda, Yasuo; Mayanagi, Taira; Amagai, Aiko

    2009-03-01

    Folic acid (folate; vitamin Bc) is well recognized as essential for the proper metabolism of the essential amino acid methionine as well as for the synthesis of adenine and thymine. A folate deficiency has been Implicated in a wide variety of disorders from Alzheimer's disease to depression and neural tube defects. In the cellular slime molds, including Dictyostelium, vegetative growth-phase cells are known to chemotactically move toward folate that is secreted by bacterial food sources such as Escherichia coli. Intracellular folate signal transductlon, including G proteins, Ca(2+)channels, and the PIP3 pathway, has been reported in D. discoideum. To our surprise, the genuine chemoattractant(s) of free-living protozoan amoebae have remained to be determined, possibly because of lack of a pertinent method for assaying chemotaxis. We recently isolated a primitive free-living amoeba from the soil of Costa Rica and identified it as a new species of the genus Vahlkampfia belonging to Subclass Gymnamoebia, which includes Entamoeba and Acanthamoeba. The amoebae can grow and multiply quite rapidly, engulfing nearby bacteria such as E. coli. Importantly, we have demonstrated here using a quite simple but finely designed chemotaxis assay that the Vahlkampfia amoebae exhibit chemotaxis toward higher folate concentrations. Riboflavin and cyanocobalamin were also found to serve as positive chemoattractants. Among these chemoattractants, folate is of particular importance because its function seems to be evolutionarily conserved as a potent chemoattractant of amoeboid cells in a wide range of organisms as well as in the Protista and cellular slime molds.

  3. Amoebae of the genera Vannella Bovee, 1965 and Platyamoeba Page, 1969 isolated from fish and their phylogeny inferred from SSU rRNA gene and ITS sequences

    Dyková, Iva; Boháčová, Lenka; Fiala, Ivan; Macháčková, Blanka; Pecková, Hana; Dvořáková, Helena

    2005-01-01

    Roč. 41, č. 3 (2005), s. 219-230 ISSN 0932-4739 R&D Projects: GA AV ČR IAA6022202 Institutional research plan: CEZ:AV0Z60220518 Keywords : fish-isolated amoebae * Vannella * Platyamoeba Subject RIV: EA - Cell Biology Impact factor: 1.253, year: 2005

  4. Control of Influenza and Poliomyelitis with Killed Virus Vaccines

    Salk, Jonas; Salk, Darrell

    1977-01-01

    Discusses control of poliomyelitis and influenza by live and killed virus vaccines. Considered are the etiological agents, pathogenic mechanisms and epidemiology of each disease. Reviews recent scientific studies of the diseases. Recommends use of killed virus vaccines in controlling both diseases. (CS)

  5. 9 CFR 113.210 - Feline Calicivirus Vaccine, Killed Virus.

    2010-01-01

    ... Virus. 113.210 Section 113.210 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.210 Feline Calicivirus Vaccine, Killed Virus. Feline Calicivirus...

  6. 9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.

    2010-01-01

    ... Virus. 113.205 Section 113.205 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle Disease Vaccine, Killed Virus. Newcastle Disease Vaccine...

  7. 9 CFR 113.211 - Feline Rhinotracheitis Vaccine, Killed Virus.

    2010-01-01

    ... Virus. 113.211 Section 113.211 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.211 Feline Rhinotracheitis Vaccine, Killed Virus. Feline...

  8. 9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.

    2010-01-01

    ... Virus. 113.216 Section 113.216 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.216 Bovine Rhinotracheitis Vaccine, Killed Virus. Infectious Bovine...

  9. 9 CFR 113.203 - Feline Panleukopenia Vaccine, Killed Virus.

    2010-01-01

    ... Virus. 113.203 Section 113.203 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.203 Feline Panleukopenia Vaccine, Killed Virus. Feline Panleukopenia...

  10. Pseudomonas piscicida kills vibrios by two distinct mechanisms

    Pseudoalteromonas piscicida is a naturally-occurring marine bacterium which kills competing bacteria, including vibrios. In studies by Richards et al. (AEM00175-17), three strains of P. piscicida were isolated and characterized. Strains secreted proteolytic enzymes which likely killed competing or...

  11. 9 CFR 113.214 - Parvovirus Vaccine, Killed Virus (Canine).

    2010-01-01

    ... REQUIREMENTS Killed Virus Vaccines § 113.214 Parvovirus Vaccine, Killed Virus (Canine). Parvovirus Vaccine... antibody against canine parvovirus to determine susceptibility. A constant virus-varying serum... vaccinates and the controls shall be challenged with virulent canine parvovirus furnished or approved by...

  12. Killing Unwanted West Indies Mahogany Trees by Peeling and Frilling

    R. W. Nobles; C. B. Briscoe

    1966-01-01

    Peeling and frilling each killed approximately 70 percent of treated West Indies mahogany, but peeling killed a higher percentage of trees between 18 and 33 centimeters (7 and 13 inches) than did frilling. Essentially all mortality occurred within the first 15 months following treatment.

  13. Loss of Cln3 impacts protein secretion in the social amoeba Dictyostelium.

    Huber, Robert J

    2017-07-01

    Neuronal ceroid lipofuscinosis (NCL), also referred to as Batten disease, is the most common form of childhood neurodegeneration. Mutations in CLN3 cause the most prevalent subtype of the disease, which manifests during early childhood and is currently untreatable. The precise function of the CLN3 protein is still not known, which has inhibited the development of targeted therapies. In the social amoeba Dictyostelium discoideum, loss of the CLN3 homolog, Cln3, reduces adhesion during early development, which delays streaming and aggregation. The results of the present study indicate that this phenotype may be at least partly due to aberrant protein secretion in cln3 - cells. It is well-established that Cln3 localizes primarily to the contractile vacuole (CV) system in Dictyostelium, and to a lesser extent, compartments of the endocytic pathway. Intriguingly, the CV system has been linked to the secretion of proteins that do not contain a signal peptide for secretion (i.e., unconventional protein secretion). Proteins that do contain a signal peptide are secreted via a conventional mechanism involving the endoplasmic reticulum, transport through the Golgi, and secretion via vesicle release. In this study, Cln3 was observed to co-localize with the Golgi marker wheat germ agglutinin suggesting that Cln3 participates in both secretion mechanisms. Chimeras of wild-type (WT) and cln3 - cells displayed delayed streaming and aggregation, and interestingly, cln3 - cells starved in conditioned media (CM) harvested from starving WT cells showed near normal timing of streaming and aggregation suggesting aberrant protein secretion in Cln3-deficient cells. Based on these observations, LC-MS/MS was used to reveal the protein content of CM from starved cells (mass spectrometry data are available via ProteomeXchange with identifier PXD004897). A total of 450 proteins were detected in WT and cln3 - CM, of which 3 were absent in cln3 - CM. Moreover, 12 proteins that were present in

  14. Killing (absorption) versus survival in random motion

    Garbaczewski, Piotr

    2017-09-01

    We address diffusion processes in a bounded domain, while focusing on somewhat unexplored affinities between the presence of absorbing and/or inaccessible boundaries. For the Brownian motion (Lévy-stable cases are briefly mentioned) model-independent features are established of the dynamical law that underlies the short-time behavior of these random paths, whose overall lifetime is predefined to be long. As a by-product, the limiting regime of a permanent trapping in a domain is obtained. We demonstrate that the adopted conditioning method, involving the so-called Bernstein transition function, works properly also in an unbounded domain, for stochastic processes with killing (Feynman-Kac kernels play the role of transition densities), provided the spectrum of the related semigroup operator is discrete. The method is shown to be useful in the case, when the spectrum of the generator goes down to zero and no isolated minimal (ground state) eigenvalue is in existence, like in the problem of the long-term survival on a half-line with a sink at origin.

  15. Novel innate cancer killing activity in humans

    Lovato James

    2011-08-01

    Full Text Available Abstract Background In this study, we pilot tested an in vitro assay of cancer killing activity (CKA in circulating leukocytes of 22 cancer cases and 25 healthy controls. Methods Using a human cervical cancer cell line, HeLa, as target cells, we compared the CKA in circulating leukocytes, as effector cells, of cancer cases and controls. The CKA was normalized as percentages of total target cells during selected periods of incubation time and at selected effector/target cell ratios in comparison to no-effector-cell controls. Results Our results showed that CKA similar to that of our previous study of SR/CR mice was present in human circulating leukocytes but at profoundly different levels in individuals. Overall, males have a significantly higher CKA than females. The CKA levels in cancer cases were lower than that in healthy controls (mean ± SD: 36.97 ± 21.39 vs. 46.28 ± 27.22. Below-median CKA was significantly associated with case status (odds ratio = 4.36; 95% Confidence Interval = 1.06, 17.88 after adjustment of gender and race. Conclusions In freshly isolated human leukocytes, we were able to detect an apparent CKA in a similar manner to that of cancer-resistant SR/CR mice. The finding of CKA at lower levels in cancer patients suggests the possibility that it may be of a consequence of genetic, physiological, or pathological conditions, pending future studies with larger sample size.

  16. Combinatorial stresses kill pathogenic Candida species

    Kaloriti, Despoina; Tillmann, Anna; Cook, Emily; Jacobsen, Mette; You, Tao; Lenardon, Megan; Ames, Lauren; Barahona, Mauricio; Chandrasekaran, Komelapriya; Coghill, George; Goodman, Daniel; Gow, Neil A. R.; Grebogi, Celso; Ho, Hsueh-Lui; Ingram, Piers; McDonagh, Andrew; De Moura, Alessandro P. S.; Pang, Wei; Puttnam, Melanie; Radmaneshfar, Elahe; Romano, Maria Carmen; Silk, Daniel; Stark, Jaroslav; Stumpf, Michael; Thiel, Marco; Thorne, Thomas; Usher, Jane; Yin, Zhikang; Haynes, Ken; Brown, Alistair J. P.

    2012-01-01

    Pathogenic microbes exist in dynamic niches and have evolved robust adaptive responses to promote survival in their hosts. The major fungal pathogens of humans, Candida albicans and Candida glabrata, are exposed to a range of environmental stresses in their hosts including osmotic, oxidative and nitrosative stresses. Significant efforts have been devoted to the characterization of the adaptive responses to each of these stresses. In the wild, cells are frequently exposed simultaneously to combinations of these stresses and yet the effects of such combinatorial stresses have not been explored. We have developed a common experimental platform to facilitate the comparison of combinatorial stress responses in C. glabrata and C. albicans. This platform is based on the growth of cells in buffered rich medium at 30°C, and was used to define relatively low, medium and high doses of osmotic (NaCl), oxidative (H 2O2) and nitrosative stresses (e.g., dipropylenetriamine (DPTA)-NONOate). The effects of combinatorial stresses were compared with the corresponding individual stresses under these growth conditions. We show for the first time that certain combinations of combinatorial stress are especially potent in terms of their ability to kill C. albicans and C. glabrata and/or inhibit their growth. This was the case for combinations of osmotic plus oxidative stress and for oxidative plus nitrosative stress. We predict that combinatorial stresses may be highly signif cant in host defences against these pathogenic yeasts. PMID:22463109

  17. Protection against hyperthermic cell killing by alanine

    Cunningham, A.; Henle, K.J.; Moss, A.J.; Nagle, W.A.

    1987-01-01

    Compounds capable of protecting cells against hyperthermia may provide new insights into potential mechanisms of thermotolerance and cellular heat death. The authors characterized heat protection by alanine and related compounds as a function of concentration, temperature and preincubation time. Alanine was added either to complete medium or to HBSS before hyperthermia. Maximal heat protection required 3 hr, 37 0 ; longer preincubation intervals resulted in lower levels of protection. Addition of alanine to medium after hyperthermia had no protective effect. Protection was concentration dependent with a 20- or 200-fold increase in cell survival after 40 min, 45 0 C at 60 mM in medium or in HBSS, respectively. Higher alanine concentrations up to 120mM did not significantly increase heat protection. A 45 0 -heat survival curve showed that 100mM alanine increased the D/sub q/ by approx. 12 min with little change in the D/sub o/. Hyperthermia of 1 hr at temperatures between 42 0 and 45 0 indicated that 100mM alanine shifted the isotoxic temperature by 0.5 Celsius degrees. Polymers of either L or D,L alanine and related compounds, like pyruvate, also protected cells against heat killing. These results indicate that heat protection by alanine shows characteristics that are not shared by polyhydroxy compounds

  18. Managing Threat, Cost, and Incentive to Kill: The Short- and Long-Term Effects of Intervention in Mass Killings

    Kathman, Jacob D.; Wood, Reed M.

    2011-01-01

    How do third-party interventions affect the severity of mass killings? The authors theorize that episodes of mass killing are the consequence of two factors: (1) the threat perceptions of the perpetrators and (2) the cost of implementing genocidal policies relative to other alternatives. To reduce genocidal hostilities, interveners must address…

  19. Psychological traits underlying different killing methods among Malaysian male murderers.

    Kamaluddin, Mohammad Rahim; Shariff, Nadiah Syariani; Nurfarliza, Siti; Othman, Azizah; Ismail, Khaidzir H; Mat Saat, Geshina Ayu

    2014-04-01

    Murder is the most notorious crime that violates religious, social and cultural norms. Examining the types and number of different killing methods that used are pivotal in a murder case. However, the psychological traits underlying specific and multiple killing methods are still understudied. The present study attempts to fill this gap in knowledge by identifying the underlying psychological traits of different killing methods among Malaysian murderers. The study adapted an observational cross-sectional methodology using a guided self-administered questionnaire for data collection. The sampling frame consisted of 71 Malaysian male murderers from 11 Malaysian prisons who were selected using purposive sampling method. The participants were also asked to provide the types and number of different killing methods used to kill their respective victims. An independent sample t-test was performed to establish the mean score difference of psychological traits between the murderers who used single and multiple types of killing methods. Kruskal-Wallis tests were carried out to ascertain the psychological trait differences between specific types of killing methods. The results suggest that specific psychological traits underlie the type and number of different killing methods used during murder. The majority (88.7%) of murderers used a single method of killing. Multiple methods of killing was evident in 'premeditated' murder compared to 'passion' murder, and revenge was a common motive. Examples of multiple methods are combinations of stabbing and strangulation or slashing and physical force. An exception was premeditated murder committed with shooting, when it was usually a single method, attributed to the high lethality of firearms. Shooting was also notable when the motive was financial gain or related to drug dealing. Murderers who used multiple killing methods were more aggressive and sadistic than those who used a single killing method. Those who used multiple methods or

  20. Killing a Peacock: A Case Study of the Targeted Killing of Admiral Isoroku Yamamoto

    2015-03-24

    assertions by-in-large fell on deaf ears in the United States, Yamamoto nevertheless took special interest in Mitchell’s claims, and returned to Japan in...deliberations on April 17.106 Upon receiving an update brief of the planning order, Viccellio immediately identified a problem . He knew that the P-38’s fuel...what, it all happened all too fast to know and he was content on calling it a “team kill.”152 Instead, he left resolution of the issue to Barber and

  1. Kill a brand, keep a customer.

    Kumar, Nirmalya

    2003-12-01

    Most brands don't make much money. Year after year, businesses generate 80% to 90% of their profits from less than 20% of their brands. Yet most companies tend to ignore loss-making brands, unaware of the hidden costs they incur. That's because executives believe it's easy to erase a brand; they have only to stop investing in it, they assume, and it will die a natural death. But they're wrong. When companies drop brands clumsily, they antagonize loyal customers: Research shows that seven times out of eight, when firms merge two brands, the market share of the new brand never reaches the combined share of the two original ones. It doesn't have to be that way. Smart companies use a four-step process to kill brands methodically. First, CEOs make the case for rationalization by getting groups of senior executives to conduct joint audits of the brand portfolio. These audits make the need to prune brands apparent throughout the organization. In the next stage, executives need to decide how many brands will be retained, which they do either by setting broad parameters that all brands must meet or by identifying the brands they need in order to cater to all the customer segments in their markets. Third, executives must dispose of the brands they've decided to drop, deciding in each case whether it is appropriate to merge, sell, milk, or just eliminate the brand outright. Finally, it's critical that executives invest the resources they've freed to grow the brands they've retained. Done right, dropping brands will result in a company poised for new growth from the source where it's likely to be found--its profitable brands.

  2. Did Vertigo Kill America's Forgotten Astronaut?

    Bendrick, Gregg A.; Merlin, Peter W.

    2007-01-01

    On November 15, 1967, U.S. Air Force test pilot Major Michael J. Adams was killed while flying the X-15 rocket-propelled research vehicle in a parabolic spaceflight profile. This flight was part of a joint effort with NASA. An electrical short in one of the experiments aboard the vehicle caused electrical transients, resulting in excessive workload by the pilot. At altitude Major Adams inappropriately initiated a flat spin that led to a series of unusual aircraft attitudes upon atmospheric re-entry, ultimately causing structural failure of the airframe. Major Adams was known to experience vertigo (i.e. spatial disorientation) while flying the X-15, but all X-15 pilots most likely experienced vertigo (i.e. somatogravic, or "Pitch-Up", illusion) as a normal physiologic response to the accelerative forces involved. Major Adams probably experienced vertigo to a greater degree than did others, since prior aeromedical testing for astronaut selection at Brooks AFB revealed that he had an unusually high degree of labyrinthine sensitivity. Subsequent analysis reveals that after engine burnout, and through the zenith of the flight profile, he likely experienced the oculoagravic ("Elevator") illusion. Nonetheless, painstaking investigation after the mishap revealed that spatial disorientation (Type II, Recognized) was NOT the cause, but rather, a contributing factor. The cause was in fact the misinterpretation of a dual-use flight instrument (i.e. Loss of Mode Awareness), resulting in confusion between yaw and roll indications, with subsequent flight control input that was inappropriate. Because of the altitude achieved on this flight, Major Adams was awarded Astronaut wings posthumously. Understanding the potential for spatial disorientation, particularly the oculoagravic illusion, associated with parabolic spaceflight profiles, and understanding the importance of maintaining mode awareness in the context of automated cockpit design, are two lessons that have direct

  3. Generalized Killing-Yano equations in D=5 gauged supergravity

    Kubiznak, David; Kunduri, Hari K.; Yasui, Yukinori

    2009-01-01

    We propose a generalization of the (conformal) Killing-Yano equations relevant to D=5 minimal gauged supergravity. The generalization stems from the fact that the dual of the Maxwell flux, the 3-form *F, couples naturally to particles in the background as a 'torsion'. Killing-Yano tensors in the presence of torsion preserve most of the properties of the standard Killing-Yano tensors - exploited recently for the higher-dimensional rotating black holes of vacuum gravity with cosmological constant. In particular, the generalized closed conformal Killing-Yano 2-form gives rise to the tower of generalized closed conformal Killing-Yano tensors of increasing rank which in turn generate the tower of Killing tensors. An example of a generalized Killing-Yano tensor is found for the Chong-Cvetic-Lue-Pope black hole spacetime [Z.W. Chong, M. Cvetic, H. Lu, C.N. Pope, (hep-th/0506029)]. Such a tensor stands behind the separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations in this background.

  4. Biofilms associated with poultry processing equipment.

    Lindsay, D; Geornaras, I; von Holy, A

    1996-01-01

    Aerobic and Gram-negative bacteria were enumerated on non-metallic surfaces and stainless steel test pieces attached to equipment surfaces by swabbing and a mechanical dislodging procedure, respectively, in a South African grade B poultry processing plant. Changes in bacterial numbers were also monitored over time on metal test pieces. The highest bacterial counts were obtained from non-metallic surfaces such as rubber fingered pluckers and plastic defeathering curtains which exceeded the highest counts found on the metal surfaces by at least 1 log CFU cm-2. Gram-negative bacterial counts on all non-metallic surface types were at least 2 log CFU cm-2 lower than corresponding aerobic plate counts. On metal surfaces, the highest microbial numbers were obtained after 14 days exposure, with aerobic plate counts ranging from 3.57 log CFU cm-2 to 5.13 log CFU cm-2, and Gram-negative counts from 0.70 log CFU cm-2 to 3.31 log CFU cm-2. Scanning electron microscopy confirmed the presence of bacterial cells on non-metallic and metallic surfaces associated with poultry processing. Rubber 'fingers', plastic curtains, conveyor belt material and stainless steel test surfaces placed on the scald tank overflow and several chutes revealed extensive and often confluent bacterial biofilms. Extracellular polymeric substances, but few bacterial cells were visible on test pieces placed on evisceration equipment, spinchiller blades and the spinchiller outlet.

  5. Some spacetimes with higher rank Killing-Staeckel tensors

    Gibbons, G.W.; Houri, T.; Kubiznak, D.; Warnick, C.M.

    2011-01-01

    By applying the lightlike Eisenhart lift to several known examples of low-dimensional integrable systems admitting integrals of motion of higher-order in momenta, we obtain four- and higher-dimensional Lorentzian spacetimes with irreducible higher-rank Killing tensors. Such metrics, we believe, are first examples of spacetimes admitting higher-rank Killing tensors. Included in our examples is a four-dimensional supersymmetric pp-wave spacetime, whose geodesic flow is superintegrable. The Killing tensors satisfy a non-trivial Poisson-Schouten-Nijenhuis algebra. We discuss the extension to the quantum regime.

  6. HIV transcription is induced with some forms of cell killing

    Woloschak, G.E.; Schreck, S.; Chang-Liu, C.-M.; Libertin, C.R.

    1996-01-01

    Using HeLa cells stably transfected with an HIV-LTR-CAT construct', we demonstrated a peak in CAT induction that occurs in viable (but not necessarily cell-division-competent) cells 24 h following exposure to some cell-killing agents. Γ rays were the only cell-killing agent which did not induce HIV transcription; this can be attributed to the fact that γ-ray-induced apoptotic death requires function p53, which is missing in HeLa cells. For all other agents, HIV-LTR induction was dose-dependent and correlated with the amount of cell killing that occurred in the culture

  7. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  8. On different types of hereditable changes in the viability of Amoeba protens cells x-irradiated with varying doses

    Bychkovskaya, I.B.; Ochinskaya, G.K.; Erokhina, G.M.

    1976-01-01

    Qualitatively different types of cells lethality have been observed in the posterity of amoebae irradiated with doses ranging from 0.5 to 40 kR and from 60 to 120 kR. At doses of 0.5 to 40 kR, a certain part of cells in a population dies, and the effect is characterized by stability and independency of a radiation dose, hereditable radiation damage of all the cells in the population, and by the fact that it might be caused not only by a derect action of radiation but also by a preirradiated culture medium. Higher doses (60 to 120 kR) cause a more drastic but sell stable effect. Depending on a dose value, a varying percentage of cells has shown the effect not being caused by the action of the preirradiated medium. The data obtained indicate that there are different mechanisms of hereditable radiation damages to cells caused by varying radiation doses

  9. 40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

    2010-07-01

    ... thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens is exempt from the...

  10. Selective Killing of Prostate Tumor Cells by Cytocidal Viruses

    Lyles, Douglas

    2003-01-01

    .... The novelty in our approach is our ability to enhance the selectivity of killing of tumor cells versus normal cells by manipulating the viral genes that control the antiviral interferon response...

  11. Selective Killing of Prostate Tumor Cells by Cytocidal Viruses

    Lyles, Douglas

    2004-01-01

    .... The novelty in our approach is our ability to enhance the selectivity of killing of tumor cells versus normal cells by manipulating the viral genes that control the antiviral interferon response...

  12. On Discrete Killing Vector Fields and Patterns on Surfaces

    Ben-Chen, Mirela; Butscher, Adrian; Solomon, Justin; Guibas, Leonidas

    2010-01-01

    , and show how to discretize these concepts for generating such vector fields on a triangulated mesh. We discuss the properties of approximate Killing Vector Fields, and propose an application to utilize them for texture and geometry synthesis. Journal

  13. Selective Killing of Prostate Tumor Cells by Cytocidal Viruses

    Lyles, Douglas S

    2005-01-01

    ...). The novelty in our approach is our ability to enhance the selectivity of VSV-induced killing of tumor cells versus normal cells by manipulating the viral genes that control the antiviral interferon response...

  14. Thou Shalt Not Kill: Conscientious Objection and the Decalogue

    2012-04-01

    used to condone animal cruelty .66 Second, n¥1 (ratsach) is not used in the context of proper punishment for a crime.67 Alan Cole explains...used to refer to the killing animals for food and sacrifices.63 Scripture records that God allowed the killing of animals for food.64 God also allowed...the slaying of animals for sacrifices.65 Consequently, the sixth commandment cannot be used to support the practice of vegetarianism nor can it be

  15. Vertebrate road kill survey on a highway in southern Brazil

    Luiz Liberato Costa Corrêa

    2017-06-01

    Full Text Available Highways are a major factor acting in the decline of several wildlife populations. Impact occurs due to the continuous flow of motor vehicles over tracks and collision with animals using the same area. This study aimed to list road killed wild vertebrates found in highways in the Pampa Biome, state of Rio Grande do Sul, over an entire year. The taxa found (amphibians, reptiles, birds and mammals were identified to species level and their frequency of occurrence was seasonally registered. Along 2,160 km, we found 318 road killed individuals, totaling 65 species. This number represents an average of 0.147 road killed specimens by kilometer (that is, 1 individual each 7 km. Of these, seven species are under threat of extinction in the state of Rio Grande do Sul. We also found a seasonal pattern among road kills, in which the highest number of road killed animals was registered in the summer and spring months. These results contribute to increase knowledge about which species are most impacted by road kill on highways of the Pampa Biome. Such data can be used as an indicator for the implementation of measures by competent bodies to mitigate impacts of highways in the state of Rio Grande do Sul.

  16. Role of nitric oxide and superoxide in Giardia lamblia killing

    P.D. Fernandes

    1997-01-01

    Full Text Available Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine. Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites. This effect was inhibited (>90% by an NO synthase inhibitor (200 µM and unaffected by superoxide dismutase (SOD, 300 U/ml. Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP and sodium nitroprusside (SNP in a dose-dependent manner (LD50 300 and 50 µM, respectively. A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1, did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM. The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM. These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite

  17. Karr’s Kill Cult: Virtual Cults and Pseudo-Killing in the Digital Age

    Jeremy Biles

    2012-03-01

    Full Text Available Most readers will recall the 1996 tragedy in which six-year-old beauty-pageant princess JonBenét Ramsey was found bound, gagged, and strangled in the basement of her parents’ home, inciting an orgy of media coverage. What readers may not know is that John Mark Karr—the imminently creepy individual who falsely confessed to the killing, and whose sordid past includes an arrest for possession of child pornography—has continued to make news as an alleged cyberstalker and would-be cult leader. This article claims that whereas a real serial killer is compelled to murder again and again with different victims, Karr is compelled to repeat the singular murder of JonBenét Ramsey the only way he can—in a virtual reality constituted by writing.

  18. Changes in Structure and Functioning of Protist (Testate Amoebae Communities Due to Conversion of Lowland Rainforest into Rubber and Oil Palm Plantations.

    Valentyna Krashevska

    Full Text Available Large areas of tropical rainforest are being converted to agricultural and plantation land uses, but little is known of biodiversity and ecological functioning under these replacement land uses. We investigated the effects of conversion of rainforest into jungle rubber, intensive rubber and oil palm plantations on testate amoebae, diverse and functionally important protists in litter and soil. Living testate amoebae species richness, density and biomass were all lower in replacement land uses than in rainforest, with the impact being more pronounced in litter than in soil. Similar abundances of species of high and low trophic level in rainforest suggest that trophic interactions are more balanced, with a high number of functionally redundant species, than in rubber and oil palm. In contrast, plantations had a low density of high trophic level species indicating losses of functions. This was particularly so in oil palm plantations. In addition, the relative density of species with siliceous shells was >50% lower in the litter layer of oil palm and rubber compared to rainforest and jungle rubber. This difference suggests that rainforest conversion changes biogenic silicon pools and increases silicon losses. Overall, the lower species richness, density and biomass in plantations than in rainforest, and the changes in the functional composition of the testate amoebae community, indicate detrimental effects of rainforest conversion on the structure and functioning of microbial food webs.

  19. Changes in Structure and Functioning of Protist (Testate Amoebae) Communities Due to Conversion of Lowland Rainforest into Rubber and Oil Palm Plantations.

    Krashevska, Valentyna; Klarner, Bernhard; Widyastuti, Rahayu; Maraun, Mark; Scheu, Stefan

    2016-01-01

    Large areas of tropical rainforest are being converted to agricultural and plantation land uses, but little is known of biodiversity and ecological functioning under these replacement land uses. We investigated the effects of conversion of rainforest into jungle rubber, intensive rubber and oil palm plantations on testate amoebae, diverse and functionally important protists in litter and soil. Living testate amoebae species richness, density and biomass were all lower in replacement land uses than in rainforest, with the impact being more pronounced in litter than in soil. Similar abundances of species of high and low trophic level in rainforest suggest that trophic interactions are more balanced, with a high number of functionally redundant species, than in rubber and oil palm. In contrast, plantations had a low density of high trophic level species indicating losses of functions. This was particularly so in oil palm plantations. In addition, the relative density of species with siliceous shells was >50% lower in the litter layer of oil palm and rubber compared to rainforest and jungle rubber. This difference suggests that rainforest conversion changes biogenic silicon pools and increases silicon losses. Overall, the lower species richness, density and biomass in plantations than in rainforest, and the changes in the functional composition of the testate amoebae community, indicate detrimental effects of rainforest conversion on the structure and functioning of microbial food webs.

  20. First Record of Potentially Pathogenic Amoeba Vermamoeba vermiformis (Lobosea: Gymnamoebia Isolated from a Freshwater of Dokdo Island in the East Sea, Korea

    Jong Soo Park

    2016-01-01

    Full Text Available Vermamoeba vermiformis is a very important free-living amoeba for human health in association with Legionnaires’ disease and keratitis. This interesting amoeba was firstly isolated from a freshwater of Dokdo (island, which was historically used for drinking water. Trophozoites and cyst forms of V. vermiformis strain MG1 are very similar to previous reported species. Trophozoites of V. vermiformis strain MG1 showed cylindrical shape with prominent anterior hyaline region. The average ratio of length and width was about 6.5. Typically, cysts of the strain MG1 showed a spherical or slightly ovoidal shape with smooth wall, and lacked cyst pores. Some cysts had crenulatewalled ectocyst, which was separated from endocyst wall. Further, 18S rRNA gene sequence of V. vermiformis strain MG1 showed very high similarity to other V. vermiformis species (99.4%-99.9% identity. Molecular phylogenetic analysis based on 18S rRNA gene sequences clearly confirmed that the isolate was one strain of V. vermiformis with maximum bootstrap value (maximum likelihood: 100% and Bayesian posterior probability of 1. Thus, the freshwater of Dokdo in Korea could harbor potentially pathogenic amoeba that may cause diseases in humans.

  1. Neutrophils kill the parasite Trichomonas vaginalis using trogocytosis

    Mercer, Frances; Ng, Shek Hang; Brown, Taylor M.; Boatman, Grace; Johnson, Patricia J.

    2018-01-01

    T. vaginalis, a human-infective parasite, causes the most common nonviral sexually transmitted infection (STI) worldwide and contributes to adverse inflammatory disorders. The immune response to T. vaginalis is poorly understood. Neutrophils (polymorphonuclear cells [PMNs]) are the major immune cell present at the T. vaginalis–host interface and are thought to clear T. vaginalis. However, the mechanism of PMN clearance of T. vaginalis has not been characterized. We demonstrate that human PMNs rapidly kill T. vaginalis in a dose-dependent, contact-dependent, and neutrophil extracellular trap (NET)-independent manner. In contrast to phagocytosis, we observed that PMN killing of T. vaginalis involves taking “bites” of T. vaginalis prior to parasite death, using trogocytosis to achieve pathogen killing. Both trogocytosis and parasite killing are dependent on the presence of PMN serine proteases and human serum factors. Our analyses provide the first demonstration, to our knowledge, of a mammalian phagocyte using trogocytosis for pathogen clearance and reveal a novel mechanism used by PMNs to kill a large, highly motile target. PMID:29408891

  2. Structural equations for Killing tensors of order two. II

    Hauser, I.; Malhiot, R.J.

    1975-01-01

    In a preceding paper, a new form of the structural equations for any Killing tensor of order two have been derived; these equations constitute a system analogous to the Killing vector equations Nabla/sub alpha/ K/sub beta/ = ω/sub alpha beta/ = -ω/sub beta alpha/ and Nabla/sub gamma/ ω/sub alpha beta = R/sub alpha beta gamma delta/ K/sup delta/. The first integrability condition for the Killing tensor structural equations is now derived. The structural equations and the integrability condition have forms which can readily be expressed in terms of a null tetrad to furnish a Killing tensor parallel of the Newman--Penrose equations; this is briefly described. The integrability condition implies the new result, for any given space--time, that the dimension of the set of second-order Killing tensors attains its maximum possible value of 50 only if the space--time is of constant curvature. Potential applications of the structural equations are discussed

  3. Prairie dogs increase fitness by killing interspecific competitors.

    Hoogland, John L; Brown, Charles R

    2016-03-30

    Interspecific competition commonly selects for divergence in ecology, morphology or physiology, but direct observation of interspecific competition under natural conditions is difficult. Herbivorous white-tailed prairie dogs (Cynomys leucurus) employ an unusual strategy to reduce interspecific competition: they kill, but do not consume, herbivorous Wyoming ground squirrels (Urocitellus elegans) encountered in the prairie dog territories. Results from a 6-year study in Colorado, USA, revealed that interspecific killing of ground squirrels by prairie dogs was common, involving 47 different killers; 19 prairie dogs were serial killers in the same or consecutive years, and 30% of female prairie dogs killed at least one ground squirrel over their lifetimes. Females that killed ground squirrels had significantly higher annual and lifetime fitness than non-killers, probably because of decreased interspecific competition for vegetation. Our results document the first case of interspecific killing of competing individuals unrelated to predation (IK) among herbivorous mammals in the wild, and show that IK enhances fitness for animals living under natural conditions. © 2016 The Author(s).

  4. 77 FR 10960 - Security Zone, East River and Bronx Kill; Randalls and Wards Islands, NY

    2012-02-24

    ...'' W (Port Morris Stacks), and all waters of the Bronx Kill southeast of the Bronx Kill Rail Road...-AA87 Security Zone, East River and Bronx Kill; Randalls and Wards Islands, NY AGENCY: Coast Guard, DHS... waters of the East River and Bronx Kill, in the vicinity of Randalls and Wards Islands, New York. This...

  5. Isolamento de amebas de vida livre potencialmente patogênicas em poeira de hospitais Isolation of potencially pathogenic free-living amoebas in hospital dust

    Maria Aparecida da Silva

    2003-04-01

    Full Text Available OBJETIVO: Observar a ocorrência de amebas de vida livre dos gêneros Acanthamoeba e Naegleria em amostras de poeira coletadas em hospitais. MÉTODOS: Foram coletadas 132 amostras de poeira em dois hospitais do município de Presidente Prudente, São Paulo. Os locais da coleta foram: Unidade de Terapia Intensiva, Centro Cirúrgico, Isolamento de Moléstias Infecciosas, Berçário, Emergência e Cozinha. As amostras foram semeadas em três meios de cultura: meio de ágar não nutriente com Escherichia coli, meio de ágar infusão de soja e microcultivo em meio de Pavlova modificado por Giazzi. As amebas isoladas foram identificadas segundo critérios morfológicos. RESULTADOS: O índice geral de positividade para amebas de vida livre, potencialmente patogênicas, dos gêneros Acanthamoeba e Naegleria, foi de 45,5%, sendo positivas 41,6% das amostras de poeira coletadas no hospital universitário e 50% no hospital estadual. Obtiveram-se 45,5% de positividade do gênero Acanthamoeba e 3,8% para amebas do gênero Naegleria. CONCLUSÕES: As amebas de vida livre, potencialmente patogênicas, estavam presentes em todos os ambientes estudados dos dois hospitais, sendo que as espécies do gênero Acanthamoeba foram as isoladas com maior freqüência.OBJECTIVE: To evaluate the occurrence of free-living amoebas of the genera Acanthamoeba and Naegleria is dust samples colleted in two hospitals. METHODS: One-hundred and thirty-two dust samples were collected in two hospitals in Brazil. Hospital collection sites were the following: intensive care unit, operation rooms, nursery, kitchen, emergency and infectious diseases isolation room . The isolation of the amoebas was performed in three culture media: non-nutrient agar inoculated with Escherichia coli, soy agar, and microculture in Giazzi-modified Pavlova's medium. The amoebas were identified according to morphological criteria. RESULTS: Amoebas of the genera Acanthamoeba and Naegleria were found in 45.5% of

  6. Metformin kills and radiosensitizes cancer cells and preferentially kills cancer stem cells

    Song, Chang W.; Lee, Hyemi; Dings, Ruud P. M.; Williams, Brent; Powers, John; Santos, Troy Dos; Choi, Bo-Hwa; Park, Heon Joo

    2012-01-01

    The anti-cancer effects of metformin, the most widely used drug for type 2 diabetes, alone or in combination with ionizing radiation were studied with MCF-7 human breast cancer cells and FSaII mouse fibrosarcoma cells. Clinically achievable concentrations of metformin caused significant clonogenic death in cancer cells. Importantly, metformin was preferentially cytotoxic to cancer stem cells relative to non-cancer stem cells. Metformin increased the radiosensitivity of cancer cells in vitro, and significantly enhanced the radiation-induced growth delay of FSaII tumors (s.c.) in the legs of C3H mice. Both metformin and ionizing radiation activated AMPK leading to inactivation of mTOR and suppression of its downstream effectors such as S6K1 and 4EBP1, a crucial signaling pathway for proliferation and survival of cancer cells, in vitro as well as in the in vivo tumors. Conclusion: Metformin kills and radiosensitizes cancer cells and eradicates radioresistant cancer stem cells by activating AMPK and suppressing mTOR. PMID:22500211

  7. Inflatable kill packers used in working over Kuwaiti wells

    Miller, D. (Baker Oil Tools, Houston, TX (US)); Conover, G. (Baker Service Tools, Houston, TX (US))

    1992-03-09

    This paper reports on inflatable packers which are being used with great success in post-well capping workover operations in Kuwait oil fields. In mid-January, about one kill packer was being run per day. Use is expected to increase in March when a second post-capping crew arrives. Of several thousand unconventional ideas submitted to Kuwait Oil Co. (KOC) for controlling the well fires left in the aftermath of lst year's Gulf War, only about a dozen were actually used. Inflatable kill packers, designed and manufactured by Baker Service Tools and marketed by Baker Oil Tools, were one of the ideas that proved effective. The kill packers are modifications of Baker's inflatable packers that have successfully been used in capping producers on many blowouts throughout the world, including the Piper Alpha disaster in the North Sea and the Saga blowout offshore Norway.

  8. γ-rays kill grasshopper primary spermatocytes in groups

    Al-Taweel, A.A.; Shawkit, M.A.; Fox, D.P.

    1985-01-01

    Primary spermatocyte killing by γ-rays was studied in the grasshopper Heteracris littoralis in which spermatogenic development occurs in cysts containing a maximum of 64 cells during the first meiotic division. Cell killing at this stage is not random and mainly involves the death of whole cysts. The dose-response curve for cell killing has complex kinetics with at least two components but lacks any shoulder at low doses, thus indicating no repair of the lethal damage. Cell loss is apparent from surviving cysts as early as 45 min post irradiation but loss of > 24 cells is incompatible with cyst survival. Loss of fewer than 24 cells also is not random since certain values for cell loss are frequently observed while other, interspersed values are not seen at all. (Auth.)

  9. Supersymmetric backgrounds, the Killing superalgebra, and generalised special holonomy

    Coimbra, André [Institut des Hautes Études Scientifiques, Le Bois-Marie,35 route de Chartres, F-91440 Bures-sur-Yvette (France); Strickland-Constable, Charles [Institut des Hautes Études Scientifiques, Le Bois-Marie,35 route de Chartres, F-91440 Bures-sur-Yvette (France); Institut de physique théorique, Université Paris Saclay, CEA, CNRS,Orme des Merisiers, F-91191 Gif-sur-Yvette (France)

    2016-11-10

    We prove that, for M theory or type II, generic Minkowski flux backgrounds preserving N supersymmetries in dimensions D≥4 correspond precisely to integrable generalised G{sub N} structures, where G{sub N} is the generalised structure group defined by the Killing spinors. In other words, they are the analogues of special holonomy manifolds in E{sub d(d)}×ℝ{sup +} generalised geometry. In establishing this result, we introduce the Kosmann-Dorfman bracket, a generalisation of Kosmann’s Lie derivative of spinors. This allows us to write down the internal sector of the Killing superalgebra, which takes a rather simple form and whose closure is the key step in proving the main result. In addition, we find that the eleven-dimensional Killing superalgebra of these backgrounds is necessarily the supertranslational part of the N-extended super-Poincaré algebra.

  10. On Discrete Killing Vector Fields and Patterns on Surfaces

    Ben-Chen, Mirela

    2010-09-21

    Symmetry is one of the most important properties of a shape, unifying form and function. It encodes semantic information on one hand, and affects the shape\\'s aesthetic value on the other. Symmetry comes in many flavors, amongst the most interesting being intrinsic symmetry, which is defined only in terms of the intrinsic geometry of the shape. Continuous intrinsic symmetries can be represented using infinitesimal rigid transformations, which are given as tangent vector fields on the surface - known as Killing Vector Fields. As exact symmetries are quite rare, especially when considering noisy sampled surfaces, we propose a method for relaxing the exact symmetry constraint to allow for approximate symmetries and approximate Killing Vector Fields, and show how to discretize these concepts for generating such vector fields on a triangulated mesh. We discuss the properties of approximate Killing Vector Fields, and propose an application to utilize them for texture and geometry synthesis. Journal compilation © 2010 The Eurographics Association and Blackwell Publishing Ltd.

  11. Role of copper oxides in contact killing of bacteria.

    Hans, Michael; Erbe, Andreas; Mathews, Salima; Chen, Ying; Solioz, Marc; Mücklich, Frank

    2013-12-31

    The potential of metallic copper as an intrinsically antibacterial material is gaining increasing attention in the face of growing antibiotics resistance of bacteria. However, the mechanism of the so-called "contact killing" of bacteria by copper surfaces is poorly understood and requires further investigation. In particular, the influences of bacteria-metal interaction, media composition, and copper surface chemistry on contact killing are not fully understood. In this study, copper oxide formation on copper during standard antimicrobial testing was measured in situ by spectroscopic ellipsometry. In parallel, contact killing under these conditions was assessed with bacteria in phosphate buffered saline (PBS) or Tris-Cl. For comparison, defined Cu2O and CuO layers were thermally generated and characterized by grazing incidence X-ray diffraction. The antibacterial properties of these copper oxides were tested under the conditions used above. Finally, copper ion release was recorded for both buffer systems by inductively coupled plasma atomic absorption spectroscopy, and exposed copper samples were analyzed for topographical surface alterations. It was found that there was a fairly even growth of CuO under wet plating conditions, reaching 4-10 nm in 300 min, but no measurable Cu2O was formed during this time. CuO was found to significantly inhibit contact killing, compared to pure copper. In contrast, thermally generated Cu2O was essentially as effective in contact killing as pure copper. Copper ion release from the different surfaces roughly correlated with their antibacterial efficacy and was highest for pure copper, followed by Cu2O and CuO. Tris-Cl induced a 10-50-fold faster copper ion release compared to PBS. Since the Cu2O that primarily forms on copper under ambient conditions is as active in contact killing as pure copper, antimicrobial objects will retain their antimicrobial properties even after oxide formation.

  12. Single-hit mechanism of tumour cell killing by radiation.

    Chapman, J D

    2003-02-01

    To review the relative importance of the single-hit mechanism of radiation killing for tumour response to 1.8-2.0 Gy day(-1) fractions and to low dose-rate brachytherapy. Tumour cell killing by ionizing radiation is well described by the linear-quadratic equation that contains two independent components distinguished by dose kinetics. Analyses of tumour cell survival curves that contain six or more dose points usually provide good estimates of the alpha- and beta-inactivation coefficients. Superior estimates of tumour cell intrinsic radiosensitivity are obtained when synchronized populations are employed. The characteristics of single-hit inactivation of tumour cells are reviewed and compared with the characteristics of beta-inactivation. Potential molecular targets associated with single-hit inactivation are discussed along with strategies for potentiating cell killing by this mechanism. The single-hit mechanism of tumour cell killing shows no dependence on dose-rate and, consequently, no evidence of sublethal damage repair. It is uniquely potentiated by high linear-energy-transfer radiation, exhibits a smaller oxygen enhancement ratio and exhibits a larger indirect effect by hydroxyl radicals than the beta-mechanism. alpha-inactivation coefficients vary slightly throughout interphase but mitotic cells exhibit extremely high alpha-coefficients in the range of those observed for lymphocytes and some repair-deficient cells. Evidence is accumulating to suggest that chromatin in compacted form could be a radiation-hypersensitive target associated with single-hit radiation killing. Analyses of tumour cell survival curves demonstrate that it is the single-hit mechanism (alpha) that determines the majority of cell killing after doses of 2Gy and that this mechanism is highly variable between tumour cell lines. The characteristics of single-hit inactivation are qualitatively and quantitatively distinct from those of beta-inactivation. Compacted chromatin in tumour cells

  13. It?s Not Just Conflict That Motivates Killing of Orangutans

    Davis, Jacqueline T.; Mengersen, Kerrie; Abram, Nicola K.; Ancrenaz, Marc; Wells, Jessie A.; Meijaard, Erik

    2013-01-01

    We investigated why orangutans are being killed in Kalimantan, Indonesia, and the role of conflict in these killings. Based on an analysis of interview data from over 5,000 respondents in over 450 villages, we also assessed the socio-ecological factors associated with conflict and non-conflict killings. Most respondents never kill orangutans. Those who reported having personally killed an orangutan primarily did so for non-conflict reasons; for example, 56% of these respondents said that the ...

  14. Traffics and wildlife: A preliminary study on road-kill

    Rustiati, Elly Lestari

    2012-01-01

    This paper presents the preliminary finding on road kill survey by direct observations onthe high ways. The road-kills recorded of small wildlife, including medium size-mammal (2.50%, n =1), birds (5.00%, n = 2) and small mammals (92.50%, n = 37). The small mammals include the mostcommon mammals in the areas, squirrels, raccoons, skunks and woodchuck. Of mammals, squirrels(35.00%) were the highest recorded, followed by woodchucks (25.00%), mice/shrew (17.50%),raccoons (10.00%), skunk (5.00%) ...

  15. Perturbative stability of the approximate Killing field eigenvalue problem

    Beetle, Christopher; Wilder, Shawn

    2014-01-01

    An approximate Killing field may be defined on a compact, Riemannian geometry by solving an eigenvalue problem for a certain elliptic operator. This paper studies the effect of small perturbations in the Riemannian metric on the resulting vector field. It shows that small metric perturbations, as measured using a Sobolev-type supremum norm on the space of Riemannian geometries on a fixed manifold, yield small perturbations in the approximate Killing field, as measured using a Hilbert-type square integral norm. It also discusses applications to the problem of computing the spin of a generic black hole in general relativity. (paper)

  16. A radiolabel release microassay for phagocytic killing of Candida albicans

    Bistoni, F.; Baccarini, M.; Blasi, E.; Marconi, P.; Puccetti, P.

    1982-01-01

    The chromium-51 release technique for quantifying intracellular killing of radiolabelled Candida albicans particles was exploited in a microassay in which murine and human phagocytes acted as effectors under peculiarly simple conditions. At appropriate effector: target ratios and with a 4 h incubation, up to 50% specific chromium release could be detected in the supernatant with no need for opsonization or lysis of phagocytes. This simple microassay permits easy-to-perform, simultaneous testing of a variety of different phagocytes even if only available in limited amounts, and provides an objective measurement of intracellular killing of Candida albicans. (Auth.)

  17. Keberanian Dalam Novel to Kill a Mockingbird Karya Harper Lee

    Tiolemba, Melissa

    2013-01-01

    The skripsi is entitled “Keberanian dalam Novel To Kill a Mockingbird by Harper Lee”. The objective of this research is to analyze the bravery as the main theme in the novel To Kill a Mockingbird. The data are collected by focusing on the character, plot and setting which describe about the main theme in the story. This research uses the theory of Stanton (1965) in analyzing the data. The writer uses descriptive method intrinsically. Intrinsic approach is to examine the elements within the no...

  18. Estimation in Discretely Observed Diffusions Killed at a Threshold

    Bibbona, Enrico; Ditlevsen, Susanne

    2013-01-01

    are modelled as discretely observed diffusions which are killed when the threshold is reached. Statistical inference is often based on a misspecified likelihood ignoring the presence of the threshold causing severe bias, e.g. the bias incurred in the drift parameters of the Ornstein–Uhlenbeck model...... for biological relevant parameters can be up to 25–100 per cent. We compute or approximate the likelihood function of the killed process. When estimating from a single trajectory, considerable bias may still be present, and the distribution of the estimates can be heavily skewed and with a huge variance...

  19. Impact of two hot and dry summers on the community structure and functional diversity of testate amoebae in an artificial bog, illustrating their use as bioindicators of peatland health

    I. Koenig

    2018-04-01

    Full Text Available Ongoing climate warming threatens the survival of bogs at the warm/dry limit of their distribution (e.g. in central Europe, and jeopardises the restoration of damaged bogs even more. Because vegetation changes can be slow, early indicators of hydrological change such as testate amoebae are useful. We used testate amoeba community structure and community weighted mean of functional traits to monitor the impact of two very hot and dry summers on a small (around 100 m2 artificial peatland constructed in the botanic garden of Neuchâtel, Switzerland. We collected analogous samples in a naturally regenerating cutover peatland at 1000 m a.s.l. in the Jura Mountains as a reference. The comparison of living and dead assemblages in the botanic garden showed an increased representation of smaller testate amoeba taxa (Corythion dubium, small Euglypha sp. with a small pseudostome (indicative of dry conditions and a loss of mixotrophy in 2015, followed by a weaker further shift in 2016. Nevertheless, the testate amoeba community structure in 2016 still indicated a dry Sphagnum bog. Testate amoeba analysis allows rapid assessment of peatland health and/or restoration success. The comparison of living and dead assemblages makes it possible to observe changes within a season in a single sampling campaign.

  20. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season. Copyright © 2011 Elsevier GmbH. All rights reserved.

  1. Detection of viable Helicobacter pylori inside free-living amoebae in wastewater and drinking water samples from Eastern Spain.

    Moreno-Mesonero, Laura; Moreno, Yolanda; Alonso, José Luis; Ferrús, M Antonia

    2017-10-01

    Helicobacter pylori is one of the most concerning emerging waterborne pathogens. It has been suggested that it could survive in water inside free-living amoebae (FLA), but nobody has studied this relationship in the environment yet. Thus, we aimed to detect viable H. pylori cells from inside FLA in water samples. Sixty-nine wastewater and 31 drinking water samples were collected. FLA were purified and identified by PCR and sequencing. For exclusively detecting H. pylori inside FLA, samples were exposed to sodium hypochlorite and assayed by specific PMA-qPCR, DVC-FISH and culture. FLA were detected in 38.7% of drinking water and 79.7% of wastewater samples, even after disinfection. In wastewater, Acanthamoeba spp. and members of the family Vahlkampfiidae were identified. In drinking water, Acanthamoeba spp. and Echinamoeba and/or Vermamoeba were present. In 39 (58.2%) FLA-positive samples, H. pylori was detected by PMA-qPCR. After DVC-FISH, 21 (31.3%) samples harboured viable H. pylori internalized cells. H. pylori was cultured from 10 wastewater samples. To our knowledge, this is the first report that demonstrates that H. pylori can survive inside FLA in drinking water and wastewater, strongly supporting the hypothesis that FLA could play an important role in the transmission of H. pylori to humans. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. The TOM Complex of Amoebozoans: the Cases of the Amoeba Acanthamoeba castellanii and the Slime Mold Dictyostelium discoideum.

    Wojtkowska, Małgorzata; Buczek, Dorota; Stobienia, Olgierd; Karachitos, Andonis; Antoniewicz, Monika; Slocinska, Małgorzata; Makałowski, Wojciech; Kmita, Hanna

    2015-07-01

    Protein import into mitochondria requires a wide variety of proteins, forming complexes in both mitochondrial membranes. The TOM complex (translocase of the outer membrane) is responsible for decoding of targeting signals, translocation of imported proteins across or into the outer membrane, and their subsequent sorting. Thus the TOM complex is regarded as the main gate into mitochondria for imported proteins. Available data indicate that mitochondria of representative organisms from across the major phylogenetic lineages of eukaryotes differ in subunit organization of the TOM complex. The subunit organization of the TOM complex in the Amoebozoa is still elusive, so we decided to investigate its organization in the soil amoeba Acanthamoeba castellanii and the slime mold Dictyostelium discoideum. They represent two major subclades of the Amoebozoa: the Lobosa and Conosa, respectively. Our results confirm the presence of Tom70, Tom40 and Tom7 in the A. castellanii and D. discoideum TOM complex, while the presence of Tom22 and Tom20 is less supported. Interestingly, the Tom proteins display the highest similarity to Opisthokonta cognate proteins, with the exception of Tom40. Thus representatives of two major subclades of the Amoebozoa appear to be similar in organization of the TOM complex, despite differences in their lifestyle. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

  3. Response of forest soil euglyphid testate amoebae (Rhizaria: Cercozoa) to pig cadavers assessed by high-throughput sequencing.

    Seppey, Christophe V W; Fournier, Bertrand; Szelecz, Ildikò; Singer, David; Mitchell, Edward A D; Lara, Enrique

    2016-03-01

    Decomposing cadavers modify the soil environment, but the effect on soil organisms and especially on soil protists is still poorly documented. We conducted a 35-month experiment in a deciduous forest where soil samples were taken under pig cadavers, control plots and fake pigs (bags of similar volume as the pigs). We extracted total soil DNA, amplified the SSU ribosomal RNA (rRNA) gene V9 region and sequenced it by Illumina technology and analysed the data for euglyphid testate amoebae (Rhizaria: Euglyphida), a common group of protozoa known to respond to micro-environmental changes. We found 51 euglyphid operational taxonomic units (OTUs), 45 of which did not match any known sequence. Most OTUs decreased in abundance underneath cadavers between days 0 and 309, but some responded positively after a time lag. We sequenced the full-length SSU rRNA gene of two common OTUs that responded positively to cadavers; a phylogenetic analysis showed that they did not belong to any known euglyphid family. This study confirmed the existence of an unknown diversity of euglyphids and that they react to cadavers. Results suggest that metabarcoding of soil euglyphids could be used as a forensic tool to estimate the post-mortem interval (PMI) particularly for long-term (>2 months) PMI, for which no reliable tool exists.

  4. Systematic Analysis of γ-Aminobutyric Acid (GABA) Metabolism and Function in the Social Amoeba Dictyostelium discoideum*

    Wu, Yuantai; Janetopoulos, Chris

    2013-01-01

    While GABA has been suggested to regulate spore encapsulation in the social amoeba Dictyostelium discoideum, the metabolic profile and other potential functions of GABA during development remain unclear. In this study, we investigated the homeostasis of GABA metabolism by disrupting genes related to GABA metabolism and signaling. Extracellular levels of GABA are tightly regulated during early development, and GABA is generated by the glutamate decarboxylase, GadB, during growth and in early development. However, overexpression of the prespore-specific homologue, GadA, in the presence of GadB reduces production of extracellular GABA. Perturbation of extracellular GABA levels delays the process of aggregation. Cytosolic GABA is degraded by the GABA transaminase, GabT, in the mitochondria. Disruption of a putative vesicular GABA transporter (vGAT) homologue DdvGAT reduces secreted GABA. We identified the GABAB receptor-like family member GrlB as the major GABA receptor during early development, and either disruption or overexpression of GrlB delays aggregation. This delay is likely the result of an abolished pre-starvation response and late expression of several “early” developmental genes. Distinct genes are employed for GABA generation during sporulation. During sporulation, GadA alone is required for generating GABA and DdvGAT is likely responsible for GABA secretion. GrlE but not GrlB is the GABA receptor during late development. PMID:23548898

  5. Environmental factors shaping cultured free-living amoebae and their associated bacterial community within drinking water network.

    Delafont, Vincent; Bouchon, Didier; Héchard, Yann; Moulin, Laurent

    2016-09-01

    Free-living amoebae (FLA) constitute an important part of eukaryotic populations colonising drinking water networks. However, little is known about the factors influencing their ecology in such environments. Because of their status as reservoir of potentially pathogenic bacteria, understanding environmental factors impacting FLA populations and their associated bacterial community is crucial. Through sampling of a large drinking water network, the diversity of cultivable FLA and their bacterial community were investigated by an amplicon sequencing approach, and their correlation with physicochemical parameters was studied. While FLA ubiquitously colonised the water network all year long, significant changes in population composition were observed. These changes were partially explained by several environmental parameters, namely water origin, temperature, pH and chlorine concentration. The characterisation of FLA associated bacterial community reflected a diverse but rather stable consortium composed of nearly 1400 OTUs. The definition of a core community highlighted the predominance of only few genera, majorly dominated by Pseudomonas and Stenotrophomonas. Co-occurrence analysis also showed significant patterns of FLA-bacteria association, and allowed uncovering potentially new FLA - bacteria interactions. From our knowledge, this study is the first that combines a large sampling scheme with high-throughput identification of FLA together with associated bacteria, along with their influencing environmental parameters. Our results demonstrate the importance of physicochemical parameters in the ecology of FLA and their bacterial community in water networks. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Cars kill chimpanzees: case report of a wild chimpanzee killed on a road at Bulindi, Uganda.

    McLennan, Matthew R; Asiimwe, Caroline

    2016-07-01

    Roads have broadly adverse impacts on wildlife, including nonhuman primates. One direct effect is mortality from collisions with vehicles. While highly undesirable, roadkills provide valuable information on the health and condition of endangered species. We present a case report of a wild chimpanzee (Pan troglodytes schweinfurthii) killed crossing a road in Bulindi, Uganda, where chimpanzees inhabit forest fragments amid farmland. Details of the collision are constructed from eyewitness accounts of pedestrians. Physical examination of the cadaver indicated good overall body condition; at 40 kg, the deceased female was heavier than usual for an adult female East African chimpanzee. No external wounds or fractures were noted. Coprological assessment demonstrated infection by several gastrointestinal parasites commonly reported in living wild chimpanzees. Histopathology revealed eosinophilic enteritis and biliary hyperplasia potentially caused by parasite infection. However, eosinophilia was not widely spread into the submucosa, while egg/cyst counts suggested low-intensity parasite infections compared to healthy female chimpanzees of similar age in nearby Budongo Forest. No behavioral indicators of ill health were noted in the deceased female in the month prior to the accident. We conclude that cause of death was acute, i.e., shock from the collision, and was probably unrelated to parasite infection or any other underlying health condition. Notably, this female had asymmetrical polythelia, and, while nursing at the time of her death, had one functioning mammary gland only. In Uganda, where primates often inhabit human-dominated landscapes, human population growth and economic development has given rise to increasing motor traffic, while road development is enabling motorists to travel at greater speeds. Thus, the danger of roads to apes and other wildlife is rising, necessitating urgent strategies to reduce risks. Installation of simple speed-bumps-common on Ugandan

  7. IIB solutions with N>28 Killing spinors are maximally supersymmetric

    Gran, U.; Gutowski, J.; Papadopoulos, G.; Roest, D.

    2007-01-01

    We show that all IIB supergravity backgrounds which admit more than 28 Killing spinors are maximally supersymmetric. In particular, we find that for all N>28 backgrounds the supercovariant curvature vanishes, and that the quotients of maximally supersymmetric backgrounds either preserve all 32 or N<29 supersymmetries

  8. Denaturation of membrane proteins and hyperthermic cell killing

    Burgman, Paulus Wilhelmus Johannes Jozef

    1993-01-01

    Summarizing: heat induced denaturation of membrane proteins is probably related to hyperthermic cell killing. Induced resistance of heat sensitive proteins seems to be involved in the development of thermotolerance. Although many questions remain still to be answered, it appears that HSP72, when

  9. Self-dual metrics with self-dual Killing vectors

    Tod, K.P.; Ward, R.S.

    1979-01-01

    Twistor methods are used to derive a class of solutions to Einstein's vacuum equations, with anti-self dual Weyl tensor. In particular, all metrics with a Killing vector whose derivative is anti-self-dual and which admit a real positive-definite section are exhibited and shown to coincide with the metrics of Hawking. (author)

  10. Prevent Tipping Furniture from Injuring or Killing Young Children

    ... more upsetting than the sudden death of a child — killed by a piece of a furniture, appliance or a television falling on them. “It can happen in a ... be secured. Check with home improvement stores or child retail stores and ask experts what they ... television and computer equipment low to the ground. Do ...

  11. Kill Shakespeare – This Bard contains graphic language!

    Mauro Gentile

    2017-11-01

    Full Text Available Today, adapting Shakespearean plays into comic books or graphic novels appears to be a well-established literary practice in contemporary storytelling. One of the most interesting examples is ÒKill ShakespeareÓ, a graphic novel written by Anthony Del Col and Conor McCreery and illustrated by Andy Belanger. In ÒKill ShakespeareÓ, the authors abandon the idea of adapting a single play to create a Shakespearian mashup in which Hamlet and Juliet fight such villains as Richard III and Lady Macbeth who try to kill a wizard named William Shakespeare.This is the premise for a compelling narration that intertwines various elements of the Shakespearean tradition and attempts to convey an idea of Elizabethan language to contemporary readers. While the characters are familiar, the quest is wholly new and triggers a series of transformations in the narrative, turning upside down the well-established images of Hamlet, Juliet and Othello. Beside the intriguing depictions of the female characters, especially Lady Macbeth,whose image poses questions about the representation of women in comic books, one of the most fertile narrative elements in Kill Shakespeare is the actual presence of William Shakespeare as a character. In conclusion, Del Col and McCreery prove they know their Shakespeare, surprising readers with a fresh approach which, hopefully, will enlarge the Shakespearean audience.

  12. Efficacy of Killed Adjuvanted FMD Vaccine Developed with ...

    In this study the potency of killed Foot and Mouth Disease (FMD) vaccines serotypes SAT1 (Nig 1/98) and SAT 2 (Nig 2/97) virus isolates, formulated with montanide ISA 206 adjuvant was determined in guinea pigs and cattle by antibody assay using Complement Fixation and Serum Neutralization tests. The antibody titres ...

  13. Dynamics of Human Complement–Mediated Killing of Klebsiella pneumoniae

    Nypaver, Christina M.; Thornton, Margaret M.; Yin, Suellen M.; Bracho, David O.; Nelson, Patrick W.; Jones, Alan E.; Bortz, David M.; Younger, John G.

    2010-01-01

    With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B–depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation. PMID:20008281

  14. Dynamics of human complement-mediated killing of Klebsiella pneumoniae.

    Nypaver, Christina M; Thornton, Margaret M; Yin, Suellen M; Bracho, David O; Nelson, Patrick W; Jones, Alan E; Bortz, David M; Younger, John G

    2010-11-01

    With an in vitro system that used a luminescent strain of Klebsiella pneumoniae to assess bacterial metabolic activity in near-real-time, we investigated the dynamics of complement-mediated attack in healthy individuals and in patients presenting to the emergency department with community-acquired severe sepsis. A novel mathematical/statistical model was developed to simplify light output trajectories over time into two fitted parameters, the rate of complement activation and the delay from activation to the onset of killing. Using Factor B-depleted serum, the alternative pathway was found to be the primary bactericidal effector: In the absence of B, C3 opsonization as measured by flow cytometry did not progress and bacteria proliferated near exponentially. Defects in bacterial killing were easily demonstrable in patients with severe sepsis compared with healthy volunteers. In most patients with sepsis, the rate of activation was higher than in normal subjects but was associated with a prolonged delay between activation and bacterial killing (P < 0.05 for both). Theoretical modeling suggested that this combination of accentuated but delayed function should allow successful bacterial killing but with significantly greater complement activation. The use of luminescent bacteria allowed for the development of a novel and powerful tool for assessing complement immunology for the purposes of mechanistic study and patient evaluation.

  15. What Is John Dewey Doing in "To Kill a Mockingbird"?

    Frank, Jeff

    2015-01-01

    Harper Lee's novel "To Kill a Mockingbird" is taught in countless public schools and is beloved by many teachers and future teachers. Embedded within this novel--interestingly--is a strong criticism of an approach to education mockingly referred to as the "Dewey Decimal System." In this essay I explore Lee's criticism of…

  16. Developing a Critical Literacy Approach with "To Kill a Mockingbird."

    Spires, Marian

    2000-01-01

    Ponders why the novel "To Kill a Mockingbird" has held a place in the secondary school canon for 40 years. Describes a 10-week unit for year 10 English students that takes a critical literacy approach to the novel. Outlines a set of pre-reading activities, during reading activities and post-reading activities. (SR)

  17. Suppression of mouse-killing in rats following irradiation

    O'Boyle, M.

    1976-01-01

    Suppression of mouse-killing was produced following pairings of mouse-presentations (CS) with 96 roentgens of ionizing radiation (US) at 0 (less than 2 min.) and 30 min. US-CS interstimulus intervals. No suppression was found at CS-US intervals of 30 min., 1 hr., and 2 hr., or at US-CS intervals of 1 hr. and 2 hr

  18. Fish Kill in the Philippines—Déjà Vu

    Gil Jacinto

    2011-12-01

    Full Text Available Almost ten years ago today, the country woke up toscreaming headlines— “Massive Fish Kill inPangasinan” or something akin to that. The fish killphenomenon, familiar to fishers in freshwater andcoastal bodies of water where fish farming was beingpursued, was suddenly manifested at a scale that hadheretofore not been experienced.

  19. The algebra of Killing vectors in five-dimensional space

    Rcheulishvili, G.L.

    1990-01-01

    This paper presents algebras which are formed by the found earlier Killing vectors in the space with linear element ds. Under some conditions, an explicit dependence of r is given for the functions entering in linear element ds. The curvature two-forms are described. 7 refs

  20. Killing for Girls: Predation Play and Female Empowerment

    Bertozzi, Elena

    2012-01-01

    Predation games--games in which the player is actively encouraged and often required to hunt and kill in order to survive--have historically been the purview of male players. Females, though now much more involved in digital games than before, generally play games that stress traditionally feminine values such as socializing with others, shopping,…

  1. Targeted killing with drones? Old arguments, new technologies

    Meisels Tamar

    2018-01-01

    Full Text Available The question of how to contend with terrorism in keeping with our preexisting moral and legal commitments now challenges Europe as well as Israel and the United States: how do we apply Just War Theory and International Law to asymmetrical warfare, specifically to our counter terrorism measures? What can the classic moral argument in Just and Unjust Wars teach us about contemporary targeted killings with drones? I begin with a defense of targeted killing, arguing for the advantages of pin pointed attacks over any alternative measure available for combatting terrorism. Assuming the legitimacy of killing combatants in wartime, I argue, there is nothing wrong, and in fact much that is right, with targeting particular terrorists selected by name, as long as their assassinations can be reasonably expected to reduce terrorist hostilities rather than increase it. Subsequently, I offer some further thoughts and comments on the use of remotely piloted aircrafts to carry out targeted killings, and address the various sources for discomfort with this practice identified by Michael Walzer and others.

  2. Partner Killing by Men in Cohabiting and Marital Relationships

    Shackelford, Todd K.; Mouzos, Jenny

    2005-01-01

    Using a national-level U.S. database, T. K. Shackelford (2001) calculated rates of uxoricide (the murder of a woman by her romantic partner) by relationship type (cohabiting or marital), by ages of the partners, and by the age difference between partners. Women in cohabiting relationships were 9 times more likely to be killed by their partner than…

  3. Nordic Noir on Television: The Killing I-III

    Agger, Gunhild

    2012-01-01

    The Nordic Noir has been applied by many countries as a slightly distorting mirror of tendencies in their own societies. On the background of its international appeal, the article analyses the prevalent genre of The Killing – the thriller – and relates it to the genres of crime fiction, political...

  4. Pseudomonas Exotoxin A: optimized by evolution for effective killing

    Marta eMichalska

    2015-09-01

    Full Text Available Pseudomonas Exotoxin A (PE is the most toxic virulence factor of the pathogenic bacterium Pseudomonas aeruginosa. This review describes current knowledge about the intoxication pathways of PE. Moreover, PE represents a remarkable example for pathoadaptive evolution, how bacterial molecules have been structurally and functionally optimized under evolutionary pressure to effectively impair and kill their host cells.

  5. Benzothiazinones kill Mycobacterium tuberculosis by blocking arabinan synthesis

    Makarov, Vadim; Manina, Giulia; Mikusova, Katarina

    2009-01-01

    New drugs are required to counter the tuberculosis (TB) pandemic. Here, we describe the synthesis and characterization of 1,3-benzothiazin-4-ones (BTZs), a new class of antimycobacterial agents that kill Mycobacterium tuberculosis in vitro, ex vivo, and in mouse models of TB. Using genetics...

  6. Illegal killing for ivory drives global decline in African elephants.

    Wittemyer, George; Northrup, Joseph M; Blanc, Julian; Douglas-Hamilton, Iain; Omondi, Patrick; Burnham, Kenneth P

    2014-09-09

    Illegal wildlife trade has reached alarming levels globally, extirpating populations of commercially valuable species. As a driver of biodiversity loss, quantifying illegal harvest is essential for conservation and sociopolitical affairs but notoriously difficult. Here we combine field-based carcass monitoring with fine-scale demographic data from an intensively studied wild African elephant population in Samburu, Kenya, to partition mortality into natural and illegal causes. We then expand our analytical framework to model illegal killing rates and population trends of elephants at regional and continental scales using carcass data collected by a Convention on International Trade in Endangered Species program. At the intensively monitored site, illegal killing increased markedly after 2008 and was correlated strongly with the local black market ivory price and increased seizures of ivory destined for China. More broadly, results from application to continental data indicated illegal killing levels were unsustainable for the species between 2010 and 2012, peaking to ∼ 8% in 2011 which extrapolates to ∼ 40,000 elephants illegally killed and a probable species reduction of ∼ 3% that year. Preliminary data from 2013 indicate overharvesting continued. In contrast to the rest of Africa, our analysis corroborates that Central African forest elephants experienced decline throughout the last decade. These results provide the most comprehensive assessment of illegal ivory harvest to date and confirm that current ivory consumption is not sustainable. Further, our approach provides a powerful basis to determine cryptic mortality and gain understanding of the demography of at-risk species.

  7. In vitro time kill assessment of crude methanol extract of ...

    The in vitro antibacterial activities and time kill regimes of crude methanol extract of Helichrysum pedunculatum was assessed using standard microbiological procedures. The experiment was conducted against a panel of bacterial species made up of clinical, environmental and reference strains. The extract was active ...

  8. [Killing effect of polymorphonuclear neutrophils on Trichomonas vaginalis].

    Zhao, Jian-Ling; Gao, Xing-Zheng; Qu, Ming

    2008-10-30

    To study the killing effect of polymorphonuclear neutrophils (PMNs) on Trichomonas vaginalis. The vaginal secretion from a patient with vaginitis was incubated in the liver infusion liquid medium to get T. vaginalis. One ml serum was collected from the patient and heated for 30 min at 56 degrees C to inactivate complement in serum, and was absorbed three times with the parasites at 0 degree C to make the serum free of antibodies. PMNs were separated from the patient's blood and purified with density gradient centrifugation and polymer accelerating sedimentation. NBT and safranin O were used to stain the sample. The interaction between PMNs and the parasites was observed under microscope. 300 trichomonads and 3x10(4) PMNs were incubated for 10, 20, 30, 40, 50, 60 minutes under the conditions of aerobic or anaerobic, with superoxide dismutase (SOD) and catalase (CAT) or without SOD and CAT, and with complement or without complement. They were then inoculated in solid medium for another five days under the anaerobic condition, and surviving organisms were enumerated. PMNs were observed to surround and kill a single trichomonad. In the petri-dish containing PMNs, the surviving rate of the parasites in anaerobic condition was 85%, only 3% in aerobic condition (P<0.01). SOD and CAT reduced the killing effect of PMNs, with a surviving rate of 98% and 94% respectively after 60 min incubation. Without SOD and CAT, the surviving rate is only 2% (P<0.05). PMNs in the serum without antibodies killed all the parasites, while the complement-inactivated serum fail to kill them. The trichomonacidal activity of PMNs relies on the presence of oxygen and complement in the serum of patient.

  9. Broadening the future of value account of the wrongness of killing

    Di Nucci, Ezio

    2015-01-01

    On Don Marquis's future of value account of the wrongness of killing, 'what makes it wrong to kill those individuals we all believe it is wrong to kill, is that killing them deprives them of their future of value'. Marquis has recently argued for a narrow interpretation of his future of value...... account of the wrongness of killing and against the broad interpretation that I had put forward in response to Carson Strong. In this article I argue that the narrow view is problematic because it violates some basic principles of equality and because it allows for some of the very killing that Marquis...

  10. Ubiquiter circovirus sequences raise challenges in laboratory diagnosis: the case of honey bee and bee mite, reptiles, and free living amoebae.

    Marton, Szilvia; Ihász, Katalin; Lengyel, György; Farkas, Szilvia L; Dán, Ádám; Paulus, Petra; Bányai, Krisztián; Fehér, Enikő

    2015-03-01

    Circoviruses of pigs and birds are established pathogens, however, the exact role of other, recently described circoviruses and circovirus-like viruses remains to be elucidated. The aim of this study was the detection of circoviruses in neglected host species, including honey bees, exotic reptiles and free-living amoebae by widely used broad-spectrum polymerase chain reaction (PCR) assays specific for the replication initiation protein coding gene of these viruses. The majority of sequences obtained from honey bees were highly similar to canine and porcine circoviruses, or, were distantly related to dragonfly cycloviruses. Other rep sequences detected in some honey bees, reptiles and amoebae showed similarities to various rep sequences deposited in the GenBank. Back-to-back PCR primers designed for the amplification of whole viral genomes failed to work that suggested the existence of integrated rep-like elements in many samples. Rolling circle amplification and exonuclease treatment confirmed the absence of small circular DNA genomes in the specimens analysed. In case of honey bees Varroa mite DNA contamination might be a source of the identified endogenous rep-like elements. The reptile and amoebae rep-like sequences were nearly identical with each other and with sequences detected in chimpanzee feces raising the possibility that detection of novel or unusual rep-like elements in some host species might originate from the microbial community of the host. Our results indicate that attention is needed when broad-spectrum rep gene specific polymerase chain reaction is chosen for laboratory diagnosis of circovirus infections.

  11. Male-killing bacteria as agents of insect pest control

    Berec, Ludek; Maxin, Daniel; Bernhauerová, Veronika

    2016-01-01

    1. Continual effort is needed to reduce the impact of exotic species in the context of increased globalization. Any innovation in this respect would be an asset. 2. We assess the potential of combining two pest control techniques: the well-established sterile insect technique (SIT) and a novel male-killing technique (MKT), which comprises inoculation of a pest population with bacteria that kill the infected male embryos. 3. Population models are developed to assess the efficiency of using the MKT for insect pest control, either alone or together with the SIT. We seek for conditions under which the MKT weakens requirements on the SIT. 4. Regarding the SIT, we consider both non-heritable and inherited sterility. In both cases, the MKT and SIT benefit one another. The MKT may prevent the SIT from failing when not enough sterilized males are released due to high production costs and/or uncertainty on their mating ability following a high irradiation dose. Conversely, with already established SIT, pest eradication can be achieved after introduction of male-killing bacteria with lower vertical transmission efficiency than if the MKT was applied alone. 5. For tephritid fruit flies with non-heritable sterility, maximal impact of the SIT is achieved when the released males are fully sterile. Conversely, for lepidopterans with inherited sterility, maximal impact of the SIT is achieved for intermediate irradiation doses. In both cases, increasing vertical transmission efficiency of male-killing bacteria benefits the SIT; high enough vertical transmission efficiency allows for pest eradication where the SIT is absent or induces only pest suppression when used alone. 6. Synthesis and applications. While both techniques can suppress or eliminate the pest on their own, combined application of the male-killing technique and the sterile insect technique substantially increases pest control efficiency. If male-killing bacteria are already established in the pest, any assessment of

  12. Acetate and succinate production in amoebae, helminths, diplomonads, trichomonads and trypanosomatids: common and diverse metabolic strategies used by parasitic lower eukaryotes.

    Bringaud, F; Ebikeme, C; Boshart, M

    2010-08-01

    Parasites that often grow anaerobically in their hosts have adopted a fermentative strategy relying on the production of partially oxidized end products, including lactate, glycerol, ethanol, succinate and acetate. This review focuses on recent progress in understanding acetate production in protist parasites, such as amoebae, diplomonads, trichomonads, trypanosomatids and in the metazoan parasites helminths, as well as the succinate production pathway(s) present in some of them. We also describe the unconventional organisation of the tricarboxylic acid cycle associated with the fermentative strategy adopted by the procyclic trypanosomes, which may resemble the probable structure of the primordial TCA cycle in prokaryotes.

  13. Whole genome sequencing of mutation accumulation lines reveals a low mutation rate in the social amoeba Dictyostelium discoideum.

    Gerda Saxer

    Full Text Available Spontaneous mutations play a central role in evolution. Despite their importance, mutation rates are some of the most elusive parameters to measure in evolutionary biology. The combination of mutation accumulation (MA experiments and whole-genome sequencing now makes it possible to estimate mutation rates by directly observing new mutations at the molecular level across the whole genome. We performed an MA experiment with the social amoeba Dictyostelium discoideum and sequenced the genomes of three randomly chosen lines using high-throughput sequencing to estimate the spontaneous mutation rate in this model organism. The mitochondrial mutation rate of 6.76×10(-9, with a Poisson confidence interval of 4.1×10(-9 - 9.5×10(-9, per nucleotide per generation is slightly lower than estimates for other taxa. The mutation rate estimate for the nuclear DNA of 2.9×10(-11, with a Poisson confidence interval ranging from 7.4×10(-13 to 1.6×10(-10, is the lowest reported for any eukaryote. These results are consistent with low microsatellite mutation rates previously observed in D. discoideum and low levels of genetic variation observed in wild D. discoideum populations. In addition, D. discoideum has been shown to be quite resistant to DNA damage, which suggests an efficient DNA-repair mechanism that could be an adaptation to life in soil and frequent exposure to intracellular and extracellular mutagenic compounds. The social aspect of the life cycle of D. discoideum and a large portion of the genome under relaxed selection during vegetative growth could also select for a low mutation rate. This hypothesis is supported by a significantly lower mutation rate per cell division in multicellular eukaryotes compared with unicellular eukaryotes.

  14. Amoeba-inspired Tug-of-War algorithms for exploration-exploitation dilemma in extended Bandit Problem.

    Aono, Masashi; Kim, Song-Ju; Hara, Masahiko; Munakata, Toshinori

    2014-03-01

    The true slime mold Physarum polycephalum, a single-celled amoeboid organism, is capable of efficiently allocating a constant amount of intracellular resource to its pseudopod-like branches that best fit the environment where dynamic light stimuli are applied. Inspired by the resource allocation process, the authors formulated a concurrent search algorithm, called the Tug-of-War (TOW) model, for maximizing the profit in the multi-armed Bandit Problem (BP). A player (gambler) of the BP should decide as quickly and accurately as possible which slot machine to invest in out of the N machines and faces an "exploration-exploitation dilemma." The dilemma is a trade-off between the speed and accuracy of the decision making that are conflicted objectives. The TOW model maintains a constant intracellular resource volume while collecting environmental information by concurrently expanding and shrinking its branches. The conservation law entails a nonlocal correlation among the branches, i.e., volume increment in one branch is immediately compensated by volume decrement(s) in the other branch(es). Owing to this nonlocal correlation, the TOW model can efficiently manage the dilemma. In this study, we extend the TOW model to apply it to a stretched variant of BP, the Extended Bandit Problem (EBP), which is a problem of selecting the best M-tuple of the N machines. We demonstrate that the extended TOW model exhibits better performances for 2-tuple-3-machine and 2-tuple-4-machine instances of EBP compared with the extended versions of well-known algorithms for BP, the ϵ-Greedy and SoftMax algorithms, particularly in terms of its short-term decision-making capability that is essential for the survival of the amoeba in a hostile environment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Scientific projection paper for mutagenesis, transformation and cell killing

    Todd, P.

    1980-01-01

    Our knowledge about mutagenesis, transformation, and cell killing by ionizing radiation consists of large bodies of data, which are potentially useful in terms of application to human risk assessment and to the constructive use of radiation, as in cancer treatment. The three end-points discussed above are united by at least five significant concepts in radiation research strategy: (1) The inter-relationships among the important end-points, mutation, carcinogenesis, and cell killing. Research on one is meaningful only in the context of information about the other two. (2) The interaction of radiations with other agents in producing these end-points. (3) The mechanisms of action of other environmental mutagenic, carcinogenic, and cytotoxic agents. (4) The use of repair deficient human mutant cells. (5) The study of radiation damage mechanisms. There is no better way to extrapolate laboratory data to the clinical and public worlds than to understand the underlying biological mechanisms that produced the data

  16. "Reversed" intraguild predation: red fox cubs killed by pine marten.

    Brzeziński, Marcin; Rodak, Lukasz; Zalewski, Andrzej

    2014-01-01

    Camera traps deployed at a badger Meles meles set in mixed pine forest in north-eastern Poland recorded interspecific killing of red fox Vulpes vulpes cubs by pine marten Martes martes . The vixen and her cubs settled in the set at the beginning of May 2013, and it was abandoned by the badgers shortly afterwards. Five fox cubs were recorded playing in front of the den each night. Ten days after the first recording of the foxes, a pine marten was filmed at the set; it arrived in the morning, made a reconnaissance and returned at night when the vixen was away from the set. The pine marten entered the den several times and killed at least two fox cubs. It was active at the set for about 2 h. This observation proves that red foxes are not completely safe from predation by smaller carnivores, even those considered to be subordinate species in interspecific competition.

  17. Kill ratio calculation for in-line yield prediction

    Lorenzo, Alfonso; Oter, David; Cruceta, Sergio; Valtuena, Juan F.; Gonzalez, Gerardo; Mata, Carlos

    1999-04-01

    The search for better yields in IC manufacturing calls for a smarter use of the vast amount of data that can be generated by a world class production line.In this scenario, in-line inspection processes produce thousands of wafer maps, number of defects, defect type and pictures every day. A step forward is to correlate these with the other big data- generator area: test. In this paper, we present how these data can be put together and correlated to obtain a very useful yield predicting tool. This correlation will first allow us to calculate the kill ratio, i.e. the probability for a defect of a certain size in a certain layer to kill the die. Then we will use that number to estimate the cosmetic yield that a wafer will have.

  18. Great tits search for, capture, kill and eat hibernating bats

    Estók, Péter; Zsebők, Sándor; Siemers, Björn M.

    2010-01-01

    Ecological pressure paired with opportunism can lead to surprising innovations in animal behaviour. Here, we report predation of great tits (Parus major) on hibernating pipistrelle bats (Pipistrellus pipistrellus) at a Hungarian cave. Over two winters, we directly observed 18 predation events. The tits specifically and systematically searched for and killed bats for food. A substantial decrease in predation on bats after experimental provisioning of food to the tits further supports the hypothesis that bat-killing serves a foraging purpose in times of food scarcity. We finally conducted a playback experiment to test whether tits would eavesdrop on calls of awakening bats to find them in rock crevices. The tits could clearly hear the calls and were attracted to the loudspeaker. Records for tit predation on bats at this cave now span more than ten years and thus raise the question of whether cultural transmission plays a role for the spread of this foraging innovation. PMID:19740892

  19. A Research for Massive Fish Kills in Lake Bafa (Turkey

    Murat Yabanlı

    2011-06-01

    Full Text Available As there were massive fish kills in Lake Bafa which is a lagoon situated in Southwestern Turkey in October, 2006, water and fish samples were taken from the region. Water samples were analysed physicochemically, toxicologically and microbiologically and fish samples were subjected to toxicological analysis. The analyses of lake water revealed on oxygen value of approximately 5.0 mg/L, salinity 16.2 ‰, nitrogen from ammonia 0.1 mg/L, nitrogen nitrite 0.013 mg/L, and total organic carbon 13 mg/L. Total coliform count was 1100 MPN/100 ml and faecal coliform count was 28 MPN/100 ml. There was no detection of any pesticide residues in fish and water samples. Massive fish kills are thought to be due to the decrease in water quality.

  20. The killing of African trypanosomes by ethidium bromide.

    Arnab Roy Chowdhury

    2010-12-01

    Full Text Available Introduced in the 1950s, ethidium bromide (EB is still used as an anti-trypanosomal drug for African cattle although its mechanism of killing has been unclear and controversial. EB has long been known to cause loss of the mitochondrial genome, named kinetoplast DNA (kDNA, a giant network of interlocked minicircles and maxicircles. However, the existence of viable parasites lacking kDNA (dyskinetoplastic led many to think that kDNA loss could not be the mechanism of killing. When recent studies indicated that kDNA is indeed essential in bloodstream trypanosomes and that dyskinetoplastic cells survive only if they have a compensating mutation in the nuclear genome, we investigated the effect of EB on kDNA and its replication. We here report some remarkable effects of EB. Using EM and other techniques, we found that binding of EB to network minicircles is low, probably because of their association with proteins that prevent helix unwinding. In contrast, covalently-closed minicircles that had been released from the network for replication bind EB extensively, causing them, after isolation, to become highly supertwisted and to develop regions of left-handed Z-DNA (without EB, these circles are fully relaxed. In vivo, EB causes helix distortion of free minicircles, preventing replication initiation and resulting in kDNA loss and cell death. Unexpectedly, EB also kills dyskinetoplastic trypanosomes, lacking kDNA, by inhibiting nuclear replication. Since the effect on kDNA occurs at a >10-fold lower EB concentration than that on nuclear DNA, we conclude that minicircle replication initiation is likely EB's most vulnerable target, but the effect on nuclear replication may also contribute to cell killing.

  1. Targeted Killing: Managing American Perceptions On Unmanned Aerial Vehicle Operations

    2016-02-01

    Requirements Proposal Advisor: Dr. Patricia Williams Lessane Project Advisor: Dr. Andrew Niesiobedzki Maxwell AFB, AL February 2016...epistemology of remote fighting." Ethics and Information Technology 15. no. 2. 87-98. Cullen , Peter. 2008. "The Role of Targeted Killing in the...in the Sky." New Statesman 19-25. June. 48. Patterson, Margot. 2015. "Are We Safer." America 212. no. 204. 12. Raven-Hansen, William C. Banks and

  2. Comments on conformal Killing vector fields and quantum field theory

    Brown, M.R.; Ottewill, A.C.; Siklos, S.T.C.

    1982-01-01

    We give a comprehensive analysis of those vacuums for flat and conformally flat space-times which can be defined by timelike, hypersurface-orthogonal, conformal Killing vector fields. We obtain formulas for the difference in stress-energy density between any two such states and display the correspondence with the renormalized stress tensors. A brief discussion is given of the relevance of these results to quantum-mechanical measurements made by noninertial observers moving through flat space

  3. Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

    Caccia, Silvia; Di Lelio, Ilaria; La Storia, Antonietta; Marinelli, Adriana; Varricchio, Paola; Franzetti, Eleonora; Banyuls, Núria; Tettamanti, Gianluca; Casartelli, Morena; Giordana, Barbara; Ferré, Juan; Gigliotti, Silvia; Ercolini, Danilo; Pennacchio, Francesco

    2016-01-01

    Bacillus thuringiensis and its toxins are widely used for insect control. Notwithstanding the remarkable importance of this insect pathogen, its killing mechanism has yet to be fully elucidated. Here we show that the microbiota resident in the host midgut triggers a lethal septicemia. The infection process is enhanced by reducing the host immune response and its control on replication of midgut bacteria invading the body cavity through toxin-induced epithelial lesions. The experimental approa...

  4. Does Host Complement Kill Borrelia burgdorferi within Ticks?

    Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M.

    2003-01-01

    The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within ...

  5. Shearfree congruences of null geodesics and Killing tensors

    Dietz, W.; Ruediger, R.

    1980-01-01

    In this communication, the mutual connections between quantities that are generalizations of the notion of a a Killing vector field are investigated. A classification of these quantities in terms of a complex vector field αsub(a) is given. A common feature of all these quantities is that they imply the existence of a pair of shearfree geodetic null congruences. There are no explicit restrictions posed on the Ricci tensor. (author)

  6. From Attitudes to Actions: Predictors of Lion Killing by Maasai Warriors.

    Hazzah, Leela; Bath, Alistair; Dolrenry, Stephanie; Dickman, Amy; Frank, Laurence

    2017-01-01

    Despite legal protection, deliberate killing by local people is one of the major threats to the conservation of lions and other large carnivores in Africa. Addressing this problem poses particular challenges, mainly because it is difficult to uncover illicit behavior. This article examined two groups of Maasai warriors: individuals who have killed African lions (Panthera leo) and those who have not. We conducted interviews to explore the relationship between attitudes, intentions and known lion killing behavior. Factor analysis and logistic regression revealed that lion killing was mainly determined by: (a) general attitudes toward lions, (b) engagement in traditional customs, (c) lion killing intentions to defend property, and (d) socio-cultural killing intentions. Our results indicated that general attitudes toward lions were the strongest predictor of lion killing behavior. Influencing attitudes to encourage pro-conservation behavior may help reduce killing.

  7. Leadership Matters : The Effects of Targeted Killings on Militant Group Tactics

    Abrahms, Max; Mierau, Jochen

    2017-01-01

    Targeted killings have become a central component of counter-terrorism strategy. In response to the unprecedented prevalence of this strategy around the world, numerous empirical studies have recently examined whether "decapitating" militant groups with targeted killings is strategically effective.

  8. Default risk modeling with position-dependent killing

    Katz, Yuri A.

    2013-04-01

    Diffusion in a linear potential in the presence of position-dependent killing is used to mimic a default process. Different assumptions regarding transport coefficients, initial conditions, and elasticity of the killing measure lead to diverse models of bankruptcy. One “stylized fact” is fundamental for our consideration: empirically default is a rather rare event, especially in the investment grade categories of credit ratings. Hence, the action of killing may be considered as a small parameter. In a number of special cases we derive closed-form expressions for the entire term structure of the cumulative probability of default, its hazard rate, and intensity. Comparison with historical data on aggregate global corporate defaults confirms the validity of the perturbation method for estimations of long-term probability of default for companies with high credit quality. On a single company level, we implement the derived formulas to estimate the one-year likelihood of default of Enron on a daily basis from August 2000 to August 2001, three months before its default, and compare the obtained results with forecasts of traditional structural models.

  9. Killing effect of carboranyl uridine on boron neutron capture reaction

    Takagaki, M.; Oda, Y.; Zhang, Z.

    1994-01-01

    This paper deals with the killing effect of carboranyl uridine (CU) on thermal neutron capture reaction in cultured glioma cell line (C6). The tumoricidal effect of CU for boron neutron capture therapy in the cultured cell system is presented. To assess the uptake of CU, the number of germ cells was determined by comparing protein concentrations of C6 cells in vitro with that of intracranially transplanted C6 tumor cells in vivo. To assess tumoricidal effects of CU, human glioma cells (T98G), containing 25 ppm natural boron of CU, were irradiated with various doses of thermal neutrons at a constant fluence rate. The uptake and killing effects of mercaptoboron and boric acid were also investigated as controls. Subcellular boron concentrations confirmed the selective affinity to the nucleic acid synthesis. CU was found to have an affinity to nucleic acid synthesis and to be accumulated into nucleus of tumor cells. The irradiation dose which yielded 37% survival rate in the case of CU and control were 3.78+12E nvt and 5.80+12E nvt, respectively. The killing effect of CU was slightly higher than that of B-SH or BA. The effective way of CU injection should be further studied to obtain the uniform CU uptake in tumor cells. (N.K.)

  10. Intestinal mucus protects Giardia lamblia from killing by human milk.

    Zenian, A J; Gillin, F D

    1987-02-01

    We have previously shown that nonimmune human milk kills Giardia lamblia trophozoites in vitro. Killing requires a bile salt and the activity of the milk bile salt-stimulated lipase. We now show that human small-intestinal mucus protects trophozoites from killing by milk. Parasite survival increased with mucus concentration, but protection was overcome during longer incubation times or with greater milk concentrations. Trophozoites preincubated with mucus and then washed were not protected. Protective activity was associated with non-mucin CsCl density gradient fractions. Moreover, it was heat-stable, non-dialyzable, and non-lipid. Whereas whole mucus inhibited milk lipolytic activity, protective mucus fractions did not inhibit the enzyme. Furthermore, mucus partially protected G. lamblia trophozoites against the toxicity of oleic acid, a fatty acid which is released from milk triglycerides by lipase. These studies show that mucus protects G. lamblia both by inhibiting lipase activity and by decreasing the toxicity of products of lipolysis. The ability of mucus to protect G. lamblia from toxic lipolytic products may help to promote intestinal colonization by this parasite.

  11. Photoexcited quantum dots for killing multidrug-resistant bacteria

    Courtney, Colleen M.; Goodman, Samuel M.; McDaniel, Jessica A.; Madinger, Nancy E.; Chatterjee, Anushree; Nagpal, Prashant

    2016-05-01

    Multidrug-resistant bacterial infections are an ever-growing threat because of the shrinking arsenal of efficacious antibiotics. Metal nanoparticles can induce cell death, yet the toxicity effect is typically nonspecific. Here, we show that photoexcited quantum dots (QDs) can kill a wide range of multidrug-resistant bacterial clinical isolates, including methicillin-resistant Staphylococcus aureus, carbapenem-resistant Escherichia coli, and extended-spectrum β-lactamase-producing Klebsiella pneumoniae and Salmonella typhimurium. The killing effect is independent of material and controlled by the redox potentials of the photogenerated charge carriers, which selectively alter the cellular redox state. We also show that the QDs can be tailored to kill 92% of bacterial cells in a monoculture, and in a co-culture of E. coli and HEK 293T cells, while leaving the mammalian cells intact, or to increase bacterial proliferation. Photoexcited QDs could be used in the study of the effect of redox states on living systems, and lead to clinical phototherapy for the treatment of infections.

  12. Effects of lead on the killing mechanisms of polymorphonuclear leukocytes

    Silberstein, C.F.

    1984-01-01

    The effects of lead on the killing mechanisms of rat polymorphonuclear leukocytes (PMN) were investigated, using male Long-Evans rats exposed to 1% lead acetate in the drinking water for varying periods of time to achieve blood lead levels ranging from 20-200 μg/dl. Studies of PMN bacterial and fungal killing activity, chemotaxis and phagocytosis demonstrated that: 1) bactericidal activity of PMN from rats exposed to lead was not altered; 2) chemotactic activity remained within normal limits; 3) the phagocytic ability of the PMN also remained unaltered. In addition to these normal findings, one major abnormality was demonstrated: a significant decrease in the ability of PMN from rats exposed to lead to kill Candida albicans. This defect was not related to age or to length of exposure. It could not be produced by addition of lead to the test system in vitro. Further investigation revealed significant decreases in PMN glucose-6-phosphate dehydrogenase, catalase, and myeloperoxidase activities. These data support two possible mechanisms for the abnormal fungicidal activity of PMN from lead-exposed rats: decrease in ability to reduce oxygen to active metabolites, or reduction in myeloperoxidase activity due to diminshed synthesis of the heme moiety required for its function

  13. Polyanhydride Nanoparticle Delivery Platform Dramatically Enhances Killing of Filarial Worms.

    Andrea M Binnebose

    Full Text Available Filarial diseases represent a significant social and economic burden to over 120 million people worldwide and are caused by endoparasites that require the presence of symbiotic bacteria of the genus Wolbachia for fertility and viability of the host parasite. Targeting Wolbachia for elimination is a therapeutic approach that shows promise in the treatment of onchocerciasis and lymphatic filariasis. Here we demonstrate the use of a biodegradable polyanhydride nanoparticle-based platform for the co-delivery of the antibiotic doxycycline with the antiparasitic drug, ivermectin, to reduce microfilarial burden and rapidly kill adult worms. When doxycycline and ivermectin were co-delivered within polyanhydride nanoparticles, effective killing of adult female Brugia malayi filarial worms was achieved with approximately 4,000-fold reduction in the amount of drug used. Additionally the time to death of the macrofilaria was also significantly reduced (five-fold when the anti-filarial drug cocktail was delivered within polyanhydride nanoparticles. We hypothesize that the mechanism behind this dramatically enhanced killing of the macrofilaria is the ability of the polyanhydride nanoparticles to behave as a Trojan horse and penetrate the cuticle, bypassing excretory pumps of B. malayi, and effectively deliver drug directly to both the worm and Wolbachia at high enough microenvironmental concentrations to cause death. These provocative findings may have significant consequences for the reduction in the amount of drug and the length of treatment required for filarial infections in terms of patient compliance and reduced cost of treatment.

  14. It’s Not Just Conflict That Motivates Killing of Orangutans

    Davis, Jacqueline T.; Mengersen, Kerrie; Abram, Nicola K.; Ancrenaz, Marc; Wells, Jessie A.; Meijaard, Erik

    2013-01-01

    We investigated why orangutans are being killed in Kalimantan, Indonesia, and the role of conflict in these killings. Based on an analysis of interview data from over 5,000 respondents in over 450 villages, we also assessed the socio-ecological factors associated with conflict and non-conflict killings. Most respondents never kill orangutans. Those who reported having personally killed an orangutan primarily did so for non-conflict reasons; for example, 56% of these respondents said that the reason they had killed an orangutan was to eat it. Of the conflict-related reasons for killing, the most common reasons orangutans were killed was fear of orangutans or in self-defence. A similar pattern was evident among reports of orangutan killing by other people in the villages. Regression analyses indicated that religion and the percentage of intact forest around villages were the strongest socio-ecological predictors of whether orangutans were killed for conflict or non-conflict related reasons. Our data indicate that between 44,170 and 66,570 orangutans were killed in Kalimantan within the respondents’ active hunting lifetimes: between 12,690 and 29,024 for conflict reasons (95%CI) and between 26,361 and 41,688 for non-conflict reasons (95% CI). These findings confirm that habitat protection alone will not ensure the survival of orangutans in Indonesian Borneo, and that effective reduction of orangutan killings is urgently needed. PMID:24130707

  15. Preliminary study of killing the larva of plodia interpunella by irradiation

    Wang Jide; Ma Xiaoping

    1994-01-01

    The results of killing the larva of plodia interpunella in the fruit by 60 Co γ-irradiation are described. The lowest effective dose for killing larva by irradiation is ca. 2000 Gy; the effective dose for immediately killing larva is 3000 Gy. The method is simple and easy and also suitable for the study of commercial irradiation of dry-fruit

  16. 40 CFR 180.1108 - Delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas...

    2010-07-01

    ... thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens is...

  17. Testate amoebae analysis in the peat deposits of the swamp Dolgon’koye in the south of Western Siberia and peatland paleohydrology for last 3100 years

    Kurina, Irina V.; Blyakharchuk, Tatiana A.

    2018-03-01

    Our research is devoted to paleohydrological reconstruction in the swamp located in the river valley on the piedmont of the Altai Mountains in the south of Western Siberia. The reconstruction was carried out based on rhizopod analysis for the last 3100 cal yr. A large amount of different testate amoebae was found in the peat. Total 64 testate amoebae taxa were recorded in the peat core with the most abundant being: Trinema lineare, Centropyxis aculeata, C. aerophila, Euglypha rotunda, Cryptodifflugia sp. Decrease of surface wetness in the swamp are observed 2280, 2140, 1900–600 cal yr BP and increase – in 2700, 2500–1900, 230–215 cal yr BP. The results of our reconstruction of the swamp paleohydrology agrees well with the paleoclimatic data obtained earlier for the central area of the south of Western Siberia Plain. It indicates a high sensitivity of the swamp to climatic changes in the Holocene. The rhizopod analysis proved to be very effective when used for paleohydrology reconstruction in minerotrophic peat.

  18. MicroRNAs in Amoebozoa: deep sequencing of the small RNA population in the social amoeba Dictyostelium discoideum reveals developmentally regulated microRNAs.

    Avesson, Lotta; Reimegård, Johan; Wagner, E Gerhart H; Söderbom, Fredrik

    2012-10-01

    The RNA interference machinery has served as a guardian of eukaryotic genomes since the divergence from prokaryotes. Although the basic components have a shared origin, silencing pathways directed by small RNAs have evolved in diverse directions in different eukaryotic lineages. Micro (mi)RNAs regulate protein-coding genes and play vital roles in plants and animals, but less is known about their functions in other organisms. Here, we report, for the first time, deep sequencing of small RNAs from the social amoeba Dictyostelium discoideum. RNA from growing single-cell amoebae as well as from two multicellular developmental stages was sequenced. Computational analyses combined with experimental data reveal the expression of miRNAs, several of them exhibiting distinct expression patterns during development. To our knowledge, this is the first report of miRNAs in the Amoebozoa supergroup. We also show that overexpressed miRNA precursors generate miRNAs and, in most cases, miRNA* sequences, whose biogenesis is dependent on the Dicer-like protein DrnB, further supporting the presence of miRNAs in D. discoideum. In addition, we find miRNAs processed from hairpin structures originating from an intron as well as from a class of repetitive elements. We believe that these repetitive elements are sources for newly evolved miRNAs.

  19. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    Tsyganov, A.N.; Aerts, R.; Nijs, I.; Cornelissen, J.H.C.; Beyens, L.

    2012-01-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming,

  20. Comparing Road-Kill Datasets from Hunters and Citizen Scientists in a Landscape Context

    Florian Heigl; Carina R. Stretz; Wolfgang Steiner; Franz Suppan; Thomas Bauer; Gregor Laaha; Johann G. Zaller

    2016-01-01

    Road traffic has severe effects on animals, especially when road-kills are involved. In many countries, official road-kill data are provided by hunters or police; there are also road-kill observations reported by citizen scientists. The aim of the current study was to test whether road-kill reports by hunters stem from similar landscapes than those reported by citizen scientists. We analysed the surrounding landscapes of 712 road-kill reportings of European hares in the province of Lower Aust...

  1. Response of sphagnum peatland testate amoebae to a 1-year transplantation experiment along an artificial hydrological gradient.

    Marcisz, Katarzyna; Fournier, Bertrand; Gilbert, Daniel; Lamentowicz, Mariusz; Mitchell, Edward A D

    2014-05-01

    Peatland testate amoebae (TA) are well-established bioindicators for depth to water table (DWT), but effects of hydrological changes on TA communities have never been tested experimentally. We tested this in a field experiment by placing Sphagnum carpets (15 cm diameter) collected in hummock, lawn and pool microsites (origin) at three local conditions (dry, moist and wet) using trenches dug in a peatland. One series of samples was seeded with microorganism extract from all microsites. TA community were analysed at T0: 8-2008, T1: 5-2009 and T2: 8-2009. We analysed the data using conditional inference trees, principal response curves (PRC) and DWT inferred from TA communities using a transfer function used for paleoecological reconstruction. Density declined from T0 to T1 and then increased sharply by T2. Species richness, Simpson diversity and Simpson evenness were lower at T2 than at T0 and T1. Seeded communities had higher species richness in pool samples at T0. Pool samples tended to have higher density, lower species richness, Simpson diversity and Simpson Evenness than hummock and/or lawn samples until T1. In the PRC, the effect of origin was significant at T0 and T1, but the effect faded away by T2. Seeding effect was strongest at T1 and lowest vanished by T2. Local condition effect was strong but not in line with the wetness gradient at T1 but started to reflect it by T2. Likewise, TA-inferred DWT started to match the experimental conditions by T2, but more so in hummock and lawn samples than in pool samples. This study confirmed that TA responds to hydrological changes over a 1-year period. However, sensitivity of TA to hydrological fluctuations, and thus the accuracy of inferred DWT changes, was habitat specific, pool TA communities being least responsive to environmental changes. Lawns and hummocks may be thus better suited than pools for paleoecological reconstructions. This, however, contrasts with the higher prediction error and species' tolerance for

  2. Killing in More-than-human Spaces: Pasteurisation, Fungi, and the Metabolic Lives of Wine

    Brice, Jeremy

    2014-05-01

    Full Text Available What place might killing occupy in a more-than-human world, where human life is always-already entangled among nonhumans? In this article I attempt to unsettle the assumption that only individual organisms can be killed, and to render other sites and spaces of killing visible. Drawing on ethnographic fieldwork among winemakers in South Australia I examine pasteurisation, a killing practice that acts not on organisms but on the fluids within which they live. Examining the pasteurisation of wine damaged by the fungus Botrytis cinerea, I argue that this practice shifts the locus of killing from botrytis’ body to metabolic life processes which embrace extracellular enzymes diffused throughout the wine. I suggest that pasteurisation thus displaces killing into spaces, such as wine-in-the-making, within which many metabolic lives coexist and interpenetrate. Pasteurisation therefore renders killing an intervention into the metabolic relationships that tie together numerous species of microbes living within wine. In acting on wine as a whole it kills rather indiscriminately, simultaneously terminating multiple lives that relate to humans in different ways. Pasteurisation therefore both protects and spoils wine, reconfiguring multiple human-nonhuman relationships in conflicting and sometimes economically costly ways. In so doing, it illustrates that in a more-than-human world killing becomes difficult to confine to a single unwanted organism or species. Killing instead becomes disturbingly mobile and communicable, prone to rebound upon the valued human lives of those who kill in unsettling and potentially harmful ways.

  3. Killed oral cholera vaccines: history, development and implementation challenges.

    Lopez, Anna Lena; Gonzales, Maria Liza Antoinette; Aldaba, Josephine G; Nair, G Balakrish

    2014-09-01

    Cholera is still a major global health problem, affecting mainly people living in unsanitary conditions and who are at risk for outbreaks of cholera. During the past decade, outbreaks are increasingly reported from more countries. From the early killed oral cholera vaccine, rapid improvements in vaccine development occurred as a result of a better understanding of the epidemiology of the disease, pathogenesis of cholera infection and immunity. The newer-generation oral killed cholera vaccines have been shown to be safe and effective in field trials conducted in cholera endemic areas. Likewise, they have been shown to be protective when used during outbreak settings. Aside from providing direct protection to vaccinated individuals, recent studies have demonstrated that these killed oral vaccines also confer indirect protection through herd immunity. Although new-generation oral cholera vaccines should not be considered in isolation from other preventive approaches in countries where they are most needed, especially improved water quality and sanitation, these vaccines serve as immediately available public health tools for preventing further morbidity and mortality from cholera. However, despite its availability for more than two decades, use of these vaccines has not been optimized. Although there are limitations of the currently available oral cholera vaccines, recent data show that the vaccines are safe, feasible to use even in difficult circumstances and able to provide protection in various settings. Clear identification of the areas and target population groups who will benefit from the use of the cholera vaccines will be required and strategies to facilitate accessibility and usage of these vaccines in these areas and population groups will need to be developed.

  4. Ground Zero/Fresh Kills: Cataloguing Ruins, Garbage, and Memory

    Cinzia Scarpino

    2011-01-01

    The aim of this paper is to show how the rise and fall of the Twin Towers can be read in relation to the rise and fall of the Staten Island Fresh Kills landfill, how their destinies were entwined from the start, and how the immediate cultural response to the collapse of the former and the closing of the latter recurred to the form of catalogues of objects, words, and images. From this angle it will be possible to posit the events within a larger, if somewhat unusual, cultural frame encompassi...

  5. Double suicide genes selectively kill human umbilical vein endothelial cells

    Liu Lunxu

    2011-02-01

    Full Text Available Abstract Background To construct a recombinant adenovirus containing CDglyTK double suicide genes and evaluate the killing effect of the double suicide genes driven by kinase domain insert containing receptor (KDR promoter on human umbilical vein endothelial cells. Methods Human KDR promoter, Escherichia coli (E. coli cytosine deaminase (CD gene and the herpes simplex virus-thymidine kinase (TK gene were cloned using polymerase chain reaction (PCR. Plasmid pKDR-CDglyTK was constructed with the KDR promoter and CDglyTK genes. A recombinant adenoviral plasmid AdKDR-CDglyTK was then constructed and transfected into 293 packaging cells to grow and harvest adenoviruses. KDR-expressing human umbilical vein endothelial cells (ECV304 and KDR-negative liver cancer cell line (HepG2 were infected with the recombinant adenoviruses at different multiplicity of infection (MOI. The infection rate was measured by green fluorescent protein (GFP expression. The infected cells were cultured in culture media containing different concentrations of prodrugs ganciclovir (GCV and/or 5-fluorocytosine (5-FC. The killing effects were measured using two different methods, i.e. annexin V-FITC staining and terminal transferase-mediated dUTP nick end-labeling (TUNEL staining. Results Recombinant adenoviruses AdKDR-CDglyTK were successfully constructed and they infected ECV304 and HepG2 cells efficiently. The infection rate was dependent on MOI of recombinant adenoviruses. ECV304 cells infected with AdKDR-CDglyTK were highly sensitive to GCV and 5-FC. The cell survival rate was dependent on both the concentration of the prodrugs and the MOI of recombinant adenoviruses. In contrast, there were no killing effects in the HepG2 cells. The combination of two prodrugs was much more effective in killing ECV304 cells than GCV or 5-FC alone. The growth of transgenic ECV304 cells was suppressed in the presence of prodrugs. Conclusion AdKDR-CDglyTK/double prodrog system may be a useful

  6. Sabretoothed carnivores and the killing of large prey.

    Ki Andersson

    Full Text Available Sabre-like canines clearly have the potential to inflict grievous wounds leading to massive blood loss and rapid death. Hypotheses concerning sabretooth killing modes include attack to soft parts such as the belly or throat, where biting deep is essential to generate strikes reaching major blood vessels. Sabretoothed carnivorans are widely interpreted as hunters of larger and more powerful prey than that of their present-day nonsabretoothed relatives. However, the precise functional advantage of the sabretooth bite, particularly in relation to prey size, is unknown. Here, we present a new point-to-point bite model and show that, for sabretooths, depth of the killing bite decreases dramatically with increasing prey size. The extended gape of sabretooths only results in considerable increase in bite depth when biting into prey with a radius of less than ∼10 cm. For sabretooths, this size-reversed functional advantage suggests predation on species within a similar size range to those attacked by present-day carnivorans, rather than "megaherbivores" as previously believed. The development of the sabretooth condition appears to represent a shift in function and killing behaviour, rather than one in predator-prey relations. Furthermore, our results demonstrate how sabretoothed carnivorans are likely to have evolved along a functionally continuous trajectory: beginning as an extension of a jaw-powered killing bite, as adopted by present-day pantherine cats, followed by neck-powered biting and thereafter shifting to neck-powered shear-biting. We anticipate this new insight to be a starting point for detailed study of the evolution of pathways that encompass extreme specialisation, for example, understanding how neck-powered biting shifts into shear-biting and its significance for predator-prey interactions. We also expect that our model for point-to-point biting and bite depth estimations will yield new insights into the behaviours of a broad range of

  7. Mercy killing without consent. Historical comments on a controversial issue.

    Lauter, H; Meyer, J E

    1982-02-01

    In recent discussions on euthanasia the question about mercy killing without consent of mentally ill persons has turned up, particularly in cases of hopeless suffering among senile or chronically insane patients. Possible analogies to the actions under the German Nazi-regimen and relations to the concept of Social Darwinism with suggestions about active eugenic control as propagated in the early part of this century are outlined in a historical review. The implications and obvious dangers of misuse of any such kind of active euthanasia in psychiatry are discussed on this background.

  8. Fractional Killing-Yano Tensors and Killing Vectors Using the Caputo Derivative in Some One- and Two-Dimensional Curved Space

    Ehab Malkawi

    2014-01-01

    Full Text Available The classical free Lagrangian admitting a constant of motion, in one- and two-dimensional space, is generalized using the Caputo derivative of fractional calculus. The corresponding metric is obtained and the fractional Christoffel symbols, Killing vectors, and Killing-Yano tensors are derived. Some exact solutions of these quantities are reported.

  9. Emergence of Buprestidae, Cerambycidae, and Scolytinae (Coleoptera) from mountain pine beetle-killed and fire-killed ponderosa pines in the Black Hills, South Dakota, USA

    Sheryl L. Costello; William R. Jacobi; Jose F. Negron

    2013-01-01

    Wood borers (Coleoptera: Cerambycidae and Buprestidae) and bark beetles (Coleoptera: Curculionidae) infest ponderosa pines, Pinus ponderosa P. Lawson and C. Lawson, killed by mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, and fire. No data is available comparing wood borer and bark beetle densities or species guilds associated with MPB-killed or fire-...

  10. Ground Zero/Fresh Kills: Cataloguing Ruins, Garbage, and Memory

    Cinzia Scarpino

    2011-09-01

    Full Text Available The aim of this paper is to show how the rise and fall of the Twin Towers can be read in relation to the rise and fall of the Staten Island Fresh Kills landfill, how their destinies were entwined from the start, and how the immediate cultural response to the collapse of the former and the closing of the latter recurred to the form of catalogues of objects, words, and images. From this angle it will be possible to posit the events within a larger, if somewhat unusual, cultural frame encompassing the history of two different yet complementary symbols of New York up to 2001 (the WTC and Fresh Kills. From Don DeLillo’s Underworld (1997 and Falling Man (2007 through Holman, Steve Zeitlin e Joe Dobkin’s Crisis (2001-2002; from Art Spiegelman’s In the Shadows of No Tower (2004 to Artists Respond’s 9-11 (2002; from the New York Times to Bearing Witness to History, the 2003-2006 retrospective of the Smithsonian Museum, relevant collective or individual responses to the 2001 attacks took the form of a catalogue, a list, a vertical or horizontal juxtaposition of data, objects, and memories, evoking a suggestive parallel to the organizing principle of past relics collected in museums and garbage stratified in sanitary landfills.

  11. Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

    Caccia, Silvia; Di Lelio, Ilaria; La Storia, Antonietta; Marinelli, Adriana; Varricchio, Paola; Franzetti, Eleonora; Banyuls, Núria; Tettamanti, Gianluca; Casartelli, Morena; Giordana, Barbara; Ferré, Juan; Gigliotti, Silvia; Pennacchio, Francesco

    2016-01-01

    Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. Here this key issue is addressed by RNAi-mediated silencing of an immune gene in a lepidopteran host Spodoptera littoralis, leaving the midgut microbiota unaltered. The resulting cellular immunosuppression was characterized by a reduced nodulation response, which was associated with a significant enhancement of host larvae mortality triggered by B. thuringiensis and a Cry toxin. This was determined by an uncontrolled proliferation of midgut bacteria, after entering the body cavity through toxin-induced epithelial lesions. Consequently, the hemolymphatic microbiota dramatically changed upon treatment with Cry1Ca toxin, showing a remarkable predominance of Serratia and Clostridium species, which switched from asymptomatic gut symbionts to hemocoelic pathogens. These experimental results demonstrate the important contribution of host enteric flora in B. thuringiensis-killing activity and provide a sound foundation for developing new insect control strategies aimed at enhancing the impact of biocontrol agents by reducing the immunocompetence of the host. PMID:27506800

  12. Does host complement kill Borrelia burgdorferi within ticks?

    Rathinavelu, Sivaprakash; Broadwater, Anne; de Silva, Aravinda M

    2003-02-01

    The Lyme disease spirochete, Borrelia burgdorferi, inhabits the gut lumen of the tick vector. At this location the spirochete is exposed to host blood when a tick feeds. We report here on studies that were done with normal and complement-deficient (C3-knockout) mice to determine if the host complement system killed spirochetes within the vector. We found that spirochete numbers within feeding nymphs were not influenced by complement, most likely because host complement was inactivated within the vector. The Lyme disease outer surface protein A (OspA) vaccine is a transmission-blocking vaccine that targets spirochetes in the vector. In experiments with mice hyperimmunized with OspA, complement was not required to kill spirochetes within nymphs and to block transmission from nymphs to the vaccinated host. However, host complement did enhance the ability of OspA antibody to block larvae from acquiring spirochetes. Thus, the effects of OspA antibody on nymphal transmission and larval acquisition appear to be based on different mechanisms.

  13. Photoacoustically-guided photothermal killing of mosquitoes targeted by nanoparticles.

    Foster, Stephen R; Galanzha, Ekaterina I; Totten, Daniel C; Beneš, Helen; Shmookler Reis, Robert J; Zharov, Vladimir P

    2014-07-01

    In biomedical applications, nanoparticles have demonstrated the potential to eradicate abnormal cells in small localized pathological zones associated with cancer or infections. Here, we introduce a method for nanotechnology-based photothermal (PT) killing of whole organisms considered harmful to humans or the environment. We demonstrate that laser-induced thermal, and accompanying nano- and microbubble phenomena, can injure or kill C. elegans and mosquitoes fed carbon nanotubes, gold nanospheres, gold nanoshells, or magnetic nanoparticles at laser energies that are safe for humans. In addition, a photoacoustic (PA) effect was used to control nanoparticle delivery. Through the integration of this technique with molecular targeting, nanoparticle clustering, magnetic capturing and spectral sharpening of PA and PT plasmonic resonances, our laser-based PA-PT nano-theranostic platform can be applied to detection and the physical destruction of small organisms and carriers of pathogens, such as malaria vectors, spiders, bed bugs, fleas, ants, locusts, grasshoppers, phytophagous mites, or other arthropod pests, irrespective of their resistance to conventional treatments. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Rate-limiting events in hyperthermic cell killing

    Landry, J.; Marceau, N.

    1978-01-01

    The inactivation rate of HeLa cells for temperatures ranging from 41 to 55 0 C and treatment durations varying from 2 to 300 min was analyzed in thermodynamic terms by considering the dependence of cell free energy (ΔG + ) on temperature. Within this temperature range the loss of proliferative capacity exhibits a complex temperature dependence which is characterized by entropy and enthalpy values that gradually decrease as temperature increases. This complex process of heat-induced cell killing was postulated to be the result of a series of reactions, each of them being alternatively rate limiting within a certain temperature range. From this kinetic scheme a mathematical model was derived and, in the case of HeLa cells, the use of a least-squares search parameter procedure (as applied to the derived survival regression function) demonstrated that three such sequential reactions were sufficient to explain all experimental data points obtained within the 41 to 55 0 C range. The proposed model was also shown to be adequate for explaining survival data of HeLa cells exposed to nanosecond heat pulses of infrared laser energy. Considerations of thermodynamic properties of known biochemical reactions suggest plausible rate-limiting events in hyperthermic cell killing

  15. Identification of Pseudomonas aeruginosa phenazines that kill Caenorhabditis elegans.

    Cezairliyan, Brent; Vinayavekhin, Nawaporn; Grenfell-Lee, Daniel; Yuen, Grace J; Saghatelian, Alan; Ausubel, Frederick M

    2013-01-01

    Pathogenic microbes employ a variety of methods to overcome host defenses, including the production and dispersal of molecules that are toxic to their hosts. Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. In this study, we identify three small molecules in the phenazine class that are produced by P. aeruginosa strain PA14 that are toxic to C. elegans. We demonstrate that 1-hydroxyphenazine, phenazine-1-carboxylic acid, and pyocyanin are capable of killing nematodes in a matter of hours. 1-hydroxyphenazine is toxic over a wide pH range, whereas the toxicities of phenazine-1-carboxylic acid and pyocyanin are pH-dependent at non-overlapping pH ranges. We found that acidification of the growth medium by PA14 activates the toxicity of phenazine-1-carboxylic acid, which is the primary toxic agent towards C. elegans in our assay. Pyocyanin is not toxic under acidic conditions and 1-hydroxyphenazine is produced at concentrations too low to kill C. elegans. These results suggest a role for phenazine-1-carboxylic acid in mammalian pathogenesis because PA14 mutants deficient in phenazine production have been shown to be defective in pathogenesis in mice. More generally, these data demonstrate how diversity within a class of metabolites could affect bacterial toxicity in different environmental niches.

  16. Identification of Pseudomonas aeruginosa phenazines that kill Caenorhabditis elegans.

    Brent Cezairliyan

    2013-01-01

    Full Text Available Pathogenic microbes employ a variety of methods to overcome host defenses, including the production and dispersal of molecules that are toxic to their hosts. Pseudomonas aeruginosa, a Gram-negative bacterium, is a pathogen of a diverse variety of hosts including mammals and the nematode Caenorhabditis elegans. In this study, we identify three small molecules in the phenazine class that are produced by P. aeruginosa strain PA14 that are toxic to C. elegans. We demonstrate that 1-hydroxyphenazine, phenazine-1-carboxylic acid, and pyocyanin are capable of killing nematodes in a matter of hours. 1-hydroxyphenazine is toxic over a wide pH range, whereas the toxicities of phenazine-1-carboxylic acid and pyocyanin are pH-dependent at non-overlapping pH ranges. We found that acidification of the growth medium by PA14 activates the toxicity of phenazine-1-carboxylic acid, which is the primary toxic agent towards C. elegans in our assay. Pyocyanin is not toxic under acidic conditions and 1-hydroxyphenazine is produced at concentrations too low to kill C. elegans. These results suggest a role for phenazine-1-carboxylic acid in mammalian pathogenesis because PA14 mutants deficient in phenazine production have been shown to be defective in pathogenesis in mice. More generally, these data demonstrate how diversity within a class of metabolites could affect bacterial toxicity in different environmental niches.

  17. Effect of pulsed electron beam on cell killing

    Acharya, Santhosh; Joseph, Praveen; Sanjeev, Ganesh; Narayana, Y.; Bhat, N.N.

    2009-01-01

    The extent of repairable and irreparable damage in a living cell produced by ionizing radiation depends on the quality of the radiation. In the case of sparsely ionizing radiation, the dose rate and the pattern of energy deposition of the radiation are the important physical factors which can affect the amount of damage in living cells. In the present study, radio-sensitive and radioresistive bacteria cells were exposed to 8 MeV pulsed electron beam and the efficiency of cell-killing was investigated to evaluate the Do, the mean lethal dose. The dose to the cell was delivered in micro-second pulses at an instantaneous dose rate of 2.6 x 10 5 Gy s -1 . Fricke dosimeter was used to measure the absorbed dose of electron beam. The results were compared with those of gamma rays. The survival curve of radio-resistive Deinococcus-radiodurans (DR) is found to be sigmoidal and the survival response for radio-sensitive Escherichia-coli (E-coli) is found to be exponential without any shoulder. Comparison of Do values indicate that irradiation with pulsed electron beam resulted in more cell-killing than was observed for gamma irradiation. (author)

  18. [i]Legionella spp[/i]., amoebae and not-fermenting Gram negative bacteria in an Italian university hospital water system

    Pasqualina Laganà

    2014-09-01

    Full Text Available [b]Introduction. [/b]In hospital and other health care facilities, contamination of water systems by potentially infectious microorganisms, such as bacteria, viruses and protozoa, is a source of nosocomial infections, which may originate fromcolonization of water pipes, cooling towers, spa pools, taps, showers and water supplies. [b]Objective. [/b]The study focuses on the occurrence of [i]Legionella spp.[/i], free-living amoebae and non-fermenting Gram-negative microorganisms in a University hospital water system located in the town of Messina (Sicily, Italy, which had never been examined previously. Materials and Methods. From January 2008 – March 2009, hot tap water samples were collected from 10 wards.[i] Legionella spp[/i]. recovered on selective culture medium were identified by microagglutination latex test; free-living amoebae were cultured using [i]Escherichia coli [/i]as a food source. Non-fermenting Gram negative microorganisms were identified by API 20 NE strips. [b]Results.[/b] [i]Legionella spp.[/i] were found in 33.33% of the samples. [i]L. pneumophila[/i] serogroup 1 was recovered from the Laboratory Diagnostic and Anaesthesia-Neurology Wards, with a peak of 3.5 × 10[sup]4[/sup] cfu/L in May 2008. [i]L. pneumophila[/i] serogroups 2–14 were found in the Othorhinolaryngology, Pathologic Anatomy, Paediatrics and Surgery Wards, and peaked (4 × 10[sup]4[/sup] cfu/L in April 2008. Pseudomonadaceae and Hyphomycetes were also detected. Legionella spp. were recovered from samples positive for non-pathogenic amoebae [i]Hartmannella spp[/i]. [b]Conclusion.[/b] This first study of a Messina hospital water system suggested potential health risks related to the detection of [i]Hartmannella spp[/i]., as reservoirs for[i] Legionella spp.[/i], and Pseudomonas aeruginosa, a Gram negative non-fermenting bacterium frequently causing nosocomial pneumonia. The urgent need for monitoring programmes and prevention measures to ensure hospital water

  19. Species richness of testate amoebae in different environments from the upper Paraná river floodplain (PR/MS - doi: 10.4025/actascibiolsci.v33i3.7261 Species richness of testate amoebae in different environments from the upper Paraná river floodplain (PR/MS - doi: 10.4025/actascibiolsci.v33i3.7261

    Fábio Amodêo Lansac-Tôha

    2011-07-01

    Full Text Available This study evaluated the species richness of testate amoebae in the plankton from different environments of the upper Paraná river floodplain. Samplings were performed at subsurface of pelagic region from twelve environments using motorized pump and plankton net (68 µm, during four hydrological periods. We identified 67 taxa, distributed in seven families and Arcellidae, Difflugiidae and Centropyxidae were the most representative families. Higher values of species richness were observed in the lakes (connected and isolated during the flood pulses. Centropyxis aculeata, Difflugia gramem and D. pseudogramem were frequent throughout the study period. Seasonal variability of species in the channels and isolated lakes was evidenced by beta diversity. Besides that, in the rivers, extreme changes in species composition were verified during the high-water period. Our results highlight the importance of the present study to improve the knowledge about the diversity and geographic distribution of these organisms in Brazil and emphasize the importance of current flow in the displacement of testate amoebae from their preferred habitats, marginal vegetation and sediment.This study evaluated the species richness of testate amoebae in the plankton from different environments of the upper Paraná river floodplain. Samplings were performed at subsurface of pelagic region from twelve environments using motorized pump and plankton net (68 µm, during four hydrological periods. We identified 67 taxa, distributed in seven families and Arcellidae, Difflugiidae and Centropyxidae were the most representative families. Higher values of species richness were observed in the lakes (connected and isolated during the flood pulses. Centropyxis aculeata, Difflugia gramem and D. pseudogramem were frequent throughout the study period. Seasonal variability of species in the channels and isolated lakes was evidenced by beta diversity. Besides that, in the rivers, extreme

  20. Competition between apex predators? Brown bears decrease wolf kill rate on two continents.

    Tallian, Aimee; Ordiz, Andrés; Metz, Matthew C; Milleret, Cyril; Wikenros, Camilla; Smith, Douglas W; Stahler, Daniel R; Kindberg, Jonas; MacNulty, Daniel R; Wabakken, Petter; Swenson, Jon E; Sand, Håkan

    2017-02-08

    Trophic interactions are a fundamental topic in ecology, but we know little about how competition between apex predators affects predation, the mechanism driving top-down forcing in ecosystems. We used long-term datasets from Scandinavia (Europe) and Yellowstone National Park (North America) to evaluate how grey wolf ( Canis lupus ) kill rate was affected by a sympatric apex predator, the brown bear ( Ursus arctos ). We used kill interval (i.e. the number of days between consecutive ungulate kills) as a proxy of kill rate. Although brown bears can monopolize wolf kills, we found no support in either study system for the common assumption that they cause wolves to kill more often. On the contrary, our results showed the opposite effect. In Scandinavia, wolf packs sympatric with brown bears killed less often than allopatric packs during both spring (after bear den emergence) and summer. Similarly, the presence of bears at wolf-killed ungulates was associated with wolves killing less often during summer in Yellowstone. The consistency in results between the two systems suggests that brown bear presence actually reduces wolf kill rate. Our results suggest that the influence of predation on lower trophic levels may depend on the composition of predator communities. © 2017 The Authors.

  1. Lactoferricin Peptides Increase Macrophages' Capacity To Kill Mycobacterium avium.

    Silva, Tânia; Moreira, Ana C; Nazmi, Kamran; Moniz, Tânia; Vale, Nuno; Rangel, Maria; Gomes, Paula; Bolscher, Jan G M; Rodrigues, Pedro N; Bastos, Margarida; Gomes, Maria Salomé

    2017-01-01

    Mycobacterial infections cause a significant burden of disease and death worldwide. Their treatment is long, toxic, costly, and increasingly prone to failure due to bacterial resistance to currently available antibiotics. New therapeutic options are thus clearly needed. Antimicrobial peptides represent an important source of new antimicrobial molecules, both for their direct activity and for their immunomodulatory potential. We have previously reported that a short version of the bovine antimicrobial peptide lactoferricin with amino acids 17 to 30 (LFcin17-30), along with its variants obtained by specific amino acid substitutions, killed Mycobacterium avium in broth culture. In the present work, those peptides were tested against M. avium living inside its natural host cell, the macrophage. We found that the peptides increased the antimicrobial action of the conventional antibiotic ethambutol inside macrophages. Moreover, the d-enantiomer of the lactoferricin peptide (d-LFcin17-30) was more stable and induced significant killing of intracellular mycobacteria by itself. Interestingly, d-LFcin17-30 did not localize to M. avium -harboring phagosomes but induced the production of proinflammatory cytokines and increased the formation of lysosomes and autophagosome-like vesicles. These results lead us to conclude that d-LFcin17-30 primes macrophages for intracellular microbial digestion through phagosomal maturation and/or autophagy, culminating in mycobacterial killing. IMPORTANCE The genus Mycobacterium comprises several pathogenic species, including M. tuberculosis , M. leprae , M. avium , etc. Infections caused by these bacteria are particularly difficult to treat due to their intrinsic impermeability, low growth rate, and intracellular localization. Antimicrobial peptides are increasingly acknowledged as potential treatment tools, as they have a high spectrum of activity, low tendency to induce bacterial resistance, and immunomodulatory properties. In this study, we

  2. Opinions of university students on honour killings: Perspective from Islamabad and Rawalpindi.

    Shaikh, Masood Ali; Kamal, Anila; Naqvi, Irum

    2015-04-01

    Honour killing incidents have been reported from every province of Pakistan. In 2014 a pregnant woman was killed in front of Lahore High Court, by her family members, in the name of honour. This study was conducted to determine the perspective of university students on honour killing with specific reference to one such killing incident in Lahore. Cumulatively, 989 students participated in the survey. Compared with female students, male students were less likely to agree and were more unequivocal that a woman has a right to marry any man she wants despite her family's disapproval, in a statistically significant manner. Similarly, male students were statistically significantly more likely to report that killing in the name of honour is always justified and were less equivocal about it compared to female students. Nonetheless, cumulatively 824 (83.3%) students believed that killing in the name of honour is not always justified.

  3. Efficient Kill-Save Ratios Ease Up the Cognitive Demands on Counterintuitive Moral Utilitarianism.

    Trémolière, Bastien; Bonnefon, Jean-François

    2014-07-01

    The dual-process model of moral judgment postulates that utilitarian responses to moral dilemmas (e.g., accepting to kill one to save five) are demanding of cognitive resources. Here we show that utilitarian responses can become effortless, even when they involve to kill someone, as long as the kill-save ratio is efficient (e.g., 1 is killed to save 500). In Experiment 1, participants responded to moral dilemmas featuring different kill-save ratios under high or low cognitive load. In Experiments 2 and 3, participants responded at their own pace or under time pressure. Efficient kill-save ratios promoted utilitarian responding and neutered the effect of load or time pressure. We discuss whether this effect is more easily explained by a parallel-activation model or by a default-interventionist model. © 2014 by the Society for Personality and Social Psychology, Inc.

  4. An evolutionarily significant unicellular strategy in response to starvation stress in Dictyostelium social amoebae [v1; ref status: indexed, http://f1000r.es/3hg

    Darja Dubravcic

    2014-06-01

    Full Text Available The social amoeba Dictyostelium discoideum is widely studied for its multicellular development program as a response to starvation and constitutes a model of choice in microbial cooperation studies. Aggregates of up to 106 cells form fruiting bodies containing two cell types: (i dormant spores (~80% that can persist for months in the absence of nutrients, and (ii dead stalk cells (~20% that promote the dispersion of the spores towards nutrient-rich areas. It is often overlooked that not all cells aggregate upon starvation. Using a new quantitative approach based on time-lapse fluorescence microscopy and a low ratio of reporting cells, we have quantified this fraction of non-aggregating cells. In realistic starvation conditions, up to 15% of cells do not aggregate, which makes this third cell fate a significant component of the population-level response of social amoebae to starvation. Non-aggregating cells have an advantage over cells in aggregates since they resume growth earlier upon arrival of new nutrients, but have a shorter lifespan under prolonged starvation. We find that phenotypic heterogeneities linked to cell nutritional state bias the representation of cells in the aggregating vs. non-aggregating fractions, and thus regulate population partitioning. Next, we report that the fraction of non-aggregating cells depends on genetic factors that regulate the timing of starvation, signal sensing efficiency and aggregation efficiency. In addition, interactions between clones in mixtures of non-isogenic cells affect the partitioning of each clone into both fractions. We further test the evolutionary significance of the non-aggregating cell fraction. The partitioning of cells into aggregating and non-aggregating fractions is optimal in fluctuating environments with an unpredictable duration of starvation periods. D. discoideum thus constitutes a model system lying at the intersection of microbial cooperation and bet hedging, defining a new

  5. DNA-repair, cell killing and normal tissue damage

    Dahm-Daphi, J.; Dikomey, E.; Brammer, I.

    1998-01-01

    Background: Side effects of radiotherapy in normal tissue is determined by a variety of factors of which cellular and genetic contributions are described here. Material and methods: Review. Results: Normal tissue damage after irradiation is largely due to loss of cellular proliferative capacity. This can be due to mitotic cell death, apoptosis, or terminal differentiation. Dead or differentiated cells release cytokines which additionally modulate the tissue response. DNA damage, in particular non-reparable or misrepaired double-strand breaks are considered the basic lesion leading to G1-arrest and ultimately to cell inactivation. Conclusion: Evidence for genetic bases of normal tissue response, cell killing and DNA-repair capacity is presented. However, a direct link of all 3 endpoints has not yet been proved directly. (orig.) [de

  6. Medicolegal investigation of political killings in El Salvador.

    Thomsen, J L; Gruschow, J; Stover, E

    1989-06-17

    An axiom of Thomas Hobbes states that "people are never more helpless than when the force meant to protect their rights turns against them." Hobbes' axiom holds true today, with Amnesty International reporting that hundreds of thousands have been murdered by their governments. This article examines the medicolegal aspects of an investigation into the deaths of two Salvadoran peasants who were reportedly tortured and executed by soldiers in February 1988. One of the authors, Thomsen, participated in the investigation as a court-ordered expert, and as a representative of the American Association for the Advancement of Science and of a Salvadoran legal aid organization. His necropsy findings are reported with observations and comments. The article concludes with suggestions for initiatives that might be undertaken by individual physicians and institutions to improve the quality and impartiality of medicolegal investigations into political killings.

  7. Invariant Killing spinors in 11D and type II supergravities

    Gran, U; Gutowski, J; Papadopoulos, G

    2009-01-01

    We present all isotropy groups and associated Σ groups, up to discrete identifications of the component connected to the identity, of spinors of 11-dimensional and type II supergravities. The Σ groups are products of a Spin group and an R-symmetry group of a suitable lower dimensional supergravity theory. Using the case of SU(4)-invariant spinors as a paradigm, we demonstrate that the Σ groups, and so the R-symmetry groups of lower dimensional supergravity theories arising from compactifications, have disconnected components. These lead us to discrete symmetry groups reminiscent of R-parity. We examine the role of disconnected components of the Σ groups in the choice of Killing spinor representatives and in the context of compactifications.

  8. Fish Kill Incidents and Harmful Algal Blooms in Omani Waters

    Hamed Mohammed Al Gheilani

    2011-01-01

    Full Text Available Red tide, one of the harmful algal blooms (HABs is a natural ecological phenomenon and often this event is accompanied by severe impacts on coastal resources, local economies, and public health. The occurrence of red tides has become more frequent in Omani waters in recent years. Some of them caused fish kill, damaged fishery resources and mariculture, threatened the marine environment and the osmosis membranes of desalination plants. However, a number of them have been harmless. The most common dinoflagellate Noctiluca scintillans is associated with the red tide events in Omani waters. Toxic species like Karenia selliformis, Prorocentrum arabianum, and Trichodesmium erythraeum have also been reported recently. Although red tides in Oman have been considered a consequence of upwelling in the summer season (May to September, recent phytoplankton outbreaks in Oman are not restricted to summer. Frequent algal blooms have been reported during winter (December to March. HABs may have contributed to hypoxia and/or other negative ecological impacts.

  9. Terrorism as Genocide: Killing with “Intent”

    Ashlie Perry

    2012-07-01

    Full Text Available It is plausible that terrorism can manifest itself as a form of genocide. Using Raphael Lemkin’s definition of genocide and the UN Genocide Convention’s definition of genocide, non-state and state terrorism are assessed as a form of genocide. Commonalities found in the definitions of both genocide and terrorism supports the argument. The psychology of terrorism and Lemkin’s psychology of genocide describe similar motivations of perpetrators. The September 11th attacks and the U.S. invasion of Iraq are used as case studies to illustrate that terrorism can result in genocide or genocidal acts. Framing acts of terrorism as genocide allows for prosecution in international courts and brings a new perspective to the concept of killing with intent.

  10. Necessity, private defence and the killing of Mary.

    Rogers, J

    2001-07-01

    This article examines the reasons used by the Court of Appeal in Re A (Children) to authorise and justify an operation which would inevitably kill the weaker of a pair of conjoined twins in order to offer the stronger twin a good chance of a long and happy life. The crux of the judgment was that a utilitarian theory of necessity could justify this operation. This article seeks to define the criminal law defences at issue in the case and to argue that utilitarian necessity is such a dangerous doctrine that it should never be employed if there is any other defence which can be made to serve the same purpose--as there was in the present case.

  11. Beyond Democratic Tolerance: Witch Killings in Timor-Leste

    Rebecca Strating

    2015-01-01

    Full Text Available Newly democratising states experience challenges in reconciling “traditional” or “customary” dispute resolution practices with newly established state-based legal systems based on the rule of law. For Timor-Leste, these tensions are pronounced in continuing debates concerning the killing or injuring of women accused of witchcraft. Defences of extrajudicial punishments tend to conflate democracy with local support and fail to deal with the key institutions of democratic systems, including the rule of law, political equality, and civil rights. In Timor-Leste’s case, where equality and social rights were incorporated into the Constitution as fundamental governmental obligations, localised extrajudicial punishments threaten internal and external state legitimacy and highlight the difficulties of ensuring the primacy of state-based institutions. Extrajudicial punishments challenge Timor-Leste’s capacity to consolidate new liberal democratic political institutions.

  12. Age and sex composition of seals killed by polar bears in the eastern Beaufort Sea.

    Nicholas W Pilfold

    Full Text Available Polar bears (Ursus maritimus of the Beaufort Sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. We collected information on seals killed by polar bears (n=650 and hunting attempts on ringed seal (Pusa hispida lairs (n=1396 observed from a helicopter during polar bear mark-recapture studies in the eastern Beaufort Sea in spring in 1985-2011. We investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspecific vulnerabilities of ringed seals to polar bear predation.Polar bears primarily preyed on ringed seals (90.2% while bearded seals (Erignathus barbatus only comprised 9.8% of the kills, but 33% of the biomass. Adults comprised 43.6% (150/344 of the ringed seals killed, while their pups comprised 38.4% (132/344. Juvenile ringed seals were killed at the lowest proportion, comprising 18.0% (62/344 of the ringed seal kills. The proportion of ringed seal pups was highest between 2007-2011, in association with high ringed seal productivity. Half of the adult ringed seal kills were ≥ 21 years (60/121, and kill rates of adults increased following the peak of parturition. Determination of sex from DNA revealed that polar bears killed adult male and adult female ringed seals equally (0.50, n=78. The number of hunting attempts at ringed seal subnivean lair sites was positively correlated with the number of pup kills (r(2 =0.30, P=0.04, but was not correlated with the number of adult kills (P=0.37.Results are consistent with decadal trends in ringed seal productivity, with low numbers of pups killed by polar bears in spring in years of low pup productivity, and conversely when pup productivity was high. Vulnerability of adult ringed seals to predation increased in relation to reproductive activities and age, but not gender.

  13. Break the Kill Chain, Not the Budget: How to Avoid U.S. Strategic Retrenchment

    2016-06-10

    mass quantities. The United States maintained a Cold War offset strategy focused on technology and kill chain annihilation with an understanding of...Annihilating the kill chain with advanced instruments of war is more the norm than the exception in the post- Cold War era U.S. military. The U.S. Air...Masters Thesis 3. DATES COVERED (From - To) 27-07-2015 to 10-06-2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER BREAK THE KILL CHAIN

  14. How Effective Is Road Mitigation at Reducing Road-Kill? A Meta-Analysis

    Rytwinski, Trina; Soanes, Kylie; Jaeger, Jochen A. G.; Fahrig, Lenore; Findlay, C. Scott; Houlahan, Jeff; van der Ree, Rodney; van der Grift, Edgar A

    2016-01-01

    Road traffic kills hundreds of millions of animals every year, posing a critical threat to the populations of many species. To address this problem there are more than forty types of road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill). For road planners, deciding on what mitigation method to use has been problematic because there is little good information about the relative effectiveness of these measures in reducing road-kill, and the costs of these...

  15. Multiple factors and processes involved in host cell killing by bacteriophage Mu: characterization and mapping.

    Waggoner, B T; Marrs, C F; Howe, M M; Pato, M L

    1984-07-15

    The regions of bacteriophage Mu involved in host cell killing were determined by infection of a lambda-immune host with 12 lambda pMu-transducing phages carrying different amounts of Mu DNA beginning at the left end. Infecting lambda pMu phages containing 5.0 (+/- 0.2) kb or less of the left end of Mu DNA did not kill the lambda-immune host, whereas lambda pMu containing 5.1 kb did kill, thus locating the right end of the kil gene between approximately 5.0 and 5.1 kb. For the Kil+ phages the extent of killing increased as the multiplicity of infection (m.o.i.) increased. In addition, killing was also affected by the presence of at least two other regions of Mu DNA: one, located between 5.1 and 5.8 kb, decreased the extent of killing; the other, located between 6.3 and 7.9 kb, greatly increased host cell killing. Killing was also assayed after lambda pMu infection of a lambda-immune host carrying a mini-Mu deleted for most of the B gene and the middle region of Mu DNA. Complementation of mini-Mu replication by infecting B+ lambda pMu phages resulted in killing of the lambda-immune, mini-Mu-containing host, regardless of the presence or absence of the Mu kil gene. The extent of host cell killing increased as the m.o.i. of the infecting lambda pMu increased, and was further enhanced by both the presence of the kil gene and the region located between 6.3 and 7.9 kb. These distinct processes of kil-mediated killing in the absence of replication and non-kil-mediated killing in the presence of replication were also observed after induction of replication-deficient and kil mutant prophages, respectively.

  16. An Analysis Of Intrinsic Elements In Harper Lee’s To Kill A Mockingbird

    Simbolon, Hendra Halomoan

    2011-01-01

    Skripsi ini berjudul “An Analysis of Intrinsic Elements in Harper Lee’s To Kill A Mockingbird”. Skripsi ini mengenai unsur-unsur intrinsik yakni karakter, plot, setting, tema, sudut pandang dan gaya penulisan yang terdapat pada karya Charles Dickens yang berjudul To Kill A Mockingbird. Di dalam skripsi ini, penulis ingin membuktikan keterkaitan unsur-unsur intrinsik yang terdapat dalam novel To Kill A Mockingbird karya Harper Lee. Adapun metode yang digunakan penul...

  17. Experiment for dose measurement during beam killing at Indus-1 synchrotron radiation source

    Nayak, M.K.; Dev, Vipin; Haridas, G.; Thakkar, K.K.; Sarkar, P.K.; Sharma, D.N.

    2006-01-01

    Experimental measurement of radiation dose likely to be received by an occupational worker in the experimental hall of Indus-1 during accidental beam killing was carried out. Various accidental beam-killing scenarios were experimentally simulated for the measurement. The measurement was carried out using direct reading dosimeters. Result shows that in the event of accidental beam killing, dose likely to be received by an occupational worker outside the shield is negligible. (author)

  18. The number of killings in southern rural Norway, 1300–1569

    Kadane, Joseph B.; Næshagen, Ferdinand L.

    2013-01-01

    Three dual systems estimates are employed to study the number of killings in southern rural Norway in a period of slightly over 250 years. The first system is a set of five letters sent to each killer as part of the legal process. The second system is the mention of killings from all other contemporary sources. The posterior distributions derived suggest fewer such killings than rough demographic estimates.

  19. Age and sex composition of seals killed by polar bears in the eastern Beaufort Sea.

    Pilfold, Nicholas W; Derocher, Andrew E; Stirling, Ian; Richardson, Evan; Andriashek, Dennis

    2012-01-01

    Polar bears (Ursus maritimus) of the Beaufort Sea enter hyperphagia in spring and gain fat reserves to survive periods of low prey availability. We collected information on seals killed by polar bears (n=650) and hunting attempts on ringed seal (Pusa hispida) lairs (n=1396) observed from a helicopter during polar bear mark-recapture studies in the eastern Beaufort Sea in spring in 1985-2011. We investigated how temporal shifts in ringed seal reproduction affect kill composition and the intraspecific vulnerabilities of ringed seals to polar bear predation. Polar bears primarily preyed on ringed seals (90.2%) while bearded seals (Erignathus barbatus) only comprised 9.8% of the kills, but 33% of the biomass. Adults comprised 43.6% (150/344) of the ringed seals killed, while their pups comprised 38.4% (132/344). Juvenile ringed seals were killed at the lowest proportion, comprising 18.0% (62/344) of the ringed seal kills. The proportion of ringed seal pups was highest between 2007-2011, in association with high ringed seal productivity. Half of the adult ringed seal kills were ≥ 21 years (60/121), and kill rates of adults increased following the peak of parturition. Determination of sex from DNA revealed that polar bears killed adult male and adult female ringed seals equally (0.50, n=78). The number of hunting attempts at ringed seal subnivean lair sites was positively correlated with the number of pup kills (r(2) =0.30, P=0.04), but was not correlated with the number of adult kills (P=0.37). Results are consistent with decadal trends in ringed seal productivity, with low numbers of pups killed by polar bears in spring in years of low pup productivity, and conversely when pup productivity was high. Vulnerability of adult ringed seals to predation increased in relation to reproductive activities and age, but not gender.

  20. An evaluation of sex-age-kill (SAK) model performance

    Millspaugh, Joshua J.; Skalski, John R.; Townsend, Richard L.; Diefenbach, Duane R.; Boyce, Mark S.; Hansen, Lonnie P.; Kammermeyer, Kent

    2009-01-01

    The sex-age-kill (SAK) model is widely used to estimate abundance of harvested large mammals, including white-tailed deer (Odocoileus virginianus). Despite a long history of use, few formal evaluations of SAK performance exist. We investigated how violations of the stable age distribution and stationary population assumption, changes to male or female harvest, stochastic effects (i.e., random fluctuations in recruitment and survival), and sampling efforts influenced SAK estimation. When the simulated population had a stable age distribution and λ > 1, the SAK model underestimated abundance. Conversely, when λ < 1, the SAK overestimated abundance. When changes to male harvest were introduced, SAK estimates were opposite the true population trend. In contrast, SAK estimates were robust to changes in female harvest rates. Stochastic effects caused SAK estimates to fluctuate about their equilibrium abundance, but the effect dampened as the size of the surveyed population increased. When we considered both stochastic effects and sampling error at a deer management unit scale the resultant abundance estimates were within ±121.9% of the true population level 95% of the time. These combined results demonstrate extreme sensitivity to model violations and scale of analysis. Without changes to model formulation, the SAK model will be biased when λ ≠ 1. Furthermore, any factor that alters the male harvest rate, such as changes to regulations or changes in hunter attitudes, will bias population estimates. Sex-age-kill estimates may be precise at large spatial scales, such as the state level, but less so at the individual management unit level. Alternative models, such as statistical age-at-harvest models, which require similar data types, might allow for more robust, broad-scale demographic assessments.

  1. Bystander Host Cell Killing Effects of Clostridium perfringens Enterotoxin

    Archana Shrestha

    2016-12-01

    Full Text Available Clostridium perfringens enterotoxin (CPE binds to claudin receptors, e.g., claudin-4, and then forms a pore that triggers cell death. Pure cultures of host cells that do not express claudin receptors, e.g., fibroblasts, are unaffected by pathophysiologically relevant CPE concentrations in vitro. However, both CPE-insensitive and CPE-sensitive host cells are present in vivo. Therefore, this study tested whether CPE treatment might affect fibroblasts when cocultured with CPE-sensitive claudin-4 fibroblast transfectants or Caco-2 cells. Under these conditions, immunofluorescence microscopy detected increased death of fibroblasts. This cytotoxic effect involved release of a toxic factor from the dying CPE-sensitive cells, since it could be reproduced using culture supernatants from CPE-treated sensitive cells. Supernatants from CPE-treated sensitive cells, particularly Caco-2 cells, were found to contain high levels of membrane vesicles, often containing a CPE species. However, most cytotoxic activity remained in those supernatants even after membrane vesicle depletion, and CPE was not detected in fibroblasts treated with supernatants from CPE-treated sensitive cells. Instead, characterization studies suggest that a major cytotoxic factor present in supernatants from CPE-treated sensitive cells may be a 10- to 30-kDa host serine protease or require the action of that host serine protease. Induction of caspase-3-mediated apoptosis was found to be important for triggering release of the cytotoxic factor(s from CPE-treated sensitive host cells. Furthermore, the cytotoxic factor(s in these supernatants was shown to induce a caspase-3-mediated killing of fibroblasts. This bystander killing effect due to release of cytotoxic factors from CPE-treated sensitive cells could contribute to CPE-mediated disease.

  2. Melanoma stem cells in experimental melanoma are killed by radioimmunotherapy

    Jandl, Thomas; Revskaya, Ekaterina; Jiang, Zewei; Harris, Matthew; Dorokhova, Olena; Tsukrov, Dina; Casadevall, Arturo; Dadachova, Ekaterina

    2013-01-01

    Introduction: In spite of recently approved B-RAF inhibitors and immunomodulating antibodies, metastatic melanoma has poor prognosis and novel treatments are needed. Melanoma stem cells (MSC) have been implicated in the resistance of this tumor to chemotherapy. Recently we demonstrated in a Phase I clinical trial in patients with metastatic melanoma that radioimmunotherapy (RIT) with 188-Rhenium( 188 Re)-6D2 antibody to melanin was a safe and effective modality. Here we investigated the interaction of MSC with RIT as a possible mechanism for RIT efficacy. Methods: Mice bearing A2058 melanoma xenografts were treated with either 1.5 mCi 188 Re-6D2 antibody, saline, unlabeled 6D2 antibody or 188 Re-labeled non-specific IgM. Results: On Day 28 post-treatment the tumor size in the RIT group was 4-times less than in controls (P < 0.001). The tumors were analyzed by immunohistochemistry and FACS for two MSC markers — chemoresistance mediator ABCB5 and H3K4 demethylase JARID1B. There were no significant differences between RIT and control groups in percentage of ABCB5 or JARID1B-positive cells in the tumor population. Our results demonstrate that unlike chemotherapy, which kills tumor cells but leaves behind MSC leading to recurrence, RIT kills MSC at the same rate as the rest of tumor cells. Conclusions: These results have two main implications for melanoma treatment and possibly other cancers. First, the susceptibility of ABCB5 + and JARID1B + cells to RIT in melanoma might be indicative of their susceptibility to antibody-targeted radiation in other cancers where they are present as well. Second, specifically targeting cancer stem cells with radiolabeled antibodies to ABCB5 or JARID1B might help to completely eradicate cancer stem cells in various cancers

  3. Potentiation of radiation-induced cell kill by synthetic metalloporphyrins

    O'Hara, J.A.; Douple, E.B.; Abrams, M.J.; Picker, D.J.; Giandomenico, C.M.; Vollano, J.F.

    1989-01-01

    The effects of the combination of several meso-substituted, water soluble metalloporphyrins with ionizing radiation on hypoxic and oxic monolayers of Chinese hamster fibroblast (V79N) cells were studied. The metalloporphyrins tested included a series of cationic metalloporphyrins complexed with Co(III), Zn(II), Fe(III), Cu(II), Pd(II) or Mn(III) and a series of anionic porphyrins chelated with Co(III), Fe(III), Cu(II), Rh(III), Mn(III) or Sn(IV). Both cationic and anionic free porphyrins were also tested. Cationic ligands were tetrakis(4N-methylpyridyl)porphine [TMPyP], tetrakis(4N-trimethylamino phenyl)porphine [TMAP], tetrakis(4N-butylpyridyl)porphine [TBPyP] and tetrakis(3N-methylpyridyl)porphine [3TMPyP]. Anionic ligands tested were tetrakis(4-sulfonato phenyl)porphine [TPPS], tetrakis(biphenyl)porphine sulfonate [TBPS] and tetrakis(4-carboxyphenyl)porphine [TCPP]. SER calculated from survival curves and SFR from one radiation dose were used to assess the relative effectiveness of this class as non-cytotoxic hypoxic and oxic cell-kill potentiators. Comparisons were made at 100 microM, which was essentially non-toxic (greater than 70% survival) for all porphyrins tested except for Co[TMPyP] (approximately 50% survival after 1 hour at 37 degrees C under oxic conditions). The greatest effects on radiation-induced cell kill were achieved with Co[TPPS] and Co[TMPyP] with SER values of 2.3 and 2.4 respectively. Porphyrin analogs with no coordinated metal were found to be less active than the same compound with metal. The overall charge on the molecule did not systematically relate to the biological activity of the compounds tested

  4. Male killing Spiroplasma protects Drosophila melanogaster against two parasitoid wasps

    Xie, J; Butler, S; Sanchez, G; Mateos, M

    2014-01-01

    Maternally transmitted associations between endosymbiotic bacteria and insects are diverse and widespread in nature. Owing to imperfect vertical transmission, many heritable microbes have evolved compensational mechanisms to enhance their persistence in host lineages, such as manipulating host reproduction and conferring fitness benefits to host. Symbiont-mediated defense against natural enemies of hosts is increasingly recognized as an important mechanism by which endosymbionts enhance host fitness. Members of the genus Spiroplasma associated with distantly related Drosophila hosts are known to engage in either reproductive parasitism (i.e., male killing) or defense against natural enemies (the parasitic wasp Leptopilina heterotoma and a nematode). A male-killing strain of Spiroplasma (strain Melanogaster Sex Ratio Organism (MSRO)) co-occurs with Wolbachia (strain wMel) in certain wild populations of the model organism Drosophila melanogaster. We examined the effects of Spiroplasma MSRO and Wolbachia wMel on Drosophila survival against parasitism by two common wasps, Leptopilina heterotoma and Leptopilina boulardi, that differ in their host ranges and host evasion strategies. The results indicate that Spiroplasma MSRO prevents successful development of both wasps, and confers a small, albeit significant, increase in larva-to-adult survival of flies subjected to wasp attacks. We modeled the conditions under which defense can contribute to Spiroplasma persistence. Wolbachia also confers a weak, but significant, survival advantage to flies attacked by L. heterotoma. The host protective effects exhibited by Spiroplasma and Wolbachia are additive and may provide the conditions for such cotransmitted symbionts to become mutualists. Occurrence of Spiroplasma-mediated protection against distinct parasitoids in divergent Drosophila hosts suggests a general protection mechanism. PMID:24281548

  5. To Kill, Stay or Flee: The Effects of Lions and Landscape Factors on Habitat and Kill Site Selection of Cheetahs in South Africa

    Rostro-Garc?a, Susana; Kamler, Jan F.; Hunter, Luke T. B.

    2015-01-01

    Understanding how animals utilize available space is important for their conservation, as it provides insight into the ecological needs of the species, including those related to habitat, prey and inter and intraspecific interactions. We used 28 months of radio telemetry data and information from 200 kill locations to assess habitat selection at the 3rd order (selection of habitats within home ranges) and 4th order (selection of kill sites within the habitats used) of a reintroduced populatio...

  6. Carbon stocks of trees killed by bark beetles and wildfire in the western United States

    Hicke, Jeffrey A; Meddens, Arjan J H; Kolden, Crystal A; Allen, Craig D

    2013-01-01

    Forests are major components of the carbon cycle, and disturbances are important influences of forest carbon. Our objective was to contribute to the understanding of forest carbon cycling by quantifying the amount of carbon in trees killed by two disturbance types, fires and bark beetles, in the western United States in recent decades. We combined existing spatial data sets of forest biomass, burn severity, and beetle-caused tree mortality to estimate the amount of aboveground and belowground carbon in killed trees across the region. We found that during 1984–2010, fires killed trees that contained 5–11 Tg C year −1 and during 1997–2010, beetles killed trees that contained 2–24 Tg C year −1 , with more trees killed since 2000 than in earlier periods. Over their periods of record, amounts of carbon in trees killed by fires and by beetle outbreaks were similar, and together these disturbances killed trees representing 9% of the total tree carbon in western forests, a similar amount to harvesting. Fires killed more trees in lower-elevation forest types such as Douglas-fir than higher-elevation forest types, whereas bark beetle outbreaks also killed trees in higher-elevation forest types such as lodgepole pine and Engelmann spruce. Over 15% of the carbon in lodgepole pine and spruce/fir forest types was in trees killed by beetle outbreaks; other forest types had 5–10% of the carbon in killed trees. Our results document the importance of these natural disturbances in the carbon budget of the western United States. (letter)

  7. Effects of Vegetation Structure on the Location of Lion Kill Sites in African Thicket.

    Andrew B Davies

    Full Text Available Predator-prey relationships are integral to ecosystem stability and functioning. These relationships are, however, difficult to maintain in protected areas where large predators are increasingly being reintroduced and confined. Where predators make kills has a profound influence on their role in ecosystems, but the relative importance of environmental variables in determining kill sites, and how these might vary across ecosystems is poorly known. We investigated kill sites for lions in South Africa's thicket biome, testing the importance of vegetation structure for kill site locations compared to other environmental variables. Kill sites were located over four years using GPS telemetry and compared to non-kill sites that had been occupied by lions, as well as to random sites within lion ranges. Measurements of 3D vegetation structure obtained from Light Detection and Ranging (LiDAR were used to calculate the visible area (viewshed around each site and, along with wind and moonlight data, used to compare kill sites between lion sexes, prey species and prey sexes. Viewshed area was the most important predictor of kill sites (sites in dense vegetation were twice as likely to be kill sites compared to open areas, followed by wind speed and, less so, moonlight. Kill sites for different prey species varied with vegetation structure, and male prey were killed when wind speeds were higher compared to female prey of the same species. Our results demonstrate that vegetation structure is an important component of predator-prey interactions, with varying effects across ecosystems. Such differences require consideration in terms of the ecological roles performed by predators, and in predator and prey conservation.

  8. Effects of Vegetation Structure on the Location of Lion Kill Sites in African Thicket.

    Davies, Andrew B; Tambling, Craig J; Kerley, Graham I H; Asner, Gregory P

    2016-01-01

    Predator-prey relationships are integral to ecosystem stability and functioning. These relationships are, however, difficult to maintain in protected areas where large predators are increasingly being reintroduced and confined. Where predators make kills has a profound influence on their role in ecosystems, but the relative importance of environmental variables in determining kill sites, and how these might vary across ecosystems is poorly known. We investigated kill sites for lions in South Africa's thicket biome, testing the importance of vegetation structure for kill site locations compared to other environmental variables. Kill sites were located over four years using GPS telemetry and compared to non-kill sites that had been occupied by lions, as well as to random sites within lion ranges. Measurements of 3D vegetation structure obtained from Light Detection and Ranging (LiDAR) were used to calculate the visible area (viewshed) around each site and, along with wind and moonlight data, used to compare kill sites between lion sexes, prey species and prey sexes. Viewshed area was the most important predictor of kill sites (sites in dense vegetation were twice as likely to be kill sites compared to open areas), followed by wind speed and, less so, moonlight. Kill sites for different prey species varied with vegetation structure, and male prey were killed when wind speeds were higher compared to female prey of the same species. Our results demonstrate that vegetation structure is an important component of predator-prey interactions, with varying effects across ecosystems. Such differences require consideration in terms of the ecological roles performed by predators, and in predator and prey conservation.

  9. Patterns and Composition of Road-Killed Wildlife in Northwest Argentina

    Cuyckens, Griet An Erica; Mochi, Lucía Sol; Vallejos, María; Perovic, Pablo Gastón; Biganzoli, Fernando

    2016-11-01

    Roads have important effects on wildlife, such as natural habitat fragmentation and degradation and direct killing of fauna, which leads to reductions in wildlife population size. We focused on a principal road in Northwest Argentina to test for the effect of seasonality and landscape features on the composition of road-killed wildlife. We conducted regularly scheduled road trips during the dry and wet seasons. We recorded the presence or absence of a vegetation curtain or hedge along the road. We measured land use by remote sensing in a 500 m buffer along the road. We compared the abundance of animals killed between seasons (dry and wet) for different taxonomic groups (mammals, birds and reptiles) and for different origins (domestic and native). We built linear mixed models to test the effect of landscape features on the abundance of killed animals. Two hundred and ninety-three individuals were killed, belonging to 35 species; 75.8 % were native and 24.2 % domestic species. The majority of animals killed were mid-sized mammals. More animals were killed during the dry season. The most important factors to explain the wildlife road-killing were the season and the proportion of agricultural landscape. The composition of the killed animals changed with the season. The proportion of agricultural landscape incremented the number of killed birds and mammals during both seasons, without affecting reptiles. The ratio of wild to domestic animals killed was dependent on the season. This study sets a precedent as the first in road ecology in Northwest Argentina and should be taken into account for road planning and regulation.

  10. Peptidoglycan recognition proteins kill bacteria by inducing oxidative, thiol, and metal stress.

    Des Raj Kashyap

    2014-07-01

    Full Text Available Mammalian Peptidoglycan Recognition Proteins (PGRPs are a family of evolutionary conserved bactericidal innate immunity proteins, but the mechanism through which they kill bacteria is unclear. We previously proposed that PGRPs are bactericidal due to induction of reactive oxygen species (ROS, a mechanism of killing that was also postulated, and later refuted, for several bactericidal antibiotics. Here, using whole genome expression arrays, qRT-PCR, and biochemical tests we show that in both Escherichia coli and Bacillus subtilis PGRPs induce a transcriptomic signature characteristic of oxidative stress, as well as correlated biochemical changes. However, induction of ROS was required, but not sufficient for PGRP killing. PGRPs also induced depletion of intracellular thiols and increased cytosolic concentrations of zinc and copper, as evidenced by transcriptome changes and supported by direct measurements. Depletion of thiols and elevated concentrations of metals were also required, but by themselves not sufficient, for bacterial killing. Chemical treatment studies demonstrated that efficient bacterial killing can be recapitulated only by the simultaneous addition of agents leading to production of ROS, depletion of thiols, and elevation of intracellular metal concentrations. These results identify a novel mechanism of bacterial killing by innate immunity proteins, which depends on synergistic effect of oxidative, thiol, and metal stress and differs from bacterial killing by antibiotics. These results offer potential targets for developing new antibacterial agents that would kill antibiotic-resistant bacteria.

  11. Quantification of dichlorvos released from kill strips used in boll weevil eradication programs

    Two types of kill strips, Hercon Vaportape II and Plato Insecticide Strip, are used by boll weevil, Anthonomus grandis (Boheman), eradication programs in the U.S. Both types utilize dichlorvos as the killing agent and are marketed to last up to a month in traps. Consequently, programs typically re...

  12. 9 CFR 113.202 - Canine Hepatitis and Canine Adenovirus Type 2 Vaccine, Killed Virus.

    2010-01-01

    ... Type 2 Vaccine, Killed Virus. 113.202 Section 113.202 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.202 Canine Hepatitis and Canine...

  13. 9 CFR 113.207 - Encephalomyelitis Vaccine, Eastern, Western, and Venezuelan, Killed Virus.

    2010-01-01

    ..., Western, and Venezuelan, Killed Virus. 113.207 Section 113.207 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.207 Encephalomyelitis...

  14. Habitat or matrix: which is more relevant to predict road-kill of vertebrates?

    Bueno, C; Sousa, C O M; Freitas, S R

    2015-11-01

    We believe that in tropics we need a community approach to evaluate road impacts on wildlife, and thus, suggest mitigation measures for groups of species instead a focal-species approach. Understanding which landscape characteristics indicate road-kill events may also provide models that can be applied in other regions. We intend to evaluate if habitat or matrix is more relevant to predict road-kill events for a group of species. Our hypothesis is: more permeable matrix is the most relevant factor to explain road-kill events. To test this hypothesis, we chose vertebrates as the studied assemblage and a highway crossing in an Atlantic Forest region in southeastern Brazil as the study site. Logistic regression models were designed using presence/absence of road-kill events as dependent variables and landscape characteristics as independent variables, which were selected by Akaike's Information Criterion. We considered a set of candidate models containing four types of simple regression models: Habitat effect model; Matrix types effect models; Highway effect model; and, Reference models (intercept and buffer distance). Almost three hundred road-kills and 70 species were recorded. River proximity and herbaceous vegetation cover, both matrix effect models, were associated to most road-killed vertebrate groups. Matrix was more relevant than habitat to predict road-kill of vertebrates. The association between river proximity and road-kill indicates that rivers may be a preferential route for most species. We discuss multi-species mitigation measures and implications to movement ecology and conservation strategies.

  15. How effective is road mitigation at reducing road-kill? A meta-analysis

    Rytwinski, Trina; Soanes, Kylie; Jaeger, Jochen A.G.; Fahrig, Lenore; Findlay, C.S.; Houlahan, Jeff; Ree, van der Rodney; Grift, van der Edgar A.

    2016-01-01

    Road traffic kills hundreds of millions of animals every year, posing a critical threat to the populations of many species. To address this problem there are more than forty types of road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill). For road planners,

  16. Comparing Road-Kill Datasets from Hunters and Citizen Scientists in a Landscape Context

    Florian Heigl

    2016-10-01

    Full Text Available Road traffic has severe effects on animals, especially when road-kills are involved. In many countries, official road-kill data are provided by hunters or police; there are also road-kill observations reported by citizen scientists. The aim of the current study was to test whether road-kill reports by hunters stem from similar landscapes than those reported by citizen scientists. We analysed the surrounding landscapes of 712 road-kill reportings of European hares in the province of Lower Austria. Our data showed that road-killed hares reported both by hunters and citizens are predominantly surrounded by arable land. No difference of hedges and solitary trees could be found between the two datasets. However, significant differences in landcover classes and surrounding road networks indicate that hunters’ and citizen scientists’ data are different. Hunters reported hares from landscapes with significantly higher percentages of arable land, and greater lengths of secondary roads. In contrast, citizens reported hares from landscapes with significantly higher percentages of urban or industrial areas and greater lengths of motorways, primary roads, and residential roads. From this we argue that hunters tend to report data mainly from their hunting areas, whereas citizens report data during their daily routine on the way to/from work. We conclude that a citizen science approach is an important source for road-kill data when used in addition to official data with the aim of obtaining an overview of road-kill events on a landscape scale.

  17. A New Calculation Method of Dynamic Kill Fluid Density Variation during Deep Water Drilling

    Honghai Fan

    2017-01-01

    Full Text Available There are plenty of uncertainties and enormous challenges in deep water drilling due to complicated shallow flow and deep strata of high temperature and pressure. This paper investigates density of dynamic kill fluid and optimum density during the kill operation process in which dynamic kill process can be divided into two stages, that is, dynamic stable stage and static stable stage. The dynamic kill fluid consists of a single liquid phase and different solid phases. In addition, liquid phase is a mixture of water and oil. Therefore, a new method in calculating the temperature and pressure field of deep water wellbore is proposed. The paper calculates the changing trend of kill fluid density under different temperature and pressure by means of superposition method, nonlinear regression, and segment processing technique. By employing the improved model of kill fluid density, deep water kill operation in a well is investigated. By comparison, the calculated density results are in line with the field data. The model proposed in this paper proves to be satisfactory in optimizing dynamic kill operations to ensure the safety in deep water.

  18. Using DNA to describe and quantify interspecific killing of fishers in California

    Greta M. Wengert; Mourad W. Gabriel; Sean M. Matthews; J. Mark Higley; Rick A. Sweitzer; Craig. M. Thompson; Kathryn L. Purcell; Reginald H. Barrett; Leslie W. Woods; Rebecca E. Green; Stefan M. Keller; Patricia M. Gaffney; Megan Jones; Benjamin N. Sacks

    2014-01-01

    Interspecific killing is common among carnivores and can have population-level effects on imperiled species. The fisher (Pekania [Martes] pennant) is a rare forest carnivore in western North America and a candidate for listing under the United States Endangered Species Act. Interspecific killing and...

  19. Mothers Who Kill Their Offspring: Testing Evolutionary Hypothesis in a 110-Case Italian Sample

    Camperio Ciani, Andrea S.; Fontanesi, Lilybeth

    2012-01-01

    Objectives: This research aimed to identify incidents of mothers in Italy killing their own children and to test an adaptive evolutionary hypothesis to explain their occurrence. Methods: 110 cases of mothers killing 123 of their own offspring from 1976 to 2010 were analyzed. Each case was classified using 13 dichotomic variables. Descriptive…

  20. ANALYSIS OF MATERIALS IN AN EXPERIMENTAL TESTING PIPE SYSTEM FOR AN INHIBITOR OF MUSSEL KILL

    Daniel P. Molloy

    2003-06-04

    A comprehensive series of 16 laboratory experiments demonstrated that the presence of vinyl tubing within a recirculating pipe system was responsible for lowering zebra mussel kill following treatment with the bacterium Pseudomonas fluorescens. All vinyl tubing was replaced in all testing units with silicone tubing, and high mussel kill (>95%) was then obtained.

  1. Comparison of two mathematical models for describing heat-induced cell killing

    Roti Roti, J.L.; Henle, K.J.

    1980-01-01

    A computer-based minimization algorithm is utilized to obtain the optimum fits of two models to hyperthermic cell killing data. The models chosen are the multitarget, single-hit equation, which is in general use, and the linear-quadratic equation, which has been applied to cell killing by ionizing irradiation but not to heat-induced cell killing. The linear-quadratic equation fits hyperthermic cell killing data as well as the multitarget, single-hit equation. Both parameters of the linear-quadratic equation obey the Arrhenius law, whereas only one of the two parameters of the multitarget, single-hit equation obeys the Arrhenius law. Thus the linear-quadratic function can completely define cell killing as a function of both time and temperature. In addition, the linear-quadratic model will provide a simplified approach to the study of the synergism between heat and X irradiation

  2. NH125 kills methicillin-resistant Staphylococcus aureus persisters by lipid bilayer disruption.

    Kim, Wooseong; Fricke, Nico; Conery, Annie L; Fuchs, Beth Burgwyn; Rajamuthiah, Rajmohan; Jayamani, Elamparithi; Vlahovska, Petia M; Ausubel, Frederick M; Mylonakis, Eleftherios

    2016-01-01

    NH125, a known WalK inhibitor kills MRSA persisters. However, its precise mode of action is still unknown. The mode of action of NH125 was investigated by comparing its spectrum of antimicrobial activity and its effects on membrane permeability and giant unilamellar vesicles (GUVs) with walrycin B, a WalR inhibitor and benzyldimethylhexadecylammonium chloride (16-BAC), a cationic surfactant. NH125 killed persister cells of a variety of Staphylococcus aureus strains. Similar to 16-BAC, NH125 killed MRSA persisters by inducing rapid membrane permeabilization and caused the rupture of GUVs, whereas walrycin B did not kill MRSA persisters or induce membrane permeabilization and did not affect GUVs. NH125 kills MRSA persisters by interacting with and disrupting membranes in a detergent-like manner.

  3. Rapid kill-novel endodontic sealer and Enterococcus faecalis.

    Nurit Beyth

    Full Text Available With growing concern over bacterial resistance, the identification of new antimicrobial means is paramount. In the oral cavity microorganisms are essential to the development of periradicular diseases and are the major causative factors associated with endodontic treatment failure. As quaternary ammonium compounds have the ability to kill a wide array of bacteria through electrostatic interactions with multiple anionic targets on the bacterial surface, it is likely that they can overcome bacterial resistance. Melding these ideas, we investigated the potency of a novel endodontic sealer in limiting Enterococcus faecalis growth. We used a polyethyleneimine scaffold to synthesize nano-sized particles, optimized for incorporation into an epoxy-based endodontic sealer. The novel endodontic sealer was tested for its antimicrobial efficacy and evaluated for biocompatibility and physical eligibility. Our results show that the novel sealer foundation affixes the nanoparticles, achieving surface bactericidal properties, but at the same time impeding nanoparticle penetration into eukaryotic cells and thereby mitigating a possible toxic effect. Moreover, adequate physical properties are maintained. The nanosized quaternary amine particles interact within minutes with bacteria, triggering cell death across wide pH values. Throughout this study we demonstrate a new antibacterial perspective for endodontic sealers; a novel antibacterial, effective and safe antimicrobial means.

  4. Targeted Anticancer Immunotoxins and Cytotoxic Agents with Direct Killing Moieties

    Koji Kawakami

    2006-01-01

    Full Text Available Despite the progress of the bioinformatics approach to characterize cell-surface antigens and receptors on tumor cells, it remains difficult to generate novel cancer vaccines or neutralizing monoclonal antibody therapeutics. Among targeted cancer therapeutics, biologicals with targetable antibodies or ligands conjugated or fused to toxins or chemicals for direct cell-killing ability have been developed over the last 2 decades. These conjugated or fused chimeric proteins are termed immunotoxins or cytotoxic agents. Two agents, DAB389IL-2 (ONTAKTM targeting the interleukin-2 receptor and CD33-calicheamicin (Mylotarg®, have been approved by the FDA for cutaneous T-cell lymphoma (CTCL and relapsed acute myeloid leukemia (AML, respectively. Such targetable agents, including RFB4(dsFv-PE38 (BL22, IL13-PE38QQR, and Tf-CRM107, are being tested in clinical trials. Several agents using unique technology such as a cleavable adapter or immunoliposomes with antibodies are also in the preclinical stage. This review summarizes the generation, mechanism, and development of these agents. In addition, possible future directions of this therapeutic approach are discussed.

  5. Killing mediated spatial structure in V. Cholerae biofilms

    Yanni, David

    Most bacteria live in biofilms, which are implicated in 60 - 80 % of microbial infections in the body. The spatial structure of a biofilm confers advantages to its member-cells, such as antibiotic resistance, and is strongly affected by competition between strains and taxa. However, A complete picture of how competition affects the self-organized structure of these complex, far-from-equilibrium systems, is yet to emerge. To that end, we investigate phase separation dynamics driven by T6SS-facilitated bacterial warfare in a system composed of two strains of mutually antagonistic V. cholerae. T6SS is a contact mediated killing mechanism present in 25 % of all gram negative bacteria, and has been shown by recent work to play a major role in the spatial assortment of biofilms. T6SS events induce lysis, causing variations in local mechanical pressure, and acting as thermalizing events. We study cells immobilized in biofilms at the air-solid interface, so our experimental system represents a different type active matter, wherein activity is due to cell death and reproduction, not mobility. Here, we show how that activity imposes a constraint of minimal curvature on strain-strain interfaces; an effective Laplace pressure is characterized which governs interfacial dynamics.

  6. Resistance to and killing by the sporicidal microbicide peracetic acid.

    Leggett, Mark J; Schwarz, J Spencer; Burke, Peter A; Mcdonnell, Gerald; Denyer, Stephen P; Maillard, Jean-Yves

    2015-03-01

    To elucidate the mechanisms of spore resistance to and killing by the oxidizing microbicide peracetic acid (PAA). Mutants of Bacillus subtilis lacking specific spore structures were used to identify resistance properties in spores and to understand the mechanism of action of PAA. We also assessed the effect of PAA treatment on a number of spore properties including heat tolerance, membrane integrity and germination. The spore coat is essential for spore PAA resistance as spores with defective coats were greatly sensitized to PAA treatment. Small acid-soluble spore proteins apparently provide no protection against PAA. Defects in spore germination, specifically in germination via the GerB and GerK but not the GerA germination receptors, as well as leakage of internal components suggest that PAA is active at the spore inner membrane. It is therefore likely that the inner membrane is the major site of PAA's sporicidal activity. PAA treatment targets the spore membrane, with some of its activity directed specifically against the GerB and GerK germination receptors. © The Author 2014. 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.

  7. Filicide: mental illness in those who kill their children.

    Flynn, Sandra M; Shaw, Jenny J; Abel, Kathryn M

    2013-01-01

    Most child victims of homicide are killed by a parent or step-parent. This large population study provides a contemporary and detailed description of filicide perpetrators. We examined the relationship between filicide and mental illness at the time of the offence, and care received from mental health services in the past. All filicide and filicide-suicide cases in England and Wales (1997-2006) were drawn from a national index of homicide perpetrators. Data on people in contact with mental health services were obtained via a questionnaire from mental health teams. Additional clinical information was collected from psychiatric reports. 6144 people were convicted of homicide, 297 were filicides, and 45 cases were filicide-suicides. 195 (66%) perpetrators were fathers. Mothers were more likely than fathers to have a history of mental disorder (66% v 27%) and symptoms at the time of the offence (53% v 23%), most often affective disorder. 17% of mothers had schizophrenia or other delusional disorders. Overall 8% had schizophrenia. 37% were mentally ill at the time of the offence. 20% had previously been in contact with mental health services, 12% within a year of the offence. In the majority of cases, mental illness was not a feature of filicide. However, young mothers and parents with severe mental illness, especially affective and personality disorder who are providing care for children, require careful monitoring by mental health and other support services. Identifying risk factors for filicide requires further research.

  8. Filicide: mental illness in those who kill their children.

    Sandra M Flynn

    Full Text Available Most child victims of homicide are killed by a parent or step-parent. This large population study provides a contemporary and detailed description of filicide perpetrators. We examined the relationship between filicide and mental illness at the time of the offence, and care received from mental health services in the past.All filicide and filicide-suicide cases in England and Wales (1997-2006 were drawn from a national index of homicide perpetrators. Data on people in contact with mental health services were obtained via a questionnaire from mental health teams. Additional clinical information was collected from psychiatric reports.6144 people were convicted of homicide, 297 were filicides, and 45 cases were filicide-suicides. 195 (66% perpetrators were fathers. Mothers were more likely than fathers to have a history of mental disorder (66% v 27% and symptoms at the time of the offence (53% v 23%, most often affective disorder. 17% of mothers had schizophrenia or other delusional disorders. Overall 8% had schizophrenia. 37% were mentally ill at the time of the offence. 20% had previously been in contact with mental health services, 12% within a year of the offence.In the majority of cases, mental illness was not a feature of filicide. However, young mothers and parents with severe mental illness, especially affective and personality disorder who are providing care for children, require careful monitoring by mental health and other support services. Identifying risk factors for filicide requires further research.

  9. Book review: Mosquito eradication: The story of killing Campto

    Lapointe, Dennis

    2015-01-01

    In 1826, the paradise that was the Hawaiian Islands was changed forever when the first mosquito species was accidentally introduced to the island of Maui. Though it has not lived up to its potential as a vector of human disease in the islands, Culex quinquefasciatus and the avian pathogens it transmits laid waste to perhaps the world's most remarkable insular avifauna. Today the lowland native forests, once deafening with birdsong, are largely devoid of native birds and Cx. quinquefasciatus has become an inextricable part of our natural areas. In the Hawaiian Islands, the conservation community struggles to keep invasive species out and to control a number of species that have become naturalized. Despite the millions of dollars spent, these efforts never seem enough to slow the erosion of our native biota. The restoration and long-term preservation of Hawaiian forest birds depend on the nearly complete control of mosquito-borne avian disease, an obstacle that to many land managers appears insurmountable. To rally hope in Hawai`i, the conservation community needs to see a success. As a Pacific island, Hawai`i shares similar conservation problems with New Zealand and has often looked to that nation for innovation and inspiration. Mosquito Eradication: The Story of Killing Campto may be our latest inspiration.

  10. Homicide in the Canadian Prairies: elderly and nonelderly killings.

    Ahmed, A G; Menzies, Robin P D

    2002-11-01

    To examine the psychosocial and clinical characteristics of male perpetrators of elderly and nonelderly homicides in the Canadian Prairies. We examined data drawn from a study of 901 adult homicide offenders who were incarcerated or on parole between 1988 and 1992 in Alberta, Saskatchewan, and Manitoba. Of those studied, 67 men were convicted of homicide involving 79 elderly victims, and 671 were convicted of homicide involving 675 nonelderly victims. Most perpetrators were single and engaged in irregular patterns of employment at the time of their index offence. Fourteen (20.8%) offenders with elderly victims had a history of psychiatric treatment, compared with 98 (14.6%) offenders with nonelderly victims; however, this difference was not statistically significant. Approximately 30% of both groups were diagnosed with personality disorders. A comparison of the index- offence characteristics showed no significant differences between the 2 groups. Our findings suggest that elderly individuals are more likely to be killed in their own homes by strangers. Social isolation appears to be a significant risk factor in cases of elderly homicide.

  11. Infective endocarditis and phlebotomies may have killed mozart.

    Lee, Simon Jong-Koo

    2010-12-01

    Thirty-five year-old Amadeus Mozart died in Vienna after an acute illness that lasted only 15 days but no consensus has been reached on the cause of his death. From many letters written by his farther it is almost certain that he experienced at least three episodes of acute rheumatic fever attack in his childhood, and a relapse of rheumatic fever was suggested to have killed Mozart, although death from acute rheumatic fever is very rare in adults. His last illness was characterized by high fever, massive edema, vomiting and skin rash. His last illness can be explained by infectious endocarditis and heart failure. During his last hours, he was given phlebotomy, possibly for the third time in two weeks, and soon after he became unconscious and died. As such, phlebotomy performed on a man dehydrated by high fever and vomiting may have caused systemic shock. In summary, Mozart probably died from chronic rheumatic heart disease complicated by infective endocarditis and heart failure, and repeated phlebotomy-induced hypovolemic shock.

  12. Epirubicin-adsorbed nanodiamonds kill chemoresistant hepatic cancer stem cells.

    Wang, Xin; Low, Xinyi Casuarine; Hou, Weixin; Abdullah, Lissa Nurrul; Toh, Tan Boon; Mohd Abdul Rashid, Masturah; Ho, Dean; Chow, Edward Kai-Hua

    2014-12-23

    Chemoresistance is a primary cause of treatment failure in cancer and a common property of tumor-initiating cancer stem cells. Overcoming mechanisms of chemoresistance, particularly in cancer stem cells, can markedly enhance cancer therapy and prevent recurrence and metastasis. This study demonstrates that the delivery of Epirubicin by nanodiamonds is a highly effective nanomedicine-based approach to overcoming chemoresistance in hepatic cancer stem cells. The potent physical adsorption of Epirubicin to nanodiamonds creates a rapidly synthesized and stable nanodiamond-drug complex that promotes endocytic uptake and enhanced tumor cell retention. These attributes mediate the effective killing of both cancer stem cells and noncancer stem cells in vitro and in vivo. Enhanced treatment of both tumor cell populations results in an improved impairment of secondary tumor formation in vivo compared with treatment by unmodified chemotherapeutics. On the basis of these results, nanodiamond-mediated drug delivery may serve as a powerful method for overcoming chemoresistance in cancer stem cells and markedly improving overall treatment against hepatic cancers.

  13. Axisymmetric Electrovacuum Spacetimes with AN Additional Killing Vector and Radiation

    Pravdová, A.; Bičák, J.

    2002-12-01

    In the present note we briefly summarize our recent work [1, 2] on possible additional symmetries of axially symmetric electrovacuum spacetimes which admit radiation. The main result states that only boost and rotation (axially) symmetric electrovacuum spacetimes can be radiative and asymptotically flat at null infinity {J} which admits global sections. If an additional symmetry is a translational spacelike or null Killing field the spacetime represents cylindrical or plane-type waves, local {J} may still exist but some of its generators are missing. Boost-rotation symmetric spacetimes are the only known exact explicit radiative solutions of Einstein's equations describing moving objects - singularities or black holes uniformly accelerated along the axis of symmetry. They are radiative and admit a smooth {J} although at least four points of {J} are missing. They represent the only known examples in which arbitrarily strong initial data with the given symmetry can be chosen on a hyperboloidal hypersurface which evolve into a complete, smooth null infinity and regular timelike infinity. For the latest reviews, containing a number of relevant references, see [3, 4]...

  14. Comparisons of boll weevil (Coleoptera: Curculionidae) pheromone traps with and without kill strips.

    Suh, C P C; Armstrong, J S; Spurgeon, D W; Duke, S

    2009-02-01

    Boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), eradication programs typically equip pheromone traps with an insecticide-impregnated kill strip. These strips are intended to kill captured insects, thereby simplifying trap servicing and reducing the loss of weevils from predation and escape. However, the effectiveness of kill strips has not been extensively evaluated. We examined the influences of kill strips on weevil captures, trap servicing, and the incidences of weevil predation and trap obstruction (e.g., by spider webs). Evaluations were conducted weekly during three different production periods (pre- to early-, late-, and postseason) of cotton, Gossypium hirsutum L., to represent different environmental conditions and weevil population levels. Within each period, mean weekly captures of weevils in traps with and without kill strips were statistically similar. On average, traps with kill strips took 9 s longer to service than traps without kill strips, but statistical differences were only detected during the late-season period. Overall, the mean weekly proportion of traps with evidence of weevil predation or trap obstruction was significantly lower for traps with kill strips (0.25) than for traps without kill strips (0.37). However, this reduction in the frequency of weevil predation or trap obstruction was too small to produce a corresponding increase in the numbers of weevils captured. In light of these findings, the use of kill strips is likely unnecessary in eradication programs, but may be a consideration in situations when the numbers of deployed traps are reduced and chronic problems with weevil predation or trap obstruction exist.

  15. Welfare Risks of Repeated Application of On-Farm Killing Methods for Poultry

    Jessica E. Martin

    2018-03-01

    Full Text Available Council Regulation (EC no. 1099/2009 on the protection of animals at the time of killing restricts the use of manual cervical dislocation in poultry on farms in the European Union (EU to birds weighing up to 3 kg and 70 birds per person per day. However, few studies have examined whether repeated application of manual cervical dislocation has welfare implications and whether these are dependent on individual operator skill or susceptibility to fatigue. We investigated the effects of repeated application (100 birds at a fixed killing rate of 1 bird per 2 min and multiple operators on two methods of killing of broilers, laying hens, and turkeys in commercial settings. We compared the efficacy and welfare impact of repeated application of cervical dislocation and a percussive killer (Cash Poultry Killer, CPK, using 12 male stockworkers on three farms (one farm per bird type. Both methods achieved over 96% kill success at the first attempt. The killing methods were equally effective for each bird type and there was no evidence of reduced performance with time and/or bird number. Both methods of killing caused a rapid loss of reflexes, indicating loss of brain function. There was more variation in reflex durations and post-mortem damage in birds killed by cervical dislocation than that found using CPK. High neck dislocation was associated with improved kill success and more rapid loss of reflexes. The CPK caused damage to multiple brain areas with little variation. Overall, the CPK was associated with faster abolition of reflexes, with fewer birds exhibiting them at all, suggestive of better welfare outcomes. However, technical difficulties with the CPK highlighted the advantages of cervical dislocation, which can be performed immediately with no equipment. At the killing rates tested, we did not find evidence to justify the current EU limit on the number of birds that one operator can kill on–farm by manual cervical dislocation.

  16. Reptile road-kills in Southern Brazil: Composition, hot moments and hotspots.

    Gonçalves, Larissa Oliveira; Alvares, Diego Janisch; Teixeira, Fernanda Zimmermann; Schuck, Gabriela; Coelho, Igor Pfeifer; Esperandio, Isadora Beraldi; Anza, Juan; Beduschi, Júlia; Bastazini, Vinicius Augusto Galvão; Kindel, Andreas

    2018-02-15

    Understanding road-kill patterns is the first step to assess the potential effects of road mortality on wildlife populations, as well as to define the need for mitigation and support its planning. Reptiles are one of the vertebrate groups most affected by roads through vehicle collisions, both because they are intentionally killed by drivers, and due to their biological needs, such as thermoregulation, which make them more prone to collisions. We conducted monthly road surveys (33months), searching for carcasses of freshwater turtles, lizards, and snakes on a 277-km stretch of BR-101 road in Southernmost Brazil to estimate road-kill composition and magnitude and to describe the main periods and locations of road-kills. We modeled the distribution of road-kills in space according to land cover classes and local traffic volume. Considering the detection capacity of our method and carcass persistence probability, we estimated that 15,377 reptiles are road-killed per year (55reptiles/km/year). Road-kills, especially lizards and snakes, were concentrated during summer, probably due to their higher activity in this period. Road-kill hotspots were coincident among freshwater turtles, lizards, and snakes. Road-kill distribution was negatively related to pine plantations, and positively related to rice plantations and traffic volume. A cost-benefit analysis highlighted that if mitigation measures were installed at road-kill hotspots, which correspond to 21% of the road, they could have avoided up to 45% of recorded reptile fatalities, assuming a 100% mitigation effectiveness. Given the congruent patterns found for all three taxa, the same mitigation measures could be used to minimize the impacts of collision on local herpetofauna. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Liming Poultry Manures to Kill Pathogens and Decrease Soluble Phosphorus

    Maguire, R.; Hesterberg, D.; Gernat, A.; Anderson, K.; Wineland, M.; Grimes, J.

    2006-01-01

    Received for publication September 9, 2005. Stabilizing phosphorus (P) in poultry waste to reduce P losses from manured soils is important to protect surface waters, while pathogens in manures are an emerging issue. This study was conducted to evaluate CaO and Ca(OH) 2 for killing manure bacterial populations (pathogens) and stabilizing P in poultry wastes and to investigate the influence on soils following amendment with the treated wastes. Layer manure and broiler litter varying in moisture content were treated with CaO and Ca(OH) 2 at rates of 2.5, 5, 10, and 15% by weight. All treated wastes were analyzed for microbial plate counts, pH, and water-soluble phosphorus (WSP), while a few selected layer manures were analyzed by phosphorus X-ray absorption near edge structure (XANES). A loamy sand and a silt loam were amended with broiler litter and layer manure treated with CaO at rates of 0, 2.5, 5, 10, and 15% and soil WSP and pH were measured at times 1, 8, and 29 d. Liming reduced bacterial populations, with greater rates of lime leading to greater reductions; for example 10% CaO applied to 20% solids broiler litter reduced the plate counts from 793 000 to 6500 mL -1 . Liming also reduced the WSP in the manures by over 90% in all cases where at least 10% CaO was added. Liming the manures also reduced WSP in soils immediately following application and raised soil pH. The liming process used successfully reduced plate counts and concerns about P losses in runoff following land application of these limed products due to decreased WSP

  18. Investigation of hot ductility in Al-killed boron steels

    Chown, L.H.; Cornish, L.A.

    2008-01-01

    The influence of boron to nitrogen ratio, strain rate and cooling rate on hot ductility of aluminium-killed, low carbon, boron microalloyed steel was investigated. Hot tensile testing was performed on steel samples reheated in argon to 1300 deg. C, cooled at rates of 0.3, 1.2 and 3.0 deg. C s -1 to temperatures in the range 750-1050 deg. C, and then strained to failure at initial strain rates of 1 x 10 -4 or 1 x 10 -3 s -1 . It was found that the steel with a B:N ratio of 0.19 showed deep hot ductility troughs for all tested conditions; the steel with a B:N ratio of 0.47 showed a deep ductility trough for a high cooling rate of 3.0 deg. C s -1 and the steel with a near-stoichiometric B:N ratio of 0.75 showed no ductility troughs for the tested conditions. The ductility troughs extended from ∼900 deg. C (near the Ae 3 temperature) to ∼1000 or 1050 deg. C in the single-phase austenite region. The proposed mechanism of hot ductility improvement with increase in B:N ratio in these steels is that the B removes N from solution, thus reducing the strain-induced precipitation of AlN. Additionally, BN co-precipitates with sulphides, preventing precipitation of fine MnS, CuS and FeS, and forming large, complex precipitates that have no effect on hot ductility

  19. Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria

    Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

    2013-01-01

    Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID

  20. Staphylococcus epidermidis strategies to avoid killing by human neutrophils.

    Gordon Y C Cheung

    2010-10-01

    Full Text Available Staphylococcus epidermidis is a leading nosocomial pathogen. In contrast to its more aggressive relative S. aureus, it causes chronic rather than acute infections. In highly virulent S. aureus, phenol-soluble modulins (PSMs contribute significantly to immune evasion and aggressive virulence by their strong ability to lyse human neutrophils. Members of the PSM family are also produced by S. epidermidis, but their role in immune evasion is not known. Notably, strong cytolytic capacity of S. epidermidis PSMs would be at odds with the notion that S. epidermidis is a less aggressive pathogen than S. aureus, prompting us to examine the biological activities of S. epidermidis PSMs. Surprisingly, we found that S. epidermidis has the capacity to produce PSMδ, a potent leukocyte toxin, representing the first potent cytolysin to be identified in that pathogen. However, production of strongly cytolytic PSMs was low in S. epidermidis, explaining its low cytolytic potency. Interestingly, the different approaches of S. epidermidis and S. aureus to causing human disease are thus reflected by the adaptation of biological activities within one family of virulence determinants, the PSMs. Nevertheless, S. epidermidis has the capacity to evade neutrophil killing, a phenomenon we found is partly mediated by resistance mechanisms to antimicrobial peptides (AMPs, including the protease SepA, which degrades AMPs, and the AMP sensor/resistance regulator, Aps (GraRS. These findings establish a significant function of SepA and Aps in S. epidermidis immune evasion and explain in part why S. epidermidis may evade elimination by innate host defense despite the lack of cytolytic toxin expression. Our study shows that the strategy of S. epidermidis to evade elimination by human neutrophils is characterized by a passive defense approach and provides molecular evidence to support the notion that S. epidermidis is a less aggressive pathogen than S. aureus.

  1. Can patriotism justify killing in defense of one’s country?

    Pavković Aleksandar

    2007-01-01

    Full Text Available Cosmopolitan liberals would be ready to fight - and to kill and be killed for the sake of restoring international justice or for the abolition of profoundly unjust political institutions. Patriots are ready to do the same for their own country. Sometimes the cosmopolitan liberals and patriots would fight on the same side and sometimes on the opposite sides of the conflict. Thus the former would join the latter in the defense of Serbia against Austria-Hungary (in 1914 but would oppose the white Southerner patriots in the American Civil War (in 1861. In this paper I argue that fighting and killing for one’s country is, in both of those cases, different from the defense of one’s own life and the lives of those who cannot defend themselves. Killing for one’s country is killing in order to fulfill a particular political preference. The same is the case with fighting for the abolition of a profoundly unjust political institution. It is not amoral or immoral to refuse to kill for any one of these two political preferences because there is no reason to believe that either political preference trumps our moral constraints against killing.

  2. Commuting symmetry operators of the Dirac equation, Killing-Yano and Schouten-Nijenhuis brackets

    Cariglia, Marco; Krtous, Pavel; Kubiznak, David

    2011-01-01

    In this paper we derive the most general first-order symmetry operator commuting with the Dirac operator in all dimensions and signatures. Such an operator splits into Clifford even and Clifford odd parts which are given in terms of odd Killing-Yano and even closed conformal Killing-Yano inhomogeneous forms, respectively. We study commutators of these symmetry operators and give necessary and sufficient conditions under which they remain of the first-order. In this specific setting we can introduce a Killing-Yano bracket, a bilinear operation acting on odd Killing-Yano and even closed conformal Killing-Yano forms, and demonstrate that it is closely related to the Schouten-Nijenhuis bracket. An important nontrivial example of vanishing Killing-Yano brackets is given by Dirac symmetry operators generated from the principal conformal Killing-Yano tensor [hep-th/0612029]. We show that among these operators one can find a complete subset of mutually commuting operators. These operators underlie separability of the Dirac equation in Kerr-NUT-(A)dS spacetimes in all dimensions [arXiv:0711.0078].

  3. Kill rate of mastitis pathogens by a combination of cefalexin and kanamycin.

    Maneke, E; Pridmore, A; Goby, L; Lang, I

    2011-01-01

    To assess the bacterial killing rate produced by a combination of cefalexin and kanamycin at two different concentration ratios. Time-kill kinetics of cefalexin and kanamycin, individually and in combination, were determined against one strain each of Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae and Streptococcus uberis. The combination was tested using two fixed ratios (cefalexin : kanamycin ratios of 1·25 : 1 and 1 : 2·3) and two concentrations of each ratio. Time-kill curves produced with either ratio were quite similar. Against most bacterial species, higher concentrations produced faster kill. In all cases, the combination of cefalexin and kanamycin showed faster and greater kill at lower antibiotic concentrations than those observed with either drug alone. The combination of cefalexin and kanamycin results in a fast initial killing of major mastitis pathogens at both concentration ratios. The combination of cefalexin and kanamycin achieved rapid bacterial kill at concentrations and ratios that can be achieved in vivo following intramammary infusion of a mastitis treatment. © 2010 Boehringer Ingelheim Vetmedica GmbH. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.

  4. Mechanisms of Bacterial (Serratia marcescens) Attachment to, Migration along, and Killing of Fungal Hyphae.

    Hover, Tal; Maya, Tal; Ron, Sapir; Sandovsky, Hani; Shadkchan, Yana; Kijner, Nitzan; Mitiagin, Yulia; Fichtman, Boris; Harel, Amnon; Shanks, Robert M Q; Bruna, Roberto E; García-Véscovi, Eleonora; Osherov, Nir

    2016-05-01

    We have found a remarkable capacity for the ubiquitous Gram-negative rod bacterium Serratia marcescens to migrate along and kill the mycelia of zygomycete molds. This migration was restricted to zygomycete molds and several basidiomycete species. No migration was seen on any molds of the phylum Ascomycota. S. marcescens migration did not require fungal viability or surrounding growth medium, as bacteria migrated along aerial hyphae as well.S. marcescens did not exhibit growth tropism toward zygomycete mycelium. Bacterial migration along hyphae proceeded only when the hyphae grew into the bacterial colony. S. marcescens cells initially migrated along the hyphae, forming attached microcolonies that grew and coalesced to generate a biofilm that covered and killed the mycelium. Flagellum-defective strains of S. marcescens were able to migrate along zygomycete hyphae, although they were significantly slower than the wild-type strain and were delayed in fungal killing. Bacterial attachment to the mycelium does not necessitate type 1 fimbrial adhesion, since mutants defective in this adhesin migrated equally well as or faster than the wild-type strain. Killing does not depend on the secretion of S. marcescens chitinases, as mutants in which all three chitinase genes were deleted retained wild-type killing abilities. A better understanding of the mechanisms by which S. marcescens binds to, spreads on, and kills fungal hyphae might serve as an excellent model system for such interactions in general; fungal killing could be employed in agricultural fungal biocontrol. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  5. Killing of Pseudomonas aeruginosa by Chicken Cathelicidin-2 Is Immunogenically Silent, Preventing Lung Inflammation In Vivo

    Coorens, Maarten; Banaschewski, Brandon J. H.; Baer, Brandon J.; Yamashita, Cory; van Dijk, Albert; Veldhuizen, Ruud A. W.; Veldhuizen, Edwin J. A.

    2017-01-01

    ABSTRACT The development of antibiotic resistance by Pseudomonas aeruginosa is a major concern in the treatment of bacterial pneumonia. In the search for novel anti-infective therapies, the chicken-derived peptide cathelicidin-2 (CATH-2) has emerged as a potential candidate, with strong broad-spectrum antimicrobial activity and the ability to limit inflammation by inhibiting Toll-like receptor 2 (TLR2) and TLR4 activation. However, as it is unknown how CATH-2 affects inflammation in vivo, we investigated how CATH-2-mediated killing of P. aeruginosa affects lung inflammation in a murine model. First, murine macrophages were used to determine whether CATH-2-mediated killing of P. aeruginosa reduced proinflammatory cytokine production in vitro. Next, a murine lung model was used to analyze how CATH-2-mediated killing of P. aeruginosa affects neutrophil and macrophage recruitment as well as cytokine/chemokine production in the lung. Our results show that CATH-2 kills P. aeruginosa in an immunogenically silent manner both in vitro and in vivo. Treatment with CATH-2-killed P. aeruginosa showed reduced neutrophil recruitment to the lung as well as inhibition of cytokine and chemokine production, compared to treatment with heat- or gentamicin-killed bacteria. Together, these results show the potential for CATH-2 as a dual-activity antibiotic in bacterial pneumonia, which can both kill P. aeruginosa and prevent excessive inflammation. PMID:28947647

  6. Mitigation options for fish kills in L Lake and Pond C

    Paller, M.H.

    1989-11-01

    This report concerns mitigation options for reducing or eliminating the fish kills that occur in L Lake and Pond C as a result of reactor operations. These kills occur when fish that have entered the discharge areas during outages are killed by the rapid rises in temperature that follow reactor re-starts. Factors that have been observed to influence the severity of the kills include the length of the outage, season during which the outage occurs, reactor power level, and size of the fish in the discharge area. Without mitigation, fish kills can be expected to occur in Pond C with approximately the same frequency and severity as in the past. Even in the absence of mitigation, however, it is unlikely that future fish kills in L Lake will be as severe as the large kill that occurred in December 1986. Fish abundance in Region 2 of L Lake (where severe kills occurred in the past) has declined over 90% since 1986, largely due to a reduction in the abundance of juvenile sunfish (which constituted approximately 99% of past kills). There are basically three categories of mitigation options: changes in reactor operations, methods to exclude fish from time discharge areas, and methods to promote the escapement of fish from the discharge area. These options vary in approach, scope, and anticipated expense. Most would need to be researched in greater depth before it would be possible to predict their effectiveness more definitively. While the options have the potential to greatly reduce mortalities, none can totally eliminate mortalities. The only way of ensuring the elimination of all mortalities is to reduce effluent temperatures to sublethal levels with properly designed and operated cooling technology. 18 refs., 2 figs., 1 tab

  7. Prevalence of alcohol and other psychoactive substances in injured and killed drivers

    Isalberti, Cristina; Linden, Trudy Van der; Legrand, Sara-Ann

    2011-01-01

    regarding the prevalence of alcohol and other psychoactive substances in drivers who have been injured/killed in traffic accidents. Part 1 of this report presents the general results of the hospital & killed driver studies. After a short introduction, the representativeness of the populations in the EU...... countries as well as the representativeness of hospitalised and killed driver samples are addressed. An overview of the non-response issues in the various countries is also included. Based on the toxicological findings, a general summary of the prevalence of drug use is given for the 9 participating...

  8. 43 CFR 30.251 - What happens if an heir or devisee participates in the killing of the decedent?

    2010-10-01

    ... participates in the killing of the decedent? 30.251 Section 30.251 Public Lands: Interior Office of the... if an heir or devisee participates in the killing of the decedent? Any person who knowingly participates, either as a principal or as an accessory before the fact, in the willful and unlawful killing of...

  9. Loss of Cln3 Function in the Social Amoeba Dictyostelium discoideum Causes Pleiotropic Effects That Are Rescued by Human CLN3

    Huber, Robert J.

    2014-01-01

    The neuronal ceroid lipofuscinoses (NCL) are a group of inherited, severe neurodegenerative disorders also known as Batten disease. Juvenile NCL (JNCL) is caused by recessive loss-of-function mutations in CLN3, which encodes a transmembrane protein that regulates endocytic pathway trafficking, though its primary function is not yet known. The social amoeba Dictyostelium discoideum is increasingly utilized for neurological disease research and is particularly suited for investigation of protein function in trafficking. Therefore, here we establish new overexpression and knockout Dictyostelium cell lines for JNCL research. Dictyostelium Cln3 fused to GFP localized to the contractile vacuole system and to compartments of the endocytic pathway. cln3− cells displayed increased rates of proliferation and an associated reduction in the extracellular levels and cleavage of the autocrine proliferation repressor, AprA. Mid- and late development of cln3− cells was precocious and cln3− slugs displayed increased migration. Expression of either Dictyostelium Cln3 or human CLN3 in cln3− cells suppressed the precocious development and aberrant slug migration, which were also suppressed by calcium chelation. Taken together, our results show that Cln3 is a pleiotropic protein that negatively regulates proliferation and development in Dictyostelium. This new model system, which allows for the study of Cln3 function in both single cells and a multicellular organism, together with the observation that expression of human CLN3 restores abnormalities in Dictyostelium cln3− cells, strongly supports the use of this new model for JNCL research. PMID:25330233

  10. Loss of Cln3 function in the social amoeba Dictyostelium discoideum causes pleiotropic effects that are rescued by human CLN3.

    Robert J Huber

    Full Text Available The neuronal ceroid lipofuscinoses (NCL are a group of inherited, severe neurodegenerative disorders also known as Batten disease. Juvenile NCL (JNCL is caused by recessive loss-of-function mutations in CLN3, which encodes a transmembrane protein that regulates endocytic pathway trafficking, though its primary function is not yet known. The social amoeba Dictyostelium discoideum is increasingly utilized for neurological disease research and is particularly suited for investigation of protein function in trafficking. Therefore, here we establish new overexpression and knockout Dictyostelium cell lines for JNCL research. Dictyostelium Cln3 fused to GFP localized to the contractile vacuole system and to compartments of the endocytic pathway. cln3- cells displayed increased rates of proliferation and an associated reduction in the extracellular levels and cleavage of the autocrine proliferation repressor, AprA. Mid- and late development of cln3- cells was precocious and cln3- slugs displayed increased migration. Expression of either Dictyostelium Cln3 or human CLN3 in cln3- cells suppressed the precocious development and aberrant slug migration, which were also suppressed by calcium chelation. Taken together, our results show that Cln3 is a pleiotropic protein that negatively regulates proliferation and development in Dictyostelium. This new model system, which allows for the study of Cln3 function in both single cells and a multicellular organism, together with the observation that expression of human CLN3 restores abnormalities in Dictyostelium cln3- cells, strongly supports the use of this new model for JNCL research.

  11. A CHALLENGE OF TRUST: CAN DISTRUST KILL THE EURO?

    Nataliia Kostiuchenko

    2015-11-01

    Full Text Available The purpose of the paper is to determine the dynamics of trust in the ECB in the most recent period, to compare the findings with a previous study of Farvaque et al. (2010 and to explore the question of importance of citizen’s trust in public institution for the economic performance of the country. This paper is dedicated to the study of the determinants of trust in the European Central Bank. The study attempts to give an answer to a question posed in introduction: can distrust kill the euro? After the world economic crisis the trust in the ECB began to deteriorate. Citizen’s trust in public institutions plays an important role for the economic performance of the country. Methology. We rely on the micro data from the European Commission’s Eurobarometer survey. This paper contributes empirically to the existing literature dedicated to the issue of trust in public institutions. The responses in 15 EU-member countries were taken into account. The present work uses the model of Farvaque et al. (2010 extending the time frame considered previously, giving a broader picture on this issue using the most recent data. Results. In accordance with our findings, the population that support the ECB is approximately equal to the population that does not trust in the community bank, with a mean value of 0,51. Even if there are still more supporters of the ECB, this data should provide an alarm for the European institutional framework, in consideration that in 1999 (in accordance with Farvaque et al. (2010 the mean value was 0,67. Practical implications. According to our findings, still people with higher level of education, people with a higher social status, people with center or right-wing political orientation, people with optimistic expectations on the economic situation have more trust in the ECB. However, we have found that women have become more supportive about the ECB than men in contrast with the findings of Farvaque et al. (2010. Value

  12. The 1965 Indonesian Killing Discourse by Generation 2000 Writers

    Diah Ariani Arimbi

    2011-06-01

    Full Text Available The fall of Soeharto’s authority in 1998 has indeed impacted numerous sides of Indonesian life: political, social and cultural. The shifting of authoritative government to the state of “reformation” and “democratization” has forced the nation to redefine its authority to its members. This paper aims to look at these public responses which are narrated in contemporary Indonesian fiction. Although fiction may be seen as imaginative production, discursive ideologies can be examined clearly. By examining thematic significant of the narratives about G30S/PKI and the killings aftermath in the literary writings published in post 1998 by contemporary Indonesia writers, who are known as the Generation 2000 writers (who were mostly born in 1970s at least five years after the 1965 incident: also known as the millennials, this paper will attempt to answer whether or not this generation presents shift and creates its own notions of the incident. Abstrak: Jatuhnya kekuasaan Soeharto pada tahun 1998 berdampak pada berbagai sisi kehidupan di Indonesia: politik, sosial, dan budaya. Pergeseran dari pemerintahan yang dulunya otoritatif menjadi pemerintahan yang sarat dengan "reformasi" dan "demokratisasi" telah memaksa negara untuk mendefinisikan kembali wewenangnya kepada para anggotanya. Makalah ini bertujuan untuk melihat respons publik yang diceritakan dalam fiksi Indonesia kontemporer. Walaupun fiksi dapat dipandang sebagai produk imajinatif, ideologi diskursif dapat dilihat dengan je-las. Dengan memeriksa tema-tema yang secara signifikan dimunculkan dari narasi tentang G30S/PKI dan tragedi pembunuhan sesudahnya dalam tulisan-tulisan sastra yang diterbitkan pasca tahun 1998 oleh penulis Indonesia kontemporer, yang dikenal sebagai penulis Generasi 2000 (penulis yang kebanyakan lahir di tahun 1970-an setidaknya 5 tahun setelah 1965 kejadian: juga dikenal sebagai millenials, makalah ini berusaha menjawab apakah generasi baru mengalami pergeseran dalam

  13. [gammadelta T cells stimulated by zoledronate kill osteosarcoma cells].

    Jiang, Hui; Xu, Qiang; Yang, Chao; Cao, Zhen-Guo; Li, Zhao-Xu; Ye, Zhao-Ming

    2010-12-01

    To investigate the cytotoxicity of human γδT cells from PBMCs stimulated by zoledronate against osteosarcoma cell line HOS in vitro and in vivo and evaluate the relavent pathways. The peripheral blood mononuclear cells (PBMCs)of healthy donors were stimulated by single dose zoledronate and cultured in the present of IL-2 for two weeks, analysising the percentage of γδT cells on a FACSCalibur cytometer.Study the cytotoxicity of γδT cells against the osteosarcoma line HOS using LDH release assay kit. Pre-treatment of γδT cells with anti-human γδTCR antibody, anti-human NKG2D antibody and concanamycin A to bolck the relavent pathways for evaluating the mechenisms of its cytotoxicity. In vivo, BALB/c mice were inoculated subcutaneously osteosarcoma cell HOS for developing hypodermal tumors. And they were randomized into two groups: unteated group, γδT cell therapy group. Tumor volume and weight of the two groups were compared. After two weeks of culture, γδT cells from zoledronate-stimulated PBMCs could reach (95±3)%. When the E:T as 6:1, 12:1, 25:1, 50:1, the percentage of osteosarcoma cell HOS killed by γδT cells was 26.8%, 31.5%, 37.8%, 40.9%, respectively.When anti-huma γδTCR antibody, anti-human NKG2D antibody and concanamycin A blocked the relavent pathways, the percentage was 32.3%, 4.7%, 16.7% ( E:T as 25:1), respectively. In vivo, the tumor inhibition rate of the group of γδT cell therapy was 42.78%. γδT cells derived from PBMCs stimulated by zoledronate can acquired pure γδT cells. And they show strong cytoxicity against osteosarcoma cell line HOS in vitro and in vivo.

  14. Hot tensile behaviour in silicon-killed boron microalloyed steels

    Chown, Lesley H.; Cornish, Lesley A.

    2017-10-01

    Low carbon steel for drawing and cold heading applications should have low strength, high ductility and low strain ageing rates. To achieve this, nitrogen must be removed from solid solution, which can be done by low additions of boron. A wire producer had been experiencing occasional problems with severe cracking on silicon-killed, boron steel billets during continuous casting, but the solution was not obvious. Samples from four billets, each from different casts, were removed for analysis and testing. The tested steel compositions were within the specification limits, with boron to nitrogen ratios of 0.40-1.19. Hot ductility testing was performed on a Gleeble 1500 using parameters approximating the capabilities of this particular billet caster. The steel specimens were subjected to in situ melting, then cooled at a rate of 2 C.s-1 to temperatures in the range 750-1250°C, where they were then pulled to failure at a strain rate of 8x10-4 s-1. In this work, it was found that both the boron to nitrogen ratio and the manganese to sulphur ratio influenced the hot ductility and hence the crack susceptibility. Excellent hot ductility was found for B:N ratios above 1.0, which confirmed that the B:N ratio should be above a stoichiometric value of 0.8 to remove all nitrogen from solid solution. TEM analysis showed that coarse BN precipitates nucleated on other precipitates, such as (Fe,Mn)S, which have relatively low melting points, and are detrimental to hot ductility. Low Mn:S ratios of 10 - 12 were shown to promote precipitation of FeS, so a Mn:S > 14 was recommended. A narrower billet surface temperature range for straightening was recommended to prevent transverse surface cracking. Additionally, analysis of industrial casting data showed that the scrap percentage due to transverse cracking increased significantly for Mn:S < 14. An exponential decay relationship between the manganese to sulphur ratio and the average scrap percentage due to transverse cracking was

  15. Pathogen analysis of NYSDOT road-killed deer carcass compost facilities.

    2008-09-01

    Composting of deer carcasses was effective in reducing pathogen levels, decomposing the : carcasses and producing a useable end product after 12 months. The composting process used in this project : involved enveloping the carcasses of road-killed de...

  16. Optimal Fixed-Interval Integrated Guidance-Control Laws for Hit-to-Kill Missiles

    Menon, P. K; Sweriduk, G. D; Ohlmeyer, E. J

    2003-01-01

    Due to their potential for reducing the weapon size and efficiency, design methods for realizing hit-to- kill capabilities in missile systems are of significant research interest in the missile flight control community...

  17. IN VITRO KILLING OF PERKINSUS MARINUS BY HEMOCYTES OF OYSTERS CRASSOSTREA VIRGINICA

    A colorimetric microbicidal assay was adapted, optimized and applied in experiments to characterize the in vitro capacity of eastern oyster (Crassostrea virginica) hemocytes to kill cultured isolates of Perkinsus marinus, a protozoan parasite causing a highly destructive disease...

  18. Novel contaminants identified in fish kills in the Red River watershed, 2011–2013

    Provisional molecular weights and chemical formulas were assigned to four significant previously unidentified contaminants present during active fish kills in the Red River region of Oklahoma. The provisional identifications of these contaminants were determined using high-resolu...

  19. Time-kill profiles and cell-surface morphological effects of crude ...

    Methods: Time-kill assays were conducted by incubating test bacteria with the extract and sampling at selected time points within ... activity against both bacteria and fungi [14]. Also, a protein ..... be developed as novel drugs for the treatment of.

  20. Research on killing Escherichia Coli by reactive oxygen species based on strong ionization discharging plasma

    Li, Y J; Tian, Y P; Zhang, Z T; Li, R H; Cai, L J; Gao, J Y

    2013-01-01

    Reactive oxygen species solution produced by strong ionization discharging plasma was used to kill Escherichia coli by spraying. Several effect factors such as pH value, solution temperature, spraying time and exposure time were observed in this study, and their effects on killing rate of Escherichia coli were discussed and analysed. Results show that the treating efficiency of ROS solution for Escherichia coli is higher in alkaline solution than that in acid solution. The killing rate of Escherichia coli increases while the spraying time and exposure time are longer and the temperature is lower. The effects of different factors on killing rate of Escherichia coli are as follows: spraying time > pH value > exposure time > solution temperature.

  1. Nurses Writing about Psychiatric Nurses' Involvement in Killings during the Nazi Era: A Preliminary Discourse Analysis.

    Holmes, Colin A; McAllister, Margaret; Crowther, Andrew

    2016-01-01

    Nurses actively killed people in Nazi Europe between 1939 and 1945. The so-called ‘science of eugenics’ underpinned Nazi ideology, used to further the Nazi racist agenda. Edicts sanctioned selection and medically supervised killing of people, and nurses, principally in mental hospitals, participated in the killing of between 100–300 thousand patients. Erroneously termed ‘euthanasia', there were three phases: the initial programme involving children, the T4 adult programme, and ‘wild euthanasia'. Unofficial killings also took place before 1939. This paper uses discourse analysis to map and analyse published texts which explore the role of nurses in Nazi Germany. The aim is to identify its characteristics as a body of literature, to note strengths and weaknesses, emphases and silences, and to note aspects that need further exploration. It acknowledges that how these events are to be understood and represented in contemporary discourse constitutes a significant problem for historians of nursing.

  2. Targeted Killing as an Element of U.S. Foreign Policy in the War On Terror

    Machon, Matthew J

    2006-01-01

    ...) launched a lethal missile strike, killing Qaed Salim Sinan al-Harethi, a high ranking al-Qaeda member and suspected architect of the USS Cole bombing, in an isolated and sparsely populated region within Yemen...

  3. The curvature and the algebra of Killing vectors in five-dimensional space

    Rcheulishvili, G.

    1990-12-01

    This paper presents the Killing vectors for a five-dimensional space with the line element. The algebras which are formed by these vectors are written down. The curvature two-forms are described. (author). 10 refs

  4. Time-kill profiles and cell-surface morphological effects of crude ...

    MK1201 mycelial extract on the viability and cell surface morphology of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). Methods: Time-kill assays were conducted by incubating test ...

  5. Shell biofilm-associated nitrous oxide production in marine molluscs

    Heisterkamp, I.M.; Schramm, Andreas; Larsen, Lone Heimann

    2013-01-01

    Emission of the greenhouse gas nitrous oxide (N2O) from freshwater and terrestrial invertebrates has exclusively been ascribed to N2O production by ingested denitrifying bacteria in the anoxic gut of the animals. Our study of marine molluscs now shows that also microbial biofilms on shell surfaces...... are important sites of N2O production. The shell biofilms of Mytilus edulis, Littorina littorea and Hinia reticulata contributed 18-94% to the total animal-associated N2O emission. Nitrification and denitrification were equally important sources of N2O in shell biofilms as revealed by 15N-stable isotope...... mollusc species. Ammonium excretion by the animals was found to be sufficient to sustain N2O production in the shell biofilm. Apparently, the animals provide a nutrient-enriched microenvironment that stimulates growth and N2O production of the shell biofilm. This animal-induced stimulation...

  6. Antibiotic polymeric nanoparticles for biofilm-associated infection therapy.

    Cheow, Wean Sin; Hadinoto, Kunn

    2014-01-01

    Polymeric nanoparticles are highly attractive as drug delivery vehicles due to their high structural integrity, stability during storage, ease of preparation and functionalization, and controlled release capability. Similarly, lipid-polymer hybrid nanoparticles, which retain the benefits of polymeric nanoparticles plus the enhanced biocompatibility and prolonged circulation time owed to the lipids, have recently emerged as a superior alternative to polymeric nanoparticles. Drug nanoparticle complex prepared by electrostatic interaction of oppositely charged drug and polyelectrolytes represents another type of polymeric nanoparticle. This chapter details the preparation, characterization, and antibiofilm efficacy testing of antibiotic-loaded polymeric and hybrid nanoparticles and antibiotic nanoparticle complex.

  7. Biofilms associated with bowel necrosis: A newly recognised ...

    role of biofilms has been established for oral infections, chronic wounds, indwelling ... bowel in infants and may be of significance in the pathogenesis of bowel necrosis and the ... implications in the understanding of the disease process. .... showed areas of mucosal ulceration and ... venous and urinary catheters, and dental.

  8. Biofilms associated with bowel necrosis: A newly recognised ...

    All specimens showed varying degrees of bowel necrosis and an organising acute peritoneal reaction. In addition, all showed colonies of Gram-negative bacteria within a mucopolysaccharide matrix. Conclusions. The identification of biofilms in necrotic bowel has raised questions regarding their clinical implications. Further ...

  9. From Attitudes to Actions: Predictors of Lion Killing by Maasai Warriors

    Hazzah, Leela; Bath, Alistair; Dolrenry, Stephanie; Dickman, Amy; Frank, Laurence

    2017-01-01

    Despite legal protection, deliberate killing by local people is one of the major threats to the conservation of lions and other large carnivores in Africa. Addressing this problem poses particular challenges, mainly because it is difficult to uncover illicit behavior. This article examined two groups of Maasai warriors: individuals who have killed African lions (Panthera leo) and those who have not. We conducted interviews to explore the relationship between attitudes, intentions and known li...

  10. ANALYZE THE IMPACT OF HABITAT PATCHES ON WILDLIFE ROAD-KILL

    Seok, S.; Lee, J.

    2015-01-01

    The ecosystem fragmentation due to transportation infrastructure causes a road-kill phenomenon. When making policies for mitigating road-kill it is important to select target-species in order to enhance its efficiency. However, many wildlife crossing structures have been questioned regarding their effectiveness due to lack of considerations such as target-species selection, site selection, management, etc. The purpose of this study is to analyse the impact of habitat patches on wildlife road-...

  11. Landscape integration of freeways: how does it affect road kill rates?

    Sanz, Luis

    2001-01-01

    Some ecological processes are affected by the transportation infrastructure development. The barrier effect caused by roads, which alters the movement patterns of terrestrial wildlife and increases its road kill risk, is just an example. Road kills must be considered both from environmental and highway safety perspectives, and are related to road permeability and to the surrounding environment. This paper compares the landscape fragmentation caused by two freeways in Navarra (north of Spain) ...

  12. Habitat or matrix: which is more relevant to predict road-kill of vertebrates?

    C. Bueno

    Full Text Available Abstract We believe that in tropics we need a community approach to evaluate road impacts on wildlife, and thus, suggest mitigation measures for groups of species instead a focal-species approach. Understanding which landscape characteristics indicate road-kill events may also provide models that can be applied in other regions. We intend to evaluate if habitat or matrix is more relevant to predict road-kill events for a group of species. Our hypothesis is: more permeable matrix is the most relevant factor to explain road-kill events. To test this hypothesis, we chose vertebrates as the studied assemblage and a highway crossing in an Atlantic Forest region in southeastern Brazil as the study site. Logistic regression models were designed using presence/absence of road-kill events as dependent variables and landscape characteristics as independent variables, which were selected by Akaike’s Information Criterion. We considered a set of candidate models containing four types of simple regression models: Habitat effect model; Matrix types effect models; Highway effect model; and, Reference models (intercept and buffer distance. Almost three hundred road-kills and 70 species were recorded. River proximity and herbaceous vegetation cover, both matrix effect models, were associated to most road-killed vertebrate groups. Matrix was more relevant than habitat to predict road-kill of vertebrates. The association between river proximity and road-kill indicates that rivers may be a preferential route for most species. We discuss multi-species mitigation measures and implications to movement ecology and conservation strategies.

  13. Enhanced oxidative killing of azole-resistant Candida glabrata strains with ERG11 deletion.

    Kan, V L; Geber, A; Bennett, J E

    1996-01-01

    The susceptibility of genetically defined Candida glabrata strains to killing by H2O2 and neutrophils was assessed. Fluconazole-susceptible L5L and L5D strains demonstrated survival rates higher than those of two fluconazole-resistant strains lacking the ERG11 gene coding for 14 alpha-demethylase. Fluconazole resistance can occur by mechanisms which increase fungal susceptibility to oxidative killing by H2O2 and neutrophils. PMID:8807069

  14. Subordinations In “To Kill A Mockingbird” By Harper Lee

    Siregar, Rut Sri Novitawaty

    2011-01-01

    Salah satu yang dipelajari mahasiswa adalah tulis menulis. Secara ilmiah tulis menulis adalah penyampaian informasi dalam bentuk tulisan serta bagaimana informasi itu disampaikan. Judul kertas karya ini adalah Kalimat Subordinat yang ditemukan dalam novel To Kill a Mockingbird karya Harper Lee: SUBORDINATION IN TO KILL A MOCKINGBIRD BY HARPER LEE. Penulis mengangkat hal ini karena penulis tertarik dengan bentuk–bentuk serta fungsi-fungsi kalimat subordinat yang terdapat dalam tulisan-tulisan ...

  15. Comparative antianaerobic activities of doripenem determined by MIC and time-kill analysis.

    Credito, Kim L; Ednie, Lois M; Appelbaum, Peter C

    2008-01-01

    Against 447 anaerobe strains, the investigational carbapenem doripenem had an MIC 50 of 0.125 microg/ml and an MIC 90 of 1 microg/ml. Results were similar to those for imipenem, meropenem, and ertapenem. Time-kill studies showed that doripenem had very good bactericidal activity compared to other carbapenems, with 99.9% killing of 11 strains at 2x MIC after 48 h.

  16. Comparative Antianaerobic Activities of Doripenem Determined by MIC and Time-Kill Analysis▿

    Credito, Kim L.; Ednie, Lois M.; Appelbaum, Peter C.

    2008-01-01

    Against 447 anaerobe strains, the investigational carbapenem doripenem had an MIC50 of 0.125 μg/ml and an MIC90 of 1 μg/ml. Results were similar to those for imipenem, meropenem, and ertapenem. Time-kill studies showed that doripenem had very good bactericidal activity compared to other carbapenems, with 99.9% killing of 11 strains at 2× MIC after 48 h. PMID:17938185

  17. Killing in Combat: Utilizing a Christian Perspective, When is a Soldier Justified in Taking a Life?

    2014-06-13

    Vietnam War combat veterans suffering from PTSD, has to say concerning subjects such as grief, guilt , honor, suffering, and healing while investigating...Gray, who served as an intelligence 11 officer in World War I, offers his thoughts on death and killing while discussing the guilt Soldiers so...battlefield (1959, 104). Gray also discusses the need for hating one’s enemy while having pride in the number of kills on the battlefield as a necessity

  18. Vacuum spacetimes with a spacelike, hypersurface-orthogonal Killing vector: reduced equations in a canonical frame

    Bonanos, S

    2003-01-01

    The Newman-Penrose equations for spacetimes having one spacelike Killing vector are reduced-in a geometrically defined 'canonical frame' - to a minimal set, and its differential structure is studied. Expressions for the frame vectors in an arbitrary coordinate basis are given, and coordinate-independent choices of the metric functions are suggested which make the components of the Ricci tensor in the direction of the Killing vector vanish

  19. Road kills of amphibians in different land use areas from Sharavathi river basin, central Western Ghats, India

    K.S. Seshadri

    2009-11-01

    Full Text Available A survey of amphibian mortality on roads was carried out in the Sharavathi river basin in the central Western Ghats. Road kills in three different land use areas: agricultural fields, water bodies and forests were recorded for four days along three 100m stretches in each type of area. One-hundred-and-forty-four individuals belonging to two orders, eight families, 11 genera and 13 species were recorded in the survey. Kills/km observed were: in forest 55, agricultural fields 38 and water bodies 27, for an overall average of 40 kills/km. Kill species compositions varied significantly between land use areas, but not overall kill rates.

  20. Human Neutrophils Use Different Mechanisms To Kill Aspergillus fumigatus Conidia and Hyphae: Evidence from Phagocyte Defects.

    Gazendam, Roel P; van Hamme, John L; Tool, Anton T J; Hoogenboezem, Mark; van den Berg, J Merlijn; Prins, Jan M; Vitkov, Ljubomir; van de Veerdonk, Frank L; van den Berg, Timo K; Roos, Dirk; Kuijpers, Taco W

    2016-02-01

    Neutrophils are known to play a pivotal role in the host defense against Aspergillus infections. This is illustrated by the prevalence of Aspergillus infections in patients with neutropenia or phagocyte functional defects, such as chronic granulomatous disease. However, the mechanisms by which human neutrophils recognize and kill Aspergillus are poorly understood. In this work, we have studied in detail which neutrophil functions, including neutrophil extracellular trap (NET) formation, are involved in the killing of Aspergillus fumigatus conidia and hyphae, using neutrophils from patients with well-defined genetic immunodeficiencies. Recognition of conidia involves integrin CD11b/CD18 (and not dectin-1), which triggers a PI3K-dependent nonoxidative intracellular mechanism of killing. When the conidia escape from early killing and germinate, the extracellular destruction of the Aspergillus hyphae needs opsonization by Abs and involves predominantly recognition via Fcγ receptors, signaling via Syk, PI3K, and protein kinase C to trigger the production of toxic reactive oxygen metabolites by the NADPH oxidase and myeloperoxidase. A. fumigatus induces NET formation; however, NETs did not contribute to A. fumigatus killing. Thus, our findings reveal distinct killing mechanisms of Aspergillus conidia and hyphae by human neutrophils, leading to a comprehensive insight in the innate antifungal response. Copyright © 2016 by The American Association of Immunologists, Inc.

  1. Assisted suicide and the killing of people? Maybe. Physician-assisted suicide and the killing of patients? No: the rejection of Shaw's new perspective on euthanasia.

    McLachlan, Hugh V

    2010-05-01

    David Shaw presents a new argument to support the old claim that there is not a significant moral difference between killing and letting die and, by implication, between active and passive euthanasia. He concludes that doctors should not make a distinction between them. However, whether or not killing and letting die are morally equivalent is not as important a question as he suggests. One can justify legal distinctions on non-moral grounds. One might oppose physician-assisted suicide and active euthanasia when performed by doctors on patients whether or not one is in favour of the legalisation of assisted suicide and active euthanasia. Furthermore, one can consider particular actions to be contrary to appropriate professional conduct even in the absence of legal and ethical objections to them. Someone who wants to die might want only a doctor to kill him or to help him to kill himself. However, we are not entitled to everything that we want in life or death. A doctor cannot always fittingly provide all that a patient wants or needs. It is appropriate that doctors provide their expert advice with regard to the performance of active euthanasia but they can and should do so while, qua doctors, they remain hors de combat.

  2. Activity of telithromycin (HMR 3647) against anaerobic bacteria compared to those of eight other agents by time-kill methodology.

    Credito, K L; Ednie, L M; Jacobs, M R; Appelbaum, P C

    1999-08-01

    Time-kill studies examined the activities of telithromycin (HMR 3647), erythromycin A, azithromycin, clarithromycin, roxithromycin, clindamycin, pristinamycin, amoxicillin-clavulanate, and metronidazole against 11 gram-positive and gram-negative anaerobic bacteria. Time-kill studies were carried out with the addition of Oxyrase in order to prevent the introduction of CO(2). Macrolide-azalide-ketolide MICs were 0.004 to 32.0 microg/ml. Of the latter group, telithromycin had the lowest MICs, especially against non-Bacteroides fragilis group strains, followed by azithromycin, clarithromycin, erythromycin A, and roxithromycin. Clindamycin was active (MIC /=99.9% killing) against 6 strains, with 99% killing of 9 strains and 90% killing of 10 strains. After 24 h at twice the MIC, 90, 99, and 99.9% killing of nine, six, and three strains, respectively, occurred. Lower rates of killing were seen at earlier times. Similar kill kinetics relative to the MIC were seen with other macrolides. After 48 h at the MIC, clindamycin was bactericidal against 8 strains, with 99 and 90% killing of 9 and 10 strains, respectively. After 24 h, 90% killing of 10 strains occurred at the MIC. The kinetics of clindamycin were similar to those of pristinamycin. After 48 h at the MIC, amoxicillin-clavulanate showed 99.9% killing of seven strains, with 99% killing of eight strains and 90% killing of nine strains. At four times the MIC, metronidazole was bactericidal against 8 of 10 strains tested after 48 h and against all 10 strains after 24 h; after 12 h, 99% killing of all 10 strains occurred.

  3. How Effective Is Road Mitigation at Reducing Road-Kill? A Meta-Analysis.

    Rytwinski, Trina; Soanes, Kylie; Jaeger, Jochen A G; Fahrig, Lenore; Findlay, C Scott; Houlahan, Jeff; van der Ree, Rodney; van der Grift, Edgar A

    2016-01-01

    Road traffic kills hundreds of millions of animals every year, posing a critical threat to the populations of many species. To address this problem there are more than forty types of road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill). For road planners, deciding on what mitigation method to use has been problematic because there is little good information about the relative effectiveness of these measures in reducing road-kill, and the costs of these measures vary greatly. We conducted a meta-analysis using data from 50 studies that quantified the relationship between road-kill and a mitigation measure designed to reduce road-kill. Overall, mitigation measures reduce road-kill by 40% compared to controls. Fences, with or without crossing structures, reduce road-kill by 54%. We found no detectable effect on road-kill of crossing structures without fencing. We found that comparatively expensive mitigation measures reduce large mammal road-kill much more than inexpensive measures. For example, the combination of fencing and crossing structures led to an 83% reduction in road-kill of large mammals, compared to a 57% reduction for animal detection systems, and only a 1% for wildlife reflectors. We suggest that inexpensive measures such as reflectors should not be used until and unless their effectiveness is tested using a high-quality experimental approach. Our meta-analysis also highlights the fact that there are insufficient data to answer many of the most pressing questions that road planners ask about the effectiveness of road mitigation measures, such as whether other less common mitigation measures (e.g., measures to reduce traffic volume and/or speed) reduce road mortality, or to what extent the attributes of crossing structures and fences influence their effectiveness. To improve evaluations of mitigation effectiveness, studies should incorporate data collection before the mitigation is applied, and we recommend a

  4. How Effective Is Road Mitigation at Reducing Road-Kill? A Meta-Analysis.

    Trina Rytwinski

    Full Text Available Road traffic kills hundreds of millions of animals every year, posing a critical threat to the populations of many species. To address this problem there are more than forty types of road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill. For road planners, deciding on what mitigation method to use has been problematic because there is little good information about the relative effectiveness of these measures in reducing road-kill, and the costs of these measures vary greatly. We conducted a meta-analysis using data from 50 studies that quantified the relationship between road-kill and a mitigation measure designed to reduce road-kill. Overall, mitigation measures reduce road-kill by 40% compared to controls. Fences, with or without crossing structures, reduce road-kill by 54%. We found no detectable effect on road-kill of crossing structures without fencing. We found that comparatively expensive mitigation measures reduce large mammal road-kill much more than inexpensive measures. For example, the combination of fencing and crossing structures led to an 83% reduction in road-kill of large mammals, compared to a 57% reduction for animal detection systems, and only a 1% for wildlife reflectors. We suggest that inexpensive measures such as reflectors should not be used until and unless their effectiveness is tested using a high-quality experimental approach. Our meta-analysis also highlights the fact that there are insufficient data to answer many of the most pressing questions that road planners ask about the effectiveness of road mitigation measures, such as whether other less common mitigation measures (e.g., measures to reduce traffic volume and/or speed reduce road mortality, or to what extent the attributes of crossing structures and fences influence their effectiveness. To improve evaluations of mitigation effectiveness, studies should incorporate data collection before the mitigation is applied, and we

  5. How Effective Is Road Mitigation at Reducing Road-Kill? A Meta-Analysis

    Rytwinski, Trina; Soanes, Kylie; Jaeger, Jochen A. G.; Fahrig, Lenore; Findlay, C. Scott; Houlahan, Jeff; van der Ree, Rodney; van der Grift, Edgar A

    2016-01-01

    Road traffic kills hundreds of millions of animals every year, posing a critical threat to the populations of many species. To address this problem there are more than forty types of road mitigation measures available that aim to reduce wildlife mortality on roads (road-kill). For road planners, deciding on what mitigation method to use has been problematic because there is little good information about the relative effectiveness of these measures in reducing road-kill, and the costs of these measures vary greatly. We conducted a meta-analysis using data from 50 studies that quantified the relationship between road-kill and a mitigation measure designed to reduce road-kill. Overall, mitigation measures reduce road-kill by 40% compared to controls. Fences, with or without crossing structures, reduce road-kill by 54%. We found no detectable effect on road-kill of crossing structures without fencing. We found that comparatively expensive mitigation measures reduce large mammal road-kill much more than inexpensive measures. For example, the combination of fencing and crossing structures led to an 83% reduction in road-kill of large mammals, compared to a 57% reduction for animal detection systems, and only a 1% for wildlife reflectors. We suggest that inexpensive measures such as reflectors should not be used until and unless their effectiveness is tested using a high-quality experimental approach. Our meta-analysis also highlights the fact that there are insufficient data to answer many of the most pressing questions that road planners ask about the effectiveness of road mitigation measures, such as whether other less common mitigation measures (e.g., measures to reduce traffic volume and/or speed) reduce road mortality, or to what extent the attributes of crossing structures and fences influence their effectiveness. To improve evaluations of mitigation effectiveness, studies should incorporate data collection before the mitigation is applied, and we recommend a

  6. Targeting hunter distribution based on host resource selection and kill sites to manage disease risk.

    Dugal, Cherie J; van Beest, Floris M; Vander Wal, Eric; Brook, Ryan K

    2013-10-01

    Endemic and emerging diseases are rarely uniform in their spatial distribution or prevalence among cohorts of wildlife. Spatial models that quantify risk-driven differences in resource selection and hunter mortality of animals at fine spatial scales can assist disease management by identifying high-risk areas and individuals. We used resource selection functions (RSFs) and selection ratios (SRs) to quantify sex- and age-specific resource selection patterns of collared (n = 67) and hunter-killed (n = 796) nonmigratory elk (Cervus canadensis manitobensis) during the hunting season between 2002 and 2012, in southwestern Manitoba, Canada. Distance to protected area was the most important covariate influencing resource selection and hunter-kill sites of elk (AICw = 1.00). Collared adult males (which are most likely to be infected with bovine tuberculosis (Mycobacterium bovis) and chronic wasting disease) rarely selected for sites outside of parks during the hunting season in contrast to adult females and juvenile males. The RSFs showed selection by adult females and juvenile males to be negatively associated with landscape-level forest cover, high road density, and water cover, whereas hunter-kill sites of these cohorts were positively associated with landscape-level forest cover and increasing distance to streams and negatively associated with high road density. Local-level forest was positively associated with collared animal locations and hunter-kill sites; however, selection was stronger for collared juvenile males and hunter-killed adult females. In instances where disease infects a metapopulation and eradication is infeasible, a principle goal of management is to limit the spread of disease among infected animals. We map high-risk areas that are regularly used by potentially infectious hosts but currently underrepresented in the distribution of kill sites. We present a novel application of widely available data to target hunter distribution based on host resource

  7. Complement-mediated killing of Borrelia burgdorferi by nonimmune sera from sika deer.

    Nelson, D R; Rooney, S; Miller, N J; Mather, T N

    2000-12-01

    Various species of cervid deer are the preferred hosts for adult, black-legged ticks (Ixodes scapularis and Ixodes pacificus) in the United States. Although frequently exposed to the agent of Lyme disease (Borrelia burgdorferi), these animals, for the most part, are incompetent as transmission reservoirs. We examined the borreliacidal activity of normal and B. burgdorferi-immune sera from sika deer (Cervus nippon) maintained in a laboratory setting and compared it to that of similar sera from reservoir-competent mice and rabbits. All normal deer sera (NDS) tested killed > 90% of B. burgdorferi cells. In contrast, normal mouse and rabbit sera killed feeding exhibited IFA titers of 1:256, whereas sera from mice and rabbits similarly exposed had titers of > 1:1,024. Heat treatment (56 C, 30 min) of NDS reduced borreliacidal activity, with complement-mediated killing. The chelators EGTA and EDTA were used to block the classical or both the classical and alternative complement pathways, respectively. Addition of 10 mM EGTA to NDS had a negligible effect on borreliacidal activity, with > 90% of the cells killed. Addition of 10 mM EDTA reduced the killing to approximately 30%, whereas the addition of Mg2+ (10 mM) restored borreliacidal activity to NDS. The addition of zymosan A, an activator of the alternative pathway, increased the survival of B. burgdorferi cells to approximately 80% in NDS. These data suggest that the alternative complement activation pathway plays a major role in the borreliacidal activity of NDS. Additionally, 10 mM EGTA had almost no effect on the killing activity of B. burgdorferi-exposed deer sera, suggesting that the classical pathway is not involved in Borrelia killing, even in sera from B. burgdorferi-exposed deer.

  8. An Assessment of Sub-Meter Scale Spatial Variability of Arcellinida (Testate Lobose Amoebae) Assemblages in a Temperate Lake: Implications for Limnological Studies.

    Steele, Riley E; Nasser, Nawaf A; Patterson, R Timothy; Gregory, Braden R B; Roe, Helen M; Reinhardt, Eduard G

    2018-03-04

    Arcellinida (testate lobose amoebae), a group of benthic protists, were examined from 46 sediment-water interface samples collected from oligotrophic Oromocto Lake, New Brunswick, Canada. To assess (1) assemblage homogeneity at a sub-meter spatial scale and (2) the necessity for collecting samples from multiple stations during intra-lake surveys; multiple samples were collected from three stations (quadrats 1, 2, and 3) across the north basin of Oromocto Lake, with quadrat 1 (n = 16) being the furthest to the west, quadrat 2 (n = 15) situated closer to the center of the basin, and quadrat 3 (n = 15) positioned 300 m south of the mouth of Dead Brook, an inlet stream. Results from cluster analysis and non-metric multidimensional scaling (NMDS) analysis identified two major Arcellinida assemblages, A1 and A2, the latter containing two sub-assemblages (A2a and A2b). Redundancy analysis and variance partitioning results indicated that seven statistically significant environmental variables (K, S, Sb, Ti, Zn, Fe, and Mn) explained 41.5% of the total variation in the Arcellinida distribution. Iron, Ti and K, indicators of detrital runoff, had the greatest influence on assemblage variance. The results of this study reveal that closely spaced samples (~ 10 cm) in an open-water setting are comprised of homogenous arcellinidan assemblages, indicating that replicate sampling is not required. The results, however, must be tempered with respect to the various water properties and physical characteristics that comprise individual lakes as collection of several samples may likely be necessary when sampling multiple sites of a lake basin characterized by varying water depths (e.g., littoral zone vs. open water), or lakes impacted by geogenic or anthropogenic stressors (e.g., eutrophication, or industrial contamination).

  9. Molecular Detection of Legionella spp. and their associations with Mycobacterium spp., Pseudomonas aeruginosa and amoeba hosts in a drinking water distribution system.

    Lu, J; Struewing, I; Vereen, E; Kirby, A E; Levy, K; Moe, C; Ashbolt, N

    2016-02-01

    This study investigated waterborne opportunistic pathogens (OPs) including potential hosts, and evaluated the use of Legionella spp. for indicating microbial water quality for OPs within a full-scale operating drinking water distribution system (DWDS). To investigate the occurrence of specific microbial pathogens within a major city DWDS we examined large volume (90 l drinking water) ultrafiltration (UF) concentrates collected from six sites between February, 2012 and June, 2013. The detection frequency and concentration estimates by qPCR were: Legionella spp. (57%/85 cell equivalent, CE l(-1) ), Mycobacterium spp. (88%/324 CE l(-1) ), Pseudomonas aeruginosa (24%/2 CE l(-1) ), Vermamoeba vermiformis (24%/2 CE l(-1) ) and Acanthamoeba spp. (42%/5 cyst equivalent, CE l(-1) ). There was no detection of the following microorganisms: human faecal indicator Bacteroides (HF183), Salmonella enterica, Campylobacter spp., Escherichia coli O157:H7, Giardia intestinalis, Cryptosporidium spp. or Naegleria fowleri. There were significant correlations between the qPCR signals of Legionella spp. and Mycobacterium spp., and their potential hosts V. vermiformis and Acanthamoeba spp. Sequencing of Legionella spp. demonstrated limited diversity, with most sequences coming from two dominant groups, of which the larger dominant group was an unidentified species. Other known species including Legionella pneumophila were detected, but at low frequency. The densities of Legionella spp. and Mycobacterium spp. were generally higher (17 and 324 folds, respectively) for distal sites relative to the entry point to the DWDS. Legionella spp. occurred, had significant growth and were strongly associated with free-living amoebae (FLA) and Mycobacterium spp., suggesting that Legionella spp. could provide a useful DWDS monitoring role to indicate potential conditions for non-faecal OPs. The results provide insight into microbial pathogen detection that may aid in the monitoring of microbial water

  10. Prevalence of pathogenic free-living amoeba and other protozoa in natural and communal piped tap water from Queen Elizabeth protected area, Uganda.

    Sente, Celsus; Erume, Joseph; Naigaga, Irene; Mulindwa, Julius; Ochwo, Sylvester; Magambo, Phillip Kimuda; Namara, Benigna Gabriela; Kato, Charles Drago; Sebyatika, George; Muwonge, Kevin; Ocaido, Michael

    2016-08-03

    Pathogenic water dwelling protozoa such as Acanthamoeba spp., Hartmannella spp., Naegleria spp., Cryptosporidium spp. and Giardia spp. are often responsible for devastating illnesses especially in children and immunocompromised individuals, yet their presence and prevalence in certain environment in sub-Saharan Africa is still unknown to most researchers, public health officials and medical practitioners. The objective of this study was to establish the presence and prevalence of pathogenic free-living amoeba (FLA), Cryptosporidium and Giardia in Queen Elizabeth Protected Area (QEPA). Samples were collected from communal taps and natural water sites in QEPA. Physical water parameters were measured in situ. The samples were processed to detect the presence of FLA trophozoites by xenic cultivation, Cryptosporidium oocysts by Ziehl-Neelsen stain and Giardia cysts by Zinc Sulphate floatation technique. Parasites were observed microscopically, identified, counted and recorded. For FLA, genomic DNA was extracted for amplification and sequencing. Both natural and tap water sources were contaminated with FLA, Cryptosporidium spp. and Giardia spp. All protozoan parasites were more abundant in the colder rainy season except for Harmannella spp. and Naegleria spp. which occurred more in the warmer months. The prevalence of all parasites was higher in tap water than in natural water samples. There was a strong negative correlation between the presence of Acanthamoeba spp., Hartmannella spp., Cryptosporidium spp. and Giardia spp. with Dissolved Oxygen (DO) (P protozoa that could possibly be the cause of a number of silent morbidities and mortalities among rural households in QEPA. This implies that water used by communities in QEPA is of poor quality and predisposes them to a variety of protozoan infections including the FLA whose public health importance was never reported, thus necessitating adoption of proper water safety measures.

  11. Effect of Silicon on Desulfurization of Aluminum-killed Steels

    Roy, Debdutta

    Recent reports have suggested that silicon has a beneficial effect on the rate of desulfurization of Al-killed steel. This effect is difficult to understand looking at the overall desulfurization reaction which does not include silicon. However an explanation is proposed by taking into account the (SiO2)/[Si] equilibrium in which some Al reaching the slag-metal interface is used in reducing the SiO2 in the slag. This reaction can be suppressed to some extent if the silicon content of the metal is increased and in doing so, more Al will be available at the slag-metal interface for the desulfurization reaction and this would increase the rate of the desulfurization reaction. A model was developed, assuming the rates are controlled by mass transfer, taking into account the coupled reactions of the reduction of silica, and other unstable oxides, namely iron oxide and manganese oxide, in the slag and desulfurization reaction in the steel by aluminum. The model predicts that increasing silicon increases the rate and extent of desulfurization. Plant data was analyzed to obtain rough estimates of ladle desulfurization rates and also used to validate the model predictions. Experiments have been conducted on a kilogram scale of material in an induction furnace to test the hypothesis. The major conclusions of the study are as follows: The rate and extent of desulfurization improve with increasing initial silicon content in the steel; the effect diminishes at silicon contents higher than approximately 0.2% and with increasing slag basicity. This was confirmed with kilogram-scale laboratory experiments. The effects of the silicon content in the steel (and of initial FeO and MnO in the slag) largely arise from the dominant effects of these reactions on the equilibrium aluminum content of the steel: as far as aluminum consumption or pick-up is concerned, the Si/SiO2 reaction dominates, and desulfurization has only a minor effect on aluminum consumption. The rate is primarily

  12. ANALYZE THE IMPACT OF HABITAT PATCHES ON WILDLIFE ROAD-KILL

    S. Seok

    2015-10-01

    Full Text Available The ecosystem fragmentation due to transportation infrastructure causes a road-kill phenomenon. When making policies for mitigating road-kill it is important to select target-species in order to enhance its efficiency. However, many wildlife crossing structures have been questioned regarding their effectiveness due to lack of considerations such as target-species selection, site selection, management, etc. The purpose of this study is to analyse the impact of habitat patches on wildlife road-kill and to suggest that spatial location of habitat patches should be considered as one of the important factors when making policies for mitigating road-kill. Habitat patches were presumed from habitat variables and a suitability index on target-species that was chosen by literature review. The road-kill hotspot was calculated using Getis-Ord Gi*. After that, we performed a correlation analysis between Gi Z-score and the distance from habitat patches to the roads. As a result, there is a low negative correlation between two variables and it increases the Gi Z-score if the habitat patches and the roads become closer.

  13. Analyze the Impact of Habitat Patches on Wildlife Road-Kill

    Seok, S.; Lee, J.

    2015-10-01

    The ecosystem fragmentation due to transportation infrastructure causes a road-kill phenomenon. When making policies for mitigating road-kill it is important to select target-species in order to enhance its efficiency. However, many wildlife crossing structures have been questioned regarding their effectiveness due to lack of considerations such as target-species selection, site selection, management, etc. The purpose of this study is to analyse the impact of habitat patches on wildlife road-kill and to suggest that spatial location of habitat patches should be considered as one of the important factors when making policies for mitigating road-kill. Habitat patches were presumed from habitat variables and a suitability index on target-species that was chosen by literature review. The road-kill hotspot was calculated using Getis-Ord Gi*. After that, we performed a correlation analysis between Gi Z-score and the distance from habitat patches to the roads. As a result, there is a low negative correlation between two variables and it increases the Gi Z-score if the habitat patches and the roads become closer.

  14. Characterization of cell lysis in Pseudomonas putida induced upon expression of heterologous killing genes

    Ronchel, M.C.; Molina, L.; Witte, A.

    1998-01-01

    Active biological containment systems are based on the controlled expression of killing genes. These systems are of interest for the Pseudomonadaceae because of the potential applications of these microbes as bioremediation agents and biopesticides, The physiological effects that lead to cell dea...... protein was the killing agent. In both cases, cell death occurred as a result of impaired respiration, altered membrane permeability, and the release of some cytoplasmic contents to the extracellular medium.......Active biological containment systems are based on the controlled expression of killing genes. These systems are of interest for the Pseudomonadaceae because of the potential applications of these microbes as bioremediation agents and biopesticides, The physiological effects that lead to cell death......, respectively. Expression of the killing genes is controlled by the LacI protein, whose expression is initiated from the XylS-dependent Pm promoter. Under induced conditions, killing of P. putida CMC12 cells mediated by phi X174 lysis protein E was faster than that observed for P. putida CMC4, for which the Gef...

  15. Quantifying Killing of Orangutans and Human-Orangutan Conflict in Kalimantan, Indonesia

    Meijaard, Erik; Buchori, Damayanti; Hadiprakarsa, Yokyok; Utami-Atmoko, Sri Suci; Nurcahyo, Anton; Tjiu, Albertus; Prasetyo, Didik; Nardiyono; Christie, Lenny; Ancrenaz, Marc; Abadi, Firman; Antoni, I Nyoman Gede; Armayadi, Dedy; Dinato, Adi; Ella; Gumelar, Pajar; Indrawan, Tito P.; Kussaritano; Munajat, Cecep; Priyono, C. Wawan Puji; Purwanto, Yadi; Puspitasari, Dewi; Putra, M. Syukur Wahyu; Rahmat, Abdi; Ramadani, Harri; Sammy, Jim; Siswanto, Dedi; Syamsuri, Muhammad; Andayani, Noviar; Wu, Huanhuan; Wells, Jessie Anne; Mengersen, Kerrie

    2011-01-01

    Human-orangutan conflict and hunting are thought to pose a serious threat to orangutan existence in Kalimantan, the Indonesian part of Borneo. No data existed prior to the present study to substantiate these threats. We investigated the rates, spatial distribution and causes of conflict and hunting through an interview-based survey in the orangutan's range in Kalimantan, Indonesia. Between April 2008 and September 2009, we interviewed 6983 respondents in 687 villages to obtain socio-economic information, assess knowledge of local wildlife in general and orangutan encounters specifically, and to query respondents about their knowledge on orangutan conflicts and killing, and relevant laws. This survey revealed estimated killing rates of between 750 and 1800 animals killed in the last year, and between 1950 and 3100 animals killed per year on average within the lifetime of the survey respondents. These killing rates are higher than previously thought and are high enough to pose a serious threat to the continued existence of orangutans in Kalimantan. Importantly, the study contributes to our understanding of the spatial variation in threats, and the underlying causes of those threats, which can be used to facilitate the development of targeted conservation management. PMID:22096582

  16. Effect of Shark Liver Oil on Peritoneal Murine Macrophages in Responses to Killed-Candida albicans

    Monire Hajimoradi

    2009-09-01

    Full Text Available Objective(sShark Liver Oil (SLO is an immunomodulator. Macrophages play a key role in host defense against pathogens like fungi. Candida albicans have mechanisms to escape immune system. We determined the effect of killed-Candida on the in vitro viability of macrophages and the effect of SLO on augmentation of this potency.Materials and MethodsPeritoneal macrophages were separated and cultured (3×105/well. At first, the effect of killed-Candida (200 cells/well on macrophage viability was evaluated, using MTT test. Then, MTT was performed on macrophages stimulated with killed-Candida in the presence of SLO. ResultsKilled-Candida suppressed the ability of MTT reduction and hence macrophages viability (P=0.026, but addition of SLO (100 mg/ml significantly enhanced cell viability (P=0.00. So, SLO could neutralize the inhibitory effect of Candida.ConclusionSimultaneous with cytotoxic effect of killed-Candida cells on macrophages viability, SLO augment macrophages viability. So, it can be applied in candidiasis as a complement.

  17. Killing vector fields in three dimensions: a method to solve massive gravity field equations

    Guerses, Metin, E-mail: gurses@fen.bilkent.edu.t [Department of Mathematics, Faculty of Sciences, Bilkent University, 06800 Ankara (Turkey)

    2010-10-21

    Killing vector fields in three dimensions play an important role in the construction of the related spacetime geometry. In this work we show that when a three-dimensional geometry admits a Killing vector field then the Ricci tensor of the geometry is determined in terms of the Killing vector field and its scalars. In this way we can generate all products and covariant derivatives at any order of the Ricci tensor. Using this property we give ways to solve the field equations of topologically massive gravity (TMG) and new massive gravity (NMG) introduced recently. In particular when the scalars of the Killing vector field (timelike, spacelike and null cases) are constants then all three-dimensional symmetric tensors of the geometry, the Ricci and Einstein tensors, their covariant derivatives at all orders, and their products of all orders are completely determined by the Killing vector field and the metric. Hence, the corresponding three-dimensional metrics are strong candidates for solving all higher derivative gravitational field equations in three dimensions.

  18. Relative susceptibility of Giardia muris trophozoites to killing by mouse antibodies of different isotypes.

    Heyworth, M F

    1992-02-01

    The aim of this work was to examine the ability of mouse IgA, IgG, and IgM anti-Giardia antibodies to kill Giardia muris trophozoites in the presence and absence of complement. Using a 2-color flow cytometry assay, binding of antibody to trophozoites was assessed with fluorescein-conjugated anti-mouse immunoglobulin, and percentages of killed trophozoites were quantified by staining with propidium iodide. Trophozoites were killed in the presence of complement by IgG3 and IgM anti-trophozoite monoclonal antibodies. Anti-trophozoite IgA, obtained from the intestinal lumen of G. muris-infected BALB/c mice, became bound to trophozoites in vitro but did not kill these organisms in the presence or absence of complement. The results suggest that clearance of G. muris infection by intestinal IgA directed against G. muris trophozoites does not involve antibody-dependent killing of trophozoites in the intestinal lumen.

  19. Quantifying killing of orangutans and human-orangutan conflict in Kalimantan, Indonesia.

    Erik Meijaard

    Full Text Available Human-orangutan conflict and hunting are thought to pose a serious threat to orangutan existence in Kalimantan, the Indonesian part of Borneo. No data existed prior to the present study to substantiate these threats. We investigated the rates, spatial distribution and causes of conflict and hunting through an interview-based survey in the orangutan's range in Kalimantan, Indonesia. Between April 2008 and September 2009, we interviewed 6983 respondents in 687 villages to obtain socio-economic information, assess knowledge of local wildlife in general and orangutan encounters specifically, and to query respondents about their knowledge on orangutan conflicts and killing, and relevant laws. This survey revealed estimated killing rates of between 750 and 1800 animals killed in the last year, and between 1950 and 3100 animals killed per year on average within the lifetime of the survey respondents. These killing rates are higher than previously thought and are high enough to pose a serious threat to the continued existence of orangutans in Kalimantan. Importantly, the study contributes to our understanding of the spatial variation in threats, and the underlying causes of those threats, which can be used to facilitate the development of targeted conservation management.

  20. To kill, stay or flee: the effects of lions and landscape factors on habitat and kill site selection of cheetahs in South Africa.

    Susana Rostro-García

    Full Text Available Understanding how animals utilize available space is important for their conservation, as it provides insight into the ecological needs of the species, including those related to habitat, prey and inter and intraspecific interactions. We used 28 months of radio telemetry data and information from 200 kill locations to assess habitat selection at the 3rd order (selection of habitats within home ranges and 4th order (selection of kill sites within the habitats used of a reintroduced population of cheetahs Acinonyx jubatus in Phinda Private Game Reserve, South Africa. Along with landscape characteristics, we investigated if lion Panthera leo presence affected habitat selection of cheetahs. Our results indicated that cheetah habitat selection was driven by a trade-off between resource acquisition and lion avoidance, and the balance of this trade-off varied with scale: more open habitats with high prey densities were positively selected within home ranges, whereas more closed habitats with low prey densities were positively selected for kill sites. We also showed that habitat selection, feeding ecology, and avoidance of lions differed depending on the sex and reproductive status of cheetahs. The results highlight the importance of scale when investigating a species' habitat selection. We conclude that the adaptability of cheetahs, together with the habitat heterogeneity found within Phinda, explained their success in this small fenced reserve. The results provide information for the conservation and management of this threatened species, especially with regards to reintroduction efforts in South Africa.

  1. To Kill, Stay or Flee: The Effects of Lions and Landscape Factors on Habitat and Kill Site Selection of Cheetahs in South Africa

    Rostro-García, Susana; Kamler, Jan F.; Hunter, Luke T. B.

    2015-01-01

    Understanding how animals utilize available space is important for their conservation, as it provides insight into the ecological needs of the species, including those related to habitat, prey and inter and intraspecific interactions. We used 28 months of radio telemetry data and information from 200 kill locations to assess habitat selection at the 3rd order (selection of habitats within home ranges) and 4th order (selection of kill sites within the habitats used) of a reintroduced population of cheetahs Acinonyx jubatus in Phinda Private Game Reserve, South Africa. Along with landscape characteristics, we investigated if lion Panthera leo presence affected habitat selection of cheetahs. Our results indicated that cheetah habitat selection was driven by a trade-off between resource acquisition and lion avoidance, and the balance of this trade-off varied with scale: more open habitats with high prey densities were positively selected within home ranges, whereas more closed habitats with low prey densities were positively selected for kill sites. We also showed that habitat selection, feeding ecology, and avoidance of lions differed depending on the sex and reproductive status of cheetahs. The results highlight the importance of scale when investigating a species’ habitat selection. We conclude that the adaptability of cheetahs, together with the habitat heterogeneity found within Phinda, explained their success in this small fenced reserve. The results provide information for the conservation and management of this threatened species, especially with regards to reintroduction efforts in South Africa. PMID:25693067

  2. To kill, stay or flee: the effects of lions and landscape factors on habitat and kill site selection of cheetahs in South Africa.

    Rostro-García, Susana; Kamler, Jan F; Hunter, Luke T B

    2015-01-01

    Understanding how animals utilize available space is important for their conservation, as it provides insight into the ecological needs of the species, including those related to habitat, prey and inter and intraspecific interactions. We used 28 months of radio telemetry data and information from 200 kill locations to assess habitat selection at the 3rd order (selection of habitats within home ranges) and 4th order (selection of kill sites within the habitats used) of a reintroduced population of cheetahs Acinonyx jubatus in Phinda Private Game Reserve, South Africa. Along with landscape characteristics, we investigated if lion Panthera leo presence affected habitat selection of cheetahs. Our results indicated that cheetah habitat selection was driven by a trade-off between resource acquisition and lion avoidance, and the balance of this trade-off varied with scale: more open habitats with high prey densities were positively selected within home ranges, whereas more closed habitats with low prey densities were positively selected for kill sites. We also showed that habitat selection, feeding ecology, and avoidance of lions differed depending on the sex and reproductive status of cheetahs. The results highlight the importance of scale when investigating a species' habitat selection. We conclude that the adaptability of cheetahs, together with the habitat heterogeneity found within Phinda, explained their success in this small fenced reserve. The results provide information for the conservation and management of this threatened species, especially with regards to reintroduction efforts in South Africa.

  3. Gray Wolf (Canis lupus) movements and behavior around a kill site and implications for GPS collar studies

    Mech, L. David

    2011-01-01

    Global Positioning System (GPS) radio-collars are increasingly used to estimate Gray Wolf (Canis lupus) kill rates. In interpreting results from this technology, researchers make various assumptions about wolf behavior around kills, yet no detailed description of this behavior has been published. This article describes the behavior of six wolves in an area of constant daylight during 30 hours, from when the pack killed a Muskox (Ovibos moschatus) calf and yearling on Ellesmere Island, Nunavut, Canada, to when they abandoned the kill remains. Although this is only a single incident, it demonstrates one possible scenario of pack behavior around a kill. Combined with the literature, this observation supports placing a radio-collar on the breeding male to maximize finding kills via GPS collars and qualifying results depending on whatever other information is available about the collared wolf's pack.

  4. Offensive Counterterrorism Targeted killing in eliminating terrorist target: the case of the USA and Israel

    Hermínio Matos

    2012-01-01

    Full Text Available Due to the "global terrorism project", some States have adopted offensive counterterrorism measures which, though within national strategies on security and defense, contemplate the use of military power and the use of lethal force against non-state actors - individuals, groups or terrorist organizations - beyond their national borders. Reformulating the security paradigm has led, in these cases, to policies against terrorism. This is the case of targeted killing - the killing of selected targets - by the USA and Israel. Targeted killing actions - using essentially but not only drones - in Pakistan and Yemen by the American administration, a well as the Israeli response to Palestinian terrorism, are under heated debate in terms of their efficiency and legality. Thus, this paper aims to not only provide an analytical framework on this theme but also analyze the scope and impact of these counter terrorist strategies by the two countries.

  5. Killing people: what Kant could have said about suicide and euthanasia but did not

    Brassington, I

    2006-01-01

    An agent who takes his own life acts in violation of the moral law, according to Kant; suicide, and, by extension, assisted suicide are therefore wrong. By a similar argument, and with a few important exceptions, killing is wrong; implicitly, then, voluntary euthanasia is also wrong. Kant's conclusions are uncompelling and his argument in these matters is undermined on considering other areas of his thought. Kant, in forbidding suicide and euthanasia, is conflating respect for persons and respect for people, and assuming that, in killing a person (either oneself or another), we are thereby undermining personhood. But an argument along these lines is faulty according to Kant's own standards. There is no reason why Kantians have to accept that self‐killing and euthanasia are contrary to the moral law. Even if some Kantians adhere to this doctrine, others can reject it. PMID:17012496

  6. Efficacy of common laboratory disinfectants and heat on killing trypanosomatid parasites

    Tyler Kevin M

    2008-09-01

    Full Text Available Abstract The disinfectants TriGene, bleach, ethanol and liquid hand soap, and water and temperature were tested for their ability to kill bloodstream forms of Trypanosoma brucei, epimastigotes of Trypanosoma rangeli and promastigotes of Leishmania major. A 5-min exposure to 0.2% TriGene, 0.1% liquid hand soap and 0.05% bleach (0.05% NaOCl killed all three trypanosomatids. Ethanol and water destroyed the parasites within 5 min at concentrations of 15–17.5% and 80–90%, respectively. All three organisms were also killed when treated for 5 min at 50°C. The results indicate that the disinfectants, water and temperature treatment (i.e. autoclaving are suitable laboratory hygiene measures against trypanosomatid parasites.

  7. Effect of Legionella pneumophila sonicate on killing of Listeria monocytogenes by human polymorphonuclear neutrophils and monocytes

    Rechnitzer, C; Bangsborg, Jette Marie; Shand, G H

    1993-01-01

    Legionella pneumophila shares with other intracellular pathogens the ability to resist intracellular killing within phagocytes. An increasing number of cellular components of L. pneumophila are proposed as pathogenic factors of the organism. At the site of infection, the phagocytic cells will be ......Legionella pneumophila shares with other intracellular pathogens the ability to resist intracellular killing within phagocytes. An increasing number of cellular components of L. pneumophila are proposed as pathogenic factors of the organism. At the site of infection, the phagocytic cells...... are most likely to represent the inhibitory factors. The inhibitory activity of L. pneumophila sonic extract appears to be related to inhibition of killing mechanisms since uptake of Listeria was not affected by the sonicate. Our observations indicate that as Legionella infection progresses, bacterial...

  8. 'David and Goliath' of the soil food web - Flagellates that kill nematodes

    Strandmark, Lisa Bjørnlund; Rønn, Regin

    2008-01-01

    Nematodes and flagellates are important bacterial predators in soil and sediments. Generally, these organisms are considered to be competitors for bacterial food. We studied the interaction among flagellates and nematodes using axenic liquid cultures amended with heat-killed bacteria as food...... and showed for the first time that a small and common soil flagellate (Cercomonas sp.) is able to attack and kill the much larger nematode Caenorhabditis elegans. The killing process is not caused by soluble metabolites but requires direct contact between the flagellate cells and the nematode surface...... and occurs rapidly (within a few hours) at high flagellate density. At lower flagellate density, adult nematodes sometimes avoid attachment of flagellates, feed on them and become the dominant bacterial predator. Considering that bacterial feeders affect bacterial communities differently, and that one...

  9. Killing people: what Kant could have said about suicide and euthanasia but did not.

    Brassington, I

    2006-10-01

    An agent who takes his own life acts in violation of the moral law, according to Kant; suicide, and, by extension, assisted suicide are therefore wrong. By a similar argument, and with a few important exceptions, killing is wrong; implicitly, then, voluntary euthanasia is also wrong. Kant's conclusions are uncompelling and his argument in these matters is undermined on considering other areas of his thought. Kant, in forbidding suicide and euthanasia, is conflating respect for persons and respect for people, and assuming that, in killing a person (either oneself or another), we are thereby undermining personhood. But an argument along these lines is faulty according to Kant's own standards. There is no reason why Kantians have to accept that self-killing and euthanasia are contrary to the moral law. Even if some Kantians adhere to this doctrine, others can reject it.

  10. Bacteria killing effect of pulsed plasmas in oxygen+air at atmospheric pressure

    Akan, T.

    2005-01-01

    Bacteria Killing Method. The high voltage pulsed plasma is a non-equilibrium plasma and generates UV photons, ozone and active oxygen. The aim of this paper is to present a simple device to generate plasma able to kill efficiently bacteria. One of the probes charged with bacteria, was kept as a control probes (not exposed to the pulsed plasma), the rest of the probes were exposed to the pulsed plasma and afterwards compared with above mentioned control probe (reference sample). During treatment the bacteria were exposed to the active atoms, molecules, charged particles and photons generated by the pulsed plasma. The temperature of the support of samples with bacteria exposed to plasma increased during the treatment with only 1-2 degrees. Full killing time of Staphylococcus species as low as 3 minutes have been obtained quite easily

  11. Staphylococcus aureus virulence factors identified by using a high-throughput Caenorhabditis elegans-killing model.

    Begun, Jakob; Sifri, Costi D; Goldman, Samuel; Calderwood, Stephen B; Ausubel, Frederick M

    2005-02-01

    Staphylococcus aureus is an important human pathogen that is also able to kill the model nematode Caenorhabditis elegans. We constructed a 2,950-member Tn917 transposon insertion library in S. aureus strain NCTC 8325. Twenty-one of these insertions exhibited attenuated C. elegans killing, and of these, 12 contained insertions in different genes or chromosomal locations. Ten of these 12 insertions showed attenuated killing phenotypes when transduced into two different S. aureus strains, and 5 of the 10 mutants correspond to genes that have not been previously identified in signature-tagged mutagenesis studies. These latter five mutants were tested in a murine renal abscess model, and one mutant harboring an insertion in nagD exhibited attenuated virulence. Interestingly, Tn917 was shown to have a very strong bias for insertions near the terminus of DNA replication.

  12. Killing spinors for the bosonic string and Kaluza-Klein theory with scalar potentials

    Liu, Haishan; Lue, H.; Wang, Zhao-Long

    2012-01-01

    The paper consists mainly of two parts. In the first part, we obtain well-defined Killing spinor equations for the low-energy effective action of the bosonic string with the conformal anomaly term. We show that the conformal anomaly term is the only scalar potential that one can add into the action that is consistent with the Killing spinor equations. In the second part, we demonstrate that Kaluza-Klein theory can be gauged so that the Killing spinors are charged under the Kaluza-Klein vector. This gauging process generates a scalar potential with a maximum that gives rise to an AdS spacetime. We also construct solutions of these theories. (orig.)

  13. Predator-dependent functional response in wolves: from food limitation to surplus killing.

    Zimmermann, Barbara; Sand, Håkan; Wabakken, Petter; Liberg, Olof; Andreassen, Harry Peter

    2015-01-01

    The functional response of a predator describes the change in per capita kill rate to changes in prey density. This response can be influenced by predator densities, giving a predator-dependent functional response. In social carnivores which defend a territory, kill rates also depend on the individual energetic requirements of group members and their contribution to the kill rate. This study aims to provide empirical data for the functional response of wolves Canis lupus to the highly managed moose Alces alces population in Scandinavia. We explored prey and predator dependence, and how the functional response relates to the energetic requirements of wolf packs. Winter kill rates of GPS-collared wolves and densities of cervids were estimated for a total of 22 study periods in 15 wolf territories. The adult wolves were identified as the individuals responsible for providing kills to the wolf pack, while pups could be described as inept hunters. The predator-dependent, asymptotic functional response models (i.e. Hassell-Varley type II and Crowley-Martin) performed best among a set of 23 competing linear, asymptotic and sigmoid models. Small wolf packs acquired >3 times as much moose biomass as required to sustain their field metabolic rate (FMR), even at relatively low moose abundances. Large packs (6-9 wolves) acquired less biomass than required in territories with low moose abundance. We suggest the surplus killing by small packs is a result of an optimal foraging strategy to consume only the most nutritious parts of easy accessible prey while avoiding the risk of being detected by humans. Food limitation may have a stabilizing effect on pack size in wolves, as supported by the observed negative relationship between body weight of pups and pack size. © 2014 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  14. Anuran road-kills neighboring a peri-urban reserve in the Atlantic Forest, Brazil.

    Coelho, Igor Pfeifer; Teixeira, Fernanda Zimmermann; Colombo, Patrick; Coelho, Artur Vicente Pfeifer; Kindel, Andreas

    2012-12-15

    Mortality from road-kills may figure among the important causes of decline in amphibian populations and species extinctions worldwide. Evaluation of the magnitude, composition, and temporal and spatial distributions of amphibian road-kills is a key step for mitigation planning, especially in peri-urban reserves. Once a month for 16 months, we surveyed, on foot, a 4.4 km section of state road ERS-389 bordering the Itapeva reserve in the southern Atlantic Forest. We recorded 1433 anuran road-kills and estimated a mortality rate of 9002 road-kills/km/year. The species most often recorded were the largest ones: Leptodactylus latrans, Rhinella icterica, Leptodactylus gracilis and Hypsiboas faber; 54.5% of the carcasses could not be identified. Anuran mortality was concentrated in summer, and was associated with temperature, rainfall and photoperiod. Leptodactylus road-kills were strongly influenced by vehicle traffic, probably because of its high abundance during the entire study period. Road-kill hotspots differed for anurans as a group and for single species, and we found an association among spatial patterns of mortality and types of land cover, distance from the nearest waterbody, roadside ditches, and artificial light. Traffic should be banned temporarily during periods of high mortality, which can be forecasted based on meteorological data. A comprehensive mitigation approach should take into account hotspots of all anuran records, and also of target species for selecting locations for amphibian passages and fencing. Roadside ditches, artificial waterbodies, and conventional street lights should be reduced as much as possible, since they may represent ecological traps for anuran populations. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

    Peter J Hart

    Full Text Available Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

  16. Estimated Number of Birds Killed by House Cats (Felis catus in Canada

    Peter Blancher

    2013-12-01

    Full Text Available Predation by house cats (Felis catus is one of the largest human-related sources of mortality for wild birds in the United States and elsewhere, and has been implicated in extinctions and population declines of several species. However, relatively little is known about this topic in Canada. The objectives of this study were to provide plausible estimates for the number of birds killed by house cats in Canada, identify information that would help improve those estimates, and identify species potentially vulnerable to population impacts. In total, cats are estimated to kill between 100 and 350 million birds per year in Canada (> 95% of estimates were in this range, with the majority likely to be killed by feral cats. This range of estimates is based on surveys indicating that Canadians own about 8.5 million pet cats, a rough approximation of 1.4 to 4.2 million feral cats, and literature values of predation rates from studies conducted elsewhere. Reliability of the total kill estimate would be improved most by better knowledge of feral cat numbers and diet in Canada, though any data on birds killed by cats in Canada would be helpful. These estimates suggest that 2-7% of birds in southern Canada are killed by cats per year. Even at the low end, predation by house cats is probably the largest human-related source of bird mortality in Canada. Many species of birds are potentially vulnerable to at least local population impacts in southern Canada, by virtue of nesting or feeding on or near ground level, and habitat choices that bring them into contact with human-dominated landscapes where cats are abundant. Because cat predation is likely to remain a primary source of bird mortality in Canada for some time, this issue needs more scientific attention in Canada.

  17. Differential Killing of Salmonella enterica Serovar Typhi by Antibodies Targeting Vi and Lipopolysaccharide O:9 Antigen.

    Hart, Peter J; O'Shaughnessy, Colette M; Siggins, Matthew K; Bobat, Saeeda; Kingsley, Robert A; Goulding, David A; Crump, John A; Reyburn, Hugh; Micoli, Francesca; Dougan, Gordon; Cunningham, Adam F; MacLennan, Calman A

    2016-01-01

    Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

  18. Cell killing and mutation induction on Chinese hamster cells by photoradiations

    Lam, C.K.C.

    1982-11-01

    Applying radiation directly on cells, far-uv is more effective than black light, and black light is more effective than white light in inducing proliferative death and in inducing resistance to 6-thioguanine (6-TG), ouabain and diptheria toxin (DT). Gold light has no killing and mutagenic effects on CHO (Chinese hamster ovary) cells. Use of filters showed that a small percentage of shorter wavelengths in the far-uv region is responsible for most of the killing and mutagenic effects in the unfiltered broad spectra of black and white light

  19. Tumour-cell killing by X-rays and immunity quantitated in a mouse model system

    Porteous, D.D.; Porteous, K.M.; Hughes, M.J.

    1979-01-01

    As part of an investigation of the interaction of X-rays and immune cytotoxicity in tumour control, an experimental mouse model system has been used in which quantitative anti-tumour immunity was raised in prospective recipients of tumour-cell suspensions exposed to varying doses of X-rays in vitro before injection. Findings reported here indicate that, whilst X-rays kill a proportion of cells, induced immunity deals with a fixed number dependent upon the immune status of the host, and that X-rays and anti-tumour immunity do not act synergistically in tumour-cell killing. The tumour used was the ascites sarcoma BP8. (author)

  20. Habitat or matrix: which is more relevant to predict road-kill of vertebrates?

    Bueno,C.; Sousa,C. O. M.; Freitas,S. R.

    2015-01-01

    Abstract We believe that in tropics we need a community approach to evaluate road impacts on wildlife, and thus, suggest mitigation measures for groups of species instead a focal-species approach. Understanding which landscape characteristics indicate road-kill events may also provide models that can be applied in other regions. We intend to evaluate if habitat or matrix is more relevant to predict road-kill events for a group of species. Our hypothesis is: more permeable matrix is the most r...

  1. Intergenomic arms races: detection of a nuclear rescue gene of male-killing in a ladybird.

    Tamsin M O Majerus

    Full Text Available Many species of arthropod are infected by deleterious inherited micro-organisms. Typically these micro-organisms are inherited maternally. Consequently, some, particularly bacteria of the genus Wolbachia, employ a variety of strategies that favour female over male hosts. These strategies include feminisation, induction of parthenogenesis and male-killing. These strategies result in female biased sex ratios in host populations, which lead to selection for host factors that promote male production. In addition, the intra-genomic conflict produced by the difference in transmission of these cytoplasmic endosymbionts and nuclear factors will impose a pressure favouring nuclear factors that suppress the effects of the symbiont. During investigations of the diversity of male-killing bacteria in ladybirds (Coccinellidae, unexpected patterns of vertical transmission of a newly discovered male-killing taxon were observed in the ladybird Cheilomenes sexmaculata. Initial analysis suggested that the expression of the bacterial male-killing trait varies according to the male(s a female has mated with. By swapping males between females, a male influence on the expression of the male-killing trait was confirmed. Experiments were then performed to determine the nature of the interaction. These studies showed that a single dominant allele, which rescues male progeny of infected females from the pathological effect of the male-killer, exists in this species. The gene shows typical Mendelian autosomal inheritance and is expressed irrespective of the parent from which it is inherited. Presence of the rescue gene in either parent does not significantly affect the inheritance of the symbiont. We conclude that C. sexmaculata is host to a male-killing gamma-proteobacterium. Further, this beetle is polymorphic for a nuclear gene, the dominant allele of which rescues infected males from the pathogenic effects of the male-killing agent. These findings represent the first

  2. Raping and making love are different concepts: so are killing and voluntary euthanasia.

    Davies, J

    1988-01-01

    The distinction between 'kill' and 'help to die' is argued by analogy with the distinction between 'rape' and 'make love to'. The difference is the consent of the receiver of the act, therefore 'kill' is the wrong word for an act of active voluntary euthanasia. The argument that doctors must not be allowed by law to perform active voluntary euthanasia because this would recognise an infringement of the sanctity of life ('the red light principle') is countered by comparing such doctors with the drivers of emergency vehicles, who are allowed to drive through red lights. PMID:3184136

  3. Surface-Selective Preferential Production of Reactive Oxygen Species on Piezoelectric Ceramics for Bacterial Killing.

    Tan, Guoxin; Wang, Shuangying; Zhu, Ye; Zhou, Lei; Yu, Peng; Wang, Xiaolan; He, Tianrui; Chen, Junqi; Mao, Chuanbin; Ning, Chengyun

    2016-09-21

    Reactive oxygen species (ROS) can be used to kill bacterial cells, and thus the selective generation of ROS from material surfaces is an emerging direction in antibacterial material discovery. We found the polarization of piezoelectric ceramic causes the two sides of the disk to become positively and negatively charged, which translate into cathode and anode surfaces in an aqueous solution. Because of the microelectrolysis of water, ROS are preferentially formed on the cathode surface. Consequently, the bacteria are selectively killed on the cathode surface. However, the cell experiment suggested that the level of ROS is safe for normal mammalian cells.

  4. Regions on plasmid pCU1 required for the killing of Klebsiella pneumoniae.

    Thatte, V; Gill, S; Iyer, V N

    1985-01-01

    Plasmid pCU1 was Kik+ (promotes killing of Klebsiella pneumoniae). All Tn5 insertions within the tra region of pCU1 were Kik-. Two other regions, kikA and kikB, were needed. They may be separated on different plasmids, but both must be mobilized into Klebsiella pneumoniae. Establishment of one kik region in K. pneumoniae followed by receipt of the second did not lead to killing. Kik was therefore intracellular and required concerted and transient action of both regions.

  5. Cell killing and mutation induction on Chinese hamster cells by photoradiations

    Lam, C.K.C.

    1982-11-01

    Applying radiation directly on cells, far-uv is more effective than black light, and black light is more effective than white light in inducing proliferative death and in inducing resistance to 6-thioguanine (6-TG), ouabain and diptheria toxin (DT). Gold light has no killing and mutagenic effects on CHO (Chinese hamster ovary) cells. Use of filters showed that a small percentage of shorter wavelengths in the far-uv region is responsible for most of the killing and mutagenic effects in the unfiltered broad spectra of black and white light.

  6. "Shades of Foreign Evil": "Honor Killings" and "Family Murders" in the Canadian Press.

    Shier, Allie; Shor, Eran

    2016-09-01

    This article compares murder cases labeled "honor killings" with cases labeled "family/spousal murders" in the Canadian news media, exploring the construction of boundaries between these two practices. We conducted a systematic qualitative content analysis, examining a sample of 486 articles from three major Canadian newspapers between 2000 and 2012. Our analysis shows that "honor killings" are framed in terms of culture and ethnic background, presenting a dichotomy between South Asian/Muslim and Western values. Conversely, articles presenting cases as "family/spousal murders" tend to focus on the perpetrators' personalities or psychological characteristics, often ignoring factors such as culture, patriarchy, honor, and shame. © The Author(s) 2015.

  7. Honor killings in the Middle East and North Africa: a systematic review of the literature.

    Kulczycki, Andrzej; Windle, Sarah

    2011-11-01

    A systematic review of the research literature on honor killings in the Middle East and North Africa (MENA) indicates a paucity of studies relative to the presumed magnitude of the problem. Forty articles were reviewed and critically appraised, of which only 9 contained primary data and 11 presented original secondary analyses. Despite a recent increase in published studies, persistent methodological limitations restrict the generalizability of findings. Most studies focus on legal aspects, determinants, and characteristics of victims and perpetrators. Victims are mostly young females murdered by their male kin. Unambiguous evidence of a decline in tolerance of honor killings remains elusive.

  8. The psychological reactions after witnessing a killing in public in a Danish high school

    Elklit, A.; Kurdahl, S.

    2013-01-01

    BACKGROUND: School killings attract immense media and public attention but psychological studies surrounding these events are rare. OBJECTIVE: To examine the prevalence of posttraumatic stress disorder (PTSD) and possible risk factors of PTSD in 320 Danish high school students (mean age 18 years) 7.......5%. Furthermore, 25% had PTSD at a subclinical level. Intimacy with the deceased girl; feeling fear, helplessness, or horror during the killing; lack of expressive ability; feeling let down by others; negative affectivity; and dissociation predicted 78% of the variance of the HTQ total scores. CONCLUSION...

  9. Vectores de Killing y cantidades conservadas para espacio-tiempos cuasi-esféricos

    J. Carot

    2007-01-01

    Full Text Available En este trabajo se estudian los espacio-tiempos con deformación de tipo B, con simetría axial y cuasi-esféricos. Se obtiene un elemento de linea tal que admite vectores de Killing de la familia 1 propuesta por J. Flores et. al. [1]. Se encuentran las cantidades conservadas asociadas a estos vectores de Killing y por tanto una primera integral de las ecuaciones de las geodésicas que describen una partícula libre inmersa en este tipo espacio- tiempo.

  10. Holocene palaeohydrological history of the Tǎul Muced peat bog (Northern Carpathians, Romania) based on testate amoebae (Protozoa) and plant macrofossils

    Cosmin Diaconu, Andrei; Feurdean, Angelica; Lamentowicz, Mariusz; Gałka, Mariusz; Tanţǎu, Ioan

    2016-04-01

    Knowledge of past local vs. regional hydro-climate variability is a priority in climate research. This is because ecosystems and human depend on local climatic conditions and the magnitude of these climate changes is more variable at local and regional rather than at global scales. Ombrotrophic bogs are highly suitable for hydro-climate reconstructions as they are entirely dependent on the water from precipitation. We used stratigraphy, radiocarbon dating, testate amoebae (TA) and plant macrofossils on a peat profile from an ombrotrophic bog (Tǎul Muced) located in the Biosphere Reserve of the Rodna National Park Romania. We performed quantitative reconstruction of the depth to water table (DWT) and pH over the last 8000 years in a continental area of CE Europe. We identified six main stages in the development of the bog based on changes in TA assemblages in time. Wet conditions and pH between 2 and 4.5 were recorded between 4600-2750 and 1300-400 cal. yr BP, by the occurrence of Archerella flavum, Amphitrema wrightianum and Hyalosphenia papilio. This was associated to a local vegetation primarily composed of Sphagnum magellanicum and S. angustifolium. Dry stages and pH of 2.5 to 5 were inferred between 7550-4600, 2750-1300 and -50 cal. yr BP, by the dominance of Nebela militaris, Difflugia pulex and Phryganella acropodia. These overall dry conditions were also connected with increased abundance of Eriophorum vaginatum. The period between 400 and -50 cal. yr BP was characterized by a rapid shift from dry to wet conditions on the surface of the bog. Vegetation shifted from Sphagnum magellanicum to Sphagnum russowii dominated community. Our reconstruction remains in relatively good agreement with other palaeohydrological records from Central Eastern Europe. However, it shows contrasting conditions to others particularly with records from NW Europe. The valuable information regarding bog hydrology offered by our record puts an accent on the need of more regional TA

  11. Modification of oxide inclusions in calcium-treated Al-killed high sulphur steels

    Gollapalli, Veerababu; Rao, M.B.Venkata; Karamched, P.S.; Borra, C.R.; Roy, G.G.; Srirangam, Prakash

    2018-01-01

    A study has been carried out to understand the modification of alumina inclusions in Al-killed high sulphur steel with calcium treatment. For calcium treatment to be effective, a general practice is to desulphurise the steel to prevent the formation of solid CaS inclusions that are harmful to

  12. Killing-Yano tensors and generalized supersymmetries in black hole and monopole geometries

    Holten, J.W. van.

    1994-01-01

    New kinds of supersymmetry arise in supersymmetric σ-models describing the motion of spinning point-particles in classical backgrounds, for example black-holes, or the dynamics of monopoles. Their geometric origin is the existence of Killing-Yano tensors. The relation between these concepts is explained and examples are given. (orig.)

  13. Glucocorticoids and Polyamine Inhibitors Synergize to Kill Human Leukemic CEM Cells1

    Miller, Aaron L; Johnson, Betty H; Medh, Rheem D; Townsend, Courtney M; Thompson, E Brad

    2002-01-01

    Abstract Glucocorticoids are well-known apoptotic agents in certain classes of lymphoid cell malignancies. Reduction of intracellular polyamine levels by use of inhibitors that block polyamine synthesis slows or inhibits growth of many cells in vitro. Several such inhibitors have shown efficacy in clinical trials, though the toxicity of some compounds has limited their usefulness. We have tested the effects of combinations of the glucocorticoid dexamethasone (Dex) and two polyamine inhibitors, difluoromethylornithine (DFMO) and methyl glyoxal bis guanylhydrazone (MGBG), on the clonal line of human acute lymphoblastic leukemia cells, CEM-C7-14. Dex alone kills these cells, though only after a delay of at least 24 hours. We also evaluated a partially glucocorticoid-resistant c-Myc-expressing CEM-C7-14 clone. We show that Dex downregulates ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis. Pretreatment with the ODC inhibitor DFMO, followed by addition of Dex, enhances steroid-evoked kill slightly. The combination of pretreatment with sublethal concentrations of both DFMO and the inhibitor of S-adenosylmethionine decarboxylase, MGBG, followed by addition of Dex, results in strong synergistic cell kill. Both the rapidity and extent of cell kill are enhanced compared to the effects of Dex alone. These results suggest that use of such combinations in vivo may result in apoptosis of malignant cells with lower overall toxicity. PMID:11922393

  14. Glucocorticoids and Polyamine Inhibitors Synergize to Kill Human Leukemic CEM Cells

    Aaron L. Miller

    2002-01-01

    Full Text Available Glucocorticoids are well-known apoptotic agents in certain classes of lymphoid cell malignancies. Reduction of intracellular polyamine levels by use of inhibitors that block polyamine synthesis slows or inhibits growth of many cells in vitro. Several such inhibitors have shown efficacy in clinical trials, though the toxicity of some compounds has limited their usefulness. We have tested the effects of combinations of the glucocorticoid dexamethasone. (20Dex and two polyamine inhibitors, difluoromethylornithine. (20DFMO and methyl glyoxal bis guanylhydrazone. (20MGBG, on the clonal line of human acute lymphoblastic leukemia cells, CEM-C7-14. Dex alone kills these cells, though only after a delay of at least 24 hours. We also evaluated a partially glucocorticoid-resistant c-Myc-expressing CEM-C7-14 clone. We show that Dex downregulates ornithine decarboxylase. (20ODC, the rate-limiting enzyme in polyamine synthesis. Pretreatment with the ODC inhibitor DFMO, followed by addition of Dex, enhances steroid-evoked kill slightly. The combination of pretreatment with sublethal concentrations of both DFMO and the inhibitor of S-adenosylmethionine decarboxylase, MGBG, followed by addition of Dex, results in strong synergistic cell kill. Both the rapidity and extent of cell kill are enhanced compared to the effects of Dex alone. These results suggest that use of such combinations in vivo may result in apoptosis of malignant cells with lower overall toxicity.

  15. Red fox, Vulpes vulpes, kills a European beaver, Castor fiber, kit

    Kile, Nils B.; Nakken, Petter J.; Rosell, Frank; Espeland, Sigurd

    1996-01-01

    We observed an adult Red Fox (Vulpes vulpes) attack, kill and partially consume a 2-month-old female kit European Beaver (Castor fiber) near its lodge in Norway. The inner organs were consumed first. One adult beaver apparently attempted to frighten the fox away by tail-slapping.

  16. Reactivation of neutron killed mammalian cells by gamma irradiation: The observations, possible mechanism and implication

    Calkins, J.; Harrison, W.; Einspenner, M.

    1990-01-01

    We have observed that combinations of neutron plus gamma ray exposure can significantly increase the colony forming ability of monkey and human cell cultures over the neutron dose alone. The 'reactivation' of neutron killed mammalian cells by gamma rays is analogous to observations made in lower eukaryotic organisms and fits the pattern termed 'T repair' previously postulated for yeast and protozoans. (orig.)

  17. Spatial distribution of lion kills determined by the water dependency of prey species

    Boer, de W.F.; Vis, M.J.P.; Knegt, de H.J.; Rowles, C.; Kohi, E.; Langevelde, van F.; Peel, M.J.S.; Pretorius, Y.; Skidmore, A.K.; Slotow, R.; Wieren, van S.E.; Prins, H.H.T.

    2010-01-01

    Predation risk from lions (Panthera leo) has been linked to habitat characteristics and availability and traits of prey. We separated the effects of vegetation density and the presence of drinking water by analyzing locations of lion kills in relation to rivers with dense vegetation, which offer

  18. Compensating for livestock killed by lions: payment for environmental services as a policy arrangement

    Anyango, M.N.; Duim, van der V.R.; Visseren-Hamakers, I.J.

    2015-01-01

    To address human–wildlife conflicts and the related threat of extinction of the African lion, in 2003, the Maasailand Preservation Trust established a fund at the Mbirikani Group Ranch in southern Kenya to provide monetary compensation for livestock killed by wildlife. In this paper, the policy

  19. 9 CFR 113.215 - Bovine Virus Diarrhea Vaccine, Killed Virus.

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Bovine Virus Diarrhea Vaccine, Killed Virus. 113.215 Section 113.215 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD...

  20. Influence of Sampling Effort on the Estimated Richness of Road-Killed Vertebrate Wildlife

    Bager, Alex; da Rosa, Clarissa A.

    2011-05-01

    Road-killed mammals, birds, and reptiles were collected weekly from highways in southern Brazil in 2002 and 2005. The objective was to assess variation in estimates of road-kill impacts on species richness produced by different sampling efforts, and to provide information to aid in the experimental design of future sampling. Richness observed in weekly samples was compared with sampling for different periods. In each period, the list of road-killed species was evaluated based on estimates the community structure derived from weekly samplings, and by the presence of the ten species most subject to road mortality, and also of threatened species. Weekly samples were sufficient only for reptiles and mammals, considered separately. Richness estimated from the biweekly samples was equal to that found in the weekly samples, and gave satisfactory results for sampling the most abundant and threatened species. The ten most affected species showed constant road-mortality rates, independent of sampling interval, and also maintained their dominance structure. Birds required greater sampling effort. When the composition of road-killed species varies seasonally, it is necessary to take biweekly samples for a minimum of one year. Weekly or more-frequent sampling for periods longer than two years is necessary to provide a reliable estimate of total species richness.