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1

Defects in the oxidative killing of microorganisms by phagocytic leukocytes.  

PubMed

One of the most important mechanisms of phagocytic killing of ingested microorganisms by leukocytes is the generation of toxic oxygen products. During phagocytosis, neutrophils, as well as monocytes and macrophages, display a strongly increased cell respiration. Quantitatively the most important product of this reaction is hydrogen peroxide. Superoxide is also generated in large amounts, probably as an intermediate in the formation of hydrogen peroxide. Indications exist that singlet oxygen and hydroxyl radicals are also formed in this process. Some of these oxygen products have microbicidal properties by themselves. The effect of hydrogen peroxide is greatly enhanced by the enzyme myeloperoxidase. Several dysfunctions of this sytem are known. In chronic granulomatous disease the enzyme system that produces superoxide is not operative. Thus, no superoxide or hydrogen peroxide is generated, leading to a severely decreased bacterial killing capacity. The exact molecular defects in the X-linked and the autosomal form are as yet undefined. Two variants are also known: lipochrome histiocytosis, with different clinical and histological manifestations, and a 'triggering defect' where only strongly opsonized particles trigger the respiratory burst. Myeloperoxidase deficiency leads to slightly decreased killing capacity, especially for yeasts. In glucose-6-phosphate dehydrogenase deficiency no oxygen radicals or hydrogen peroxide are produced because no equivalents for oxygen reduction can be generated in the hexose-monophosphate shunt. Deficiencies in the glutathione redox system also result in impaired phagocyte function, probably because the cells have to be protected against their own toxic oxygen products. PMID:225141

Roos, D; Weening, R S

2

Plankton Microorganisms Coinciding with Two Consecutive Mass Fish Kills in a Newly Reconstructed Lake  

PubMed Central

Lake Karla, Greece, was dried up in 1962 and its refilling started in 2009. We examined the Cyanobacteria and unicellular eukaryotes found during two fish kill incidents, in March and April 2010, in order to detect possible causative agents. Both microscopic and molecular (16S/18S rRNA gene diversity) identification were applied. Potentially toxic Cyanobacteria included representatives of the Planktothrix and Anabaena groups. Known toxic eukaryotes or parasites related to fish kill events were Prymnesium parvum and Pfiesteria cf. piscicida, the latter being reported in an inland lake for the second time. Other potentially harmful microorganisms, for fish and other aquatic life, included representatives of Fungi, Mesomycetozoa, Alveolata, and Heterokontophyta (stramenopiles). In addition, Euglenophyta, Chlorophyta, and diatoms were represented by species indicative of hypertrophic conditions. The pioneers of L. Karla's plankton during the first months of its water refilling process included species that could cause the two observed fish kill events. PMID:22654619

Oikonomou, Andreas; Katsiapi, Matina; Karayanni, Hera; Moustaka-Gouni, Maria; Kormas, Konstantinos Ar.

2012-01-01

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

Study on the killing of oceanic harmful micro-organisms in ship's ballast water using oxygen active particles  

NASA Astrophysics Data System (ADS)

Global Environment Facility has identified that the spread of marine invasive alien species is one of the four major risk factors threatening the safety of global marine environments. Ballast water discharge is the main cause of biological invasion. With physical methods of strong electric field ionization discharge at atmospheric pressure, O2 and sea water (gaseous) were ionized, and then dissociated to a number of oxygen active particles (ROS) such as ·OH, O2+, H2O+, etc. ROS was injected into 0.6 t h-1 ballast water treatment system to form high concentration ROS solution in order to kill the harmful micro-organisms in ballast water. According to the land-based test standard of International Maritime Organization (IMO) Guidelines for Approval of Ballast Water Management Systems (G8), this paper concludes that single-cell algae of 3.0 × 104 cell ml-1 and bacteria of 2.0 × 104 cfu ml-1 were killed by ROS solution of 2.0 ppm. Death rate could reach almost 100%. The results meet the requirements of Regulation D-2 of International Convention for the Control and Management of Ships' Ballast Water and Sediments completely.

Chen, C.; Meng, X. Y.; Bai, M. D.; Tian, Y. P.; Jing, Y.

2013-03-01

5

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.

6

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

7

Silent Invaders  

NSDL National Science Digital Library

Silent Invaders introduces the problem of invasive species and provides information on control activities. The videos explain how invasive species get into the United States, why some do so well here, and how we can keep invasive species out. There is an interactive section where the user tries to eliminate musk thistle by applying a combination of biological, fire, chemical and mechanical controls. Other featured species include cheatgrass, tamarisk, woolly adelgid, zebra mussel, and fire ants. The field guide contains a list of invasive plant and animal species as well as photographs and movies. The instructor guide is a weed science primer for teachers.

David LaHart

8

Naturally Processed Dermcidin-Derived Peptides Do Not Permeabilize Bacterial Membranes and Kill Microorganisms Irrespective of Their Charge  

PubMed Central

Dermcidin (DCD) is a recently described antimicrobial peptide, which is constitutively expressed in eccrine sweat glands and transported via sweat to the epidermal surface. By postsecretory proteolytic processing in sweat the dermcidin protein gives rise to several truncated DCD peptides which differ in length and net charge. In order to understand the mechanism of antimicrobial activity, we analyzed the spectrum of activity of several naturally processed dermcidin-derived peptides, the secondary structure in different solvents, and the ability of these peptides to interact with or permeabilize the bacterial membrane. Interestingly, although all naturally processed DCD peptides can adopt an ?-helical conformation in solvents, they have a diverse and partially overlapping spectrum of activity against gram-positive and gram-negative bacteria. This indicates that the net charge and the secondary structure of the peptides are not important for the toxic activity. Furthermore, using carboxyfluorescein-loaded liposomes, membrane permeability studies and electron microscopy we investigated whether DCD peptides are able to permeabilize bacterial membranes. The data convincingly show that irrespective of charge the different DCD peptides are not able to permeabilize bacterial membranes. However, bacterial mutants lacking specific cell envelope modifications exhibited different susceptibilities to killing by DCD peptides than wild-type bacterial strains. Finally, immunoelectron microscopy studies indicated that DCD peptides are able to bind to the bacterial surface; however, signs of membrane perturbation were not observed. These studies indicate that DCD peptides do not exert their activity by permeabilizing bacterial membranes. PMID:16870749

Steffen, H.; Rieg, S.; Wiedemann, I.; Kalbacher, H.; Deeg, M.; Sahl, H.-G.; Peschel, A.; Götz, F.; Garbe, C.; Schittek, B.

2006-01-01

9

Silent Invaders  

NSDL National Science Digital Library

A joint effort of the Interactive Media Science Projects at Florida State University and the Bureau of Land Management, US Department of the Interior, Silent Invaders presents a comprehensive and very visual introduction to invasive species in the US and Guam. Click on Introduction to view five QuickTime documentary-style movies that provide an overview of the topic. Other categories offer detailed information, photographs, and more movies addressing invasive plant and animal species, control measures, and prevention. Teachers may access a downloadable weed science primer from the Educator's Guide. The developers at Florida State University invite educators to take advantage of "the flexible framework -- clear, strong, and simple activity structures" provided by this Web site. With its many QuickTime movies, this site is best viewed with a high-speed connection.

1969-12-31

10

Invasion of one insect species, Adalia bipunctata, by two different male-killing bacteria.  

PubMed

Male-killing bacteria, which are inherited through the female line and kill male progeny only, are known from five different orders of insect. Our knowledge of the incidence of these elements has stemmed from discovery of their phenotype in different species. Our estimate of the frequency with which insects have been invaded by these elements therefore depends on each observation of the male-killing phenotype within a species being associated with a single microorganism. We here record an example of a single insect species being infected with two taxonomically distinct male-killing bacteria. Western European populations of the two-spot ladybird, Adalia bipunctata, have previously been shown to bear a male-killing Rickettsia. However, we here show that the majority of the male-killing lines tested from Central and Eastern Europe do not bear this bacterium. Rather, 16S rDNA sequence analysis suggests male-killing is associated with a member of the genus Spiroplasma. We discuss this conclusion in relation to the evolutionary genetics of male-killing bacteria, and the evolution of male-killing behaviour in the eubacteria. PMID:9927182

Hurst, G D; Graf von der Schulenburg, J H; Majerus, T M; Bertrand, D; Zakharov, I A; Baungaard, J; Völkl, W; Stouthamer, R; Majerus, M E

1999-02-01

11

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.

12

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

13

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.

14

Killing Range  

PubMed Central

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

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

2015-01-01

15

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

16

Activation of AMPK Enhances Neutrophil Chemotaxis and Bacterial Killing  

PubMed Central

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

17

Microorganism Billiards  

E-print Network

Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of such a body inside a regular polygon and show that the dynamics can settle on a stable periodic orbit, or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square ...

Wahl, Colin; Spagnolie, Saverio E; Thiffeault, Jean-Luc

2015-01-01

18

Microorganism Billiards  

E-print Network

Recent experiments and numerical simulations have shown that certain types of microorganisms "reflect" off of a flat surface at a critical angle of departure, independent of the angle of incidence. The nature of the reflection may be active (cell and flagellar contact with the surface) or passive (hydrodynamic) interactions. We explore the billiard-like motion of such a body inside a regular polygon and show that the dynamics can settle on a stable periodic orbit, or can be chaotic, depending on the swimmer's departure angle and the domain geometry. The dynamics are often found to be robust to the introduction of weak random fluctuations. The Lyapunov exponent of swimmer trajectories can be positive or negative, can have extremal values, and can have discontinuities depending on the degree of the polygon. A passive sorting device is proposed that traps swimmers of different departure angles into separate bins. We also study the external problem of a microorganism swimming in a patterned environment of square obstacles, where the departure angle dictates the possibility of trapping or diffusive trajectories.

Colin Wahl; Joseph Lukasik; Saverio E. Spagnolie; Jean-Luc Thiffeault

2015-02-05

19

The ail gene of Yersinia enterocolitica has a role in the ability of the organism to survive serum killing.  

PubMed

Two Yersinia enterocolitica genes, inv and ail, play a major role in the ability of this microorganism to enter cultured mammalian cells. ail-homologous sequences are present only in pathogenic species and strains of Yersinia. We previously demonstrated (D. E. Pierson and S. Falkow, Infect. Immun. 58:1059-1064, 1990) that four different nonpathogenic isolates of Y. enterocolitica are not able to invade tissue culture cells because they contain functionally inactive variants of the inv gene. When a functional version was introduced into these strains, they became invasive. In this study, we introduced a functional ail gene into the same strains and found that the ail gene was expressed but that these strains neither adhere to nor invade cultured animal cells. However, these recombinant strains became resistant to killing by human serum, whereas their parental strains were not. Using an ail mutant, we also demonstrate that the ail gene has a role in both invasion/adherence and serum resistance in a pathogenic isolate of Y. enterocolitica. These results support a role for Ail in the pathogenesis of Y. enterocolitica infection and disease. PMID:7682996

Pierson, D E; Falkow, S

1993-05-01

20

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

21

Toxoplasma Co-opts Host Cells It Does Not Invade  

PubMed Central

Like many intracellular microbes, the protozoan parasite Toxoplasma gondii injects effector proteins into cells it invades. One group of these effector proteins is injected from specialized organelles called the rhoptries, which have previously been described to discharge their contents only during successful invasion of a host cell. In this report, using several reporter systems, we show that in vitro the parasite injects rhoptry proteins into cells it does not productively invade and that the rhoptry effector proteins can manipulate the uninfected cell in a similar manner to infected cells. In addition, as one of the reporter systems uses a rhoptry:Cre recombinase fusion protein, we show that in Cre-reporter mice infected with an encysting Toxoplasma-Cre strain, uninfected-injected cells, which could be derived from aborted invasion or cell-intrinsic killing after invasion, are actually more common than infected-injected cells, especially in the mouse brain, where Toxoplasma encysts and persists. This phenomenon has important implications for how Toxoplasma globally affects its host and opens a new avenue for how other intracellular microbes may similarly manipulate the host environment at large. PMID:22910631

Koshy, Anita A.; Dietrich, Hans K.; Christian, David A.; Melehani, Jason H.; Shastri, Anjali J.; Hunter, Christopher A.; Boothroyd, John C.

2012-01-01

22

Revegetating sagebrush rangelands invaded by medusahead  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objectives of this study were to determine: 1) effective treatments for controlling medusahead and 2) the appropriate plant materials for revegetating medusahead-invaded rangelands. Initial treatments of prescribed burning immediately followed with applications of the preemergent herbicide imaza...

23

Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity  

PubMed Central

Streptococcus pneumoniae, a Gram-positive bacterium, is a major cause of invasive infection-related diseases such as pneumonia and sepsis. In blood, erythrocytes are considered to be an important factor for bacterial growth, as they contain abundant nutrients. However, the relationship between S. pneumoniae and erythrocytes remains unclear. We analyzed interactions between S. pneumoniae and erythrocytes, and found that iron ion present in human erythrocytes supported the growth of Staphylococcus aureus, another major Gram-positive sepsis pathogen, while it partially inhibited pneumococcal growth by generating free radicals. S. pneumoniae cells incubated with human erythrocytes or blood were subjected to scanning electron and confocal fluorescence microscopic analyses, which showed that the bacterial cells adhered to and invaded human erythrocytes. In addition, S. pneumoniae cells were found associated with human erythrocytes in cultures of blood from patients with an invasive pneumococcal infection. Erythrocyte invasion assays indicated that LPXTG motif-containing pneumococcal proteins, erythrocyte lipid rafts, and erythrocyte actin remodeling are all involved in the invasion mechanism. In a neutrophil killing assay, the viability of S. pneumoniae co-incubated with erythrocytes was higher than that without erythrocytes. Also, H2O2 killing of S. pneumoniae was nearly completely ineffective in the presence of erythrocytes. These results indicate that even when S. pneumoniae organisms are partially killed by iron ion-induced free radicals, they can still invade erythrocytes. Furthermore, in the presence of erythrocytes, S. pneumoniae can more effectively evade antibiotics, neutrophil phagocytosis, and H2O2 killing. PMID:24194877

Yamaguchi, Masaya; Terao, Yutaka; Mori-Yamaguchi, Yuka; Domon, Hisanori; Sakaue, Yuuki; Yagi, Tetsuya; Nishino, Kunihiko; Yamaguchi, Akihito; Nizet, Victor; Kawabata, Shigetada

2013-01-01

24

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

25

Shallow moving structures promote marine invader dominance.  

PubMed

Global increases in urban development have resulted in severe habitat modification in many estuaries. Most are now dominated by artificial structures, which might have a myriad of effects on native species. The provision of extra hard substrata presents additional free space, and recent research suggests non-indigenous epifauna may be able to exploit these artificial structures (particularly pontoons) more effectively than native species. The early development of fouling assemblages was compared on settlement plates attached to fixed or moving experimental structures at depths of 0.5 m and 2 m. Invertebrate invaders as a group were disproportionately more numerous on shallow, moving plates (essentially floating surfaces) than on deeper plates, whereas native epifauna were less numerous than invaders in all treatments. Importantly, however, individual invasive species showed differing effects of movement and depth. Future management strategies should take into account the potential for shallow, moving structures to enhance invader dominance and strongly consider using fixed structures to reduce opportunities for invaders. PMID:19180352

Dafforn, K A; Johnston, E L; Glasby, T M

2009-01-01

26

HOW NEUTROPHILS KILL MICROBES  

Microsoft Academic Search

? Abstract Neutrophils provide the first line of defense of the innate immune,sys- tem by phagocytosing, killing, and digesting bacteria and fungi. Killing was previously believed to be accomplished,by oxygen,free radicals and other reactive oxygen,species generated by the NADPH oxidase, and by oxidized halides produced by myeloperoxi- dase. We now,know,this is incorrect. The oxidase pumps,electrons into the phagocytic vacuole, thereby

Anthony W. Segal

2005-01-01

27

Structural changes in soil communities after triclopyr application in soils invaded by Acacia dealbata Link.  

PubMed

Triclopyr is a commonly used herbicide in the control of woody plants and can exhibit toxic effects to soil microorganisms. However, the impact on soils invaded by plant exotics has not yet been addressed. Here, we present the results of an 18-month field study conducted to evaluate the impact of triclopyr on the structure of fungal and bacterial communities in soils invaded by Acacia dealbata Link, through the use of denature gradient gel electrophoresis. After triclopyr application, analyses of bacterial fingerprints suggested a change in the structure of the soil bacterial community, whereas the structure of the soil fungal community remained unaltered. Bacterial density and F:B ratio values changed across the year but were not altered due to herbicide spraying. On the contrary, fungal diversity was increased in plots sprayed with triclopyr 5 months after the first application. Richness and diversity (H') of both bacteria and fungi were not modified after triclopyr application. PMID:25602151

Souza-Alonso, Pablo; Guisande, Alejandra; González, Luís

2015-01-01

28

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.

1998-01-01

29

Ecology. Plant invader may use chemical weapons.  

PubMed

On page 521, plant ecologists offer a novel explanation for the success of invasive plants. By comparing how one species of knapweed, Centaurea diffusa, behaves with its natural neighbors and with foreign plant species that evolved separately, they found that the invader apparently gains an edges in its adopted home not only by ditching its herbivores but by wielding weaponry: chemicals exuded from its roots that hamper its new neighbors' growth. PMID:11183749

Jensen, M N

2000-10-20

30

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

31

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

32

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

Code of Federal Regulations, 2013 CFR

... false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117...801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a...bridges across Newtown Creek, Dutch Kills, English Kills, and their tributaries:...

2013-07-01

33

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

Code of Federal Regulations, 2014 CFR

... false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117...801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a...bridges across Newtown Creek, Dutch Kills, English Kills, and their tributaries:...

2014-07-01

34

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

Code of Federal Regulations, 2012 CFR

... false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117...801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a...bridges across Newtown Creek, Dutch Kills, English Kills, and their tributaries:...

2012-07-01

35

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

Code of Federal Regulations, 2011 CFR

... false Newtown Creek, Dutch Kills, English Kills and their tributaries. 117...801 Newtown Creek, Dutch Kills, English Kills and their tributaries. (a...bridges across Newtown Creek, Dutch Kills, English Kills, and their tributaries:...

2011-07-01

36

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

37

Emerging and opportunistic diseases are caused by a microorganism invading a new  

E-print Network

sources of genetic variation that can facilitate adaptation to new habitats -- horizontal acquisition of new genes and alteration of existing genes. Horizontal transfer between differ- ent bacterial clones) into the genome, and to gene replacement or modification by recombination1 . The second type of variation includes

Gomulkiewicz, Richard

38

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.

Melissa Lenczewski

39

Chinese Tallow: Invading the Southeastern Coastal Plain  

USGS Publications Warehouse

Chinese tallow is an ornamental tree with colorful autumn foliage that can survive full sunlight and shade, flooding, drought, and in some cases fire. To horticulturists this kind of tree sounds like a dream, but to ecologists, land managers, and land owners this kind of tree can be a nightmare, especially when it invades an area and takes over native vegetation. Chinese tallow (Triadica sebifera), a nonnative tree from China, is currently transforming the southeastern Coastal Plain. Over the last 30 years, Chinese tallow has become a common tree in old fields and bottomland swamps of coastal Louisiana. Several studies at the U.S. Geological Survey's National Wetlands Research Center (NWRC), Lafayette, Louisiana, are aimed at understanding the factors that contribute to Chinese tallow growth, spread, and management. When tallow invades, it eventually monopolizes an area, creating a forest without native animal or plant species. This tree exhibits classic traits of most nonnative invaders: it is attractive so people want to distribute it, it has incredible resiliency, it grows quickly and in a variety of soils, and it is resistant to pests. In the coastal prairie of Louisiana and Texas, Chinese tallow can grow up to 30 feet and shade out native sun-loving prairie species. The disappearing of prairie species is troublesome because less than 1% of original coastal prairie remains, and in Louisiana, less than 500 of the original 2.2 million acres still exist. Tallow reproduces and grows quickly and can cause large-scale ecosystem modification (fig. 1). For example, when it completely replaces native vegetation, it has a negative effect on birds by degrading the habitat. Besides shading out grasses that cattle like to eat, it can also be potentially harmful to humans and animals because of its berries (fig. 2) and plant sap that contain toxins. There is some concern its leaves may shed toxins that change the soil chemistry and make it difficult for other plants to grow.

U.S. Geological Survey

2000-01-01

40

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

41

[Resection of bronchogenic carcinoma invading the diaphragm].  

PubMed

The prognosis for survival when small cell non-anaplastic bronchogenic carcinoma (SCN-ABC) invades the diaphragm has not been clearly established because the diagnosis is rare. We report a series of eight patients who underwent full resection of SCN-ABC with diaphragm invasion. One died during the postoperative period. Mean survival was eight months for the remaining seven and no patient lived five years. All died as a result of remote metastasis. Given these results, we question whether surgery is the most appropriate treatment for these patients. PMID:10410211

Padilla, J; Calvo, V; Morcillo, A; García Zarza, A; Blasco, E; Pastor, J

1999-06-01

42

Micro-Organ Device  

NASA Technical Reports Server (NTRS)

A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

2013-01-01

43

Micro-organ device  

NASA Technical Reports Server (NTRS)

A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

Gonda, Steve R. (Inventor); von Gustedt-Gonda, legal representative, Iris (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

2013-01-01

44

The Fish Kill Mystery  

NSDL National Science Digital Library

In this case study, 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. The case is appropriate for an introductory environmental science course, a general biology course that covers ecology, or a general zoology course.

Erica F. Kosal

2003-01-01

45

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

46

Whisper of a Kill  

E-print Network

...lijLoU p3eltiH# / o; go.-;. >-/ ;J" f/i I by Lois Welling Cover by Suzan Lovett P.O. Box 592 Goleta,CA 93116 AGE STATEMENT REQUIRED Whisper of a Kill isavailable from Manacles Press for$18.00plus postage. SASE forcurrent rates... floor window, he reached inside his leather jacket and retrieved the Browning Highpower. His other hand secured the suppressor from a hidden pocket in his jacket sleeve and with a soft click the weapon was ready. He didn't really expect his target...

Weilling, L.

1992-01-01

47

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

48

Charged conformal Killing spinors  

NASA Astrophysics Data System (ADS)

We study the twistor equation on pseudo-Riemannian Spinc-manifolds whose solutions we call charged conformal Killing spinors (CCKSs). We derive several integrability conditions for the existence of CCKS and study their relations to spinor bilinears. A construction principle for Lorentzian manifolds admitting CCKS with nontrivial charge starting from CR-geometry is presented. We obtain a partial classification result in the Lorentzian case under the additional assumption that the associated Dirac current is normal conformal and complete the classification of manifolds admitting CCKS in all dimensions and signatures ?5 which has recently been initiated in the study of supersymmetric field theories on curved space.

Lischewski, Andree

2015-01-01

49

Killing Horizons and Spinors  

E-print Network

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.

Bruno Carneiro da Cunha; Amilcar de Queiroz

2014-06-19

50

Micro-Organ Devices  

NASA Technical Reports Server (NTRS)

Micro-organ devices (MODs) are being developed to satisfy an emerging need for small, lightweight, reproducible, biological-experimentati on apparatuses that are amenable to automated operation and that imp ose minimal demands for resources (principally, power and fluids). I n simplest terms, a MOD is a microfluidic device containing a variety of microstructures and assemblies of cells, all designed to mimic a complex in vivo microenvironment by replicating one or more in vivo micro-organ structures, the architectures and composition of the extr acellular matrices in the organs of interest, and the in vivo fluid flows. In addition to microscopic flow channels, a MOD contains one or more micro-organ wells containing cells residing in microscopic e xtracellular matrices and/or scaffolds, the shapes and compositions o f which enable replication of the corresponding in vivo cell assembl ies and flows.

Gonda, Steven R.; Leslie, Julia; Chang, Robert C.; Starly, Binil; Sun, Wei; Culbertson, Christopher; Holtorf, Heidi

2009-01-01

51

[Psychrotrophic microorganisms in raw and pasteurized milk].  

PubMed

The studied were carried out in 360 samples of unboiled milk and 1080 samples of pasteurized milk taken from three processing and distributing dairies having a different capacity and equipment. It was proved that the content of psychrotrophic microorganisms in unboiled milk from the three dairies varied from 120000 up to 200000 in 1 cm3 and was in close connection with the seasons of the year. The conditions applied for pasteurization in the three dairies killed (with the exception of those forming spores) nearly all psychrotrophic bacteria. The secondary seeding of the pasteurized milk by means of psychotrophics was carried out after the pasteurization along the whole technological route till its packing. The pasteurized milk packed in bottles showed a contamination with psychrotrophic microorganisms 4-6 times higher than that of milk packed in plastic bags. In the unboiled and in the pasteurized milk we found the psychrotrophic microorganisms of the species: Pseudomonas--respectively 64% and 53.8%, Micrococcus--8.2% and 30.7%, Enterobacter--9.8% and 2.6%, Bacillus--6.6% and 2.6%, Flavobacter--1.6% and 1.3% and Torula--2.6%. A comparatively high percentage (37.7%) of the isolated strains the psychrotrophic bacteria were lipolytic in the unboiled milk, 24.6%--proteolytic and 9.8% were simultaneously proteolytic and lipolytic. In the pasteurized milk 11.5% of the strains were lipolytic and 5.13% were proteolytic. PMID:6894344

Gogov, I; Ilieva, R; Slavchev, G

1980-01-01

52

Antimicrobial properties of the Escherichia coli R1 plasmid host killing peptide  

Microsoft Academic Search

The 52 amino acid host killing peptide (Hok) from the hok\\/sok post-segregational killer system of the Escherichia coli plasmid R1 was synthesized using Fmoc (9-fluorenylmethoxycarbonyl) chemistry, and its molecular weight was confirmed by mass spectroscopy. Hok kills cells by depolarizing the cytoplasmic membrane when it is made in the cytosol. Six microorganisms, E. coli, Bacillus subtilis,Pseudomonas aeruginosa, P. putida, Salmonella

Douglas C. Pecota; George Osapay; Michael E. Selsted; Thomas K. Wood

2003-01-01

53

Donor and recipient regions: The biogeography of macrobenthic invaders  

EPA Science Inventory

Aquatic invaders are a major threat to ecological integrity and biodiversity of marine, estuarine, and freshwater ecosystems around the world. These invaders have been successful in passing through four discrete phases in their invasion of a new environment: (1) transport, (2) ...

54

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. PMID:25568047

Lankau, Richard A

2012-01-01

55

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.

2012-11-09

56

Material Processing Using Microorganisms  

Microsoft Academic Search

The possibilities for developing a new type of material processing using a microbiogenic function are investigated with a microbial corrosion test of metals under the sea. The behavior of microorganisms in the corrosion of metals (mild steel, copper and aluminum sheets) is examined, and their action on these metals is discussed. As a result, three processing methods (biomachining, biodeposition and

Yasushi Kurosaki; Masahito Matsui; Yuichi Nakamura; Kenichi Murai; Toshio Kimura

2003-01-01

57

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

58

Brucella melitensis invades murine erythrocytes during infection.  

PubMed

Brucella spp. are facultative intracellular Gram-negative coccobacilli responsible for brucellosis, a worldwide zoonosis. We observed that Brucella melitensis is able to persist for several weeks in the blood of intraperitoneally infected mice and that transferred blood at any time point tested is able to induce infection in naive recipient mice. Bacterial persistence in the blood is dramatically impaired by specific antibodies induced following Brucella vaccination. In contrast to Bartonella, the type IV secretion system and flagellar expression are not critically required for the persistence of Brucella in blood. ImageStream analysis of blood cells showed that following a brief extracellular phase, Brucella is associated mainly with the erythrocytes. Examination by confocal microscopy and transmission electron microscopy formally demonstrated that B. melitensis is able to invade erythrocytes in vivo. The bacteria do not seem to multiply in erythrocytes and are found free in the cytoplasm. Our results open up new areas for investigation and should serve in the development of novel strategies for the treatment or prophylaxis of brucellosis. Invasion of erythrocytes could potentially protect the bacterial cells from the host's immune response and hamper antibiotic treatment and suggests possible Brucella transmission by bloodsucking insects in nature. PMID:25001604

Vitry, Marie-Alice; Hanot Mambres, Delphine; Deghelt, Michaël; Hack, Katrin; Machelart, Arnaud; Lhomme, Frédéric; Vanderwinden, Jean-Marie; Vermeersch, Marjorie; De Trez, Carl; Pérez-Morga, David; Letesson, Jean-Jacques; Muraille, Eric

2014-09-01

59

Brucella melitensis Invades Murine Erythrocytes during Infection  

PubMed Central

Brucella spp. are facultative intracellular Gram-negative coccobacilli responsible for brucellosis, a worldwide zoonosis. We observed that Brucella melitensis is able to persist for several weeks in the blood of intraperitoneally infected mice and that transferred blood at any time point tested is able to induce infection in naive recipient mice. Bacterial persistence in the blood is dramatically impaired by specific antibodies induced following Brucella vaccination. In contrast to Bartonella, the type IV secretion system and flagellar expression are not critically required for the persistence of Brucella in blood. ImageStream analysis of blood cells showed that following a brief extracellular phase, Brucella is associated mainly with the erythrocytes. Examination by confocal microscopy and transmission electron microscopy formally demonstrated that B. melitensis is able to invade erythrocytes in vivo. The bacteria do not seem to multiply in erythrocytes and are found free in the cytoplasm. Our results open up new areas for investigation and should serve in the development of novel strategies for the treatment or prophylaxis of brucellosis. Invasion of erythrocytes could potentially protect the bacterial cells from the host's immune response and hamper antibiotic treatment and suggests possible Brucella transmission by bloodsucking insects in nature. PMID:25001604

Vitry, Marie-Alice; Hanot Mambres, Delphine; Deghelt, Michaël; Hack, Katrin; Machelart, Arnaud; Lhomme, Frédéric; Vanderwinden, Jean-Marie; Vermeersch, Marjorie; De Trez, Carl; Pérez-Morga, David; Letesson, Jean-Jacques

2014-01-01

60

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. PMID:24790764

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

2014-01-01

61

Polyesters from microorganisms.  

PubMed

Bacterial polyesters have been found to have useful properties for applications as thermoplastics, elastomers, and adhesives and are biodegradable and biocompatible. Poly(3-hydroxyalkanoates) (PHAs) and poly(beta-malate) are the most representative polyesters synthesized by microorganisms. PHAs containing a wide variety of repeating units can be produced by bacteria, including those containing many types of pendant functional groups which can be synthesized by microorganisms that are grown on unnatural organic substrates. Poly(beta-malate) is of interest primarily for medical applications, especially for drug delivery systems. In this chapter, the bacterial production and properties of poly(3-hydroxyalkanoates) and poly(beta-malate) are described with emphasis on the former. PMID:11217417

Kim, Y B; Lenz, R W

2001-01-01

62

Microorganisms and psoriasis.  

PubMed Central

It has been suggested previously that psoriasis is best explained as a distinctive inflammatory response to a variety of microbial stimuli, all acting primarily through activation of the alternative complement pathway. For the past several years we have conducted a "Problem Psoriasis Clinic" based on that premise. Patients are questioned, examined, and subjected to microbiologic laboratory investigations in an attempt to identify possibly relevant microorganisms, and then are treated with antibiotics. This article lists the most commonly found microorganisms in psoriasis patients and describes the usual treatment for each. Results obtained with this approach compare favorably with those achieved with more usual anti-psoriasis treatments. We recommend that a microbiologic investigation and a trial of antimicrobial treatment should precede any plan to treat psoriasis patients with anything more than the simplest topical agents. PMID:8040907

Rosenberg, E. W.; Noah, P. W.; Skinner, R. B.

1994-01-01

63

Conflict theory and police killings  

Microsoft Academic Search

Although there has been considerable interest in the homicide of law enforcement officers, there has been little systematic analysis of the effects of structural variables on police killings across macro social units. Recently, Peterson and Bailey (1988) have examined the macro social determinants of police killings within a theoretical context and concluded that social conditons which bring civilians and law

Mitchell B. Chamlin

1989-01-01

64

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

65

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

66

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

67

Two Different Rickettsial Bacteria Invading Volvox carteri  

PubMed Central

Background Bacteria of the family Rickettsiaceae are principally associated with arthropods. Recently, endosymbionts of the Rickettsiaceae have been found in non-phagotrophic cells of the volvocalean green algae Carteria cerasiformis, Pleodorina japonica, and Volvox carteri. Such endosymbionts were present in only C. cerasiformis strain NIES-425 and V. carteri strain UTEX 2180, of various strains of Carteria and V. carteri examined, suggesting that rickettsial endosymbionts may have been transmitted to only a few algal strains very recently. However, in preliminary work, we detected a sequence similar to that of a rickettsial gene in the nuclear genome of V. carteri strain EVE. Methodology/Principal Findings Here we explored the origin of the rickettsial gene-like sequences in the endosymbiont-lacking V. carteri strain EVE, by performing comparative analyses on 13 strains of V. carteri. By reference to our ongoing genomic sequence of rickettsial endosymbionts in C. cerasiformis strain NIES-425 cells, we confirmed that an approximately 9-kbp DNA sequence encompassing a region similar to that of four rickettsial genes was present in the nuclear genome of V. carteri strain EVE. Phylogenetic analyses, and comparisons of the synteny of rickettsial gene-like sequences from various strains of V. carteri, indicated that the rickettsial gene-like sequences in the nuclear genome of V. carteri strain EVE were closely related to rickettsial gene sequences of P. japonica, rather than those of V. carteri strain UTEX 2180. Conclusion/Significance At least two different rickettsial organisms may have invaded the V. carteri lineage, one of which may be the direct ancestor of the endosymbiont of V. carteri strain UTEX 2180, whereas the other may be closely related to the endosymbiont of P. japonica. Endosymbiotic gene transfer from the latter rickettsial organism may have occurred in an ancestor of V. carteri. Thus, the rickettsiae may be widely associated with V. carteri, and likely have often been lost during host evolution. PMID:25671568

Kawafune, Kaoru; Hongoh, Yuichi; Hamaji, Takashi; Sakamoto, Tomoaki; Kurata, Tetsuya; Hirooka, Shunsuke; Miyagishima, Shin-ya; Nozaki, Hisayoshi

2015-01-01

68

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

69

Microorganisms for producing organic acids  

DOEpatents

Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

Pfleger, Brian Frederick; Begemann, Matthew Brett

2014-09-30

70

Dissecting impact of plant invaders: do invaders behave differently in the new range?  

PubMed

Knowledge from basic plant ecology suggests that impact of one plant species on another is driven by either competition for the same limiting resources, or by unique plant traits. These processes might be context specific, explaining a differential impact of exotic plant invaders in the native vs. introduced range. With the help of a conceptual framework, we aimed at identifying the relationship between invader biomass and impact in the invasive Centaurea stoebe by conducting pairwise competition experiments with 15 European (old) and 15 North American (new) neighboring species. Old neighbors grew larger and could use available soil moisture more efficiently for growth than new neighbors. Interestingly, biomass of C. stoebe explained a substantial amount of the variation in biomass of the coevolved neighbors, but not of the new "naive" neighbors. Thus, impact in the home range appears to be driven by competition for the same limiting resources, but by other factors in the introduced range, possibly by exploitation of resources that are not used by the new neighbors or by interference competition. This distinction has important consequences for the management of invasive species, as in our study ecosystem recovery is less likely after simple biomass reduction. PMID:24358696

Sun, Yan; Collins, Alexandra R; Schaffner, Urs; Müller-Schärer, Heinz

2013-10-01

71

Wolbachia, sex ratio bias and apparent male killing in the harlequin beetle riding pseudoscorpion  

Microsoft Academic Search

Bacterial endosymbionts that manipulate host reproduction are now known to be widespread in insects and other arthropods. Since they inhabit the cytoplasm and are maternally inherited, these microorganisms can enhance their fitness by biasing host sex ratio in favour of females. At its most extreme, sex ratio manipulation may be achieved by killing male embryos, as occurs in a number

D W Zeh; J A Zeh; M M Bonilla

2005-01-01

72

Male-killing bacterium in a fifth ladybird beetle, Coleomegilla maculata (Coleoptera: Coccinellidae)  

Microsoft Academic Search

Inherited symbionts which selectively cause the death of male hosts are found widely across the Insecta. Previous studies have shown a single, but different micro-organism to be responsible for male-killing in each taxonomic group studied. We here produce evidence that within a group of insects, the Coccinellidae, there is more than one causal agent of male lethality. We report a

Gregory D D Hurst; Tansy C Hammarton; John J Obrycki; Tamsin M O Majerus; Linda E Walker; Dominique Bertrand; Michael E N Majerus; Gregory DD Hurst

1996-01-01

73

How Many, And Which, Plants Will Invade Natural Areas?  

Microsoft Academic Search

Of established nonindigenous plant species in California, Florida, and Tennessee, 5.8%, 9.7%, and 13.4%, respectively, invade\\u000a natural areas according to designations tabulated by state Exotic Pest Plant Councils. Only Florida accords strictly with\\u000a the tens rule, though California and Tennessee fall within the range loosely viewed as obeying the rule. The species that\\u000a invaded natural areas in each state were

Julie L. Lockwood; Daniel Simberloff; Michael L. McKinney; Betsy Von Holle

2001-01-01

74

How many, and which, plants will invade natural areas?  

Microsoft Academic Search

Of established nonindigenous plant species in California, Florida, and Tennessee, 5.8%, 9.7%, and 13.4%, respec- tively, invade natural areas according to designations tabulated by state Exotic Pest Plant Councils. Only Florida accords strictly with the tens rule, though California and Tennessee fall within the range loosely viewed as obeying the rule. The species that invaded natural areas in each state

Julie L. Lockwood; Daniel Simberloff; Michael L. McKinney; Betsy Von Holle

2001-01-01

75

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

76

The race of microorganisms  

NSDL National Science Digital Library

This reading, part of a site devoted to the science of cooking, explores how beneficial bacteria are involved in the fermentation process that is used to pickle vegetables. The reading focuses on the competition between those microorganisms that facilitate fermentation and those microbes that damage this food production process. Lactic acid bacteria are key players in the creation of pickles. The reading explains the functions of these bacteria and describes the conditions in a pickle crock--including the appropriate salt concentration, a lack of oxygen, and optimal temperature--that allow them to thrive. A sidebar points out how pickles become crunchy through osmosis. Copyright 2005 Eisenhower National Clearinghouse

Exploratorium

2004-01-01

77

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. PMID:11932229

Donlan, Rodney M.; Costerton, J. William

2002-01-01

78

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

79

Gravitaxis in unicellular microorganisms  

NASA Astrophysics Data System (ADS)

Orientation of organisms with respect to the gravitational field of the Earth has been studied for more than 100 years in a number of unicellular microorganisms including flagellates and ciliates. Several hypotheses have been developed how the weak stimulus is perceived. Intracellular statoliths have been found to be involved in gravitaxis of Loxodes, while no specialized organelles have been detected in other ciliates, e.g. Paramecium. Also in the slime mold Physarum no specialized gravireceptors have been identified yet. In the flagellate Euglena gracilis the whole cell body, which is denser than the surrounding medium, seems to act as a statolith pressing onto the lower membrane where it activates mechanosensitive ion channels. Similar results were obtained for the ciliate Paramecium. In contrast to the flagellate Euglena, several ciliates have been found to show gravikinesis, which is defined as a dependence of the swimming velocity on the direction of movement in the gravity field.

Häder, D.-P.

1999-01-01

80

Thermal inactivation of microorganisms.  

PubMed

This paper serves as an overview of various aspects of thermal processing. Heat processing of foods has a long history and is still one of the most important preservation methods. To guarantee microbiological safety and stability, large safety margins are often applied in traditional heat processes. Because of the need for more fresh like foods, there is a need for milder preservation methods without compromising on safety and stability. The review deals with heat resistance data and mathematical models that describe heat inactivation. The effects of food composition are not yet fully clear and more knowledge of the cell physiology of the target microorganism could be of help in predicting the effects of food constituents. Finally, special attention has been paid to biological time temperature indicators to enable proper process calculations. PMID:24564593

Smelt, J P P M; Brul, S

2014-01-01

81

Male-killing bacterium in a fifth ladybird beetle, Coleomegilla maculata (Coleoptera:Coccinellidae).  

PubMed

Inherited symbionts which selectively cause the death of male hosts are found widely across the Insecta. Previous studies have shown a single, but different micro-organism to be responsible for male-killing in each taxonomic group studied. We here produce evidence that within a group of insects, the Coccinellidae, there is more than one causal agent of male lethality. We report a novel observation of a male-killing trait in the species Coleomegilla maculata. Six of 26 crosses were found to produce a female-biased sex ratio associated with a low egg hatch-rate. The trait was matrilinearly inherited and was observed to be tetracycline-sensitive. However, tests which indicate the presence of a Rickettsia, previously found to cause male-killing in another member of the Coccinellidae, Adalia bipunctata, proved negative. We therefore conclude that the phenomenon of male-killing is multicausal, within, as well as between, taxonomic groups of the Insecta. PMID:8760399

Hurst, G D; Hammarton, T C; Obrycki, J J; Majerus, T M; Walker, L E; Bertrand, D; Majerus, M E

1996-08-01

82

THE COLLECTING OF AIRBORNE MICROORGANISMS  

Microsoft Academic Search

During an investigation of the effects of two standard humidity control systems on airborne microorganisms an extensive study was made of the techniques for collecting airborne microorganisms from air streams and ventilated rooms. The results of the studies on collecting techniques as well as the data obtained for the two air conditioning facilities are presented herein. The purpose of studying

ARCHIE N. SOLBERG; HAROLD C. SHAFFER; GILBERT A. KELLEY

83

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

84

[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

85

Interaction of Species Traits and Environmental Disturbance Predicts Invasion Success of Aquatic Microorganisms  

PubMed Central

Factors such as increased mobility of humans, global trade and climate change are affecting the range of many species, and cause large-scale translocations of species beyond their native range. Many introduced species have a strong negative influence on the new local environment and lead to high economic costs. There is a strong interest to understand why some species are successful in invading new environments and others not. Most of our understanding and generalizations thereof, however, are based on studies of plants and animals, and little is known on invasion processes of microorganisms. We conducted a microcosm experiment to understand factors promoting the success of biological invasions of aquatic microorganisms. In a controlled lab experiment, protist and rotifer species originally isolated in North America invaded into a natural, field-collected community of microorganisms of European origin. To identify the importance of environmental disturbances on invasion success, we either repeatedly disturbed the local patches, or kept them as undisturbed controls. We measured both short-term establishment and long-term invasion success, and correlated it with species-specific life-history traits. We found that environmental disturbances significantly affected invasion success. Depending on the invading species’ identity, disturbances were either promoting or decreasing invasion success. The interaction between habitat disturbance and species identity was especially pronounced for long-term invasion success. Growth rate was the most important trait promoting invasion success, especially when the species invaded into a disturbed local community. We conclude that neither species traits nor environmental factors alone conclusively predict invasion success, but an integration of both of them is necessary. PMID:23028985

Mächler, Elvira; Altermatt, Florian

2012-01-01

86

Low temperature reveals genetic variability against male-killing Spiroplasma in Drosophila melanogaster natural populations.  

PubMed

Spiroplasma endosymbionts are maternally inherited microorganisms which infect many arthropod species. In some Drosophila species, it acts as a reproductive manipulator, spreading in populations by killing the sons of infected mothers. Distinct Drosophila melanogaster populations from Brazil exhibit variable male-killing Spiroplasma prevalences. In this study, we investigated the presence of variability for the male-killing phenotype among Drosophila and/or Spiroplasma strains and verified if it correlates with the endosymbiont prevalence in natural populations. For that, we analyzed the male-killing expression when Spiroplasma strains from different populations were transferred to a standard D. melanogaster line (Canton-S) and when a common Spiroplasma strain was transferred to different wild-caught D. melanogaster lines, both at optimal and challenging temperatures for the bacteria. No variation was observed in the male-killing phenotype induced by different Spiroplasma strains. No phenotypic variability among fly lines was detected at optimal temperature (23 °C), as well. Conversely, significant variation in the male-killing expression was revealed among D. melanogaster lines at 18.5 °C, probably caused by imperfect transmission of the endosymbiont. Distinct lines differed in their average sex ratios as well as in the pattern of male-killing expression as the infected females aged. Greater variation occurred among lines from one locality, although there was no clear correlation between the male-killing intensity and the endosymbiont prevalence in each population. Imperfect transmission or male killing may also occur in the field, thus helping to explain the low or intermediate prevalences reported in nature. We discuss the implications of our results for the dynamics of male-killing Spiroplasma in natural populations. PMID:24121800

Ventura, Iuri Matteuzzo; Costa, Thais; Klaczko, Louis Bernard

2014-01-01

87

Forgotten creatures: A survey of microorganisms  

NSDL National Science Digital Library

Microorganisms are often overlooked in the study of biology because they are not visible to the human eye. In fact, there is a great diversity of microorganisms. Microorganisms include bacteria, protozoa, algae, lichens, and fungi.

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

2007-01-12

88

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

89

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

90

Phagocyte roulette in Salmonella killing.  

PubMed

Salmonella propagates in macrophages to cause life-threatening infections, but the role of neutrophils in combating Salmonella has been controversial. In this issue, Burton et al. (2014) use single cell analyses and modeling to explain the ability of Salmonella to survive in macrophages while being killed by neutrophils. PMID:24439894

Fenlon, Luke A; Slauch, James M

2014-01-15

91

Euthanasia: Killing as Due Care?  

Microsoft Academic Search

Summary 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

Fuat S. Oduncu

2003-01-01

92

Human Neutrophils Kill Bacillus anthracis  

PubMed Central

Bacillus anthracis spores cause natural infections and are used as biological weapons. Inhalation infection with B. anthracis, the etiological agent of anthrax, is almost always lethal, yet cutaneous infections usually remain localized and resolve spontaneously. Neutrophils are typically recruited to cutaneous but seldom to other forms of anthrax infections, raising the possibility that neutrophils kill B. anthracis. In this study we infected human neutrophils with either spores or vegetative bacteria of a wild-type strain, or strains, expressing only one of the two major virulence factors. The human neutrophils engulfed B. anthracis spores, which germinated intracellularly and were then efficiently killed. Interestingly, neutrophil killing was independent of reactive oxygen species production. We fractionated a human neutrophil granule extract by high-performance liquid chromatography and identified ?-defensins as the component responsible for B. anthracis killing. These data suggest that the timely recruitment of neutrophils can control cutaneous infections and possibly other forms of B. anthracis infections, and that ?-defensins play an important role in the potent anti-B. anthracis activity of neutrophils. PMID:16292357

2005-01-01

93

Farm Education at Stony Kill.  

ERIC Educational Resources Information Center

Describes typical winter farm lessons for students visiting Stony Kill Farm Environmental Education Center located 70 miles north of New York City: butter and corncake making, soil erosion experiments, dissecting and growing seeds. Emphasizes major theme of conservation of farmland from destructive farming practices and careless development. (NEC)

Parisio, Richard

1986-01-01

94

Leaf Litter Disappearance in Earthworm-Invaded Northern  

E-print Network

Leaf Litter Disappearance in Earthworm-Invaded Northern Hardwood Forests: Role of Tree Species and the Chemistry and Diversity of Litter Andrew R. Holdsworth,1,2 * Lee E. Frelich,2 and Peter B. Reich2,3 1 floor mass, yet the interactions between litter composition, invasive earthworm community composition

Minnesota, University of

95

Introducing the Newest Invader of the Nation's Waters  

Microsoft Academic Search

The zebra mussel, a small freshwater shellfish native to Europe, is one of the newest invaders of U.S. waters. They are D-shaped in outline and average one-half inch in length-the size of your fingernail-but can grow to two inches during their five year lifespan. The conspicuous, dark brown or green bandsalternate in a \\

Louis A. Helfrich; Diana L. Weigmann; Rene Speenburgh; Richard Neves; Lisie Kitchel; Sue Bruenderman

2009-01-01

96

INVASIONS AND INFECTIONS Invading with biological weapons: the importance of  

E-print Network

INVASIONS AND INFECTIONS Invading with biological weapons: the importance of disease-mediated invasions Alex Strauss1 , Andy White2 and Mike Boots*,3 1 Department of Biology, Indiana University and ecosystem functioning. 2. Typically, when parasites are considered in invasion biology, it is in the context

White, Andrew

97

Ecology and Restoration of Invaded Ecosystems FOR 4934 (3 credits)  

E-print Network

Ecology and Restoration of Invaded Ecosystems FOR 4934 (3 credits) Spring 2014 Course Description This advanced ecosystem management course will begin with an overview of the ecological basis for plant in ecology and applied plant science, graduate students in the Masters of Science, Ecological Restoration

Slatton, Clint

98

Ecology and Restoration of Invaded Ecosystems FOR 6934 (3 credits)  

E-print Network

Ecology and Restoration of Invaded Ecosystems FOR 6934 (3 credits) Spring 2014 Course Description This advanced ecosystem management course will begin with an overview of the ecological basis for plant in ecology and applied plant science, graduate students in the Masters of Science, Ecological Restoration

Watson, Craig A.

99

Revegetating medusahead-invaded sagebrush rangelands in the intermountain west  

Technology Transfer Automated Retrieval System (TEKTRAN)

Revegetation of medusahead-invaded rangeland is needed to increase forage production, decrease the risk of wildfires, and improve wildlife habitat. Successful revegetation starts with effective control of medusahead. Prescribed burning followed by a fall application of a pre-emergent herbicide has...

100

Revegetating medusahead-invaded sagebrush rangelands in the Intermountain West  

Technology Transfer Automated Retrieval System (TEKTRAN)

Revegetation of medusahead-invaded rangeland is needed to increase forage production, decrease the risk of wildfires, and improve wildlife habitat. Successful revegetation starts with effective control of medusahead. Prescribed burning followed by a fall application of a pre-emergent herbicide has...

101

A taste for novelty in invading house sparrows, Passer domesticus  

Microsoft Academic Search

One of the central questions in invasion biology involves why some introductions succeed and others fail. Although several correlates of invasion success have been identified, patterns alone cannot identify the mechanisms underlying the invasion process. Here, we test the hypothesis that one predictor of invasion success, behavioral flexibility, is different between invading and established populations of the same species of

Lynn B. Martin II; Lisa Fitzgerald

2005-01-01

102

Phagocytosis and killing of Staphylococcus aureus by human neutrophils.  

PubMed

Neutrophils are essential for host defense against Staphylococcus aureus infections. Although significant progress has been made, our understanding of neutrophil interactions with S. aureus remains incomplete. To provide a more comprehensive view of this process, we investigated phagocytosis and killing of S. aureus by human neutrophils using varied assay conditions in vitro. A greater percentage of bacteria were internalized by adherent neutrophils compared to those in suspension, and, unexpectedly, uptake of S. aureus by adherent neutrophils occurred efficiently in the absence of opsonins. An antibody specific for S. aureus promoted uptake of unopsonized bacteria in suspension, but had little or no capacity to enhance phagocytosis of S. aureus opsonized with normal human serum or by adherent neutrophils. Collectively, these results indicate that assay conditions can have a significant influence on the phagocytosis and killing of S. aureus by neutrophils. More importantly, the results suggest a vaccine approach directed to enhance opsonophagocytosis alone is not sufficient to promote increased killing of S. aureus by human neutrophils. With the emergence and reemergence of antibiotic-resistant microorganisms, establishing parameters that are optimal for studying neutrophil-S. aureus interactions will pave the way towards developing immune-directed strategies for anti-staphylococcal therapies. PMID:24713863

Lu, Thea; Porter, Adeline R; Kennedy, Adam D; Kobayashi, Scott D; DeLeo, Frank R

2014-01-01

103

Phagocytosis and Killing of Staphylococcus aureus by Human Neutrophils  

PubMed Central

Neutrophils are essential for host defense against Staphylococcus aureus infections. Although significant progress has been made, our understanding of neutrophil interactions with S. aureus remains incomplete. To provide a more comprehensive view of this process, we investigated phagocytosis and killing of S. aureus by human neutrophils using varied assay conditions in vitro. A greater percentage of bacteria were internalized by adherent neutrophils compared to those in suspension, and unexpectedly, uptake of S. aureus by adherent neutrophils occurred efficiently in the absence of opsonins. Antibody specific for S. aureus promoted uptake of unopsonized bacteria in suspension, but had little or no capacity to enhance phagocytosis of S. aureus opsonized with normal human serum or by adherent neutrophils. Collectively, these results indicate that assay conditions can have a significant influence on the phagocytosis and killing of S. aureus by neutrophils. More importantly, the results suggest a vaccine approach directed to enhance opsonophagocytosis alone is not sufficient to promote increased killing of S. aureus by human neutrophils. With the emergence and reemergence of antibiotic resistant microorganisms, establishing parameters that are optimal for studying neutrophil-S. aureus interactions will pave the way towards developing immune-directed strategies for anti-staphylococcal therapies. PMID:24713863

Lu, Thea; Porter, Adeline R.; Kennedy, Adam D.; Kobayashi, Scott D.; DeLeo, Frank R.

2014-01-01

104

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

105

EFFICACY OF OZONE IN KILLING LISTERIA MONOCYTOGENES ON ALFALFA SEEDS AND SPROUTS, AND EFFECTS ON SENSORY QUALITY OF SPROUTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

A study was done to determine the efficacy of aqueous ozone treatment in killing Listeria monocytogenes on inoculated alfalfa seeds and sprouts. Reduction in populations of naturally occurring aerobic microorganisms on sprouts and changes in sensory quality of sprouts were also determined. Treatme...

106

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

107

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

108

Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity  

E-print Network

Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity Hospital for Infection Control, Nagoya University Hospital, Nagoya, Aichi, Japan Abstract Streptococcus. (2013) Streptococcus pneumoniae Invades Erythrocytes and Utilizes Them to Evade Human Innate Immunity

Nizet, Victor

109

Land-use change in a tropical mountain rainforest region of southern Ecuador affects soil microorganisms and nutrient cycling  

Microsoft Academic Search

Over the past decades, the tropical mountain rainforest of southern Ecuador has been threatened by conversion to cattle pastures.\\u000a Frequently, these pastures are invaded by bracken fern and abandoned when bracken becomes dominant. Changes in land-use (forest–pasture–abandoned\\u000a pasture) can affect soil microorganisms and their physiological responses with respect to soil carbon and nutrient cycling.\\u000a In situ investigations on litter decomposition

Karin Potthast; Ute Hamer; Franz Makeschin

110

Shock Compression and Recovery of Microorganism-Loaded Broths and AN Emulsion  

NASA Astrophysics Data System (ADS)

The microorganisms Escherichia coli, Enterococcus faecalis and Zygosaccharomyces bailii and an oil-based emulsion, have been subjected to shock compression using the flyer-plate technique to initial pressures of 0.8 GPa (in the suspension). In each experiment, a stainless steel capsule was used to contain the broths and allow for recovery without contamination. Where cavitation was mostly suppressed by virtue of simultaneous shock and dynamic compression, no kill was observed. By introducing an air gap behind the suspension, limited kill was measured in the yeast. Results also suggest that stable emulsification occurs in coarse oil-based emulsions that are subjected to shock.

Hazell, P. J.; Beveridge, C.; Groves, K.; Stennett, C.

2009-12-01

111

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

112

Exotic Plant Species Invade Hot Spots of Native Plant Diversity  

Microsoft Academic Search

Some theories and experimental studies suggest that areas of low plant spe- cies richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in

Thomas J. Stohlgren; Dan Binkley; Geneva W. Chong; Mohammed A. Kalkhan; Lisa D. Schell; Kelly A. Bull; Yuka Otsuki; Gregory Newman; Michael Bashkin; Yowhan Son

1999-01-01

113

Invited Invaders: Beetles used successfully in biological control of saltcedar  

E-print Network

10 tx H2O Winter 2011 Story by Kathy Wythe InvitedInvaders Beetles used successfully in biological control of saltcedar Winter 2011 tx H2O 11 ] Scientists in Texas are using the saltcedar beetle to control invasive saltcedar trees.... No species of saltcedar or its close relative, athel tree, are native to North or South America. Photo by Jerry Michels, Texas AgriLife Research. Beetles used successfully in biological control of saltcedar They are tiny. #22;ey are hungry...

Wythe, Kathy

2011-01-01

114

Invited Invaders: Beetles used sucessfully in biological control of saltcedar  

E-print Network

10 tx H2O Winter 2011 Story by Kathy Wythe InvitedInvaders Beetles used successfully in biological control of saltcedar Winter 2011 tx H2O 11 ] Scientists in Texas are using the saltcedar beetle to control invasive saltcedar trees.... No species of saltcedar or its close relative, athel tree, are native to North or South America. Photo by Jerry Michels, Texas AgriLife Research. Beetles used successfully in biological control of saltcedar They are tiny. #22;ey are hungry...

Wythe, Kathy

2011-01-01

115

What is the impact of Impatiens glandulifera on species diversity of invaded riparian vegetation?  

Microsoft Academic Search

Effect of invasion by Impatiens glandulifera (Balsaminaceae) on the community characteristics and species composition of invaded riparian communities was studied at six rivers in the Czech Republic. Two approaches were used: space for time substitution approach, i.e., comparing invaded and uninvaded sites under the same habitat conditions, and removal of the invader from experimental plots. Differences in the number of

Martin Hejda; Petr Pyšek

2006-01-01

116

Desert Dust Kills Florida Fish  

NSDL National Science Digital Library

This National Aeronautics and Space Administration (NASA) article discusses the connection between dust storms in Africa, and red tides along the Florida coast. Red tides are blooms of toxic algae that kill fish, birds, and mammals, as well as cause health problems in humans. Storm activity in the Sahara Desert region kicks up topsoil that winds transport into the Gulf of Mexico. These clouds fertilize the water with iron, which bacteria named Trichodesmium use to create nitrogen. The nitrogen makes the water a friendly environment for the toxic algae. This article discusses this process and research that is going on to help solve the problem. Audio version is available as well.

117

Integrability conditions for Killing-Yano tensors and conformal Killing-Yano tensors  

NASA Astrophysics Data System (ADS)

The integrability conditions for the existence of a conformal Killing-Yano tensor of arbitrary order are worked out in all dimensions and expressed in terms of the Weyl tensor. As a consequence, the integrability conditions for the existence of a Killing-Yano tensor are also obtained. By means of such conditions, it is shown that in certain Einstein spaces one can use a conformal Killing-Yano tensor of order p to generate a Killing-Yano tensor of order (p -1 ) . Finally, it is proved that in maximally symmetric spaces the covariant derivative of a Killing-Yano tensor is a closed conformal Killing-Yano tensor and that every conformal Killing-Yano tensor is uniquely decomposed as the sum of a Killing-Yano tensor and a closed conformal Killing-Yano tensor.

Batista, Carlos

2015-01-01

118

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

119

ANALYSIS OF ANAEROBIC MICROORGANISMS METABOLITES  

Microsoft Academic Search

This paper presents an overwiew of anaerobic bacterias metabolites and their effects on Microbially Improved oil recovery (MIOR). Chemical analysis methods for coexisting gas-, water-, and oil phases of MIOR field tests or laboratory experiments are described for mixtures of potential metabolites of anaerobic microorganisms. The obtained data are compared with literature values. The metabolites in the gas- and oil

G. Jacobs; D. Severin

1997-01-01

120

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. PMID:24278736

Hyman, Paul; Abedon, Stephen T.

2012-01-01

121

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...

122

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

123

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

124

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-10-12

125

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

Federal Register 2010, 2011, 2012, 2013, 2014

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

2010-06-01

126

The killing consensus : homicide detectives, police that kill and organized crime in São Paulo, Brazil  

E-print Network

Policing is widely understood, empirically and theoretically, as a core function of the state. Much of the knowledge presumes that police are the only body that may kill and arbitrate killing, routinely and without retaliation ...

Willis, Graham Arthur Neill, 1979-

2013-01-01

127

4, 26672697, 2007 Micro-organisms in  

E-print Network

BGD 4, 2667­2697, 2007 Micro-organisms in the South-East Pacific S. Masquelier and D. Vaulot Title Distribution of micro-organisms along a transect in the South-East Pacific Ocean (BIOSOPE cruise) from, 2667­2697, 2007 Micro-organisms in the South-East Pacific S. Masquelier and D. Vaulot Title Page

Paris-Sud XI, Université de

128

ALLELOPATHIC GROWTH STIMULATION OF PLANTS AND MICROORGANISMS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Growth promotion of plants by other plants and microorganisms, as well as of microorganisms by plants and other microorganisms, is discussed. Agrostemma githago in mixed culture with wheat, enhances growth and yield of wheat. Allantoin, a purine derivative and the principal component of agrostem...

129

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

130

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

131

Microsphere fluoroimmunoassay for microorganisms: An update  

SciTech Connect

Microspheres are used as labels in a fluorescence immunoassay for individual microorganisms. The diameter of a sphere that has reacted with microorganisms is determined from measurements of the optical resonance frequencies. The spheres have been coated with antibodies so that each microsphere diameter corresponds to a different species of microorganism. Further experiments on specificity and on optical resonance measurements are presented.

Whitten, W.B.; Ramsey, J.M. [Oak Ridge National Lab., TN (United States); Bronk, B.V. [Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, MD (United States)

1994-12-31

132

Microorganism Utilization for Synthetic Milk  

NASA Technical Reports Server (NTRS)

A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required environment/organisms for the production of desired sugar and lipid end-products.

Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

2014-01-01

133

Microorganisms  

NSDL National Science Digital Library

Learn About Microbes Name three places where microbes live. Meet the Microbes Select the word infection at the top of the Meet the Microbe page. Meet the Microbes Go into at least three different areas and do the activity. In your notebook record where you went, what you did and write down at least three things you ...

Ms. Kirby

2009-09-16

134

Passive Electrical Properties of Microorganisms  

PubMed Central

Effective conductivities are reported for the bacteria Escherichia coli and Micrococcus lysodeikticus over a range of environmental conductivity. The apparent conductivities of the organisms can be explained in terms of the properties of the cell wall. At low conductivities of the environment, the conductivity of the cell appears to be dominated by the counterions of the fixed charge of the cell wall. At higher conductivities of the suspending medium, evidence suggests that ions from the environment invade the cell wall causing an increase in the effective conductivity of the cell so that it takes on values roughly proportional to that of the environment. The model points to the usefulness of dielectric techniques in studies of the properties of intact cell walls. PMID:19431334

Carstensen, E. L.; Cox, H. A.; Mercer, W. B.; Natale, L. A.

1965-01-01

135

Intergenomic arms races: detection of a nuclear rescue gene of male-killing in a ladybird.  

PubMed

Many species of arthropod are infected by deleterious inherited micro-organisms. Typically these micro-organisms are inherited maternally. Consequently, some, particularly bacteria of the genus Wolbachia, employ a variety of strategies that favour female over male hosts. These strategies include feminisation, induction of parthenogenesis and male-killing. These strategies result in female biased sex ratios in host populations, which lead to selection for host factors that promote male production. In addition, the intra-genomic conflict produced by the difference in transmission of these cytoplasmic endosymbionts and nuclear factors will impose a pressure favouring nuclear factors that suppress the effects of the symbiont. During investigations of the diversity of male-killing bacteria in ladybirds (Coccinellidae), unexpected patterns of vertical transmission of a newly discovered male-killing taxon were observed in the ladybird Cheilomenes sexmaculata. Initial analysis suggested that the expression of the bacterial male-killing trait varies according to the male(s) a female has mated with. By swapping males between females, a male influence on the expression of the male-killing trait was confirmed. Experiments were then performed to determine the nature of the interaction. These studies showed that a single dominant allele, which rescues male progeny of infected females from the pathological effect of the male-killer, exists in this species. The gene shows typical Mendelian autosomal inheritance and is expressed irrespective of the parent from which it is inherited. Presence of the rescue gene in either parent does not significantly affect the inheritance of the symbiont. We conclude that C. sexmaculata is host to a male-killing gamma-proteobacterium. Further, this beetle is polymorphic for a nuclear gene, the dominant allele of which rescues infected males from the pathogenic effects of the male-killing agent. These findings represent the first 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. PMID:20628578

Majerus, Tamsin M O; Majerus, Michael E N

2010-01-01

136

Approximate Killing Vectors on S^2  

E-print Network

We present a new method for computing the best approximation to a Killing vector on closed 2-surfaces that are topologically S^2. When solutions of Killing's equation do not exist, this method is shown to yield results superior to those produced by existing methods. In addition, this method appears to provide a new tool for studying the horizon geometry of distorted black holes.

Gregory B. Cook; Bernard F. Whiting

2007-06-01

137

Autophagy Defends Cells Against Invading Group A Streptococcus  

Microsoft Academic Search

We found that the autophagic machinery could effectively eliminate pathogenic group A Streptococcus (GAS) within nonphagocytic cells. After escaping from endosomes into the cytoplasm, GAS became enveloped by autophagosome-like compartments and were killed upon fusion of these compartments with lysosomes. In autophagy-deficient Atg5-\\/- cells, GAS survived, multiplied, and were released from the cells. Thus, the autophagic machinery can act as

Ichiro Nakagawa; Atsuo Amano; Noboru Mizushima; Akitsugu Yamamoto; Hitomi Yamaguchi; Takahiro Kamimoto; Atsuki Nara; Junko Funao; Masanobu Nakata; Kayoko Tsuda; Shigeyuki Hamada; Tamotsu Yoshimori

2004-01-01

138

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). PMID:17632573

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

2009-01-01

139

Macrophages sense and kill bacteria through carbon monoxide–dependent inflammasome activation  

PubMed Central

Microbial clearance by eukaryotes relies on complex and coordinated processes that remain poorly understood. The gasotransmitter carbon monoxide (CO) is generated by the stress-responsive enzyme heme oxygenase-1 (HO-1, encoded by Hmox1), which is highly induced in macrophages in response to bacterial infection. HO-1 deficiency results in inadequate pathogen clearance, exaggerated tissue damage, and increased mortality. Here, we determined that macrophage-generated CO promotes ATP production and release by bacteria, which then activates the Nacht, LRR, and PYD domains-containing protein 3 (NALP3) inflammasome, intensifying bacterial killing. Bacterial killing defects in HO-1–deficient murine macrophages were restored by administration of CO. Moreover, increased CO levels enhanced the bacterial clearance capacity of human macrophages and WT murine macrophages. CO-dependent bacterial clearance required the NALP3 inflammasome, as CO did not increase bacterial killing in macrophages isolated from NALP3-deficient or caspase-1–deficient mice. IL-1? cleavage and secretion were impaired in HO-1–deficient macrophages, and CO-dependent processing of IL-1? required the presence of bacteria-derived ATP. We found that bacteria remained viable to generate and release ATP in response to CO. The ATP then bound to macrophage nucleotide P2 receptors, resulting in activation of the NALP3/IL-1? inflammasome to amplify bacterial phagocytosis by macrophages. Taken together, our results indicate that macrophage-derived CO permits efficient and coordinated regulation of the host innate response to invading microbes. PMID:25295542

Wegiel, Barbara; Larsen, Rasmus; Gallo, David; Chin, Beek Yoke; Harris, Clair; Mannam, Praveen; Kaczmarek, Elzbieta; Lee, Patty J.; Zuckerbraun, Brian S.; Flavell, Richard; Soares, Miguel P.; Otterbein, Leo E.

2014-01-01

140

Killing in Okaraygua: An Inspector Irronogaray Mystery  

E-print Network

1 Citation: Levine, Stuart. (2012) Killing in Okaraygua: An Inspector Irronogaray Mystery [Kindle Edition]. Amazon Digital Services, Amazon.com. Published version: http://www.amazon.com/Killing-Okaraygua-Inspector-Irronogaray- ebook.../dp/B0096TUC9K/ref=sr_1_9?ie=UTF8&qid=1347294990&sr=8-9&keywords=Stuart+Levine Description: Killing in Okaraygua is an historical novel as well as a murder mystery that takes place in an imaginary Latin American nation in the 1980s. The characters found...

Levine, Stuart

2012-09-05

141

Invaders eating invaders: Exploitation of novel alien prey by the alien shimofuri goby in the San Francisco Estuary, California  

USGS Publications Warehouse

The shimofuri goby (Tridentiger bifasciatus), which is native to Asian estuaries, was recently introduced to the San Francisco Estuary, California, USA. We conducted gut content analyses to examine the goby's feeding ecology in this highly invaded estuary. Shimofuri gobies were generalist predators on benthic invertebrates, consuming seasonally abundant prey, especially amphipods (Corophium spp.). In addition, shimofuri goby utilized two novel prey items not exploited by other resident fishes - hydroids (Cordylophora caspia) and barnacle (Balanus improvisus) cirri, both of which are alien. The shimofuri goby's feeding ecology appears well-suited to the fluctuating environment of the San Francisco Estuary and may partially explain observed increases in shimofuri goby abundance compared with declines in populations of some native species. ?? Springer 2005.

Matern, S.A.; Brown, L.R.

2005-01-01

142

Cellulolytic Microorganisms from Thermal Environments  

SciTech Connect

Thermal, anaerobic environments rich in decaying plant material are a potential source of novel cellulolytic bacteria. Samples collected from geothermal aquifers in the Yellowstone National Park (YNP) were used to select for cellulolytic thermophiles. Laboratory enrichments on dilute-acid pretreated plant biomass (switchgrass, Populus), and crystalline cellulose (Avicel) resulted in the isolation of 247 environmental clones. The majority of individual clones were affiliated with the cellulolytic bacteria of phylum Firmicutes, followed by xylanolytic and saccharolytic members of the phylum Dictyoglomi. Among the Firmicutes, the clones were affiliated with the genera Caldicellulosiruptor (54.4%), Caloramator (11.5%), Thermoanaerobacter (8.8%), Thermovenabulum (4.1%), and Clostridium (2.0%). From established anaerobic thermophilic enrichments a total of 81 single strains of the genera Caldicellulosiruptor (57%) and Thermoanaerobacter (43%) were isolated. With continuous flow enrichment on Avicel, increases in the relative abundance of Caloramator sp. was observed over clones detected from the Caldicellulosiruptor. Complex communities of interacting microorganisms bring about cellulose decomposition in nature, therefore using up-to-date approaches may yield novel cellulolytic microorganisms with high activity and a rapid rate of biomass conversion to biofuels.

Vishnivetskaya, Tatiana A [ORNL; Raman, Babu [ORNL; Phelps, Tommy Joe [ORNL; Podar, Mircea [ORNL; Elkins, James G [ORNL

2012-01-01

143

HOW INVADED IS INVADED?  

EPA Science Inventory

One thrust of invasion biology has been to compare the extent of invasion among communities and biogeographic regions. A problem with such comparisons has been the plethora of metrics used and the lack of standardization as to what data are incorporated into the metrics. One sour...

144

Seasonal variation in the size and abundance of the invading Bythotrephes in Harp Lake, Ontario, Canada  

Microsoft Academic Search

Bythotrephes invaded Harp Lake, Ontario, Canada, in the early 1990s. Here we describe seasonal changes in the size, abundance and life history of the invader. The weight of Bythotrephes could be accurately estimated (r2 =0.90) from the length of its body and the state of development of its brood, but substantial (22%) corrections for shrinkage in sugarformalin were required. The

Norman D. Yan; Trevor W. Pawson

1997-01-01

145

Impact of Alien Plant Invaders on Pollination Networks in Two Archipelagos  

E-print Network

Impact of Alien Plant Invaders on Pollination Networks in Two Archipelagos Benigno Padro´ n1-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems. Citation: Padro´n B, Traveset A, Biedenweg T, Di´az D, Nogales M, et al. (2009) Impact of Alien Plant

Traveset, Anna

146

Control and the management of a spreading invader David Finnoff a,  

E-print Network

Keywords: Natural resources Biological invasions Invasive species A B S T R A C T We consider the problem of management of an aquatic invader spreading in a lake system. We assume that each year the invader can optimization across asymptotic steady states. Control close to eradication of the invasive species is always

Lewis, Mark

147

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

148

Tailored synthesis of amine N-halamine copolymerized polystyrene with capability of killing bacteria.  

PubMed

Novel amine N-halamine copolymerized polystyrene (ANHCPS) nanostructures were controllably fabricated as potent antibiotics by using the surfactant-free emulsion copolymerization for killing pathogenic bacteria. The morphology and size of the ANHCPS were well tailored by tuning reaction conditions such as monomer molar ratio, temperature, and copolymerization time. Effect of chlorination aging time on the oxidative chlorine content in the ANHCPS was established, and the oxidative chlorine content was determined by the modified iodometric/thiosulfate technique. Antibacterial behavior of the ANHCPS on bacterial strain was evaluated using Staphylococcusaureus and Escherichiacoli as model pathogenic bacteria via the plate counting technique, inhibition zone study, and time-kill assay. Antimicrobial results illustrated that the ANHCPS possessed superior antibacterial capability of killing pathogenic bacteria. The destruction induced by the ANHCPS on bacterial surface structure was proven by using SEM technique. The effect of the oxidative chlorine content and morphology/size on the antimicrobial capability was constructed as well. This study provides us a novel approach for controllably synthesizing amine N-halamine polymers, and making them the potent candidates for killing bacteria or even the control of microorganism contamination. PMID:25585280

Cai, Qian; Bao, Sarina; Zhao, Yue; Zhao, Tianyi; Xiao, Linghan; Gao, Ge; Chokto, Harnoode; Dong, Alideertu

2015-04-15

149

Killing vector fields and harmonic superfield theories  

NASA Astrophysics Data System (ADS)

The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.

Groeger, Josua

2014-09-01

150

Exotic plant species invade hot spots of native plant diversity  

USGS Publications Warehouse

Some theories and experimental studies suggest that areas of low plant species richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2 subplots (20 1000-m2 modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2 subplots (16 1000-m2 plots) in the Central Grasslands in Colorado, Wyoming, South Dakota, and Minnesota (USA) to test the generality of this paradigm. At the 1-m2 scale, the paradigm was supported in four prairie types in the Central Grasslands, where exotic species richness declined with increasing plant species richness and cover. At the 1-m2 scale, five forest and meadow vegetation types in the Colorado Rockies contradicted the paradigm; exotic species richness increased with native-plant species richness and foliar cover. At the 1000-m2 plot scale (among vegetation types), 83% of the variance in exotic species richness in the Central Grasslands was explained by the total percentage of nitrogen in the soil and the cover of native plant species. In the Colorado Rockies, 69% of the variance in exotic species richness in 1000-m2 plots was explained by the number of native plant species and the total percentage of soil carbon. At landscape and biome scales, exotic species primarily invaded areas of high species richness in the four Central Grasslands sites and in the five Colorado Rockies vegetation types. For the nine vegetation types in both biomes, exotic species cover was positively correlated with mean foliar cover, mean soil percentage N, and the total number of exotic species. These patterns of invasibility depend on spatial scale, biome and vegetation type, spatial autocorrelation effects, availability of resources, and species-specific responses to grazing and other disturbances. We conclude that: (1) sites high in herbaceous foliar cover and soil fertility, and hot spots of plant diversity (and biodiversity), are invasible in many landscapes; and (2) this pattern may be more closely related to the degree resources are available in native plant communities, independent of species richness. Exotic plant invasions in rare habitats and distinctive plant communities pose a significant challenge to land managers and conservation biologists.

Stohlgren, T.J.; Binkley, D.; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.; Bull, K.A.; Otsuki, Y.; Newman, G.; Bashkin, M.; Yowhan, S.

1999-01-01

151

Mycobacterium tuberculosis invades and replicates within type II alveolar cells.  

PubMed Central

Although Mycobacterium tuberculosis is assumed to infect primarily alveolar macrophages after being aspirated into the lung in aerosol form, it is plausible to hypothesize that M. tuberculosis can come in contact with alveolar epithelial cells upon arrival into the alveolar space. Therefore, as a first step toward investigation of the interaction between M. tuberculosis and alveolar epithelial cells, we examined the ability of M. tuberculosis to bind to and invade alveolar epithelial cells in vitro. The H37Rv and H37Ra strains of M. tuberculosis were cultured to mid-log phase and used in both adherence and invasion assays. The A549 human type II alveolar cell line was cultured to confluence in RPMI 1640 supplemented with 5% fetal bovine serum, L-glutamine, and nonessential amino acids. H37Rv was more efficient in entering A549 cells than H37Ra, Mycobacterium avium, and Escherichia coli Hb101, and nonpiliated strain (4.7% +/- 1.0% of the initial inoculum in 2 h compared with 3.1% +/- 0.8%, 2.1% +/- 0.9%, and 0.03% +/- 0.0%, respectively). The invasion was more efficient at 37 degrees C than 30 degrees C (4.7% +/- 1.0% compared with 2.3% +/- 0.8%). H37Rv and H37Ra were both capable of multiplying intracellularly at a similar ration over 4 days. Binding was inhibited up to 55.7% by anti-CD51 antibody (antivitronectin receptor), up to 55% with anti-CD29 antibody (beta(1) integrin), and 79% with both antibodies used together. Update of M. tuberculosis H37Rv was microtubule and microfilament dependent. It was inhibited by 6l.4% in the presence of 10 micron colchicine and by 72.3% in the presence of 3 micron cytochalasin D, suggesting two separate pathways for uptake. Our results show that M. tuberculosis is capable of invading type II alveolar epithelial cells and raise the possibility that invasion of alveolar epithelial cells is associated with the pathogenesis of lung infection. PMID:8606107

Bermudez, L E; Goodman, J

1996-01-01

152

A combined microfluidic/dielectrophoretic microorganism concentrator  

E-print Network

This thesis presents the development of a high-throughput microfluidic microorganism concentrator for pathogen detection applications. Interdigitated electrodes lining the bottom of the channel use positive dielectrophoretic ...

Gadish, Nitzan

2005-01-01

153

40 CFR 725.420 - Recipient microorganisms.  

Code of Federal Regulations, 2014 CFR

...recipient microorganisms are eligible for either exemption under this subpart: (a) Acetobacter aceti. (b) Aspergillus niger. (c) Aspergillus oryzae. (d) Bacillus licheniformis. (e) Bacillus subtilis. (f) Clostridium...

2014-07-01

154

40 CFR 725.420 - Recipient microorganisms.  

Code of Federal Regulations, 2011 CFR

...recipient microorganisms are eligible for either exemption under this subpart: (a) Acetobacter aceti . (b) Aspergillus niger. (c) Aspergillus oryzae. (d) Bacillus licheniformis. (e) Bacillus subtilis. (f) Clostridium...

2011-07-01

155

40 CFR 725.420 - Recipient microorganisms.  

Code of Federal Regulations, 2012 CFR

...recipient microorganisms are eligible for either exemption under this subpart: (a) Acetobacter aceti . (b) Aspergillus niger. (c) Aspergillus oryzae. (d) Bacillus licheniformis. (e) Bacillus subtilis. (f) Clostridium...

2012-07-01

156

40 CFR 725.420 - Recipient microorganisms.  

Code of Federal Regulations, 2010 CFR

...recipient microorganisms are eligible for either exemption under this subpart: (a) Acetobacter aceti . (b) Aspergillus niger. (c) Aspergillus oryzae. (d) Bacillus licheniformis. (e) Bacillus subtilis. (f) Clostridium...

2010-07-01

157

40 CFR 725.420 - Recipient microorganisms.  

Code of Federal Regulations, 2013 CFR

...recipient microorganisms are eligible for either exemption under this subpart: (a) Acetobacter aceti . (b) Aspergillus niger. (c) Aspergillus oryzae. (d) Bacillus licheniformis. (e) Bacillus subtilis. (f) Clostridium...

2013-07-01

158

Biocorrosion produced by Thiobacillus-like microorganisms.  

PubMed

Biocorrosion can be produced by many different microorganisms through diverse mechanisms. The biocorrosion produced by acidophilic microorganisms of the genus Thiobacillus is based on the production of sulfuric acid and ferric ion from pyrites or related mineral structures, as a result of the chemolithotrophic metabolism of these microorganisms. The products of this aerobic respiration are also powerful oxidant elements, which can produce chemical oxidations of other metallic structures. The Tinto River, a very unusual extremophilic habitat (pH around 2, and high concentration of ferric ion), product of the growth of strict chemolithotrophic microorganisms, is discussed as a model case. PMID:7946115

López, A I; Marín, I; Amils, R

1994-01-01

159

Recruitment of two Opuntia species invading abandoned olive groves  

NASA Astrophysics Data System (ADS)

In Europe, many agricultural areas are now abandoned and hence can be invaded by exotic species. The abundance and spatial distribution patterns of two Opuntia species were studied in old olive groves in the Parc Natural del Cap de Creus, Catalonia (Spain). Seedling recruitment (97.3% and 51.5% of juveniles for O. maxima and O. stricta, respectively) was higher than recruitment by cladodes. O. maxima had more seedlings recruited beneath olive trees and beneath Opuntia adults than expected. Most O. stricta seedlings were also located beneath Opuntia adult plants. However, although most seedlings were recruited beneath Opuntia, some (10-30%) were found away from putative parental plants. This may be due to seed dispersal by birds and wild boars. Seeds dispersed by wild boars were not significantly more viable than seeds from intact fruits. Seedlings grow very slowly but have a high survival rate. In conclusion, Opuntia seedling recruitment is very successful and ensures the persistence of these species within old olive groves. Consequently, it prevents restoration from an agricultural land-use back to the native community.

Gimeno, Isabel; Vilà, Montserrat

2002-08-01

160

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

161

Vegetative Regeneration Capacities of Five Ornamental Plant Invaders After Shredding  

NASA Astrophysics Data System (ADS)

Vegetation management often involves shredding to dispose of cut plant material or to destroy the vegetation itself. In the case of invasive plants, this can represent an environmental risk if the shredded material exhibits vegetative regeneration capacities. We tested the effect of shredding on aboveground and below-ground vegetative material of five ornamental widespread invaders in Western Europe that are likely to be managed by cutting and shredding techniques: Buddleja davidii (butterfly bush, Scrophulariaceae), Fallopia japonica (Japanese knotweed, Polygonaceae), Spiraea × billardii Hérincq (Billard's bridewort, Rosaceae), Solidago gigantea (giant goldenrod, Asteraceae), and Rhus typhina L. (staghorn sumac, Anacardiaceae). We looked at signs of vegetative regeneration and biomass production, and analyzed the data with respect to the season of plant cutting (spring vs summer), the type of plant material (aboveground vs below-ground), and the shredding treatment (shredded vs control). All species were capable of vegetative regeneration, especially the below-ground material. We found differences among species, but the regeneration potential was generally still present after shredding despite a reduction of growth rates. Although it should not be excluded in all cases (e.g., destruction of giant goldenrod and staghorn sumac aboveground material), the use of a shredder to destroy woody alien plant material cannot be considered as a general management option without significant environmental risk.

Monty, Arnaud; Eugène, Marie; Mahy, Grégory

2015-02-01

162

Invading slugs (Arion vulgaris) can be vectors for Listeria monocytogenes  

PubMed Central

Aims Listeriosis is a frequent silage-associated disease in ruminants. The slugs Arion vulgaris are invaders in gardens, vegetable crops and meadows for silage production. Field and laboratory studies were conducted to clarify whether slugs could host Listeria monocytogenes and thereby constitute a threat to animal feed safety. Methods and Results Selective culture of L. monocytogenes from 79 pooled slug samples (710 slugs) resulted in 43% positive, 16% with mean L. monocytogenes values of 405 CFU g?1 slug tissues. Of 62 individual slugs cultured, 11% also tested positive from surface/mucus. Multilocus sequence typing analysis of 36 isolates from different slug pools identified 20 sequence types belonging to L. monocytogenes lineages I and II. Slugs fed ?4·0 × 105 CFUL. monocytogenes, excreted viable L. monocytogenes in faeces for up to 22 days. Excretion of L. monocytogenes decreased with time, although there were indications of a short enrichment period during the first 24 h. Conclusions Arion vulgaris may act as a vector for L. monocytogenes. Significance and Impact of the Study Highly slug-contaminated grass silage may pose a potential threat to animal feed safety. PMID:25580873

Gismervik, K; Aspholm, M; Rørvik, LM; Bruheim, T; Andersen, A; Skaar, I

2015-01-01

163

Lactobacillus equigenerosi Strain Le1 Invades Equine Epithelial Cells  

PubMed Central

Lactobacillus equigenerosi strain Le1, a natural inhabitant of the equine gastrointestinal tract, survived pH 3.0 and incubation in the presence of 1.5% (wt/vol) bile salts for at least 2 h. Strain Le1 showed 8% cell surface hydrophobicity, 60% auto-aggregation, and 47% coaggregation with Clostridium difficile C6. Only 1% of the cells adhered to viable buccal epithelial cells and invaded the cells within 20 min after contact. Preincubation of strain Le1 in a buffer containing pronase prevented adhesion to viable epithelial cells. Preincubation in a pepsin buffer delayed invasion from 20 min to 1 h. Strain Le1 did not adhere to nonviable epithelial cells. Administration of L. equigenerosi Le1 (1 × 109 CFU per 50 kg body weight) to healthy horses did not increase white blood cell numbers. Differential white blood cell counts and aspartate aminotransferase levels remained constant. Glucose, lactate, cholesterol, and urea levels remained constant during administration with L. equigenerosi Le1 but decreased during the week after administration. PMID:22504808

Botha, Marlie; Botes, Marelize; Loos, Ben; Smith, Carine

2012-01-01

164

Vegetative regeneration capacities of five ornamental plant invaders after shredding.  

PubMed

Vegetation management often involves shredding to dispose of cut plant material or to destroy the vegetation itself. In the case of invasive plants, this can represent an environmental risk if the shredded material exhibits vegetative regeneration capacities. We tested the effect of shredding on aboveground and below-ground vegetative material of five ornamental widespread invaders in Western Europe that are likely to be managed by cutting and shredding techniques: Buddleja davidii (butterfly bush, Scrophulariaceae), Fallopia japonica (Japanese knotweed, Polygonaceae), Spiraea × billardii Hérincq (Billard's bridewort, Rosaceae), Solidago gigantea (giant goldenrod, Asteraceae), and Rhus typhina L. (staghorn sumac, Anacardiaceae). We looked at signs of vegetative regeneration and biomass production, and analyzed the data with respect to the season of plant cutting (spring vs summer), the type of plant material (aboveground vs below-ground), and the shredding treatment (shredded vs control). All species were capable of vegetative regeneration, especially the below-ground material. We found differences among species, but the regeneration potential was generally still present after shredding despite a reduction of growth rates. Although it should not be excluded in all cases (e.g., destruction of giant goldenrod and staghorn sumac aboveground material), the use of a shredder to destroy woody alien plant material cannot be considered as a general management option without significant environmental risk. PMID:25387455

Monty, Arnaud; Eugène, Marie; Mahy, Grégory

2015-02-01

165

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 PMID:3141287

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

1988-01-01

166

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

167

Degradation of polychlorinated biphenyls by microorganisms  

SciTech Connect

The biodegradation of PCB's by microorganisms and the degradation pathway of PCB's are investigated. Experimental methods and materials are described. Only several strains of bacteria, Achromobacter sp., Alcaligenes sp., Acinetobacter sp., Pseudomonas sp., and soil microorganisms were able to decompose PCB's. A possible relationships between the structure and biodegradability of related biphenyl compounds was examined. (5 diagrams, 11 graphs, 18 references, 1 table)

Yagi, O.; Sudo, R.

1980-05-01

168

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

169

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

170

Evaluation of five kill traps for effective capture and killing of Australian brushtail possums (Trichosurus vulpecula)  

Microsoft Academic Search

Five types of kill trap for possible use by professional possum trappers in New Zealand were tested for their potential to kill possums quickly and for their capture efficiency. Traps were evaluated using the testing requirements outlined in a draft International Trap Standard. This involved sequential mechanical testing, pen testing with free?moving possums, and field testing. The Banya and Loka?asklem

B. Warburton; I. Orchard

1996-01-01

171

Proteasomes Control Caspase-1 Activation in Anthrax Lethal Toxin-mediated Cell Killing*S  

E-print Network

Proteasomes Control Caspase-1 Activation in Anthrax Lethal Toxin-mediated Cell Killing*S Received York 10461 Activation of caspase-1 through the inflammasome protein Nalp1b controls anthrax lethal. The spore-forming bacterium Bacillus anthracis is the caus- ative agent of anthrax disease (1

Brojatsch, Jürgen

172

Grassland invader responses to realistic changes in native species richness.  

PubMed

The importance of species richness for repelling exotic plant invasions varies from ecosystem to ecosystem. Thus, in order to prioritize conservation objectives, it is critical to identify those ecosystems where decreasing richness will most greatly magnify invasion risks. Our goal was to determine if invasion risks greatly increase in response to common reductions in grassland species richness. We imposed treatments that mimic management-induced reductions in grassland species richness (i.e., removal of shallow- and/or deep-rooted forbs and/or grasses and/or cryptogam layers). Then we introduced and monitored the performance of a notorious invasive species (i.e., Centaurea maculosa). We found that, on a per-gram-of-biomass basis, each resident plant group similarly suppressed invader growth. Hence, with respect to preventing C. maculosa invasions, maintaining overall productivity is probably more important than maintaining the productivity of particular plant groups or species. But at the sites we studied, all plant groups may be needed to maintain overall productivity because removing forbs decreased overall productivity in two of three years. Alternatively, removing forbs increased productivity in another year, and this led us to posit that removing forbs may inflate the temporal productivity variance as opposed to greatly affecting time-averaged productivity. In either case, overall productivity responses to single plant group removals were inconsistent and fairly modest, and only when all plant groups were removed did C. maculosa growth increase substantially over a no-removal treatment. As such, it seems that intense disturbances (e.g., prolonged drought, overgrazing) that deplete multiple plant groups may often be a prerequisite for C. maculosa invasion. PMID:17913143

Rinella, Matthew J; Pokorny, Monica L; Rekaya, Romdhane

2007-09-01

173

Rapid Kill—Novel Endodontic Sealer and Enterococcus faecalis  

PubMed Central

With growing concern over bacterial resistance, the identification of new antimicrobial means is paramount. In the oral cavity microorganisms are essential to the development of periradicular diseases and are the major causative factors associated with endodontic treatment failure. As quaternary ammonium compounds have the ability to kill a wide array of bacteria through electrostatic interactions with multiple anionic targets on the bacterial surface, it is likely that they can overcome bacterial resistance. Melding these ideas, we investigated the potency of a novel endodontic sealer in limiting Enterococcus faecalis growth. We used a polyethyleneimine scaffold to synthesize nano-sized particles, optimized for incorporation into an epoxy-based endodontic sealer. The novel endodontic sealer was tested for its antimicrobial efficacy and evaluated for biocompatibility and physical eligibility. Our results show that the novel sealer foundation affixes the nanoparticles, achieving surface bactericidal properties, but at the same time impeding nanoparticle penetration into eukaryotic cells and thereby mitigating a possible toxic effect. Moreover, adequate physical properties are maintained. The nanosized quaternary amine particles interact within minutes with bacteria, triggering cell death across wide pH values. Throughout this study we demonstrate a new antibacterial perspective for endodontic sealers; a novel antibacterial, effective and safe antimicrobial means. PMID:24223159

Zaltsman, Nathan; Houri-Haddad, Yael; Abramovitz, Itzhak; Davidi, Michael Perez; Weiss, Ervin I.

2013-01-01

174

Native Cuscuta campestris restrains exotic Mikania micrantha and enhances soil resources beneficial to natives in the invaded communities  

Microsoft Academic Search

Nutrients in exotic species and invaded communities play a key role in determining the dynamics of invaders and the invasibility\\u000a of a receipt community. This study focused on the effects of the native holoparasite Cuscuta campestris (for short Cuscuta) on nutrients in the exotic invasive Mikania micrantha (for short Mikania) and stands invaded by Mikania. We conducted a set of

Hua Yu; Wei-Ming He; Jian Liu; Shi-Li Miao; Ming Dong

2009-01-01

175

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. PMID:25083373

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

2014-01-01

176

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

177

Hydrogen production by photosynthetic microorganisms  

SciTech Connect

Hydrogen is a clean energy alternative to the fossil fuels, the main source of greenhouse gas emissions. We developed a stable system for the conversion of solar energy into hydrogen using photosynthetic microorganisms. Our system consists of the following three stages: (1) Photosynthetic starch accumulation in green microalgae (400 L x2); (2) Dark anaerobic fermentation of the algal starch biomass to produce hydrogen and organic compounds (155 L x2); and (3) Further conversion of the organic compounds to produce hydrogen using photosynthetic bacteria (three types of reactors, parallel plate, raceway, and tubular). We constructed a test plant of this process at Nankoh power plant of Kansai Electric Power Company in Osaka, Japan, and carried out a series of tests using CO{sub 2} obtained from a chemical absorption pilot-plant. The photobiological hydrogen production process used a combination of a marine alga, Chlamydomonas sp. MGA 161 and marine photosynthetic bacterium, Rhodopseudomonas sp. W-1S. The dark anaerobic fermentation of algal starch biomass was also investigated. Sustained and stable starch accumulation, starch degradation in the algal cell, and hydrogen production from algal fermentation and photosynthetic bacteria in the light were demonstrated during several experiments. 3 refs., 12 figs., 1 tab.

Akano, T.; Fukatsu, K.; Miyasaka, H. [Kansai Electric Power Co., Hyogo (Japan)]|[Nankoh Labs., Hyogo (Japan)] [and others

1996-12-31

178

HIV transcription is induced with cell killing  

SciTech Connect

In this report, we demonstrate that this induction of HIV-LTR transcription occurs when stably transfected HeLa cells are exposed to agents which mediate cell killing, such as UV radiation, electroporation of sucrose buffer, prolonged heating, and low and high pH. Cells cultured following UV exposure demonstrated a peak in CAT expression that is evident in viable (but not necessarily cell division-competent) cells 24 h after exposure; this inductive response continued until at least 72 h after exposure. HIV-LTR induction was dose-dependent, and the amount of CAT transcription induced was correlated with the amount of cell killing that occurred in the culture.

Woloschak, G.E.; Schreck, S.; Chang-Liu, Chin-Mei [Argonne National Lab., IL (United States); Panozzo, J.; Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1993-11-01

179

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.

180

Cytotoxic Killing and Immune Evasion by Repair  

NASA Astrophysics Data System (ADS)

The interaction between the immune system and pathogens is a complex one, with pathogens constantly developing new ways of evading destruction by the immune system. The immune system's task is made even harder when the pathogen in question is an intra-cellular one (such as a virus or certain bacteria) and it is necessary to kill the infected host cell in order to eliminate the pathogen. This causes damage to the host, and such killing therefore needs to be carefully controlled, particularly in tissues with poor regenerative potential, or those involved in the immune response itself. Host cells therefore possess repair mechanisms which can counteract killing by immune cells. These in turn can be subverted by pathogens which up-regulate the resistance of infected cells to killing. In this paper, we explore the hypothesis that this repair process plays an important role in determining the efficacy of evasion and escape from immune control. We model a situation where cytotoxic T lymphocytes (CTL) and natural killer (NK) cells kill pathogen-infected and tumour cells by directed secretion of preformed granules containing perforin and granzymes. Resistance to such killing can be conferred by the expression of serine protease inhibitors (serpins). These are utilized by several virally infected and tumour cells, as well as playing a role in the protection of host bystander, immune and immuneprivileged cells. We build a simple stochastic model of cytotoxic killing, where serpins can neutralize granzymes stoichiometrically by forming an irreversible complex, and the survival of the cell is determined by the balance between serpin depletion and replenishment, which in its simplest form is equivalent to the well known shot noise process. We use existing analytical results for this process, and additional simulations to analyse the effects of repair on cytotoxic killing. We then extend the model to the case of a replicating target cell population, which gives a branching process coupled to shot noise. We show how the process of repair can have a major impact on the dynamics of pathogen evasion and escape of tumour cells from immune surveillance

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

2007-07-01

181

Timelike Killing Fields and Relativistic Statistical Mechanics  

E-print Network

For spacetimes with timelike Killing fields, we introduce a "Fermi-Walker-Killing" coordinate system and use it to prove a Liouville Theorem for an appropriate volume element of phase space for a statistical mechanical system of particles. We derive an exact relativistic formula for the Helmholtz free energy of an ideal gas and compare it, for a class of spacetimes, to its Newtonian analog, derived both independently and as the Newtonian limit of our formula. We also find the relativistic thermodynamic equation of state. Specific examples are given in Kerr spacetime.

David Klein; Peter Collas

2008-12-12

182

Generalized Korn's inequality and conformal Killing vectors  

E-print Network

Korn's inequality plays an important role in linear elasticity theory. This inequality bounds the norm of the derivatives of the displacement vector by the norm of the linearized strain tensor. The kernel of the linearized strain tensor are the infinitesimal rigid-body translations and rotations (Killing vectors). We generalize this inequality by replacing the linearized strain tensor by its trace free part. That is, we obtain a stronger inequality in which the kernel of the relevant operator are the conformal Killing vectors. The new inequality has applications in General Relativity.

Sergio Dain

2005-05-04

183

40 CFR 725.88 - Uses of a microorganism.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 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...

2010-07-01

184

Decline in exotic tree density facilitates increased plant diversity: the experience from Melaleuca quinquenervia invaded wetlands  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Australian tree Melaleuca quinquenervia (melaleuca) formed dense monocultural forests several decades after invading Florida and the Caribbean islands. These dominant forests have displaced native vegetation in sensitive wetland systems. We hypothesized that native plant diversity would increa...

185

Are early summer wildfires an opportunity to revegetate medusahead-invaded rangelands?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Successful revegetation of medusdahead-invaded plant communities can be prohibitively expensive, because it often requires iterative applications of integrated control and revegetation treatments. Prescribed burning has been used to control medusahead and prepare seedbeds for revegetation, but burni...

186

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

E-print Network

REVIEW AND SYNTHESIS Invisible invaders: non-pathogenic invasive microbes in aquatic, invasive species, invasiveness, microbial biogeography, protists, symbiotic, traits. Ecology Letters (2010 on invasive plants and animals has risen exponentially, little is known about invasive microbes, especially

187

Cryptic Fitness Advantage: Diploids Invade Haploid Populations Despite Lacking Any Apparent Advantage as  

E-print Network

Cryptic Fitness Advantage: Diploids Invade Haploid Populations Despite Lacking Any Apparent Advantage as Measured by Standard Fitness Assays Aleeza C. Gerstein*, Sarah P. Otto Zoology Department. Surprisingly, none of our fitness component measures (lag phase, growth rate, biomass production) indicated

Otto, Sarah

188

Success of seeding native compared to introduced perennial vegetation for revegetating medusahead-invaded sagebrush rangeland  

Technology Transfer Automated Retrieval System (TEKTRAN)

Millions of hectares of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &Young) rangeland have been invaded by medusahead (Taeniatherum caput-medusae [L.] Nevski), an exotic annual grass that degrades wildlife habitat, reduces forage production, and decreases biodiversity....

189

More than one way to invade: lessons from genetic studies of Carcinus shore crabs  

EPA Science Inventory

The European green crab Carcinus maenas is one of the world's most widely recognized marine invaders. The success of this species has provided opportunities to explore genetic patterns associated with establishment and population expansion following independent introduction event...

190

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

191

Comparative Population Dynamics of an Invading Species in its Native and Novel Ranges  

Microsoft Academic Search

Although the ecology of many exotic invaders has been intensively examined in the novel range, few studies have comparatively\\u000a explored how population dynamics differ in native and novel parts of an invading plants’ range. The population dynamics of\\u000a mile-a-minute weed, Polygonum perfoliatum L., was explored in both the native (Japan) and novel (northeastern USA) portions of its range and evaluated

Laura A. Hyatt; Sachiko Araki

2006-01-01

192

Long-term population dynamics of seeded plants in invaded grasslands.  

PubMed

In recent decades, dozens of studies have involved attempts to introduce native and desirable nonnative plant species into grasslands dominated by invasive weeds. The newly introduced plants have proved capable of establishing, but because they are rarely monitored for more than four years, it is unknown if they have a high likelihood of persisting and suppressing invaders for the long-term. Beyond invaded grasslands, this lack of long-term monitoring is a general problem plaguing efforts to reintroduce a range of taxa into a range of ecosystems. We introduced species from seed and then periodically measured plant abundances for nine years at one site and 15 years at a second site. To our knowledge, our 15-year data are the longest to date from a seeding experiment in invaded, never-cultivated grassland. At one site, three seeded grasses maintained high densities for three or more years, but then all or nearly all individuals died. At the second site, one grass performed similarly, but two other grasses proliferated and at least one greatly suppressed the dominant invader (Centaurea maculosa). In one study, our point estimate suggests that the seeded grass Thinopyrum intermedium reduced C. maculosa biomass by 93% 15 years after seeding. In some cases, data from three and fewer years after seeding falsely suggested that seeded species were capable of persisting within the invaded grassland. In other cases, data from as late as nine years after seeding falsely suggested seeded populations would not become large enough to suppress the invader. These results show that seeded species sometimes persist and suppress invaders for long periods, but short-term data cannot predict if, when, or where this will occur. Because short-term data are not predictive of long-term seeded species performances, additional long-term data are needed to identify effective practices, traits, and species for revegetating invaded grasslands. PMID:22827138

Rinella, Matthew J; Mangold, Jane M; Espeland, Erin K; Sheley, Roger L; Jacobs, James S

2012-06-01

193

Alien plant invasions--incorporating emerging invaders in regional prioritization: a pragmatic approach for Southern Africa.  

PubMed

Plant invasions are a serious threat to natural and semi-natural ecosystems worldwide. Most management-orientated research on invasions focuses on invaders that are already widespread and often have major impacts. This paper deals with "emerging" invaders-those alien species with the potential to become important problems without timely intervention. A climate matching procedure was developed to define areas of South Africa, Lesotho and Swaziland that could be invaded by 28 plant species that had previously been classified as emerging invaders. Information on the location of populations of these species in the study area was combined with information on their distributions (as native or alien) in parts of Australia and the United States of America. These two countries had the best available distribution data for this study. They also share many invasive alien plant species with South Africa. Climatic data obtained for weather stations near points of known occurrence in these countries were used to define the climatically suitable areas for each species in the study area. Almost 80% of the remaining natural environment in southern Africa was found to be vulnerable to invasion by at least one of these species, 50% by six or more and 24% by 16 or more species. The most vulnerable areas are the highveld grasslands and the eastern escarpment. The emerging invaders with the greatest potential range included Acacia podalyriifolia and Cortaderia selloana. The globally important invaders Ulex europaeus and Lythrum salicaria had a more limited invasion potential but could still become major invaders. There was no relationship between the extent of the climatically suitable areas for the different species and an expert ranking of their invasion potential, emphasising the uncertainties inherent in making expert assessments based on very little information. The methods used in this analysis establish a protocol for future modelling exercises to assess the invasion potential of other emerging invaders. PMID:17067735

Mgidi, Theresa N; Le Maitre, David C; Schonegevel, Lucille; Nel, Jeanne L; Rouget, Mathieu; Richardson, David M

2007-07-01

194

Fusarium solani invader of the eggs of the insect Panstrongylus geniculatus in a vivarium  

Microsoft Academic Search

A strain ofFusarium solani sensu Snyder & Hansen invaded the eggs of the insectPanstrongylus geniculatus in a vivarium. None of the invaded eggs hatched. To establish experimentally the pathogenicity of thisFusarium species against the eggs ofP. geniculatus, the fungus and the eggs were incubated together under different relative humidities and temperatures. At 64% relative humidity\\u000a and 26 °C, the fungus

Claudia Hartung; Matias Reyes Lugo

1996-01-01

195

Selective tumor kill of cerebral glioma by photodynamic therapy using a boronated porphyrin photosensitizer.  

PubMed Central

The prognosis for patients with the high-grade cerebral glioma glioblastoma multiforme is poor. The median survival for primary tumors is < 12 months, with most recurring at the site of the original tumor, indicating that a more aggressive local therapy is required to eradicate the unresectable "nests" of tumor cells invading into adjacent brain. Two adjuvant therapies with the potential to destroy these cells are porphyrin-sensitized photodynamic therapy (PDT) and boron-sensitized boron neutron capture therapy (BNCT). The ability of a boronated porphyrin, 2,4-(alpha, beta-dihydroxyethyl) deuteroporphyrin IX tetrakiscarborane carboxylate ester (BOPP), to act as a photosensitizing agent was investigated in vitro with the C6 rat glioma cell line and in vivo with C6 cells grown as an intracerebral tumor after implantation into Wistar rats. These studies determined the doses of BOPP and light required to achieve maximal cell kill in vitro and selective tumor kill in vivo. The data show that BOPP is more dose effective in vivo by a factor of 10 than the current clinically used photosensitizer hematoporphyrin derivative and suggest that BOPP may have potential as a dual PDT/BNCT sensitizer. Images Fig. 3 PMID:8618857

Hill, J S; Kahl, S B; Stylli, S S; Nakamura, Y; Koo, M S; Kaye, A H

1995-01-01

196

Integrating Poetry and "To Kill a Mockingbird."  

ERIC Educational Resources Information Center

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

Jolley, Susan Arpajian

2002-01-01

197

MECHANISM BY WHICH AMMONIUM FERTILIZERS KILL LARKSPUR  

Technology Transfer Automated Retrieval System (TEKTRAN)

Environmental concerns of using pesticides on public lands have greatly reduced the use of herbicides to control tall larkspur (Delphinium barbeyi). Alternative methods of control have used ammonium sulfate placed in the crown of individual plants to kill larkspur. The objective of this study was ...

198

Oxidative killing of microbes by neutrophils  

Microsoft Academic Search

Neutrophils and other phagocytic leukocytes contain a phagocyte NADPH oxidase enzyme that generates superoxide after cell activation. Reactive oxygen species derived from superoxide, together with proteases liberated from the granules, are used to kill ingested microbes. Dysfunction of the phagocyte NADPH oxidase results in chronic granulomatous disease, with life-threatening infections.

Dirk Roos; Robin van Bruggen; Christof Meischl

2003-01-01

199

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.

CBS News

200

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.

201

Pulpability of Beetle-Killed Spruce  

E-print Network

stands of dead and dying timber on the Kenai Penin- sula in Alaska. Tests were conducted to evaluate the value of beetle-killed spruce as pulpwood. The results showed that live and dead spruce wood can of race, color, national origin, sex, religion, age, disability, political beliefs, and marital

Abubakr, Said

202

Pfiesteria shumwayae kills fish by micropredation not  

E-print Network

and the lateral line canal, associated with extensive tissue damage, has been observed16 . A direct physical, acute fish kills and human disease in mid-Atlantic USA estuaries1­7 . However, Pfies- teria toxins have recently demonstrated that A. invadans is a primary pathogen, able to elicit menhaden ulcer disease

203

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

204

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. 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

205

Emerging contaminants and microorganisms into the environment  

E-print Network

Workshop Emerging contaminants and microorganisms into the environment: contamination pathways contaminants into the environment: contamination pathways and risk assessment Vincenzo Belgiorno, University Andrzejewski, Adam Mickiewicz, University of Poznan (Poland) Photodegradation pathways of emerging contaminants

Costagliola, Gennaro

206

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

207

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

208

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...

209

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

210

PARTICLE-ASSOCIATED MICROORGANISMS IN STORMWATER RUNOFF  

EPA Science Inventory

This research investigated the effects of blending and chemical addition before analysis of the concentration of microorganisms in stormwater runoff to determine whether clumped or particle-associated organisms play a significant role. All organisms, except for Escherichia coli, ...

211

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

212

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

213

Wolbachia-Mediated Male Killing Is Associated with Defective Chromatin Remodeling  

PubMed Central

Male killing, induced by different bacterial taxa of maternally inherited microorganisms, resulting in highly distorted female-biased sex-ratios, is a common phenomenon among arthropods. Some strains of the endosymbiont bacteria Wolbachia have been shown to induce this phenotype in particular insect hosts. High altitude populations of Drosophila bifasciata infected with Wolbachia show selective male killing during embryonic development. However, since this was first reported, circa 60 years ago, the interaction between Wolbachia and its host has remained unclear. Herein we show that D. bifasciata male embryos display defective chromatin remodeling, improper chromatid segregation and chromosome bridging, as well as abnormal mitotic spindles and gradual loss of their centrosomes. These defects occur at different times in the early development of male embryos leading to death during early nuclear division cycles or large defective areas of the cellular blastoderm, culminating in abnormal embryos that die before eclosion. We propose that Wolbachia affects the development of male embryos by specifically targeting male chromatin remodeling and thus disturbing mitotic spindle assembly and chromosome behavior. These are the first observations that demonstrate fundamental aspects of the cytological mechanism of male killing and represent a solid base for further molecular studies of this phenomenon. PMID:22291901

Riparbelli, Maria Giovanna; Giordano, Rosanna; Ueyama, Morio; Callaini, Giuliano

2012-01-01

214

Automated systems for identification of microorganisms.  

PubMed Central

Automated instruments for the identification of microorganisms were introduced into clinical microbiology laboratories in the 1970s. During the past two decades, the capabilities and performance characteristics of automated identification systems have steadily progressed and improved. This article explores the development of the various automated identification systems available in the United States and reviews their performance for identification of microorganisms. Observations regarding deficiencies and suggested improvements for these systems are provided. PMID:1498768

Stager, C E; Davis, J R

1992-01-01

215

Defensive properties of pyrrolizidine alkaloids against microorganisms  

Microsoft Academic Search

The understanding of the selection factors that drive chemical diversification of secondary metabolites of constitutive defence\\u000a systems in plants, such as pyrrolizidine alkaloids (PAs), is still incomplete. Historically, plants always have been confronted\\u000a with microorganisms. Long before herbivores existed on this planet, plants had to cope with microbial pathogens. Therefore,\\u000a plant pathogenic microorganisms may have played an important role in

Lotte JoostenJohannes; Johannes A. van Veen

2011-01-01

216

Mammal invaders on islands: impact, control and control impact.  

PubMed

The invasion of ecosystems by exotic species is currently viewed as one of the most important sources of biodiversity loss. The largest part of this loss occurs on islands, where indigenous species have often evolved in the absence of strong competition, herbivory, parasitism or predation. As a result, introduced species thrive in those optimal insular ecosystems affecting their plant food, competitors or animal prey. As islands are characterised by a high rate of endemism, the impacted populations often correspond to local subspecies or even unique species. One of the most important taxa concerning biological invasions on islands is mammals. A small number of mammal species is responsible for most of the damage to invaded insular ecosystems: rats, cats, goats, rabbits, pigs and a few others. The effect of alien invasive species may be simple or very complex, especially since a large array of invasive species, mammals and others, can be present simultaneously and interact among themselves as well as with the indigenous species. In most cases, introduced species generally have a strong impact and they often are responsible for the impoverishment of the local flora and fauna. The best response to these effects is almost always to control the alien population, either by regularly reducing their numbers, or better still, by eradicating the population as a whole from the island. Several types of methods are currently used: physical (trapping, shooting), chemical (poisoning) and biological (e.g. directed use of diseases). Each has its own set of advantages and disadvantages, depending on the mammal species targeted. The best strategy is almost always to combine several methods. Whatever the strategy used, its long-term success is critically dependent on solid support from several different areas, including financial support, staff commitment, and public support, to name only a few. In many cases, the elimination of the alien invasive species is followed by a rapid and often spectacular recovery of the impacted local populations. However, in other cases, the removal of the alien is not sufficient for the damaged ecosystem to revert to its former state, and complementary actions, such as species re-introduction, are required. A third situation may be widespread: the sudden removal of the alien species may generate a further disequilibrium, resulting in further or greater damage to the ecosystem. Given the numerous and complex population interactions among island species, it is difficult to predict the outcome of the removal of key species, such as a top predator. This justifies careful pre-control study and preparation prior to initiating the eradication of an alien species, in order to avoid an ecological catastrophe. In addition, long-term monitoring ofthe post-eradication ecosystem is crucial to assess success and prevent reinvasion. PMID:14558589

Courchamp, Franck; Chapuis, Jean-Louis; Pascal, Michel

2003-08-01

217

Anti-biofilm activity of silver nanoparticles against different microorganisms.  

PubMed

Biofilms confer protection from adverse environmental conditions and can be reservoirs for pathogenic organisms and sources of disease outbreaks, especially in medical devices. The goal of this research was to evaluate the anti-biofilm activities of silver nanoparticles (AgNPs) against several microorganisms of clinical interest. The antimicrobial activity of AgNPs was tested within biofilms generated under static conditions and also under high fluid shears conditions using a bioreactor. A 4-log reduction in the number of colony-forming units of Pseudomonas aeruginosa was recorded under turbulent fluid conditions in the CDC reactor on exposure to 100?mg?ml(-1) of AgNPs. The antibacterial activity of AgNPs on various microbial strains grown on polycarbonate membranes is reported. In conclusion, AgNPs effectively prevent the formation of biofilms and kill bacteria in established biofilms, which suggests that AgNPs could be used for prevention and treatment of biofilm-related infections. Further research and development are necessary to translate this technology into therapeutic and preventive strategies. PMID:23731460

Martinez-Gutierrez, Fidel; Boegli, Laura; Agostinho, Alessandra; Sánchez, Elpidio Morales; Bach, Horacio; Ruiz, Facundo; James, Garth

2013-01-01

218

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Code of Federal Regulations, 2014 CFR

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2014-01-01

219

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Code of Federal Regulations, 2013 CFR

...false Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113.205 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle...

2013-01-01

220

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

...false Mink Enteritis Vaccine, Killed Virus. 113.204 Section 113.204 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204 Mink...

2010-01-01

221

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Code of Federal Regulations, 2014 CFR

...false Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113.205 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle...

2014-01-01

222

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113.206 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart...

2012-01-01

223

9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

...Avian Encephalomyelitis Vaccine, Killed Virus. 113.208 Section 113.208 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian...

2010-01-01

224

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113.206 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart...

2011-01-01

225

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113.206 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart...

2013-01-01

226

9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2014 CFR

...Avian Encephalomyelitis Vaccine, Killed Virus. 113.208 Section 113.208 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian...

2014-01-01

227

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Code of Federal Regulations, 2012 CFR

...false Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113.205 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle...

2012-01-01

228

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

...false Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113.205 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle...

2010-01-01

229

9 CFR 113.205 - Newcastle Disease Vaccine, Killed Virus.  

Code of Federal Regulations, 2011 CFR

...false Newcastle Disease Vaccine, Killed Virus. 113.205 Section 113.205 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.205 Newcastle...

2011-01-01

230

9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2011 CFR

...Avian Encephalomyelitis Vaccine, Killed Virus. 113.208 Section 113.208 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian...

2011-01-01

231

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113.206 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart...

2010-01-01

232

9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2013 CFR

...Avian Encephalomyelitis Vaccine, Killed Virus. 113.208 Section 113.208 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian...

2013-01-01

233

9 CFR 113.208 - Avian Encephalomyelitis Vaccine, Killed Virus.  

Code of Federal Regulations, 2012 CFR

...Avian Encephalomyelitis Vaccine, Killed Virus. 113.208 Section 113.208 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.208 Avian...

2012-01-01

234

9 CFR 113.206 - Wart Vaccine, Killed Virus.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 false Wart Vaccine, Killed Virus. 113.206 Section 113.206 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.206 Wart...

2014-01-01

235

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Code of Federal Regulations, 2012 CFR

...false Mink Enteritis Vaccine, Killed Virus. 113.204 Section 113.204 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204 Mink...

2012-01-01

236

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Code of Federal Regulations, 2011 CFR

...false Mink Enteritis Vaccine, Killed Virus. 113.204 Section 113.204 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204 Mink...

2011-01-01

237

9 CFR 113.204 - Mink Enteritis Vaccine, Killed Virus.  

Code of Federal Regulations, 2013 CFR

...false Mink Enteritis Vaccine, Killed Virus. 113.204 Section 113.204 Animals...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.204 Mink...

2013-01-01

238

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

239

Conformal Killing Tensors and covariant Hamiltonian Dynamics  

E-print Network

A covariant algorithm for deriving the conserved quantities for natural Hamiltonian systems is combined with the non-relativistic framework of Eisenhart, and of Duval, in which the classical trajectories arise as geodesics in a higher dimensional space-time, realized by Brinkmann manifolds. Conserved quantities which are polynomial in the momenta can be built using time-dependent conformal Killing tensors with flux. The latter are associated with terms proportional to the Hamiltonian in the lower dimensional theory and with spectrum generating algebras for higher dimensional quantities of order $1$ and $2$ in the momenta. Illustrations of the general theory include the Runge-Lenz vector for planetary motion with a time-dependent gravitational constant $G(t)$, motion in a time-dependent electromagnetic field of a certain form, quantum dots, the H\\'enon-Heiles and Holt systems, respectively, providing us with Killing tensors of rank that ranges from one to six.

M. Cariglia; G. W. Gibbons; J. -W. van Holten; P. A. Horvathy; P. -M. Zhang

2014-10-31

240

Underground blowout killed with quick snubbing operation  

SciTech Connect

A shallow underground blowout off the island of Trinidad required quick action and the importing of snubbing equipment to kill the well and avert cratering the sea floor beneath the platform. The blowout was controlled in 16 days. The blowout at Trintomar's Pelican platform on the east coast of Trinidad posed a most challenging well control problem. Most of the service companies with equipment to control the well were not available in this relatively remote area. Because of the high gas and condensate flow rates and high pressure, the blowout at the Pelican platform had the potential to destroy the entire platform, endanger the lives of many crew members, result in the loss of natural resources, and interrupt the supply of natural gas to the island of Trinidad. The paper discusses the Pelican platform, the underground blowout, temperature survey, the kill plan, and snubbing operations.

Grace, R. (Grace, Shursen, Moore and Associates Inc., Amarillo, TX (United States)); Stanislaus, G. (Trinmar Ltd., Point Fortin (Trinidad and Tobago)); Cudd, B. (Cudd Pressure Control, Woodward, OK (United States))

1993-10-18

241

Conformal killing tensors and covariant Hamiltonian dynamics  

NASA Astrophysics Data System (ADS)

A covariant algorithm for deriving the conserved quantities for natural Hamiltonian systems is combined with the non-relativistic framework of Eisenhart, and of Duval, in which the classical trajectories arise as geodesics in a higher dimensional space-time, realized by Brinkmann manifolds. Conserved quantities which are polynomial in the momenta can be built using time-dependent conformal Killing tensors with flux. The latter are associated with terms proportional to the Hamiltonian in the lower dimensional theory and with spectrum generating algebras for higher dimensional quantities of order 1 and 2 in the momenta. Illustrations of the general theory include the Runge-Lenz vector for planetary motion with a time-dependent gravitational constant G(t), motion in a time-dependent electromagnetic field of a certain form, quantum dots, the Hénon-Heiles and Holt systems, respectively, providing us with Killing tensors of rank that ranges from one to six.

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

2014-12-01

242

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

Code of Federal Regulations, 2011 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2011-07-01

243

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

Code of Federal Regulations, 2012 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2012-07-01

244

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

Code of Federal Regulations, 2010 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2010-07-01

245

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

Code of Federal Regulations, 2014 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2014-07-01

246

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

Code of Federal Regulations, 2013 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2013-07-01

247

killed-virus influenza vaccine Polio vaccine  

E-print Network

killed-virus influenza vaccine Polio vaccine FluMist Thomas Francis, Jr. National Institutes of Health live-virus influenza vaccine Hunein Maassab Jonas Salk Type-A virus trivalent cold-adapted retrofitting virus 18 19Findings L A B O R A T O R Y D R E A M S U N I V E R S I T Y O F M I C H I G A N S C H

Shyy, Wei

248

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.

249

Killed Vaccines: Cholera, Typhoid, and Plague  

Microsoft Academic Search

\\u000a As reviewed in previous chapters of this work, the earliest vaccines were of the live variety, either based on a naturally\\u000a occurring weaker version of pathogen, as with Jenner’s use of cowpox, or the laboratory-manipulated, attenuated forms of anthrax\\u000a and rabies employed by his vaccine heir, Pasteur. The next important concept in vaccine science, killed vaccines, was introduced\\u000a in animals

Charles C. J. Carpenter; Richard B. Hornick

250

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. PMID:21097600

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

2011-01-01

251

Inhomogeneous problems Q. How do you kill a blue elephant?  

E-print Network

Inhomogeneous problems Q. How do you kill a blue elephant? A. With a blue elephant gun Q. How do you kill a pink elephant? A. Squeeze its trunk until it turns blue, and then shoot it with a blue elephant gun. Q. How do you kill a white elephant? A. Tickle it pink, then squeeze its trunk until it turns

DeTurck, Dennis

252

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

253

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

254

Detection of genomic polymorphisms associated with venous thrombosis using the invader biplex assay.  

PubMed

A multi-site study to assess the accuracy and performance of the biplex Invader assay for genotyping five polymorphisms implicated in venous thrombosis was carried out in seven laboratories. Genotyping results obtained using the Invader biplex assay were compared to those obtained from a reference method, either allele-specific polymerase chain reaction (AS-PCR), restriction fragment length polymorphism (PCR-RFLP) or PCR-mass spectrometry. Results were compared for five loci associated with venous thrombosis: Factor V Leiden, Factor II (prothrombin) G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, and plasminogen activator inhibitor (PAI-1) 4G/5G. Of a total of 1448 genotypes tested in this study, there were 22 samples that gave different results between the Invader biplex assay and the PCR-based methods. On further testing, 21 were determined to be correctly genotyped by the Invader Assay and only a single discrepancy was resolved in favor of the PCR-based assays. The compiled results demonstrate that the Invader biplex assay provides results more than 99.9% concordant with standard PCR-based techniques and is a rapid and highly accurate alternative to target amplification-based methods. PMID:15096570

Patnaik, Madhumita; Dlott, Jeffrey S; Fontaine, Robert N; Subbiah, M T; Hessner, Martin J; Joyner, Kelly A; Ledford, Marlies R; Lau, Eduardo C; Moehlenkamp, Cynthia; Amos, Jean; Zhang, Bailing; Williams, Thomas M

2004-05-01

255

Detection of Genomic Polymorphisms Associated with Venous Thrombosis Using the Invader Biplex Assay  

PubMed Central

A multi-site study to assess the accuracy and performance of the biplex Invader assay for genotyping five polymorphisms implicated in venous thrombosis was carried out in seven laboratories. Genotyping results obtained using the Invader biplex assay were compared to those obtained from a reference method, either allele-specific polymerase chain reaction (AS-PCR), restriction fragment length polymorphism (PCR-RFLP) or PCR-mass spectrometry. Results were compared for five loci associated with venous thrombosis: Factor V Leiden, Factor II (prothrombin) G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, and plasminogen activator inhibitor (PAI-1) 4G/5G. Of a total of 1448 genotypes tested in this study, there were 22 samples that gave different results between the Invader biplex assay and the PCR-based methods. On further testing, 21 were determined to be correctly genotyped by the Invader Assay and only a single discrepancy was resolved in favor of the PCR-based assays. The compiled results demonstrate that the Invader biplex assay provides results more than 99.9% concordant with standard PCR-based techniques and is a rapid and highly accurate alternative to target amplification-based methods. PMID:15096570

Patnaik, Madhumita; Dlott, Jeffrey S.; Fontaine, Robert N.; Subbiah, M.T.; Hessner, Martin J.; Joyner, Kelly A.; Ledford, Marlies R.; Lau, Eduardo C.; Moehlenkamp, Cynthia; Amos, Jean; Zhang, Bailing; Williams, Thomas M.

2004-01-01

256

Native Birds and Alien Insects: Spatial Density Dependence in Songbird Predation of Invading Oak Gallwasps  

PubMed Central

Revealing the interactions between alien species and native communities is central to understanding the ecological consequences of range expansion. Much has been learned through study of the communities developing around invading herbivorous insects. Much less, however, is known about the significance of such aliens for native vertebrate predators for which invaders may represent a novel food source. We quantified spatial patterns in native bird predation of invading gall-inducing Andricus wasps associated with introduced Turkey oak (Quercus cerris) at eight sites across the UK. These gallwasps are available at high density before the emergence of caterpillars that are the principle spring food of native insectivorous birds. Native birds showed positive spatial density dependence in gall attack rates at two sites in southern England, foraging most extensively on trees with highest gall densities. In a subsequent study at one of these sites, positive spatial density dependence persisted through four of five sequential week-long periods of data collection. Both patterns imply that invading galls are a significant resource for at least some native bird populations. Density dependence was strongest in southern UK bird populations that have had longest exposure to the invading gallwasps. We hypothesise that this pattern results from the time taken for native bird populations to learn how to exploit this novel resource. PMID:23342048

Schönrogge, Karsten; Begg, Tracey; Stone, Graham N.

2013-01-01

257

Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria  

PubMed Central

Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID:23550545

Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

2013-01-01

258

Antifungal and antibacterial activity of marine microorganisms.  

PubMed

In order to explore marine microorganisms with pharmaceutical potential, marine bacteria, collected from different coastal areas of the Moroccan Atlantic Ocean, were previously isolated from seawater, sediment, marine invertebrates and seaweeds. The antimicrobial activities of these microorganisms were investigated against the pathogens involved in human pathologies. Whole cultures of 34 marine microorganisms were screened for antimicrobial activities using the method of agar diffusion against three Gram-positive bacteria, two Gram-negative bacteria, and against yeast. The results showed that among the 34 isolates studied, 28 (82%) strains have antimicrobial activity against at least one pathogen studied, 11 (32%) strains have antifungal activity and 24 (76%) strains are active against Gram-positive bacteria, while 21 (62%) strains are active against Gram-negative bacteria. Among isolates having antimicrobial activity, 14 were identified and were assigned to the genera Acinetobacter, Aeromonas, Alcaligenes, Bacillus, Chromobacterium, Enterococcus, Pantoea and Pseudomonas. Due to a competitive role for space and nutrient, the marine microorganisms can produce antibiotic substance; therefore, these marine microorganisms were expected to be potential resources of natural antibiotic products. PMID:24630312

El Amraoui, B; El Amraoui, M; Cohen, N; Fassouane, A

2014-03-01

259

Effect of lemon extract on foodborne microorganisms.  

PubMed

A quantitative investigation was conducted on the antimicrobial effect of lemon extract against some food spoilage microorganisms: yeasts, Bacillus species, and lactic acid bacteria. Growth kinetics and dose-response profiles were determined from experimental data obtained with a suitable macrodilution methodology based on a turbidimetric technique. Growth and no-growth status of microbial suspensions were expressed in terms of noninhibitory concentration (NIC) and MIC. Lemon extract was effective in inhibiting the growth of the investigated vegetative cells and spores of microorganisms; effects were similar for bacteria and yeasts. The NICs for all microorganisms were very small, at around 10 ppm. Based on MICs, among the Bacillus species, the more resistant was Bacillus licheniformis. For yeasts, Saccharomyces cerevisiae was the least resistant, and similar results were obtained for Pichia subpelliculosa. Candida lusitaniae had an MIC of more than 100 ppm. Both Lactobacillus species were more resistant to lemon extract; concentrations necessary to provoke complete inhibition were approximately 150 ppm. PMID:17803147

Conte, A; Speranza, B; Sinigaglia, M; Del Nobile, M A

2007-08-01

260

Microorganism Utilization for Synthetic Milk Production  

NASA Technical Reports Server (NTRS)

A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms.

Birmele, Michele; Morford, Megan; Khodadad, Christina; Spencer, Lashelle; Richards, Jeffrey; Strayer, Richard; Caro, Janicce; Hummerick, Mary; Wheeler, Ray

2014-01-01

261

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

262

Life history variation in a temperate plant invader, Verbascum thapsus along a tropical elevational gradient in Hawaii  

Microsoft Academic Search

Few studies have examined the life history of temperate plant invaders in the tropics. Temperate invaders that utilize seasonal\\u000a cues to influence their life histories may be expected to behave differently in the tropics. This study examined variation\\u000a in life history in an invading temperate weed, Verbascum thapsus, across an elevation gradient (1,690–2,720 m) along the montane and subalpine slopes of

Shahin AnsariCurtis; Curtis C. Daehler

2010-01-01

263

An invader differentially affects leaf physiology of two natives across a gradient in diversity.  

PubMed

Little is known about how exotics influence the ecophysiology of co-occurring native plants or how invader impact on plant physiology may be mediated by community diversity or resource levels. We measured the effect of the widespread invasive forb spotted knapweed (Centaurea maculosa) on leaf traits (leaf dry matter content, specific leaf area, leaf nitrogen percentage, leaf C:N ratios, and delta13C as a proxy for water use efficiency) of two co-occurring native perennial grassland species, Monarda fistulosa (bee balm) and Koeleria macrantha (Junegrass). The impact of spotted knapweed was assessed across plots that varied in functional diversity and that either experienced ambient rainfall or received supplemental water. Impact was determined by comparing leaf traits between identical knapweed-invaded and noninvaded assemblages. Virtually all M. fistulosa leaf traits were affected by spotted knapweed. Knapweed impact, however, did not scale with its abundance; the impact of knapweed on M. fistulosa was similar across heavily invaded low-diversity assemblages and lightly invaded high-diversity assemblages. In uninvaded assemblages, M. fistulosa delta13C, leaf nitrogen, and C:N ratios were unaffected by native functional group richness, whereas leaf dry matter content significantly increased and specific leaf area significantly decreased across the diversity gradient. The effects of spotted knapweed on K. macrantha were weak; instead native functional group richness strongly affected K. macrantha leaf C:N ratio, delta13C, and specific leaf area, but not leaf dry matter content. Leaf traits for both species changed in response to spotted knapweed or functional richness, and in a manner that may promote slower biomass accumulation and efficient conservation of resources. Taken together, our results show that an invader can alter native plant physiology, but that these effects are not a simple function of how many invaders exist in the community. PMID:18543627

Kittelson, Pamela; Maron, John; Marler, Marilyn

2008-05-01

264

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 PMID:11041053

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

2000-01-01

265

Diversity of phosphorus reserves in microorganisms.  

PubMed

Phosphorus compounds are indispensable components of the Earth's biomass metabolized by all living organisms. Under excess of phosphorus compounds in the environment, microorganisms accumulate reserve phosphorus compounds that are used under phosphorus limitation. These compounds vary in their structure and also perform structural and regulatory functions in microbial cells. The most common phosphorus reserve in microorganism is inorganic polyphosphates, but in some archae and bacteria insoluble magnesium phosphate plays this role. Some yeasts produce phosphomannan as a phosphorus reserve. This review covers also other topics, i.e. accumulation of phosphorus reserves under nutrient limitation, phosphorus reserves in activated sludge, mycorrhiza, and the role of mineral phosphorus compounds in mammals. PMID:25749167

Kulakovskaya, T V; Lichko, L P; Ryazanova, L P

2014-12-01

266

Metabolic activity of microorganisms in evaporites  

NASA Technical Reports Server (NTRS)

Crystalline salt is generally considered so hostile to most forms of life that it has been used for centuries as a preservative. Here, we present evidence that prokaryotes inhabiting a natural evaporite crust of halite and gypsum are metabolically active while inside the evaporite for at least 10 months. In situ measurements demonstrated that some of these "endoevaporitic" microorganisms (probably the cyanobacterium Synechococcus Nageli) fixed carbon and nitrogen. Denitrification was not observed. Our results quantified the slow microbial activity that can occur in salt crystals. Implications of this study include the possibility that microorganisms found in ancient evaporite deposits may have been part of an evaporite community.

Rothschild, L. J.; Giver, L. J.; White, M. R.; Mancinelli, R. L.

1994-01-01

267

Cell death in planktonic, photosynthetic microorganisms  

Microsoft Academic Search

Phytoplankton evolved in the Archaean oceans more than 2.8 billion years ago and are of crucial importance in regulating aquatic food webs, biogeochemical cycles and the Earth's climate. Until recently, phytoplankton were considered immortal unless killed or eaten by predators. However, over the past decade, it has become clear that these organisms can either be infected by viruses or undergo

Kay D. Bidle; Paul G. Falkowski

2004-01-01

268

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. PMID:21148701

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

2011-01-01

269

Distinctive Activity of a Nonthermal Atmospheric-Pressure Plasma Jet on Eukaryotic and Prokaryotic Cells in a Cocultivation Approach of Keratinocytes and Microorganisms  

Microsoft Academic Search

Nonthermal atmospheric-pressure plasmas provide new hope for medical application due to their potency in killing microorganisms. However, effectiveness and safety need evaluation. Here, the interaction of a nonthermal atmospheric-pressure plasma jet (APPJ) with human keratinocytes and cocultivated bacteria in an in vitro wound model is described. To evaluate the effects of the APPJ to 2-D cell cultures of human keratinocytes

Kristian Wende; Kati Landsberg; Ulrike Lindequist; Klaus-Dieter Weltmann; Thomas von Woedtke

2010-01-01

270

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. PMID:22980327

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

2013-01-01

271

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...

272

Biodiversity and ecology of acidophilic microorganisms  

Microsoft Academic Search

Microbial life in extremely low pH (<3) natural and man-made environments may be considerably diverse. Prokaryotic acidophiles (eubacteria and archaea) have been the focus of much of the research activity in this area, primarily because of the importance of these microorganisms in biotechnology (predominantly the commercial biological processing of metal ores) and in environmental pollution (genesis of `acid mine drainage');

D. Barrie Johnson

1998-01-01

273

Metagenomics: Application of Genomics to Uncultured Microorganisms  

PubMed Central

Metagenomics (also referred to as environmental and community genomics) is the genomic analysis of microorganisms by direct extraction and cloning of DNA from an assemblage of microorganisms. The development of metagenomics stemmed from the ineluctable evidence that as-yet-uncultured microorganisms represent the vast majority of organisms in most environments on earth. This evidence was derived from analyses of 16S rRNA gene sequences amplified directly from the environment, an approach that avoided the bias imposed by culturing and led to the discovery of vast new lineages of microbial life. Although the portrait of the microbial world was revolutionized by analysis of 16S rRNA genes, such studies yielded only a phylogenetic description of community membership, providing little insight into the genetics, physiology, and biochemistry of the members. Metagenomics provides a second tier of technical innovation that facilitates study of the physiology and ecology of environmental microorganisms. Novel genes and gene products discovered through metagenomics include the first bacteriorhodopsin of bacterial origin; novel small molecules with antimicrobial activity; and new members of families of known proteins, such as an Na+(Li+)/H+ antiporter, RecA, DNA polymerase, and antibiotic resistance determinants. Reassembly of multiple genomes has provided insight into energy and nutrient cycling within the community, genome structure, gene function, population genetics and microheterogeneity, and lateral gene transfer among members of an uncultured community. The application of metagenomic sequence information will facilitate the design of better culturing strategies to link genomic analysis with pure culture studies. PMID:15590779

Handelsman, Jo

2004-01-01

274

Guide to Identification of Fresh Water Microorganisms  

NSDL National Science Digital Library

This seven-page guide can be used to identify freshwater microorganisms. Categories include microscopic autotrophic organisms (i.e. algae), heterotrophic protozoa, other freshwater plankton (Animalia, Monera, etc), and arthropods. The guide is in the form of a table, with columns for name, picture, characteristic, and taxonomy.

Math/Science Nucleus

275

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2011 CFR

...submitter either that one of the proposed generic names...necessary. (5) Use of generic name. If a submitter claims microorganism identity as confidential under paragraph (a) of this section, and if...this section, EPA will issue for publication in...

2011-07-01

276

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2010 CFR

...submitter either that one of the proposed generic names...necessary. (5) Use of generic name. If a submitter claims microorganism identity as confidential under paragraph (a) of this section, and if...this section, EPA will issue for publication in...

2010-07-01

277

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2013 CFR

...submitter either that one of the proposed generic names...necessary. (5) Use of generic name. If a submitter claims microorganism identity as confidential under paragraph (a) of this section, and if...this section, EPA will issue for publication in...

2013-07-01

278

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2012 CFR

...submitter either that one of the proposed generic names...necessary. (5) Use of generic name. If a submitter claims microorganism identity as confidential under paragraph (a) of this section, and if...this section, EPA will issue for publication in...

2012-07-01

279

40 CFR 725.85 - Microorganism identity.  

Code of Federal Regulations, 2014 CFR

...submitter either that one of the proposed generic names...necessary. (5) Use of generic name. If a submitter claims microorganism identity as confidential under paragraph (a) of this section, and if...this section, EPA will issue for publication in...

2014-07-01

280

Removal of microorganisms by deep well injection  

Microsoft Academic Search

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

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

2000-01-01

281

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

282

Microorganism lipid droplets and biofuel development  

PubMed Central

Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from CO2 via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech ‘factories’ to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development. [BMB Reports 2013; 46(12): 575-581] PMID:24355300

Liu, Yingmei; Zhang, Congyan; Shen, Xipeng; Zhang, Xuelin; Cichello, Simon; Guan, Hongbin; Liu, Pingsheng

2013-01-01

283

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

284

Biomechanics of Aquatic Micro-Organisms  

NASA Astrophysics Data System (ADS)

Aquatic micro-organisms play a major role in ocean ecology, the global carbon cycle and bioreactor engineering. The complex foodweb of an oceanic ecosystem may be modelled in terms of a few species of different types whose population densities obey coupled differential equations. However the functions and constants that appear in those equations depend in a complex way on the details of the dynamics of individual organisms and how they interact in larger scale phenomena. This talk will survey some of the following topics: (1) the fluid dynamics of micro-organism swimming, (2) the effect on nutrient uptake of an organism’s swimming motions, (3) chemotaxis in bacteria, (4) capture rate of phytoplankton by zooplankton when they all swim in a turbulent environment, (5) pattern-formation (e.g. bioconvection) in suspensions of upswimming micro-organisms (algae and bacteria), (6) the hydrodynamic interactions between swimming model micro-organisms and (7) their effect on the rheology and transport properties of the suspension as a whole. The long-term goal is to formulate a continuum model for concentrated suspensions of swimmers; this is not yet realised and may be impossible!

Pedley, T. J.

285

PESTICIDE METABOLISM IN PLANTS AND MICROORGANISMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Understanding pesticide metabolism in plants and microorganisms is necessary for pesticide development, safe and efficient use, as well as for developing pesticide bioremediation strategies for contaminated soil and water. Pesticide biotransformation may occur via multi-step processes known as meta...

286

The Proteasome-Ubiquitin System Is Required for Efficient Killing of Intracellular Streptococcus pneumoniae by Brain Endothelial Cells  

PubMed Central

ABSTRACT Streptococcus pneumoniae (pneumococcus) is a Gram-positive bacterium that causes serious invasive diseases, such as pneumonia, bacteremia, and meningitis, with high morbidity and mortality throughout the world. Before causing invasive disease, S. pneumoniae encounters cellular barriers, which are often composed of endothelial cells, like the alveolar-capillary barrier and the blood-brain barrier. S. pneumoniae adheres to endothelial cells and may invade them, which requires an efficient host response to the intracellular bacteria. The precise intracellular fate of S. pneumoniae during infection still remains a subject of debate. The proteasome-ubiquitin system is largely responsible for the degradation of misfolded, damaged, or no-longer-useful proteins. Recently, the role of the proteasome-ubiquitin system in the clearing of invading bacteria and viruses has been more closely studied. In this study, we show that inhibition of the proteasome-ubiquitin system leads to a marked increase in S. pneumoniae survival inside host cells. Immunofluorescence analysis showed that intracellular pneumococci colocalized with proteasome and ubiquitin in human endothelial cells in vitro. Confocal imaging analysis demonstrated that in the brains of mice intravenously infected with S. pneumoniae, the bacteria were inside endothelial cells, where they colocalized with proteasome and ubiquitin signals. In conclusion, our data indicate that a fully functional proteasome-ubiquitin system in endothelial cells is crucial for efficient killing of intracellular S. pneumoniae. PMID:24987087

Iovino, Federico; Gradstedt, Henrik

2014-01-01

287

A generic risk-based surveying method for invading plant pathogens  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive plant pathogens are increasing with international trade and travel with damaging environmental and economic consequences. Recent examples include tree diseases such as Sudden Oak Death in the Western US and Ash Dieback in Europe. To control an invading pathogen it is crucial that newly in...

288

Behavioral correlations provide a mechanism for explaining high invader densities and increased impacts on native prey.  

PubMed

The fact that superabundant invasive pests are also sometimes highly aggressive represents an interesting paradox. Strong intraspecific aggression should result in high intraspecific competition and limit the densities reached by exotic species. One mechanism that can allow invaders to attain high densities despite high intraspecific aggression, involves positive correlations between aggression and other behaviors such as foraging activity. We conducted a mesocosm experiment to quantify the ecological implications of correlations between aggressiveness and foraging activity among groups of exotic signal crayfish (Pacifastacus leniusculus) at low and high densities. Our results showed that high invader densities increased intraspecific aggression and per capita interactions between crayfish, but also increased foraging activity and impacts on preferred prey. As a result, exotic crayfish did not show density-dependent reductions in per capita feeding or growth rates. We suggest that the positive correlation between aggression and activity is part of an aggression syndrome whereby some individuals are generally more aggressive/active than others across situations. An aggression syndrome can couple aggressive behaviors important to population establishment of invasive species with foraging activity that enhances the ability of invaders to attain high densities and have large impacts on invaded communities. PMID:19341130

Pintor, Lauren M; Sih, Andrew; Kerby, Jacob L

2009-03-01

289

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

290

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

291

"Invented Invaders": An Engaging Activity to Teach Characteristics Control of Invasive Species  

ERIC Educational Resources Information Center

Invasive species, defined as exotic species that reach pest status, are major threats to global biodiversity. Although invasive species can belong to any taxonomic group, general characteristics such as rapid growth and reproduction are shared by many invasive species. "Invented Invaders" is a collaborative activity in which students…

Lampert, Evan

2015-01-01

292

Root-invading fungi of milk vetch on the Loess Plateau, China  

Microsoft Academic Search

Root-invading fungi of milk vetch (Astragalus adsurgens) at different growth stages grown in three ages of sown pasture soil were studied in Huanxian county, Gansu province, China. Pathogenicity was tested by seed and soil inoculation. A total of 44 fungi were isolated from milk vetch roots, 32 from the roots of field plants and 37 from the roots of potted

Yali Yin; Z. B. Nan; Chunjie Li; Fujiang Hou

2008-01-01

293

The impact of invading alien plants on surface water resources in South Africa: A preliminary assessment  

Microsoft Academic Search

The impacts of the widespread invasions by alien plants in South Africa are increasingly recognised. Most of the past concern has been about the impacts on conservation areas, other areas of natural vegetation, and on agricultural productivity. The potenti al impact of invading alien woody plants on water resources was known to be serious but there has been no information

DC Le Maitre; DB Versfeld; RA Chapman

2000-01-01

294

Invading populations of an ornamental shrub show rapid life history evolution despite genetic  

E-print Network

highlight the potential for even genetically depauperate founding populations to adapt and evolve invasiveLETTER Invading populations of an ornamental shrub show rapid life history evolution despite genetic bottlenecks Katrina M. Dlugosch* and Ingrid M. Parker Ecology and Evolutionary Biology, University

Linder, Tamás

295

Effects of nest invaders on honey bee ( Apis mellifera) pollination efficacy  

Microsoft Academic Search

The work of pollinators is crucial to the sustainability of plant communities in natural and agricultural ecosystems; however, pollinators are declining in much of the developed world due to a variety of parasites, diseases, and environmental stresses. These experiments are the first to examine directly the impact of honey bee, Apis mellifera, nest invaders on plant pollination and fitness. A

Amanda Ellis; Keith S. Delaplane

2008-01-01

296

Clinal patterns of desiccation and starvation resistance in ancestral and invading populations of Drosophila subobscura  

PubMed Central

As invading species expand, they eventually encounter physical and biotic stressors that limit their spread. We examine latitudinal and climatic variation in physiological tolerance in one native and two invading populations of Drosophila subobscura. These flies are native to the Palearctic region, but invaded both South and North America around 1980 and spread rapidly across 15° of latitude on each continent. Invading flies rapidly evolved latitudinal clines in chromosome inversion frequencies and in wing size that parallel those of native populations in the Old World. Here we investigate whether flies on all three continents have evolved parallel clines in desiccation and starvation tolerance, such that flies in low-latitude regions (hot, dry) might have increased stress resistance. Starvation tolerance does not vary with latitude or climate on any continent. In contrast, desiccation tolerance varies clinally with latitude on all three continents, although not in parallel. In North American and Europe, desiccation tolerance is inversely related to latitude, as expected. But in South America, desiccation tolerance increases with latitude and is greatest in relatively cool and wet areas. Differences among continents in latitudinal patterns of interspecific-competition potentially influence clinal selection for physiological resistance, but no simple pattern is evident on these continents. PMID:25567732

Gilchrist, George W; Jeffers, Lisa M; West, Brianna; Folk, Donna G; Suess, Jeremy; Huey, Raymond B

2008-01-01

297

Ecology and management of Sheoak (Casuarina spp.), an invader of coastal Florida, U.S.A.  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Casuarina spp. are invasive weeds in Florida that threaten biological diversity and beach integrity of coastal habitats. The trees include three species and their hybrids that aggressively invade riverine and coastal areas. Of the three species, C. equisetifolia and C. glauca are highly salt tol...

298

I smell an invasive invader: Using portable gas spectrometry at ports of entry  

Technology Transfer Automated Retrieval System (TEKTRAN)

Inspectors at ports of entry are faced with the daunting task of finding a visual sign of a pest or disease. Small insects, pests concealed inside plant material and plant diseases could escape detection and invade the country. In a collaborative effort, portable gas chromatography technology was te...

299

Growth and persistence of a recent invader Carcinus maenas in estuaries of the northeastern Pacific  

Microsoft Academic Search

During the summer of 1998 a new year class of the invasive European green crab, Carcinus maenas, appeared in Oregon and Washington estuaries as well as in northern California, USA, and on Vancouver Island, Canada. This invader was first discovered in San Francisco Bay almost a decade earlier and by 1995 it had spread to northern California. The coast-wide colonization

Sylvia Behrens Yamada; Brett R. Dumbauld; Alex Kalin; Christopher E. Hunt; Ron Figlar-Barnes; Andrea Randall

2005-01-01

300

Habitat shift in invading species: Zebra and quagga mussel population characteristics on shallow soft substrates  

USGS Publications Warehouse

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 western Lake Erie. Haphazard SCUBA collections of these invading species indicated that combined densities of zebra and quagga mussels ranged from 0 to 32,500 individuals per square meter between 1994 and 1998, with D. polymorpha comprising 75-100% of the assemblages. These mixed mussel populations, which were attached by byssal threads to each other and underlying sand-grain sediments, had size-frequency distributions that were typical of colonizing populations on hard substrates. Moreover, the presence of two mussel cohorts within the 1994 samples indicated that these species began expanding onto soft substrates not later than 1992, within 4 years of their initial invasion in western Lake Erie. Such historical data provide baselines for interpreting adaptive innovations, ecological interactions and habitat shifts among the two invading dreissenid mussel species in North America.

Berkman, P.A.; Garton, D.W.; Haltuch, M.A.; Kennedy, G.W.; Febo, L.R.

2000-01-01

301

ORIGINAL PAPER Invading with biological weapons: the role of shared disease  

E-print Network

ORIGINAL PAPER Invading with biological weapons: the role of shared disease in ecological invasion Theory has been developed that examines the role of infectious disease in ecological invasions in invasions is lacking. Here, we develop a strategic theoretical framework to determine the role of disease

Sherratt, Jonathan A.

302

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

303

Passive restoration potential of riparian areas invaded by giant reed (Arundo donax) in Texas  

Technology Transfer Automated Retrieval System (TEKTRAN)

Giant reed (Arundo donax L.) is a rhizomatous woody non-native grass that has invaded much of the riparian areas of the southwest. By forming thick impenetrable swaths along riverbanks and waterways, giant reed has driven riparian ecosystem decline and displaced native biodiversity. It’s document...

304

The genus Acacia as invader: the characteristic case of Acacia dealbata Link in Europe  

Microsoft Academic Search

– \\u000a \\u000a • We review current knowledge about the biology of the genus Acacia, and Acacia dealbata Link (silver wattle) in particular, as an invader in Europe, focusing on (i) the biology of the genus Acacia; (ii) biological attributes that are important for the invasiveness of the genus and A. dealbata; (iii) possible hypotheses for the invasion success; and (iv) control

Paula Lorenzo; Luís González; Manuel J. Reigosa

2010-01-01

305

Impact of invasive plants on the species richness, diversity and composition of invaded communities  

Microsoft Academic Search

Summary 1. Much attention has been paid to negative effects of alien species on resident communities but studies that quantify community-level effects of a number of invasive plants are scarce. We address this issue by assessing the impact of 13 species invasive in the Czech Republic on a wide range of plant communities. 2. Vegetation in invaded and uninvaded plots

Martin Hejda; Petr Pyšek; Vojt?ch Jarošík

2009-01-01

306

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

307

Genetic cryptic species as biological invaders: the case of a Lessepsian fish migrant,  

E-print Network

that are invading the Mediterranean from the Red Sea via the Suez Canal. We PCR amplified and sequenced. The opening of the Suez Canal in 1869, connecting the tropical Red Sea to the subtropical waters the opening of the Suez Canal (Tillier, 1902). It is a small inshore pelagic species, with a very wide

Bernardi, Giacomo

308

Biotic resistance to invader establishment of a southern Appalachian plant community is determined by environmental conditions  

Microsoft Academic Search

Summary 1 Tests of the relationship between resident plant species richness and habitat invasib- ility have yielded variable results. I investigated the roles of experimental manipulation of understorey species richness and overstorey characteristics in resistance to invader establishment in a floodplain forest in south-western Virginia, USA. 2 I manipulated resident species richness in experimental plots along a flooding gradient, keeping

BETSY VON HOLLE

2005-01-01

309

COMMUNITY ECOLOGY -ORIGINAL PAPER Interactions among invaders: community and ecosystem effects  

E-print Network

of multiple invasive species in an experimental aquatic system Pieter T. J. Johnson Ã? Julian D. Olden Ã? mul- tiple invasive species, interactions among invaders could magnify or ameliorate the undesired species. Together, these findings highlight the importance of understanding interactions among invasive

Olden, Julian D.

310

Differential influence of Pomphorhynchus laevis (Acanthocephala) on the behaviour of native and invader gammarid species  

Microsoft Academic Search

Although various species of acanthocephalan parasites can increase the vulnerability of their amphipod intermediate hosts to predation, particularly by altering their photophobic behaviour, their influence on the structure of amphipod communities and the success of invader species has so far received little attention. We compared the prevalence and behavioural influence of a fish acanthocephalan parasite, Pomphorhynchus laevis, in two species

Alexandre Bauer; Sandrine Trouvé; Arnaud Grégoire; Frank Cézilly

2000-01-01

311

Impact of alien plant invaders on pollination networks in two archipelagos.  

PubMed

Mutualistic interactions between plants and animals promote integration of invasive species into native communities. In turn, the integrated invaders may alter existing patterns of mutualistic interactions. Here we simultaneously map in detail effects of invaders on parameters describing the topology of both plant-pollinator (bi-modal) and plant-plant (uni-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems: Tenerife (Canary Islands) and Menorca (Balearic Islands). Opuntia was found to modify the number of links between plants and pollinators, and was integrated into the new communities via the most generalist pollinators, but did not affect the general network pattern. The plant uni-modal networks showed disassortative linkage, i.e. species with many links tended to connect to species with few links. Thus, by linking to generalist natives, Opuntia remained peripheral to network topology, and this is probably why native network properties were not affected at least in one of the islands. We conclude that the network analytical approach is indeed a valuable tool to evaluate the effect of invaders on native communities. PMID:19609437

Padrón, Benigno; Traveset, Anna; Biedenweg, Tine; Díaz, Diana; Nogales, Manuel; Olesen, Jens M

2009-01-01

312

Estimating the Probability of Long-Distance Overland Dispersal of Invading Aquatic Species  

Microsoft Academic Search

Accurately predicting the pattern and rate of spread of invading species is difficult, particularly for species that disperse long distances. Though relatively rare, and often stochastic, long-distance dispersal events increase the maximum rate and geographic extent of invasion. Human activities are responsible for the spread of many exotic species, particularly aquatic species such as the zebra mussel, which are primarily

Lucy A. J. Buchan; Dianna K. Padilla

1999-01-01

313

Ecosystem effects of Diorhabda elongata (leaf beetle) on Tamarix invaded riparian systems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Saltcedar (Tamarix ramosissima) is a pernicious invader of riparian areas in western rangelands. The release of a biocontrol agent, Diorhabda elongata (leaf beetle), was done across several western states in an effort to control saltcedar by defoliating Tamarix with a predator from its native range....

314

Neurohypophyseal Granulomatous Germinoma Invading the Right Cavernous Sinus: Case Report and Review of the Literature  

Microsoft Academic Search

We encountered a rare case of neurohypophyseal germinoma with a prominent granulomatous reaction, which invaded the right cavernous sinus. The neuroimaging and histopathology features in this case were unique, distinguishing it from other types of suprasellar lesions. A 13-year-old boy presented with loss of appetite and polyuria; both symptoms were present for 1 year, and headache, general fatigue and blurred

Takeo Fukushima; Yusuke Takemura; Hitoshi Tsugu; Mitsutoshi Iwaasa; Kazuki Nabeshima; Koichi Takano; Hidetsuna Utsunomiya

2007-01-01

315

Cost/benefit analysis of managing annual invasive grasses in partially invaded sagebrush steppe ecosystems  

Technology Transfer Automated Retrieval System (TEKTRAN)

Our objective was to evaluate the cost-benefit of a single herbicide application or targeted grazing of annual grasses during restoration of partially invaded sagebrush steppe ecosystems used for livestock production. The cost/benefit model used is based on estimating the production of vegetation i...

316

Impact of Alien Plant Invaders on Pollination Networks in Two Archipelagos  

PubMed Central

Mutualistic interactions between plants and animals promote integration of invasive species into native communities. In turn, the integrated invaders may alter existing patterns of mutualistic interactions. Here we simultaneously map in detail effects of invaders on parameters describing the topology of both plant-pollinator (bi-modal) and plant-plant (uni-modal) networks. We focus on the invader Opuntia spp., a cosmopolitan alien cactus. We compare two island systems: Tenerife (Canary Islands) and Menorca (Balearic Islands). Opuntia was found to modify the number of links between plants and pollinators, and was integrated into the new communities via the most generalist pollinators, but did not affect the general network pattern. The plant uni-modal networks showed disassortative linkage, i.e. species with many links tended to connect to species with few links. Thus, by linking to generalist natives, Opuntia remained peripheral to network topology, and this is probably why native network properties were not affected at least in one of the islands. We conclude that the network analytical approach is indeed a valuable tool to evaluate the effect of invaders on native communities. PMID:19609437

Padrón, Benigno; Traveset, Anna; Biedenweg, Tine; Díaz, Diana; Nogales, Manuel; Olesen, Jens M.

2009-01-01

317

Using the Science Fiction Film "Invaders from Mars" in a Child Psychiatry Seminar  

ERIC Educational Resources Information Center

Objective: The science fiction film "Invaders From Mars" is used to teach principles of child development; clinical features of separation anxiety and nightmares; and clinical interventions, including child psychotherapy, child protective issues, and crisis management. Methods: Commercial films have been used as teaching aids in child psychiatry…

Zerby, Stephen A.

2005-01-01

318

Can HIV invade a population which is already sick? Rinaldo B. Schinazi  

E-print Network

Can HIV invade a population which is already sick? Rinaldo B. Schinazi University of Colorado and Universit´e de Provence email: schinazi@math.uccs.edu Abstract. It is known that an HIV infection when concomitant with another disease such as tuberculosis or pneumonia is a lot more lethal than HIV alone. We

Schinazi, Rinaldo

319

Are early summer wildfires an opportunity to revegetate exotic annual grass-invaded plant communities?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Medusahead (Taeniatherum caput-medusae (L.) Nevski) is an exotic annual grass reducing biodiversity and altering ecosystem function and processes in rangelands. Revegetation of medusahead-invaded plant communities is needed to improve ecosystem function, increase livestock forage production, and im...

320

Evaluation of sheep grazing as a tool to restore mountain pastures invaded by Euphorbia polygalifolia  

Microsoft Academic Search

SUMMARY - Two experiments were conducted to (i) study whether sheep grazing pastures infested by a spurge (Euphorbia polygalifolia) consume this invasive weed and its consequences on animal performance, and (ii) detect differences between sheep and cattle in ruminal degradation of infested pastures. In the first trial, sheep grazed fenced paddocks highly invaded by spurge at instantaneous stocking rates of

M. J. Mora; J. Busqué; G. Hervás; A. R. Mantecón; B. Fernández; P. Frutos

321

Effects of native species diversity and resource additions on invader impact.  

PubMed

Theory and empirical work have demonstrated that diverse communities can inhibit invasion. Yet, it is unclear how diversity influences invader impact, how impact varies among exotics, and what the relative importance of diversity is versus extrinsic factors that themselves can influence invasion. To address these issues, we established plant assemblages that varied in native species and functional richness and crossed this gradient in diversity with resource (water) addition. Identical assemblages were either uninvaded or invaded with one of three exotic forbs: spotted knapweed (Centaurea maculosa), dalmatian toadflax (Linaria dalmatica), or sulfur cinquefoil (Potentilla recta). To determine impacts, we measured the effects of exotics on native biomass and, for spotted knapweed, on soil moisture and nitrogen levels. Assemblages with high species richness were less invaded and less impacted than less diverse assemblages. Impact scaled with exotic biomass; spotted knapweed had the largest impact on native biomass compared with the other exotics. Although invasion depressed native biomass, the net result was to increase total community yield. Water addition increased invasibility (for knapweed only) but had no effect on invader impact. Together, these results suggest that diversity inhibits invasion and reduces impact more than resource additions facilitate invasion or impact. PMID:18554141

Maron, John L; Marler, Marilyn

2008-07-01

322

Restoration of exotic annual grass-invaded rangelands: importance of seed mix composition  

Technology Transfer Automated Retrieval System (TEKTRAN)

Restoration of exotic annual grass-invaded rangelands is needed to improve ecosystem function and services. Increasing plant species and plant functional group diversity is generally believed to increase resistance to invasion and increase desired vegetation. However, the effects of diversity and ...

323

Biocontrol alters litter chemistry and short-term decomposition in a Tamarisk-invaded ecosystem  

Technology Transfer Automated Retrieval System (TEKTRAN)

The release of the leaf beetle (Diorhabda elongata) has resulted in the defoliation of tens of 1000’s of hectares of Tamarix-invaded systems, however little is known about the effects of biocontrol on ecosystem nutrient dynamics. Weed invasion has been linked to disturbance-induced increases in nut...

324

A complex relationship: the interaction among symbiotic microbes, invading pathogens, and their mammalian host  

Microsoft Academic Search

Symbiosis between microbes and their mammalian host is vital to maintaining homeostasis. Symbiotic microbes within the gastrointestinal tract provide an array of benefits to the host, including promotion of host immunity. A coordinated effort of the host and symbiotic microbes deters the colonization and survival of many invading pathogens. However, pathogens have devised strategies to overcome these mechanisms. Furthermore, some

M M Curtis; V Sperandio

2011-01-01

325

Why are potential women being killed?  

PubMed

The persistence of traditional practices that provide disincentives to having daughters is giving rise to widespread infanticide in India. In a survey conducted in Madras in 1993, over half of the mothers interviewed acknowledged having killed an infant girl. The infanticide rate is believed to be even higher in India's rural areas. Families who can afford ultrasound to determine the fetal sex are reportedly using selective abortion to avert the birth of a daughter. Of 8000 abortions induced in a Bombay clinic, 7999 involved a female fetus. Families cite the financial burden inherent in providing a dowry as the primary reason for female infanticide. Also cited is the need for a son to both provide financial support to parents in old age and to light their funeral pyre. There are reports of mothers who refuse to kill female infants being abandoned or physically battered by their husbands. At present, there are 116 males to every 100 females in India--an imbalance that is likely to increase in the future and make it impossible for many men to form families. Just as television has been implicated in creating a demand for large dowries that would enable husbands' families to purchase Western luxury items, the mass media should use its influence to alter the attitudes that perpetuate the low status of women in India. PMID:8283950

Thomson, A

1993-12-01

326

of pattern formation by swimming microorgan-isms. J. Protozool. 22: 296-306.  

E-print Network

suspension ofgyrotactic micro-organisms. J. Fluid Mech. 195: 223-237. RICHARDSON, L.L.,C. AGUILAR,AND K. Numerical study of small-scale intermittency in three-dimensional turbulence. J. Fluid Mech. 107: 375

327

Estimation of dynamic petrophysical properties of water-bearing sands invaded with oil-base mud from the interpretation  

E-print Network

Estimation of dynamic petrophysical properties of water-bearing sands invaded with oil-base mud dynamic petrophysical properties in the water-bearing portion of the reservoir are in agreement) invades connate water- saturated rocks. This is a favorable condition for the estimation of dynamic

Torres-Verdín, Carlos

328

Effects of Introduced Common Carp and Invading Zebra Mussels on Water Quality and the Native Biological Community of Clear Lake,  

E-print Network

Effects of Introduced Common Carp and Invading Zebra Mussels on Water Quality and the Native success evaluating the impacts of ongoing lake restoration and invasive common carp and zebra mussels and effects of introduced common carp, invading zebra mussels, and the native biological community on water

Koford, Rolf R.

329

Greater male fitness of a rare invader (Spartina alterniflora, Poaceae) threatens a common native (Spartina foliosa) with hybridization.  

PubMed

Hybridization with abundant invaders is a well-known threat to rare native species. Our study addresses mechanisms of hybridization between a rare invader, smooth cordgrass (Spartina alterniflora) and the common native California cordgrass (S. foliosa) in the salt marshes of San Francisco Bay. These species are wind-pollinated and flower in summer. The invader produced 21-fold the viable pollen of the native, and 28% of invader pollen germinated on native stigmas (1.5-fold the rate of the native's own pollen). Invader pollen increased the seed set of native plants almost eightfold over that produced with native pollen, while native pollen failed to increase seed set of the invader. This pollen swamping and superior siring ability by the invader could lead to serial genetic assimilation of a very large native population. Unlike California cordgrass, smooth cordgrass can grow into low intertidal habitats and cover open mud necessary to foraging shorebirds, marine life, navigation, and flood control in channels. To the extent that intertidal range of the hybrids is more similar to the invader than to the native parent, introgression will lead to habitat loss for shore birds and marine life as well to genetic pollution of native California cordgrass. PMID:21680319

Anttila, C K; Daehler, C C; Rank, N E; Strong, D R

1998-11-01

330

78 FR 42451 - Animal Feeds Contaminated With Salmonella Microorganisms  

Federal Register 2010, 2011, 2012, 2013, 2014

...Docket No. FDA-2013-N-0253] Animal Feeds Contaminated With Salmonella Microorganisms...Agency) is revoking an advisory opinion on animal feeds contaminated with Salmonella microorganisms...guide (CPG) on Salmonella in food for animals. DATES: This rule is effective...

2013-07-16

331

AN INTRODUCTION TO FARMER'S BEST FRIENDS - SOIL MICROORGANISMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Soil microorganisms are essential to life, and to all agricultural practices. They are numerous, diverse, and metabolically flexible. Basic information regarding the soil microorganisms and their roles with respect to crop production are summarized for the layman....

332

Electric DNA chips for determination of pathogenic microorganisms  

E-print Network

Electric DNA chips for determination of pathogenic microorganisms Yanling Liu Doctoral thesis Liu (2008): Electric DNA chips for determination of pathogenic microorganisms. School of Biotechnology, Royal Institute of Technology (KTH), Stockholm, Sweden Abstract Silicon-based electric DNA chip arrays

Enfors, Sven-Olof

333

ShippingInfectious Substances, Genetically Modified Microorganisms, and Exempt Specimens  

E-print Network

ShippingInfectious Substances, Genetically Modified Microorganisms, and Exempt Specimens Goods: Biological Substances, Category B (BSCB), Genetically Modified Microorganisms (GMMO) and Exempt · Individuals wishing to ship Biological Substances Category B (BSCB) and/or Genetically Modified

Jia, Songtao

334

MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF 2007  

EPA Science Inventory

Stormwater best management practices (BMPs) are often considered effective tools to mitigate the effects of stormwater pollutants before they are discharged to receiving waters. However, BMP performance for microorganisms removal is not well documented. Microorganisms die-off in ...

335

MICROORGANISMS DIE-OFF RATES IN URBAN STORMWATER RUNOFF 2007  

EPA Science Inventory

Stormwater best management practices (BMPs) are often considered effective tools to mitigate the effects of stormwater pollutants before they are discharged to receiving waters. However, BMP performance for microorganisms removal is not well documented. Microorganisms die-off in...

336

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

337

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...

338

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.

Terry McGenity

339

Killing forms and toric Sasaki-Einstein spaces  

NASA Astrophysics Data System (ADS)

The construction of the special Killing forms on toric Sasaki-Einstein manifolds is presented. This goal is achieved using the interplay between complex coordinates of the Calabi-Yau metric cone and the special Killing forms on the toric Sasaki-Einstein space. As a concrete example, we present the complete set of special Killing forms on the five-dimensional Einstein-Sasaki Yp,q spaces. It is pointed out the existence of two additional special Killing forms associated with the complex holomorphic volume form of Calabi-Yau cone manifold.

Slesar, Vladimir; Visinescu, Mihai; Vîlcu, Gabriel Eduard

2014-11-01

340

BioEd Online: Lessons: Microorganisms  

NSDL National Science Digital Library

The BioEd Online site, created by the dedicated staff at the Baylor College of Medicine, is a veritable cornucopia of material for science educators. The lesson plans are all classroom tested and high-quality. This particular corner of the site focuses on the world of microorganisms. The site includes 15 lessons, complete with video clips, slideshows, and .pdf files. The offerings here include "Comparing Sizes of Microorganisms," "Observing Different Microbes," and "Microbes and Disease." The videos are quite nice as they offer a brief introduction to each subject, along with suggestions for how to conduct the associated classroom activity. If visitors enjoy these lesson plans, they should explore the other categories under Classroom Lessons, such as Animals, Genetics, and History & Nature of Science.

2012-03-05

341

UV inactivation of pathogenic and indicator microorganisms  

SciTech Connect

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.

1985-06-01

342

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

343

Local climatic adaptation in a widespread microorganism  

PubMed Central

Exploring the ability of organisms to locally adapt is critical for determining the outcome of rapid climate changes, yet few studies have addressed this question in microorganisms. We investigated the role of a heterogeneous climate on adaptation of North American populations of the wild yeast Saccharomyces paradoxus. We found abundant among-strain variation for fitness components across a range of temperatures, but this variation was only partially explained by climatic variation in the distribution area. Most of fitness variation was explained by the divergence of genetically distinct groups, distributed along a north–south cline, suggesting that these groups have adapted to distinct climatic conditions. Within-group fitness components were correlated with climatic conditions, illustrating that even ubiquitous microorganisms locally adapt and harbour standing genetic variation for climate-related traits. Our results suggest that global climatic changes could lead to adaptation to new conditions within groups, or changes in their geographical distributions. PMID:24403328

Leducq, Jean-Baptiste; Charron, Guillaume; Samani, Pedram; Dubé, Alexandre K.; Sylvester, Kayla; James, Brielle; Almeida, Pedro; Sampaio, José Paulo; Hittinger, Chris Todd; Bell, Graham; Landry, Christian R.

2014-01-01

344

How could haloalkaliphilic microorganisms contribute to biotechnology?  

PubMed

Haloalkaliphiles are microorganisms requiring Na(+) concentrations of at least 0.5 mol·L(-1) and an alkaline pH of 9 for optimal growth. Their unique features enable them to make significant contributions to a wide array of biotechnological applications. Organic compatible solutes produced by haloalkaliphiles, such as ectoine and glycine betaine, are correlated with osmoadaptation and may serve as stabilizers of intracellular proteins, salt antagonists, osmoprotectants, and dermatological moisturizers. Haloalkaliphiles are an important source of secondary metabolites like rhodopsin, polyhydroxyalkanoates, and exopolysaccharides that play essential roles in biogeocycling organic compounds. These microorganisms also can secrete unique exoenzymes, including proteases, amylases, and cellulases, that are highly active and stable in extreme haloalkaline conditions and can be used for the production of laundry detergent. Furthermore, the unique metabolic pathways of haloalkaliphiles can be applied in the biodegradation and (or) biotransformation of a broad range of toxic industrial pollutants and heavy metals, in wastewater treatment, and in the biofuel industry. PMID:25372346

Zhao, Baisuo; Yan, Yanchun; Chen, Shulin

2014-11-01

345

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

346

Solubilization of Australian lignites by microorganisms  

SciTech Connect

Australia has substantial lignite deposits, particularly in the Latrobe Valley in Victoria where 4.10/sup 10/ tons are accessible with available technologies. The authors have investigated the susceptibility of these coal to solubilization by microorganisms, including species additional to those already identified as active on North American lignites. The data presented here show that acid oxidized lignites from the Latrobe Valley are solubilized by each of seven species of microorganisms previously found to be active on Leonardite and oxidized North American lignites. These are the wood rot fungi: Trametes versicolor, Poria placenta and Phanerochaete chrysosporium, the lignin degrading prokaryote Streptomyces viridosporus and three fungi isolated from lignite in Mississippi: Candida ML-13, Cunninghamelia YML-1 and Penicillium waksmanii.

Catcheside, D.E.A.; Mallett, K.J.; Cox, R.E.

1988-01-01

347

BioEd Online: Lessons: Microorganisms  

NSDL National Science Digital Library

The BioEd Online site, created by the dedicated staff at the Baylor College of Medicine, is a veritable cornucopia of material for science educators. The lesson plans are all classroom tested and high-quality. This particular corner of the site focuses on the world of microorganisms. The site includes lessons, complete with video clips, slideshows, and .pdf files. The offerings here include "Comparing Sizes of Microorganisms," "Observing Different Microbes," and "Microbes and Disease." The videos are quite nice as they offer a brief introduction to each subject, along with suggestions for how to conduct the associated classroom activity. If visitors enjoy these lesson plans, they should explore the other categories under Classroom Lessons, such as Animals, Genetics, and History & Nature of Science.

2012-03-02

348

Masters graduation project COLLECTIVE MOTION OF MICRO-ORGANISMS  

E-print Network

Masters graduation project COLLECTIVE MOTION OF MICRO-ORGANISMS Investigation of flow patterns induced by the collective motion of micro- organisms Problem: Dense suspensions of micro-organisms have fraction as well as the details of the swimming mechanisms of the micro-organisms. Project: This project

Lindken, Ralph

349

Isolation of microorganisms for biological detoxification of lignocellulosic hydrolysates  

Microsoft Academic Search

Acid pretreatment of lignocellulosic biomass releases furan and phenolic compounds, which are toxic to microorganisms used for subsequent fermentation. In this study, we isolated new microorganisms for depletion of inhibitors in lignocellulosic acid hydrolysates. A sequential enrichment strategy was used to isolate microorganisms from soil. Selection was carried out in a defined mineral medium containing a mixture of ferulic acid

M. J. López; N. N. Nichols; B. S. Dien; J. Moreno; R. J. Bothast

2004-01-01

350

Self-forces from generalized Killing fields  

NASA Astrophysics Data System (ADS)

A non-perturbative formalism is developed that simplifies the understanding of self-forces and self-torques acting on extended scalar charges in curved spacetimes. Laws of motion are locally derived using momenta generated by a set of generalized Killing fields. Self-interactions that may be interpreted as arising from the details of a body's internal structure are shown to have very simple geometric and physical interpretations. Certain modifications to the usual definition for a center-of-mass are identified that significantly simplify the motions of charges with strong self-fields. A derivation is also provided for a generalized form of the Detweiler Whiting axiom that pointlike charges should react only to the so-called regular component of their self-field. Standard results are shown to be recovered for sufficiently small charge distributions.

Harte, Abraham I.

2008-12-01

351

Antimicrobial peptide killing of African trypanosomes.  

PubMed

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 severe side effects of approved drugs, resistance and major difficulties in delivering drugs. Antimicrobial peptides (AMPs) are ubiquitous components of immune defence and are being rigorously pursued as novel sources of new therapeutics for a variety of pathogens. Here, we review the role of AMPs in the innate immune response of the tsetse fly to African trypanosomes, catalogue trypanocidal AMPs from diverse organisms and highlight the susceptibility of bloodstream form African trypanosomes to killing by unconventional toxic peptides. PMID:21517904

Harrington, J M

2011-08-01

352

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

353

Microorganisms and Calcium Oxalate Stone Disease  

Microsoft Academic Search

Microorganisms may have a role in the pathogenesis and prevention of kidney stones. The subjects of this review include nanobacteria, Oxalobacter formigenes, and lactic acid bacteria. Not reviewed here is the well-described role of infections of the urinary tract with Proteus species and other urease-producing organisms associated with struvite stone formation. Nanobacteria have been proposed to be very small (0.08–0.5

David S. Goldfarb

2004-01-01

354

Fibrinogenolytic and fibrinolytic activity in oral microorganisms.  

PubMed Central

Samples were taken from blood accumulated in dental alveoli after surgical removal of mandibular third molars, from subgingival plaque of teeth with advanced periodontal destructions, from teeth with infected necrotic pulps, and from subjects suffering from angular cheilitis. Of the microorganisms subcultured from these samples, 116 strains were assayed for enzymes degrading fibrinogen and fibrin. Enzymes degrading fibrinogen were assayed with the thin-layer enzyme assay cultivation technique. This assay involves the cultivation of microorganisms on culture agars applied over fibrinogen-coated polystyrene surfaces. Enzymes degrading fibrin were assayed with both a plate assay and a tube assay, in which fibrin was mixed with a microbial culture medium. Microorganisms degrading fibrinogen or fibrin or both were isolated from all sampling sites. Activity was mainly detected in strains of Actinomyces, Bacteroides, Fusobacterium, Peptococcus, Propionibacterium, and Staphylococcus aureus. Most Fusobacterium strains degraded fibrinogen only. Enzymes degrading fibrinogen as well as enzymes degrading fibrin via activation of plasminogen were revealed in strains of Clostridium, S. aureus, and Streptococcus pyogenes. It was generally found that fibrinogen was degraded by more strains than was fibrin, which indicates that different proteases may be involved. PMID:6345573

Wikström, M B; Dahlén, G; Linde, A

1983-01-01

355

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. PMID:24828817

Grzymski, Joseph J.; Marsh, Adam G.

2014-01-01

356

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

357

Biomining: metal recovery from ores with microorganisms.  

PubMed

Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms. PMID:23793914

Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

2014-01-01

358

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

359

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

360

The adaptive value of remnant native plants in invaded communities: an example from the Great Basin.  

PubMed

Changes in the species composition of biotic communities may alter patterns of natural selection occurring within them. Native perennial grass species in the Intermountain West are experiencing a shift in the composition of interspecific competitors from primarily perennial species to an exotic, annual grass. Thus traits that confer an advantage to perennial grasses in the presence of novel annual competitors may evolve in invaded communities. Here I show that such traits are apparent in populations of a native perennial grass, big squirreltail (Elymus multisetus M.E. Jones), exposed to cheatgrass (Bromus tectorum L.) competitors. Dormant big squirreltail plants were collected from cheatgrass-invaded and uninvaded sites near Bordertown, California, USA, a mid-elevation (1600 m) sagebrush community, and transplanted into pots in a greenhouse. Individual plants were split into equal halves. One half was grown with competition from cheatgrass, and the other half was grown without competition. Plants collected from invaded sites responded more quickly to watering, growing more leaves in the first 10 days after transplanting. In addition, big squirreltail plants collected from invaded areas experienced a smaller decrease in plant size when grown with competition than did plants collected from uninvaded areas. Accordingly, while there were fewer big squirreltail individuals in the invaded sites, they were more competitive with cheatgrass than were the more abundant conspecifics in nearby uninvaded areas. It is possible that annual grasses were the selective force that caused these population differences, which may contribute to the long-term persistence of the native populations. While it is tempting to restore degraded areas to higher densities of natives (usually done by bringing in outside seed material), such actions may impede long-term adaptation to new conditions by arresting or reversing the direction of ongoing natural selection in the resident population. If hot spots of rapid evolutionary change can be identified within invaded systems, these areas should be managed to promote desirable change and could serve as possible sources of restoration material or reveal traits that should be prioritized during the development of restoration seed material. PMID:18686583

Leger, Elizabeth A

2008-07-01

361

Kinetics of killing Listeria monocytogenes by macrophages: rapid killing accompanying phagocytosis  

SciTech Connect

The kinetics of bactericidal activity of activated macrophages can be precisely described by a mathematical model in which phagocytosis, killing, digestion, and release of degraded bacterial material are considered to occur continuously. To gain a better understanding of these events, I have determined the period of time between first contact of bacteria with macrophages and the onset of killing. Activated rat peritoneal macrophages were incubated for various times up to 15 min with Listeria monocytogenes previously labeled with /sup 3/H-thymidine and the unassociated bacteria removed by two centrifugations through a density interface. Both cell-associated radioactivity and cell-associated viable bacteria, determined as colony forming units after sonication of the cell pellet, increased with time of incubation. However, the specific viability of these bacteria, expressed as the ratio of number of viable bacteria per unit radioactivity declined with time, as an approximate inverse exponential, after a lag period of 2.9 +/- 0.8 min. Evidence is given that other possible causes for this decline in specific viability, other than death of the bacteria, such as preferential ingestion of dead Listeria, clumping of bacteria, variations in autolytic activity, or release of Listericidins are unlikely. I conclude therefore that activated macrophages kill Listeria approximately 3 min after the cell and the bacterium first make contact.

Davies, W.A.

1983-08-01

362

Resection of a Catecholamine-Elaborating Retroperitoneal Paraganglioma Invading the Inferior Vena Cava  

PubMed Central

Paragangliomas are rare tumors originating outside of the adrenal medulla which can be associated with catecholamine secretion or mass effect, one of which typically leads to their discovery. The differences between these tumors and traditional intra-adrenal pheochromocytomas are a subject of recent investigations. Standard of care therapy is medical management and surgical resection of the tumor. When tumors are biochemically active, medical optimization of the autonomic nervous system is a critical component to a safe, definitive resection. Tumors arising in the retroperitoneum present technical challenges for the surgeon as they are often large and difficult to access, making an oncologic resection much more difficult. Lastly, these tumors are mostly benign and rarely invade adjacent structures—an operative finding not always predicted by preoperative imaging—which, if present, adds significant complexity and risk to the resection. A case illustrating these challenges in the management of a biochemically active retroperitoneal paraganglioma invading the inferior vena cava follows. PMID:25610696

Mannina, E. M.; Xiong, Z.; Self, R.; Kandil, E.

2014-01-01

363

The effect of road kills on amphibian populations  

Microsoft Academic Search

The diurnal movement patterns of Triturus vulgaris, Triturus cristatus, Pelobates fuscus, Bufo bufo, Rana temporaria, and Rana arvalis were investigated during five breeding seasons (1994–1998). Two main questions were addressed: (1) What is the probability of an individual amphibian getting killed when crossing the road? and (2) What fraction of the amphibian populations gets killed by traffic? The rate of

Tove Hels; Erik Buchwald

2001-01-01

364

Microwave irradiation for rapid killing and fixing of plant tissue  

SciTech Connect

Irradiation by microwaves allows for rapid killing and fixing of plant tissue, with excellent cellular integrity for histological examination. One or two exposures to microwaves for three seconds in formalin/acetic acid/alcohol gave good preservation of nuclei, chloroplasts, and other plant structures. The microwave method offers a considerable saving of time over traditional methods for killing and fixing plant tissue.

Walsh, G.E.; Bohannon, P.M.; Wessinger-Duvall, P.B.

1989-01-01

365

9. GENERAL INTERIOR VIEW OF BEEF KILLING FLOOR; LOOKING SOUTHEAST; ...  

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

9. GENERAL INTERIOR VIEW OF BEEF KILLING FLOOR; LOOKING SOUTHEAST; PLATFORMS IN FOREGROUND WERE USED BY SPLITTERS, TRIMMERS AND GOVERNMENT INSPECTORS; SKINNING TABLE RAN ALONG THE WINDOWS NEAR THE CENTER OF THE PHOTO - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

366

The Seal Killing Controversy: What Are the Facts?  

ERIC Educational Resources Information Center

Discusses the seal controversy using the harp and Alaska fur seals to illustrate the two distinct issues, i.e., conservation (the effect of killing upon the animal population); and two, morality (the effect of killing upon the human spirit). Factual information combines with personal philosophy. (LK)

Scheffer, Victor B.

1973-01-01

367

PDE5 Inhibitors Enhance Celecoxib Killing in Multiple Tumor Types.  

PubMed

The present studies determined whether clinically relevant phosphodiesterase 5 (PDE5) inhibitors interacted with a clinically relevant NSAID, celecoxib, to kill tumor cells. Celecoxib and PDE5 inhibitors interacted in a greater than additive fashion to kill multiple tumor cell types. Celecoxib and sildenafil killed ex vivo primary human glioma cells as well as their associated activated microglia. Knock down of PDE5 recapitulated the effects of PDE5 inhibitor treatment; the nitric oxide synthase inhibitor L-NAME suppressed drug combination toxicity. The effects of celecoxib were COX2 independent. Over-expression of c-FLIP-s or knock down of CD95/FADD significantly reduced killing by the drug combination. CD95 activation was dependent on nitric oxide and ceramide signaling. CD95 signaling activated the JNK pathway and inhibition of JNK suppressed cell killing. The drug combination inactivated mTOR and increased the levels of autophagy and knock down of Beclin1 or ATG5 strongly suppressed killing by the drug combination. The drug combination caused an ER stress response; knock down of IRE1?/XBP1 enhanced killing whereas knock down of eIF2?/ATF4/CHOP suppressed killing. Sildenafil and celecoxib treatment suppressed the growth of mammary tumors in vivo. Collectively our data demonstrate that clinically achievable concentrations of celecoxib and sildenafil have the potential to be a new therapeutic approach for cancer. J. Cell. Physiol. 230: 1115-1127, 2015. © 2014 Wiley Periodicals, Inc., A Wiley Company. PMID:25303541

Booth, Laurence; Roberts, Jane L; Cruickshanks, Nichola; Tavallai, Seyedmehrad; Webb, Timothy; Samuel, Peter; Conley, Adam; Binion, Brittany; Young, Harold F; Poklepovic, Andrew; Spiegel, Sarah; Dent, Paul

2015-05-01

368

Life After Fresh Kills: Moving Beyond New York City's  

E-print Network

no position as to the appropriateness of the city's current waste export plan in the short-term, it doesLife After Fresh Kills: Moving Beyond New York City's Current Waste Management Plan Policy disposal plan and the impact of the Fresh Kills landfill closing. The report concludes that New York City

Columbia University

369

Pseudomonas aeruginosa PAO1 Kills Caenorhabditis elegans by Cyanide Poisoning  

Microsoft Academic Search

In this report we describe experiments to investigate a simple virulence model in which Pseudomonas aerugi- nosa PAO1 rapidly paralyzes and kills the nematode Caenorhabditis elegans. Our results imply that hydrogen cyanide is the sole or primary toxic factor produced by P. aeruginosa that is responsible for killing of the nematode. Four lines of evidence support this conclusion. First, a

LARRY A. GALLAGHER; COLIN MANOIL

2001-01-01

370

KILLING ELEPHANTS: BRIEF COMMENTS ON PROFESSOR HENNIE LOTTER'S PAPER, "SHOULD  

E-print Network

KILLING ELEPHANTS: BRIEF COMMENTS ON PROFESSOR HENNIE LOTTER'S PAPER, "SHOULD ELEPHANTS BE CULLED situated and the killing of elephants sanctioned. In this view, individuality is denied. As long the animal represents the gene pool of its species and that is what defines it as an elephant or whatever

371

FACTORS AFFECTING SECONDARY KILL OF THE GERMAN COCKROACH (DICTYOPTERA  

E-print Network

153 FACTORS AFFECTING SECONDARY KILL OF THE GERMAN COCKROACH (DICTYOPTERA: BLATTELLIDAE) BY GEL of Forestry, Nanning, Guangxi 530022, China Abstract Secondary kill of the German cockroach, Blattella of four cockroach gel baits against various developmental stages of a laboratory (Jwax) and a field (Dorie

Wang, Changlu

372

Rickettsia associated with male-killing in a buprestid beetle  

E-print Network

bacterium that causes male-killing in an unrelated ladybird beetle species. Low levels of parthenogenesisRickettsia associated with male-killing in a buprestid beetle EILLEEN T. LAWSON , TIMOTHY A populations of the buprestid leaf-mining beetle, Brachys tessellatus, from central South Carolina, USA, show

Werren, John H.

373

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

PubMed

With ecosystems increasingly supporting multiple invasive species, interactions among invaders could magnify or ameliorate the undesired consequences for native communities and ecosystems. We evaluated the individual and combined effects of rusty 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 are widespread in the USA and commonly co-occur within northern temperate lakes, underscoring the importance of understanding their singular and joint effects. An outdoor mesocosm experiment revealed that while the two invaders had only weakly negative effects upon one another, both negatively affected the abundance and biomass of native snails, and their combined presence drove one native species to extinction and reduced a second by >95%. Owing to its larger size and thicker shell, adult Bellamya were protected from crayfish attack relative to native species (especially Physa and Lymnaea), suggesting the co-occurrence of these invaders in nature could have elevated consequences for native communities. The per capita impacts of Orconectes (a snail predator) on native snails were substantially greater than those of Bellamya (a snail competitor). Crayfish predation also had a cascading effect by reducing native snail biomass, leading to increased periphyton growth. Bellamya, in contrast, reduced periphyton biomass, likely causing a reduction in growth by native lymnaeid snails. Bellamya also increased water column N:P ratio, possibly because of a low P excretion rate relative to native snail species. Together, these findings highlight the importance of understanding interactions among invasive species, which can have significant community- and ecosystem-level effects. PMID:18941789

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

2009-02-01

374

Factors associated with woody alien species distribution in a newly invaded mountain system of central Argentina  

Microsoft Academic Search

To help determine the major factors associated with alien plant in a newly invaded mountain range; we analyzed the distribution\\u000a patterns of woody alien species along the altitudinal gradient of the Córdoba mountains, in relation to biotic, abiotic and\\u000a anthropogenic factors. We selected 303 plots using a Geographic Information System (GIS) covering all the variability of these\\u000a factors. In the

Melisa A. GiorgisPaula; Paula A. Tecco; Ana M. Cingolani; Daniel Renison; Paula Marcora; Valeria Paiaro

2011-01-01

375

Differences in population dynamics and potential impacts of a freshwater invader driven by temporal habitat stability  

Microsoft Academic Search

Understanding population dynamics and population regulation of invasive species is critical for predicting their effects on\\u000a native ecosystems as well as for control strategies. Many species of gastropod in the genus Pomacea are successful aquatic invaders that have caused economic and ecological impacts in Southeastern Asia where their large fecundity\\u000a and broad reproductive window helps them to colonize and take

Lyubov E. Burlakova; Dianna K. Padilla; Alexander Y. Karatayev; David N. Hollas; Leah D. Cartwright; Kevin D. Nichol

2010-01-01

376

Invading Cancer Cells Share the Metabolic Burden | Physical Sciences in Oncology  

Cancer.gov

Metastatic cancer cells are able to cut through the dense extracellular collagen matrix that surround tumors, but doing so comes at a significant energy cost. Now, using a novel synthetic microenvironment to observe how groups of metastatic breast tumor cells move cooperatively in three dimensions, researchers have found that invading cancer cells follow the same strategy as geese do when traveling long distances through the air.

377

Co-invaders: The effects of alien parasites on native hosts.  

PubMed

We define co-introduced parasites as those which have been transported with an alien host to a new locality, outside of their natural range, and co-invading parasites as those which have been co-introduced and then spread to new, native hosts. Of 98 published studies of co-introductions, over 50% of hosts were freshwater fishes and 49% of parasites were helminths. Although we would expect parasites with simple, direct life cycles to be much more likely to be introduced and establish in a new locality, a substantial proportion (36%) of co-introductions were of parasites with an indirect life cycle. Seventy-eight per cent of co-introduced parasites were found in native host species and can therefore be classed as co-invaders. Host switching was equally common among parasites with direct and indirect life cycles. The magnitude of the threat posed to native species by co-invaders will depend, among other things, on parasite virulence. In 16 cases where co-introduced parasites have switched to native hosts and information was available on relative virulence, 14 (85%) were more virulent in native hosts than in the co-introduced alien host. We argue that this does not necessarily support the naïve host theory that co-invading parasites will have greater pathogenic effects in native hosts with which they have no coevolutionary history, but may instead be a consequence of the greater likelihood for parasites with lower virulence in their natural host to be co-introduced. PMID:25180161

Lymbery, Alan J; Morine, Mikayla; Kanani, Hosna Gholipour; Beatty, Stephen J; Morgan, David L

2014-08-01

378

Co-invaders: The effects of alien parasites on native hosts  

PubMed Central

We define co-introduced parasites as those which have been transported with an alien host to a new locality, outside of their natural range, and co-invading parasites as those which have been co-introduced and then spread to new, native hosts. Of 98 published studies of co-introductions, over 50% of hosts were freshwater fishes and 49% of parasites were helminths. Although we would expect parasites with simple, direct life cycles to be much more likely to be introduced and establish in a new locality, a substantial proportion (36%) of co-introductions were of parasites with an indirect life cycle. Seventy-eight per cent of co-introduced parasites were found in native host species and can therefore be classed as co-invaders. Host switching was equally common among parasites with direct and indirect life cycles. The magnitude of the threat posed to native species by co-invaders will depend, among other things, on parasite virulence. In 16 cases where co-introduced parasites have switched to native hosts and information was available on relative virulence, 14 (85%) were more virulent in native hosts than in the co-introduced alien host. We argue that this does not necessarily support the naïve host theory that co-invading parasites will have greater pathogenic effects in native hosts with which they have no coevolutionary history, but may instead be a consequence of the greater likelihood for parasites with lower virulence in their natural host to be co-introduced. PMID:25180161

Lymbery, Alan J.; Morine, Mikayla; Kanani, Hosna Gholipour; Beatty, Stephen J.; Morgan, David L.

2014-01-01

379

Competitive interactions between co-occurring invaders: identifying asymmetries between two invasive crayfish species  

Microsoft Academic Search

Ecosystems today increasingly suffer invasions by multiple invasive species. Complex interactions between invasive species\\u000a can have different fitness implications for each invader, which can in turn determine the future progression of their invasions\\u000a and result in differential impacts on native species and ecosystems. To this end, through pair-wise and group scale experiments,\\u000a we examined possible interaction outcomes, competition effects and

Sandra Hudina; Nika Gali?; Ivo Roessink; Karlo Hock

2011-01-01

380

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.

Christine Stracey

2008-02-01

381

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.

382

AN INVADER DIFFERENTIALLY AFFECTS LEAF PHYSIOLOGY OF TWO NATIVES ACROSS A GRADIENT IN DIVERSITY  

Microsoft Academic Search

Little is known about how exotics influence the ecophysiology of co-occurring native plants or how invader impact on plant physiology may be mediated by community diversity or resource levels. We measured the effect of the widespread invasive forb spotted knapweed (Centaurea maculosa) on leaf traits (leaf dry matter content, specific leaf area, leaf nitrogen percentage, leaf C:N ratios, and d13C

Pamela Kittelson; John Maron; Marilyn Marler

2008-01-01

383

Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus  

NASA Astrophysics Data System (ADS)

Cryptococcus neoformans is an opportunistic pulmonary fungal pathogen that disseminates to the CNS causing fatal meningitis in immunocompromised patients. Dendritic cells (DCs) phagocytose C. neoformans following inhalation. Following uptake, cryptococci translocate to the DC lysosomal compartment and are killed by oxidative and non-oxidative mechanisms. DC lysosomal extracts kill cryptococci in vitro; however, the means of antifungal activity remain unknown. Our studies determined non-oxidative antifungal activity by DC lysosomal extract. We examined DC lysosomal killing of cryptococcal strains, anti-fungal activity of purified lysosomal enzymes, and mechanisms of killing against C. neoformans. Results confirmed DC lysosome fungicidal activity against all cryptococcal serotypes. Purified lysosomal enzymes, specifically cathepsin B, inhibited cryptococcal growth. Interestingly, cathepsin B combined with its enzymatic inhibitors led to enhanced cryptococcal killing. Electron microscopy revealed structural changes and ruptured cryptococcal cell walls following treatment. Finally, additional studies demonstrated that osmotic lysis was responsible for cryptococcal death.

Hole, Camaron R.; Bui, Hoang; Wormley, Floyd L.; Wozniak, Karen L.

2012-10-01

384

Functional equivalence, competitive hierarchy and facilitation determine species coexistence in highly invaded grasslands.  

PubMed

Alien and native plant species often differ in functional traits. Trait differences could lead to niche differences that minimize competitive interactions and stabilize coexistence. However, trait differences could also translate into average fitness differences, leading to a competitive hierarchy that prevents coexistence. We tested whether trait differences between alien and native species translated into average fitness or stabilizing niche differences, and whether competition could explain observed coexistence within invaded grassland communities (New Zealand). Trait differences reflected marked competitive hierarchy, suggesting average fitness differences. Species coexistence was determined by a trade-off between species susceptibility to herbivory vs competitive hierarchy and facilitation. Importantly, although aliens and natives differed in their trait values, they did not differ in their competitive response, highlighting the importance of equalizing mechanisms in structuring invaded communities. Only a few alien species with a particular set of traits were able to jeopardize species coexistence when grazing was ceased. Our study explains why some alien species coexist with natives, whereas others have strong impacts on native communities. It highlights that trait differences can underlie several coexistence processes and that the demonstration of trait differences between aliens and natives is only a first step to understanding the role of biotic interactions in structuring invaded communities. PMID:25388949

Gross, Nicolas; Liancourt, Pierre; Butters, Robyn; Duncan, Richard P; Hulme, Philip E

2015-04-01

385

Predicting current and future biological invasions: both native and invaded ranges matter.  

PubMed

The classical approach to predicting the geographical extent of species invasions consists of training models in the native range and projecting them in distinct, potentially invasible areas. However, recent studies have demonstrated that this approach could be hampered by a change of the realized climatic niche, allowing invasive species to spread into habitats in the invaded ranges that are climatically distinct from those occupied in the native range. We propose an alternative approach that involves fitting models with pooled data from all ranges. We show that this pooled approach improves prediction of the extent of invasion of spotted knapweed (Centaurea maculosa) in North America on models based solely on the European native range. Furthermore, it performs equally well on models based on the invaded range, while ensuring the inclusion of areas with similar climate to the European niche, where the species is likely to spread further. We then compare projections from these models for 2080 under a severe climate warming scenario. Projections from the pooled models show fewer areas of intermediate climatic suitability than projections from the native or invaded range models, suggesting a better consensus among modelling techniques and reduced uncertainty. PMID:18664415

Broennimann, Olivier; Guisan, Antoine

2008-10-23

386

Cas6 is an endoribonuclease that generates guide RNAs for invader defense in prokaryotes  

SciTech Connect

An RNA-based gene silencing pathway that protects bacteria and archaea from viruses and other genome invaders is hypothesized to arise from guide RNAs encoded by CRISPR loci and proteins encoded by the cas genes. CRISPR loci contain multiple short invader-derived sequences separated by short repeats. The presence of virus-specific sequences within CRISPR loci of prokaryotic genomes confers resistance against corresponding viruses. The CRISPR loci are transcribed as long RNAs that must be processed to smaller guide RNAs. Here we identified Pyrococcus furiosus Cas6 as a novel endoribonuclease that cleaves CRISPR RNAs within the repeat sequences to release individual invader targeting RNAs. Cas6 interacts with a specific sequence motif in the 5{prime} region of the CRISPR repeat element and cleaves at a defined site within the 3{prime} region of the repeat. The 1.8 angstrom crystal structure of the enzyme reveals two ferredoxin-like folds that are also found in other RNA-binding proteins. The predicted active site of the enzyme is similar to that of tRNA splicing endonucleases, and concordantly, Cas6 activity is metal-independent. cas6 is one of the most widely distributed CRISPR-associated genes. Our findings indicate that Cas6 functions in the generation of CRISPR-derived guide RNAs in numerous bacteria and archaea.

Carte, Jason; Wang, Ruiying; Li, Hong; Terns, Rebecca M.; Terns, Michael P. (FSU); (Georgia)

2010-11-09

387

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.

388

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)

389

The use of stable isotope ratio analysis to distinguish multiple prey kill events from mass kill events  

Microsoft Academic Search

Archaeologists working with prey animal bonebeds are interested in determining whether the animals were obtained through a single, mass kill event or instead accumulated over time from multiple hunting events. This is often difficult to determine. The author investigated the use of stable isotope ratio analysis to distinguish accumulations of individuals derived from multiple populations from mass kills of individuals

Jack N. Fenner

2008-01-01

390

Dirty hands: photodynamic killing of human pathogens like EHEC, MRSA and Candida within seconds.  

PubMed

Hand hygiene is one of the most important interventions for reducing transmission of nosocomial life-threatening microorganisms, like methicillin resistant Staphylococcus aureus (MRSA), enterohemorrhagic Escherichia coli (EHEC) or Candida albicans. All three pathogens have become a leading cause of infections in hospitals. Especially EHEC is causing severe diarrhoea and, in a small percentage of cases, haemolytic-uremic syndrome (HUS) as reported for E. coli 104:H4 in Germany 2011. We revealed the possibility to inactivate very fast and efficiently MRSA, EHEC and C. albicans using the photodynamic approach. MRSA, EHEC and C. albicans were incubated in vitro with different concentrations of TMPyP for 10 s and illuminated with visible light (50 mW cm(-2)) for 10 and 60 s. 1 ?mol l(-1) of TMPyP and an applied radiant exposure of 0.5 J cm(-2) achieved a photodynamic killing of ?99.9% of MRSA and EHEC. Incubation with higher concentrations (up to 100 ?mol l(-1)) of TMPyP caused bacteria killing of >5 log(10) (?99.999%) after illumination. Efficient Candida killing (?99.999%) was achieved first at a higher light dose of 12 J cm(-2). Different rise and decay times of singlet oxygen luminescence signals could be detected in Candida cell suspensions for the first time, indicating different oxygen concentrations in the surrounding for the photosensitizer and singlet oxygen, respectively. This confirms that TMPyP is not only found in the water-dominated cell surrounding, but also within the C. albicans cells. Applying a water-ethanol solution of TMPyP on ex vivo porcine skin, fluorescence microscopy of histology showed that the photosensitizer was exclusively localized in the stratum corneum regardless of the incubation time. TMPyP exhibited a fast and very effective killing rate of life-threatening pathogens within a couple of seconds that encourages further testing in an in vivo setting. Being fast and effective, antimicrobial photodynamic applications might become acceptable as a tool for hand hygiene procedures and also in other skin areas. PMID:22855122

Eichner, Anja; Gonzales, Fernanda Pereira; Felgenträger, Ariane; Regensburger, Johannes; Holzmann, Thomas; Schneider-Brachert, Wulf; Bäumler, Wolfgang; Maisch, Tim

2013-01-01

391

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

392

ACTION OF FORMALDEHYDE ON MICROORGANISMS I.  

PubMed Central

Neely, W. Brock (The Dow Chemical Co., Midland, Mich.). Action of formaldehyde on microorganisms. I. Correlation of activity with formaldehyde metabolism. J. Bacteriol. 85:1028–1031. 1963.—The action of formaldehyde in concentrations sublethal for the culture appeared to be at least twofold. The first phase caused a drop in viability, followed by a second phase where bacteriostatic conditions existed. During both these intervals, formaldehyde was being metabolized. As soon as the organism had lowered the formaldehyde concentration to a critical level, the normal growth cycle was resumed, with a resultant increase in cell population. PMID:14043990

Neely, W. Brock

1963-01-01

393

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

394

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

395

Combinatorial stresses kill pathogenic Candida species  

PubMed Central

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

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

2012-01-01

396

Combinatorial stresses kill pathogenic Candida species.  

PubMed

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

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

2012-10-01

397

History of infection with different male-killing bacteria in the two-spot ladybird beetle Adalia bipunctata revealed through mitochondrial DNA sequence analysis.  

PubMed Central

The two-spot ladybird beetle Adalia bipunctata (Coleoptera: Coccinellidae) is host to four different intracellular maternally inherited bacteria that kill male hosts during embryogenesis: one each of the genus Rickettsia (alpha-Proteobacteria) and Spiroplasma (Mollicutes) and two distinct strains of Wolbachia (alpha-Proteobacteria). The history of infection with these male-killers was explored using host mitochondrial DNA, which is linked with the bacteria due to joint maternal inheritance. Two variable regions, 610 bp of cytochrome oxidase subunit I and 563 bp of NADH dehydrogenase subunit 5, were isolated from 52 A. bipunctata with known infection status and different geographic origin from across Eurasia. Two outgroup taxa were also considered. DNA sequence analysis revealed that the distribution of mitochondrial haplotypes is not associated with geography. Rather, it correlates with infection status, confirming linkage disequilibrium between mitochondria and bacteria. The data strongly suggest that the Rickettsia male-killer invaded the host earlier than the other taxa. Further, the male-killing Spiroplasma is indicated to have undergone a recent and extensive spread through host populations. In general, male-killing in A. bipunctata seems to represent a highly dynamic system, which should prove useful in future studies on the evolutionary dynamics of this peculiar type of symbiont-host association. PMID:11901123

v d Schulenburg, J Hinrich G; Hurst, Gregory D D; Tetzlaff, Dagmar; Booth, Gwendolen E; Zakharov, Ilia A; Majerus, Michael E N

2002-01-01

398

History of infection with different male-killing bacteria in the two-spot ladybird beetle Adalia bipunctata revealed through mitochondrial DNA sequence analysis.  

PubMed

The two-spot ladybird beetle Adalia bipunctata (Coleoptera: Coccinellidae) is host to four different intracellular maternally inherited bacteria that kill male hosts during embryogenesis: one each of the genus Rickettsia (alpha-Proteobacteria) and Spiroplasma (Mollicutes) and two distinct strains of Wolbachia (alpha-Proteobacteria). The history of infection with these male-killers was explored using host mitochondrial DNA, which is linked with the bacteria due to joint maternal inheritance. Two variable regions, 610 bp of cytochrome oxidase subunit I and 563 bp of NADH dehydrogenase subunit 5, were isolated from 52 A. bipunctata with known infection status and different geographic origin from across Eurasia. Two outgroup taxa were also considered. DNA sequence analysis revealed that the distribution of mitochondrial haplotypes is not associated with geography. Rather, it correlates with infection status, confirming linkage disequilibrium between mitochondria and bacteria. The data strongly suggest that the Rickettsia male-killer invaded the host earlier than the other taxa. Further, the male-killing Spiroplasma is indicated to have undergone a recent and extensive spread through host populations. In general, male-killing in A. bipunctata seems to represent a highly dynamic system, which should prove useful in future studies on the evolutionary dynamics of this peculiar type of symbiont-host association. PMID:11901123

v d Schulenburg, J Hinrich G; Hurst, Gregory D D; Tetzlaff, Dagmar; Booth, Gwendolen E; Zakharov, Ilia A; Majerus, Michael E N

2002-03-01

399

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

400

Microorganisms Resistant to Free-Living Amoebae  

PubMed Central

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

2004-01-01

401

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

402

Bioremediation of trinitrotolulene by a ruminal microorganism  

SciTech Connect

2,4,6-trinitrotoluene (TNT) has been widely used for the production of explosives because of its low boiling point, high stability, low impact sensitivity, and safe manufacture. More than 1,100 military facilities, each potentially contaminated with munitions waste, are expected to require treatment of more than one million cubic yards of contaminated soils. The cost associated with remediation of these sites has been estimated to be in excess of $1.5 billion. Recently, researchers have studied ruminal microorganisms in relation to their ability to degrade xenobiotic compounds. Many of these organisms are strict anaerobes with optimal redox potentials as low as -420 mV. Ruminal organisms have been shown capable of destroying some pesticides, such as parathion, p-nitrophenol, and biphenyl-type compounds; thiono isomers, and nitrogen-containing heterocyclic plant toxins such as the pyrrolizidine alkaloids. Many of these compounds have structures similar to TNT. A TNT-degrading ruminal microorganism has been isolated from goat rumen fluid with successive enrichments on triaminotoluene (TAT) and TNT. The isolate, designated G.8, utilizes nitrate and lactate as the primary energy source. G.8 was able to tolerate and metabolite levels of TNT up to the saturation point of 125 mg/l.

Lee, Taejin; Williamson, K.J.; Craig, A.M. [Oregon State Univ., Corvallis, OR (United States)

1995-10-01

403

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

404

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

Code of Federal Regulations, 2010 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2010-07-01

405

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

Code of Federal Regulations, 2013 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2013-07-01

406

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

Code of Federal Regulations, 2014 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2014-07-01

407

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

Code of Federal Regulations, 2011 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2011-07-01

408

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

Code of Federal Regulations, 2012 CFR

...encapsulated into killed Pseudomonas fluorescens; exemption from the requirement...encapsulated into killed Pseudomonas fluorescens; exemption from the...encapsulated into killed Pseudomonas fluorescens is exempt from the...

2012-07-01

409

Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens  

SciTech Connect

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

Daniel P. Molloy

2004-02-24

410

HIV transcription is induced with some forms of cell killing  

SciTech Connect

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

Woloschak, G.E. [Argonne National Lab., IL (United States); Schreck, S. [Argonne National Lab., IL (United States)][South Carolina Univ., Columbia, SC (United States). Dept. of Chemistry; Panozzo, J. [Loyola Univ. Medical Center, Maywood, IL (United States); Chang-Liu, C.-M. [Argonne National Lab., IL (United States); Libertin, C.R. [Loyola Univ. Medical Center, Maywood, IL (United States)

1996-11-01

411

Can Nanomedicines Kill Cancer Stem Cells?  

PubMed Central

Most tumors are heterogeneous and many cancers contain small population of highly tumorigenic and intrinsically drug resistant cancer stem cells (CSCs). Like normal stem cell, CSCs have ability to self-renew and differentiate to other tumor cell types. They are believed to be a source for drug resistance, tumor recurrence and metastasis. CSCs often overexpress drug efflux transporters, spend most of their time in non-dividing G0 cell cycle state, and therefore, can escape the conventional chemotherapies. Thus, targeting CSCs is essential for developing novel therapies to prevent cancer relapse and emerging of drug resistance. Nanocarrier-based therapeutic agents (nanomedicines) have been used to achieve longer circulation times, better stability and bioavailability over current therapeutics. Recently, some groups have successfully applied nanomedicines to target CSCs to eliminate the tumor and prevent its recurrence. These approaches include 1) delivery of therapeutic agents (small molecules, siRNA, antibodies) that affect embryonic signaling pathways implicated in self-renewal and differentiation in CSCs, 2) inhibiting drug efflux transporters in an attempt to sensitize CSCs to therapy, 3) targeting metabolism in CSCs through nanoformulated chemicals and field-responsive magnetic nanoparticles and carbon nanotubes, and 4) disruption of multiple pathways in drug resistant cells using combination of chemotherapeutic drugs with amphiphilic Pluronic block copolymers. Despite clear progress of these studies the challenges of targeting CSCs by nanomedicines still exist and leave plenty of room for improvement and development. This review summarizes biological processes that are related to CSCs, overviews the current state of anti-CSCs therapies, and discusses state-of-the-art nanomedicine approaches developed to kill CSCs. PMID:24120657

Zhao, Yi; Alakhova, Daria Y.; Kabanov, Alexander V.

2014-01-01

412

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

413

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

414

Microorganic compounds associated with sediments in the Humber rivers  

Microsoft Academic Search

The study investigates pollution by micro-organic contaminants in riverine systems in NE England with the following four key objectives: (1) to establish the range and concentrations of micro-organic compounds in relation to land use; (2) investigate how the type and concentrations of micro-organics can vary seasonally; (3) compare bed-sediment and suspended-sediment concentrations, and to (4) assess the use of `whole-water'

Juliet L. A Long; William A House; Andrew Parker; Joy E Rae

1998-01-01

415

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

416

Molecular genetics of biosurfactant synthesis in microorganisms.  

PubMed

Biosurfactant (BS)/bioemulsifier (BE) produced by varied microorganisms exemplify immense structural/functional diversity and consequently signify the involvement of particular molecular machinery in their biosynthesis. The present chapter aims to compile information on molecular genetics of BS/BE production in microorganisms. Polymer synthesis in Acinetobacter species is controlled by an intricate operon system and its further excretion being controlled by enzymes. Quorum sensing system (QSS) plays a fundamental role in rhamnolipid and surfactin synthesis. Depending upon the cell density, signal molecules (autoinducers) of regulatory pathways accomplish the biosynthesis of BS. The regulation of serrawettin production by Serratia is believed to be through non ribosomal peptide synthetases (NRPSs) and N-acylhomoserine lactones (AHLs) encoded by QSS located on mobile transposon. This regulation is under positive as well as negative control of QSS operon products. In case of yeast and fungi, glycolipid precursor production is catalyzed by genes that encode enzyme cytochrome P450 monooxygenase. BS/BE production is dictated by genes present on the chromosomes. This chapter also gives a glimpse of recent biotechnological developments which helped to realize molecular genetics of BS/BE production in microorganisms. Hyper-producing recombinants as well as mutant strains have been constructed successfully to improve the yield and quality of BS/BE. Thus promising biotechnological advances have expanded the applicability of BS/BE in therapeutics, cosmetics, agriculture, food, beverages and bioremediation etc. In brief, our knowledge on genetics of BS/BE production in prokaryotes is extensive as compared to yeast and fungi. Meticulous and concerted study will lead to an understanding of the molecular phenomena in unexplored microbes. In addition to this, recent promising advances will facilitate in broadening applications of BS/BE to diverse fields. Over the decades, valuable information on molecular genetics of BS/BE has been generated and this strong foundation would facilitate application oriented output of the surfactant industry and broaden its use in diverse fields. To accomplish our objectives, interaction among experts from diverse fields likes microbiology, physiology, biochemistry, molecular biology and genetics is indispensable. PMID:20545271

Satpute, Surekha K; Bhuyan, Smita S; Pardesi, Karishma R; Mujumdar, Shilpa S; Dhakephalkar, Prashant K; Shete, Ashvini M; Chopade, Balu A

2010-01-01

417

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

418

Engineered microorganisms capable of producing target compounds under anaerobic conditions  

DOEpatents

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

419

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

420

21 CFR 866.2660 - Microorganism differentiation and identification device.  

Code of Federal Regulations, 2014 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)...

2014-04-01

421

21 CFR 866.2660 - Microorganism differentiation and identification device.  

Code of Federal Regulations, 2011 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)...

2011-04-01

422

21 CFR 866.2660 - Microorganism differentiation and identification device.  

Code of Federal Regulations, 2013 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)...

2013-04-01

423

21 CFR 866.2660 - Microorganism differentiation and identification device.  

Code of Federal Regulations, 2012 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)...

2012-04-01

424

Modulation of Intestinal TLR4-Inflammatory Signaling Pathways by Probiotic Microorganisms: Lessons Learned from Lactobacillus jensenii TL2937  

PubMed Central

The intestinal mucosa plays a critical role in the host’s interactions with innocuous commensal microbiota and invading pathogenic microorganisms. Intestinal epithelial cells (IECs) and gut associated immune cells recognize the bacterial components via pattern-recognition receptors (PRRs) and are responsible for maintaining tolerance to the large communities of resident luminal bacteria while being also able to mount inflammatory responses against pathogens. Toll-like receptors (TLRs) are a major class of PRRs that are present on IECs and immune cells which are involved in the induction of both tolerance and inflammation. A growing body of experimental and clinical evidence supports the therapeutic and preventive application of probiotics for several gastrointestinal inflammatory disorders in which?TLRs exert a significant role. This review aims to summarize the current knowledge of the beneficial effects of probiotic microorganisms with the capacity to modulate the immune system (immunobiotics) in the regulation of intestinal inflammation in pigs, which are very important as both livestock and human model. Especially we discuss the role of?TLRs, their signaling pathways, and their negative regulators in both the inflammatory intestinal injury and the beneficial effects of immunobiotics in general, and Lactobacillus jensenii?TL2937 in particular. This review article emphasizes the cellular and molecular interactions of immunobiotics with IECs and immune cells through?TLRs and their application for improving animal and human health. PMID:24459463

Villena, Julio; Kitazawa, Haruki

2014-01-01

425

On the Lie subalgebra of Killing-Milne and Killing-Cartan vector fields in Newtonian space-time  

E-print Network

The Galilean (and more generally Milne) invariance of Newtonian theory allows for Killing vector fields of a general kind, whereby the Lie derivative of a field is not required to vanish but only to be cancellable by some infinitesimal Galilean (respectively Milne) gauge transformation. In this paper, it is shown that both the Killing-Milne vector fields, which preserve the background Newtonian space-time structure, and the Killing-Cartan vector fields, which in addition preserve the gravitational field, form a Lie subalgebra.

Chamel, N

2014-01-01

426

On the Lie subalgebra of Killing-Milne and Killing-Cartan vector fields in Newtonian space-time  

E-print Network

The Galilean (and more generally Milne) invariance of Newtonian theory allows for Killing vector fields of a general kind, whereby the Lie derivative of a field is not required to vanish but only to be cancellable by some infinitesimal Galilean (respectively Milne) gauge transformation. In this paper, it is shown that both the Killing-Milne vector fields, which preserve the background Newtonian space-time structure, and the Killing-Cartan vector fields, which in addition preserve the gravitational field, form a Lie subalgebra.

N. Chamel

2014-12-18

427

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. PMID:24223169

Olofsson, Jenny; Axelsson-Olsson, Diana; Brudin, Lars; Olsen, Björn; Ellström, Patrik

2013-01-01

428

Plasmodium falciparum evades mosquito immunity by disrupting JNK-mediated apoptosis of invaded midgut cells  

PubMed Central

The malaria parasite, Plasmodium, must survive and develop in the mosquito vector to be successfully transmitted to a new host. The Plasmodium falciparum Pfs47 gene is critical for malaria transmission. Parasites that express Pfs47 (NF54 WT) evade mosquito immunity and survive, whereas Pfs47 knockouts (KO) are efficiently eliminated by the complement-like system. Two alternative approaches were used to investigate the mechanism of action of Pfs47 on immune evasion. First, we examined whether Pfs47 affected signal transduction pathways mediating mosquito immune responses, and show that the Jun-N-terminal kinase (JNK) pathway is a key mediator of Anopheles gambiae antiplasmodial responses to P. falciparum infection and that Pfs47 disrupts JNK signaling. Second, we used microarrays to compare the global transcriptional responses of A. gambiae midguts to infection with WT and KO parasites. The presence of Pfs47 results in broad and profound changes in gene expression in response to infection that are already evident 12 h postfeeding, but become most prominent at 26 h postfeeding, the time when ookinetes invade the mosquito midgut. Silencing of 15 differentially expressed candidate genes identified caspase-S2 as a key effector of Plasmodium elimination in parasites lacking Pfs47. We provide experimental evidence that JNK pathway regulates activation of caspases in Plasmodium-invaded midgut cells, and that caspase activation is required to trigger midgut epithelial nitration. Pfs47 alters the cell death pathway of invaded midgut cells by disrupting JNK signaling and prevents the activation of several caspases, resulting in an ineffective nitration response that makes the parasite undetectable by the mosquito complement-like system. PMID:25552553

Ramphul, Urvashi N.; Garver, Lindsey S.; Molina-Cruz, Alvaro; Canepa, Gaspar E.; Barillas-Mury, Carolina

2015-01-01

429

Baseline histopathological survey of a recently invading island population of 'killer shrimp', Dikerogammarus villosus.  

PubMed

Dikerogammarus villosus, an invasive amphipod, has recently been detected in UK freshwaters. To assess the potential for pathogen introduction with the invader, a year-long histopathology survey of the D. villosus population inhabiting the initial site of detection (Grafham Water, Cambridgeshire, UK) was conducted. Additional samples were collected from 2 other subsequently identified populations within the UK (Cardiff Bay and Norfolk Broads), and from established populations in France (River Rhine) and Poland (River Vistula). The data revealed a range of pathogens and commensals. Several pathogens occurring within continental populations were not present within the UK populations. Microsporidian parasites and a novel viral pathogen were amongst those not observed in the UK. The absence of these pathogens at UK sites may therefore impart significant survival advantages to D. villosus over native fauna, thereby increasing its success as an invader. The contrast in pathogen profile between UK and continental-invasive populations of D. villosus provides preliminary evidence for so-called 'enemy release' in UK populations of D. villosus and is suggestive of single-point introductions, rather than continual incursion events as previously observed throughout its continental invasive range. This baseline survey provides important data on the pathogen and commensal profile of a high-impact, invasive species early in its invasion history of the UK. It can be utilised to assess potential for temporal pathogen acquisition by non-native invasive aquatic species and to investigate competitive advantages placed upon this invader due to absence of important pathogens experienced within its native range. PMID:24192001

Bojko, J; Stebbing, P D; Bateman, K S; Meatyard, J E; Bacela-Spychalska, K; Dunn, A M; Stentiford, G D

2013-11-01

430

Enterococcus faecalis Subverts and Invades the Host Urothelium in Patients with Chronic Urinary Tract Infection  

PubMed Central

Bacterial urinary tract infections (UTI) are a major growing concern worldwide. Uropathogenic Escherichia coli has been shown to invade the urothelium during acute UTI in mice and humans, forming intracellular reservoirs that can evade antibiotics and the immune response, allowing recurrence at a later date. Other bacterial species, such as Staphylococcus saprophyticus, Klebsiella pneumonia and Salmonella enterica have also been shown to be invasive in acute UTI. However, the role of intracellular infection in chronic UTI causing more subtle lower urinary tract symptoms (LUTS), a particular problem in the elderly population, is poorly understood. Moreover, the species of bacteria involved remains largely unknown. A previous study of a large cohort of non-acute LUTS patients found that Enterococcus faecalis was frequently found in urine specimens. E. faecalis accounts for a significant proportion of chronic bladder infections worldwide, although the invasive lifestyle of this uropathogen has yet to be reported. Here, we wanted to explore this question in more detail. We harvested urothelial cells shed in response to inflammation and, using advanced imaging techniques, inspected them for signs of bacterial pathology and invasion. We found strong evidence of intracellular E. faecalis harboured within urothelial cells shed from the bladder of LUTS patients. Furthermore, using a culture model system, these patient-isolated strains of E. faecalis were able to invade a transitional carcinoma cell line. In contrast, we found no evidence of cellular invasion by E. coli in the patient cells or the culture model system. Our data show that E. faecalis is highly competent to invade in this context; therefore, these results have implications for both the diagnosis and treatment of chronic LUTS. PMID:24363814

Horsley, Harry; Malone-Lee, James; Holland, David; Tuz, Madeleine; Hibbert, Andrew; Kelsey, Michael; Kupelian, Anthony; Rohn, Jennifer L.

2013-01-01

431

NK cells kill mycobacteria directly by releasing perforin and granulysin.  

PubMed

Although the mechanisms underlying the cytotoxic effect of NK cells on tumor cells and intracellular bacteria have been studied extensively, it remains unclear how these cells kill extracellular bacterial pathogens. In this study, we examine how human NK cells kill Mycobacterium kansasii and M.tb. The underlying mechanism is contact dependent and requires two cytolytic proteins: perforin and granulysin. Mycobacteria induce enhanced expression of the cytolytic proteins via activation of the NKG2D/NCR cell-surface receptors and intracellular signaling pathways involving ERK, JNK, and p38 MAPKs. These results suggest that NK cells use similar cellular mechanisms to kill both bacterial pathogens and target host cells. This report reveals a novel role for NK cells, perforin, and granulysin in killing mycobacteria and highlights a potential alternative defense mechanism that the immune system can use against mycobacterial infection. PMID:25139289

Lu, Chia-Chen; Wu, Ting-Shu; Hsu, Ya-Jing; Chang, Chih-Jung; Lin, Chuan-Sheng; Chia, Ju-Hsin; Wu, Tsu-Lan; Huang, Tsung-Teng; Martel, Jan; Ojcius, David M; Young, John D; Lai, Hsin-Chih

2014-12-01

432

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. PMID:24740976

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

2014-01-01

433

The Variety of Integrable Killing Tensors on the 3-Sphere  

NASA Astrophysics Data System (ADS)

Integrable Killing tensors are used to classify orthogonal coordinates in which the classical Hamilton-Jacobi equation can be solved by a separation of variables. We completely solve the Nijenhuis integrability conditions for Killing tensors on the sphere S^3 and give a set of isometry invariants for the integrability of a Killing tensor. We describe explicitly the space of solutions as well as its quotient under isometries as projective varieties and interpret their algebro-geometric properties in terms of Killing tensors. Furthermore, we identify all Stäckel systems in these varieties. This allows us to recover the known list of separation coordinates on S^3 in a simple and purely algebraic way. In particular, we prove that their moduli space is homeomorphic to the associahedron K_4.

Schöbel, Konrad

2014-07-01

434

Alcohol Poisoning Kills 6 Americans Every Day, CDC Says  

MedlinePLUS

... enable JavaScript. Alcohol Poisoning Kills 6 Americans Every Day, CDC Says Older adults hardest hit by binge- ... six people die in the United States each day after consuming far too much alcohol in too ...

435

(M-theory-)Killing spinors on symmetric spaces  

E-print Network

We show how the theory of invariant principal bundle connections for reductive homogeneous spaces can be applied to determine the holonomy of generalised Killing spinor covariant derivatives of the form $D= \

Hustler, Noel

2015-01-01

436

Erythrocyte and leukocyte: two partners in bacteria killing.  

PubMed

Leukocytes can't perform phagocytosis in blood stream. Blood velocity prevents phagocytosis because there is no time for leukocyte to recognize and catch bacteria. Bloodstream clearance from pathogens is performed by erythrocytes. During motion in bloodstream erythrocytes become charged by triboelectric effect. This charge attracts bacteria and fixes them on the surface of erythrocyte, then bacteria are engulfed and killed by hemoglobin oxygen. In bloodstream, leukocyte thin-wrinkled elastic membrane can't be charged by triboelectric effect and so leukocyte can't catch bacteria by means of electrostatic attraction force. Leukocytes engulf and kill bacteria out of blood circulatory system: in tissues, lymph nodes, slow velocity lymph, etc. Erythrocyte and leukocyte are bactericidal partners: the first kills bacteria in bloodstream, the second kills them locally, out of blood circulation. PMID:25259410

Minasyan, Hayk A

2014-01-01

437

Drought and Beetle-Killed Piñon Pines in Arizona  

USGS Multimedia Gallery

Drought and beetle-killed piñon pines in Walnut Canyon National Monument near Flagstaff, Arizona, amid some surviving trees. Forest drought stress is highly correlated with mortality from poor growth, bark beetle outbreaks, and high-severity fire....

438

Drought and Beetle-Killed Piñon Pines in Arizona  

USGS Multimedia Gallery

Drought and beetle-killed piñon pines in Walnut Canyon National Monument near Flagstaff, Arizona, amid a few surviving trees. Forest drought stress is strongly correlated with tree mortality from poor growth, bark beetle outbreaks, and high-severity fire....

439

Why Are Bad Products So Hard to Kill?  

E-print Network

It is puzzling that firms often continue to invest in product development projects when they should know that demand will be low. We argue that bad products are hard to kill because firms face an inherent conflict when ...

Simester, Duncan

440

PFIESTERIA SHUMWAYAE KILLS FISH BY MICROPREDATION NOT ECOTOXIN SECRETION  

EPA Science Inventory

Massive fish kills in mid-Atlantic USA estuaries involving several million Atlantic menhaden, Brevoortia tyrannus,have been attributed to dinoflagellates of the toxic Pfiesteria complex (TPC). Potent ichthyotoxins secreted during Pfiesteria blooms are thought to be responsible fo...

441

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

442

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

443

Genetic engineering of microorganisms for biodiesel production.  

PubMed

Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples. PMID:23222170

Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

2013-01-01

444

Chelating versatility of toxic metal resistant microorganisms  

SciTech Connect

Thorium- and uranium-resistant strains of Pseudomonas aeruginosa when grown in high concentration of these metals (100 to 1000 ppM) in citrate- or succinate-containing media produce several chelating agents. Crude extracts of the metal-induced products, when tested for their toxicity and decorporation potential from mammalian tissues have shown that their efficiency is comparable to DTPA (Diethylene triamine pentaacetic acid) and DFOA (Desferrioxamine). Washed biomass of P. aeruginosa also bioaccumulates heavy metals. Bioaccumulation is selective and several microorganisms have been tested for selective adsorption of uranium, thorium, cobalt, chromium, manganese, tin, and platinum. The results have shown that P. aeruginosa CSU has a preference for uranium, while P. aeruginosa PAO-1 and P. fluorescens exhibit a preference for thorium, and Aspergillus niger is selective for chromium and thorium. 8 refs., 3 figs., 2 tabs.

Premuzic, E.T.; Lin, M.

1985-05-01

445

Alanine, Aspartate, and Asparagine Metabolism in Microorganisms  

Microsoft Academic Search

\\u000a l-Alanine, l-aspartate,\\u000a and l-asparagine are non-essential amino acids that can be produced\\u000a in microorganisms with various enzymes. l-Alanine is produced by\\u000a alanine transaminase (EC 2.6.1.2), alanine:oxo-acid aminotransferase (EC 2.6.1.12), ?-alanine -pyruvate\\u000a aminotransferase (EC 2.6.1.18), alanine-glyoxylate transaminase (EC 2.6.1.44), aspartate 1-decarboxylase\\u000a (EC 4.1.1.11), aspartate 4-decarboxylase (EC 4.1.1.12), alanine racemase (EC 5.1.1.1), and alanine-tRNA\\u000a ligase (EC 6.1.1.7). l-Aspartate is produced by aspartate transaminase

Tadao Oikawa

446

Genetic engineering of microorganisms for biodiesel production  

PubMed Central

Biodiesel, as one type of renewable energy, is an ideal substitute for petroleum-based diesel fuel and is usually made from triacylglycerides by transesterification with alcohols. Biodiesel production based on microbial fermentation aiming to establish more efficient, less-cost and sustainable biodiesel production strategies is under current investigation by various start-up biotechnology companies and research centers. Genetic engineering plays a key role in the transformation of microbes into the desired cell factories with high efficiency of biodiesel production. Here, we present an overview of principal microorganisms used in the microbial biodiesel production and recent advances in metabolic engineering for the modification required. Overexpression or deletion of the related enzymes for de novo synthesis of biodiesel is highlighted with relevant examples. PMID:23222170

Lin, Hui; Wang, Qun; Shen, Qi; Zhan, Jumei; Zhao, Yuhua

2013-01-01

447

Filtration of airborne microorganisms: Modeling and prediction  

SciTech Connect

The filtration of airborne particulates has been studied extensively and removal efficiencies can be adequately predicted from theory or from catalog data. The filtrations of airborne microorganisms, however, has not been specifically addressed by theory and has seen limited empirical study. This paper addresses the variety of factors that may cause microbial filtration efficiency to deviate from predicted values based on particulate size alone. A model is developed to incorporate those factors likely to have significant impact, namely, aspect ratios and lognormal size distributions. This model is then challenged with a database of known airborne pathogens and allergens for which these parameters have been established. Results suggest existing filtration models are accurate within reason for the prediction of filtration efficiencies of airborne bacteria and spores, provided logmean diameters are used. Implications for the use of filtration in health care facilities are discussed.

Kowalski, W.J.; Bahnfleth, W.P.; Whittam, T.S.

1999-07-01

448

Toxicity of calcium salts to aqueous microorganisms  

SciTech Connect

This article investigates the toxicity of calcium to aqueous microogranisms by means of a procedure developed by VNII VODGEO (All-Union Scientific-Research Institute of Water Supply, Sewer Systems, Hydrotechnical Facilities, and Engineering Hydrogeology), with certain changes in the preparation of the culture water. Proposes that with this method, calcium toxicity can be determined for groups of microorganisms that are among the most important in biochemical wastewater treatment and self-purification of water bodies (saprophytes, phase I and II nitrifiers). Finds that calcium in the form of the hydroxide and chloride is nontoxic under the following conditions: for protozoa in concentrations up to 2 g/liter, for saprophytic bacteria up to 3 g/liter, for phase I nitrifiers up to 1 g/liter, and for phase II nitrifiers up to 0.1 g/liter.

Lakhina, K.G.; Dolganova, A.V.; Yakobi, L.K.

1983-03-01

449

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

450

POLYPEPTIDE AND POLYSACCHARIDE PROCESSING IN HYPERTHERMOPHILIC MICROORGANISMS  

SciTech Connect

This project focused on the microbial physiology and biochemistry of heterotrophic hyperthermophiles with respect to mechanisms by which these organisms process polypeptides and polysaccharides under normal and stressed conditions. Emphasis is on two model organisms, for which completed genome sequences are available: Pyrococcus furiosus (growth Topt of 98°C), an archaeon, and Thermotoga maritima (growth Topt of 80°C), a bacterium. Both organisms are obligately anaerobic heterotrophs that reduce sulfur facultatively. Whole genome cDNA spotted microarrays were used to follow transcriptional response to a variety of environmental conditions in order to identify genes encoding proteins involved in the acquisition, synthesis, processing and utilization of polypeptides and polysaccharides. This project provided new insights into the physiological aspects of hyperthermophiles as these relate to microbial biochemistry and biological function in high temperature habitats. The capacity of these microorganisms to produce biohydrogen from renewable feedstocks makes them important for future efforts to develop biofuels.

KELLY, ROBERT M.

2008-12-22

451

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

452

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

453

Approximate Killing vectors on S{sup 2}  

SciTech Connect

We present a new method for computing the best approximation to a Killing vector on closed 2-surfaces that are topologically S{sup 2}. When solutions of Killing's equation do not exist, this method is shown to yield results superior to those produced by existing methods. In addition, this method appears to provide a new tool for studying the horizon geometry of distorted black holes.

Cook, Gregory B. [Department of Physics, Wake Forest University, Winston-Salem, North Carolina 27006 (United States); Whiting, Bernard F. [Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)

2007-08-15

454

STJ X-ray detectors with killed electrode  

NASA Astrophysics Data System (ADS)

Tunnel junctions Al(0)/Nb/Al(1)/AlOx/Al(2)/Nb/NbN with bottom electrode Al(0)/Nb/Al(1) as a killed electrode were studied at temperatures 1.35 and 0.3 K. It was found that at T=0.3 K tunneling from the killed electrode, absent at T=1.35 K, appeared. It increases the detector signal and broadens the spectrum. .

Andrianov, V. A.; Dmitriev, P. N.; Koshelets, V. P.; Kozin, M. G.; Romashkina, I. L.; Sergeev, S. A.

2002-02-01

455

On completeness of orbits of Killing vector fields  

E-print Network

A Theorem is proved which reduces the problem of completeness of orbits of Killing vector fields in maximal globally hyperbolic, say vacuum, space--times to some properties of the orbits near the Cauchy surface. In particular it is shown that all Killing orbits are complete in maximal developements of asymptotically flat Cauchy data, or of Cauchy data prescribed on a compact manifold. This result gives a significant strengthening of the uniqueness theorems for black holes.

Piotr T. Chrusciel

1993-04-21

456

Conformal Killing vector fields and a virial theorem  

NASA Astrophysics Data System (ADS)

The virial theorem is formulated both intrinsically and in local coordinates for a Lagrangian system of a mechanical type on a Riemann manifold. An important case studied in this paper is that of an affine virial function associated with a vector field on the configuration manifold. The special cases of a virial function associated with a Killing, a homothetic, and a conformal Killing vector field are considered and the corresponding virial theorems are established for these types of functions.

Cariñena, José F.; Gheorghiu, Irina; Martínez, Eduardo; Santos, Patrícia

2014-11-01

457

Rates of CTL Killing in Persistent Viral Infection In Vivo  

PubMed Central

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

2014-01-01

458

COMPOSTING: STABILIZATION, DEWATERING, VOLUME REDUCTION, AND PATHOGEN KILL  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aerobic composting is the biological oxidative decomposition of organic materials by successive communities of microorganisms under different temperature regimes which produces a humified end-product. Composting reduces moisture content of organic byproducts. Thermophilic temperatures attained dur...

459

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

NASA Astrophysics Data System (ADS)

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 to 8 ppt. Adult feeding on lettuce increased significantly at 8 ppt compared to 0 ppt (p = 0.002), while hatchling consumption of algae did not vary (p = 0.284). To see how these consumers responded to predators from the invaded ecosystem, we tested behavioural responses to predatory cues from fish, turtles, crayfish and adult applesnails. Results indicated that fish and crayfish prompted similar predator-avoidance behaviors in hatchlings (p's < 0.05) and that hatchling response changed over time. Consumption rates of juvenile redear sunfish did not vary (x2, p > 0.05) between native (ramshorn) and exotic applesnails, whereas adult fish consumed more applesnails (x2, p < 0.001). Our current efforts focus on examining if predator presence or macrophyte choice alters applesnail feeding rates. Research providing insight into the basic ecology of applesnails can foster management efforts at the ecosystem scale.

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

2005-05-01

460

Aerial arthropod communities of native and invaded forests, Robinson Crusoe Island, Chile.  

PubMed

Invasive species significantly contribute to biological change and threaten biodiversity, with a growing body of evidence that plant invasions affect higher trophic levels. We explored the relative importance of plant invasion and forest structure on aerial arthropod abundance, diversity, and composition on Robinson Crusoe Island, Chile. We used flight intercept traps to sample aerial arthropods within distinct canopy strata of native and invaded forests over 3-mo periods in 2006 and 2007. Arthropod abundance and diversity were higher in native than invaded forest, and arthropod communities were distinct between forest types. In both forest types, arthropod abundance was highest in the lower canopy, and canopy strata exhibited some differences in arthropod community composition. Several morphospecies were distinctly associated with each forest type. The strong differences in aerial arthropod communities associated with the invasion of native forest by non-native plants may affect other trophic levels, such as insectivorous birds. Steps to stop invasive plant spread and to restore native forest composition and structure are needed to safeguard the integrity of native communities, from plants to higher-level consumers. PMID:22127166

Hagen, Erin N; Bakker, Jonathan D; Gara, Robert I

2010-08-01

461

Fine-scale geographical origin of an insect pest invading North America.  

PubMed

Invasive species may rapidly spread throughout new areas once introduced, which may potentially lead to serious damage to local fauna and flora. Information on geographical origins, introduction routes, and biology in native regions of such invasive species is of critical importance in identifying means of transport, preventing reintroduction, and establishing control/eradication methods. The plataspid stinkbug Megacopta cribraria, known as kudzu bug, recently invaded North America and now has become not only an agricultural pest of soybean but also a nuisance pest. Here we investigate the geographical origin of the invasive M. cribraria populations. Phylogeographical analyses based on 8.7 kb mitochondrial DNA sequences of the introduced and East Asian native Megacopta populations identified a well-supported clade consisting of the introduced populations and M. punctatissima populations in the Kyushu region of Japan, which strongly suggests that the invading M. cribraria populations are derived from a M. punctatissima population in the Kyushu region. Therefore, the region is proposed as a promising source of natural enemies for biological control of the invasive pest. Based on the phylogenetic information, relationship and treatment of the two Megacopta species are discussed. PMID:24551228

Hosokawa, Takahiro; Nikoh, Naruo; Fukatsu, Takema

2014-01-01

462

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. PMID:25567967

Carroll, Scott P

2011-01-01

463

Curvilinear effects of invasive plants on plant diversity: plant community invaded by Sphagneticola trilobata.  

PubMed

The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%), compared with the native plants (over 60%). Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants. PMID:25426856

Qi, Shan-Shan; Dai, Zhi-Cong; Zhai, De-Li; Chen, Si-Chong; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Zhong, Qiong-Xin; Du, Dao-Lin

2014-01-01

464

Curvilinear Effects of Invasive Plants on Plant Diversity: Plant Community Invaded by Sphagneticola trilobata  

PubMed Central

The effects of invasive plants on the species diversity of plant communities are controversial, showing either a positive or negative linear relationship. Based on community data collected from forty 5 m×5 m plots invaded by Sphagneticola trilobata in eight cities across Hainan Island, China, we found S. trilobata decreased plant community diversity once its cover was beyond 10%. We demonstrated that the effects of invasive/native plants on the plant diversity of communities invaded by S. trilobata were curvilinear. These effects, which showed peaks under different degrees of vegetation cover, appeared not only for S. trilobata and all invasive plants, but also for all native plants. Invasive plants primarily had negative effects on plant diversity when they became abundant at a much lower cover level (less than 35%), compared with the native plants (over 60%). Thus, it is necessary to distinguish a range for assessing the effects of plants, especially invasive plants. Our results also confirmed that the invasion intensity of invasive alien plants increased with the intensity of local economic development. We highlight and further discuss the critical importance of curvilinear effects of biological invasion to provide ideas regarding the conservation of local biodiversity and the management of invasive plants. PMID:25426856

Zhai, De-Li; Chen, Si-Chong; Si, Chun-Can; Huang, Ping; Wang, Rui-Ping; Zhong, Qiong-Xin; Du, Dao-Lin

2014-01-01

465

A Successful Crayfish Invader Is Capable of Facultative Parthenogenesis: A Novel Reproductive Mode in Decapod Crustaceans  

PubMed Central

Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the “tens rule” which states that only a minority of species introduced to new regions become established, and only a minority of those become invasive and pests. So far, success of cambarid invaders has largely been attributed to rapid maturation, high reproductive output, aggressiveness, and tolerance to pollution. We provide experimental evidence that females of one cambarid species particularly widespread in Europe, the spiny-cheek crayfish Orconectes limosus, are capable of facultative parthenogenesis. Such reproductive mode has never before been recognized in decapods, the most diverse crustacean order. As shown by analysis of seven microsatellite loci, crayfish females kept physically separated from males produced genetically homogeneous offspring identical with maternal individuals; this suggests they reproduced by apomixis, unlike those females which mated with males and had a diverse offspring. Further research is needed to clarify what environmental conditions are necessary for a switch to parthenogenesis in O. limosus, and what role it plays in natural crayfish populations. However, if such reproductive plasticity is present in other cambarid crayfish species, it may contribute to the overwhelming invasive success of this group. PMID:21655282

Bu?i?, Miloš; Hulák, Martin; Kouba, Antonín

2011-01-01

466

Fine-Scale Geographical Origin of an Insect Pest Invading North America  

PubMed Central

Invasive species may rapidly spread throughout new areas once introduced, which may potentially lead to serious damage to local fauna and flora. Information on geographical origins, introduction routes, and biology in native regions of such invasive species is of critical importance in identifying means of transport, preventing reintroduction, and establishing control/eradication methods. The plataspid stinkbug Megacopta cribraria, known as kudzu bug, recently invaded North America and now has become not only an agricultural pest of soybean but also a nuisance pest. Here we investigate the geographical origin of the invasive M. cribraria populations. Phylogeographical analyses based on 8.7 kb mitochondrial DNA sequences of the introduced and East Asian native Megacopta populations identified a well-supported clade consisting of the introduced populations and M. punctatissima populations in the Kyushu region of Japan, which strongly suggests that the invading M. cribraria populations are derived from a M. punctatissima population in the Kyushu region. Therefore, the region is proposed as a promising source of natural enemies for biological control of the invasive pest. Based on the phylogenetic information, relationship and treatment of the two Megacopta species are discussed. PMID:24551228

Hosokawa, Takahiro; Nikoh, Naruo; Fukatsu, Takema

2014-01-01

467

Biological ablation of sentinel lymph node metastasis in submucosally invaded early gastrointestinal cancer.  

PubMed

Currently, early gastrointestinal cancers are treated endoscopically, as long as there are no lymph node metastases. However, once a gastrointestinal cancer invades the submucosal layer, the lymph node metastatic rate rises to higher than 10%. Therefore, surgery is still the gold standard to remove regional lymph nodes containing possible metastases. Here, to avoid prophylactic surgery, we propose a less-invasive biological ablation of lymph node metastasis in submucosally invaded gastrointestinal cancer patients. We have established an orthotopic early rectal cancer xenograft model with spontaneous lymph node metastasis by implantation of green fluorescent protein (GFP)-labeled human colon cancer cells into the submucosal layer of the murine rectum. A solution containing telomerase-specific oncolytic adenovirus was injected into the peritumoral submucosal space, followed by excision of the primary rectal tumors mimicking the endoscopic submucosal dissection (ESD) technique. Seven days after treatment, GFP signals had completely disappeared indicating that sentinel lymph node metastasis was selectively eradicated. Moreover, biologically treated mice were confirmed to be relapse-free even 4 weeks after treatment. These results indicate that virus-mediated biological ablation selectively targets lymph node metastasis and provides a potential alternative to surgery for submucosal invasive gastrointestinal cancer patients. PMID:25523761

Kikuchi, Satoru; Kishimoto, Hiroyuki; Tazawa, Hiroshi; Hashimoto, Yuuri; Kuroda, Shinji; Nishizaki, Masahiko; Nagasaka, Takeshi; Shirakawa, Yasuhiro; Kagawa, Shunsuke; Urata, Yasuo; Hoffman, Robert M; Fujiwara, Toshiyoshi

2015-03-01

468

Apoptosis of T lymphocytes invading glioblastomas multiforme: a possible tumor defense mechanism  

PubMed Central

Object The goal of this study was to investigate whether apoptosis occurs in T lymphocytes that invade Fas ligand (FasL)–expressing glioblastomas multiforme (GBMs) and if its induction could be mediated by Fas. Methods Apoptotic T lymphocytes were detected in GBMs by using detection of cell-type markers combined with active caspase-3 immunohistochemical analysis, a recently introduced apoptosis-specific in situ ligation assay, as well as by examining morphological criteria. Apoptotic T cells expressed Fas and were localized in the vicinity or in direct contact with FasL-expressing tumor cells. The T lymphocytes were undergoing apoptosis in spite of Bcl-2 expression. Expression of Bax was also detected in dying T cells, which can explain the absence of the protective effect of Bcl-2, because Bax inhibits Bcl-2 death–repressor activity. Conclusions On the basis of the data presented in this paper, the authors suggest that GBM cells that express FasL can induce apoptosis in invading immune cells. This phenomenon may play an important role in these tumors’ maintenance of immune privilege and evasion of immune attacks. Awareness of this phenomenon should be helpful for the development of novel strategies for treatment of malignant gliomas. PMID:11883844

Didenko, Vladimir V.; Ngo, Hop N.; Minchew, Candace; Baskin, David S.

2007-01-01

469

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

470

Phenanthrene degradation by microorganisms isolated from a contaminated stream  

Microsoft Academic Search

Autochthonous yeast and bacteria strains were isolated from a contaminated stream and studied for their potential to degrade phenanthrene, a three-ring polycyclic aromatic hydrocarbon (PAH), as their only source of carbon and energy. Rhodotorula glutinis and Pseudomonas aeruginosa were the prevailing microorganisms utilizing phenanthrene. Cells of these microorganisms were inoculated in liquid mineral basal medium at 25, 50, 100 and

M. C. Romero; M. C. Cazau; S. Giorgieri; A. M. Arambarri

1998-01-01

471

Role and functions of beneficial microorganisms in sustainable aquaculture  

Microsoft Academic Search

This paper aims to review the development of scientific concepts of microecology and ecology of microbes and the role and functions of beneficial microorganisms in aquaculture and mariculture. Beneficial microorganisms play a great role in natural and man-made aquatic ecosystems based on the co-evolution theory in living biosphere on earth. Their functions are to adjust algal population in water bodies

Qunlan Zhou; Kangmin Li; Xie Jun; Liu Bo

2009-01-01

472

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

473

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

474

INACTIVATION OF DIFFERENT MICROORGANISMS WITH PULSED MAGNETIC FIELD TREATMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Pulsed magnetic field treatment has shown a great potential in non-thermal treatment in food processing to inactivate microorganisms. The objective of this study was to investigate the effect of medium parameters such as temperature (8-40°C), pH (3-9), and initial numbers of microorganisms (105-109...

475

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

476

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...

477

Cybernetic modeling of adaptive prediction of environmental changes by microorganisms.  

PubMed

Microorganisms exhibit varied regulatory strategies such as direct regulation, symmetric anticipatory regulation, asymmetric anticipatory regulation, etc. Current mathematical modeling frameworks for the growth of microorganisms either do not incorporate regulation or assume that the microorganisms utilize the direct regulation strategy. In the present study, we extend the cybernetic modeling framework to account for asymmetric anticipatory regulation strategy. The extended model accurately captures various experimental observations. We use the developed model to explore the fitness advantage provided by the asymmetric anticipatory regulation strategy and observe that the optimal extent of asymmetric regulation depends on the selective pressure that the microorganisms experience. We also explore the importance of timing the response in anticipatory regulation and find that there is an optimal time, dependent on the extent of asymmetric regulation, at which microorganisms should respond anticipatorily to maximize their fitness. We then discuss the advantages offered by the cybernetic modeling framework over other modeling frameworks in modeling the asymmetric anticipatory regulation strategy. PMID:24296040

Mandli, Aravinda R; Modak, Jayant M

2014-02-01

478

The enemy of my enemy is my friend: intraguild predation between invaders and natives facilitates coexistence with shared invasive prey.  

PubMed

Understanding and predicting the outcomes of biological invasions is challenging where multiple invader and native species interact. We hypothesize that antagonistic interactions between invaders and natives could divert their impact on subsequent invasive species, thus facilitating coexistence. From field data, we found that, when existing together in freshwater sites, the native amphipod Gammarus duebeni celticus and a previous invader G. pulex appear to facilitate the establishment of a second invader, their shared prey Crangonyx pseudogracilis. Indeed, the latter species was rarely found at sites where each Gammarus species was present on its own. Experiments indicated that this may be the result of G. d. celticus and G. pulex engaging in more intraguild predation (IGP) than cannibalism; when the 'enemy' of either Gammarus species was present, that is, the other Gammarus species, C. pseudogracilis significantly more often escaped predation. Thus, the presence of mutual enemies and the stronger inter- than intraspecific interactions they engage in can facilitate other invaders. With some invasive species such as C. pseudogracilis having no known detrimental effects on native species, and indeed having some positive ecological effects, we also conclude that some invasions could promote biodiversity and ecosystem functioning. PMID:25122739

MacNeil, Calum; Dick, Jaimie T A

2014-08-01

479

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

480

Laboratory study on activating indigenous microorganisms to enhance oil recovery in Shengli Oilfield  

Microsoft Academic Search

Microbial enhanced oil recovery (MEOR) offers an economic alternative to enhanced oil recovery (EOR). In accordance to the source of the microorganisms used, microbial enhanced oil recovery can be categorized into two types: injected exogenous microorganisms or utilized indigenous microorganisms for enhanced oil recovery. Indigenous microorganisms for MEOR have greater advantages compared to injected microorganisms. For example, this technology does

Mutai Bao; Xiangping Kong; Guancheng Jiang; Xiulin Wang; Ximing Li

2009-01-01

481

RNA polymerase gene, microorganism having said gene and the production of RNA polymerase by the use of said microorganism  

DOEpatents

SP6 bacteriophage RNA polymerase is produced by cultivating a new microorganism (particularly new strains of Escherichia coli) harboring a plasmid that carries SP6 bacteriophage RNA polymerase gene and recovering SP6 bacteriophage RNA polymerase from the culture broth. SP6 bacteriophage RNA polymerase gene is provided as are new microorganisms harboring a plasmid that carries SP6 bacteriophage RNA polymerase gene.

Kotani, Hirokazu (Muko, JP); Hiraoka, Nobutsugu (Muko, JP); Obayashi, Akira (Uji, JP)

1991-01-01

482

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

483

Proteomics for routine identification of microorganisms.  

PubMed

The invention of MALDI-TOF-MS enormously contributed to the understanding of protein chemistry and cell biology. Without this technique proteomics would most likely not be the important discipline it is today. Besides 'true' proteomics, MALDI-TOF-MS was applied for the analysis of microorganisms for their taxonomic characterization from its beginning. This approach has since been developed as a diagnostic tool readily available for routine, high-throughput analysis of microbial isolates from clinical specimens by intact-cell mass spectrometry (ICMS), the direct analysis of whole bacterial cell without a preceding fractionation or separation by chromatography or electrophoresis. ICMS exploits the reproducibility of mass fingerprints for individual bacterial and fungal strains as well as the high similarity of mass fingerprints within a species. Comparison of mass spectral data to genomic sequences emphasized the validity of peak patterns as taxonomic markers. Supported by comprehensive databases, MALDI-TOF-MS-based identification has been widely accepted in clinical laboratories within only a few years. PMID:21726051

Welker, Martin

2011-08-01

484

Rapidly evolving microorganisms with high biofuel tolerance  

NASA Astrophysics Data System (ADS)

Replacing non-renewable energy sources is one of the biggest and most exciting challenges of our generation. Algae and bacteria are poised to become major renewable biofuels if strains can be developed that provide a high,consistent and robust yield of oil. One major stumbling block towards this goal is the lack of tolerance to high concentrations of biofuels like isobutanol. Using traditional bioengineering techniques to remedy this face the hurdle of identifying the correct pathway or gene to modify. But the multiplicity of interactions inside a cell makes it very hard to determine what to modify a priori. Instead, we propose a technology that does not require prior knowledge of the genes or pathways to modify. In our approach that marries microfabrication and ecology, spatial heterogeneity is used as a knob to speed up evolution in the desired direction. Recently, we have successfully used this approach to demonstrate the rapid emergence of bacterial antibiotic resistance in as little as ten hours. Here, we describe our experimental results in developing new strains of micro-organisms with high oil tolerance. Besides biofuel production, our work is also relevant to oil spill clean-ups.

Vyawahare, Saurabh; Zhang, Qiucen; Lang, Wendy; Austin, Robert

2012-02-01

485

Snow as a habitat for microorganisms  

NASA Technical Reports Server (NTRS)

There are three major habitats involving ice and snow, and the microorganisms studied from these habitats are most eukaryotic. Sea ice is inhabited by algae called diatoms, glacial ice has sparse populations of green algai cal desmids, and the temporary and permanent snows in mountainous regions and high latitudes are inhabited mostly by green algal flagellates. The life cycle of green algal flagellates is summarized by discussing the effects of light, temperature, nutrients, and snow melts. Specific examples of optimal conditions and environmental effects for various snow algae are given. It is not likely that the eukaryotic snow algae presented are candidated for life on the planet Mars. Evolutionally, eukaryotic cells as know on Earth may not have had the opportunity to develop on Mars (if life evolved at all on Mars) since eukaryotes did not appear on Earth until almost two billion years after the first prokaryotic organisms. However, the snow/ice ecosystems on Earth present themselves as extreme habitats were there is evidence of prokaryotic life (eubacteria and cyanbacteria) of which literally nothing is known. Any future surveillances of extant and/or extinct life on Mars should include probes (if not landing sites) to investigate sites of concentrations of ice water. The possibility of signs of life in Martian polar regions should not be overlooked.

Hoham, Ronald W.

1989-01-01

486

DNA Fragmentation in Microorganisms Assessed In Situ?  

PubMed Central

Chromosomal DNA fragmentation may be a direct or indirect outcome of cell death. Unlike DNA fragmentation in higher eukaryotic cells, DNA fragmentation in microorganisms is rarely studied. We report an adaptation of a diffusion-based assay, developed as a kit, which allows for simple and rapid discrimination of bacteria with fragmented DNA. Intact cells were embedded in an agarose microgel on a slide, incubated in a lysis buffer to partially remove the cell walls, membranes, and proteins, and then stained with a DNA fluorochrome, SYBR Gold. Identifying cells with fragmented DNA uses peripheral diffusion of DNA fragments. Cells without DNA fragmentation show only limited spreading of DNA fiber loops. These results have been seen in several gram-negative and gram-positive bacteria, as well as in yeasts. Detection of DNA fragmentation was confirmed by fluoroquinolone treatment and by DNA breakage detection-fluorescence in situ hybridization. Proteus mirabilis with spontaneously fragmented DNA during exponential and stationary growth or Escherichia coli with DNA damaged after exposure to hydrogen peroxide or antibiotics, such as ciprofloxacin or ampicillin, was clearly detected. Similarly, fragmented DNA was detected in Saccharomyces cerevisiae after amphotericin B treatment. Our assay may be useful for the simple and rapid evaluation of DNA damage and repair as well as cell death, either spontaneous or induced by exogenous stimuli, including antimicrobial agents or environmental conditions. PMID:18689511

Fernández, José Luis; Cartelle, Mónica; Muriel, Lourdes; Santiso, Rebeca; Tamayo, María; Goyanes, Vicente; Gosálvez, Jaime; Bou, Germán

2008-01-01

487

DNA fragmentation in microorganisms assessed in situ.  

PubMed

Chromosomal DNA fragmentation may be a direct or indirect outcome of cell death. Unlike DNA fragmentation in higher eukaryotic cells, DNA fragmentation in microorganisms is rarely studied. We report an adaptation of a diffusion-based assay, developed as a kit, which allows for simple and rapid discrimination of bacteria with fragmented DNA. Intact cells were embedded in an agarose microgel on a slide, incubated in a lysis buffer to partially remove the cell walls, membranes, and proteins, and then stained with a DNA fluorochrome, SYBR Gold. Identifying cells with fragmented DNA uses peripheral diffusion of DNA fragments. Cells without DNA fragmentation show only limited spreading of DNA fiber loops. These results have been seen in several gram-negative and gram-positive bacteria, as well as in yeasts. Detection of DNA fragmentation was confirmed by fluoroquinolone treatment and by DNA breakage detection-fluorescence in situ hybridization. Proteus mirabilis with spontaneously fragmented DNA during exponential and stationary growth or Escherichia coli with DNA damaged after exposure to hydrogen peroxide or antibiotics, such as ciprofloxacin or ampicillin, was clearly detected. Similarly, fragmented DNA was detected in Saccharomyces cerevisiae after amphotericin B treatment. Our assay may be useful for the simple and rapid evaluation of DNA damage and repair as well as cell death, either spontaneous or induced by exogenous stimuli, including antimicrobial agents or environmental conditions. PMID:18689511

Fernández, José Luis; Cartelle, Mónica; Muriel, Lourdes; Santiso, Rebeca; Tamayo, María; Goyanes, Vicente; Gosálvez, Jaime; Bou, Germán

2008-10-01

488

Evaluation of actinide biosorption by microorganisms  

SciTech Connect

Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

Happel, A.M.

1996-06-01

489

Heavy metal removal and recovery using microorganisms  

SciTech Connect

Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

Wilde, E.W. (Westinghouse Savannah River Co., Aiken, SC (United States)); Benemann, J.R. (Benemann (J.R.), Pinole, CA (United States))

1991-02-01

490

Autonomous support for microorganism research in space  

NASA Technical Reports Server (NTRS)

A preliminary design for performing on-orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the COMmercial Experiment Transported (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with inflight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibration, and radiation are provided for environmental regulation and experimental data collection. Additional experiment data acquisition includes optical density measurement, microscopy, video, and file photography. Onboard full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing.

Luttges, M. W.; Klaus, D. M.; Fleet, M. L.; Miller, M. S.; Shipley, D. E.; Smith, J. D.

1992-01-01

491

Autonomous support for microorganism research in space  

NASA Technical Reports Server (NTRS)

A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investi