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1

Killing of microorganisms by pulsed electric fields  

Microsoft Academic Search

Lethal effects of pulsed electric fields (PEF) on suspensions of various bacteria, yeast, and spores in buffer solutions and\\u000a liquid foodstuffs were examined. Living-cell counts of vegetative cell types were reduced by PEF treatment by up to more than\\u000a four orders of magnitude (> 99.99%). On the other hand, endoand ascospores were not inactivated or killed to any great extent.

T. Grahl; H. Märkl

1996-01-01

2

Streptococcus pneumoniae Invades Endothelial Host Cells via Multiple Pathways and Is Killed in a Lysosome Dependent Manner  

PubMed Central

Streptococcus pneumoniae is one of the major causative agents of pneumonia, sepsis, meningitis and other morbidities. In spite of its heavy disease burden, surprisingly little is known about the mechanisms involved in the switch of life style, from commensal colonizer of the nasopharynx to invasive pathogen. In vitro experiments, and mouse models have shown that S. pneumoniae can be internalized by host cells, which coupled with intracellular vesicle transport through the cells, i.e. transcytosis, is suggested to be the first step of invasive disease. To further dissect the process of S. pneumoniae internalization, we chemically inhibited discrete parts of the cellular uptake system. We show that this invasion of the host cells was facilitated via both clathrin- and caveolae-mediated endocytosis. After internalization we demonstrated that the bulk of the internalized S. pneumoniae was killed in the lysosome. Interestingly, inhibition of the lysosome altered transcytosis dynamics as it resulted in an increase in the transport of the internalized bacteria out of the cells via the basal side. These results show that uptake of S. pneumoniae into host cells occurs via multiple pathways, as opposed to the often proposed view of invasion being dependent on specific, and singular receptor-mediated endocytosis. This indicates that the endothelium not only has a critical role as a physical barrier against S. pneumoniae in the blood stream, but also in degrading S. pneumonia cells that have adhered to, and invaded the endothelial cells.

Gradstedt, Henrik; Iovino, Federico; Bijlsma, Jetta J. E.

2013-01-01

3

Hallmarks, Invading tissues: Hanahan  

NSDL National Science Digital Library

Professor Douglas Hanahan discusses how cancers kill you, in general, not just because they grow into a large lump, but because they invade into normal tissues and disrupt the functions of those tissues.

2009-12-26

4

The Action of Lysozyme on Heat-killed Gram-positive Microorganisms  

Microsoft Academic Search

SUMMARY: The change in the Gram staining reaction which occurs when heat- killed Gram-positive Clostridium welchii and Staphylococcus albus are incubated with lysozyme is due to the removal of the ribonucleic acid component of the Gram complex, and is brought about by the hydrolysis of certain sugar linkages in polysaccharides located at the cell surface. Lysozyme, the enzyme in egg-white

M. Webb

1948-01-01

5

Direct activation of human peritoneal mesothelial cells by heat-killed microorganisms.  

PubMed Central

OBJECTIVE: The aim of the study was to determine if human peritoneal mesothelial cells (HPMCs) can be activated directly by bacterial products contained in preparations of heat-killed Escherichia coli and staphylococci. SUMMARY BACKGROUND DATA: It has been shown recently that cytokine-activated HPMCs produce the inflammatory mediators, interleukin-1, interleukin-6, interleukin-8, and macrophage chemotactic protein-1. Studies concerning the effects of bacterial products on HPMCs are scarce and have not yielded conclusive results. METHODS: Growth-arrested HPMC monolayers were prepared from cell suspensions obtained by enzymatic disaggregation of small pieces of omentum. They were incubated for 24 hours with heat-killed E. coli (ATCC 25922), heat-killed staphylococci (ATCC 25933), or E. coli lipopolysaccharide, and the release of various cytokines in the culture media was measured by radioimmunoassays or enzyme-linked immunosorbent assays. Results were expressed as mean +/- standard error of the mean in picograms per milliliter of supernatant and analyzed with the Wilcoxon test; p values of less than 0.05 were considered significant. RESULTS: Baseline production of interleukin-6, interleukin-8, the chemokine "regulated upon activation, normal T cell expressed and secreted" (RANTES), and macrophage chemotactic protein-1 varied widely from one omental preparation to the other. E. coli increased the release of these mediators: from 1206 +/- 316 pg/mL to 8480 +/- 2189 pg/mL for interleukin-6, from 285 +/- 58 pg/mL to 3164 +/- 1053 pg/mL for interleukin-8, from 7 +/- 5 pg/mL to 684 +/- 264 pg/mL for RANTES, and from 2212 +/- 346 pg/mL to 7726 +/- 1473 pg/mL for macrophage chemotactic protein-1. Heat-killed staphylococci did not alter significantly the production of RANTES or macrophage chemotactic protein-1 but increased the production of the two other cytokines from 1325 +/- 389 pg/mL to 2206 +/- 523 pg/mL for interleukin-6 and from 318 +/- 70 pg/mL to 819 +/- 265 pg/mL for interleukin-8. CONCLUSIONS: The authors' results show that HPMCs are able to react to a direct stimulation with heat-killed microbes. They suggest that HPMCs, as well as resident macrophages, participate actively in the initiation and possibly in the modulation of intraperitonen inflammatory reactions.

Kinnaert, P; De Wilde, J P; Bournonville, B; Husson, C; Salmon, I

1996-01-01

6

INVADERS Database  

NSDL National Science Digital Library

Based at the University of Montana and directed by Dr. Peter Rice, the INVADERS Database is "a comprehensive database of exotic plant names and weed distribution records for five states in the northwestern United States." Designed for use by land management and weed regulatory agencies, INVADERS uses a query interface (plant name or location) to sort and display information. Data are updated regularly so as to increase the chance of detecting and halting the rapid spread of alien weeds. Highlights of the site include the noxious weed listings for all US states and six Canadian provinces, historic distribution records against which to compare current plant distributions, and summary statistics such as the number of invasive species detected per state or a summary of the 120 year invasion, among others. The INVADERS database will prove both interesting and useful to managers and academics, alike.

1997-01-01

7

Alien invaders.  

PubMed

Thousands of species have invaded new territories in recent decades, often aided by global trade and man-made habitat change. While many remain harmless, some may cause serious damage. Therefore, we need improvements in surveillance and in our understanding of which factors make a successful invasion possible. PMID:23227487

Gross, Michael

2012-10-01

8

Invasional meltdown: invader-invader mutualism facilitates a secondary invasion.  

PubMed

In multiply invaded ecosystems, introduced species should interact with each other as well as with native species. Invader-invader interactions may affect the success of further invaders by altering attributes of recipient communities and propagule pressure. The invasional meltdown hypothesis (IMH) posits that positive interactions among invaders initiate positive population-level feedback that intensifies impacts and promotes secondary invasions. IMH remains controversial: few studies show feedback between invaders that amplifies their effects, and none yet demonstrate facilitation of entry and spread of secondary invaders. Our results show that supercolonies of an alien ant, promoted by mutualism with introduced honeydew-secreting scale insects, permitted invasion by an exotic land snail on Christmas Island, Indian Ocean. Modeling of land snail spread over 750 sites across 135 km2 over seven years showed that the probability of land snail invasion was facilitated 253-fold in ant supercolonies but impeded in intact forest where predaceous native land crabs remained abundant. Land snail occurrence at neighboring sites, a measure of propagule pressure, also promoted land snail spread. Site comparisons and experiments revealed that ant supercolonies, by killing land crabs but not land snails, disrupted biotic resistance and provided enemy-free space. Predation pressure on land snails was lower (28.6%), survival 115 times longer, and abundance 20-fold greater in supercolonies than in intact forest. Whole-ecosystem suppression of supercolonies reversed the probability of land snail invasion by allowing recolonization of land crabs; land snails were much less likely (0.79%) to invade sites where supercolonies were suppressed than where they remained intact. Our results provide strong empirical evidence for IMH by demonstrating that mutualism between invaders reconfigures key interactions in the recipient community. This facilitates entry of secondary invaders and elevates propagule pressure, propagating their spread at the whole-ecosystem level. We show that identification and management of key facilitative interactions in invaded ecosystems can be used to reverse impacts and restore resistance to further invasions. PMID:21939072

Green, Peter T; O'Dowd, Dennis J; Abbott, Kirsti L; Jeffery, Mick; Retallick, Kent; Mac Nally, Ralph

2011-09-01

9

Nab the Aquatic Invader!  

NSDL National Science Digital Library

In this activity, younger students assume the roles of detectives investigating the ten "most wanted" invasive species. They examine background information on these species and learn about how they came to be invaders, how they spread, some environmental and economic impacts, and some solutions for controlling them. When they think they have enough information to "book" an invasive species, they click on the "Book 'em" file and answer questions about each one.

10

Peroxynitrite, a potent macrophage-derived oxidizing cytotoxin to combat invading pathogens.  

PubMed

Macrophages are among the first cellular actors facing the invasion of microorganisms. These cells are able to internalize pathogens and destroy them by means of toxic mediators, many of which are produced enzymatically and have strong oxidizing capacity. Indeed, macrophages count on the NADPH oxidase complex activity, which is triggered during pathogen invasion and leads to the production of superoxide radical inside the phagosome. At the same time, the induction of nitric oxide synthase results in the production of nitric oxide in the cytosol which is able to readily diffuse to the phagocytic vacuole. Superoxide radical and nitric oxide react at diffusion controlled rates with each other inside the phagosome to yield peroxynitrite, a powerful oxidant capable to kill micro-organisms. Peroxynitrite toxicity resides on oxidations and nitrations of biomolecules in the target cell. The central role of peroxynitrite as a key effector molecule in the control of infections has been proven in a wide number of models. However, some microorganisms and virulent strains adapt to survive inside the potentially hostile oxidizing microenvironment of the phagosome by either impeding peroxynitrite formation or rapidly detoxifying it once formed. In this context, the outcome of the infection process is a result of the interplay between the macrophage-derived oxidizing cytotoxins such as peroxynitrite and the antioxidant defense machinery of the invading pathogens. © 2013 BioFactors, 40(2):215-225, 2014. PMID:24281946

Prolo, Carolina; Alvarez, María Noel; Radi, Rafael

2014-03-01

11

Insect Invaders Capture Headlines  

NSDL National Science Digital Library

Lately, a few insects not native to the North American continent have made headlines while making themselves at home. According to a recent study from the journal Science, a European fruit fly species, Drosophila subobscura, has replaced close to 95 percent of native North and South American fruit flies in the 20 years it has been in these climes. Even more striking is the fact that the non-native flies have evolved in the process. Over the last 10,000 years, European D. subobscura flies that lived in higher latitudes produced individuals with wing sizes that were four percent larger than their lower latitude counterparts. Strangely, in North America, it has taken less than two decades for the higher latitude fruit fly to grow to be four percent larger than those living south. In essence, the fruit fly population has transformed itself almost as fast as it has taken over its new environment. The findings point scientists to new questions regarding both the rapid evolution of an invader along with the ecological consequences of its arrival. Another recent report, from Reuters, describes the Asian long-horned beetle's devastation of trees in New York and Chicago. The beetle has been called the worst non-native pest since the gypsy moth, and the government is searching for solutions to this menace which bores holes into trees and damages their vascular systems. This week's In the News takes a closer look at these adaptable invaders and the problems of invasive species in general.

Ramanujan, Krishna.

12

Killing Coyotes.  

ERIC Educational Resources Information Center

Presents different viewpoints concerning the federal government's Animal Damage Control (ADC) Program cited as responsible for killing millions of predators. Critics provide evidence of outdated and inhumane methods exemplified in the coyote killings. The ADC emphasizes new, nonlethal methods of controlling animals cited as "noxious." (MCO)

Beasley, Conger, Jr.

1993-01-01

13

Myeloperoxidase: a front-line defender against phagocytosed microorganisms  

PubMed Central

Successful immune defense requires integration of multiple effector systems to match the diverse virulence properties that members of the microbial world might express as they initiate and promote infection. Human neutrophils—the first cellular responders to invading microbes—exert most of their antimicrobial activity in phagosomes, specialized membrane-bound intracellular compartments formed by ingestion of microorganisms. The toxins generated de novo by the phagocyte NADPH oxidase and delivered by fusion of neutrophil granules with nascent phagosomes create conditions that kill and degrade ingested microbes. Antimicrobial activity reflects multiple and complex synergies among the phagosomal contents, and optimal action relies on oxidants generated in the presence of MPO. The absence of life-threatening infectious complications in individuals with MPO deficiency is frequently offered as evidence that the MPO oxidant system is ancillary rather than essential for neutrophil-mediated antimicrobial activity. However, that argument fails to consider observations from humans and KO mice that demonstrate that microbial killing by MPO-deficient cells is less efficient than that of normal neutrophils. We present evidence in support of MPO as a major arm of oxidative killing by neutrophils and propose that the essential contribution of MPO to normal innate host defense is manifest only when exposure to pathogens overwhelms the capacity of other host defense mechanisms.

Klebanoff, Seymour J.; Kettle, Anthony J.; Rosen, Henry; Winterbourn, Christine C.; Nauseef, William M.

2013-01-01

14

Microorganism immobilization  

DOEpatents

Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

Compere, Alicia L. (Knoxville, TN); Griffith, William L. (Oak Ridge, TN)

1981-01-01

15

Activation of AMPK enhances neutrophil chemotaxis and bacterial killing.  

PubMed

An inability of neutrophils to eliminate invading microorganisms is frequently associated with severe infection and may contribute to the high mortality rates associated with sepsis. In the present studies, we examined whether metformin and other 5' adenosine monophosphate-activated protein kinase (AMPK) activators affect neutrophil motility, phagocytosis and bacterial killing. We found that activation of AMPK enhanced neutrophil chemotaxis in vitro and in vivo, and also counteracted the inhibition of chemotaxis induced by exposure of neutrophils to lipopolysaccharide (LPS). In contrast, small interfering RNA (siRNA)-mediated knockdown of AMPK?1 or blockade of AMPK activation through treatment of neutrophils with the AMPK inhibitor compound C diminished neutrophil chemotaxis. In addition to their effects on chemotaxis, treatment of neutrophils with metformin or aminoimidazole carboxamide ribonucleotide (AICAR) improved phagocytosis and bacterial killing, including more efficient eradication of bacteria in a mouse model of peritonitis-induced sepsis. Immunocytochemistry showed that, in contrast to LPS, metformin or AICAR induced robust actin polymerization and distinct formation of neutrophil leading edges. Although LPS diminished AMPK phosphorylation, metformin or AICAR was able to partially decrease the effects of LPS/toll-like receptor 4 (TLR4) engagement on downstream signaling events, particularly LPS-induced I?B? degradation. The I?B kinase (IKK) inhibitor PS-1145 diminished I?B? degradation and also prevented LPS-induced inhibition of chemotaxis. These results suggest that AMPK activation with clinically approved agents, such as metformin, may facilitate bacterial eradication in sepsis and other inflammatory conditions associated with inhibition of neutrophil activation and chemotaxis. PMID:24091934

Park, Dae Won; Jiang, Shaoning; Tadie, Jean-Marc; Stigler, William S; Gao, Yong; Deshane, Jessy; Abraham, Edward; Zmijewski, Jaroslaw W

2013-01-01

16

Progress in invasion biology: predicting invaders  

Microsoft Academic Search

Predicting which species are probable invaders has been a long-standing goal of ecologists, but only recently have quantitative methods been used to achieve such a goal. Although restricted to few taxa, these studies reveal clear relationships between the characteristics of releases and the species involved, and the successful establishment and spread of invaders. For example, the probability of bird establishment

Cynthia S. Kolar; David M. Lodge

2001-01-01

17

Classifying Microorganisms.  

ERIC Educational Resources Information Center

Focuses on an activity in which students sample air at school and generate ideas about how to classify the microorganisms they observe. The results are used to compare air quality among schools via the Internet. Supports the development of scientific inquiry and technology skills. (DDR)

Baker, William P.; Leyva, Kathryn J.; Lang, Michael; Goodmanis, Ben

2002-01-01

18

Plant Sacrifices Cells to Fight Invaders  

NSF Publications Database

... create a zone of dead cells around viral infection site. Credit and Larger Version May 19, 2005 ... a protective zone of dead cells around the infection site to prevent the invading pathogen from ...

19

Treponema pallidum Invades Intercellular Junctions of Endothelial Cell Monolayers  

NASA Astrophysics Data System (ADS)

The pathogenesis of syphilis reflects invasive properties of Treponema pallidum, but the actual mode of tissue invasion is unknown. We have found two in vitro parallels of treponemal invasiveness. We tested whether motile T. pallidum could invade host cells by determining the fate of radiolabeled motile organisms added to a HeLa cell monolayer; 26% of treponemes associated with the monolayer in a trypsin-resistant niche, presumably between the monolayer and the surface to which it adhered, but did not attain intracellularity. Attachment of T. pallidum to cultured human and rabbit aortic and human umbilical vein endothelial cells was 2-fold greater than to HeLa cells. We added T. pallidum to aortic endothelial cells grown on membrane filters under conditions in which tight intercellular junctions had formed. T. pallidum was able to pass through the endothelial cell monolayers without altering tight junctions, as measured by electrical resistance. In contrast, heat-killed T. pallidum and the nonpathogen Treponema phagedenis biotype Reiter failed to penetrate the monolayer. Transmission electron micrographs of sections of the monolayer showed T. pallidum in intercellular junctions. Our in vitro observations suggest that these highly motile spirochetes may leave the circulation by invading the junctions between endothelial cells.

Thomas, D. Denee; Navab, Mahamad; Haake, David A.; Fogelman, Alan M.; Miller, James N.; Lovett, Michael A.

1988-05-01

20

Planning a dynamic kill  

SciTech Connect

This article discusses the methodology, design philosophy, and guidelines for planning a dynamic-kill operation for a wild well. The topics covered are two methods of computer analysis for designing dynamic-kill requirements, the design process, determining the pumping spread, and the pitfalls that a designer faces in planning a dynamic kill.

Abel, L.W. [Abel Engineering, Houston, TX (United States)

1996-05-01

21

Sinonasal undifferentiated carcinoma invading the orbit.  

PubMed

Sinonasal undifferentiated carcinoma (SNUC) is an infrequent tumor described by Frierson et al. in 1986. Since its initial description, fewer than 100 patients have been reported. We present a case of a SNUC invading the orbit in a 57-year-old woman, for which the findings are documented by CT scan, light and electron microscopy. PMID:7711477

Ascaso, F J; Adiego, M I; Garcia, J; Royo, J; Valles, H; Palomar, A; Ramon y Cajal, S

1994-01-01

22

Age Invaders: Intergenerational Mixed Reality Family Game  

Microsoft Academic Search

This paper introduces Age Invaders (AI), a novel interactive inter-generation social-physical game which allows the elderly to play harmoniously together with children in physical space while parents can participate in the game play in real time remotely through the internet.

Khoo Eng Tat; Adrian David Cheok

2006-01-01

23

Ability of Escherichia coli isolates that cause meningitis in newborns to invade epithelial and endothelial cells.  

PubMed Central

Escherichia coli isolates that cause meningitis in newborns are able to invade the circulation and subsequently cross the blood-brain barrier. One mechanism for traversing the blood-brain barrier might involve transcytosis through the endothelial cells. The ability of the meningitis isolate E. coli IHE3034, of serotype 018:K1:H7, to invade epithelial (T24) and endothelial (EA-hy926) cells was investigated by the standard gentamicin survival assay and by electron microscopy. Human bladder epithelial and endothelial cells were efficiently invaded by strain IHE3034, whereas epithelial human colon Caco-2 cells, canine kidney MDCK cells, and the opossum [correction of opposum] epithelial kidney cell line OK were not invaded. The ability to invade human epithelial cells of the bladder could also be demonstrated for several other newborn meningitis E. coli strains and one septicemic E. coli strain. Studies utilizing inhibitors which act on eukaryotic cells revealed a dependence on microfilaments as well as on microtubules in the process of E. coli IHE3034 entry into T24 and EA-hy926 cells. These results indicated that cell cytoskeletal rearrangements are involved in bacterial uptake and suggest that there are either two pathways (microtubule dependent and microfilament dependent) or one complex pathway involving both microtubules and microfilaments. The intracellular IHE3034 organisms were contained in a host-membrane-confined compartment mainly as single microorganisms. Intracellular replication of 1HE3034 was not detected, nor did the number of intracellular bacteria decrease significantly during a 48-h period. The ability of E. coli O18:K1 to invade and survive within certain eukaryotic cells may be another virulence factor of meningitis-associated E. coli.

Meier, C; Oelschlaeger, T A; Merkert, H; Korhonen, T K; Hacker, J

1996-01-01

24

Bemisia tabaci , the Capacity to Invade  

Microsoft Academic Search

\\u000a \\u000a Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic ­species complex composed of numerous morphologically indistinguishable\\u000a species, a number of which have been shown to be either completely or partially reproductively isolated. Several members of\\u000a the complex have invaded beyond their home ranges and two, Middle East-Asia Minor 1 (commonly known as the B biotype) and\\u000a Mediterranean (commonly known as the

P. J. De Barro

25

Cercopagis Pengoi Invades the Great Lakes  

NSDL National Science Digital Library

The Environmental Protection Agency (EPA)'s Great Lakes National Program Office provides this research information page on the recent invasion of the exotic crustacean, Cercopagis pengoi, into the Great Lakes. Cercopagis, a predatory cladoceran, is similar to Bythotrephes cederstroemi, another recent Great Lakes invader; both species occur in freshwater and brackish environments. The site provides background information, images (including figures showing distribution and abundance), links, and selected references regarding this exotic species.

Barbiero, Rick.; Dimartino, Mark.; Kuhns, Linda.

1998-01-01

26

The Invader ® assay for SNP genotyping  

Microsoft Academic Search

The Invader® assay uses a structure-specific flap endonuclease (FEN) to cleave a three-dimensional complex formed by hybridization of allele-specific overlapping oligonucleotides to target DNA containing a single nucleotide polymorphism (SNP) site. Annealing of the oligonucleotide complementary to the SNP allele in the target molecule triggers the cleavage of the oligonucleotide by cleavase, a thermostable FEN. Cleavage can be detected by

Michael Olivier

2005-01-01

27

Novel silver nano-wedges for killing microorganisms  

Microsoft Academic Search

In the current study, for the first time, photochemical facile green synthesis of salep capped silver nano-wedges was reported via the wet chemical synthesis procedure. Sunlight-UV as an available reducing agent caused mild reduction of silver ions to the silver nano-wedges. Salep as an effective capping\\/shaping polysaccharide bioresource material was used in the reaction medium and caused creation of flower-like

Ali Pourjavadi; Rouhollah Soleyman

2011-01-01

28

BB Guns Can Kill  

MedlinePLUS

... Kill BB guns can kill a person. High-velocity BB guns, which have muzzle velocities higher than 350 feet per second, can increase ... do not realize that BB guns, especially high-velocity guns, can cause death. Therefore the CPSC warns ...

29

Ion-kill dosimetry  

NASA Technical Reports Server (NTRS)

Unanticipated late effects in neutron and heavy ion therapy, not attributable to overdose, imply a qualitative difference between low and high LET therapy. We identify that difference as 'ion kill', associated with the spectrum of z/beta in the radiation field, whose measurement we label 'ion-kill dosimetry'.

Katz, R.; Cucinotta, F. A.; Fromm, M.; Chambaudet, A.

2001-01-01

30

[Action of physical agents on microorganisms].  

PubMed

Among numerous physical agents exerting their deleterious effect on microorganisms only a few have been applied to sterilisation or disinfection used for medical purposes. Temperature is the most important agent, which from one side in a very wide range enables supporting of metabolic processes of psycho-, mezo- and thermophilic microorganisms, but beyond these limits causes their death. High temperature induces at first damage of cytoplasmic membrane and then denaturation of RNA leading to death. On the other hand, a low temperature slowly decreasing below 0 degree C induces crystallisation of water in cells and destruction of cytoplasmic structures. Ultraviolet radiation causes mutations resulting in stopping of DNA replication in all forms of the microorganisms. The same way of the lethal activity is exerted by ionising radiation. Its kinetic energy induces mutations affecting not single bases but also whole operons making gene expression impossible. Gaseous plasma is a new physical agent applied recently to sterilisation. High frequency energy initiates generation of the plasma from hydrogen peroxide vapours in a high vacuum and creates reactive species particles from the vapours that collide and kill microorganisms. On the other hand, application of ultrasound radiation to killing of microorganisms needs for further studies because of a high variability depending upon used frequency and energy. It is not known, for example, if destruction of microorganisms by ultrasounds is related to a phenomenon of cavitation or thermal energy. Nevertheless, even a range of frequency and energy used in commercial microwave ovens kills vegetative cells of coliform rods in about 15 minutes. PMID:9432703

Strus, M

1997-01-01

31

Evolution of coalitionary killing.  

PubMed

Warfare has traditionally been considered unique to humans. It has, therefore, often been explained as deriving from features that are unique to humans, such as the possession of weapons or the adoption of a patriarchal ideology. Mounting evidence suggests, however, that coalitional killing of adults in neighboring groups also occurs regularly in other species, including wolves and chimpanzees. This implies that selection can favor components of intergroup aggression important to human warfare, including lethal raiding. Here I present the principal adaptive hypothesis for explaining the species distribution of intergroup coalitional killing. This is the "imbalance-of-power hypothesis," which suggests that coalitional killing is the expression of a drive for dominance over neighbors. Two conditions are proposed to be both necessary and sufficient to account for coalitional killing of neighbors: (1) a state of intergroup hostility; (2) sufficient imbalances of power between parties that one party can attack the other with impunity. Under these conditions, it is suggested, selection favors the tendency to hunt and kill rivals when the costs are sufficiently low. The imbalance-of-power hypothesis has been criticized on a variety of empirical and theoretical grounds which are discussed. To be further tested, studies of the proximate determinants of aggression are needed. However, current evidence supports the hypothesis that selection has favored a hunt-and-kill propensity in chimpanzees and humans, and that coalitional killing has a long history in the evolution of both species. PMID:10601982

Wrangham, R W

1999-01-01

32

Wanted Dead, Not Alive: Invading Species  

NSDL National Science Digital Library

The Why Files (last mentioned in the June 28, 2002 NSDL Scout Report for the Life Sciences) is "a popular and critically acclaimed web site that explores the science behind the news." Check out this recent feature of the Web site, which presents information about a number of harmful invasive species in an entertaining way. The notorious snakehead fish is included in the species lineup, and the related text helps to clear up misconceptions some may have about this invader. While some species and the problems associated with them are described in more detail than others, nearly all descriptions include links to related Web sites that offer much more detailed information.

2002-01-01

33

Medulloblastoma invading the transverse sinus: case report.  

PubMed

Medulloblastoma is a highly malignant brain tumor of childhood. Although craniospinal dissemination within the subarachnoid space is common, invasion of the dural sinuses is rare. Here, the authors report on a 15-year-old girl who presented with a right cerebellar mass, obstructive hydrocephalus, and radiographic evidence of tumor invasion into the right transverse-sigmoid sinus junction. The patient underwent posterior fossa craniotomy, gross-total resection of the intraparenchymal component of the right cerebellar tumor, and coagulation of the tumor invading the transverse sinus. After pathological confirmation of anaplastic medulloblastoma, the patient underwent craniospinal radiation therapy and high-dose chemotherapy. At 2 years posttreatment, the child was neurologically intact with no radiographic evidence of residual disease or recurrence. The implications for disease prognosis and management are discussed. PMID:23952029

Nadi, Mustafa; Khezri, Navid; Ahmad, Tahani; Ellis, Michael; Bouffet, Eric; Rutka, James T; Taylor, Michael D

2013-10-01

34

Cellulase-Producing Microorganism.  

National Technical Information Service (NTIS)

A process and a microorganism for synthesizing cellulase enzymes are described. The microorganism is a mutant strain of an Ascomycete fungus capable of synthesizing cellulases. The synthesis of cellulases by the mutant is nonrepressed by glycerol, repress...

B. J. Gallo

1978-01-01

35

New Health Potentials of Orally Consumed Probiotic Microorganisms  

Microsoft Academic Search

\\u000a The microorganism and their live formulations upon consumption contribute to intestinal microbial balance are known as probiotics.\\u000a They generally live in our gut mucosal layer and also in some other body parts like mouth, vagina and offer a number of health\\u000a benefits to the host. They fight with the invading pathogens by producing a number of active principles like bacteriocins

Vivekananda Mandal; Narayan C. Mandal

36

Male-killing bacteria in insects: mechanisms, incidence, and implications.  

PubMed Central

Bacteria that are vertically transmitted through female hosts and kill male hosts that inherit them were first recorded in insects during the 1950s. Recent studies have shown these "male-killers" to be diverse and have led to a reappraisal of the biology of many groups of bacteria. Rickettsia, for instance, have been regarded as human pathogens transmitted by arthropods. The finding of a male-killing Rickettsia obligately associated with an insect suggests that the genus' members may be primarily associated with arthropods and are only sometimes pathogens of vertebrates. We examined both how killing of male hosts affects the dynamics of inherited bacteria and how male-killing bacteria affect their host populations. Finally, we assessed the potential use of these microorganisms in the control of insect populations.

Hurst, G. D.; Jiggins, F. M.

2000-01-01

37

The Fish Kill Mystery  

NSDL National Science Digital Library

In this case, students speculate on what may have caused a major fish kill in an estuary in North Carolina. In the process they explore how land runoff and excess nutrients affect aquatic communities and learn about the complex life cycle of the dinoflagellate Pfiesteria.

Kosal, Erica F.

2004-02-01

38

Interpopulation variation in allelopathic traits informs restoration of invaded landscapes  

PubMed Central

Invasive species can show substantial genetic variation in ecologically important traits, across ranges as well within the introduced range. If these traits affect competition with native species, then management may benefit from considering the genetic landscape of the invader. Across their introduced range, Alliaria petiolata populations vary in their investment in allelopathic traits according to invasion history, which could lead to gradients of impact on native species. Red oak (Quercus rubra) seedlings were transplanted into eight A. petiolata-invaded sites that varied in their invasion history and allelochemical concentrations. At each site, an invader removal treatment was crossed with experimental inoculations of native soil biota, to test whether the benefits of these restoration actions differed across invader populations. Q. rubra seedlings grew faster in invader populations with a longer invasion history and lower allelochemical concentrations. Invader removal and soil inoculation interacted to determine seedling growth, with the benefits of soil inoculation increasing in younger and more highly allelopathic invader populations. A greenhouse experiment using soils collected from experimentally inoculated field plots found similar patterns. These results suggest that the impact of this invader varies across landscapes and that knowledge of this variation could improve the efficacy and efficiency of restoration activities.

Lankau, Richard A

2012-01-01

39

Older women and mercy killing.  

PubMed

Mercy killing is usually defined as intentional killing, often by family members or friends, with the stated intent to end perceived suffering. International evidence suggests that mercy killing typically involves an older man killing his ailing wife. In this study, we examined U.S. cases of mercy killing recorded by The Hemlock Society for the period 1960-1993. We found that the typical case involved an older woman being killed by a man, often her husband, with her poor health as the justification for the killing. A firearm was often used in these incidents. These patterns of mercy killing are consistent with patterns of homicide-suicide among older adults. Future research should seek to understand why women are typically the targets, and men the agents of mercy killing. PMID:12557885

Canetto, S S; Hollenshead, J D

40

Isolated Retroperitoneal Hydatid Cyst Invading Splenic Hilum  

PubMed Central

Introduction. Hydatid disease (HD) is an infestation that is caused by the larval stage of Echinococcus granulosus. The liver is affected in approximately two-thirds of patients, the lungs in 25%, and other organs in a small proportion. Primary retroperitoneal hydatid cyst is extremely rare. The most common complaint is abdominal pain; however, the clinical features of HD may be generally dependent on the location of the cyst. Case Presentation. A 43-year-old female was admitted with the complaint of abdominal pain. Her physical examination was normal. Computed tomography (CT) revealed a 17 × 11?cm cystic lesion, with a thick and smooth wall that is located among the left liver lobe, diaphragm, spleen, tail of the pancreas, and transverse colon and invading the splenic hilum. Total cystectomy and splenectomy were performed. Pathological examination was reported as cyst hydatid. Discussion. Cysts in the peritoneal cavity are mainly the result of the spontaneous or traumatic rupture of concomitant hepatic cysts or surgical inoculation of a hepatic cyst. Serological tests contribute to diagnosis. In symptomatic and large hydatid peritoneal cysts, surgical resection is the only curative treatment. Total cystectomy is the gold standard. Albendazole or praziquantel is indicated for inoperable and disseminated cases. Percutaneous aspiration, injection, and reaspiration (PAIR) technique is another nonsurgical option.

Ozturk, Safak; Unver, Mutlu; Kibar Ozturk, Burcin; Kebapci, Eyup; Bozbiyik, Osman; Erol, Varl?k; Zalluhoglu, Nihat; Olmez, Mustafa

2014-01-01

41

Biosurfactants from marine microorganisms  

Microsoft Academic Search

Maneerat, S. Biosurfactants from marine microorganisms Songklanakarin J. Sci. Technol., 2005, 27(6) : 1263-1272 Biosurfactants are the surface-active molecules synthesized by microorganisms. With the advantage of environmental compatibility, the demand for biosurfactants has been steadily increasing and may even- tually replace their chemically synthesized counterparts. Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the

Suppasil Maneerat

42

'Doctors must not kill'.  

PubMed

Four physicians respond to "It's over, Debbie," an anonymous resident physician's account of an incident when he or she injected a terminally ill cancer patient with a lethal dose of morphine (JAMA 1988 Jan 8; 259(2): 272). Gaylin and his colleagues condemn both the physician's violation of legal and ethical norms, and the conduct of JAMA's editor in publishing the article without editorial rebuke or comment. They warn that the issue of active euthanasia "touches medicine at its very moral center," and that, as pressure to legalize euthanasia in response to patient demand increases, the medical profession must repudiate direct and intentional killing of patients and discipline doctors who kill. PMID:3346989

Gaylin, W; Kass, L R; Pellegrino, E D; Siegler, M

1988-04-01

43

Killing tensors and canonical geometry  

NASA Astrophysics Data System (ADS)

The systematic derivation of constants of the motion, based on Killing tensors and the gauge covariant approach, is outlined. Quantum dots are shown to support second-, third- and fourth-rank Killing tensors.

Cariglia, M.; Gibbons, G. W.; van Holten, J.-W.; Horvathy, P. A.; Kosi?ski, P.; Zhang, P.-M.

2014-06-01

44

Battered women who kill  

Microsoft Academic Search

This study assesses acquital rates using mock jurors in cases involving a battered woman charged with killing her husband. The simulated trial format was based on actual courtroom proceedings including witness cross-examination and jury deliberation proceedings. The type of plea entered was varied and reflected either self-defense, automatism, or a hypothetical plea of psychological self-defense. The severity of abuse incurred

Marilyn Kasian; Nicholas P. Spanos; Cheryl A. Terrance; Suzanne Peeblesi

1993-01-01

45

Microorganisms and Chemical Pollution  

ERIC Educational Resources Information Center

Discusses the importance of microorganisms in chemical pollution and pollution abatement. Selected chemical pollutants are chosen to illustrate that microorganisms synthesize hazardous substances from reasonably innocuous precursors, while others act as excellent environmental decontaminating agents by removing undesirable natural and synthetic…

Alexander, M.

1973-01-01

46

Fossilization of Acidophilic Microorganisms  

Microsoft Academic Search

This study examines fossil microorganisms found in iron-rich deposits in an extreme acidic environment, the Tinto River in SW Spain. Both electron microscopy (SEM and TEM) and non-destructive in situ microanalytical techniques (EDS, EMP and XPS) were used to determine the role of permineralization and encrustation in preserving microorganisms forming biofilms in the sediments. Unicellular algae were preserved by silica

Virginia Souza-Egipsy; Angeles Aguilera; Eva Mateo-Martí; José Angel Martín-Gago; Ricardo Amils

2010-01-01

47

Saddam Hussein's Decision to Invade Kuwait - Where Was Plan B.  

National Technical Information Service (NTIS)

Two objectives characterize Saddam Hussein's statecraft his personal survival as Iraq's leader and his desire to assert Iraqi influence in the Middle East Both of these objectives figured in his decision to invade Kuwait in August 1990 Surveying the damag...

F. R. Culpepper

1997-01-01

48

Killing horizons and spinors  

NASA Astrophysics Data System (ADS)

We study the near-horizon geometry of generic Killing horizons constructing suitable coordinates and taking the appropriate scaling limit. We are able to show that the geometry will always show an enhancement of symmetries, and, in the extremal case, will develop a causally disconnected "throat" as expected. We analyze the implications of this to the Kerr/CFT conjecture and the attractor mechanism. We are also able to construct a set of special (pure) spinors associated with the horizon structure using their interpretation as maximally isotropic planes. The structure generalizes the usual reduced holonomy manifold in an interesting way and may be fruitful to the search of new types of compactification backgrounds.

Carneiro da Cunha, Bruno; de Queiroz, Amilcar

2014-05-01

49

Nematicidal enzymes from microorganisms and their applications.  

PubMed

Microorganisms can attack and kill nematodes by diverse processes such as capturing, parasitizing, and producing toxins and enzymes. Extracellular enzymes, including serine proteases, chitinases, and collagenases are shown to be important virulence factors that can degrade the main chemical constituents of the nematode cuticle and eggshell. Here, we review the structure, function, regulation, and evolution of these nematicidal enzymes and provide insights into the mechanisms of microbial infections against nematodes. We discuss the practical applications of these nematicidal enzymes in agriculture and other areas. PMID:23832084

Yang, Jinkui; Liang, Lianming; Li, Juan; Zhang, Ke-Qin

2013-08-01

50

Development of static system procedures to study aquatic biofilms and their responses to disinfection and invading species  

NASA Technical Reports Server (NTRS)

The microbial ecology facility in the Analytical and Physical Chemistry Branch at Marshall Space Flight Center is tasked with anticipation of potential microbial problems (and opportunities to exploit microorganisms) which may occur in partially closed systems such as space station/vehicles habitats and in water reclamation systems therein, with particular emphasis on the degradation of materials. Within this context, procedures for microbial biofilm research are being developed. Reported here is the development of static system procedures to study aquatic biofilms and their responses to disinfection and invading species. Preliminary investigations have been completed. As procedures are refined, it will be possible to focus more closely on the elucidation of biofilm phenomena.

Smithers, G. A.

1992-01-01

51

Pathogenic Microorganisms in Water  

NSDL National Science Digital Library

Pathogenic Microorganisms in Water: Traditionally, groundwater has been used without treatment because the soil acts as a filter, removing pathogenic microorganisms. Some potential sources of pathogens (or disease causing organisms) in groundwater include septic tanks, leaking sewer lines, sewage sludge, intentional groundwater recharge with sewage, irrigation with sewage, direct injection of sewage, domestic solid waste disposal (landfills) and sewage oxidation ponds. The objective of the session is to introduce hydrogeologist to the types of microorganisms, sources of pathogens, and a simple exercise that can be incorporated into a hydrogeology class.

Lenczewski, Melissa

52

Microorganisms on a rock  

NSDL National Science Digital Library

Often times, microorganisms will compete for space on rotting or burnt logs and rocks. They are an important part of many nutrient cycles by decomposing dead organic matter and releasing unused nutrients such as nitrogen and phosphorous.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2007-01-12

53

Microorganisms in the Stratosphere.  

National Technical Information Service (NTIS)

Microbiological analyses of the stratosphere by meteorological rockets carrying sampling devices are reported. Among colonies of microorganisms, the microscopic fungi Circinelle muscae, Penicillium, Aspergillus niger, and Mycelia sterilia were found. In a...

A. A. Imshenetskiy S. V. Lysenko G. A. Kazakov

1976-01-01

54

Electricity from microorganisms  

Microsoft Academic Search

Over the last ten years, the recently discovered process of direct electron transfer from anaerobically grown microorganisms\\u000a to an electrode of a fuel cell has been the object of intense study. The microorganisms responsible for such electron transport\\u000a were termed electrogenic; the devices using them to generate electric current, microbial fuel cells (MFCs). The review discussed\\u000a the molecular mechanisms of

V. G. Debabov

2008-01-01

55

Kill operation requires thorough analysis  

SciTech Connect

Full control of a blowout well requires a properly designed post-capping kill operation because failures in regaining well control usually occur during the kill operation, not during capping. Capping (the installation of pressure control or diverter equipment on the wellhead) is generally very reliable in gaining control of a blowout well. The following techniques are some of the viable means of killing blowout wells once the capping assemblies are in place: direct shut in of the flow; bullheading; momentum kill; volumetric control for migration of fluids or lubrication after migration ceases; and dynamic kills (friction-based dynamic kills or mass flow rate kills) The objective of most post-capping operations is to stop the flow and put the well under hydrostatic control. The means of killing a blowout once capping assemblies are in place should be chosen with care to avoid problems such as cratering, equipment failure, and underground blowouts. The particular circumstances and well integrity will dictate which kill method will be the most viable. Each of these five methods are explained.

Abel, L.W. [Wild Well Control Inc., Spring, TX (United States)

1995-05-15

56

Fossil Microorganisms in Archaean  

NASA Technical Reports Server (NTRS)

Ancient Archean and Proterozoic rocks are the model objects for investigation of rocks comprising astromaterials. The first of Archean fossil microorganisms from Baltic shield have been reported at the last SPIE Conference in 2005. Since this confeence biomorphic structures have been revealed in Archean rocks of Karelia. It was determined that there are 3 types of such bion structures: 1. structures found in situ, in other words microorganisms even-aged with rock matrix, that is real Archean fossils biomorphic structures, that is to say forms inhabited early formed rocks, and 3. younger than Archean-Protherozoic minerali microorganisms, that is later contamination. We made attempt to differentiate these 3 types of findings and tried to understand of burial of microorganisms. The structures belongs (from our point of view) to the first type, or real Archean, forms were under examination. Practical investigation of ancient microorganisms from Green-Stone-Belt of Northern Karelia turns to be very perspective. It shows that even in such ancient time as Archean ancient diverse world existed. Moreover probably such relatively highly organized cyanobacteria and perhaps eukaryotic formes existed in Archean world.

Astafleva, Marina; Hoover, Richard; Rozanov, Alexei; Vrevskiy, A.

2006-01-01

57

How electroshock weapons kill!  

NASA Astrophysics Data System (ADS)

Growing numbers of law enforcement officers now carry an electroshock weapon (ESW). Over 500 U.S. deaths have followed ESW use in the past 26 years; over 450 of these deaths followed use of an electromuscular disruptor in the past 9 years. Most training courses teach that ESWs are safe; that they can kill only by the direct effect of electric current on the heart; and that a death following use of an ESW always has some other cause. All these teachings are false! The last was disproved by Lundquist.^1 Williams^2 ruled out direct electrical effects as a cause of almost all the 213 deaths he studied, leaving disruption of normal physiological processes as the only alternative explanation. Careful study of all such deaths identifies 4 different ways that death has or could have been brought about by the ESW: kidney failure following rhabdomyolysis [rare]; cardiac arrest from hyperkalemia following rhabdomyolysis [undocumented]; lactic acid-induced ventricular fibrillation [conclusive proof impossible]; and [most common] anoxia from so much lactic acid in the circulating blood that it acts as an oxygen scavenger, continuously depleting the blood of oxygen until most of the lactate has been metabolized. ^1M. Lundquist, BAPS 54(1) K1.270(2009). ^2Howard E. Williams, Taser Electronic Control Devices and Sudden In-Custody Death, 2008.

Lundquist, Marjorie

2010-03-01

58

[Electricity from microorganisms].  

PubMed

Over the last ten years, the recently discovered process of direct electron transfer from anaerobically grown microorganisms to an electrode of a fuel cell has been the object of intense study. The microorganisms responsible for such electron transport were termed electrogenic; the devices using them to generate electric current, microbial fuel cells (MFCS). The review discussed the molecular mechanisms of electron transfer to the environment in the case of the two best studied microorganisms, Shewanella oneidensis and Geobacter sulfurreducens. The discovery of bacterial conducting pili (nanowires) used for electron transfer to the electrode and between bacterial cells was sensational. In the real MFCS, which use complex substrates (industrial liquid waste), microbial associations are active, often as biofilms. The progress in MFCS design and the prospects of their practical application are considered. PMID:18522314

Debabov, V G

2008-01-01

59

(Genetically engineered microorganisms)  

SciTech Connect

The traveler attended the First International Conference on the Release of Genetically Engineered Microorganisms at the request of the United Nations Environment Programme (UNEP). The purpose of the conference was to provide an international forum for the discussion of the issues and concerns related to the release of genetically engineered microorganisms for environmental and agricultural applications. The cost of attendance was paid by UNEP, a group with whom a small Work-for-Others contract (to participate in developing international biosafety guidelines) is under discussion.

Sharples, F.E.

1988-04-18

60

An electron microscopic study of Babesia microti invading erythrocytes  

Microsoft Academic Search

Intracellular sporozoan parasites invade the host cell through the invagination of the plasma membrane of the host and a vacuole is formed which accommodates the entering parasite. The vacuole may disappear and the invaginated membrane of the host then becomes closely apposed to that of the parasite's own membrane. As a result the parasite is covered by two membranes. Members

Maria A. Rudzinska; William Trager; Sondra J. Lewengrub; Erminio Gubert

1976-01-01

61

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117.801 Section 117...Requirements New York § 117.801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a)...

2013-07-01

62

Metabolism in hyperthermophilic microorganisms  

Microsoft Academic Search

Hyperthermophilic microorganisms grow at temperatures of 90 °C and above and are a recent discovery in the microbial world. They are considered to be the most ancient of all extant life forms, and have been isolated mainly from near shallow and deep sea hydrothermal vents. All but two of the nearly twenty known genera are classified asArchaea (formerly archaebacteria). Virtually

Robert M. Kelly; Michael W. W. Adams

1994-01-01

63

Comparing Sizes of Microorganisms  

NSDL National Science Digital Library

In this activity related to microbes, learners create scale models of microorganisms and compare relative sizes of common bacteria, viruses, fungi and protozoa using metric measures: meters, centimeters and micrometers. Learners will discover that microbes come in many different sizes and shapes, and frequently are measured in micrometers. This lesson guide includes background information and handouts.

Moreno, Nancy P.; Tharp, Barbara Z.; Erdmann, Deanne B.; Clayton, Sonia R.; Denk, James P.

2008-01-01

64

Microorganisms and Man.  

ERIC Educational Resources Information Center

Provides information to update Institute of Biology's Studies in Biology No. 111, "Microorganisms and Man," by W. C. Noble and Jay Naidoo (Edward Arnold, 1979). Topics include: (1) food poisoning; (2) airborn infections in man; (3) infection in animals and plants; and (4) biodegradation and biosynthesis. (JN)

Noble, W. C.

1983-01-01

65

Subsurface Microorganisms: Ecological significance  

SciTech Connect

Terrestrial subsurface environments are inhabited almost exclusively by microorganisms and are in essence 'aphotic' ecosystems. Photosynthesis plays only an indirect role in subsurface microbial ecology, providing reduced organic compounds that can be metabolized by aerobic or anaerobic heterotrophic bacteria. Organic compounds are introduced into the subsurface, in general, via burial of detrital organic matter or as solutes that are transported to the subsurface in the form of dissolved organic carbon (DOC) in waters that percolate downward and recharge aquifers. Microbial generation of energy in deep subsurface environments results from biochemical reactions involving the oxidation of reduced compounds and the subsequent transfer of electrons to an adjacent oxidized compound. It is these metabolic processes that have a great impact on microbial ecological interactions in the subsurface and subsequent impacts of microbial metabolism on groundwater geochemistry and geological processes such as diagenesis (1). This article will provide an overview of the sources of energy that drive microbial metabolism in the subsurface and the physical constraints on the presence and function of subsurface microorganisms. The distributions and general characteristics of microorganisms in the subsurface will be examined and critical issues with regards to sampling the subsurface and enumerating associated microorganisms will be discussed. Finally, the extent of the subsurface biosphere on earth will be explored along with how this concept has focused the search for life elsewhere in the solar system to the subsurface of other planetary bodies.

Fredrickson, Jim K.

2003-01-15

66

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

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Newtown Creek, Dutch Kills, English Kills and their tributaries...New York § 117.801 Newtown Creek, Dutch Kills, English Kills and their tributaries...apply to all bridges across Newtown Creek, Dutch Kills, English Kills, and their...

2009-07-01

67

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Newtown Creek, Dutch Kills, English Kills and their tributaries...New York § 117.801 Newtown Creek, Dutch Kills, English Kills and their tributaries...apply to all bridges across Newtown Creek, Dutch Kills, English Kills, and their...

2010-07-01

68

Analogy between temperature-dependent and concentration-dependent bacterial killing  

Microsoft Academic Search

In this article an analogy between temperature-dependent and concentration-dependent bacterial killing is described. The validation process of autoclaves uses parameters such as reduction rate constant k, decimal reduction time D and resistance coefficient z from an imaginary microorganism to describe the sterilization process. Total lethality of the process is calculated as the integral of the lethality (a function of the

C. Neef; S. A. van Gils; W. L. IJzerman

2002-01-01

69

Mechanism of lethal action of 2,450-MHz radiation on microorganisms.  

PubMed Central

Various bacteria, actinomycetes, fungi, and bacteriophages were exposed to microwaves of 2,450 +/- 20 MHz in the presence and in the absence of water. It was found that microorganisms were inactivated only when in the presence of water and that dry or lyophilized organisms were not affected even by extended exposures. The data presented here prove that microorganisms are killed by "thermal effect" only and that, most likely, there is no "nonthermal effect"; cell constituents other than water do not absorb sufficient energy to kill microbial cells.

Vela, G R; Wu, J F

1979-01-01

70

Kills Germs by the Millions!  

ERIC Educational Resources Information Center

Described is a science experiment involving the isolation and study of microorganisms. Bacteria from the mouth are cultured on blood agar culture plates and are then exposed to four different mouthwashes to test their effectiveness. (DS)

Swails, Molly

1980-01-01

71

Proteomic Studies of Psychrophilic Microorganisms  

Microsoft Academic Search

Research on psychrophilic microorganisms has entered the post-genomic era [in this chapter, psychrophilic and psychrotolerant\\u000a (or psychrotrophic) microorganisms are not distinguished, and the term “psychrophilic microorganisms” is used throughout].\\u000a As of December 2006, complete genomic DNA sequences are available for the following eight psychrophilic microorganisms according\\u000a to Genomes OnLine Database (http:\\/\\/www.genomesonline.org\\/): Desulfotalea psychrophila LSv54 (Rabus et al. 2004), Photobacterium profundum

Tatsuo Kurihara; Nobuyoshi Esaki

72

Inactivation of Microorganisms  

Microsoft Academic Search

\\u000a Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient\\u000a content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated\\u000a in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures\\u000a (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed

Stella Maris Alzamora; Sandra N. Guerrero; Marcela Schenk; Silvia Raffellini; Aurelio López-Malo

2011-01-01

73

Detecting the presence of microorganisms  

NASA Technical Reports Server (NTRS)

The presence of microorganisms in a sample is determined by culturing microorganisms in a growth medium which is in contact with a measuring electrode and a reference electrode and detecting a change in potential between the electrodes caused by the presence of the microorganisms in the medium with a high impedance potentiometer.

Wilkins, Judd R. (Inventor); Stoner, Glenn E. (Inventor)

1977-01-01

74

Porphyromonas gingivalis invades osteoblasts and inhibits bone formation.  

PubMed

Porphyromonas gingivalis is etiologically associated with adult periodontitis, but it is unclear how P. gingivalis long-term interactions with bone cells contribute to this disease. This study investigates P. gingivalis interactions with osteoblasts over an extended time course. A primary mouse calvarial osteoblast culture was established and inoculated with P. gingivalis 33277 repeatedly every other day for up to four weeks. Invasion of osteoblasts by P. gingivalis, and the resulting effects on the proliferation, differentiation, and mineralization of osteoblasts were evaluated. P. gingivalis was found to invade osteoblasts in a dose-dependent manner, and repetitive inoculation increased the percentage of osteoblasts with internalized P. gingivalis. P. gingivalis did not affect osteoblast proliferation, but inhibited their differentiation and mineralization, partially via an inhibition of the differentiation regulatory transcription factors Cbfa-1 and osterix. In conclusion, P. gingivalis invades osteoblasts and inhibits bone formation, which likely contributes to alveolar bone loss in chronic periodontitis. PMID:20538069

Zhang, Wenjian; Swearingen, Elizabeth B; Ju, Jun; Rigney, Todd; Tribble, Gena D

2010-10-01

75

Quantitation of microRNAs using a modified Invader assay.  

PubMed

The short lengths of microRNAs (miRNAs) present a significant challenge for detection and quantitation using conventional methods for RNA analysis. To address this problem, we developed a quantitative, sensitive, and rapid miRNA assay based on our previously described messenger RNA Invader assay. This assay was used successfully in the analysis of several miRNAs, using as little as 50-100 ng of total cellular RNA or as few as 1,000 lysed cells. Its specificity allowed for discrimination between miRNAs differing by a single nucleotide, and between precursor and mature miRNAs. The Invader miRNA assay, which can be performed in unfractionated detergent lysates, uses fluorescence detection in microtiter plates and requires only 2-3 h incubation time, allowing for parallel analysis of multiple samples in high-throughput screening analyses. PMID:15208450

Allawi, Hatim T; Dahlberg, James E; Olson, Sarah; Lund, Elsebet; Olson, Marilyn; Ma, Wu-Po; Takova, Tsetska; Neri, Bruce P; Lyamichev, Victor I

2004-07-01

76

[Prevention and control of invaded plant Phytolacca americana in sandy coastal shelter forests].  

PubMed

The invasion of Phytolacca americana has produced serious damage to the coastal shelter forests in China. In order to search for the effective measures for controlling the growth of P. americana, several plots in the Robinia pseudoacacia forest invaded by P. Americana to the relatively same extent were installed, and the measures of physical control (mowing and root cutting) and chemical control (spraying herbicides) were adopted to control the invasion of P. Americana, taking the site with good growth of Amorpha fruticosa in the forest and without any control measures as the comparison. The results showed that mowing could rapidly decrease the growth of P. americana in the same year, but the growth recovered in the next year. 1/3 root cutting only reduced the aboveground growth of P. americana in the same year, and the growth was recovered in the third year; while 2/3 root cutting and whole cutting could effectively cleanup the P. americana plants all the time. Spraying quizalofop-p-ethyl and paraquat only killed the aboveground part of P. americana in the same year, but this part of P. americana recovered to the normal level in the next year; while spraying 45 g x L(-1) of glyphosate could completely kill the whole P. americana plants till the third year. The growth of P. americana at the site with good growth of A. fruticosa and without any control measures maintained at a low level all the time, suggesting that planting A. fruticosa in R. pseudoacacia forest would be an effective approach to prevent and control the P. americana invasion. PMID:22803465

Fu, Jun-Peng; Li, Chuan-Rong; Xu, Jing-Wei; Cheng, Wan-Li; Song, Rui-Feng; Liu, Yun

2012-04-01

77

Surgical treatment of gastric cancer invading the oesophagus  

Microsoft Academic Search

Introduction There is controversy regarding which type of surgical treatment is most appropriate for upper gastric cancer invading the oesophagus. Methods A review of the pertinent literature was carried out regarding oesophageal involvement in gastric cancer. Results Invasion of the oesophagus occurred in 26–63% of Western surgical series. It was more frequent in Borrmann IV type, linitis plastica, pT3–pT4, diffuse

F. Bozzetti; P. Bignami; L. Bertario; S. Fissi; M. Eboli

2000-01-01

78

Antimicrobial peptides: promising compounds against pathogenic microorganisms.  

PubMed

In the last decades, the indiscriminate use of conventional antibiotics has generated high rates of microbial resistance. This situation has increased the need for obtaining new antimicrobial compounds against infectious diseases. Among these, antimicrobial peptides (AMPs) constitute a promising alternative as therapeutic agents against various pathogenic microbes. These therapeutic agents can be isolated from different organisms, being widespread in nature and synthesized by microorganisms, plants and animals (both invertebrates and vertebrates). Additionally, AMPs are usually produced by a non-specific innate immune response. These peptides are involved in the inhibition of cell growth and in the killing of several microorganisms, such as bacteria, fungi, enveloped viruses, protozoans and other parasites. They have many interesting properties as potential antibiotics, such as relatively small sizes (below 25-30 kDa), amphipathic structures, cationic nature, and offer low probability for the generation of microbial resistance. In recent years, many novel AMPs, with very promising therapeutic properties, have been discovered. These peptides have been the base for the production of chemical analogs, which have been designed, chemically synthesized and tested in vitro for their antimicrobial activity. This review is focused on antibacterial (against Gram (-) and Gram (+) bacteria) and antifungal peptides, discussing action mode of AMPs, and recent advances in the study of the molecular basis of their anti-microbial activity. Finally, we emphasize on their current pharmacological development, future directions and applications of AMPs as promising antibiotics of therapeutic use for microbial infections. PMID:24533812

Cruz, J; Ortiz, C; Guzmán, F; Fernández-Lafuente, R; Torres, R

2014-01-01

79

Invisible invaders: non-pathogenic invasive microbes in aquatic and terrestrial ecosystems.  

PubMed

Although the number of studies on invasive plants and animals has risen exponentially, little is known about invasive microbes, especially non-pathogenic ones. Microbial invasions by viruses, bacteria, fungi and protists occur worldwide but are much harder to detect than invasions by macroorganisms. Invasive microbes have the potential to significantly alter community structure and ecosystem functioning in diverse terrestrial and aquatic ecosystems. Consequently, increased attention is needed on non-pathogenic invasive microbes, both free-living and symbiotic, and their impacts on communities and ecosystems. Major unknowns include the characteristics that make microbes invasive and properties of the resident communities and the environment that facilitate invasions. A comparison of microbial invasions with invasions of macroorganisms should provide valuable insights into general principles that apply to invasions across all domains of life and to taxon-specific invasion patterns. Invasive microbes appear to possess traits thought to be common in many invasive macroorganisms: high growth rate and resource utilization efficiency, and superior competitive abilities. Invading microorganisms are often similar to native species, but with enhanced performance traits, and tend to spread in lower diversity communities. Global change can exacerbate microbial invasions; therefore, they will likely increase in the future. PMID:21054733

Litchman, Elena

2010-12-01

80

Biofilms: Survival Mechanisms of Clinically Relevant Microorganisms  

PubMed Central

Though biofilms were first described by Antonie van Leeuwenhoek, the theory describing the biofilm process was not developed until 1978. We now understand that biofilms are universal, occurring in aquatic and industrial water systems as well as a large number of environments and medical devices relevant for public health. Using tools such as the scanning electron microscope and, more recently, the confocal laser scanning microscope, biofilm researchers now understand that biofilms are not unstructured, homogeneous deposits of cells and accumulated slime, but complex communities of surface-associated cells enclosed in a polymer matrix containing open water channels. Further studies have shown that the biofilm phenotype can be described in terms of the genes expressed by biofilm-associated cells. Microorganisms growing in a biofilm are highly resistant to antimicrobial agents by one or more mechanisms. Biofilm-associated microorganisms have been shown to be associated with several human diseases, such as native valve endocarditis and cystic fibrosis, and to colonize a wide variety of medical devices. Though epidemiologic evidence points to biofilms as a source of several infectious diseases, the exact mechanisms by which biofilm-associated microorganisms elicit disease are poorly understood. Detachment of cells or cell aggregates, production of endotoxin, increased resistance to the host immune system, and provision of a niche for the generation of resistant organisms are all biofilm processes which could initiate the disease process. Effective strategies to prevent or control biofilms on medical devices must take into consideration the unique and tenacious nature of biofilms. Current intervention strategies are designed to prevent initial device colonization, minimize microbial cell attachment to the device, penetrate the biofilm matrix and kill the associated cells, or remove the device from the patient. In the future, treatments may be based on inhibition of genes involved in cell attachment and biofilm formation.

Donlan, Rodney M.; Costerton, J. William

2002-01-01

81

Does Assessment Kill Student Creativity?  

Microsoft Academic Search

Does assessment kill creativity? In this article, creativity is defined and discussed and an overview of creativity and motivational research is provided to describe how assessment practices can influence students' creativity. Recommendations for protecting creativity when assessing students also are provided.

Ronald A. Beghetto

2005-01-01

82

To kill a man's pride  

Microsoft Academic Search

This excerpt from To Kill a Man's Pride was published in the February 1980 issue of the South African literary magazine Staffrider. The publishers of Staffrider, Ravan Press, announced at that time that the full text would appear in Forced Landing, a new collection of contemporary black South African writings edited by Mothobi Mutloatse. The next issue of Staffrider (June

Mtutuzeli Matshoba

1981-01-01

83

Dispersal data and the spread of invading organisms  

Microsoft Academic Search

Models that describe the spread of invading organisms often assume that\\u000a the dispersal distances of propagules are normally distributed. In\\u000a contrast, measured dispersal curves are typically leptokurtic, not\\u000a normal. In this paper, we consider a class of models, integrodifference\\u000a equations, that directly incorporate detailed dispersal data as well as\\u000a population growth dynamics. We provide explicit formulas for the speed\\u000a of

M. Kot; M. A. Lewis; P vandenDriessche

1996-01-01

84

Invader technology for DNA and RNA analysis: principles and applications.  

PubMed

Concomitant advances made by the Human Genome Project and in the development of nucleic acid screening technologies are driving the expansion of pharmacogenomic research and molecular diagnostics. However, most current technologies are restrictive due to their complexity and/or cost, limiting the potential of personalized medicine. The invader assay, which can be used for genotyping as well as for gene expression monitoring without the need for intervening target amplification steps, presents an immediate solution that is accurate, simple to use, scaleable and cost-effective. PMID:12271820

de Arruda, Monika; Lyamichev, Victor I; Eis, Peggy S; Iszczyszyn, Walter; Kwiatkowski, Robert W; Law, Scott M; Olson, Marilyn C; Rasmussen, Eric B

2002-09-01

85

Patterned electrical pulse microorganism aggregation  

US Patent & Trademark Office Database

Described herein are systems, methods, and apparatuses for aggregating microorganism in an aqueous suspension. In particular, are systems, methods, and apparatuses that apply an electrical field to an aqueous suspension comprising microorganisms as the aqueous suspension follows a flow path to cause aggregation of the microorganisms. The electrical field may comprise different types of pulses. In some embodiments, the flow path for the aqueous suspension may vary.

2014-04-29

86

Cell killing by lysosomotropic detergents  

PubMed Central

We have studied the mechanism by which lysosomotropic detergents kill baby hamster kidney cells. Lysosomotropic detergents are lysosomotropic amines (compounds with pK between 5 and 9, such as imidazole or morpholine) containing straight-chain hydrocarbon "tails" of 9-14 carbon atoms (Firestone, R. A., J. M. Pisano, and R. J. Bonney. 1979, J. Med. Chem., 22:1130-1133). Using lucifer yellow CH as a specific fluorescent label for lysosomes, it was shown by light microscopy that N-dodecyl (C12)-imidazole acted rapidly to damage lysosomes, causing leakage of dye into the cytoplasm. This was followed at later times by vacuolization, blebbing of the plasma membrane, cell rounding, and cell death. 3H-labeled C12-imidazole rapidly diffused into cells where much of it was trapped in lysosomes as shown by its co-migration with lysosomes in Percoll gradients. Cells preincubated with C12-imidazole released it slowly into C12-imidazole-free media, permitting the cells to be killed by the preincubation dose. Cell killing by the lysosomotropic detergents exhibited strongly sigmoidal dose-response curves. The sensitivity of baby hamster kidney cells to killing by C12- imidazole was density dependent, the cells being most sensitive at lowest cell densities, and relatively resistant at confluence. The amount of 3H-C12-imidazole taken up by the cells was also density dependent, with highest specific uptake occurring at the lowest cell density. A rise in lysosomal pH, measured in fluoresceinated dextran- labeled cells, commenced immediately upon addition of C12-imidazole to cells, and continued for over an hour. This was followed after a lag of 1-2 h by inhibition of protein and RNA synthesis and by lactate dehydrogenase release. Ionophores or lysosomotropic amines, such as methylamine, that raise intralysosomal pH provided substantial protection of the cells from killing by lysosomotropic detergents. These findings provide strong support for the idea that lysosomotropic detergents kill cells by disrupting lysosomes from within.

1983-01-01

87

Pseudomonas aeruginosa invades corneal epithelial cells during experimental infection.  

PubMed Central

Pseudomonas aeruginosa is considered an extracellular pathogen. Using assays to determine intracellular survival in the presence of gentamicin, we have demonstrated that some strains of P. aeruginosa are able to invade corneal cells during experimental bacterial keratitis in mice. Although intracellular bacteria were detectable 15 min after inoculation, the number of intracellular bacteria increased in a time-dependent manner over a 24-h period. Levels of invasion were similar when bacteria were grown as a biofilm on solid medium and when they were grown in suspension. Intracellular bacteria survived in vitro for at least 24 h, although only minimal bacterial multiplication within cells was observed. P. aeruginosa PAK and Escherichia coli HB101 did not cause disease in this model and were not isolated from corneas after 24 h even when an inoculum of 10(8) CFU was applied. Transmission electron microscopy of corneal epithelium from eyes infected for 8 h revealed that intracellular bacteria were present within membrane-bound vacuoles, which suggests that bacterial entry was an endocytic process. At 24 h, the observation of many bacteria free in the cytoplasm indicated that P. aeruginosa was able to escape the endocytic vacuole. The ability of some P. aeruginosa strains to invade corneal epithelial cells may contribute to the pathogenesis or to the progression of disease, since intracellular bacteria can evade host immune effectors and antibiotics commonly used to treat infection. Images

Fleiszig, S M; Zaidi, T S; Fletcher, E L; Preston, M J; Pier, G B

1994-01-01

88

Beetle Kill Wall at NREL  

ScienceCinema

When it comes to designing an interior decorative feature for one of the most energy efficient office buildings in the world, very few would consider bringing in a beetle to do the job. But thats what happened at the U.S. Department of Energy's (DOE) Research Support Facility (RSF) located on the National Renewable Energy Laboratory (NREL) campus.In June, the RSF will become home to more than 800 workers from DOE and NREL and building visitors will be greeted with a soaring, two-story high wall entirely covered with wood harvested from the bark beetle infestation that has killed millions of pine trees in the Western U.S. But, the use of beetle kill wood is just one example of the resources being leveraged to make the RSF a model for sustainability and one more step toward NRELs goal to be a net zero energy campus.

None

2013-05-29

89

Beetle Kill Wall at NREL  

SciTech Connect

When it comes to designing an interior decorative feature for one of the most energy efficient office buildings in the world, very few would consider bringing in a beetle to do the job. But thats what happened at the U.S. Department of Energy's (DOE) Research Support Facility (RSF) located on the National Renewable Energy Laboratory (NREL) campus.In June, the RSF will become home to more than 800 workers from DOE and NREL and building visitors will be greeted with a soaring, two-story high wall entirely covered with wood harvested from the bark beetle infestation that has killed millions of pine trees in the Western U.S. But, the use of beetle kill wood is just one example of the resources being leveraged to make the RSF a model for sustainability and one more step toward NRELs goal to be a net zero energy campus.

None

2010-01-01

90

Beetle Kill Wall at NREL  

ScienceCinema

When it comes to designing an interior decorative feature for one of the most energy efficient office buildings in the world, very few would consider bringing in a beetle to do the job. But thats what happened at the U.S. Department of Energy's (DOE) Research Support Facility (RSF) located on the National Renewable Energy Laboratory (NREL) campus.In June, the RSF will become home to more than 800 workers from DOE and NREL and building visitors will be greeted with a soaring, two-story high wall entirely covered with wood harvested from the bark beetle infestation that has killed millions of pine trees in the Western U.S. But, the use of beetle kill wood is just one example of the resources being leveraged to make the RSF a model for sustainability and one more step toward NRELs goal to be a net zero energy campus.

91

Women who kill their mates.  

PubMed

Spousal homicide perpetrators are much more likely to be men than women. Accordingly, little research has focused on delineating characteristics of women who have committed spousal homicide. A retrospective clinical review of coroners' files containing all cases of spousal homicide occurring in Quebec over a 20-year period was carried out. A total of 276 spousal homicides occurred between 1991 and 2010, with 42 homicides by female spouses and 234 homicides by male spouses. Differences between homicides committed by female offenders and male offenders are discussed, and findings on spousal homicide committed by women are compared with those of previous studies. Findings regarding offenses perpetrated by females in the context of mental illness, domestic violence, and homicide-suicide are explored. The finding that only 28% of the female offenders in the Quebec sample had previously been subjected to violence by their victim is in contrast to the popular belief and reports that indicate that most female-perpetrated spousal homicide occurs in self-defense or in reaction to long-term abuse. In fact, women rarely gave a warning before killing their mates. Most did not suffer from a mental illness, although one-fifth were acutely intoxicated at the time of the killing. In the vast majority of cases of women who killed their mates, there were very few indicators that might have signaled the risk and helped predict the violent lethal behavior. PMID:23015414

Bourget, Dominique; Gagné, Pierre

2012-01-01

92

Transport of microorganisms through soil  

Microsoft Academic Search

Microorganisms migrating into and through soil from sources on the land surface may cause a serious threat to both ground and surface waters. It has been estimated that microorganisms can migrate significant distances in the field. Results from various studies suggested that preferential flow through macropores, worm holes, cracks, and fractures is the main reason for such observations. However, a

Jamal Abu-Ashour; Douglas M. Joy; Hung Lee; Hugh R. Whiteley; Samuel Zelin

1994-01-01

93

33 CFR 117.702 - Arthur Kill.  

Code of Federal Regulations, 2010 CFR

...1 2009-07-01 2009-07-01 false Arthur Kill. 117.702 Section 117.702 Navigation...Specific Requirements New Jersey § 117.702 Arthur Kill. (a) The draw of the Arthur Kill (AK) Railroad Bridge shall be...

2009-07-01

94

33 CFR 117.702 - Arthur Kill.  

Code of Federal Regulations, 2010 CFR

...1 2010-07-01 2010-07-01 false Arthur Kill. 117.702 Section 117.702 Navigation...Specific Requirements New Jersey § 117.702 Arthur Kill. (a) The draw of the Arthur Kill (AK) Railroad Bridge shall be...

2010-07-01

95

Multicellular microorganisms: laboratory versus nature  

PubMed Central

Our present in-depth knowledge of the physiology and regulatory mechanisms of microorganisms has arisen from our ability to remove them from their natural, complex ecosystems into pure liquid cultures. These cultures are grown under optimized laboratory conditions and allow us to study microorganisms as individuals. However, microorganisms naturally grow in conditions that are far from optimal, which causes them to become organized into multicellular communities that are better protected against the harmful environment. Moreover, this multicellular existence allows individual cells to differentiate and acquire specific properties, such as forming resistant spores, which benefit the whole population. The relocation of natural microorganisms to the laboratory can result in their adaptation to these favourable conditions, which is accompanied by complex changes that include the repression of some protective mechanisms that are essential in nature. Laboratory microorganisms that have been cultured for long periods under optimized conditions might therefore differ markedly from those that exist in natural ecosystems.

Palkova, Zdena

2004-01-01

96

On the isolation of halophilic microorganisms from salt deposits of great geological age  

NASA Technical Reports Server (NTRS)

From salt sediments of Triassic or Permian age from various locations in the world halophilic microorganisms were isolated. Molecular characteristics of several of the isolates suggested they belong to the archaebacteria. One group appears to represent novel strains; several properties of one such isolate, strain BIp, are described here. The existence of viable microorganisms in ancient sediment would have great implications with respect to our notions on evolution, the research for life in extraterrestrial environments, and the longterm survival of functional biological structures. Of crucial importance is thus the question if these microorganisms existed in the salt since the time of deposition or invaded at some later date. Some suggestions to address these issues experimentally are discussed.

Stan-Lotter, Helga; Denner, Ewald

1993-01-01

97

On the Isolation of Halophilic Microorganisms from Salt Deposits of Great Geological Age  

NASA Technical Reports Server (NTRS)

From salt sediments of Triassic or Permian ace from various locations in the world halophilic microorganisms were isolated. Molecular characteristics of several of the isolates suggested they belong to the archaebacteriae. One group appears to represent novel strains; several properties or one such isolate, strain BIp, are described here. The existence of viable microorganisms in ancient sediments would have great implications with respect to our notions on evolution, the search for life in extraterrestrial environments and the long- term survival of functional biological structures. Of crucial importance is thus the question if these microorganisms existed in the salt since the time of deposition or invaded at some later date. Some suggestions to address these issues experimentally are discussed.

Stan-Lotter, Helga; Denner, Ewald; Orans, Robin (Editor)

1993-01-01

98

[Ecological relationships between Bursaphelenchus xylophilus and its companion microorganisms].  

PubMed

Pine wood nematode Bursaphelenchus xylophilus is a notorious invasive species from North America, which can kill a large amount of pine trees and causes economic losses and ecosystem destruction. There is a close relationship and ecological interaction between B. xylophilus and its companion microorganisms. This paper listed the species of companion microorganisms, reviewed their important ecological roles in the propagation and pathogenicity of the nematode, and discussed the pine wilt disease from the viewpoint of microecosystem. The companion fungi can supply food for B. xylophilus, hold the cycle of second infection of the nematode, increase the proportions of dauer juveniles, and benefit the infection and distribution of B. xylophilus. The companion bacteria can enhance the pathogenicity of B. xylophilus, promote the propagation of the nematode, benefit the pinene degradation, and thereby, promote the adaptability of the nematode. PMID:21657042

Tian, Xue-liang; Mao, Zhen-chuan; Chen, Guo-hua; Xie, Bing-yan

2011-03-01

99

How rhizobial symbionts invade plants: the Sinorhizobium-Medicago model  

PubMed Central

Nitrogen-fixing rhizobial bacteria and leguminous plants have evolved complex signal exchange mechanisms that allow a specific bacterial species to induce its host plant to form invasion structures through which the bacteria can enter the plant root. Once the bacteria have been endocytosed within a host-membrane-bound compartment by root cells, the bacteria differentiate into a new form that can convert atmospheric nitrogen into ammonia. Bacterial differentiation and nitrogen fixation are dependent on the microaerobic environment and other support factors provided by the plant. In return, the plant receives nitrogen from the bacteria, which allows it to grow in the absence of an external nitrogen source. Here, we review recent discoveries about the mutual recognition process that allows the model rhizobial symbiont Sinorhizobium meliloti to invade and differentiate inside its host plant alfalfa (Medicago sativa) and the model host plant barrel medic (Medicago truncatula).

Jones, Kathryn M.; Kobayashi, Hajime; Davies, Bryan W.; Taga, Michiko E.; Walker, Graham C.

2009-01-01

100

Group II Introns: Mobile Ribozymes that Invade DNA  

PubMed Central

SUMMARY Group II introns are mobile ribozymes that self-splice from precursor RNAs to yield excised intron lariat RNAs, which then invade new genomic DNA sites by reverse splicing. The introns encode a reverse transcriptase that stabilizes the catalytically active RNA structure for forward and reverse splicing, and afterwards converts the integrated intron RNA back into DNA. The characteristics of group II introns suggest that they or their close relatives were evolutionary ancestors of spliceosomal introns, the spliceosome, and retrotransposons in eukaryotes. Further, their ribozyme-based DNA integration mechanism enabled the development of group II introns into gene targeting vectors (“targetrons”), which have the unique feature of readily programmable DNA target specificity.

Lambowitz, Alan M.; Zimmerly, Steven

2011-01-01

101

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Microorganism identity. 725.85 Section...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a)...

2009-07-01

102

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Microorganism identity. 725.85 Section...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a)...

2010-07-01

103

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Microorganism identity. 725.85 Section...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public Access to Information § 725.85 Microorganism identity. (a)...

2013-07-01

104

Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea  

Microsoft Academic Search

Chronic diarrhea is a common bowel disorder; disturbance of intestinal microorganisms may play a role in its pathogenesis.\\u000a This study assessed the clinical efficacy of lyophilized, heat-killedLactobacillus acidophilus LB versus living lactobacilli in the treatment of chronic diarrhea. One hundred thirty-seven patients with chronic diarrhea\\u000a were randomly allocated to receive either a 4-week course of 2 capsules of Lacteol® Fort

Shy-Dong Xiao; Zhong De Zhang; Hong Lu; Shi Hu Jiang; Hou Yu Liu; Geng Sheng Wang; Guo Ming Xu; Zhong Bing Zhang; Geng Jin Lin; Guo Liang Wang

2003-01-01

105

Ebola outbreak killed 5000 gorillas.  

PubMed

Over the past decade, the Zaire strain of Ebola virus (ZEBOV) has repeatedly emerged in Gabon and Congo. Each human outbreak has been accompanied by reports of gorilla and chimpanzee carcasses in neighboring forests, but both the extent of ape mortality and the causal role of ZEBOV have been hotly debated. Here, we present data suggesting that in 2002 and 2003 ZEBOV killed about 5000 gorillas in our study area. The lag between neighboring gorilla groups in mortality onset was close to the ZEBOV disease cycle length, evidence that group-to-group transmission has amplified gorilla die-offs. PMID:17158318

Bermejo, Magdalena; Rodríguez-Teijeiro, José Domingo; Illera, Germán; Barroso, Alex; Vilà, Carles; Walsh, Peter D

2006-12-01

106

9 CFR 113.211 - Feline Rhinotracheitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Feline Rhinotracheitis Vaccine, Killed Virus...REQUIREMENTS Killed Virus Vaccines § 113.211 Feline Rhinotracheitis Vaccine, Killed Virus. Feline Rhinotracheitis Vaccine, Killed...

2010-01-01

107

9 CFR 113.203 - Feline Panleukopenia Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 2009-01-01 false Feline Panleukopenia Vaccine, Killed Virus. 113...REQUIREMENTS Killed Virus Vaccines § 113.203 Feline Panleukopenia Vaccine, Killed Virus. Feline Panleukopenia Vaccine, Killed...

2009-01-01

108

9 CFR 113.203 - Feline Panleukopenia Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Feline Panleukopenia Vaccine, Killed Virus. 113...REQUIREMENTS Killed Virus Vaccines § 113.203 Feline Panleukopenia Vaccine, Killed Virus. Feline Panleukopenia Vaccine, Killed...

2010-01-01

109

9 CFR 113.211 - Feline Rhinotracheitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

... 2009-01-01 2009-01-01 false Feline Rhinotracheitis Vaccine, Killed Virus...REQUIREMENTS Killed Virus Vaccines § 113.211 Feline Rhinotracheitis Vaccine, Killed Virus. Feline Rhinotracheitis Vaccine, Killed...

2009-01-01

110

Euthanasia: killing as due care?  

PubMed

On 10 April 2001, the Netherlands was the first country to pass a law on the killing of patients at their request (euthanasia), which took effect on 1 April 2002. Belgium followed and passed a euthanasia law on 16 May 2002, which took effect on 23 September 2002 and is even more liberal than the Dutch one. Physicians will be exempted from criminal liability provided they satisfy the so-called 'due care criteria'. However, in medical history euthanasia has never been part of the medical duty of care. Instead, the goals of medicine have always been the relief of pain and suffering. The current article provides insights into the Dutch, Belgian and Oregon euthanasia and physician-assisted suicide practices and reflects upon some central medical and legal documents on the regulation of euthanasia and the provision of palliative care. Modern palliative care includes both the delivery of competent palliative skills and a virtuous attitude of compassionate caring about the terminally ill patient as an autonomous person. Here, the author rejects killing as due care and proposes a novel concept of 'RAHME' (Aramaic: compassion, love, mercy), which calls for a holistically oriented concept where physicians act as companions to the terminally ill and dying patients. PMID:14571664

Oduncu, Fuat S

2003-01-01

111

Letting die and mercy killing.  

PubMed

We are all called to make moral decisions, not only about preserving life and health, but also about accepting our death and dying. There are situations, when it is morally right, and indeed obligatory, to allow a dying person to die in peace and dignity. But there is a world of difference between allowing a peaceful death, and deliberately setting out to bring death of the person either by acts of commission (s.c. 'active euthanasia'), or by acts of omission (s.c. 'passive euthanasia'). The word "killing" seems proper for euthanasia, because "to kill" does mean " to intentionally cause the death of someone." It can be morally acceptable to withhold or withdraw a treatment precisely because it is reasonably judged as inefficacious (futile), or excessively burdensome for the patient. One's reason for withholding such treatment must not be a judgement about the desirability of putting an end to the patient's life, but a judgement about the desirability of putting an end to the treatment, which is futile or burdensome. PMID:16294443

Narbekovas, Andrius; Meilius, Kazimieras

2003-01-01

112

Variability and Selection of Microorganisms.  

National Technical Information Service (NTIS)

The variability of organisms in general and that of microorganisms in particular depends on their development in the conditions of inhabitual life. Organisms acquire new properties entirely corresponding to new conditions of existence. The disciples of I....

A. Imscenieski

1968-01-01

113

Sensor arrays for detecting microorganisms  

NASA Technical Reports Server (NTRS)

A sensor array for detecting a microorganism comprising first and second sensors electrically connected to an electrical measuring apparatus, wherein the sensors comprise a region of nonconducting organic material and a region of conducting material compositionally that is different than the nonconducting organic material and an electrical path through the regions of nonconducting organic material and the conducting material. A system for identifying microorganisms using the sensor array, a computer and a pattern recognition algorithm, such as a neural net are also disclosed.

Lewis, Nathan S. (Inventor); Freund, Michael S. (Inventor)

2000-01-01

114

Evidence that Killing Escalates Within-Subjects in a Bug-Killing Paradigm.  

PubMed

Prior research has examined killing behavior using a paradigm in which participants believe (falsely) that they are killing bugs. This work suggests that killing behavior escalates. In the present study, we sought to replicate the basic escalation effect within-subjects. Further, in doing so, we controlled for experimenter "sanctioning" of killing that may have differed with key between-subjects manipulations in the prior research. To control for this possible confound, the present experiment held experimenter instructions constant and examined whether killing naturally escalated within-subjects across two 12-sec bug-killing tasks. Additionally, to verify that escalation is due to killing per se and not just physical practice of the procedure, we manipulated whether the procedure was described as real killing or simulated killing. Results showed that when participants thought they were killing bugs, the number of bugs put into the grinder increased from the first to the second killing task. No such escalation occurred when participants performed the procedure while knowing the killing was simulated. Thus, killing of bugs escalates and is not simply a consequence of perceived sanctioning of killing by an experimenter or simulated practice of the procedure. PMID:22331599

Martens, Andy; Kosloff, Spee

2012-02-13

115

Habitat Shift in Invading Species: Zebra and Quagga Mussel Population Characteristics on Shallow Soft Substrates  

Microsoft Academic Search

Unexpected habitat innovations among invading species are illustrated by the expansion of dreissenid mussels across sedimentary environments in shallow water unlike the hard substrates where they are conventionally known. In this note, records of population characteristics of invading zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels from 1994 through 1998 are reported from shallow (less than 20?m) sedimentary habitats in

Paul Arthur Berkman; David W. Garton; Melissa A. Haltuch; Gregory W. Kennedy; Lawrence R. Febo

2000-01-01

116

Predicting the identity and impact of future biological invaders: a priority for aquatic resource management  

Microsoft Academic Search

The identification and risk assessment of potential biological invaders would provide valuable criteria for the allocation of resources toward the detection and control of invasion threats. Yet, freshwater biologists have made few attempts at predicting potential invaders, apparently because such efforts are perceived to be costly and futile. We describe some simple, low-cost empirical approaches that would facilitate prediction and

Anthony Ricciardi; Joseph B. Rasmussen

1998-01-01

117

Clinical, genetic, and pharmacogenetic applications of the Invader assay.  

PubMed

The Invader technology has been developed for the detection of nucleic acids. It is a signal amplification system able to accurately quantify DNA and RNA targets with high sensitivity. Exquisite specificity is achieved by combining hybridization with enzyme recognition, which provides the ability to discriminate mutant from wild-type at ratios greater than 1/1000 (mutant/wt). The technology is isothermal and flexible and incorporates a homogeneous fluorescence readout. It is therefore readily adaptable for use in clinical reference laboratories, as well as high-throughput applications using 96-, 384-, and 1,536-well microtiter plate formats. The molecular mechanism of the system and specific applications for use in clinical and research laboratories are described. These include direct analysis of unamplified human genomic DNA to detect mutations and single-nucleotide polymorphisms associated with factor V Leiden, factor II, cystic fibrosis, and apolipoprotein E, and gene expression assays that quantify messenger RNA levels in cells using direct lysates. PMID:10671646

Kwiatkowski, R W; Lyamichev, V; de Arruda, M; Neri, B

1999-12-01

118

Killed but metabolically active vaccines.  

PubMed

Beginning in the 20th century and continuing into the new millennia, vaccines against numerous diseases have had an unquestioned principal role of both enhancing the quality of life and increasing life expectancy (Rappuoli R, Mandl CW, Black S, De Gregorio E: Vaccines for the twenty-first century society. Nat Rev Immunol 2011, 11:865-872). Despite this success and the development of sophisticated new vaccine technologies, there remain multiple infectious diseases including tuberculosis, malaria and AIDS that await an effective prophylactic vaccine. In addition, there have been recent clinical successes among individuals with cancer using vaccine treatment strategies-so-called therapeutic vaccines-that stimulate tumor specific immunity and increase survival (Kantoff PW, Higano CS, Shore ND, Berger ER, Small EJ, Penson DF, Redfern CH, Ferrari AC, Dreicer R, Sims RB, et al.: Sipuleucel-T immunotherapy for castration-resistant prostate cancer. New Engl J Med 2010, 363:411-422). Here we summarize a new class of vaccines termed Killed But Metabolically Active (KBMA). KBMA vaccines are whole pathogenic or attenuated organisms killed through photochemical inactivation and cannot cause disease, yet retain sufficient metabolic activity to initiate a potent immune response. KBMA vaccines have two broad applications. First, recombinant KBMA vaccines encoding selected antigens relevant to infectious disease or cancer can be used to elicit a desired immune response. In the second application, KBMA vaccines can be derived from attenuated forms of a targeted pathogen, allowing for the presentation of the entire antigenic repertoire to the immune system, of particular importance when the correlates of protection are unknown. PMID:22608846

Dubensky, Thomas W; Skoble, Justin; Lauer, Peter; Brockstedt, Dirk G

2012-12-01

119

A kill curve for Phanerozoic marine species  

NASA Technical Reports Server (NTRS)

A kill curve for Phanerozoic species is developed from an analysis of the stratigraphic ranges of 17,621 genera, as compiled by Sepkoski. The kill curve shows that a typical species' risk of extinction varies greatly, with most time intervals being characterized by very low risk. The mean extinction rate of 0.25/m.y. is thus a mixture of long periods of negligible extinction and occasional pulses of much higher rate. Because the kill curve is merely a description of the fossil record, it does not speak directly to the causes of extinction. The kill curve may be useful, however, to li inverted question markmit choices of extinction mechanisms.

Raup, D. M.

1991-01-01

120

Quantitative aspects of the interactive killing effects between X rays and other mutagens in microorganisms  

SciTech Connect

Recently we presented a mathematical description of the synergistic interaction which occurs when Escherichia coli B/r is exposed to both X rays and 254 nm ultraviolet light. Here we extend this approach to other bacteria and describe a graphical technique which can be used to determine the nature and relative importance of second and third degree terms in the function h(x, y), which describes the dose dependence of such effects. In most cases, interaction functions appear to be dominated, in the biologically interesting dose range, by a second degree term in the product, xy, of the doses of the two agents. We find that the magnitudes of these interactions vary among the organisms examined and can be surprisingly large. Finally, we show that the simple xy dependence observed for most interactions does not carry any unambiguous implications with respect to previous speculations on the mechanisms of these effects.

Ager, D.D.; Haynes, R.H.

1988-07-01

121

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

Federal Register 2010, 2011, 2012, 2013

...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...

2010-10-12

122

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

Federal Register 2010, 2011, 2012, 2013

...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...

2010-06-01

123

Interaction between Trichomonas vaginalis and other pathogenic micro-organisms of the human genital tract.  

PubMed Central

Trichomonas vaginalis organisms were mixed with suspensions of Neisseria gonorrhoeae, Mycoplasma hominis or Chlamydia trachomatis to allow ingestion of these micro-organisms by the trichomonads. Culture studies indicated that gonococci and mycoplasmas were ingested and that the number of intracellular viable organisms decreased rapidly, most gonococci being killed within six hours and all mycoplasmas within three hours. Electron microscopy revealed phagocytic uptake and destruction of these two micro-organisms within the trichomonads, gonococcal degradation being associated with lysosomal enzyme activity. There was no evidence from cultural or electron microscopy studies that C trachomatis organisms persisted in mixed culture with T vaginalis. Images

Street, D A; Wells, C; Taylor-Robinson, D; Ackers, J P

1984-01-01

124

Babesia microti Primarily Invades Mature Erythrocytes in Mice  

PubMed Central

Babesia microti is a tick-borne red blood cell parasite that causes babesiosis in people. Its most common vertebrate reservoir is the white-footed mouse. To determine whether B. microti invades reticulocytes, as does the canine pathogen B. gibsoni, we infected the susceptible inbred mouse strains C.B-17.scid and DBA/2 with a clinical isolate of B. microti. Staining of fixed permeabilized red blood cells with 4?,6?-diamidino-2-phenylindole or YOYO-1, a sensitive nucleic acid stain, revealed parasite nuclei as large bright dots. Flow cytometric analysis indicated that parasite DNA is primarily found in mature erythrocytes that expressed Babesia antigens but not the transferrin receptor CD71. In contrast, CD71-positive reticulocytes rarely contained Babesia nuclei and failed to express Babesia antigens. Accordingly, the frequency of YOYO-1-positive, CD71-negative cells strongly correlated with parasitemia, defined as the frequency of infected red blood cells assessed on Giemsa-stained blood smears. Importantly, the absolute numbers generated by the two techniques were similar. Parasitemia was modest and transient in DBA/2 mice but intense and sustained in C.B-17.scid mice. In both strains, parasitemia preceded reticulocytosis, but reticulocytes remained refractory to B. microti. In immunocompetent C.B-17 mice, reticulocytosis developed early, despite a marginal and short-lived parasitemia. Likewise, an early reticulocytosis developed in resistant BALB/cBy and B10.D2 mice. These studies establish that B. microti has a tropism for mature erythrocytes. Although reticulocytes are rarely infected, the delayed reticulocytosis in susceptible strains may result from parasite or host activities to limit renewal of the mature erythrocyte pool, thereby preventing an overwhelming parasitemia.

Borggraefe, Ingo; Yuan, Jie; Telford, Sam R.; Menon, Sanjay; Hunter, Rouette; Shah, Sohela; Spielman, Andrew; Gelfand, Jeffrey A.; Wortis, Henry H.; Vannier, Edouard

2006-01-01

125

On the moral acceptability of killing animals  

Microsoft Academic Search

According to a “rights view” it is acceptable to kill animals if they are innocent threats or shields or are in a “lifeboat situation.” However, according to advocates of such a view, our practices of killing animals for food or scientific research may be morally unacceptable. In this paper we argue that, even if we grant the basic assumptions of

Hugh Lehman

1988-01-01

126

Children killed by genetic parents versus stepparents  

Microsoft Academic Search

Despite many empirical studies of children killed by parents, there has been little theoretical progress. An examination of 378 cases in a national register revealed that circumstances differed for genetic parents versus stepparents. Infants were at greatest risk of filicide, especially by genetic mothers. Genetic mothers who killed offspring, especially older children, disproportionately had a mental illness and received relatively

Grant T. Harris; N. Zoe Hilton; Marnie E. Rice; Angela W. Eke

2007-01-01

127

Time-kill studies of tea tree oils on clinical isolates.  

PubMed

Tea tree oil has recently emerged as an effective topical antimicrobial agent active against a wide range of organisms. Tea tree oil may have a clinical application in both the hospital and community, especially for clearance of methicillin-resistant Staphylococcus aureus (MRSA) carriage or as a hand disinfectant to prevent cross-infection with Gram-positive and Gramnegative epidemic organisms. Our study, based on the time-kill approach, determined the kill rate of tea tree oil against several multidrug-resistant organisms, including MRSA, glycopeptide-resistant enterococci, aminoglycoside-resistant klebsiellae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia, and also against sensitive microorganisms. The study was performed with two chemically different tea tree oils. One was a standard oil and the other was Clone 88 extracted from a specially bred tree, which has been selected and bred for increased activity and decreased skin irritation. Our results confirm that the cloned oil had increased antimicrobial activity when compared with the standard oil. Most results indicated that the susceptibility pattern and Gram reaction of the organism did not influence the kill rate. A rapid killing time (less than 60 min) was achieved with both tea tree oils with most isolates, but MRSA was killed more slowly than other organisms. PMID:10797086

May, J; Chan, C H; King, A; Williams, L; French, G L

2000-05-01

128

Effect of glucocorticosteroids on the phagocytosis and intracellular killing by peritoneal macrophages.  

PubMed Central

The effect of hydrocortisone on the phagocytosis and intracellular killing by mouse peritoneal macrophages in vitro was studied by a method making it possible to measure these processes separately. The results showed that in vivo treatment with 15 mg of hydrocortisone acetate did not significantly decrease the phagocytosis of several bacterial species such as Staphylococcus albus, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The killing indexes of normal macrophages for the various microorganisms were found to be significantly different. This may indicate that the bactericidal mechanisms are not uniform for these bacteria. The effect of hydrocortisone on the intracellular killing was also variable. For Staphylococcus albus a normal killing index was found. For the other species of bacterial and for Candida albicans some decrease was found, but this was only significant for Salmonella typhimurium. It is concluded that a decrease host resistance due to glucocorticosterioid treatment is not caused by a direct effect of these drugs on the phagocytosis and intracellular killing by mononuclear phagocytes.

Zwet, T L; Thompson, J; Furth, R

1975-01-01

129

Novel drugs from marine microorganisms.  

PubMed

Marine microorganisms have expected mounting consideration on the basis of bioactive metabolites and propose an exclusive prospect to both enhance the amount of aquatic natural foodstuffs in clinical trials as well as speed up their progress. This review focuses particularly on those molecules, originated from marine microorganisms, presently in the medical pipeline that have been recognized or highly expected to be identified based on growing incidental evidence. Particularly karlotoxin class compounds, isolated from dinoflagellate Karlodinium veneficum, offer chances to create new molecules for control of cancer and high serum cholesterol levels. PMID:21599497

Javed, Faraza; Qadir, M Imran; Janbaz, Khalid Hussain; Ali, Muhammad

2011-08-01

130

PCB breakdown by anaerobic microorganisms  

SciTech Connect

Recently, altered PCB cogener distribution patterns observed in anaerobic sediment samples from the upper Hudson River are being attributed to biologically mediated reductive dechlorination. The authors report their successful demonstration of biologically mediated reductive dechlorination of an Aroclor mixture. In their investigation, they assessed the ability of microorganisms from PCB-contaminated Hudson River sediments (60-562 ppm PCBs) to dechlorinate Aroclor 1242 under anaerobic conditions by eluting microorganisms from the PCB- contaminated sediments and transferring them to a slurry of reduced anaerobic mineral medium and PCB-free sediments in tightly stoppered bottles. They observed dechlorination to be the most rapid at the highest PCB concentration tried by them.

Not Available

1989-03-01

131

Momentum kill procedure can quickly control blowouts  

SciTech Connect

The momentum kill method can help in quickly regaining control of a blowing well, providing the blowing well rate and fluid properties can be estimated reasonably. The momentum of the kill fluid counteracts and overcomes the flowing momentum of formation fluids. In other words, sufficient mud density pumped at a sufficient rate is directed into the flow stream to force the escaping fluid column back into the well bore. Sufficient kill fluid hydrostatic pressure must be stacked'' in the hole so that the well remains dead after the operation. The momentum kill is not a panacea for all blowouts. An assessment must be made of the potential problems unique to this method, and certain requirements must be met if the technique is to be successful. The paper discusses some of the considerations for evaluating the use of the momentum kill method.

Watson, W.D. (Southern International Inc., Oklahoma City, OK (United States)); Moore, P. (Preston L. Moore and Associates Inc., Norman, OK (United States))

1993-08-30

132

Killing cells by targeting mitosis  

PubMed Central

Cell cycle deregulation is a common feature of human cancer. Tumor cells accumulate mutations that result in unscheduled proliferation, genomic instability and chromosomal instability. Several therapeutic strategies have been proposed for targeting the cell division cycle in cancer. Whereas inhibiting the initial phases of the cell cycle is likely to generate viable quiescent cells, targeting mitosis offers several possibilities for killing cancer cells. Microtubule poisons have proved efficacy in the clinic against a broad range of malignancies, and novel targeted strategies are now evaluating the inhibition of critical activities, such as cyclin-dependent kinase 1, Aurora or Polo kinases or spindle kinesins. Abrogation of the mitotic checkpoint or targeting the energetic or proteotoxic stress of aneuploid or chromosomally instable cells may also provide further benefits by inducing lethal levels of instability. Although cancer cells may display different responses to these treatments, recent data suggest that targeting mitotic exit by inhibiting the anaphase-promoting complex generates metaphase cells that invariably die in mitosis. As the efficacy of cell–cycle targeting approaches has been limited so far, further understanding of the molecular pathways modulating mitotic cell death will be required to move forward these new proposals to the clinic.

Manchado, E; Guillamot, M; Malumbres, M

2012-01-01

133

Giant Cell Tumor of the Temporal Bone Invading into the Pterygoid Muscle through the Temporomandibular Joint  

PubMed Central

We report a case of giant cell tumor of the temporal bone invading into the pterygoid muscle through the temporomandibular joint. The patient was a 43-year-old woman who developed left ear fullness 2 years earlier with a mass in the external auditory canal. Radiologic evaluation revealed extension into the infratemporal fossa and confirmed that the tumor was invading into pterygoid muscle. A middle cranial fossa approach along with tympanoplasty was used for total resection of the tumor. Once a tumor invades into muscle tissue, meticulous care is required to remove it because identification of tumor tissue becomes extremely difficult.

Mohamed, Aboshanif; Ishikawa, Kazuo; Omi, Eigo; Honda, Kohei; Suzuki, Shinsuke; Sato, Teruyuki; Fukui, Naoko; Takahasi, Masataka

2014-01-01

134

Intergenomic Arms Races: Detection of a Nuclear Rescue Gene of Male-Killing in a Ladybird  

PubMed Central

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 ?-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 reported case of a nuclear suppressor of male-killing in a ladybird. They are considered in regard to sex ratio and intra-genomic conflict theories, and models of the evolutionary dynamics and distribution of inherited symbionts.

Majerus, Tamsin M. O.

2010-01-01

135

Bioactive metabolites from marine microorganisms  

Microsoft Academic Search

Diverse arrays of new bioactive secondary metabolites have been isolated from marine microorganisms; and the number of publications in this area has greatly increased in recent years. In this review, the emphasis is placed on new compounds with antitumor, enzyme inhibitors, antivirus, and other bioactive metabolites from fungi, bacteria, actinomycetes, and cyanobacteria reported between 2000 and 2005. Supply is a

Xiaohong Liu; Fang Xu; Changlun Shao; Zhigang She; Yongcheng Lin; Wing Lai Chan

2008-01-01

136

Eukaryotic Microorganisms and Stone Biodeterioration  

Microsoft Academic Search

Eukaryotic microorganisms (especially green algae and fungi) can have a significant impact on the structure and appearance of stone cultural heritage. This paper reviews current knowledge on the role of eukaryotes in the biodeterioration of stone. Considerable uncertainty remains over community-level interactions and the response of lithobiontic communities to environmental change. Three inter-linked approaches to future research are proposed: (1)

Nick Cutler; Heather Viles

2010-01-01

137

Automated microorganism Sample Collection Module  

NASA Technical Reports Server (NTRS)

Modified Gelman Sampler obtains representative sample of microorganism population. Proposed Sample Collection Module is based on direct inoculation of selected solid growth media encased in a cartridge at all times except during inoculation. Cartridge can be handled with no danger of contamination to sample or operator.

Gall, L. S.; Graham, M. D.; Umbreit, W.

1969-01-01

138

Smaller Fleas: Viruses of Microorganisms  

PubMed Central

Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world's most abundant somewhat autonomous genetic entities and include the viruses of domain Bacteria (bacteriophages), the viruses of domain Archaea (archaeal viruses), the viruses of protists, the viruses of microscopic fungi such as yeasts (mycoviruses), and even the viruses of other viruses (satellite viruses). In this paper we provide an introduction to the concept of viruses of microorganisms, a.k.a., viruses of microbes. We provide broad discussion particularly of VoM diversity. VoM diversity currently spans, in total, at least three-dozen virus families. This is roughly ten families per category—bacterial, archaeal, fungal, and protist—with some virus families infecting more than one of these microorganism major taxa. Such estimations, however, will vary with further discovery and taxon assignment and also are dependent upon what forms of life one includes among microorganisms.

Hyman, Paul; Abedon, Stephen T.

2012-01-01

139

MicroOrganisms and Fermentation  

Microsoft Academic Search

IN your issue dated April 5, in a review of Jörgensen's ``Micro-Organisms and Fermentation,'' occurs the following :- ``In England, however, we are slow in applying scientific research to industrial pursuits, and though a number of brewers already use Hansen's system, it can hardly be said that it has received the attention it deserves, and chance, tradition, and blind empiricism

Frank E. Lott

1894-01-01

140

BIOCONCENTRATION OF TOXAPHENE BY MICROORGANISMS  

EPA Science Inventory

Analyses (glc) of extracts from whole cultures (medium and microorganisms) gave the same 'fingerprint' chromatogram as the control, indicating that toxaphene was not degraded even after extended periods of time. The insecticide was also added to autoclaved cultures of bacteria, f...

141

The remote sensing of microorganisms  

Microsoft Academic Search

An approach for detecting microbial life in extreme environments, including glacial ice and deep water, using autofluorescence is described. The emission spectra for a variety of microorganisms and common minerals were measured for excitation at 224 nm and it is shown that exciting autofluorescence at 224 nm provides adequate separation between mineral and microbial emission spectra to detect a single

Nathan Earl Bramall

2007-01-01

142

Airborne microorganisms from waste containers.  

PubMed

In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste. PMID:23047084

Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

2012-01-01

143

Maternal Decidual Macrophages Inhibit NK Cell Killing of Invasive Cytotrophoblasts During Human Pregnancy1  

PubMed Central

ABSTRACT Human pregnancy is an immunological paradox. Semiallogeneic (fetal) placental cells (extravillous cytotrophoblasts [CTBs]) invade the uterine lining (decidua), which contains a unique decidual natural killer (dNK) cell population, identified by the cell surface phenotype CD56bright CD16? CD3? and CD14+ CD206+ macrophages (dMac). Previous reports suggested that human dNK cells are not a threat to the fetoplacental unit because they are anergic. In contrast, here we showed that purified and exogenously stimulated dNK cells are capable killers of cellular targets, including semiallogeneic CTBs. However, dMacs in the decidual leukocyte (DL) population restrained dNK killing through a transforming growth factor beta1 (TGF-beta1)-dependent mechanism. Our findings support a new model whereby dNK cells, capable of killing CTBs, are prevented from doing so by neighboring macrophages, thus protecting the fetal cells from NK cell attack. We speculate that this mechanism would inhibit dNK cell-mediated killing, even under conditions where high levels of cytokines may stimulate dNK cells, which could pose a threat to the developing placenta.

Co, Elizabeth C.; Gormley, Matthew; Kapidzic, Mirhan; Rosen, David B.; Scott, Marvin A.; Stolp, Haley A.R.; McMaster, Michael; Lanier, Lewis L.; Barcena, Alicia; Fisher, Susan J.

2013-01-01

144

The Inhibition of Ga Cl3 on the rat bones invaded by tumor cell Walker 256  

Microsoft Academic Search

Objective To observe the inhibition of GaCl3 on the rat bones invaded by tumor cell Walker256. Metho ds We injected Walker256 into the upper one2third medial tibia of the right posterior limb and made the rat model of bone invaded by the tumor cells , and then observed X2ray , biochemical and pathological indicators . Re sult s GaCl3 inhibited

Du Heng; Cui Gang; Zhang Zengtie; Zhang Fujun; Geng Dong; Zhai Lianbang; Liu Miao

145

Interactions among invaders: community and ecosystem effects of multiple invasive species in an experimental aquatic system  

Microsoft Academic Search

With ecosystems increasingly supporting multiple invasive species, interactions among invaders could magnify or ameliorate\\u000a the undesired consequences for native communities and ecosystems. We evaluated the individual and combined effects of rusty\\u000a crayfish (Orconectes rusticus) and Chinese mystery snails [Bellamya (=Cipangopaludina) chinensis] on native snail communities (Physa, Helisoma and Lymnaea sp.) and ecosystem attributes (algal chlorophyll a and nutrient concentrations). Both invaders

Pieter T. J. Johnson; Julian D. Olden; Christopher T. Solomon; M. Jake Vander Zanden

2009-01-01

146

Early emergence and resource availability can competitively favour natives over a functionally similar invader  

Microsoft Academic Search

Invasive plant species can form dense populations across large tracts of land. Based on these observations of dominance, invaders\\u000a are often described as competitively superior, despite little direct evidence of competitive interactions with natives. The\\u000a few studies that have measured competitive interactions have tended to compare an invader to natives that are unlikely to\\u000a be strong competitors because they are

Jennifer FirnAndrew; Andrew S. MacDougall; Susanne Schmidt; Yvonne M. Buckley

2010-01-01

147

Effects of a habitat-altering invader on nesting sparrows: An ecological trap?  

Microsoft Academic Search

Many invading species impact native species through predation, parasitism or competition, while others affect natives indirectly\\u000a by restructuring their habitat. How invasive plants affect native animals, and to what extent native animals respond to changes\\u000a in their habitat and the novel selection pressures that follow, is not well known. We investigated the impacts of a habitat-altering\\u000a invader, the Atlantic cordgrass

J. Cully Nordby; Andrew N. Cohen; Steven R. Beissinger

2009-01-01

148

Fish Kills Caused by Pollution in 1975 - Sixteenth Annual Report.  

National Technical Information Service (NTIS)

The report is an analysis of pollution-caused fish kills compiled from data supplied by State officials. It includes analytical text and the following tables: major kills, historical summary, summaries by State, source, water body, kills within EPA region...

1977-01-01

149

Interaction of Herbicides and Soil Microorganisms.  

National Technical Information Service (NTIS)

The introduction of microorganisms with specific degradative capacities into the soil was shown to be a possible means of ridding the soil of contaminating chemicals. An investigation of the interactions of soil microorganisms and several groups of herbic...

1971-01-01

150

Law Enforcement Officers Killed and Assaulted, 1999.  

National Technical Information Service (NTIS)

Tables, charts, and narrative comments addressing the number of law enforcement officers killed or assaulted are presented throughout this publication. The unit of count is the victim officer, not the number of incidents or weapons employed. In tabulation...

1999-01-01

151

Is All That TV Killing You?  

MedlinePLUS

... features on this page, please enable JavaScript. Is All That TV Killing You? Study suggests more than ... premature death went up by 55 percent for all other causes, compared to people who said they ...

152

Toxicity of paraquat to microorganisms.  

PubMed Central

The biochemical response of the microorganisms Lipomyces starkeyi (Lod & Rij), Escherichia coli K-12 W3110, Bacillus subtilis 168 (Marburg) and Pseudomonas sp. strain TTO1 to the presence of growth-inhibitory concentrations of paraquat was studied. Paraquat was added to each culture at a concentration previously determined to reduce the culture growth rate by up to 50%. The changes in activity of a number of enzymes previously shown to be associated with the defense of the mammalian system against the action of paraquat were studied. While the response of E. coli was in agreement with that found in other studies of this microorganism and supports a commonly accepted mechanism for paraquat toxicity, the results obtained with L. starkeyi, B. subtilis, and Pseudomonas sp. strain TTO1 suggest that other mechanisms exist for protection against the toxicity of paraquat.

Carr, R J; Bilton, R F; Atkinson, T

1986-01-01

153

Toxicity of paraquat to microorganisms.  

PubMed

The biochemical response of the microorganisms Lipomyces starkeyi (Lod & Rij), Escherichia coli K-12 W3110, Bacillus subtilis 168 (Marburg) and Pseudomonas sp. strain TTO1 to the presence of growth-inhibitory concentrations of paraquat was studied. Paraquat was added to each culture at a concentration previously determined to reduce the culture growth rate by up to 50%. The changes in activity of a number of enzymes previously shown to be associated with the defense of the mammalian system against the action of paraquat were studied. While the response of E. coli was in agreement with that found in other studies of this microorganism and supports a commonly accepted mechanism for paraquat toxicity, the results obtained with L. starkeyi, B. subtilis, and Pseudomonas sp. strain TTO1 suggest that other mechanisms exist for protection against the toxicity of paraquat. PMID:3098166

Carr, R J; Bilton, R F; Atkinson, T

1986-11-01

154

Phosphate Biomineralization of Cambrian Microorganisms  

NASA Technical Reports Server (NTRS)

As part of a long term study of biological markers (biomarkers), we are documenting a variety of features which reflect the previous presence of living organisms. As we study meteorites and samples returned from Mars, our main clue to recognizing possible microbial material may be the presence of biomarkers rather than the organisms themselves. One class of biomarkers consists of biominerals which have either been precipitated directly by microorganisms, or whose precipitation has been influenced by the organisms. Such microbe-mediated mineral formation may include important clues to the size, shape, and environment of the microorganisms. The process of fossilization or mineralization can cause major changes in morphologies and textures of the original organisms. The study of fossilized terrestrial organisms can help provide insight into the interpretation of mineral biomarkers. This paper describes the results of investigations of microfossils in Cambrian phosphate-rich rocks (phosphorites) that were found in Khubsugul, Northern Mongolia.

McKay, David S.; Rozanov, Alexei Yu.; Hoover, Richard B.; Westall, Frances

1998-01-01

155

Selective accumulation of heavy metals by microorganisms  

Microsoft Academic Search

An investigation of the removal and recovery of urnnium from aqueous systems using microbial biomass has been described previously (Nakajima et al. 1982). To establish which microorganisms accumulate the most uranium, we extended our investigation of uranium uptake to 83 species of microorganisms, 32 bacteria, 15 yeasts, 16 fungi and 20 actinomycetes. Of these 83 species of microorganisms tested, extremely

Akira Nakajima; Takashi Sakaguchi

1986-01-01

156

Predatory Microorganisms Would Help Reclaim Water  

NASA Technical Reports Server (NTRS)

Wastewater-reclamation systems of proposed type use predatory, nonpathogenic microorganisms to consume pathogenic microorganisms. Unlike some other wastewater-reclamation systems, these systems do not require use of toxic chemicals, intense heat, or ionizing radiation (conductivity rays or ultraviolet) to destroy microorganisms.

Benjaminson, Morris A.; Lehrer, Stanley

1995-01-01

157

Inorganic materials using 'unusual' microorganisms.  

PubMed

A promising avenue of research in materials science is to follow the strategies used by Mother Nature to fabricate ornate hierarchical structures as exemplified by organisms such as diatoms, sponges and magnetotactic bacteria. Some of the strategies used in the biological world to create functional inorganic materials may well have practical implications in the world of nanomaterials. Therefore, the strive towards exploring nature's ingenious work for designing strategies to create inorganic nanomaterials in our laboratories has led to development of biological and biomimetic synthesis routes over the past decade or so. A large proportion of these relentless efforts have explored the use of those microorganisms, which are typically not known to encounter these inorganic materials in their natural environment. Therefore, one can consider these microorganisms as 'unusual' for the purpose for which they have been utilized - it is in this context that this review has been penned down. In this extensive review, we discuss the use of these 'unusual' microorganisms for deliberate biosynthesis of various nanomaterials including biominerals, metals, sulfides and oxides nanoparticles. In addition to biosynthesis approach, we have also discussed a bioleaching approach, which can provide a noble platform for room-temperature synthesis of inorganic nanomaterials using naturally available raw materials. Moreover, the unique properties and functionalities displayed by these biogenic inorganic materials have been discussed, wherever such properties have been investigated previously. Finally, towards the end of this review, we have made efforts to summarize the common outcomes of the biosynthesis process and draw conclusions, which provide a perspective on the current status of the biosynthesis research field and highlights areas where future research in this field should be directed to realize the full potential of biological routes towards nanomaterials synthesis. Furthermore, the review clearly demonstrates that the biological route to inorganic materials synthesis is not merely an addition to the existing list of synthesis routes; biological routes using 'unusual' microorganisms might in fact provide an edge over other nanomaterials synthesis routes in terms of their eco-friendliness, low energy intensiveness, and economically-viable synthesis. This review has significant importance for colloids and interface science since it underpins the synthesis of colloidal materials using 'unusual' microorganism, wherein the role of biological interfaces for controlled synthesis of technologically important nanomaterials is clearly evident. PMID:22818492

Bansal, Vipul; Bharde, Atul; Ramanathan, Rajesh; Bhargava, Suresh K

2012-11-01

158

Community impacts of anthropogenic disturbance: natural enemies exploit multiple routes in pursuit of invading herbivore hosts  

PubMed Central

Background Biological invasions provide a window on the process of community assembly. In particular, tracking natural enemy recruitment to invading hosts can reveal the relative roles of co-evolution (including local adaptation) and ecological sorting. We use molecular data to examine colonisation of northern Europe by the parasitoid Megastigmus stigmatizans following invasions of its herbivorous oak gallwasp hosts from the Balkans. Local host adaptation predicts that invading gallwasp populations will have been tracked primarily by sympatric Balkan populations of M. stigmatizans (Host Pursuit Hypothesis). Alternatively, ecological sorting allows parasitoid recruitment from geographically distinct populations with no recent experience of the invading hosts (Host Shift Hypothesis). Finally, we test for long-term persistence of parasitoids introduced via human trade of their hosts' galls (Introduction Hypothesis). Results Polymorphism diagnostic of different southern refugial regions was present in both mitochondrial and nuclear microsatellite markers, allowing us to identify the origins of northern European invaded range M. stigmatizans populations. As with their hosts, some invaded range populations showed genetic variation diagnostic of Balkan sources, supporting the Host Pursuit Hypothesis. In contrast, other invading populations had an Iberian origin, unlike their hosts in northern Europe, supporting the Host Shift Hypothesis. Finally, both British and Italian M. stigmatizans populations show signatures compatible with the Introduction Hypothesis from eastern Mediterranean sources. Conclusions These data reveal the continental scale of multi-trophic impacts of anthropogenic disturbance and highlight the fact that herbivores and their natural enemies may face very different constraints on range expansion. The ability of natural enemies to exploit ecologically-similar hosts with which they have had no historical association supports a major role for ecological sorting processes in the recent assembly of these communities. The multitude of origins of invading natural enemy populations in this study emphasises the diversity of mechanisms requiring consideration when predicting consequences of other biological invasions or biological control introductions.

2010-01-01

159

T cells kill bacteria captured by transinfection from dendritic cells and confer protection in mice.  

PubMed

Dendritic cells (DCs) phagocytose, process, and present bacterial antigens to T lymphocytes to trigger adaptive immunity. In vivo, bacteria can also be found inside T lymphocytes. However, T cells are refractory to direct bacterial infection, leaving the mechanisms by which bacteria invade T cells unclear. We show that T cells take up bacteria from infected DCs by the process of transinfection, which requires direct contact between the two cells and is enhanced by antigen recognition. Prior to transfer, bacteria localize to the immunological synapse, an intimate DC/T cell contact structure that activates T cells. Strikingly, T cells efficiently eliminate the transinfecting bacteria within the first hours after infection. Transinfected T cells produced high levels of proinflammatory cytokines and were able to protect mice from bacterial challenge following adoptive transfer. Thus, T lymphocytes can capture and kill bacteria in a manner reminiscent of innate immunity. PMID:24832455

Cruz-Adalia, Aránzazu; Ramirez-Santiago, Guillermo; Calabia-Linares, Carmen; Torres-Torresano, Mónica; Feo, Lidia; Galán-Díez, Marta; Fernández-Ruiz, Elena; Pereiro, Eva; Guttmann, Peter; Chiappi, Michele; Schneider, Gerd; Carrascosa, José López; Chichón, Francisco Javier; Martínez Del Hoyo, Gloria; Sánchez-Madrid, Francisco; Veiga, Esteban

2014-05-14

160

Novel water-based antiseptic lotion demonstrates rapid, broad-spectrum kill compared with alcohol antiseptic.  

PubMed

A novel alcohol-based antiseptic and a novel water-based antiseptic lotion, both with a synergistic combination of antimicrobial ingredients containing 0.2% benzethonium chloride, were evaluated using the standard time-kill method against 25 FDA-specified challenge microorganisms. The purpose of the testing was to determine whether a non-alcohol product could have equivalent rapid and broad-spectrum kill to a traditional alcohol sanitizer. Both the alcohol- and water-based products showed rapid and broad-spectrum antimicrobial activity. The average 15-s kill was 99.999% of the challenge organism for the alcohol-based antiseptic and 99.971% for the water-based antiseptic. The alcohol-based product demonstrated 100% of peak efficacy (60s) within the first 15s, whereas the water-based product showed 99.97%. The novel alcohol-based antiseptic reduced concentrations of 100% of organisms by 99.999%, whereas the water-based antiseptic lotion showed the same reduction for 96% of organisms. A novel water-based antiseptic product demonstrated equivalent rapid, broad-spectrum antimicrobial activity to an alcohol-based sanitizer and provided additional benefits of reduced irritation, persistent effect, and greater efficacy against common viruses. The combination of rapid, broad-spectrum immediate kill and persistent efficacy against pathogens may have significant clinical benefit in limiting the spread of disease. PMID:24810728

Czerwinski, Steven E; Cozean, Jesse; Cozean, Colette

2014-01-01

161

Biocidal activity of metalloacid-coated surfaces against multidrug-resistant microorganisms  

PubMed Central

Background The antimicrobial effects of a coating of molybdenum trioxide (MoO3) has been recently described. The metalloacid material produces oxonium ions (H3O+), which creates an acidic pH that is an effective, non specific antimicrobial. We determined the in vitro antimicrobial activity of molybdenum trioxide metalloacid-coated surfaces. Methods Metalloacid-coated and non-coated (control) surfaces were contaminated by exposing them for 15 minutes to microbial suspensions containing 105 cfu/mL. Eleven microorganisms responsible for nosocomial infections were tested: two Staphylococcus aureus strains (the hetero-vancomycin intermediate MRSA Mu50 strain and a ST80-PVL-producing MRSA strain); a vancomycin-resistant vanA Enterococcus faecium strain; three extended-spectrum beta-lactamase-producing Enterobacteriaceae strains; a MBL-producing Pseudomonas aeruginosa strain; a multidrug-resistant Acinetobacter baumannii strain; a toxin-producing Clostridium difficile strain; and two fungi (Candida albicans and Aspergillus fumigatus). The assay tested the ability of the coated surfaces to kill microorganisms. Results Against all non-sporulating microorganisms tested, metalloacid-coated surfaces exhibited significant antimicrobial activity relative to that of the control surfaces within two to six hours after contact with the microorganisms (p?Microorganism survival on the coated surfaces was greatly impaired, whereas microorganism survival on control surfaces remained substantial. Conclusions We suggest that, facing the continuing shedding of microorganisms in the vicinity of colonized or infected patients, the continuous biocidal effect of hydroxonium oxides against multidrug-resistant microorganisms may help limit environmental contamination between consecutive cleaning procedures.

2012-01-01

162

Chemically enhanced sunlight for killing bacteria  

SciTech Connect

Solar ultraviolet (UV) photocatalyzed oxidation of chemicals with titanium dioxide (TiO{sub 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 effect it. Bacteria in aqueous solution were given solar exposure with titanium dioxide and their survival with time was detected. Lamps with a predominantly solar ultraviolet spectrum were also used in the experiments. Without exposure to UV light, TiO{sub 2} does not affect the bacteria. However, several common bacteria were killed in just a few minutes on solar exposure in the presence of TiO{sub 2}. Whereas without TiO{sub 2} it took more than an hour to destroy them. A concentration of 0.01 percent TiO{sub 2} was most effective in killing bacteria and tenfold concentrations lower or higher were successively less effective. Inorganic and organic compounds in solution, even in small amounts, interfered with the efficiency of killing. An alkaline solution also reduced the bactericidal activity. Circulation and agitation provided by stirring to keep the TiO{sub 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{sub 2}. This suggests that TiO{sub 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 shows that the organisms are sensitized with a minimum intensity of radiation and that an increase doesn`t greatly increase the rate of the kill. Below this critical intensity, however, the time required for killing markedly increases as the intensity is decreased.

Block, S.S.; Seng, V.P.; Goswami, D.W. [Univ. of Florida, Gainesville, FL (United States)

1997-02-01

163

Killing of Brucella abortus by bovine serum.  

PubMed Central

Studies of the serum bactericidal system in bovine brucellosis were undertaken to investigate the role of the humoral immune response in protection of cattle against the facultative intracellular parasite Brucella abortus. Fresh sera from normal control cattle, infected cattle, and cattle immunized with B. abortus cell envelopes were collected before treatment and during the course of immunization or infection. Normal fresh bovine serum or fresh agammaglobulinemic serum from colostrum-deprived calves was effective in killing smooth virulent B. abortus 2308, but rough strains RB51 (a rough mutant of strain 2308) and 45/20 were much more sensitive to serum. The difference in susceptibility to serum was shown to be correlated with differences in lipopolysaccharide chemotype, with the more resistant strain 2308 having O polysaccharide and the more susceptible strains 45/20 and RB51 lacking O side chains. By treatment of fresh serum with MgCl2 and EGTA [ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid] killing was shown to occur via the classical pathway of complement activation. When antibody to B. abortus was present, killing of strain RB51 increased but killing of smooth strain 2308 decreased. The earliest antibody response in serum from infected animals did not interfere with killing. When affinity-purified bovine immunoglobulins specific for B. abortus smooth lipopolysaccharide were added to fresh normal bovine serum, immunoglobulin G1 (IgG1) and IgG2 isotypes blocked killing but IgM and IgA isotypes did not. Thus, it appears that serum from previously unexposed animals or animals early during infection can kill smooth B. abortus, an appropriate defense mechanism before the organism becomes intracellular. At later stages of infection, blocking antibodies predominate. Images

Corbeil, L B; Blau, K; Inzana, T J; Nielsen, K H; Jacobson, R H; Corbeil, R R; Winter, A J

1988-01-01

164

Kill fluid for oil field operations  

SciTech Connect

This patent describes a process employing a kill fluid to substantially reduce the volumetric flow of formation fluid into a wellbore penetrating a formation containing the formation fluid below an earthen surface. It comprises: admixing components of a continuous flowing gel at the surface comprising of water-soluble carboxylate-containing polymer, a complex capable of crosslinking the polymer and formed of at least one electropositive chromium III species and at least one electronegative carboxylatespecies, and an aqueous solvent for the polymer and the complex; crosslinking the polymer and the complex to form the gel, wherein the kill fluid comprises the gel; placing a volume of the kill fluid in the wellbore sufficient to create a hydrostatic head which exerts a kill fluid pressure against the formation fluid substantially equal to or greater than the formation fluid pressure and thereby substantially reduces the volumetric flow of the formation fluid into the wellbore; performing an oil field operation after placing the volume of the kill fluid in the wellbore; and removing the gel from the wellbore to substantially restore the volumetric flow of the formation fluid into the wellbore.

Sydansk, R.D.

1990-08-14

165

Metastatic Breast Cancer Cells Collectively Invade Collagen by Following a Glucose Gradient  

NASA Astrophysics Data System (ADS)

We show that MDA-MB-231 metastatic breast cancer cells collectively invade a three dimensional collagen matrix by following a glucose gradient. We observe that due to the 3D physical deformation of the matrix, as measured by the displacement of reporter beads within the matrix, there exists a long range deformation mechanical field inside the matrix which serves to couple the motions of the invading metastatic cell. The invasion front of the cells is a dynamic one, with different cells assuming the lead on a time scale of 24 hours due to certain cells having higher speeds of penetration, which are not sustained. The front cell leadership is dynamic presumably due to metabolic costs associated with the long range strain field which proceeds the invading cell front, which we have imaged using confocal imaging and marker beads imbedded in the collagen matrix.

Sun, Bo; Austin, Robert; Liu, Liyu; Duclos, Guillaume; Lee, Jeongseog; Wu, Amy; Kam, Yooseok; Sontag, Eduardo; Stone, Howard; Sturm, James; Gatenby, Robert

2013-03-01

166

Extracellular killing of inhaled pneumococci in rats  

SciTech Connect

Early clearance of inhaled Staphylococcus aureus is believed to be caused by phagocytosis by alveolar macrophages. In murine models inhaled pneumococci are cleared even more rapidly than S. aureus. Conventional opsonins appear to play no role in this clearance, and recently it has been shown that murine alveolar lining material contains free fatty acids and other soluble factors that are directly bactericidal for pneumococci. To determine whether non-phagocytic factors are involved in pneumococcal clearance, we compared the site of killing of inhaled pneumococci and S. aureus in rats using histologic methods and bronchoalveolar lavage. Spontaneous lysis of pneumococci was prevented by use of autolysin-defective pneumococci or by substitution of ethanolamine for choline in the cell wall. Histologic studies showed that the percent of inhaled staphylococci associated with alveolar macrophages always exceeded the percent of staphylococci cleared, whereas there was little association of pneumococci with macrophages during clearance. Analysis of the intracellular or extracellular location of iron 59 in bronchoalveolar lavage fluid of rats that had inhaled aerosols of /sup 59/Fe-labeled bacteria suggested that staphylococci were killed predominantly in macrophages and pneumococci in the extracellular space. When /sup 59/Fe-labeled pneumococci or staphylococci were ingested and killed by macrophages in vitro, the /sup 59/Fe remained with the macrophages, suggesting that the extracellular location of /sup 59/Fe during pneumococcal killing in vivo was not caused by rapid turnover of /sup 59/Fe in macrophages. Studies of the site of killing of inhaled type 25 pneumococci labeled exclusively in the cell wall with carbon 14-ethanolamine confirmed the results obtained with /sup 59/Fe-labeled pneumococci. Thus, early killing of inhaled pneumococci, unlike staphylococci, appears to take place outside of macrophages.

Coonrod, J.D.; Marple, S.; Holmes, G.P.; Rehm, S.R.

1987-12-01

167

Utilization of high temperature compost in space agriculture: the model compost kills Escherichia coli  

NASA Astrophysics Data System (ADS)

The author and his colleagues have proposed the use of high temperature composting in space inhabitation. Composting has many advantages over burning in organic waste treatments. Composting is self-heating processes and needs no extra fuel. Composting requires no sophis-ticated equipment such as an incinerator. Composting emits no hazardous gases such as NOx, SOx and dioxines which are often produced by burning. The final product can be used as fer-tilizer in space farm land; resources recycling society can be constructed in space stations and space cities. In addition to these advantages, composting and compost soil may contribute to the environmental cleanup. During composting processes, harmful compounds to agricultural plants and animals can be destroyed. Seeds of weeds can be killed by high heat. Likewise pathogenic microbes in the waste can be eliminated during fermentation inside the composts. Recently we measured the survivability of E. coli in compost. E. coli was used as the represen-tative of the Gram-negative bacteria. Since many pathogenic strains belong to Gram-negative bacteria and Gram-negative bacteria are more resistant to antibiotics than gram-positive bac-teria. When E. coli cells were mixed in the compost pile of which inside temperature reaches up to 75oC, they died within a short period as expected. However, E. coli DNA was detected even after a day in high temperature compost. RNA has a shorter life-span than DNA, but was detected after incubation in compost for several hours. In addition to sterilizing effects due to high temperature, we found our compost soil has E. coli killing activity. When mixed with the compost soil at room temperature, E. coli died gradually. Extract of the compost soil also killed E. coli at room temperature, but it took a few days to eliminate E. coli completely. During the killing process, total number of living bacteria did not change, indicating that the killing activity is limited to some specific microorganisms. These findings suggest that the compost can be used to eliminate some of deleterious microbes from the environment without damages to the beneficial microbes. We are planning to test the killing activity of the com-post soil against more dangerous microorganisms such as Salmonella species, especially those pathogenic to barn animals.

Oshima, Tairo; Moriya, Toshiyuki; Yoshii, Takahiro

168

Internet Resources on Genocide and Mass Killings  

NSDL National Science Digital Library

Internet Resources on Genocide and Mass Killings is an extensive compilation of primary materials and annotated links related to "twentieth-century genocidal and mass man-made killing occurrences." Divided into fifteen sections, subject coverage includes topics such as The Jewish Holocaust, War Crimes and Criminals, Yugoslavia and Kosovo, among others. Most of the original documents in the compilation have been uploaded to the site, facilitating navigation and research. Documents not residing at the site are linked via succinct annotations. The compilation is searchable and updated continuously by its creator Dr. Stuart D. Stein, Senior Lecturer in Sociology and Social Psychology at the University of West England.

169

Plasmodium falciparum Is Able To Invade Erythrocytes through a Trypsin-Resistant Pathway Independent of Glycophorin B  

Microsoft Academic Search

Plasmodium falciparum invades erythrocytes through multiple ligand-receptor interactions, with redundan- cies in each pathway. One such alternate pathway is the trypsin-resistant pathway that enables P. falciparum to invade trypsin-treated erythrocytes. Previous studies have shown that this trypsin-resistant pathway is dependent on glycophorin B, as P. falciparum strains invade trypsin-digested glycophorin B-deficient erythro- cytes at a highly reduced efficiency. Furthermore, in

Deepak Gaur; Jill R. Storry; Marion E. Reid; John W. Barnwell; Louis H. Miller

2003-01-01

170

Mothers who killed or attempted to kill their child: life circumstances, childhood abuse, and types of killing.  

PubMed

The objectives of the present study were to examine the life circumstances, childhood abuse, and types of homicidal acts of 48 mothers who killed/attempted to kill their child(ren) under age 12 between 1970-96 in Finland. Data on the mothers'life stresses, psychological problems, and childhood abuse were collected from mental state examination (MSE) reports. The cases were divided into 15 neonaticides and 33 mothers who killed an older child. Childhood abuse was documented in 63% of the mothers' MSE reports. Qualitative analysis identified neonaticides,joint homicide-suicide attempts, impulsive aggression, psychotic acts, postpartum depression, and abusive acts. Nonlinear principal components analysis showed that different variables were related to the neonaticide and non-neonaticide cases. We concluded that despite differences in the psychosocial profiles of neonaticides and other maternal homicidal acts the cycle of violence perspective can be applied to both cases, even though it may not be a sufficient explanation for maternal child killings. PMID:10606431

Haapasalo, J; Petäjä, S

1999-01-01

171

Fish invading dinoflagellates: a synopsis of existing and newly proposed genera.  

PubMed

Th paper reviews the dinoflagellate general invading marine and freshwater fishes, presents their diagnostic features, points out the difference from tunicate-invading genus Oodinium Chatton, 1912 and comments on their pathogenicity. The genus Crepidoodinium Lom and Lawler g.n. is proposed for Oodinium cyprinodontum Lawler, 1967 from marine cyprinodontids, and Piscinoodinium g.n. is proposed to accommodate freshwater Oodinium pillularis Schäperclaus, 1954 and O. limneticum Jacobs, 1964. The most important diagnostic character is the structure of the attachment organelle which is depicted along with some other morphological features. PMID:7194841

Lom, J

1981-01-01

172

The remote sensing of microorganisms  

NASA Astrophysics Data System (ADS)

An approach for detecting microbial life in extreme environments, including glacial ice and deep water, using autofluorescence is described. The emission spectra for a variety of microorganisms and common minerals were measured for excitation at 224 nm and it is shown that exciting autofluorescence at 224 nm provides adequate separation between mineral and microbial emission spectra to detect a single microorganism in the glacial ice of Antarctica or on mineral surfaces. The different generations of borehole-logging instruments, dubbed 'biospectral loggers' (BSLs), were designed, built and deployed. The first BSL is a prototype that uses ˜375 nm excitation from UV LEDS and was deployed in the ˜1,000 m deep Siple Dome borehole (January, 2002) and in oligotrophic Lake Tahoe (October, 2002), where microbial NADH, chlorophyll, and dissolved organic matter (DOM) fluorescence was measured. The fluorescence red-shifted with depth, suggesting an increase in of terrestrially-derived DOM with depth, perhaps indicating a benthic source and little recent vertical mixing. The second BSL uses a similar optical geometry as the first, but employs a 224 nm HeAg laser to excite protein fluorescence and was deployed at the SPRESO borehole at the South Pole (January; 2004). It recorded a strong microbial signal corresponding to the time period spanning 1,200 B.P. and 900 B.P., which roughly correlates with major desiccation events in both Patagonia and the Antarctic Dry Valleys, suggesting they may have been aeolian sources of aquatic microorganisms for the South Pole. The third BSL, dubbed the mini-BSL, also uses a 224 nm laser for excitation of protein fluorescence, but its novel optical layout enabled its diameter to be reduced to less than 5.1 cm, allowing it to operate in a borehole produced by a modified JPL 'Gopher' drill[16]. High sensitivity was not sacrificed in the miniaturization process as the mBSL is capable of detecting a single B. megatcrium on a background of iron-rich biotite with a single 100 mus laser pulse. Data demonstrating its sensitivity and other optical parameters are presented and discussed. Suggestions for future upgrades and deployments conclude the dissertation.

Bramall, Nathan Earl

173

How to Make a Killing Jar  

NSDL National Science Digital Library

This Biodiversity Counts illustration shows students how to make a simple killing jar to preserve arthropods for further study. As the labeled drawing shows, all that's needed is a jar with a lid, tape for reinforcement, a few drops of ethyl acetate, and a paper towel.

174

Can Vet Schools Teach without Killing Animals?  

ERIC Educational Resources Information Center

Discusses a protest by students at the University of Illinois (Urbana) College of Veterinary Medicine over the killing of animals that led to temporary curtailing of lethal animal experiments. Examines the conflict between animal rights groups and some faculty who are openly skeptical about the effectiveness of alternatives to the hands-on…

Mangan, Katherine S.

2000-01-01

175

Law Enforcement Officers Killed and Assaulted, 2000.  

National Technical Information Service (NTIS)

This publication presents tables, charts, and narrative comments addressing the number of law enforcement officers killed and assaulted in the line of duty. The unit of count is the victim officer, not the number of incidents nor weapons employed. In tabu...

2001-01-01

176

Red Tide Kills Fish, Fouls Gulf Coast  

NSDL National Science Digital Library

This CBS news article reports a toxic algae bloom that spread along the Texas Gulf coast in 2000, killing millions of fish and fouling beaches with their remains. The article explains how red tide affects fish and describes health threats to humans.

News, Cbs

177

Mass killings and detection of impacts  

NASA Technical Reports Server (NTRS)

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.

Mclaren, Digby J.

1988-01-01

178

Killing Hitler: A Writer's Journey and Angst.  

ERIC Educational Resources Information Center

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)

Thaler, Paul

2002-01-01

179

Active Motion of Brownian Microorganisms  

NASA Astrophysics Data System (ADS)

Recently, Schweitzer, Ebeling and Tilch (SET) introduced a model for the motion of Brownian objects with internal energy depots [F. Schweitzer, W. Ebeling and B. Tilch, Phys. Rev. Lett. 80, 5044 (1998)]. This model can help us to investigate the strategies used by microorganisms to optimize the transformation of nutrient energy into mechanical energy. SET used a Langevin formalism to analyze the effects related to the depot presence. We have derived a Fokker-Planck equation that describes the depot action, obtaining an analytical form for the steady-state moment distribution, and used simulations to obtain time-dependent results. We examine the properties of the mean square speed and of the displacement moments, finding that noise can increase the mechanical efficiency.

Condat, Carlos A.; Sibona, Gustavo J.

2000-03-01

180

Life History Variation in Invading Applesnails (Pomacea canaliculata) May Pose Ecological Threats to Wetlands  

Microsoft Academic Search

In native habitats, channeled applesnails (Pomacea canaliculata) graze periphyton. However, casual observations from introduced populations suggest these invaders show variation in feeding ecology, predator response and life history strategies. Attempts to predict this consumer influence on ecosystem function suffer from a lack of basic data. We tested how salinity affected snail mortality. Both adults and hatchlings tolerated salinity levels up

R. K. Marfurt; B. B. Boland; R. L. Burks

2005-01-01

181

The evolutionary life history of P transposons: from horizontal invaders to domesticated neogenes  

Microsoft Academic Search

P elements, a family of DNA transposons, are known as aggressive intruders into the hitherto uninfected gene pool of Drosophila melanogaster. Invading through horizontal transmission from an external source they managed to spread rapidly through natural populations within a few decades. Owing to their propensity for rapid propagation within genomes as well as within populations, they are considered as the

Wilhelm Pinsker; Elisabeth Haring; Sylvia Hagemann; Wolfgang J. Miller

2001-01-01

182

Impact: Toward a Framework for Understanding the Ecological Effects of Invaders  

Microsoft Academic Search

Although ecologists commonly talk about the impacts of nonindigenous species, little formal attention has been given to defining what we mean by impact, or connecting ecological theory with particular measures of impact. The resulting lack of generalizations regarding invasion impacts is more than an academic problem; we need to be able to distinguish invaders with minor effects from those with

I. M. Parker; D. Simberloff; W. M. Lonsdale; K. Goodell; M. Wonham; P. M. Kareiva; M. H. Williamson; B. Von Holle; P. B. Moyle; J. E. Byers; L. Goldwasser

1999-01-01

183

Impact: toward a framework for understanding the ecological effects of invaders  

Microsoft Academic Search

Although ecologists commonly talk about the impacts of nonindigenous species, little formal attention has been given to defining what we mean by impact, or connecting ecological theory with particular measures of impact. The resulting lack of generalizations regarding invasion impacts is more than an academic problem; we need to be able to distinguish invaders with minor effects from those with

I. M. Parker; D. Simberloff; W. M. Lonsdale; K. Goodell; M. Wonham; P. M. Kareiva; M. H. Williamson; B. Von Holle; P. B. Moyle; J. E. Byers; L. Goldwasser

1999-01-01

184

From the Cover: Action potentials reliably invade axonal arbors of rat neocortical neurons  

Microsoft Academic Search

Neocortical pyramidal neurons have extensive axonal arborizations that make thousands of synapses. Action potentials can invade these arbors and cause calcium influx that is required for neurotransmitter release and excitation of postsynaptic targets. Thus, the regulation of action potential invasion in axonal branches might shape the spread of excitation in cortical neural networks. To measure the reliability and extent of

Charles L. Cox; Winfried Denk; David W. Tank; Karel Svoboda

2000-01-01

185

Management process invaded Ames as the Center shifted from NACA to NASA oversight. Ames constructed  

NASA Technical Reports Server (NTRS)

Management process invaded Ames as the Center shifted from NACA to NASA oversight. Ames constructed a review room in its headquarters building where, in the graphical style that prevailed in the 1960's, Ames leadership could review progress against schedule, budget and performance measures. Shown, in October 1965 is Merrill Mead chief of Ames' program and resources office. (for H Julian Allen Retirement album)

1968-01-01

186

Inefficient Complement System Clearance of Trypanosoma cruzi Metacyclic Trypomastigotes Enables Resistant Strains to Invade Eukaryotic Cells  

Microsoft Academic Search

The complement system is the main arm of the vertebrate innate immune system against pathogen infection. For the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, subverting the complement system and invading the host cells is crucial to succeed in infection. However, little attention has focused on whether the complement system can effectively control T. cruzi infection. To address

Igor Cestari; Marcel I. Ramirez; Anne Charlotte Gruner

2010-01-01

187

Fire and grazing in a shrub-invaded arid grassland community: independent or interactive ecological effects?  

Microsoft Academic Search

This study examined the response of summer and winter annuals and perennials in a shrub-invaded arid plant community to combinations of fire and grazing by cattle to determine their effects on individual abundances, species richness and diversity. Thirteen species differed significantly in abundance across the burn treatment while nine differed significantly across the grazing treatment. Summer and winter annual plants

Thomas J. Valone; Douglas A. Kelt

1999-01-01

188

Support and Opposition for Invading Iraq: Did the President's Speech Make a Difference?  

Microsoft Academic Search

Utilizing data from the annual San Antonio Survey, this research addresses the issue of support and opposition to invading Iraq among respondents randomly selected from Bexar County, Texas. Data were collected prior to and after President Bush addressed the nation on October 7, 2002, seeking broad citizen support for his plan, allowing us to ascertain whether or not his speech

Juanita M. Firestone; Richard J. Harris

2006-01-01

189

Community impacts of anthropogenic disturbance: natural enemies exploit multiple routes in pursuit of invading herbivore hosts  

Microsoft Academic Search

BACKGROUND: Biological invasions provide a window on the process of community assembly. In particular, tracking natural enemy recruitment to invading hosts can reveal the relative roles of co-evolution (including local adaptation) and ecological sorting. We use molecular data to examine colonisation of northern Europe by the parasitoid Megastigmus stigmatizans following invasions of its herbivorous oak gallwasp hosts from the Balkans.

James A Nicholls; Pablo Fuentes-Utrilla; Alexander Hayward; George Melika; György Csóka; José-Luis Nieves-Aldrey; Juli Pujade-Villar; Majid Tavakoli; Karsten Schönrogge; Graham N Stone

2010-01-01

190

Temporally variable dispersal and demography can accelerate the spread of invading species  

Microsoft Academic Search

We analyze how temporal variability in local demography and dispersal combine to affect the rate of spread of an invading species. Our model combines state-structured local demography (specified by an integral or matrix projection model) with general dispersal distributions that may depend on the state of the individual or its parent, and it allows very general patterns of stationary temporal

Stephen P. Ellner; Sebastian J. Schreiber

2011-01-01

191

Dispersal and demography contributions to population spread of Carduus nutans in its native and invaded ranges  

Microsoft Academic Search

Summary 1. Invasive species usually exhibit different spatial population dynamics in their native and invaded range. This is often attributed to demographic differences, but may be due to differences in dispersal as well. 2. Regardless of how these dispersal and demographic differences from the native range arose, studying how they contributed to increases in population spread rates will increase our

Eelke Jongejans; Katriona Shea; Olav Skarpaas; Dave Kelly; Andy W. Sheppard; Tim L. Woodburn

2008-01-01

192

Wadden Sea mussel beds invaded by oysters and slipper limpets: competition or climate control?  

NASA Astrophysics Data System (ADS)

Introduced species are often considered to be a threat to residents, but not all reciprocal trends may reflect species interaction. In the northern German Wadden Sea, native mussel Mytilus edulis beds are declining and overgrown by introduced Pacific oysters Crassostrea gigas and slipper limpets Crepidula fornicata. We review the population development of the three species and analyse whether the invading species may be responsible for the decline of native mussels. The Pacific oyster predominately settles on mussel beds in the intertidal and the slipper limpet dominates around low water line. We compare the development of mussels and invaders in two subregions: mussel beds near the islands of Sylt and Amrum decreased both in the presence (Sylt) and absence (Amrum) of the two invading species and more detailed investigations could not confirm a causal relationship between the increasing invaders and decreasing mussel beds. There is evidence that the decline of mussel beds is mainly caused by failing spatfall possibly due to mild winters, whereas the increase in slipper limpets and oysters is facilitated by mild winters and warm summers, respectively. We conclude that changing species composition is a result of the climatic conditions in the last decade and that there is no evidence yet that the exotic species caused the decline of the natives. It remains an open question whether the species shift will continue and what the consequences for the native ecosystem will be.

Nehls, Georg; Diederich, Susanne; Thieltges, David W.; Strasser, Matthias

2006-05-01

193

Microorganisms detected by enzyme-catalyzed reaction  

NASA Technical Reports Server (NTRS)

Enzymes detect the presence of microorganisms in soils. The enzyme lysozymi is used to release the enzyme catalase from the microorganisms in a soil sample. The catalase catalyzes the decomposition of added hydrogen peroxide to produce oxygen which is detected manometrically. The partial pressure of the oxygen serves as an index of the samples bacteria content.

Vango, S. P.; Weetall, H. H.; Weliky, N.

1966-01-01

194

Functional Microorganisms for Functional Food Quality  

Microsoft Academic Search

Functional microorganisms and health benefits represent a binomial with great potential for fermented functional foods. The health benefits of fermented functional foods are expressed either directly through the interactions of ingested live microorganisms with the host (probiotic effect) or indirectly as the result of the ingestion of microbial metabolites synthesized during fermentation (biogenic effect). Since the importance of high viability

M. Gobbetti; R. Di Cagno; M. De Angelis

2010-01-01

195

The role of microorganisms in aquaculture ponds  

Microsoft Academic Search

Microorganisms have major roles in pond culture, particularly with respect to productivity, nutrient cycling, the nutrition of the cultured animals, water quality, disease control and environmental impact of the effluent. Management of the activities of microorganisms in food webs and nutrient cycling in ponds is necessary for optimising production, but the objectives will differ with the type of aquaculture, the

David J. W. Moriarty

1997-01-01

196

Antimicrobial Activity of Propolis on Oral Microorganisms  

Microsoft Academic Search

.   Formation of dental caries is caused by the colonization and accumulation of oral microorganisms and extracellular polysaccharides\\u000a that are synthesized from sucrose by glucosyltransferase of Streptococcus mutans. The production of glucosyltransferase from oral microorganisms was attempted, and it was found that Streptococcus mutans produced highest activity of the enzyme. Ethanolic extracts of propolis (EEP) were examined whether EEP inhibit

Yong K. Park; Michel H. Koo; José A. S. Abreu; Masaharu Ikegaki; Jaime A. Cury; Pedro L. Rosalen

1998-01-01

197

Biotechnological applications and potentialities of halophilic microorganisms  

Microsoft Academic Search

Halophilic microorganisms are found as normal inhabitants of highly saline environments and thus are considered extremophiles. They are mainly represented, but not exclusively, by the halobacteria (extremely halophilic aerobic Archaea), the moderate halophiles (Bacteria and some methanogens) and several eukaryotic algae. These extremophilic microorganisms are already used for some biotechnological processes, for example halobacteria are used for the production of

A. Ventosa; J. J. Nieto

1995-01-01

198

Impacts of plant invaders and management techniques on native communities : ecological and social perspectives at regional and global levels  

Microsoft Academic Search

Plant invasions of natural communities threaten biodiversity and ecosystem processes across many biomes and trophic levels. Understanding and managing invader impacts are therefore significant steps in achieving conservation. Both causes and management of invasion are dependent on human behaviour and ecologists must consider this human dimension in developing management protocols. While control of invaders is routine in many conservation reserves,

Tanya J Mason

2006-01-01

199

The visualisation and speed of kill of wound isolates on a silver alginate dressing.  

PubMed

In chronic wound management, alginate dressings are used to absorb exudate and reduce the microbial burden. Silver alginate offers the added benefit of an additional antimicrobial pressure on contaminating microorganisms. This present study compares the antimicrobial activity of a RESTORE silver alginate dressing with a silver-free control dressing using a combination of in vitro culture and imaging techniques. The wound pathogens examined included Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, ?-haemolytic Streptococcus, and strictly anaerobic bacteria. The antimicrobial efficacy of the dressings was assessed using log(10) reduction and 13-day corrected zone of inhibition (CZOI) time-course assays. Confocal laser scanning microscopy (CLSM) was used to visualise the relative proportions of live/dead microorganisms sequestered into the dressings over 24 hours and estimate the comparative speed of kill. The RESTORE silver alginate dressing showed significantly greater log(10) reductions and CZOIs for all microorganisms compared with the control, indicating the antimicrobial effect of ionic silver. Antimicrobial activity was evident against all test organisms for up to 5 days and, in some cases, up to 12 days following an on-going microbial challenge. Imaging bacteria sequestered in the silver-free dressing showed that each microbial species aggregated in the dressing and remained viable for more than 20 hours. Growth was not observed inside of the dressing, indicating a possible microbiostatic effect of the alginate fibres. In comparison, organisms in the RESTORE silver alginate dressing were seen to lose viability at a considerably greater rate. After 16 hours of contact with the RESTORE silver alginate dressing, >90% of cells of all bacteria and yeast were no longer viable. In conclusion, collectively, the data highlights the rapid speed of kill and antimicrobial suitability of this RESTORE silver alginate dressing on wound isolates and highlights its overwhelming ability to manage a microbial wound bioburden in the management of infected wounds. PMID:22405034

Hooper, Samuel J; Percival, Steven L; Hill, Katja E; Thomas, David W; Hayes, A J; Williams, David W

2012-12-01

200

GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GOETHALS BRIDGE FROM NORTH SIDE OVER ARTHUR KILL. RAILROAD BRIDGE IN FOREGROUND - Goethals Bridge, Spanning Arthur Kill from New Jersey to Staten Island, Staten Island (subdivision), Richmond County, NY

201

Systems biology of industrial microorganisms.  

PubMed

The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production. PMID:20503029

Papini, Marta; Salazar, Margarita; Nielsen, Jens

2010-01-01

202

Systems Biology of Industrial Microorganisms  

NASA Astrophysics Data System (ADS)

The field of industrial biotechnology is expanding rapidly as the chemical industry is looking towards more sustainable production of chemicals that can be used as fuels or building blocks for production of solvents and materials. In connection with the development of sustainable bioprocesses, it is a major challenge to design and develop efficient cell factories that can ensure cost efficient conversion of the raw material into the chemical of interest. This is achieved through metabolic engineering, where the metabolism of the cell factory is engineered such that there is an efficient conversion of sugars, the typical raw materials in the fermentation industry, into the desired product. However, engineering of cellular metabolism is often challenging due to the complex regulation that has evolved in connection with adaptation of the different microorganisms to their ecological niches. In order to map these regulatory structures and further de-regulate them, as well as identify ingenious metabolic engineering strategies that full-fill mass balance constraints, tools from systems biology can be applied. This involves both high-throughput analysis tools like transcriptome, proteome and metabolome analysis, as well as the use of mathematical modeling to simulate the phenotypes resulting from the different metabolic engineering strategies. It is in fact expected that systems biology may substantially improve the process of cell factory development, and we therefore propose the term Industrial Systems Biology for how systems biology will enhance the development of industrial biotechnology for sustainable chemical production.

Papini, Marta; Salazar, Margarita; Nielsen, Jens

203

Lantibiotic production by pathogenic microorganisms.  

PubMed

Lantibiotics are ribosomally synthesised, post-translationally modified antimicrobial peptides produced by Gram positive bacteria, many which have broad-ranging antimicrobial activities. Lantibiotics have long been the subject of investigation with a view to their application as food preservatives or chemotherapeutic agents for clinical and veterinary medicine, while the associated biosynthetic machinery has been employed for peptide engineering purposes. However, although many lantibiotics are produced by generally regarded as safe or food-grade bacteria, it is increasingly apparent that a number of Gram positive pathogens, including strains of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus mutans, Streptococcus uberis and Enterococcus faecalis, also produce these compounds. It is proposed that production of these antimicrobials may provide the associated microorganisms with a competitive advantage when colonizing/infecting a host, thereby enhancing the virulence of the producing strain. Here we review the production of lantibiotics by these pathogens and discuss how their production may contribute to their disease-causing potential. PMID:22708496

Daly, Karen M; Cotter, Paul D; Hill, Colin; Ross, R Paul

2012-09-01

204

Monoclonal antibody targets, kills leukemia cells  

Cancer.gov

Researchers at the University of California, San Diego Moores Cancer Center have identified a humanized monoclonal antibody that targets and directly kills chronic lymphocytic leukemia (CLL) cells. The findings, published in the online Early Edition of the Proceedings of the National Academy of Sciences on March 25, 2013 represent a potential new therapy for treating at least some patients with CLL, the most common type of blood cancer in the United States.

205

Cytotoxic Killing and Immune Evasion by Repair  

Microsoft Academic Search

The interaction between the immune system and pathogens is a complex one, with pathogens constantly developing new ways of\\u000a evading destruction by the immune system. The immune system's task is made even harder when the pathogen in question is an\\u000a intra-cellular one (such as a virus or certain bacteria) and it is necessary to kill the infected host cell in

Cliburn Chan; Andrew J. T. George; Jaroslav Stark

2007-01-01

206

Designing surfaces that kill bacteria on contact  

NASA Astrophysics Data System (ADS)

Poly(4-vinyl-N-alkylpyridinium bromide) was covalently attached to glass slides to create a surface that kills airborne bacteria on contact. The antibacterial properties were assessed by spraying aqueous suspensions of bacterial cells on the surface, followed by air drying and counting the number of cells remaining viable (i.e., capable of growing colonies). Amino glass slides were acylated with acryloyl chloride, copolymerized with 4-vinylpyridine, and N-alkylated with different alkyl bromides (from propyl to hexadecyl). The resultant surfaces, depending on the alkyl group, were able to kill up to 94 ± 4% of Staphylococcus aureus cells sprayed on them. A surface alternatively created by attaching poly(4-vinylpyridine) to a glass slide and alkylating it with hexyl bromide killed 94 ± 3% of the deposited S. aureus cells. On surfaces modified with N-hexylated poly(4-vinylpyridine), the numbers of viable cells of another Gram-positive bacterium, Staphylococcus epidermidis, as well as of the Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli, dropped more than 100-fold compared with the original amino glass. In contrast, the number of viable bacterial cells did not decline significantly after spraying on such common materials as ceramics, plastics, metals, and wood.

Tiller, Joerg C.; Liao, Chun-Jen; Lewis, Kim; Klibanov, Alexander M.

2001-05-01

207

Road-Killed Animals as Resources for Ecological Studies.  

ERIC Educational Resources Information Center

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…

Adams, Clark E.

1983-01-01

208

Aquatic Invaders  

NSDL National Science Digital Library

In this lesson plan students will explore the ways that native species interact in a healthy Chesapeake Bay. They will then learn about some of the ways that exotic or invasive species can threaten the balance of the ecosystem. Students will discover how the various elements of the Bay ecosystem are interconnected and investigate some of the issues associated with invasive species.

209

40 CFR 725.88 - Uses of a microorganism.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Uses of a microorganism. 725.88 Section 725...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Confidentiality and Public...Information § 725.88 Uses of a microorganism. (a) Assertion of...

2013-07-01

210

Interrelationships between soil microorganisms and polystyrene.  

PubMed

Transmission and scanning electron microscopy along with autoradiographic procedures were used for evaluating the interrelationship between soil microorganisms and polystyrene. Two hypotheses, allowing to explain the properties of polystyrene as a soil conditioner, were investigated: the first is concerned with a possible action of soil microorganisms on the compound; the second, reciprocally, with the polystyrene interference on microorganisms. Radioactivity translocation of 14C-Ecolyte-polystyrene along fungal hyphae and asexual fructification of strains, isolated from soil, as well as cytological modification at the cell wall level of the same microfungi, cultivated in the presence of polystyrene have been ascertained. PMID:726715

Seritti, A; Citernesi, U; Lepidi, A A; Nuti, M P; Bernacchi, G; Picci, G

1978-01-01

211

Mechanisms of Contact-Mediated Killing of Yeast Cells on Dry Metallic Copper Surfaces?  

PubMed Central

Surfaces made of copper or its alloys have strong antimicrobial properties against a wide variety of microorganisms. However, the molecular mode of action responsible for the antimicrobial efficacy of metallic copper is not known. Here, we show that dry copper surfaces inactivate Candida albicans and Saccharomyces cerevisiae within minutes in a process called contact-mediated killing. Cellular copper ion homeostasis systems influenced the kinetics of contact-mediated killing in both organisms. Deregulated copper ion uptake through a hyperactive S. cerevisiae Ctr1p (ScCtr1p) copper uptake transporter in Saccharomyces resulted in faster inactivation of mutant cells than of wild-type cells. Similarly, lack of the C. albicans Crp1p (CaCrp1p) copper-efflux P-type ATPase or the metallothionein CaCup1p caused more-rapid killing of Candida mutant cells than of wild-type cells. Candida and Saccharomyces took up large quantities of copper ions as soon as they were in contact with copper surfaces, as indicated by inductively coupled plasma mass spectroscopy (ICP-MS) analysis and by the intracellular copper ion-reporting dye coppersensor-1. Exposure to metallic copper did not cause lethality through genotoxicity, deleterious action on a cell's genetic material, as indicated by a mutation assay with Saccharomyces. Instead, toxicity mediated by metallic copper surfaces targeted membranes in both yeast species. With the use of Live/Dead staining, onset of rapid and extensive cytoplasmic membrane damage was observed in cells from copper surfaces. Fluorescence microscopy using the indicator dye DiSBaC2(3) indicated that cell membranes were depolarized. Also, during contact-mediated killing, vacuoles first became enlarged and then disappeared from the cells. Lastly, in metallic copper-stressed yeasts, oxidative stress in the cytoplasm and in mitochondria was elevated.

Quaranta, Davide; Krans, Travis; Santo, Christophe Espirito; Elowsky, Christian G.; Domaille, Dylan W.; Chang, Christopher J.; Grass, Gregor

2011-01-01

212

Hepatocellular Carcinoma Invading the Main Portal Vein: Treatment with Transcatheter Arterial Chemoembolization and Portal Vein Stenting  

Microsoft Academic Search

To retrospectively analyze the therapeutic results of percutaneous transhepatic portal vein stenting (PTPVS) and transcatheter\\u000a arterial chemoembolization (TACE) treatment in 58 patients with hepatocellular carcinoma (HCC) invading the main portal vein\\u000a (MPV). A total of 58 procedures of PTPVS were performed, immediately after which TACE was undertaken to control HCC. The clinical\\u000a effects, complications, digital subtraction angiographic appearance, stent patency

Xue-Bin Zhang; Jian-Hua Wang; Zhi-Ping Yan; Sheng Qian; Rong Liu

2009-01-01

213

Johns Hopkins research yields new clues to how brain cancer cells migrate and invade  

Cancer.gov

Johns Hopkins researchers have discovered that a protein that transports sodium, potassium and chloride may hold clues to how glioblastoma, the most common and deadliest type of brain cancer, moves and invades nearby healthy brain tissue. The findings, reported in the journal PLoS Biology, also suggest that a cheap FDA-approved drug already on the market could slow movement of glioblastoma cells, and contain their spread.

214

Science Sampler: Alien Invaders! A board game about the threats posed by introduced species  

NSDL National Science Digital Library

Alien Invaders!--loosely modeled after the game of Life, helps students to understand how introduced species can affect native species. This board game allows students to role-play native birds in a world of introduced species, facing the hazards posed by those species. By playing this game, students come to understand some of the effects, such as competition and predation, of invasive species on native species.

Stracey, Christine

2008-02-01

215

Evaluation of Single Nucleotide Polymorphism Typing with Invader on PCR Amplicons and Its Automation  

PubMed Central

Large-scale pharmacogenetics and complex disease association studies will require typing of thousands of single-nucleotide polymorphisms (SNPs) in thousands of individuals. Such projects would benefit from a genotyping system with accuracy >99% and a failure rate <5% on a simple, reliable, and flexible platform. However, such a system is not yet available for routine laboratory use. We have evaluated a modification of the previously reported Invader SNP-typing chemistry for use in a genotyping laboratory and tested its automation. The Invader technology uses a Flap Endonuclease for allele discrimination and a universal fluorescence resonance energy transfer (FRET) reporter system. Three hundred and eighty-four individuals were genotyped across a panel of 36 SNPs and one insertion/deletion polymorphism with Invader assays using PCR product as template, a total of 14,208 genotypes. An average failure rate of 2.3% was recorded, mostly associated with PCR failure, and the typing was 99.2% accurate when compared with genotypes generated with established techniques. An average signal-to-noise ratio (9:1) was obtained. The high degree of discrimination for single base changes, coupled with homogeneous format, has allowed us to deploy liquid handling robots in a 384-well microtitre plate format and an automated end-point capture of fluorescent signal. Simple semiautomated data interpretation allows the generation of ?25,000 genotypes per person per week, which is 10-fold greater than gel-based SNP typing and microsatellite typing in our laboratory. Savings on labor costs are considerable. We conclude that Invader chemistry using PCR products as template represents a useful technology for typing large numbers of SNPs rapidly and efficiently.

Mein, Charles A.; Barratt, Bryan J.; Dunn, Michael G.; Siegmund, Thorsten; Smith, Annabel N.; Esposito, Laura; Nutland, Sarah; Stevens, Helen E.; Wilson, Amanda J.; Phillips, Michael S.; Jarvis, Nancy; Law, Scott; de Arruda, Monika; Todd, John A.

2000-01-01

216

Carbon ion beam radiotherapy for sinonasal malignant tumors invading skull base.  

PubMed

Objective. To evaluate the treatment outcome and prognostic factors in patients with sinonasal malignant tumors invading skull base. Study Design and Setting. A retrospective clinical study at the Yamagata University School of Medicine. Subjects and Methods. Three patients with sinonasal malignant tumors invading skull base were presented in present study. All patients were treated with carbon ion beam radiotherapy. The prescribed dose to the center of the clinical target volume was 64.0?GyE/16 fractions over 4 weeks at 4.0?GyE/fraction per day. Results. All patients completed carbon ion beam radiotherapy without an interval. The mean observation period was 39.6 months (range: 11-54 months). There were no local or regional recurrences in all cases; however, one patient had a metastasis in distant organs. Regarding the complications, visual loss was observed in one eye of one patient whose optic nerve was entirely involved by the tumor and field of carbon ion beam radiotherapy. Radiation induced brain injury was observed in two patients; however, these patients do not complain about neurological abnormality and had no treatment for radiation induced brain necrosis. Conclusions. Carbon ion beam radiotherapy for sinonasal malignant tumors invading the skull base showed therapeutic effectiveness. PMID:25013734

Ohta, Nobuo; Suzuki, Yusuke; Hasegawa, Azusa; Aoyagi, Masaru; Kakehata, Seiji

2014-01-01

217

Carbon Ion Beam Radiotherapy for Sinonasal Malignant Tumors Invading Skull Base  

PubMed Central

Objective. To evaluate the treatment outcome and prognostic factors in patients with sinonasal malignant tumors invading skull base. Study Design and Setting. A retrospective clinical study at the Yamagata University School of Medicine. Subjects and Methods. Three patients with sinonasal malignant tumors invading skull base were presented in present study. All patients were treated with carbon ion beam radiotherapy. The prescribed dose to the center of the clinical target volume was 64.0?GyE/16 fractions over 4 weeks at 4.0?GyE/fraction per day. Results. All patients completed carbon ion beam radiotherapy without an interval. The mean observation period was 39.6 months (range: 11–54 months). There were no local or regional recurrences in all cases; however, one patient had a metastasis in distant organs. Regarding the complications, visual loss was observed in one eye of one patient whose optic nerve was entirely involved by the tumor and field of carbon ion beam radiotherapy. Radiation induced brain injury was observed in two patients; however, these patients do not complain about neurological abnormality and had no treatment for radiation induced brain necrosis. Conclusions. Carbon ion beam radiotherapy for sinonasal malignant tumors invading the skull base showed therapeutic effectiveness.

Ohta, Nobuo; Suzuki, Yusuke; Hasegawa, Azusa; Aoyagi, Masaru; Kakehata, Seiji

2014-01-01

218

Tumors invading the cavernous sinus that cause internal carotid artery compression are rarely pituitary adenomas.  

PubMed

There is a clinical impression that when tumors invade the cavernous sinus, compression of the internal carotid artery is rare with pituitary adenomas and more common with other types of lesions but there are no actual data to support this impression. To confirm the impression that the finding of internal carotid artery compression by tumors invading the cavernous sinus is inconsistent with a diagnosis of a pituitary adenoma, we performed a retrospective analysis of MRI scans performed between 2000 and July 2009. An initial search of the radiology database was performed using the terms "invasive mass cavernous MRI" and subsequent refinement narrowed the evaluation to 141 patients with cavernous sinus invasion by sellar/parasellar tumors for whom there were clinical/pathological data to determine tumor type. 83 of the 141 patients with cavernous sinus invasion had carotid artery encasement; 58 were pituitary adenomas and 25 were other types of lesions. Eight of these 83 scans revealed compression of the internal carotid lumen, with only one being a pituitary adenoma and seven being other types of lesions. Therefore, only 1/58 (1.7%) of pituitary adenomas and 7/25 (28%) of non-pituitary adenoma lesions that encased the internal carotid artery caused compression of the artery (P = 0.0007). A mass lesion that invades the cavernous sinus and encases the internal carotid artery is very unlikely, therefore, to be a pituitary adenoma if it compresses the lumen of the internal carotid artery. PMID:22307822

Molitch, Mark E; Cowen, Laura; Stadiem, Raymond; Uihlein, Alexander; Naidich, Michelle; Russell, Eric

2012-12-01

219

Dynamic kill: controlling wild wells a new way  

SciTech Connect

Dynamic kill describes a technique for terminating a blowout utilizing flowing frictional pressure to supplement the hydrostatic pressure of the kill fluid being injected through the relief well and up the blowing well. Therefore, a lighter kill fluid such as water can be implemented. The objective is to allow a blowout to be killed without breaking down the formation so the maximum amount of fluid can be circulated through the relief well by not losing fluid to a fractured formation. This allows optimum control during the kill operation and stable communication between the two wells. By allowing more fluid to be applied to the kill through one relief well, dynamic kill also increases the probability that one relief well will be sufficient. When the well is dynamically dead, the initial kill fluid, which will usually be too light to hold the well dead in a static condition, is replaced with a heavier kill mud. In fact, three weights of mud may be required to allow control during the transition from low density initial dynamic kill mud to heavy final kill mud. 5 refs.

Blount, E.M.; Soeiinah, E.

1981-10-01

220

Detection of microorganisms using terahertz metamaterials.  

PubMed

Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area. PMID:24832607

Park, S J; Hong, J T; Choi, S J; Kim, H S; Park, W K; Han, S T; Park, J Y; Lee, S; Kim, D S; Ahn, Y H

2014-01-01

221

Mass Spectrometry for Rapid Characterization of Microorganisms  

NASA Astrophysics Data System (ADS)

Advances in instrumentation, proteomics, and bioinformatics have contributed to the successful applications of mass spectrometry (MS) for detection, identification, and classification of microorganisms. These MS applications are based on the detection of organism-specific biomarker molecules, which allow differentiation between organisms to be made. Intact proteins, their proteolytic peptides, and nonribosomal peptides have been successfully utilized as biomarkers. Sequence-specific fragments for biomarkers are generated by tandem MS of intact proteins or proteolytic peptides, obtained after, for instance, microwave-assisted acid hydrolysis. In combination with proteome database searching, individual biomarker proteins are unambiguously identified from their tandem mass spectra, and from there the source microorganism is also identified. Such top-down or bottom-up proteomics approaches permit rapid, sensitive, and confident characterization of individual microorganisms in mixtures and are reviewed here. Examples of MS-based functional assays for detection of targeted microorganisms, e.g., Bacillus anthracis, in environmental or clinically relevant backgrounds are also reviewed.

Demirev, Plamen A.; Fenselau, Catherine

2008-07-01

222

Studies of Soil Microorganisms of North Norway.  

National Technical Information Service (NTIS)

Soils of northern Norway have fewer microorganisms than are found in temperate regions. Thermophilic bacteria are present rarely except where cultivation has taken place or where possible pollution or disturbance has occurred. Mesophilic and psychrophilic...

W. L. Boyd J. W. Boyd

1971-01-01

223

Detection of microorganisms using terahertz metamaterials  

NASA Astrophysics Data System (ADS)

Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area.

Park, S. J.; Hong, J. T.; Choi, S. J.; Kim, H. S.; Park, W. K.; Han, S. T.; Park, J. Y.; Lee, S.; Kim, D. S.; Ahn, Y. H.

2014-05-01

224

Alteration of glasses by micro-organisms  

NASA Astrophysics Data System (ADS)

Micro-organisms are suspected to play a basic part in materials alteration. Obviously, they will be present in nuclear waste repositories, either introduced by technological activity or laid by fluids circulation. Their metabolism may induce chemical modifications to the surrounding media and then affect the durability of storage materials. Biodegradation of glasses is studied in the Pierre Süe Laboratory. In the frame of a collaboration with microbiologists interested in stained glasses alteration, leaching experiments with various species of bacteria and fungi are carried out. Ion beam analysis techniques are performed to quantify surface modification of glasses and elemental incorporation in micro-organisms. Analyses of the solutions will lead to a complete assessment of elemental exchanges between glass sample, culture media and micro-organisms. In this paper, preliminary results on characterisation of glasses and micro-organisms and the first results of leaching experiments are presented.

Gallien, Jean-Paul; Gouget, Barbara; Carrot, Francine; Orial, Geneviève; Brunet, Anne

2001-07-01

225

Detection of microorganisms using terahertz metamaterials  

PubMed Central

Microorganisms such as fungi and bacteria cause many human diseases and therefore rapid and accurate identification of these substances is essential for effective treatment and prevention of further infections. In particular, contemporary microbial detection technique is limited by the low detection speed which usually extends over a couple of days. Here we demonstrate that metamaterials operating in the terahertz frequency range shows promising potential for use in fabricating the highly sensitive and selective microbial sensors that are capable of high-speed on-site detection of microorganisms in both ambient and aqueous environments. We were able to detect extremely small amounts of the microorganisms, because their sizes are on the same scale as the micro-gaps of the terahertz metamaterials. The resonant frequency shift of the metamaterials was investigated in terms of the number density and the dielectric constants of the microorganisms, which was successfully interpreted by the change in the effective dielectric constant of a gap area.

Park, S. J.; Hong, J. T.; Choi, S. J.; Kim, H. S.; Park, W. K.; Han, S. T.; Park, J. Y.; Lee, S.; Kim, D. S.; Ahn, Y. H.

2014-01-01

226

EFFECTS OF KEPONE ON ESTUARINE MICROORGANISMS  

EPA Science Inventory

Low concentration of the insecticide Kepone, approaching those found in contaminated James River sediment, were shown to be inhibitory to the growth and oxygen uptake of microorganisms randomly selected from estuarine environments. No significant correlations were noted between g...

227

Effects of Kepone on Estuarine Microorganisms.  

National Technical Information Service (NTIS)

Low concentration of the insecticide Kepone, approaching those found in contaminated James River sediment, were shown to be inhibitory to the growth and oxygen uptake of microorganisms randomly selected from estuarine environments. No significant correlat...

A. W. Bourquin P. H. Pritchard W. R. Mahaffey

1978-01-01

228

Characterization of Microorganisms by MALDI Mass Spectrometry  

Microsoft Academic Search

Matrix-assisted laser desorption\\/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for characterization and analysis of microorganisms, specifically bacteria, is described here as a rapid screening tool. The objective of this technique is not comprehensive protein analysis of a microorganism but rather a rapid screening of the organism and the accessible protein pattern for characterization and distinction. This method is based on the ionization

Catherine E. Petersen; Nancy B. Valentine; Karen L. Wahl

2008-01-01

229

Enumeration of petroleum-degrading microorganisms  

Microsoft Academic Search

A variety of factors, including concentration of oil, antibiotics, dyes, and inoculum washes, were examined to determine their effect on the total counts of microorganisms on oil-containing media. The media found to be best for enumerating petroleum-degrading microorganisms contained 0.5 percent (vol\\/vol) oil and 0.003 percent phenol red, with Fungizone added for isolating bacteria and streptomycin and tetracycline added for

J. D. Walker; R. R. Colwell

1976-01-01

230

Enhanced oil recovery using denitrifying microorganisms  

SciTech Connect

This patent describes a method of microbial enhanced oil recovery. It comprises the step of introducing, into a carbonate-containing rock formation that defines an anaerobic environment, denitrifying microorganisms, an aqueous liquid carrier and a nonoxygen electron accepter, such that the microorganism reduce the non-oxygen electron accepter in the presence of a sulfur-containing compound and produce sulfuric acid, which dissolves carbonate in the rock formation to release oil.

Sperl, G.T.; Sperl, P.L.

1991-09-03

231

What Killed The Dinosaurs?: The Great Mystery  

NSDL National Science Digital Library

This site presents theories about why the dinosaurs became extinct. The first page provides background information covering not only the "great dying" at the K-T boundary but also the mass extinction at the end of the Paleozoic Era. The author covers six factors that complicate the study of mass extinction including time resolution, the Signor-Lipps Effect, and falsifiability. A link then takes the reader to a second page where invalid extinction hypotheses are explained. These range from "hay fever killed the dinosaurs" to "the dinosaurs just faded away," (no causation implied). The final link leads us to current thinking about extinction including volcanism, plate tectonics, and the Alvarez Hypothesis.

Hutchinson, John

232

Bacterial Killing by Dry Metallic Copper Surfaces?  

PubMed Central

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 first steps for revealing the molecular sensitive targets in cells lethally challenged by exposure to copper surfaces and provide a scientific explanation for the use of copper surfaces as antimicrobial agents for supporting public hygiene.

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

2011-01-01

233

Neutrophils Exert Protection in the Early Tuberculous Granuloma by Oxidative Killing of Mycobacteria Phagocytosed from Infected Macrophages  

PubMed Central

SUMMARY Neutrophils are typically the first responders in host defense against invading pathogens, which they destroy by both oxidative and nonoxidative mechanisms. However, despite a longstanding recognition of neutrophil presence at disease sites in tuberculosis, their role in defense against mycobacteria is unclear. Here we exploit the genetic tractability and optical transparency of zebrafish to monitor neutrophil behavior and its consequences during infection with Mycobacterium marinum, a natural fish pathogen. In contrast to macrophages, neutrophils do not interact with mycobacteria at initial infection sites. Neutrophils are subsequently recruited to the nascent granuloma in response to signals from dying infected macrophages within the granuloma, which they phagocytose. Some neutrophils then rapidly kill the internalized mycobacteria through NADPH oxidase-dependent mechanisms. Our results provide a mechanistic link to the observed patterns of neutrophils in human tuberculous granulomas and the susceptibility of humans with chronic granulomatous disease to mycobacterial infection.

Yang, Chao-Tsung; Cambier, C.J.; Davis, J. Muse; Hall, Christopher J.; Crosier, Philip S.; Ramakrishnan, Lalita

2013-01-01

234

TEMPERATURE-GRADIENT PLATES FOR GROWTH OF MICROORGANISMS  

PubMed Central

Landman, Otto E. (Fort Detrick, Frederick, Md.), Howard T. Bausum, and Thomas S. Matney. Temperature-gradient plates for growth of microorganisms. J. Bacteriol. 83:463–469. 1962.—Different temperature-gradient plates have been devised for the study of microbial growth on solid media through continuous temperature ranges or in liquid media at finely graded temperatures. All plates are made of heavy-gauge aluminum; heat supplied at one end is dissipated along the length of the metal so that a gradient is produced. The shape and range of the gradient depends on the amount of heat supplied, the insulation, the ambient temperature, and other factors. Differences of 0.2 C in temperature sensitivity between bacterial strains can be detected. The plates are simple to construct and operate. The dimensions of the aluminum, the mode of temperature measurement, and the method of heating may all be modified without diminishing the basic utility of the device. A sharp growth front develops at the maximal temperature of growth of bacteria. In most strains, all bacteria below the front form colonies and all bacteria above the front are killed, except for a few temperature-resistant mutants. Images

Landman, Otto E.; Bausum, Howard T.; Matney, Thomas S.

1962-01-01

235

Effect of microorganisms on in situ uranium mining  

SciTech Connect

The extraction of some metal values, e.g., uranium or copper, may be accomplished by using solutions to remove metals from ore bodies without practicing conventional mining. This process is referred to as in situ leaching and has been used industrially to recover uranium. The growth of microbial populations during in situ leaching is believed to be one of the causes of flow path plugging in the ore body, which results in decreased uranium production. Leach solution and solid samples from well casings and submersible pumps were collected from an in situ mining operation experiencing plugging problems. Bacillus sp., Micrococcus sp., pseudomonads, and xanthomonads were isolated from these samples on concentrations of 10/sup 5/ colony-forming units per milliliter. A mixed culture of these organisms was inoculated into a uranium core specimen in the laboratory to assess the role of microbes in the plugging problem. A one-third decrease in permeability was effected in 16 days. Hydrogen peroxide killed the microorganisms in the core and alleviated the plugging problems. Periodically injecting hydrogen peroxide into the ore body through the production wells may reduce microbial plugging problems.

Yates, M.V.; Brierley, J.A.; Brierley, C.L.; Follin, S.

1983-10-01

236

Effect of Microorganisms on In Situ Uranium Mining  

PubMed Central

The extraction of some metal values, e.g., uranium or copper, may be accomplished by using solutions to remove metals from ore bodies without practicing conventional mining. This process is referred to as in situ leaching and has been used industrially to recover uranium. The growth of microbial populations during in situ leaching is believed to be one of the causes of flow path plugging in the ore body, which results in decreased uranium production. Leach solution and solid samples from well casings and submersible pumps were collected from an in situ mining operation experiencing plugging problems. Bacillus sp., Micrococcus sp., pseudomonads, and xanthomonads were isolated from these samples in concentrations of 105 CFU ml?1. A mixed culture of these organisms was inoculated into a uranium core specimen in the laboratory to assess the role of microbes in the plugging problem. A one-third decrease in permeability was effected in 16 days. Hydrogen peroxide (0.2 g liter?1) killed the microorganisms in the core and alleviated the plugging problem. Periodically injecting hydrogen peroxide into the ore body through the production wells may reduce microbial plugging problems.

Yates, Marylynn V.; Brierley, James A.; Brierley, Corale L.; Follin, Steven

1983-01-01

237

Long-Term Ecological Behaviour of Abandoned Uranium Mill Tailings. 1. Synoptic Survey and Identification of Invading Biota.  

National Technical Information Service (NTIS)

Inactive uranium mill tailings were surveyed in the Province of Ontario to describe their surface characteristics, identify naturally invading biota, and determine essential chemical and physical parameters associated with the tailings. Inactive tailings ...

M. Kalin

1983-01-01

238

Improving Photodynamic Inactivation of Bacteria in Dentistry: Highly Effective and Fast Killing of Oral Key Pathogens with Novel Tooth-Colored Type-II Photosensitizers.  

PubMed

Increasing antibiotic resistances in microorganisms create serious problems in public health. This demands alternative approaches for killing pathogens to supplement standard treatment methods. Photodynamic inactivation of bacteria (PIB) uses light activated photosensitizers (PS) to generate reactive oxygen species immediately upon illumination, inducing lethal phototoxicity. Positively charged phenalen-1-one derivatives are a new generation of PS for light-mediated killing of pathogens with outstanding singlet oxygen quantum yield ?? of >97%. Upon irradiation with a standard photopolymerizer light (bluephase C8, 1260 ± 50 mW/cm(2)) the PS showed high activity against the oral key pathogens Enterococcus faecalis, Actinomyces naeslundii, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans. At a concentration of 10 ?M, a maximum efficacy of more than 6 log10 steps (?99.9999%) of bacteria killing is reached in less than 1 min (light dose 50 J/cm(2)) after one single treatment. The pyridinium substituent as positively charged moiety is especially advantageous for antimicrobial action. PMID:24884918

Späth, Andreas; Leibl, Christoph; Cieplik, Fabian; Lehner, Karin; Regensburger, Johannes; Hiller, Karl-Anton; Bäumler, Wolfgang; Schmalz, Gottfried; Maisch, Tim

2014-06-26

239

Conservative treatment for a symptomatic solitary ganglion cyst of the anterior meniscus invading into the infrapatellar fat pad  

Microsoft Academic Search

Symptomatic meniscal cysts without accompanying meniscal tears are uncommon, especially those which are formed from the anterior\\u000a meniscus and invading into the infrapatellar fat pad (IPFP). The current recommended treatment for such cysts is excision\\u000a through open method or arthroscopy. To our knowledge, this is the first case study about a symptomatic solitary meniscal cyst\\u000a invading the IPFP that was

Yu-Chih Liu; Ko-Huang Lue; Ko-Hsiu Lu

2007-01-01

240

Plant litter chemistry and microbial priming regulate the accrual, composition and stability of soil carbon in invaded ecosystems.  

PubMed

Soil carbon (C) sequestration, as an ecosystem property, may be strongly influenced by invasive plants capable of depositing disproportionately high quantities of chemically distinct litter that disrupt ecosystem processes. However, a mechanistic understanding of the processes that regulate soil C storage in invaded ecosystems remains surprisingly elusive. Here, we studied the impact of the invasion of two noxious nonnative species, Polygonum cuspidatum, which produces recalcitrant litter, and Pueraria lobata, which produces labile litter, on the quantity, molecular composition, and stability of C in the soils they invade. Compared with an adjacent noninvaded old-field, P. cuspidatum-invaded soils exhibited a 26% increase in C, partially through selective preservation of plant polymers. Despite receiving a 22% higher litter input, P. lobata-invaded Pinus stands exhibited a 28% decrease in soil C and a twofold decrease in plant biomarkers, indicating microbial priming of native soil C. The stability of C exhibited an opposite trend: the proportion of C that was resistant to oxidation was 21% lower in P. cuspidatum-invaded soils and 50% higher in P. lobata-invaded soils. Our results highlight the capacity of invasive plants to feed back to climate change by destabilizing native soil C stocks and indicate that environments that promote the biochemical decomposition of plant litter would enhance the long-term storage of soil C. Further, our study highlights the concurrent influence of dominant plant species on both selective preservation and humification of soil organic matter. PMID:24720813

Tamura, Mioko; Tharayil, Nishanth

2014-07-01

241

The effects of heat conduction on the vaporization of liquid invading superheated permeable rock  

SciTech Connect

We examine the role of conductive and convective heat transfer in the vaporization of liquid as it slowly invades a superheated permeable rock. For very slow migration, virtually all of the liquid vaporizes. As the liquid supply rate increases beyond the rate of heat transfer by thermal conduction, a decreasing fraction of the liquid can vaporize. Indeed, for sufficiently high flow rates, the fraction vaporizing depends solely on the superheat of the rock, and any heat transfer from the superheated region is negligible. These results complement earlier studies of vaporization under very high injection rates, in which case the dynamic vapour pressure reduces the mass fraction vaporizing to very small values.

Woods, Andrew, W.; Fitzgerald, Shaun D.

1996-01-24

242

Epiphyte Water Retention and Evaporation in Native and Invaded Tropical Montane Cloud Forests in Hawaii  

NASA Astrophysics Data System (ADS)

Epiphyte water retention was quantified at two montane cloud forest sites in Hawai'i Volcanoes National Park, one native and the other invaded by an alien tree species. Water storage elements measured included all epiphytic mosses, leafy liverworts, and filmy ferns. Tree surface area was estimated and a careful survey was taken to account for all epiphytes in the sample area of the forest. Samples were collected and analyzed in the lab for epiphyte water retention capacity (WRC). Based on the volume of the different kinds of epiphytes and their corresponding WRC, forest stand water retention capacity for each survey area was estimated. Evaporation from the epiphyte mass was quantified using artificial reference samples attached to trees that were weighed at intervals to determine changes in stored water on days without significant rain or fog. In addition, a soil moisture sensor was wrapped in an epiphyte sample and left in the forest for a 6-day period. Epiphyte biomass at the Native Site and Invaded Site were estimated to be 2.89 t ha-1 and 1.05 t ha-1, respectively. Average WRC at the Native Site and Invaded Site were estimated at 1.45 mm and 0.68 mm, respectively. The difference is likely due to the presence of the invasive Psidium cattleianum at the Invaded Site because its smooth stem surface is unable to support a significant epiphytic layer. The evaporation rate from the epiphyte mass near WSC for the forest stand at the Native Site was measured at 0.38 mm day-1, which represented 10.6 % of the total ET from the forest canopy at the Native Site during the period. The above research has been recently complemented by a thorough investigation of the WSC of all water storage elements (tree stems, tree leaves, shrubs, grasses, litter, fallen branches, and epiphytes) at six forested sites at different elevations within, above, and below the zone of frequent cloud-cover. The goal of this study was to create an inexpensive and efficient methodology for acquiring estimates of above-ground water retention in different types of forests by means of minimally-destructive sampling and surveying. The results of this work serve as baseline data providing a range of possible values of the water retention of specific forest elements and the entire above-ground total where no values have been previously recorded.

Mudd, R. G.; Giambelluca, T. W.

2006-12-01

243

Heat production due to intracellular killing activity.  

PubMed

Using Saccharomyces ceravisiae, Candida albicans and Stapylococcus aureus, heat production during phagocytosis was measured in U937 cells which are capable of differentiating to monocytic phagocytes. No increase in heat production of non-differentiated U937 was observed since they were not phagocytic cells. However after differentiation to monocytic phagocytes by lymphokine, U937 cells produced a remarkable amount of heat during phagocytosis. Although Ehrlich ascites tumor cells sensitized with antibody were capable of engulfing S. aureus, no increase in heat nor in superoxide anion production during phagocytosis was detected. It was also found that no heat increase occurred in neutrophils from a patient with chronic granulomatous disease (CGD). It can thus be concluded that the heat production during phagocytosis is due to the intercellular killing process of phagocytic cells. PMID:2131646

Hayatsu, H; Masuda, S; Miyamae, T; Yamamura, M

1990-09-01

244

Antimicrobial Peptide Killing of African Trypanosomes  

PubMed Central

Summary The diseases caused by trypanosomes are medically and economically devastating to the population of sub-Saharan Africa. Parasites of the genus Trypanosoma, infect both humans, causing African sleeping sickness, and livestock, causing Nagana. The development of effective treatment strategies has suffered from the severe side effects of approved drugs, resistance and major difficulties in delivering drugs. Antimicrobial peptides are ubiquitous components of immune defense and are being rigorously pursued as novel sources of new therapeutics for a variety of pathogens. Here we review the role of antimicrobial peptides in the innate immune response of the tsetse fly to African trypanosomes, catalogue trypanocidal antimicrobial peptides from diverse organisms and highlight the susceptibility of bloodstream form African trypanosomes to killing by unconventional toxic peptides.

Harrington, John M.

2011-01-01

245

Advancements in dynamic kill calculations for blowout wells  

SciTech Connect

This paper addresses the development, interpretation, and use of dynamic kill equations. To this end, three simple calculation techniques are developed for determining the minimum dynamic kill rate. Two techniques contain only single-phase calculations and are independent of reservoir inflow performance. Despite these limitations, these two methods are useful for bracketing the minimum flow rates necessary to kill a blowing well. For the third technique, a simplified mechanistic multiphase-flow model is used to determine a most-probable minimum kill rate.

Kouba, G.E. (Chevron Petroleum Technology Co., La Habra, CA (United States). Production Fluids Div.); MacDougall, G.R. (Chevron Canada Resources Ltd., Slave Lake, (Canada)); Schumacher, B.W. (Chevron Petroleum Technology Co., Houston, TX (United States). Information Technology Dept.)

1993-09-01

246

Tailored oils produced from recombinant oleaginous microorganisms  

US Patent & Trademark Office Database

Methods and compositions for the production of oil, fuels, oleochemicals, and other compounds in recombinant microorganisms are provided, including oil-bearing microorganisms and methods of low cost cultivation of such microorganisms. Microalgal cells containing exogenous genes encoding, for example, a lipase, a sucrose transporter, a sucrose invertase, a fructokinase, a polysaccharide-degrading enzyme, a keto acyl-ACP synthase enzyme, a fatty acyl-ACP thioesterase, a fatty acyl-CoA/aldehyde reductase, a fatty acyl-CoA reductase, a fatty aldehyde reductase, a fatty acid hydroxylase, a desaturase enzyme, a fatty aldehyde decarbonylase, and/or an acyl carrier protein are useful in manufacturing transportation fuels such as renewable diesel, biodiesel, and renewable jet fuel, as well as oleochemicals such as functional fluids, surfactants, soaps and lubricants.

2014-01-21

247

Biosurfactants, bioemulsifiers and exopolysaccharides from marine microorganisms.  

PubMed

Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas, Halomonas, Myroides, Corynebacteria, Bacillus, Alteromonas sp. have been studied for production of BS/BE and exopolysaccharides (EPS). Due to the enormity of marine biosphere, most of the marine microbial world remains unexplored. The discovery of potent BS/BE producing marine microorganism would enhance the use of environmental biodegradable surface active molecule and hopefully reduce total dependence or number of new application oriented towards the chemical synthetic surfactant industry. Our present review gives comprehensive information on BS/BE which has been reported to be produced by marine microorganisms and their possible potential future applications. PMID:20172021

Satpute, Surekha K; Banat, Ibrahim M; Dhakephalkar, Prashant K; Banpurkar, Arun G; Chopade, Balu A

2010-01-01

248

Transport and hydrolysis of peptides by microorganisms.  

PubMed

The structural specificities of the dipeptide and oligopeptide permeases of E. coli are briefly reviewed and related to the requirements found for other microorganisms. New, quick, sensitive methods for studying peptide transport are described, based on the following: (i) peptide-dependent incorporation of free radioactive amino acid into newly synthesized protein by a double amino acid auxotroph, (ii) colorimetric assay of peptide-dependent enzyme synthesis by an amino acid auxotroph, (iii) dansyl fingerprint technique. These approaches provide information on peptide binding affinity to a permease and rates of peptide uptake and amino acid efflux. Among current and future research areas considered are: the influence of the pKb of the N-terminal amino group on transport, generality of peptide transport in microorganisms, energy coupling and regulation, involvement of binding proteins, and the 'smugglin' concept. Peptide hydrolysis, and nutritional ultilization of peptides, by microorganisms are briefly discussed. PMID:340177

Payne, J W

1977-01-01

249

Campylobacter jejuni Actively Invades the Amoeba Acanthamoeba polyphaga and Survives within Non Digestive Vacuoles  

PubMed Central

The Gram-negative bacterium Campylobacter jejuni is able to enter, survive and multiply within the free living amoeba Acanthamoeba polyphaga, but the molecular mechanisms behind these events are still unclear. We have studied the uptake and intracellular trafficking of viable and heat killed bacterial cells of the C. jejuni strain 81–176 in A. polyphaga. We found that viable bacteria associated with a substantially higher proportion of Acanthamoeba trophozoites than heat killed bacteria. Furthermore, the kinetics of internalization, the total number of internalized bacteria as well as the intracellular localization of internalized C. jejuni were dramatically influenced by bacterial viability. Viable bacteria were internalized at a high rate already after 1 h of co-incubation and were observed in small vacuoles tightly surrounding the bacteria. In contrast, internalization of heat killed C. jejuni was low at early time points and did not peak until 96 h. These cells were gathered in large spacious vacuoles that were part of the degradative pathway as determined by the uptake of fluorescently labeled dextran. The amount of heat killed bacteria internalized by A. polyphaga did never reach the maximal amount of internalized viable bacteria. These results suggest that the uptake and intracellular survival of C. jejuni in A. polyphaga is bacterially induced.

Olofsson, Jenny; Axelsson-Olsson, Diana; Brudin, Lars; Olsen, Bjorn; Ellstrom, Patrik

2013-01-01

250

Physiologically anaerobic microorganisms of the deep subsurface  

SciTech Connect

This study seeks to determine numbers, diversity, and morphology of anaerobic microorganisms in 15 samples of subsurface material from the Idaho National Engineering Laboratory, in 18 samples from the Hanford Reservation and in 1 rock sample from the Nevada Test Site; set up long term experiments on the chemical activities of anaerobic microorganisms based on these same samples; work to improve methods for the micro-scale determination of in situ anaerobic microbial activity;and to begin to isolate anaerobes from these samples into axenic culture with identification of the axenic isolates.

Stevens, S.E. Jr.; Chung, K.T.

1991-06-01

251

Microorganisms in the aetiology of atherosclerosis  

PubMed Central

Recent publications have suggested that infective pathogens might play an important role in the pathogenesis of atherosclerosis. This review focuses on these microorganisms in the process of atherosclerosis. The results of in vitro studies, animal studies, tissue studies, and serological studies will be summarised, followed by an overall conclusion concerning the strength of the association of the microorganism with the pathogenesis of atherosclerosis. The role of the bacteria Chlamydia pneumoniae and Helicobacter pylori, and the viruses human immunodeficiency virus, coxsackie B virus, cytomegalovirus, Epstein-Barr virus, herpes simplex virus, and measles virus will be discussed. Key Words: atherosclerosis • Chlamydia pneumoniae • Helicobacter pylori

Morre, S; Stooker, W; Lagrand, W; van den Brule, A J C; Niessen, H

2000-01-01

252

[The occurrence of microorganisms in intraoral abscesses].  

PubMed

The aim of this study was to assess the occurrence of microorganisms in 39 intraoral abscesses. The samples were place in transport medium. The materials were inoculated on adequate enrichment and selective media and cultivated under anaerobic and aerobic conditions. The microorganisms were found in all samples (100%), Anaerobic bacteria most frequently were recovered. The predominant anaerobes were from genus Prevotella, Bacteroides, Fusobacterium and Peptostreptococcus. Among aerobic bacteria, the most frequent were gram-positive cocci. The microaerophilic bacteria and fungi most rarely were isolated from pus samples. PMID:16134393

Kedzia, Anna; Kiewlicz, Wojciech; Maciejewska, Katarzyna; Zienkiewicz, Józef; Dijakiewicz, Maciej; Kwapisz, Ewa; Ziemlewski, Adam

2005-01-01

253

Killing of adherent oral microbes by a non-thermal atmospheric plasma jet.  

PubMed

Atmospheric plasma jets are being intensively studied with respect to potential applications in medicine. The aim of this in vitro study was to test a microwave-powered non-thermal atmospheric plasma jet for its antimicrobial efficacy against adherent oral micro-organisms. Agar plates and dentin slices were inoculated with 6 log(10) c.f.u. cm(-2) of Lactobacillus casei, Streptococcus mutans and Candida albicans, with Escherichia coli as a control. Areas of 1 cm(2) on the agar plates or the complete dentin slices were irradiated with a helium plasma jet for 0.3, 0.6 or 0.9 s mm(-2), respectively. The agar plates were incubated at 37 degrees C, and dentin slices were vortexed in liquid media and suspensions were placed on agar plates. The killing efficacy of the plasma jet was assessed by counting the number of c.f.u. on the irradiated areas of the agar plates, as well as by determination of the number of c.f.u. recovered from dentin slices. A microbe-killing effect was found on the irradiated parts of the agar plates for L. casei, S. mutans, C. albicans and E. coli. The plasma-jet treatment reduced the c.f.u. by 3-4 log(10) intervals on the dentin slices in comparison to recovery rates from untreated controls. The microbe-killing effect was correlated with increasing irradiation times. Thus, non-thermal atmospheric plasma jets could be used for the disinfection of dental surfaces. PMID:19910483

Rupf, Stefan; Lehmann, Antje; Hannig, Matthias; Schäfer, Barbara; Schubert, Andreas; Feldmann, Uwe; Schindler, Axel

2010-02-01

254

Predicting how altering propagule pressure changes establishment rates of biological invaders across species pools.  

PubMed

Biological invasions resulting from international trade can cause major environmental and economic impacts. Propagule pressure is perhaps the most important factor influencing establishment, although actual arrival rates of species are rarely recorded. Furthermore, the pool of potential invaders includes many species that vary in their arrival rate and establishment potential. Therefore, we stress that it is essential to consider the size and composition of species pools arriving from source regions when estimating probabilities of establishment and effects of pathway infestation rates. To address this, we developed a novel framework and modeling approach to enable prediction of future establishments in relation to changes in arrival rate across entire species pools. We utilized 13 828 border interception records from the United States and New Zealand for 444 true bark beetle (Scolytinae) and longhorned beetle (Cerambycidae) species detected between 1949 and 2008 as proxies for arrival rates to model the relationship between arrival and establishment rates. Nonlinearity in this relationship implies that measures intended to reduce the unintended transport of potential invaders (such as phytosanitary treatments) must be highly effective in order to substantially reduce the rate of future invasions, particularly if trade volumes continue to increase. PMID:24804438

Brockerhoff, Eckehard G; Kimberley, Mark; Liebhold, Andrew M; Haack, Robert A; Cavey, Joseph F

2014-03-01

255

Competitive naïveté between a highly successful invader and a functionally similar native species.  

PubMed

Naïveté can occur within any novel antagonistic interaction, and competitive forces play a fundamental role in shaping community structure, yet competitive naïveté has received very little attention in the literature to date. Naïveté towards a novel competitor is unlikely to result in immediate mortality, but could potentially affect access to resources and hence population growth and survival. In cases where only one species (either native or alien) remains naïve to the other, the species that recognizes the other will gain advantage, with implications for both the persistence of the native species and the establishment and spread of the invasive. The invasive black rat (Rattus rattus) has spread throughout many coastal areas of Australia, and competes with the native bush rat (Rattus fuscipes) wherever they coexist. As these rats have now been interacting for approximately 200 years, and multi-species rodent communities generally maintain their structure through olfactory communication, our aim was to determine whether these two very closely related species recognize one another's odors and use them to mediate their interactions. We used remote-sensing cameras deployed in single- and mixed-species sites to record the behavioral responses of each species to conspecific, heterospecific and control odors. Black rats investigated bush rat odors but not vice versa, suggesting that bush rats may remain naïve towards their new competitor. Highly successful invaders such as black rats may possess traits such as broad recognition templates and rapid learning capabilities that contribute to their ongoing success in invading new environments. PMID:24390480

Heavener, Stephen J; Carthey, Alexandra J R; Banks, Peter B

2014-05-01

256

Conciliation biology: the eco-evolutionary management of permanently invaded biotic systems  

PubMed Central

Biotic invaders and similar anthropogenic novelties such as domesticates, transgenics, and cancers can alter ecology and evolution in environmental, agricultural, natural resource, public health, and medical systems. The resulting biological changes may either hinder or serve management objectives. For example, biological control and eradication programs are often defeated by unanticipated resistance evolution and by irreversibility of invader impacts. Moreover, eradication may be ill-advised when nonnatives introduce beneficial functions. Thus, contexts that appear to call for eradication may instead demand managed coexistence of natives with nonnatives, and yet applied biologists have not generally considered the need to manage the eco-evolutionary dynamics that commonly result from interactions of natives with nonnatives. Here, I advocate a conciliatory approach to managing systems where novel organisms cannot or should not be eradicated. Conciliatory strategies incorporate benefits of nonnatives to address many practical needs including slowing rates of resistance evolution, promoting evolution of indigenous biological control, cultivating replacement services and novel functions, and managing native–nonnative coevolution. Evolutionary links across disciplines foster cohesion essential for managing the broad impacts of novel biotic systems. Rather than signaling defeat, conciliation biology thus utilizes the predictive power of evolutionary theory to offer diverse and flexible pathways to more sustainable outcomes.

Carroll, Scott P

2011-01-01

257

Haemophilus ducreyi attaches to and invades human epithelial cells in vitro.  

PubMed Central

Haemophilus ducreyi is a sexually transmitted pathogen that causes genital ulcers and inguinal adenopathy. Because chancroidal ulcers are most commonly located on the foreskins of uncircumcised males, we utilized human foreskin epithelial cells (HFECs) to investigate the initial interaction of H. ducreyi with its host. The eight different strains of H. ducreyi that were studied varied in their abilities to attach to these epithelial cells, with six strains consistently attaching to > or = 90% of HFECs and two strains attaching to < 25% of HFECs. The strains with low levels of adherence also failed to exhibit chaining in broth culture and were avirulent in the rabbit model, suggesting that virulence in this model and attachment may be linked. The most adherent strain, LA228R, was further evaluated for its ability to invade HFECs and HEp-2 cells. Scanning electron microscopy and transmission electron microscopy of HFECs after interaction with LA228R produced images consistent with attachment, ingestion into vesicles, and escape from the vesicles into the cytoplasm. In addition, the gentamicin protection assay and inhibition of invasion by cytochalasin B and D indicated that LA228R was able to invade both HFECs and HEp-2 cells. Further examination of the mechanisms involved in the adherence and invasion of H. ducreyi into epithelial cells and their correlation with virulence will provide a better understanding of the pathogenesis of the disease caused by this important pathogen. Images

Totten, P A; Lara, J C; Norn, D V; Stamm, W E

1994-01-01

258

Glycosylation status of the C. albicans cell wall affects the efficiency of neutrophil phagocytosis and killing but not cytokine signaling  

PubMed Central

The cell wall of the opportunistic human fungal pathogen, Candida albicans is a complex, layered network of rigid structural polysaccharides composed of ?-glucans and chitin that is covered with a fibrillar matrix of highly glycosylated mannoproteins. Poly-morphonuclear cells (PMNs, neutrophils) are the most prevalent circulating phagocytic leukocyte in peripheral blood and they are pivotal in the clearance of invading fungal cells from tissues. The importance of cell-wall mannans for the recognition and uptake of C. albicans by human PMNs was therefore investigated. N- and O-glycosylation-deficient mutants were attenuated in binding and phagocytosis by PMNs and this was associated with reduced killing of C. albicans yeast cells. No differences were found in the production of the respiratory burst enzyme myeloperoxidase (MPO) and the neutrophil chemokine IL-8 in PMNs exposed to control and glycosylation-deficient C. albicans strains. Thus, the significant decrease in killing of glycan-deficient C. albicans strains by PMNs is a consequence of a marked reduction in phagocytosis rather than changes in the release of inflammatory mediators by PMNs.

Sheth, Chirag C; Hall, Rebecca; Lewis, Leanne; Brown, Alistair J P; Odds, Frank C; Erwig, Lars P; Gow, Neil A R

2011-01-01

259

Glycosylation status of the C. albicans cell wall affects the efficiency of neutrophil phagocytosis and killing but not cytokine signaling.  

PubMed

The cell wall of the opportunistic human fungal pathogen, Candida albicans is a complex, layered network of rigid structural polysaccharides composed of ?-glucans and chitin that is covered with a fibrillar matrix of highly glycosylated mannoproteins. Polymorphonuclear cells (PMNs, neutrophils) are the most prevalent circulating phagocytic leukocyte in peripheral blood and they are pivotal in the clearance of invading fungal cells from tissues. The importance of cell-wall mannans for the recognition and uptake of C. albicans by human PMNs was therefore investigated. N- and O-glycosylation-deficient mutants were attenuated in binding and phagocytosis by PMNs and this was associated with reduced killing of C. albicans yeast cells. No differences were found in the production of the respiratory burst enzyme myeloperoxidase (MPO) and the neutrophil chemokine IL-8 in PMNs exposed to control and glycosylation-deficient C. albicans strains. Thus, the significant decrease in killing of glycan-deficient C. albicans strains by PMNs is a consequence of a marked reduction in phagocytosis rather than changes in the release of inflammatory mediators by PMNs. PMID:21254968

Sheth, Chirag C; Hall, Rebecca; Lewis, Leanne; Brown, Alistair J P; Odds, Frank C; Erwig, Lars P; Gow, Neil A R

2011-07-01

260

Industrial and environmental applications of halophilic microorganisms  

Microsoft Academic Search

In comparison with the thermophilic and the alkaliphilic extremophiles, halophilic microorganisms have as yet found relatively few biotechnological applications. Halophiles are involved in centuries?old processes such as the manufacturing of solar salt from seawater and the production of traditional fermented foods. Two biotechnological processes involving halophiles are highly successful: the production of ??carotene by the green alga Dunaliella and the

Aharon Oren

2010-01-01

261

Biosurfactants, bioemulsifiers and exopolysaccharides from marine microorganisms  

Microsoft Academic Search

Marine biosphere offers wealthy flora and fauna, which represents a vast natural resource of imperative functional commercial grade products. Among the various bioactive compounds, biosurfactant (BS)\\/bioemulsifiers (BE) are attracting major interest and attention due to their structural and functional diversity. The versatile properties of surface active molecules find numerous applications in various industries. Marine microorganisms such as Acinetobacter, Arthrobacter, Pseudomonas,

Surekha K. Satpute; Ibrahim M. Banat; Prashant K. Dhakephalkar; Arun G. Banpurkar; Balu A. Chopade

2010-01-01

262

Radiation sensitivity of hyperthermal composting microorganisms  

NASA Astrophysics Data System (ADS)

In the space station and vehicles designed for long human mission, high-temperature compost is a promising technology for decomposing organic waste and producing the fertilizers. In space, the microorganisms could have the changed biological activities or even be mutated by ionizing irradiation. Therefore, in this study, the effect of gamma irradiation on the sensitivity of bacteria in hyperthermal composting was investigated. The sequence analysis of the amplified 16s rDNA genes and amoA gene were used for the identification of composting microorganisms. Viability of microorganisms in compost soil after gamma irradiation was directly visualized with LIVE/DEAD Baclight viability kit. The dominant bacterial genera are Weissella cibaria and Leuconostoc sp. and fungus genera are Metschnikowia bicuspidate and Pichia guilliermondii, respectively. By the gamma irradiation up to the dose of 1 kGy, the microbial population was not changed. Also, the enzyme activities of amylase and cellulose were sustained by the gamma irradiation. These results show that these hyperthermia microorganisms might have the high resistance to gamma radiation and could be used for agriculture in the Space Station.

Choi, Jong-Il; Yoon, Min-Chul; Kim, Jae-Hun; Yamashita, Masamichi; Kim, Geun Joong; Lee, Ju-Woon

263

Biotreatment of persistent substances using effective microorganisms  

Microsoft Academic Search

To efficiently biotreat the persistent substances contained in wastewater, it is necessary to fully elucidate the degradation mechanisms of the substances by specific degrading microorganisms. Especially clarifying the enzymatic reactions responsible for the degradation of persistent substances is very important. Here three different kinds of aerobic or oxidative degradation reactions of persistent substances are introduced. Polyvinyl alcohol (PVA) degradation by

M. Fujita; M. Ike; Y. Kawagoshi; N. Miyata

2000-01-01

264

ATMOSPHERIC BENZENE DEPLETION BY SOIL MICROORGANISMS  

EPA Science Inventory

Gaseous benzene was rapidly depleted in exposure chambers containing viable soils and plants. When separate components of the system were analyzed, no benzene was detected in soils, plants, or water. Soil microorganisms were shown to be responsible for metabolizing benzene, yield...

265

Microbial biogeography: putting microorganisms on the map  

Microsoft Academic Search

We review the biogeography of microorganisms in light of the biogeography of macroorganisms. A large body of research supports the idea that free-living microbial taxa exhibit biogeographic patterns. Current evidence confirms that, as proposed by the Baas-Becking hypothesis, 'the environment selects' and is, in part, responsible for spatial variation in microbial diversity. However, recent studies also dispute the idea that

Jennifer B. Hughes Martiny; Brendan J. M. Bohannan; James H. Brown; Robert K. Colwell; Jed A. Fuhrman; Jessica L. Green; M. Claire Horner-Devine; Matthew Kane; Jennifer Adams Krumins; Cheryl R. Kuske; Peter J. Morin; Shahid Naeem; Lise Øvreås; Anna-Louise Reysenbach; Val H. Smith; James T. Staley

2006-01-01

266

Measuring micro-organism gas production  

NASA Technical Reports Server (NTRS)

Transducer, which senses pressure buildup, is easy to assemble and use, and rate of gas produced can be measured automatically and accurately. Method can be used in research, in clinical laboratories, and for environmental pollution studies because of its ability to detect and quantify rapidly the number of gas-producing microorganisms in water, beverages, and clinical samples.

Wilkins, J. R.; Pearson, A. O.; Mills, S. M.

1973-01-01

267

Extremophilic microorganisms as candidates for extraterrestrial life  

Microsoft Academic Search

Microbial life is found all over the globe. Diverse communities are even found in such places in which extreme conditions with respect of temperature, salinity, pH, and pressure prevail. Many of these environments were until recently considered too harsh to harbor microbial life. The micro-organisms adapted to an existence at the edge of life are termed extremophiles. They include members

Joseph Seckbach; Aharon Oren

2000-01-01

268

Metabolism of Selected Pesticides by Marine Microorganisms.  

National Technical Information Service (NTIS)

A number of marine microorganisms including algae, bacteria, fungi and yeasts were treated for their ability to metabolize carbaryl (1-naphthyl-N-methyl-carbamate) and 1-naphthol. None of the species included in the study were able to degrade carbaryl to ...

H. C. Sikka S. Miyazaki C. P. Rice

1973-01-01

269

[Sorption of microorganisms by fiber materials].  

PubMed

Candida guilliermondii and Escherichia coli cells were adsorbed on glass and basalt fibres with a similar specific surface, but with a different charge. The quantity of adsorbed microorganisms did not depend on the type and charge of a fibre surface. However, cells were adsorbed faster and more firmly on positively charged and uncharged fibres than on negatively charged fibres. PMID:3534527

Nikovskaia, G N; Gordienko, A S; Globa, L I

1986-01-01

270

Heat shock response in hyperthermophilic microorganisms  

Microsoft Academic Search

Hydrothermal environments contain steep thermal gradients and variable temperature conditions. Hyperthermophilic microorganisms, those which grow at temperatures exceeding 90°C, are common in these environments and have numerous means for tolerating hyperthermal stress. All hyperthermophiles examined produce a heteromeric chaperonin complex which is the primary protein produced during heat shock, though other proteins of unknown function are also produced. Furthermore, many

James F. Holden; Michael W. W. Adams; John A. Baross

2000-01-01

271

Degradation of nitroaromatic compounds by microorganisms  

Microsoft Academic Search

Nitroaromatic compounds are abundantly present in nature, but are in most cases highly toxic to living organisms. Several microorganisms, however, are capable of mineralizing or converting these compounds. Until now four pathways for the complete degradation of nitroaromatics have been described, which start with either the oxygenolytic or reductive removal of the nitro group from the aromatic ring or with

F. D. Marvin-Sikkema; J. A. M. de Bont

1994-01-01

272

TOWARDS A UNIFIED EVOLUTIONARY GENETICS OF MICROORGANISMS  

Microsoft Academic Search

I propose here that evolutionary genetics, apart from improving our basic knowl- edge of the taxonomy and evolution of microbes (either eukaryotes or prokary- otes), can also greatly contribute to applied research in microbiology. Evolution- ary genetics provides convenient guidelines for better interpreting genetic and molecular data dealing with microorganisms. The three main potential applica- tions of evolutionary genetics in

M. Tibayrenc

1996-01-01

273

Design of Targeted B Cell Killing Agents  

PubMed Central

B cells play an important role in the pathogenesis of both systemic and organ-specific autoimmune diseases. Autoreactive B cells not only produce autoantibodies, but also are capable to efficiently present specific autoantigens to T cells. Furthermore, B cells can secrete proinflammatory cytokines and amplify the vicious process of self-destruction. B cell-directed therapy is a potentially important approach for treatment of various autoimmune diseases. The depletion of B cells by anti-CD20/19 monoclonal antibody Retuximab® used in autoimmune diseases therapy leads to systemic side effects and should be significantly improved. In this study we designed a repertoire of genetically engineered B cell killers that specifically affected one kind of cells carrying a respective B cell receptor. We constructed immunotoxins (ITs), fused with c-myc epitope as a model targeting sequence, based on barnase, Pseudomonas toxin, Shiga-like toxin E.coli and Fc domain of human antibody IgG?1. C-MYC hybridoma cell line producing anti-c-myc IgG was chosen as a model for targeted cell depletion. C-myc sequence fused with toxins provided addressed delivery of the toxic agent to the target cells. We demonstrated functional activity of designed ITs in vitro and showed recognition of the fusion molecules by antibodies produced by targeted hybridoma. To study specificity of the proposed B cells killing molecules, we tested a set of created ITs ex vivo, using C-MYC and irrelevant hybridoma cell lines. Pseudomonas-containing IT showed one of the highest cytotoxic effects on the model cells, however, possessed promiscuous specificity. Shiga-like toxin construct demonstrated mild both cytotoxicity and specificity. Barnase and Fc-containing ITs revealed excellent balance between their legibility and toxic properties. Moreover, barnase and Fc molecules fused with c-myc epitope were able to selectively deplete c-myc-specific B cells and decrease production of anti-c-myc antibodies in culture of native splenocytes, suggesting their highest therapeutic potential as targeted B cell killing agents.

Ponomarenko, Natalia A.; Stremovskiy, Oleg A.; Kozlov, Leonid V.; Bichucher, Anna M.; Dmitriev, Sergey E.; Smirnov, Ivan V.; Shamborant, Olga G.; Balabashin, Dmitry S.; Sashchenko, Lidia P.; Tonevitsky, Alexander G.; Friboulet, Alain; Gabibov, Alexander G.; Deyev, Sergey M.

2011-01-01

274

Control of Influenza and Poliomyelitis with Killed Virus Vaccines  

ERIC Educational Resources Information Center

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)

Salk, Jonas; Salk, Darrell

1977-01-01

275

Potatis: Ny Teknik foer Blastdoedning (Potatoes: Haulm Killing).  

National Technical Information Service (NTIS)

Treatment and killing of haulm is an important part of potato-growing. Haulm killing is a means of terminating growth when the tubers have reached a suitable size, and also to prepare the tubers for harvesting. The resistance of the skin and the tuber to ...

K. Larsson

1992-01-01

276

Infant Killing and Cannibalism in Free-Living Chimpanzees  

Microsoft Academic Search

Male chimpanzees at the Gombe National Park were twice seen to attack ‘stranger’ females and seize their infants. One infant was then killed and partially eaten: the other was ‘rescued’ and carried by three different males. Once several males were found eating a freshly killed ‘stranger’ infant. A similar event was observed in Uganda by Dr. Suzuki, and Dr. Nishida

Jane Goodall

1977-01-01

277

Clustering of apoptotic cells via bystander killing by peroxides  

Microsoft Academic Search

Clustering of apoptotic cells is a char- acteristic of many developing or renewing systems, suggesting that apoptotic cells kill bystanders. By- stander killing can be triggered experimentally by inducing apoptosis in single cells and may be based on the exchange of as yet unidentified chemical cell death signals between nearby cells without the need for cell-to-cell communication via gap junctions.

KYRILL REZNIKOV; LARISSA KOLESNIKOVA; ALADDIN PRAMANIK; KOICHI TAN-NO; IRINA GILEVA; TATJANA YAKOVLEVA; RUDOLF RIGLER; LARS TERENIUS; GEORGY BAKALKIN

2000-01-01

278

Flat deformation of a spacetime with two Killing fields  

NASA Astrophysics Data System (ADS)

It is shown that, given an analytic Lorentzian metric on a 4-manifold, gab, which admits two Killing vector fields, it exists a local deformation law ?ab = agab + b Hab, where Hab is a 2-dimensional projector, such that ?ab is flat and admits the same Killing vectors.

Llosa, Josep; Carot, Jaume

2010-05-01

279

Killing of Bacteria by Copper Surfaces Involves Dissolved Copper?  

PubMed Central

Bacteria are rapidly killed on copper surfaces. However, the mechanism of this process remains unclear. Using Enterococcus hirae, the effect of inactivation of copper homeostatic genes and of medium compositions on survival and copper dissolution was tested. The results support a role for dissolved copper ions in killing.

Molteni, Cristina; Abicht, Helge K.; Solioz, Marc

2010-01-01

280

Characterization of a novel C-type lectin, Bombyx mori multibinding protein, from the B. mori hemolymph: mechanism of wide-range microorganism recognition and role in immunity.  

PubMed

To investigate the system used by insects to recognize invading microorganisms, we examined proteins from the larval hemolymph of Bombyx mori that bind to the cell surface of microorganisms. Two hemolymph proteins that bound to the cell surfaces of Micrococcus luteus and Saccharomyces cerevisiae were shown to be identical. This protein bound to all 11 microorganisms examined-5 Gram-negative bacteria, 3 Gram-positive bacteria, and 3 yeasts-and was consequently designated B. mori multibinding protein (BmMBP). The sequence of the cDNA encoding BmMBP revealed that it was a C-type lectin with two dissimilar carbohydrate-recognition domains (CRD1 and CRD2) distantly related to known insect C-type lectins. CRD1 and CRD2 were prepared as recombinant proteins and their binding properties were investigated using inhibition assays. Each domain had wide, dissimilar binding spectra to sugars. These properties enable BmMBP to bind to two sites on a microorganism, facilitating high-affinity binding to many types of microorganisms. The dissociation constants of BmMBP with M. luteus cells and S. cerevisiae were 1.23 x 10(-8) and 1.00 x 10(-11) M, respectively. rBmMBP triggered the aggregation of hemocytes from B. mori larvae in vitro and microorganisms recognized by BmMBP were surrounded by aggregated hemocytes in vivo, forming a nodule, which is the typical cellular reaction in insect immune responses. These observations suggest that BmMBP functions as a trigger for the nodule reaction and that the multirecognition characteristic of BmMBP plays an important role in the early stages of infection by a variety of microorganisms. PMID:16982897

Watanabe, Ayako; Miyazawa, Sousui; Kitami, Madoka; Tabunoki, Hiroko; Ueda, Kenjiro; Sato, Ryoichi

2006-10-01

281

When CO2 kills: effects of magmatic CO2 flux on belowground biota at Mammoth Mountain, CA  

NASA Astrophysics Data System (ADS)

The biomass, composition, and activity of the soil microbial community is tightly linked to the composition of the aboveground plant community. Microorganisms in aerobic surface soils, both free-living and plant-associated are largely structured by the availability of growth limiting carbon (C) substrates derived from plant inputs. When C availability declines following a catastrophic event such as the death of large swaths of trees, the number and composition of microorganisms in soil would be expected to decline and/or shift to unique microorganisms that have better survival strategies under starvation conditions. High concentrations of volcanic cold CO2 emanating from Mammoth Mountain near Horseshoe Lake on the southwestern edge of Long Valley Caldera, CA has resulted in a large kill zone of tree species, and associated soil microbial species. In July 2010, we assessed belowground microbial community structure in response to disturbance of the plant community along a gradient of soil CO2 concentrations grading from <0.6% (ambient forest) to >80% (no plant life). We employed a microbial community fingerprinting technique (automated ribosomal intergenic spacer analysis) to determine changes in overall community composition for three broad functional groups: fungi, bacteria, and archaea. To evaluate changes in ectomycorrhizal fungal associates along the CO2 gradient, we harvested root tips from lodgepole pine seedlings collected in unaffected forest as well as at the leading edge of colonization into the kill zone. We also measured soil C fractions (dissolved organic C, microbial biomass C, and non-extractable C) at 10 and 30 cm depth, as well as NH4+. Not surprisingly, our results indicate a precipitous decline in soil C, and microbial C with increasing soil CO2; phospholipid fatty acid analysis in conjunction with community fingerprinting indicate both a loss of fungal diversity as well as a dramatic decrease in biomass as one proceeds further into the kill zone. This observation was concomitant with a relative increase in bacterial and archaeal contributions to microbial community structure. Root tip analyses among lodgepole seedlings recolonizing the kill zone area demonstrated a significant reduction in the overall diversity of fungal symbionts, as well as a distinct shift in fungal assemblages. In particular, within elevated CO2 areas, we observed a high infection level for the ascomycetous fungi, Wilcoxina spp., which appear particularly well-adapted for colonization in disturbed environments. It remains unclear whether dominance by ascomycetes among seedlings in elevated CO2 areas represents a coordinated shift orchestrated by the plant in response to physiological stress, or whether these fungi are simply more opportunistic than their basdiomycetous counterparts. Our results demonstrate the impact of large-scale disturbances on plant-microbial interactions and belowground processes in previously forested ecosystems.

McFarland, J.; Waldrop, M. P.; Mangan, M.

2011-12-01

282

Stand Structural Controls on Evapotranspiration in Native and Invaded Tropical Montane Cloud Forest in Hawai'i  

NASA Astrophysics Data System (ADS)

Tropical montane cloud forests (TMCFs) in Hawai'i are important zones of water input and stores of critically important native plant and animal species. Invasion by alien tree species threatens these forests and may alter the hydrological services they provide. At two TMCF sites in Hawai'i, one within native Metrosideros polymorpha forest and the other at a site heavily invaded by Psidium cattleianum, we are conducting measurements of stand-level evapotranspiration (ET), transpiration (using sapflow techniques), energy balance, and related processes. Previously presented results showed that ET as a function of available energy was 27% higher at the invaded site than the native site, with the difference rising to 53% during dry- canopy periods. In this presentation, mechanisms for the observed higher ET rate at the invaded site are explored. The difference in measured xylem flow velocities of native and alien trees cannot explain the observed stand level ET difference. Tree basal area is lower at the invaded site than the native site, again contrary to the ET difference. However, the alien trees have much smaller stem diameters, on average, than the native trees, with little or no heartwood. Hence, the cross-sectional xylem area is much greater in the invaded stand, facilitating higher transpiration rates. These results demonstrate the importance of stand structural controls on ET and raise questions about whether higher ET is a transient feature of the succession or a persistent characteristic of invasive trees.

Giambelluca, T. W.; Delay, J. K.; Asner, G. P.; Martin, R. E.; Nullet, M. A.; Huang, M.; Mudd, R. G.; Takahashi, M.

2008-12-01

283

Killing, letting die and moral perception.  

PubMed

There are a number of arguments that purport to show, in general terms, that there is no difference between killing and letting die. These are used to justify active euthanasia on the basis of the reasons given for allowing patients to die. I argue that the general and abstract arguments fail to take account of the complex and particular situations which are found in the care of those with terminal illness. When in such situations, there are perceptions and intuitions available that do not easily find propositional form but lead most of those whose practice is in the care of the dying to resist active euthanasia. I make a plea for their intuitions to be heeded above the sterile voice of abstract premises and arguments by examining the completeness of the outline form of the pro-euthanasia argument. In doing so, I make use of Nussbaum's discussion of moral perception and general claims to be found in the literature of moral particularism. PMID:11654118

Gillett, Grant

1994-10-01

284

Killing of Leishmania parasites in activated murine macrophages is based on an L-arginine-dependent process that produces nitrogen derivatives  

SciTech Connect

The experiments described in this report were aimed at determining whether L-arginine (L-arg)-derived nitrogen oxidation products (nitric oxide, nitrous acid, nitrites) are involved in the intracellular killing of Leishmania parasites by activated murine macrophages in vitro. Peritoneal or bone marrow-derived macrophages were infected with L. enriettii or L. major, then activated by exposure to recombinant murine interferon-gamma or to macrophage activating factor (MAF)-rich media in the presence of lipopolysaccharide. Activation of macrophages in regular (i.e., arginine-containing) culture medium led to complete destruction of the microorganisms within 24 h (L. enriettii) or 48 h (L. major), concomitant with accumulation of nitrites (NO2-) in the culture fluids. When macrophage activation was carried out in L-arg-free medium, however, neither parasite killing nor NO2- production was obtained. A similar inhibition of macrophage leishmanicidal activity and of NO2- release was observed using media treated with arginase (which converts L-arg to urea and ornithine), or supplemented with NG-monomethyl-L-arg or guanidine (which inhibit the conversion of L-arg to nitrogen oxidation products). In all these situations, an excellent correlation between the levels of NO2- production by macrophages and intracellular killing of Leishmania was observed, whereas no strict correlation was detectable between leishmanicidal activity and superoxide production. Intracellular parasite killing by activated macrophages could be prevented by addition of iron salts to the incubation fluids. Incubation of free parasites with NaNO2 at acid pH led to immobilisation, multiplication arrest, and morphological degeneration of the microorganisms. Similarly, exposure of infected cells to NaNO2 led to killing of the intracellular parasite without affecting macrophage viability.

Maul, J.R.; Ransijn, A.; Buchmueller-Rouiller, Y. (Institute of Biochemistry, Epalinges (Switzerland))

1991-01-01

285

Psychological traits underlying different killing methods among Malaysian male murderers.  

PubMed

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 slashing also displayed a higher level of minimisation traits. Despite its limitations, this study has provided some light on the underlying psychological traits of different killing methods which is useful in the field of criminology. PMID:24763234

Kamaluddin, M R; Shariff, N S; Nur-Farliza, S; Othman, A; Ismail, K; Mat Saat, G A

2014-04-01

286

Cryopreserved Reticulocytes Derived from Hematopoietic Stem Cells Can Be Invaded by Cryopreserved Plasmodium vivax Isolates  

PubMed Central

The development of a system for the continuous culture of Plasmodium vivax in vitro would benefit from the use of reticulocytes derived from differentiated hematopoietic stem cells (HCS). At present, the need to use both fresh reticulocytes and fresh P. vivax isolates represents a major obstacle towards this goal, particularly for laboratories located in non-endemic countries. Here, we describe a new method for the cryopreservation of HSC-derived reticulocytes to be used for both P. falciparum and P. vivax invasion tests. Cryopreserved P. falciparum and P. vivax isolates could invade both fresh and cryopreserved HSC-derived reticulocytes with similar efficiency. This new technique allows the storage of HSC-derived reticulocytes which can be used for later invasion tests and represents an important step towards the establishment of a continuous P. vivax culture.

Noulin, Florian; Borlon, Celine; van den Eede, Peter; Boel, Luc; Verfaillie, Catherine M.; D'Alessandro, Umberto; Erhart, Annette

2012-01-01

287

Invaded grassland communities have altered stability-maintenance mechanisms but equal stability compared to native communities.  

PubMed

Theory predicts that stability should increase with diversity via several mechanisms. We tested predictions in a 5-year experiment that compared low-diversity exotic to high-diversity native plant mixtures under two irrigation treatments. The study included both wet and dry years. Variation in biomass across years (CV) was 50% lower in mixtures than monocultures of both native and exotic species. Growth among species was more asynchronous and overyielding values were greater during and after a drought in native than exotic mixtures. Mean-variance slopes indicated strong portfolio effects in both community types, but the intercept was higher for exotics than for natives, suggesting that exotics were inherently more variable than native species. However, this failed to result in higher CV's in exotic communities because species that heavily dominated plots tended to have lower than expected variance. Results indicate that diversity-stability mechanisms are altered in invaded systems compared to native ones they replaced. PMID:24325664

Wilsey, Brian J; Daneshgar, Pedram P; Hofmockel, Kirsten; Polley, H Wayne

2014-01-01

288

Marsh thistle in New York: early detection and rapid response to a recent invader.  

PubMed

Case studies implementing early detection and rapid response (EDRR) protocols are crucial to our understanding of how to evaluate the threat of a new invasive organism. Most EDRR schematics depict a linear approach to EDRR beginning with detection, then assessment, and concluding with the rapid response. Our case study exemplified the need to adjust this protocol by interlacing all three phases. Our target species is a recent invader to central New York: Cirsium palustre (marsh thistle). We observed 192 populations and reported them on iMapInvasives.org. These locations were used to generate risk maps of neighboring counties. Six test plots evaluated the plant's bienniality and monocarpism. A life-stage analysis allowed us to delineate the invasion front to target control and management solutions where they are most effective for marsh thistle. An adaptive approach to EDRR can expedite response strategies, develop risk maps, and train partners for better control. PMID:23777579

Hinchey, Eamonn; Vogler, Donna; Stressler, Joseph

2013-06-18

289

Heparan Sulfate Proteoglycans Provide a Signal to Plasmodium Sporozoites to Stop Migrating and Productively Invade Cells  

PubMed Central

Summary Malaria infection is initiated when Anopheline mosquitoes inject sporozoites into the skin. Further development requires that sporozoites reach the liver, invade hepatocytes and develop into exoerythrocytic forms. Sporozoites contact and traverse many cell types as they migrate from skin to liver, however, the mechanism by which they switch from a migratory mode to an invasive mode is unknown. Using a rodent model system, we show that sporozoites use the sulfation level of host heparan-sulfate proteoglycans (HSPGs) to navigate in the mammalian host. Sporozoites migrate through cells expressing low-sulfated HSPGs, such as those in skin and endothelium, while highly-sulfated HSPGs of hepatocytes activate sporozoites for invasion. A calcium-dependent protein kinase is critical for the switch to an invasive phenotype and the process is accompanied by proteolytic cleavage of the sporozoite’s major surface protein. These findings explain how sporozoites retain their infectivity for an organ that is far from their site of entry.

Coppi, Alida; Tewari, Rita; Bishop, Joseph R.; Bennett, Brandy L.; Lawrence, Roger; Esko, Jeffrey D.; Billker, Oliver; Sinnis, Photini

2007-01-01

290

The steepest S curve of spreading and collecting flows: Discovering the invading tree, not assuming it  

NASA Astrophysics Data System (ADS)

Spreading and collecting flows are united by the flow design known as the S-curve: when plotted versus time, the size of the domain that is filled or emptied has a history that is shaped as an S. Here, we show that the fastest spreading or collecting (i.e., the steepest S curve) is discovered by allowing the tree architecture to morph freely, toward greater access over time, in accord with the constructal law of design in nature. The angles between the lines of the invading flow architecture can be selected such that the overall flow proceeds the fastest, covering the greatest territory at any moment. The design is a sequence of two distinct phenomena: ``invasion'' by channels and branches that grow fast, and ``consolidation'' by slow diffusion perpendicular to the channels. Invasion and consolidation collaborate hand-in-glove to facilitate the spreading or collecting over the available finite area or volume.

Cetkin, E.; Lorente, S.; Bejan, A.

2012-05-01

291

The steepest S curve of spreading and collecting flows: Discovering the invading tree, not assuming it  

NASA Astrophysics Data System (ADS)

Spreading and collecting flows are united by the flow design known as the S-curve: when plotted versus time, the size of the domain that is filled or emptied has a history that is shaped as an S. Here, we show that the fastest spreading or collecting (i.e., the steepest S curve) is discovered by allowing the tree architecture to morph freely, toward greater access over time, in accord with the constructal law of design in nature. The angles between the lines of the invading flow architecture can be selected such that the overall flow proceeds the fastest, covering the greatest territory at any moment. The design is a sequence of two distinct phenomena: ``invasion'' by channels and branches that grow fast, and ``consolidation'' by slow diffusion perpendicular to the channels. Invasion and consolidation collaborate hand-in-glove to facilitate the spreading or collecting over the available finite area or volume.

Cetkin, E.; Lorente, S.; Bejan, A.

2012-06-01

292

Atypical esthesioneuroblastoma invading oral cavity: a case report and review of the literature  

PubMed Central

Esthesioneuroblastoma is an uncommon tumour of neuroectodermal origin. The authors describe a rare presentation of an atypical esthesioneuroblastoma invading oral cavity. The clinical presentation, aetiology, diagnosis, and management of this condition are discussed. The patient developed significant swelling in the right anterosuperior alveolar mucosa and had moderate tooth mobility. Conventional x-rays and computed tomography revealed a large osteolytic lesion, with imprecise limits. Histological findings along with immunohistochemical staining results and clinical features led to the diagnosis of high-grade esthesioneuroblastoma. Local recurrences and neck metastasis were detected. The rare oral findings produced delayed in diagnosis which may lead to a compromise in planning and execution of further radical management and thus a poor prognosis. Virtual slides The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1168853011139286.

2014-01-01

293

Stoichiometric Constraints Do Not Limit Successful Invaders: Zebra Mussels in Swedish Lakes  

PubMed Central

Background Elemental imbalances of carbon (C): nitrogen (N): phosphorus (P) ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel how a successful invader tackles ecological barriers in novel ecosystems. Methodology/Principal Findings We examined the C?P and N?P ratios and the condition factor of a successful invader in lakes, the zebra mussel (Dreissena polymorpha), collected from two Swedish lakes. Concurrently, we analyzed the elemental composition of the food (seston) and tissue of the mussels in which nutrient composition of food and mussels varied over time. Zebra mussel condition factor was weakly related to the their own tissue N?P and C?P ratios, although the relation with the later ratio was not significant. Smaller mussels had relatively lower tissue N?P ratio and higher condition factor. There was no difference in C?P and N?P ratios between seston and mussels' tissues. Our results indicated that the variation in nutrient stoichiometry of zebra mussels can be explained by food quality and quantity. Conclusions/Significance Our study suggests that fitness of invasive zebra mussels is not constrained by nutrient stoichiometry which is likely to be important for their proliferation in novel ecosystems. The lack of imbalance in C?P and N?P ratios between seston and mussels along with high tissue C?P ratio of the mussel allow them to tolerate potential P limitation and maintain high growth rate. Moreover, zebra mussels are able to change their tissue C?P and N?P ratios in response to the variation in elemental composition of their food. This can also help them to bypass potential nutrient stoichiometric constraints. Our finding is an important step towards understanding the mechanisms contributing to the success of exotic species from stoichiometric principles.

Naddafi, Rahmat; Eklov, Peter; Pettersson, Kurt

2009-01-01

294

Differences in ecological structure, function, and native species abundance between native and invaded Hawaiian streams.  

PubMed

Poeciliids, one of the most invasive species worldwide, are found on almost every continent and have been identified as an "invasive species of concern" in the United States, New Zealand, and Australia. Despite their global prevalence, few studies have quantified their impacts on tropical stream ecosystem structure, function, and biodiversity. Utilizing Hawaiian streams as model ecosystems, we documented how ecological structure, function, and native species abundance differed between poeciliid-free and poeciliid-invaded tropical streams. Stream nutrient yields, benthic biofilm biomass, densities of macroinvertebrates and fish, and community structures of benthic algae, macroinvertebrates, and fish were compared between streams with and without established poeciliid populations on the island of Hawai'i, Hawaii, USA. Sum nitrate (sigmaNO3(-) = NO3(-) + NO2(-)), total nitrogen, and total organic carbon yields were eight times, six times, and five times higher, respectively, in poeciliid streams than in poeciliid-free streams. Benthic biofilm ash-free dry mass was 1.5x higher in poeciliid streams than in poeciliid-free streams. Percentage contributions of chironomids and hydroptilid caddisflies to macroinvertebrate densities were lower in poeciliid streams compared to poeciliid-free streams, while percentage contributions of Cheumatopsyche analis caddisflies, Dugesia sp. flatworms, and oligochaetes were higher. Additionally, mean densities of native gobies were two times lower in poeciliid streams than in poeciliid-free ones, with poeciliid densities being approximately eight times higher than native fish densities. Our results, coupled with the wide distribution of invasive poeciliids across Hawaii and elsewhere in the tropics, suggest that poeciliids may negatively impact the ecosystem structure, function, and native species abundance of tropical streams they invade. This underscores the need for increased public awareness to prevent future introductions and for developing and implementing effective eradication and restoration strategies. PMID:24147409

Holitzki, Tara M; MacKenzie, Richard A; Wiegner, Tracy N; McDermid, Karla J

2013-09-01

295

Grassland invaders and their mycorrhizal symbionts: a study across climate and invasion gradients.  

PubMed

Controlled experiments show that arbuscular mycorrhizal fungi (AMF) can increase competitiveness of exotic plants, potentially increasing invasion success. We surveyed AMF abundance and community composition in Centaurea stoebe and Potentilla recta invasions in the western USA to assess whether patterns were consistent with mycorrhizal-mediated invasions. We asked whether (1) AMF abundance and community composition differ between native and exotic forbs, (2) associations between native plants and AMF shift with invading exotic plants, and (3) AMF abundance and/or community composition differ in areas where exotic plants are highly invasive and in areas where they are not. We collected soil and roots from invaded and native forb communities along invasion gradients and in regions with different invasion densities. We used AMF root colonization as a measure of AMF abundance and characterized AMF communities in roots using 454-sequencing of the LSU-rDNA region. All plants were highly colonized (>60%), but exotic forbs tended to be more colonized than natives (P < 0.001). We identified 30 AMF operational taxonomic units (OTUs) across sites, and community composition was best predicted by abiotic factors (soil texture, pH). Two OTUs in the genera Glomus and Rhizophagus dominated in most communities, and their dominance increased with invasion density (r = 0.57, P = 0.010), while overall OTU richness decreased with invasion density (r = -0.61, P = 0.006). Samples along P. recta invasion gradients revealed small and reciprocal shifts in AMF communities with >45% fungal OTUs shared between neighboring native and P. recta plants. Overall, we observed significant, but modest, differences in AMF colonization and communities between co-occurring exotic and native forbs and among exotic forbs across regions that differ in invasion pressure. While experimental manipulations are required to assess functional consequences, the observed patterns are not consistent with those expected from strong mycorrhizal-mediated invasions. PMID:24683461

Bunn, Rebecca A; Lekberg, Ylva; Gallagher, Christopher; Rosendahl, Søren; Ramsey, Philip W

2014-03-01

296

Listeria monocytogenes Invades the Epithelial Junctions at Sites of Cell Extrusion  

PubMed Central

Listeria monocytogenes causes invasive disease by crossing the intestinal epithelial barrier. This process depends on the interaction between the bacterial surface protein Internalin A and the host protein E-cadherin, located below the epithelial tight junctions at the lateral cell-to-cell contacts. We used polarized MDCK cells as a model epithelium to determine how L. monocytogenes breaches the tight junctions to gain access to this basolateral receptor protein. We determined that L. monocytogenes does not actively disrupt the tight junctions, but finds E-cadherin at a morphologically distinct subset of intercellular junctions. We identified these sites as naturally occurring regions where single senescent cells are expelled and detached from the epithelium by extrusion. The surrounding cells reorganize to form a multicellular junction that maintains epithelial continuity. We found that E-cadherin is transiently exposed to the lumenal surface at multicellular junctions during and after cell extrusion, and that L. monocytogenes takes advantage of junctional remodeling to adhere to and subsequently invade the epithelium. In intact epithelial monolayers, an anti-E-cadherin antibody specifically decorates multicellular junctions and blocks L. monocytogenes adhesion. Furthermore, an L. monocytogenes mutant in the Internalin A gene is completely deficient in attachment to the epithelial apical surface and is unable to invade. We hypothesized that L. monocytogenes utilizes analogous extrusion sites for epithelial invasion in vivo. By infecting rabbit ileal loops, we found that the junctions at the cell extrusion zone of villus tips are the specific target for L. monocytogenes adhesion and invasion. Thus, L. monocytogenes exploits the dynamic nature of epithelial renewal and junctional remodeling to breach the intestinal barrier.

Pentecost, Mickey; Otto, Glen

2006-01-01

297

Bone invading NSCLC cells produce IL-7: mice model and human histologic data  

PubMed Central

Background Bone metastases are a common and dismal consequence of lung cancer that is a leading cause of death. The role of IL-7 in promoting bone metastases has been previously investigated in NSCLC, but many aspects remain to be disclosed. To further study IL-7 function in bone metastasis, we developed a human-in-mice model of bone aggression by NSCLC and analyzed human bone metastasis biopsies. Methods We used NOD/SCID mice implanted with human bone. After bone engraftment, two groups of mice were injected subcutaneously with A549, a human NSCLC cell line, either close or at the contralateral flank to the human bone implant, while a third control group did not receive cancer cells. Tumor and bone vitality and IL-7 expression were assessed in implanted bone, affected or not by A549. Serum IL-7 levels were evaluated by ELISA. IL-7 immunohistochemistry was performed on 10 human bone NSCLC metastasis biopsies for comparison. Results At 12 weeks after bone implant, we observed osteogenic activity and neovascularization, confirming bone vitality. Tumor aggressive cells implanted close to human bone invaded the bone tissue. The bone-aggressive cancer cells were positive for IL-7 staining both in the mice model and in human biopsies. Higher IL-7 serum levels were found in mice injected with A549 cells close to the bone implant compared to mice injected with A549 cells in the flank opposite to the bone implant. Conclusions We demonstrated that bone-invading cells express and produce IL-7, which is known to promote osteoclast activation and osteolytic lesions. Tumor-bone interaction increases IL-7 production, with an increase in IL-7 serum levels. The presented mice model of bone invasion by contiguous tumor is suitable to study bone-tumor cell interaction. IL-7 plays a role in the first steps of metastatic process.

2010-01-01

298

New microorganisms and processes for MEOR. Final report.  

National Technical Information Service (NTIS)

Oil reservoirs naturally contain inorganic and organic materials which may be exploited through simple mineral supplementation to support the growth of denitrifying microorganisms. The growth and metabolic products from the presence of these microorganism...

P. L. Sperl G. T. Sperl

1993-01-01

299

Investigation to identify paint coatings resistive to microorganism growth  

NASA Technical Reports Server (NTRS)

All selected coatings contain nutrients that support microbial growth and survival. Incorporation of microbiocidal agents into coatings more susceptible to attack is recommended for improved inhibition of microorganism growth and for increased protection against deterioration of coatings by microorganisms.

Cooper, C. W.; Kemp, H. T.

1971-01-01

300

MODELING THE FATE OF MICROORGANISMS IN WATER, WASTEWATER, AND SOIL  

EPA Science Inventory

The natural environment is filled with microorganisms, most of which are natural residents and colonize various ecological niches. These microorganisms either live independently within the environment, or live in association with various host organisms. There also are places and ...

301

ESTIMATING MICROORGANISM DENSITIES IN AEROSOLS FROM SPRAY IRRIGATION OF WASTEWATER  

EPA Science Inventory

This document summarizes current knowledge about estimating the density of microorganisms in the air near wastewater management facilities, with emphasis on spray irrigation sites. One technique for modeling microorganism density in air is provided and an aerosol density estimati...

302

Did Vertigo Kill America's Forgotten Astronaut?  

NASA Technical Reports Server (NTRS)

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 application to the commercial space industry today.

Bendrick, Gregg A.; Merlin, Peter W.

2007-01-01

303

Generalized Killing-Yano equations in D=5 gauged supergravity  

NASA Astrophysics Data System (ADS)

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-Cveti?-Lü-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.

Kubiz?ák, David; Kunduri, Hari K.; Yasui, Yukinori

2009-07-01

304

Invader plus method detects herpes simplex virus in cerebrospinal fluid and simultaneously differentiates types 1 and 2.  

PubMed

We report here on the development and validation of a prototype Invader Plus method for the qualitative detection of herpes simplex virus types 1 and 2 in cerebrospinal fluid (CSF). The method combines PCR and Invader techniques in a single, closed-tube, continuous-reaction format that gives an analytical sensitivity of approximately 10 copies per reaction. The clinical sensitivity and specificity were 100.0% and 98.6%, respectively, when the results of the method were validated against the results obtained with a PCR colorimetric microtiter plate system by use of clinical CSF specimens. PMID:16954297

Allawi, Hatim T; Li, Haijing; Sander, Tamara; Aslanukov, Azamat; Lyamichev, Victor I; Blackman, Amondrea; Elagin, Slava; Tang, Yi-Wei

2006-09-01

305

Bioactive secondary metabolites produced by microorganisms associated with plants  

Microsoft Academic Search

In the past few decades groups of scientists have focused their study on relatively new microorganisms called endophytes.\\u000a By definition these microorganisms, mostly fungi and bacteria, colonise the intercellular spaces of the plant tissues. The\\u000a mutual relationship between endophytic microorganisms and their host plants, taxanomy and ecology of endophytes are being\\u000a studied. Some of these microorganisms produce bioactive secondary metabolites

Silvia Firáková; Mária Šturdíková; Marta Mú?ková

2007-01-01

306

Origins of Halophilic Microorganisms in Ancient Salt Deposits  

NSDL National Science Digital Library

This eight-page review article considers the evidence for and against long-term survival of halophilic microorganisms in ancient salt deposits. Included sections are hypersaline environments and their inhabitants, haloarchaea and halite precipitation, isolations of microorganisms from brines in salt mines, isolations of microorganisms from ancient rock salt, isolations of microorganisms directly from fluid inclusions, relationship of subsurface haloarchaea to surface isolates, dispersal of haloarchaea, and long-term survival of haloarchaea inside salt crystals.

Mcgenity, Terry; Gemmell, Renia; Grant, William; Stan-Lotter, Helga; Microbiology, Environmental

307

Potassium channels mediate killing by human natural killer cells  

SciTech Connect

Human natural killer (NK) cells in peripheral blood spontaneously recognize and kill a wide variety of target cells. It has been suggested that ion channels are involved in the killing process because there is a Ca-dependent stage and because killing by presensitized cytotoxic T lymphocytes, which in many respects resembles NK killing, is associated with changes in K and Na transport in the target cell. Using the whole-cell variation of the patch-clamp technique, the authors found a voltage-dependent potassium (K/sup +/) current in NK cells. The K/sup +/ current was reduced in a dose-dependent manner by the K-channel blockers 4-aminopyridine and quinidine and by the traditional Ca-channel blockers verapamil and Cd/sup 2 +/. They tested the effects of ion-channel blockers on killing of two commonly used target cell lines: K562, which is derived from a human myeloid leukemia, and U937, which is derived from a human histiocytic leukemia. Killing of K562 target cells, determined in a standard /sup 51/Cr-release assay, was inhibited in a dose-dependent manner by verapamil, quinidine, Cd/sup 2 +/, and 4-aminopyridine at concentrations comparable to those that blocked the K/sup +/ current in NK cells. In K562 target cells only a voltage-dependent Na= current was found and it was blocked by concentrations of tetrodotoxin that had no effect on killing. Killing of U937 target cells was also inhibited by the two ion-channel blockers tested, quinidine and verapamil. In this cell line only a small K/sup +/ current was found that was similar to the one in NK cells. The findings show that there are K channels in NK cells and that these channels play a necessary role in the killing process.

Schlichter, L.; Sidell N.; Hagiwara, S.

1986-01-01

308

Microorganisms detection on substrates using QCL spectroscopy  

NASA Astrophysics Data System (ADS)

Recent investigations have focused on the improvement of rapid and accurate methods to develop spectroscopic markers of compounds constituting microorganisms that are considered biological threats. Quantum cascade lasers (QCL) systems have revolutionized many areas of research and development in defense and security applications, including his area of research. Infrared spectroscopy detection based on QCL was employed to acquire mid infrared (MIR) spectral signatures of Bacillus thuringiensis (Bt), Escherichia coli (Ec) and Staphylococcus epidermidis (Se), which were used as biological agent simulants of biothreats. The experiments were carried out in reflection mode on various substrates such as cardboard, glass, travel baggage, wood and stainless steel. Chemometrics statistical routines such as principal component analysis (PCA) regression and partial least squares-discriminant analysis (PLS-DA) were applied to the recorded MIR spectra. The results show that the infrared vibrational techniques investigated are useful for classification/detection of the target microorganisms on the types of substrates studied.

Padilla-Jiménez, Amira C.; Ortiz-Rivera, William; Castro-Suarez, John R.; Ríos-Velázquez, Carlos; Vázquez-Ayala, Iris; Hernández-Rivera, Samuel P.

2013-05-01

309

Biotechnological applications and potentialities of halophilic microorganisms.  

PubMed

Halophilic microorganisms are found as normal inhabitants of highly saline environments and thus are considered extremophiles. They are mainly represented, but not exclusively, by the halobacteria (extremely halophilic aerobic Archaea), the moderate halophiles (Bacteria and some methanogens) and several eukaryotic algae. These extremophilic microorganisms are already used for some biotechnological processes, for example halobacteria are used for the production of bacteriorhodopsin, and the alga Dunaliella is used in the commercial production of ?-carotene. Several other present or potential applications of halophiles are reviewed, including the production of polymers (polyhydroxyalcanoates and polysaccharides), enzymes, and compatible solutes, and the use of these extremophiles in enhanced oil recovery, cancer detection, drug screening and the biodegradation of residues and toxic compounds. PMID:24414413

Ventosa, A; Nieto, J J

1995-01-01

310

Characterization of Microorganisms by MALDI Mass Spectrometry  

SciTech Connect

Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) for characterization and analysis of microorganisms, specifically bacteria, is described here as a rapid screening tool. The objective of this technique is not comprehensive protein analysis of a microorganism but rather a rapid screening of the organism and the accessible protein pattern for characterization and distinction. This method is based on the ionization of the readily accessible and easily ionizable portion of the protein profile of an organism that is often characteristic of different bacterial species. The utility of this screening approach is yet to reach its full potential but could be applied to food safety, disease outbreak monitoring in hospitals, culture stock integrity and verification, microbial forensics or homeland security applications.

Petersen, Catherine E.; Valentine, Nancy B.; Wahl, Karen L.

2008-10-02

311

Sensitivity of environmental microorganisms to antimicrobial agents.  

PubMed Central

The sensitivity of different microorganisms, considered as typical representatives of the microflora of soil and water, was established to evaluate the influence of the nonmedical use of antimicrobial agents on bacterial ecology. Only seven strains, six chemoorganotrophs and one chemolithotroph, could be considered as relatively sensitive to the 21 antimicrobial compounds tested. The other 29 microorganisms may be regarded as resistant to most antimicrobial agents. Streptomyces were sensitive to high concentrations of active substances. Broad-spectrum antibiotics showed an effect on environmental bacteria similar to that on human pathogens. Cephalothin stimulated the growth of a Chlorella sp. From these experiments, it appears that spilled antimicrobial agents have little chance of causing an alteration in the microbial ecology.

Van Dijck, P; van de Voorde, H

1976-01-01

312

BINDING OF STEROIDS BY MICROORGANISMS1  

PubMed Central

Hartman, Ronald E. (American Cyanamid Co., Pearl River, N.Y.) and Chester E. Holmlund. Binding of steroids by microorganisms. J. Bacteriol. 84:1254–1259. 1962.—Certain microorganisms, particularly higher fungi, are able to bind steroids. The steroids can be recovered by solvent extraction only after lyophilization of the cultures. There appears to be a relationship between steroid structure and avidity for the microbial-binding component from Penicillium canescens. Sterols which possess a long side chain and a 3?-hydroxy-5-ene group are particularly susceptible to microbial binding. The sterol-binding component of P. canescens is released by rupture of the cells. After liberation from the intact cells, it appears to be highly unstable in the presence of other cellular constituents.

Hartman, R. E.; Holmlund, C. E.

1962-01-01

313

Bioleaching of chalcopyrite by moderately thermophilic microorganisms.  

PubMed

The leaching of chalcopyrite by moderately thermophilic microorganisms was investigated by employing cyclic voltammetry (CV), accompanying with the leaching behavior elucidation. Leaching experiment showed that there was clear benefit in leaching chalcopyrite within the low solution potential (below 400 mV vs. SCE), compared to the high potential leach (above 550 mV vs. SCE). Simultaneous maintenance of an appropriate concentration of total dissolved iron was necessary and also beneficial to leach chalcopyrite. The leaching results showed the existence of an optimum pH in the leaching of chalcopyrite by the moderately thermophilic microorganisms. The analysis of CV results revealed that the chalcopyrite was reduced to a series of intermediate products (such as talnakhite, bornite and chalcocite) in the cathodic, and then the intermediate product (chalcocite) was oxidized in the anodic. PMID:23246761

Qin, Wenqing; Yang, Congren; Lai, Shaoshi; Wang, Jun; Liu, Kai; Zhang, Bo

2013-02-01

314

UV inactivation of pathogenic and indicator microorganisms.  

PubMed Central

Survival was measured as a function of the dose of germicidal UV light for the bacteria Escherichia coli, Salmonella typhi, Shigella sonnei, Streptococcus faecalis, Staphylococcus aureus, and Bacillus subtilis spores, the enteric viruses poliovirus type 1 and simian rotavirus SA11, the cysts of the protozoan Acanthamoeba castellanii, as well as for total coliforms and standard plate count microorganisms from secondary effluent. The doses of UV light necessary for a 99.9% inactivation of the cultured vegetative bacteria, total coliforms, and standard plate count microorganisms were comparable. However, the viruses, the bacterial spores, and the amoebic cysts required about 3 to 4 times, 9 times, and 15 times, respectively, the dose required for E. coli. These ratios covered a narrower relative dose range than that previously reported for chlorine disinfection of E. coli, viruses, spores, and cysts.

Chang, J C; Ossoff, S F; Lobe, D C; Dorfman, M H; Dumais, C M; Qualls, R G; Johnson, J D

1985-01-01

315

The transfer of viable microorganisms between planets.  

PubMed

There is increasing acceptance that catastrophic cosmic impacts have played an important role in shaping the history of terrestrial life. Large asteroid and cometary impacts are also capable of displacing substantial quantities of planetary surface material into space. The discovery of Martian rocks on Earth suggests that viable microorganisms within such ejecta could be exchanged between planets. If this conjecture is correct, it will have profound implications for the origin and evolution of life in the solar system. PMID:9243022

Davies, P C

1996-01-01

316

Protein microarrays: a chance to study microorganisms?  

Microsoft Academic Search

Within the last 5 years, protein microarrays have been developed and applied to multiple approaches: identification of protein–protein\\u000a interactions or protein–small molecule interactions, cancer profiling, detection of microorganisms and toxins, and identification\\u000a of antibodies due to allergens, autoantigens, and pathogens. Protein microarrays are small size (typically in the microscopy\\u000a slide format) planar analytical devices with probes arranged in high density to

Jürgen Kreutzberger

2006-01-01

317

Adaptogenic functions of extracellular autoregulators of microorganisms  

Microsoft Academic Search

Information about the functions of extracellular autoregulators, which adapt microorganisms to the stresses “scheduled” in\\u000a the development cycle of microbial cultures (stresses of new medium, starvation, or space exhaustion (high cell density))\\u000a is summarized in the review. In a number of bacteria and yeasts, derivatives of alkylhydroxybenzenes (AHB), particularly of\\u000a the class of alkyl resorcinols, act as autoregulators with adaptogenic

G. I. El-Registan; A. L. Mulyukin; Yu. A. Nikolaev; N. E. Suzina; V. F. Gal’chenko; V. I. Duda

2006-01-01

318

Effects of Thymol on Ruminal Microorganisms  

Microsoft Academic Search

Thymol (5-methyl-2-isopropylphenol) is a phenolic compound that is used to inhibit oral bacteria. Because little is known\\u000a regarding the effects of this compound on ruminal microorganisms, the objective of this study was to determine the effects\\u000a of thymol on growth and lactate production by the ruminal bacteria Streptococcus bovis JB1 and Selenomonas ruminantium HD4. In addition, the effect of thymol

Jeff D. Evans; Scott A. Martin

2000-01-01

319

Effects of Chlorhexidine Diacetate on Ruminal Microorganisms  

Microsoft Academic Search

.   The objectives of this study were to examine the effects of chlorhexidine diacetate on growth and L-lactate production by\\u000a Streptococcus bovis JB1 as well as the effects of this antimicrobial compound on the mixed ruminal microorganism fermentation. Addition of 1.8\\u000a ?M chlorhexidine diacetate to glucose medium resulted in a lag in growth by S. bovis JB1, and growth was

Salah A. Attia-Ismail; Scott A. Martin

1998-01-01

320

Mass Spectrometer for Airborne Micro-Organisms  

NASA Technical Reports Server (NTRS)

Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

Sinha, M. P.; Friedlander, S. K.

1986-01-01

321

[UV-inactivation of microorganisms in water].  

PubMed

UV-Inactivation of Escherichia coli, Bacillus subtilis spores, Staphylococcus-Phage A 994, Poliovirus type Mahoney and Rotavirus SA 11 was tested under controlled physical conditions. B. subtilis-spores were found to be the most resistant of these microorganisms, followed by Rotavirus, Bacteriophage and Poliovirus. E. coli required the lowest irradiation dose for inactivation. Causes and meaning of these dose-survival-reactions are discussed. PMID:2560633

Sommer, R; Weber, G; Cabaj, A; Wekerle, J; Keck, G; Schauberger, G

1989-12-01

322

Cold-Tolerant Agriculturally Important Microorganisms  

Microsoft Academic Search

\\u000a Cold-tolerant microorganisms are endowed with the ability to grow at 0°C, though their growth optima lie in the mesophilic\\u000a range. To overcome the stress induced by low temperatures they have evolved a variety of adaptive responses at the cellular\\u000a and molecular levels. Multiple cell membrane modifications ensure that solute transport is not impaired at low temperatures.\\u000a Other mechanisms include the

Pankaj Kumar Mishra; Piyush Joshi; Shekhar Bisht; Jaideep Bisht; Govindan Selvakumar

323

40 CFR 725.67 - Applications to exempt new microorganisms from this part.  

Code of Federal Regulations, 2010 CFR

... Applications to exempt new microorganisms from this part. 725.67...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Administrative Procedures... Applications to exempt new microorganisms from this part. (a)...

2010-07-01

324

40 CFR 725.67 - Applications to exempt new microorganisms from this part.  

Code of Federal Regulations, 2010 CFR

... Applications to exempt new microorganisms from this part. 725.67...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Administrative Procedures... Applications to exempt new microorganisms from this part. (a)...

2009-07-01

325

40 CFR 725.67 - Applications to exempt new microorganisms from this part.  

Code of Federal Regulations, 2013 CFR

... Applications to exempt new microorganisms from this part. 725.67...REQUIREMENTS AND REVIEW PROCESSES FOR MICROORGANISMS Administrative Procedures... Applications to exempt new microorganisms from this part. (a)...

2013-07-01

326

Polycyclic Aromatic Hydrocarbon Degrading Microorganisms in Great Lakes Sediments  

Microsoft Academic Search

Biodegradation is a chemical transformation process that may result in the decontamination of sediments. A criterion for the potential success of biode gradation is the ability of indigenous microorganisms to catabolize contaminants, such as polycyclic aromatic hydrocarbons (PAHs). The number of microorganisms displaying this ability may be influenced by the extent of their exposure to PAHs. In this study, microorganisms

Dan L. McNally; James R. Mihelcic; Donald R. Lueking

1998-01-01

327

Bioaccumulation and Biosorption of Lead by Poultry Litter Microorganisms  

Microsoft Academic Search

Microorganisms are known to interact with metals through a number of mechanisms, including binding the metals to their cells' walls and intracellular accumulation. Poultry litter has a high density of various microorganisms along with many nutrients. The objective of this research was to study the removal of Pb from an aqueous solution by the microorganisms found in poultry litter under

GIAN GUPTA; BRIDGET KEEGAN

328

Protein Languages Differ Depending on Microorganism Lifestyle  

PubMed Central

Few quantitative measures of genome architecture or organization exist to support assumptions of differences between microorganisms that are broadly defined as being free-living or pathogenic. General principles about complete proteomes exist for codon usage, amino acid biases and essential or core genes. Genome-wide shifts in amino acid usage between free-living and pathogenic microorganisms result in fundamental differences in the complexity of their respective proteomes that are size and gene content independent. These differences are evident across broad phylogenetic groups–a result of environmental factors and population genetic forces rather than phylogenetic distance. A novel comparative analysis of amino acid usage–utilizing linguistic analyses of word frequency in language and text–identified a global pattern of higher peptide word repetition in 376 free-living versus 421 pathogen genomes across broad ranges of genome size, G+C content and phylogenetic ancestry. This imprint of repetitive word usage indicates free-living microorganisms have a bias for repetitive sequence usage compared to pathogens. These findings quantify fundamental differences in microbial genomes relative to life-history function.

Grzymski, Joseph J.; Marsh, Adam G.

2014-01-01

329

Endodontic microorganism susceptibility by direct contact test.  

PubMed

The aim of this study was to evaluate in vitro the duration of the antimicrobial effect of endodontic sealers by means of the Direct Contact Test. The sealers tested were: Endomethasone - Septodont, Endomethasone C-Septodont, Endion-Voco, Diaket-ESPE, Pulp Canal Sealer-SybronEndo, and AH26-Dentsply DeTrey. The endodontopathic microorganisms (MO) confronted were: Staphylococcus aureus (Sa), Candida albicans (Ca), Enterococcus faecalis (Ef), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). Test specimens of each sealer were prepared and placed on the surface of agar plates that had been inoculated with each MO, and after predetermined periods, transfers were made from the contact area between the test specimen and the cultured agar and from the area that had not been in contact with the test specimens (control). The results were read as presence/absence of microbial growth and analyzed statistically using the Kruskal-Wallis test. It was concluded that the structural features and virulence of endodontopathic microorganisms determine their response to the sealers, independently of the time during which sealers act and the mechanism by which the antiseptic reaches the microorganism, which in this case was by direct contact. PMID:19177855

Pérez, Sandra B; Tejerina, Denise P; Pérez Tito, Romina I; Bozza, Florencia L; Kaplan, Andrea E; Molgatini, Susana L

2008-01-01

330

Effect of Gas Hydrate Formers on Microorganisms  

PubMed Central

Various bacteria, yeasts, and molds important to the food industry were incubated in aerosol cans containing A C Broth and one of the following three gas hydrate formers: propane, dichlorodifluoromethane (f-12), and 1,1-difluoro-1-chloroethane (f-142b). Most hydrate formers were tested at three concentrations: low (vapor state), intermediate (liquid state, low level), and high (liquid state, high level). Samples were continuously agitated for 48 hr at 21 ± 3 C. Changes in numbers of microorganisms were determined by plate count. With hydrate formers in the vapor state, propane was more toxic to the microorganisms tested than either f-12 or f-142b. The most resistant organisms from these trials were then tested against f-12 or f-142b in the liquid state. Hydrate formers were far more toxic in the liquid state than in the vapor state. With the exception of sporulated cultures of Bacillus cereus, all microorganisms tested were greatly reduced in numbers when agitated for 48 hr at 21 C in the presence of f-12 or f-142b.

Prior, B. A.; Fennema, O.; Marth, E. H.

1970-01-01

331

Prokaryotic silicon utilizing microorganisms in the biosphere  

NASA Astrophysics Data System (ADS)

Although a little study has been done to determine the silicon utilizing prokaryotes, our previous experiments indicated that almost all Gram-positive bacteria are silicon utilizing; one of them, Streptococci survived exposure on the lunar surface for a long period in experiment done by others. Our initial experiments with these Gram positive microorganisms showed that there were limited growths of these microorganisms on carbon free silicate medium probably with the help of some carry over carbon and nitrogen during cultivation procedures. However, increase in growth rate after repeated subcultures could not be explained at present. The main groups of prokaryotes which were found silicon utilizing microorganisms were Mycobacterium, Bacillus, Nocardia, Streptomyces, Staphylococcus, Streptococcus, Lactobacillus, and Clostridium. In a another previous study by us when silicon level was studied in such grown up cells on carbon "free" silicate medium by electron prove microanalyser, it was found that silicon in cells grown on carbon "free" silicate medium was much higher (24.9%) than those grown on conventional carbon based medium (0.84%). However, these initial findings are encouraging for our future application of this group of organisms on extraterrestrial surfaces for artificial micro-ecosystem formation. It was found that when electropositive elements are less in extraterrestrial situation, then polymerization of silicon-oxygen profusion may occur easily, particularly in carbon and nitrogen paucity in the rocky worlds of the Universe.

Gupta, D.; Das, S.

2012-12-01

332

Surface structure influences contact killing of bacteria by copper  

PubMed Central

Copper kills bacteria rapidly by a mechanism that is not yet fully resolved. The antibacterial property of copper has raised interest in its use in hospitals, in place of plastic or stainless steel. On the latter surfaces, bacteria can survive for days or even weeks. Copper surfaces could thus provide a powerful accessory measure to curb nosocomial infections. We here investigated the effect of the copper surface structure on the efficiency of contact killing of Escherichia coli, an aspect which so far has received very little attention. It was shown that electroplated copper surfaces killed bacteria more rapidly than either polished copper or native rolled copper. The release of ionic copper was also more rapid from electroplated copper compared to the other materials. Scanning electron microscopy revealed that the bacteria nudged into the grooves between the copper grains of deposited copper. The findings suggest that, in terms of contact killing, more efficient copper surfaces can be engineered.

Zeiger, Marco; Solioz, Marc; Edongue, Hervais; Arzt, Eduard; Schneider, Andreas S

2014-01-01

333

Scientists Report New Lead in How Anthrax Kills Cells  

Cancer.gov

For years scientists have known that anthrax bacillus produces a toxin containing a deadly protein called lethal factor. However, researchers have never been able to identify how lethal factor kills cells.

334

Immunization Against Coccidioidomycosis by Killed Cell and Cell Fraction Vaccines.  

National Technical Information Service (NTIS)

Aerosol and subcutaneous vaccination with killed arthrosporess and subcutaneous vaccination using a boivin-type fraction were compared for their efficacy in protecting rhesus monkeys against lethal aerosol challenge with C. immitis. Complete protection ag...

J. T. Sinski E. P. Lowe N. F. Conant H. F. Hardin M. W. Castleberry

1964-01-01

335

Surface structure influences contact killing of bacteria by copper.  

PubMed

Copper kills bacteria rapidly by a mechanism that is not yet fully resolved. The antibacterial property of copper has raised interest in its use in hospitals, in place of plastic or stainless steel. On the latter surfaces, bacteria can survive for days or even weeks. Copper surfaces could thus provide a powerful accessory measure to curb nosocomial infections. We here investigated the effect of the copper surface structure on the efficiency of contact killing of Escherichia coli, an aspect which so far has received very little attention. It was shown that electroplated copper surfaces killed bacteria more rapidly than either polished copper or native rolled copper. The release of ionic copper was also more rapid from electroplated copper compared to the other materials. Scanning electron microscopy revealed that the bacteria nudged into the grooves between the copper grains of deposited copper. The findings suggest that, in terms of contact killing, more efficient copper surfaces can be engineered. PMID:24740976

Zeiger, Marco; Solioz, Marc; Edongué, Hervais; Arzt, Eduard; Schneider, Andreas S

2014-06-01

336

Potassium Channels Mediate Killing by Human Natural Killer Cells  

NASA Astrophysics Data System (ADS)

Human natural killer (NK) cells in peripheral blood spontaneously recognize and kill a wide variety of target cells. It has been suggested that ion channels are involved in the killing process because there is a Ca-dependent stage and because killing by presensitized cytotoxic T lymphocytes, which in many respects resembles NK killing, is associated with changes in K and Na transport in the target cell. However, no direct evidence exists for ion channels in NK cells or in their target cells. Using the whole-cell variation of the patch-clamp technique, we found a voltage-dependent potassium (K+) current in NK cells. The K+ current was reduced in a dose-dependent manner by the K-channel blockers 4-aminopyridine and quinidine and by the traditional Ca-channel blockers verapamil and Cd2+. We tested the effects of ion-channel blockers on killing of two commonly used target cell lines: K562, which is derived from a human myeloid leukemia, and U937, which is derived from a human histiocytic leukemia. Killing of K562 target cells, determined in a standard 51Cr-release assay, was inhibited in a dose-dependent manner by verapamil, quinidine, Cd2+, and 4-aminopyridine at concentrations comparable to those that blocked the K+ current in NK cells. In K562 target cells only a voltage-dependent Na+ current was found and it was blocked by concentrations of tetrodotoxin that had no effect on killing. Killing of U937 target cells was also inhibited by the two ion-channel blockers tested, quinidine and verapamil. In this cell line only a small K+ current was found that was similar to the one in NK cells. We could not find any evidence of a Ca2+ current in target cells or in NK cells; therefore, our results cannot explain the Ca dependence of killing. Our findings show that there are K channels in NK cells and that these channels play a necessary role in the killing process. In contrast, the endogenous channel type in the target cell is probably not a factor in determining target cell sensitivity to natural killing.

Schlichter, Lyanne; Sidell, Neil; Hagiwara, Susumu

1986-01-01

337

Variation in self-fertility and the reproductive advantage of self-fertility for an invading plant (Spartina alterniflora)  

Microsoft Academic Search

The factors responsible for the reproductive success or failure of individuals in small, founding populations have received little attention. Previous work on a small population of smooth cordgrass (Spartina alterniflora) invading San Francisco Bay, California found that most clones flower prolifically but set little or no seed, while a few clones have high rates of viable seed set, producing most

Curtis C. Daehler

1998-01-01

338

Reshaping the Ecology of Invading Populations of Hemlock Woolly Adelgid, Adelges tsugae (Homoptera: Adelgidae), in Eastern North America  

Microsoft Academic Search

Hemlock woolly adelgid, Adelges tsugae Annand (Homoptera: Adelgidae), is native to Japan where it is an innocuous inhabitant of Tsuga diversifolia Masters and T. sieboldii Carriere throughout their natural growing areas. Native adelgid populations are regulated by host resistance and natural enemies, in particular the oribatid mite, Diapterobates humeralis (Hermann) and the coccinellid beetle, Pseudoscymnus tsugae Sasaji and McClure. Invading

Mark S. McClure; Carole A. S.-J. Cheah

1999-01-01

339

Population development of the invader ctenophore Mnemiopsis leidyi , in the Black Sea and in other seas of the Mediterranean basin  

Microsoft Academic Search

In the last two decades of the twentieth century, the ctenophore Mnemiopsis leidyi (A. Agassiz) has invaded the Black, Azov, Marmara and Aegean Seas, and, recently, the Caspian Sea. Here, we compare its spatial and temporal distribution, seasonal dynamics and the time and duration of reproduction. We also discuss factors that control its abundance throughout its invasive range and its

T. Shiganova; Z. Mirzoyan; E. Studenikina; S. Volovik; I. Siokou-Frangou; S. Zervoudaki; E. Christou; A. Skirta; H. Dumont

2001-01-01

340

43 CFR 3873.3 - Non-mineral entry of residue of subdivisions invaded by mining claims.  

Code of Federal Regulations, 2010 CFR

...has already been lotted to exclude such claims. If not so lotted, and if the original lot or legal subdivision is invaded by patented mining claims, or by mining claims covered by pending applications for patent which the non-mineral applicant does...

2010-10-01

341

Elevated CO 2 differentially alters belowground plant and soil microbial community structure in reed canary grass-invaded experimental wetlands  

Microsoft Academic Search

Several recent studies have indicated that an enriched atmosphere of carbon dioxide (CO2) could exacerbate the intensity of plant invasions within natural ecosystems, but little is known of how rising CO2 impacts the belowground characteristics of these invaded systems. In this study, we examined the effects of elevated CO2 and nitrogen (N) inputs on plant and soil microbial community characteristics

Jenny Kao-Kniffin; Teri C. Balser

2007-01-01

342

[Parasites-invaders of the Volga river basin: history of invasion, perspective of dispersion, possibility of epizootic].  

PubMed

The fauna of fish parasites in the Volga river increased by 15 species in last time. These parasites have invaded together with introduced hosts or dispersed after destruction of some physical and ecological barriers. The infusoria Ambiphrya ameuri, cestode Cestobothrium acheilognathi, trematodes Amurotrema dombrovskajae and Sanguinicola skrabini have been introduced together with their hosts. A creation of water reservoirs destroyed ecological barriers and created favorable conditions for the migration and dispersion of parasites. The cestodes Eubothrium rugosum, Proteocephalus longicollis, and nematode Cystidicola farionis migrated from the North, Aspidogaster limacoides migrated from the South. The leech Caspiobdella fadejevi, trematodes Rossicotrema donicus, Apophallus muehlingi, Niccola skrjabini, Plagioporus skrjabini migrated through the Volga-Don channel. Some invader have already finished their dispersion in the water reservoirs of Volga river, other parasites still continue this process. South border of the E. rugosum range is in the Kujbyshev water basin, the leech C. fadejevi is distributed in all water basins, trematodes R. donicus, A. muehlingi and P. skrjabini are found in the Volga delta, while N. skrjabini has already reached the Saratov water basin. Perspectives of new invaders and epizootic significance of invaders is discussed. PMID:11558337

Zhokhov, A E; Pugacheva, M N

2001-01-01

343

Effect of Ertapenem Protein Binding on Killing of Bacteria  

Microsoft Academic Search

The effect of protein binding on the antimicrobial activity of ertapenem was evaluated using the bacterial kill rate and concentration-response studies. Various proportions of human serum were utilized to determine the total and free-drug concentrations using a validated high-performance liquid chromatography assay. The MICs and kill curves were determined for test isolates of Enterobacter cloacae and Staphylococcus aureus at various

David E. Nix; Kathryn R. Matthias; Emily C. Ferguson

2004-01-01

344

Flat deformation of a spacetime admitting two commuting Killing fields  

NASA Astrophysics Data System (ADS)

It is shown that, given an analytic Lorentzian metric on a 4-manifold, gab, which admits two Killing vector fields, there exists a local deformation law ?ab = a gab + b Hab, where Hab is a two-dimensional projector, such that ?ab is flat and admits the same Killing vectors. We also characterize the particular case when the projector Hab coincides with the quotient metric. We apply some of our results to general stationary axisymmetric spacetimes.

Llosa, Josep; Carot, Jaume

2010-12-01

345

Impunity for Political Killing in a Comparative Perspective  

Microsoft Academic Search

\\u000a In this chapter, I examine the relationship between electoral competition in the 1990s and the (un)rule of law for political\\u000a killings in Mexico and other democratizing nations. Electoral competition in Mexico in the 1990s between the PRI and the PRD\\u000a occurred across multiple municipalities within different states in the 1989–2000 period but PRD leaders and members were not\\u000a all killed

Sara Schatz

346

Rates of CTL killing in persistent viral infection in vivo.  

PubMed

The CD8+ cytotoxic T lymphocyte (CTL) response is an important defence against viral invasion. Although CTL-mediated cytotoxicity has been widely studied for many years, the rate at which virus-infected cells are killed in vivo by the CTL response is poorly understood. To date the rate of CTL killing in vivo has been estimated for three virus infections but the estimates differ considerably, and killing of HIV-1-infected cells was unexpectedly low. This raises questions about the typical anti-viral capability of CTL and whether CTL killing is abnormally low in HIV-1. We estimated the rate of killing of infected cells by CD8+ T cells in two distinct persistent virus infections: sheep infected with Bovine Leukemia Virus (BLV) and humans infected with Human T Lymphotropic Virus type 1 (HTLV-1) which together with existing data allows us to study a total of five viruses in parallel. Although both BLV and HTLV-1 infection are characterised by large expansions of chronically activated CTL with immediate effector function ex vivo and no evidence of overt immune suppression, our estimates are at the lower end of the reported range. This enables us to put current estimates into perspective and shows that CTL killing of HIV-infected cells may not be atypically low. The estimates at the higher end of the range are obtained in more manipulated systems and may thus represent the potential rather than the realised CTL efficiency. PMID:24699260

Elemans, Marjet; Florins, Arnaud; Willems, Luc; Asquith, Becca

2014-04-01

347

How Many Microorganisms Are Present? Techniques for Enumerating Microorganisms in Oilfields  

NASA Astrophysics Data System (ADS)

The different techniques that exist for enumerating microorganisms will often yield very different results when applied to oilfield samples. For example, enumeration of sulphate-reducing bacteria (SRB) by cultivation may fail to find any microorganisms in samples for which molecular microbiological methods (MMM) indicate levels of thousands or even millions per millilitre or gram. Therefore, it is important to realise the limitations and advantages of the different techniques available to the industry and to take them into account when interpreting data. In oil systems, the most widely used techniques for quantification are based either on culturing, epifluorescence microscopy, or quantitative PCR. In complex samples in which live, inactive, and dead cells are present together with cell material in various states of decomposition, each of these three methodologies enumerates a different subset of microorganisms (Fig. 10.1).

Sørensen, Ketil Bernt; Skovhus, Torben Lund; Larsen, Jan

348

Effects of Canopy Wetness on Evapotranspiration in Native and Invaded Tropical Montane Cloud Forest in Hawai‘i  

NASA Astrophysics Data System (ADS)

Canopy wetness has profound effects on ecosystem processes. Canopy-atmosphere gas and energy exchanges are strongly altered when leaves are wetted by rainfall, fog, or dew. In some tropical forests, wet-canopy evaporation contributes a large portion of total evapotranspiration. On the other hand, transpiration is minimized when leaves are wet. The overall hydrological effects of canopy wetting depend on the canopy structure and on the frequency and duration of wetting events. At two field sites in Hawai‘i, one within native Metrosideros polymorpha forest and the other at a site heavily invaded by Psidium cattleianum, we are conducting measurements of canopy water balance, stand-level evapotranspiration (ET), transpiration (using sapflow techniques), energy balance, and related processes. Preliminary canopy water balance results show that wet canopy evaporation is 588 mm/yr (33% of potential ET) at the native site and 376 mm/yr (22% of potential ET) at the invaded site. Based on sapflow measurements in canopy branches, mean transpiration for partially and fully wetted canopy periods (categorized using leaf wetness sensor observations) was 47% and 17% of dry canopy transpiration at the native forest site. For the invaded site, transpiration for partially and fully wetted canopy periods was 67% and 33% of dry canopy transpiration. It appears that the invaded site is able to maintain higher transpiration rates, along with lower wet-canopy evaporation rates, during wet-canopy periods. Previously reported stand level measurements have shown that total ET represents a larger portion of available energy at the invaded site than the native site. These findings suggest that alien plant invasion is shifting evaporative water loss from wet-canopy evaporation to transpiration, while increasing overall water loss. Higher transpiration is likely to be associated with higher rates of carbon exchange, which may contribute to the success of this invasive tree.

Giambelluca, T. W.; Delay, J. K.; Takahashi, M.; Mudd, R. G.; Huang, M.; Asner, G. P.; Martin, R. E.; Nullet, M. A.

2009-12-01

349

Lack of intracellular bubble formation in microorganisms at very high gas supersaturations.  

PubMed

Eucaryotic unicellular (a yeast, a cellular slime mold, and various protozoans) and two multicellular (aschelminths) microorganisms were saturated with gas at high pressures and rapidly decompressed. No effect was observed with pressures of argon up to 125 atm, nitrogen up to 175 atm, and helium up to 350 atm, showing that the induced gas supersaturations did not cause intracellular bubbles to form. With 25--50 atm higher gas pressures, the decompression usually produced killing and cell rupture, although differences in tolerances existed among the various organisms. Substantial fractions of the populations survived gas supersaturations well above the threshold values for massive spontaneous nucleation of bubbles in the water. When killing occurred, external rather than internal bubbles appeared to be the cause. Even with the 300 atm argon or nitrogen pressures, yeast cells were unaffected, apparently because of the external protection provided by their cell wall. It is concluded that the gas supersaturations required for intracellular formation of bubbles generally are at least equal to and probably higher than the bubble nucleation thresholds for water or aqueous solutions. PMID:395143

Hemmingsen, E A; Hemmingsen, B B

1979-12-01

350

Safe Micro-organism: Micro-organisms for Investigations in Schools and Colleges  

NSDL National Science Digital Library

This 6-page online safety form lists microorganisms that are considered suitable for use in schools and colleges. It includes a table that describes selected bacteria and fungi which present minimum risk given good practice. Fields of the table include microbe name, educational use/interest/suitability, and ease of use/maintenance. The document also addresses the use of viruses, algae protozoa (including slime molds), and lichens in the classroom. A group of microorganisms that were previously suggested for use in schools but are no longer considered suitable are also listed.

Society for General Microbiology (SGM); On-Line, Microbiology

351

Extremophilic microorganisms as candidates for extraterrestrial life  

NASA Astrophysics Data System (ADS)

Microbial life is found all over the globe. Diverse communities are even found in such places in which extreme conditions with respect of temperature, salinity, pH, and pressure prevail. Many of these environments were until recently considered too harsh to harbor microbial life. The micro-organisms adapted to an existence at the edge of life are termed extremophiles. They include members of the Prokaryotes (domains Archaea and Bacteria) and the Eukarya, including algae and protozoa. Extremophilic microbes thrive at low and high temperatures -- from subzero levels to above the boiling point of water, at both sides of the pH scale -- in acidic as well as in alkaline media, in hypersaline environments with salt concentrations of up to saturation, at high pressure, both in the deep sea and in the terrestrial deep subsurface where they are exposed to pressures of hundreds of atmospheres, and in other extreme conditions. In many cases they tolerate combinations of more than one environmental stress factor. Some of the extremophiles may be considered as 'living fossils' since their environment resembles the conditions that may have existed during the time life arose on Earth, more than 3.5 billion years ago. In view of these properties the extremophilic micro-organisms may be considered as model organisms when exploring the possibilities of the existence of extraterrestrial life. For example, the microbes discovered in ice cores recovered from the depth of the Lake Vostok in Antarctica may serve as a model simulating conditions prevailing in the permafrost subsurface of Mars or Jupiter's moon Europa. Microbial life in the Dead Sea or in Great Salt Lake may resemble halophilic life forms that may exist elsewhere in the universe, adapted to life at low water activities. Likewise, hyperthermophilic micro-organisms present on Earth in hot springs, hydrothermal vents and other sites heated by volcanic activity in terrestrial or marine areas, may resemble life forms that may exist on hot planets such as Venus.

Seckbach, Joseph; Oren, Aharon

2000-12-01

352

Resistance of soil microorganisms to starvation.  

NASA Technical Reports Server (NTRS)

Most groups of soil microorganisms died when exposed to prolonged starvation in a carbon-free solution, but the relative abundance of Bacillus and actinomycetes increased with time. Certain nonspore-forming bacteria also persisted. The ability of individual soil isolates to endure starvation in solution was not correlated with their glycogen content or rate of endogenous respiration. However, cells of the resistant populations were rich in poly-beta-hydroxybutyrate, whereas the starvation-susceptible bacteria generally contained little of this substance. Poly-beta-hydroxybutyrate was used rapidly in cells deprived of exogenous sources of carbon.

Chen, M.; Alexander, M.

1972-01-01

353

Propulsion of Microorganisms by Surface Distortions  

SciTech Connect

Swimming strategies of microorganisms must conform to the principles of self-propulsion at low Reynolds numbers. Here we relate the translational and rotational speeds to the surface motions of a swimmer and, for spheres, make evident novel constraints on mechanisms for propulsion. The results are applied to a cyanobacterium, an organism while motile mechanism is unknown, by considering incompressible streaming of the cell surface and oscillatory, tangential surface deformations. Finally, swimming efficiency using tangential motions is related to the surface velocities and a bound on the efficiency is obtained. {copyright} {ital 1996 The American Physical Society.}

Stone, H.A. [Division of Engineering & Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)] [Division of Engineering & Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Samuel, A.D. [Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 and Rowland Institute for Science, Cambridge, Massachusetts 02142 (United States)] [Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138 and Rowland Institute for Science, Cambridge, Massachusetts 02142 (United States)

1996-11-01

354

[Thermophilic chitinolytic microorganisms of brown semidesert soil].  

PubMed

In brown semidesert soil, thermophilic prokaryotic organisms identified as Streptomyces roseolilacinus and Silanimonas lenta were shown to play the main role in chitin transformation at 50 degrees C. The phylogenetic positions of the isolated dominant chitinolytic microorganisms were determined on the basis of 16S rRNA gene sequencing. The consumption of chitin as a source of carbon and nitrogen by both the bacterium and the actinomycete was shown by considerable biomass accumulation, high emission of carbon dioxide, and presence in the medium of the chitinase exoenzyme. PMID:19004351

Manucharova, N A; Vlasenko, A N; Turova, T P; Panteleeva, A N; Stepanov, A L; Zenova, G M

2008-01-01

355

Microorganisms and biomolecules in space hard environment  

NASA Technical Reports Server (NTRS)

Microorganisms and biomolecules exposed to space vacuum and to different intensities of selected wavelengths of solar ultraviolet radiation is studied. The influence of these factors, applied singly or simultaneously, on the integrity of microbial systems and biomolecules is measured. Specifically, this experiment will study in Bacillus subtilis spores (1) disturbances in subsequent germination, outgrowth, and colony formation; (2) photochemical reactions of the DNA and protein in vivo and in vitro and their role in biological injury; and (3) the efficiency of repair processes in these events.

Horneck, G.

1981-01-01

356

Temperature response of Antarctic cryptoendolithic photosynthetic microorganisms  

NASA Technical Reports Server (NTRS)

Growth responses to temperatures between 12.5 [degrees] C and 25 degrees C were determined for five photosynthetic microorganisms isolated from the Ross Desert cryptoendolithic community. Among eukaryotic algae, two strains of Trebouxia sp. have an upper temperature limit of 20 degrees C, and two strains of Hemichloris antarctica of 25 degrees C. The cyanobacterium Chroococcidiopsis sp., in contrast, grows at temperatures above 25 degrees C. These and earlier studies suggest that the eukaryotic algae of the Antarctic cryptoendolithic community have an upper temperature limit near 25 degrees C.

Ocampo-Friedmann, R.; Meyer, M. A.; Chen, M.; Friedmann, E. I.

1988-01-01

357

Lead resistance in micro-organisms.  

PubMed

Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation. PMID:24124204

Jaros?awiecka, Anna; Piotrowska-Seget, Zofia

2014-01-01

358

Studies on the kinetics of killing and the proposed mechanism of action of microemulsions against fungi.  

PubMed

Microemulsions are physically stable oil/water clear dispersions, spontaneously formed and thermodynamically stable. They are composed in most cases of water, oil, surfactant and cosurfactant. Microemulsions are stable, self-preserving antimicrobial agents in their own right. The observed levels of antimicrobial activity associated with microemulsions may be due to the direct effect of the microemulsions themselves on the bacterial cytoplasmic membrane. The aim of this work is to study the growth behaviour of different microbes in presence of certain prepared physically stable microemulsion formulae over extended periods of time. An experiment was designed to study the kinetics of killing of a microemulsion preparation (17.3% Tween-80, 8.5% n-pentanol, 5% isopropyl myristate and 69.2% sterile distilled water) against selected test microorganisms (Candida albicans, Aspergillus niger, Schizosaccharomyces pombe and Rhodotorula spp.). Secondly, an experiment was designed to study the effects of the microemulsion preparation on the cytoplasmic membrane structure and function of selected fungal species by observation of 260 nm component leakage. Finally, the effects of the microemulsion on the fungal membrane structure and function using S. pombe were studied using transmission electron microscopy. The results showed that the prepared microemulsions are stable, effective antimicrobial systems with effective killing rates against C. albicans, A. niger, S. pombe and Rhodotorula spp. The results indicate a proposed mechanism of action of significant anti-membrane activity, resulting in the gross disturbance and dysfunction of the cytoplasmic membrane structure which is followed by cell wall modifications, cytoplasmic coagulation, disruption of intracellular metabolism and cell death. PMID:23830945

Al-Adham, Ibrahim S I; Ashour, Hana; Al-Kaissi, Elham; Khalil, Enam; Kierans, Martin; Collier, Phillip J

2013-09-15

359

Porphyromonas gingivalis invades human trophoblasts and inhibits proliferation by inducing G1 arrest and apoptosis  

PubMed Central

Summary Porphyromonas gingivalis is an oral pathogen that is also associated with serious systemic conditions such as preterm delivery. Here we investigated the interaction between P. gingivalis and a cell line of extravillous trophoblasts (HTR-8) derived from the human placenta. P. gingivalis internalized within HTR-8 cells and inhibited proliferation through induction of arrest in the G1 phase of the cell cycle. G1 arrest was associated with decreased expression of cyclin D and of CDKs 2, 4 and 6. In addition, levels of CDK inhibitors p15, p16, p18 and p21 were increased following P. gingivalis infection. The amount of Rb was diminished by P. gingivalis, and transient overexpression of Rb, with concomitant upregulation of phospho-Rb, relieved P. gingivalis-induced G1 arrest. HTR-8 cells halted in the G1 phase became apoptotic, and apoptosis was accompanied by an increase in the ratio of Bax/Bcl-2 and increased activity of caspases 3, 7 and 9. HTR-8 cells infected with P. gingivalis also exhibited a sustained activation of ERK1/2, and knockdown of ERK1/2 activity with siRNA abrogated both G1 arrest and apoptosis. Thus, P. gingivalis can invade placental trophoblasts and induce G1 arrest and apoptosis through pathways involving ERK1/2 and its downstream effectors, properties that provide a mechanistic basis for pathogenicity in complications of pregnancy.

Inaba, Hiroaki; Kuboniwa, Masae; Bainbridge, Brian; Yilmaz, Ozlem; Katz, Joseph; Shiverick, Kathleen T.; Amano, Atsuo; Lamont, Richard J.

2009-01-01

360

Porphyromonas gingivalis invades human trophoblasts and inhibits proliferation by inducing G1 arrest and apoptosis.  

PubMed

Porphyromonas gingivalis is an oral pathogen that is also associated with serious systemic conditions such as preterm delivery. Here we investigated the interaction between P. gingivalis and a cell line of extravillous trophoblasts (HTR-8) derived from the human placenta. P. gingivalis internalized within HTR-8 cells and inhibited proliferation through induction of arrest in the G1 phase of the cell cycle. G1 arrest was associated with decreased expression of cyclin D and of CDKs 2, 4 and 6. In addition, levels of CDK inhibitors p15, p16, p18 and p21 were increased following P. gingivalis infection. The amount of Rb was diminished by P. gingivalis, and transient overexpression of Rb, with concomitant upregulation of phospho-Rb, relieved P. gingivalis-induced G1 arrest. HTR-8 cells halted in the G1 phase became apoptotic, and apoptosis was accompanied by an increase in the ratio of Bax/Bcl-2 and increased activity of caspases 3, 7 and 9. HTR-8 cells infected with P. gingivalis also exhibited a sustained activation of ERK1/2, and knock-down of ERK1/2 activity with siRNA abrogated both G1 arrest and apoptosis. Thus, P. gingivalis can invade placental trophoblasts and induce G1 arrest and apoptosis through pathways involving ERK1/2 and its downstream effectors, properties that provide a mechanistic basis for pathogenicity in complications of pregnancy. PMID:19523155

Inaba, Hiroaki; Kuboniwa, Masae; Bainbridge, Brian; Yilmaz, Ozlem; Katz, Joseph; Shiverick, Kathleen T; Amano, Atsuo; Lamont, Richard J

2009-10-01

361

Alien roadside species more easily invade alpine than lowland plant communities in a subarctic mountain ecosystem.  

PubMed

Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

Lembrechts, Jonas J; Milbau, Ann; Nijs, Ivan

2014-01-01

362

An Archaeal Immune System Can Detect Multiple Protospacer Adjacent Motifs (PAMs) to Target Invader DNA*  

PubMed Central

The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) system provides adaptive and heritable immunity against foreign genetic elements in most archaea and many bacteria. Although this system is widespread and diverse with many subtypes, only a few species have been investigated to elucidate the precise mechanisms for the defense of viruses or plasmids. Approximately 90% of all sequenced archaea encode CRISPR/Cas systems, but their molecular details have so far only been examined in three archaeal species: Sulfolobus solfataricus, Sulfolobus islandicus, and Pyrococcus furiosus. Here, we analyzed the CRISPR/Cas system of Haloferax volcanii using a plasmid-based invader assay. Haloferax encodes a type I-B CRISPR/Cas system with eight Cas proteins and three CRISPR loci for which the identity of protospacer adjacent motifs (PAMs) was unknown until now. We identified six different PAM sequences that are required upstream of the protospacer to permit target DNA recognition. This is only the second archaeon for which PAM sequences have been determined, and the first CRISPR group with such a high number of PAM sequences. Cells could survive the plasmid challenge if their CRISPR/Cas system was altered or defective, e.g. by deletion of the cas gene cassette. Experimental PAM data were supplemented with bioinformatics data on Haloferax and Haloquadratum.

Fischer, Susan; Maier, Lisa-Katharina; Stoll, Britta; Brendel, Jutta; Fischer, Eike; Pfeiffer, Friedhelm; Dyall-Smith, Mike; Marchfelder, Anita

2012-01-01

363

Subepicardial endothelial cells invade the embryonic ventricle wall to form coronary arteries  

PubMed Central

Coronary arteries bring blood flow to the heart muscle. Understanding the developmental program of the coronary arteries provides insights into the treatment of coronary artery diseases. Multiple sources have been described as contributing to coronary arteries including the proepicardium, sinus venosus (SV), and endocardium. However, the developmental origins of coronary vessels are still under intense study. We have produced a new genetic tool for studying coronary development, an AplnCreER mouse line, which expresses an inducible Cre recombinase specifically in developing coronary vessels. Quantitative analysis of coronary development and timed induction of AplnCreER fate tracing showed that the progenies of subepicardial endothelial cells (ECs) both invade the compact myocardium to form coronary arteries and remain on the surface to produce veins. We found that these subepicardial ECs are the major sources of intramyocardial coronary vessels in the developing heart. In vitro explant assays indicate that the majority of these subepicardial ECs arise from endocardium of the SV and atrium, but not from ventricular endocardium. Clonal analysis of Apln-positive cells indicates that a single subepicardial EC contributes equally to both coronary arteries and veins. Collectively, these data suggested that subepicardial ECs are the major source of intramyocardial coronary arteries in the ventricle wall, and that coronary arteries and veins have a common origin in the developing heart.

Tian, Xueying; Hu, Tianyuan; Zhang, Hui; He, Lingjuan; Huang, Xiuzhen; Liu, Qiaozhen; Yu, Wei; He, Liang; Yang, Zhongzhou; Zhang, Zhen; Zhong, Tao P; Yang, Xiao; Yang, Zhen; Yan, Yan; Baldini, Antonio; Sun, Yunfu; Lu, Jie; Schwartz, Robert J; Evans, Sylvia M; Gittenberger-de Groot, Adriana C; Red-Horse, Kristy; Zhou, Bin

2013-01-01

364

Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario  

USGS Publications Warehouse

Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.

Walsh, Maureen G.; Lantry, Brian F.; Boscarino, Brent; Bowen, Kelly; Gerlofsma, Jocelyn; Schaner, Ted; Back, Richard; Questel, Jennifer; Smythe, A. Garry; Cap, Roberta; Goehle, Michael; Young, Bryan; Chalupnicki, Marc; Johnson, James H.; McKenna, James E.

2010-01-01

365

[Photosynthetic characteristics and coenological survey of Lactuca serriola in its invaded area].  

PubMed

Lactuca serriola, a national class quarantine object, is a new invasive species in the coastal area of Southeast China. The coenological survey showed that because of its big individual, L. serriola could easily form dominant population in its invaded area, and its main accompany species were Conyza canadensis, C. bonarinisis, Bidentis bipinnata, Oenothera laciniata, Ipomoea hederacea, Setaria viridis, Daucus carota, Xanthium sibiricum, Erigeron annuus, L. indica, Humulus scandens, Solanum nigrum and Aster sublatus. The measurements with LCA-4 portable photosynthesis and transpiration system (ADC, England) revealed that the net photosynthetic rate of L. serriola was as high as 21.22 +/- 0.45 micromol CO2 x m(-2) x s(-1), being slightly lower than that of E. annuus and C. bonarinisis, similar to that of C. canadensis, and higher than that of Chenopodium album, Plantago virginica and L. indica. Based on the photosynthesis-light response equation, the theoretic light compensation point of L. serriola was 37.58 micromol m(-2) x s(-1), its theoretic light saturation point was 1 480 micromol x m(-2) x s(-1), and theoretic maximal net photosynthetic rate was 20.81 micromol CO2 x m(-2) x s(-1). A distinct "noon break" phenomenon was observed in L. serriola photosynthesis, which might result from the high stomatal resistance against high light intensity and temperature. The main factors affecting the net photosynthetic rate of L. serriola were leaf photosynthetic active radiation, stomatal conductance, and leaf transpiration rate. PMID:17330472

Guo, Shui-Liang; Fang, Fang; Ni, Liping; Chen, Wanlin; Shi, Laidi

2006-12-01

366

Carcinoma cells misuse the host tissue damage response to invade the brain  

PubMed Central

The metastatic colonization of the brain by carcinoma cells is still barely understood, in particular when considering interactions with the host tissue. The colonization comes with a substantial destruction of the surrounding host tissue. This leads to activation of damage responses by resident innate immune cells to protect, repair, and organize the wound healing, but may distract from tumoricidal actions. We recently demonstrated that microglia, innate immune cells of the CNS, assist carcinoma cell invasion. Here we report that this is a fatal side effect of a physiological damage response of the brain tissue. In a brain slice coculture model, contact with both benign and malignant epithelial cells induced a response by microglia and astrocytes comparable to that seen at the interface of human cerebral metastases. While the glial damage response intended to protect the brain from intrusion of benign epithelial cells by inducing apoptosis, it proved ineffective against various malignant cell types. They did not undergo apoptosis and actually exploited the local tissue reaction to invade instead. Gene expression and functional analyses revealed that the C-X-C chemokine receptor type 4 (CXCR4) and WNT signaling were involved in this process. Furthermore, CXCR4-regulated microglia were recruited to sites of brain injury in a zebrafish model and CXCR4 was expressed in human stroke patients, suggesting a conserved role in damage responses to various types of brain injuries. Together, our findings point to a detrimental misuse of the glial damage response program by carcinoma cells resistant to glia-induced apoptosis.

Chuang, Han-Ning; van Rossum, Denise; Sieger, Dirk; Siam, Laila; Klemm, Florian; Bleckmann, Annalen; Bayerlova, Michaela; Farhat, Katja; Scheffel, Jorg; Schulz, Matthias; Dehghani, Faramarz; Stadelmann, Christine; Hanisch, Uwe-Karsten; Binder, Claudia; Pukrop, Tobias

2013-01-01

367

Genotype-by-environment interaction for salinity tolerance in the freshwater-invading copepod Eurytemora affinis.  

PubMed

This study examined the extent of phenotypic plasticity for salinity tolerance and genetic variation in plasticity in the invasive copepod Eurytemora affinis. Euryemora affinis is a species complex inhabiting brackish to hypersaline environments but has invaded freshwater lakes and reservoirs within the past century. Reaction norm experiments were performed on a relatively euryhaline population collected from a brackish lake with fluctuating salinity. Life history traits (hatching rate, survival, and development time) were measured for 20 full-sib clutches that were split and reared at four salinities (fresh, 5, 10, and 27 practical salinity units [PSU]). On average, higher salinities (10 and 27 PSU) were more favorable for larval growth, yielding greater survival and faster development rate. Clutches differed significantly in their response to salinity, with a significant genotype-by-environment interaction for development time. In addition, genetic (clutch) effects were evident in response to low salinity, given that survival in fresh (lake) water was significantly positively correlated with survival at 5 PSU for individual clutches. Clutches raised in fresh water could not survive beyond metamorphosis, suggesting that acclimation to fresh water could not occur in a single generation. Results suggest the importance of natural selection during freshwater invasion events, given the inability of plasticity to generate a freshwater phenotype, and the presence of genetic variation for plasticity upon which natural selection could act. PMID:12324889

Lee, Carol Eunmi; Petersen, Christine H

2002-01-01

368

Development of new HLA-B*3505 genotyping method using Invader assay.  

PubMed

Several pharmacogenetic studies have revealed strong associations between specific human leukocyte antigen (HLA) alleles and the susceptibility to drug hypersensitivity. Recently, we reported HLA-B*3505 as a strong genetic biomarker for the nevirapine-induced skin rash in Thai population. Here, we developed a new HLA-B*3505 genotyping method by a combination of the Universal Invader assay and sequence-specific primer PCR. From the sequence alignment of 68 HLA-B alleles in the Thai population, we selected the two most discriminative SNPs (rs1140412 and rs4997052) as target SNP sites. When we carried out the assay using 324 Thai individuals, fluorescence intensities of HLA-B*3505-positive and HLA-B*3505-negative samples were apparently discriminated at the endpoint of the reaction. Our results were 100% concordant with those obtained by a sequence-based typing method. As our assay is simple and rapid, we believe our method will be a useful tool for pharmacogenetic testing of the nevirapine-induced skin rash. PMID:20679961

Hosono, Naoya; Chantarangsu, Soranun; Kiyotani, Kazuma; Takata, Sadaaki; Tsuchiya, Yumiko; Mahasirimongkol, Surakameth; Chantratita, Wasun; Mushiroda, Taisei; Nakamura, Yusuke; Kubo, Michiaki

2010-10-01

369

Surgical treatment of T3 lung cancer invading the chest wall.  

PubMed

Lung tumors invading the chest wall are classed as belonging to the T3 group and are considered potentially resectable. Their management, however, is controversial, and extrapleural resection, when possible, is preferred to en bloc resection which is regarded as a far more invasive and dangerous operation. Five year survival rates for completely resected cases range in the literature from 25 to 35%, but survival rates are much worse if lymph node metastases are present. These poor outcomes have prompted the development of combined surgical approaches: preoperative radiation therapy, with or without chemotherapy, has been used with an improvement in resectability rates, but only modest results in terms of median survival; in a number of case series, increased operative morbidity and mortality have been reported with this approach. The present report relates to 122 patients treated by en bloc (20 cases) or extrapleural (102 cases) resection, 31 of whom also received neoadjuvant treatment. The operative mortality was 4.6%. Median survival was 17 months after en bloc resection and 19 months after extrapleural resection. Though no statistically significant difference was found, extrapleural resection would appear to yield better results than the en bloc procedure. PMID:10742890

Beltrami, V; Bezzi, M; Illuminati, G; Forte, A; Angelici, A; Bertagni, A; Ciulli, A; Gallinaro, L; Lorenzotti, A; Montesano, G; Palumbo, P G; Prece, V

1999-01-01

370

Temporally variable dispersal and demography can accelerate the spread of invading species.  

PubMed

We analyze how temporal variability in local demography and dispersal combine to affect the rate of spread of an invading species. Our model combines state-structured local demography (specified by an integral or matrix projection model) with general dispersal distributions that may depend on the state of the individual or its parent. It allows very general patterns of stationary temporal variation in both local demography and in the frequency and distribution of dispersal distances. We show that expressions for the asymptotic spread rate and its sensitivity to parameters, which have been derived previously for less general models, continue to hold. Using these results we show that random temporal variability in dispersal can accelerate population spread. Demographic variability can further accelerate spread if it is positively correlated with dispersal variability, for example if high-fecundity years are also years in which juveniles tend to settle further away from their parents. A simple model for the growth and spread of patches of an invasive plant (perennial pepperweed, Lepidium latifolium) illustrates these effects and shows that they can have substantial impacts on the predicted speed of an invasion wave. Temporal variability in dispersal has received very little attention in both the theoretical and empirical literature on invasive species spread. Our results suggest that this needs to change. PMID:23316492

Ellner, Stephen P; Schreiber, Sebastian J

2012-12-01

371

Oxidative burst in hard clam ( Mercenaria mercenaria) haemocytes  

Microsoft Academic Search

Haemocytes of bivalve molluscs are known to be responsible for many immunological functions, including recognition, phagocytosis, and killing or elimination of invading microorgansisms, such as potentially infective bacteria and parasites. In many bivalves, killing of microorganisms engulfed by haemocytes is accomplished by a sudden release of reactive oxygen species (ROS) within the haemocytes; this response is referred to as an

Deenie M. Buggea; Hélène Hégaret; Gary H. Wikfors; Bassem Allam

2007-01-01

372

Microorganisms within Human Follicular Fluid: Effects on IVF  

PubMed Central

Our previous study reported microorganisms in human follicular fluid. The objective of this study was to test human follicular fluid for the presence of microorganisms and to correlate these findings with the in vitro fertilization (IVF) outcomes. In this study, 263 paired follicular fluids and vaginal swabs were collected from women undergoing IVF cycles, with various causes for infertility, and were cultured to detect microorganisms. The cause of infertility and the IVF outcomes for each woman were correlated with the microorganisms detected within follicular fluid collected at the time of trans-vaginal oocyte retrieval. Microorganisms isolated from follicular fluids were classified as: (1) ‘colonizers’ if microorganisms were detected within the follicular fluid, but not within the vaginal swab (at the time of oocyte retrieval); or (2) ‘contaminants’ if microorganisms detected in the vagina at the time of oocyte retrieval were also detected within the follicular fluid. The presence of Lactobacillus spp. in ovarian follicular fluids was associated with embryo maturation and transfer. This study revealed microorganisms in follicular fluid itself and that the presence of particular microorganisms has an adverse affect on IVF outcomes as seen by an overall decrease in embryo transfer rates and pregnancy rates in both fertile and infertile women, and live birth rates in women with idiopathic infertility. Follicular fluid microorganisms are a potential cause of adverse pregnancy outcomes in IVF in both infertile women and in fertile women with infertile male partners.

Pelzer, Elise S.; Allan, John A.; Waterhouse, Mary A.; Ross, Tara; Beagley, Kenneth W.; Knox, Christine L.

2013-01-01

373

Medical Significance of Microorganisms in Spacecraft Environment  

NASA Technical Reports Server (NTRS)

Microorganisms can spoil food supplies, contaminate drinking water, release noxious volatile compounds, initiate allergic responses, contaminate the environment, and cause infectious diseases. International acceptability limits have been established for bacterial and fungal contaminants in air and on surfaces, and environmental monitoring is conducted to ensure compliance. Allowable levels of microorganism in water and food have also been established. Environmental monitoring of the space shuttle, the Mir, and the ISS have allowed for some general conclusions. Generally, the bacteria found in air and on interior surfaces are largely of human origin such as Staphylococcus spp., Micrococcus spp. Common environmental genera such as Bacillus spp. are the most commonly isolated bacteria from all spacecraft. Yeast species associated with humans such as Candida spp. are commonly found. Aspergillus spp., Penicillium spp., and Cladosporium spp. are the most commonly isolated filamentous fungi. Microbial levels in the environment differ significantly depending upon humidity levels, condensate accumulation, and availability of carbon sources. However, human "normal flora" of bacteria and fungi can result in serious, life-threatening diseases if human immunity is compromised. Disease incidence is expected to increase as mission duration increases.

Pierson, Duane L.; Ott, C. Mark

2007-01-01

374

Microorganisms resistant to free-living amoebae.  

PubMed

Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human "Troy," and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens. PMID:15084508

Greub, Gilbert; Raoult, Didier

2004-04-01

375

From chemosensing in microorganisms to practical biosensors  

NASA Astrophysics Data System (ADS)

Microorganisms like bacteria can sense concentrations of chemoattractants in their medium very accurately. They achieve this through interaction between the receptors on their cell surfaces and chemoattractant molecules (like sugar). Physical processes like diffusion set some limits on the accuracy of detection, which was discussed by Berg and Purcell in the late seventies. We re-examine their work in order to assess what insight it may offer for making efficient, practical biosensors. We model the functioning of a typical biosensor as a reaction-diffusion process in a confined geometry. Using available data first we characterize the system by estimating the kinetic constants for the binding and unbinding reactions between the chemoattractants and the receptors. Then we compute the binding flux for this system, which Berg and Purcell had discussed. Unlike in microorganisms where the interval between successive measurements determines the efficiency of the nutrient searching process, it turns out that biosensors depend on long time properties like signal saturation time, which we study in detail. We also develop a mean field description of the kinetics of the system.

Ghosh, Surya K.; Kundu, Tapanendu; Sain, Anirban

2012-11-01

376

Diversity of Thermophilic Microorganisms within Hawaiian Fumaroles  

NASA Astrophysics Data System (ADS)

Fumaroles provide heat and moisture characteristic of an environment suitable for thermophilic microorganisms. On the Island of Hawaii, fumaroles are scattered across the southeastern portion of the island as a result of the volcanic activity from Kilauea Crater and Pu'u' O'o vent. We used metagenomics to detect 16S rDNA from archaeal and bacterial thermophilic microorganisms indicating their presence in Hawaiian fumaroles. The fumaroles sampled exist along elevation and precipitation gradients; varying from sea level to 4,012ft and annual rainfall from less than 20in to greater than 80in. To determine the effects of environmental gradients (including temperature, pH, elevation, and precipitation) on microbial diversity within and among fumaroles, we obtained 22 samples from 7 fumaroles over a three-day period in February of 2007. Temperature variations within individual fumaroles vary from 2.3oC to 35oC and the pH variances that range from 0.4 to 2.0. Temperatures of the different fumaroles range from 29.9oC to greater than 105oC, with pH values that vary from 2.55 to 6.93. Further data on the microbial diversity within fumaroles and among fumaroles will be determined once the sequencing of the microbial 16S rDNA regions is completed. We are currently assembling and sequencing clone libraries of bacterial and archaeal 16S rDNA fragments from fumaroles.

Ackerman, C. A.; Anderson, S.; Anderson, C.

2007-12-01

377

The role of microorganisms in atopic dermatitis  

PubMed Central

Atopic dermatitis (AD) is a common, fluctuating skin disease that is often associated with atopic conditions such as asthma and IgE-mediated food allergy and whose skin lesions are characterized by a Th-2 cell-mediated response to environmental antigens. The increasing prevalence and severity of atopic diseases including AD over the last three decades has been attributed to decreased exposure to microorganisms during early life, which may result in an altered Th-1/Th-2-balance and/or reduced T cell regulation of the immune response. Patients with AD exhibit defects in innate and acquired immune responses resulting in a heightened susceptibility to bacterial, fungal and viral infections, most notably colonization by S. aureus. Toxins produced by S. aureus exacerbate disease activity by both the induction of toxin-specific IgE and the activation of various cell types including Th-2 cells, eosinophils and keratinocytes. Allergens expressed by the yeast Malazessia furfur, a component of normal skin flora, have also been implicated in disease pathogenesis in a subset of AD patients. Microorganisms play an influential role in AD pathogenesis, interacting with disease susceptibility genes to cause initiation and/or exacerbation of disease activity.

Baker, B S

2006-01-01

378

Industrial and environmental applications of halophilic microorganisms.  

PubMed

In comparison with the thermophilic and the alkaliphilic extremophiles, halophilic microorganisms have as yet found relatively few biotechnological applications. Halophiles are involved in centuries-old processes such as the manufacturing of solar salt from seawater and the production of traditional fermented foods. Two biotechnological processes involving halophiles are highly successful: the production of beta-carotene by the green alga Dunaliella and the production of ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid), used as a stabilizer for enzymes and now also applied in cosmetic products, from moderately halophilic bacteria. The potential use of bacteriorhodopsin, the retinal protein proton pump of Halobacterium, in optoelectronic devices and photochemical processes is being explored, and may well lead to commercial applications in the near future. Demand for salt-tolerant enzymes in current manufacturing or related processes is limited. Other possible uses of halophilic microorganisms such as treatment of saline and hypersaline wastewaters, and the production of exopolysaccharides, poly-beta-hydroxyalkanoate bioplastics and biofuel are being investigated, but no large-scale applications have yet been reported. PMID:20662374

Oren, Aharon

2010-01-01

379

Biochemical and morphological characterization of the killing of human monocytes by a leukotoxin derived from Actinobacillus actinomycetemcomitans.  

PubMed Central

A potent, heat-labile leukotoxic material was extracted from Actinobacillus actinomycetemcomitans (strain Y4), an anaerobic gram-negative microorganism originally isolated from subgingival plaque in a patient with juvenile periodontitis. The cytopathic effects of Y4 toxin on purified monocytes were studied by the extracellular release of radioactive cytoplasmic markers and cell enzymes and by time-lapse microcinematography. Y4 toxin rapidly bound to the cells, producing dose- and time-dependent alterations culminating in cell death and release of intracellular constituents into the culture medium. The evidence to be presented suggests that the cell membrane of the monocyte may be the primary target in the development of these phenomena. Previous studies have shown that Y4 toxin also kills human polymorphonuclear leukocytes but not other cell types. It is conceivable that disruption of polymorphonuclear leukocytes and monocytes by Y4 toxin in the gingival crevice area may be relevant in the pathogenesis of juvenile periodontitis. Images Fig. 1

Taichman, N S; Dean, R T; Sanderson, C J

1980-01-01

380

Temporins A and B Stimulate Migration of HaCaT Keratinocytes and Kill Intracellular Staphylococcus aureus.  

PubMed

The growing number of microbial pathogens resistant to available antibiotics is a serious threat to human life. Among them is the bacterium Staphylococcus aureus, which colonizes keratinocytes, the most abundant cell type in the epidermis. Its intracellular accumulation complicates treatments against resulting infections, mainly due to the limited diffusion of conventional drugs into the cells. Temporins A (Ta) and B (Tb) are short frog skin antimicrobial peptides (AMPs). Despite extensive studies regarding their antimicrobial activity, very little is known about their activity on infected cells or involvement in various immunomodulatory functions. Here we show that Tb kills both ATCC-derived and multidrug-resistant clinical isolates of S. aureus within infected HaCaT keratinocytes (80% and 40% bacterial mortality, respectively) at a nontoxic concentration, i.e., 16 ?M, whereas a weaker effect is displayed by Ta. Furthermore, the peptides prevent killing of keratinocytes by the invading bacteria. Further studies revealed that both temporins promote wound healing in a monolayer of HaCaT cells, with front speed migrations of 19 ?m/h and 12 ?m/h for Ta and Tb, respectively. Migration is inhibited by mitomycin C and involves the epidermal growth factor receptor (EGFR) signaling pathway. Finally, confocal fluorescence microscopy indicated that the peptides diffuse into the cells. By combining antibacterial and wound-healing activities, Ta and Tb may act as multifunctional mediators of innate immunity in humans. Particularly, their nonendogenous origin may reduce microbial resistance to them as well as the risk of autoimmune diseases in mammals. PMID:24514087

Di Grazia, Antonio; Luca, Vincenzo; Segev-Zarko, Li-Av T; Shai, Yechiel; Mangoni, Maria Luisa

2014-05-01

381

Minerals and Microorganisms in Evaporite Environments  

NASA Astrophysics Data System (ADS)

Traditional analysis of evaporite environments have either focused on the geology or the halophilic organisms. It is relatively rare that the two have been combined and even rarer that both disciplines have been incorporated in comparing evaporite sites. The variation in evaporite environments does influence microbial ecology and fossilization processes as each site varies in pH, temperature, presence or absence springs, and spring chemistry. Understanding the evaporite environments is important for planetary scientists as they serve as analogs for evaluating extraterrestrial materials, including the potential for water and ultimately life. For example Mars lander, rover and orbital missions have identified the evaporite signatures of gypsum, carbonates and chlorides, all indicating that water existed at sometime in the planets geological history. Terrestrial evaporite sites all possess halophilic tolerant life. In some instances such as the Dead Sea, Israel, it is restricted to microbial life, but in other sites there are higher life forms. The microbes associated with these evaporite sites can produce biofilms as a method to develop their own microenvironments. Microorganisms can be observed colonizing specific ecological niches or gradients can be created by these environments. These gradients occur due the localized drying and weathering patterns that create different soil chemistry. The microorganisms in turn colonize specific areas more suitable to their specific metabolic needs. For example, under anaerobic conditions with sulfur and methane prevalent methanogenic and/or sulfur reducing microbial species may be observed. However, under similar chemistry environments with the exception of aerobic conditions sulfur oxidizer and/or methanotrophic microorganism may occur. Because of their conspicuous colored pigments purple sulfur bacteria are frequently observed in anoxic zones of lakes, sulfur springs, and stratified evaporite crusts. Some of these bacteria are of particular interest including Ectothiorhodospira spp. that deposit extracellular sulfur and are halophilic growing at high pH with NaCl concentrations approaching saturation. Fossilization and biofilm production appears to be relevant to the geochemistry of the systems. For example Dead Sea, Israel, microbes produce minimal biofilms, reside in the sediments, and the incidence of fossilization is low while hypersaline Storrs Lake, San Salvador, Bahamas microbes produce prodigious amounts of biofilms with many examples of fossilization. Some of the microbes appear to prefer solid substrates and may exhibit a preference, such as detrital or mineral, etc. In our studies we have found that some of the organisms, in relation to their substrate, can be tentatively characterized with laser confocal scanning microscopy. Terrestrial evaporite sites and understanding potential biomarkers and/or mineral signatures are important for identifying potential exoplanetary sites such as Mars that may harbor life.

Morris, P. A.; Brigmon, R. L.

2010-12-01

382

Removal of microorganisms by deep well injection  

NASA Astrophysics Data System (ADS)

The removal of bacteriophages MS2 and PRD1, spores of Clostridium bifermentans (R5) and Escherichia coli (WR1) by deep well injection into a sandy aquifer, was studied at a pilot field site in the southeast of the Netherlands. Injection water was seeded with the microorganisms for 5 days. Breakthrough was monitored for 93 days at 4 monitoring wells with their screens at a depth of about 310 m below surface. Within the first 8 m of soil passage, concentrations of MS2 and PRD1 were reduced by 6 log 10, that of R5 spores by 5 log 10 and that of WR1 by 7.5 log 10. Breakthrough of MS2 and R5 could also be followed at greater distances from the injection well. Concentrations of MS2 were reduced only by about 2 log 10 in the following 30 m, and reduction of concentrations of R5 was negligible. Apparently, attachment was greater during the first 8 m of aquifer passage. At the point of injection, the inactivation rate coefficient of free MS2 was found to be 0.081 day -1, that of free PRD1 0.060 day -1, and that of E. coli strain WR1 0.063 day -1. In injection water that had passed 8 m of soil, inactivation of MS2 phages was found to be less than in water from the injection well: 0.039 day -1. Probably, the higher inactivation rate of MS2 in water from the injection well may be ascribed to the activity of aerobic bacteria. Inactivation of the R5 spores was not significant. From geochemical mass balances, it could be deduced that within the first 8 m distance from the injection well, ferric oxyhydroxides precipitated as a consequence of pyrite oxidation, but not at larger distances. Ferric oxyhydroxides provide positively charged patches onto which fast attachment of the negatively charged microorganisms may take place. The non-linear logarithmic reduction of concentrations with distance may therefore be ascribed to preferable attachment of microorganisms to patches of ferric oxyhydroxides that are present within 8 m distance from the injection point, but not thereafter. Declogging of the injection well introduced hydrodynamic shear that remobilized MS2, which was then transported farther downstream.

Schijven, Jack F.; Medema, Gertjan; Vogelaar, Ad J.; Hassanizadeh, S. Majid

2000-08-01

383

Changes in the soil bacterial communities in a cedar plantation invaded by moso bamboo.  

PubMed

Moso bamboo is fast-growing and negatively allelopathic to neighboring plants. However, there is little information on the effects of its establishment and expansion to adjacent forest soil communities. To better understand the impacts of bamboo invasion on soil communities, the phylogenetic structure and diversity of the soil bacterial communities in moso bamboo forest, adjacent Japanese cedar plantation, and bamboo-invaded transition zone were examined using a combination of 16S rRNA gene clone libraries and bar-coded pyrosequencing techniques. Based on the number of operational taxonomic units (OTUs), Shannon diversity index, Chao1 estimator, and rarefaction analysis of both techniques, the bamboo soil bacterial community was the most diverse, followed by the transition zone, with the cedar plantation possessing the lowest diversity. The results from both techniques revealed that the Acidobacteria and Proteobacteria predominated in the three communities, though the relative abundance was different. The 250 most abundant OTUs represented about 70% of the total sequences found by pyrosequencing. Most of these OTUs were found in all three soil communities, demonstrating the overall similarity among the bacterial communities. Nonmetric multidimensional scaling analysis showed further that the bamboo and transition soil communities were more similar with each other than the cedar soils. These results suggest that bamboo invasion to the adjacent cedar plantation gradually increased the bacterial diversity and changed the soil community. In addition, while the 10 most abundant OTUs were distributed worldwide, related sequences were not abundant in soils from outside the forest studied here. This result may be an indication of the uniqueness of this region. PMID:24072077

Lin, Yu-Te; Tang, Sen-Lin; Pai, Chuang-Wen; Whitman, William B; Coleman, David C; Chiu, Chih-Yu

2014-02-01

384

Augmentation of Epithelial Resistance to Invading Bacteria by Using mRNA Transfections  

PubMed Central

To protect against invading bacteria, oral epithelial cells appear to use two effector antimicrobial peptides (AMPs): calprotectin (S100A8-S100A9 heterodimer [S100A8/A9]) in the cytosol and cathelicidin antimicrobial protein (CAMP) in endosomes. We sought to learn whether innate immunity might be augmented benignly to increase resistance against invasive bacteria. Epithelial cells were transiently transfected with mRNA constructs containing either the CAMP, S100A8, and S100A9 open reading frames, A8-IRES-A9 (fusion sequence), or A8-nIRES-A9 (fusion with native internal ribosome entry site [IRES] sequence). CAMP, S100A8, and S100A9 protein levels generally peaked between 16 and 44 h after mRNA transfection, depending on the construct; CAMP was processed to LL-37 over time. Following transfection with the respective mRNAs, CAMP and S100A8/A9 each independently increased resistance of epithelial cells to invasion by Listeria and Salmonella for up to 48 h; tandem S100A8/A9 constructs were also effective. Cotransfection to express S100A8/A9 and CAMP together augmented resistance, but synergy was not seen. Independent of the new proteins produced, transfection reduced cell viability after 48 h by 20%, with only 2% attributable to apoptosis. Taken together, these results suggest that epithelial cell resistance to invasive pathogens can be augmented by transient transfection of antimicrobial mRNAs into epithelial cells.

Zou, Xianqiong; Sorenson, Brent S.; Ross, Karen F.

2013-01-01

385

Invader danger: lizards faced with novel predators exhibit an altered behavioral response to stress.  

PubMed

Animals respond to stressors by producing glucocorticoid stress hormones, such as corticosterone (CORT). CORT acts too slowly to trigger immediate behavioral responses to a threat, but can change longer-term behavior, facilitating an individual's survival to subsequent threats. To be adaptive, the nature of an animal's behavior following elevated CORT levels should be matched to the predominant threats that they face. Seeking refuge following a stressful encounter could be beneficial if the predominant predator is a visual hunter, but may prove detrimental when the predominant predator is able to enter these refuge sites. As a result, an individual's behavior when their CORT levels are high may differ among populations of a single species. Invasive species impose novel pressures on native populations, which may select for a shift in their behavior when CORT levels are high. We tested whether the presence of predatory invasive fire ants (Solenopsis invicta) at a site affects the behavioral response of native eastern fence lizards (Sceloporus undulatus) to elevated CORT levels. Lizards from an uninvaded site were more likely to hide when their CORT levels were experimentally elevated; a response that likely provides a survival advantage for lizards faced with native predatory threats (e.g. birds and snakes). Lizards from a fire ant invaded site showed the opposite response; spending more time moving and up on the basking log when their CORT levels were elevated. Use of the basking log likely reflects a refuge-seeking behavior, rather than thermoregulatory activity, as selected body temperatures were not affected by CORT. Fleeing off the ground may prove more effective than hiding for lizards that regularly encounter small, terrestrially-foraging fire ant predators. This study suggests that invasive species may alter the relationship between the physiological and behavioral stress response of native species. PMID:21549122

Trompeter, Whitney P; Langkilde, Tracy

2011-07-01

386

The ant genomes have been invaded by several types of mariner transposable elements  

NASA Astrophysics Data System (ADS)

To date, only three types of full-length mariner elements have been described in ants, each one in a different genus of the Myrmicinae subfamily: Sinvmar was isolated from various Solenopsis species, Myrmar from Myrmica ruginodis, and Mboumar from Messor bouvieri. In this study, we report the coexistence of three mariner elements ( Tnigmar- Si, Tnigmar- Mr, and Tnigmar- Mb) in the genome of a single species, Tapinoma nigerrimum (subfamily Dolichoderinae). Molecular evolutionary analyses of the nucleotide sequence data revealed a general agreement between the evolutionary history of most the elements and the ant species that harbour them, and suggest that they are at the vertical inactivation stage of the so-called Mariner Life Cycle. In contrast, significantly reduced levels of synonymous divergence between Mboumar and Tnigmar- Mb and between Myrmar and Botmar (a mariner element isolated from Bombus terrestris), relative to those observed between their hosts, suggest that these elements arrived to the species that host them by horizontal transfer, long after the species' split. The horizontal transfer events for the two pairs of elements could be roughly dated within the last 2 million years and about 14 million years, respectively. As would be expected under this scenario, the coding sequences of the youngest elements, Tnigmar- Mb and Mboumar, are intact and, thus, potentially functional. Each mariner element has a different chromosomal distribution pattern according to their stage within the Mariner Life Cycle. Finally, a new defective transposable element ( Azteca) has also been found inserted into the Tnigmar- Mr sequences showing that the ant genomes have been invaded by at least four different types of mariner elements.

Lorite, Pedro; Maside, Xulio; Sanllorente, Olivia; Torres, María I.; Periquet, Georges; Palomeque, Teresa

2012-12-01

387

Phenological niches and the future of invaded ecosystems with climate change.  

PubMed

In recent years, research in invasion biology has focused increasing attention on understanding the role of phenology in shaping plant invasions. Multiple studies have found non-native species that tend to flower distinctly early or late in the growing season, advance more with warming or have shifted earlier with climate change compared with native species. This growing body of literature has focused on patterns of phenological differences, but there is a need now for mechanistic studies of how phenology contributes to invasions. To do this, however, requires understanding how phenology fits within complex functional trait relationships. Towards this goal, we review recent literature linking phenology with other functional traits, and discuss the role of phenology in mediating how plants experience disturbance and stress-via climate, herbivory and competition-across the growing season. Because climate change may alter the timing and severity of stress and disturbance in many systems, it could provide novel opportunities for invasion-depending upon the dominant climate controller of the system, the projected climate change, and the traits of native and non-native species. Based on our current understanding of plant phenological and growth strategies-especially rapid growing, early-flowering species versus later-flowering species that make slower-return investments in growth-we project optimal periods for invasions across three distinct systems under current climate change scenarios. Research on plant invasions and phenology within this predictive framework would provide a more rigorous test of what drives invader success, while at the same time testing basic plant ecological theory. Additionally, extensions could provide the basis to model how ecosystem processes may shift in the future with continued climate change. PMID:24876295

Wolkovich, Elizabeth M; Cleland, Elsa E

2014-01-01

388

Comparative parasitism of the fish Plagioscion squamosissimus in native and invaded river basins.  

PubMed

Biological invasions are considered a major threat to biodiversity around the world, but the role of parasites in this process is still little investigated. Here, we compared parasite infections of a host species in the areas where it originated and where it was introduced, and in native and introduced species in the same environment, using the endoparasites of the fish Plagioscion squamosissimus (Sciaenidae) in 3 Brazilian basins. Samples were taken in 2 rivers where the species is native, i.e., Solimões River (SO) and Tocantins River (TO), and where the species was introduced, the upper Paraná River (PR). In addition, abundances of diplostomids and larval nematodes were compared between P. squamosissimus and 2 native competitors in the PR, Hoplias malabaricus and Raphiodon vulpinus. In total, 13 species of endoparasites were recorded, but only Austrodiplostomum sp. and cestode cysts were present in all localities. Although infracommunity richness was similar, their species composition was slightly different among localities. General linear models using the relative condition factor of fish as response variables, and abundance of the most prevalent parasites as possible predictors showed that the condition of fish is negatively correlated with parasite abundance only in the native range (TO). Abundance of diplostomid eye flukes was higher in the PR, and in the native species H. malabaricus when compared to the invader, which might present an advantage for P. squamosissimus if they compete for prey. However, although P. squamosissimus may have lost some of its native parasites during its introduction to the PR, it is now possibly acting as a host for native generalist parasites. PMID:22468610

Lacerda, A C F; Takemoto, R M; Tavares-Dias, M; Poulin, R; Pavanelli, G C

2012-08-01

389

High Invasive Pollen Transfer, Yet Low Deposition on Native Stigmas in a Carpobrotus-invaded Community  

PubMed Central

Background and Aims Invasive plants are potential agents of disruption in plant–pollinator interactions. They may affect pollinator visitation rates to native plants and modify the plant–pollinator interaction network. However, there is little information about the extent to which invasive pollen is incorporated into the pollination network and about the rates of invasive pollen deposition on the stigmas of native plants. Methods The degree of pollinator sharing between the invasive plant Carpobrotus affine acinaciformis and the main co-flowering native plants was tested in a Mediterranean coastal shrubland. Pollen loads were identified from the bodies of the ten most common pollinator species and stigmatic pollen deposition in the five most common native plant species. Key Results It was found that pollinators visited Carpobrotus extensively. Seventy-three per cent of pollinator specimens collected on native plants carried Carpobrotus pollen. On average 23 % of the pollen on the bodies of pollinators visiting native plants was Carpobrotus. However, most of the pollen found on the body of pollinators belonged to the species on which they were collected. Similarly, most pollen on native plant stigmas was conspecific. Invasive pollen was present on native plant stigmas, but in low quantity. Conclusions Carpobrotus is highly integrated in the pollen transport network. However, the plant-pollination network in the invaded community seems to be sufficiently robust to withstand the impacts of the presence of alien pollen on native plant pollination, as shown by the low levels of heterospecific pollen deposition on native stigmas. Several mechanisms are discussed for the low invasive pollen deposition on native stigmas.

Bartomeus, Ignasi; Bosch, Jordi; Vila, Montserrat

2008-01-01

390

Carcinoma cells misuse the host tissue damage response to invade the brain.  

PubMed

The metastatic colonization of the brain by carcinoma cells is still barely understood, in particular when considering interactions with the host tissue. The colonization comes with a substantial destruction of the surrounding host tissue. This leads to activation of damage responses by resident innate immune cells to protect, repair, and organize the wound healing, but may distract from tumoricidal actions. We recently demonstrated that microglia, innate immune cells of the CNS, assist carcinoma cell invasion. Here we report that this is a fatal side effect of a physiological damage response of the brain tissue. In a brain slice coculture model, contact with both benign and malignant epithelial cells induced a response by microglia and astrocytes comparable to that seen at the interface of human cerebral metastases. While the glial damage response intended to protect the brain from intrusion of benign epithelial cells by inducing apoptosis, it proved ineffective against various malignant cell types. They did not undergo apoptosis and actually exploited the local tissue reaction to invade instead. Gene expression and functional analyses revealed that the C-X-C chemokine receptor type 4 (CXCR4) and WNT signaling were involved in this process. Furthermore, CXCR4-regulated microglia were recruited to sites of brain injury in a zebrafish model and CXCR4 was expressed in human stroke patients, suggesting a conserved role in damage responses to various types of brain injuries. Together, our findings point to a detrimental misuse of the glial damage response program by carcinoma cells resistant to glia-induced apoptosis. PMID:23832647

Chuang, Han-Ning; van Rossum, Denise; Sieger, Dirk; Siam, Laila; Klemm, Florian; Bleckmann, Annalen; Bayerlová, Michaela; Farhat, Katja; Scheffel, Jörg; Schulz, Matthias; Dehghani, Faramarz; Stadelmann, Christine; Hanisch, Uwe-Karsten; Binder, Claudia; Pukrop, Tobias

2013-08-01

391

Phenological niches and the future of invaded ecosystems with climate change  

PubMed Central

In recent years, research in invasion biology has focused increasing attention on understanding the role of phenology in shaping plant invasions. Multiple studies have found non-native species that tend to flower distinctly early or late in the growing season, advance more with warming or have shifted earlier with climate change compared with native species. This growing body of literature has focused on patterns of phenological differences, but there is a need now for mechanistic studies of how phenology contributes to invasions. To do this, however, requires understanding how phenology fits within complex functional trait relationships. Towards this goal, we review recent literature linking phenology with other functional traits, and discuss the role of phenology in mediating how plants experience disturbance and stress—via climate, herbivory and competition—across the growing season. Because climate change may alter the timing and severity of stress and disturbance in many systems, it could provide novel opportunities for invasion—depending upon the dominant climate controller of the system, the projected climate change, and the traits of native and non-native species. Based on our current understanding of plant phenological and growth strategies—especially rapid growing, early-flowering species versus later-flowering species that make slower-return investments in growth—we project optimal periods for invasions across three distinct systems under current climate change scenarios. Research on plant invasions and phenology within this predictive framework would provide a more rigorous test of what drives invader success, while at the same time testing basic plant ecological theory. Additionally, extensions could provide the basis to model how ecosystem processes may shift in the future with continued climate change.

Wolkovich, Elizabeth M.; Cleland, Elsa E.

2014-01-01

392

Inflatable kill packers used in working over Kuwaiti wells  

SciTech Connect

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.

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

1992-03-09

393

Aeromonas salmonicida resistance to complement-mediated killing.  

PubMed Central

The resistance of Aeromonas salmonicida to complement-mediated killing was investigated by using different strains and their isogenic mutants that had been previously characterized for their surface components. We found that the classical complement pathway is involved in serum killing of susceptible A. salmonicida strains, while the alternative complement pathway seems not to be involved. All of the A. salmonicida strains are able to activate complement, but the smooth strains (with or without the A-layer) are resistant to complement-mediated killing. The reasons for this resistance are that C3b may be bound far from the cell membrane and that it is rapidly degraded; therefore, the lytic final complex C5b-9 (membrane attack complex) is not formed. Isogenic rough mutants are serum sensitive because they bind more C3b than the smooth strains, and if C3b is not completely degraded, then the lytic complex (C5b-9) is formed. Images

Merino, S; Alberti, S; Tomas, J M

1994-01-01

394

Experimental Lactococcus garvieae infection in zebrafish and first evidence of its ability to invade non-phagocytic cells.  

PubMed

Zebrafish has been used for studying infections and host-pathogen interactions in different bacterial fish pathogens. In the present study we evaluated the ability of Lactococcus garvieae to infect zebrafish when inoculated intraperitoneally with 2×10(7)UFC of this pathogen. L. garvieae can colonize and invade zebrafish at multiple anatomical sites causing a lethal acute septicemic infection with clinical signs and lesions consistent with those observed in lactococcosis outbreaks. Immunohistochemical studies showed the presence of L. garvieae into macrophages as well as into non-phagocytic zebrafish cells of liver (hepatocytes). The internalization capacity showed by L. garvieae in zebrafish cells was confirmed in the rainbow trout cell line RTG-2. Our results provide the first evidence that L. garvieae is able to invade non-phagocytic host cells. PMID:24768002

Aguado-Urda, Mónica; Rodríguez-Bertos, Antonio; de Las Heras, Ana I; Blanco, María M; Acosta, Félix; Cid, Raquel; Fernández-Garayzábal, José F; Gibello, Alicia

2014-06-25

395

Engineered microorganisms capable of producing target compounds under anaerobic conditions  

SciTech Connect

The present invention is generally provides recombinant microorganisms comprising engineered metabolic pathways capable of producing C3-C5 alcohols under aerobic and anaerobic conditions. The invention further provides ketol-acid reductoisomerase enzymes which have been mutated or modified to increase their NADH-dependent activity or to switch the cofactor preference from NADPH to NADH and are expressed in the modified microorganisms. In addition, the invention provides isobutyraldehyde dehydrogenase enzymes expressed in modified microorganisms. Also provided are methods of producing beneficial metabolites under aerobic and anaerobic conditions by contacting a suitable substrate with the modified microorganisms of the present invention.

Buelter, Thomas (Denver, CO); Meinhold, Peter (Denver, CO); Feldman, Reid M. Renny (San Francisco, CA); Hawkins, Andrew C. (Parker, CO); Urano, Jun (Irvine, CA); Bastian, Sabine (Pasadena, CA); Arnold, Frances (La Canada, CA)

2012-01-17

396

Metabolic Physiology of Microorganisms and the Evolution of Functions.  

National Technical Information Service (NTIS)

CONTENTS: Scientific terminology; Physiological and biochemical characteristics of microorganisms; carbon dioxide in metabolism; a. photosynthesis; b. heterotrophic photoassimilation; c. autrotrophic chemosynthesis; d. heterotrophic chemoassimilation of c...

V. N. Shaposhnikov

1966-01-01

397

21 CFR 866.2660 - Microorganism differentiation and identification device.  

Code of Federal Regulations, 2010 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2660 Microorganism differentiation and identification device. (a)...

2010-04-01

398

Analysis of Membrane Lipids of Airborne Micro-Organisms  

NASA Technical Reports Server (NTRS)

A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry. This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings ("sick-building syndrome"). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

MacNaughton, Sarah

2006-01-01

399

The ecology of micro-organisms in a closed environment  

NASA Technical Reports Server (NTRS)

Microorganisms under closed environmental ecological conditions with reference to astronauts infectious diseases, discussing bacteria growth in Biosatellite 2 and earth based closed chamber experiments

Fox, L.

1971-01-01

400

Humane killing of animals for disease control purposes.  

PubMed

Killing for disease control purposes is an emotional issue for everyone concerned. Large-scale euthanasia or depopulation of animals may be necessary for the emergency control or eradication of animal diseases, to remove animals from a compromised situation (e.g. following flood, storm, fire, drought or a feed contamination event), to effect welfare depopulation when there is an oversupply due to a dysfunctional or closed marketing channel, or to depopulate and dispose of animals with minimal handling to decrease the risk of a zoonotic disease infecting humans. The World Organisation for Animal Health (OIE) developed international standards to provide advice on humane killing for various species and situations. Some fundamental issues are defined, such as competency of animal handling and implementation of humane killing techniques. Some of these methods have been used for many years, but novel approaches for the mass killing of particular species are being explored. Novel vaccines and new diagnostic techniques that differentiate between vaccinated and infected animals will save many animals from being killed as part of biosecurity response measures. Unfortunately, the destruction of affected livestock will still be required to control diseases whilst vaccination programmes are activated or where effective vaccines are not available. This paper reviews the principles of humane destruction and depopulation and explores available techniques with their associated advantages and disadvantages. It also identifies some current issues that merit consideration, such as legislative conflicts (emergency disease legislation versus animal welfare legislation, occupational health and safety), media issues, opinions on the future approaches to killing for disease control, and animal welfare. PMID:25000803

Thornber, P M; Rubira, R J; Styles, D K

2014-04-01

401

Synergy of itraconazole with macrophages in killing Blastomyces dermatitidis.  

PubMed Central

We examined in vitro interaction between the azole antifungal agents itraconazole and ketoconazole and macrophages and their activities against Blastomyces dermatitidis. Fungistatic and fungicidal concentrations for B. dermatitidis in vitro were assessed in a microculture system in which fungistasis was measured as inhibition of multiplication and fungicidal activity was measured as reduction of inoculum CFU. Resident peritoneal murine macrophages, which surround but do not phagocytize the fungus, were not fungicidal for B. dermatitidis isolates but were fungistatic for some isolates studied. Synergy was demonstrated when fungistatic concentrations (e.g., 0.01 micrograms/ml) of itraconazole, which limited growth 55% compared with that of controls, were cocultured with macrophages; this resulted in fungicidal activity (85% killing) against B. dermatitidis (ATCC 26199) in 72-h assays. This synergy could occur even if itraconazole was added after the macrophages had surrounded the fungus. Ketoconazole at fungistatic concentrations did not act synergistically with macrophages to kill B. dermatitidis. Lymph node lymphocytes could not substitute for macrophages in synergy with itraconazole to kill B. dermatitidis. When B. dermatitidis was separated by a filter from macrophages in Transwell cultures, fungicidal synergy with itraconazole was less efficient. Pretreatment of B. dermatitidis with itraconazole for 24 h did not render the fungus susceptible to killing by macrophages in the absence of itraconazole, whereas pretreatment of nonfungistatic macrophages with itraconazole rendered them fungistatic in a dose-dependent manner. Three other isolates were killed by otherwise fungistatic concentrations of itraconazole when the isolates were cocultured with macrophages. These findings indicate that one basis for the efficacy of itraconazole versus ketoconazole in treating blastomycosis could be synergy of a fungistatic concentration of itraconazole with macrophages in killing of B. dermatitidis.

Brummer, E; Bhagavathula, P R; Hanson, L H; Stevens, D A

1992-01-01

402

Essential requirements for the detection and degradation of invaders by the Haloferax volcanii CRISPR/Cas system I-B  

PubMed Central

To fend off foreign genetic elements, prokaryotes have developed several defense systems. The most recently discovered defense system, CRISPR/Cas, is sequence-specific, adaptive and heritable. The two central components of this system are the Cas proteins and the CRISPR RNA. The latter consists of repeat sequences that are interspersed with spacer sequences. The CRISPR locus is transcribed into a precursor RNA that is subsequently processed into short crRNAs. CRISPR/Cas systems have been identified in bacteria and archaea, and data show that many variations of this system exist. We analyzed the requirements for a successful defense reaction in the halophilic archaeon Haloferax volcanii. Haloferax encodes a CRISPR/Cas system of the I-B subtype, about which very little is known. Analysis of the mature crRNAs revealed that they contain a spacer as their central element, which is preceded by an eight-nucleotide-long 5? handle that originates from the upstream repeat. The repeat sequences have the potential to fold into a minimal stem loop. Sequencing of the crRNA population indicated that not all of the spacers that are encoded by the three CRISPR loci are present in the same abundance. By challenging Haloferax with an invader plasmid, we demonstrated that the interaction of the crRNA with the invader DNA requires a 10-nucleotide-long seed sequence. In addition, we found that not all of the crRNAs from the three CRISPR loci are effective at triggering the degradation of invader plasmids. The interference does not seem to be influenced by the copy number of the invader plasmid.

Maier, Lisa-Katharina; Lange, Sita J.; Stoll, Britta; Haas, Karina A.; Fischer, Susan; Fischer, Eike; Duchardt-Ferner, Elke; Wohnert, Jens; Backofen, Rolf; Marchfelder, Anita

2013-01-01

403

Listeria monocytogenes efficiently invades Caco-2 cells after low-temperature storage in broth and on deli meat.  

PubMed

The objective of this study was to investigate how various growth conditions influence the virulence of Listeria monocytogenes monitored by its ability to invade the epithelial cell lines Caco-2 and INT-407. The growth conditions examined were modified atmosphere-packaged deli meat and brain heart infusion broth (BHI) with and without salt. Five strains of L. monocytogenes were selected to investigate their invasiveness and all strains invaded Caco-2 cells at higher levels than INT-407 cells. Further, the clinical strains (3443 and 3734) were more invasive (p < 0.05) than the strains isolated from meat and food-processing environments (3008, 3126, and 4140) after grown in BHI at 30 degrees C. This attenuation could not be ascribed to a defective Internalin A as all strains encoded an intact inlA gene. To determine the influence of food products on virulence, the ability of L. monocytogenes to invade Caco-2 cells was compared after growth on a fermented sausage and on cured cooked ham to that of bacteria grown in BHI broth supplemented with salt. Samples were stored under chilling conditions for up to 4 weeks. The results showed no difference (p > 0.05) in invasiveness after 7 days at 10 degrees C in BHI broth or on sausage, whereas a slight increase (p < 0.05) was observed after incubation on ham for 2 and 4 weeks compared to that in BHI broth. Most importantly, our results show that L. monocytogenes efficiently invade Caco-2 cells even after 4 weeks of storage at chilled temperature. This is highly relevant for safety assessment of this organism in food as these conditions reflect storage of ready-to-eat food products in domestic refrigerators. PMID:20443727

Larsen, Marianne Halberg; Koch, Anette Granly; Ingmer, Hanne

2010-09-01

404

How bad are invaders in coastal waters? The case of the American slipper limpet Crepidula fornicata in western Europe  

Microsoft Academic Search

Introduced species are assumed to exert a variety of negative ecological effects in their new environments. However, rigid\\u000a studies on such effects are still rare. Using a case study we exemplify pitfalls and obstacles for research on ecological\\u000a effects of invaders and highlight the need for a concise framework. The suspension feeding gastropod Crepidula fornicata was accidentally introduced with American

David W. Thieltges; Matthias Strasser; Karsten Reise

2006-01-01

405

A new mechanism of invader success: Exotic plant inhibits natural vegetation restoration by changing soil microbe community  

Microsoft Academic Search

Since the 1950s of the last century, the exotic plant, Eupatorium adenophorum, has spread rapidly across southwest China, damaging native ecosystems and causing great economic losses. We examined the\\u000a pH, N, P, K, and organic matter concentrations, and the bacterial community character (by Biolog EcoPlate™) in soils from\\u000a sites heavily and lightly invaded by this exotic species. Also, soil from

Xingjun Yu; Dan Yu; Zhijun Lu; Keping Ma

2005-01-01

406

Responses to invasion and invader removal differ between native and exotic plant groups in a coastal dune.  

PubMed

The spread of exotic, invasive species is a global phenomenon that is recognized as a major source of environmental change. Although many studies have addressed the effects of exotic plants on the communities they invade, few have quantified the effects of invader removal on plant communities, or considered the degree to which different plant groups vary in response to invasion and invader removal. We evaluated the effects of an exotic succulent, iceplant (Carpobrotus edulis), on a coastal dune plant community in northern California, as well as the community responses to its removal. To assess possible mechanisms by which iceplant affects other plants, we also evaluated its above- and belowground influences on the germination and growth of a dominant exotic annual grass, Bromus diandrus. We found that iceplant invasion was associated with reduced native plant cover as well as increased cover and density of some exotic plants-especially exotic annual grasses. However, iceplant removal did not necessarily lead to a reversal of these effects: removal increased the cover and density of both native and exotic species. We also found that B. diandrus grown in iceplant patches, or in soil where iceplant had been removed, had poorer germination and growth than B. diandrus grown in soil not influenced by iceplant. This suggests that the influence of iceplant on this dune plant community occurs, at least in part, due to belowground effects, and that these effects remain after iceplant has been removed. Our study demonstrates the importance of considering how exotic invasive plants affect not only native species, but also co-occurring exotic taxa. It also shows that combining observational studies with removal experiments can lead to important insights into the influence of invaders and the mechanisms of their effects. PMID:23839266

Magnoli, Susan M; Kleinhesselink, Andrew R; Cushman, J Hall

2013-12-01

407

CO2 CONCENTRATING MECHANISMS IN PHOTOSYNTHETIC MICROORGANISMS.  

PubMed

Many microorganisms possess inducible mechanisms that concentrate CO2 at the carboxylation site, compensating for the relatively low affinity of Rubisco for its substrate, and allowing acclimation to a wide range of CO2 concentrations. The organization of the carboxysomes in prokaryotes and of the pyrenoids in eukaryotes, and the presence of membrane mechanisms for inorganic carbon (Ci) transport, are central to the concentrating mechanism. The presence of multiple Ci transporting systems in cyanobacteria has been indicated. Certain genes involved in structural organization, Ci transport and the energization of the latter have been identified. Massive Ci fluxes associated with the CO2-concentrating mechanism have wide-reaching ecological and geochemical implications. PMID:15012219

Kaplan, Aaron; Reinhold, Leonora

1999-06-01

408

Rapid screening and cultivation of oleaginous microorganisms.  

PubMed

Oleaginous microbial strains were cultivated to identify the best oil-producing strain amongst Yarrowia lipolytica (CGMCC 2.1398), Lipomyces starkeyi (CGMCC 2.1608), Rhodosporidium toruloides (CGMCC 2.1389), Mortierella isabellina (CGMCC 3.3410), Cunninghamella blakeleana (CGMCC 3.970), and Mycobacterium QJ311. A method for rapid determination of oil content and fatty acid composition was established to identify the optimum oil-producing strains. This method had a relative standard deviation of 4.09%, an average recovery ratio of 97.09% and a detection limit of 0.1-1.0 g. Mortierella isabellina CGMCC 3.3410 was identified as the best oil-producing strain amongst the six strains tested, with a total biomass of 75 g/10 L and a lipid content of 35%. A rapid screening method of oleaginous microorganisms is discussed for the first time. PMID:22611917

Gao, Xinlei; Liu, Ye; Che, Zhongju; Wu, Li

2012-04-01

409

Early photosynthetic microorganisms and environmental evolution  

NASA Technical Reports Server (NTRS)

Microfossils which are preserved as shrivelled kerogenous residues provide little information about cellular organization and almost none about the metabolic properties of the organisms. The distinction between prokaryotic vs eukaryotic, and phototrophic vs chemo- and organotrophic fossil microorganisms rests entirely on morphological comparisons with recent counterparts. The residual nature of the microbial fossil record promotes the conclusion that it must be biased toward (a) most abundant organisms, (b) those most resistant to degradation, and (c) those inhabiting environments with high preservation potential e.g., stromatolites. These criteria support the cyanophyte identity of most Precambrian microbial fossils on the following grounds: (1) as primary producers they dominate prokaryotic communities in modern extreme environments, e.g., intertidal zone; (2) several morphological counterparts of modern cyanophytes and microbial fossils have been established based on structure, cell division patterns and degradation sequences. The impact of anaerobic and oxygenic microbial photosynthesis on the evolution of Precambrian environments is discussed.

Golubic, S.

1980-01-01

410

Adsorption of Sr by immobilized microorganisms  

SciTech Connect

Wastewaters from numerous industrial and laboratory operations can contain toxic or undesirable components such as metal ions, which must be removed before discharge to surface waters. Adsorption processes that have high removal efficiencies are attractive methods for removing such contaminants. For economic operations, it is desirable to have an adsorbent that is selective for the metal contaminant of interest, has high capacity for the contaminant, has rapid adsorption kinetics, can be economically produced, and can be regenerated to a concentrated waste product or decomposed to a low-volume waste. Selected microorganisms are potentially useful adsorbents for these applications because they can be inexpensive, have high selectivities, and have high capacities for adsorption of many heavy metals, which are often problems in a variety of industries. A laboratory-scale packed column containing microbial cells immobilized within a gelatin matrix has been prepared, and its application to removal of Sr from a simulated wastewater is described. 6 refs., 2 figs., 3 tabs.

Watson, J.S.; Scott, C.D.; Faison, B.D.

1988-01-01

411

Cellulases from psychrophilic microorganisms: a review.  

PubMed

Cellulases are hydrolytic enzymes that catalyze total hydrolysis of cellulose into sugars. Cellulases are produced by various groups of microorganisms and animals; however, psychrophiles are the ideal candidates for the production of enzymes active at low temperature and stable under alkaline conditions, in the presence of oxidants and detergents, which are in large demand as laundry additives. The cellulases from psychrophiles also find application in environmental bioremediation, food industry and molecular biology. Research work on cellulase has been done over the last six decades, but there is no exclusive review available on the cellulases from psychrophiles. This review is an attempt to fill this gap by providing all the relevant information exclusively for cellulases from psychrophiles, with a focus on the present status of knowledge on their activity, molecular characteristics, gene cloning, statistical experimental designs, crystal structure, and strategies for the improvement of psychrophilic cellulases. PMID:21656807

Kasana, Ramesh C; Gulati, Arvind

2011-12-01

412

Laboratory studies of ocean mixing by microorganisms  

NASA Astrophysics Data System (ADS)

Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

Martinez-Ortiz, Monica; Dabiri, John O.

2011-11-01

413

A Multi-Site Study for Detection of the Factor V (Leiden) Mutation from Genomic DNA Using a Homogeneous Invader Microtiter Plate Fluorescence Resonance Energy Transfer (FRET) Assay  

PubMed Central

The goal of this multicenter study was to evaluate the second-generation Invader technology for detecting the factor V (Leiden) mutation directly from genomic DNA of different sample types. Invader assay results were compared with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or allele-specific PCR (AS-PCR) analysis. The Invader assay is a PCR-independent methodology that uses a microtiter plate format. In the assay, a specific upstream Invader oligonucleotide and a downstream probe hybridize in tandem to a complementary DNA template and form a partially overlapping structure. The Cleavase VIII enzyme recognizes and cuts this structure to release the 5? flap of the probe. This flap then serves as an Invader oligonucleotide to direct cleavage of a fluorescence resonance energy transfer (FRET) probe in a second invasive cleavage reaction. Cleavage of this FRET probe results in the generation of a fluorescent signal. The results of the Invader assay were 99.5% concordant with the PCR-based methods. Of the 372 samples tested once, only two gave discordant results (one from operator error and one from unknown causes), but were concordant on retesting. These results indicate that a simple microtiter plate-based Invader assay can reliably genotype clinical patient samples for the factor V (Leiden) point mutation directly from genomic DNA without prior target amplification.

Ledford, Marlies; Friedman, Kenneth D.; Hessner, Martin J.; Moehlenkamp, Cynthia; Williams, Thomas M.; Larson, Richard S.

2000-01-01

414

Targeted Killing of Streptococcus mutans by a Pheromone-Guided "Smart" Antimicrobial Peptide  

PubMed Central

Within the repertoire of antibiotics available to a prescribing clinician, the majority affect a broad range of microorganisms, including the normal flora. The ecological disruption resulting from antibiotic treatment frequently results in secondary infections or other negative clinical consequences. To address this problem, our laboratory has recently developed a new class of pathogen-selective molecules, called specifically (or selectively) targeted antimicrobial peptides (STAMPs), based on the fusion of a species-specific targeting peptide domain with a wide-spectrum antimicrobial peptide domain. In the current study, we focused on achieving targeted killing of Streptococcus mutans, a cavity-causing bacterium that resides in a multispecies microbial community (dental plaque). In particular, we explored the possibility of utilizing a pheromone produced by S. mutans, namely, the competence stimulating peptide (CSP), as a STAMP targeting domain to mediate S. mutans-specific delivery of an antimicrobial peptide domain. We discovered that STAMPs constructed with peptides derived from CSP were potent against S. mutans grown in liquid or biofilm states but did not affect other oral streptococci tested. Further studies showed that an 8-amino-acid region within the CSP sequence is sufficient for targeted delivery of the antimicrobial peptide domain to S. mutans. The STAMPs presented here are capable of eliminating S. mutans from multispecies biofilms without affecting closely related noncariogenic oral streptococci, indicating the potential of these molecules to be developed into “probiotic” antibiotics which could selectively eliminate pathogens while preserving the protective benefits of a healthy normal flora.

Eckert, Randal; He, Jian; Yarbrough, Daniel K.; Qi, Fengxia; Anderson, Maxwell H.; Shi, Wenyuan

2006-01-01

415

Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea.  

PubMed

Chronic diarrhea is a common bowel disorder; disturbance of intestinal microorganisms may play a role in its pathogenesis. This study assessed the clinical efficacy of lyophilized, heat-killed Lactobacillus acidophilus LB versus living lactobacilli in the treatment of chronic diarrhea. One hundred thirty-seven patients with chronic diarrhea were randomly allocated to receive either a 4-week course of 2 capsules of Lacteol Fort twice a day (Lacteol group, 69 patients) or a 4-week course of 5 chewable tablets of Lacidophilin three times a day (Lacidophilin group, 64 patients). The frequency of stools was recorded quantitatively, and semiquantitative parameters such as stool consistency, abdominal pain, distention, and feeling of incomplete evacuation were evaluated. At the second and fourth week of treatment, mean bowel frequency was significantly lower in the Lacteol group than in the Lacidophilin group (1.88 +/- 1.24 vs 2.64 +/- 1.12, 1.39 +/- 0.92 vs 2.19 +/- 1.05; P<.05). At the end of the treatment, the clinical symptoms were markedly improved in the Lacteol group, indicating that L. acidophilus LB is more effective than living lactobacilli in the treatment of chronic diarrhea. PMID:14964345

Xiao, Shu-Dong; Zhang, De Zhong; Lu, Hong; Jiang, Shi Hu; Liu, Hou Yu; Wang, Geng Sheng; Xu, Guo Ming; Zhang, Zhong Bing; Lin, Geng Jin; Wang, Guo Liang

2003-01-01

416

Development of Static System Procedures to Study Aquatic Biofilms and Their Responses to Disinfection and Invading Species.  

National Technical Information Service (NTIS)

The microbial ecology facility in the Analytical and Physical Chemistry Branch at Marshall Space Flight Center is tasked with anticipation of potential microbial problems (and opportunities to exploit microorganisms) which may occur in partially closed sy...

G. A. Smithers

1992-01-01

417

Polymers used to direct kill fluids to blowout  

SciTech Connect

In many reservoirs, it is difficult to establish communication between a relief well and a blowout well because of high fluid loss between the wells. In such cases, the polymer kill technique can be an important method to establish the required communication. This method will only work in very high permeability or fractured, vugular formations. However, these reservoirs are most likely to blowout at rates that will need a relief well. Once communication has been established, cheaper, less-viscous fluids can then be used to perform a dynamic kill. After this succeeds, drilling mud or other heavy fluids can be pumped to contain the well.

Ely, J.W.; Holditch, S.A.

1988-08-01

418

The nonnecrotic invaded muscle fibers of polymyositis and sporadic inclusion body myositis: on the interplay of chemokines and stress proteins.  

PubMed

Although polymyositis (PM) and sporadic inclusion body myositis (IBM) represent distinct disease entities, both are associated with the autoimmune destruction of muscle fibers. We investigated the pro-inflammatory mechanisms around the nonnecrotic invaded muscle fiber, comparing between PM and IBM. The expression and distribution of chemokines, inducible NO synthase (iNOS), and heat shock proteins (HSP) was studied in detail, using immunofluorescence, and western blotting. Important upregulation of the cytotoxic tandem HSP90/iNOS and the chemokines: IFN? inducible protein of 10kd, stromal cell-derived factor and monocyte chemoattractant protein 1, were observed in the actively invading inflammatory cells. From our results, we propose a model in which the joint action of chemokines and cytotoxic factors in cytotoxic T-cells, macrophages and myeloid dendritic cells invading the myofiber, ultimately leads to its demise. The processes described seem to be universal to PM and IBM alike. Our observations further consolidate the important autoimmune component of IBM, a feature still under debate within the scientific community. PMID:23295907

De Paepe, Boel; De Bleecker, Jan L

2013-02-22

419

Placenta percreta invading broad ligament and parametrium in a woman with two previous cesarean sections: a case report.  

PubMed

Introduction. The incidence of placenta accreta has dramatically increased due to increasing caesarean section rate all over the world. Placenta percreta is the most severe form of placenta accretes. It frequently results in maternal morbidity and mortality mainly caused by massive obstetric hemorrhage or emergency hysterectomy. Percreta invading into the broad ligament has rarely been previously reported. Case presenting. We presented a case of placenta percreta invading left broad ligament and parametrium in a woman with two previous cesarean sections, which led to massive intraoperative hemorrhage during hysterectomy and transient ischemic encephalopathy. Conclusion. In cases of parametrial involvement, it would be more difficult to decide whether to remove placenta or leave it in site. In surgical removal neither local excision of placental bed and uterine repair nor traditional hysterectomy is adequate if parametrium invaded by placenta. We suggest delayed elective hysterectomy in such cases. So, pregnancy-induced pelvic congestion would be decreased, we can gather an expert team of gynecologists, urologists, and vascular surgeons, we could get plenty of blood products, and we may have the chance to administer methotrexate. PMID:23097727

Vahdat, Mansoureh; Mehdizadeh, Abolfazl; Sariri, Elaheh; Chaichian, Shahla; Najmi, Zahra; Kadivar, Maryam

2012-01-01

420

Placenta Percreta Invading Broad Ligament and Parametrium in a Woman with Two Previous Cesarean Sections: A Case Report  

PubMed Central

Introduction. The incidence of placenta accreta has dramatically increased due to increasing caesarean section rate all over the world. Placenta percreta is the most severe form of placenta accretes. It frequently results in maternal morbidity and mortality mainly caused by massive obstetric hemorrhage or emergency hysterectomy. Percreta invading into the broad ligament has rarely been previously reported. Case presenting. We presented a case of placenta percreta invading left broad ligament and parametrium in a woman with two previous cesarean sections, which led to massive intraoperative hemorrhage during hysterectomy and transient ischemic encephalopathy. Conclusion. In cases of parametrial involvement, it would be more difficult to decide whether to remove placenta or leave it in site. In surgical removal neither local excision of placental bed and uterine repair nor traditional hysterectomy is adequate if parametrium invaded by placenta. We suggest delayed elective hysterectomy in such cases. So, pregnancy-induced pelvic congestion would be decreased, we can gather an expert team of gynecologists, urologists, and vascular surgeons, we could get plenty of blood products, and we may have the chance to administer methotrexate.

Vahdat, Mansoureh; Mehdizadeh, Abolfazl; Sariri, Elaheh; Chaichian, Shahla; Najmi, Zahra; Kadivar, Maryam

2012-01-01

421

Invading cancer cells are predominantly in G0/G1 resulting in chemoresistance demonstrated by real-time FUCCI imaging.  

PubMed

Invasive cancer cells are a critical target in order to prevent metastasis. In the present report, we demonstrate real-time visualization of cell cycle kinetics of invading cancer cells in 3-dimensional (3D) Gelfoam® histoculture, which is in vivo-like. A fluorescence ubiquitination cell cycle indicator (FUCCI) whereby G0/G1 cells express a red fluorescent protein and S/G2/M cells express a green fluorescent protein was used to determine the cell cycle position of invading and non-invading cells. With FUCCI 3D confocal imaging, we observed that cancer cells in G0/G1 phase in Gelfoam® histoculture migrated more rapidly and further than cancer cells in S/G2/M phases. Cancer cells ceased migrating when they entered S/G2/M phases and restarted migrating after cell division when the cells re-entered G0/G1. Migrating cancer cells also were resistant to cytotoxic chemotherapy, since they were preponderantly in G0/G1, where cytotoxic chemotherapy is not effective. The results of the present report suggest that novel therapy targeting G0/G1 cancer cells should be developed to prevent metastasis. PMID:24552821

Yano, Shuya; Miwa, Shinji; Mii, Sumiyuki; Hiroshima, Yukihiko; Uehara, Fuminari; Yamamoto, Mako; Kishimoto, Hiroyuki; Tazawa, Hiroshi; Bouvet, Michael; Fujiwara, Toshiyoshi; Hoffman, Robert M

2014-03-15

422

Coupled fluid and solid mechanics study for improved permeability estimation of fines' invaded porous materials  

NASA Astrophysics Data System (ADS)

The problem of fine particle infiltration is seen in fields from subsurface transport, to drug delivery to industrial slurry flows. Sediment filtration and pathogen retention are well-known subsurface engineering problems that have been extensively studied through different macroscopic, microscopic and experimental modeling techniques Due to heterogeneity, standard constitutive relationships and models yield poor predictions for flow (e.g. permeability) and rock properties (e.g. elastic moduli) of the invaded (damaged) porous media. This severely reduces our ability to, for instance, predict retention, pressure build-up, newly formed flow pathways or porous medium mechanical behavior. We chose a coupled computational fluid dynamics (CFD) - discrete element modeling (DEM) approach to simulate the particulate flow through porous media represented by sphere packings. In order to minimize the uncertainty involved in estimating the flow properties of porous media on Darcy scale and address the dynamic nature of filtration process, this microscopic approach is adapted as a robust method that can incorporate particle interaction physics as well as the heterogeneity of the porous medium.. The coupled simulation was done in open-source packages which has both CFD (openFOAM) and DEM components (LIGGGHTS). We ran several sensitivity analyses over different parameters such as particle/grain size ratio, fluid viscosity, flow rate and sphere packing porosity in order to investigate their effects on the depth of invasion and damaged porous medium permeability. The response of the system to the variation of different parameters is reflected through different clogging mechanism; for instance, bridging is the dominant mechanism of pore-throat clogging when larger particles penetrate into the packing, whereas, in case of fine particles which are much smaller than porous medium grains (1/20 in diameter), this mechanism is not very effective due to the frequent formation and destruction of particle bridges. Finally, depending on the material and fluids that penetrate into the porous medium, the ionic forces might play a significant role in the filtration process. We thus also report on influence of particle attachment (and detachment) on the type of clogging mechanisms. Pore scale simulations allow for visualization and understanding of fundamental processes, and, further, the velocity fields are integrated into a distinctly non-monotonic permeability-porosity/(depth of penetration) relationship.

Mirabolghasemi, M.; Prodanovic, M.

2012-12-01

423

Effects of developmental acclimation on adult salinity tolerance in the freshwater-invading copepod Eurytemora affinis.  

PubMed

Invasive species are commonly thought to have broad tolerances that enable them to colonize new habitats, but this assumption has rarely been tested. In particular, the relative importance of acclimation (plasticity) and adaptation for invasion success are poorly understood. This study examined effects of short-term and developmental acclimation on adult salinity tolerance in the copepod Eurytemora affinis. This microcrustacean occurs in estuarine and salt marsh habitats but has invaded freshwater habitats within the past century. Effects of short-term acclimation were determined by comparing adult survival in response to acute versus gradual salinity change to low salinity (fresh water). Effects of developmental acclimation on adult tolerance were determined using a split-brood 4 x 2 factorial experimental design for one brackish-water population from Edgartown Great Pond, Massachusetts. Twenty full-sib clutches were split and reared at four salinities (fresh, 5, 10, and 27 practical salinity units [PSU]). On reaching adulthood, clutches from three of the salinity treatments (no survivors at fresh) were split into low- (fresh) and high- (40 PSU) salinity stress treatments, at which survival was measured for 24 h. Short-term acclimation of adults did not appear to have a long-term affect on low-salinity tolerance, given that gradual transfers to fresh water enhanced survival relative to acute transfers in the short term (after 7 h) but not over a longer period of 8 d. Developmental acclimation had contrasting effects on low- versus high-salinity tolerance. Namely, rearing salinity had a significant effect on tolerance of high-salinity (40 PSU) stress but no significant effect on tolerance of low-salinity (freshwater) stress. In addition, there was a significant effect of clutch on survival under freshwater conditions, indicating a genetic component to low-salinity tolerance but no significant clutch effect in response to high salinity. While developmental acclimation might enhance survival at higher salinities, the minimal effect of acclimation and significant effect of clutch on low-salinity tolerance suggest the importance of natural selection during freshwater invasion events. PMID:12905115

Lee, Carol Eunmi; Petersen, Christine H

2003-01-01

424

Karo-kari: a form of honour killing in pakistan.  

PubMed

Karo-Kari is a type of premeditated honour killing, which originated in rural and tribal areas of Sindh, Pakistan. The homicidal acts are primarily committed against women who are thought to have brought dishonour to their family by engaging in illicit pre-marital or extra-marital relations. In order to restore this honour, a male family member must kill the female in question. We conducted a systematic review of the published literature other sources on karo-kari and related forms of honour killing or violence against women. Media and non-governmental organization reports were utilized for case studies and analysis. Although legally proscribed, socio-cultural factors and gender role expectations have given legitimacy to karo-kari within some tribal communities. In addition to its persistence in areas of Pakistan, there is evidence that karo-kari may be increasing in incidence in other parts of the world in association with migration. Moreover, perpetrators of ;honour killings' often have motives outside of female adultery. Analysis of the socio-cultural and psycho-pathological factors associated with the practice of karo-kari can guide the development of prevention strategies. PMID:19091732

Patel, Sujay; Gadit, Amin Muhammad

2008-12-01

425

Targeted Killing in U.S. Counterterrorism Strategy and Law  

Microsoft Academic Search

Targeted killing, particularly through the use of missiles fired from Predator drone aircraft, has become an important, and internationally controversial, part of the US war against al Qaeda in Pakistan and other places. The Obama administration, both during the campaign and in its first months in office, has publicly embraced the strategy as a form of counterterrorism. This paper argues,

Kenneth Anderson

2009-01-01

426

Probability of Kill for VLA ASROC Torpedo Launch.  

National Technical Information Service (NTIS)

The purpose of this thesis is to generate a tactical decision aid (TDA) capable of calculating the probability of kill of a submarine when targeted with a vertical launched (VLA) anti-submarine rocket propelled torpedo (ASROC). In determining the submarin...

S. J. Valerio

2009-01-01

427

Endotoxin-induced serum factor kills malarial parasites in vitro.  

PubMed Central

We investigated the possibility that malarial parasites may be killed by nonspecific soluble mediators, such as those in tumor necrosis serum, that are obtained from mice given macrophage-activating agents like Corynebacterium parvum or Mycobacterium bovis BCG, followed by endotoxin. Such sera killed parasites in vitro after overnight incubation; killing was measured directly by using an in vivo infectivity assay. Parasite infectivity was not decreased by incubation in sera from mice given C. parvum or BCG alone (no endotoxin) or by incubation in sera from normal mice given endotoxin. Plasmodium yoelii, its lethal variant, and Plasmodium berghei were equally susceptible to inactivation. Sera obtained from mice given endotoxin during the course of infection with these parasites also contained parasite-killing factor. The activity of this factor appeared to be proportional to parasitemia in that it was higher in the sera from mice infected with the lethal parasites than in the sera from mice with infections which resolved either spontaneously or after vaccination.

Taverne, J; Dockrell, H M; Playfair, J H

1981-01-01

428

Aspen Successfully Regenerated after Killing Residual Vegetation with Herbicides.  

National Technical Information Service (NTIS)

Three pounds per acre acid equivalent of aerially applied 2, 4-D, or 2, 4-D plus 2,4,5-T, were used to release young quaking aspen suckers from unmerchantable hardwoods left after commercial clearcutting. Although one-year-old suckers were killed to the g...

D. A. Perala

1971-01-01

429

Making the Case: What is the Problem with Targeted Killing.  

National Technical Information Service (NTIS)

What is the problem with targeted killing. The problem is not simply the legal and moral grounds for the policy, nor the tactical implementation of the policy. Rather, the problem is that current research does not convincingly articulate the causal relati...

A. W. Boyden I. R. Ramirez V. P. Menard

2009-01-01

430

Patterns of Amphotericin B Killing Kinetics against Seven Candida Species  

Microsoft Academic Search

In a previous study tolerance to amphotericin B (AMB) was found among Candida parapsilosis and C. dubliniensis strains by seeding the whole volumes of wells used for MIC determinations, and minimum fungicidal concentrations (MFC) for non-C. albicans Candida strains were demonstrated to be above the levels safely achievable in serum. As an extension of that study, we performed time-kill assays

Emilia Canton; Javier Peman; Miguel Gobernado; Angel Viudes; Ana Espinel-Ingroff

2004-01-01

431

How Moist Heat Kills Spores of Bacillus subtilis?  

PubMed Central

Populations of Bacillus subtilis spores in which 90 to 99.9% of the spores had been killed by moist heat gave only two fractions on equilibrium density gradient centrifugation: a fraction comprised of less dense spores that had lost their dipicolinic acid (DPA), undergone significant protein denaturation, and were all dead and a fraction with the same higher density as that of unheated spores. The latter fraction from heat-killed spore populations retained all of its DPA, but ?98% of the spores could be dead. The dead spores that retained DPA germinated relatively normally with nutrient and nonnutrient germinants, but the outgrowth of these germinated spores was significantly compromised, perhaps because they had suffered damage to some proteins such that metabolic activity during outgrowth was greatly decreased. These results indicate that DPA release takes place well after spore killing by moist heat and that DPA release during moist-heat treatment is an all-or-nothing phenomenon; these findings also suggest that damage to one or more key spore proteins causes spore killing by moist heat.

Coleman, William H.; Chen, De; Li, Yong-qing; Cowan, Ann E.; Setlow, Peter

2007-01-01

432

Evaluation of Voriconazole Pharmacodynamics Using Time-Kill Methodology  

Microsoft Academic Search

Voriconazole is an investigational azole antifungal agent with activity against a variety of fungal species, including fluconazole-susceptible and -resistant Candida species and Cryptococcus neoformans. In this study, we employed in vitro time-kill methods to characterize the relationship between concentrations of voriconazole and its fungistatic activity against Candida albicans, Candida glabrata, Candida tropicalis, and C. neoformans. Isolates were exposed to voriconazole

MICHAEL E. KLEPSER; DENNIS MALONE; RUSSELL E. LEWIS; ERIKA J. ERNST; MICHAEL A. PFALLER

2000-01-01

433

Does Host Complement Kill Borrelia burgdorferi within Ticks?  

Microsoft Academic Search

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

Sivaprakash Rathinavelu; Anne Broadwater; Aravinda M. de Silva

2003-01-01

434

Identification of Microorganisms Encountered in the Upper Respiratory Tract  

NSDL National Science Digital Library

This resource is a detailed laboratory manual for instructing students in a laboratory exercise focusing on the identification of the micro-organisms commonly found in the upper respiratory tract. Detailed information on different micro-organisms including identification keys and laboratory tests. This would be a suitable introduction to bacterial identification for any course requiring such taxonomic skills.

Iris L. Sun (Purdue University;)

1996-01-01

435

Microorganisms in Food--Their Significance and Methods of Enumeration.  

ERIC Educational Resources Information Center

Described are laboratory methods for enumerating microorganisms in food. These methods are utilized to determine if foods are potentially hazardous to the consumer due to high concentrations of microorganisms. Discussed are indicator organisms, including coliforms, interococci, yeasts, and molds; food poisoning organisms (staphylococci and…

Andrews, S.

1980-01-01

436

78 FR 42451 - Animal Feeds Contaminated With Salmonella Microorganisms  

Federal Register 2010, 2011, 2012, 2013

...FDA-2013-N-0253] Animal Feeds Contaminated With Salmonella Microorganisms AGENCY: Food and Drug...opinion on animal feeds contaminated with Salmonella microorganisms. This action is being...final compliance policy guide (CPG) on Salmonella in food for animals. DATES: This...

2013-07-16

437

ON THE SPECIFIC RESISTANCE OF CAKES OF MICROORGANISMS  

Microsoft Academic Search

The mean specific resistance of the cakes of various microorganisms was evaluated by measurement of either a change in the amount of permeate with time or of steady-state flux under constant pressure. The mean specific resistance was different with different shapes and sizes of microorganisms. The large differences arose from different packing structures of the cake. The effect of a

KAZUHIRO NAKANISHI; TAKAAKI TADOKORO; RYUICHI MATSUNO

1987-01-01

438

Biodiversity and potentials of marine-derived microorganisms  

Microsoft Academic Search

The marine environment is a prolific resource for the isolation of less exploited microorganisms. As a matter of fact, in the sea, untapped habitats exist with unique characteristics. In addition, the potential contribution of marine sources to the discovery of new bioactive molecules was recently recognized. Biosearch Italia possesses a collection of about 40000 microorganisms, isolated from different ecological niches.

Federica Sponga; Linda Cavaletti; Ameriga Lazzarini; Angelo Borghi; Ismaela Ciciliato; D. Losi; Flavia Marinelli

1999-01-01

439

Biodiversity and potentials of marine-derived microorganisms  

Microsoft Academic Search

The marine environment is a prolific resource for the isolation of less exploited microorganisms. As a matter of fact, in the sea, untapped habitats exist with unique characteristics. In addition, the potential contribution of marine sources to the discovery of new bioactive molecules was recently recognized. Biosearch Italia possesses a collection of about 40?000 microorganisms, isolated from different ecological niches.

Federica Sponga; Linda Cavaletti; Ameriga Lazzarini; Angelo Borghi; Ismaela Ciciliato; D. Losi; Flavia Marinelli

1999-01-01

440

Prospects for thermophilic microorganisms in microbial enhanced oil recovery (MEOR)  

Microsoft Academic Search

Studies in this laboratory have shown that certain species of thermophilic microorganisms may satisfy microbial enhanced oil recovery (MEOR) requirements. Several species of thermophilic microorganisms have been grown in the presence of varying concentrations of crude oils at different temperatures and pressures. Experimental evidence indicates that some thermophiles are viable over long periods of time (six months) at 70°C and

E. T. Premuzic; M. S. Lin

1990-01-01

441

MICROORGANISMS IN MUNICIPAL SOLID WASTE AND PUBLIC HEALTH IMPLICATIONS  

EPA Science Inventory

The composition of municipal solid waste is quite heterogeneous. This mixed composition results in the presence of a variety of microorganisms that reach densities which are relatively high, and which remain high even after many years in a landfill. Microorganism densities in the...

442

Competition for nitrogen between plants and soil microorganisms  

Microsoft Academic Search

Experiments suggest that plants and soil microorganisms are both limited by inorganic nitrogen, even on relatively fertile sites. Consequently, plants and soil microorganisms may compete for nitrogen. While past research has focused on competition for inorganic nitrogen, recent studies have found that plants\\/mycorrhizae in a wide range of ecosystems can use organic nitrogen. A new view of competitive interactions between

Jason P. Kaye; Stephen C. Hart

1997-01-01

443

Effect of Selected Microorganisms on Fusarium Toxins Production  

Microsoft Academic Search

The aim of this study was to examine the effect of selected microorganisms on mycotoxins production by moulds of the genus Fusarium, namely HT-2 and T-2 toxins. Appropriate nutritive media were inoculated with test microorganisms (Rhodotorula spp., Leuconostoc spp., Pantoea agglomerans), subsequently inoculated with Fusarium moulds, then incubated under various conditions. Content of Fusarium mycotoxins in individual samples was determined

Lucie Hlavá?ková; Jarmila Vyt?asová; Šárka Novotná; Petra Mo?ková-Šnévajsová; Iveta Brožková; Alena Honzlová

2012-01-01

444

(Application of selected microorganisms for organic sulfur removal from coal)  

SciTech Connect

Research continues on the use of microorganisms to desulfurize coal. Topics reported on for this term include: coal procurement and preparation, analytical procedures for characterization of total organic sulfur, search for new microorganisms, coal desulfurization, dibenzothiophene/sulfate bioassay, and plasmid mediation techniques. (VC)

Boyden, B.H.

1989-12-15

445

Detection and quantification of microorganisms in anaerobic bioreactors  

Microsoft Academic Search

The presence of sulfate in anaerobic reactors can trigger competitive and syntrophic interactions between various groups of microorganisms, such as sulfate reducers, methanogens and acetogens. In order to steer the reactor process in the direction of sulfidogenesis or methanogenesis, it is essential to get insight into the population dynamics of these groups of microorganisms upon changes in the reactor operating

S. J. W. H. Oude Elferink; R. van Lis; H. G. H. J. Heilig; A. D. L. Akkermans; A. J. M. Stams

1998-01-01

446

Effect of bromidehypochlorite bactericides on microorganisms.  

PubMed

A new principle in compounding stable, granular bactericidal products led to unique combinations of a water-soluble inorganic bromide salt with a hypochlorite-type disinfectant of either inorganic or organic type. Microbiological results are shown for an inorganic bactericide composed of chlorinated trisodium phosphate containing 3.1% "available chlorine" and 2% potassium bromide, and for an organic bactericide formulated from sodium dichloroisocyanurate so as to contain 13.4% "available chlorine" and 8% potassium bromide. Comparison of these products with their nonbromide counterparts are reported for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus lactis, Aerobacter aerogenes, and Proteus vulgaris. Test methods employed were the Chambers test, the A.O.A.C. Germicidal and Detergent Sanitizer-Official test, and the Available Chlorine Germicidal Equivalent Concentration test. The minimal killing concentrations for the bromide-hypochlorite bactericides against this variety of organisms were reduced by a factor 2 to 24 times those required for similar hypochlorite-type disinfectants not containing the bromide. PMID:13977149

SHERE, L; KELLEY, M J; RICHARDSON, J H

1962-11-01

447

Comparison of pixel and sub-pixel based techniques to separate Pteronia incana invaded areas using multi-temporal high resolution imagery  

Microsoft Academic Search

Remote Sensing using high resolution imagery (HRI) is fast becoming an important tool in detailed land-cover mapping and analysis of plant species invasion. In this study, we sought to test the separability of Pteronia incana invader species by pixel content aggregation and pixel content de-convolution using multi-temporal infrared HRI. An invaded area in Eastern Cape, South Africa was flown in

John Odindi; Vincent Kakembo

2009-01-01

448

Polyhydroxybutyrate: plastic made and degraded by microorganisms.  

PubMed

Polyhydroxybutyrate (PHB) offers many advantages over traditional petrochemically derived plastics. In addition to its complete biodegradability, PHB is formed from renewable resources. It possesses better physical properties than polypropylene for food packaging applications and is completely nontoxic. The poor low-impact strength of PHB is solved by incorporation of hydroxyvalerate monomers into the polymer to produce polyhydroxybutyrate-co-valerate (PHBV), which is commercially marketed under the trade name Biopol. Like PHB, PHBV completely degrades into carbon dioxide and water under aerobic conditions. Microbial synthesis of PHB is the best method for industrial production because it ensures the proper stereochemistry for biodegradation. Microorganisms synthesize and store PHB under nutrient-limited conditions and degrade and metabolize it when the limitation is removed. Current production employs Alcaligenes eutrophus because it grows efficiently on glucose as a carbon source, accumulates PHB up to 80% of its dry weight, and is able to synthesize PHBV when propionic acid is added to the feedstock. PHBV is currently 16 times the price of polypropylene. However, the development of transgenic PHA-producing organisms is expected to greatly reduce its cost. Benefits of using transgenic systems include lack of a depolymerase system, ability to use faster-growing organisms, production of highly purified polymers, and ability to utilize inexpensive carbon sources. Because transgenic plants may someday result in the evolution of plastic crops that could lower the price of PHA to a competitive level, future research will surely focus on such recombinant DNA techniques. PMID:9921137

Hankermeyer, C R; Tjeerdema, R S

1999-01-01

449

Ultrasonication assisted lipid extraction from oleaginous microorganisms.  

PubMed

Various solvents, including water, hexane, methanol, and chloroform/methanol (1:1 v/v), were tested to identify the efficiency of lipid extraction from Trichosporon oleaginosus and an oleaginous fungal strain SKF-5 under ultrasonication (520kHz 40W and 50Hz 2800W) and compared with the conventional chloroform methanol (2:1 v/v) extraction method. The highest lipid recovery 10.2% and 9.3% with water, 43.2% and 33.2% with hexane, 75.7% and 65.1% with methanol, 100% and 100% w/w biomass with chloroform/methanol were obtained from T. oleaginosus and SKF-5 strain, respectively, at ultrasonication frequency 50Hz and power input 2800W. Ultrasonication chloroform/methanol extraction recovered total lipid in a short time (15min) and low temperature (25°C). Whereas the conventional chloroform methanol extraction to achieve total lipid recovery required 12h at 60°C. Ultrasonication chloroform/methanol extraction would be a promising method of lipid extraction from the microorganisms. PMID:24607462

Zhang, Xiaolei; Yan, Song; Tyagi, Rajeshwar D; Drogui, Patrick; Surampalli, Rao Y

2014-04-01