Widespread Wolbachia infection in terrestrial isopods and other crustaceans

Directory of Open Access Journals (Sweden)

Richard Cordaux

2012-03-01

Full Text Available Wolbachia bacteria are obligate intracellular alpha-Proteobacteria of arthropods and nematodes. Although widespread among isopod crustaceans, they have seldom been found in non-isopod crustacean species. Here, we report Wolbachia infection in fourteen new crustacean species. Our results extend the range of Wolbachia infections in terrestrial isopods and amphipods (class Malacostraca. We report the occurrence of two different Wolbachia strains in two host species (a terrestrial isopod and an amphipod. Moreover, the discovery of Wolbachia in the goose barnacle Lepas anatifera (subclass Thecostraca establishes Wolbachia infection in class Maxillopoda. The new bacterial strains are closely related to B-supergroup Wolbachia strains previously reported from crustacean hosts. Our results suggest that Wolbachia infection may be much more widespread in crustaceans than previously thought. The presence of related Wolbachia strains in highly divergent crustacean hosts suggests that Wolbachia endosymbionts can naturally adapt to a wide range of crustacean hosts. Given the ability of isopod Wolbachia strains to induce feminization of genetic males or cytoplasmic incompatibility, we speculate that manipulation of crustacean-borne Wolbachia bacteria might represent potential tools for controlling crustacean species of commercial interest and crustacean or insect disease vectors.

Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

Science.gov (United States)

Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.

2013-01-01

The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

TESTING THE LINK BETWEEN TERRESTRIAL CLIMATE CHANGE AND GALACTIC SPIRAL ARM TRANSIT

International Nuclear Information System (INIS)

Overholt, Andrew C.; Melott, Adrian L.; Pohl, Martin

2009-01-01

We re-examine past suggestions of a close link between terrestrial climate change and the Sun's transit of spiral arms in its path through the Milky Way galaxy. These links produced concrete fits, deriving the unknown spiral pattern speed from terrestrial climate correlations. We test these fits against new data on spiral structure based on CO data that do not make simplifying assumptions about symmetry and circular rotation. If we compare the times of these transits with changes in the climate of Earth, the claimed correlations not only disappear, but we also find that they cannot be resurrected for any reasonable pattern speed.

The deep biosphere in terrestrial sediments in the Chesapeake Bay area, Virginia, USA

Directory of Open Access Journals (Sweden)

Anja eBreuker

2011-07-01

Full Text Available For the first time quantitative data on the abundance of Bacteria, Archaea and Eukarya in deep terrestrial sediments are provided using multiple methods (total cell counting, quantitative real-time PCR (Q-PCR and catalyzed reporter deposition – fluorescence in situ hybridization (CARD-FISH. The oligotrophic (organic carbon content of ~ 0.2 % deep terrestrial sediments in the Chesapeake Bay area at Eyreville, Virginia, USA, were drilled and sampled up to a depth of 140 m in 2006. The possibility of contamination during drilling was checked using fluorescent microspheres. Total cell counts decreased from 109 to 106 cells per g dry weight (dw within the uppermost 20 m depth, and did not further decrease with depth below. A significant proportion of the total cell counts could be detected with CARD-FISH within the uppermost 7 m depth. The CARD-FISH numbers for Bacteria were about an order of magnitude higher than those for Archaea. The dominance of Bacteria over Archaea was confirmed by Q-PCR. The down core quantitative distribution of prokaryotic and eukaryotic small subunit ribosomal RNA genes as well as functional genes involved in different biogeochemical processes was revealed by Q-PCR for the uppermost 10 m and for 80-140 m depth. Eukarya and the Fe(III- and Mn(IV-reducing bacterial group Geobacteriaceae were almost only found in the uppermost meter (arable soil, where reactive iron was detected in higher amounts. The bacterial candidate division JS-1 and the classes Anaerolineae and Caldilineae of the phylum Chloroflexi, highly abundant in marine sediments, were found up to the maximum sampling depth in high copy numbers at this terrestrial site as well. A similar high abundance of the functional gene cbbL encoding for the large subunit of RubisCO suggests that autotrophic microorganisms could be relevant in addition to heterotrophs. The functional gene aprA of sulfate reducing bacteria was found within distinct layers up to ca. 100 m depth

Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar

NARCIS (Netherlands)

Grove, C.A.; Zinke, J.; Scheufen, T.; Maina, J.; Epping, E.; Boer, W.; Randriamanantsoa, B.; Brummer, G.-J.A.

2012-01-01

Coral cores provide vital climate reconstructions for site-specific temporal variability in river flow and sediment load. Yet, their ability to record spatial differences across multiple catchments is relatively unknown. Here, we investigate spatial linkages between four coral proxies of terrestrial

Hyphae colonizing bacteria associated with Penicillium bilaii

DEFF Research Database (Denmark)

Ghodsalavi, Behnoushsadat

shown that mycorrhizal helper bacteria presenting in mycorrhizal fungi could stimulate fungal growth, promote establishment of root-fungus symbiosis and enhance plant production. But it is unknown if the comparable relationship exist between the non-mycorrhizal fungus P. bilaii and its hyphae associated...... bacteria. In the current PhD thesis, we assumed that hyphae-associated microbiome of P. bilaii might harbor helper bacteria with ability to improve fungal growth and P solubilization performance. Therefore, we aimed to isolate bacteria associated with the P. bilaii hyphae and identify the fungal growth...... stimulating bacteria with the perspective of promoting efficiency of Jumpstart in soil – plant system. For this purpose, most of the work within the current project was carried out by development of suitable model systems by mimicking the natural soil habitat to reach to the reliable performance in soil...

Molecular characterization of sulfate-reducing bacteria in the Guaymas Basin

Science.gov (United States)

Dhillon, Ashita; Teske, Andreas; Dillon, Jesse; Stahl, David A.; Sogin, Mitchell L.

2003-01-01

The Guaymas Basin (Gulf of California) is a hydrothermal vent site where thermal alteration of deposited planktonic and terrestrial organic matter forms petroliferous material which supports diverse sulfate-reducing bacteria. We explored the phylogenetic and functional diversity of the sulfate-reducing bacteria by characterizing PCR-amplified dissimilatory sulfite reductase (dsrAB) and 16S rRNA genes from the upper 4 cm of the Guaymas sediment. The dsrAB sequences revealed that there was a major clade closely related to the acetate-oxidizing delta-proteobacterial genus Desulfobacter and a clade of novel, deeply branching dsr sequences related to environmental dsr sequences from marine sediments in Aarhus Bay and Kysing Fjord (Denmark). Other dsr clones were affiliated with gram-positive thermophilic sulfate reducers (genus Desulfotomaculum) and the delta-proteobacterial species Desulforhabdus amnigena and Thermodesulforhabdus norvegica. Phylogenetic analysis of 16S rRNAs from the same environmental samples resulted in identification of four clones affiliated with Desulfobacterium niacini, a member of the acetate-oxidizing, nutritionally versatile genus Desulfobacterium, and one clone related to Desulfobacula toluolica and Desulfotignum balticum. Other bacterial 16S rRNA bacterial phylotypes were represented by non-sulfate reducers and uncultured lineages with unknown physiology, like OP9, OP8, as well as a group with no clear affiliation. In summary, analyses of both 16S rRNA and dsrAB clone libraries resulted in identification of members of the Desulfobacteriales in the Guaymas sediments. In addition, the dsrAB sequencing approach revealed a novel group of sulfate-reducing prokaryotes that could not be identified by 16S rRNA sequencing.

Gene clusters involved in isethionate degradation by terrestrial and marine bacteria.

KAUST Repository

Weinitschke, Sonja; Sharma, Pia I; Stingl, Ulrich; Cook, Alasdair M; Smits, Theo H M

2010-01-01

Ubiquitous isethionate (2-hydroxyethanesulfonate) is dissimilated by diverse bacteria. Growth of Cupriavidus necator H16 with isethionate was observed, as was inducible membrane-bound isethionate dehydrogenase (IseJ) and inducible transcription of the genes predicted to encode IseJ and a transporter (IseU). Biodiversity in isethionate transport genes was observed and investigated by transcription experiments.

Microbial metagenomes from three aquifers in the Fennoscandian shield terrestrial deep biosphere reveal metabolic partitioning among populations.

Science.gov (United States)

Wu, Xiaofen; Holmfeldt, Karin; Hubalek, Valerie; Lundin, Daniel; Åström, Mats; Bertilsson, Stefan; Dopson, Mark

2016-05-01

Microorganisms in the terrestrial deep biosphere host up to 20% of the earth's biomass and are suggested to be sustained by the gases hydrogen and carbon dioxide. A metagenome analysis of three deep subsurface water types of contrasting age (from 86% coverage. The populations were dominated by Proteobacteria, Candidate divisions, unclassified archaea and unclassified bacteria. The estimated genome sizes of the biosphere. The data were finally used to create a combined metabolic model of the deep terrestrial biosphere microbial community.

Isolation of chromium resistant bacteria from a former bauxite mine ...

African Journals Online (AJOL)

The Cr (VI) reducing capacity of bacteria has been investigated in many different soils and waters but little or no information is available from soils originating from bauxite mine areas. From soil, mud and rhizospheres of the floating aquatic plant Potamogeton natans L. and the terrestrial plant Carduus acanthoides L., the Cr ...

Sulfate- and Sulfur-Reducing Bacteria as Terrestrial Analogs for Microbial Life on Jupiter's Satellite Io

Science.gov (United States)

Pikuta, Elena V.; Hoover, Richard B.; Six, N. Frank (Technical Monitor)

2001-01-01

Observations from the Voyager and Galileo spacecraft have revealed Jupiter's moon Io to be the most volcanically active body of our Solar System. The Galileo Near Infrared Imaging Spectrometer (NIMS) detected extensive deposits of sulfur compounds, elemental sulfur and SO2 frost on the surface of Io. There are extreme temperature variations on Io's surface, ranging from -130 C to over 2000 C at the Pillan Patera volcanic vent. The active volcanoes, fumaroles, calderas, and lava lakes and vast sulfur deposits on this frozen moon indicate that analogs of sulfur- and sulfate-reducing bacteria might inhabit Io. Hence Io may have great significance to Astrobiology. Earth's life forms that depend on sulfur respiration are members of two domains: Bacteria and Archaea. Two basic links of the biogeochemical sulfur cycle of Earth have been studied: 1) the sulfur oxidizing process (occurring at aerobic conditions) and 2) the process of sulfur-reduction to hydrogen sulfide (anaerobic conditions). Sulfate-reducing bacteria (StRB) and sulfur-reducing bacteria (SrRB) are responsible for anaerobic reducing processes. At the present time the systematics of StRB include over 112 species distributed into 35 genera of Bacteria and Archaea. Moderately thermophilic and mesophilic SrRB belong to the Bacteria. The hyperthermophilic SrRB predominately belong to the domain Archaea and are included in the genera: Pyrodictium, Thermoproteus, Pyrobaculum, Thermophilum, Desulfurococcus, and Thermodiscus. The StRB and SrRB use a wide spectrum of substrates as electron donors for lithotrophic and heterotrophic type nutrition. The electron acceptors for the StRB include: sulfate, thiosulfate, sulfite, sulfur, arsenate, dithionite, tetrathionate, sulfur monoxide, iron, nitrite, selenite, fumarate, oxygen, carbon dioxide, and chlorine-containing phenol compounds. The Sulfate- and Sulfur-reducing bacteria are widely distributed in anaerobic ecosystems, including extreme environments like hot springs

Terrestrial dissolved organic matter distribution in the North Sea.

Science.gov (United States)

Painter, Stuart C; Lapworth, Dan J; Woodward, E Malcolm S; Kroeger, Silke; Evans, Chris D; Mayor, Daniel J; Sanders, Richard J

2018-07-15

The flow of terrestrial carbon to rivers and inland waters is a major term in the global carbon cycle. The organic fraction of this flux may be buried, remineralized or ultimately stored in the deep ocean. The latter can only occur if terrestrial organic carbon can pass through the coastal and estuarine filter, a process of unknown efficiency. Here, data are presented on the spatial distribution of terrestrial fluorescent and chromophoric dissolved organic matter (FDOM and CDOM, respectively) throughout the North Sea, which receives organic matter from multiple distinct sources. We use FDOM and CDOM as proxies for terrestrial dissolved organic matter (tDOM) to test the hypothesis that tDOM is quantitatively transferred through the North Sea to the open North Atlantic Ocean. Excitation emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC) revealed a single terrestrial humic-like class of compounds whose distribution was restricted to the coastal margins and, via an inverse salinity relationship, to major riverine inputs. Two distinct sources of fluorescent humic-like material were observed associated with the combined outflows of the Rhine, Weser and Elbe rivers in the south-eastern North Sea and the Baltic Sea outflow to the eastern central North Sea. The flux of tDOM from the North Sea to the Atlantic Ocean appears insignificant, although tDOM export may occur through Norwegian coastal waters unsampled in our study. Our analysis suggests that the bulk of tDOM exported from the Northwest European and Scandinavian landmasses is buried or remineralized internally, with potential losses to the atmosphere. This interpretation implies that the residence time in estuarine and coastal systems exerts an important control over the fate of tDOM and needs to be considered when evaluating the role of terrestrial carbon losses in the global carbon cycle. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Microbial plant litter decomposition in aquatic and terrestrial boreal systems along a natural fertility gradient

Science.gov (United States)

Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

2017-04-01

Plant litter decomposition is a global ecosystem process, with a crucial role in carbon and nutrient cycling. The majority of litter processing occurs in terrestrial systems, but an important fraction also takes place in inland waters. Among environmental factors, pH impacts the litter decomposition through its selective influence on microbial decomposers. Fungal communities are less affected by pH than bacteria, possibly owing to a wider pH tolerance by this group. On the other hand, bacterial pH optima are constrained to a narrower range of pH values. The microbial decomposition of litter is universally nutrient limited; but few comparisons exist between terrestrial and aquatic systems. We investigated the microbial colonisation and decomposition of plant litter along a fertility gradient, which varied in both pH and N availability in both soil and adjacent water. To do this we installed litterbags with birch (Betula pendula) in streams and corresponding soils in adjacent riparian areas in a boreal system, in Krycklan, Sweden. During the four months covering the ice-free growth season we monitored the successional dynamics of fungal (acetate incorporation into ergosterol) and bacterial growth (thymidine incorporation), microbial respiration in leaf litter, and quantitative and qualitative changes in litter over time. We observed that bacterial growth rates were initially higher in litter decomposing in streams than those in soils, but differences between terrestrial and aquatic bacterial production converged towards the end of the experiment. In litter bags installed in soils, bacterial growth was lower at sites with more acidic pH and lower N availability, while aquatic bacteria were relatively unaffected by the fertility level. Fungal growth rates were two-fold higher for litter decomposing in streams than in soils. In aquatic systems, fungal growth was initially lower in low fertility sites, but differences gradually disappeared over the time course. Fungal

RESISTANCE OF KARST CAVERNS NITROGEN-FIXING BACTERIA TO EXTREME FACTORS

Directory of Open Access Journals (Sweden)

Tashyrev O. B.

2014-10-01

Full Text Available To determine the studied bacteria resistance quantitative parameters of extreme factors such as toxic metals (Cu2+, organic xenobiotics (p-nitrochlorobenzene and UV-irradiation were the aim of the research. Six strains of nitrogen-fixing bacteria isolated from clays of two caverns Mushkarova Yama (Podolia, Ukraine and Kuybyshevskaya (Western Caucasus, Abkhazia and Azotobacter vinelandii УКМ В-6017 as a reference strain have been tested. For this purpose the maximum permissible concentration of Cu2+ and p-nitrochlorobenzene in the concentration gradient and lethal doses of UV by the survival caverns have been determined. Maximum permissible concentrations for strains were as 10 ppm Cu2+, 70–120 ppm of p-nitrochlorobenzene. The maximum doses of UV-irradiation varied in the range of 55–85 J/m2 (LD99.99. It is shown that three classes of extreme factors resistance parameters of karst caverns strains are similar to the strain of terrestrial soil ecosystems. The most active studied strains reduce the concentration of p-nitrochlorobenzene in the medium in 13 times. The ability of nitrogen-fixing bacteria to degrade p-nitrochlorobenzene could be used in creation new environmental biotechnology for industrial wastewater treatment from nitrochloroaromatic xenobiotics. Isolated strains could be used as destructors for soils bioremediation in agrobiotechnologies and to optimize plants nitrogen nutrition in terrestrial ecosystems.

Terrestrial microorganisms at an altitude of 20,000 m in Earth's atmosphere

Science.gov (United States)

Griffin, Dale W.

2004-01-01

A joint effort between the U.S. Geological Survey's (USGS) Global Desert Dust and NASA's Stratospheric and Cosmic Dust Programs identified culturable microbes from an air sample collected at an altitude of 20,000 m. A total of 4 fungal (Penicillium sp.) and 71 bacteria colonyforming units (70 colonies of Bacillus luciferensis believed to have originated from a single cell collected at altitude and one colony of Bacillus sphaericus) were enumerated, isolated and identified using a morphological key and 16S rDNA sequencing respectively. All of the isolates identified were sporeforming pigmented fungi or bacteria of terrestrial origin and demonstrate that the presence of viable microorganisms in Earth's upper atmosphere may not be uncommon.

Deep Atomic Binding (DAB) Approach in Interpretation of Fission Products Behavior in Terrestrial and Water Ecosystems

International Nuclear Information System (INIS)

Ajlouni, Abdul-Wali M.S.

2006-01-01

A large number of studies and models were established to explain the fission products (FP) behavior within terrestrial and water ecosystems, but a number of behaviors were non understandable, which always attributed to unknown reasons. According to DAB hypothesis, almost all fission products behaviors in terrestrial and water ecosystems could be interpreted in a wide coincidence. The gab between former models predictions, and field behavior of fission products after accidents like Chernobyl have been explained. DAB represents a tool to reduce radio-phobia as well as radiation protection expenses. (author)

Comparative metagenomics of eight geographically remote terrestrial hot springs

DEFF Research Database (Denmark)

Menzel, Peter; Islin, Sóley Ruth; Rike, Anne Gunn

2015-01-01

Hot springs are natural habitats for thermophilic Archaea and Bacteria. In this paper, we present the metagenomic analysis of eight globally distributed terrestrial hot springs from China, Iceland, Italy, Russia, and the USA with a temperature range between 61 and 92 (∘)C and pH between 1.8 and 7....... A comparison of the biodiversity and community composition generally showed a decrease in biodiversity with increasing temperature and decreasing pH. Another important factor shaping microbial diversity of the studied sites was the abundance of organic substrates. Several species of the Crenarchaeal order...

Molecular Characterization of Sulfate-Reducing Bacteria in the Guaymas Basin†

Science.gov (United States)

Dhillon, Ashita; Teske, Andreas; Dillon, Jesse; Stahl, David A.; Sogin, Mitchell L.

2003-01-01

The Guaymas Basin (Gulf of California) is a hydrothermal vent site where thermal alteration of deposited planktonic and terrestrial organic matter forms petroliferous material which supports diverse sulfate-reducing bacteria. We explored the phylogenetic and functional diversity of the sulfate-reducing bacteria by characterizing PCR-amplified dissimilatory sulfite reductase (dsrAB) and 16S rRNA genes from the upper 4 cm of the Guaymas sediment. The dsrAB sequences revealed that there was a major clade closely related to the acetate-oxidizing delta-proteobacterial genus Desulfobacter and a clade of novel, deeply branching dsr sequences related to environmental dsr sequences from marine sediments in Aarhus Bay and Kysing Fjord (Denmark). Other dsr clones were affiliated with gram-positive thermophilic sulfate reducers (genus Desulfotomaculum) and the delta-proteobacterial species Desulforhabdus amnigena and Thermodesulforhabdus norvegica. Phylogenetic analysis of 16S rRNAs from the same environmental samples resulted in identification of four clones affiliated with Desulfobacterium niacini, a member of the acetate-oxidizing, nutritionally versatile genus Desulfobacterium, and one clone related to Desulfobacula toluolica and Desulfotignum balticum. Other bacterial 16S rRNA bacterial phylotypes were represented by non-sulfate reducers and uncultured lineages with unknown physiology, like OP9, OP8, as well as a group with no clear affiliation. In summary, analyses of both 16S rRNA and dsrAB clone libraries resulted in identification of members of the Desulfobacteriales in the Guaymas sediments. In addition, the dsrAB sequencing approach revealed a novel group of sulfate-reducing prokaryotes that could not be identified by 16S rRNA sequencing. PMID:12732547

The terrestrial isopod microbiome: An all-in-one toolbox for animal-microbe interactions of ecological relevance

Directory of Open Access Journals (Sweden)

Didier Bouchon

2016-09-01

Full Text Available Bacterial symbionts represent essential drivers of arthropod ecology and evolution, influencing host traits such as nutrition, reproduction, immunity and speciation. However, the majority of work on arthropod microbiota has been conducted in insects and more studies in non-model species across different ecological niches will be needed to complete our understanding of host-microbiota interactions. In this review, we present terrestrial isopod crustaceans as an emerging model organism to investigate symbiotic associations with potential relevance to ecosystem functioning. Terrestrial isopods comprise a group of crustaceans that have evolved a terrestrial lifestyle and represent keystone species in terrestrial ecosystems, contributing to the decomposition of organic matter and regulating the microbial food web. Since their nutrition is based on plant detritus, it has long been suspected that bacterial symbionts located in the digestive tissues might play an important role in host nutrition via the provisioning of digestive enzymes, thereby enabling the utilization of recalcitrant food compounds (e.g. cellulose or lignins. If this were the case, then (i the acquisition of these bacteria might have been an important evolutionary prerequisite for the colonization of land by isopods, and (ii these bacterial symbionts would directly mediate the role of their hosts in ecosystem functioning. Several bacterial symbionts have indeed been discovered in the midgut caeca of terrestrial isopods and some of them might be specific to this group of animals (i.e. Candidatus Hepatoplasma crinochetorum, Candidatus Hepatincola porcellionum and Rhabdochlamydia porcellionis, while others are well-known intracellular pathogens (Rickettsiella spp. or reproductive parasites (Wolbachia sp.. Moreover, a recent investigation of the microbiota in Armadillidium vulgare has revealed that this species harbors a highly diverse bacterial community which varies between host

The Terrestrial Isopod Microbiome: An All-in-One Toolbox for Animal-Microbe Interactions of Ecological Relevance.

Science.gov (United States)

Bouchon, Didier; Zimmer, Martin; Dittmer, Jessica

2016-01-01

Bacterial symbionts represent essential drivers of arthropod ecology and evolution, influencing host traits such as nutrition, reproduction, immunity, and speciation. However, the majority of work on arthropod microbiota has been conducted in insects and more studies in non-model species across different ecological niches will be needed to complete our understanding of host-microbiota interactions. In this review, we present terrestrial isopod crustaceans as an emerging model organism to investigate symbiotic associations with potential relevance to ecosystem functioning. Terrestrial isopods comprise a group of crustaceans that have evolved a terrestrial lifestyle and represent keystone species in terrestrial ecosystems, contributing to the decomposition of organic matter and regulating the microbial food web. Since their nutrition is based on plant detritus, it has long been suspected that bacterial symbionts located in the digestive tissues might play an important role in host nutrition via the provisioning of digestive enzymes, thereby enabling the utilization of recalcitrant food compounds (e.g., cellulose or lignins). If this were the case, then (i) the acquisition of these bacteria might have been an important evolutionary prerequisite for the colonization of land by isopods, and (ii) these bacterial symbionts would directly mediate the role of their hosts in ecosystem functioning. Several bacterial symbionts have indeed been discovered in the midgut caeca of terrestrial isopods and some of them might be specific to this group of animals (i.e., Candidatus Hepatoplasma crinochetorum, Candidatus Hepatincola porcellionum, and Rhabdochlamydia porcellionis ), while others are well-known intracellular pathogens ( Rickettsiella spp.) or reproductive parasites ( Wolbachia sp.). Moreover, a recent investigation of the microbiota in Armadillidium vulgare has revealed that this species harbors a highly diverse bacterial community which varies between host populations

The ecological role of type three secretion systems in the interaction of bacteria with fungi in soil and related habitats is diverse and context-dependent

NARCIS (Netherlands)

Nazir, Rashid; Mazurier, Sylvie; Yang, Pu; Lemanceau, Philippe; van Elsas, Jan Dirk

2017-01-01

Bacteria and fungi constitute important organisms in many ecosystems, in particular terrestrial ones. Both organismal groups contribute significantly to biogeochemical cycling processes. Ecological theory postulates that bacteria capable of receiving benefits from host fungi are likely to evolve

Growth inhibition of fouling bacteria and diatoms by extract of terrestrial plant, Derris scandens (Dicotyledonae:Leguminocae)

Digital Repository Service at National Institute of Oceanography (India)

Sawant, S.S.; Sonak, S.; Garg, A.

Methanol extract of terrestrial plant, Derris scandens Benth, was found to inhibit growth of four diatoms and 7 bacterial species of fouling community. The concentrations required to bring about 100% inhibition of growth of the diatoms ranged...

Identification of marine methanol-utilizing bacteria

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, M; Iwaki, H; Kouno, K; Inui, T

1980-01-01

A taxonomical study of 65 marine methanol-utilizing bacteria is described. They were Gram-negative, non-spore-forming rods with a polar flagellum and had marine bacterial properties and required vitamin B/sub 12/ for growth. All of them assimilated fructose in addition to C/sub 1/-compounds and produced acid oxidatively from fructose. Twenty-four strains assimilated only C/sub 1/-compounds. They were resistant to penicillin, oxytetracycline and 0/129 substance (Vibrio stat), and tolerant to 12% NaCl. Guanine-cytosine contents of deoxyribonucleic acid in typical strains fell in the range of 43.8 to 47.6%. Other morphological and physiological properties were almost the same as those of terrestrial methanol-utilizers. Bacteria in the first group (41 strains) were facultative methylotrophs and were divided into three subgroups by the assimilation of methylated amines, that is, subgroup I (30 strains) assimilated mono-, di- and tri-methylamine, subgroup II (9 strains) assimilated only mono-methylamine, the bacteria of subgroups I and II were named Alteromonas thalassomethanolica sp. nov. and subgroup III (2 strains) did not assimilate methylated amines, and was tentatively assigned as Alteromonas sp. The second group of bacteria (24 strains) was obligate methylotrophs, named Methylomonas thalassica sp. nov. and was divided into subgroup IV (15 strains) which assimilated mono-, di and tri-methylamine and subgroup V (9 strains) which assimilated mono-methylamine.

Genome mining reveals unlocked bioactive potential of marine Gram-negative bacteria

DEFF Research Database (Denmark)

Machado, Henrique; Sonnenschein, Eva; Melchiorsen, Jette

2015-01-01

Background: Antibiotic resistance in bacteria spreads quickly, overtaking the pace at which new compounds are discovered and this emphasizes the immediate need to discover new compounds for control of infectious diseases. Terrestrial bacteria have for decades been investigated as a source......- and Gammaproteobacteria collected during the Galathea 3 expedition were sequenced and mined for natural product encoding gene clusters. Results: Independently of genome size, bacteria of all tested genera carried a large number of clusters encoding different potential bioactivities, especially within the Vibrionaceae...... and Pseudoalteromonas species that commonly live in close association with eukaryotic organisms in the environment. Chitin regulation by the ChiS histidine-kinase seems to be a general trait of the Vibrionaceae family, however it is absent in the Pseudomonadaceae. Hence, the degree to which chitin influences secondary...

Synergistic Antimicrobial Effect of Tribulus terrestris and Bitter Almond Extracts

Directory of Open Access Journals (Sweden)

Hamid Abtahi

2014-12-01

Full Text Available Background: The antimicrobial effects of the extracts of different kinds of plants have been demonstrated in several studies. However, no study has been conducted so far on the synergistic effects of two herbal extracts on their germicidal effects. In this study, in addition to antibacterial effects of the aqueous, methanol or ethanol extracts of Tribulus terrestris and bitter almond on some bacteria, the synergistic effects of the extracts of these two plants were also evaluated. Materials and Methods: In this experimental study, water, methanol and ethanol extracts of seeds were screened against some bacterial strains. Seeds were extracted by percolation method. Aliquots of the extracts at variable concentrations were then incubated with different bacterial strains, and the antimicrobial activities of the extracts from seeds were determined by MIC. Three antibiotics were used as reference compounds for antibacterial activities. Seeds extract inhibited significantly the growth of the tested bacterial strains. Results: The greatest synergistic effect of T. terrestris and bitter almond extracts is detected in methanol and aqueous extracts. Among the bacterial strains tested, Staphylococcus aureus was most susceptibility. Conclusion: The results showed the highest antibacterial effect in the combination of methanol extract of T. terrestris and the aqueous extract of the bitter almond.

Amphibians at risk? Susceptibility of terrestrial amphibian life stages to pesticides.

Science.gov (United States)

Brühl, Carsten A; Pieper, Silvia; Weber, Brigitte

2011-11-01

Current pesticide risk assessment does not specifically consider amphibians. Amphibians in the aquatic environment (aquatic life stages or postmetamorphic aquatic amphibians) and terrestrial living juvenile or adult amphibians are assumed to be covered by the risk assessment for aquatic invertebrates and fish, or mammals and birds, respectively. This procedure has been evaluated as being sufficiently protective regarding the acute risk posed by a number of pesticides to aquatic amphibian life stages (eggs, larvae). However, it is unknown whether the exposure and sensitivity of terrestrial living amphibians are comparable to mammalian and avian exposure and sensitivity. We reviewed the literature on dermal pesticide absorption and toxicity studies for terrestrial life stages of amphibians, focusing on the dermal exposure pathway, that is, through treated soil or direct overspray. In vitro studies demonstrated that cutaneous absorption of chemicals is significant and that chemical percutaneous passage, P (cm/h), is higher in amphibians than in mammals. In vivo, the rapid and substantial uptake of the herbicide atrazine from treated soil by toads (Bufo americanus) has been described. Severe toxic effects on various amphibian species have been reported for field-relevant application rates of different pesticides. In general, exposure and toxicity studies for terrestrial amphibian life stages are scarce, and the reported data indicate the need for further research, especially in light of the global amphibian decline. Copyright © 2011 SETAC.

Search for EPR markers of the history and origin of the insoluble organic matter in extraterrestrial and terrestrial rocks

Science.gov (United States)

Gourier, Didier; Binet, Laurent; Scrzypczak, Audrey; Derenne, Sylvie; Robert, François

2004-05-01

The insoluble organic matter (IOM) of three carbonaceous meteorites (Orgueil, Murchison and Tagish Lake meteorites) and three samples of cherts (microcrystalline SiO 2 rock) containing microfossils with age ranging between 45 million years and 3.5 billion years is studied by electron paramagnetic resonance (EPR). The age of the meteorites is that of the solar system (4.6 billion years). The purpose of this work was to determine the EPR parameters, which allow us to discriminate between biogenic and extra terrestrial origin for the organic matter. Such indicators should be relevant for the controversy regarding the biogenicity of the organic matter in the oldest cheroot (3.5 billion years) and in Martian meteorites containing microbe-like microstructures. The organic matter of meteorites contains a high concentration of diradicaloid moieties characterised by a diamagnetic ground state S=0 and a thermally accessible triplet state S=1. The three meteorites exhibit the same singlet-triplet gap (ST gap) Δ E≈0.1 eV. To the best of our knowledge, such diradicaloids are unknown in insoluble organic matter of terrestrial origin. We have also shown that the EPR linewidth of insoluble organic matter in cherts and coals decrease logarithmically with the age of the organic matter. We conclude from this result that the organic matter in the oldest cherts (3.5 billion years) has the same age as their SiO 2 matrix, and is not due to a latter contamination by bacteria, as was recently found in meteoritic samples.

Bacteria in atmospheric waters: Detection, characteristics and implications

Science.gov (United States)

Hu, Wei; Niu, Hongya; Murata, Kotaro; Wu, Zhijun; Hu, Min; Kojima, Tomoko; Zhang, Daizhou

2018-04-01

In this review paper, we synthesize the current knowledges about bacteria in atmospheric waters, e.g., cloud, fog, rain, and snow, most of which were obtained very recently. First, we briefly describe the importance of bacteria in atmospheric waters, i.e., the essentiality of studying bacteria in atmospheric waters in understanding aerosol-cloud-precipitation-climate interactions in the Earth system. Next, approaches to collect atmospheric water samples for the detection of bacteria and methods to identify the bacteria are summarized and compared. Then the available data on the abundance, viability and community composition of bacteria in atmospheric waters are summarized. The average bacterial concentration in cloud water was usually on the order 104-105 cells mL-1, while that in precipitation on the order 103-104 cells mL-1. Most of the bacteria were viable or metabolically active. Their community composition was highly diverse and differed at various sites. Factors potentially influencing the bacteria, e.g., air pollution levels and sources, meteorological conditions, seasonal effect, and physicochemical properties of atmospheric waters, are described. After that, the implications of bacteria present in atmospheric waters, including their effect on nucleation in clouds, atmospheric chemistry, ecosystems and public health, are briefly discussed. Finally, based on the current knowledges on bacteria in atmospheric waters, which in fact remains largely unknown, we give perspectives that should be paid attention to in future studies.

Polyhydroxyalkanoate biosynthesis by oxalotrophic bacteria from high Andean soil

Directory of Open Access Journals (Sweden)

Roger David Castillo-Arteaga

2018-02-01

Full Text Available Oxalate is a highly oxidized organic acid anion used as a carbon and energy source by oxalotrophic bacteria. Oxalogenic plants convert atmospheric CO2 into oxalic acid and oxalic salts. Oxalate-salt formation acts as a carbon sink in terrestrial ecosystems via the oxalate-carbonate pathway (OCP. Oxalotrophic bacteria might be implicated in other carbon-storage processes, including the synthesis of polyhydroxyalkanoates (PHAs. More recently, a variety of bacteria from the Andean region of Colombia in Nariño have been reported for their PHA-producing abilities. These species can degrade oxalate and participate in the oxalate-carbonate pathway. The aim of this study was to isolate and characterize oxalotrophic bacteria with the capacity to accumulate PHA biopolymers. Plants of the genus Oxalis were collected and bacteria were isolated from the soil adhering to the roots. The isolated bacterial strains were characterized using biochemical and molecular biological methods. The consumption of oxalate in culture was quantified, and PHA production was monitored in batch fermentation. The polymeric composition was characterized using gas chromatography. Finally, a biosynthetic pathway based on our findings and on those from published sources is proposed. Strains of Bacillus spp. and Serratia sp. were found to metabolize calcium oxalate and synthesize PHA.

Characterization of Bacteria Associated with Pinewood Nematode Bursaphelenchus xylophilus

Science.gov (United States)

Vicente, Claudia S. L.; Nascimento, Francisco; Espada, Margarida; Barbosa, Pedro; Mota, Manuel; Glick, Bernard R.; Oliveira, Solange

2012-01-01

Pine wilt disease (PWD) is a complex disease integrating three major agents: the pathogenic agent, the pinewood nematode Bursaphelenchus xylophilus; the insect-vector Monochamus spp.; and the host pine tree, Pinus sp. Since the early 80's, the notion that another pathogenic agent, namely bacteria, may play a role in PWD has been gaining traction, however the role of bacteria in PWD is still unknown. The present work supports the possibility that some B. xylophilus-associated bacteria may play a significant role in the development of this disease. This is inferred as a consequence of: (i) the phenotypic characterization of a collection of 35 isolates of B. xylophilus-associated bacteria, in different tests broadly used to test plant pathogenic and plant growth promoting bacteria, and (ii) greenhouse experiments that infer the pathogenicity of these bacteria in maritime pine, Pinus pinaster. The results illustrate the presence of a heterogeneous microbial community associated with B. xylophilus and the traits exhibited by at least, some of these bacteria, appear to be related to PWD symptoms. The inoculation of four specific B. xylophilus-associated bacteria isolates in P. pinaster seedlings resulted in the development of some PWD symptoms suggesting that these bacteria likely play an active role with B. xylophilus in PWD. PMID:23091599

Evaluation of terrestrial microcosms for detection, fate, and survival analysis of genetically engineered microorganisms and their recombinant genetic material

Energy Technology Data Exchange (ETDEWEB)

Fredrickson, J.K.; Seidler, R.J.

1989-02-01

The research included in this document represents the current scientific information available regarding the applicability of terrestrial microcosms and related methodologies for evaluating detection methods and the fate and survival of microorganisms in the environment. The three terrestrial microcosms described in this document were used to evaluate the survival and fate of recombinant bacteria in soils and in association with plant surfaces and insects and their transport through soil with percolating water and root systems, and to test new methods and procedures to improve detection and enumeration of bacteria in soil. Simple (potting soil composed of peat mix and perlite, lacking environmental control and monitoring) and complex microcosms (agricultural soil with partial control and monitoring of environmental conditions) were demonstrated to be useful tools for preliminary assessments of microbial viability in terrestrial ecosystems. These studies evaluated the survival patterns of Enterobacter cloacae (pBR322) in soil and on plant surfaces and the ingestion of this same microorganism by cutworms and survival in the foregut and frass. The Versacore microcosm design was used to monitor the fate and competitiveness of genetically engineered bacteria in soil. Both selective media and gene probes were used successfully to follow the fate of two recombinant Pseudomonas sp. introduced into Versacore microcosms. Intact soil-core microcosms were employed to evaluate the fate and transport of genetically altered Azospirillum sp. and Pseudomonas sp. in soil and the plant rhizosphere. The usefulness of these various microcosms as a tool for risk assessment is underscored by the ease in obtaining soil from a proposed field release site to evaluate subsequent GEM fate and survival.

Growth inhibition of fouling bacteria and diatoms by extract of terrestrial plant, @iDerris scandens@@ (Dicotyledonae:Leguminocae)

Digital Repository Service at National Institute of Oceanography (India)

Sawant, S.S.; Sonak, S.; Garg, A.

Methanol extract of terrestrial plant, @iDerris scandens@@ Benth, was found to inhibit growth of four diatoms and 7 bacterial species of fouling community. The concentrations required to bring about 100% inhibition of growth of the diatoms ranged...

Bacteria-Mineral Interactions on the Surfaces of Metal-Resistant Bacteria

International Nuclear Information System (INIS)

Malkin, A.J.

2010-01-01

The extraordinary ability of indigenous microorganisms, like metal-resistant bacteria, for biotransformation of toxic compounds is of considerable interest for the emerging area of environmental bioremediation. However, the underlying mechanisms by which metal-resistant bacteria transform toxic compounds are currently unknown and await elucidation. The project's objective was to study stress-induced responses of metal-resistant bacteria to environmental changes and chemical stimulants. This project involved a multi-institutional collaboration of our LLNL group with the group of Dr. H.-Y. Holman (Lawrence Berkeley National Laboratory). In this project, we have utilized metal-resistant bacteria Arthrobacter oxydans as a model bacterial system. We have utilized atomic force microscopy (AFM) to visualize for the first time at the nanometer scale formation of stress-induced structures on bacterial surfaces in response to Cr (VI) exposure. We have demonstrated that structure, assembly, and composition of these stress-induced structures are dependent on Cr (VI) concentrations. Our AFM observations of the appearance and development of stress-induced layers on the surfaces of Arthrobacter oxydans bacteria exposed to Cr (VI) were confirmed by Dr. Holman's biochemical, electron microscopy, and synchrotron infrared spectromicroscopy studies. In general, in vitro imaging of live microbial and cellular systems represents one of the most challenging issues in application of AFM. Various approaches for immobilization of bacteria on the substrate for in vitro imaging were tested in this project. Imaging of live bacteria was achieved, however further optimization of experimental methods are needed for high-resolution visualization of the cellular environmental structural dynamics by AFM. This project enhanced the current insight into molecular architecture, structural and environmental variability of bacterial systems. The project partially funded research for two book chapters (1

Viable Legionella pneumophila bacteria in natural soil and rainwater puddles

NARCIS (Netherlands)

van Heijnsbergen, E.; de Roda Husman, A. M.; Lodder, W. J.; Bouwknegt, M.; Docters van Leeuwen, A. E.; Bruin, J. P.; Euser, S. M.; den Boer, J. W.; Schalk, J. A C

Aims: For the majority of sporadic Legionnaires' disease cases the source of infection remains unknown. Infection may possible result from exposure to Legionella bacteria in sources that are not yet considered in outbreak investigations. Therefore, potential sources of pathogenic Legionella

Microbial ecology of Thailand tsunami and non-tsunami affected terrestrials.

Science.gov (United States)

Somboonna, Naraporn; Wilantho, Alisa; Jankaew, Kruawun; Assawamakin, Anunchai; Sangsrakru, Duangjai; Tangphatsornruang, Sithichoke; Tongsima, Sissades

2014-01-01

The effects of tsunamis on microbial ecologies have been ill-defined, especially in Phang Nga province, Thailand. This ecosystem was catastrophically impacted by the 2004 Indian Ocean tsunami as well as the 600 year-old tsunami in Phra Thong island, Phang Nga province. No study has been conducted to elucidate their effects on microbial ecology. This study represents the first to elucidate their effects on microbial ecology. We utilized metagenomics with 16S and 18S rDNA-barcoded pyrosequencing to obtain prokaryotic and eukaryotic profiles for this terrestrial site, tsunami affected (S1), as well as a parallel unaffected terrestrial site, non-tsunami affected (S2). S1 demonstrated unique microbial community patterns than S2. The dendrogram constructed using the prokaryotic profiles supported the unique S1 microbial communities. S1 contained more proportions of archaea and bacteria domains, specifically species belonging to Bacteroidetes became more frequent, in replacing of the other typical floras like Proteobacteria, Acidobacteria and Basidiomycota. Pathogenic microbes, including Acinetobacter haemolyticus, Flavobacterium spp. and Photobacterium spp., were also found frequently in S1. Furthermore, different metabolic potentials highlighted this microbial community change could impact the functional ecology of the site. Moreover, the habitat prediction based on percent of species indicators for marine, brackish, freshwater and terrestrial niches pointed the S1 to largely comprise marine habitat indicating-species.

Conspicuous veils formed by vibrioid bacteria on sulfidic marine sediment

DEFF Research Database (Denmark)

Thar, Roland Matthias; Kühl, Michael

2002-01-01

, but the bacteria have so far not been isolated in pure culture, and a detailed characterization of their metabolism is still lacking. The bacteria are colorless, gram-negative, and vibrioid-shaped (1.3- to 2.5- by 4- to 10-µm) cells that multiply by binary division and contain several spherical inclusions of poly......We describe the morphology and behavior of a hitherto unknown bacterial species that forms conspicuous veils (typical dimensions, 30 by 30 mm) on sulfidic marine sediment. The new bacteria were enriched on complex sulfidic medium within a benthic gradient chamber in oxygen-sulfide countergradients......, forming a cohesive whitish veil at the oxic-anoxic interface. Bacteria attached to the veil kept rotating and adapted their stalk lengths dynamically to changing oxygen concentrations. The joint action of rotating bacteria on the veil induced a homogeneous water flow from the oxic water region toward...

Upstream freshwater and terrestrial sources are differentially reflected in the bacterial community structure along a small Arctic river and its estuary

Directory of Open Access Journals (Sweden)

Aviaja Lyberth Hauptmann

2016-09-01

Full Text Available Glacier melting and altered precipitation patterns influence Arctic freshwater and coastal ecosystems. Arctic rivers are central to Arctic water ecosystems by linking glacier meltwaters and precipitation with the ocean through transport of particulate matter and microorganisms. However, the impact of different water sources on the microbial communities in Arctic rivers and estuaries remains unknown. In this study we used 16S rRNA gene amplicon sequencing to assess a small river and its estuary on the Disko Island, West Greenland (69°N. Samples were taken in August when there is maximum precipitation and temperatures are high in the Disko Bay area. We describe the bacterial community through a river into the estuary, including communities originating in a glacier and a proglacial lake. Our results show that water from the glacier and lake transports distinct communities into the river in terms of diversity and community composition. Bacteria of terrestrial origin were among the dominating OTUs in the main river, while the glacier and lake supplied the river with water containing fewer terrestrial organisms. Also, more psychrophilic taxa were found in the community supplied by the lake. At the river mouth, the presence of dominant bacterial taxa from the lake and glacier was unnoticeable, but these taxa increased their abundances again further into the estuary. On average 23% of the estuary community consisted of indicator OTUs from different sites along the river. Environmental variables showed only weak correlations with community composition, suggesting that hydrology largely influences the observed patterns.

Upstream Freshwater and Terrestrial Sources Are Differentially Reflected in the Bacterial Community Structure along a Small Arctic River and Its Estuary

Science.gov (United States)

Hauptmann, Aviaja L.; Markussen, Thor N.; Stibal, Marek; Olsen, Nikoline S.; Elberling, Bo; Bælum, Jacob; Sicheritz-Pontén, Thomas; Jacobsen, Carsten S.

2016-01-01

Glacier melting and altered precipitation patterns influence Arctic freshwater and coastal ecosystems. Arctic rivers are central to Arctic water ecosystems by linking glacier meltwaters and precipitation with the ocean through transport of particulate matter and microorganisms. However, the impact of different water sources on the microbial communities in Arctic rivers and estuaries remains unknown. In this study we used 16S rRNA gene amplicon sequencing to assess a small river and its estuary on the Disko Island, West Greenland (69°N). Samples were taken in August when there is maximum precipitation and temperatures are high in the Disko Bay area. We describe the bacterial community through a river into the estuary, including communities originating in a glacier and a proglacial lake. Our results show that water from the glacier and lake transports distinct communities into the river in terms of diversity and community composition. Bacteria of terrestrial origin were among the dominating OTUs in the main river, while the glacier and lake supplied the river with water containing fewer terrestrial organisms. Also, more psychrophilic taxa were found in the community supplied by the lake. At the river mouth, the presence of dominant bacterial taxa from the lake and glacier was unnoticeable, but these taxa increased their abundances again further into the estuary. On average 23% of the estuary community consisted of indicator OTUs from different sites along the river. Environmental variables showed only weak correlations with community composition, suggesting that hydrology largely influences the observed patterns. PMID:27708629

The prey’s scent – Volatile organic compound mediated interactions between soil bacteria and their protist predators

NARCIS (Netherlands)

Schulz, K.B.; Geisen, Stefan; Wubs, E.R.J.; Song, C.; Boer, de W.; Garbeva, Paolina

2017-01-01

Protists are major predators of bacteria in soils. However, it remains unknown how protists sense their prey in this highly complex environment. Here, we investigated whether volatile organic compounds (VOCs) of six phylogenetic distinct soil bacteria affect the performance of three different soil

Anaerobic bacteria as producers of antibiotics.

Science.gov (United States)

Behnken, Swantje; Hertweck, Christian

2012-10-01

Anaerobic bacteria are the oldest terrestrial creatures. They occur ubiquitously in soil and in the intestine of higher organisms and play a major role in human health, ecology, and industry. However, until lately no antibiotic or any other secondary metabolite has been known from anaerobes. Mining the genome sequences of Clostridium spp. has revealed a high prevalence of putative biosynthesis genes (PKS and NRPS), and only recently the first antibiotic from the anaerobic world, closthioamide, has been isolated from the cellulose degrading bacterium Clostridium cellulolyticum. The successful genetic induction of antibiotic biosynthesis in an anaerobe encourages further investigations of obligate anaerobes to tap their hidden biosynthetic potential.

Deep-sea biodiversity in the Mediterranean Sea: the known, the unknown, and the unknowable.

Directory of Open Access Journals (Sweden)

Roberto Danovaro

Full Text Available Deep-sea ecosystems represent the largest biome of the global biosphere, but knowledge of their biodiversity is still scant. The Mediterranean basin has been proposed as a hot spot of terrestrial and coastal marine biodiversity but has been supposed to be impoverished of deep-sea species richness. We summarized all available information on benthic biodiversity (Prokaryotes, Foraminifera, Meiofauna, Macrofauna, and Megafauna in different deep-sea ecosystems of the Mediterranean Sea (200 to more than 4,000 m depth, including open slopes, deep basins, canyons, cold seeps, seamounts, deep-water corals and deep-hypersaline anoxic basins and analyzed overall longitudinal and bathymetric patterns. We show that in contrast to what was expected from the sharp decrease in organic carbon fluxes and reduced faunal abundance, the deep-sea biodiversity of both the eastern and the western basins of the Mediterranean Sea is similarly high. All of the biodiversity components, except Bacteria and Archaea, displayed a decreasing pattern with increasing water depth, but to a different extent for each component. Unlike patterns observed for faunal abundance, highest negative values of the slopes of the biodiversity patterns were observed for Meiofauna, followed by Macrofauna and Megafauna. Comparison of the biodiversity associated with open slopes, deep basins, canyons, and deep-water corals showed that the deep basins were the least diverse. Rarefaction curves allowed us to estimate the expected number of species for each benthic component in different bathymetric ranges. A large fraction of exclusive species was associated with each specific habitat or ecosystem. Thus, each deep-sea ecosystem contributes significantly to overall biodiversity. From theoretical extrapolations we estimate that the overall deep-sea Mediterranean biodiversity (excluding prokaryotes reaches approximately 2805 species of which about 66% is still undiscovered. Among the biotic components

Persistence of ectomycorrhizas by Thelephora terrestris on outplanted Scots pine seedlings

Directory of Open Access Journals (Sweden)

Dorota Hilszczańska

2013-12-01

Full Text Available Thelephora terrestris (Erhr. Fr. is a very common ectomycorrhizal symbiont (ECM in conifer trees, however the role of this ubiquitous fungus in nurseries and Scots pine plantations is still unknown. It is described as tolerant of high nitrogen availability and therefore was taken into consideration as an important ECM partner of seedlings, particularly after replanting on post agricultural land. In laboratory the seedlings of Scots pine (Pinus sylvestris L. were inoculated with T. terrestris (Tt/IBL/2 or not inoculated (control and grown in containers in two different regimes of nitrogen fertilization (4g N x kg-1 and 6 g N x kg-1. Next year these seedlings were outplanted in post agricultural land and 6 months later, the number and identity of some mycorrhizas were studied. It was found, that mycorrhizal abundance was higher in the inoculated treatments than in non-inoculated ones. PCR RFLP analysis confirmed share of two different isolates of Thelephora engaged in mycorrhizal symbiosis. Part of mycorrhizas had the same pattern of RFLP as the isolate used to inoculation. Similar results were obtained in second year of experimental study in the field what confirmed the persistence of artificially introduced T. terrestris in post agricultural soil as an important component of the ECM community.

Symbiotic bacteria of helminths: what role may they play in ecosystems under anthropogenic stress?

Science.gov (United States)

Morley, N J

2016-11-01

Symbiotic bacteria are a common feature of many animals, particularly invertebrates, from both aquatic and terrestrial habitats. These bacteria have increasingly been recognized as performing an important role in maintaining invertebrate health. Both ecto- and endoparasitic helminths have also been found to harbour a range of bacterial species which provide a similar function. The part symbiotic bacteria play in sustaining homeostasis of free-living invertebrates exposed to anthropogenic pressure (climate change, pollution), and the consequences to invertebrate populations when their symbionts succumb to poor environmental conditions, are increasingly important areas of research. Helminths are also susceptible to environmental stress and their symbiotic bacteria may be a key aspect of their responses to deteriorating conditions. This article summarizes the ecophysiological relationship helminths have with symbiotic bacteria and the role they play in maintaining a healthy parasite and the relevance of specific changes that occur in free-living invertebrate-bacteria interactions under anthropogenic pressure to helminths and their bacterial communities. It also discusses the importance of understanding the mechanistic sensitivity of helminth-bacteria relationships to environmental stress for comprehending the responses of parasites to challenging conditions.

Non-thermal plasma mills bacteria: Scanning electron microscopy observations

International Nuclear Information System (INIS)

Lunov, O.; Churpita, O.; Zablotskii, V.; Jäger, A.; Dejneka, A.; Deyneka, I. G.; Meshkovskii, I. K.; Syková, E.; Kubinová, Š.

2015-01-01

Non-thermal plasmas hold great promise for a variety of biomedical applications. To ensure safe clinical application of plasma, a rigorous analysis of plasma-induced effects on cell functions is required. Yet mechanisms of bacteria deactivation by non-thermal plasma remain largely unknown. We therefore analyzed the influence of low-temperature atmospheric plasma on Gram-positive and Gram-negative bacteria. Using scanning electron microscopy, we demonstrate that both Gram-positive and Gram-negative bacteria strains in a minute were completely destroyed by helium plasma. In contrast, mesenchymal stem cells (MSCs) were not affected by the same treatment. Furthermore, histopathological analysis of hematoxylin and eosin–stained rat skin sections from plasma–treated animals did not reveal any abnormalities in comparison to control ones. We discuss possible physical mechanisms leading to the shred of bacteria under non-thermal plasma irradiation. Our findings disclose how helium plasma destroys bacteria and demonstrates the safe use of plasma treatment for MSCs and skin cells, highlighting the favorability of plasma applications for chronic wound therapy

Effects of Tribulus terrestris on monosodium iodoacetate‑induced osteoarthritis pain in rats.

Science.gov (United States)

Park, Young Jin; Cho, Young-Rak; Oh, Joa Sub; Ahn, Eun-Kyung

2017-10-01

Tribulus terrestris L. (T. terrestris) has been used as a traditional medicine for the treatment of diuretic, lithontriptic, edema and urinary infections. Previous studies have indicated that it is effective in improving inflammation by regulating tumor necrosis factor‑α (TNF)‑α, interleukin (IL)‑6, IL‑10, nitric oxide (NO) and cyclooxygenase (COX)‑2. However, the effects and mechanism of action of T. terrestris on osteoarthritis (OA) remain unknown. Therefore, the present study aimed to evaluate the effects of the ethanolic extract of T. terrestris (ETT) in a monosodium iodoacetate (MIA)‑induced OA animal model. OA was induced in LEW/SSNHSD rats by intra‑articular injection of MIA. Morphometric changes and parameters of the tibial trabecular bone were determined using micro‑computed tomography. The molecular mechanisms of ETT in OA were investigated using reverse transcription‑polymerase chain reaction, western blotting and gelatin zymogram analysis. Treatment with ETT attenuated MIA‑induced OA, and this effect was mediated by the downregulation of NO synthase 2, COX‑2, TNF‑α and IL‑6. Furthermore, the ETT‑mediated attenuation of OA was also dependent on the expression of matrix metalloproteinases‑2 and ‑9. The results of the current study indicate that further evaluation of the mechanisms underlying the attenuation of MIA‑induced OA by ETT are required, and may support the development of ETT as a potential therapeutic agent for the treatment of inflammatory diseases such as OA.

Effects of Tribulus terrestris on monosodium iodoacetate-induced osteoarthritis pain in rats

Science.gov (United States)

Park, Young Jin; Cho, Young-Rak; Oh, Joa Sub; Ahn, Eun-Kyung

2017-01-01

Tribulus terrestris L. (T. terrestris) has been used as a traditional medicine for the treatment of diuretic, lithontriptic, edema and urinary infections. Previous studies have indicated that it is effective in improving inflammation by regulating tumor necrosis factor-α (TNF)-α, interleukin (IL)-6, IL-10, nitric oxide (NO) and cyclooxygenase (COX)-2. However, the effects and mechanism of action of T. terrestris on osteoarthritis (OA) remain unknown. Therefore, the present study aimed to evaluate the effects of the ethanolic extract of T. terrestris (ETT) in a monosodium iodoacetate (MIA)-induced OA animal model. OA was induced in LEW/SSNHSD rats by intra-articular injection of MIA. Morphometric changes and parameters of the tibial trabecular bone were determined using micro-computed tomography. The molecular mechanisms of ETT in OA were investigated using reverse transcription-polymerase chain reaction, western blotting and gelatin zymogram analysis. Treatment with ETT attenuated MIA-induced OA, and this effect was mediated by the downregulation of NO synthase 2, COX-2, TNF-α and IL-6. Furthermore, the ETT-mediated attenuation of OA was also dependent on the expression of matrix metalloproteinases-2 and −9. The results of the current study indicate that further evaluation of the mechanisms underlying the attenuation of MIA-induced OA by ETT are required, and may support the development of ETT as a potential therapeutic agent for the treatment of inflammatory diseases such as OA. PMID:28849084

U.V. repair in deep-sea bacteria

International Nuclear Information System (INIS)

Lutz, L.; Yayanos, A.A.

1986-01-01

Exposure of cells to light of less than 320 nanometers wavelengths may lead to lethal lesions and perhaps carcinogenesis. Many organisms have evolved mechanisms to repair U.V. light-induced damage. Organisms such as deep-sea bacteria are presumably never exposed to U.V. light and perhaps occasionally to visible from bioluminescence. Thus, the repair of U.V. damage in deep-sea bacterial DNA might be inefficient and repair by photoreactivation unlikely. The bacteria utilized in this investigation are temperature sensitive and barophilic. Four deep-sea isolates were chosen for this study: PE-36 from 3584 m, CNPT-3 from 5782 m, HS-34 from 5682 m, and MT-41 from 10,476 m, all are from the North Pacific ocean. The deep-sea extends from 1100 m to depths greater than 7000 m. It is a region of relatively uniform conditions. The temperature ranges from 5 to -1 0 C. There is no solar light in the deep-sea. Deep-sea bacteria are sensitive to U.V. light; in fact more sensitive than a variety of terrestrial and sea-surface bacteria. All four isolates demonstrate thymine dimer repair. Photoreactivation was observed in only MT-41. The other strains from shallower depths displayed no photoreactivation. The presence of DNA sequences homologous to the rec A, uvr A, B, and C and phr genes of E. coli have been examined by Southern hybridization techniques

A potential mechanism for allometric trabecular bone scaling in terrestrial mammals.

Science.gov (United States)

Christen, Patrik; Ito, Keita; van Rietbergen, Bert

2015-03-01

Trabecular bone microstructural parameters, including trabecular thickness, spacing, and number, have been reported to scale with animal size with negative allometry, whereas bone volume fraction is animal size-invariant in terrestrial mammals. As for the majority of scaling patterns described in animals, its underlying mechanism is unknown. However, it has also been found that osteocyte density is inversely related to animal size, possibly adapted to metabolic rate, which shows a negative relationship as well. In addition, the signalling reach of osteocytes is limited by the extent of the lacuno-canalicular network, depending on trabecular dimensions and thus also on animal size. Here we propose animal size-dependent variations in osteocyte density and their signalling influence distance as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. Using an established and tested computational model of bone modelling and remodelling, we run simulations with different osteocyte densities and influence distances mimicking six terrestrial mammals covering a large range of body masses. Simulated trabecular structures revealed negative allometric scaling for trabecular thickness, spacing, and number, constant bone volume fraction, and bone turnover rates inversely related to animal size. These results are in agreement with previous observations supporting our proposal of osteocyte density and influence distance variation as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. The inverse relationship between bone turnover rates and animal size further indicates that trabecular bone scaling may be linked to metabolic rather than mechanical adaptations. © 2015 Anatomical Society.

Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study.

Science.gov (United States)

Soleimanpour, Saman; Sedighinia, Fereshteh Sadat; Safipour Afshar, Akbar; Zarif, Reza; Ghazvini, Kiarash

2015-01-01

In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05). No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts.

Contaminant exposure in terrestrial vertebrates

International Nuclear Information System (INIS)

Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.

2007-01-01

Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

Bacteria in the Tatahouine meteorite: nanometric-scale life in rocks.

Science.gov (United States)

Gillet, P h; Barrat, J A; Heulin, T h; Achouak, W; Lesourd, M; Guyot, F; Benzerara, K

2000-02-15

We present a study of the textural signature of terrestrial weathering and related biological activity in the Tatahouine meteorite. Scanning and transmission electron microscopy images obtained on the weathered samples of the Tatahouine meteorite and surrounding soil show two types of bacteria-like forms lying on mineral surfaces: (1) rod-shaped forms (RSF) about 70-80 nm wide and ranging from 100 nm to 600 nm in length; (2) ovoid forms (OVF) with diameters between 70 and 300 nm. They look like single cells surrounded by a cell wall. Only Na, K, C, O and N with traces of P and S are observed in the bulk of these objects. The chemical analyses and electron diffraction patterns confirm that the RSF and OVF cannot be magnetite or other iron oxides, iron hydroxides, silicates or carbonates. The sizes of the RSF and OVF are below those commonly observed for bacteria but are very similar to some bacteria-like forms described in the Martian meteorite ALH84001. All the previous observations strongly suggest that they are bacteria or their remnants. This conclusion is further supported by microbiological experiments in which pleomorphic bacteria with morphology similar to the OVF and RSF objects are obtained from biological culture of the soil surrounding the meteorite pieces. The present results show that bacteriomorphs of diameter less than 100 nm may in fact represent real bacteria or their remnants.

Large historical growth in global terrestrial gross primary production

Energy Technology Data Exchange (ETDEWEB)

Campbell, J. E.; Berry, J. A.; Seibt, U.; Smith, S. J.; Montzka, S. A.; Launois, T.; Belviso, S.; Bopp, L.; Laine, M.

2017-04-05

Growth in terrestrial gross primary production (GPP) may provide a feedback for climate change, but there is still strong disagreement on the extent to which biogeochemical processes may suppress this GPP growth at the ecosystem to continental scales. The consequent uncertainty in modeling of future carbon storage by the terrestrial biosphere constitutes one of the largest unknowns in global climate projections for the next century. Here we provide a global, measurement-based estimate of historical GPP growth using long-term atmospheric carbonyl sulfide (COS) records derived from ice core, firn, and ambient air samples. We interpret these records using a model that relates changes in the COS concentration to changes in its sources and sinks, the largest of which is proportional to GPP. The COS history was most consistent with simulations that assume a large historical GPP growth. Carbon-climate models that assume little to no GPP growth predicted trajectories of COS concentration over the anthropogenic era that differ from those observed. Continued COS monitoring may be useful for detecting ongoing changes in GPP while extending the ice core record to glacial cycles could provide further opportunities to evaluate earth system models.

Lactic acid bacteria in the quality improvement and depreciation of wine.

Science.gov (United States)

Lonvaud-Funel, A

1999-01-01

The winemaking process includes two main steps: lactic acid bacteria are responsible for the malolactic fermentation which follows the alcoholic fermentation by yeasts. Both types of microorganisms are present on grapes and on cellar equipment. Yeasts are better adapted to growth in grape must than lactic acid bacteria, so the alcoholic fermentation starts quickly. In must, up to ten lactic acid bacteria species can be identified. They belong to the Lactobacillus, Pediococcus, Leuconostoc and Oenococcus genera. Throughout alcoholic fermentation, a natural selection occurs and finally the dominant species is O. oeni, due to interactions between yeasts and bacteria and between bacteria themselves. After bacterial growth, when the population is over 10(6) CFU/ml, malolactic transformation is the obvious change in wine composition. However, many other substrates can be metabolized. Some like remaining sugars and citric acid are always assimilated by lactic acid bacteria, thus providing them with energy and carbon. Other substrates such as some amino acids may be used following pathways restricted to strains carrying the adequate enzymes. Some strains can also produce exopolysaccharides. All these transformations greatly influence the sensory and hygienic quality of wine. Malic acid transformation is encouraged because it induces deacidification. Diacetyl produced from citric acid is also helpful to some extent. Sensory analyses show that many other reactions change the aromas and make malolactic fermentation beneficial, but they are as yet unknown. On the contrary, an excess of acetic acid, the synthesis of glucane, biogenic amines and precursors of ethylcarbamate are undesirable. Fortunately, lactic acid bacteria normally multiply in dry wines; moreover some of these activities are not widespread. Moreover, the most striking trait of wine lactic acid bacteria is their capacity to adapt to a hostile environment. The mechanisms for this are not yet completely elucidated

Bacteria and fluorescent organic matter: processing and production.

Science.gov (United States)

Fox, B. G.; Thorn, R. M. S.; Reynolds, D. M.

2017-12-01

There is a need for a greater understanding of the importance of aquatic organic matter (OM) within global biogeochemical cycling. This need has prompted characterisation of OM using fluorescence spectroscopy. The origin, transformation and fate of fluorescent organic matter (FOM) is not fully understood within freshwater systems. This work demonstrates the importance of microbial processing in the creation and transformation of FOM, highlighting the dynamics of microbial-FOM interactions, using a model system. The FOM signature of different bacterial species common to surface freshwaters were analysed using a non-fluorescent media; Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa. By undertaking bacterial growth curves, alongside fluorescence spectroscopy, we have been able to determine FOM development in relation to population growth. Within this, we have identified that FOM peaks are associated with different species and driven by bacterial processes, such as cell multiplication or as metabolic by-products. The intracellular and extracellular fluorescence signature of each species has also been analysed to better understand how the microbial community structure may impact the FOM signal in aquatic systems. For example, Peak T develops within the growth curves of all the cultured species and has been identified as both intracellular and extracellular FOM. Whilst Peak T has been termed `microbially-derived' previously, other fluorescence peaks associated with terrestrial high molecular weight compounds, e.g. Peak C, have also been shown to be produced by bacteria throughout growth stages. Additionally, the notion that cell lysis is responsible for the presence of larger FOM compounds was also explored. Our work highlights the capacity of bacteria to not only utilise and process OM but to actively be a source of both labile and recalcitrant OM in situ. The bacteria fluorescence signatures seen are complex with comparable fluorescence peaks to those

Arctic Terrestrial Biodiversity Monitoring Plan

DEFF Research Database (Denmark)

Christensen, Tom; Payne, J.; Doyle, M.

The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments. The CBMP includes an international...... on developing and implementing long-term plans for monitoring the integrity of Arctic biomes: terrestrial, marine, freshwater, and coastal (under development) environments. The CBMP Terrestrial Expert Monitoring Group (CBMP-TEMG) has developed the Arctic Terrestrial Biodiversity Monitoring Plan (CBMP......-Terrestrial Plan/the Plan) as the framework for coordinated, long-term Arctic terrestrial biodiversity monitoring. The goal of the CBMP-Terrestrial Plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect, understand and report on long...

Biogeochemical signals from deep microbial life in terrestrial crust.

Directory of Open Access Journals (Sweden)

Yohey Suzuki

Full Text Available In contrast to the deep subseafloor biosphere, a volumetrically vast and stable habitat for microbial life in the terrestrial crust remains poorly explored. For the long-term sustainability of a crustal biome, high-energy fluxes derived from hydrothermal circulation and water radiolysis in uranium-enriched rocks are seemingly essential. However, the crustal habitability depending on a low supply of energy is unknown. We present multi-isotopic evidence of microbially mediated sulfate reduction in a granitic aquifer, a representative of the terrestrial crust habitat. Deep meteoric groundwater was collected from underground boreholes drilled into Cretaceous Toki granite (central Japan. A large sulfur isotopic fractionation of 20-60‰ diagnostic to microbial sulfate reduction is associated with the investigated groundwater containing sulfate below 0.2 mM. In contrast, a small carbon isotopic fractionation (<30‰ is not indicative of methanogenesis. Except for 2011, the concentrations of H2 ranged mostly from 1 to 5 nM, which is also consistent with an aquifer where a terminal electron accepting process is dominantly controlled by ongoing sulfate reduction. High isotopic ratios of mantle-derived 3He relative to radiogenic 4He in groundwater and the flux of H2 along adjacent faults suggest that, in addition to low concentrations of organic matter (<70 µM, H2 from deeper sources might partly fuel metabolic activities. Our results demonstrate that the deep biosphere in the terrestrial crust is metabolically active and playing a crucial role in the formation of reducing groundwater even under low-energy fluxes.

The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective

Directory of Open Access Journals (Sweden)

Panagiotis Gkorezis

2016-11-01

Full Text Available Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant – associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially-driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g. oxygen and fertilization to supply limiting nutrients (e.g. nitrogen, phosphorous, potassium in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors, and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for

The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective.

Science.gov (United States)

Gkorezis, Panagiotis; Daghio, Matteo; Franzetti, Andrea; Van Hamme, Jonathan D; Sillen, Wouter; Vangronsveld, Jaco

2016-01-01

Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs) has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant-associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric, and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g., oxygen) and fertilization to supply limiting nutrients (e.g., nitrogen, phosphorous, potassium) in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors), and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for remediation of PHC

The Interaction between Plants and Bacteria in the Remediation of Petroleum Hydrocarbons: An Environmental Perspective

Science.gov (United States)

Gkorezis, Panagiotis; Daghio, Matteo; Franzetti, Andrea; Van Hamme, Jonathan D.; Sillen, Wouter; Vangronsveld, Jaco

2016-01-01

Widespread pollution of terrestrial ecosystems with petroleum hydrocarbons (PHCs) has generated a need for remediation and, given that many PHCs are biodegradable, bio- and phyto-remediation are often viable approaches for active and passive remediation. This review focuses on phytoremediation with particular interest on the interactions between and use of plant-associated bacteria to restore PHC polluted sites. Plant-associated bacteria include endophytic, phyllospheric, and rhizospheric bacteria, and cooperation between these bacteria and their host plants allows for greater plant survivability and treatment outcomes in contaminated sites. Bacterially driven PHC bioremediation is attributed to the presence of diverse suites of metabolic genes for aliphatic and aromatic hydrocarbons, along with a broader suite of physiological properties including biosurfactant production, biofilm formation, chemotaxis to hydrocarbons, and flexibility in cell-surface hydrophobicity. In soils impacted by PHC contamination, microbial bioremediation generally relies on the addition of high-energy electron acceptors (e.g., oxygen) and fertilization to supply limiting nutrients (e.g., nitrogen, phosphorous, potassium) in the face of excess PHC carbon. As an alternative, the addition of plants can greatly improve bioremediation rates and outcomes as plants provide microbial habitats, improve soil porosity (thereby increasing mass transfer of substrates and electron acceptors), and exchange limiting nutrients with their microbial counterparts. In return, plant-associated microorganisms improve plant growth by reducing soil toxicity through contaminant removal, producing plant growth promoting metabolites, liberating sequestered plant nutrients from soil, fixing nitrogen, and more generally establishing the foundations of soil nutrient cycling. In a practical and applied sense, the collective action of plants and their associated microorganisms is advantageous for remediation of PHC

Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics.

Science.gov (United States)

Xu, Sai; Lu, Wenjing; Mustafa, Muhammad Farooq; Caicedo, Luis Miguel; Guo, Hanwen; Fu, Xindi; Wang, Hongtao

2017-11-01

Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures and their abundance in sewage sludge collected from wastewater treatment plants were analysed. Results indicated that ANAMMOX and DAMO bacteria co-existed in sewage sludge in different seasons and their abundance was positively correlated (P bacteria in autumn and winter indicated that these seasons were the preferred time to favour the growth of ANAMMOX and DAMO bacteria. The community structure of ANNAMOX and DAMO bacteria could also shift with seasonal changes. The "Candidatus Brocadia" genus of ANAMMOX bacteria was mainly recovered in spring and summer, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion. The redundancy analysis revealed that pH and nitrate were the most significant factors affecting community structures of these two groups (P < 0.01). This study reported the diversity of ANAMMOX and DAMO in wastewater treatment plants that may be the basis for new nitrogen removal technologies.

The Global Influence of Cloud Optical Thickness on Terrestrial Carbon Uptake

Science.gov (United States)

Zhu, P.; Cheng, S. J.; Keppel-Aleks, G.; Butterfield, Z.; Steiner, A. L.

2016-12-01

Clouds play a critical role in regulating Earth's climate. One important way is by changing the type and intensity of solar radiation reaching the Earth's surface, which impacts plant photosynthesis. Specifically, the presence of clouds modifies photosynthesis rates by influencing the amount of diffuse radiation as well as the spectral distribution of solar radiation. Satellite-derived cloud optical thickness (COT) may provide the observational constraint necessary to assess the role of clouds on ecosystems and terrestrial carbon uptake across the globe. Previous studies using ground-based observations at individual sites suggest that below a COT of 7, there is a greater increase in light use efficiency than at higher COT values, providing evidence for higher carbon uptake rates than expected given the reduction in radiation by clouds. However, the strength of the COT-terrestrial carbon uptake correlation across the globe remains unknown. In this study, we investigate the influence of COT on terrestrial carbon uptake on a global scale, which may provide insights into cloud conditions favorable for plant photosynthesis and improve our estimates of the land carbon sink. Global satellite-derived MODIS data show that tropical and subtropical regions tend to have COT values around or below the threshold during growing seasons. We find weak correlations between COT and GPP with Fluxnet MTE global GPP data, which may be due to the uncertainty of upscaling GPP from individual site measurements. Analysis with solar-induced fluorescence (SIF) as a proxy for GPP is also evaluated. Overall, this work constructs a global picture of the role of COT on terrestrial carbon uptake, including its temporal and spatial variations.

Microplastics in the terrestrial ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae)

NARCIS (Netherlands)

Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.D.; Salanki, T.E.; Ploeg, van der M.J.C.; Besseling, E.; Koelmans, A.A.; Geissen, V.

2016-01-01

Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, <150 μm)

Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study

Science.gov (United States)

Soleimanpour, Saman; Sedighinia, Fereshteh Sadat; Safipour Afshar, Akbar; Zarif, Reza; Ghazvini, Kiarash

2015-01-01

Objective: In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Materials and methods: Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Results: Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05). No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. Conclusion: This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts. PMID:26101754

Antibacterial activity of Tribulus terrestris and its synergistic effect with Capsella bursa-pastoris and Glycyrrhiza glabra against oral pathogens: an in-vitro study

Directory of Open Access Journals (Sweden)

Saman Soleimanpour

2015-04-01

Full Text Available Objective: In this study, antimicrobial activities of an ethanol extract of Tribulus terrestris aloneand in combination with Capsella bursa-pastoris and Glycyrrhiza glabra were examined in vitro against six pathogens namely Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Enterococcus faecalis Staphylococcus aureus, and Escherichia coli. Materials and methods: Antibacterial activities of the extracts were examined using disc and well diffusion methods and the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC of ethanol extracts were determined against these microorganisms using agar and broth dilution methods. Chlorhexidine was used as positive control. Results: Tribulus terrestris extract exhibited good antibacterial activity against all bacteria. Antibacterial activity of mixed extract was evaluated and exhibited that mixed extract was more effective against all bacteria than any of the cases alone which indicates the synergistic effect between these three extracts (p˂0.05. No strain showed resistance against these extracts. In agar dilution, Tribulus terrestris exhibited MIC values ranging from 35.0 to 20.0 mg/ml and mixed extract showed MIC values ranging from 12.5 to 5.0 mg/ml. The results of broth dilution method were consistent with the findings of the agar dilution method. Conclusion: This in-vitro study was a preliminary evaluation of antibacterial activity of the plants. It provided scientific evidence to support uses of T. terrestris and its mixture with C. bursa-pastoris and G. glabra for the treatment of oral infections. In-vivo studies are also required to better evaluate the effect of these extracts.

Microplastics in the Terrestrial Ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae).

Science.gov (United States)

Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

2016-03-01

Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, digestion of ingested organic matter, microplastic was concentrated in cast, especially at the lowest dose (i.e., 7% in litter) because that dose had the highest proportion of digestible organic matter. Whereas 50 percent of the microplastics had a size of earthworms. These concentration-transport and size-selection mechanisms may have important implications for fate and risk of microplastic in terrestrial ecosystems.

V. Terrestrial vertebrates

Science.gov (United States)

Dean Pearson; Deborah Finch

2011-01-01

Within the Interior West, terrestrial vertebrates do not represent a large number of invasive species relative to invasive weeds, aquatic vertebrates, and invertebrates. However, several invasive terrestrial vertebrate species do cause substantial economic and ecological damage in the U.S. and in this region (Pimental 2000, 2007; Bergman and others 2002; Finch and...

Dental lesions in the lowland tapir (Tapirus terrestris)

DEFF Research Database (Denmark)

Tjørnelund, Karen B.; Jonsson, Lena M.; Kortegaard, Hanne Ellen

2015-01-01

Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs ( Tapirus terrestris ) in particular, is scarce. A recent study identified resorptive lesions...... of unknown etiology as a common problem in the Malayan tapir ( Tapirus indicus ). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually...... with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions...

Anaerobic Ammonium-Oxidizing Bacteria: Unique Microorganisms with Exceptional Properties

Science.gov (United States)

Jetten, Mike S. M.

2012-01-01

Summary: Anaerobic ammonium-oxidizing (anammox) bacteria defy many microbiological concepts and share numerous properties with both eukaryotes and archaea. Among their most intriguing characteristics are their compartmentalized cell plan and archaeon-like cell wall. Here we review our current knowledge about anammox cell biology. The anammox cell is divided into three separate compartments by bilayer membranes. The anammox cell consists of (from outside to inside) the cell wall, paryphoplasm, riboplasm, and anammoxosome. Not much is known about the composition or function of both the anammox cell wall and the paryphoplasm compartment. The cell wall is proposed to be proteinaceous and to lack both peptidoglycan and an outer membrane typical of Gram-negative bacteria. The function of the paryphoplasm is unknown, but it contains the cell division ring. The riboplasm resembles the standard cytoplasmic compartment of other bacteria; it contains ribosomes and the nucleoid. The anammoxosome occupies most of the cell volume and is a so-called “prokaryotic organelle” analogous to the eukaryotic mitochondrion. This is the site where the anammox reaction takes place, coupled over the curved anammoxosome membrane, possibly giving rise to a proton motive force and subsequent ATP synthesis. With these unique properties, anammox bacteria are food for thought concerning the early evolution of the domains Bacteria, Archaea, and Eukarya. PMID:22933561

Terrestrial Analogs to Mars

Science.gov (United States)

Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

2002-08-01

It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

Microbial characterization of toluene-degrading denitrifying consortia obtained from terrestrial and marine ecosystems.

Science.gov (United States)

An, Y-J; Joo, Y-H; Hong, I-Y; Ryu, H-W; Cho, K-S

2004-10-01

The degradation characteristics of toluene coupled to nitrate reduction were investigated in enrichment culture and the microbial communities of toluene-degrading denitrifying consortia were characterized by denaturing gradient gel electrophoresis (DGGE) technique. Anaerobic nitrate-reducing bacteria were enriched from oil-contaminated soil samples collected from terrestrial (rice field) and marine (tidal flat) ecosystems. Enriched consortia degraded toluene in the presence of nitrate as a terminal electron acceptor. The degradation rate of toluene was affected by the initial substrate concentration and co-existence of other hydrocarbons. The types of toluene-degrading denitrifying consortia depended on the type of ecosystem. The clone RS-7 obtained from the enriched consortium of the rice field was most closely related to a toluene-degrading and denitrifying bacterium, Azoarcus denitrificians (A. tolulyticus sp. nov.). The clone TS-11 detected in the tidal flat enriched consortium was affiliated to Thauera sp. strain S2 (T. aminoaromatica sp. nov.) that was able to degrade toluene under denitrifying conditions. This indicates that environmental factors greatly influence microbial communities obtained from terrestrial (rice field) and marine (tidal flat) ecosystems.

Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

Directory of Open Access Journals (Sweden)

Thomas Larsen

Full Text Available Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13C patterns among amino acids (δ(13CAA could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13CAA patterns in contrast to bulk δ(13C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

Science.gov (United States)

Larsen, Thomas; Ventura, Marc; Andersen, Nils; O'Brien, Diane M; Piatkowski, Uwe; McCarthy, Matthew D

2013-01-01

Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13)C patterns among amino acids (δ(13)CAA) could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13)CAA patterns in contrast to bulk δ(13)C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13)CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13)C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13)C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

A Latitudinal Diversity Gradient in Terrestrial Bacteria of the Genus Streptomyces

Science.gov (United States)

Andam, Cheryl P.; Doroghazi, James R.; Campbell, Ashley N.; Kelly, Peter J.; Choudoir, Mallory J.

2016-01-01

ABSTRACT We show that Streptomyces biogeography in soils across North America is influenced by the regional diversification of microorganisms due to dispersal limitation and genetic drift. Streptomyces spp. form desiccation-resistant spores, which can be dispersed on the wind, allowing for a strong test of whether dispersal limitation governs patterns of terrestrial microbial diversity. We employed an approach that has high sensitivity for determining the effects of genetic drift. Specifically, we examined the genetic diversity and phylogeography of physiologically similar Streptomyces strains isolated from geographically distributed yet ecologically similar habitats. We found that Streptomyces beta diversity scales with geographic distance and both beta diversity and phylogenetic diversity manifest in a latitudinal diversity gradient. This pattern of Streptomyces biogeography resembles patterns seen for diverse species of plants and animals, and we therefore evaluated these data in the context of ecological and evolutionary hypotheses proposed to explain latitudinal diversity gradients. The data are consistent with the hypothesis that niche conservatism limits dispersal, and historical patterns of glaciation have limited the time for speciation in higher-latitude sites. Most notably, higher-latitude sites have lower phylogenetic diversity, higher phylogenetic clustering, and evidence of range expansion from lower latitudes. In addition, patterns of beta diversity partition with respect to the glacial history of sites. Hence, the data support the hypothesis that extant patterns of Streptomyces biogeography have been driven by historical patterns of glaciation and are the result of demographic range expansion, dispersal limitation, and regional diversification due to drift. PMID:27073097

A Latitudinal Diversity Gradient in Terrestrial Bacteria of the Genus Streptomyces

Directory of Open Access Journals (Sweden)

Cheryl P. Andam

2016-04-01

Full Text Available We show that Streptomyces biogeography in soils across North America is influenced by the regional diversification of microorganisms due to dispersal limitation and genetic drift. Streptomyces spp. form desiccation-resistant spores, which can be dispersed on the wind, allowing for a strong test of whether dispersal limitation governs patterns of terrestrial microbial diversity. We employed an approach that has high sensitivity for determining the effects of genetic drift. Specifically, we examined the genetic diversity and phylogeography of physiologically similar Streptomyces strains isolated from geographically distributed yet ecologically similar habitats. We found that Streptomyces beta diversity scales with geographic distance and both beta diversity and phylogenetic diversity manifest in a latitudinal diversity gradient. This pattern of Streptomyces biogeography resembles patterns seen for diverse species of plants and animals, and we therefore evaluated these data in the context of ecological and evolutionary hypotheses proposed to explain latitudinal diversity gradients. The data are consistent with the hypothesis that niche conservatism limits dispersal, and historical patterns of glaciation have limited the time for speciation in higher-latitude sites. Most notably, higher-latitude sites have lower phylogenetic diversity, higher phylogenetic clustering, and evidence of range expansion from lower latitudes. In addition, patterns of beta diversity partition with respect to the glacial history of sites. Hence, the data support the hypothesis that extant patterns of Streptomyces biogeography have been driven by historical patterns of glaciation and are the result of demographic range expansion, dispersal limitation, and regional diversification due to drift.

Peptidoglycan architecture of Gram-positive bacteria by solid-state NMR.

Science.gov (United States)

Kim, Sung Joon; Chang, James; Singh, Manmilan

2015-01-01

Peptidoglycan is an essential component of cell wall in Gram-positive bacteria with unknown architecture. In this review, we summarize solid-state NMR approaches to address some of the unknowns in the Gram-positive bacteria peptidoglycan architecture: 1) peptidoglycan backbone conformation, 2) PG-lattice structure, 3) variations in the peptidoglycan architecture and composition, 4) the effects of peptidoglycan bridge-length on the peptidoglycan architecture in Fem mutants, 5) the orientation of glycan strands with respect to the membrane, and 6) the relationship between the peptidoglycan structure and the glycopeptide antibiotic mode of action. Solid-state NMR analyses of Staphylococcus aureus cell wall show that peptidoglycan chains are surprisingly ordered and densely packed. The peptidoglycan disaccharide backbone adopts 4-fold screw helical symmetry with the disaccharide unit periodicity of 40Å. Peptidoglycan lattice in the S. aureus cell wall is formed by cross-linked PG stems that have parallel orientations. The structural characterization of Fem-mutants of S. aureus with varying lengths of bridge structures suggests that the PG-bridge length is an important determining factor for the PG architecture. Copyright © 2014 Elsevier B.V. All rights reserved.

Hyperresolution global land surface modeling: Meeting a grand challenge for monitoring Earth's terrestrial water

Science.gov (United States)

Wood, Eric F.; Roundy, Joshua K.; Troy, Tara J.; van Beek, L. P. H.; Bierkens, Marc F. P.; Blyth, Eleanor; de Roo, Ad; DöLl, Petra; Ek, Mike; Famiglietti, James; Gochis, David; van de Giesen, Nick; Houser, Paul; Jaffé, Peter R.; Kollet, Stefan; Lehner, Bernhard; Lettenmaier, Dennis P.; Peters-Lidard, Christa; Sivapalan, Murugesu; Sheffield, Justin; Wade, Andrew; Whitehead, Paul

2011-05-01

Monitoring Earth's terrestrial water conditions is critically important to many hydrological applications such as global food production; assessing water resources sustainability; and flood, drought, and climate change prediction. These needs have motivated the development of pilot monitoring and prediction systems for terrestrial hydrologic and vegetative states, but to date only at the rather coarse spatial resolutions (˜10-100 km) over continental to global domains. Adequately addressing critical water cycle science questions and applications requires systems that are implemented globally at much higher resolutions, on the order of 1 km, resolutions referred to as hyperresolution in the context of global land surface models. This opinion paper sets forth the needs and benefits for a system that would monitor and predict the Earth's terrestrial water, energy, and biogeochemical cycles. We discuss six major challenges in developing a system: improved representation of surface-subsurface interactions due to fine-scale topography and vegetation; improved representation of land-atmospheric interactions and resulting spatial information on soil moisture and evapotranspiration; inclusion of water quality as part of the biogeochemical cycle; representation of human impacts from water management; utilizing massively parallel computer systems and recent computational advances in solving hyperresolution models that will have up to 109 unknowns; and developing the required in situ and remote sensing global data sets. We deem the development of a global hyperresolution model for monitoring the terrestrial water, energy, and biogeochemical cycles a "grand challenge" to the community, and we call upon the international hydrologic community and the hydrological science support infrastructure to endorse the effort.

Hyperresolution Global Land Surface Modeling: Meeting a Grand Challenge for Monitoring Earth's Terrestrial Water

Science.gov (United States)

Wood, Eric F.; Roundy, Joshua K.; Troy, Tara J.; van Beek, L. P. H.; Bierkens, Marc F. P.; 4 Blyth, Eleanor; de Roo, Ad; Doell. Petra; Ek, Mike; Famiglietti, James;

Global screening for Critical Habitat in the terrestrial realm.

Science.gov (United States)

Brauneder, Kerstin M; Montes, Chloe; Blyth, Simon; Bennun, Leon; Butchart, Stuart H M; Hoffmann, Michael; Burgess, Neil D; Cuttelod, Annabelle; Jones, Matt I; Kapos, Val; Pilgrim, John; Tolley, Melissa J; Underwood, Emma C; Weatherdon, Lauren V; Brooks, Sharon E

2018-01-01

Critical Habitat has become an increasingly important concept used by the finance sector and businesses to identify areas of high biodiversity value. The International Finance Corporation (IFC) defines Critical Habitat in their highly influential Performance Standard 6 (PS6), requiring projects in Critical Habitat to achieve a net gain of biodiversity. Here we present a global screening layer of Critical Habitat in the terrestrial realm, derived from global spatial datasets covering the distributions of 12 biodiversity features aligned with guidance provided by the IFC. Each biodiversity feature is categorised as 'likely' or 'potential' Critical Habitat based on: 1. Alignment between the biodiversity feature and the IFC Critical Habitat definition; and 2. Suitability of the spatial resolution for indicating a feature's presence on the ground. Following the initial screening process, Critical Habitat must then be assessed in-situ by a qualified assessor. This analysis indicates that a total of 10% and 5% of the global terrestrial environment can be considered as likely and potential Critical Habitat, respectively, while the remaining 85% did not overlap with any of the biodiversity features assessed and was classified as 'unknown'. Likely Critical Habitat was determined principally by the occurrence of Key Biodiversity Areas and Protected Areas. Potential Critical Habitat was predominantly characterised by data representing highly threatened and unique ecosystems such as ever-wet tropical forests and tropical dry forests. The areas we identified as likely or potential Critical Habitat are based on the best available global-scale data for the terrestrial realm that is aligned with IFC's Critical Habitat definition. Our results can help businesses screen potential development sites at the early project stage based on a range of biodiversity features. However, the study also demonstrates several important data gaps and highlights the need to incorporate new and

H2S: a universal defense against antibiotics in bacteria.

Science.gov (United States)

Shatalin, Konstantin; Shatalina, Elena; Mironov, Alexander; Nudler, Evgeny

2011-11-18

Many prokaryotic species generate hydrogen sulfide (H(2)S) in their natural environments. However, the biochemistry and physiological role of this gas in nonsulfur bacteria remain largely unknown. Here we demonstrate that inactivation of putative cystathionine β-synthase, cystathionine γ-lyase, or 3-mercaptopyruvate sulfurtransferase in Bacillus anthracis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli suppresses H(2)S production, rendering these pathogens highly sensitive to a multitude of antibiotics. Exogenous H(2)S suppresses this effect. Moreover, in bacteria that normally produce H(2)S and nitric oxide, these two gases act synergistically to sustain growth. The mechanism of gas-mediated antibiotic resistance relies on mitigation of oxidative stress imposed by antibiotics.

Grazing livestock are exposed to terrestrial cyanobacteria.

Science.gov (United States)

McGorum, Bruce C; Pirie, R Scott; Glendinning, Laura; McLachlan, Gerry; Metcalf, James S; Banack, Sandra A; Cox, Paul A; Codd, Geoffrey A

2015-02-25

While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in all samples tested, including 6 plant washings, 1 soil sample and ileal contents from 2 grazing horses. Further work was performed to test the hypothesis that ingestion of cyanotoxins contributes to the pathogenesis of some currently unexplained diseases of grazing horses, including equine grass sickness (EGS), equine motor neuron disease (EMND) and hepatopathy. Phormidium population density was significantly higher on EGS fields than on control fields. The cyanobacterial neurotoxic amino acid 2,4-diaminobutyric acid (DAB) was detected in plant washings from EGS fields, but worst case scenario estimations suggested the dose would be insufficient to cause disease. Neither DAB nor the cyanobacterial neurotoxins β-N-methylamino-L-alanine and N-(2-aminoethyl) glycine were detected in neural tissue from 6 EGS horses, 2 EMND horses and 7 control horses. Phormidium was present in low numbers on plants where horses had unexplained hepatopathy. This study did not yield evidence linking known cyanotoxins with disease in grazing horses. However, further study is warranted to identify and quantify toxins produced by cyanobacteria on livestock fields, and determine whether, under appropriate conditions, known or unknown cyanotoxins contribute to currently unexplained diseases in grazing livestock.

Lindane Bioremediation Capability of Bacteria Associated with the Demosponge Hymeniacidon perlevis

Directory of Open Access Journals (Sweden)

Stabili Loredana

2017-04-01

Full Text Available Lindane is an organochlorine pesticide belonging to persistent organic pollutants (POPs that has been widely used to treat agricultural pests. It is of particular concern because of its toxicity, persistence and tendency to bioaccumulate in terrestrial and aquatic ecosystems. In this context, we assessed the role of bacteria associated with the sponge Hymeniacidon perlevis in lindane degradation. Seven bacteria isolates were characterized and identified. These isolates showed a remarkable capacity to utilize lindane as a sole carbon source leading to a percentage of residual lindane ranging from 3% to 13% after 12 days of incubation with the pesticide. The lindane metabolite, 1,3–6-pentachloro-cyclohexene, was identified as result of lindane degradation and determined by gas chromatography–mass spectrometry (GC–MS. The bacteria capable of lindane degradation were identified on the basis of the phenotypic characterization by morphological, biochemical and cultural tests, completed with 16S rDNA sequence analysis, and assigned to Mameliella phaeodactyli, Pseudovibrio ascidiaceicola, Oceanicaulis stylophorae, Ruegeria atlantica and to three new uncharacterized species. The results obtained are a prelude to the development of future strategies for the in situ bioremediation of lindane.

Enrichment of Bacteria From Eastern Mediterranean Sea Involved in Lignin Degradation via the Phenylacetyl-CoA Pathway

Directory of Open Access Journals (Sweden)

Hannah L. Woo

2018-05-01

Full Text Available The degradation of allochthonous terrestrial organic matter, such as recalcitrant lignin and hemicellulose from plants, occurs in the ocean. We hypothesize that bacteria instead of white-rot fungi, the model organisms of aerobic lignin degradation within terrestrial environments, are responsible for lignin degradation in the ocean due to the ocean’s oligotrophy and hypersalinity. Warm oxic seawater from the Eastern Mediterranean Sea was enriched on lignin in laboratory microcosms. Lignin mineralization rates by the lignin-adapted consortia improved after two sequential incubations. Shotgun metagenomic sequencing detected a higher abundance of aromatic compound degradation genes in response to lignin, particularly phenylacetyl-CoA, which may be an effective strategy for marine microbes in fluctuating oxygen concentrations. 16S rRNA gene amplicon sequencing detected a higher abundance of Gammaproteobacteria and Alphaproteobacteria bacteria such as taxonomic families Idiomarinaceae, Alcanivoraceae, and Alteromonadaceae in response to lignin. Meanwhile, fungal Ascomycetes and Basidiomycetes remained at very low abundance. Our findings demonstrate the significant potential of bacteria and microbes utilizing the phenylacetyl-CoA pathway to contribute to lignin degradation in the Eastern Mediterranean where environmental conditions are unfavorable for fungi. Exploring the diversity of bacterial lignin degraders may provide important enzymes for lignin conversion in industry. Enzymes may be key in breaking down high molecular weight lignin and enabling industry to use it as a low-cost and sustainable feedstock for biofuels or other higher-value products.

Facile synthesis of silver nanoparticles and its antibacterial activity against Escherichia coli and unknown bacteria on mobile phone touch surfaces/computer keyboards

Science.gov (United States)

Reddy, T. Ranjeth Kumar; Kim, Hyun-Joong

2016-07-01

In recent years, there has been significant interest in the development of novel metallic nanoparticles using various top-down and bottom-up synthesis techniques. Kenaf is a huge biomass product and a potential component for industrial applications. In this work, we investigated the green synthesis of silver nanoparticles (AgNPs) by using kenaf ( Hibiscus cannabinus) cellulose extract and sucrose, which act as stabilizing and reducing agents in solution. With this method, by changing the pH of the solution as a function of time, we studied the optical, morphological and antibacterial properties of the synthesized AgNPs. In addition, these nanoparticles were characterized by Ultraviolet-visible spectroscopy, transmission electron microscopy (TEM), field-emission scanning electron microscopy, Fourier transform infrared (FTIR) spectroscopy and energy-dispersive X-ray spectroscopy (EDX). As the pH of the solution varies, the surface plasmon resonance peak also varies. A fast rate of reaction at pH 10 compared with that at pH 5 was identified. TEM micrographs confirm that the shapes of the particles are spherical and polygonal. Furthermore, the average size of the nanoparticles synthesized at pH 5, pH 8 and pH 10 is 40.26, 28.57 and 24.57 nm, respectively. The structure of the synthesized AgNPs was identified as face-centered cubic (fcc) by XRD. The compositional analysis was determined by EDX. FTIR confirms that the kenaf cellulose extract and sucrose act as stabilizing and reducing agents for the silver nanoparticles. Meanwhile, these AgNPs exhibited size-dependent antibacterial activity against Escherichia coli ( E. coli) and two other unknown bacteria from mobile phone screens and computer keyboard surfaces.

Diversity and characterization of mercury-resistant bacteria in snow, freshwater and sea-ice brine from the High Arctic

DEFF Research Database (Denmark)

Møller, Annette; Barkay, Tamar; Abu Al-Soud, Waleed

2011-01-01

It is well-established that atmospheric deposition transports mercury from lower latitudes to the Arctic. The role of bacteria in the dynamics of the deposited mercury, however, is unknown. We characterized mercury-resistant bacteria from High Arctic snow, freshwater and sea-ice brine. Bacterial...... densities were 9.4 × 10(5), 5 × 10(5) and 0.9-3.1 × 10(3) cells mL(-1) in freshwater, brine and snow, respectively. Highest cultivability was observed in snow (11.9%), followed by freshwater (0.3%) and brine (0.03%). In snow, the mercury-resistant bacteria accounted for up to 31% of the culturable bacteria, but...

Hg-contaminated terrestrial spiders pose a potential risk to songbirds at Caddo Lake (Texas/Louisiana, USA).

Science.gov (United States)

Gann, Gretchen L; Powell, Cleveland H; Chumchal, Matthew M; Drenner, Ray W

2015-02-01

Methylmercury (MeHg) is an environmental contaminant that can have adverse effects on wildlife. Because MeHg is produced by bacteria in aquatic ecosystems, studies of MeHg contamination of food webs historically have focused on aquatic organisms. However, recent studies have shown that terrestrial organisms such as songbirds can be contaminated with MeHg by feeding on MeHg-contaminated spiders. In the present study, the authors examined the risk that MeHg-contaminated terrestrial long-jawed orb weaver spiders (Tetragnatha sp.) pose to songbirds at Caddo Lake (Texas/Louisiana, USA). Methylmercury concentrations in spiders were significantly different in river, wetland, and open-water habitats. The authors calculated spider-based wildlife values (the minimum spider MeHg concentrations causing physiologically significant doses in consumers) to assess exposure risks for arachnivorous birds. Methylmercury concentrations in spiders exceeded wildlife values for Carolina chickadee (Poecile carolinensis) nestlings, with the highest risk in the river habitat. The present study indicates that MeHg concentrations in terrestrial spiders vary with habitat and can pose a threat to small-bodied nestling birds that consume large amounts of spiders at Caddo Lake. This MeHg threat to songbirds may not be unique to Caddo Lake and may extend throughout the southeastern United States. © 2014 SETAC.

Evaluation of meteorites as habitats for terrestrial microorganisms: Results from the Nullarbor Plain, Australia, a Mars analogue site

Science.gov (United States)

Tait, Alastair W.; Wilson, Siobhan A.; Tomkins, Andrew G.; Gagen, Emma J.; Fallon, Stewart J.; Southam, Gordon

2017-10-01

Unambiguous identification of biosignatures on Mars requires access to well-characterized, long-lasting geochemical standards at the planet's surface that can be modified by theoretical martian life. Ordinary chondrites, which are ancient meteorites that commonly fall to the surface of Mars and Earth, have well-characterized, narrow ranges in trace element and isotope geochemistry compared to martian rocks. Given that their mineralogy is more attractive to known chemolithotrophic life than the basaltic rocks that dominate the martian surface, exogenic rocks (e.g., chondritic meteorites) may be good places to look for signs of prior life endemic to Mars. In this study, we show that ordinary chondrites, collected from the arid Australian Nullarbor Plain, are commonly colonized and inhabited by terrestrial microorganisms that are endemic to this Mars analogue site. These terrestrial endolithic and chasmolithic microbial contaminants are commonly found in close association with hygroscopic veins of gypsum and Mg-calcite, which have formed within cracks penetrating deep into the meteorites. Terrestrial bacteria are observed within corrosion cavities, where troilite (FeS) oxidation has produced jarosite [KFe3(SO4)2(OH)6]. Where terrestrial microorganisms have colonized primary silicate minerals and secondary calcite, these mineral surfaces are heavily etched. Our results show that inhabitation of meteorites by terrestrial microorganisms in arid environments relies upon humidity and pH regulation by minerals. Furthermore, microbial colonization affects the weathering of meteorites and production of sulfate, carbonate, Fe-oxide and smectite minerals that can preserve chemical and isotopic biosignatures for thousands to millions of years on Earth. Meteorites are thus habitable by terrestrial microorganisms, even under highly desiccating environmental conditions of relevance to Mars. They may therefore be useful as chemical and isotopic ;standards; that preserve evidence of

Terrestrial planet formation.

Science.gov (United States)

Righter, K; O'Brien, D P

2011-11-29

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

Consequences of simulating terrestrial N dynamics for projecting future terrestrial C storage

Science.gov (United States)

Zaehle, S.; Friend, A. D.; Friedlingstein, P.

2009-04-01

We present results of a new land surface model, O-CN, which includes a process-based coupling between the terrestrial cycling of energy, water, carbon, and nitrogen. The model represents the controls of the terrestrial nitrogen (N) cycling on carbon (C) pools and fluxes through photosynthesis, respiration, changes in allocation patterns, as well as soil organic matter decomposition, and explicitly accounts for N leaching and gaseous losses. O-CN has been shown to give realistic results in comparison to observations at a wide range of scales, including in situ flux measurements, productivity databases, and atmospheric CO2 concentration data. Notably, O-CN simulates realistic responses of net primary productivity, foliage area, and foliage N content to elevated atmospheric [CO2] as evidenced at free air carbon dioxide enrichment (FACE) sites (Duke, Oak Ridge). We re-examine earlier model-based assessments of the terrestrial C sequestration potential using a global transient O-CN simulation driven by increases in atmospheric [CO2], N deposition and climatic changes over the 21st century. We find that accounting for terrestrial N cycling about halves the potential to store C in response to increases in atmospheric CO2 concentrations; mainly due to a reduction of the net C uptake in temperate and boreal forests. Nitrogen deposition partially alleviates the effect of N limitation, but is by far not sufficient to compensate for the effect completely. These findings underline the importance of an accurate representation of nutrient limitations in future projections of the terrestrial net CO2 exchanges and therefore land-climate feedback studies.

Allocating monitoring effort in the face of unknown unknowns

Science.gov (United States)

Wintle, B.A.; Runge, M.C.; Bekessy, S.A.

2010-01-01

There is a growing view that to make efficient use of resources, ecological monitoring should be hypothesis-driven and targeted to address specific management questions. 'Targeted' monitoring has been contrasted with other approaches in which a range of quantities are monitored in case they exhibit an alarming trend or provide ad hoc ecological insights. The second form of monitoring, described as surveillance, has been criticized because it does not usually aim to discern between competing hypotheses, and its benefits are harder to identify a priori. The alternative view is that the existence of surveillance data may enable rapid corroboration of emerging hypotheses or help to detect important 'unknown unknowns' that, if undetected, could lead to catastrophic outcomes or missed opportunities. We derive a model to evaluate and compare the efficiency of investments in surveillance and targeted monitoring. We find that a decision to invest in surveillance monitoring may be defensible if: (1) the surveillance design is more likely to discover or corroborate previously unknown phenomena than a targeted design and (2) the expected benefits (or avoided costs) arising from discovery are substantially higher than those arising from a well-planned targeted design. Our examination highlights the importance of being explicit about the objectives, costs and expected benefits of monitoring in a decision analytic framework. ?? 2010 Blackwell Publishing Ltd/CNRS.

Papain-like protease (PLpro) inhibitory effects of cinnamic amides from Tribulus terrestris fruits.

Science.gov (United States)

Song, Yeong Hun; Kim, Dae Wook; Curtis-Long, Marcus John; Yuk, Heung Joo; Wang, Yan; Zhuang, Ningning; Lee, Kon Ho; Jeon, Kwon Seok; Park, Ki Hun

2014-01-01

Tribulus terrestris fruits are well known for their usage in pharmaceutical preparations and food supplements. The methanol extract of T. terrestris fruits showed potent inhibition against the papain-like protease (PLpro), an essential proteolylic enzyme for protection to pathogenic virus and bacteria. Subsequent bioactivity-guided fractionation of this extract led to six cinnamic amides (1-6) and ferulic acid (7). Compound 6 emerged as new compound possessing the very rare carbinolamide motif. These compounds (1-7) were evaluated for severe acute respiratory syndrome coronavirus (SARS-CoV) PLpro inhibitory activity to identify their potencies and kinetic behavior. Compounds (1-6) displayed significant inhibitory activity with IC50 values in the range 15.8-70.1 µM. The new cinnamic amide 6 was found to be most potent inhibitor with an IC50 of 15.8 µM. In kinetic studies, all inhibitors exhibited mixed type inhibition. Furthermore, the most active PLpro inhibitors (1-6) were proven to be present in the native fruits in high quantities by HPLC chromatogram and liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS).

Financial Development and Economic Growth: Known Knowns, Known Unknowns, and Unknown Unknowns

OpenAIRE

Ugo Panizza

2014-01-01

This paper summarizes the main findings of the literature on the relationship between financial and economic development (the known knowns), points to directions for future research (the known unknowns), and then speculates on the third Rumsfeldian category. The known knowns section organizes the empirical literature on finance and growth into three strands: (i) the traditional literature which established the link between finance and growth; (ii) the new literature which qualified some of th...

Prevalence of potential nitrogen-fixing, green sulphur bacteria in the skeleton of reef-building coral Isopora palifera

Science.gov (United States)

Yang, S. H.

2016-02-01

Microbial endoliths, which inhabit interior pores of rocks, skeletons and coral, are ubiquitous in terrestrial and marine environments. In the present study, various colored layers stratified the endolithic environment within the skeleton of Isopora palifera; however, there was a distinct green-pigmented layer in the skeleton (beneath the living coral tissue). To characterize diversity of endolithic microorganisms, 16S ribosomal RNA gene amplicon pyrosequencing was used to investigate bacterial communities in the green layer of Isopora palifera coral colonies retrieved fromGreen Island, Taiwan. The dominant bacterial group in the green layer belonged to the bacterial phylum Chlorobi, green sulphur bacteria capable of anoxygenic photosynthesis and nitrogen fixation. Specifically, bacteria of the genus Prosthecochloris were dominant in this green layer. To our knowledge, this is the first study to provide a detailed profile of endolithic bacteria in coral and to determine prevalence of Prosthecochloris in the green layer. Based on our findings, we infer that these bacteria may have an important functional role in the coral holobiont in the nutrient-limited coral reef ecosystem.

The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems.

Science.gov (United States)

Young, Hillary S; McCauley, Douglas J; Dunbar, Robert B; Hutson, Michael S; Ter-Kuile, Ana Miller; Dirzo, Rodolfo

2013-03-01

Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.

A terrestrial Eocene stack: tying terrestrial lake ecology to marine carbon cycling through the Early Eocene Climatic Optimum

Science.gov (United States)

Grogan, D. S.; Whiteside, J. H.; Musher, D.; Rosengard, S. Z.; Vankeuren, M. A.; Pancost, R. D.

2010-12-01

The lacustrine Green River Formation is known to span ≥15 million years through the early-middle Eocene, and recent work on radioisotopic dating has provided a framework on which to build ties to the orbitally-tuned marine Eocene record. Here we present a spliced stack of Fischer assay data from drilled cores of the Green River Formation that span both an East-West and a North-South transect of the Uinta Basin of Utah. Detailed work on two cores demonstrate that Fischer assay measurements covary with total organic carbon and bulk carbon isotopes, allowing us to use Fisher assay results as a representative carbon cycling proxy throughout the stack. We provide an age model for this core record by combining radioisotopic dates of tuff layers with frequency analysis of Fischer assay measurements. Identification of orbital frequencies tied directly to magnetochrons through radioisotopic dates allows for a direct comparison of the terrestrial to the marine Eocene record. Our analysis indicates that the marker beds used to correlate the stack cores represent periods of enhanced lake productivity and extreme carbon burial; however, unlike the hyperthermal events that are clearly marked in the marine Eocene record, the hydrocarbon-rich "Mahogany Bed" period of burial does not correspond to a clear carbon isotope excursion. This suggests that the terrestrial realm may have experienced extreme ecological responses to relatively small perturbations in the carbon cycle during the Early Eocene Climatic Optimum. To investigate the ecological responses to carbon cycle perturbations through the hydrocarbon rich beds, we analyzed a suite of microbial biomarkers, finding evidence for cyanobacteria, dinoflagellates, and potentially green sulfur bacteria. These taxa indicate fluctuating oxic/anoxic conditions in the lake during abrupt intervals of carbon burial, suggesting a lake biogeochemical regime with no modern analogues.

Aquatic and Terrestrial Environment 2004

DEFF Research Database (Denmark)

Andersen, J. M.; Boutrup, S.; Bijl, L. van der

This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

Anthropogenic transformation of the terrestrial biosphere.

Science.gov (United States)

Ellis, Erle C

2011-03-13

Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.

Histories of terrestrial planets

International Nuclear Information System (INIS)

Benes, K.

1981-01-01

The uneven historical development of terrestrial planets - Mercury, Venus, Earth, Moon and Mars - is probably due to the differences in their size, weight and rotational dynamics in association with the internal planet structure, their distance from the Sun, etc. A systematic study of extraterrestrial planets showed that the time span of internal activity was not the same for all bodies. It is assumed that the initial history of all terrestrial planets was marked with catastrophic events connected with the overall dynamic development of the solar system. In view of the fact that the cores of small terrestrial bodies cooled quicker, their geological development almost stagnated after two or three thousand million years. This is what probably happened to the Mercury and the Moon as well as the Mars. Therefore, traces of previous catastrophic events were preserved on the surface of the planets. On the other hand, the Earth is the most metamorphosed terrestrial planet and compared to the other planets appears to be atypical. Its biosphere is significantly developed as well as the other shell components, its hydrosphere and atmosphere, and its crust is considerably differentiated. (J.P.)

Hydrocarbon-degrading sulfate-reducing bacteria in marine hydrocarbon seep sediments

OpenAIRE

Kleindienst, Sara

2012-01-01

Microorganisms are key players in our biosphere because of their ability to degrade various organic compounds including a wide range of hydrocarbons. At marine hydrocarbon seeps, more than 90% of sulfate reduction (SR) is potentially coupled to non-methane hydrocarbon oxidation. Several hydrocarbon-degrading sulfate-reducing bacteria (SRB) were enriched or isolated from marine sediments. However, in situ active SRB remained largely unknown. In the present thesis, the global distribution and a...

Deposition rates of viruses and bacteria above the atmospheric boundary layer.

Science.gov (United States)

Reche, Isabel; D'Orta, Gaetano; Mladenov, Natalie; Winget, Danielle M; Suttle, Curtis A

2018-04-01

Aerosolization of soil-dust and organic aggregates in sea spray facilitates the long-range transport of bacteria, and likely viruses across the free atmosphere. Although long-distance transport occurs, there are many uncertainties associated with their deposition rates. Here, we demonstrate that even in pristine environments, above the atmospheric boundary layer, the downward flux of viruses ranged from 0.26 × 10 9 to >7 × 10 9  m -2 per day. These deposition rates were 9-461 times greater than the rates for bacteria, which ranged from 0.3 × 10 7 to >8 × 10 7  m -2 per day. The highest relative deposition rates for viruses were associated with atmospheric transport from marine rather than terrestrial sources. Deposition rates of bacteria were significantly higher during rain events and Saharan dust intrusions, whereas, rainfall did not significantly influence virus deposition. Virus deposition rates were positively correlated with organic aerosols 0.7 μm, implying that viruses could have longer residence times in the atmosphere and, consequently, will be dispersed further. These results provide an explanation for enigmatic observations that viruses with very high genetic identity can be found in very distant and different environments.

Riparian vegetation in the alpine connectome: Terrestrial-aquatic and terrestrial-terrestrial interactions.

Science.gov (United States)

Zaharescu, Dragos G; Palanca-Soler, Antonio; Hooda, Peter S; Tanase, Catalin; Burghelea, Carmen I; Lester, Richard N

2017-12-01

Alpine regions are under increased attention worldwide for their critical role in early biogeochemical cycles, their high sensitivity to environmental change, and as repositories of natural resources of high quality. Their riparian ecosystems, at the interface between aquatic and terrestrial environments, play important geochemical functions in the watershed and are biodiversity hotspots, despite a harsh climate and topographic setting. With climate change rapidly affecting the alpine biome, we still lack a comprehensive understanding of the extent of interactions between riparian surface, lake and catchment environments. A total of 189 glacial - origin lakes were surveyed in the Central Pyrenees to test how key elements of the lake and terrestrial environments interact at different scales to shape riparian plant composition. Secondly, we evaluated how underlying ecotope features drive the formation of natural communities potentially sensitive to environmental change and assessed their habitat distribution. At the macroscale, vegetation composition responded to pan-climatic gradients altitude and latitude, which captured in a narrow geographic area the transition between large European climatic zones. Hydrodynamics was the main catchment-scale factor connecting riparian vegetation with major water fluxes, followed by topography and geomorphology. Lake sediment Mg and Pb, and water Mn and Fe contents reflected local influences from mafic bedrock and soil water saturation. Community analysis identified four keystone ecosystems: (i) damp ecotone, (ii) snow bed-silicate bedrock, (iii) wet heath, and (iv) calcareous substrate. These communities and their connections with ecotope elements could be at risk from a number of environmental change factors including warmer seasons, snow line and lowland species advancement, increased nutrient/metal input and water level fluctuations. The results imply important natural terrestrial-aquatic linkages in the riparian environment

Infection of California sea lions (Zalophus californianus) with terrestrial Brucella spp.

Science.gov (United States)

Avalos-Téllez, Rosalía; Ramírez-Pfeiffer, Carlos; Hernández-Castro, Rigoberto; Díaz-Aparicio, Efrén; Sánchez-Domínguez, Carlos; Zavala-Norzagaray, Alan; Arellano-Reynoso, Beatriz; Suárez-Güemes, Francisco; Aguirre, A Alonso; Aurioles-Gamboa, David

2014-10-01

Infections with Brucella ceti and pinnipedialis are prevalent in marine mammals worldwide. A total of 22 California sea lions (Zalophus californianus) were examined to determine their exposure to Brucella spp. at San Esteban Island in the Gulf of California, Mexico, in June and July 2011. Although samples of blood, vaginal mucus and milk cultured negative for these bacteria, the application of rose Bengal, agar gel immunodiffusion, PCR and modified fluorescence polarization assays found that five animals (22.7%) had evidence of exposure to Brucella strains. The data also suggested that in two of these five sea lions the strains involved were of terrestrial origin, a novel finding in marine mammals. Further work will be required to validate and determine the epidemiological significance of this finding. Copyright © 2014 Elsevier Ltd. All rights reserved.

A preliminary study on the pathogenicity of Bacillus licheniformis bacteria in immunodepressed mice

DEFF Research Database (Denmark)

Agerholm, J.S.; Jensen, N.E.; Giese, Steen Bjørck

1997-01-01

The pathogenicity of 13 strains of Bacillus licheniformis was studied in immunodepressed mice. The strains had been isolated from cases of bovine abortions (n=5), bovine feedstuffs (n=3), soil (n=l), and grain products (n=2). The origin of two strains was unknown. Groups of 10 mice were inoculated...... intravenously with B. licheniformis bacteria at doses from...

Microalgae growth-promoting bacteria: A novel approach in wastewater treatment

Directory of Open Access Journals (Sweden)

Luz E. de-Bashan

2003-07-01

Full Text Available Plant growth-promoting bacteria (PGPB from the genus Azospirillum are known to enhance the growth of numerous agricultural crops. The use of these bacteria is proposed as "micro-algae-growth promoting bacteria" (MGPB for enhancing freshwater micro-algae Chlorella vulgaris and C. sorokiniana capadty to clean polluted water. The deliberate inoculation of Chlorella sp. with a terrestrial PGPB has not been reported prior to these studies, perhaps because of the different origin of the two micro-organisms. Chlorella spp. is not known to harbour any plant growth-promoting bacteria and Azospirillum sp. is rarely used for inoculation in aquatic environments. Co-immobilisation of C. vulgaris and A. brasilense Cd in small alginate beads resulted in significant increases in numerous micro-algae growth parameters. Dry and fresh weight, total number of cells, micro-algal cluster (colonies size within the bead, number of micro-algal cells per cluster and micro-algal pigments levels significantly increased. Lipids and the variety of fatty adds also significantly increased, as did the combination of micro-algae. MGPB had superior capacity for removing ammonium and phosphorus from polluted synthetic and municipal wastewaters than the micro-algae by itself. Other PGPB (i.e. Flavobacterium sp. Azospirillum sp. and Azotobacter sp. are currently being tested in aquaculture; carp farming using enhanced phytoplankton growth and stabilising mass marine micro-algae culture for use as feed for marine organisms are both retuming promising results. This aspect of PGPB effect on water micro-organisms is currently in its infancy. We pro pose that co-immobilising micro-algae and plant growth-promoting bacteria represent an effective means of increasing micro-algal populations and also their capacity for cleaning polluted water. Key words: PGPB; micro-algae; wastewater treatment; co-immobilised

Does terrestrial epidemiology apply to marine systems?

Science.gov (United States)

McCallum, Hamish I.; Kuris, Armand M.; Harvell, C. Drew; Lafferty, Kevin D.; Smith, Garriet W.; Porter, James

2004-01-01

Most of epidemiological theory has been developed for terrestrial systems, but the significance of disease in the ocean is now being recognized. However, the extent to which terrestrial epidemiology can be directly transferred to marine systems is uncertain. Many broad types of disease-causing organism occur both on land and in the sea, and it is clear that some emergent disease problems in marine environments are caused by pathogens moving from terrestrial to marine systems. However, marine systems are qualitatively different from terrestrial environments, and these differences affect the application of modelling and management approaches that have been developed for terrestrial systems. Phyla and body plans are more diverse in marine environments and marine organisms have different life histories and probably different disease transmission modes than many of their terrestrial counterparts. Marine populations are typically more open than terrestrial ones, with the potential for long-distance dispersal of larvae. Potentially, this might enable unusually rapid propagation of epidemics in marine systems, and there are several examples of this. Taken together, these differences will require the development of new approaches to modelling and control of infectious disease in the ocean.

Co-existence of Anaerobic Ammonium Oxidation Bacteria and Denitrifying Anaerobic Methane Oxidation Bacteria in Sewage Sludge: Community Diversity and Seasonal Dynamics

DEFF Research Database (Denmark)

Xu, Sai; Lu, Wenjing; Mustafa, Muhammad Farooq

2017-01-01

Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) have been recently discovered as relevant processes in the carbon and nitrogen cycles of wastewater treatment plants. In this study, the seasonal dynamics of ANAMMOX and DAMO bacterial community structures......, and an unknown cluster was primarily detected in autumn and winter. Similar patterns of seasonal variation in the community structure of DAMO bacteria were also observed. Group B was the dominant in spring and summer, whereas in autumn and winter, group A and group B presented almost the same proportion...

Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

International Nuclear Information System (INIS)

Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T.; Hiraishi, A.

2014-01-01

Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at −1 was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process

Designing towards the unknown

DEFF Research Database (Denmark)

Wilde, Danielle; Underwood, Jenny

2018-01-01

the research potential to far-ranging possibilities. In this article we unpack the motivations driving the PKI project. We present our mixed-methodology, which entangles textile crafts, design interactions and materiality to shape an embodied enquiry. Our research outcomes are procedural and methodological......New materials with new capabilities demand new ways of approaching design. Destabilising existing methods is crucial to develop new methods. Yet, radical destabilisation—where outcomes remain unknown long enough that new discoveries become possible—is not easy in technology design where complex......, to design towards unknown outcomes, using unknown materials. The impossibility of this task is proving as useful as it is disruptive. At its most potent, it is destabilising expectations, aesthetics and processes. Keeping the researchers, collaborators and participants in a state of unknowing, is opening...

Long-term social dynamics drive loss of function in pathogenic bacteria

DEFF Research Database (Denmark)

Breum Andersen, Sandra; Marvig, Rasmus Lykke; Molin, Søren

2015-01-01

Laboratory experiments show that social interactions between bacterial cells can drive evolutionary change at the population level, but significant challenges limit attempts to assess the relevance of these findings to natural populations, where selection pressures are unknown. We have increasingly...... sophisticated methods for monitoring phenotypic and genotypic dynamics in bacteria causing infectious disease, but in contrast, we lack evidence-based adaptive explanations for those changes. Evolutionary change during infection is often interpreted as host adaptation, but this assumption neglects to consider...... social dynamics shown to drive evolutionary change in vitro. We provide evidence to show that long-term behavioral dynamics observed in a pathogen are driven by selection to outcompete neighboring conspecific cells through social interactions. We find that Pseudomonas aeruginosa bacteria, causing lung...

Recension: Mao - The Unknown Story

DEFF Research Database (Denmark)

Clausen, Søren

2005-01-01

Anmeldelse - kritisk! - til Sveriges førende Kinatidsskrift af Jung Chang & Jon Halliday's sensationelle "Mao - the Unknown Story".......Anmeldelse - kritisk! - til Sveriges førende Kinatidsskrift af Jung Chang & Jon Halliday's sensationelle "Mao - the Unknown Story"....

Terrestrial Steering Group. 2014. Arctic Terrestrial Biodiversity Monitoring Plan

DEFF Research Database (Denmark)

Aastrup, Peter; Aronsson, Mora; Barry, Tom

capacity and information may be currently available and (b) to outline near-term required steps to begin implementing the plan and reporting on an initial set of Arctic terrestrial biodiversity focal ecosystem component attributes. The specific objectives of the workshop were to: Identify key products...... for TSG for the next two years. Identify key components of a pan-Arctic status report for priority focal ecosystem components (FEC) attributes for policy and decision makers. Develop a prioritized set of activities to meet reporting objectives. Identify key milestones and timelines for the successful...... implementation of the Arctic Terrestrial Biodiversity Monitoring Plan for the next two years. Identify expert networks required for successful implementation of the plan. Identify key gaps and opportunities for the TSG related to plan implementation and identify near-term next steps to address gaps....

MODIS-derived terrestrial primary production [chapter 28

Science.gov (United States)

Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

2011-01-01

Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems not only create environments suitable for human habitation, but also provide materials essential for survival, such as food, fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of...

Recurrent severe invasive pneumococcal disease in an adult with previously unknown hyposplenia

DEFF Research Database (Denmark)

Ballegaard, Vibe C; Schejbel, Lone; Hoffmann, Steen

2015-01-01

was found. Despite immunization against S. pneumoniae and measurement of what was interpreted as protective levels of serotype-specific IgG antibodies after vaccination, the patient suffered from a third episode of IPD. CONCLUSIONS: Individuals with predisposing medical conditions or a history of severe......BACKGROUND: The risk of life-threatening and invasive infections with encapsulated bacteria is increased in patients with hyposplenia or asplenia. We report a case of recurrent invasive pneumococcal meningitis in a woman with previous unknown hyposplenia. She was vaccinated after the first episode...... of meningitis and developed sufficient levels of pneumococcal antibodies. The pneumococcal strains isolated were serotype 7 F and 17 F. To our knowledge, there has been no previously reported case of recurrent invasive pneumococcal disease in a pneumococcal vaccinated adult with hyposplenia and apparently...

The Planetary Terrestrial Analogues Library (PTAL)

Science.gov (United States)

Werner, S. C.; Dypvik, H.; Poulet, F.; Rull Perez, F.; Bibring, J.-P.; Bultel, B.; Casanova Roque, C.; Carter, J.; Cousin, A.; Guzman, A.; Hamm, V.; Hellevang, H.; Lantz, C.; Lopez-Reyes, G.; Manrique, J. A.; Maurice, S.; Medina Garcia, J.; Navarro, R.; Negro, J. I.; Neumann, E. R.; Pilorget, C.; Riu, L.; Sætre, C.; Sansano Caramazana, A.; Sanz Arranz, A.; Sobron Grañón, F.; Veneranda, M.; Viennet, J.-C.; PTAL Team

2018-04-01

The Planetary Terrestrial Analogues Library project aims to build and exploit a spectral data base for the characterisation of the mineralogical and geological evolution of terrestrial planets and small solar system bodies.

Intermittent Astrophysical Radiation Sources and Terrestrial Life

Science.gov (United States)

Melott, Adrian

2013-04-01

Terrestrial life is exposed to a variety of radiation sources. Astrophysical observations suggest that strong excursions in cosmic ray flux and spectral hardness are expected. Gamma-ray bursts and supernovae are expected to irradiate the atmosphere with keV to GeV photons at irregular intervals. Supernovae will produce large cosmic ray excursions, with time development varying with distance from the event. Large fluxes of keV to MeV protons from the Sun pose a strong threat to electromagnetic technology. The terrestrial record shows cosmogenic isotope excursions which are consistent with major solar proton events, and there are observations of G-stars suggesting that the rate of such events may be much higher than previously assumed. In addition there are unknown and unexplained astronomical transients which may indicate new classes of events. The Sun, supernovae, and gamma-ray bursts are all capable of producing lethal fluences, and some are expected on intervals of 10^8 years or so. The history of life on Earth is filled with mass extinctions at a variety of levels of intensity. Most are not understood. Astrophysical radiation may play a role, particularly from large increases in muon irradiation on the ground, and changes in atmospheric chemistry which deplete ozone, admitting increased solar UVB. UVB is strongly absorbed by DNA and proteins, and breaks the chemical bonds---it is a known carcinogen. High muon fluxes will also be damaging to such molecules, but experiments are needed to pin down the rate. Solar proton events which are not directly dangerous for the biota may nevertheless pose a major threat to modern electromagnetic technology through direct impact on satellites and magnetic induction of large currents in power grids, disabling transformers. We will look at the kind of events that are expected on timescales from human to geological, and their likely consequences.

Fungi, bacteria and soil pH: the oxalate-carbonate pathway as a model for metabolic interaction.

Science.gov (United States)

Martin, Gaëtan; Guggiari, Matteo; Bravo, Daniel; Zopfi, Jakob; Cailleau, Guillaume; Aragno, Michel; Job, Daniel; Verrecchia, Eric; Junier, Pilar

2012-11-01

The oxalate-carbonate pathway involves the oxidation of calcium oxalate to low-magnesium calcite and represents a potential long-term terrestrial sink for atmospheric CO(2). In this pathway, bacterial oxalate degradation is associated with a strong local alkalinization and subsequent carbonate precipitation. In order to test whether this process occurs in soil, the role of bacteria, fungi and calcium oxalate amendments was studied using microcosms. In a model system with sterile soil amended with laboratory cultures of oxalotrophic bacteria and fungi, the addition of calcium oxalate induced a distinct pH shift and led to the final precipitation of calcite. However, the simultaneous presence of bacteria and fungi was essential to drive this pH shift. Growth of both oxalotrophic bacteria and fungi was confirmed by qPCR on the frc (oxalotrophic bacteria) and 16S rRNA genes, and the quantification of ergosterol (active fungal biomass) respectively. The experiment was replicated in microcosms with non-sterilized soil. In this case, the bacterial and fungal contribution to oxalate degradation was evaluated by treatments with specific biocides (cycloheximide and bronopol). Results showed that the autochthonous microflora oxidized calcium oxalate and induced a significant soil alkalinization. Moreover, data confirmed the results from the model soil showing that bacteria are essentially responsible for the pH shift, but require the presence of fungi for their oxalotrophic activity. The combined results highlight that the interaction between bacteria and fungi is essential to drive metabolic processes in complex environments such as soil. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

Terrestrial ecosystems and biodiversity

CSIR Research Space (South Africa)

Davis-Reddy, Claire

2017-10-01

Full Text Available Ecoregions Terrestrial Biomes Protected Areas Climate Risk and Vulnerability: A Handbook for Southern Africa | 75 7.2. Non-climatic drivers of ecosystem change 7.2.1. Land-use change, habitat loss and fragmentation Land-use change and landscape... concentrations of endemic plant and animal species, but these mainly occur in areas that are most threatened by human activity. Diverse terrestrial ecosystems in the region include tropical and sub-tropical forests, deserts, savannas, grasslands, mangroves...

Utilization of the terrestrial cyanobacteria

Science.gov (United States)

Katoh, Hiroshi; Tomita-Yokotani, Kaori; Furukawa, Jun; Kimura, Shunta; Yokoshima, Mika; Yamaguchi, Yuji; Takenaka, Hiroyuki

The terrestrial, N _{2}-fixing cyanobacterium, Nostoc commune has expected to utilize for agriculture, food and terraforming cause of its extracellular polysaccharide, desiccation tolerance and nitrogen fixation. Previously, the first author indicated that desiccation related genes were analyzed and the suggested that the genes were related to nitrogen fixation and metabolisms. In this report, we suggest possibility of agriculture, using the cyanobacterium. Further, we also found radioactive compounds accumulated N. commune (cyanobacterium) in Fukushima, Japan after nuclear accident. Thus, it is investigated to decontaminate radioactive compounds from the surface soil by the cyanobacterium and showed to accumulate radioactive compounds using the cyanobacterium. We will discuss utilization of terrestrial cyanobacteria under closed environment. Keyword: Desiccation, terrestrial cyanobacteria, bioremediation, agriculture

Terrestrial and extraterrestrial fullerenes

Energy Technology Data Exchange (ETDEWEB)

Heymann, D.; Jenneskens, L.W.; Jehlicka, J; Koper, C.; Vlietstra, E. [Rice Univ, Houston, TX (United States). Dept. of Earth Science

2003-07-01

This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous-Tertiary-Boundary and Pennian-Triassic-Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated processes of fullerene formation, including the suggestion that some natural fullerenes might have formed from biological (algal) remains.

Parallel Computing for Terrestrial Ecosystem Carbon Modeling

International Nuclear Information System (INIS)

Wang, Dali; Post, Wilfred M.; Ricciuto, Daniel M.; Berry, Michael

2011-01-01

Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO 2 . The influence of terrestrial ecosystems on atmospheric CO 2 can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO 2 concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO 2 uptake and respiratory CO 2 release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change

Anaerobic bacteria

Science.gov (United States)

Anaerobic bacteria are bacteria that do not live or grow when oxygen is present. In humans, these bacteria ... Brook I. Diseases caused by non-spore-forming anaerobic bacteria. In: Goldman L, Schafer AI, eds. Goldman-Cecil ...

Can terrestrial diversity be predicted from soil morphology?

Science.gov (United States)

Fournier, Bertrand; Guenat, Claire; Mitchell, Edward

2010-05-01

equivalently for all taxonomic group. In this study, we explored the potential of soil morphology as a proxy for biodiversity. We used results of a previous research seeking at developing soil morphology based indicators for floodplain restoration assessment, as well as surveys of vegetation, bacteria, earthworms, and terrestrial arthropods from the same site (River Thur, CCES project RECORD: http://www.swiss-experiment.ch/index.php/Record:Home) to analyse the relationships among soil morphology and biodiversity variables and assess the efficiency of this river widening. Furthermore, we defined the best performing predictive soil variables for each taxa. Soil morphology indicators performed well in predicting terrestrial arthropod richness supporting the idea that this relatively simple indicator may represent a useful tool for the rapid assessment of floodplain restoration success. However, the indicators performed variously concerning other taxa highlighting the methods limitation and giving clues for future improvements. We conclude by discussing the potential of soil morphology in conservation biology and its possible applications for nature practitioners.

Identification of symbiotic nitrogen-fixing bacteria from three African leguminous trees in Gorongosa National Park.

Science.gov (United States)

Teixeira, Helena; Rodríguez-Echeverría, Susana

2016-07-01

The symbiosis between leguminous plants and symbiotic nitrogen-fixing bacteria is a key component of terrestrial ecosystems. Woody legumes are well represented in tropical African forests but despite their ecological and socio-economic importance, they have been little studied for this symbiosis. In this study, we examined the identity and diversity of symbiotic-nitrogen fixing bacteria associated with Acacia xanthophloea, Faidherbia albida and Albizia versicolor in the Gorongosa National Park (GNP) in Mozambique. To the best of our knowledge, this is the first report on the identity of symbiotic-nitrogen fixing bacteria in this region. 166 isolates were obtained and subjected to molecular identification. BOX-A1R PCR was used to discriminate different bacterial isolates and PCR-sequencing of 16S rDNA, and two housekeeping genes, glnII and recA, was used to identify the obtained bacteria. The gene nifH was also analyzed to assess the symbiotic capacity of the obtained bacteria. All isolates from F. albida and Al. versicolor belonged to the Bradyrhizobium genus whereas isolates from Ac. xanthophloea clustered with Mesorhizobium, Rhizobium or Ensifer strains. Soil chemical analysis revealed significant differences between the soils occupied by the three studied species. Thus, we found a clear delimitation in the rhizobial communities and soils associated with Ac. xanthophloea, F. albida and Al. versicolor, and higher rhizobial diversity for Ac. xanthophloea than previously reported. Copyright © 2016 Elsevier GmbH. All rights reserved.

Twelve previously unknown phage genera are ubiquitous in global oceans.

Science.gov (United States)

Holmfeldt, Karin; Solonenko, Natalie; Shah, Manesh; Corrier, Kristen; Riemann, Lasse; Verberkmoes, Nathan C; Sullivan, Matthew B

2013-07-30

Viruses are fundamental to ecosystems ranging from oceans to humans, yet our ability to study them is bottlenecked by the lack of ecologically relevant isolates, resulting in "unknowns" dominating culture-independent surveys. Here we present genomes from 31 phages infecting multiple strains of the aquatic bacterium Cellulophaga baltica (Bacteroidetes) to provide data for an underrepresented and environmentally abundant bacterial lineage. Comparative genomics delineated 12 phage groups that (i) each represent a new genus, and (ii) represent one novel and four well-known viral families. This diversity contrasts the few well-studied marine phage systems, but parallels the diversity of phages infecting human-associated bacteria. Although all 12 Cellulophaga phages represent new genera, the podoviruses and icosahedral, nontailed ssDNA phages were exceptional, with genomes up to twice as large as those previously observed for each phage type. Structural novelty was also substantial, requiring experimental phage proteomics to identify 83% of the structural proteins. The presence of uncommon nucleotide metabolism genes in four genera likely underscores the importance of scavenging nutrient-rich molecules as previously seen for phages in marine environments. Metagenomic recruitment analyses suggest that these particular Cellulophaga phages are rare and may represent a first glimpse into the phage side of the rare biosphere. However, these analyses also revealed that these phage genera are widespread, occurring in 94% of 137 investigated metagenomes. Together, this diverse and novel collection of phages identifies a small but ubiquitous fraction of unknown marine viral diversity and provides numerous environmentally relevant phage-host systems for experimental hypothesis testing.

Diversity of both the cultivable protease-producing bacteria and bacterial extracellular proteases in the coastal sediments of King George Island, Antarctica.

Directory of Open Access Journals (Sweden)

Ming-Yang Zhou

Full Text Available Protease-producing bacteria play a vital role in degrading sedimentary organic nitrogen. However, the diversity of these bacteria and their extracellular proteases in most regions remain unknown. In this paper, the diversity of the cultivable protease-producing bacteria and of bacterial extracellular proteases in the sediments of Maxwell Bay, King George Island, Antarctica was investigated. The cultivable protease-producing bacteria reached 10(5 cells/g in all 8 sediment samples. The cultivated protease-producing bacteria were mainly affiliated with the phyla Actinobacteria, Firmicutes, Bacteroidetes, and Proteobacteria, and the predominant genera were Bacillus (22.9%, Flavobacterium (21.0% and Lacinutrix (16.2%. Among these strains, Pseudoalteromonas and Flavobacteria showed relatively high protease production. Inhibitor analysis showed that nearly all the extracellular proteases from the bacteria were serine proteases or metalloproteases. These results begin to address the diversity of protease-producing bacteria and bacterial extracellular proteases in the sediments of the Antarctic Sea.

Microplastics as an emerging threat to terrestrial ecosystems.

Science.gov (United States)

de Souza Machado, Anderson Abel; Kloas, Werner; Zarfl, Christiane; Hempel, Stefan; Rillig, Matthias C

2018-04-01

Microplastics (plastics plastic litter or from direct environmental emission. Their potential impacts in terrestrial ecosystems remain largely unexplored despite numerous reported effects on marine organisms. Most plastics arriving in the oceans were produced, used, and often disposed on land. Hence, it is within terrestrial systems that microplastics might first interact with biota eliciting ecologically relevant impacts. This article introduces the pervasive microplastic contamination as a potential agent of global change in terrestrial systems, highlights the physical and chemical nature of the respective observed effects, and discusses the broad toxicity of nanoplastics derived from plastic breakdown. Making relevant links to the fate of microplastics in aquatic continental systems, we here present new insights into the mechanisms of impacts on terrestrial geochemistry, the biophysical environment, and ecotoxicology. Broad changes in continental environments are possible even in particle-rich habitats such as soils. Furthermore, there is a growing body of evidence indicating that microplastics interact with terrestrial organisms that mediate essential ecosystem services and functions, such as soil dwelling invertebrates, terrestrial fungi, and plant-pollinators. Therefore, research is needed to clarify the terrestrial fate and effects of microplastics. We suggest that due to the widespread presence, environmental persistence, and various interactions with continental biota, microplastic pollution might represent an emerging global change threat to terrestrial ecosystems. © 2017 John Wiley & Sons Ltd.

Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota

DEFF Research Database (Denmark)

Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie

2012-01-01

of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella...... spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria...... provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella...

Characterizing Terrestrial Exoplanets

Science.gov (United States)

Meadows, V. S.; Lustig-Yaeger, J.; Lincowski, A.; Arney, G. N.; Robinson, T. D.; Schwieterman, E. W.; Deming, L. D.; Tovar, G.

2017-11-01

We will provide an overview of the measurements, techniques, and upcoming missions required to characterize terrestrial planet environments and evolution, and search for signs of habitability and life.

Uptake and transformation of arsenic during the vegetative life stage of terrestrial fungi

International Nuclear Information System (INIS)

Nearing, Michelle M.; Koch, Iris; Reimer, Kenneth J.

2015-01-01

Many species of terrestrial fungi produce fruiting bodies that contain high proportions of arsenobetaine (AB), an arsenic compound of no known toxicity. It is unknown whether fungi produce or accumulate AB from the surrounding environment. The present study targets the vegetative life stage (mycelium) of fungi, to examine the role of this stage in arsenic transformations and potential formation of AB. The mycelia of three different fungi species were cultured axenically and exposed to AB, arsenate (As(V)) and dimethylarsinoyl acetic acid for 60 days. Agaricus bisporus was additionally exposed to hypothesized precursors for AB and the exposure time to As(V) and dimethlyarsinic acid was also extended to 120 days. The mycelia of all fungi species accumulated all arsenic compounds with two species accumulating significantly more AB than other compounds. Few biotransformations were observed in these experiments indicating that it is unlikely that the mycelium of the fungus is responsible for biosynthesizing AB. - Highlights: • Mycelia of terrestrial fungi were exposed to arsenobetaine (AB) and potential precursors. • Mycelium may be selectively accumulating AB and transporting it to fruiting bodies. • Mycelium did not biosynthesize AB. - Mycelia of edible mushrooms preferentially accumulate arsenobetaine but do not biosynthesize this non-toxic arsenical

Technical Note: Reactivity of C1 and C2 organohalogens formation – from plant litter to bacteria

Directory of Open Access Journals (Sweden)

J. J. Wang

2012-10-01

Full Text Available C1/C2 organohalogens (organohalogens with one or two carbon atoms can have significant environmental toxicity and ecological impact, such as carcinogenesis, ozone depletion and global warming. Natural halogenation processes have been identified for a wide range of natural organic matter, including soils, plant and animal debris, algae, and fungi. Yet, few have considered these organohalogens generated from the ubiquitous bacteria, one of the largest biomass pools on earth. Here, we report and confirm the formation of chloroform (CHCl₃ dichloro-acetonitrile (CHCl₂CN, chloral hydrate (CCl₃CH(OH₂ and their brominated analogues by direct halogenation of seven strains of common bacteria and nine cellular monomers. Comparing different major C stocks during litter decomposition stages in terrestrial ecosystems, from plant litter, decomposed litter, to bacteria, we found increasing reactivity for nitrogenous organohalogen yield with decreasing C/N ratio. Our results raise the possibility that natural halogenation of bacteria represents a significant and overlooked contribution to global organohalogen burdens. As bacteria are decomposers that alter the C quality by transforming organic matter pools from high to low C/N ratio and constitute a large organic N pool, the bacterial activity is expected to affect the C, N, and halogen cycling through natural halogenation reactions.

[Distribution of bacteria of Methylobacterium genus in the terrestrial biotopes of the Antarctic region].

Science.gov (United States)

Romanovskaia, V A; Rokitko, P V; Shilin, S O; Chernaia, N A; Tashirev, A B

2009-01-01

Methylotrophs distribution has been studied in the terrestrial biotopes (moss, lichen, grass, soil, sludge of lakes) on the islands of Galindez, Barkhans, Irizar, Uruguay, Jalour, Petermann, Berthelot, Cruls, King George, Corner, Skua located in the Pacific sector of the Antarctic Region, as well as in analogous biotopes on the western shore of the Antarctic peninsula Basing on a complex of diagnosis features the isolated pink-pigmented strains, which facultatively use methanol and realize the serine cycle of assimilation of one-carbon compounds, are attributed to Methylobacterium genus. Methylobacterium strains occur more often in mosses, grass Deschampsia antarctica and lichens, than in the soil and lake sludge. Some regions ofAntarctica are comparable by the number of Methylobacterium cells with the same in the regions with moderate climate. An analysis of gene sequences 16S rRNA of the Antarctic methylobacteria with those of GenBank has shown a high extent of similarity with Methylobacterium extorquens (99.4-99.7%). Notwithstanding that the strains of Methylobacterium are resistant to the broad range of extreme factors (gamma-irradiation, UV-irradiation, dehydration), the Antarctic and collection strains of the genus were sensitive to the ions of such heavy metals as Cu, Hg, Cd, Cr (10 mg/l).

Aeolian dispersal of bacteria in southwest Greenland: their sources, abundance, diversity and physiological states.

Science.gov (United States)

Šantl-Temkiv, Tina; Gosewinkel, Ulrich; Starnawski, Piotr; Lever, Mark; Finster, Kai

2018-04-01

The Arctic is undergoing dramatic climatic changes that cause profound transformations in its terrestrial ecosystems and consequently in the microbial communities that inhabit them. The assembly of these communities is affected by aeolian deposition. However, the abundance, diversity, sources and activity of airborne microorganisms in the Arctic are poorly understood. We studied bacteria in the atmosphere over southwest Greenland and found that the diversity of bacterial communities correlated positively with air temperature and negatively with relative humidity. The communities consisted of 1.3×103 ± 1.0×103 cells m-3, which were aerosolized from local terrestrial environments or transported from marine, glaciated and terrestrial surfaces over long distances. On average, airborne bacterial cells displayed a high activity potential, reflected in the high 16S rRNA copy number (590 ± 300 rRNA cell-1), that correlated positively with water vapor pressure. We observed that bacterial clades differed in their activity potential. For instance, a high activity potential was seen for Rubrobacteridae and Clostridiales, while a low activity potential was observed for Proteobacteria. Of those bacterial families that harbor ice-nucleation active species, which are known to facilitate freezing and may thus be involved in cloud and rain formation, cells with a high activity potential were rare in air, but were enriched in rain.

Removal of bacteria Legionella pneumophila, Escherichia coli, and Bacillus subtilis by (super)cavitation.

Science.gov (United States)

Šarc, Andrej; Kosel, Janez; Stopar, David; Oder, Martina; Dular, Matevž

2018-04-01

In sufficient concentrations, the pathogenic bacteria L. pneumophila can cause a respiratory illness that is known as the "Legionnaires" disease. Moreover, toxic Shiga strains of bacteria E. coli can cause life-threatening hemolytic-uremic syndrome. Because of the recent restrictions imposed on the usage of chlorine, outbreaks of these two bacterial species have become more common. In this study we have developed a novel rotation generator and its effectiveness against bacteria Legionella pneumophila and Escherichia coli was tested for various types of hydrodynamic cavitation (attached steady cavitation, developed unsteady cavitation and supercavitation). The results show that the supercavitation was the only effective form of cavitation. It enabled more than 3 logs reductions for both bacterial species and was also effective against a more persistent Gram positive bacteria, B. subtilis. The deactivation mechanism is at present unknown. It is proposed that when bacterial cells enter a supercavitation cavity, an immediate pressure drop occurs and this results in bursting of the cellular membrane. The new rotation generator that induced supercavitation proved to be economically and microbiologically far more effective than the classical Venturi section (super)cavitation. Copyright © 2017 Elsevier B.V. All rights reserved.

Commercialization of terrestrial applications of aerospace power technology

International Nuclear Information System (INIS)

Landsberg, D.R.

1992-01-01

The potential for commercialization of terrestrial energy systems based upon aerospace power technology's explored. Threats to the aerospace power technology industry, caused by the end of the cold war and weak world economy are described. There are also new opportunities caused by increasing terrestrial energy needs and world-wide concern for the environment. In this paper, the strengths and weaknesses of the aerospace power industry in commercializing terrestrial energy technologies are reviewed. Finally, actions which will enable the aerospace power technology industry to commercialize products into terrestrial energy markets are described

Freshwater bacteria are stoichiometrically flexible with a nutrient composition similar to seston

Science.gov (United States)

Cotner, James B.; Hall, Edward K.; Scott, J. Thad; Heldal, Mikal

2010-01-01

Although aquatic bacteria are assumed to be nutrient-rich, they out-compete other foodweb osmotrophs for nitrogen (N) and phosphorus (P) an apparent contradiction to resource ratio theory. This paradox could be resolved if aquatic bacteria were demonstrated to be nutrient-poor relative other portions of the planktonic food web. In a survey of >120 lakes in the upper Midwest of the USA, the nutrient content of bacteria was lower than previously reported and very similar to the Redfield ratio, with a mean biomass composition of 102:12:1 (C:N:P). Individual freshwater bacterial isolates grown under P-limiting and P-replete conditions had even higher C:P and N:P ratios with a mean community biomass composition ratio of 875C:179N:1P suggesting that individual strains can be extremely nutrient-poor, especially with respect to P. Cell-specific measurements of individual cells from one lake confirmed that low P content could be observed at the community level in natural systems with a mean biomass composition of 259C:69N:1P. Variability in bacterial stoichiometry is typically not recognized in the literature as most studies assume constant and nutrient-rich bacterial biomass composition. We present evidence that bacteria can be extremely P-poor in individual systems and in culture, suggesting that bacteria in freshwater ecosystems can either play a role as regenerators or consumers of inorganic nutrients and that this role could switch depending on the relationship between bacterial biomass stoichiometry and resource stoichiometry. This ability to switch roles between nutrient retention and regeneration likely facilitates processing of terrestrial organic matter in lakes and rivers and has important implications for a wide range of bacterially mediated biogeochemical processes.

Sexually transmitted bacteria affect female cloacal assemblages in a wild bird

Science.gov (United States)

White, Joël; Mirleau, Pascal; Danchin, Etienne; Mulard, Hervé; Hatch, Scott A.; Heeb, Phillipp; Wagner, Richard H.

2010-01-01

Sexual transmission is an important mode of disease propagation, yet its mechanisms remain largely unknown in wild populations. Birds comprise an important model for studying sexually transmitted microbes because their cloaca provides a potential for both gastrointestinal pathogens and endosymbionts to become incorporated into ejaculates. We experimentally demonstrate in a wild population of kittiwakes (Rissa tridactyla) that bacteria are transmitted during copulation and affect the composition and diversity of female bacterial communities. We used an anti-insemination device attached to males in combination with a molecular technique (automated ribosomal intergenic spacer analysis) that describes bacterial communities. After inseminations were experimentally blocked, the cloacal communities of mates became increasingly dissimilar. Moreover, female cloacal diversity decreased and the extinction of mate-shared bacteria increased, indicating that female cloacal assemblages revert to their pre-copulatory state and that the cloaca comprises a resilient microbial ecosystem.

Louisiana ESI: T_MAMMAL (Terrestrial Mammal Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for terrestrial mammals in Louisiana. Vector polygons in this data set represent terrestrial mammal...

Linking animals aloft with the terrestrial landscape

Science.gov (United States)

Buler, Jeffrey J.; Barrow, Wylie; Boone, Matthew; Dawson, Deanna K.; Diehl, Robert H.; Moore, Frank R.; Randall, Lori A.; Schreckengost, Timothy; Smolinsky, Jaclyn A.

2018-01-01

Despite using the aerosphere for many facets of their life, most flying animals (i.e., birds, bats, some insects) are still bound to terrestrial habitats for resting, feeding, and reproduction. Comprehensive broad-scale observations by weather surveillance radars of animals as they leave terrestrial habitats for migration or feeding flights can be used to map their terrestrial distributions either as point locations (e.g., communal roosts) or as continuous surface layers (e.g., animal densities in habitats across a landscape). We discuss some of the technical challenges to reducing measurement biases related to how radars sample the aerosphere and the flight behavior of animals. We highlight a recently developed methodological approach that precisely and quantitatively links the horizontal spatial structure of birds aloft to their terrestrial distributions and provides novel insights into avian ecology and conservation across broad landscapes. Specifically, we present case studies that (1) elucidate how migrating birds contend with crossing ecological barriers and extreme weather events, (2) identify important stopover areas and habitat use patterns of birds along their migration routes, and (3) assess waterfowl response to wetland habitat management and restoration. These studies aid our understanding of how anthropogenic modification of the terrestrial landscape (e.g., urbanization, habitat management), natural geographic features, and weather (e.g., hurricanes) can affect the terrestrial distributions of flying animals.

Comparative Metagenomics of Eight Geographically Remote Terrestrial Hot Springs.

Science.gov (United States)

Menzel, Peter; Gudbergsdóttir, Sóley Ruth; Rike, Anne Gunn; Lin, Lianbing; Zhang, Qi; Contursi, Patrizia; Moracci, Marco; Kristjansson, Jakob K; Bolduc, Benjamin; Gavrilov, Sergey; Ravin, Nikolai; Mardanov, Andrey; Bonch-Osmolovskaya, Elizaveta; Young, Mark; Krogh, Anders; Peng, Xu

2015-08-01

Hot springs are natural habitats for thermophilic Archaea and Bacteria. In this paper, we present the metagenomic analysis of eight globally distributed terrestrial hot springs from China, Iceland, Italy, Russia, and the USA with a temperature range between 61 and 92 (∘)C and pH between 1.8 and 7. A comparison of the biodiversity and community composition generally showed a decrease in biodiversity with increasing temperature and decreasing pH. Another important factor shaping microbial diversity of the studied sites was the abundance of organic substrates. Several species of the Crenarchaeal order Thermoprotei were detected, whereas no single bacterial species was found in all samples, suggesting a better adaptation of certain archaeal species to different thermophilic environments. Two hot springs show high abundance of Acidithiobacillus, supporting the idea of a true thermophilic Acidithiobacillus species that can thrive in hyperthermophilic environments. Depending on the sample, up to 58 % of sequencing reads could not be assigned to a known phylum, reinforcing the fact that a large number of microorganisms in nature, including those thriving in hot environments remain to be isolated and characterized.

Molecular evolution of the androgenic hormone in terrestrial isopods.

Science.gov (United States)

Cerveau, Nicolas; Bouchon, Didier; Bergès, Thierry; Grève, Pierre

2014-04-25

In crustaceans, the androgenic gland (AG), thanks to the synthesis of the androgenic gland hormone (AGH), controls the differentiation of the primary and secondary male sexual characters. In this study, we amplified 12 new AGH cDNAs in species belonging to five different families of the infra-order Ligiamorpha of terrestrial isopods. Putative essential amino acids for the production of a functional AGH protein exhibit signatures of negative selection and are strictly conserved including typical proteolytic cleavage motifs, a putative N-linked glycosylation motif on the A chains and the eight Cys positions. An insulin-like growth factor motif was also identified in Armadillidium AGH sequences. The phylogenetic relationships of AGH sequences allowed one to distinguish two main clades, corresponding to members of the Armadillidiidae and the Porcellionidae families which are congruent with the narrow specificity of AG heterospecific grafting. An in-depth understanding of the regulation of AGH expression would help deciphering the interaction between Wolbachia, widespread feminizing endosymbiotic bacteria in isopods, and the sex differentiation of their hosts. Copyright © 2014 Elsevier B.V. All rights reserved.

Terrestrial Permafrost Models of Martian Habitats and Inhabitants

Science.gov (United States)

Gilichinsky, D.

2011-12-01

Martian permafrost is still 100 times older. Only one terrestrial environment is close to Mars in age - volcanoes in permafrost areas. The age of volcanic deposits frozen after eruption is much younger than the age of surrounding permafrost. Culture- and culture-independent methods show the presence of viable thermophiles and their genes within pyroclastic frozen material on Deception Island, Antarctica and Kamchatka peninsula. These bacteria and archeae have not been found in permafrost outside the volcanic areas. The only way for thermophiles to get into frozen soil is through deposition during eruption, i.e. the catastrophic geological events transport microbes from the depths to the surface and they survive at subzero temperatures. The past activity of Martian volcanoes periodically burned through the frozen strata and products of eruptions rose from the depths to the surface and froze. Images taken by the Stereo Camera on board the Mars Express discovered volcanoes 2-15Myr old that date back to ages close to permafrost on Earth. Terrestrial communities might serve as a model of inhabitants for these young volcanoes. 3. The only opportunity for free water on Mars is the overcooled water brines, and halo/psychrophilc community of Arctic cryopegs, sandwiched within permafrost, represents a plausible prototype for Martian microbial life.

The decadal state of the terrestrial carbon cycle : Global retrievals of terrestrial carbon allocation, pools, and residence times

NARCIS (Netherlands)

Bloom, A Anthony; Exbrayat, Jean-François; van der Velde, Ivar R; Feng, Liang; Williams, Mathew

2016-01-01

The terrestrial carbon cycle is currently the least constrained component of the global carbon budget. Large uncertainties stem from a poor understanding of plant carbon allocation, stocks, residence times, and carbon use efficiency. Imposing observational constraints on the terrestrial carbon cycle

Known knowns, known unknowns and unknown unknowns in prokaryotic transposition.

Science.gov (United States)

Siguier, Patricia; Gourbeyre, Edith; Chandler, Michael

2017-08-01

Although the phenomenon of transposition has been known for over 60 years, its overarching importance in modifying and streamlining genomes took some time to recognize. In spite of a robust understanding of transposition of some TE, there remain a number of important TE groups with potential high genome impact and unknown transposition mechanisms and yet others, only recently identified by bioinformatics, yet to be formally confirmed as mobile. Here, we point to some areas of limited understanding concerning well established important TE groups with DDE Tpases, to address central gaps in our knowledge of characterised Tn with other types of Tpases and finally, to highlight new potentially mobile DNA species. It is not exhaustive. Examples have been chosen to provide encouragement in the continued exploration of the considerable prokaryotic mobilome especially in light of the current threat to public health posed by the spread of multiple Ab R . Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantum circuits cannot control unknown operations

International Nuclear Information System (INIS)

Araújo, Mateus; Feix, Adrien; Costa, Fabio; Brukner, Časlav

2014-01-01

One of the essential building blocks of classical computer programs is the ‘if’ clause, which executes a subroutine depending on the value of a control variable. Similarly, several quantum algorithms rely on applying a unitary operation conditioned on the state of a control system. Here we show that this control cannot be performed by a quantum circuit if the unitary is completely unknown. The task remains impossible even if we allow the control to be done modulo a global phase. However, this no-go theorem does not prevent implementing quantum control of unknown unitaries in practice, as any physical implementation of an unknown unitary provides additional information that makes the control possible. We then argue that one should extend the quantum circuit formalism to capture this possibility in a straightforward way. This is done by allowing unknown unitaries to be applied to subspaces and not only to subsystems. (paper)

Sex ratio variation in the bumblebee Bombus terrestris

DEFF Research Database (Denmark)

Duchateau, Marie José; Velthuis, Hayo H. W.; Boomsma, Jacobus Jan

2004-01-01

Bombus terrestris, bumblebees, colony development, queen control, reproductive strategies, sex allocation......Bombus terrestris, bumblebees, colony development, queen control, reproductive strategies, sex allocation...

Impact of Matric Potential and Pore Size Distribution on Growth Dynamics of Filamentous and Non-Filamentous Soil Bacteria

NARCIS (Netherlands)

Wolf, A.B.; Vos, de M.; Boer, de W.; Kowalchuk, G.A.

2013-01-01

The filamentous growth form is an important strategy for soil microbes to bridge air-filled pores in unsaturated soils. In particular, fungi perform better than bacteria in soils during drought, a property that has been ascribed to the hyphal growth form of fungi. However, it is unknown if, and to

Impact of matric potential and pore size distribution on growth dynamics of filamentous and non-filamentous soil bacteria

NARCIS (Netherlands)

Wolf, A.B.; Vos, M.; De Boer, W.; Kowalchuk, G.A.

2013-01-01

The filamentous growth form is an important strategy for soil microbes to bridge air-filled pores in unsaturated soils. In particular, fungi perform better than bacteria in soils during drought, a property that has been ascribed to the hyphal growth form of fungi. However, it is unknown if, and to

The Circumpolar Biodiversity Monitoring Program Terrestrial Plan

DEFF Research Database (Denmark)

Christensen, Tom; Payne, J.; Doyle, M.

, understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity, and to identify knowledge gaps and priorities. This poster will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based monitoring...... and coastal environments. The CBMP Terrestrial Plan is a framework to focus and coordinate monitoring of terrestrial biodiversity across the Arctic. The goal of the plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect...

Terrestrial nitrogen-carbon cycle interactions at the global scale.

Science.gov (United States)

Zaehle, S

2013-07-05

Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen-carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001-2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr(-1) (1.9 Pg C yr(-1)), of which 10 Tg N yr(-1) (0.2 Pg C yr(-1)) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO2 fertilization (regionally by up to 70% compared with an estimate without considering nitrogen-carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO2 in the atmosphere. However, increases of N2O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr(-1) per 1°C degree climate warming) will add an important long-term climate forcing.

Typing of unknown microorganisms based on quantitative analysis of fatty acids by mass spectrometry and hierarchical clustering

Energy Technology Data Exchange (ETDEWEB)

Li Tingting; Dai Ling; Li Lun; Hu Xuejiao; Dong Linjie; Li Jianjian; Salim, Sule Khalfan; Fu Jieying [Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079 (China); Zhong Hongying, E-mail: hyzhong@mail.ccnu.edu.cn [Key Laboratory of Pesticides and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079 (China)

2011-01-17

Rapid identification of unknown microorganisms of clinical and agricultural importance is not only critical for accurate diagnosis of infections but also essential for appropriate and prompt treatment. We describe here a rapid method for microorganisms typing based on quantitative analysis of fatty acids by iFAT approach (Isotope-coded Fatty Acid Transmethylation). In this work, lyophilized cell lysates were directly mixed with 0.5 M NaOH solution in d3-methanol and n-hexane. After 1 min of ultrasonication, the top n-hexane layer was combined with a mixture of standard d0-methanol derived fatty acid methylesters with known concentration. Measurement of intensity ratios of d3/d0 labeled fragment ion and molecular ion pairs at the corresponding target fatty acids provides a quantitative basis for hierarchical clustering. In the resultant dendrogram, the Euclidean distance between unknown species and known species quantitatively reveals their differences or shared similarities in fatty acid related pathways. It is of particular interest to apply this method for typing fungal species because fungi has distinguished lipid biosynthetic pathways that have been targeted for lots of drugs or fungicides compared with bacteria and animals. The proposed method has no dependence on the availability of genome or proteome databases. Therefore, it is can be applicable for a broad range of unknown microorganisms or mutant species.

Ontogenetic shifts in terrestrial reliance of stream-dwelling brown trout

Directory of Open Access Journals (Sweden)

Javier Sánchez-Hernández

2016-07-01

Full Text Available This study focuses on terrestrial reliance of brown trout (Salmo trutta and compared it to the potential prey available (macrozoobenthos and drifting invertebrates in three temperate rivers (Galicia, NW Spain, with special emphasis on variations in terrestrial energy intake through the ontogeny of brown trout. Additionally, we paid particular attention to individual variation of terrestrial resource use within and between age classes. Prey items were grouped in four categories: i aquatic invertebrates; ii imagoes of aquatic invertebrates; iii terrestrial invertebrates; and iv fish prey. Next, energy composition was measured according to dry weight-energy equations for each individual in line with above-mentioned prey categories. Our findings illustrate that terrestrial invertebrates appeared to be scarce in the environment, whereas aquatic food resources were rather abundant and accessible. The use of terrestrial invertebrates tended to increase with age, but with a high degree of inter-individual variation in resource use. In fact, the individual reliance of brown trout on terrestrial invertebrates may vary considerably (between 0% and 76.9%. Besides, the frequency of terrestrial foragers, i.e., individuals with terrestrial invertebrates in their stomachs, increased with age, except in one population which had the maximum value in the age-2 class. The acquisition of terrestrial invertebrates thus appears to be a process strongly dependent upon the actual food availability in the environment, but with a high degree of individual variance in resource use within the same age class. Finally, we discuss that terrestrial invertebrates may largely contribute to cover the energy intake of the species, highlighting the interface between terrestrial and aquatic ecosystems, and thereby the importance of riparian canopy cover as a key factor for food supply of stream-dwelling salmonids species.

Priapism caused by 'Tribulus terrestris'.

Science.gov (United States)

Campanelli, M; De Thomasis, R; Tenaglia, R L

2016-01-01

A 36-year-old Caucasian man was diagnosed with a 72-h-lasting priapism that occurred after the assumption of a Herbal supplement based on Tribulus terrestris, which is becoming increasingly popular for the treatment of sexual dysfunction. The patient underwent a cavernoglandular shunt (Ebbehoj shunt) in order to obtain complete detumescence, from which derived negative post-episode outcomes on sexual function. All patients consuming non-FDA-approved alternative supplements such as Tribulus terrestris should be warned about the possible serious side effects.

Durable terrestrial bedrock predicts submarine canyon formation

Science.gov (United States)

Smith, Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

2017-01-01

Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

Tribulus terrestris Extract Improves Human Sperm Parameters In Vitro

Science.gov (United States)

Khaleghi, Sara; Bakhtiari, Mitra; Asadmobini, Atefeh; Esmaeili, Farzane

2016-01-01

Objective. The object of present study was to investigate the effects of direct addition of Tribulus terrestris extract on human sperm parameters. Design. Semen specimens from 40 healthy men volunteers were divided into 4 groups: one group received no treatment (control group) while the others were incubated with 20, 40, and 50 µg/mL of T terrestris extract (experimental groups). Motility, viability, and DNA fragmentation were assessed in all groups. Results. The incubation of human semen with 40 and 50 μg/mL of T terrestris extract significantly enhanced total sperm motility, number of progressive motile spermatozoa, and curvilinear velocity over 60 to 120 minutes’ holding time (P terrestris extract (P terrestris extract to human sperm could affect male fertility capacity. PMID:27694560

Tribulus terrestris Extract Improves Human Sperm Parameters In Vitro.

Science.gov (United States)

Khaleghi, Sara; Bakhtiari, Mitra; Asadmobini, Atefeh; Esmaeili, Farzane

2016-09-30

The object of present study was to investigate the effects of direct addition of Tribulus terrestris extract on human sperm parameters. Semen specimens from 40 healthy men volunteers were divided into 4 groups: one group received no treatment (control group) while the others were incubated with 20, 40, and 50 µg/mL of T terrestris extract (experimental groups). Motility, viability, and DNA fragmentation were assessed in all groups. The incubation of human semen with 40 and 50 μg/mL of T terrestris extract significantly enhanced total sperm motility, number of progressive motile spermatozoa, and curvilinear velocity over 60 to 120 minutes' holding time (P terrestris extract (P terrestris extract to human sperm could affect male fertility capacity. © The Author(s) 2016.

Hepatoprotective and Antioxidant Activities of Tribulus Terrestris

NARCIS (Netherlands)

Harraz, Fathalla M; Ghazy, Nabila M; Hammoda, Hala M; Nafeaa, Abeer A.; Abdallah, Ingy I.

2015-01-01

Tribulus terrestris L. has been used in folk medicine throughout history. The present study examined the acute toxicity of the total ethanolic extract of T. Terrestris followed by investigation of the hepatoprotective activity of the total ethanolic extract and different fractions of the aerial

Debris disks as signposts of terrestrial planet formation

Science.gov (United States)

Raymond, S. N.; Armitage, P. J.; Moro-Martín, A.; Booth, M.; Wyatt, M. C.; Armstrong, J. C.; Mandell, A. M.; Selsis, F.; West, A. A.

2011-06-01

There exists strong circumstantial evidence from their eccentric orbits that most of the known extra-solar planetary systems are the survivors of violent dynamical instabilities. Here we explore the effect of giant planet instabilities on the formation and survival of terrestrial planets. We numerically simulate the evolution of planetary systems around Sun-like stars that include three components: (i) an inner disk of planetesimals and planetary embryos; (ii) three giant planets at Jupiter-Saturn distances; and (iii) an outer disk of planetesimals comparable to estimates of the primitive Kuiper belt. We calculate the dust production and spectral energy distribution of each system by assuming that each planetesimal particle represents an ensemble of smaller bodies in collisional equilibrium. Our main result is a strong correlation between the evolution of the inner and outer parts of planetary systems, i.e. between the presence of terrestrial planets and debris disks. Strong giant planet instabilities - that produce very eccentric surviving planets - destroy all rocky material in the system, including fully-formed terrestrial planets if the instabilities occur late, and also destroy the icy planetesimal population. Stable or weakly unstable systems allow terrestrial planets to accrete in their inner regions and significant dust to be produced in their outer regions, detectable at mid-infrared wavelengths as debris disks. Stars older than ~100 Myr with bright cold dust emission (in particular at λ ~ 70 μm) signpost dynamically calm environments that were conducive to efficient terrestrial accretion. Such emission is present around ~16% of billion-year old Solar-type stars. Our simulations yield numerous secondary results: 1) the typical eccentricities of as-yet undetected terrestrial planets are ~0.1 but there exists a novel class of terrestrial planet system whose single planet undergoes large amplitude oscillations in orbital eccentricity and inclination; 2) by

The fragmentation of Pangaea and Mesozoic terrestrial vertebrate biodiversity.

Science.gov (United States)

Vavrek, Matthew J

2016-09-01

During the Mesozoic (242-66 million years ago), terrestrial regions underwent a massive shift in their size, position and connectivity. At the beginning of the era, the land masses were joined into a single supercontinent called Pangaea. However, by the end of the Mesozoic, terrestrial regions had become highly fragmented, both owing to the drifting apart of the continental plates and the extremely high sea levels that flooded and divided many regions. How terrestrial biodiversity was affected by this fragmentation and large-scale flooding of the Earth's landmasses is uncertain. Based on a model using the species-area relationship (SAR), terrestrial vertebrate biodiversity would be expected to nearly double through the Mesozoic owing to continental fragmentation, despite a decrease of 24% in total terrestrial area. Previous studies of Mesozoic vertebrates have generally found increases in terrestrial diversity towards the end of the era, although these increases are often attributed to intrinsic or climatic factors. Instead, continental fragmentation over this time may largely explain any observed increase in terrestrial biodiversity. This study demonstrates the importance that non-intrinsic effects can have on the taxonomic success of a group, and the importance of geography to understanding past biodiversity. © 2016 The Author(s).

Ancient Terrestrial Carbon: Lost and Found

Science.gov (United States)

Freeman, K. H.

2017-12-01

Carbon fluxes in terrestrial environments dominate the global carbon cycle. The fluxes of terrestrial carbon are strongly tied to regional climate due to the influences of temperature, water, and nutrient dynamics on plant productivity. However, climate also influences the destruction of terrestrial organic matter, through weathering, erosion, and biomass loss via fire and oxidative microbial processes. Organic geochemical methods enable us to interrogate past terrestrial carbon dynamics and learn how continental processes might accelerate, or mitigate carbon transfer to the atmosphere, and the associated greenhouse warming. Terrestrial soil systems represent the weathering rind of the continents, and are inherently non-depositional and erosive. The production, transport, and depositional processes affecting organics in continental settings each impart their own biases on the amount and characteristics of preserved carbon. Typically, the best archives for biomarker records are sediments in ancient lakes or subaqueous fans, which represents a preservation bias that tends to favor wetter environments. Paleosols, or ancient soils, formed under depositional conditions that, for one reason or another, truncated soil ablation, erosion, or other loss processes. In modern soils, widely ranging organic carbon abundances are almost always substantially greater than the trace amounts of carbon left behind in ancient soils. Even so, measureable amounts of organic biomarkers persist in paleosols. We have been investigating processes that preserve soil organic carbon on geologic timescales, and how these mechanisms may be sensitive to past climate change. Climate-linked changes in temperature, moisture, pH, and weathering processes can impact carbon preservation via organo-mineral sorption, soil biogeochemistry, and stability based on the physical and chemical properties of organic compounds. These will be discussed and illustrated with examples from our studies of Cenozoic

Accelerator mass analyses of meteorites - carbon-14 terrestrial ages

International Nuclear Information System (INIS)

Miura, Y.; Rucklidge, J.; Beukens, R.; Fireman, E.

1988-01-01

Carbon-14 terrestrial ages of ten Antarctic meteorites have been measured by the IsoTrace accelerator mass spectrometry (AMS). The 14 C terrestrial age of 1 gram sample was determined from 14 C concentrations collected at melt and re-melt temperatures, compared with the 14 C concentration of the known Bruderheim chondrite. Yamato-790448 (LL3) chondrite was found to be the oldest terrestrial age of 3x10 4 years in the nine Yamato chondrites, whereas Yamato-791630 (L4) chondrite is considered to be the youngest chondrites less than thousand years. Allan Hills chondrite of ALH-77231 (L6) shows older terrestrial age than the nine Yamato chondrites. New accelerator data of the terrestrial age show higher accuracy with smaller sample than the previous counting method. (author)

Action of an aerobic hydrogenotroph bacteria isolated from ultrapure water systems on AISI 304 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Gales, Gregoire [DTN/SMTM/LMTE, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France)]|[DSV/DEVM/LEMIR, UMR 6191 CNRS-CEA-Universite Aix-Marseille II, CEA Cadarache, F- 13108 Saint-Paul-lez-Durance (France); Roy, Marc; Feron, Damien [DEN/DPC/SCCME/LECA, Bat 458, CEA Saclay F- 91191 Gif sur Yvette (France); Libert, Marie-Francoise; Sellier, Regine [DTN/SMTM/LMTE, CEA Cadarache, F-13108 Saint-Paul-lez-Durance (France); Cournac, Laurent [DSV/DEVM/LEP, UMR 6191 CNRS-CEA-Universite Aix-Marseille II, CEA Cadarache, F- 13108 Saint-Paul-lez-Durance (France); Heulin, Thierry [DSV/DEVM/LEMIR, UMR 6191 CNRS-CEA-Universite Aix-Marseille II, CEA Cadarache, F- 13108 Saint-Paul-lez-Durance (France)

2004-07-01

Several microbial studies have been recently performed in nuclear power stations. These studies concerned essentially the formation of bio-films on submerged metal coupons. Heterotrophic micro-organisms have been found in bulk water of nuclear fuel storage basins but the in situ nutrient sources for bacterial development in such highly oligo-trophic water was unknown. In nuclear environments, radiations lead to the production of molecular hydrogen, hydrogen peroxide and some radicals (OH, O{sub 2}{sup -}) by radiolysis of water or embedding matrices. Bacterial oxidation of molecular H{sub 2} commonly occurs in nature, as molecular hydrogen represents a high-energy reductant. We investigated the microbiology of a ultra-pure water basin containing irradiating waste. The initial aim of this study was to determine if autotrophic bacterial growth was possible in this basin. A major bacteria was isolated (Ralstonia sp. GGLH002) which was able to grow autotrophically with hydrogen as the electron donor and oxygen as the electron acceptor, and heterotrophically with organic nutrients. Its hydrogenase activity has been characterized. We focused then our study on the effects of this strain on 304L AISI stainless steel depending on the nutrient source used for bacterial development, e.g hydrogen or organics. In conclusion, the mechanism of passivation enhanced by Ralstonia sp. GGLH002 on AISI 304L SS still remains unknown. Several techniques could give substantial information, including XPS and polarization curves. It seems for the moment that the major bacteria inhabiting an oxic environment containing hydrogen due to radiolysis is not aggressive to stainless steel in conditions near from its environment. Further investigations are needed to test this hypothesis, including a study of the molecular diversity of the bacteria using culture-independent techniques, as cultivatable bacterial populations represent in general only a fraction of the total bacteria. (authors)

Action of an aerobic hydrogenotroph bacteria isolated from ultrapure water systems on AISI 304 stainless steel

International Nuclear Information System (INIS)

Gales, Gregoire; Roy, Marc; Feron, Damien; Libert, Marie-Francoise; Sellier, Regine; Cournac, Laurent; Heulin, Thierry

2004-01-01

Several microbial studies have been recently performed in nuclear power stations. These studies concerned essentially the formation of bio-films on submerged metal coupons. Heterotrophic micro-organisms have been found in bulk water of nuclear fuel storage basins but the in situ nutrient sources for bacterial development in such highly oligo-trophic water was unknown. In nuclear environments, radiations lead to the production of molecular hydrogen, hydrogen peroxide and some radicals (OH, O 2 - ) by radiolysis of water or embedding matrices. Bacterial oxidation of molecular H 2 commonly occurs in nature, as molecular hydrogen represents a high-energy reductant. We investigated the microbiology of a ultra-pure water basin containing irradiating waste. The initial aim of this study was to determine if autotrophic bacterial growth was possible in this basin. A major bacteria was isolated (Ralstonia sp. GGLH002) which was able to grow autotrophically with hydrogen as the electron donor and oxygen as the electron acceptor, and heterotrophically with organic nutrients. Its hydrogenase activity has been characterized. We focused then our study on the effects of this strain on 304L AISI stainless steel depending on the nutrient source used for bacterial development, e.g hydrogen or organics. In conclusion, the mechanism of passivation enhanced by Ralstonia sp. GGLH002 on AISI 304L SS still remains unknown. Several techniques could give substantial information, including XPS and polarization curves. It seems for the moment that the major bacteria inhabiting an oxic environment containing hydrogen due to radiolysis is not aggressive to stainless steel in conditions near from its environment. Further investigations are needed to test this hypothesis, including a study of the molecular diversity of the bacteria using culture-independent techniques, as cultivatable bacterial populations represent in general only a fraction of the total bacteria. (authors)

Structure of the terrestrial planets

International Nuclear Information System (INIS)

Lyttleton, R.A.

1977-01-01

Recent reviews (cf. Runcorn, 1968; or Cook, 1972, 1975) on the structure of the planets omit reference to the phase-change hypothesis for the nature of the terrestrial core, despite that numerous prior predictions of the theory based on this hypothesis have subsequently been borne out as correct. These reviews also ignore the existence of theoretical calculations of the internal structure of Venus which can be computed with high accuracy by use of the terrestrial seismic data. Several examples of numerous mistakes committed in these reviews are pointed out. (Auth.)

Is litter decomposition 'primed' by primary producer-release of labile carbon in terrestrial and aquatic experimental systems?

Science.gov (United States)

Soares, A. Margarida P. M.; Kritzberg, Emma S.; Rousk, Johannes

2015-04-01

It is possible that recalcitrant organic matter (ROM) can be 'activated' by inputs of labile organic matter (LOM) through the priming effect (PE). Investigating the PE is of major importance to fully understand the microbial use of ROM and its role on carbon (C) and nutrient cycling in both aquatic and terrestrial ecosystems. In aquatic ecosystems it is thought that the PE is triggered by periphytic algae release of LOM. Analogously, in terrestrial systems it is hypothesized that the LOM released in plant rhizospheres, or from the green crusts on the surface of agricultural soils, stimulate the activity and growth of ROM decomposers. Most previous studies on PE have utilised pulse additions of single substrates at high concentrations. However, to achieve an assessment of the true importance of the PE, it is important to simulate a realistic delivery of LOM. We investigated, in a series of 2-week laboratory experiments, how primary producer (PP)-release of LOM influence litter degradation in terrestrial and aquatic experimental systems. We used soil (terrestrial) and pond water (aquatic) microbial communities to which litter was added under light and dark conditions. In addition, glucose was added at PP delivery rates in dark treatments to test if the putative PE in light systems could be reproduced. We observed an initial peak of bacterial growth rate followed by an overall decrease over time with no treatment differences. In light treatments, periphytic algae growth and increased fungal production was stimulated when bacterial growth declined. In contrast, both fungal growth and algal production were negligible in dark treatments. This reveals a direct positive influence of photosynthesis on fungal growth. To investigate if PP LOM supplements, and the associated fungal growth, translate into a modulated litter decomposition, we are using stable isotopes to track the use of litter and algal-derived carbon by determining the δ13C in produced CO2. Fungi and bacteria

Community Decadal Panel for Terrestrial Analogs to Mars

Science.gov (United States)

Barlow, N. G.; Farr, T.; Baker, V. R.; Bridges, N.; Carsey, F.; Duxbury, N.; Gilmore, M. S.; Green, J. R.; Grin, E.; Hansen, V.; Keszthelyi, L.; Lanagan, P.; Lentz, R.; Marinangeli, L.; Morris, P. A.; Ori, G. G.; Paillou, P.; Robinson, C.; Thomson, B.

2001-11-01

It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites for Mars, instrument tests, laboratory measurements (including analysis of martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel is considering the following two key questions: (1) How do terrestrial analog studies tie in to the MEPAG science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel is considering the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

Chemotactic behavior of deep subsurface bacteria toward carbohydrates, amino acids and a chlorinated alkene

Energy Technology Data Exchange (ETDEWEB)

Lopez de Victoria, G. (Puerto Rico Univ., Rio Piedras (Puerto Rico). Dept. of Biology)

1989-02-01

The chemotactic behavior of deep terrestrial subsurface bacteria toward amino acids, carbohydrates and trichloroethylene was assayed using a modification of the capillary method and bacterial enumeration by acridine orange direct counts. Eleven isolates of bacteria isolated from six different geological formations were investigated. A bimodal response rather than an absolute positive or negative response was observed in most assays. Most of the isolates were positively chemotactic to low concentrations of substrates and were repelled by high concentrations of the same substrate. However, this was not the case for trichloroethylene (TCE) which was mostly an attractant and elicited the highest responses in all the isolates when compared with amino acids and carbohydrates. The movement rates of these isolates in aseptic subsurface sediments in the absence and presence of TCE were also determined using a laboratory model. All of the isolates showed distinct response range, peak, and threshold concentrations when exposed to the same substrates suggesting that they are possibly different species as has been inferred from DNA homology studies. 101 refs., 4 figs., 57 tabs.

Terrestrial magnetosphere

International Nuclear Information System (INIS)

Pande, D.C.; Agarwal, D.C.

1982-01-01

This paper presents a review about terrestrial magnetosphere. During the last few years considerable investigation have been carried out about the properties of Solar Wind and its interaction with planetary magnetic fields. It is therefore of high importance to accumulate all the investigations in a comprehensive form. The paper reviews the property of earth's magnetosphere, magnetosheath, magneto pause, polar cusps, bow shook and plasma sheath. (author)

Introduced Terrestrial Species (Future)

Data.gov (United States)

U.S. Environmental Protection Agency — These data represent predicted future potential distributions of terrestrial plants, animals, and pathogens non-native to the Middle-Atlantic region. These data are...

TERRESTRIAL, HABITABLE-ZONE EXOPLANET FREQUENCY FROM KEPLER

International Nuclear Information System (INIS)

Traub, Wesley A.

2012-01-01

Data from Kepler's first 136 days of operation are analyzed to determine the distribution of exoplanets with respect to radius, period, and host-star spectral type. The analysis is extrapolated to estimate the percentage of terrestrial, habitable-zone (HZ) exoplanets. The Kepler census is assumed to be complete for bright stars (magnitude 0.5 Earth radius and periods β–1 , with β ≅ 0.71 ± 0.08; and an extrapolation to longer periods gives the frequency of terrestrial planets in the HZs of FGK stars as η ⊕ ≅ (34 ± 14)%. Thus about one-third of FGK stars are predicted to have at least one terrestrial, HZ planet.

Chinese Unknown Word Recognition for PCFG-LA Parsing

Directory of Open Access Journals (Sweden)

Qiuping Huang

2014-01-01

Full Text Available This paper investigates the recognition of unknown words in Chinese parsing. Two methods are proposed to handle this problem. One is the modification of a character-based model. We model the emission probability of an unknown word using the first and last characters in the word. It aims to reduce the POS tag ambiguities of unknown words to improve the parsing performance. In addition, a novel method, using graph-based semisupervised learning (SSL, is proposed to improve the syntax parsing of unknown words. Its goal is to discover additional lexical knowledge from a large amount of unlabeled data to help the syntax parsing. The method is mainly to propagate lexical emission probabilities to unknown words by building the similarity graphs over the words of labeled and unlabeled data. The derived distributions are incorporated into the parsing process. The proposed methods are effective in dealing with the unknown words to improve the parsing. Empirical results for Penn Chinese Treebank and TCT Treebank revealed its effectiveness.

Spatial vision in Bombus terrestris

Directory of Open Access Journals (Sweden)

Aravin eChakravarthi

2016-02-01

Full Text Available Bombus terrestris is one of the most commonly used insect models to investigate visually guided behavior and spatial vision in particular. Two fundamental measures of spatial vision are spatial resolution and contrast sensitivity. In this study, we report the threshold of spatial resolution in B. terrestris and characterize the contrast sensitivity function of the bumblebee visual system for a dual choice discrimination task. We trained bumblebees in a Y-maze experimental set-up to associate a vertical sinusoidal grating with a sucrose reward, and a horizontal grating with absence of a reward. Using a logistic psychometric function, we estimated a resolution threshold of 0.21 cycles deg-1 of visual angle. This resolution is in the same range but slightly lower than that found in honeybees (Apis mellifera and A. cerana and another bumblebee species (B. impatiens. We also found that the contrast sensitivity of B. terrestris was 1.57 for the spatial frequency 0.09 cycles deg-1 and 1.26. for 0.18 cycles deg-1.

DGGE detection and screening of lignocellulolytic bacteria from the termite gut of Coptotermes formosanus

Directory of Open Access Journals (Sweden)

Mathew, G.M.

2011-01-01

Full Text Available Aims: Termites thrive in terrestrial ecosystems and play an important role in the bio-recycling of lignocellulose. The objective of this study is to isolate and detect bacteria from the termite gut of Coptotermes formosanus and to screen their various enzyme activities by qualitative methods. In addition, this study was aimed to isolate lignin and furfural tolerant strains for various industrial bioprocesses.Methodology and Results: In this study, 50 worker termites of Coptotermes formosanus were collected from dead trees, from a forest in Taichung, Taiwan in June 2008 and the composition of the microbial flora from the termite guts was analyzed by DGGE analysis. The results proved that anaerobic and facultatively anaerobic bacteria consisting of Acinetobacter, Bacteroides thetaiotaomicron, Escherichia coli, and Caulobacter readily existed in the guts of termites. Although the majority of these gut symbionts have not yet been cultivated or identified, some related bacteria were isolated. Two isolates 1-8 and 2-2 of Genus Bacillus, exhibited endocellulase, protease, lipase, amylase, peroxidase and lignin peroxidase activity. Under aerobic conditions, the growth density of isolate 1-8 cultured in 1000 ppm lignin containing MSM medium was two-folds higher than cultured in MSM medium without lignin. Furthermore, the isolate 1-8 was tolerant to 20 mM furfural supplemented in the MSM medium. HPLC analysis confirmed Bacillus isolate 1-8 could degrade up to 15 mM furfural.Conclusion, significance and impact of study: Hind gut bacteria from C. formosanus were detected by culture independent DGGE method. Also, Bacillus isolates 1-8 and 2-2 obtained by culture dependent methods could withstand higher concentration of furfural and as well as lignin. These isolates may be co-cultured with ethanologenic bacteria and be used as an industrial biocatalyst for biofuel production.

Ecotoxic heavy metals transformation by bacteria and fungi in aquatic ecosystem.

Science.gov (United States)

Chaturvedi, Amiy Dutt; Pal, Dharm; Penta, Santhosh; Kumar, Awanish

2015-10-01

Water is the most important and vital molecule of our planet and covers 75% of earth surface. But it is getting polluted due to high industrial growth. The heavy metals produced by industrial activities are recurrently added to it and considered as dangerous pollutants. Increasing concentration of toxic heavy metals (Pb(2+), Cd(2+), Hg(2+), Ni(2+)) in water is a severe threat for human. Heavy metal contaminated water is highly carcinogenic and poisonous at even relatively low concentrations. When they discharged in water bodies, they dissolve in the water and are distributed in the food chain. Bacteria and fungi are efficient microbes that frequently transform heavy metals and remove toxicity. The application of bacteria and fungi may offer cost benefit in water treatment plants for heavy metal transformation and directly related to public health and environmental safety issues. The heavy metals transformation rate in water is also dependent on the enzymatic capability of microorganisms. By transforming toxic heavy metals microbes sustain aquatic and terrestrial life. Therefore the application of microbiological biomass for heavy metal transformation and removal from aquatic ecosystem is highly significant and striking. This paper reviews the microbial transformation of heavy metal, microbe metal interaction and different approaches for microbial heavy metal remediation from water bodies.

Soil and terrestrial biology studies

International Nuclear Information System (INIS)

Anon.

1976-01-01

Soil and terrestrial biology studies focused on developing an understanding of the uptake of gaseous substances from the atmosphere by plants, biodegradation of oil, and the movement of Pu in the terrestrial ecosystems of the southeastern United States. Mathematical models were developed for SO 2 and tritium uptake from the atmosphere by plants; the uptake of tritium by soil microorganisms was measured; and the relationships among the Pu content of soil, plants, and animals of the Savannah River Plant area were studied. Preliminary results are reported for studies on the biodegradation of waste oil on soil surfaces

The early evolution of the atmospheres of terrestrial planets

CERN Document Server

Raulin, François; Muller, Christian; Nixon, Conor; Astrophysics and Space Science Proceedings : Volume 35

2013-01-01

“The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are ...

Water vapor estimation using digital terrestrial broadcasting waves

Science.gov (United States)

Kawamura, S.; Ohta, H.; Hanado, H.; Yamamoto, M. K.; Shiga, N.; Kido, K.; Yasuda, S.; Goto, T.; Ichikawa, R.; Amagai, J.; Imamura, K.; Fujieda, M.; Iwai, H.; Sugitani, S.; Iguchi, T.

2017-03-01

A method of estimating water vapor (propagation delay due to water vapor) using digital terrestrial broadcasting waves is proposed. Our target is to improve the accuracy of numerical weather forecast for severe weather phenomena such as localized heavy rainstorms in urban areas through data assimilation. In this method, we estimate water vapor near a ground surface from the propagation delay of digital terrestrial broadcasting waves. A real-time delay measurement system with a software-defined radio technique is developed and tested. The data obtained using digital terrestrial broadcasting waves show good agreement with those obtained by ground-based meteorological observation. The main features of this observation are, no need for transmitters (receiving only), applicable wherever digital terrestrial broadcasting is available and its high time resolution. This study shows a possibility to estimate water vapor using digital terrestrial broadcasting waves. In the future, we will investigate the impact of these data toward numerical weather forecast through data assimilation. Developing a system that monitors water vapor near the ground surface with time and space resolutions of 30 s and several kilometers would improve the accuracy of the numerical weather forecast of localized severe weather phenomena.

Potential for hydrogen-oxidizing chemolithoautotrophic and diazotrophic populations to initiate biofilm formation in oligotrophic, deep terrestrial subsurface waters.

Science.gov (United States)

Wu, Xiaofen; Pedersen, Karsten; Edlund, Johanna; Eriksson, Lena; Åström, Mats; Andersson, Anders F; Bertilsson, Stefan; Dopson, Mark

2017-03-23

Deep terrestrial biosphere waters are separated from the light-driven surface by the time required to percolate to the subsurface. Despite biofilms being the dominant form of microbial life in many natural environments, they have received little attention in the oligotrophic and anaerobic waters found in deep bedrock fractures. This study is the first to use community DNA sequencing to describe biofilm formation under in situ conditions in the deep terrestrial biosphere. In this study, flow cells were attached to boreholes containing either "modern marine" or "old saline" waters of different origin and degree of isolation from the light-driven surface of the earth. Using 16S rRNA gene sequencing, we showed that planktonic and attached populations were dissimilar while gene frequencies in the metagenomes suggested that hydrogen-fed, carbon dioxide- and nitrogen-fixing populations were responsible for biofilm formation across the two aquifers. Metagenome analyses further suggested that only a subset of the populations were able to attach and produce an extracellular polysaccharide matrix. Initial biofilm formation is thus likely to be mediated by a few bacterial populations which were similar to Epsilonproteobacteria, Deltaproteobacteria, Betaproteobacteria, Verrucomicrobia, and unclassified bacteria. Populations potentially capable of attaching to a surface and to produce extracellular polysaccharide matrix for attachment were identified in the terrestrial deep biosphere. Our results suggest that the biofilm populations were taxonomically distinct from the planktonic community and were enriched in populations with a chemolithoautotrophic and diazotrophic metabolism coupling hydrogen oxidation to energy conservation under oligotrophic conditions.

Bacteria within the gastrointestinal tract microbiota correlated with improved growth and feed conversion: Challenges presented for the identification of performance enhancing probiotic bacteria

Directory of Open Access Journals (Sweden)

Dragana eStanley

2016-02-01

Full Text Available Identification of bacteria associated with desirable productivity outcomes in animals may offer a direct approach to the identification of probiotic bacteria for use in animal production. We performed three controlled chicken trials (n=96 to investigate caecal microbiota differences between the best and poorest performing birds using four performance measures; Feed Conversion Rate (FCR, utilisation of energy from the feed measured as Apparent Metabolisable Energy (AME, gain rate (GR and amount of feed eaten (FE. The shifts in microbiota composition associated with the performance measures were very different between the three trials. Analysis of the caecal microbiota revealed that the high and low FCR birds had significant differences in the abundance of some bacteria as demonstrated by shifts in microbiota alpha and beta diversity. Trials 1 and 2 showed significant overall community shifts, however the microbial changes driving the difference between good and poor performers were very different. Lachnospiraceae, Ruminococcaceae and Erysipelotrichaceae families and genera Ruminococcus, Faecalibacterium and multiple lineages of genus Clostridium (from families Lachnospiraceae, Ruminococcaceae and Erysipelotrichaceae were highly abundant in good FCR birds in Trial 1. Different microbiota was associated with FCR in Trial 2; Catabacteriaceae and unknown Clostridiales family members were increased in good FCR and genera Clostridium (from family Clostridiaceae and Lactobacillus were associated with poor FCR. Trial 3 had only mild microbiota differences associated with all 4 performance measures. Overall, the genus Lactobacillus was correlated with feed intake which resulted in poor FCR performance. The genus Faecalibacterium correlated with improved FCR, increased GR and reduced FE. There was overlap in phylotypes correlated with improved FCR and GR, while different microbial cohorts appeared to be correlated with FE. Even under controlled conditions

The decadal state of the terrestrial carbon cycle

NARCIS (Netherlands)

Velde, van der I.R.; Bloom, J.; Exbrayat, J.; Feng, L.; Williams, M.

2016-01-01

The terrestrial carbon cycle is currently the least constrained component of the global carbon budget. Large uncertainties stem from a poor understanding of plant carbon allocation, stocks, residence times, and carbon use efficiency. Imposing observational constraints on the terrestrial carbon cycle

Phytopharmacology of Tribulus terrestris.

Science.gov (United States)

Shahid, M; Riaz, M; Talpur, M M A; Pirzada, T

2016-01-01

Tribulus terrestris is an annual herb which belongs to the Zygophyllaceae family. This plant has been used in traditional medicine for the treatment of various diseases for hundreds of decades. The main active phytoconstituents of this plant include flavonoids, alkaloids, saponins, lignin, amides, and glycosides. The plant parts have different pharmacological activities including aphrodisiac, antiinflammatory, antimicrobial and antioxidant potential. T. terrestris is most often used for infertility and loss of libido. It has potential application as immunomodulatory, hepatoprotective, hypolipidemic, anthelmintic and anticarcinogenic activities. The aim of the present article is to create a database for further investigation of the phytopharmacological properties of this plant to promote research. This study will definitely help to confirm its traditional use along with its value-added utility, eventually leading to higher revenues from the plant.

Known Unknowns in Judgment and Choice

OpenAIRE

Walters, Daniel

2017-01-01

This dissertation investigates how people make inferences about missing information. Whereas most prior literature focuses on how people process known information, I show that the extent to which people make inferences about missing information impacts judgments and choices. Specifically, I investigate how (1) awareness of known unknowns affects overconfidence in judgment in Chapter 1, (2) beliefs about the knowability of unknowns impacts investment strategies in Chapter 2, and (3) inferences...

Equilibration of the terrestrial water, nitrogen, and carbon cycles

OpenAIRE

Schimel, David S.; Braswell, B. H.; Parton, W. J.

1997-01-01

Recent advances in biologically based ecosystem models of the coupled terrestrial, hydrological, carbon, and nutrient cycles have provided new perspectives on the terrestrial biosphere’s behavior globally, over a range of time scales. We used the terrestrial ecosystem model Century to examine relationships between carbon, nitrogen, and water dynamics. The model, run to a quasi-steady-state, shows strong correlations between carbon, water, and nitrogen fluxes that l...

Animal water balance drives top-down effects in a riparian forest-implications for terrestrial trophic cascades.

Science.gov (United States)

McCluney, Kevin E; Sabo, John L

2016-08-17

Despite the clear importance of water balance to the evolution of terrestrial life, much remains unknown about the effects of animal water balance on food webs. Based on recent research suggesting animal water imbalance can increase trophic interaction strengths in cages, we hypothesized that water availability could drive top-down effects in open environments, influencing the occurrence of trophic cascades. We manipulated large spider abundance and water availability in 20 × 20 m open-air plots in a streamside forest in Arizona, USA, and measured changes in cricket and small spider abundance and leaf damage. As expected, large spiders reduced both cricket abundance and herbivory under ambient, dry conditions, but not where free water was added. When water was added (free or within moist leaves), cricket abundance was unaffected by large spiders, but spiders still altered herbivory, suggesting behavioural effects. Moreover, we found threshold-type increases in herbivory at moderately low soil moisture (between 5.5% and 7% by volume), suggesting the possibility that water balance may commonly influence top-down effects. Overall, our results point towards animal water balance as an important driver of direct and indirect species interactions and food web dynamics in terrestrial ecosystems. © 2016 The Author(s).

Taiwan's industrial heavy metal pollution threatens terrestrial biota

International Nuclear Information System (INIS)

Hsu, M.J.; Selvaraj, K.; Agoramoorthy, G.

2006-01-01

The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. - Metal effects occur at any terrestrial levels in Taiwan

Biosynthesis of polybrominated aromatic organic compounds by marine bacteria

Science.gov (United States)

Agarwal, Vinayak; El Gamal, Abrahim A.; Yamanaka, Kazuya; Poth, Dennis; Kersten, Roland D.; Schorn, Michelle; Allen, Eric E.; Moore, Bradley S.

2014-01-01

Polybrominated diphenyl ethers (PBDEs) and polybrominated bipyrroles are natural products that bioaccumulate in the marine food chain. PBDEs have attracted widespread attention due to their persistence in the environment and potential toxicity to humans. However, the natural origins of PBDE biosynthesis are not known. Here we report marine bacteria as producers of PBDEs and establish a genetic and molecular foundation for their production that unifies paradigms for the elaboration of bromophenols and bromopyrroles abundant in marine biota. We provide biochemical evidence of marine brominase enzymes revealing decarboxylative-halogenation enzymology previously unknown among halogenating enzymes. Biosynthetic motifs discovered in our study were used to mine sequence databases to discover unrealized marine bacterial producers of organobromine compounds. PMID:24974229

Bioinformatic Analysis Reveals Archaeal tRNATyr and tRNATrp Identities in Bacteria

Directory of Open Access Journals (Sweden)

Takahito Mukai

2017-02-01

Full Text Available The tRNA identity elements for some amino acids are distinct between the bacterial and archaeal domains. Searching in recent genomic and metagenomic sequence data, we found some candidate phyla radiation (CPR bacteria with archaeal tRNA identity for Tyr-tRNA and Trp-tRNA synthesis. These bacteria possess genes for tyrosyl-tRNA synthetase (TyrRS and tryptophanyl-tRNA synthetase (TrpRS predicted to be derived from DPANN superphylum archaea, while the cognate tRNATyr and tRNATrp genes reveal bacterial or archaeal origins. We identified a trace of domain fusion and swapping in the archaeal-type TyrRS gene of a bacterial lineage, suggesting that CPR bacteria may have used this mechanism to create diverse proteins. Archaeal-type TrpRS of bacteria and a few TrpRS species of DPANN archaea represent a new phylogenetic clade (named TrpRS-A. The TrpRS-A open reading frames (ORFs are always associated with another ORF (named ORF1 encoding an unknown protein without global sequence identity to any known protein. However, our protein structure prediction identified a putative HIGH-motif and KMSKS-motif as well as many α-helices that are characteristic of class I aminoacyl-tRNA synthetase (aaRS homologs. These results provide another example of the diversity of molecular components that implement the genetic code and provide a clue to the early evolution of life and the genetic code.

Terrestrial Energy bets on molten salt reactors

International Nuclear Information System (INIS)

Anon.

2015-01-01

Terrestrial Energy is a Canadian enterprise, founded in 2013, for marketing the integral molten salt reactor (IMSR). A first prototype (called MSRE and with an energy output of 8 MW) was designed and operated between 1965 and 1969 by the Oak Ridge National Laboratory. IMSR is a small, modular reactor with a thermal energy output of 400 MW. According to Terrestrial Energy the technology of conventional power reactors is too complicated and too expensive. On the contrary IMSR's technology appears to be simple, easy to operate and affordable. With a staff of 30 people Terrestrial Energy appears to be a start-up in the nuclear sector. A process of pre-licensing will be launched in 2016 with the Canadian nuclear safety authority. (A.C.)

Molecular detection of Campylobacter spp. and fecal indicator bacteria during the northern migration of Sandhill Cranes (Grus canadensis) at the Central Platte River

Science.gov (United States)

The annual Sandhill crane (Grus canadensis) migration through Nebraska is thought to be a major source of fecal pollution to the Platte River, but of unknown human health risk. To better understand potential risks, the presence of Campylobacter species and fecal bacteria were exa...

Interworking evolution of mobile satellite and terrestrial networks

Science.gov (United States)

Matyas, R.; Kelleher, P.; Moller, P.; Jones, T.

1993-01-01

There is considerable interest among mobile satellite service providers in interworking with terrestrial networks to provide a universal global network. With such interworking, subscribers may be provided a common set of services such as those planned for the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN), and future Intelligent Networks (IN's). This paper first reviews issues in satellite interworking. Next the status and interworking plans of terrestrial mobile communications service providers are examined with early examples of mobile satellite interworking including a discussion of the anticipated evolution towards full interworking between mobile satellite and both fixed and mobile terrestrial networks.

Protection from Staphylococcus aureus mastitis associated with poly-N-acetyl β-1,6 glucosamine specific antibody production using biofilm-embedded bacteria

Science.gov (United States)

Pérez, M. M.; Prenafeta, A.; Valle, J.; Penadés, J.; Rota, C.; Solano, C.; Marco, J.; Grilló, M.J.; Lasa, I.; Irache, J.M.; Maira-Litran, T.; Jiménez-Barbero, J.; Costa, L.; Pier, G.B.; de Andrés, D.; Amorena, B.

2010-01-01

Staphylococcus aureus vaccines based on bacterins surrounded by slime, surface polysaccharides coupled to protein carriers and polysaccharides embedded in liposomes administered together with non-biofilm bacterins confer protection against mastitis. However, it remains unknown whether protective antibodies are directed to slime-associated known exopolysaccharides and could be produced in the absence of bacterin immunizations. Here, a sheep mastitis vaccination study was carried out using bacterins, crude bacterial extracts or a purified exopolysaccharide from biofilm bacteria delivered in different vehicles. This polysaccharide reacted specifically with antibodies to poly-N-acetyl-β-1,6-glucosamine (PNAG) and not with antibodies to other capsular antigens or bacterial components. Following intra-mammary challenge with biofilm-producing bacteria, antibody production against the polysaccharide, milk bacterial counts and mastitis lesions were determined. Bacterins from strong biofilm-producing bacteria triggered the highest production of antibodies to PNAG and conferred the highest protection against infection and mastitis, compared with weak biofilm-producing bacteria and non-cellular inocula. Thus, bacterins from strong biofilm bacteria, rather than purified polysaccharide, are proposed as a cost-efficient vaccination against S. aureus ruminant mastitis. PMID:19428854

Divergent apparent temperature sensitivity of terrestrial ecosystem respiration

Science.gov (United States)

Bing Song; Shuli Niu; Ruise Luo; Yiqi Luo; Jiquan Chen; Guirui Yu; Janusz Olejnik; Georg Wohlfahrt; Gerard Kiely; Ako Noormets; Leonardo Montagnani; Alessandro Cescatti; Vincenzo Magliulo; Beverly Elizabeth Law; Magnus Lund; Andrej Varlagin; Antonio Raschi; Matthias Peichl; Mats B. Nilsson; Lutz Merbold

2014-01-01

Recent studies revealed convergent temperature sensitivity of ecosystem respiration (Re) within aquatic ecosystems and between terrestrial and aquatic ecosystems. We do not know yet whether various terrestrial ecosystems have consistent or divergent temperature sensitivity. Here, we synthesized 163 eddy covariance flux sites across the world and...

Evolutionary tracks of the terrestrial planets

International Nuclear Information System (INIS)

Matsui, Takafumi; Abe, Yutaka

1987-01-01

On the basis of the model proposed by Matsui and Abe, the authors show that two major factors - distance from the Sun and the efficiency of retention of accretional energy - control the early evolution of the terrestrial planets. A diagram of accretional energy versus the optical depth of a proto-atmosphere provides a means to follow the evolutionary track of surface temperature of the terrestrial planets and an explanation for why the third planet in our solar system is an 'aqua'-planet. 15 refs; 3 figs

Intersystem Interference Reduction for Overlaid HAPS-Terrestrial CDMA System

Science.gov (United States)

Huang, Jeng-Ji; Wang, Wei-Ting; Li, Mingfu; Shiung, David; Ferng, Huei-Wen

In this letter, we propose that directional antennas, combined with power management, be incorporated to reduce intersystem interference in a shared band overlaid high altitude platform station (HAPS)-terrestrial code division multiple access (CDMA) system. To eliminate the HAPS to terrestrial interference, the HAPS is accessed only via directional antennas under the proposed scheme. By doing so, the uplink power to the HAPS can accordingly be increased, so that the terrestrial to HAPS interference is also effectively suppressed.

Mobile assistant for unknown caller identification

OpenAIRE

Hribernik, Andraž

2012-01-01

The main motivation of this diploma thesis is a development of Android application, which helps user of application to find out who is the owner of unknown phone number. Data source for finding unknown phone number are free available web sources. Through the development of prototype, data from different web sources were integrated. Result of this integration is shown in Android application. Data integration includes access to semi-structured data on web portal of Phone Directory of Slovenia, ...

The friendly bacteria within us Commensal bacteria of the intestine ...

Indian Academy of Sciences (India)

Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 from HT-29 cells · Lactobacillus GG prevents the IL-8 release in response to pathogens · Effect of probiotic bacteria on chemokine response of epithelia to pathogens · PCR array studies in colon ...

Investigation on the toxic potential of Tribulus terrestris in vitro.

Science.gov (United States)

Abudayyak, M; Jannuzzi, A T; Özhan, G; Alpertunga, B

2015-04-01

Tribulus terrestris L. (Zygophyllaceae) has been commonly used to energize, vitalize, and improve sexual function and physical performance in men. This study investigates the potential cytotoxic and genotoxic, and endocrine disrupting activities of T. terrestris in vitro. The whole T. terrestris plant was extracted with water, methanol, and chloroform. The genotoxic potential of T. terrestris extracts at 3-2400 µg/mL was assessed by Comet assay in a rat kidney cell line (NRK-52E) and by Ames assay in Salmonella typhimurium TA98 and TA100 strains. Endocrine disrupting effects of the extracts at concentrations of 0.22-25 000 µg/mL were assessed by YES/YAS assay in Saccharomyces cerevisiae. Cytotoxic activity of the extracts was determined by the MTT test in NRK-52E cells. The different exposure times were used for four tests (3-48 h). The methanol extract of T. terrestris IC50 value was 160 µg/mL. The other extracts did not show cytotoxic effects. In the Comet and Ames genotoxicity assays, none of the extracts possessed genotoxic activities at concentrations of 0-2400 µg/mL. Only the water extract of T. terrestris induced frame shift mutations after metabolic activation. The water extract also showed estrogenic activity by YES/YAS assay in S. cerevisiae at concentrations ≥27 µg/mL (≥2.6-fold), while the other T. terrestris extracts had anti-estrogenic properties. Tribulus terrestris had estrogenic and genotoxic activities. The study was useful in determining its toxicological effects and the precautions regarding consumption.

Mineral transformations during the dissolution of uranium ore minerals by dissimilatory metal-reducing bacteria

Science.gov (United States)

Glasauer, S.; Weidler, P.; Fakra, S.; Tyliszczak, T.; Shuh, D.

2011-12-01

Carnotite minerals [X2(UO2)2(VO4)2]; X = K, Ca, Ba, Mn, Na, Cu or Pb] form the major ore of uranium in the Colorado Plateau. These deposits are highly oxidized and contain U(VI) and V(IV). The biotransformation of U(VI) bound in carnotite by bacteria during dissimilatory metal reduction presents a complex puzzle in mineral chemistry. Both U(VI) and V(V) can be respired by metal reducing bacteria, and the mineral structure can change depending on the associated counterion. We incubated anaerobic cultures of S. putrefaciens CN32 with natural carnotite minerals from southeastern Utah in a nutrient-limited defined medium. Strain CN32 is a gram negative bacterium and a terrestrial isolate from New Mexico. The mineral and metal transformations were compared to a system that contained similar concentrations of soluble U(VI) and V(V). Electron (SEM, TEM) microscopies and x-ray spectromicroscopy (STXM) were used in conjunction with XRD to track mineral changes, and bacterial survival was monitored throughout the incubations. Slow rates of metal reduction over 10 months for the treatment with carnotite minerals revealed distinct biotic and abiotic processes, providing insight on mineral transformation and bacteria-metal interactions. The bacteria existed as small flocs or individual cells attached to the mineral phase, but did not adsorb soluble U or V, and accumulated very little of the biominerals. Reduction of mineral V(V) necessarily led to a dismantling of the carnotite structure. Bioreduction of V(V) by CN32 contributed small but profound changes to the mineral system, resulting in new minerals. Abiotic cation exchange within the carnotite group minerals induced the rearrangement of the mineral structures, leading to further mineral transformation. In contrast, bacteria survival was poor for treatments with soluble U(VI) and V(V), although both metals were reduced completely and formed solid UO2 and VO2; we also detected V(III). For these treatments, the bacteria

THE COMPOSITIONAL DIVERSITY OF EXTRASOLAR TERRESTRIAL PLANETS. II. MIGRATION SIMULATIONS

International Nuclear Information System (INIS)

Carter-Bond, Jade C.; O'Brien, David P.; Raymond, Sean N.

2012-01-01

Prior work has found that a variety of terrestrial planetary compositions are expected to occur within known extrasolar planetary systems. However, such studies ignored the effects of giant planet migration, which is thought to be very common in extrasolar systems. Here we present calculations of the compositions of terrestrial planets that formed in dynamical simulations incorporating varying degrees of giant planet migration. We used chemical equilibrium models of the solid material present in the disks of five known planetary host stars: the Sun, GJ 777, HD4203, HD19994, and HD213240. Giant planet migration has a strong effect on the compositions of simulated terrestrial planets as the migration results in large-scale mixing between terrestrial planet building blocks that condensed at a range of temperatures. This mixing acts to (1) increase the typical abundance of Mg-rich silicates in the terrestrial planets' feeding zones and thus increase the frequency of planets with Earth-like compositions compared with simulations with static giant planet orbits, and (2) drastically increase the efficiency of the delivery of hydrous phases (water and serpentine) to terrestrial planets and thus produce waterworlds and/or wet Earths. Our results demonstrate that although a wide variety of terrestrial planet compositions can still be produced, planets with Earth-like compositions should be common within extrasolar planetary systems.

Big bacteria

DEFF Research Database (Denmark)

Schulz, HN; Jørgensen, BB

2001-01-01

A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

Terrestrial propagation of long electromagnetic waves

CERN Document Server

Galejs, Janis; Fock, V A

2013-01-01

Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapte

Research progress in airborne surveys of terrestrial gamma radiation

International Nuclear Information System (INIS)

Burson, Z.G.

1974-01-01

Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

Diverse antimicrobial interactions of halophilic archaea and bacteria extend over geographical distances and cross the domain barrier.

Science.gov (United States)

Atanasova, Nina S; Pietilä, Maija K; Oksanen, Hanna M

2013-10-01

The significance of antimicrobial substances, halocins, produced by halophilic archaea and bacteria thriving in hypersaline environments is relatively unknown. It is suggested that their production might increase species diversity and give transient competitive advances to the producer strain. Halocin production is considered to be common among halophilic archaea, but there is a lack of information about halocins produced by bacteria in highly saline environments. We studied the antimicrobial activity of 68 halophilic archaea and 22 bacteria isolated from numerous geographically distant hypersaline environments. Altogether 144 antimicrobial interactions were found between the strains and aside haloarchaea, halophilic bacteria from various genera were identified as halocin producers. Close to 80% of the interactions were detected between microorganisms from different genera and in few cases, even across the domain boundary. Several of the strains produced halocins with a wide inhibitory spectrum as has been observed before. Most of the antimicrobial interactions were found between strains from distant sampling sites indicating that hypersaline environments around the world have similar microorganisms with the potential to produce wide activity range antimicrobials. © 2013 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Grazing livestock are exposed to terrestrial cyanobacteria

OpenAIRE

McGorum , Bruce C; Pirie , R Scott; Glendinning , Laura; McLachlan , Gerry; Metcalf , James S; Banack , Sandra A; Cox , Paul A; Codd , Geoffrey A

2015-01-01

While toxins from aquatic cyanobacteria are a well-recognised cause of disease in birds and animals, exposure of grazing livestock to terrestrial cyanobacteria has not been described. This study identified terrestrial cyanobacteria, predominantly Phormidium spp., in the biofilm of plants from most livestock fields investigated. Lower numbers of other cyanobacteria, microalgae and fungi were present on many plants. Cyanobacterial 16S rDNA, predominantly from Phormidium spp., was detected in al...

The diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge

Science.gov (United States)

Yuan, Jun; Lai, Qiliang; Sun, Fengqin; Zheng, Tianling; Shao, Zongze

2015-01-01

The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR). After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene, and pyrene), nine bacterial consortia were obtained from depths of 3946–4746 m. While the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene, and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium, and Rhodovulum occurred most frequently in different PAH-degrading consortia. By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis, and Stappia were found to be PAH degraders. To the best of our knowledge, this is the first time these bacteria have been identified in this context. In summary, this report revealed significant diversity among the PAH-degrading bacteria in the deep-sea water column. These bacteria may play a role in PAH removal in deep-sea environments. PMID:26379634

The diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge.

Science.gov (United States)

Yuan, Jun; Lai, Qiliang; Sun, Fengqin; Zheng, Tianling; Shao, Zongze

2015-01-01

The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon (PAH)-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR). After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene, and pyrene), nine bacterial consortia were obtained from depths of 3946-4746 m. While the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene, and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE) analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium, and Rhodovulum occurred most frequently in different PAH-degrading consortia. By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis, and Stappia were found to be PAH degraders. To the best of our knowledge, this is the first time these bacteria have been identified in this context. In summary, this report revealed significant diversity among the PAH-degrading bacteria in the deep-sea water column. These bacteria may play a role in PAH removal in deep-sea environments.

Ocean acidification impacts bacteria-phytoplankton coupling at low-nutrient conditions

Science.gov (United States)

Hornick, Thomas; Bach, Lennart T.; Crawfurd, Katharine J.; Spilling, Kristian; Achterberg, Eric P.; Woodhouse, Jason N.; Schulz, Kai G.; Brussaard, Corina P. D.; Riebesell, Ulf; Grossart, Hans-Peter

2017-01-01

The oceans absorb about a quarter of the annually produced anthropogenic atmospheric carbon dioxide (CO2), resulting in a decrease in surface water pH, a process termed ocean acidification (OA). Surprisingly little is known about how OA affects the physiology of heterotrophic bacteria or the coupling of heterotrophic bacteria to phytoplankton when nutrients are limited. Previous experiments were, for the most part, undertaken during productive phases or following nutrient additions designed to stimulate algal blooms. Therefore, we performed an in situ large-volume mesocosm ( ˜ 55 m3) experiment in the Baltic Sea by simulating different fugacities of CO2 (fCO2) extending from present to future conditions. The study was conducted in July-August after the nominal spring bloom, in order to maintain low-nutrient conditions throughout the experiment. This resulted in phytoplankton communities dominated by small-sized functional groups (picophytoplankton). There was no consistent fCO2-induced effect on bacterial protein production (BPP), cell-specific BPP (csBPP) or biovolumes (BVs) of either free-living (FL) or particle-associated (PA) heterotrophic bacteria, when considered as individual components (univariate analyses). Permutational Multivariate Analysis of Variance (PERMANOVA) revealed a significant effect of the fCO2 treatment on entire assemblages of dissolved and particulate nutrients, metabolic parameters and the bacteria-phytoplankton community. However, distance-based linear modelling only identified fCO2 as a factor explaining the variability observed amongst the microbial community composition, but not for explaining variability within the metabolic parameters. This suggests that fCO2 impacts on microbial metabolic parameters occurred indirectly through varying physicochemical parameters and microbial species composition. Cluster analyses examining the co-occurrence of different functional groups of bacteria and phytoplankton further revealed a separation of

Characterization of the volatile profile of Antarctic bacteria by using solid-phase microextraction-gas chromatography-mass spectrometry.

Science.gov (United States)

Romoli, Riccardo; Papaleo, Maria Cristiana; de Pascale, Donatella; Tutino, Maria Luisa; Michaud, Luigi; LoGiudice, Angelina; Fani, Renato; Bartolucci, Gianluca

2011-10-01

Bacteria belonging to the Burkholderia cepacia complex (Bcc) are significant pathogens in Cystic Fibrosis (CF) patients and are resistant to a plethora of antibiotics. In this context, microorganisms from Antarctica are interesting because they produce antimicrobial compounds inhibiting the growth of other bacteria. This is particularly true for bacteria isolated from Antarctic sponges. The aim of this work was to characterize a set of Antarctic bacteria for their ability to produce new natural drugs that could be exploited in the control of infections in CF patients by Bcc bacteria. Hence, 11 bacterial strains allocated to different genera (e.g., Pseudoalteromonas, Arthrobacter and Psychrobacter) were tested for their ability to inhibit the growth of 21 Bcc strains and some other human pathogens. All these bacteria completely inhibited the growth of most, if not all, Bcc strains, suggesting a highly specific activity toward Bcc strains. Experimental evidences showed that the antimicrobial compounds are small volatile organic compounds, and are constitutively produced via an unknown pathway. The microbial volatile profile was obtained by SPME-GC-MS within the m/z interval of 40-450. Solid phase micro extraction technique affords the possibility to extract the volatile compounds in head space with a minimal sample perturbation. Principal component analysis and successive cluster discriminant analysis was applied to evaluate the relationships among the volatile organic compounds with the aim of classifying the microorganisms by their volatile profile. These data highlight the potentiality of Antarctic bacteria as novel sources of antibacterial substances to face Bcc infections in CF patients. Copyright © 2011 John Wiley & Sons, Ltd.

In vitro antibacterial activity of crude extracts of 9 selected medicinal plants against UTI causing MDR bacteria

Directory of Open Access Journals (Sweden)

Monali P. Mishra

2017-01-01

Full Text Available Urinary tract infection (UTI has become a more grievous problem today, due to multidrug resistance of infecting Gram-positive (GP and Gram-negative (GN bacteria, sometimes even with multiple infections. This study examines effectivity of 9 tropical flowering plants (Anogeissus acuminata, Azadirachta indica, Bauhinia variegata, Boerhaavia diffusa, Punica granatum, Soymida febrifuga, Terminalia chebula, Tinospora cordifolia and Tribulus terrestris for possible use as source of antimicrobials for multidrug resistant (MDR bacteria, along with main-stream antibiotics. Pathogenic bacteria were isolated from urine samples of patients attending and admitted in the hospital. Antibiograms of 11 isolated bacteria (GPs, Enterococcus faecalis and Staphylococcus aureus; and GNs, Acinetobacter baumannii, Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Proteus mirabilis, Proteus vulgaris and Pseudomonas aeruginosa were ascertained by the disc-diffusion method, and antibacterial effectivity of plant extracts was monitored by the agar-well diffusion method. Isolated bacteria were floridly MDR to most antibiotics of the day. Methanol extracts of 9 plants were used, and extracts of 3 plants, A. acuminata, P. granatum and S. febrifuga at least caused 25–29 mm as the maximum size of zone of inhibition on bacterial lawns. Minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC values of methanol extracts of 9 plants were recorded. The methanol extract of A. acuminata had 0.29 mg/ml as the lowest MIC value and 0.67 mg/ml as the lowest MBC value, against MDR S. aureus, signifying effectivity; but, it had the highest MIC value of 3.41 mg/ml. and the highest MBC value of 4.27 mg/ml for most other MDR bacteria including E. coli. Qualitative phytochemical analysis was done for these 9 plants and information on leading phytochemicals was presented retrieved from PubChem database. Thus

Coexistence of Terrestrial and HAP 3G Networks during Disaster Scenarios

Directory of Open Access Journals (Sweden)

P. Pechac

2008-12-01

Full Text Available The aim of this paper is to show the possible coexistence of an HAP and a terrestrial component of 3G networks at a single carrier frequency. The main goal is to compare the basic parameters of terrestrial and HAP com-ponent 3G networks modeled in suburban (macrocell and urban (macro/microcell areas and to demonstrate the way they impact on each other. This study should present what we assume are the better capabilities of HAP 3G networks compared to their terrestrial counterparts. The parameters of the HAP and terrestrial component of 3G networks, were the terrestrial cells to be disabled during disasters, are also presented.

Broad-Scale Comparison of Photosynthesis in Terrestrial and Aquatic Plant Communities

DEFF Research Database (Denmark)

Sand-Jensen, Kaj; Krause-Jensen, D.

1997-01-01

Comparisons of photosynthesis in terrestrial and aquatic habitats have been impaired by differences in methods and time-scales of measurements. We compiled information on gross photosynthesis at high irradiance and photosynthetic efficiency at low irradiance from 109 published terrestrial studies...... communities probably due to more efficient light utilization and gas exchange in the terrestrial habitats. By contrast only small differences were found within different aquatic plant communities or within different terrestrial plant communities....... of forests, grasslands and crops and 319 aquatic studies of phytoplankton, macrophyte and attached microalgal communities to test if specific differences existed between the communities. Maximum gross photosynthesis and photosynthetic efficiency were systematically higher in terrestrial than in aquatic...

Impact of non-native terrestrial mammals on the structure of the terrestrial mammal food web of Newfoundland, Canada.

Directory of Open Access Journals (Sweden)

Justin S Strong

Full Text Available The island of Newfoundland is unique because it has as many non-native terrestrial mammals as native ones. The impacts of non-native species on native flora and fauna can be profound and invasive species have been identified as one of the primary drivers of species extinction. Few studies, however, have investigated the effects of a non-native species assemblage on community and ecosystem properties. We reviewed the literature to build the first terrestrial mammal food web for the island of Newfoundland and then used network analyses to investigate how the timing of introductions and trophic position of non-native species has affected the structure of the terrestrial mammal food web in Newfoundland. The first non-native mammals (house mouse and brown rat became established in Newfoundland with human settlement in the late 15th and early 16th centuries. Coyotes and southern red-backed voles are the most recent mammals to establish themselves on the island in 1985 and 1998, respectively. The fraction of intermediate species increased with the addition of non-native mammals over time whereas the fraction of basal and top species declined over time. This increase in intermediate species mediated by non-native species arrivals led to an overall increase in the terrestrial mammal food web connectance and generality (i.e. mean number of prey per predator. This diverse prey base and sources of carrion may have facilitated the natural establishment of coyotes on the island. Also, there is some evidence that the introduction of non-native prey species such as the southern red-backed vole has contributed to the recovery of the threatened American marten. Long-term monitoring of the food web is required to understand and predict the impacts of the diverse novel interactions that are developing in the terrestrial mammal food web of Newfoundland.

Ice nucleation active bacteria in precipitation are genetically diverse and nucleate ice by employing different mechanisms.

Science.gov (United States)

Failor, K C; Schmale, D G; Vinatzer, B A; Monteil, C L

2017-12-01

A growing body of circumstantial evidence suggests that ice nucleation active (Ice + ) bacteria contribute to the initiation of precipitation by heterologous freezing of super-cooled water in clouds. However, little is known about the concentration of Ice + bacteria in precipitation, their genetic and phenotypic diversity, and their relationship to air mass trajectories and precipitation chemistry. In this study, 23 precipitation events were collected over 15 months in Virginia, USA. Air mass trajectories and water chemistry were determined and 33 134 isolates were screened for ice nucleation activity (INA) at -8 °C. Of 1144 isolates that tested positive during initial screening, 593 had confirmed INA at -8 °C in repeated tests. Concentrations of Ice + strains in precipitation were found to range from 0 to 13 219 colony forming units per liter, with a mean of 384±147. Most Ice + bacteria were identified as members of known and unknown Ice + species in the Pseudomonadaceae, Enterobacteriaceae and Xanthomonadaceae families, which nucleate ice employing the well-characterized membrane-bound INA protein. Two Ice + strains, however, were identified as Lysinibacillus, a Gram-positive genus not previously known to include Ice + bacteria. INA of the Lysinibacillus strains is due to a nanometer-sized molecule that is heat resistant, lysozyme and proteinase resistant, and secreted. Ice + bacteria and the INA mechanisms they employ are thus more diverse than expected. We discuss to what extent the concentration of culturable Ice + bacteria in precipitation and the identification of a new heat-resistant biological INA mechanism support a role for Ice + bacteria in the initiation of precipitation.

Big bacteria

DEFF Research Database (Denmark)

Schulz, HN; Jørgensen, BB

2001-01-01

A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

Sulfate-reducing bacteria colonize pouches formed for ulcerative colitis but not for familial adenomatous polyposis.

LENUS (Irish Health Repository)

Duffy, M

2012-02-03

PURPOSE: Ileal pouch-anal anastomosis remains the "gold standard" in surgical treatment of ulcerative colitis and familial adenomatous polyposis. Pouchitis occurs mainly in patients with a background of ulcerative colitis, although the reasons for this are unknown. The aim of this study was to characterize differences in pouch bacterial populations between ulcerative colitis and familial adenomatous pouches. METHODS: After ethical approval was obtained, fresh stool samples were collected from patients with ulcerative colitis pouches (n = 10), familial adenomatous polyposis (n = 7) pouches, and ulcerative colitis ileostomies (n = 8). Quantitative measurements of aerobic and anaerobic bacteria were performed. RESULTS: Sulfate-reducing bacteria were isolated from 80 percent (n = 8) of ulcerative colitis pouches. Sulfate-reducing bacteria were absent from familial adenomatous polyposis pouches and also from ulcerative colitis ileostomy effluent. Pouch Lactobacilli, Bifidobacterium, Bacteroides sp, and Clostridium perfringens counts were increased relative to ileostomy counts in patients with ulcerative colitis. Total pouch enterococci and coliform counts were also increased relative to ileostomy levels. There were no significant quantitative or qualitative differences between pouch types when these bacteria were evaluated. CONCLUSIONS: Sulfate-reducing bacteria are exclusive to patients with a background of ulcerative colitis. Not all ulcerative colitis pouches harbor sulfate-reducing bacteria because two ulcerative colitis pouches in this study were free of the latter. They are not present in familial adenomatous polyposis pouches or in ileostomy effluent collected from patients with ulcerative colitis. Total bacterial counts increase in ulcerative colitis pouches after stoma closure. Levels of Lactobacilli, Bifidobacterium, Bacteroides sp, Clostridium perfringens, enterococci, and coliforms were similar in both pouch groups. Because sulfate-reducing bacteria are

MoCha: Molecular Characterization of Unknown Pathways.

Science.gov (United States)

Lobo, Daniel; Hammelman, Jennifer; Levin, Michael

2016-04-01

Automated methods for the reverse-engineering of complex regulatory networks are paving the way for the inference of mechanistic comprehensive models directly from experimental data. These novel methods can infer not only the relations and parameters of the known molecules defined in their input datasets, but also unknown components and pathways identified as necessary by the automated algorithms. Identifying the molecular nature of these unknown components is a crucial step for making testable predictions and experimentally validating the models, yet no specific and efficient tools exist to aid in this process. To this end, we present here MoCha (Molecular Characterization), a tool optimized for the search of unknown proteins and their pathways from a given set of known interacting proteins. MoCha uses the comprehensive dataset of protein-protein interactions provided by the STRING database, which currently includes more than a billion interactions from over 2,000 organisms. MoCha is highly optimized, performing typical searches within seconds. We demonstrate the use of MoCha with the characterization of unknown components from reverse-engineered models from the literature. MoCha is useful for working on network models by hand or as a downstream step of a model inference engine workflow and represents a valuable and efficient tool for the characterization of unknown pathways using known data from thousands of organisms. MoCha and its source code are freely available online under the GPLv3 license.

Multi-model analysis of terrestrial carbon cycles in Japan: reducing uncertainties in model outputs among different terrestrial biosphere models using flux observations

Science.gov (United States)

Ichii, K.; Suzuki, T.; Kato, T.; Ito, A.; Hajima, T.; Ueyama, M.; Sasai, T.; Hirata, R.; Saigusa, N.; Ohtani, Y.; Takagi, K.

2009-08-01

Terrestrial biosphere models show large uncertainties when simulating carbon and water cycles, and reducing these uncertainties is a priority for developing more accurate estimates of both terrestrial ecosystem statuses and future climate changes. To reduce uncertainties and improve the understanding of these carbon budgets, we investigated the ability of flux datasets to improve model simulations and reduce variabilities among multi-model outputs of terrestrial biosphere models in Japan. Using 9 terrestrial biosphere models (Support Vector Machine-based regressions, TOPS, CASA, VISIT, Biome-BGC, DAYCENT, SEIB, LPJ, and TRIFFID), we conducted two simulations: (1) point simulations at four flux sites in Japan and (2) spatial simulations for Japan with a default model (based on original settings) and an improved model (based on calibration using flux observations). Generally, models using default model settings showed large deviations in model outputs from observation with large model-by-model variability. However, after we calibrated the model parameters using flux observations (GPP, RE and NEP), most models successfully simulated seasonal variations in the carbon cycle, with less variability among models. We also found that interannual variations in the carbon cycle are mostly consistent among models and observations. Spatial analysis also showed a large reduction in the variability among model outputs, and model calibration using flux observations significantly improved the model outputs. These results show that to reduce uncertainties among terrestrial biosphere models, we need to conduct careful validation and calibration with available flux observations. Flux observation data significantly improved terrestrial biosphere models, not only on a point scale but also on spatial scales.

Protection of Nitrate-Reducing Fe(II)-Oxidizing Bacteria from UV Radiation by Biogenic Fe(III) Minerals

Science.gov (United States)

Gauger, Tina; Konhauser, Kurt; Kappler, Andreas

2016-04-01

Due to the lack of an ozone layer in the Archean, ultraviolet radiation (UVR) reached early Earth's surface almost unattenuated; as a consequence, a terrestrial biosphere in the form of biological soil crusts would have been highly susceptible to lethal doses of irradiation. However, a self-produced external screen in the form of nanoparticular Fe(III) minerals could have effectively protected those early microorganisms. In this study, we use viability studies by quantifying colony-forming units (CFUs), as well as Fe(II) oxidation and nitrate reduction rates, to show that encrustation in biogenic and abiogenic Fe(III) minerals can protect a common soil bacteria such as the nitrate-reducing Fe(II)-oxidizing microorganisms Acidovorax sp. strain BoFeN1 and strain 2AN from harmful UVC radiation. Analysis of DNA damage by quantifying cyclobutane pyrimidine dimers (CPD) confirmed the protecting effect by Fe(III) minerals. This study suggests that Fe(II)-oxidizing microorganisms, as would have grown in association with mafic and ultramafic soils/outcrops, would have been able to produce their own UV screen, enabling them to live in terrestrial habitats on early Earth.

Coastal niches for terrestrial predators: a stable isotope study

Energy Technology Data Exchange (ETDEWEB)

Mellbrand, K.; Hamback, P.A., E-mail: peter.hamback@botan.su.se [Stockholm Univ., Dept. of Botany, Stockholm (Sweden)

2010-12-15

The purpose of this study was to identify the use of marine versus terrestrial food items by terrestrial arthropod predators on Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g., chironomids). Diets of coastal arthropods were examined using carbon and nitrogen stable isotope analysis in a two source mixing model. The results suggest that spiders are the terrestrial predators mainly utilizing nutrients and energy of marine origin on Baltic Sea shores, whereas insect predators such as beetles and heteropterans mainly utilize nutrients and energy derived from terrestrial sources, possibly owing to differences in hunting behaviour. That spiders are the predators which benefit the most from the marine inflow suggest that eventual effects of marine subsidies for the coastal ecosystem as a whole are likely mediated by spiders. (author)

Coastal niches for terrestrial predators: a stable isotope study

International Nuclear Information System (INIS)

Mellbrand, K.; Hamback, P.A.

2010-01-01

The purpose of this study was to identify the use of marine versus terrestrial food items by terrestrial arthropod predators on Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g., chironomids). Diets of coastal arthropods were examined using carbon and nitrogen stable isotope analysis in a two source mixing model. The results suggest that spiders are the terrestrial predators mainly utilizing nutrients and energy of marine origin on Baltic Sea shores, whereas insect predators such as beetles and heteropterans mainly utilize nutrients and energy derived from terrestrial sources, possibly owing to differences in hunting behaviour. That spiders are the predators which benefit the most from the marine inflow suggest that eventual effects of marine subsidies for the coastal ecosystem as a whole are likely mediated by spiders. (author)

Origin and evolution of life on terrestrial planets.

Science.gov (United States)

Brack, A; Horneck, G; Cockell, C S; Bérces, A; Belisheva, N K; Eiroa, Carlos; Henning, Thomas; Herbst, Tom; Kaltenegger, Lisa; Léger, Alain; Liseau, Réne; Lammer, Helmut; Selsis, Franck; Beichman, Charles; Danchi, William; Fridlund, Malcolm; Lunine, Jonathan; Paresce, Francesco; Penny, Alan; Quirrenbach, Andreas; Röttgering, Huub; Schneider, Jean; Stam, Daphne; Tinetti, Giovanna; White, Glenn J

2010-01-01

The ultimate goal of terrestrial planet-finding missions is not only to discover terrestrial exoplanets inside the habitable zone (HZ) of their host stars but also to address the major question as to whether life may have evolved on a habitable Earth-like exoplanet outside our Solar System. We note that the chemical evolution that finally led to the origin of life on Earth must be studied if we hope to understand the principles of how life might evolve on other terrestrial planets in the Universe. This is not just an anthropocentric point of view: the basic ingredients of terrestrial life, that is, reduced carbon-based molecules and liquid H(2)O, have very specific properties. We discuss the origin of life from the chemical evolution of its precursors to the earliest life-forms and the biological implications of the stellar radiation and energetic particle environments. Likewise, the study of the biological evolution that has generated the various life-forms on Earth provides clues toward the understanding of the interconnectedness of life with its environment.

Programmed evolution for optimization of orthogonal metabolic output in bacteria.

Directory of Open Access Journals (Sweden)

Todd T Eckdahl

Full Text Available Current use of microbes for metabolic engineering suffers from loss of metabolic output due to natural selection. Rather than combat the evolution of bacterial populations, we chose to embrace what makes biological engineering unique among engineering fields - evolving materials. We harnessed bacteria to compute solutions to the biological problem of metabolic pathway optimization. Our approach is called Programmed Evolution to capture two concepts. First, a population of cells is programmed with DNA code to enable it to compute solutions to a chosen optimization problem. As analog computers, bacteria process known and unknown inputs and direct the output of their biochemical hardware. Second, the system employs the evolution of bacteria toward an optimal metabolic solution by imposing fitness defined by metabolic output. The current study is a proof-of-concept for Programmed Evolution applied to the optimization of a metabolic pathway for the conversion of caffeine to theophylline in E. coli. Introduced genotype variations included strength of the promoter and ribosome binding site, plasmid copy number, and chaperone proteins. We constructed 24 strains using all combinations of the genetic variables. We used a theophylline riboswitch and a tetracycline resistance gene to link theophylline production to fitness. After subjecting the mixed population to selection, we measured a change in the distribution of genotypes in the population and an increased conversion of caffeine to theophylline among the most fit strains, demonstrating Programmed Evolution. Programmed Evolution inverts the standard paradigm in metabolic engineering by harnessing evolution instead of fighting it. Our modular system enables researchers to program bacteria and use evolution to determine the combination of genetic control elements that optimizes catabolic or anabolic output and to maintain it in a population of cells. Programmed Evolution could be used for applications in

Programmed Evolution for Optimization of Orthogonal Metabolic Output in Bacteria

Science.gov (United States)

Eckdahl, Todd T.; Campbell, A. Malcolm; Heyer, Laurie J.; Poet, Jeffrey L.; Blauch, David N.; Snyder, Nicole L.; Atchley, Dustin T.; Baker, Erich J.; Brown, Micah; Brunner, Elizabeth C.; Callen, Sean A.; Campbell, Jesse S.; Carr, Caleb J.; Carr, David R.; Chadinha, Spencer A.; Chester, Grace I.; Chester, Josh; Clarkson, Ben R.; Cochran, Kelly E.; Doherty, Shannon E.; Doyle, Catherine; Dwyer, Sarah; Edlin, Linnea M.; Evans, Rebecca A.; Fluharty, Taylor; Frederick, Janna; Galeota-Sprung, Jonah; Gammon, Betsy L.; Grieshaber, Brandon; Gronniger, Jessica; Gutteridge, Katelyn; Henningsen, Joel; Isom, Bradley; Itell, Hannah L.; Keffeler, Erica C.; Lantz, Andrew J.; Lim, Jonathan N.; McGuire, Erin P.; Moore, Alexander K.; Morton, Jerrad; Nakano, Meredith; Pearson, Sara A.; Perkins, Virginia; Parrish, Phoebe; Pierson, Claire E.; Polpityaarachchige, Sachith; Quaney, Michael J.; Slattery, Abagael; Smith, Kathryn E.; Spell, Jackson; Spencer, Morgan; Taye, Telavive; Trueblood, Kamay; Vrana, Caroline J.; Whitesides, E. Tucker

2015-01-01

Current use of microbes for metabolic engineering suffers from loss of metabolic output due to natural selection. Rather than combat the evolution of bacterial populations, we chose to embrace what makes biological engineering unique among engineering fields – evolving materials. We harnessed bacteria to compute solutions to the biological problem of metabolic pathway optimization. Our approach is called Programmed Evolution to capture two concepts. First, a population of cells is programmed with DNA code to enable it to compute solutions to a chosen optimization problem. As analog computers, bacteria process known and unknown inputs and direct the output of their biochemical hardware. Second, the system employs the evolution of bacteria toward an optimal metabolic solution by imposing fitness defined by metabolic output. The current study is a proof-of-concept for Programmed Evolution applied to the optimization of a metabolic pathway for the conversion of caffeine to theophylline in E. coli. Introduced genotype variations included strength of the promoter and ribosome binding site, plasmid copy number, and chaperone proteins. We constructed 24 strains using all combinations of the genetic variables. We used a theophylline riboswitch and a tetracycline resistance gene to link theophylline production to fitness. After subjecting the mixed population to selection, we measured a change in the distribution of genotypes in the population and an increased conversion of caffeine to theophylline among the most fit strains, demonstrating Programmed Evolution. Programmed Evolution inverts the standard paradigm in metabolic engineering by harnessing evolution instead of fighting it. Our modular system enables researchers to program bacteria and use evolution to determine the combination of genetic control elements that optimizes catabolic or anabolic output and to maintain it in a population of cells. Programmed Evolution could be used for applications in energy

Terrestrial forest management plan for Palmyra Atoll

Science.gov (United States)

Hathaway, Stacie A.; McEachern, Kathryn; Fisher, Robert N.

2011-01-01

This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll

A High-Resolution LC-MS-Based Secondary Metabolite Fingerprint Database of Marine Bacteria

KAUST Repository

Lu, Liang

2014-10-09

© 2014 Macmillan Publishers Limited. All rights reserved. Marine bacteria are the most widely distributed organisms in the ocean environment and produce a wide variety of secondary metabolites. However, traditional screening for bioactive natural compounds is greatly hindered by the lack of a systematic way of cataloguing the chemical profiles of bacterial strains found in nature. Here we present a chemical fingerprint database of marine bacteria based on their secondary metabolite profiles, acquired by high-resolution LC-MS. Till now, 1,430 bacterial strains spanning 168 known species collected from different marine environments were cultured and profiled. Using this database, we demonstrated that secondary metabolite profile similarity is approximately, but not always, correlated with taxonomical similarity. We also validated the ability of this database to find species-specific metabolites, as well as to discover known bioactive compounds from previously unknown sources. An online interface to this database, as well as the accompanying software, is provided freely for the community to use.

Gut Microbiota-Induced Immunoglobulin G Controls Systemic Infection by Symbiotic Bacteria and Pathogens

Science.gov (United States)

Zeng, Melody Y.; Cisalpino, Daniel; Varadarajan, Saranyaraajan; Hellman, Judith; Warren, H. Shaw; Cascalho, Marilia; Inohara, Naohiro; Núñez, Gabriel

2016-01-01

The gut microbiota is compartmentalized in the intestinal lumen and induces local immune responses, but it remains unknown whether the gut microbiota can induce systemic response and contribute to systemic immunity. We report that selective gut symbiotic gram-negative bacteria were able to disseminate systemically to induce immunoglobulin G (IgG) response, which primarily targeted gram-negative bacterial antigens and conferred protection against systemic infections by E. coli and Salmonella by directly coating bacteria to promote killing by phagocytes. T cells and Toll-like receptor 4 on B cells were important in the generation of microbiota-specific IgG. We identified murein lipoprotein (MLP), a highly conserved gram-negative outer membrane protein, as a major antigen that induced systemic IgG homeostatically in both mice and humans. Administration of anti-MLP IgG conferred crucial protection against systemic Salmonella infection. Thus, our findings reveal an important function for the gut microbiota in combating systemic infection through the induction of protective IgG. PMID:26944199

Super-resolution microscopy reveals cell wall dynamics and peptidoglycan architecture in ovococcal bacteria.

Science.gov (United States)

Wheeler, Richard; Mesnage, Stéphane; Boneca, Ivo G; Hobbs, Jamie K; Foster, Simon J

2011-12-01

Cell morphology and viability in Eubacteria is dictated by the architecture of peptidoglycan, the major and essential structural component of the cell wall. Although the biochemical composition of peptidoglycan is well understood, how the peptidoglycan architecture can accommodate the dynamics of growth and division while maintaining cell shape remains largely unknown. Here, we elucidate the peptidoglycan architecture and dynamics of bacteria with ovoid cell shape (ovococci), which includes a number of important pathogens, by combining biochemical analyses with atomic force and super-resolution microscopies. Atomic force microscopy analysis showed preferential orientation of the peptidoglycan network parallel to the short axis of the cell, with distinct architectural features associated with septal and peripheral wall synthesis. Super-resolution three-dimensional structured illumination fluorescence microscopy was applied for the first time in bacteria to unravel the dynamics of peptidoglycan assembly in ovococci. The ovococci have a unique peptidoglycan architecture and growth mode not observed in other model organisms. © 2011 Blackwell Publishing Ltd.

A High-Resolution LC-MS-Based Secondary Metabolite Fingerprint Database of Marine Bacteria

KAUST Repository

Lu, Liang; Wang, Jijie; Xu, Ying; Wang, Kailing; Hu, Yingwei; Tian, Renmao; Yang, Bo; Lai, Qiliang; Li, Yongxin; Zhang, Weipeng; Shao, Zongze; Lam, Henry; Qian, Pei-Yuan

2014-01-01

© 2014 Macmillan Publishers Limited. All rights reserved. Marine bacteria are the most widely distributed organisms in the ocean environment and produce a wide variety of secondary metabolites. However, traditional screening for bioactive natural compounds is greatly hindered by the lack of a systematic way of cataloguing the chemical profiles of bacterial strains found in nature. Here we present a chemical fingerprint database of marine bacteria based on their secondary metabolite profiles, acquired by high-resolution LC-MS. Till now, 1,430 bacterial strains spanning 168 known species collected from different marine environments were cultured and profiled. Using this database, we demonstrated that secondary metabolite profile similarity is approximately, but not always, correlated with taxonomical similarity. We also validated the ability of this database to find species-specific metabolites, as well as to discover known bioactive compounds from previously unknown sources. An online interface to this database, as well as the accompanying software, is provided freely for the community to use.

The incidence of bacterial endosymbionts in terrestrial arthropods.

Science.gov (United States)

Weinert, Lucy A; Araujo-Jnr, Eli V; Ahmed, Muhammad Z; Welch, John J

2015-05-22

Intracellular endosymbiotic bacteria are found in many terrestrial arthropods and have a profound influence on host biology. A basic question about these symbionts is why they infect the hosts that they do, but estimating symbiont incidence (the proportion of potential host species that are actually infected) is complicated by dynamic or low prevalence infections. We develop a maximum-likelihood approach to estimating incidence, and testing hypotheses about its variation. We apply our method to a database of screens for bacterial symbionts, containing more than 3600 distinct arthropod species and more than 150 000 individual arthropods. After accounting for sampling bias, we estimate that 52% (CIs: 48-57) of arthropod species are infected with Wolbachia, 24% (CIs: 20-42) with Rickettsia and 13% (CIs: 13-55) with Cardinium. We then show that these differences stem from the significantly reduced incidence of Rickettsia and Cardinium in most hexapod orders, which might be explained by evolutionary differences in the arthropod immune response. Finally, we test the prediction that symbiont incidence should be higher in speciose host clades. But while some groups do show a trend for more infection in species-rich families, the correlations are generally weak and inconsistent. These results argue against a major role for parasitic symbionts in driving arthropod diversification. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Isolation and characterization of novel chitinolytic bacteria

Science.gov (United States)

Gürkök, Sümeyra; Görmez, Arzu

2016-04-01

Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolymers widely distributed in the marine and terrestrial environments. It is found as a structural component of insects, crustaceans and the cell walls of fungi. Chitinases, the enzymes degrading chitin by cleaving the β-(1-4) bond, have gained increased attention due to their wide range of biotechnological applications, especially for biocontrol of harmful insects and phytopathogenic fungi in agriculture. In the present study, 200 bacterial isolates from Western Anatolia Region of Turkey were screened for chitinolytic activity on agar media amended with colloidal chitin. Based on the chitin hydrolysis zone, 13 isolates were selected for further study. Bacterial isolates with the highest chitinase activity were identified as Acinetobacter calcoaceticus, Arthrobacter oxydans, Bacillus cereus, Bacillus megaterium, Brevibacillus reuszeri, Kocuria erythromyxa, Kocuria rosea, Novosphingobium capsulatum, Rhodococcus bratislaviensis, Rhodococcus fascians and Staphylococcus cohnii by MIS and BIOLOG systems. The next aims of the study are to compare the productivity of these bacteria quantitatively, to purify the enzyme from the most potent producer and to apply the pure enzyme for the fight against the phytopathogenic fungi and harmful insects.

Evaluation of terrestrial microcosms for assessing the fate and effects of genetically engineered microorganisms on ecological processes

Energy Technology Data Exchange (ETDEWEB)

Fredrickson, J.K.; Bentjen, S.A.; Bolton, H. Jr.; Li, S.W.; Ligotke, M.W.; McFadden, K.M.; Van Voris, P.

1989-04-01

This project evaluates and modifies the existing US Environmental Protection Agency's Office of Pesticides and Toxic Substances (EPA/OPTS) terrestrial microcosm test system and test protocols such that they can be used to determine the environmental fate and ecological hazards of genetically engineered microorganisms (GEMs). The intact soil-core microcosm represents terrestrial ecosystems, and when coupled with appropriate test protocols, such microcosms may be appropriate to define and limit risks associated with the intentional release of GEMs. The terrestrial microcosm test system was used to investigate the survival and transport of two model GEMs (Azospirillum lipoferum and Pseudomonas sp. Tn5 mutants) to various trophic levels and niches and through intact soil cores. Subsequent effects on nutrient cycling and displacement of indigenous microorganisms were evaluated. The model organisms were a diazotrophic root-colonizing bacterium (A. lipoferum) and a wheat root growth-inhibiting rhizobacterium (Pseudomonas sp.). The transposable element Tn5 was used as a genetic marker for both microorganisms in two separate experiments. The organisms were subjected to transposon mutagenesis using a broad host-range-mobilizable suicide plasmid. The transposon Tn5 conferred levels of kanamycin resistance up to 500 ..mu..g/ml (Pseudomonas sp.), which allowed for selection of the bacteria from environmental samples. The presence of Tn5 DNA in the genome of the model GEMs also allowed the use of Tn5 gene probes to confirm and enumerate the microorganisms in different samples from the microcosms. Two types of root growth-inhibiting Pseudomonas sp. Tn5 mutants were obtained and used in microcosm studies: those that lacked the ability to inhibit either wheat root growth or the growth of other microorganisms in vitro (tox/sup /minus//) and those which retained these properties (tox/sup +/). 53 refs., 7 figs., 6 tabs.

The interaction of Plutonium with Bacteria in the Repository Environment

International Nuclear Information System (INIS)

Gillow, J. B.; Francis, A. J.; Lucero, D. A.; Papenguth, H. W.

2000-01-01

Microorganisms in the nuclear waste repository environment may interact with plutonium through (1) sorption, (2) intracellular accumulation, and (3) transformation speciation. These interactions may retard or enhance the mobility of Pu by precipitation reactions, biocolloid formation, or production of more soluble species. Current and planned radioactive waste repository environments, such as deep subsurface halite and granite formations, are considered extreme relative to life processes in the near-surface terrestrial environment. There is a paucity of information on the biotransformation of radionuclides by microorganisms present in such extreme environments. In order to gain a better understanding of the interaction of plutonium with microorganisms present in the waste repository sites we investigated a pure culture (Halomonas sp.) and a mixed culture of bacteria (Haloarcula sinaiiensis, Marinobacter hydrocarbonoclasticus, Altermonas sp., and a γ-proteobacterium) isolated from the Waste Isolation Pilot Plant (WIPP) site and an Acetobacterium sp. from alkaline groundwater at the Grimsel Test Site in Switzerland

Working group 4: Terrestrial

International Nuclear Information System (INIS)

Anon.

1993-01-01

A working group at a Canada/USA symposium on climate change and the Arctic identified major concerns and issues related to terrestrial resources. The group examined the need for, and the means of, involving resource managers and users at local and territorial levels in the process of identifying and examining the impacts and consequences of climatic change. Climatic change will be important to the Arctic because of the magnitude of the change projected for northern latitudes; the apparent sensitivity of its terrestrial ecosystems, natural resources, and human support systems; and the dependence of the social, cultural, and economic welfare of Arctic communities, businesses, and industries on the health and quality of their environment. Impacts of climatic change on the physical, biological, and associated socio-economic environment are outlined. Gaps in knowledge needed to quantify these impacts are listed along with their relationships with resource management. Finally, potential actions for response and adaptation are presented

Carbon dioxide efficiency of terrestrial enhanced weathering

OpenAIRE

Moosdorf, Nils; Renforth, Philip; Hartmann, Jens

2014-01-01

Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimi...

Pulses, linkages, and boundaries of coupled aquatic-terrestrial ecosystems

Science.gov (United States)

Tockner, K.

2009-04-01

Riverine floodplains are linked ecosystems where terrestrial and aquatic habitats overlap, creating a zone where they interact, the aquatic-terrestrial interface. The interface or boundary between aquatic and terrestrial habitats is an area of transition, contact or separation; and connectivity between these habitats may be defined as the ease with which organisms, matter or energy traverse these boundaries. Coupling of aquatic and terrestrial systems generates intertwining food webs, and we may predict that coupled systems are more productive than separated ones. For example, riparian consumers (aquatic and terrestrial) have alternative prey items external to their respective habitats. Such subsidized assemblages occupy a significant higher trophic position than assemblages in unsubsidized areas. Further, cross-habitat linkages are often pulsed; and even small pulses of a driver (e.g. short-term increases in flow) can cause major resource pulses (i.e. emerging aquatic insects) that control the recipient community. For example, short-term additions of resources, simulating pulsed inputs of aquatic food to terrestrial systems, suggest that due to resource partitioning and temporal separation among riparian arthropod taxa the resource flux from the river to the riparian zone increases with increasing riparian consumer diversity. I will discuss the multiple transfer and transformation processes of matter and organisms across aquatic-terrestrial habitats. Key landscape elements along river corridors are vegetated islands that function as instream riparian areas. Results from Central European rivers demonstrate that islands are in general more natural than fringing riparian areas, contribute substantially to total ecotone length, and create diverse habitats in the aquatic and terrestrial realm. In braided rivers, vegetated islands are highly productive landscape elements compared to the adjacent aquatic area. However, aquatic habitats exhibit a much higher decomposition

Determination of the origin of unknown irradiated nuclear fuel.

Science.gov (United States)

Nicolaou, G

2006-01-01

An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' material with U, Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. Then, the 'unknown' fuel has the same origin as the commercial fuel with which it exhibits the highest similarity in U, Pu compositions.

Determination of the origin of unknown irradiated nuclear fuel

International Nuclear Information System (INIS)

Nicolaou, G.

2006-01-01

An isotopic fingerprinting method is presented to determine the origin of unknown nuclear material with forensic importance. Spent nuclear fuel of known origin has been considered as the 'unknown' nuclear material in order to demonstrate the method and verify its prediction capabilities. The method compares, using factor analysis, the measured U, Pu isotopic compositions of the 'unknown' material with U, Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. Then, the 'unknown' fuel has the same origin as the commercial fuel with which it exhibits the highest similarity in U, Pu compositions

Function analysis of unknown genes

DEFF Research Database (Denmark)

Rogowska-Wrzesinska, A.

2002-01-01

  This thesis entitled "Function analysis of unknown genes" presents the use of proteome analysis for the characterisation of yeast (Saccharomyces cerevisiae) genes and their products (proteins especially those of unknown function). This study illustrates that proteome analysis can be used...... to describe different aspects of molecular biology of the cell, to study changes that occur in the cell due to overexpression or deletion of a gene and to identify various protein modifications. The biological questions and the results of the described studies show the diversity of the information that can...... genes and proteins. It reports the first global proteome database collecting 36 yeast single gene deletion mutants and selecting over 650 differences between analysed mutants and the wild type strain. The obtained results show that two-dimensional gel electrophoresis and mass spectrometry based proteome...

Terrestrial Analogs to Mars: NRC Community Panel Decadal Report

Science.gov (United States)

Farr, T. G.

2002-12-01

A report was completed recently by a Community Panel for the NRC Decadal Study of Solar System Exploration. The desire was for a review of the current state of knowledge and for recommendations for action over the next decade. The topic of this panel, Terrestrial Analogs to Mars, was chosen to bring attention to the need for an increase in analog studies in support of the increased pace of Mars exploration. It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of martian meteorites), and computer and laboratory modeling. The combination of all of these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the overarching science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel considered the issues of data collection and archiving, value of field workshops, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities. Parts of this work were performed under contract to NASA.

Radionuclides in terrestrial ecosystems

International Nuclear Information System (INIS)

Bocock, K.L.

1981-01-01

This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

Insect symbiotic bacteria harbour viral pathogens for transovarial transmission.

Science.gov (United States)

Jia, Dongsheng; Mao, Qianzhuo; Chen, Yong; Liu, Yuyan; Chen, Qian; Wu, Wei; Zhang, Xiaofeng; Chen, Hongyan; Li, Yi; Wei, Taiyun

2017-03-06

Many insects, including mosquitoes, planthoppers, aphids and leafhoppers, are the hosts of bacterial symbionts and the vectors for transmitting viral pathogens 1-3 . In general, symbiotic bacteria can indirectly affect viral transmission by enhancing immunity and resistance to viruses in insects 3-5 . Whether symbiotic bacteria can directly interact with the virus and mediate its transmission has been unknown. Here, we show that an insect symbiotic bacterium directly harbours a viral pathogen and mediates its transovarial transmission to offspring. We observe rice dwarf virus (a plant reovirus) binding to the envelopes of the bacterium Sulcia, a common obligate symbiont of leafhoppers 6-8 , allowing the virus to exploit the ancient oocyte entry path of Sulcia in rice leafhopper vectors. Such virus-bacterium binding is mediated by the specific interaction of the viral capsid protein and the Sulcia outer membrane protein. Treatment with antibiotics or antibodies against Sulcia outer membrane protein interferes with this interaction and strongly prevents viral transmission to insect offspring. This newly discovered virus-bacterium interaction represents the first evidence that a viral pathogen can directly exploit a symbiotic bacterium for its transmission. We believe that such a model of virus-bacterium communication is a common phenomenon in nature.

Antibacterial and antifungal activities of different parts of Tribulus terrestris L. growing in Iraq

Science.gov (United States)

Al-Bayati, Firas A.; Al-Mola, Hassan F.

2008-01-01

Antimicrobial activity of organic and aqueous extracts from fruits, leaves and roots of Tribulus terrestris L., an Iraqi medicinal plant used as urinary anti-infective in folk medicine, was examined against 11 species of pathogenic and non-pathogenic microorganisms: Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Corynebacterium diphtheriae, Escherichia coli, Proteus vulgaris, Serratia marcescens, Salmonella typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans using microdilution method in 96 multiwell microtiter plates. All the extracts from the different parts of the plant showed antimicrobial activity against most tested microorganisms. The most active extract against both Gram-negative and Gram-positive bacteria was ethanol extract from the fruits with a minimal inhibitory concentration (MIC) value of 0.15 mg/ml against B. subtilis, B. cereus, P. vulgaris and C. diphtheriae. In addition, the same extract from the same plant part demonstrated the strongest antifungal activity against C. albicans with an MIC value of 0.15 mg/ml. PMID:18257138

Growing technology earthy Tribulus terrestris (Tribulus terrestris L.) and its use

OpenAIRE

HUDSKÁ, Miluše

2015-01-01

This bachelor thesis deals with Puncturevine (Tribulus terrestris) as for planting, content substances, pharmacological use and with influences of planting technology or elicitors upon the active substance contents. Saponines, flavonoids, and phytosterols are the main active substances of Puncturevine. The saponines act as aphrodisiacs, the flavonoids treat with heart diseases and the phytosterols decrease the cholesterol concentration in blood plasma. The active substance contents depend on ...

Transfer coefficients for terrestrial foodchain: their derivation and limitations

International Nuclear Information System (INIS)

Ng, Y.C.; Colsher, C.S.; Thompson, S.E.

1979-01-01

Transfer coefficients to predict the passage of isotopes from the environment to terrestrial foods have been derived for various radionuclides of importance in the nuclear fuel cycle. These data update and extend previously recommended handbook values. We derive transfer coefficients to terrestrial foods and describe the systematics of the derived transfer coefficients. Suggestions are offered for changes in the values of transfer coefficients to terrestrial foods that now appear in federal regulatory guides. Deficiencies in our present knowledge concerning transfer coefficients and limitations in the use of these values to ensure compliance with radiation protection standards are discussed

Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

Science.gov (United States)

Rolf, Christer G; Fu, Sai-Chuen; Hopkins, Chelsea; Luan, Ju; Ip, Margaret; Yung, Shu-Hang; Friman, Göran; Qin, Ling; Chan, Kai-Ming

2017-07-01

The structural pathology of Achilles tendon (AT) ruptures resembles tendinopathy, but the causes remain unknown. Recently, a number of diseases were found to be attributed to bacterial infections, resulting in low-grade inflammation and progressive matrix disturbance. The authors speculate that spontaneous AT ruptures may also be influenced by the presence of bacteria. Bacteria are present in ruptured ATs but not in healthy tendons. Cross-sectional study; Level of evidence, 3. Patients with spontaneous AT ruptures and patients undergoing anterior cruciate ligament (ACL) reconstruction were recruited for this study. During AT surgical repair, excised tendinopathic tissue was collected, and healthy tendon samples were obtained as controls from hamstring tendon grafts used in ACL reconstruction. Half of every sample was reserved for DNA extraction and the other half for histology. Polymerase chain reaction (PCR) was conducted using 16S rRNA gene universal primers, and the PCR products were sequenced for the identification of bacterial species. A histological examination was performed to compare tendinopathic changes in the case and control samples. Five of 20 AT rupture samples were positive for the presence of bacterial DNA, while none of the 23 hamstring tendon samples were positive. Sterile operating and experimental conditions and tests on samples, controlling for harvesting and processing procedures, ruled out the chance of postoperative bacterial contamination. The species identified predominantly belonged to the Staphylococcus genus. AT rupture samples exhibited histopathological features characteristic of tendinopathy, and most healthy hamstring tendon samples displayed normal tendon features. There were no apparent differences in histopathology between the bacterial DNA-positive and bacterial DNA-negative AT rupture samples. The authors have demonstrated the presence of bacterial DNA in ruptured AT samples. It may suggest the potential involvement of bacteria

Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

Energy Technology Data Exchange (ETDEWEB)

Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580 (Japan); Hiraishi, A. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan and Electronics-inspired Interdisciplinary Institute (EIIRIS), Toyohashi University of Technology, Toyohashi 441-8580 (Japan)

2014-02-20

Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at < pH 4 and harboring bacteria of the candidate phylum 'TM7' as the major constituents of the microbial community. In light of the fact that the 16S rRNA of TM7 bacteria has a highly atypical base substitution possibly responsible for resistance to streptomycin at the ribosome level, this study was undertaken to construct streptomycin-resistant acidophilic nitrifying (SRAN) reactors and to demonstrate whether TM7 bacteria are abundant in these reactors. The SRAN reactors were constructed by seeding with nitrifying sludge from an ANSBR and cultivating with ammonium-containing mineral medium (pH 4.0), to which streptomycin at a concentration of 10, 30 and 50 mg L{sup −1} was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process.

Organizational Conditions for Dealing with The Unknown Unknown Illustrated by how a Dutch water management authority is preparing for climate change

NARCIS (Netherlands)

Termeer, Catrien J. A. M.; van den Brink, Margo A.

2013-01-01

The central question of this article is the extent to which organizations, governmental authorities in particular, are able to deal with the unknown unknown. Drawing on Weick's work on sensemaking, we introduce seven organizational conditions that can facilitate organizations to be reliable under

Magnetic reconnection in the terrestrial magnetosphere

International Nuclear Information System (INIS)

Feldman, W.C.

1984-01-01

An overview is given of quantitative comparisons between measured phenomena in the terrestrial magnetosphere thought to be associated with magnetic reconnection, and related theoretical predictions based on Petschek's simple model. Although such a comparison cannot be comprehensive because of the extended nature of the process and the relatively few in situ multipoint measurements made to date, the agreement is impressive where comparisons have been possible. This result leaves little doubt that magnetic reconnection does indeed occur in the terrestrial magnetosphere. The maximum reconnection rate, expressed in terms of the inflow Mach number, M/sub A/, is measured to be M/sub A/ = 0.2 +- 0.1

Implications of Uncertainty in Fossil Fuel Emissions for Terrestrial Ecosystem Modeling

Science.gov (United States)

King, A. W.; Ricciuto, D. M.; Mao, J.; Andres, R. J.

2017-12-01

Given observations of the increase in atmospheric CO2, estimates of anthropogenic emissions and models of oceanic CO2 uptake, one can estimate net global CO2 exchange between the atmosphere and terrestrial ecosystems as the residual of the balanced global carbon budget. Estimates from the Global Carbon Project 2016 show that terrestrial ecosystems are a growing sink for atmospheric CO2 (averaging 2.12 Gt C y-1 for the period 1959-2015 with a growth rate of 0.03 Gt C y-1 per year) but with considerable year-to-year variability (standard deviation of 1.07 Gt C y-1). Within the uncertainty of the observations, emissions estimates and ocean modeling, this residual calculation is a robust estimate of a global terrestrial sink for CO2. A task of terrestrial ecosystem science is to explain the trend and variability in this estimate. However, "within the uncertainty" is an important caveat. The uncertainty (2σ; 95% confidence interval) in fossil fuel emissions is 8.4% (±0.8 Gt C in 2015). Combined with uncertainty in other carbon budget components, the 2σ uncertainty surrounding the global net terrestrial ecosystem CO2 exchange is ±1.6 Gt C y-1. Ignoring the uncertainty, the estimate of a general terrestrial sink includes 2 years (1987 and 1998) in which terrestrial ecosystems are a small source of CO2 to the atmosphere. However, with 2σ uncertainty, terrestrial ecosystems may have been a source in as many as 18 years. We examine how well global terrestrial biosphere models simulate the trend and interannual variability of the global-budget estimate of the terrestrial sink within the context of this uncertainty (e.g., which models fall outside the 2σ uncertainty and in what years). Models are generally capable of reproducing the trend in net terrestrial exchange, but are less able to capture interannual variability and often fall outside the 2σ uncertainty. The trend in the residual carbon budget estimate is primarily associated with the increase in atmospheric CO2

Unknown foundation determination for scour.

Science.gov (United States)

2012-04-01

Unknown foundations affect about 9,000 bridges in Texas. For bridges over rivers, this creates a problem : regarding scour decisions as the calculated scour depth cannot be compared to the foundation depth, and a : very conservative costly approach m...

Transformation procedures in 3D terrestrial coordinate systems

Directory of Open Access Journals (Sweden)

Sedlák Vladimír

2001-12-01

Full Text Available Transformation procedures belong to the main tasks of surveyor working in a field of geodesy, for example in satellite geodesy or astronomical geodesy. It is necessary to know transformation procedures in 3D terrestrial (Earth coordinate systems. Increasingly a dynamic advance growth of application of satellite navigation systems, for example GPS (Global Positioning System into engineering surveying, real estate register and others spheres of applied geodesy and geo-surveying (mine surveying exacts knowledge of these transformation procedures between coordinates in various coordinate systems. These tasks are common for daily work for various practical surveyors too, not only for theoretical scientific working surveyors.Conventional Terrestrial System is 3D coordinate system what is the most important coordinate system in global geodesy. Conventional Terrestrial System is an approximation of the nature coordinate system of the Earth. The origin of this coordinate system is placed in the earth substantial centre of gravity and in the centre of geoid. Conventional Terrestrial System is the Cartesian right-handed coordinate system, i.e. positive one. The Local Astronomical System is 3D coordinate system too and it belongs to an important coordinate system in geodesy from its practical point of view. Many geodetic measurements are realized in this coordinate system. Designation of this coordinate system as astronomical system expresses its sticking to a normal line to an equipotential plane, i.e. to a vertical. Local Astronomical system is the left-handed cartesian coordinate system.Transformation procedures in 3D terrestrial coordinate systems with theory of these systems are presented in the paper. Transformation in the local astronomical coordinate system presents common transformation in a frame of an adjustment of various local geodetic networks. In a case of satellite measurements (GPS, satellite altimetry, etc. transformation between local and

DENTAL LESIONS IN THE LOWLAND TAPIR (TAPIRUS TERRESTRIS).

Science.gov (United States)

Tjørnelund, Karen B; Jonsson, Lena M; Kortegaard, Hanne; Arnbjerg, Jens; Nielsen, Søren S; Bertelsen, Mads F

2015-06-01

Dental ailments, mandibular swelling, and dentoalveolar abscesses are common in tapirs, but knowledge about prevalence or etiology of these lesions in the Tapiridae family in general, and in lowland tapirs (Tapirus terrestris) in particular, is scarce. A recent study identified resorptive lesions of unknown etiology as a common problem in the Malayan tapir (Tapirus indicus). In order to investigate the type and prevalence of dental lesions occurring in lowland tapirs, and to compare these with findings with the Malayan tapir, skulls and teeth from 46 deceased lowland tapirs were visually and radiographically examined. The specimens were divided into subpopulations according to age (juveniles, young adults, adults) and origin (free-range or captive). Dental lesions were identified in 24% (11/46) of the study population. The most common pathologic findings were complicated dental fractures with associated periapical reaction (15%) and periapical reactions of various degrees without associated detectable dental pathology (13%). All these lesions likely originated from dental trauma. As in Malayan tapirs, juveniles had significantly fewer lesions than adults. This study shows that dental lesions present frequent problems for lowland tapirs, occurring both in captive and in free-ranging individuals, and indicates that increasing age should be considered a risk factor for the development of these lesions. Notably, the predominant dental problems in lowland tapirs and Malayan tapirs are not the same.

Linking terrestrial and marine conservation planning and threats analysis.

Science.gov (United States)

Tallis, Heather; Ferdaña, Zach; Gray, Elizabeth

2008-02-01

The existence of the Gulf of Mexico dead zone makes it clear that marine ecosystems can be damaged by terrestrial inputs. Marine and terrestrial conservation planning need to be aligned in an explicit fashion to fully represent threats to marine systems. To integrate conservation planning for terrestrial and marine systems, we used a novel threats assessment that included 5 cross-system threats in a site-prioritization exercise for the Pacific Northwest coast ecoregion (U.S.A.). Cross-system threats are actions or features in one ecological realm that have effects on species in another realm. We considered bulkheads and other forms of shoreline hardening threats to terrestrial systems and roads, logging, agriculture, and urban areas threats to marine systems. We used 2 proxies of freshwater influence on marine environments, validated against a mechanistic model and field observations, to propagate land-based threats into marine sites. We evaluated the influence of cross-system threats on conservation priorities by comparing MARXAN outputs for 3 scenarios that identified terrestrial and marine priorities simultaneously: (1) no threats, (2) single-system threats, and (3) single- and cross-system threats. Including cross-system threats changed the threat landscape dramatically. As a result the best plan that included only single-system threats identified 323 sites (161,500 ha) at risk from cross-system threats. Including these threats changed the location of best sites. By comparing the best and sum solutions of the single- and cross-system scenarios, we identified areas ideal for preservation or restoration through integrated management. Our findings lend quantitative support to the call for explicitly integrated decision making and management action in terrestrial and marine ecosystems.

Organizational conditions for dealing with the unknown unknown : illustrated by how a Dutch water management authority is preparing for climate change

NARCIS (Netherlands)

Termeer, C.J.A.M.; Brink, van den M.A.

2013-01-01

The central question of this article is the extent to which organizations, governmental authorities in particular, are able to deal with the unknown unknown. Drawing on Weick’s work on sensemaking, we introduce seven organizational conditions that can facilitate organizations to be reliable under

Isolation of butanol- and isobutanol-tolerant bacteria and physiological characterization of their butanol tolerance.

Science.gov (United States)

Kanno, Manabu; Katayama, Taiki; Tamaki, Hideyuki; Mitani, Yasuo; Meng, Xian-Ying; Hori, Tomoyuki; Narihiro, Takashi; Morita, Naoki; Hoshino, Tamotsu; Yumoto, Isao; Kimura, Nobutada; Hanada, Satoshi; Kamagata, Yoichi

2013-11-01

Despite their importance as a biofuel production platform, only a very limited number of butanol-tolerant bacteria have been identified thus far. Here, we extensively explored butanol- and isobutanol-tolerant bacteria from various environmental samples. A total of 16 aerobic and anaerobic bacteria that could tolerate greater than 2.0% (vol/vol) butanol and isobutanol were isolated. A 16S rRNA gene sequencing analysis revealed that the isolates were phylogenetically distributed over at least nine genera: Bacillus, Lysinibacillus, Rummeliibacillus, Brevibacillus, Coprothermobacter, Caloribacterium, Enterococcus, Hydrogenoanaerobacterium, and Cellulosimicrobium, within the phyla Firmicutes and Actinobacteria. Ten of the isolates were phylogenetically distinct from previously identified butanol-tolerant bacteria. Two relatively highly butanol-tolerant strains CM4A (aerobe) and GK12 (obligate anaerobe) were characterized further. Both strains changed their membrane fatty acid composition in response to butanol exposure, i.e., CM4A and GK12 exhibited increased saturated and cyclopropane fatty acids (CFAs) and long-chain fatty acids, respectively, which may serve to maintain membrane fluidity. The gene (cfa) encoding CFA synthase was cloned from strain CM4A and expressed in Escherichia coli. The recombinant E. coli showed relatively higher butanol and isobutanol tolerance than E. coli without the cfa gene, suggesting that cfa can confer solvent tolerance. The exposure of strain GK12 to butanol by consecutive passages even enhanced the growth rate, indicating that yet-unknown mechanisms may also contribute to solvent tolerance. Taken together, the results demonstrate that a wide variety of butanol- and isobutanol-tolerant bacteria that can grow in 2.0% butanol exist in the environment and have various strategies to maintain structural integrity against detrimental solvents.

Diversity and characterization of mercury-resistant bacteria in snow, freshwater and sea-ice brine from the High Arctic.

Science.gov (United States)

Møller, Annette K; Barkay, Tamar; Abu Al-Soud, Waleed; Sørensen, Søren J; Skov, Henrik; Kroer, Niels

2011-03-01

It is well-established that atmospheric deposition transports mercury from lower latitudes to the Arctic. The role of bacteria in the dynamics of the deposited mercury, however, is unknown. We characterized mercury-resistant bacteria from High Arctic snow, freshwater and sea-ice brine. Bacterial densities were 9.4 × 10(5), 5 × 10(5) and 0.9-3.1 × 10(3) cells mL(-1) in freshwater, brine and snow, respectively. Highest cultivability was observed in snow (11.9%), followed by freshwater (0.3%) and brine (0.03%). In snow, the mercury-resistant bacteria accounted for up to 31% of the culturable bacteria, but levels of most isolates were not temperature dependent. Of the resistant isolates, 25% reduced Hg(II) to Hg(0). No relation between resistance level, ability to reduce Hg(II) and phylogenetic group was observed. An estimation of the potential bacterial reduction of Hg(II) in snow suggested that it was important in the deeper snow layers where light attenuation inhibited photoreduction. Thus, by reducing Hg(II) to Hg(0), mercury-resistant bacteria may limit the supply of substrate for methylation processes and, hence, contribute to lowering the risk that methylmercury is being incorporated into the Arctic food chains. © 2010 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Chemical ecology of fungi.

Science.gov (United States)

Spiteller, Peter

2015-07-01

Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology.

Bacteria and lignin degradation

Institute of Scientific and Technical Information of China (English)

Jing LI; Hongli YUAN; Jinshui YANG

2009-01-01

Lignin is both the most abundant aromatic (phenolic) polymer and the second most abundant raw material.It is degraded and modified by bacteria in the natural world,and bacteria seem to play a leading role in decomposing lignin in aquatic ecosystems.Lignin-degrading bacteria approach the polymer by mechanisms such as tunneling,erosion,and cavitation.With the advantages of immense environmental adaptability and biochemical versatility,bacteria deserve to be studied for their ligninolytic potential.

Biodiversity of polycyclic aromatic hydrocarbon-degrading bacteria from deep sea sediments of the Middle Atlantic Ridge

OpenAIRE

Cui, Zhisong; Lai, Qiliang; Dong, Chunming; Shao, Zongze

2008-01-01

The bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in deep sea subsurface environments are largely unknown. In order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the Middle Atlantic Ridge with a gravity column sampler. The sediments were promptly enriched with either crude oil or a mixture of PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched w...

Sterol Synthesis in Diverse Bacteria.

Science.gov (United States)

Wei, Jeremy H; Yin, Xinchi; Welander, Paula V

2016-01-01

Sterols are essential components of eukaryotic cells whose biosynthesis and function has been studied extensively. Sterols are also recognized as the diagenetic precursors of steranes preserved in sedimentary rocks where they can function as geological proxies for eukaryotic organisms and/or aerobic metabolisms and environments. However, production of these lipids is not restricted to the eukaryotic domain as a few bacterial species also synthesize sterols. Phylogenomic studies have identified genes encoding homologs of sterol biosynthesis proteins in the genomes of several additional species, indicating that sterol production may be more widespread in the bacterial domain than previously thought. Although the occurrence of sterol synthesis genes in a genome indicates the potential for sterol production, it provides neither conclusive evidence of sterol synthesis nor information about the composition and abundance of basic and modified sterols that are actually being produced. Here, we coupled bioinformatics with lipid analyses to investigate the scope of bacterial sterol production. We identified oxidosqualene cyclase (Osc), which catalyzes the initial cyclization of oxidosqualene to the basic sterol structure, in 34 bacterial genomes from five phyla (Bacteroidetes, Cyanobacteria, Planctomycetes, Proteobacteria, and Verrucomicrobia) and in 176 metagenomes. Our data indicate that bacterial sterol synthesis likely occurs in diverse organisms and environments and also provides evidence that there are as yet uncultured groups of bacterial sterol producers. Phylogenetic analysis of bacterial and eukaryotic Osc sequences confirmed a complex evolutionary history of sterol synthesis in this domain. Finally, we characterized the lipids produced by Osc-containing bacteria and found that we could generally predict the ability to synthesize sterols. However, predicting the final modified sterol based on our current knowledge of sterol synthesis was difficult. Some bacteria

A genomic investigation of ecological differentiation between free-living and Drosophila-associated bacteria.

Science.gov (United States)

Winans, Nathan J; Walter, Alec; Chouaia, Bessem; Chaston, John M; Douglas, Angela E; Newell, Peter D

2017-09-01

Various bacterial taxa have been identified both in association with animals and in the external environment, but the extent to which related bacteria from the two habitat types are ecologically and evolutionarily distinct is largely unknown. This study investigated the scale and pattern of genetic differentiation between bacteria of the family Acetobacteraceae isolated from the guts of Drosophila fruit flies, plant material and industrial fermentations. Genome-scale analysis of the phylogenetic relationships and predicted functions was conducted on 44 Acetobacteraceae isolates, including newly sequenced genomes from 18 isolates from wild and laboratory Drosophila. Isolates from the external environment and Drosophila could not be assigned to distinct phylogenetic groups, nor are their genomes enriched for any different sets of genes or category of predicted gene functions. In contrast, analysis of bacteria from laboratory Drosophila showed they were genetically distinct in their universal capacity to degrade uric acid (a major nitrogenous waste product of Drosophila) and absence of flagellar motility, while these traits vary among wild Drosophila isolates. Analysis of the competitive fitness of Acetobacter discordant for these traits revealed a significant fitness deficit for bacteria that cannot degrade uric acid in culture with Drosophila. We propose that, for wild populations, frequent cycling of Acetobacter between Drosophila and the external environment prevents genetic differentiation by maintaining selection for traits adaptive in both the gut and external habitats. However, laboratory isolates bear the signs of adaptation to persistent association with the Drosophila host under tightly defined environmental conditions. © 2017 John Wiley & Sons Ltd.

Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency

OpenAIRE

Taipale, Sami J.; Galloway, Aaron W. E.; Aalto, Sanni L.; Kahilainen, Kimmo K.; Strandberg, Ursula; Kankaala, Paula

2016-01-01

Freshwater food webs can be partly supported by terrestrial primary production, often deriving from plant litter of surrounding catchment vegetation. Although consisting mainly of poorly bioavailable lignin, with low protein and lipid content, the carbohydrates from fallen tree leaves and shoreline vegetation may be utilized by aquatic consumers. Here we show that during phytoplankton deficiency, zooplankton (Daphnia magna) can benefit from terrestrial particulate organic matter by using terr...

Applications of landscape genetics to connectivity research in terrestrial animals [Chapter 12

Science.gov (United States)

Lisette P. Waits; Samuel A. Cushman; Steve F. Spear

2016-01-01

Landscape genetic studies have focused on terrestrial animals more than any other taxonomic group. This chapter focuses on applications of landscape genetics for understanding connectivity of terrestrial animal populations. It starts with a general introduction covering unique characteristics and challenges of the terrestrial study system. This is followed by...

A Transcriptomic Approach to Identify Novel Drug Efflux Pumps in Bacteria.

Science.gov (United States)

Li, Liping; Tetu, Sasha G; Paulsen, Ian T; Hassan, Karl A

2018-01-01

The core genomes of most bacterial species include a large number of genes encoding putative efflux pumps. The functional roles of most of these pumps are unknown, however, they are often under tight regulatory control and expressed in response to their substrates. Therefore, one way to identify pumps that function in antimicrobial resistance is to examine the transcriptional responses of efflux pump genes to antimicrobial shock. By conducting complete transcriptomic experiments following antimicrobial shock treatments, it may be possible to identify novel drug efflux pumps encoded in bacterial genomes. In this chapter we describe a complete workflow for conducting transcriptomic analyses by RNA sequencing, to determine transcriptional changes in bacteria responding to antimicrobials.

Effect of Tribulus terrestris on Haloperidol-induced Catalepsy in Mice

Science.gov (United States)

Nishchal, B. S.; Rai, S.; Prabhu, M. N.; Ullal, Sheetal D.; Rajeswari, S.; Gopalakrishna, H. N.

2014-01-01

Haloperidol, an antipsychotic drug, leads to the development of a behavioural state called catalepsy, in which the animal is not able to correct an externally imposed posture. In the present study we have attempted to evaluate the anticataleptic effect of Tribulus terrestris on haloperidol-induced catalepsy in albino mice. Mice were allocated to four groups, each group containing six animals. Both, the test drug, Tribulus terrestris and the standard drug trihexyphenidyl were uniformly suspended in 1% gum acacia solution. Catalepsy was induced in mice with haloperidol (1.0 mg/kg, intraperitoneally). The first group received the vehicle (10 ml/kg, orally), the second group received trihexyphenidyl (10 mg/kg, orally) and the remaining two groups received Tribulus terrestris (100, 200 mg/kg, orally). The animals were assessed after single and repeated dose administration for ten days, 30 min prior to haloperidol, using standard bar test. The result of the present study demonstrates Tribulus terrestris has a protective effect against haloperidol-induced catalepsy, which is comparable to the standard drug used for the same purpose. Our study indicates Tribulus terrestris can be used to prevent haloperidol-induced extrapyramidal side effects. PMID:25593394

Effect of Tribulus terrestris on Haloperidol-induced Catalepsy in Mice.

Science.gov (United States)

Nishchal, B S; Rai, S; Prabhu, M N; Ullal, Sheetal D; Rajeswari, S; Gopalakrishna, H N

2014-01-01

Haloperidol, an antipsychotic drug, leads to the development of a behavioural state called catalepsy, in which the animal is not able to correct an externally imposed posture. In the present study we have attempted to evaluate the anticataleptic effect of Tribulus terrestris on haloperidol-induced catalepsy in albino mice. Mice were allocated to four groups, each group containing six animals. Both, the test drug, Tribulus terrestris and the standard drug trihexyphenidyl were uniformly suspended in 1% gum acacia solution. Catalepsy was induced in mice with haloperidol (1.0 mg/kg, intraperitoneally). The first group received the vehicle (10 ml/kg, orally), the second group received trihexyphenidyl (10 mg/kg, orally) and the remaining two groups received Tribulus terrestris (100, 200 mg/kg, orally). The animals were assessed after single and repeated dose administration for ten days, 30 min prior to haloperidol, using standard bar test. The result of the present study demonstrates Tribulus terrestris has a protective effect against haloperidol-induced catalepsy, which is comparable to the standard drug used for the same purpose. Our study indicates Tribulus terrestris can be used to prevent haloperidol-induced extrapyramidal side effects.

An investigation of Martian and terrestrial dust devils

Science.gov (United States)

Ringrose, Timothy John

2004-10-01

It is the purpose of this work to provide an insight into the theoretical and practical dynamics of dust devils and how they are detected remotely from orbit or in situ on planetary surfaces. There is particular interest in the detection of convective vortices on Mars; this has been driven by involvement in the development of the Beagle 2 Environmental Sensor Suite. This suite of sensors is essentially a martian weather station and will be the first planetary lander experiment specifically looking for the presence of dust devils on Mars. Dust devils are characterised by their visible dusty core and intense rotation. The physics of particle motion, including dust lofting and the rotational dynamics within convective vortices are explained and modelled. This modelling has helped in identifying dust devils in meteorological data from both terrestrial and martian investigations. An automated technique for dust devil detection using meteorological data has been developed. This technique searches data looking for the specific vortex signature as well as detecting other transient events. This method has been tested on both terrestrial and martian data with surprising results. 38 possible convective vortices were detected in the first 60 sols of the Viking Lander 2 meteorological data. Tests were also carried out on data from a terrestrial dust devil campaign, which provided conclusive evidence from visual observations of the reliability of this technique. A considerable amount of this work does focus on terrestrial vortices. This is to aid in the understanding of dust devils, specifically how, why and when they form. Both laboratory and terrestrial fieldwork is investigated, providing useful data on the general structure of dust devils.

NASA HRP Immunology Discipline - Use of Terrestrial Analogs

Science.gov (United States)

Crucian, Brian

2014-01-01

Due to the cost and operational constraints, as well as technical implementation limitations, it is desirous to perform relevant space physiology investigations first in terrestrial 'space analogs'. This is particularly true for initial investigations, which may then provide appropriate focus for subsequent flight investigations, or for mechanistic investigations that simply cannot be performed during spaceflight. Appropriate analog choice is extremely important. There are a wide variety of terrestrial space analogs, each relevant to a particular physiological discipline (or disciplines) and each with a particular fidelity (or lack thereof) to spaceflight, and each with unique operational constraints. The HRP Immunology Discipline is tasked with managing the HRP Risk concerning clinical risk for Astronaut crews related to spaceflight-associated immune dysregulation. Such dysregulation has been documented to occur during spaceflight, and found to persist for the duration of a 6-month ISS mission. Studies continue to characterize the onorbit phenomenon, but it generally consists of diminished immunocyte function, dysregulated cytokine profiles, and persistent herpesvirus reactivation. Causes are thought to synergistically include microgravity, psychological or physiological stress, radiation, and/or circadian misalignment. An appropriate terrestrial analog for immune dysregulation would replicate as many of these influences as possible. Such analogs may include clinostat or bioreactor cell culture (microgravity), hindlimb suspension (stress, fluid shifts, hypokinesis), or human deployment to remote or extreme environments (isolation, stress, circadian). Also, the laboratory setting may be used as an analog, or to augment analogs, such as sleep deprivation/misalignment or human centrifugation to replicate gravitational stress. As an appropriate example of a NASA Disciplines use of Terrestrial space analogs, this talk will discuss spaceflight associated immune

Preparation and characterization of Tribulus terrestris-loaded nanoparticles

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M. Khanavi*

2017-11-01

Full Text Available Background and objectives: Tribulus terrestris is a flowering herb (Zygophyllaceae with several properties in folk medicine such as diuretic, tonic, aphrodisiac, analgesic, astringent, and stomachic-lithotripter activities. Although, some extracts and phytochemicals represent excellent bio-activity in vitro, less or no in vivo activity is observed due to their improper molecular size. The intend of this research was investigation of the feasibility of encapsulating T. terrestris into [poly (lactic-co-glycolic acid] PLGA nanoparticles. Methods: Aerial parts of the plant were extracted with aqueous ethanol 85% by percolation apparatus. The nanoparticles of T. terrestris-loaded were prepared using a modified simultaneous double-emulsion solvent evaporation/diffusion method. Elucidations were made on the basis of scanning electron microscopy (SEM and differential scanning calorimetry (DSC. The content of nanoparticles was analyzed by HPLC with indirect method. Results: The results stated that increasing the portion of plant extract could cause bigger size with no considerable increase in polydispersity index (PDI. The encapsulation efficiency of T. terrestris-loaded nanoparticles was 40.3 to 78.5 and the drug loadings were 0.806 to 6.104, with different ratios of extract. The overall pattern of the release in SDS 1% in dialysis bag in all formulations showed similar and biphasic release kinetic, an initial burst release in the first day followed by constant release over 10 days. Conclusion: An effective approach for the preparation of T. terrestris-loaded PLGA nanoparticles was performed. The controlled release profile showed that these biodegradable PLGA nanoparticles had great potential and should be given particular consideration in further biological researches.

Facial trauma among victims of terrestrial transport accidents.

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d'Avila, Sérgio; Barbosa, Kevan Guilherme Nóbrega; Bernardino, Ítalo de Macedo; da Nóbrega, Lorena Marques; Bento, Patrícia Meira; E Ferreira, Efigênia Ferreira

2016-01-01

In developing countries, terrestrial transport accidents - TTA, especially those involving automobiles and motorcycles - are a major cause of facial trauma, surpassing urban violence. This cross-sectional census study attempted to determine facial trauma occurrence with terrestrial transport accidents etiology, involving cars, motorcycles, or accidents with pedestrians in the northeastern region of Brazil, and examine victims' socio-demographic characteristics. Morbidity data from forensic service reports of victims who sought care from January to December 2012 were analyzed. Altogether, 2379 reports were evaluated, of which 673 were related to terrestrial transport accidents and 103 involved facial trauma. Three previously trained and calibrated researchers collected data using a specific form. Facial trauma occurrence rate was 15.3% (n=103). The most affected age group was 20-29 years (48.3%), and more men than women were affected (2.81:1). Motorcycles were involved in the majority of accidents resulting in facial trauma (66.3%). The occurrence of facial trauma in terrestrial transport accident victims tends to affect a greater proportion of young and male subjects, and the most prevalent accidents involve motorcycles. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Long gravitational-wave transients and associated detection strategies for a network of terrestrial interferometers

International Nuclear Information System (INIS)

Thrane, Eric; Kandhasamy, Shivaraj; Dorsher, Steven; Mandic, Vuk; Prestegard, Tanner; Ott, Christian D.; Anderson, Warren G.; Christensen, Nelson L.; Coughlin, Michael W.; Giampanis, Stefanos; Mytidis, Antonis; Whiting, Bernard; Raffai, Peter

2011-01-01

Searches for gravitational waves (GWs) traditionally focus on persistent sources (e.g., pulsars or the stochastic background) or on transients sources (e.g., compact binary inspirals or core-collapse supernovae), which last for time scales of milliseconds to seconds. We explore the possibility of long GW transients with unknown waveforms lasting from many seconds to weeks. We propose a novel analysis technique to bridge the gap between short O(s)''burst'' analyses and persistent stochastic analyses. Our technique utilizes frequency-time maps of GW strain cross power between two spatially separated terrestrial GW detectors. The application of our cross power statistic to searches for GW transients is framed as a pattern recognition problem, and we discuss several pattern-recognition techniques. We demonstrate these techniques by recovering simulated GW signals in simulated detector noise. We also recover environmental noise artifacts, thereby demonstrating a novel technique for the identification of such artifacts in GW interferometers. We compare the efficiency of this framework to other techniques such as matched filtering.

The fecal bacteria

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Sadowsky, Michael J.; Whitman, Richard L.

2011-01-01

The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

Microbial rhodopsins on leaf surfaces of terrestrial plants

OpenAIRE

Atamna-Ismaeel, Nof; Finkel, Omri M.; Glaser, Fabian; Sharon, Itai; Schneider, Ron; Post, Anton F.; Spudich, John L.; von Mering, Christian; Vorholt, Julia A.; Iluz, David; Béjà, Oded; Belkin, Shimshon

2011-01-01

The above-ground surfaces of terrestrial plants, the phyllosphere, comprise the main interface between the terrestrial biosphere and solar radiation. It is estimated to host up to 1026 microbial cells that may intercept part of the photon flux impinging on the leaves. Based on 454-pyrosequencing-generated metagenome data, we report on the existence of diverse microbial rhodopsins in five distinct phyllospheres from tamarisk (Tamarix nilotica), soybean (Glycine max), Arabidopsis (Arabidopsis t...

Bleach vs. Bacteria

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... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

OpenAIRE

Denoncourt, Alix M.; Paquet, Valérie E.; Charette, Steve J.

2014-01-01

Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging...

Terrestrial contributions to the aquatic food web in the middle Yangtze River.

Science.gov (United States)

Wang, Jianzhu; Gu, Binhe; Huang, Jianhui; Han, Xingguo; Lin, Guanghui; Zheng, Fawen; Li, Yuncong

2014-01-01

Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD) in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish) at an upstream constricted-channel site (Luoqi), a midstream estuarine site (Huanghua) and a near dam limnetic site (Maoping) of the TGD were collected for stable isotope (δ13C and δ15N) and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping), particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

Biotic survival in the cryobiosphere on geological scale: implication for astro/terrestrial biogeoscience

Science.gov (United States)

Gilichinsky, D.

2003-04-01

In current opinion the most fundamental aspect of any environment, the temperature regime, acts as a regulator of all of the physical-chemical reactions and forms the basis of all biological processes. Now hard data indicate the biotic survival over geological periods from subzero temperatures (down to -27oC in permafrost and to -50oC in ice) to positive one in amber and halite. All these very different environments have, nevertheless, common features: complete isolation, stability and waterproof. In such unique physical-chemical complexes, the dehydration of macromolecules and the reorganization of membrane components apparently lead to a considerable decrease or stop of metabolic activity independently of temperature. This allowed the prolonged survival of ancient microbial lineage that realize unknown possibilities of physiological and biochemical adaptation incomparably longer than any other known habitat. The ability of microorganisms to survive on geological scale within the broad limits of natural systems forces us to redefine the spatial and temporal limits of the terrestrial and extraterrestrial biospheres and suggested that universal mechanisms of such adaptation might operate for millions of years. Among new scientific directions formed on this base, the most general is the fundamental question: how long the life might be preserved and what mechanisms could ensure survival? Because the length of lifetime cannot be reproduced, this highlights the natural storages that make possible the observation of the results of biotic survival on geological scale. Of special interest is the interaction of knowledge to understanding of the limits of the deep cold biosphere as a depository of ancient active biosignatures (biogases, biominerals, pigments, lipids, enzymes, proteins, RNA/DNA fragments) and viable cells. The last are the only known a huge mass of organisms that have retained viability over geological periods and upon thawing, renew physiological activity

Comparative Climatology of Terrestrial Planets

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Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.

Public awareness of climate change on Earth is currently very high, promoting significant interest in atmospheric processes. We are fortunate to live in an era where it is possible to study the climates of many planets, including our own, using spacecraft and groundbased observations as well as advanced computational power that allows detailed modeling. Planetary atmospheric dynamics and structure are all governed by the same basic physics. Thus differences in the input variables (such as composition, internal structure, and solar radiation) among the known planets provide a broad suite of natural laboratory settings for gaining new understanding of these physical processes and their outcomes. Diverse planetary settings provide insightful comparisons to atmospheric processes and feedbacks on Earth, allowing a greater understanding of the driving forces and external influences on our own planetary climate. They also inform us in our search for habitable environments on planets orbiting distant stars, a topic that was a focus of Exoplanets, the preceding book in the University of Arizona Press Space Sciences Series. Quite naturally, and perhaps inevitably, our fascination with climate is largely driven toward investigating the interplay between the early development of life and the presence of a suitable planetary climate. Our understanding of how habitable planets come to be begins with the worlds closest to home. Venus, Earth, and Mars differ only modestly in their mass and distance from the Sun, yet their current climates could scarcely be more divergent. Our purpose for this book is to set forth the foundations for this emerging science and to bring to the forefront our current understanding of atmospheric formation and climate evolution. Although there is significant comparison to be made to atmospheric processes on nonterrestrial planets in our solar system — the gas and ice giants — here we focus on the terrestrial planets, leaving even broader comparisons

Aerosol-induced thermal effects increase modelled terrestrial photosynthesis and transpiration

International Nuclear Information System (INIS)

Steiner, Allison L.; Chameides, W.L.

2005-01-01

Previous studies suggest that the radiative effects of atmospheric aerosols (reducing total radiation while increasing the diffuse fraction) can enhance terrestrial productivity. Here, simulations using a regional climate/terrestrial biosphere model suggest that atmospheric aerosols could also enhance terrestrial photosynthesis and transpiration through an interaction between solar radiation, leaf temperature and stomatal conductance. During midday, clear-sky conditions, sunlit-leaf temperatures can exceed the optimum for photosynthesis, depressing both photosynthesis and transpiration. Aerosols decrease surface solar radiation, thereby reducing leaf temperatures and enhancing sunlit-leaf photosynthesis and transpiration. This modelling study finds that, under certain conditions, this thermal response of aerosols can have a greater impact on photosynthesis and transpiration than the radiative response. This implies that a full understanding of the impact of aerosols on climate and the global carbon cycle requires consideration of the biophysical responses of terrestrial vegetation as well as atmospheric radiative and thermodynamic effects

Taiwan's industrial heavy metal pollution threatens terrestrial biota

Energy Technology Data Exchange (ETDEWEB)

Hsu, M.J. [Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Selvaraj, K. [Institute of Marine Geology and Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Agoramoorthy, G. [Department of Pharmacy, Tajen University, Yanpu, Pingtung 907, Taiwan (China)]. E-mail: agoram@mail.tajen.edu.tw

2006-09-15

The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. - Metal effects occur at any terrestrial levels in Taiwan.

Limno-terrestrial Tardigrada of the Nearctic Realm

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Juliana G. HINTON

2007-09-01

Full Text Available We examined all available records of limno-terrestrial tardigrade distribution in the Nearctic realm (Greenland, Canada, Alaska, the continental United States of America, and northern Mexico, both to compare this fauna with other realms and to investigate distribution within North America. We included only those records in which tardigrades had been identified to species. Of 204 Nearctic limno-terrestrial tardigrade species, 38 were cosmopolitan, while 55 were unique to the Nearctic realm. The Nearctic tardigrade fauna is most similar to the Palearctic, with 135 species in common, 39 of which have not been reported elsewhere. The Nearctic realm shares 82 species with the Neotropical realm, only 10 which are not also Palearctic. These data are consistent with the geological history of the three realms, and indicate a distinction between Laurasian and Gondwanan tardigrade faunas. Although little is known about limno-terrestrial tardigrade distribution in much of North America, there are several excellent regional or local surveys. Many species are distributed widely throughout the continent, but 30.0% of Nearctic species have been reported from a single site. Cluster analysis of the fauna of 11 Nearctic regions shows that the Arctic and sub-Arctic fauna constitute a regional fauna distinct from the rest of the continent. Ecological analysis is hampered by inconsistent reporting of tardigrade substrate, though available data suggest little substrate specificity in terrestrial tardigrades. Most species are found in both mosses and lichens. Many are also present in soil and leaf litter, but few are found only in these substrates.

The role of intestinal microflora and probiotic bacteria in prophylactic and development of colorectal cancer

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Ewa Wasilewska

2013-08-01

Full Text Available The gut microbiota comprises a large and diverse range of microorganisms whose activities have a significant impact on health. It interacts with its host at both the local and systemic level, resulting in a broad range of beneficial or detrimental outcomes for nutrition, infections, xenobiotic metabolism, and cancer. The current paper reviews research on the role of intestinal microflora in colorectal cancer development. Especially a protective effect of beneficial bacteria and probiotics on the risk of cancer development is highly discussed. There is substantial experimental evidence that the beneficial gut bacteria and their metabolism have the potential to inhibit the development and progression of neoplasia in the large intestine. Most of the data derive, however, from experimental and animal trials. Over a dozen well-documented animal studies have been published, wherein it has been clearly revealed that some lactic acid bacteria, especially lactobacilli and bifidobacteria, inhibit initiation and progression of colorectal cancer. Studies on cancer suppression in humans as a result of the consumption of probiotics are still sparse. Nevertheless, some epidemiological and interventional studies seem to confirm the bacterial anticancerogenic activity also in human gut. The mechanism by which probiotics may inhibit cancer development is unknown. Probiotics increase the amount of beneficial bacteria and decrease the pathogen level in the gut, consequently altering metabolic, enzymatic and carcinogenic activity in the intestine, decreasing inflammation and enhancing immune function, which may contribute to cancer defense.

Cinnamic acid amides from Tribulus terrestris displaying uncompetitive α-glucosidase inhibition.

Science.gov (United States)

Song, Yeong Hun; Kim, Dae Wook; Curtis-Long, Marcus J; Park, Chanin; Son, Minky; Kim, Jeong Yoon; Yuk, Heung Joo; Lee, Keun Woo; Park, Ki Hun

2016-05-23

The α-glucosidase inhibitory potential of Tribulus terrestris extracts has been reported but as yet the active ingredients are unknown. This study attempted to isolate the responsible metabolites and elucidate their inhibition mechanism of α-glucosidase. By fractionating T. terristris extracts, three cinnamic acid amide derivatives (1-3) were ascertained to be active components against α-glucosidase. The lead structure, N-trans-coumaroyltyramine 1, showed significant inhibition of α-glucosidase (IC50 = 0.42 μM). Moreover, all active compounds displayed uncompetitive inhibition mechanisms that have rarely been reported for α-glucosidase inhibitors. This kinetic behavior was fully demonstrated by showing a decrease of both Km and Vmax, and Kik/Kiv ratio ranging between 1.029 and 1.053. We progressed to study how chemical modifications to the lead structure 1 may impact inhibition. An α, β-unsaturation carbonyl group and hydroxyl group in A-ring of cinnamic acid amide emerged to be critical functionalities for α-glucosidase inhibition. The molecular modeling study revealed that the inhibitory activities are tightly related to π-π interaction as well as hydrogen bond interaction between enzyme and inhibitors. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Population structure of manganese-oxidizing bacteria in stratified soils and properties of manganese oxide aggregates under manganese-complex medium enrichment.

Directory of Open Access Journals (Sweden)

Weihong Yang

Full Text Available Manganese-oxidizing bacteria in the aquatic environment have been comprehensively investigated. However, little information is available about the distribution and biogeochemical significance of these bacteria in terrestrial soil environments. In this study, stratified soils were initially examined to investigate the community structure and diversity of manganese-oxidizing bacteria. Total 344 culturable bacterial isolates from all substrata exhibited Mn(II-oxidizing activities at the range of 1 µM to 240 µM of the equivalent MnO2. The high Mn(II-oxidizing isolates (>50 mM MnO2 were identified as the species of phyla Actinobacteria, Firmicutes and Proteobacteria. Seven novel Mn(II-oxidizing bacterial genera (species, namely, Escherichia, Agromyces, Cellulomonas, Cupriavidus, Microbacterium, Ralstonia, and Variovorax, were revealed via comparative phylogenetic analysis. Moreover, an increase in the diversity of soil bacterial community was observed after the combined enrichment of Mn(II and carbon-rich complex. The phylogenetic classification of the enriched bacteria represented by predominant denaturing gradient gel electrophoresis bands, was apparently similar to culturable Mn(II-oxidizing bacteria. The experiments were further undertaken to investigate the properties of the Mn oxide aggregates formed by the bacterial isolates with high Mn(II-oxidizing activity. Results showed that these bacteria were closely encrusted with their Mn oxides and formed regular microspherical aggregates under prolonged Mn(II and carbon-rich medium enrichment for three weeks. The biotic oxidation of Mn(II to Mn(III/IV by these isolates was confirmed by kinetic examinations. X-ray diffraction assays showed the characteristic peaks of several Mn oxides and rhodochrosite from these aggregates. Leucoberbelin blue tests also verified the Mn(II-oxidizing activity of these aggregates. These results demonstrated that Mn oxides were formed at certain amounts under the

Marine echinoderms as reservoirs of antimicrobial resistant bacteria

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Catarina Marinho

2014-06-01

(Marinho et al., 2013. Erythromycin and tetracycline are widely used in human therapy, and this may have contributed to the increasing resistance to these antibiotics (Hummel et al., 2007, Barros et al., 2011. It also highlights the lack of antibiotic efficiency in medicine, doing with resistance dissemination. Also, several genes associated with antimicrobial resistance were already found in antimicrobial-resistant enterococci from echinoderms: tet(M/tet(L, erm(A/erm(B, vat(D/vat(E, aac(6’-aph(2'' and aph(3'-IIIa genes were detected in tetracycline, erythromycin, quinupristin-dalfopristin, gentamicin and kanamycin-resistant isolates, respectively (Marinho et al., 2013. Despite of the small number of Escherichia coli isolates from echinoderms samples, they displayed an antibiotic-resistant phenotype to: tetracycline, streptomycin, tobramycin and amoxicillin + clavulanic acid. E. coli isolates from echinoderms tetracycline-resistant had tet(A and tet(B genes present in their genome. Besides, the aadA gene was detected in all E. coli streptomycin-resistant strains isolated from echinoderms (Marinho et al., 2013. According to some results, enterococci and E. coli displaying phenotype and resistance genes to some antibiotics that were already documented in marine animals, humans, wastewaters and numerous wildlife animals (Marinho et al., 2013, Barros et al., 2011, Sousa et al., 2011, Foti et al., 2009. Echinoderms are coastal animals and, consequently, it is possible that sewage discharges at the ocean may represent the main source of antibiotic-resistant bacteria deriving from several habitats. Indirect effects in micro-systems from the antibiotic disturbance are largely unknown; however, it is expected that such disorder might have significant long-term effects on the rate and stability of the ecosystem. Nevertheless, the consumption of exotic food is an example of a potential pathway for human contact with marine echinoderms microbiota, which may contain antibiotic

Terrestrial carbon storage dynamics: Chasing a moving target

Science.gov (United States)

Luo, Y.; Shi, Z.; Jiang, L.; Xia, J.; Wang, Y.; Kc, M.; Liang, J.; Lu, X.; Niu, S.; Ahlström, A.; Hararuk, O.; Hastings, A.; Hoffman, F. M.; Medlyn, B. E.; Rasmussen, M.; Smith, M. J.; Todd-Brown, K. E.; Wang, Y.

2015-12-01

Terrestrial ecosystems have been estimated to absorb roughly 30% of anthropogenic CO2 emissions. Past studies have identified myriad drivers of terrestrial carbon storage changes, such as fire, climate change, and land use changes. Those drivers influence the carbon storage change via diverse mechanisms, which have not been unified into a general theory so as to identify what control the direction and rate of terrestrial carbon storage dynamics. Here we propose a theoretical framework to quantitatively determine the response of terrestrial carbon storage to different exogenous drivers. With a combination of conceptual reasoning, mathematical analysis, and numeric experiments, we demonstrated that the maximal capacity of an ecosystem to store carbon is time-dependent and equals carbon input (i.e., net primary production, NPP) multiplying by residence time. The capacity is a moving target toward which carbon storage approaches (i.e., the direction of carbon storage change) but usually does not attain. The difference between the capacity and the carbon storage at a given time t is the unrealized carbon storage potential. The rate of the storage change is proportional to the magnitude of the unrealized potential. We also demonstrated that a parameter space of NPP, residence time, and carbon storage potential can well characterize carbon storage dynamics quantified at six sites ranging from tropical forests to tundra and simulated by two versions (carbon-only and coupled carbon-nitrogen) of the Australian Community Atmosphere-Biosphere Land Ecosystem (CABLE) Model under three climate change scenarios (CO2 rising only, climate warming only, and RCP8.5). Overall this study reveals the unified mechanism unerlying terrestrial carbon storage dynamics to guide transient traceability analysis of global land models and synthesis of empirical studies.

[Darwin and bacteria].

Science.gov (United States)

Ledermann D, Walter

2009-02-01

As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

Biofilm Formation by Bacteria Isolated from Intravenous Catheters

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Sina Hedayati

2015-10-01

Full Text Available Background: Reports on the association of nosocomial bacterial infections with indwelling medical devices such as intravenous catheters (IVC has increased in recent years. The potential to form biofilm on these devices seems to be the main reason for establishment of such infections. The aim of this study was to measure the potential of biofilm formation by bacterialisolates from IVCs.Methods: Seventy-one IVCs were collected from hospitalized patients in ICU, NICU, hematology and oncology wards at Taleghani Hospital from Jan 2010 to Jan 2011. The bacterial isolates were identified using the standard biochemical tests and the potential to form biofilms was determined by the microtiter plate assay method (MTP and colony morphology using Congo red agar plates (CRA.Results: Overall, 54 (71% IVCs were colonized and 76 bacteria were isolated among which, 64 (84.2% were coagulase negative staphylococci (CoNS, 3 (3.9% S. aureus, 3 (3.9% Enterococcus spp., 2 (2.6% E. coli and 4 (5.3% were miscellaneous isolates not further identified. Among the CoNS, biofilm formation was observed in 68.7% and 82.8% of bacteriausing MTP and CRA methods, respectively. S. aureus and E. coli isolates also were biofilm producers but Enterococcus and other unknown isolates were biofilm negative.Conclusions: Our results confirm that the prevalent biofilm forming bacteria on IVCs were CoNS and that was the reason for high rates of nosocomial infections.

Divergent pro-inflammatory profile of human dendritic cells in response to commensal and pathogenic bacteria associated with the airway microbiota.

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Larsen, Jeppe Madura; Steen-Jensen, Daniel Bisgaard; Laursen, Janne Marie; Søndergaard, Jonas Nørskov; Musavian, Hanieh Sadat; Butt, Tariq Mahmood; Brix, Susanne

2012-01-01

Recent studies using culture-independent methods have characterized the human airway microbiota and report microbial communities distinct from other body sites. Changes in these airway bacterial communities appear to be associated with inflammatory lung disease, yet the pro-inflammatory properties of individual bacterial species are unknown. In this study, we compared the immune stimulatory capacity on human monocyte-derived dendritic cells (DCs) of selected airway commensal and pathogenic bacteria predominantly associated with lungs of asthma or COPD patients (pathogenic Haemophillus spp. and Moraxella spp.), healthy lungs (commensal Prevotella spp.) or both (commensal Veillonella spp. and Actinomyces spp.). All bacteria were found to induce activation of DCs as demonstrated by similar induction of CD83, CD40 and CD86 surface expression. However, asthma and COPD-associated pathogenic bacteria provoked a 3-5 fold higher production of IL-23, IL-12p70 and IL-10 cytokines compared to the commensal bacteria. Based on the differential cytokine production profiles, the studied airway bacteria could be segregated into three groups (Haemophilus spp. and Moraxella spp. vs. Prevotella spp. and Veillonella spp. vs. Actinomyces spp.) reflecting their pro-inflammatory effects on DCs. Co-culture experiments found that Prevotella spp. were able to reduce Haemophillus influenzae-induced IL-12p70 in DCs, whereas no effect was observed on IL-23 and IL-10 production. This study demonstrates intrinsic differences in DC stimulating properties of bacteria associated with the airway microbiota.

Beyond the principle of plentitude: a review of terrestrial planet habitability.

Science.gov (United States)

Gaidos, E; Deschenes, B; Dundon, L; Fagan, K; Menviel-Hessler, L; Moskovitz, N; Workman, M

2005-04-01

We review recent work that directly or indirectly addresses the habitability of terrestrial (rocky) planets like the Earth. Habitability has been traditionally defined in terms of an orbital semimajor axis within a range known as the habitable zone, but it is also well known that the habitability of Earth is due to many other astrophysical, geological, and geochemical factors. We focus this review on (1) recent refinements to habitable zone calculations; (2) the formation and orbital stability of terrestrial planets; (3) the tempo and mode of geologic activity (e.g., plate tectonics) on terrestrial planets; (4) the delivery of water to terrestrial planets in the habitable zone; and (5) the acquisition and loss of terrestrial planet carbon and nitrogen, elements that constitute important atmospheric gases responsible for habitable conditions on Earth's surface as well as being the building blocks of the biosphere itself. Finally, we consider recent work on evidence for the earliest habitable environments and the appearance of life itself on our planet. Such evidence provides us with an important, if nominal, calibration point for our search for other habitable worlds.

Generation of terrestrial radiation database in the Larsemann Hills, Antarctica

International Nuclear Information System (INIS)

Pal, Rupali; Dhabekar, Bhushan; Jose, Jis Romal; Chinnaesakki, S.; Bakshi, A.K.; Datta, D.; Pradeepkumar, K.S.

2018-01-01

Natural background radiation in the environment includes terrestrial radiation, cosmic radiation from space and air activity due to radon/thoron. It is known that cosmic contribution increases near the poles. The terrestrial component is largely due to 232 Th and 238 U series and 40 K. BARC under the cosmic ray dosimetry project with National Centre for Antarctic and Ocean Research (NCAOR) has taken up measurement of natural background radiation at Larsemann Hills, Antarctica. The project includes generation of baseline data on terrestrial radioactivity in water, soil and rock and estimation of cosmic ray doses. Extensive radiation surveys were carried out by the BARC team in the 35 th and 36 th expedition in and around Larsemann hills in East Antarctica where the third Indian station 'Bharati' is situated. This paper presents mapping of terrestrial radiation levels in Antarctica which will help in strengthening the background radiation database and develop a Radiation Informatics System (RIS)

Classification of plant associated bacteria using RIF, a computationally derived DNA marker.

Directory of Open Access Journals (Sweden)

Kevin L Schneider

Full Text Available A DNA marker that distinguishes plant associated bacteria at the species level and below was derived by comparing six sequenced genomes of Xanthomonas, a genus that contains many important phytopathogens. This DNA marker comprises a portion of the dnaA replication initiation factor (RIF. Unlike the rRNA genes, dnaA is a single copy gene in the vast majority of sequenced bacterial genomes, and amplification of RIF requires genus-specific primers. In silico analysis revealed that RIF has equal or greater ability to differentiate closely related species of Xanthomonas than the widely used ribosomal intergenic spacer region (ITS. Furthermore, in a set of 263 Xanthomonas, Ralstonia and Clavibacter strains, the RIF marker was directly sequenced in both directions with a success rate approximately 16% higher than that for ITS. RIF frameworks for Xanthomonas, Ralstonia and Clavibacter were constructed using 682 reference strains representing different species, subspecies, pathovars, races, hosts and geographic regions, and contain a total of 109 different RIF sequences. RIF sequences showed subspecific groupings but did not place strains of X. campestris or X. axonopodis into currently named pathovars nor R. solanacearum strains into their respective races, confirming previous conclusions that pathovar and race designations do not necessarily reflect genetic relationships. The RIF marker also was sequenced for 24 reference strains from three genera in the Enterobacteriaceae: Pectobacterium, Pantoea and Dickeya. RIF sequences of 70 previously uncharacterized strains of Ralstonia, Clavibacter, Pectobacterium and Dickeya matched, or were similar to, those of known reference strains, illustrating the utility of the frameworks to classify bacteria below the species level and rapidly match unknown isolates to reference strains. The RIF sequence frameworks are available at the online RIF database, RIFdb, and can be queried for diagnostic purposes with RIF

Histopathological changes in Poecilia latipinna male gonad due to Tribulus terrestris administration.

Science.gov (United States)

Kavitha, P; Ramesh, R; Subramanian, P

2012-05-01

Tribulus terrestris is a traditionally known non-toxic aphrodisiac herb for maleness. It was experimented recently to understand the effect and mechanism on mono sex production in Poecilia latipinna. It would help to develop a new eco-friendly way to masculinize P. latipinna, since males have higher commercial value than females. The different concentration (100, 150, 200, 250 and 300 mg/L) of T. terrestris extract and a control were tested for their effect on sex transformation/reversal in P. latipinna by immersing the newly born young ones in the respective concentrations for 2 mo. The obtained results indicate that a dose dependant masculinization is obtained due to T. terrestris administration, which improved the male proportion. Histological results revealed that the testes of fish treated with T. terrestris extract contained all stages of spermatogenesis, clearly demonstrating that the administration of T. terrestris extract to P. latipinna stimulated spermatogenesis. Thus, it is discernible that 0-d-old hatchlings of P. latipinna exposed to T. terrestris extract orient/reverse their sex more towards maleness besides yielding better growth and spermatogenesis which is a mandate for fancy fish industry.

Removal of terrestrial DOC in aquatic ecosystems of a temperate river network

Science.gov (United States)

Wollheim, W.M.; Stewart, R. J.; Aiken, George R.; Butler, Kenna D.; Morse, Nathaniel B.; Salisbury, J.

2015-01-01

Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

Dietary characterization of terrestrial mammals.

Science.gov (United States)

Pineda-Munoz, Silvia; Alroy, John

2014-08-22

Understanding the feeding behaviour of the species that make up any ecosystem is essential for designing further research. Mammals have been studied intensively, but the criteria used for classifying their diets are far from being standardized. We built a database summarizing the dietary preferences of terrestrial mammals using published data regarding their stomach contents. We performed multivariate analyses in order to set up a standardized classification scheme. Ideally, food consumption percentages should be used instead of qualitative classifications. However, when highly detailed information is not available we propose classifying animals based on their main feeding resources. They should be classified as generalists when none of the feeding resources constitute over 50% of the diet. The term 'omnivore' should be avoided because it does not communicate all the complexity inherent to food choice. Moreover, the so-called omnivore diets actually involve several distinctive adaptations. Our dataset shows that terrestrial mammals are generally highly specialized and that some degree of food mixing may even be required for most species.

Climate control of terrestrial carbon exchange across biomes and continents

Science.gov (United States)

Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; John Frank; William J. Massman

2010-01-01

Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes...

Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

Directory of Open Access Journals (Sweden)

Alix M Denoncourt

2014-05-01

Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

Classification of Unknown Thermocouple Types Using Similarity Factor Measurement

Directory of Open Access Journals (Sweden)

Seshu K. DAMARLA

2011-01-01

Full Text Available In contrast to classification using PCA method, a new methodology is proposed for type identification of unknown thermocouple. The new methodology is based on calculating the degree of similarity between two multivariate datasets using two types of similarity factors. One similarity factor is based on principle component analysis and the angles between the principle component subspaces while the other is based on the Mahalanobis distance between the datasets. Datasets containing thermo-emfs against given temperature ranges are formed for each type of thermocouple (e.g. J, K, S, T, R, E, B and N type by experimentation are considered as reference datasets. Datasets corresponding to unknown type are captured. Similarity factor between the datasets one of which being the unknown type and the other being each known type are compared. When maximum similarity factor occurs, then the class of unknown type is allocated to that of known type.

Evaluation of radiological doses to the terrestrial plants around Trombay

International Nuclear Information System (INIS)

Ajay Kumar; Singhal, R.K.; Preetha, J.; Joshi, S.N.; Hegde, A.G.

2005-01-01

Existing policies for radiation protection do not provide explicit criteria for the protection of species other than humans, i.e. not for flora and fauna. Concern over this omission is now being widely expressed and moves are under way to evaluate the doses to terrestrial and aquatic biota. During the present work radiological doses (external and internal) to the terrestrial plants were evaluated by estimating the concentration of anthropogenic ( 137 Cs, 90 Sr) and natural radionuclides ( 238 U, 232 Th and 40 K) in the plant leaves and by measuring the external gamma radiation due to different radionuclide. The soil and vegetation sample were collected from fifteen sampling locations around the different locations at Trombay. The samples were processed as per IAEA (International Atomic Energy Agency) protocol for the estimation of naturally occurring and anthropogenic radionuclides in soil and terrestrial plants. The gamma emitting radionuclides were measured by high resolution gamma (HPGe) spectrometry system. Maximum exposure (external + internal) to the terrestrial plants was observed due to 232 Th while 238 U showed minimum exposure. The average value of radiation exposure to the terrestrial plants for 40 K, 137 Cs, 90 Sr, 238 U and 232 Th was 1555.2 ± 92.4, 691.2 ± 54.3, 2564.1 ± 534.9, 82.5 ±5.2, and 4419.6 ± 1165.5 μGy/y respectively. The radiation exposure (external + internal ) to the terrestrial plants due to all radionuclides was found within the permissible limits (i.e. 10 mGy/d) as per recommended by the United States, Department of Energy (DOE). (author)

Variations and trends of terrestrial NPP and its relation to climate ...

Indian Academy of Sciences (India)

Using global terrestrial ecosystem net primary productivity (NPP) data, we validated the simulated multi-model ensemble ..... tion on the solar radiation at six Canadian stations; Solar ... balance have enhanced the terrestrial carbon sink in the.

Terrestrial invasion of pomatiopsid gastropods in the heavy-snow region of the Japanese Archipelago

Directory of Open Access Journals (Sweden)

Kato Makoto

2011-05-01

Full Text Available Abstract Background Gastropod mollusks are one of the most successful animals that have diversified in the fully terrestrial habitat. They have evolved terrestrial taxa in more than nine lineages, most of which originated during the Paleozoic or Mesozoic. The rissooidean gastropod family Pomatiopsidae is one of the few groups that have evolved fully terrestrial taxa during the late Cenozoic. The pomatiopsine diversity is particularly high in the Japanese Archipelago and the terrestrial taxa occur only in this region. In this study, we conducted thorough samplings of Japanese pomatiopsid species and performed molecular phylogenetic analyses to explore the patterns of diversification and terrestrial invasion. Results Molecular phylogenetic analyses revealed that Japanese Pomatiopsinae derived from multiple colonization of the Eurasian Continent and that subsequent habitat shifts from aquatic to terrestrial life occurred at least twice within two Japanese endemic lineages. Each lineage comprises amphibious and terrestrial species, both of which are confined to the mountains in heavy-snow regions facing the Japan Sea. The estimated divergence time suggested that diversification of these terrestrial lineages started in the Late Miocene, when active orogenesis of the Japanese landmass and establishment of snowy conditions began. Conclusions The terrestrial invasion of Japanese Pomatiopsinae occurred at least twice beside the mountain streamlets of heavy-snow regions, which is considered the first case of this event in the area. Because snow coverage maintains stable temperatures and high humidity on the ground surface, heavy-snow conditions may have paved the way for these organisms from freshwater to land via mountain streamlets by preventing winter desiccation in mountain valleys. The fact that the terrestrialization of Pomatiopsidae occurred only in year-round wet environments, but not in seasonally dried regions, provides new insight into ancient

Influence of multiple global change drivers on terrestrial carbon storage

DEFF Research Database (Denmark)

Yue, Kai; Fornara, Dario A; Yang, Wanqin

2017-01-01

The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum of their indivi......The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum...... additive effects of multiple global change drivers into future assessments of the C storage ability of terrestrial ecosystems....

Lipopolysaccharides in diazotrophic bacteria.

Science.gov (United States)

Serrato, Rodrigo V

2014-01-01

Biological nitrogen fixation (BNF) is a process in which the atmospheric nitrogen (N2) is transformed into ammonia (NH3) by a select group of nitrogen-fixing organisms, or diazotrophic bacteria. In order to furnish the biologically useful nitrogen to plants, these bacteria must be in constant molecular communication with their host plants. Some of these molecular plant-microbe interactions are very specific, resulting in a symbiotic relationship between the diazotroph and the host. Others are found between associative diazotrophs and plants, resulting in plant infection and colonization of internal tissues. Independent of the type of ecological interaction, glycans, and glycoconjugates produced by these bacteria play an important role in the molecular communication prior and during colonization. Even though exopolysaccharides (EPS) and lipochitooligosaccharides (LCO) produced by diazotrophic bacteria and released onto the environment have their importance in the microbe-plant interaction, it is the lipopolysaccharides (LPS), anchored on the external membrane of these bacteria, that mediates the direct contact of the diazotroph with the host cells. These molecules are extremely variable among the several species of nitrogen fixing-bacteria, and there are evidences of the mechanisms of infection being closely related to their structure.

Cable Bacteria in Freshwater Sediments

DEFF Research Database (Denmark)

Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

2015-01-01

In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

Terrestrial and exposure histories of Antarctic meteorites

International Nuclear Information System (INIS)

Nishiizumi, K.

1986-01-01

Records of cosmogenic effects were studied in a large suite of Antarctic meteorites. The cosmogenic nuclide measurements together with cosmic ray track measurements on Antartic meteorites provide information such as exposure age, terrestrial age, size and depth in meteoroid or parent body, influx rate in the past, and pairing. The terrestrail age is the time period between the fall of the meteorite on the Earth and the present. To define terrestrial age, two or more nuclides with different half-lives and possibly noble gases are required. The cosmogenic radionuclides used are C-14, Kr-81, Cl-36, Al-26, Be-10, Mn-53, and K-40

Terrestrial and exposure histories of Antarctic meteorites

Science.gov (United States)

Nishiizumi, K.

1986-01-01

Records of cosmogenic effects were studied in a large suite of Antarctic meteorites. The cosmogenic nuclide measurements together with cosmic ray track measurements on Antartic meteorites provide information such as exposure age, terrestrial age, size and depth in meteoroid or parent body, influx rate in the past, and pairing. The terrestrail age is the time period between the fall of the meteorite on the Earth and the present. To define terrestrial age, two or more nuclides with different half-lives and possibly noble gases are required. The cosmogenic radionuclides used are C-14, Kr-81, Cl-36, Al-26, Be-10, Mn-53, and K-40.

Terrestrial ecosystems in a changing world

Energy Technology Data Exchange (ETDEWEB)

Canadell, J.G. [CSIRO Marine and Atmospheric Research, Canberra, ACT (Australia). Global Carbon Project; Pataki, D.E. [California Univ., Irvine, CA (United States). Dept. of Earth System Science]|[California Univ., Irvine, CA (United States). Dept. of Ecology and Evolutionary Biology; Pitelka, L.F. (eds.) [Maryland Univ., Frostburg, MD (United States). Appalachian Lab.

2007-07-01

Over 100 authors present 25 contributions on the impacts of global change on terrestrial ecosystems including: * key processes of the earth system such as the CO2 fertilization effect, shifts in disturbances and biome distribution, the saturation of the terrestrial carbon sink, and changes in functional biodiversity, * ecosystem services such the production of wheat, pest control, and carbon storage in croplands, and * sensitive regions in the world threaten by rapid changes in climate and land use such as high latitudes ecosystems, tropical forest in Southeast Asia, and ecosystems dominated by Monsoon climate. The book also explores new research developments on spatial thresholds and nonlinearities, the key role of urban development in global biogeochemical processes, and the integration of natural and social sciences to address complex problems of the human-environment system. (orig.)

Insights and issues with simulating terrestrial DOC loading of Arctic river networks.

Science.gov (United States)

Kicklighter, David W; Hayes, Daniel J; McClelland, James W; Peterson, Bruce J; McGuire, A David; Melillo, Jerry M

2013-12-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

Insights and issues with simulating terrestrial DOC loading of Arctic river networks

Science.gov (United States)

Kicklighter, David W.; Hayes, Daniel J.; McClelland, James W.; Peterson, Bruce J.; McGuire, A. David; Melillo, Jerry M.

2013-01-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

Cold atmospheric-pressure plasma and bacteria: understanding the mode of action using vibrational microspectroscopy

International Nuclear Information System (INIS)

Kartaschew, Konstantin; Mischo, Meike; Bründermann, Erik; Havenith, Martina; Baldus, Sabrina; Awakowicz, Peter

2016-01-01

Cold atmospheric-pressure plasma show promising antimicrobial effects, however the detailed biochemical mechanism of the bacterial inactivation is still unknown. We investigated, for the first time, plasma-treated Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacteria with Raman and infrared microspectroscopy. A dielectric barrier discharge was used as a plasma source. We were able to detect several plasma-induced chemical modifications, which suggest a pronounced oxidative effect on the cell envelope, cellular proteins and nucleotides as well as a generation of organic nitrates in the treated bacteria. Vibrational microspectroscopy is used as a comprehensive and a powerful tool for the analysis of plasma interactions with whole organisms such as bacteria. Analysis of reaction kinetics of chemical modifications allow a time-dependent insight into the plasma-mediated impact. Investigating possible synergistic effects between the plasma-produced components, our observations strongly indicate that the detected plasma-mediated chemical alterations can be mainly explained by the particle effect of the generated reactive species. By changing the polarity of the applied voltage pulse, and hence the propagation mechanisms of streamers, no significant effect on the spectral results could be detected. This method allows the analysis of the individual impact of each plasma constituent for particular chemical modifications. Our approach shows great potential to contribute to a better understanding of plasma-cell interactions. (paper)

Effects and Mechanism of Action of a Tribulus terrestris Extract on Penile Erection

Science.gov (United States)

Do, Jungmo; Choi, Seemin; Choi, Jaehwi

2013-01-01

Purpose Tribulus terrestris has been used as an aphrodisiac. However, little is known about the effects and mechanism of action of T. terrestris on penile erection. Therefore, the effect of a T. terrestris extract and the mechanism of action of the extract on relaxation of the corpus cavernosum (CC) were investigated. The erectogenic effects of an oral preparation of the extract were also assessed. Materials and Methods The relaxation effects and mechanism of action of the T. terrestris extract on rabbit CC were investigated in an organ bath. The intracavernous pressure (ICP) was calculated after oral administration of the extract for 1 month to evaluate whether the relaxation response of the CC shown in the organ bath occurred in vivo. Additionally, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in the CC by immunoassay. Smooth muscle relaxation was expressed as the percentage decrease in precontraction induced by phenylephrine. The ICP was also assessed in rats after oral administration of the extract for 1 month, and changes in concentrations of cGMP and cAMP were monitored. Results Concentration-dependent relaxation effects of the extract on the CC were detected in the organ bath study. Relaxation of the CC by the T. terrestris extract was inhibited in both an endothelium-removed group and an L-arginen methyl ester pretreatment group. The ICP measured after oral administration of the T. terrestris extract for 1 month was higher than that measured in the control group, and a significant increase in cAMP was observed in the T. terrestris extract group. Conclusions The T. terrestris extract induced concentration-dependent relaxation of the CC in an organ bath. The mechanism included a reaction involving the nitric oxide/nitric oxide synthase pathway and endothelium of the CC. Moreover, in an in vivo study, the T. terrestris extract showed a significant concentration-dependent increase in ICP. Accordingly, the T

Effects and Mechanism of Action of a Tribulus terrestris Extract on Penile Erection.

Science.gov (United States)

Do, Jungmo; Choi, Seemin; Choi, Jaehwi; Hyun, Jae Seog

2013-03-01

Tribulus terrestris has been used as an aphrodisiac. However, little is known about the effects and mechanism of action of T. terrestris on penile erection. Therefore, the effect of a T. terrestris extract and the mechanism of action of the extract on relaxation of the corpus cavernosum (CC) were investigated. The erectogenic effects of an oral preparation of the extract were also assessed. The relaxation effects and mechanism of action of the T. terrestris extract on rabbit CC were investigated in an organ bath. The intracavernous pressure (ICP) was calculated after oral administration of the extract for 1 month to evaluate whether the relaxation response of the CC shown in the organ bath occurred in vivo. Additionally, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in the CC by immunoassay. Smooth muscle relaxation was expressed as the percentage decrease in precontraction induced by phenylephrine. The ICP was also assessed in rats after oral administration of the extract for 1 month, and changes in concentrations of cGMP and cAMP were monitored. Concentration-dependent relaxation effects of the extract on the CC were detected in the organ bath study. Relaxation of the CC by the T. terrestris extract was inhibited in both an endothelium-removed group and an L-arginen methyl ester pretreatment group. The ICP measured after oral administration of the T. terrestris extract for 1 month was higher than that measured in the control group, and a significant increase in cAMP was observed in the T. terrestris extract group. The T. terrestris extract induced concentration-dependent relaxation of the CC in an organ bath. The mechanism included a reaction involving the nitric oxide/nitric oxide synthase pathway and endothelium of the CC. Moreover, in an in vivo study, the T. terrestris extract showed a significant concentration-dependent increase in ICP. Accordingly, the T. terrestris extract may improve erectile function.

Data base for terrestrial food pathways dose commitment calculations

International Nuclear Information System (INIS)

Bailey, C.E.

1979-01-01

A computer program is under development to allow calculation of the dose-to-man in Georgia and South Carolina from ingestion of radionuclides in terrestrial foods resulting from deposition of airborne radionuclides. This program is based on models described in Regulatory Guide 1.109 (USNRC, 1977). The data base describes the movement of radionuclides through the terrestrial food chain, growth and consumption factors for a variety of radionuclides

Denitrifying bacteria from the genus Rhodanobacter dominate bacterial communities in the highly contaminated subsurface of a nuclear legacy waste site.

Science.gov (United States)

Green, Stefan J; Prakash, Om; Jasrotia, Puja; Overholt, Will A; Cardenas, Erick; Hubbard, Daniela; Tiedje, James M; Watson, David B; Schadt, Christopher W; Brooks, Scott C; Kostka, Joel E

2012-02-01

The effect of long-term mixed-waste contamination, particularly uranium and nitrate, on the microbial community in the terrestrial subsurface was investigated at the field scale at the Oak Ridge Integrated Field Research Challenge (ORIFRC) site in Oak Ridge, TN. The abundance, community composition, and distribution of groundwater microorganisms were examined across the site during two seasonal sampling events. At representative locations, subsurface sediment was also examined from two boreholes, one sampled from the most heavily contaminated area of the site and another from an area with low contamination. A suite of DNA- and RNA-based molecular tools were employed for community characterization, including quantitative PCR of rRNA and nitrite reductase genes, community composition fingerprinting analysis, and high-throughput pyrotag sequencing of rRNA genes. The results demonstrate that pH is a major driver of the subsurface microbial community structure and that denitrifying bacteria from the genus Rhodanobacter (class Gammaproteobacteria) dominate at low pH. The relative abundance of bacteria from this genus was positively correlated with lower-pH conditions, and these bacteria were abundant and active in the most highly contaminated areas. Other factors, such as the concentration of nitrogen species, oxygen level, and sampling season, did not appear to strongly influence the distribution of Rhodanobacter bacteria. The results indicate that these organisms are acid-tolerant denitrifiers, well suited to the acidic, nitrate-rich subsurface conditions, and pH is confirmed as a dominant driver of bacterial community structure in this contaminated subsurface environment.

Antifungal Bacteria on Woodland Salamander Skin Exhibit High Taxonomic Diversity and Geographic Variability.

Science.gov (United States)

Muletz-Wolz, Carly R; DiRenzo, Graziella V; Yarwood, Stephanie A; Campbell Grant, Evan H; Fleischer, Robert C; Lips, Karen R

2017-05-01

protective role for these salamanders. IMPORTANCE Amphibians harbor skin bacteria that can kill an amphibian fungal pathogen, Batrachochytrium dendrobatidis Some amphibians die from B. dendrobatidis infection, whereas others do not. The bacteria that can kill B. dendrobatidis , called anti- B. dendrobatidis bacteria, are thought to influence the B. dendrobatidis infection outcome for the amphibian. Yet how anti- B. dendrobatidis bacterial species vary among amphibian species and populations is unknown. We determined the distribution of anti- B. dendrobatidis bacterial species among three salamander species ( n = 61) sampled at three localities. We identified 50 unique anti- B. dendrobatidis bacterial species and found that all of the tested salamanders were negative for B. dendrobatidis Five anti- B. dendrobatidis bacterial species were commonly detected, suggesting a stable, functional association with these salamanders. The number of anti- B. dendrobatidis bacteria per individual varied among localities but not among co-occurring salamander species, demonstrating that environment is more influential than host factors in structuring the anti- B. dendrobatidis bacterial community. These anti- B. dendrobatidis bacteria may serve a protective function for their salamander hosts. Copyright © 2017 American Society for Microbiology.

Research progress of Tribulus terrestris composition and main pharmaco-logic effects%蒺藜成分及主要药理作用研究进展

Institute of Scientific and Technical Information of China (English)

候爽; 陈长军; 杨博; 于飞飞; 崔晓莉; 孟雨; 田洪艳; 李质馨

2014-01-01

Traditional Chinese medicine (TCM) Tribulus terrestris contains a variety of important biological active substances, such as saponins, flavonoids and other compounds, which has many pharmacological effects. Modern medi-cal research indicates that Tribulus terrestris can remarkably delay senescence, reduce blood glucose and blood lipid, strengthen sexual function and enhance the sex hormones in the human body, etc. And it has good curative effects for cancer, high blood pressure, bacteria and fungal infections, diabetes and etc. This article mainly discusses the research progress on Tribulus terrestris composition and its main pharmacological activities in recent years.%中药蒺藜中含有多种重要的生物活性物质如皂苷类、黄酮类等的化合物，具有众多的药理作用。现代医学研究证明，蒺藜具有显著的抗衰老、降血糖、降血脂、性强壮及提高人体中性激素含量等的作用，对肿瘤、高血压、细菌真菌感染、糖尿病等均有较好疗效。本文主要对近年来中药蒺藜成分及主要药理作用研究进展进行综述。

Cause of Cambrian Explosion - Terrestrial or Cosmic?

Science.gov (United States)

Steele, Edward J; Al-Mufti, Shirwan; Augustyn, Kenneth A; Chandrajith, Rohana; Coghlan, John P; Coulson, S G; Ghosh, Sudipto; Gillman, Mark; Gorczynski, Reginald M; Klyce, Brig; Louis, Godfrey; Mahanama, Kithsiri; Oliver, Keith R; Padron, Julio; Qu, Jiangwen; Schuster, John A; Smith, W E; Snyder, Duane P; Steele, Julian A; Stewart, Brent J; Temple, Robert; Tokoro, Gensuke; Tout, Christopher A; Unzicker, Alexander; Wainwright, Milton; Wallis, Jamie; Wallis, Daryl H; Wallis, Max K; Wetherall, John; Wickramasinghe, D T; Wickramasinghe, J T; Wickramasinghe, N Chandra; Liu, Yongsheng

2018-08-01

We review the salient evidence consistent with or predicted by the Hoyle-Wickramasinghe (H-W) thesis of Cometary (Cosmic) Biology. Much of this physical and biological evidence is multifactorial. One particular focus are the recent studies which date the emergence of the complex retroviruses of vertebrate lines at or just before the Cambrian Explosion of ∼500 Ma. Such viruses are known to be plausibly associated with major evolutionary genomic processes. We believe this coincidence is not fortuitous but is consistent with a key prediction of H-W theory whereby major extinction-diversification evolutionary boundaries coincide with virus-bearing cometary-bolide bombardment events. A second focus is the remarkable evolution of intelligent complexity (Cephalopods) culminating in the emergence of the Octopus. A third focus concerns the micro-organism fossil evidence contained within meteorites as well as the detection in the upper atmosphere of apparent incoming life-bearing particles from space. In our view the totality of the multifactorial data and critical analyses assembled by Fred Hoyle, Chandra Wickramasinghe and their many colleagues since the 1960s leads to a very plausible conclusion - life may have been seeded here on Earth by life-bearing comets as soon as conditions on Earth allowed it to flourish (about or just before 4.1 Billion years ago); and living organisms such as space-resistant and space-hardy bacteria, viruses, more complex eukaryotic cells, fertilised ova and seeds have been continuously delivered ever since to Earth so being one important driver of further terrestrial evolution which has resulted in considerable genetic diversity and which has led to the emergence of mankind. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Environmental radionuclides tracers and timers of terrestrial processes

CERN Document Server

Froehlich, Klaus

2009-01-01

The book presents a state-of-the-art summary of knowledge on the use of radionuclides to study processes and systems in the continental part of the Earth's environment. It is conceived as a companion to the two volumes of this series, which deal with isotopes as tracers in the marine environment (Livingston, Marine Radioactivity) and with the radioecology of natural and man-made terrestrial systems (Shaw, Radioactivity in Terrestrial Ecosystems). Although the book focuses on natural and anthropogenic radionuclides (radioactive isotopes), it also refers to stable environmental isotopes, which i

Exploring the Behavior and Metabolic Transformations of SeNPs in Exposed Lactic Acid Bacteria. Effect of Nanoparticles Coating Agent

Directory of Open Access Journals (Sweden)

Maria Palomo-Siguero

2017-08-01

Full Text Available The behavior and transformation of selenium nanoparticles (SeNPs in living systems such as microorganisms is largely unknown. To address this knowledge gap, we examined the effect of three types of SeNP suspensions toward Lactobacillus delbrueckii subsp. bulgaricus LB-12 using a variety of techniques. SeNPs were synthesized using three types of coating agents (chitosan (CS-SeNPs, hydroxyethyl cellulose (HEC-SeNPs and a non-ionic surfactant, surfynol (ethoxylated-SeNPs. Morphologies of SeNPs were all spherical. Transmission electron microscopy (TEM was used to locate SeNPs in the bacteria. High performance liquid chromatography (HPLC on line coupled to inductively coupled plasma mass spectrometry (ICP-MS was applied to evaluate SeNP transformation by bacteria. Finally, flow cytometry employing the live/dead test and optical density measurements at 600 nm (OD600 were used for evaluating the percentages of bacteria viability when supplementing with SeNPs. Negligible damage was detected by flow cytometry when bacteria were exposed to HEC-SeNPs or CS-SeNPs at a level of 10 μg Se mL−1. In contrast, ethoxylated-SeNPs were found to be the most harmful nanoparticles toward bacteria. CS-SeNPs passed through the membrane without causing damage. Once inside, SeNPs were metabolically transformed to organic selenium compounds. Results evidenced the importance of capping agents when establishing the true behavior of NPs.

Terrestrial plant methane production

DEFF Research Database (Denmark)

Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

Puncturevine (Tribulus terrestris L.: noxious weed or powerful medical herb

Directory of Open Access Journals (Sweden)

Zvonko Pacanoski

2014-03-01

Full Text Available Tribulus terrestris L., an annual dicot species of the family Zygophyllaceae, is a common herb that is often found in disturbed habitats and agricultural areas in many parts of the temperate, tropical and desert regions of the world. T. terrestris is an aggressive species that has the potential to injure livestock, reduce hay and wool values, detour recreationists and reduces plant biodivesity. The species may become troublesome because of its weedy potential. It has been declared a weed in at least 37 countries and in at least 21 crops (cotton, maize, vineyards, orchards, etc.. It is adapted to a wide range of climatic conditions and grows on a wide variety of soil types. The management of T. terrestris can be achieved by herbicide application, mechanical (hand pulling, hoeing, mulching and biological control methods. Beside its invasive potential as a noxious and troublesome weed, T. terrestris is considered highly useful herb which is used for various purposes in folk and modern medicine and sport, as well.

Guidelines to elaborate a migration plan for digital terrestrial television in Venezuela

OpenAIRE

José Rafael Uzcátegui; José Francisco Torres; Nelson Pérez García; Luís Duque; Zeldívar Bruzual

2011-01-01

In October 2009, the Bolivarian Republic of Venezuela adopted the ISDB-Tb (Integrated Services Digital Broadcasting - Terrestrial Built On), released by Japan, with some improvement made by Brazil, as Digital Terrestrial Television (DTT) to be deployment in Venezuela. After standard choice, has been start the route towards the solution of transcendental aspects of legal and technical nature to enable the provision of digital terrestrial television service harmonized with the goals of true soc...

Shell bone histology indicates terrestrial palaeoecology of basal turtles.

Science.gov (United States)

Scheyer, Torsten M; Sander, P Martin

2007-08-07

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti. Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, 'aquatic' turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record.

Multifocal, chronic osteomyelitis of unknown etiology

International Nuclear Information System (INIS)

Kozlowski, K.; Beluffi, G.; Feltham, C.; James, M.; Nespoli, L.; Tamaela, L.; Pavia Univ.; Municipal Hospital, Nelson; Medical School, Jakarta

1985-01-01

Four cases of multifocal osteomyelitis of unknown origin in childhood are reported. The variable clinical and radiographic appearances of the disease are illustrated and the diagnostic difficulties in the early stages of the disease are stressed. (orig.) [de

Similar Running Economy With Different Running Patterns Along the Aerial-Terrestrial Continuum.

Science.gov (United States)

Lussiana, Thibault; Gindre, Cyrille; Hébert-Losier, Kim; Sagawa, Yoshimasa; Gimenez, Philippe; Mourot, Laurent

2017-04-01

No unique or ideal running pattern is the most economical for all runners. Classifying the global running patterns of individuals into 2 categories (aerial and terrestrial) using the Volodalen method could permit a better understanding of the relationship between running economy (RE) and biomechanics. The main purpose was to compare the RE of aerial and terrestrial runners. Two coaches classified 58 runners into aerial (n = 29) or terrestrial (n = 29) running patterns on the basis of visual observations. RE, muscle activity, kinematics, and spatiotemporal parameters of both groups were measured during a 5-min run at 12 km/h on a treadmill. Maximal oxygen uptake (V̇O 2 max) and peak treadmill speed (PTS) were assessed during an incremental running test. No differences were observed between aerial and terrestrial patterns for RE, V̇O 2 max, and PTS. However, at 12 km/h, aerial runners exhibited earlier gastrocnemius lateralis activation in preparation for contact, less dorsiflexion at ground contact, higher coactivation indexes, and greater leg stiffness during stance phase than terrestrial runners. Terrestrial runners had more pronounced semitendinosus activation at the start and end of the running cycle, shorter flight time, greater leg compression, and a more rear-foot strike. Different running patterns were associated with similar RE. Aerial runners appear to rely more on elastic energy utilization with a rapid eccentric-concentric coupling time, whereas terrestrial runners appear to propel the body more forward rather than upward to limit work against gravity. Excluding runners with a mixed running pattern from analyses did not affect study interpretation.

Subsidy or subtraction: how do terrestrial inputs influence consumer production in lakes?

Science.gov (United States)

Jones, Stuart E.; Solomon, Christopher T.; Weidel, Brian C.

2012-01-01

Cross-ecosystem fluxes are ubiquitous in food webs and are generally thought of as subsidies to consumer populations. Yet external or allochthonous inputs may in fact have complex and habitat-specific effects on recipient ecosystems. In lakes, terrestrial inputs of organic carbon contribute to basal resource availability, but can also reduce resource availability via shading effects on phytoplankton and periphyton. Terrestrial inputs might therefore either subsidise or subtract from consumer production. We developed and parameterised a simple model to explore this idea. The model estimates basal resource supply and consumer production given lake-level characteristics including total phosphorus (TP) and dissolved organic carbon (DOC) concentration, and consumer-level characteristics including resource preferences and growth efficiencies. Terrestrial inputs diminished primary production and total basal resource supply at the whole-lake level, except in ultra-oligotrophic systems. However, this system-level generalisation masked complex habitat-specific effects. In the pelagic zone, dissolved and particulate terrestrial carbon inputs were available to zooplankton via several food web pathways. Consequently, zooplankton production usually increased with terrestrial inputs, even as total whole-lake resource availability decreased. In contrast, in the benthic zone the dominant, dissolved portion of the terrestrial carbon load had predominantly negative effects on resource availability via shading of periphyton. Consequently, terrestrial inputs always decreased zoobenthic production except under extreme and unrealistic parameterisations of the model. Appreciating the complex and habitat-specific effects of allochthonous inputs may be essential for resolving the effects of cross-habitat fluxes on consumers in lakes and other food webs.

Mercury in the Canadian Arctic terrestrial environment: an update.

Science.gov (United States)

Gamberg, Mary; Chételat, John; Poulain, Alexandre J; Zdanowicz, Christian; Zheng, Jiancheng

2015-03-15

Contaminants in the Canadian Arctic have been studied over the last twenty years under the guidance of the Northern Contaminants Program. This paper provides the current state of knowledge on mercury (Hg) in the Canadian Arctic terrestrial environment. Snow, ice, and soils on land are key reservoirs for atmospheric deposition and can become sources of Hg through the melting of terrestrial ice and snow and via soil erosion. In the Canadian Arctic, new data have been collected for snow and ice that provide more information on the net accumulation and storage of Hg in the cryosphere. Concentrations of total Hg (THg) in terrestrial snow are highly variable but on average, relatively low (Porcupine caribou herd vary among years but there has been no significant increase or decrease over the last two decades. Copyright © 2014 Elsevier B.V. All rights reserved.

Terrestrial gamma radiation baseline mapping using ultra low density sampling methods

International Nuclear Information System (INIS)

Kleinschmidt, R.; Watson, D.

2016-01-01

Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km 2 ), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 49 ± 69 nGy h −1 (n = 311, 3σ 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. - Highlights: • A baseline terrestrial air kerma map of Queensland, Australia was developed using geochemical data from a major drainage catchment ultra-low density sampling program

Radiation-resistant asporogenic bacteria

Energy Technology Data Exchange (ETDEWEB)

Yano, K [Tokyo Univ. (Japan). Faculty of Agriculture

1975-09-01

This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned.

Radiation-resistant asporogenic bacteria

International Nuclear Information System (INIS)

Yano, Keiji

1975-01-01

This paper reports the biological and ecological examinations on the radiation-resistant asporogenic bacteria (mainly concerning Micrococcus radiodurans). Radiation-resistant asporogenic bacteria were isolated from the irradiated areas of the natural world as well as from the general areas and from the Rn waters in the Misasa hot spring. The acquiring of the tolerance to radiation in bacteria was also examined. In addition, the future problems of microbiological treatment with irradiation were mentioned. (Tsukamoto, Y.)

Terrestrial water fluxes dominated by transpiration.

Science.gov (United States)

Jasechko, Scott; Sharp, Zachary D; Gibson, John J; Birks, S Jean; Yi, Yi; Fawcett, Peter J

2013-04-18

Renewable fresh water over continents has input from precipitation and losses to the atmosphere through evaporation and transpiration. Global-scale estimates of transpiration from climate models are poorly constrained owing to large uncertainties in stomatal conductance and the lack of catchment-scale measurements required for model calibration, resulting in a range of predictions spanning 20 to 65 per cent of total terrestrial evapotranspiration (14,000 to 41,000 km(3) per year) (refs 1, 2, 3, 4, 5). Here we use the distinct isotope effects of transpiration and evaporation to show that transpiration is by far the largest water flux from Earth's continents, representing 80 to 90 per cent of terrestrial evapotranspiration. On the basis of our analysis of a global data set of large lakes and rivers, we conclude that transpiration recycles 62,000 ± 8,000 km(3) of water per year to the atmosphere, using half of all solar energy absorbed by land surfaces in the process. We also calculate CO2 uptake by terrestrial vegetation by connecting transpiration losses to carbon assimilation using water-use efficiency ratios of plants, and show the global gross primary productivity to be 129 ± 32 gigatonnes of carbon per year, which agrees, within the uncertainty, with previous estimates. The dominance of transpiration water fluxes in continental evapotranspiration suggests that, from the point of view of water resource forecasting, climate model development should prioritize improvements in simulations of biological fluxes rather than physical (evaporation) fluxes.

Immunomodulatory properties of probiotic bacteria

DEFF Research Database (Denmark)

Fink, Lisbeth Nielsen

2007-01-01

Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

Data-driven diagnostics of terrestrial carbon dynamics over North America

Science.gov (United States)

Jingfeng Xiao; Scott V. Ollinger; Steve Frolking; George C. Hurtt; David Y. Hollinger; Kenneth J. Davis; Yude Pan; Xiaoyang Zhang; Feng Deng; Jiquan Chen; Dennis D. Baldocchi; Bevery E. Law; M. Altaf Arain; Ankur R. Desai; Andrew D. Richardson; Ge Sun; Brian Amiro; Hank Margolis; Lianhong Gu; Russell L. Scott; Peter D. Blanken; Andrew E. Suyker

2014-01-01

The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth's climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale...

Shell bone histology indicates terrestrial palaeoecology of basal turtles

OpenAIRE

Scheyer, Torsten; Sander, P. Martin

2009-01-01

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys que...

Factors influencing aquatic-to-terrestrial contaminant transport to terrestrial arthropod consumers in a multiuse river system.

Science.gov (United States)

Alberts, Jeremy M; Sullivan, S Mažeika P

2016-06-01

Emerging aquatic insects are important vectors of contaminant transfer from aquatic to terrestrial food webs. However, the environmental factors that regulate contaminant body burdens in nearshore terrestrial consumers remain largely unexplored. We investigated the relative influences of riparian landscape composition (i.e., land use and nearshore vegetation structure) and contaminant flux via the emergent aquatic insect subsidy on selenium (Se) and mercury (Hg) body burdens of riparian ants (Formica subsericea) and spiders of the family Tetragnathidae along 11 river reaches spanning an urban-rural land-use gradient in Ohio, USA. Model-selection results indicated that fine-scale land cover (e.g., riparian zone width, shrub cover) in the riparian zone was positively associated with reach-wide body burdens of Se and Hg in both riparian F. subsericea and tetragnathid spiders (i.e., total magnitude of Hg and Se concentrations in ant and spider populations, respectively, for each reach). River distance downstream of Columbus, Ohio - where study reaches were impounded and flow through a large urban center - was also implicated as an important factor. Although stable-isotope analysis suggested that emergent aquatic insects were likely vectors of Se and Hg to tetragnathid spiders (but not to F. subsericea), emergent insect contaminant flux did not emerge as a significant predictor for either reach-wide body burdens of spider Hg or Se. Improved understanding of the pathways and influences that control aquatic-to-terrestrial contaminant transport will be critical for effective risk management and remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Protocol for counterfactually transporting an unknown qubit

Directory of Open Access Journals (Sweden)

Hatim eSalih

2016-01-01

Full Text Available Quantum teleportation circumvents the uncertainty principle using dual channels: a quantum one consisting of previously-shared entanglement, and a classical one, together allowing the disembodied transport of an unknown quantum state over distance. It has recently been shown that a classical bit can be counterfactually communicated between two parties in empty space, Alice and Bob. Here, by using our dual version of the chained quantum Zeno effect to achieve a counterfactual CNOT gate, we propose a protocol for transporting an unknown qubit counterfactually, that is without any physical particles travelling between Alice and Bob—no classical channel and no previously-shared entanglement.

Fever of unknown origin

International Nuclear Information System (INIS)

Misaki, Takashi; Matsui, Akira; Tanaka, Fumiko; Okuno, Yoshishige; Mitsumori, Michihide; Torizuka, Tatsurou; Dokoh, Shigeharu; Hayakawa, Katsumi; Shimbo, Shin-ichirou

1990-01-01

Gallium-67 scintigraphy is a commonly performed imaging modality in deteting pyrogenic lesions in cases of long-standing inexplainable fever. To re-evaluate the significance of gallium imaging in such cases, a retrospective review was made of 56 scans performed in febrile patients in whom sufficient clinical and laboratory findings were obtained. Gallium scans were true positive in 30 patients, false positive in 3, true negative in 19, and false negative in 4. In the group of true positive, local inflammatory lesions were detected in 23 patients with a final diagnosis of lung tuberculosis, urinary tract infection, and inflammatory joint disease. Abnormal gallium accumulation, as shown in the other 7 patients, provided clues to the diagnosis of generalized disorders, such as hematological malignancies (n=3), systemic autoimmune diseases (n=3), and severe infectious mononucleosis (n=one). In the group of false positive, gallium imaging revealed intestinal excretion of gallium in 2 patients and physiological pulmonary hilar accumulation in one. In the true negative group of 19 patients, fever of unknown origin was resolved spontaneously in 12 patients, and with antibiotics and corticosteroids in 2 and 5 patients, respectively. Four patients having false negative scans were finally diagnosed as having urinary tract infection (n=2), bacterial meningitis (n=one), and polyarteritis (n=one). Gallium imaging would remain the technique of choice in searching for origin of unknown fever. It may also be useful for early diagnosis of systemic disease, as well as focal inflammation. (N.K.)

Application of Terrestrial Environments in Orion Assessments

Science.gov (United States)

Barbre, Robert E.

2016-01-01

This presentation summarizes the Marshall Space Flight Center Natural Environments Terrestrial and Planetary Environments (TPE) Team support to the NASA Orion space vehicle. The TPE utilizes meteorological data to assess the sensitivities of the vehicle due to the terrestrial environment. The Orion vehicle, part of the Multi-Purpose Crew Vehicle Program, is designed to carry astronauts beyond low-earth orbit and is currently undergoing a series of tests including Exploration Test Flight (EFT) - 1. The presentation describes examples of TPE support for vehicle design and several tests, as well as support for EFT-1 and planning for upcoming Exploration Missions while emphasizing the importance of accounting for the natural environment's impact to the vehicle early in the vehicle's program.

Northern Marshall Islands radiological survey: terrestrial food chain and total doses

International Nuclear Information System (INIS)

Robison, W.L.; Mount, M.E.; Phillips, W.A.; Conrado, C.A.; Stuart, M.L.; Stoker, C.E.

1982-01-01

A radiological survey was conducted from September through November of 1978 to assess the concentrations of persistent manmade radionuclides in the terrestrial and marine environments of 11 atolls and 2 islands in the Northern Marshall Islands. The survey consisted mainly of an aerial radiological reconnaissance to map the external gamma-ray exposure rates over the islands of each atoll. The logistical support for the entire survey was designed to accommodate this operation. As a secondary phase of the survey, shore parties collected appropriate terrestrial and marine samples to assess the radiological dose from pertinent food chains to those individuals residing on the atolls, who may in the future reside on some of the presently uninhabited atolls, or who collect food from these atolls. Over 5000 terrestrial and marine samples were collected for radionuclide analysis from 76 different islands. Soils, vegetation, indigenous animals, and cistern water and groundwater were collected from the islands. Reef and pelagic fish, clams, lagoon water, and sediments were obtained from the lagoons. The concentration data for 90 Sr, 137 Cs, 238 Pu, 239 240 Pu, and 241 Am in terrestrial food crops, fowl, and animals collected at the atolls or islands are summarized. An assessment of the total dose from the major exposure pathways including external gamma, terrestrial food chain including food products and drinking water, marine food chain, and inhalation is provided. Radiological doses at each atoll or island are calculated from the average radionuclide concentrations in the terrestrial foods, marine foods, etc. assuming the average daily intake for each food item

Differentiation of water-related traits in terrestrial and epiphytic Cymbidium species

Directory of Open Access Journals (Sweden)

Shi-Bao eZhang

2015-04-01

Full Text Available Epiphytes that grow in the canopies of tropical and subtropical forests experience different water regimes when compared with terrestrial plants. However, the differences in adaptive strategies between epiphytic and terrestrial plants with respect to plant water relations remain poorly understood. To understand how water-related traits contrast between epiphytic and terrestrial growth forms within the Cymbidium (Orchidaceae, we assessed leaf anatomy, hydraulics, and physiology of seven terrestrial and 13 epiphytic species using a common garden experiment. Compared with terrestrial species, epiphytic species had higher values for leaf mass per unit area (LMA, leaf thickness (LT, epidermal thickness, saturated water content (SWC and the time required to dry saturated leaves to 70% relative water content (T70. However, vein density (Dvein, stomatal density (SD, and photosynthetic capacity (Amax did not differ significantly between the two forms. T70 was positively correlated with LT, LMA, and SWC, and negatively correlated with stomatal index (SI. Amax showed positive correlations with SD and SI, but not with Dvein. Vein density was marginally correlated with SD, and significantly correlated with SI. Overall, epiphytic orchids exhibited substantial ecophysiological differentiations from terrestrial species, with the former type showing trait values indicative of greater drought tolerance and increased water storage capacity. The ability to retain water in the leaves plays a key role in maintaining a water balance in those epiphytes. Therefore, the process of transpiration depends less upon the current substrate water supply and enables epiphytic Cymbidium species to adapt more easily to canopy habitats.

Contamination Levels and Identification of Bacteria in Milk Sampled from Three Regions of Tanzania: Evidence from Literature and Laboratory Analyses

Directory of Open Access Journals (Sweden)

G. Msalya

2017-01-01

Full Text Available Milk in Tanzania has been reported to be contaminated with large number of bacteria. This is because (1 milk is obtained from animals with unknown health status, (2 good milking and handling practices are to a large extent not observed, and (3 marketing and distribution are done in informal channels. These factors are potential causes of milk-borne diseases and milk quality loss. The aim of this study was to assess nutritional risks in milk as reported in literature over a period of 20 years and through analyses of samples collected during the present study. The issues highlighted in literature were high bacteria and coliform counts exceeding standard levels in East Africa, prevalence of bacteria and drug residues in milk, and adulteration. Based on performed analyses, total bacterial count 1.0×107 colony forming units per millilitre (cfu/ml and total coliform count 1.1×107 cfu/ml, also greater than recommended levels, were found. Ten bacteria types were isolated from milk samples (five, Pseudomonas aeruginosa, Listeria monocytogenes, Listeria innocua, Listeria ivanovii, and Klebsiella spp. are reported in Tanzanian for the first time. Two drugs tetracycline and sulphur were detected. Therefore, it is worth noting that integrated research is needed to evaluate the situation and address these challenges.

Previously unclassified bacteria dominate during thermophilic and mesophilic anaerobic pre-treatment of primary sludge.

Science.gov (United States)

Pervin, Hasina M; Batstone, Damien J; Bond, Philip L

2013-06-01

Thermophilic biological pre-treatment enables enhanced anaerobic digestion for treatment of wastewater sludges but, at present, there is limited understanding of the hydrolytic-acidogenic microbial composition and its contribution to this process. In this study, the process was assessed by comparing the microbiology of thermophilic (50-65 °C) and mesophilic (35 °C) pre-treatment reactors treating primary sludge. A full-cycle approach for the 16S rRNA genes was applied in order to monitor the diversity of bacteria and their abundance in a thermophilic pre-treatment reactor treating primary sludge. For the thermophilic pre-treatment (TP), over 90% of the sequences were previously undetected and these had less than 97% sequence similarity to cultured organisms. During the first 83 days, members of the Betaproteobacteria dominated the community sequences and a newly designed probe was used to monitor a previously unknown bacterium affiliated with the genus Brachymonas. Between days 85 and 183, three phylotypes that affiliated with the genera Comamonas, Clostridium and Lysobacter were persistently dominant in the TP community, as revealed by terminal-restriction fragment length polymorphism (T-RFLP). Hydrolytic and fermentative functions have been speculated for these bacteria. Mesophilic pre-treatment (MP) and TP communities were different but they were both relatively dynamic. Statistical correlation analysis and the function of closely allied reference organisms indicated that previously unclassified bacteria dominated the TP community and may have been functionally involved in the enhanced hydrolytic performance of thermophilic anaerobic pre-treatment. This study is the first to reveal the diversity and dynamics of bacteria during anaerobic digestion of primary sludge. Copyright © 2013 Elsevier GmbH. All rights reserved.

Variations and trends of terrestrial NPP and its relation to climate

Indian Academy of Sciences (India)

Considering global climate change, near surface temperature is the major factor affecting the terrestrial ecosystem, followed by the precipitation. This means terrestrial ecosystem NPP is more closely related to near surface temperature than precipitation. Between 1976 and 2005, NPP shows an obvious increasing temporal ...

Bacteria-surface interactions.

Science.gov (United States)

Tuson, Hannah H; Weibel, Douglas B

2013-05-14

The interaction of bacteria with surfaces has important implications in a range of areas, including bioenergy, biofouling, biofilm formation, and the infection of plants and animals. Many of the interactions of bacteria with surfaces produce changes in the expression of genes that influence cell morphology and behavior, including genes essential for motility and surface attachment. Despite the attention that these phenotypes have garnered, the bacterial systems used for sensing and responding to surfaces are still not well understood. An understanding of these mechanisms will guide the development of new classes of materials that inhibit and promote cell growth, and complement studies of the physiology of bacteria in contact with surfaces. Recent studies from a range of fields in science and engineering are poised to guide future investigations in this area. This review summarizes recent studies on bacteria-surface interactions, discusses mechanisms of surface sensing and consequences of cell attachment, provides an overview of surfaces that have been used in bacterial studies, and highlights unanswered questions in this field.

Pengaruh Jamu Dengan Tribulus Terrestris Terhadap Kualitas Sperma Tikus Wistar Jantan (Rattus Norvegicus)

OpenAIRE

Pelealu, Delano; Tendean, Lydia; Wantouw, Benny

2015-01-01

: Tribulus terrestris dikenal sebagai bahan yang dapat memperbaiki kualitas sperma. Salah satu jenis jamu yang diproduksi di Indonesia mengandung Tribulus terrestris Penelitian ini bertujuan untuk mengetahui pengaruh jamu dengan Tribulus terrestris terhadap konsentrasi, motilitas, dan morfologi spermatozoa tikus wistar jantan (Rattus norvegicus). Penelitian ini menggunakan metode eksperimental. Sampel 9 ekor tikus wistar jantan (Rattus norvegicus) dibagi menjadi 3 kelompok yakni, kelompok P0 ...

Protective effect of Tribulus terrestris fruit extract on cerulein-induced acute pancreatitis in mice

Science.gov (United States)

Borran, Mina; Minaiyan, Mohsen; Zolfaghari, Behzad; Mahzouni, Parvin

2017-01-01

Objective: Antioxidant, anti-inflammatory, analgesic and antimicrobial activities of Tribulus terrestris (T. terrestris) could be helpful in the treatment of acute pancreatitis; thus, this study was designed to investigate the effects of T. terrestris on cerulein-induced acute pancreatitis in mice. Materials and Methods: Three doses (100, 200 and 400 mg/kg) of T. terrestris hydro-alcoholic extract were administered both orally (60 minutes before pancreatitis induction, p.o.) and intra-peritoneally (30 minutes before pancreatitis induction, i.p.) to different groups of mice (n=6). Pancreatitis was induced by five injections (i.p.) of cerulein 50μg/kg body weight with 1 hr intervals. Animals were euthanized 5 hr after the last injection of cerulein and tissue injures were assessed biochemically and pathologically. Results: T. terrestris extract 200 and 400mg/kg (p.o.) and T. terrestris extract 400 mg/kg (i.p.) reduced pancreatic tissue myeloperoxidase (MPO) activity and serum amylase and lipase levels and alleviated histological parameters. Conclusion: These data suggest that T. terrestris hydro-alcoholic extract was effective in protecting against experimental acute pancreatitis and possibly the efficacy depends on dose and route of administration. PMID:28748172

Protective effect of Tribulus terrestris fruit extract on cerulein-induced acute pancreatitis in mice.

Science.gov (United States)

Borran, Mina; Minaiyan, Mohsen; Zolfaghari, Behzad; Mahzouni, Parvin

2017-01-01

Antioxidant, anti-inflammatory, analgesic and antimicrobial activities of Tribulus terrestris ( T. terrestris ) could be helpful in the treatment of acute pancreatitis; thus, this study was designed to investigate the effects of T. terrestris on cerulein-induced acute pancreatitis in mice. Three doses (100, 200 and 400 mg/kg) of T. terrestris hydro-alcoholic extract were administered both orally (60 minutes before pancreatitis induction, p.o.) and intra-peritoneally (30 minutes before pancreatitis induction, i.p.) to different groups of mice (n=6). Pancreatitis was induced by five injections (i.p.) of cerulein 50μg/kg body weight with 1 hr intervals. Animals were euthanized 5 hr after the last injection of cerulein and tissue injures were assessed biochemically and pathologically. T. terrestris extract 200 and 400mg/kg (p.o.) and T. terrestris extract 400 mg/kg (i.p.) reduced pancreatic tissue myeloperoxidase (MPO) activity and serum amylase and lipase levels and alleviated histological parameters. These data suggest that T. terrestris hydro-alcoholic extract was effective in protecting against experimental acute pancreatitis and possibly the efficacy depends on dose and route of administration.

Protective effect of Tribulus terrestris fruit extract on cerulein-induced acute pancreatitis in mice

Directory of Open Access Journals (Sweden)

Mina Borran

2017-04-01

Full Text Available Objective: Antioxidant, anti-inflammatory, analgesic and antimicrobial activities of Tribulus terrestris (T. terrestris could be helpful in the treatment of acute pancreatitis; thus, this study was designed to investigate the effects of T. terrestris on cerulein-induced acute pancreatitis in mice. Materials and Methods: Three doses (100, 200 and 400 mg/kg of T. terrestris hydro-alcoholic extract were administered both orally (60 minutes before pancreatitis induction, p.o. and intra-peritoneally (30 minutes before pancreatitis induction, i.p. to different groups of mice (n=6. Pancreatitis was induced by five injections (i.p. of cerulein 50μg/kg body weight with 1 hr intervals. Animals were euthanized 5 hr after the last injection of cerulein and tissue injures were assessed biochemically and pathologically. Results: T. terrestris extract 200 and 400mg/kg (p.o. and T. terrestris extract 400 mg/kg (i.p. reduced pancreatic tissue myeloperoxidase (MPO activity and serum amylase and lipase levels and alleviated histological parameters. Conclusion: These data suggest that T. terrestris hydro-alcoholic extract was effective in protecting against experimental acute pancreatitis and possibly the efficacy depends on dose and route of administration.

Genomics of Probiotic Bacteria

Science.gov (United States)

O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

Comparative analyses of olfactory systems in terrestrial crabs (Brachyura: evidence for aerial olfaction?

Directory of Open Access Journals (Sweden)

Jakob Krieger

2015-12-01

Full Text Available Adaptations to a terrestrial lifestyle occurred convergently multiple times during the evolution of the arthropods. This holds also true for the “true crabs” (Brachyura, a taxon that includes several lineages that invaded land independently. During an evolutionary transition from sea to land, animals have to develop a variety of physiological and anatomical adaptations to a terrestrial life style related to respiration, reproduction, development, circulation, ion and water balance. In addition, sensory systems that function in air instead of in water are essential for an animal’s life on land. Besides vision and mechanosensory systems, on land, the chemical senses have to be modified substantially in comparison to their function in water. Among arthropods, insects are the most successful ones to evolve aerial olfaction. Various aspects of terrestrial adaptation have also been analyzed in those crustacean lineages that evolved terrestrial representatives including the taxa Anomala, Brachyura, Amphipoda, and Isopoda. We are interested in how the chemical senses of terrestrial crustaceans are modified to function in air. Therefore, in this study, we analyzed the brains and more specifically the structure of the olfactory system of representatives of brachyuran crabs that display different degrees of terrestriality, from exclusively marine to mainly terrestrial. The methods we used included immunohistochemistry, detection of autofluorescence- and confocal microscopy, as well as three-dimensional reconstruction and morphometry. Our comparative approach shows that both the peripheral and central olfactory pathways are reduced in terrestrial members in comparison to their marine relatives, suggesting a limited function of their olfactory system on land. We conclude that for arthropod lineages that invaded land, evolving aerial olfaction is no trivial task.

Nitrogen-fixing methane-utilizing bacteria

NARCIS (Netherlands)

Bont, de J.A.M.

1976-01-01

Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in

Pathogenic Assay of Probiotic Bacteria Producing Proteolytic Enzymes as Bioremediation Bacteria Against Vannamei Shrimp Larvae (Litopenaeus vannamei)

OpenAIRE

Wilis Ari Setyati; Muhammad Zainuddin; Person Pesona Renta

2017-01-01

Application of bacteria in bioremediation of shrimp culture ponds is one of the methods used to clean internal pollutants. This study aimed to evaluate the pathogenicity of extracellular proteolytic enzyme produced by the probiotic bacteria as bioremediation bacteria on vannamei shrimp larvae culture. There were five probiotic bacteria, which were successfully isolated from the sediments served as substrate in mangrove area. The isolated bacteria were coded in number as 13, 19, 30, 33, and 36...

Radio Astronomy Explorer (RAE) 1 observations of terrestrial radio noise

Science.gov (United States)

Herman, J. R.; Caruso, J. A.

1971-01-01

Radio Astonomy Explorer (RAE) 1 data are analyzed to establish characteristics of HF terrestrial radio noise at an altitude of about 6000 km. Time and frequency variations in amplitude of the observed noise well above cosmic noise background are explained on the basis of temporal and spatial variations in ionospheric critical frequency coupled with those in noise source distributions. It is shown that terrestrial noise regularly breaks through the ionosphere and reaches RAE with magnitudes 15 or more db higher than cosmic noise background. Maximum terrestrial noise is observed when RAE is over the dark side of the Earth in the neighborhood of equatorial continental land masses where thunderstorms occur most frequently. The observed noise level is 30-40 db lower with RAE over oceans.

Earth as a radio source: terrestrial kilometric radiation. Progress report

International Nuclear Information System (INIS)

Gurnett, D.A.

1974-02-01

Radio wave experiments on the IMP-6 and 8 satellites have shown that the earth emits very intense electromagnetic radiation in the frequency range from about 50 kHz to 500 kHz. A peak intensity the total power emitted in this frequency range is about 1 billion watts. The earth is, therefore, a very intense planetary radio source, with a total power output comparable to the decametric radio emission from Jupiter. This radio emission from the earth is referred to as terrestrial kilometric radiation. Terrestrial kilometric radiation appears to originate from low altitudes (less than 3.0 Re) in the auroral region. Possible mechanisms which can explain the generation and propagation of the terrestrial kilometric radiation are discussed. (U.S.)

An Overview on Marine Sponge-Symbiotic Bacteria as Unexhausted Sources for Natural Product Discovery

Directory of Open Access Journals (Sweden)

Candice M. Brinkmann

2017-09-01

Full Text Available Microbial symbiotic communities of marine macro-organisms carry functional metabolic profiles different to the ones found terrestrially and within surrounding marine environments. These symbiotic bacteria have increasingly been a focus of microbiologists working in marine environments due to a wide array of reported bioactive compounds of therapeutic importance resulting in various patent registrations. Revelations of symbiont-directed host specific functions and the true nature of host-symbiont interactions, combined with metagenomic advances detecting functional gene clusters, will inevitably open new avenues for identification and discovery of novel bioactive compounds of biotechnological value from marine resources. This review article provides an overview on bioactive marine symbiotic organisms with specific emphasis placed on the sponge-associated ones and invites the international scientific community to contribute towards establishment of in-depth information of the environmental parameters defining selection and acquisition of true symbionts by the host organisms.

Cadmium resistance of endophytic bacteria and rizosféricas bacteria isolated from Oriza sativa in Colombia

Directory of Open Access Journals (Sweden)

Nataly Ayubb T

2017-12-01

Full Text Available The present study had as objective to evaluate in vitro the resistance of endophytic bacteria and rizospheric bacteria to different concentrations of Cadmium.This bacteria were isolated fron different tissues of commercial rice varieties and from bacteria isolated from the rhizosphere in rice plantations of the Nechí (Antioquía and Achí (Bolivar.  Plant growth promotion was evaluated in vitro by nitrogen fixation, phosphate solubilization and siderophores production of endophytic bacteria. Of each tissue isolated from rice plants was carried out isolation in culture medium for endophytic bacteria, and the soil samples were serially diluted in peptone water. Each sample was determined the population density by counting in CFU / g of tissue and morphotypes were separated by shape, color, size and appearance in culture media. Significant differences were observed for density population of bacteria with respect to tissue, with higher values in root (4x1011 g/root, followed of the stem (3x1010g/etem, leaf (5x109 g/ leaf, flag leaf (3x109 g/ flag leaf and with less density in panicle (4x108 g/panicle. The results of the identification with kit API were confirmed the presence of endophytic bacteria Burkholderia cepaceae and rizospheric bacteria Pseudomona fluorescens With the ability to tolerate different concentrations of Cd, fix nitrogen, solubilize phosphates and produce siderophores.

Modeling Carbon Turnover in Five Terrestrial Ecosystems in the Boreal Zone Using Multiple Criteria of Acceptance

International Nuclear Information System (INIS)

Karlberg, Louise; Gustafsson, David; Jansson, Per-Erik

2006-01-01

Estimates of carbon fluxes and turnover in ecosystems are key elements in the understanding of climate change and in predicting the accumulation of trace elements in the biosphere. In this paper we present estimates of carbon fluxes and turnover times for five terrestrial ecosystems using a modeling approach. Multiple criteria of acceptance were used to parameterize the model, thus incorporating large amounts of multi-faceted empirical data in the simulations in a standardized manner. Mean turnover times of carbon were found to be rather similar between systems with a few exceptions, even though the size of both the pools and the fluxes varied substantially. Depending on the route of the carbon through the ecosystem, turnover times varied from less than one year to more than one hundred, which may be of importance when considering trace element transport and retention. The parameterization method was useful both in the estimation of unknown parameters, and to identify variability in carbon turnover in the selected ecosystems

Mitigation of greenhouse gases emissions impact and their influence on terrestrial ecosystem.

Science.gov (United States)

Wójcik Oliveira, K.; Niedbała, G.

2018-05-01

Nowadays, one of the most important challenges faced by the humanity in the current century is the increasing temperature on Earth, caused by a growing emission of greenhouse gases into the atmosphere. Terrestrial ecosystems, as an important component of the carbon cycle, play an important role in the sequestration of carbon, which is a chance to improve the balance of greenhouse gases. Increasing CO2 absorption by terrestrial ecosystems is one way to reduce the atmospheric CO2 emissions. Sequestration of CO2 by terrestrial ecosystems is not yet fully utilized method of mitigating CO2 emission to the atmosphere. Terrestrial ecosystems, especially forests, are essential for the regulation of CO2 content in the atmosphere and more attention should be paid to seeking the natural processes of CO2 sequestration.

Synthesis of UDP-apiose in Bacteria: The marine phototroph Geminicoccus roseus and the plant pathogen Xanthomonas pisi.

Directory of Open Access Journals (Sweden)

James Amor Smith

Full Text Available The branched-chain sugar apiose was widely assumed to be synthesized only by plant species. In plants, apiose-containing polysaccharides are found in vascularized plant cell walls as the pectic polymers rhamnogalacturonan II and apiogalacturonan. Apiosylated secondary metabolites are also common in many plant species including ancestral avascular bryophytes and green algae. Apiosyl-residues have not been documented in bacteria. In a screen for new bacterial glycan structures, we detected small amounts of apiose in methanolic extracts of the aerobic phototroph Geminicoccus roseus and the pathogenic soil-dwelling bacteria Xanthomonas pisi. Apiose was also present in the cell pellet of X. pisi. Examination of these bacterial genomes uncovered genes with relatively low protein homology to plant UDP-apiose/UDP-xylose synthase (UAS. Phylogenetic analysis revealed that these bacterial UAS-like homologs belong in a clade distinct to UAS and separated from other nucleotide sugar biosynthetic enzymes. Recombinant expression of three bacterial UAS-like proteins demonstrates that they actively convert UDP-glucuronic acid to UDP-apiose and UDP-xylose. Both UDP-apiose and UDP-xylose were detectable in cell cultures of G. roseus and X. pisi. We could not, however, definitively identify the apiosides made by these bacteria, but the detection of apiosides coupled with the in vivo transcription of bUAS and production of UDP-apiose clearly demonstrate that these microbes have evolved the ability to incorporate apiose into glycans during their lifecycles. While this is the first report to describe enzymes for the formation of activated apiose in bacteria, the advantage of synthesizing apiose-containing glycans in bacteria remains unknown. The characteristics of bUAS and its products are discussed.

Medicinal properties, phytochemistry and pharmacology of tribulus terrestris l. (zygophyllaceae)

International Nuclear Information System (INIS)

Hashim, S.; Bakht, T.

2014-01-01

Tribulus terrestris (puncture vine) belongs to family Zygophyllaceae and it is a herbaceous, mat forming plant in nature. It extensively grows in warm dry tropics all over the world and ecologically adaptated as a typical C4 xeromorphic plant. T. terrestris is a noxious weed along with its use in many countries as a folk medicine for different purposes from time immemorial. Ancient records describe various medicinal properties of T. terrestris as a popular source to cure variety of different disease conditions in China, India, and Greece. The plant is used directly as a herb or as a main component for production of a number of medicines and food supplements such as for physical rejuvenation, therapy for the conditions affecting liver, kidney, cardiovascular system and immune systems. Also it is used as a folk medicine for increased muscle strength, sexual potency and in treatments of urinary infections, heart diseases and cough. It is considered invigorating stimulant, aphrodisiac, and nutritive. This review discusses the most commonly recognized medicinal properties of this herb. The chemistry of T. terrestris extracts to establish the relationship between medicinal properties of this important plant will also be reviewed. (author)

Spiral arms, comets and terrestrial catastrophism

International Nuclear Information System (INIS)

Clube, S.V.M.; Napier, W.M.

1982-01-01

A review is presented of an hypothesis of terrestrial catastrophism in which comets grow in molecular clouds and are captured by the Sun as it passes through the spiral arms of the Galaxy. Assuming that comets are a major supplier of the Earth-crossing (Appollo) asteroid population, the latter fluctuates correspondingly and leads to episodes of terrestrial bombardment. Changes in the rotational momentum of core and mantle, generated by impacts, lead to episodes of magnetic field reversal and tectonic activity, while surface phenomena lead to ice-ages and mass extinctions. An episodic geophysical history with an interstellar connection is thus implied. If comets in spiral arms are necessary intermediaries in the process of star formation, the theory also has implications relating to early solar system history and galactic chemistry. These aspects are briefly discussed with special reference to the nature of spiral arms. (author)

Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light

Science.gov (United States)

Vincent, Robert (Inventor)

2013-01-01

The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

Terrestrial gamma radiation baseline mapping using ultra low density sampling methods.

Science.gov (United States)

Kleinschmidt, R; Watson, D

2016-01-01

Baseline terrestrial gamma radiation maps are indispensable for providing basic reference information that may be used in assessing the impact of a radiation related incident, performing epidemiological studies, remediating land contaminated with radioactive materials, assessment of land use applications and resource prospectivity. For a large land mass, such as Queensland, Australia (over 1.7 million km(2)), it is prohibitively expensive and practically difficult to undertake detailed in-situ radiometric surveys of this scale. It is proposed that an existing, ultra-low density sampling program already undertaken for the purpose of a nationwide soil survey project be utilised to develop a baseline terrestrial gamma radiation map. Geoelement data derived from the National Geochemistry Survey of Australia (NGSA) was used to construct a baseline terrestrial gamma air kerma rate map, delineated by major drainage catchments, for Queensland. Three drainage catchments (sampled at the catchment outlet) spanning low, medium and high radioelement concentrations were selected for validation of the methodology using radiometric techniques including in-situ measurements and soil sampling for high resolution gamma spectrometry, and comparative non-radiometric analysis. A Queensland mean terrestrial air kerma rate, as calculated from the NGSA outlet sediment uranium, thorium and potassium concentrations, of 49 ± 69 nGy h(-1) (n = 311, 3σ 99% confidence level) is proposed as being suitable for use as a generic terrestrial air kerma rate background range. Validation results indicate that catchment outlet measurements are representative of the range of results obtained across the catchment and that the NGSA geoelement data is suitable for calculation and mapping of terrestrial air kerma rate. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Motility of electric cable bacteria

DEFF Research Database (Denmark)

Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

2016-01-01

Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

Efficacy of Tribulus Terrestris Extract on the Serum Glucose and Lipids of Women with Diabetes Mellitus.

Science.gov (United States)

Samani, Nasrin Babadai; Jokar, Azam; Soveid, Mahmood; Heydari, Mojtaba; Mosavat, Seyed Hamdollah

2016-05-01

Considering folkloric use of Tribulus terrestris (T. terrestris) in diabetes and proven anti-hyperglycemic and anti-hyperlipidemic effects of T. terrestris in animal studies, we aimed to evaluate the efficacy of the hydro alcoholic extract of T. terrestris on the serum glucose and lipid profile of women with diabetes mellitus. Ninety-eight diabetic women were randomly allocated to receive the T. terrestris (1000 mg/day) or placebo for three months. The patients were evaluated in terms of the fasting blood glucose, 2-hour postprandial glucose, glycosylated hemoglobin and lipid profile. T. terrestris showed a significant blood glucose lowering effect in diabetic women compared to placebo (Pterrestris group was significantly reduced compared with placebo, while no significant effect was observed in the triglyceride and high-density lipoprotein levels. This study showed preliminary promising hypoglycemic effect of T. terrestris in diabetic women.

The circumpolar biodiversity monitoring program - Terrestrial plan

DEFF Research Database (Denmark)

Christensen, Tom; Payne, J.; Doyle, M.

, northern communities, and scientists to detect, understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity. This presentation will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based...... monitoring with survey-based monitoring and remotely sensed data. The CBMP Terrestrial Plan intends to build upon and expand existing monitoring networks, engaging participants across a range of capacity and interests. The presentation will summarize the recommended focal soil ecosystem components...... and attributes to monitor in the plan related to soil invertebrates. Focal Ecosystem Components (FECs) of the soil decomposer system include the soil living invertebrates such as microarthropods, enchytraeids and earthworms and the functions performed by microorganisms such as nitrification, decomposition...

Fermentation of D-Tagatose by Human Intestinal Bacteria and Dairy Lactic Acid Bacteria

OpenAIRE

Bertelsen, Hans; Andersen, Hans; Tvede, Michael

2011-01-01

A number of 174 normal or pathogenic human enteric bacteria and dairy lactic acid bacteria were screened for D-tagatose fermentation by incubation for 48 hours. Selection criteria for fermentation employed included a drop in pH below 5.5 and a distance to controls of more than 0.5. Only a few of the normal occurring enteric human bacteria were able to ferment D-tagatose, among those Enterococcus faecalis, Enterococcus faecium and Lactobacillus strains. D-Tagatose fermentation seems to be comm...

METHODS FOR DETECTING BACTERIA USING POLYMER MATERIALS

NARCIS (Netherlands)

Van Grinsven Bart Robert, Nicolaas; Cleij, Thomas

2017-01-01

A method for characterizing bacteria includes passing a liquid containing an analyte comprising a first bacteria and a second bacteria over and in contact with a polymer material on a substrate. The polymer material is formulated to bind to the first bacteria, and the first bacteria binds to the

Excess 129Xe in terrestrial samples: A non-primordial hypothesis

International Nuclear Information System (INIS)

Caffee, M.W.; Hudson, G.B.

1987-03-01

Excesses of 129 Xe relative to the isotopic composition in air are observed in some terrestrial samples. Traditionally these 129 Xe excesses have been thought to be related to 129 I that was present in abundance in the early solar system. We propose an alternative hypothesis to explain terrestrial 129 Xe excesses based on the production of 129 I from the spontaneous fission of 238 U

Quantum jointly assisted cloning of an unknown three-dimensional equatorial state

Science.gov (United States)

Ma, Peng-Cheng; Chen, Gui-Bin; Li, Xiao-Wei; Zhan, You-Bang

2018-02-01

We present two schemes for perfectly cloning an unknown single-qutrit equatorial state with assistance from two and N state preparers, respectively. In the first scheme, the sender wishes to teleport an unknown single-qutrit equatorial state from two state preparers to a remote receiver, and then to create a perfect copy of the unknown state at her location. The scheme consists of two stages. The first stage of the scheme requires the usual teleportation. In the second stage, to help the sender realize the quantum cloning, two state preparers perform single-qutrit projective measurements on their own qutrits from the sender, then the sender can acquire a perfect copy of the unknown state. It is shown that, only if the two state preparers collaborate with each other, the sender can create a copy of the unknown state by means of some appropriate unitary operations. In the second scheme, we generalized the jointly assisted cloning in the first scheme to the case of N state prepares. In the present schemes, the total probability of success for assisted cloning of a perfect copy of the unknown state can reach 1.

Asymmetrical Damage Partitioning in Bacteria: A Model for the Evolution of Stochasticity, Determinism, and Genetic Assimilation.

Science.gov (United States)

Chao, Lin; Rang, Camilla Ulla; Proenca, Audrey Menegaz; Chao, Jasper Ubirajara

2016-01-01

Non-genetic phenotypic variation is common in biological organisms. The variation is potentially beneficial if the environment is changing. If the benefit is large, selection can favor the evolution of genetic assimilation, the process by which the expression of a trait is transferred from environmental to genetic control. Genetic assimilation is an important evolutionary transition, but it is poorly understood because the fitness costs and benefits of variation are often unknown. Here we show that the partitioning of damage by a mother bacterium to its two daughters can evolve through genetic assimilation. Bacterial phenotypes are also highly variable. Because gene-regulating elements can have low copy numbers, the variation is attributed to stochastic sampling. Extant Escherichia coli partition asymmetrically and deterministically more damage to the old daughter, the one receiving the mother's old pole. By modeling in silico damage partitioning in a population, we show that deterministic asymmetry is advantageous because it increases fitness variance and hence the efficiency of natural selection. However, we find that symmetrical but stochastic partitioning can be similarly beneficial. To examine why bacteria evolved deterministic asymmetry, we modeled the effect of damage anchored to the mother's old pole. While anchored damage strengthens selection for asymmetry by creating additional fitness variance, it has the opposite effect on symmetry. The difference results because anchored damage reinforces the polarization of partitioning in asymmetric bacteria. In symmetric bacteria, it dilutes the polarization. Thus, stochasticity alone may have protected early bacteria from damage, but deterministic asymmetry has evolved to be equally important in extant bacteria. We estimate that 47% of damage partitioning is deterministic in E. coli. We suggest that the evolution of deterministic asymmetry from stochasticity offers an example of Waddington's genetic assimilation

Biodiversity of polycyclic aromatic hydrocarbon-degrading bacteria from deep sea sediments of the Middle Atlantic Ridge.

Science.gov (United States)

Cui, Zhisong; Lai, Qiliang; Dong, Chunming; Shao, Zongze

2008-08-01

The bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in deep sea subsurface environments are largely unknown. In order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the Middle Atlantic Ridge with a gravity column sampler. The sediments were promptly enriched with either crude oil or a mixture of PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched with the PAH mixture mentioned above in the lab. The resulting consortia were named C2CO and C2PPN respectively. Their bacterial composition was analysed with plate cultivation, PCR-DGGE and 16S rDNA library analysis. On plates, isolates belonging to Pseudoalteromonas, Halomonas, Marinobacter, Thalassospira and Tistrella dominated the culturable populations. With PCR-DGGE, five major bands closely related to Cycloclasticus, Alteromonas, Thalassospira, Alcanivorax and Rhodospirillaceae were detected in consortium C2CO, while only one major band of Cycloclasticus was detected in consortium C2PPN. In addition, the dynamics of community structure in response to aromatic substrate alterations were examined. As a result, three ribotypes of Cycloclasticus were detected by 16S rDNA library analysis, one which played a key role in phenanthrene degradation; two Alteromonas bacteria dominated the naphthalene reselected consortium. Although bacteria of the two genera grew as the main members of the communities, none of them were isolated, probably owing to their poor cultivability. These results confirm that bacteria of Cycloclasticus are important obligate PAH degraders in marine environments, and coexist with other degrading bacteria that inhabit the deep subsurface sediment of the Atlantic. This supports the view that PAH accumulation and bioattenuation occur in remote areas consistently and continuously.

Asymmetrical Damage Partitioning in Bacteria: A Model for the Evolution of Stochasticity, Determinism, and Genetic Assimilation.

Directory of Open Access Journals (Sweden)

Lin Chao

2016-01-01

Full Text Available Non-genetic phenotypic variation is common in biological organisms. The variation is potentially beneficial if the environment is changing. If the benefit is large, selection can favor the evolution of genetic assimilation, the process by which the expression of a trait is transferred from environmental to genetic control. Genetic assimilation is an important evolutionary transition, but it is poorly understood because the fitness costs and benefits of variation are often unknown. Here we show that the partitioning of damage by a mother bacterium to its two daughters can evolve through genetic assimilation. Bacterial phenotypes are also highly variable. Because gene-regulating elements can have low copy numbers, the variation is attributed to stochastic sampling. Extant Escherichia coli partition asymmetrically and deterministically more damage to the old daughter, the one receiving the mother's old pole. By modeling in silico damage partitioning in a population, we show that deterministic asymmetry is advantageous because it increases fitness variance and hence the efficiency of natural selection. However, we find that symmetrical but stochastic partitioning can be similarly beneficial. To examine why bacteria evolved deterministic asymmetry, we modeled the effect of damage anchored to the mother's old pole. While anchored damage strengthens selection for asymmetry by creating additional fitness variance, it has the opposite effect on symmetry. The difference results because anchored damage reinforces the polarization of partitioning in asymmetric bacteria. In symmetric bacteria, it dilutes the polarization. Thus, stochasticity alone may have protected early bacteria from damage, but deterministic asymmetry has evolved to be equally important in extant bacteria. We estimate that 47% of damage partitioning is deterministic in E. coli. We suggest that the evolution of deterministic asymmetry from stochasticity offers an example of Waddington

Oasis desert farming selects environment-specific date palm root endophytic communities and cultivable bacteria that promote resistance to drought

KAUST Repository

Cherif, Hanene; Marasco, Ramona; Rolli, Eleonora; Ferjani, Raoudha; Fusi, Marco; Soussi, Asma; Mapelli, Francesca; Blilou, Ikram; Borin, Sara; Boudabous, Abdellatif; Cherif, Ameur; Daffonchio, Daniele; Ouzari, Hadda

2015-01-01

Oases are desert-farming agro-ecosystems, where date palm (Phoenix dactyliferaL.) plays a keystone role in offsetting the effects of drought and maintaining a suitable microclimate for agriculture. At present, abundance, diversity and plant growth promotion (PGP) of date palm root-associated bacteria remain unknown. Considering the environmental pressure determined by the water scarcity in the desert environments, we hypothesized that bacteria associated with date palm roots improve plant resistance to drought. Here, the ecology of date palm root endophytes from oases in the Tunisian Sahara was studied with emphasis on their capacity to promote growth under drought. Endophytic communities segregated along a north-south gradient in correlation with geo-climatic parameters. Screening of 120 endophytes indicated that date palm roots select for bacteria with multiple PGP traits. Bacteria rapidly cross-colonized the root tissues of different species of plants, including the original Tunisian date palm cultivar, Saudi Arabian cultivars and Arabidopsis. Selected endophytes significantly increased the biomass of date palms exposed to repeated drought stress periods during a 9-month greenhouse experiment. Overall, results indicate that date palm roots shape endophytic communities that are capable to promote plant growth under drought conditions, thereby contributing an essential ecological service to the entire oasis ecosystem. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Oasis desert farming selects environment-specific date palm root endophytic communities and cultivable bacteria that promote resistance to drought

KAUST Repository

Cherif, Hanene

2015-07-21

Oases are desert-farming agro-ecosystems, where date palm (Phoenix dactyliferaL.) plays a keystone role in offsetting the effects of drought and maintaining a suitable microclimate for agriculture. At present, abundance, diversity and plant growth promotion (PGP) of date palm root-associated bacteria remain unknown. Considering the environmental pressure determined by the water scarcity in the desert environments, we hypothesized that bacteria associated with date palm roots improve plant resistance to drought. Here, the ecology of date palm root endophytes from oases in the Tunisian Sahara was studied with emphasis on their capacity to promote growth under drought. Endophytic communities segregated along a north-south gradient in correlation with geo-climatic parameters. Screening of 120 endophytes indicated that date palm roots select for bacteria with multiple PGP traits. Bacteria rapidly cross-colonized the root tissues of different species of plants, including the original Tunisian date palm cultivar, Saudi Arabian cultivars and Arabidopsis. Selected endophytes significantly increased the biomass of date palms exposed to repeated drought stress periods during a 9-month greenhouse experiment. Overall, results indicate that date palm roots shape endophytic communities that are capable to promote plant growth under drought conditions, thereby contributing an essential ecological service to the entire oasis ecosystem. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Forest inventory with terrestrial LiDAR

NARCIS (Netherlands)

Bauwens, Sébastien; Bartholomeus, Harm; Calders, Kim; Lejeune, Philippe

2016-01-01

The application of static terrestrial laser scanning (TLS) in forest inventories is becoming more effective. Nevertheless, the occlusion effect is still limiting the processing efficiency to extract forest attributes. The use of a mobile laser scanner (MLS) would reduce this occlusion. In this

The solar generation childhood and adolescence of terrestrial photovoltaics

CERN Document Server

Wolfe, Philip R

2018-01-01

The first book to address the early development of the photovoltaic industry, and the pioneering researchers and companies in the sector. Well before the end of this century, solar power will be the world's dominant power source. This book looks at the origins of this smart sustainable energy technology, tracing the pioneering years from its inception following the 1973 oil crisis to the end of the last millennium—just as the sector was poised for explosive growth. It focuses on the progress of the early terrestrial photovoltaic sector, often in the face of skepticism or apathy. It also covers the research and achievements of people and organizations within the PV business. Written by a leader in the field with more than 40 years of experience and an international reputation in the sustainable energy industry, The Solar Generation: Childhood and Adolescence of Terrestrial Photovoltaics offers enlightening coverage on the terrestrial PV industry. The first part of this 3-volume set provides a historical bac...

Microalgal and Terrestrial Transport Biofuels to Displace Fossil Fuels

Directory of Open Access Journals (Sweden)

Lucas Reijnders

2009-02-01

Full Text Available Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn, sugar beet or wheat and biodiesel from rapeseed. When terrestrial biofuels are to replace mineral oil-derived transport fuels, large areas of good agricultural land are needed: about 5x108 ha in the case of biofuels from sugarcane or oil palm, and at least 1.8-3.6x109 ha in the case of ethanol from wheat, corn or sugar beet, as produced in industrialized countries. Biofuels from microalgae which are commercially produced with current technologies do not appear to outperform terrestrial plants such as sugarcane in their ability to displace fossil fuels. Whether they will able to do so on a commercial scale in the future, is uncertain.

A terrestrial ecosystem model (SOLVEG) coupled with atmospheric gas and aerosol exchange processes

International Nuclear Information System (INIS)

Katata, Genki; Ota, Masakazu

2017-01-01

In order to predict the impact of atmospheric pollutants (gases and aerosols) to the terrestrial ecosystem, new schemes for calculating the processes of dry deposition of gases and aerosols, and water and carbon cycles in terrestrial ecosystems were implemented in the one-dimensional atmosphere-SOiL-VEGetation model, SOLVEG. We made performance tests at various vegetation areas to validate the newly developed schemes. In this report, the detail in each modeled process is described with an instruction how to use the modified SOLVEG. The framework of 'terrestrial ecosystem model' was developed for investigation of a change in water, energy, and carbon cycles associated with global warming and air pollution and its impact on terrestrial ecosystems. (author)

[Feasibility study for whole plant medicinal use of Tribulus terrestris].

Science.gov (United States)

Yang, Li; Wang, Chunyu; Han, Meiw; Yang, Limin

2009-09-01

The content differences of leaf, plant and fruit of Tribulus terrestris was compared to study the feasibility of whole plant medicinal use. The samples were collected in three typical habitats and six different production areas of T. terrestris. The main medicinal ingredients saponins and flavonoids were determined in root, stem, leaf and fruit during the harvest time. The two ingredients were abounded in leaf and more than 2.61 times as in other parts of the plant. The results showed that there were no differences between the whole plant and the fruit. It should pay more attentions on the collection, preservation and utilization of the leaf of T. terrestris in the harvesting and processing stage. The whole plant for medical use was feasibility based on the content of the ingredients.

Soft Legged Wheel-Based Robot with Terrestrial Locomotion Abilities

Directory of Open Access Journals (Sweden)

Ali Sadeghi

2016-12-01

Full Text Available In recent years robotics has been influenced by a new approach, soft-robotics, bringing the idea that safe interaction with user and more adaptation to the environment can be achieved by exploiting easily deformable materials and flexible components in the structure of robots. In 2016, the soft-robotics community has promoted a new robotics challenge, named RoboSoft Grand Challenge, with the aim of bringing together different opinions on the usefulness and applicability of softness and compliancy in robotics. In this paper we describe the design and implementation of a terrestrial robot based on two soft legged wheels. The tasks predefined by the challenge were set as targets in the robot design, which finally succeeded to accomplish all the tasks. The wheels of the robot can passively climb over stairs and adapt to slippery grounds using two soft legs embedded in their structure. The soft legs, fabricated by integration of soft and rigid materials and mounted on the circumference of a conventional wheel, succeed to enhance its functionality and easily adapt to unknown grounds. The robot has a semi stiff tail that helps in the stabilization and climbing of stairs. An active wheel is embedded at the extremity of the tail in order to increase the robot maneuverability in narrow environments. Moreover two parallelogram linkages let the robot to reconfigure and shrink its size allowing entering inside gates smaller than its initial dimensions.

Sulfur metabolism in phototrophic sulfur bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Dahl, Christiane

2008-01-01

Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

Iterative Selection of Unknown Weights in Direct Weight Optimization Identification

Directory of Open Access Journals (Sweden)

Xiao Xuan

2014-01-01

Full Text Available To the direct weight optimization identification of the nonlinear system, we add some linear terms about input sequences in the former linear affine function so as to approximate the nonlinear property. To choose the two classes of unknown weights in the more linear terms, this paper derives the detailed process on how to choose these unknown weights from theoretical analysis and engineering practice, respectively, and makes sure of their key roles between the unknown weights. From the theoretical analysis, the added unknown weights’ auxiliary role can be known in the whole process of approximating the nonlinear system. From the practical analysis, we learn how to transform one complex optimization problem to its corresponding common quadratic program problem. Then, the common quadratic program problem can be solved by the basic interior point method. Finally, the efficiency and possibility of the proposed strategies can be confirmed by the simulation results.

Efficacy of Tribulus Terrestris Extract on the Serum Glucose and Lipids of Women with Diabetes Mellitus

Science.gov (United States)

Samani, Nasrin Babadai; Jokar, Azam; Soveid, Mahmood; Heydari, Mojtaba; Mosavat, Seyed Hamdollah

2016-01-01

Background: Considering folkloric use of Tribulus terrestris (T. terrestris) in diabetes and proven anti-hyperglycemic and anti-hyperlipidemic effects of T. terrestris in animal studies, we aimed to evaluate the efficacy of the hydro alcoholic extract of T. terrestris on the serum glucose and lipid profile of women with diabetes mellitus. Methods: Ninety-eight diabetic women were randomly allocated to receive the T. terrestris (1000 mg/day) or placebo for three months. The patients were evaluated in terms of the fasting blood glucose, 2-hour postprandial glucose, glycosylated hemoglobin and lipid profile. Results: T. terrestris showed a significant blood glucose lowering effect in diabetic women compared to placebo (Pterrestris group was significantly reduced compared with placebo, while no significant effect was observed in the triglyceride and high-density lipoprotein levels. Conclusion: This study showed preliminary promising hypoglycemic effect of T. terrestris in diabetic women. PMID:27840471

[Antibiotic resistance--an ambivalence of attitudes. As of now, the bacteria are in advantage].

Science.gov (United States)

Sköld, O

1995-09-13

The value of the precious medical asset that antibiotics constitute is contimualby being eroded by the spread of resistance. For some time that bacterial world has been adapting itself to contend with the toxic assault of man-made poisons, antibiotics, by developing resistance in a very rapid process of evolutionary changes occurring before our very eyes. This evolutionary adaptation is an example of natural genetic engineering entailing an interchange between bacteria of genes conferring antibiotic resistance. Trimethoprim resistance is an example where numerous genes of unknown origin (some closely interrelated), expressing drug-resistant dihydrofolate reductases, move among human commensals and pathogens. They have been shown to move as gene cassettes in and out of the recently characterised integron structure occurring in many pathogens. They are also carried by various transposons such as Tn7, or Tn5393 originally observed in a plant pathogen, Erwinia amylovora. Betalactam resistance is another example of natural genetic engineering, where new betalactamases are continually emerging, and individual enzyme substrate specificity is modified by point mutation. At present, betalactamase mutants resistant to all commercially available betalactams, including clavulanic acid used in combination with betalactam antibiotics, are to be found in clinical isolates. Thus, currently bacteria seem to be triumphing in the running battle between the pharmaceutical industry and the bacterial world, the former introducing one new antibiotic variant after another, to which bacteria promptly develop resistance by manipulating their own genomes.

Terrestrial contributions to the aquatic food web in the middle Yangtze River.

Directory of Open Access Journals (Sweden)

Jianzhu Wang

Full Text Available Understanding the carbon sources supporting aquatic consumers in large rivers is essential for the protection of ecological integrity and for wildlife management. The relative importance of terrestrial and algal carbon to the aquatic food webs is still under intensive debate. The Yangtze River is the largest river in China and the third longest river in the world. The completion of the Three Gorges Dam (TGD in 2003 has significantly altered the hydrological regime of the middle Yangtze River, but its immediate impact on carbon sources supporting the river food web is unknown. In this study, potential production sources from riparian and the main river channel, and selected aquatic consumers (invertebrates and fish at an upstream constricted-channel site (Luoqi, a midstream estuarine site (Huanghua and a near dam limnetic site (Maoping of the TGD were collected for stable isotope (δ13C and δ15N and IsoSource analyses. Model estimates indicated that terrestrial plants were the dominant carbon sources supporting the consumer taxa at the three study sites. Algal production appeared to play a supplemental role in supporting consumer production. The contribution from C4 plants was more important than that of C3 plants at the upstream site while C3 plants were the more important carbon source to the consumers at the two impacted sites (Huanghua and Maoping, particularly at the midstream site. There was no trend of increase in the contribution of autochthonous production from the upstream to the downstream sites as the flow rate decreased dramatically along the main river channel due to the construction of TGD. Our findings, along with recent studies in rivers and lakes, are contradictory to studies that demonstrate the importance of algal carbon in the aquatic food web. Differences in system geomorphology, hydrology, habitat heterogeneity, and land use may account for these contradictory findings reported in various studies.

A meteorological distribution system for high-resolution terrestrial modeling (MicroMet)

Science.gov (United States)

Glen E. Liston; Kelly Elder

2006-01-01

An intermediate-complexity, quasi-physically based, meteorological model (MicroMet) has been developed to produce high-resolution (e.g., 30-m to 1-km horizontal grid increment) atmospheric forcings required to run spatially distributed terrestrial models over a wide variety of landscapes. The following eight variables, required to run most terrestrial models, are...

Sustained periodic terrestrial locomotion in air-breathing fishes.

Science.gov (United States)

Pace, C M; Gibb, A C

2014-03-01

While emergent behaviours have long been reported for air-breathing osteichthyians, only recently have researchers undertaken quantitative analyses of terrestrial locomotion. This review summarizes studies of sustained periodic terrestrial movements by air-breathing fishes and quantifies the contributions of the paired appendages and the axial body to forward propulsion. Elongate fishes with axial-based locomotion, e.g. the ropefish Erpetoichthys calabaricus, generate an anterior-to-posterior wave of undulation that travels down the axial musculoskeletal system and pushes the body against the substratum at multiple points. In contrast, appendage-based locomotors, e.g. the barred mudskipper Periophthalmus argentilineatus, produce no axial bending during sustained locomotion, but instead use repeated protraction-retraction cycles of the pectoral fins to elevate the centre of mass and propel the entire body anteriorly. Fishes that use an axial-appendage-based mechanism, e.g. walking catfishes Clarias spp., produce side-to-side, whole-body bending in co-ordination with protraction-retraction cycles of the pectoral fins. Once the body is maximally bent to one side, the tail is pressed against the substratum and drawn back through the mid-sagittal plane, which elevates the centre of mass and rotates it about a fulcrum formed by the pectoral fin and the ground. Although appendage-based terrestrial locomotion appears to be rare in osteichthyians, many different species appear to have converged upon functionally similar axial-based and axial-appendage-based movements. Based on common forms observed across divergent taxa, it appears that dorsoventral compression of the body, elongation of the axial skeleton or the presence of robust pectoral fins can facilitate effective terrestrial movement by air-breathing fishes. © 2014 The Fisheries Society of the British Isles.

Substrate attributes determine gait in a terrestrial gastropod.

Science.gov (United States)

McKee, Amberle; Voltzow, Janice; Pernet, Bruno

2013-02-01

Some terrestrial gastropods are able to move using two gaits: adhesive crawling, where the entire foot is separated from the substrate only by a thin layer of mucus and the snail leaves a continuous mucus trail; and loping, where regions of the foot arch above the substrate and the snail leaves a discontinuous mucus trail. Loping has been interpreted as a means of rapidly escaping predators. We found that the pulmonate Cornu aspersum moved using adhesive crawling on dry acrylic or glass substrates, but loped on dry concrete or wood. Loping snails did not move more rapidly than snails using adhesive crawling. Snails moving on concrete secreted a greater volume of pedal mucus per area of trail than those moving on acrylic; locomotion on concrete thus requires greater expenditure of mucus than does locomotion on acrylic. Because loping snails deposit a smaller area of mucus per distance traveled than do snails using adhesive crawling, loping may conserve mucus when moving on porous, absorbent substrates. Members of several other terrestrial pulmonate taxa can also lope on concrete, suggesting that this plasticity in gait is widespread among terrestrial snails.

Terrestrial ecosystems: an ecological content for radionuclide research

International Nuclear Information System (INIS)

Heal, O.W.; Horrill, A.D.

1983-01-01

The distribution and retention of radionuclides within terrestrial ecosystems varies greatly with both the radionuclide and the environmental conditions. Physico-chemical conditions, particularly those of the soil, strongly influence element retention but superimposed and interacting with these conditions are the biological processes which control the dynamics of the labile fraction of most elements. Net ecosystem production expresses the complementary biological processes of primary production and decomposition which control the internal element dynamics and the balance of inputs to and outputs from terrestrial ecosystems. Analysis of ecosystem structure and function has shown that although research often concentrates on relatively stable stages of ecosystem development, element retention is high during the early stages of ecosystem succession through the accumulation of plant biomass and dead organic matter. Element output tends to increase with time reaching a balance with inputs in mature ecosystems. Following disturbance, plant uptake tends to be reduced and decomposition stimulated, resulting in increased output until secondary succession and accumulation is re-established. Research on element dynamics in ecosystems indicates that major factors influencing the mobility of radionuclides in terrestrial systems will be the successional state of the ecosystem and intensity of disturbance. (author)

Isolation and Presumptive Identification of Adherent Epithelial Bacteria (“Epimural” Bacteria) from the Ovine Rumen Wall

OpenAIRE

Mead, Lorna J.; Jones, G. A.

1981-01-01

One hundred sixty-one strains of adherent bacteria were isolated under anaerobic conditions from four sites on the rumen epithelial surface of sheep fed hay or a hay-grain ration. Before isolation of bacteria, rumen tissue was washed six times in an anaerobic dilution solution, and viable bacteria suspended in the washings were counted. Calculation indicated that unattached bacteria would have been removed from the tissue by this procedure, but a slow and progressive release of attached bacte...

Re-engineering bacteria for ethanol production

Science.gov (United States)

Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

2014-05-06

The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

Oligotrophic bacteria isolated from clinical materials.

OpenAIRE

Tada, Y; Ihmori, M; Yamaguchi, J

1995-01-01

Oligotrophic bacteria (oligotrophs) are microorganisms that grow in extremely nutritionally deficient conditions in which the concentrations of organic substances are low. Many oligotrophic bacteria were isolated from clinical materials including urine, sputum, swabbings of the throat, vaginal discharges, and others. Seventy-seven strains of oligotrophic bacteria from 871 samples of clinical material were isolated. A relatively higher frequency of isolation of oligotrophic bacteria was shown ...

Terrestrial radioactivity monitoring programme (TRAMP) report for 1986

International Nuclear Information System (INIS)

1988-01-01

The Ministry of Agriculture, Fisheries and Food (MAFF) undertakes a comprehensive independent monitoring programme for radioactivity in terrestrial foodstuffs in England and Wales, this report presents the results from the first full year of operation of this programme and complements the data published annually by the Ministry's Directorate of Fisheries Research in respect of the aquatic environment. This work is undertaken in Wales on behalf of the Secretary of State. The Terrestrial Radioactivity Monitoring Programme (TRAMP) concentrates on samples of agricultural produce (milk, crops, meat) collected from the vicinity of the major nuclear sites in England and Wales and is independent of monitoring undertaken for various purposes by site operators. (author)

Comparision of the Martian Gullies With Terrestrial Ones

Science.gov (United States)

Cedillo-Flores, Y.; Durand-Manterola, H. J.

2005-12-01

Some of the geomorphological features in Mars are the gullies. Some theories developed tried to explained its origin, either by liquid water, liquid carbon dioxide or flows of dry granular material. We made a comparative analysis of the Martian gullies with the terrestrial ones. We present the characteristics of some terrestrial gullies formed at cold enviroment, sited at the Nevado de Toluca volcanoe near Toluca City, Mexico. We compare them with Martian gullies, choisen from four different areas, to recognize possible processes evolved in its formation. Also, we measured the lenghts of those Martian gullies and their range was from 24 m 1775 m.

Cumulus convection and the terrestrial water-vapor distribution

Science.gov (United States)

Donner, Leo J.

1988-01-01

Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

Seeing green bacteria in a new light: genomics-enabled studies of the photosynthetic apparatus in green sulfur bacteria and filamentous anoxygenic phototrophic bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Bryant, Donald A

2004-01-01

Based upon their photosynthetic nature and the presence of a unique light-harvesting antenna structure, the chlorosome, the photosynthetic green bacteria are defined as a distinctive group in the Bacteria. However, members of the two taxa that comprise this group, the green sulfur bacteria...... (Chlorobi) and the filamentous anoxygenic phototrophic bacteria ("Chloroflexales"), are otherwise quite different, both physiologically and phylogenetically. This review summarizes how genome sequence information facilitated studies of the biosynthesis and function of the photosynthetic apparatus...... a and carotenoid biosynthesis enzymes, gene cluster analysis in Cfx. aurantiacus, and gene inactivation studies in Chl. tepidum. Based on these results, BChl a and BChl c biosynthesis is similar in the two organisms, whereas carotenoid biosynthesis differs significantly. In agreement with its facultative anaerobic...

Chaos Synchronization Based on Unknown Input Proportional Multiple-Integral Fuzzy Observer

Directory of Open Access Journals (Sweden)

T. Youssef

2013-01-01

Full Text Available This paper presents an unknown input Proportional Multiple-Integral Observer (PIO for synchronization of chaotic systems based on Takagi-Sugeno (TS fuzzy chaotic models subject to unmeasurable decision variables and unknown input. In a secure communication configuration, this unknown input is regarded as a message encoded in the chaotic system and recovered by the proposed PIO. Both states and outputs of the fuzzy chaotic models are subject to polynomial unknown input with kth derivative zero. Using Lyapunov stability theory, sufficient design conditions for synchronization are proposed. The PIO gains matrices are obtained by resolving linear matrix inequalities (LMIs constraints. Simulation results show through two TS fuzzy chaotic models the validity of the proposed method.

Halogens in chondritic meteorites and terrestrial accretion

Science.gov (United States)

Clay, Patricia L.; Burgess, Ray; Busemann, Henner; Ruzié-Hamilton, Lorraine; Joachim, Bastian; Day, James M. D.; Ballentine, Christopher J.

2017-11-01

Volatile element delivery and retention played a fundamental part in Earth’s formation and subsequent chemical differentiation. The heavy halogens—chlorine (Cl), bromine (Br) and iodine (I)—are key tracers of accretionary processes owing to their high volatility and incompatibility, but have low abundances in most geological and planetary materials. However, noble gas proxy isotopes produced during neutron irradiation provide a high-sensitivity tool for the determination of heavy halogen abundances. Using such isotopes, here we show that Cl, Br and I abundances in carbonaceous, enstatite, Rumuruti and primitive ordinary chondrites are about 6 times, 9 times and 15-37 times lower, respectively, than previously reported and usually accepted estimates. This is independent of the oxidation state or petrological type of the chondrites. The ratios Br/Cl and I/Cl in all studied chondrites show a limited range, indistinguishable from bulk silicate Earth estimates. Our results demonstrate that the halogen depletion of bulk silicate Earth relative to primitive meteorites is consistent with the depletion of lithophile elements of similar volatility. These results for carbonaceous chondrites reveal that late accretion, constrained to a maximum of 0.5 ± 0.2 per cent of Earth’s silicate mass, cannot solely account for present-day terrestrial halogen inventories. It is estimated that 80-90 per cent of heavy halogens are concentrated in Earth’s surface reservoirs and have not undergone the extreme early loss observed in atmosphere-forming elements. Therefore, in addition to late-stage terrestrial accretion of halogens and mantle degassing, which has removed less than half of Earth’s dissolved mantle gases, the efficient extraction of halogen-rich fluids from the solid Earth during the earliest stages of terrestrial differentiation is also required to explain the presence of these heavy halogens at the surface. The hydropilic nature of halogens, whereby they track

Nitrogen attenuation of terrestrial carbon cycle response to global environmental factors

Science.gov (United States)

Atul Jain; Xiaojuan Yang; Haroon Kheshgi; A. David McGuire; Wilfred Post; David. Kicklighter

2009-01-01

Nitrogen cycle dynamics have the capacity to attenuate the magnitude of global terrestrial carbon sinks and sources driven by CO2 fertilization and changes in climate. In this study, two versions of the terrestrial carbon and nitrogen cycle components of the Integrated Science Assessment Model (ISAM) are used to evaluate how variation in nitrogen...

Characterizing unknown systematics in large scale structure surveys

International Nuclear Information System (INIS)

Agarwal, Nishant; Ho, Shirley; Myers, Adam D.; Seo, Hee-Jong; Ross, Ashley J.; Bahcall, Neta; Brinkmann, Jonathan; Eisenstein, Daniel J.; Muna, Demitri; Palanque-Delabrouille, Nathalie; Yèche, Christophe; Pâris, Isabelle; Petitjean, Patrick; Schneider, Donald P.; Streblyanska, Alina; Weaver, Benjamin A.

2014-01-01

Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data, we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study

Characterizing unknown systematics in large scale structure surveys

Energy Technology Data Exchange (ETDEWEB)

Agarwal, Nishant; Ho, Shirley [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Seo, Hee-Jong [Berkeley Center for Cosmological Physics, LBL and Department of Physics, University of California, Berkeley, CA 94720 (United States); Ross, Ashley J. [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Bahcall, Neta [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States); Brinkmann, Jonathan [Apache Point Observatory, P.O. Box 59, Sunspot, NM 88349 (United States); Eisenstein, Daniel J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Muna, Demitri [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States); Palanque-Delabrouille, Nathalie; Yèche, Christophe [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France); Pâris, Isabelle [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Petitjean, Patrick [Université Paris 6 et CNRS, Institut d' Astrophysique de Paris, 98bis blvd. Arago, 75014 Paris (France); Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Streblyanska, Alina [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Weaver, Benjamin A., E-mail: nishanta@andrew.cmu.edu [Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)

2014-04-01

Photometric large scale structure (LSS) surveys probe the largest volumes in the Universe, but are inevitably limited by systematic uncertainties. Imperfect photometric calibration leads to biases in our measurements of the density fields of LSS tracers such as galaxies and quasars, and as a result in cosmological parameter estimation. Earlier studies have proposed using cross-correlations between different redshift slices or cross-correlations between different surveys to reduce the effects of such systematics. In this paper we develop a method to characterize unknown systematics. We demonstrate that while we do not have sufficient information to correct for unknown systematics in the data, we can obtain an estimate of their magnitude. We define a parameter to estimate contamination from unknown systematics using cross-correlations between different redshift slices and propose discarding bins in the angular power spectrum that lie outside a certain contamination tolerance level. We show that this method improves estimates of the bias using simulated data and further apply it to photometric luminous red galaxies in the Sloan Digital Sky Survey as a case study.

Halotolerant and halophilic bacteria in the oceans of the icy satellites

Science.gov (United States)

Ramirez, S. I.; Montoya, L.; Avendaño, R.

2013-05-01

Halotolerant and halophilic prokaryotes require salt concentrations equal to or higher than those present at terrestrial oceans (Rothschild and Mancinelli, 2001). They are a particular kind of extremophiles and as expected, their halotolerance is mainly expressed in terms of a certain NaCl percentage, at least on Earth. With the discovery of putative salty liquid oceans beneath the iced surfaces of some of the satellites of Jupiter and Saturn (Mueller and McKinnon, 1988; Kargel et al., 2000; Zolotov, 2007), information about the impact of other types of salts, different from NaCl, on the growth of complex biological systems is necessary. We have found that when three specific bacteria strains are growing in media enriched with salts containing chaotropic and kosmotropic ions, their specific optimal growth value is modified (Montoya et al., 2010). The changes can be broadly explained in terms of the Hofmeister series (Zhang and Cremer, 2006). These results can be used to infer an extension in the limits of biological activity. For terrestrial organisms there is scarce information to determine the impact of another salt in the growth of an organism. In these sense we have found that when media enriched with magnesium sulfate (MgSO4) at water activity values (aw) similar to those reported as optimal for NaCl, their growth and tolerance is considerably enhanced. On the other hand, the combination of chaotropic and kosmotropic ions result in salts of astrobiological importance such as the sulphate already mentioned, carbonates or chlorides that can tentatively exist in the putative ocean of Europa, Ganymedes, or Enceladus or even at the subsurface of Mars. In this frame, we studied the growth rate of Halomonas halodurans, H. magadiensis and Bacillus pumillus when exposed to media enriched with NaCl, MgSO4, Mg(NO3)2, MgCl2, Na2SO4 and NH4SO4. Equivalent values of water activity (aw) for each salt were compared and correlated with microbial activity (Montoya et al., 2010

How honey kills bacteria

NARCIS (Netherlands)

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

2010-01-01

With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria

Rates and patterns of molecular evolution in freshwater versus terrestrial insects.

Science.gov (United States)

Mitterboeck, T Fatima; Fu, Jinzhong; Adamowicz, Sarah J

2016-11-01

Insect lineages have crossed between terrestrial and aquatic habitats many times, for both immature and adult life stages. We explore patterns in molecular evolutionary rates between 42 sister pairs of related terrestrial and freshwater insect clades using publicly available protein-coding DNA sequence data from the orders Coleoptera, Diptera, Lepidoptera, Hemiptera, Mecoptera, Trichoptera, and Neuroptera. We furthermore test for habitat-associated convergent molecular evolution in the cytochrome c oxidase subunit I (COI) gene in general and at a particular amino acid site previously reported to exhibit habitat-linked convergence within an aquatic beetle group. While ratios of nonsynonymous-to-synonymous substitutions across available loci were higher in terrestrial than freshwater-associated taxa in 26 of 42 lineage pairs, a stronger trend was observed (20 of 31, p binomial = 0.15, p Wilcoxon = 0.017) when examining only terrestrial-aquatic pairs including fully aquatic taxa. We did not observe any widespread changes at particular amino acid sites in COI associated with habitat shifts, although there may be general differences in selection regime linked to habitat.

The energetic contributions of aquatic primary producers to terrestrial food webs in a mid-size river system.

Science.gov (United States)

Kautza, Adam; Mazeika, S; Sullivan, P

2016-03-01

Rivers are increasingly recognized as providing nutritional subsidies (i.e., energy and nutrients) to adjacent terrestrial food webs via depredation of aquatic organisms (e.g., emergent aquatic insects, crayfish, fish) by terrestrial consumers. However, because these prey organisms assimilate energy from both aquatic (e.g., benthic algae, phytoplankton, aquatic macrophytes) and terrestrial (e.g., riparian leaf detritus) primary producers, river subsidies to terrestrial consumers represent a combination of aquatically and terrestrially derived energy. To date, the explicit contribution of energy derived from aquatic primary producers to terrestrial consumers has not been fully explored yet might be expected to be quantitatively important to terrestrial food webs. At 12 reaches along a 185-km segment of the sixth-order Scioto River system (Ohio, USA), we quantified the relative contribution of energy derived from aquatic primary producers to a suite of terrestrial riparian consumers that integrate the adjacent landscape across multiple spatial scales through their foraging activities (tetragnathid spiders, rove beetles, adult coenagrionid damselflies, riparian swallows, and raccoons). We used naturally abundant stable isotopes (13C and 15N) of periphyton, phytoplankton, macrophytes, and terrestrial vegetation to evaluate the energetic contribution of aquatic primary producers to terrestrial food webs. Shoreline tetragnathid spiders were most reliant on aquatic primary producers (50%), followed by wider-ranging raccoons (48%), damselflies (44%), and riparian swallows (41%). Of the primary producers, phytoplankton (19%) provisioned the greatest nutritional contribution to terrestrial consumers (considered collectively), followed by periphyton (14%) and macrophytes (11%). Our findings provide empirical evidence that aquatic primary producers of large streams and rivers can be a critical nutritional resource for terrestrial food webs. We also show that aquatically

The Scattering Properties of Natural Terrestrial Snows versus Icy Satellite Surfaces

Science.gov (United States)

Domingue, Deborah; Hartman, Beth; Verbiscer, Anne

1997-01-01

Our comparisons of the single particle scattering behavior of terrestrial snows and icy satellite regoliths to the laboratory particle scattering measurements of McGuire and Hapke demonstrate that the differences between icy satellite regoliths and their terrestrial counterparts are due to particle structures and textures. Terrestrial snow particle structures define a region in the single particle scattering function parameter space separate from the regions defined by the McGuire and Hapke artificial laboratory particles. The particle structures and textures of the grains composing icy satellites regoliths are not simple or uniform but consist of a variety of particle structure and texture types, some of which may be a combination of the particle types investigated by McGuire and Hapke.

Pathogenic Assay of Probiotic Bacteria Producing Proteolytic Enzymes as Bioremediation Bacteria Against Vannamei Shrimp Larvae (Litopenaeus vannamei

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Wilis Ari Setyati

2017-06-01

Full Text Available Application of bacteria in bioremediation of shrimp culture ponds is one of the methods used to clean internal pollutants. This study aimed to evaluate the pathogenicity of extracellular proteolytic enzyme produced by the probiotic bacteria as bioremediation bacteria on vannamei shrimp larvae culture. There were five probiotic bacteria, which were successfully isolated from the sediments served as substrate in mangrove area. The isolated bacteria were coded in number as 13, 19, 30, 33, and 36. Pathogenic bacteria Vibrio harveyi was used as positive control. Pathogenic assay was carried out in two different bacterial concentrations, i.e. 10⁸ and 10⁶ cells.mL-1. The results showed that the lowest survival rate (SR of shrimp larvae in positive control V. harveyi was 53 and 65%. Whereas isolates with the highest SR value (100% were obtained from bacteria coded as 13 and 30. Isolates no. 19, 33 and 36 had SR of more than 90%. Total plate count (TPC data showed that the bacteria increased significantly at the end of the study with an average increase value of 24%. The smallest TPC value was shown by bacterial isolate no. 19, while the largest was obtained from the isolate no. 13. These results suggest that all probiotic bacteria were not pathogenic to the vannamei shrimp larvae.   Keywords: aquaculture, shrimp, bioremediation, pathogenesis, vibrio.

Osmotic stress tolerance in semi-terrestrial tardigrades

DEFF Research Database (Denmark)

Heidemann, Nanna W T; Smith, Daniel K.; Hygum, Thomas L.

2016-01-01

Little is known about ionic and osmotic stress tolerance in tardigrades. Here, we examine salt stress tolerance in Ramazzottius oberhaeuseri and Echiniscus testudo from Nivå (Denmark) and address whether limno-terrestrial tardigrades can enter a state of quiescence (osmobiosis) in the face of high......-ionic osmolytes as compared to NaCl. Ramazzottius oberhaeuseri furthermore readily regained activity following gradual increases in non-ionic osmolytes and NaCl of up to 2434 ± 28 and 1905 ± 3 mOsm kg−1, respectively, showing that short-term acclimation promoted salt stress tolerance. Our results suggest...... that the limno-terrestrial R. oberhaeuseri enters a state of quiescence in the face of high external osmotic pressure and that it, in this state, is highly tolerant of ionic and osmotic stress....

Heinrich event 4 characterized by terrestrial proxies in southwestern Europe

Directory of Open Access Journals (Sweden)

J. M. López-García

2013-05-01

Full Text Available Heinrich event 4 (H4 is well documented in the North Atlantic Ocean as a cooling event that occurred between 39 and 40 Ka. Deep-sea cores around the Iberian Peninsula coastline have been analysed to characterize the H4 event, but there are no data on the terrestrial response to this event. Here we present for the first time an analysis of terrestrial proxies for characterizing the H4 event, using the small-vertebrate assemblage (comprising small mammals, squamates and amphibians from Terrassa Riera dels Canyars, an archaeo-palaeontological deposit located on the seaboard of the northeastern Iberian Peninsula. This assemblage shows that the H4 event is characterized in northeastern Iberia by harsher and drier terrestrial conditions than today. Our results were compared with other proxies such as pollen, charcoal, phytolith, avifauna and large-mammal data available for this site, as well as with the general H4 event fluctuations and with other sites where H4 and the previous and subsequent Heinrich events (H5 and H3 have been detected in the Mediterranean and Atlantic regions of the Iberian Peninsula. We conclude that the terrestrial proxies follow the same patterns as the climatic and environmental conditions detected by the deep-sea cores at the Iberian margins.

Escherichia coli-producing extended-spectrum beta-lactamase CTX-M-15 in a captive South American tapir (Tapirus terrestris).

Science.gov (United States)

Klimes, Jiri; Machalkova, Marketa; Dolejska, Monika; Cizek, Alois; Janoszowska, Dagmar; Alexa, Pavel; Albrechtova, Katerina; Vojtech, Jiri; Literak, Ivan

2013-03-01

Only a few reports exist on the occurrence of resistant bacteria in zoo animals. Therefore, an isolation of multiresistant Escherichia coli from the lungs of a captive South American tapir (Tapirus terrestris) lead to its characterization and further investigation of samples from animals inhabiting the same paddock and from the shared environment. The tapir suffered from an intermandibular abscess and pneumonia and was euthanatized after unsuccessful therapy, including administration of antibiotics. The authors performed selective isolation of extended-spectrum beta-lactamase (ESBL)-positive E. coli strains and identification of resistance genes using polymerase chain reaction. Seven multiresistant, ESBL-producing E. coli isolates were obtained, all belonging to the B2 phylogenetic group and showing identical profile on pulsed-field gel electrophoresis. These isolates carried several resistance genes, including the gene bla(CTX-M-15). This case demonstrates the transmission of related epidemiologically important E. coli isolates whose potential transmission to other animals and zoo staff can be assumed.

Effect of air pollution on the total bacteria and pathogenic bacteria in different sizes of particulate matter.

Science.gov (United States)

Liu, Huan; Zhang, Xu; Zhang, Hao; Yao, Xiangwu; Zhou, Meng; Wang, Jiaqi; He, Zhanfei; Zhang, Huihui; Lou, Liping; Mao, Weihua; Zheng, Ping; Hu, Baolan

2018-02-01

In recent years, air pollution events have occurred frequently in China during the winter. Most studies have focused on the physical and chemical composition of polluted air. Some studies have examined the bacterial bioaerosols both indoors and outdoors. But few studies have focused on the relationship between air pollution and bacteria, especially pathogenic bacteria. Airborne PM samples with different diameters and different air quality index values were collected in Hangzhou, China from December 2014 to January 2015. High-throughput sequencing of 16S rRNA was used to categorize the airborne bacteria. Based on the NCBI database, the "Human Pathogen Database" was established, which is related to human health. Among all the PM samples, the diversity and concentration of total bacteria were lowest in the moderately or heavily polluted air. However, in the PM2.5 and PM10 samples, the relative abundances of pathogenic bacteria were highest in the heavily and moderately polluted air respectively. Considering the PM samples with different particle sizes, the diversities of total bacteria and the proportion of pathogenic bacteria in the PM10 samples were different from those in the PM2.5 and TSP samples. The composition of PM samples with different sizes range may be responsible for the variances. The relative humidity, carbon monoxide and ozone concentrations were the main factors, which affected the diversity of total bacteria and the proportion of pathogenic bacteria. Among the different environmental samples, the compositions of the total bacteria were very similar in all the airborne PM samples, but different from those in the water, surface soil, and ground dust samples. Which may be attributed to that the long-distance transport of the airflow may influence the composition of the airborne bacteria. This study of the pathogenic bacteria in airborne PM samples can provide a reference for environmental and public health researchers. Copyright © 2017 Elsevier Ltd

Antibiotics from predatory bacteria

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Juliane Korp

2016-03-01

Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

Patterns and sources of fecal coliform bacteria in three streams in Virginia, 1999-2000

Science.gov (United States)

Hyer, Kenneth; Moyer, Douglas

2003-01-01

(maximum observed concentration of 290,000 colonies/100 milliliters (col/100mL) could occur along the entire length of each stream, and that the samples collected at the downstream monitoring station of each stream were generally representative of the entire upstream reach. Seasonal patterns were observed in the base-flow fecal coliform concentrations of all streams; concentrations were typically highest in the summer and lowest in the winter. Fecal coliform concentrations were lowest during periods of base flow (typically 200?2,000 col/100mL) and increased by 3?4 orders of magnitude during storm events (as high as 700,000 col/100mL). Multiple linear regression models were developed to predict fecal coliform concentrations as a function of streamflow and other water-quality parameters. The source tracking technique provided identification of bacteria contributions from diverse sources that included (but were not limited to) humans, cattle, poultry, horses, dogs, cats, geese, ducks, raccoons, and deer. Seasonal patterns were observed in the contributions of cattle and poultry sources. There were relations between the identified sources of fecal coliform bacteria and the land-use practices within each watershed. There were only minor differences in the distribution of bacteria sources between low-flow periods and high-flow periods. A coupled approach that utilized both a large available source library and a smaller, location-specific source library provided the most success in identifying the unknown E. coli isolates. BST data should provide valuable support and guidance for producing more defendable and scientifically rigorous watershed models. Incorporation of these bacteria-source data into watershed management strategies also should result in the selection of more efficient source-reduction scenarios for improving water quality.

Terrestrial neutron-induced soft errors in advanced memory devices

CERN Document Server

Nakamura, Takashi; Ibe, Eishi; Yahagi, Yasuo; Kameyama, Hideaki

2008-01-01

Terrestrial neutron-induced soft errors in semiconductor memory devices are currently a major concern in reliability issues. Understanding the mechanism and quantifying soft-error rates are primarily crucial for the design and quality assurance of semiconductor memory devices. This book covers the relevant up-to-date topics in terrestrial neutron-induced soft errors, and aims to provide succinct knowledge on neutron-induced soft errors to the readers by presenting several valuable and unique features. Sample Chapter(s). Chapter 1: Introduction (238 KB). Table A.30 mentioned in Appendix A.6 on

Beer spoilage bacteria and hop resistance

NARCIS (Netherlands)

Sakamoto, K; Konings, WN

2003-01-01

For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

Effect of Tribulus terrestris on Haloperidol-induced Catalepsy in Mice

OpenAIRE

Nishchal, B. S.; Rai, S.; Prabhu, M. N.; Ullal, Sheetal D.; Rajeswari, S.; Gopalakrishna, H. N.

2014-01-01

Haloperidol, an antipsychotic drug, leads to the development of a behavioural state called catalepsy, in which the animal is not able to correct an externally imposed posture. In the present study we have attempted to evaluate the anticataleptic effect of Tribulus terrestris on haloperidol-induced catalepsy in albino mice. Mice were allocated to four groups, each group containing six animals. Both, the test drug, Tribulus terrestris and the standard drug trihexyphenidyl were uniformly suspend...

Contrasting elevational diversity patterns for soil bacteria between two ecosystems divided by the treeline.

Science.gov (United States)

Li, Guixiang; Xu, Guorui; Shen, Congcong; Tang, Yong; Zhang, Yuxin; Ma, Keming

2016-11-01

Above- and below-ground organisms are closely linked, but how elevational distribution pattern of soil microbes shifting across the treeline still remains unknown. Sampling of 140 plots with transect, we herein investigated soil bacterial distribution pattern from a temperate forest up to a subalpine meadow along an elevational gradient using Illumina sequencing. Our results revealed distinct elevational patterns of bacterial diversity above and below the treeline in responding to changes in soil conditions: a hollow elevational pattern in the forest (correlated with soil temperature, pH, and C:N ratio) and a significantly decreasing pattern in the meadow (correlated with soil pH, and available phosphorus). The bacterial community structure was also distinct between the forest and meadow, relating to soil pH in the forest and soil temperature in the meadow. Soil bacteria did not follow the distribution pattern of herb diversity, but bacterial community structure could be predicted by herb community composition. These results suggest that plant communities have an important influence on soil characteristics, and thus change the elevational distribution of soil bacteria. Our findings are useful for future assessments of climate change impacts on microbial community.

Outcome of Transplantation Using Organs From Donors Infected or Colonized With Carbapenem-Resistant Gram-Negative Bacteria.

Science.gov (United States)

Mularoni, A; Bertani, A; Vizzini, G; Gona, F; Campanella, M; Spada, M; Gruttadauria, S; Vitulo, P; Conaldi, P; Luca, A; Gridelli, B; Grossi, P

2015-10-01

Donor-derived infections due to multidrug-resistant bacteria are a growing problem in solid organ transplantation, and optimal management options are not clear. In a 2-year period, 30/214 (14%) recipients received an organ from 18/170 (10.5%) deceased donors with infection or colonization caused by a carbapenem-resistant gram-negative bacteria that was unknown at the time of transplantation. Among them, 14/30 recipients (47%) received a transplant from a donor with bacteremia or with infection/colonization of the transplanted organ and were considered at high risk of donor-derived infection transmission. The remaining 16/30 (53%) recipients received an organ from a nonbacteremic donor with colonization of a nontransplanted organ and were considered at low risk of infection transmission. Proven transmission occurred in 4 of the 14 high-risk recipients because donor infection was either not recognized, underestimated, or not communicated. These recipients received late, short or inappropriate posttransplant antibiotic therapy. Transmission did not occur in high-risk recipients who received appropriate and prompt antibiotic therapy for at least 7 days. The safe use of organs from donors with multidrug-resistant bacteria requires intra- and inter-institutional communication to allow appropriate management and prompt treatment of recipients in order to avoid transmission of infection. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

Effects of atmospheric deposition of pesticides on terrestrial organisms in the Netherlands

NARCIS (Netherlands)

Jong FMW de; Luttik R; SEC

2004-01-01

At present there is much focus on the atmospheric dispersal of pesticides. However, there is very little known about the effects of atmospheric deposition, especially in terrestrial ecosystems. In the study described here, a start has been made to clarify the possible effects on terrestrial

Denitrifying bacteria from the genus Rhodanobacter dominate bacterial communities in the highly contaminated subsurface of a nuclear legacy waste site

Energy Technology Data Exchange (ETDEWEB)

Green, Stefan [Florida State University; Prakash, Om [Florida State University; Jasrotia, Puja [Florida State University; Overholt, Will [Florida State University; Cardenas, Erick [Michigan State University, East Lansing; Hubbard, Daniela [Florida State University; Tiedje, James M. [Michigan State University, East Lansing; Watson, David B [ORNL; Schadt, Christopher Warren [ORNL; Brooks, Scott C [ORNL; Kostka, Joel [Florida State University

2011-01-01

The effect of long-term mixed-waste contamination, particularly uranium and nitrate, on the microbial community in the terrestrial subsurface was investigated at the field scale at the Oak Ridge Integrated Field Research Challenge (ORIFRC) site in Oak Ridge, TN. The abundance, community composition, and distribution of groundwater microorganisms were examined across the site during two seasonal sampling events. At representative locations, subsurface sediment was also examined from two boreholes, one sampled from the most heavily contaminated area of the site and another from an area with low contamination. A suite of DNA- and RNA-based molecular tools were employed for community characterization, including quantitative PCR of ribosomal RNA and nitrite reductase genes, community composition fingerprinting analysis, and high-throughput pyrotag sequencing of rRNA genes. The results demonstrate that pH is a major driver of the subsurface microbial community structure, and denitrifying bacteria from the genus Rhodanobacter (class Gammaproteobacteria) dominate at low pH. The relative abundance of bacteria from this genus was positively correlated with lower pH conditions, and these bacteria were abundant and active in the most highly contaminated areas. Other factors, such as concentration of nitrogen species, oxygen and sampling season did not appear to strongly influence the distribution of Rhodanobacter. Results indicate that these organisms are acid-tolerant denitrifiers, well suited to the acidic, nitrate-rich subsurface conditions, and pH is confirmed as a dominant driver of bacterial community structure in this contaminated subsurface environment.

Robust Fault Detection for Switched Fuzzy Systems With Unknown Input.

Science.gov (United States)

Han, Jian; Zhang, Huaguang; Wang, Yingchun; Sun, Xun

2017-10-03

This paper investigates the fault detection problem for a class of switched nonlinear systems in the T-S fuzzy framework. The unknown input is considered in the systems. A novel fault detection unknown input observer design method is proposed. Based on the proposed observer, the unknown input can be removed from the fault detection residual. The weighted H∞ performance level is considered to ensure the robustness. In addition, the weighted H₋ performance level is introduced, which can increase the sensibility of the proposed detection method. To verify the proposed scheme, a numerical simulation example and an electromechanical system simulation example are provided at the end of this paper.

Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

Science.gov (United States)

Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

2015-01-01

Increased land use by polar bears (Ursus maritimus) due to climate-change-induced reduction of their sea-ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea-ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutritional needs of polar bears as well as the physiological and environmental constraints that shape their use of terrestrial ecosystems. Only small numbers of polar bears have been documented consuming terrestrial foods even in modest quantities. Over much of the polar bear's range, limited terrestrial food availability supports only low densities of much smaller, resident brown bears (Ursus arctos), which use low-quality resources more efficiently and may compete with polar bears in these areas. Where consumption of terrestrial foods has been documented, polar bear body condition and survival rates have declined even as land use has increased. Thus far, observed consumption of terrestrial food by polar bears has been insufficient to offset lost ice-based hunting opportunities but can have ecological consequences for other species. Warming-induced loss of sea ice remains the primary threat faced by polar bears.

Mercury exposure in terrestrial birds far downstream of an historical point source

Energy Technology Data Exchange (ETDEWEB)

Jackson, Allyson K., E-mail: allyson.jackson@briloon.org [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Evers, David C.; Folsom, Sarah B. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); Condon, Anne M. [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Diener, John; Goodrick, Lizzie F. [Biodiversity Research Institute, 19 Flaggy Meadow Road, Gorham, ME 04038 (United States); McGann, Andrew J. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States); Schmerfeld, John [U.S. Fish and Wildlife Service, 6669 Short Lane, Gloucester, VA 23061 (United States); Cristol, Daniel A. [Institute for Integrative Bird Behavior Studies, Department of Biology, College of William and Mary, PO Box 8795, Williamsburg, VA 23187 (United States)

2011-12-15

Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: > We report blood mercury levels for terrestrial songbirds downstream of contamination. > Blood mercury levels remain elevated above reference for at least 137 km downstream. > Trends vary based on foraging guild and migration strategy. > Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

Alternative treatment of ovarian cysts with Tribulus terrestris extract: a rat model.

Science.gov (United States)

Dehghan, A; Esfandiari, A; Bigdeli, S Momeni

2012-02-01

Tribulus terrestris has long been used in traditional medicine to treat impotency and improve sexual functions in man. The aim of this study was to evaluate the efficiency of T. terrestris extract in the treatment of polycystic ovary (PCO) in Wistar rat. Estradiol valerate was injected to 15 mature Wistar rats to induce PCO. Rats were randomly divided into three groups (control, low-dose and high-dose groups) of five each and received 0, 5 and 10 mg of T. terrestris extract, respectively.Treatments began on days 50 and 61 after estradiol injection; at the same time, vaginal smear was prepared. The ovaries were removed on day 62, and histological sections were prepared accordingly. The number and diameter of corpora lutea, thickness of the theca interna layer and the number of all follicles were evaluated in both ovaries. In comparison with the control group, the number of corpora lutea and primary and secondary follicles significantly increased following T. terrestris treatment; however, the number of ovarian cysts significantly decreased. It can be concluded that T. terrestris have a luteinizing effect on ovarian cysts, which may relate to its gonadotropin-like activity; also, a high dose of the extract can efficiently remove ovarian cysts and resume ovarian activity. © 2011 Blackwell Verlag GmbH.

Human body may produce bacteria.

Science.gov (United States)

Salerian, Alen J

2017-06-01

"Human body may produce bacteria" proposes that human body may produce bacteria and represent an independent source of infections contrary to the current paradigm of infectious disorders proposed by Louis Pasteur in 1880. The following observations are consistent with this hypothesis: A. Bidirectional transformations of both living and nonliving things have been commonly observed in nature. B. Complex multicellular organisms harbor the necessary properties to produce bacteria (water, nitrogen and oxygen). C. Physical laws suggest any previously observed phenomenon or action will occur again (life began on earth; a non living thing). D. Animal muscle cells may generate energy (fermentation). E. Sterilized food products (i.e. boiled eggs), may produce bacteria and fungus under special conditions and without any exposure to foreign living cells. "Human body may produce bacteria" may challenge the current medical paradigm that views human infectious disorders as the exclusive causative byproducts of invading foreign cells. It may also introduce new avenues to treat infectious disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prevalence of extended-spectrum beta-lactamase-producing bacteria in food

Directory of Open Access Journals (Sweden)

Tham J

2012-10-01

Full Text Available Johan Tham,1 Mats Walder,2 Eva Melander,2,3 Inga Odenholt11Infectious Diseases Unit, Department of Clinical Sciences, 2Medical Microbiology, Department of Laboratory Medicine, Lund University, Malmö, Sweden; 3Department of Infection Control, Laboratory Medicine, Skåne County, SwedenAbstract: Extended-spectrum β-lactamase (ESBL-producing Enterobacteriaceae with Cefotaximase–München (CTX-M enzymes are rapidly increasing worldwide and pose a threat to health care. ESBLs with CTX-M enzymes have been isolated from animals and different food products, but it is unknown if food imported from the Mediterranean area may be a possible reservoir of these bacteria. During 2007–2008, swab samples from food across different retail outlets (mostly food from the Mediterranean countries and Swedish chicken were collected. Escherichia coli strains from Swedish meat and E. coli isolates from unspecified food from a Swedish food testing laboratory were also examined. In 349 of the 419 swab samples, growth of Enterobacteriaceae was found. In most of the samples, there was also growth of Gram-negative environmental bacteria. Air dry-cured products contained significantly less Enterobacteriaceae isolates compared to lettuces; however, none of the examined Enterobacteriaceae harbored ESBLs. This study did not support the theory that imported food from the Mediterranean area or Swedish domestic food might constitute an important vehicle for the dissemination of ESBL-producing Enterobacteriaceae; however, a spread from food to humans may have occurred after 2008.Keywords: ESBL, antibiotic resistance, zoonosis, food, Enterobacteriaceae

The Diversity of PAH-degrading bacteria in a deep-sea water column above the Southwest Indian Ridge

Directory of Open Access Journals (Sweden)

Zongze eShao

2015-08-01

Full Text Available The bacteria involved in organic pollutant degradation in pelagic deep-sea environments are largely unknown. In this report, the diversity of polycyclic aromatic hydrocarbon ( PAH-degrading bacteria was analyzed in deep-sea water on the Southwest Indian Ridge (SWIR. After enrichment with a PAH mixture (phenanthrene, anthracene, fluoranthene and pyrene, 9 nine bacterial consortia were obtained from depths of 3946 m to 4746 m. PAH degradation occurred to all components of the mixture, but when using a single PAH as the sole carbon and energy source, only phenanthrene can be degraded obviously. This indicates the cometabolism of anthracene, fluoranthene and pyrene with phenanthreneWhile the consortia degraded all four PAHs when supplied in a mixture, when PAHs were tested individually, only phenanthrene supported growth. Thus, degradation of the PAH mixture reflected a cometabolism of anthracene, fluoranthene and pyrene with phenanthrene. Further, both culture-dependent and independent methods revealed many new bacteria involved in PAH degradation. Specifically, the alpha and gamma subclasses of Proteobacteria were confirmed as the major groups within the communities. Additionally, Actinobacteria, the CFB group and Firmicutes were detected. Denaturing Gradient Gel Electrophoresis (DGGE analysis showed that bacteria closely affiliated with Alcanivorax, Novosphingobium and Rhodovulum occurred most frequently in different PAH-degrading consortia. More than half of the isolates (34 of 51 isolates were confirmed to have the ability to grow with the PAH mixture By using general heterotrophic media, 51 bacteria were isolated from the consortia and of these 34 grew with the PAH mixture as a sole carbon source. Of these, isolates most closely related to Alterierythrobacter, Citricella, Erythrobacter, Idiomarina, Lutibacterium, Maricaulis, Marinobacter, Martelella, Pseudidiomarina, Rhodobacter, Roseovarius, Salipiger, Sphingopyxis and Stappia were found to

Implications of land use change on the national terrestrial carbon budget of Georgia

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Olofsson Pontus

2010-09-01

Full Text Available Abstract Background Globally, the loss of forests now contributes almost 20% of carbon dioxide emissions to the atmosphere. There is an immediate need to reduce the current rates of forest loss, and the associated release of carbon dioxide, but for many areas of the world these rates are largely unknown. The Soviet Union contained a substantial part of the world's forests and the fate of those forests and their effect on carbon dynamics remain unknown for many areas of the former Eastern Bloc. For Georgia, the political and economic transitions following independence in 1991 have been dramatic. In this paper we quantify rates of land use changes and their effect on the terrestrial carbon budget for Georgia. A carbon book-keeping model traces changes in carbon stocks using historical and current rates of land use change. Landsat satellite images acquired circa 1990 and 2000 were analyzed to detect changes in forest cover since 1990. Results The remote sensing analysis showed that a modest forest loss occurred, with approximately 0.8% of the forest cover having disappeared after 1990. Nevertheless, growth of Georgian forests still contribute a current national sink of about 0.3 Tg of carbon per year, which corresponds to 31% of the country anthropogenic carbon emissions. Conclusions We assume that the observed forest loss is mainly a result of illegal logging, but we have not found any evidence of large-scale clear-cutting. Instead local harvesting of timber for household use is likely to be the underlying driver of the observed logging. The Georgian forests are a currently a carbon sink and will remain as such until about 2040 if the current rate of deforestation persists. Forest protection efforts, combined with economic growth, are essential for reducing the rate of deforestation and protecting the carbon sink provided by Georgian forests.

Implications of land use change on the national terrestrial carbon budget of Georgia.

Science.gov (United States)

Olofsson, Pontus; Torchinava, Paata; Woodcock, Curtis E; Baccini, Alessandro; Houghton, Richard A; Ozdogan, Mutlu; Zhao, Feng; Yang, Xiaoyuan

2010-09-13

Globally, the loss of forests now contributes almost 20% of carbon dioxide emissions to the atmosphere. There is an immediate need to reduce the current rates of forest loss, and the associated release of carbon dioxide, but for many areas of the world these rates are largely unknown. The Soviet Union contained a substantial part of the world's forests and the fate of those forests and their effect on carbon dynamics remain unknown for many areas of the former Eastern Bloc. For Georgia, the political and economic transitions following independence in 1991 have been dramatic. In this paper we quantify rates of land use changes and their effect on the terrestrial carbon budget for Georgia. A carbon book-keeping model traces changes in carbon stocks using historical and current rates of land use change. Landsat satellite images acquired circa 1990 and 2000 were analyzed to detect changes in forest cover since 1990. The remote sensing analysis showed that a modest forest loss occurred, with approximately 0.8% of the forest cover having disappeared after 1990. Nevertheless, growth of Georgian forests still contribute a current national sink of about 0.3 Tg of carbon per year, which corresponds to 31% of the country anthropogenic carbon emissions. We assume that the observed forest loss is mainly a result of illegal logging, but we have not found any evidence of large-scale clear-cutting. Instead local harvesting of timber for household use is likely to be the underlying driver of the observed logging. The Georgian forests are a currently a carbon sink and will remain as such until about 2040 if the current rate of deforestation persists. Forest protection efforts, combined with economic growth, are essential for reducing the rate of deforestation and protecting the carbon sink provided by Georgian forests.

Off-Policy Actor-Critic Structure for Optimal Control of Unknown Systems With Disturbances.

Science.gov (United States)

Song, Ruizhuo; Lewis, Frank L; Wei, Qinglai; Zhang, Huaguang

2016-05-01

An optimal control method is developed for unknown continuous-time systems with unknown disturbances in this paper. The integral reinforcement learning (IRL) algorithm is presented to obtain the iterative control. Off-policy learning is used to allow the dynamics to be completely unknown. Neural networks are used to construct critic and action networks. It is shown that if there are unknown disturbances, off-policy IRL may not converge or may be biased. For reducing the influence of unknown disturbances, a disturbances compensation controller is added. It is proven that the weight errors are uniformly ultimately bounded based on Lyapunov techniques. Convergence of the Hamiltonian function is also proven. The simulation study demonstrates the effectiveness of the proposed optimal control method for unknown systems with disturbances.

Effects of Ethanolic Ferolagu angulata Extract on Pathogenic Gastrointestinal Bacteria and Probiotic Bacteria in Skimmed Milk Medium

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Reza Naghiha

2016-12-01

Full Text Available Background:    Due to excessive consumption of synthetic drugs, drug resistance rate of pathogenic bacteria is increasing and there is an ever-increasing need to find new safe compounds to tackle this problem. This study was conducted to investigate the consequences of chavill extract on the growth and viability of gastrointestinal pathogenic bacterium and probiotics bacteria. Methods:    The experiment contained three levels of the chavill extract concentrations (0, 1 and 3% which were added to the milk free fat in accompany with three probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei and lactobacillus plantaram and a pathogenic gastrointestinal bacterium (Salmonella typhimurium. Bacterial inoculums (1×107 CFU/ml with different concentrations of chavill extract were added to skimmed milk medium and bacteria growth were enumerated. Results:  The concentration of 1% chavill extract significantly increased the total count of probiotic bacteria compared to the control group, while the number of pathogenic bacteria was decreased. At 3% chavill extract the growth of Lactobacillus acidophilus and Lactobacillus plantaram were increased. On the other hand, it prevented the growth of Salmonella typhimurium Conclusion:   Chavill extracts would play as an alternative to antibiotics in pharmacological studies to decreases harmful bacteria and increase probiotic bacteria.

Antibacterial activity of Tribulus terrestris methanol extract against clinical isolates of Escherichia coli

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Batoei Sara

2016-06-01

Full Text Available Introduction:Tribulus terrestris L. is traditionally used for treatment of urinary tract infections. Escherichia coli, as the most prominent agent of urinary tract infections, can be sensitive to T. terrestris extract.

A Combination of Stable Isotope Probing, Illumina Sequencing, and Co-occurrence Network to Investigate Thermophilic Acetate- and Lactate-Utilizing Bacteria.

Science.gov (United States)

Sun, Weimin; Krumins, Valdis; Dong, Yiran; Gao, Pin; Ma, Chunyan; Hu, Min; Li, Baoqin; Xia, Bingqing; He, Zijun; Xiong, Shangling

2018-01-01

Anaerobic digestion is a complicated microbiological process that involves a wide diversity of microorganisms. Acetate is one of the most important intermediates, and interactions between acetate-oxidizing bacteria and archaea could play an important role in the formation of methane in anoxic environments. Anaerobic digestion at thermophilic temperatures is known to increase methane production, but the effects on the microbial community are largely unknown. In the current study, stable isotope probing was used to characterize acetate- and lactate-oxidizing bacteria in thermophilic anaerobic digestion. In microcosms fed 13 C-acetate, bacteria related to members of Clostridium, Hydrogenophaga, Fervidobacterium, Spirochaeta, Limnohabitans, and Rhodococcus demonstrated elevated abundances of 13 C-DNA fractions, suggesting their activities in acetate oxidation. In the treatments fed 13 C-lactate, Anaeromyxobacter, Desulfobulbus, Syntrophus, Cystobacterineae, and Azospira were found to be the potential thermophilic lactate utilizers. PICRUSt predicted that enzymes related to nitrate and nitrite reduction would be enriched in 13 C-DNA fractions, suggesting that the acetate and lactate oxidation may be coupled with nitrate and/or nitrite reduction. Co-occurrence network analysis indicated bacterial taxa not enriched in 13 C-DNA fractions that may also play a critical role in thermophilic anaerobic digestion.

Cell shape acquisition and maintenance in rodlike bacteria

Science.gov (United States)

van Teeffelen, Sven; Wingreen, Ned; Gitai, Zemer

2010-03-01

The shape of rodlike bacteria such as Escherichia coli is mainly governed by the expansion and reorganization of the peptidoglycan cell wall. The cell wall is a huge, mostly single-layered molecule of stiff glycan strands that typically run perpendicular to the long axis and are crosslinked by short peptides. The wall resists the excess pressure from inside the cell. Although much is known about the enzymes that synthesize the wall, the mechanisms by which the cell maintains a constant rod diameter and uniform glycan strand orientation during growth remain unknown. Here we present quantitative results on the structure and dynamics of two essential proteins, which are believed to play an important role in cell wall synthesis. In particular, we have focused on the filament-forming protein MreB, an actin homolog that forms a long helical bundle along the inner membrane of the cell, and penicillin-binding protein 2, an essential protein for peptide bond formation in the periplasm. Based on their interplay we discuss the possibility of MreB serving as a guide and ruler for cell wall synthesis.

Bionota: Bacterias promotoras de crecimiento de microalgas: una nueva aproximación en el tratamiento de aguas residuales Microalgae growth-promoting bacteria: A novel approach in wastewater treatment

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Bashan Yoav

2003-12-01

-inmovilización; PGPB; micro-algae; wastewater treatment; co-immobilisedPlant growth-promoting bacteria (PGPB from the genus Azospirillum are known to enhance the growth of numerous agricultural crops. The use of these bacteria is proposed as "micro-algae-growth promoting bacteria" (MGPB for enhancing freshwater micro-algae Chlorella vulgaris and C. sorokiniana capadty to clean polluted water. The deliberate inoculation of Chlorella sp. with a terrestrial PGPB has not been reported prior to these studies, perhaps because of the different origin of the two micro-organisms. Chlorella spp. is not known to harbour any plant growth-promoting bacteria and Azospirillum sp. is rarely used for inoculation in aquatic environments. Co-immobilisation of C. vulgaris and A. brasilense Cd in small alginate beads resulted in significant increases in numerous micro-algae growth parameters. Dry and fresh weight, total number of cells, micro-algal cluster (colonies size within the bead, number of micro-algal cells per cluster and micro-algal pigments levels significantly increased. Lipids and the variety of fatty adds also significantly increased, as did the combination of micro-algae. MGPB had superior capacity for removing ammonium and phosphorus from polluted synthetic and municipal wastewaters than the micro-algae by itself. Other PGPB (i.e. Flavobacterium sp. Azospirillum sp. and Azotobacter sp. are currently being tested in aquaculture; carp farming using enhanced phytoplankton growth and stabilising mass marine micro-algae culture for use as feed for marine organisms are both retuming promising results. This aspect of PGPB effect on water micro-organisms is currently in its infancy. We pro pose that co-immobilising micro-algae and plant growth-promoting bacteria represent an effective means of increasing micro-algal populations and also their capacity for cleaning polluted water. Key words: PGPB; micro-algae; wastewater treatment; co-immobilised

Current strategies for improving food bacteria

NARCIS (Netherlands)

Kuipers, O P; Buist, Girbe; Kok, Jan

2000-01-01

Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in

[Badminton--unknown sport].

Science.gov (United States)

Zekan-Petrinović, Lidija

2007-01-01

For a long time, badminton was considered to be only a slow and light game for children, a game that is played outdoors and is structurally undemanding.Today, it is not an unknown and unrecognised sport, especially after it was included into the Olympics Games in 1992. Badminton is one of the oldest sports in the world. It is suitable for all ages (for children and elderly equally), women and men and even handicapped persons. Beginners can start playing badminton matches early because the basics are learned quickly. As a recreational activity, badminton is very popular in Zagreb. In the last 10 years, a number of halls specialized for badminton or offering badminton as one of available sports activities have been opened in Zagreb. At present, there are over 70 professional playgrounds for training of top contestants but also for the citizens who can play recreational badminton.

Level of terrestrial gamma radiation and doses to population in Jiangsu province

International Nuclear Information System (INIS)

1985-01-01

In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given. In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used. The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7 x 10 -8 Gy/h and 6.5 x 10 -8 Gy/h (weighted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0 x 10 -4 Sv. The collective annual effective dose equivalent was 3.6 x 10 4 man.Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background

[Unique properties of highly radioresistant bacteria].

Science.gov (United States)

Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R

2000-01-01

In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

Detection of viral sequence fragments of HIV-1 subfamilies yet unknown

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Stanke Mario

2011-04-01

Full Text Available Abstract Background Methods of determining whether or not any particular HIV-1 sequence stems - completely or in part - from some unknown HIV-1 subtype are important for the design of vaccines and molecular detection systems, as well as for epidemiological monitoring. Nevertheless, a single algorithm only, the Branching Index (BI, has been developed for this task so far. Moving along the genome of a query sequence in a sliding window, the BI computes a ratio quantifying how closely the query sequence clusters with a subtype clade. In its current version, however, the BI does not provide predicted boundaries of unknown fragments. Results We have developed Unknown Subtype Finder (USF, an algorithm based on a probabilistic model, which automatically determines which parts of an input sequence originate from a subtype yet unknown. The underlying model is based on a simple profile hidden Markov model (pHMM for each known subtype and an additional pHMM for an unknown subtype. The emission probabilities of the latter are estimated using the emission frequencies of the known subtypes by means of a (position-wise probabilistic model for the emergence of new subtypes. We have applied USF to SIV and HIV-1 sequences formerly classified as having emerged from an unknown subtype. Moreover, we have evaluated its performance on artificial HIV-1 recombinants and non-recombinant HIV-1 sequences. The results have been compared with the corresponding results of the BI. Conclusions Our results demonstrate that USF is suitable for detecting segments in HIV-1 sequences stemming from yet unknown subtypes. Comparing USF with the BI shows that our algorithm performs as good as the BI or better.

Terrestrial ecology. Comprehensive study of the grassland biome

International Nuclear Information System (INIS)

Anon.

1976-01-01

Terrestrial ecology and grassland biome studies are designed to characterize the biota of the Hanford Reservation, elucidate seasonal dynamics of plant productivity, decomposition and mineral behavior patterns of important plant communities, and, to study the response of these communities to important natural environmental stresses, such as weather, wildfire and man-induced alterations of communities (influenced by grazing cattle and severe mechanical disturbance of the soil, such as affected by plowing or burial of waste materials or construction activities). A detailed account of the important findings of a 5-yr study is currently being prepared by the terrestrial ecology section staff for publication as a contribution to the International Biological Program Grassland Biome project

Global Drainage Patterns to Modern Terrestrial Sedimentary Basins and its Influence on Large River Systems

Science.gov (United States)

Nyberg, B.; Helland-Hansen, W.

2017-12-01

Long-term preservation of alluvial sediments is dependent on the hydrological processes that deposit sediments solely within an area that has available accomodation space and net subsidence know as a sedimentary basin. An understanding of the river processes contributing to terrestrial sedimentary basins is essential to fundamentally constrain and quantify controls on the modern terrestrial sink. Furthermore, the terrestrial source to sink controls place constraints on the entire coastal, shelf and deep marine sediment routing systems. In addition, the geographical importance of modern terrestrial sedimentary basins for agriculture and human settlements has resulted in significant upstream anthropogenic catchment modification for irrigation and energy needs. Yet to our knowledge, a global catchment model depicting the drainage patterns to modern terrestrial sedimentary basins has previously not been established that may be used to address these challenging issues. Here we present a new database of 180,737 global catchments that show the surface drainage patterns to modern terrestrial sedimentary basins. This is achieved by using high resolution river networks derived from digital elevation models in relation to newly acquired maps on global modern sedimentary basins to identify terrestrial sinks. The results show that active tectonic regimes are typically characterized by larger terrestrial sedimentary basins, numerous smaller source catchments and a high source to sink relief ratio. To the contrary passive margins drain catchments to smaller terrestrial sedimentary basins, are composed of fewer source catchments that are relatively larger and a lower source to sink relief ratio. The different geomorphological characteristics of source catchments by tectonic setting influence the spatial and temporal patterns of fluvial architecture within sedimentary basins and the anthropogenic methods of exploiting those rivers. The new digital database resource is aimed to help

Bactericide for sulfate-reducing bacteria

Energy Technology Data Exchange (ETDEWEB)

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

1981-01-01

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

Effect factors for terrestrial acidification in Brazil

DEFF Research Database (Denmark)

Crespo Mendes, Natalia; Laurent, Alexis; Hauschild, Michael Zwicky

conditions, which is an essential approach considering countries like Brazil, with high biodiversity. Previous studies have assessed the impacts of terrestrial acidification from the estimations of the potential losses of vascular plants species richness as a result of exposure to acidifying substances...... for 13 biomes, with 2409 species addressed for whole world. In this context this work aims to provide spatially-differentiated effect factors (EF) for terrestrial acidification in Brazil and support the development of spatially-differentiated characterization factors for Brazil. In order to maintain...... in Brazil, represented by 33167 species, indicating that this is a comprehensive study. Maps of soil pH in Brazil were extracted at 1-km resolution and pH values were extracted for the depth range of 0-30cm. For each ecoregion, species richness was plotted against soil pH and the exposure-response curves...

Psychological profile: the problem of modeling the unknown criminal personality

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Г. М. Гетьман

2013-10-01

Full Text Available The article investigates the problem of modeling an unknown person in the preparation of criminal psychological profile. Some approaches to the concept of "psychological profile" and "psychological portrait", in particular the proposed delineation of these terms. We consider the system steps in the development of the psychological profile of an unknown perpetrator.

Multifocal chronic osteomyelitis of unknown etiology

International Nuclear Information System (INIS)

Kozlowski, K.; Masel, J.; Harbison, S.; Yu, J.; Royal Brisbane Children Hospital; Regional Hospital Bowral

1983-01-01

Five cases of chronic, inflammatory, multifocal bone lesions of unknown etiology are reported. Although bone biopsy confirmed osteomyelitis in each case in none of them were organisms found inspite of an extensive work up. Different clinical course of the disease reflects different aetiology in respective cases. These cases present changing aspects of osteomyelitis emerging since introduction of antibiotics. (orig.)

Bayesian source term determination with unknown covariance of measurements

Science.gov (United States)

Belal, Alkomiet; Tichý, Ondřej; Šmídl, Václav

2017-04-01

Determination of a source term of release of a hazardous material into the atmosphere is a very important task for emergency response. We are concerned with the problem of estimation of the source term in the conventional linear inverse problem, y = Mx, where the relationship between the vector of observations y is described using the source-receptor-sensitivity (SRS) matrix M and the unknown source term x. Since the system is typically ill-conditioned, the problem is recast as an optimization problem minR,B(y - Mx)TR-1(y - Mx) + xTB-1x. The first term minimizes the error of the measurements with covariance matrix R, and the second term is a regularization of the source term. There are different types of regularization arising for different choices of matrices R and B, for example, Tikhonov regularization assumes covariance matrix B as the identity matrix multiplied by scalar parameter. In this contribution, we adopt a Bayesian approach to make inference on the unknown source term x as well as unknown R and B. We assume prior on x to be a Gaussian with zero mean and unknown diagonal covariance matrix B. The covariance matrix of the likelihood R is also unknown. We consider two potential choices of the structure of the matrix R. First is the diagonal matrix and the second is a locally correlated structure using information on topology of the measuring network. Since the inference of the model is intractable, iterative variational Bayes algorithm is used for simultaneous estimation of all model parameters. The practical usefulness of our contribution is demonstrated on an application of the resulting algorithm to real data from the European Tracer Experiment (ETEX). This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases by Inverse Atmospheric Dispersion Modelling (STRADI).

Biodiversity of Terrestrial Vegetation during Past Warm Periods

Science.gov (United States)

Davies-Barnard, T.; Valdes, P. J.; Ridgwell, A.

2016-12-01

Previous modelling studies of vegetation have generally used a small number of plant functional types to understand how the terrestrial biosphere responds to climate changes. Whilst being useful for understanding first order climate feedbacks, this climate-envelope approach makes a lot of assumptions about past vegetation being very similar to modern. A trait-based method has the advantage for paleo modelling in that there are substantially less assumptions made. In a novel use of the trait-based dynamic vegetation model JeDi, forced with output from climate model HadCM3, we explore past biodiversity and vegetation carbon changes. We use JeDi to model an optimal 2000 combinations of fifteen different traits to enable assessment of the overall level of biodiversity as well as individual growth strategies. We assess the vegetation shifts and biodiversity changes in past greenhouse periods to better understand the impact on the terrestrial biosphere. This work provides original insights into the response of vegetation and terrestrial carbon to climate and hydrological changes in high carbon dioxide climates over time, including during the Late Permian and Cretaceous. We evaluate how the location of biodiversity hotspots and species richness in past greenhouse climates is different to the present day.

Mycorrhiza helper bacteria

Energy Technology Data Exchange (ETDEWEB)

Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Labbe, Jessy [ORNL

2016-10-01

This chapter focuses on the Mycorrhiza Helper Bacteria (MHB), a generic name given to bacteria which stimulate the formation of mycorrhizal symbiosis. By extension, some bacterial strains that positively impact the functioning of mycorrhizal symbiosis are also called MHB. These bacteria have applicative interests, as they indirectly improve the health and growth of tree seedlings. MHB are not restricted to a specific type of ecosystem, but are rather generalist in the way that they associate with both herbaceous and woody mycorrhizal plants from boreal, temperate, arid and tropical ecosystems. However, understanding the molecular mechanisms and their specificities will help us to know more about the ecology of the MHB. The process of acquisition varies between fungal species; while ectomycorrhizal fungi most probably recurrently acquire them from the environment, the association between bacterial endosymbionts and Glomeromycota probably dates back to very ancient times, and has since been vertically transmitted.

Natural radiation doses for cosmic and terrestrial components in Costa Rica

International Nuclear Information System (INIS)

Mora, Patricia; Picado, Esteban; Minato, Susumu

2007-01-01

A study of external natural radiation, cosmic and terrestrial components, was carried out with in situ measurements using NaI scintillation counters while driving along the roads in Costa Rica for the period July 2003-July 2005. The geographical distribution of the terrestrial air-absorbed dose rates and the total effective dose rates (including cosmic) are represented on contour maps. Information on the population density of the country permitted the calculation of the per capita doses. The average effective dose for the total cosmic component was 46.88±18.06 nSv h -1 and the average air-absorbed dose for the terrestrial component was 29.52±14.46 nGy h -1 . The average total effective dose rate (cosmic plus terrestrial components) was 0.60±0.18 mSv per year. The effective dose rate per capita was found to be 83.97 nSv h -1 which gives an annual dose of 0.74 mSv. Assuming the world average for the internal radiation component, the natural radiation dose for Costa Rica will be 2.29 mSv annually

A study of the terrestrial and cosmic gamma-rays in Jordan

International Nuclear Information System (INIS)

Mansi, M. A.

1996-01-01

Natural terrestrial gamma and cosmic radiations dose rates in Jordan were measured during a period of three years in thirty four stations distributed over all Jordanian territories using the thermoluminescence dosimeter(TLD) Coso 4 :Tm. The average absorbed dose rates in air from terrestrial gamma and cosmic radiations were found to vary from(57 ±3;9) n Gy/hr in Assafi to (350 ± 14; 42) n Gy/hr in Manjam Alhisa. The mean dose rate due to terrestrial gamma radiations was found to be equal to (55 ± 2; 13) nGy/hr, and that due to cosmic radiations was calculated to be(35 ± 1;4) n Gy/hr. The annual effective dose equivalent from terrestrial and cosmic gamma radiations was found to be equal to(0.65±0.02; 0.12)mSv/year. It was found that the absorbed dose rate due to cosmic radiations in Jordan can be fitted by the formula, D c osmic=27+5.2 h+1.86 h 2 where h is the altitude reference to the Dead Sea measured in km. 19 refs., 17 figs., 6 tabs.(Author)

Celiac Disease Presenting as Fever of Unknown Origin

Directory of Open Access Journals (Sweden)

Megan J. Cooney

2013-01-01

Full Text Available Celiac disease (CD is a common autoimmune enteropathy that occurs, in affected individuals, with exposure to gluten in the diet and improves with removal of dietary gluten. Although CD is readily considered in patients with classical presentations of the disease, atypical manifestations may be the only presenting symptoms. We present a case of CD in a 16-year-old female presenting as fever of unknown origin, which has not been reported previously. The postulated mechanism for fever in CD and the importance of clinicians having a low threshold for considering CD in the differential diagnosis of fever of unknown origin and other enigmatic clinical presentations is discussed.

Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo - controlled study

Science.gov (United States)

2014-01-01

Background Tribulus terrestris as a herbal remedy has shown beneficial aphrodisiac effects in a number of animal and human experiments. This study was designed as a randomized double-blind placebo-controlled trial to assess the safety and efficacy of Tribulus terrestris in women with hypoactive sexual desire disorder during their fertile years. Sixty seven women with hypoactive sexual desire disorder were randomly assigned to Tribulus terrestris extract (7.5 mg/day) or placebo for 4 weeks. Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured at baseline and after 4 weeks after the end of the treatment by using the Female Sexual Function Index (FSFI). Two groups were compared by repeated measurement ANOVA test. Results Thirty women in placebo group and thirty women in drug group completed the study. At the end of the fourth week, patients in the Tribulus terrestris group had experienced significant improvement in their total FSFI (p Tribulus terrestris may safely and effectively improve desire in women with hypoactive sexual desire disorder. Further investigation of Tribulus terrestris in women is warranted. PMID:24773615

Tribulus terrestris for treatment of sexual dysfunction in women: randomized double-blind placebo - controlled study.

Science.gov (United States)

Akhtari, Elham; Raisi, Firoozeh; Keshavarz, Mansoor; Hosseini, Hamed; Sohrabvand, Farnaz; Bioos, Soodabeh; Kamalinejad, Mohammad; Ghobadi, Ali

2014-04-28

Tribulus terrestris as a herbal remedy has shown beneficial aphrodisiac effects in a number of animal and human experiments. This study was designed as a randomized double-blind placebo-controlled trial to assess the safety and efficacy of Tribulus terrestris in women with hypoactive sexual desire disorder during their fertile years. Sixty seven women with hypoactive sexual desire disorder were randomly assigned to Tribulus terrestris extract (7.5 mg/day) or placebo for 4 weeks. Desire, arousal, lubrication, orgasm, satisfaction, and pain were measured at baseline and after 4 weeks after the end of the treatment by using the Female Sexual Function Index (FSFI). Two groups were compared by repeated measurement ANOVA test. Thirty women in placebo group and thirty women in drug group completed the study. At the end of the fourth week, patients in the Tribulus terrestris group had experienced significant improvement in their total FSFI (p Tribulus terrestris may safely and effectively improve desire in women with hypoactive sexual desire disorder. Further investigation of Tribulus terrestris in women is warranted.

Tracking acquired antibiotic resistance in commensal bacteria of Galápagos land iguanas: no man, no resistance.

Directory of Open Access Journals (Sweden)

Maria Cristina Thaller

Full Text Available BACKGROUND: Antibiotic resistance, evolving and spreading among bacterial pathogens, poses a serious threat to human health. Antibiotic use for clinical, veterinary and agricultural practices provides the major selective pressure for emergence and persistence of acquired resistance determinants. However, resistance has also been found in the absence of antibiotic exposure, such as in bacteria from wildlife, raising a question about the mechanisms of emergence and persistence of resistant strains under similar conditions, and the implications for resistance control strategies. Since previous studies yielded some contrasting results, possibly due to differences in the ecological landscapes of the studied wildlife, we further investigated this issue in wildlife from a remote setting of the Galapagos archipelago. METHODOLOGY/PRINCIPAL FINDINGS: Screening for acquired antibiotic resistance was carried out in commensal enterobacteria from Conolophus pallidus, the terrestrial iguana of Isla Santa Fe, where: i the abiotic conditions ensure to microbes good survival possibilities in the environment; ii the animal density and their habits favour microbial circulation between individuals; and iii there is no history of antibiotic exposure and the impact of humans and introduced animal species is minimal except for restricted areas. Results revealed that acquired antibiotic resistance traits were exceedingly rare among bacteria, occurring only as non-dominant strains from an area of minor human impact. CONCLUSIONS/SIGNIFICANCE: Where both the exposure to antibiotics and the anthropic pressure are minimal, acquired antibiotic resistance traits are not normally found in bacteria from wildlife, even if the ecological landscape is highly favourable to bacterial circulation among animals. Monitoring antibiotic resistance in wildlife from remote areas could also be a useful tool to evaluate the impact of anthropic pressure.

Tracking acquired antibiotic resistance in commensal bacteria of Galápagos land iguanas: no man, no resistance.

Science.gov (United States)

Thaller, Maria Cristina; Migliore, Luciana; Marquez, Cruz; Tapia, Washington; Cedeño, Virna; Rossolini, Gian Maria; Gentile, Gabriele

2010-02-01

Antibiotic resistance, evolving and spreading among bacterial pathogens, poses a serious threat to human health. Antibiotic use for clinical, veterinary and agricultural practices provides the major selective pressure for emergence and persistence of acquired resistance determinants. However, resistance has also been found in the absence of antibiotic exposure, such as in bacteria from wildlife, raising a question about the mechanisms of emergence and persistence of resistant strains under similar conditions, and the implications for resistance control strategies. Since previous studies yielded some contrasting results, possibly due to differences in the ecological landscapes of the studied wildlife, we further investigated this issue in wildlife from a remote setting of the Galapagos archipelago. Screening for acquired antibiotic resistance was carried out in commensal enterobacteria from Conolophus pallidus, the terrestrial iguana of Isla Santa Fe, where: i) the abiotic conditions ensure to microbes good survival possibilities in the environment; ii) the animal density and their habits favour microbial circulation between individuals; and iii) there is no history of antibiotic exposure and the impact of humans and introduced animal species is minimal except for restricted areas. Results revealed that acquired antibiotic resistance traits were exceedingly rare among bacteria, occurring only as non-dominant strains from an area of minor human impact. Where both the exposure to antibiotics and the anthropic pressure are minimal, acquired antibiotic resistance traits are not normally found in bacteria from wildlife, even if the ecological landscape is highly favourable to bacterial circulation among animals. Monitoring antibiotic resistance in wildlife from remote areas could also be a useful tool to evaluate the impact of anthropic pressure.

Fast grasping of unknown objects using principal component analysis

Science.gov (United States)

Lei, Qujiang; Chen, Guangming; Wisse, Martijn

2017-09-01

Fast grasping of unknown objects has crucial impact on the efficiency of robot manipulation especially subjected to unfamiliar environments. In order to accelerate grasping speed of unknown objects, principal component analysis is utilized to direct the grasping process. In particular, a single-view partial point cloud is constructed and grasp candidates are allocated along the principal axis. Force balance optimization is employed to analyze possible graspable areas. The obtained graspable area with the minimal resultant force is the best zone for the final grasping execution. It is shown that an unknown object can be more quickly grasped provided that the component analysis principle axis is determined using single-view partial point cloud. To cope with the grasp uncertainty, robot motion is assisted to obtain a new viewpoint. Virtual exploration and experimental tests are carried out to verify this fast gasping algorithm. Both simulation and experimental tests demonstrated excellent performances based on the results of grasping a series of unknown objects. To minimize the grasping uncertainty, the merits of the robot hardware with two 3D cameras can be utilized to suffice the partial point cloud. As a result of utilizing the robot hardware, the grasping reliance is highly enhanced. Therefore, this research demonstrates practical significance for increasing grasping speed and thus increasing robot efficiency under unpredictable environments.

Morphological and molecular characterization and phylogenetic relationships of a new species of trypanosome in Tapirus terrestris (lowland tapir), Trypanosoma terrestris sp. nov., from Atlantic Rainforest of southeastern Brazi.

Science.gov (United States)

Acosta, Igor da Cunha Lima; da Costa, Andrea Pereira; Nunes, Pablo Henrique; Gondim, Maria Fernanda Naegeli; Gatti, Andressa; Rossi, João Luiz; Gennari, Solange Maria; Marcili, Arlei

2013-12-11

The Lowland tapir (Tapirus terrestris) is the largest Brazilian mammal and despite being distributed in various Brazilian biomes, it is seriously endangered in the Atlantic Rainforest. These hosts were never evaluated for the presence of Trypanosoma parasites. The Lowland tapirs were captured in the Brazilian southeastern Atlantic Rainforest, Espírito Santo state. Trypanosomes were isolated by hemoculture, and the molecular phylogeny based on small subunit rDNA (SSU rDNA) and glycosomal-3-phosphate dehydrogenase (gGAPDH) gene sequences and the ultrastructural features seen via light microscopy and scanning and transmission electron microscopy are described. Phylogenetic trees using combined SSU rDNA and gGAPDH data sets clustered the trypanosomes of Lowland tapirs, which were highly divergent from other trypanosome species. The phylogenetic position and morphological discontinuities, mainly in epimastigote culture forms, made it possible to classify the trypanosomes from Lowland tapirs as a separate species. The isolated trypanosomes from Tapirus terrestris are a new species, Trypanosoma terrestris sp. n., and were positioned in a new Trypanosoma clade, named T. terrestris clade.

DECIPHERING THERMAL PHASE CURVES OF DRY, TIDALLY LOCKED TERRESTRIAL PLANETS

Energy Technology Data Exchange (ETDEWEB)

Koll, Daniel D. B.; Abbot, Dorian S., E-mail: dkoll@uchicago.edu [Department of the Geophysical Sciences, University of Chicago, Chicago, IL 60637 (United States)

2015-03-20

Next-generation space telescopes will allow us to characterize terrestrial exoplanets. To do so effectively it will be crucial to make use of all available data. We investigate which atmospheric properties can, and cannot, be inferred from the broadband thermal phase curve of a dry and tidally locked terrestrial planet. First, we use dimensional analysis to show that phase curves are controlled by six nondimensional parameters. Second, we use an idealized general circulation model to explore the relative sensitivity of phase curves to these parameters. We find that the feature of phase curves most sensitive to atmospheric parameters is the peak-to-trough amplitude. Moreover, except for hot and rapidly rotating planets, the phase amplitude is primarily sensitive to only two nondimensional parameters: (1) the ratio of dynamical to radiative timescales and (2) the longwave optical depth at the surface. As an application of this technique, we show how phase curve measurements can be combined with transit or emission spectroscopy to yield a new constraint for the surface pressure and atmospheric mass of terrestrial planets. We estimate that a single broadband phase curve, measured over half an orbit with the James Webb Space Telescope, could meaningfully constrain the atmospheric mass of a nearby super-Earth. Such constraints will be important for studying the atmospheric evolution of terrestrial exoplanets as well as characterizing the surface conditions on potentially habitable planets.

A novel proxy for terrestrial organic matter in sediments based on branched and isoprenoid tetraether lipids

NARCIS (Netherlands)

Sinninghe Damsté, J.S.; Hopmans, E.C.; Weijers, J.W.H.; Schefuß, E.; Herfort, L.; Schouten, S.

2004-01-01

We propose a novel tracer for terrestrial organic carbon in sediments based on the analysis of tetraether lipids using high-performance liquid chromatography/mass spectrometry (HPLC/MS). Analysis of terrestrial soil and peats shows that branched tetraether lipids are predominant in terrestrial

Digital terrestrial broadcasting receiver in the U.K; Eikoku chijoha digital hoso jushinki

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Digital terrestrial broadcasting is broadcasted in parallel with existing UHF analog broadcasting, whereas each of allocated channel frequencies can transmit five to six programs simultaneously. Each home can receive a number of programs with the existing antenna without a need of installing a new satellite antenna or cable. Among the countries of the world running forward to digitization of broadcasting all at once, the U.K. develops advancing movements and leads the world by starting the digital terrestrial broadcasting. In addition to the digitized broadcasting of conventional analog broadcasting programs, the `Ondigitals` (broadcasting operators) have started newly the pay broadcasting. Toshiba has been selected as one of the six developers and manufacturers of digital terrestrial broadcasting receivers, and has developed the digital terrestrial broadcasting receiver DTB2000. For the modulation system, the orthogonal frequency division multiplex (OFDM) was chosen as a system being strong against ghost and most suitable for digital terrestrial broadcasting. In addition, the receiver is equipped with software download function by using the broadcasting waves, and the common interface being the communication specification specified in the DVB (digital video broadcasting) to provide future function expandability. (translated by NEDO)

Aquatic pollution increases use of terrestrial prey subsidies by stream fish

Science.gov (United States)

Kraus, Johanna M.; Pomeranz, Justin F.; Todd, Andrew S.; Walters, David M.; Schmidt, Travis S.; Wanty, Richard B.

2016-01-01

Stream food webs are connected with their riparian zones through cross-ecosystem movements of energy and nutrients. The use and impact of terrestrial subsidies on aquatic consumers is determined in part by in situ biomass of aquatic prey. Thus, stressors such as aquatic pollutants that greatly reduce aquatic secondary production could increase the need for and reliance of stream consumers on terrestrial resource subsidies.

A new feruloyl amide derivative from the fruits of Tribulus terrestris.

Science.gov (United States)

Zhang, Xiaopo; Wei, Na; Huang, Jian; Tan, Yinfeng; Jin, Dejun

2012-01-01

A new feruloyl amide derivative, named tribulusamide C, was isolated from the fruits of Tribulus terrestris. Its structure was determined on the basis of spectroscopic analysis including IR, 1-D-, 2-D-NMR and HR-ESI-MS. The structure of tribulusamide C was characterised by a unit of pyrrolidine-2,5-dione, which distinguished it from other lignanamides previously isolated from the fruits of T. terrestris.

Enhanced transfer of terrestrially derived carbon to the atmosphere in a flooding event

Science.gov (United States)

Bianchi, Thomas S.; Garcia-Tigreros, Fenix; Yvon-Lewis, Shari A.; Shields, Michael; Mills, Heath J.; Butman, David; Osburn, Christopher; Raymond, Peter A.; Shank, G. Christopher; DiMarco, Steven F.; Walker, Nan; Kiel Reese, Brandi; Mullins-Perry, Ruth; Quigg, Antonietta; Aiken, George R.; Grossman, Ethan L.

2013-01-01

Rising CO2 concentration in the atmosphere, global climate change, and the sustainability of the Earth's biosphere are great societal concerns for the 21st century. Global climate change has, in part, resulted in a higher frequency of flooding events, which allow for greater exchange between soil/plant litter and aquatic carbon pools. Here we demonstrate that the summer 2011 flood in the Mississippi River basin, caused by extreme precipitation events, resulted in a “flushing” of terrestrially derived dissolved organic carbon (TDOC) to the northern Gulf of Mexico. Data from the lower Atchafalaya and Mississippi rivers showed that the DOC flux to the northern Gulf of Mexico during this flood was significantly higher than in previous years. We also show that consumption of radiocarbon-modern TDOC by bacteria in floodwaters in the lower Atchafalaya River and along the adjacent shelf contributed to northern Gulf shelf waters changing from a net sink to a net source of CO2 to the atmosphere in June and August 2011. This work shows that enhanced flooding, which may or may not be caused by climate change, can result in rapid losses of stored carbon in soils to the atmosphere via processes in aquatic ecosystems.

Mercury exposure in terrestrial birds far downstream of an historical point source

International Nuclear Information System (INIS)

Jackson, Allyson K.; Evers, David C.; Folsom, Sarah B.; Condon, Anne M.; Diener, John; Goodrick, Lizzie F.; McGann, Andrew J.; Schmerfeld, John; Cristol, Daniel A.

2011-01-01

Mercury (Hg) is a persistent environmental contaminant found in many freshwater and marine ecosystems. Historical Hg contamination in rivers can impact the surrounding terrestrial ecosystem, but there is little known about how far downstream this contamination persists. In 2009, we sampled terrestrial forest songbirds at five floodplain sites up to 137 km downstream of an historical source of Hg along the South and South Fork Shenandoah Rivers (Virginia, USA). We found that blood total Hg concentrations remained elevated over the entire sampling area and there was little evidence of decline with distance. While it is well known that Hg is a pervasive and long-lasting aquatic contaminant, it has only been recently recognized that it also biomagnifies effectively in floodplain forest food webs. This study extends the area of concern for terrestrial habitats near contaminated rivers for more than 100 km downstream from a waterborne Hg point source. - Highlights: → We report blood mercury levels for terrestrial songbirds downstream of contamination. → Blood mercury levels remain elevated above reference for at least 137 km downstream. → Trends vary based on foraging guild and migration strategy. → Mercury affects terrestrial biota farther downstream than previously documented. - Blood mercury levels of forest songbirds remain elevated above reference levels for at least 137 km downstream of historical point source.

Horizontal gene transfer between bacteria.

Science.gov (United States)

Heuer, Holger; Smalla, Kornelia

2007-01-01

Horizontal gene transfer (HGT) refers to the acquisition of foreign genes by organisms. The occurrence of HGT among bacteria in the environment is assumed to have implications in the risk assessment of genetically modified bacteria which are released into the environment. First, introduced genetic sequences from a genetically modified bacterium could be transferred to indigenous micro-organisms and alter their genome and subsequently their ecological niche. Second, the genetically modified bacterium released into the environment might capture mobile genetic elements (MGE) from indigenous micro-organisms which could extend its ecological potential. Thus, for a risk assessment it is important to understand the extent of HGT and genome plasticity of bacteria in the environment. This review summarizes the present state of knowledge on HGT between bacteria as a crucial mechanism contributing to bacterial adaptability and diversity. In view of the use of GM crops and microbes in agricultural settings, in this mini-review we focus particularly on the presence and role of MGE in soil and plant-associated bacteria and the factors affecting gene transfer.

A re-analysis of the Lake Suigetsu terrestrial radiocarbon calibration dataset

International Nuclear Information System (INIS)

Staff, R.A.; Bronk Ramsey, C.; Nakagawa, T.

2010-01-01

Lake Suigetsu, Honshu Island, Japan provides an ideal sedimentary sequence from which to derive a wholly terrestrial radiocarbon calibration curve back to the limits of radiocarbon detection (circa 60 ka bp). The presence of well-defined, annually-deposited laminae (varves) throughout the entirety of this period provides an independent, high resolution chronometer against which radiocarbon measurements of plant macrofossils from the sediment column can be directly related. However, data from the initial Lake Suigetsu project were found to diverge significantly from alternative, marine-based calibration datasets released around the same time (e.g. ). The main source of this divergence is thought to be the result of inaccuracies in the absolute age profile of the Suigetsu project, caused by both varve counting uncertainties and gaps in the sediment column of unknown duration between successively-drilled core sections. Here, a re-analysis of the previously-published Lake Suigetsu data is conducted. The most recent developments in Bayesian statistical modelling techniques (OxCal v4.1; ) are implemented to fit the Suigetsu data to the latest radiocarbon calibration datasets and thereby estimate the duration of the inter-core section gaps in the Suigetsu data. In this way, the absolute age of the Lake Suigetsu sediment profile is more accurately defined, providing significant information for both radiocarbon calibration and palaeoenvironmental reconstruction purposes.

Methane emissions form terrestrial plants

Energy Technology Data Exchange (ETDEWEB)

Bergamaschi, P.; Dentener, F.; Grassi, G.; Leip, A.; Somogyi, Z.; Federici, S.; Seufert, G.; Raes, F. [European Commission, DG Joint Research Centre, Institute for Environment and Sustainability, Ispra (Italy)

2006-07-01

In a recent issue of Nature Keppler et al. (2006) report the discovery that terrestrial plants emit CH4 under aerobic conditions. Until now it was thought that bacterial decomposition of plant material under anaerobic conditions, such as in wetlands and water flooded rice paddies, is the main process leading to emissions from terrestrial ecosystems. In a first attempt to upscale these measurements, the authors estimate that global total emissions may be 149 Tg CH4/yr (62-236 Tg CH4/yr), with the main contribution estimated from tropical forests and grasslands (107 Tg CH4/yr with a range of 46-169 Tg CH4/yr). If confirmed, this new source of emission would constitute a significant fraction of the total global methane sources (estimated 500-600 Tg CH4/yr for present day total natural and anthropogenic sources) and have important implications for the global CH4 budget. To accommodate it within the present budget some sources would need to be re-assessed downwards and/or some sinks re-assessed upwards. Furthermore, also considering that methane is a {approx}23 times more powerful greenhouse gas than CO2, the possible feedbacks of these hitherto unknown CH4 emissions on global warming and their impacts on greenhouse gases (GHG) mitigation strategies need to be carefully evaluated. The merit of the paper is without doubt related to the remarkable discovery of a new process of methane emissions active under aerobic conditions. However, we think that the applied approach of scaling up emissions from the leaf level to global totals by using only few measured data (mainly from herbaceous species) and the Net Primary Productivity of the main biomes is scientifically questionable and tends to overestimate considerably the global estimates, especially for forest biomes. Furthermore, some significant constraints on the upper limit of the global natural CH4 emissions arise from the pre-industrial CH4 budget. Pre-industrial atmospheric CH4 mixing ratios have been measured

Quantum key distribution with an unknown and untrusted source

Science.gov (United States)

Zhao, Yi; Qi, Bing; Lo, Hoi-Kwong

2009-03-01

The security of a standard bi-directional ``plug & play'' quantum key distribution (QKD) system has been an open question for a long time. This is mainly because its source is equivalently controlled by an eavesdropper, which means the source is unknown and untrusted. Qualitative discussion on this subject has been made previously. In this paper, we present the first quantitative security analysis on a general class of QKD protocols whose sources are unknown and untrusted. The securities of standard BB84 protocol, weak+vacuum decoy state protocol, and one-decoy decoy state protocol, with unknown and untrusted sources are rigorously proved. We derive rigorous lower bounds to the secure key generation rates of the above three protocols. Our numerical simulation results show that QKD with an untrusted source gives a key generation rate that is close to that with a trusted source. Our work is published in [1]. [4pt] [1] Y. Zhao, B. Qi, and H.-K. Lo, Phys. Rev. A, 77:052327 (2008).

Grasping Unknown Objects in an Early Cognitive Vision System

DEFF Research Database (Denmark)

Popovic, Mila

2011-01-01

Grasping of unknown objects presents an important and challenging part of robot manipulation. The growing area of service robotics depends upon the ability of robots to autonomously grasp and manipulate a wide range of objects in everyday environments. Simple, non task-specific grasps of unknown ...... and comparing vision-based grasping methods, and the creation of algorithms for bootstrapping a process of acquiring world understanding for artificial cognitive agents....... presents a system for robotic grasping of unknown objects us- ing stereo vision. Grasps are defined based on contour and surface information provided by the Early Cognitive Vision System, that organizes visual informa- tion into a biologically motivated hierarchical representation. The contributions...... of the thesis are: the extension of the Early Cognitive Vision representation with a new type of feature hierarchy in the texture domain, the definition and evaluation of contour based grasping methods, the definition and evaluation of surface based grasping methods, the definition of a benchmark for testing...

Screening and characterization of phosphate solubilizing bacteria from isolate of thermophilic bacteria

Science.gov (United States)

Yulianti, Evy; Rakhmawati, Anna

2017-08-01

The aims of this study were to select bacteria that has the ability to dissolve phosphate from thermophilic bacteria isolates after the Merapi eruption. Five isolates of selected bacteria was characterized and continued with identification. Selection was done by using a pikovskaya selective medium. Bacterial isolates were grown in selective medium and incubated for 48 hours at temperature of 55 ° C. Characterization was done by looking at the cell and colony morphology, physiological and biochemical properties. Identification was done with the Profile Matching method based on the reference genus Oscillospira traced through Bergey's Manual of Determinative Bacteriology. Dendogram was created based on similarity index SSM. The results showed there were 14 isolates of bacteria that were able to dissolve phosphate indicated by a clear zone surrounding the bacterial colony on selective media. Five isolates were selected with the largest clear zone. Isolates D79, D92, D110a, D135 and D75 have different characters. The result of phenotypic characters identification with Genus Oscillospira profile has a percentage of 100% similarity to isolate D92 and D110a; 92.31% for isolates D79, and 84.6% for isolates D75 and D135. Dendogram generated from average linkage algorithm / UPGMA using the Simple Matching Coefficient (SSM) algorithms showed, isolate thermophilic bacteria D75 and D135 are combined together to form cluster 1. D110a and D92 form a sub cluster A. Sub cluster A and D79 form cluster 2

Deployable micro-traps to sequester motile bacteria

Science.gov (United States)

di Giacomo, Raffaele; Krödel, Sebastian; Maresca, Bruno; Benzoni, Patrizia; Rusconi, Roberto; Stocker, Roman; Daraio, Chiara

2017-04-01

The development of strategies to reduce the load of unwanted bacteria is a fundamental challenge in industrial processing, environmental sciences and medical applications. Here, we report a new method to sequester motile bacteria from a liquid, based on passive, deployable micro-traps that confine bacteria using micro-funnels that open into trapping chambers. Even in low concentrations, micro-traps afford a 70% reduction in the amount of bacteria in a liquid sample, with a potential to reach >90% as shown by modelling improved geometries. This work introduces a new approach to contain the growth of bacteria without chemical means, an advantage of particular importance given the alarming growth of pan-drug-resistant bacteria.

RELATIONSHIP OF AMEBOCYTES AND TERRESTRIAL ELEMENTS TO ADULT SHELL DEPOSITION IN EASTERN OYSTERS

Science.gov (United States)

Fisher, William S. Submitted. Relationship of Amebocytes and Terrestrial Elements to Adult Shell Deposition in Eastern Oysters. J. Shellfish Res. 30 p. (ERL,GB 1197). Freshwater runoff contains terrestrial elements from geological deposits that may be vital to eastern oys...

COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

NARCIS (Netherlands)

VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for