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Sample records for ancient anoxic ecological

  1. Anaerobic animals from an ancient, anoxic ecological niche

    OpenAIRE

    Martin William; Mentel Marek

    2010-01-01

    Abstract Tiny marine animals that complete their life cycle in the total absence of light and oxygen are reported by Roberto Danovaro and colleagues in this issue of BMC Biology. These fascinating animals are new members of the phylum Loricifera and possess mitochondria that in electron micrographs look very much like hydrogenosomes, the H2-producing mitochondria found among several unicellular eukaryotic lineages. The discovery of metazoan life in a permanently anoxic and sulphidic environme...

  2. Analysis of Ancient DNA in Microbial Ecology.

    Science.gov (United States)

    Gorgé, Olivier; Bennett, E Andrew; Massilani, Diyendo; Daligault, Julien; Pruvost, Melanie; Geigl, Eva-Maria; Grange, Thierry

    2016-01-01

    The development of next-generation sequencing has led to a breakthrough in the analysis of ancient genomes, and the subsequent genomic analyses of the skeletal remains of ancient humans have revolutionized the knowledge of the evolution of our species, including the discovery of a new hominin, and demonstrated admixtures with more distantly related archaic populations such as Neandertals and Denisovans. Moreover, it has also yielded novel insights into the evolution of ancient pathogens. The analysis of ancient microbial genomes allows the study of their recent evolution, presently over the last several millennia. These spectacular results have been attained despite the degradation of DNA after the death of the host, which results in very short DNA molecules that become increasingly damaged, only low quantities of which remain. The low quantity of ancient DNA molecules renders their analysis difficult and prone to contamination with modern DNA molecules, in particular via contamination from the reagents used in DNA purification and downstream analysis steps. Finally, the rare ancient molecules are diluted in environmental DNA originating from the soil microorganisms that colonize bones and teeth. Thus, ancient skeletal remains can share DNA profiles with environmental samples and identifying ancient microbial genomes among the more recent, presently poorly characterized, environmental microbiome is particularly challenging. Here, we describe the methods developed and/or in use in our laboratory to produce reliable and reproducible paleogenomic results from ancient skeletal remains that can be used to identify the presence of ancient microbiota. PMID:26791510

  3. Using Ancient DNA to Understand Evolutionary and Ecological Processes

    DEFF Research Database (Denmark)

    Orlando, Ludovic Antoine Alexandre; Cooper, Alan

    2014-01-01

    Ancient DNA provides a unique means to record genetic change through time and directly observe evolutionary and ecological processes. Although mostly based on mitochondrial DNA, the increasing availability of genomic sequences is leading to unprecedented levels of resolution. Temporal studies of...... modern populations. Importantly, the complex series of events revealed by ancient DNA data is seldom reflected in current biogeographic patterns. DNA preserved in ancient sediments and coprolites has been used to characterize a range of paleoenvironments and reconstruct functional relationships in...... paleoecological systems. In the near future, genome-level surveys of ancient populations will play an increasingly important role in revealing, calibrating, and testing evolutionary processes....

  4. Effects of ecological engineered oxygenation on the bacterial community structure in an anoxic fjord in western Sweden

    DEFF Research Database (Denmark)

    Forth, M.; Liljebladh, B.; Stigebrandt, A.;

    2015-01-01

    study, investigating the effects of an engineered oxygenation on long-term anoxic bottom waters. The strong stratification of the water column of the Byfjord was broken up by pumping surface water into the deeper layers, triggering several inflows of oxygen-rich water and increasing oxygen levels in the...... lower water column and the benthic zone up to 110 mumol l(-1).We used molecular ecologic methods to study changes in bacterial community structure in response to the oxygenation in the Byfjord. Water column samples from before, during and after the oxygenation as well as from two nearby control fjords...... after the oxygenation was accomplished. In contrast, aerobic species like SAR11 that initially were restricted to surface waters could later be detected deep into the water column. Overall, the bacterial community in the formerly anoxic bottom waters changed to a community structure similar to those...

  5. Authigenic carbonate precipitation at the end-Guadalupian (Middle Permian) in China: Implications for the carbon cycle in ancient anoxic oceans

    Science.gov (United States)

    Saitoh, Masafumi; Ueno, Yuichiro; Isozaki, Yukio; Shibuya, Takazo; Yao, Jianxin; Ji, Zhansheng; Shozugawa, Katsumi; Matsuo, Motoyuki; Yoshida, Naohiro

    2015-12-01

    Carbonate precipitation is a major process in the global carbon cycle. It was recently proposed that authigenic carbonate (carbonate precipitated in situ at the sediment-water interface and/or within the sediment) played a major role in the carbon cycle throughout Earth's history. The carbon isotopic composition of authigenic carbonates in ancient oceans have been assumed to be significantly lower than that of dissolved inorganic carbon (DIC) in seawater, as is observed in the modern oceans. However, the δ13Ccarb values of authigenic carbonates in the past has not been analyzed in detail. Here, we report authigenic carbonates in the uppermost Guadalupian (Middle Permian) rocks at Chaotian, Sichuan, South China. Monocrystalline calcite crystals black mudstone/chert sequence that was deposited on a relatively deep anoxic slope/basin along the continental margin. Textures of the crystals indicate in situ precipitation on the seafloor and/or within the sediments. The calcite precipitation corresponds stratigraphically with denitrification and sulfate reduction in the anoxic deep-water mass, as indicated by previously reported nitrogen and sulfur isotope records, respectively. Relatively high δ13Ccarb values of the authigenic carbonates (largely -1 ‰) compared with those of organic matter in the rocks (ca. -26 ‰) suggest that the main carbon source of the carbonates was DIC in the water column. The calcite crystals precipitated in an open system with respect to carbonate, possibly near the sediment-water interface rather than deep within the sediments. The δ13Ccarb values of the carbonates were close to the δ13CDIC value of seawater due to mixing of 13C-depleted remineralized organic carbon (that was released into the water column by the water-mass anaerobic respiration) with the large DIC pool in the oceans. Our results imply that δ13Ccarb values of authigenic carbonates in the anoxic oceans might have been systematically different from the values in the oxic

  6. Microbial Diversity and Ecology in the Interfaces of the Deep-sea Anoxic Brine Pools in the Red Sea

    KAUST Repository

    Hikmawan, Tyas I.

    2015-05-01

    Deep-sea anoxic brine pools are one of the most extreme ecosystems on Earth, which are characterized by drastic changes in salinity, temperature, and oxygen concentration. The interface between the brine and overlaying seawater represents a boundary of oxic-anoxic layer and a steep gradient of redox potential that would initiate favorable conditions for divergent metabolic activities, mainly methanogenesis and sulfate reduction. This study aimed to investigate the diversity of Bacteria, particularly sulfate-reducing communities, and their ecological roles in the interfaces of five geochemically distinct brine pools in the Red Sea. Performing a comprehensive study would enable us to understand the significant role of the microbial groups in local geochemical cycles. Therefore, we combined culture-dependent approach and molecular methods, such as 454 pyrosequencing of 16S rRNA gene, phylogenetic analysis of functional marker gene encoding for the alpha subunits of dissimilatory sulfite reductase (dsrA), and single-cell genomic analysis to address these issues. Community analysis based on 16S rRNA gene sequences demonstrated high bacterial diversity and domination of Bacteria over Archaea in most locations. In the hot and multilayered Atlantis II Deep, the bacterial communities were stratified and hardly overlapped. Meanwhile in the colder brine pools, sulfatereducing Deltaproteobacteria were the most prominent bacterial groups inhabiting the interfaces. Corresponding to the bacterial community profile, the analysis of dsrA gene sequences revealed collectively high diversity of sulfate-reducing communities. Desulfatiglans-like dsrA was the prevalent group and conserved across the Red Sea brine pools. In addition to the molecular studies, more than thirty bacterial strains were successfully isolated and remarkably were found to be cytotoxic against the cancer cell lines. However, none of them were sulfate reducers. Thus, a single-cell genomic analysis was used to study

  7. Anoxic environments and oil source bed genesis

    Energy Technology Data Exchange (ETDEWEB)

    Demaison, G.J. (Chevron Overseas Petroleum Inc., San Francisco, CA); Moore, G.T.

    1980-01-01

    The anoxic, aquatic, environment is a mass of water so depleted in oxygen that virtually all aerobic biological activity has ceased. Anoxic conditions occur where the demand for oxygen in the water column exceeds the supply. The specific cause for preferential lipid enrichment probably relates to the biochemistry of anaerobic bacterial activity. Recent evidence suggests that ancient organic-rich sediments containing hydrogen-rich kerogens (potential oil source beds) were deposited in similar anoxic environments. We propose the following classification for modern aquatic anoxic settings: (1) Large anoxic lakes - Permanent stratification promotes development of anoxic bottom water, particularly in large, deep lakes, which are not subject to seasonal overturn, e.g., Lake Tanganyika. (2) Anoxic silled basins - Landlocked silled basins with positive water balance tend to become anoxic. Typical are the Baltic and Black Seas. In arid region seas (Red and Mediterranean Seas), evaporation exceeds river inflow, causing negative water balance and well-aerated, nutrient-depleted bottom waters. (3) Anoxic layers caused by upwelling - Develop only when the oxygen supply in deep water cannot match demand by decaying organisms. Examples are the Benguela current and Peru coastal upwelling. (4) Open ocean anoxic layers - Found at intermediate depths in the northeastern Pacific and northern Indian Oceans; due to distance from deep, oxygenated polar water sources. Analogous to world-wide anoxic events at times of global climatic warm-ups and major transgressions, as in late Jurassic and middle Cretaceous time. Petroleum exploration can be greatly assisted by using geochemistry to identify paleo-anoxic events in the stratigraphic record. Recognition of the proposed anoxic models in ancient sedimentary basins should help in regional mapping of oil shales and oil-source beds. 17 figures.

  8. Pre-whaling genetic diversity and population ecology in eastern Pacific gray whales: insights from ancient DNA and stable isotopes.

    Directory of Open Access Journals (Sweden)

    S Elizabeth Alter

    Full Text Available Commercial whaling decimated many whale populations, including the eastern Pacific gray whale, but little is known about how population dynamics or ecology differed prior to these removals. Of particular interest is the possibility of a large population decline prior to whaling, as such a decline could explain the ~5-fold difference between genetic estimates of prior abundance and estimates based on historical records. We analyzed genetic (mitochondrial control region and isotopic information from modern and prehistoric gray whales using serial coalescent simulations and Bayesian skyline analyses to test for a pre-whaling decline and to examine prehistoric genetic diversity, population dynamics and ecology. Simulations demonstrate that significant genetic differences observed between ancient and modern samples could be caused by a large, recent population bottleneck, roughly concurrent with commercial whaling. Stable isotopes show minimal differences between modern and ancient gray whale foraging ecology. Using rejection-based Approximate Bayesian Computation, we estimate the size of the population bottleneck at its minimum abundance and the pre-bottleneck abundance. Our results agree with previous genetic studies suggesting the historical size of the eastern gray whale population was roughly three to five times its current size.

  9. Ecological and environmental consequences of Oceanic Anoxic Events and the Cretaceous-Paleogene mass extinction event: a molecular-isotopic approach

    OpenAIRE

    Sepulveda, Julio

    2008-01-01

    The main aim of this thesis was to study the biotic and abiotic consequences of extreme environmental conditions during Cretaceous Oceanic Anoxic Events (OAE), and the recovery of primary production at the Cretaceous-Paleogene (K-Pg) mass extinction event through the use of lipid biomarkers, compound-specific stable isotopes, and bulk geochemistry. This multiproxy approach contributes new evidence for understanding the intricate environmental and biological interactions occurring during these...

  10. The obstetric dilemma: an ancient game of Russian roulette, or a variable dilemma sensitive to ecology?

    Science.gov (United States)

    Wells, Jonathan C K; DeSilva, Jeremy M; Stock, Jay T

    2012-01-01

    The difficult birth process of humans, often described as the "obstetric dilemma," is commonly assumed to reflect antagonistic selective pressures favoring neonatal encephalization and maternal bipedal locomotion. However, cephalo-pelvic disproportion is not exclusive to humans, and is present in some primate species of smaller body size. The fossil record indicates mosaic evolution of the obstetric dilemma, involving a number of different evolutionary processes, and it appears to have shifted in magnitude between Australopithecus, Pleistocene Homo, and recent human populations. Most attention to date has focused on its generic nature, rather than on its variability between populations. We re-evaluate the nature of the human obstetric dilemma using updated hominin and primate literature, and then consider the contribution of phenotypic plasticity to variability in its magnitude. Both maternal pelvic dimensions and fetal growth patterns are sensitive to ecological factors such as diet and the thermal environment. Neonatal head girth has low plasticity, whereas neonatal mass and maternal stature have higher plasticity. Secular trends in body size may therefore exacerbate or decrease the obstetric dilemma. The emergence of agriculture may have exacerbated the dilemma, by decreasing maternal stature and increasing neonatal growth and adiposity due to dietary shifts. Paleodemographic comparisons between foragers and agriculturalists suggest that foragers have considerably lower rates of perinatal mortality. In contemporary populations, maternal stature remains strongly associated with perinatal mortality in many populations. Long-term improvements in nutrition across future generations may relieve the dilemma, but in the meantime, variability in its magnitude is likely to persist. PMID:23138755

  11. Chronology and ancient feeding ecology of two upper Pleistocene megamammals from the Brazilian Intertropical Region

    Science.gov (United States)

    de Melo França, Lucas; Trindade Dantas, Mário André; Bocchiglieri, Adriana; Cherckinsky, Alexander; de Souza Ribeiro, Adauto; Bocherens, Hervé

    2014-09-01

    In Brazilian Intertropical Region (BIR) fossil remains of the giant ground sloth Eremotherium laurillardi (Lund, 1842) and of the proboscidean Notiomastodon platensis (Ameghino, 1888) are the most abundant among megaherbivores. However, the paleoecology of both species needs to be better understood to enlighten why these species disappear in the end of the Pleistocene, an issue that is still debated. During the last decades, the carbon and oxygen stable isotopes have been increasingly being used to obtain paleoecological information about extinct animals, although this information is in most cases dissociated from chronological data. Thus, the main objective of this study is to contribute to the knowledge about feeding ecology and chronology of E. laurillardi and N. platensis within BIR. For each fossil sample we performed stable isotopes analyses (δ13C/δ18O) and radiocarbon dating (14C with AMS). The results showed that N. platensis occurred between 12,125 and 19,594 cal yr BP and exhibited a grazer diet (δ13C = -1.1‰-1.3‰), while E. laurillardi lived between 11,084 and 27,690 cal yr BP, with a mixed feeder diet (C3/C4 plants; values ratio δ13C = -7.7‰ to -3.3‰). The δ18O values of N. platensis ranged between 2.20‰ and 3.60‰, while the values of E. laurillardi ranged between -3.10‰ and -1.10‰. Neither species did exhibit differences in its diet through time, which suggests that the vegetational composition of this locality did not vary in the late Pleistocene. Both species were living in an open environment, rich in herbaceous plants (C4 plants) and with tree and shrub with disjoint distribution, maybe similar to some parts of recent Caatinga, where they have partitioned the spatial and feeding niches.

  12. Historical ecology meets conservation and evolutionary genetics: a secondary contact zone between Carabus violaceus (Coleoptera, Carabidae populations inhabiting ancient and recent woodlands in north-western Germany

    Directory of Open Access Journals (Sweden)

    Andrea Matern

    2011-05-01

    Full Text Available Only very few cases have documented that an increase in connectivity after a period of fragmentation in ecological time has had an effect on the distribution, genetic structure and morphology of stenotopic species. In this study we present an example of clinal variability in a woodland ground beetle as a result of changes in the connectivity of a landscape during the last two centuries. The study area hosts both the nominate form C. violaceus s. str. and the subspecies C. v. purpurascens, which is ranked as a distinct species by some authors. We studied 12 Carabus violaceus populations from a 30 km transect of ancient and recent forests in north-western Germany. We analyzed three polymorphic enzyme loci, classified the elytron sculpture and measured the shape of the aedeagus tip of the specimens. C. violaceus showed secondary gradients both in allozyme markers and morphometric characters in our study area. A genetic differentiation of 16% between the populations is high but lies within the range of intraspecific variability in habitat specialists of the genus Carabus. Populations had no significant deficit of heterozygotes. We found many hybrid populations in terms of morphological properties. This study highlights the conservation value of ancient woodland and the consequences of landscape connectivity and defragmentation on the genetic setting of a ground beetle. Moreover, it shows that differences in the external shape of male genitalia do not prevent gene flow within the genus Carabus. Thus, the establishment of species status should not exclusively be based on this property.

  13. Ancient DNA

    DEFF Research Database (Denmark)

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair......ancient DNA, palaeontology, palaeoecology, archaeology, population genetics, DNA damage and repair...

  14. 略论古希腊的自然观及其生态意蕴%On Ancient Greek View of Nature and its Ecological Implication

    Institute of Scientific and Technical Information of China (English)

    李笑春; 王东

    2011-01-01

    With a very complex form, ancient Greek view of nature opened various possibilities. We should treat the transcendence of the Greek philosophers carefully (they were firstly embedded in the cultural traditions individually) , and keep a healthy skepticism to the logical conclusion, that to kwon Greek view of nature is not the materialized beginning of viewing nature. It did provided possibility for human to look beyond the nature, but on the other hand it also deceived people by supporting religious beliefs. Ancient Greek view of nature was not a systematic one, and the rich theoretical differences shown by its diverse theories, was where the numerous ecological concepts bred from. The extreme plasticity of Greek view of nature, rooted in the natural philosophers' effort of trying to explore the secret of nature, but they did not interrogate the na- ture as an object of study. They took the experiential phenomena as the basis and starting point, hut always went back to the metaphysics of being. All in all, from the perspective of history of ecological ideas, we will find that, with infinite possibilities, ancient Greek view of nature was the initial framework from where the ecological thought expanded, and the either way through which ecological thought could grow up.%古希腊的自然观呈现出极为复杂的形态,它开启了各种可能。在此我们要审慎地看待希腊哲人的超越性(他们也同样首先是内嵌于文化传统的个人),要对逻辑化的结论保持健康的怀疑:古希腊自然观并非物化地看待自然的开端,它为人类超越地审视自然提供可能,但同时也为人类蒙蔽于自然之内的宗教信念提供支持;古希腊自然观并不系统,在不同理论之中所表现出的丰富差异,是孕育此后诸多生态观念的温床。古希腊自然观所表现出的极强的可塑性,根源于自然哲学家们尝试性地探求自然的秘密,但并不对象性地究诘自然

  15. Management of Reflex Anoxic Seizures

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2013-10-01

    Full Text Available Investigators at the Roald Dahl EEG Unit, Alder Hey Children’s NHS Foundation, Liverpool, UK, review the definition, pathophysiology, clinical presentation, and management of reflex anoxic seizures (RAS in children.

  16. Pre-Whaling Genetic Diversity and Population Ecology in Eastern Pacific Gray Whales: Insights from Ancient DNA and Stable Isotopes

    OpenAIRE

    Elizabeth Alter, S; Newsome, Seth D.; Palumbi, Stephen R.

    2012-01-01

    Commercial whaling decimated many whale populations, including the eastern Pacific gray whale, but little is known about how population dynamics or ecology differed prior to these removals. Of particular interest is the possibility of a large population decline prior to whaling, as such a decline could explain the ~5-fold difference between genetic estimates of prior abundance and estimates based on historical records. We analyzed genetic (mitochondrial control region) and isotopic informatio...

  17. 山水与海:韩国古代文化地域想象的生态图谱%Landscape and Sea:Ecological Atlas of Cultural Geographical Imagination in Ancient Korea

    Institute of Scientific and Technical Information of China (English)

    王耘

    2014-01-01

    朝鲜半岛虽为多山而临海的半岛,但山水与海并未融合为韩国古代文人关于其文化地域想象的生态共同体。山水与海二者之间充满了“选择”的生态意趣。韩国古代文人向往山水,以山水为整个社会道德原则的立法参照,却没有对海的文化深意抱有太多的感念与同情。%The Korean Peninsula is hilly and coastal, but the landscape and the sea did not integrate as an e-cological community in ancient Korean literati's cultural geographical imagination. Between the landscape and the sea were full of ecological interest of “selection”. Ancient Korean literati aspired to landscape, and made the latter legislative reference for moral principles of whole society, but they were lack of deep gratitude and sympathy for profound cultural meanings of the sea. The Korean Peninsula is hilly and coastal, but the landscape and the sea did not integrate as an e-cological community in ancient Korean literati's cultural geographical imagination. Between the landscape and the sea were full of ecological interest of “selection”. Ancient Korean literati aspired to landscape, and made the latter legislative reference for moral principles of whole society, but they were lack of deep gratitude and sympathy for profound cultural meanings of the sea.

  18. Taoism and Deep Ecology.

    Science.gov (United States)

    Sylvan, Richard; Bennett, David

    1988-01-01

    Contrasted are the philosophies of Deep Ecology and ancient Chinese. Discusses the cosmology, morality, lifestyle, views of power, politics, and environmental philosophies of each. Concludes that Deep Ecology could gain much from Taoism. (CW)

  19. Ancient human microbiomes

    Science.gov (United States)

    Warinner, Christina; Speller, Camilla; Collins, Matthew J.; Lewis, Cecil M.

    2015-01-01

    Very recently, we discovered a vast new microbial self: the human microbiome. Our native microbiota interface with our biology and culture to influence our health, behavior, and quality of life, and yet we know very little about their origin, evolution, or ecology. With the advent of industrialization, globalization, and modern sanitation, it is intuitive that we have changed our relationship with microbes, but we have little information about the ancestral state of our microbiome, and therefore, we lack a foundation for characterizing this change. High-throughput sequencing has opened up new opportunities in the field of paleomicrobiology, allowing us to investigate the evolution of the complex microbial ecologies that inhabit our bodies. By focusing on recent coprolite and dental calculus research, we explore how emerging research on ancient human microbiomes is changing the way we think about ancient disease and how archaeological studies can contribute to a medical understanding of health and nutrition today. PMID:25559298

  20. Ancient Egypt.

    Science.gov (United States)

    Evers, Virginia

    This four-week fourth grade social studies unit dealing with religious dimensions in ancient Egyptian culture was developed by the Public Education Religion Studies Center at Wright State University. It seeks to help students understand ancient Egypt by looking at the people, the culture, and the people's world view. The unit begins with outlines…

  1. Ancient DNA

    OpenAIRE

    Willerslev, Eske; Cooper, Alan

    2004-01-01

    In the past two decades, ancient DNA research has progressed from the retrieval of small fragments of mitochondrial DNA from a few late Holocene specimens, to large-scale studies of ancient populations, phenotypically important nuclear loci, and even whole mitochondrial genome sequences of extinct species. However, the field is still regularly marred by erroneous reports, which underestimate the extent of contamination within laboratories and samples themselves. An improved understanding of t...

  2. Ancient genomics

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Allentoft, Morten Erik; Avila Arcos, Maria del Carmen;

    2015-01-01

    The past decade has witnessed a revolution in ancient DNA (aDNA) research. Although the field's focus was previously limited to mitochondrial DNA and a few nuclear markers, whole genome sequences from the deep past can now be retrieved. This breakthrough is tightly connected to the massive sequence...... increasing the number of sequence reads to billions effectively means that contamination issues that have haunted aDNA research for decades, particularly in human studies, can now be efficiently and confidently quantified. At present, whole genomes have been sequenced from ancient anatomically modern humans......, archaic hominins, ancient pathogens and megafaunal species. Those have revealed important functional and phenotypic information, as well as unexpected adaptation, migration and admixture patterns. As such, the field of aDNA has entered the new era of genomics and has provided valuable information when...

  3. Ancient Egypt

    Science.gov (United States)

    Swamy, Ashwin Balegar

    This thesis involves development of an interactive GIS (Geographic Information System) based application, which gives information about the ancient history of Egypt. The astonishing architecture, the strange burial rituals and their civilization were some of the intriguing questions that motivated me towards developing this application. The application is a historical timeline starting from 3100 BC, leading up to 664 BC, focusing on the evolution of the Egyptian dynasties. The tool holds information regarding some of the famous monuments which were constructed during that era and also about the civilizations that co-existed. It also provides details about the religions followed by their kings. It also includes the languages spoken during those periods. The tool is developed using JAVA, a programing language and MOJO (Map Objects Java Objects) a product of ESRI (Environmental Science Research Institute) to create map objects, to provide geographic information. JAVA Swing is used for designing the user interface. HTML (Hyper Text Markup Language) pages are created to provide the user with more information related to the historic period. CSS (Cascade Style Sheets) and JAVA Scripts are used with HTML5 to achieve creative display of content. The tool is kept simple and easy for the user to interact with. The tool also includes pictures and videos for the user to get a feel of the historic period. The application is built to motivate people to know more about one of the prominent and ancient civilization of the Mediterranean world.

  4. Ancient DNA from marine mammals

    DEFF Research Database (Denmark)

    Foote, Andrew David; Hofreiter, Michael; Morin, Philip A

    2012-01-01

    such as bone, tooth, baleen, skin, fur, whiskers and scrimshaw using ancient DNA (aDNA) approaches provide an oppor- tunity for investigating such changes over evolutionary and ecological timescales. Here, we review the application of aDNA techniques to the study of marine mammals. Most of the studies have...... focused on detecting changes in genetic diversity following periods of exploitation and environmental change. To date, these studies have shown that even small sample sizes can provide useful information on historical genetic diversity. Ancient DNA has also been used in investigations of changes...... in distribution and range of marine mammal species; we review these studies and discuss the limitations of such ‘presence only’ studies. Combining aDNA data with stable isotopes can provide further insights into changes in ecology and we review past studies and suggest future potential applications. We also...

  5. Sorption experiments at oxic and anoxic conditions

    International Nuclear Information System (INIS)

    Sorption of U, Pu, Np, Th and Tc at anoxic conditions were studied using radionuclides 233U, 236Pu, 237Np, 234Th and 99Tc. Samples were selected to represent common rocks and minerals in Finnish bedrock. The determinations of K-values and sorption percents in quartz plagioclase, potassium feldspar, honrnblende, biotite, mica gneiss, tonalite, granodiorite, porphyritic granite, granitic gneiss and rapakivi granite were performed by the autoradiographic method. The sorpion of these elements was studied under anoxic conditions using synthetic granitic ground water and synthetic bentonite water containing ferrous iron. For redox-sensitive U, Np and Pu experiments were made by spiking samples with water containing the radioactive isotope at one specified oxidation state

  6. Apps for Ancient Civilizations

    Science.gov (United States)

    Thompson, Stephanie

    2011-01-01

    This project incorporates technology and a historical emphasis on science drawn from ancient civilizations to promote a greater understanding of conceptual science. In the Apps for Ancient Civilizations project, students investigate an ancient culture to discover how people might have used science and math smartphone apps to make their lives…

  7. Thalamic hemorrhage in ischemic anoxic encephalopathy

    International Nuclear Information System (INIS)

    The authors have performed MR imaging, CT, and US examinations in eight infants with ischemic anoxic encephalopathy (IAE). The patients were delivered at 39-42 weeks. IAE was diagnosed by reduced Apgar score, presence of respiratory difficulty, and convulsive episodes. High-signal-intensity lesions were seen in the thalamus with inversion recovery sequences and low-signal-intensity areas were seen with PS1660/193 sequences in six of the eight infants. CT and US were positive for hemorrhage in only three of the infants. Of MR imaging, CT, and US, MR imaging was the most sensitive technique for detecting thalamic hemorrhage in IAE

  8. Release of metals from anoxic sediment

    DEFF Research Database (Denmark)

    Larsen, Martin Mørk; Jacobsen, Gitte

    sediment surface and the top of the water column on day 1, 4, 8 and 12, and the results for V, Mn, Co, Ni, Cu, Zn, Cd, Pb and Fe will be presented, together with indication of statistically significant increase in concentration between the different groups of treatment. The water was clear over both groups...... without crabs, but cloudy, indicating re-suspension in the group with crabs. The metal release from sediments will be discussed in the context of re-oxygenation of anoxic or low-oxic sediments and the effect of organism that digs into the sediment in recently re-oxidised bottom waters....

  9. Biological phosphorus uptake under anoxic and aerobic conditions

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens

    1993-01-01

    Biological phosphorus removal was investigated under anoxic and aerobic conditions. Tests were made to establish whether phosphorus accumulating bacteria can take up phosphate under anoxic conditions and thus utilise nitrate as oxidant. Furthermore, it was tested how the amount of organic matter...

  10. Methane oxidation coupled to oxygenic photosynthesis in anoxic waters.

    Science.gov (United States)

    Milucka, Jana; Kirf, Mathias; Lu, Lu; Krupke, Andreas; Lam, Phyllis; Littmann, Sten; Kuypers, Marcel M M; Schubert, Carsten J

    2015-09-01

    Freshwater lakes represent large methane sources that, in contrast to the Ocean, significantly contribute to non-anthropogenic methane emissions to the atmosphere. Particularly mixed lakes are major methane emitters, while permanently and seasonally stratified lakes with anoxic bottom waters are often characterized by strongly reduced methane emissions. The causes for this reduced methane flux from anoxic lake waters are not fully understood. Here we identified the microorganisms and processes responsible for the near complete consumption of methane in the anoxic waters of a permanently stratified lake, Lago di Cadagno. Interestingly, known anaerobic methanotrophs could not be detected in these waters. Instead, we found abundant gamma-proteobacterial aerobic methane-oxidizing bacteria active in the anoxic waters. In vitro incubations revealed that, among all the tested potential electron acceptors, only the addition of oxygen enhanced the rates of methane oxidation. An equally pronounced stimulation was also observed when the anoxic water samples were incubated in the light. Our combined results from molecular, biogeochemical and single-cell analyses indicate that methane removal at the anoxic chemocline of Lago di Cadagno is due to true aerobic oxidation of methane fuelled by in situ oxygen production by photosynthetic algae. A similar mechanism could be active in seasonally stratified lakes and marine basins such as the Black Sea, where light penetrates to the anoxic chemocline. Given the widespread occurrence of seasonally stratified anoxic lakes, aerobic methane oxidation coupled to oxygenic photosynthesis might have an important but so far neglected role in methane emissions from lakes. PMID:25679533

  11. MERCURY RELEASE FROM DISTURBED ANOXIC SOILS

    Energy Technology Data Exchange (ETDEWEB)

    Jaroslav Solc; Bethany A. Bolles

    2001-07-16

    The primary objectives of experiments conducted at the Energy & Environmental Research Center (EERC) were to provide information on the secondary release of mercury from contaminated anoxic sediments to an aqueous environment after disturbance/change of in situ physical conditions and to evaluate its migration and partitioning under controlled conditions, including implications of these processes for treatment of contaminated soils. Experimental work included (1) characterization of the mercury-contaminated sediment; (2) field bench-scale dredging simulation; (3) laboratory column study to evaluate a longer-term response to sediment disturbance; (4) mercury volatilization from sediment during controlled drying; (5) resaturation experiments to evaluate the potential for secondary release of residual mercury after disturbance, transport, drying, and resaturation, which simulate a typical scenario during soil excavation and transport to waste disposal facilities; and (6) mercury speciation and potential for methylation during column incubation experiments.

  12. MERCURY RELEASE FROM DISTURBED ANOXIC SOILS; TOPICAL

    International Nuclear Information System (INIS)

    The primary objectives of experiments conducted at the Energy and Environmental Research Center (EERC) were to provide information on the secondary release of mercury from contaminated anoxic sediments to an aqueous environment after disturbance/change of in situ physical conditions and to evaluate its migration and partitioning under controlled conditions, including implications of these processes for treatment of contaminated soils. Experimental work included (1) characterization of the mercury-contaminated sediment; (2) field bench-scale dredging simulation; (3) laboratory column study to evaluate a longer-term response to sediment disturbance; (4) mercury volatilization from sediment during controlled drying; (5) resaturation experiments to evaluate the potential for secondary release of residual mercury after disturbance, transport, drying, and resaturation, which simulate a typical scenario during soil excavation and transport to waste disposal facilities; and (6) mercury speciation and potential for methylation during column incubation experiments

  13. Anoxic phosphorus removal in a pilot scale anaerobic-anoxic oxidation ditch process

    Institute of Scientific and Technical Information of China (English)

    Hongxun HOU; Shuying WANG; Yongzhen PENG; Zhiguo YUAN; Fangfang YIN; Wang GAN

    2009-01-01

    The anaerobic-anoxic oxidation ditch (A2/O OD) process is popularly used to eliminate nutrients from domestic wastewater. In order to identify the existence of denitrifying phosphorus removing bacteria (DPB), evalu-ate the contribution of DPB to biological nutrient removal,and enhance the denitrifying phosphorus removal in the A2/O OD process, a pilot-scale A2/O OD plant (375 L)was conducted. At the same time batch tests using sequence batch reactors (12 L and 4 L) were operated to reveal the significance of anoxic phosphorus removal. The results indicated that: The average removal efficiency of COD, NH4+, pO3-4, and TN were 88.2%, 92.6%, 87.8%,and 73.1%, respectively, when the steady state of the pilotscale A2/O OD plant was reached during 31-73d,demonstrating a good denitrifying phosphorus removal performance. Phosphorus uptake took place in the anoxic zone by poly-phosphorus accumulating organisms NO2- could be used as electron receptors in denitrifying phosphorus removal, and the phosphorus uptake rate with NO2- as the electron receptor was higher than that with NO3- when the initial concentration of either NO2- or NO3 was 40 mg/L.

  14. Studying Ancient History.

    Science.gov (United States)

    Barrow, Robin

    1982-01-01

    Defends the value and relevance of the study of ancient history and classics in history curricula. The unique homogeneity of the classical period contributes to its instructional manageability. A year-long, secondary-level course on fifth-century Greece and Rome is described to illustrate effective approaches to teaching ancient history. (AM)

  15. The psychosocial outcome of anoxic brain injury following cardiac arrest

    OpenAIRE

    Wilson, Michelle

    2012-01-01

    Aim of the study The psychosocial outcome of anoxic brain injury following cardiac arrest is a relatively under researched, but clinically important area. The aim of the current study was to add to the limited existing literature exploring the psychosocial outcome for cardiac arrest survivors, but specifically explore if there is a greater impact on psychosocial outcome in individuals experiencing anoxic brain injury as a result. Methods A range of self report measures were used to c...

  16. Esotericism Ancient and Modern

    OpenAIRE

    Frazer, Michael

    2006-01-01

    Leo Strauss presents at least two distinct accounts of the idea that the authors in the political-philosophical canon have often masked their true teachings. A weaker account of esotericism, dependent on the contingent fact of persecution, is attributed to the moderns, while a stronger account, stemming from a necessary conflict between philosophy and society, is attributed to the ancients. Although most interpreters agree that Strauss here sides with the ancients, this view fails to consider...

  17. Extreme seawater compositions during Oceanic Anoxic Events

    Science.gov (United States)

    Cohen, A.; Bottini, C.; Dickson, A. J.; Izon, G. J.; Coe, A. L.

    2012-12-01

    For almost the entire duration of the Phanerozoic, the oceans have remained well oxygenated and highly conducive to the development of animal and plant life. However, there have been relatively brief intervals, known as Oceanic Anoxic Events (OAEs), when a very significant expansion of low-oxygen regions occurred throughout the world's oceans. OAEs were characterised by highly atypical seawater chemistry, as reflected in the chemical and isotopic compositions of contemporaneous sediments and fossil remains. These oxygen-deficient intervals also exerted profound pressures on many marine species as indicated by major changes in species populations and distributions. High-resolution chemical and isotopic data recovered from marine sediments and sedimentary rocks, together with biotic information, provide us with the best means of understanding the significance of OAEs and their place in the evolution of the Earth system. We present new Mo- and Os-isotope and geochemical data from OAE 1a (early Cretaceous), which help define how this event evolved in relation to the other major environmental parameters - including global warming, continental weathering and Ontong-Java volcanism - of that time. We compare these new observations with published results from other Mesozoic OAEs and the PETM. Recently published Os-isotope data from DSDP site 463 (mid-Pacific) [1] and northern Italy [1, 2] show that the Os budget of the oceans was dominated for a period of c. 880 ka during OAE 1a by the hydrothermal flux of unradiogenic Os from the Ontong-Java province. The observation of identical Os-isotope compositions at these two very distant sites indicates that seawater was well mixed at that time. Over the same interval, the seawater Mo-isotope composition, based upon well-preserved samples from Italy, was persistently atypical, with δ98/95Mo ranging between -0.7 and +0.7 permil [3]. All the samples analysed here accumulated under highly anoxic conditions and contain highly abundant

  18. Copper corrosion experiments under anoxic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ollila, Kaija [VTT Technical Research Centre of Finland, Espoo (Finland)

    2013-06-15

    This report gives results from the corrosion experiments with copper under anoxic conditions. The objective was to study whether hydrogen-evolving corrosion reaction could occur. Copper foil samples were exposed in deaerated deionized water in Erlenmeyer flasks in the glove box with inert atmosphere. Four corrosion experiments (Cu1, Cu2, Cu3 and Cu4) were started, as well as a reference test standing in air. Cu1 and Cu2 had gas tight seals, whereas Cu3 and Cu4 had palladium foils as hydrogen permeable enclosure. The test vessels were stored during the experiments in a closed stainless steel vessel to protect them from the trace oxygen of the gas atmosphere and light. After the reaction time of three and a half years, there were no visible changes in the copper surfaces in any of the tests in the glove box, in contrast the Cu surfaces looked shiny and unaltered. The Cu3 test was terminated after the reaction time of 746 days. The analysis of the Pd-membrane showed the presence of H2 in the test system. If the measured amount of 7.2{center_dot}10{sup 5} mol H{sub 2} was the result of formation of Cu{sub 2}O this would correspond to a 200 nm thick corrosion layer. This was not in agreement with the measured layer thickness with SIMS, which was 6{+-}1 nm. A clear weight loss observed for the Cu3 test vessel throughout the test period suggests the evaporation of water through the epoxy sealing to the closed steel vessel. If this occurred, the anaerobic corrosion of steel surface in humid oxygen-free atmosphere could be a source of hydrogen. A similar weight loss was not observed for the parallel test (Cu4). The reference test standing in air showed visible development of corrosion products.

  19. Copper corrosion experiments under anoxic conditions

    International Nuclear Information System (INIS)

    This report gives results from the corrosion experiments with copper under anoxic conditions. The objective was to study whether hydrogen-evolving corrosion reaction could occur. Copper foil samples were exposed in deaerated deionized water in Erlenmeyer flasks in the glove box with inert atmosphere. Four corrosion experiments (Cu1, Cu2, Cu3 and Cu4) were started, as well as a reference test standing in air. Cu1 and Cu2 had gas tight seals, whereas Cu3 and Cu4 had palladium foils as hydrogen permeable enclosure. The test vessels were stored during the experiments in a closed stainless steel vessel to protect them from the trace oxygen of the gas atmosphere and light. After the reaction time of three and a half years, there were no visible changes in the copper surfaces in any of the tests in the glove box, in contrast the Cu surfaces looked shiny and unaltered. The Cu3 test was terminated after the reaction time of 746 days. The analysis of the Pd-membrane showed the presence of H2 in the test system. If the measured amount of 7.2·105 mol H2 was the result of formation of Cu2O this would correspond to a 200 nm thick corrosion layer. This was not in agreement with the measured layer thickness with SIMS, which was 6±1 nm. A clear weight loss observed for the Cu3 test vessel throughout the test period suggests the evaporation of water through the epoxy sealing to the closed steel vessel. If this occurred, the anaerobic corrosion of steel surface in humid oxygen-free atmosphere could be a source of hydrogen. A similar weight loss was not observed for the parallel test (Cu4). The reference test standing in air showed visible development of corrosion products

  20. Microbial responses to chitin and chitosan in oxic and anoxic agricultural soil slurries

    Directory of Open Access Journals (Sweden)

    A. S. Wieczorek

    2014-02-01

    Full Text Available Chitin is the second most abundant biopolymer in terrestrial ecosystems and is subject to microbial degradation. Chitin can be deacetylated to chitosan or can be hydrolyzed to N,N′-diacetylchitobiose and oligomers of N-acetylglucosamine by aerobic and anaerobic microorganisms. Which pathway of chitin hydrolysis is preferred by soil microbial communities has previously been unknown. Supplementation of chitin stimulated microbial activity under oxic and anoxic conditions in agricultural soil slurries, whereas chitosan had no effect. Thus, the soil microbial community likely was more adapted to chitin as a substrate. In addition, this finding suggested that direct hydrolysis of chitin was preferred to the pathway that starts with deacetylation. Chitin was apparently degraded by aerobic respiration, ammonification, and nitrification to carbon dioxide and nitrate under oxic conditions. When oxygen was absent, fermentation products (acetate, butyrate, propionate, hydrogen, carbon dioxide and ammonia were detected, suggesting that butyric and propionic acid fermentation were along with ammonification likely responsible for apparent anaerobic chitin degradation. In total, 42 different chiA genotypes were detected of which twenty were novel at an amino acid sequence dissimilarity of >50%. Various chiA genotypes responded to chitin supplementation and affiliated with a novel deep-branching bacterial chiA genotype (anoxic conditions, genotypes of Beta- and Gammaproteobacteria (oxic and anoxic conditions, and Planctomycetes (oxic conditions. Thus, this study provides evidence that detected chitinolytic bacteria were catabolically diverse and occupied different ecological niches with regard to oxygen availability enabling chitin degradation under various redox conditions at the level of the community.

  1. Microbial responses to chitin and chitosan in oxic and anoxic agricultural soil slurries

    Science.gov (United States)

    Wieczorek, A. S.; Hetz, S. A.; Kolb, S.

    2014-06-01

    Microbial degradation of chitin in soil substantially contributes to carbon cycling in terrestrial ecosystems. Chitin is globally the second most abundant biopolymer after cellulose and can be deacetylated to chitosan or can be hydrolyzed to N,N'-diacetylchitobiose and oligomers of N-acetylglucosamine by aerobic and anaerobic microorganisms. Which pathway of chitin hydrolysis is preferred by soil microbial communities is unknown. Supplementation of chitin stimulated microbial activity under oxic and anoxic conditions in agricultural soil slurries, whereas chitosan had no effect. Thus, the soil microbial community likely was more adapted to chitin as a substrate. In addition, this finding suggested that direct hydrolysis of chitin was preferred to the pathway that starts with deacetylation. Chitin was apparently degraded by aerobic respiration, ammonification, and nitrification to carbon dioxide and nitrate under oxic conditions. When oxygen was absent, fermentation products (acetate, butyrate, propionate, hydrogen, and carbon dioxide) and ammonia were detected, suggesting that butyric and propionic acid fermentation, along with ammonification, were likely responsible for anaerobic chitin degradation. In total, 42 different chiA genotypes were detected of which twenty were novel at an amino acid sequence dissimilarity of less than 50%. Various chiA genotypes responded to chitin supplementation and affiliated with a novel deep-branching bacterial chiA genotype (anoxic conditions), genotypes of Beta- and Gammaproteobacteria (oxic and anoxic conditions), and Planctomycetes (oxic conditions). Thus, this study provides evidence that detected chitinolytic bacteria were catabolically diverse and occupied different ecological niches with regard to oxygen availability enabling chitin degradation under various redox conditions on community level.

  2. Studies on protozoa in ancient remains - A Review

    OpenAIRE

    Liesbeth Frías; Daniela Leles; Adauto Araújo

    2013-01-01

    Paleoparasitological research has made important contributions to the understanding of parasite evolution and ecology. Although parasitic protozoa exhibit a worldwide distribution, recovering these organisms from an archaeological context is still exceptional and relies on the availability and distribution of evidence, the ecology of infectious diseases and adequate detection techniques. Here, we present a review of the findings related to protozoa in ancient remains, with an emphasis on thei...

  3. Anoxic-cell radiosensitization induced by heterocyclic compounds

    International Nuclear Information System (INIS)

    The anoxic cell compartment of in vivo solid tumors limits to some extent the effects of therapeutic radiation. The development of anoxic-cell radiosensitizers, as represented by the imidazole derivatives, has been given considerable attention. Hyperbaric oxygen was also considered for this purpose, Misonidazole, one of the imidazole derivatives, has a radiosensitization effect on anoxic cell killing. However, clinical application was not feasible because the drug proved to be toxic to the central nervous system. The extent of neurotoxicity of the imidazole derivatives correlates with the lipophilicity of the drugs. If the hydrophilicity of the drug could be increased to the extent that the toxicity to the central nervous system would be diminished, then the effect of anoxic-cell radiosensitization of the drug in unit drug amount/body weight or body surface could be maintained. The authors assayed a series of compounds, o-, m-, and p-nitrophenyl-tatrazoles, for their possible anoxic-cell radiosensitization effects. The differential effects were observed among the three isomers by cell survival assays in colony formations of Chinese hamster V-79 strain of cells, in vitro

  4. Damage and repair of ancient DNA

    DEFF Research Database (Denmark)

    Mitchell, David; Willerslev, Eske; Hansen, Anders

    2005-01-01

    Under certain conditions small amounts of DNA can survive for long periods of time and can be used as polymerase chain reaction (PCR) substrates for the study of phylogenetic relationships and population genetics of extinct plants and animals, including hominids. Because of extensive DNA...... degradation, these studies are limited to species that lived within the past 10(4)-10(5) years (Late Pleistocene), although DNA sequences from 10(6) years have been reported. Ancient DNA (aDNA) has been used to study phylogenetic relationships of protists, fungi, algae, plants, and higher eukaryotes such as...... early native Americans. Hence, ancient DNA contains information pertinent to numerous fields of study including evolution, population genetics, ecology, climatology, medicine, archeology, and behavior. The major obstacles to the study of aDNA are its extremely low yield, contamination with modern DNA...

  5. [Psychiatry in ancient Mexico].

    Science.gov (United States)

    Calderón Narváez, G

    1992-12-01

    Using studies on prehispanic and early post-conquest documents of Ancient Mexico--such as the Badianus Manuscript, also known as Libellus de Medicinalibus Indorum Herbis, and Brother Bernardino de Sahagún's famous work History of the Things of the New Spain, a description of some existing medical and psychiatric problems, and treatments Ancient Aztecs resorted to, is presented. The structure of the Aztec family, their problems with the excessive ingestion of alcoholic beverages, and the punishments native authorities had implemented in order to check alcoholism up are also described. PMID:1341125

  6. Biological phosphorus uptake under anoxic and aerobic conditions

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens

    1993-01-01

    Biological phosphorus removal was investigated under anoxic and aerobic conditions. Tests were made to establish whether phosphorus accumulating bacteria can take up phosphate under anoxic conditions and thus utilise nitrate as oxidant. Furthermore, it was tested how the amount of organic matter...... sludge from two different pilot plants incorporating phosphorus removal. The results showed that the phosphorus accumulating bacteria can be divided into two groups in respect of process; one group capable of utilising only oxygen as oxidant and another group capable of utilising both oxygen and nitrate...... taken up by the phosphorus accumulating bacteria during the anaerobic phase affects the total denitrification rate, as well as the rate at which the phosphorus accumulating bacteria take up phosphate under anoxic conditions. The tests were conducted as batch experiments in 21. reactors with activated...

  7. Arctic black shale formation during Cretaceous Oceanic Anoxic Event 2

    DEFF Research Database (Denmark)

    Lenniger, Marc; Nøhr-Hansen, Henrik; Hills, Len V.; Bjerrum, Christian J.

    2014-01-01

    The Late Cretaceous Oceanic Anoxic Event 2 (OAE2) represents a major perturbation of the global carbon cycle caused by the widespread deposition of organic-rich black shales. Although the paleoceanographic response and the spatial extent of bottom-water anoxia in low and mid-paleolatitudes are...... is contemporaneous with the widely observed occurrence of black shale deposition during OAE2. Paleontological, lithological, and geochemical data indicate normal marine conditions with persistent anoxic bottom waters during OAE2. The results imply that the high marine primary productivity pulse...

  8. Metabolic Strategies in Energy-Limited Microbial Communities in the Anoxic Subsurface (Frasassi Cave System, Italy)

    Science.gov (United States)

    McCauley, R. L.; Jones, D. S.; Schaperdoth, I.; Steinberg, L.; Macalady, J. L.

    2010-12-01

    Two major sources of energy, light and chemical potential, are available to microorganisms. However, energy is not always abundant and is often a limiting factor in microbial survival and replication. The anoxic, terrestrial subsurface offers a unique opportunity to study microorganisms and their potentially novel metabolic strategies that are relevant for understanding biogeochemistry and biosignatures as related to the non-photosynthetic, energy-limited environments on the modern and ancient Earth and elsewhere in the solar system. Geochemical data collected in a remote stratified lake 600 m below ground surface in the sulfidic Frasassi cave system (Italy) suggest that little redox energy is available for life, consistent with low signal from domain-specific FISH probes. The carbon isotope signatures of biofilms (-33‰) and DIC (-9‰) in the anoxic water suggest in situ production by lithoautotrophs using RuBisCO. 16S rDNA libraries constructed from the biofilm are dominated by diverse sulfate reducing bacteria. The remaining bacterial and archaeal clones affiliate with more than 11 major uncultivated or novel prokaryotic lineages. Diverse dsrAB gene sequences are consistent with high sulfate concentrations and undetectable or extremely low oxygen, nitrate, and iron concentrations. However, the electron donor for sulfate reduction is unclear. Methane is detectable in the anoxic water although no 16S rDNA sequences associated with known methanogens or anaerobic methane oxidizers were retrieved. mcrA gene sequences retrieved from the biofilm by cloning are not related to cultivated methanogens or to known anaerobic methane oxidizers. Non-purgable organic carbon (NPOC) is below detection limits (i.e. metabolisms may be important. A sample collected by cave divers in October 2009 was pyrosequenced at the Pennsylvania State University Genomics Core Facility using Titanium chemistry (454 Life Sciences). We retrieved more than 420,000 metagenomic reads, of which 46

  9. Microbiology of the Red Sea (and other) deep-sea anoxic brine lakes

    KAUST Repository

    Antunes, Andre

    2011-05-30

    Summary: The Red Sea harbours approximately 25 deep-sea anoxic brine pools. They constitute extremely unique and complex habitats with the conjugation of several extreme physicochemical parameters rendering them some of the most inhospitable environments on Earth. After 50 years of research mostly driven by chemists, geophysicists and geologists, the microbiology of the brines has been receiving increased interest in the last decade. Recent molecular and cultivation-based studies have provided us with a first glimpse on the enormous biodiversity of the local microbial communities, the identification of several new taxonomic groups, and the isolation of novel extremophiles that thrive in these environments. This review presents a general overview of these unusual biotopes and compares them with other similar environments in the Mediterranean Sea and the Gulf of Mexico, with a focus on their microbial ecology. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  10. Adoption in ancient times

    OpenAIRE

    Bisha Eugena

    2015-01-01

    Since in ancient times, in all human cultures, children transfered from biological parents to parents that want them to create family, for political alliances, for inheritance, for a future marriage, or to care for elderly parents. The practice of adoption was fairly common in different places and periods. Adoption is mention on Bible and Quran. Greeks, Romans, Egyptians and Babylonians had adoption systems.

  11. Ancient deforestation revisited.

    Science.gov (United States)

    Hughes, J Donald

    2011-01-01

    The image of the classical Mediterranean environment of the Greeks and Romans had a formative influence on the art, literature, and historical perception of modern Europe and America. How closely does is this image congruent with the ancient environment as it in reality existed? In particular, how forested was the ancient Mediterranean world, was there deforestation, and if so, what were its effects? The consensus of historians, geographers, and other scholars from the mid-nineteenth century through the first three quarters of the twentieth century was that human activities had depleted the forests to a major extent and caused severe erosion. My research confirmed this general picture. Since then, revisionist historians have questioned these conclusions, maintaining instead that little environmental damage was done to forests and soils in ancient Greco-Roman times. In a reconsideration of the question, this paper looks at recent scientific work providing proxy evidence for the condition of forests at various times in ancient history. I look at three scientific methodologies, namely anthracology, palynology, and computer modeling. Each of these avenues of research offers support for the concept of forest change, both in abundance and species composition, and episodes of deforestation and erosion, and confirms my earlier work. PMID:20669043

  12. A Vibrant Ancient City

    Institute of Scientific and Technical Information of China (English)

    WANGTONG

    2004-01-01

    LIJIANG is a small city onthe Yunnan-Guizhou Plateau in southern Chinawith an 800-year history.Word of its ancient language and music, and unique natural scenery has spread over the decades, and Lijiang is now known throughout the world. It was added

  13. Ancient Egypt: History 380.

    Science.gov (United States)

    Turk, Laraine D.

    "Ancient Egypt," an upper-division, non-required history course covering Egypt from pre-dynastic time through the Roman domination is described. General descriptive information is presented first, including the method of grading, expectation of student success rate, long-range course objectives, procedures for revising the course, major course…

  14. Ancient Egypt: Personal Perspectives.

    Science.gov (United States)

    Wolinski, Arelene

    This teacher resource book provides information on ancient Egypt via short essays, photographs, maps, charts, and drawings. Egyptian social and religious life, including writing, art, architecture, and even the practice of mummification, is conveniently summarized for the teacher or other practitioner in a series of one to three page articles with…

  15. Creative Ventures: Ancient Civilizations.

    Science.gov (United States)

    Stark, Rebecca

    The open-ended activities in this book are designed to extend the imagination and creativity of students and encourage students to examine their feelings and values about historic eras. Civilizations addressed include ancient Egypt, Greece, Rome, Mayan, Stonehenge, and Mesopotamia. The activities focus upon the cognitive and affective pupil…

  16. Ancient ports of Kalinga

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.

    which plied between Kalinga and south east Asian countries. Nanda Raja, is said to have attacked Kalinga with the intention of getting access to the sea for the landlocked Kingdom of Magadha (Bihar). The ancient texa Artha Sastra (3rd-4th century B...

  17. Diatoms respire nitrate to survive dark and anoxic conditions

    DEFF Research Database (Denmark)

    Kamp, Anja; de Beer, Dirk; Nitsch, Jana L.;

    2011-01-01

    − in their cells survived for 6–28 wk. After sudden shifts to dark, anoxic conditions, the benthic diatom Amphora coffeaeformis consumed 84–87% of its intracellular NO3− pool within 1 d. A stable-isotope labeling experiment proved that 15NO3− consumption was accompanied by the production and re- lease of 15NH4...

  18. Comets in ancient India

    CERN Document Server

    Gupta, Patrick Das

    2014-01-01

    The Indo-aryans of ancient India observed stars and constellations for ascertaining auspicious times for sacrificial rites ordained by vedas. It is but natural that they would have recounted in the vedic texts about comets. In Rigveda ($\\sim $ 1700 - 1500 BC) and Atharvaveda ($\\sim $ 1150 BC), there are references to dhumaketus and ketus, which stand for comets in Sanskrit. Varahamihira in 550 AD and Ballala Sena ($\\sim $ 1100 - 1200 AD) have described a large number of comets recorded by ancient seers such as Parashara, Vriddha Garga, Narada, Garga, etc. In this article, I conjecture that an episode narrated in Mahabharata of a radiant king, Nahusha, ruling the heavens, and later turning into a serpent after he had kicked the seer Agastya (also the star Canopus), is a mythological retelling of a cometary event.

  19. 从青铜文明到生态文明——大冶古铜矿遗址保护与再利用规划模式%From Bronze Civilization to the Ecological Civilization:The Conservation and Reuse Planning Mode of the Daye Ancient Copper Mine Sites

    Institute of Scientific and Technical Information of China (English)

    李百浩; 刘婕

    2012-01-01

    In this article, based on the definition of the mining and metallurgy heritage, the history, cultural connotations and landscape features of the Daye ancient copper mine sites are studied, and the conservation ideas of the Daye ancient copper mine sites in the ecological perspective are described. Then, a variety of planning models of mining and metallurgy heritage conservation and reuse, such as systematic tourism, cultural and creative industries, comprehensive development, public spaces, museum exhibition and underground space development are proposed, trying to find a suitable way for China's mining and metallurgy heritage conservation and reuse. It aims to make more reasonable recycle use of land while protecting the mining and metallurgy heritage, which will improve the decay shape of mining and metallurgy heritage, and also achieve the sustainable use of urban land, so that ecological, economic and social aspects will reach a virtuous circle.%在矿冶遗产的定义界定的基础上,分析研究了大冶铜绿山古铜矿遗址的历史与文化内涵、景观特色,阐述了生态视角下的大冶古铜矿遗址保护思路,提出了系统化旅游、文化创意产业、综合开发以及公共空间、博物会展和地下空间开发等矿冶遗产保护与再利用的多种规划模式,试图寻求一条适合我国矿冶遗产保护与再利用的正确道路.其目的在于对矿冶遗产保护的同时,更合理地对土地循环性使用,这样既改善了矿冶遗产的衰败形态,也达到城市土地的可持续利用,使生态、经济、村会3个方面达到良性循环.

  20. Suicide in ancient Greece.

    Science.gov (United States)

    Laios, K; Tsoukalas, G; Kontaxaki, M-I; Karamanou, M; Androutsos, G

    2014-01-01

    The theme of suicide appears several times in ancient Greek literature. However, each such reference acquires special significance depending on the field from which it originates. Most of the information found in mythology, but the suicide in a mythological tale, although in terms of motivation and mental situation of heroes may be in imitation of similar incidents of real life, in fact is linked with the principles of the ancient Greek religion. In ancient drama and mainly in tragedies suicide conduces to the tragic hypostasis of the heroes and to the evolution of the plot and also is a tool in order to be presented the ideas of poets for the relations of the gods, the relation among gods and men and the relation among the men. In ancient Greek philosophy there were the deniers of suicide, who were more concerned about the impact of suicide on society and also these who accepted it, recognizing the right of the individual to put an end to his life, in order to avoid personal misfortunes. Real suicides will be found mostly from historical sources, but most of them concern leading figures of the ancient world. Closer to the problem of suicide in the everyday life of antiquity are ancient Greek medicines, who studied the phenomenon more general without references to specific incidents. Doctors did not approve in principal the suicide and dealt with it as insane behavior in the development of the mental diseases, of melancholia and mania. They considered that the discrepancy of humors in the organ of logic in the human body will cause malfunction, which will lead to the absurdity and consequently to suicide, either due to excessive concentration of black bile in melancholia or due to yellow bile in mania. They believed that greater risk to commit suicide had women, young people and the elderly. As therapy they used the drugs of their time with the intention to induce calm and repression in the ill person, therefore they mainly used mandragora. In general, we would say

  1. Characteristics of anoxic phosphors removal in sequence batch reactor

    Institute of Scientific and Technical Information of China (English)

    WANG Ya-yi; PAN Mian-li; Yan Min; PENG Yong-zhen; WANG Shu-ying

    2007-01-01

    The characteristics of anaerobic phosphorus release and anoxic phosphorus uptake was investigated in sequencing batch reactors using denitrifying phosphorus removing bacteria (DPB) sludge. The lab-scale experiments were accomplished under conditions of various nitrite concentrations (5.5, 9.5, and 15 mg/L) and mixed liquor suspended solids (MLSS) (1844, 3231, and 6730 mg/L). The results obtained confirmed that nitrite, MLSS, and pH were key factors, which had a significant impact on anaerobic phosphorus release and anoxic phosphorus uptake in the biological phosphorous removal process. The nitrites were able to successfully act as electron acceptors for phosphorous uptake at a limited concentration between 5.5 and 9.5 mg/L. The denitrification and dephosphorous were inhibited when the nitrite concentration reached 15 mg/L. This observation indicated that the nitrite would not inhibit phosphorus uptake before it exceeded a threshold concentration. It was assumed that an increase of MLSS concentration from 1844 mg/L to 6730 mg/L led to the increase of denitrification and anoxic P-uptake rate. On the contrary, the average P uptake/N denitrifying reduced from 2.10 to 1.57 mg PO43--P/mg NO3--N. Therefore, it could be concluded that increasing MLSS of the DEPHANOX system might shorten the reaction time of phosphorus release and anoxic phosphorus uptake. However, excessive MLSS might reduce the specific denitrifying rate. Meanwhile, a rapid pH increase occurred at the beginning of the anoxic conditions as a result of denitrification and anoxic phosphate uptake. Anaerobic P release rate increased with an increase in pH. Moreover, when pH exceeded a relatively high value of 8.0, the dissolved P concentration decreased in the liquid phase, because of chemical precipitation. This observation suggested that pH should be strictly controlled below 8.0 to avoid chemical precipitation if the biological denitrifying phosphorus removal capability is to be studied accurately.

  2. Dance in Ancient Greek Culture

    OpenAIRE

    Spalva, Rita

    2015-01-01

    The greatness and harmony of ancient Greece has had an impact upon the development of the Western European culture to this day. The ancient Greek culture has influenced contemporary literature genres and systems of philosophy, principles of architecture, sculpture and drama and has formed basis for such sciences as astronomy and mathematics. The art of ancient Greece with its penchant for beauty and clarity has been the example of the humanity’s search for an aesthetic ideal. Despite only bei...

  3. Does vivianite control phosphate solubility in anoxic meadow soils?

    DEFF Research Database (Denmark)

    Walpersdorf, Eva Christine; Bender Koch, Christian; Heiberg, Lisa;

    2013-01-01

    Vivianite (Fe3(PO4)2·8H2O) may precipitate in anoxic wetland soils where it may control orthophosphate (Pi) equilibrium solution concentrations at micromolar levels, and thus be of key importance in reducing excessive P from agricultural sources and eutrophication. However, vivianite equilibria and...... restored. Even after 120 days following perturbation the supersaturation was still high (SIviv~6). It seems that vivianite does contribute to Pi immobilization in anoxic soil horizons, but due to slow precipitation kinetics such soils cannot maintain Pi concentrations at levels below critical thresholds...... kinetics under in situ conditions are not fully understood and the occurrence of vivianite in wetland soils is rarely documented. In the present investigation we have monitored the temporal (November to June) variation in the pore water chemistry of a wet meadow soil (Sapric Medihemist) including a...

  4. QTL Analysis of Anoxic Tolerance at Seedling Stage in Rice

    Institute of Scientific and Technical Information of China (English)

    WANG Yang; GUO Yuan; HONG De-lin

    2010-01-01

    Coleoptile lengths of 7-day-old seedlings under anoxic stress and normal conditions were investigated in two permanently segregated populations and their parents in rice (Oryza sativa L.). Using anoxic response index, a ratio of coleoptile length under anoxic stress to coleoptile length under normal conditions, as an indicator of seedling anoxic tolerance (SAT), QTLs for SAT were detected. Two loci controlling SAT, designated as qSAT-2-R and qSAT-7-R, were detected in a recombinant inbred line (RIL) population (247 lines) derived from a cross between Xiushui 79 (japonica variety) and C Bao (japonica restorer line). qSAT-2-R, explaining 8.7% of the phenotype variation, was tightly linked with the SSR marker RM525. qSAT-7-R, explaining 9.8% of the phenotype variation, was tightly linked with the marker RM418. The positive alleles of the two loci came from C Bao. Six loci controlling SAT, designated as qSAT-2-B, qSAT-3-B, qSAT-5-B, qSAT-8-B, qSAT-9-B and qSAT-12-B, were detected in a backcross inbred line (BIL) population (98 lines) derived from a backcross of Nipponbare (japonica)/Kasalath (indica)//Nipponbare (japonica). The positive alleles of qSAT-2-B, qSAT-3-B and qSAT-9-B, which explained 16.2%, 11.4% and 9.5% of the phenotype variation, respectively, came from Nipponbare. Besides, the positive alleles of qSAT-5-B, qSAT-8-B and qSAT-12-B, which explained 7.3%, 5.8% and 14.0% of the phenotype variation, respectively, were from Kasalath.

  5. Perspectives in Cell Cycle Regulation: Lessons from an Anoxic Vertebrate

    OpenAIRE

    Biggar, Kyle K.; Storey, Kenneth B.

    2009-01-01

    The ability of an animal, normally dependent on aerobic respiration, to suspend breathing and enter an anoxic state for long term survival is clearly a fascinating feat, and has been the focus of numerous biochemical studies. When anoxia tolerant turtles are faced with periods of oxygen deprivation, numerous physiological and biochemical alterations take place in order to facilitate vital reductions in ATP consumption. Such strategies include reversible post-translational modifications as wel...

  6. Bruxism Associated with Anoxic Encephalopathy: Successful Treatment with Baclofen

    OpenAIRE

    Bruce Janati, A; Naif Saad ALGhasab; Fahad Saad ALGhassab

    2013-01-01

    Introduction. Bruxism is a movement disorder characterized by grinding and clenching of the teeth. Etiology of bruxism can be divided into three groups: psychosocial factors, peripheral factors, and pathophysiological factors. Methods. The clinical investigation was conducted at King Khaled Hospital in Hail, Saudi Arabia, in 2012. Results. A 16-year-old Saudi female was brought to the hospital in a comatose state and with generalized convulsive seizures secondary to acute anoxic encephalopath...

  7. Persistent giant U wave inversion with anoxic brain injury

    OpenAIRE

    Peters, Matthew N.; Katz, Morgan J.; Howell, Lucius A.; Moscona, John C.; Turnage, Thomas A.; Delafontaine, Patrice

    2013-01-01

    Various electrocardiographic changes have been reported in the setting of acute neurological events, among them large, upright U waves. In contrast, the occurrence of inverted U waves is strongly suggestive of cardiovascular disease, most commonly hypertension, coronary artery disease, or valvular abnormalities. Presented herein is the case of a 29-year-old man with previous anoxic brain injury (but without apparent cardiovascular disease) whose electrocardiogram demonstrated persistent giant...

  8. Living at the Limits: Evidence for Microbial Eukaryotes Thriving under Pressure in Deep Anoxic, Hypersaline Habitats

    Directory of Open Access Journals (Sweden)

    Thorsten Stoeck

    2014-01-01

    Full Text Available The advent of molecular tools in microbial ecology paved the way to exploit the diversity of microbes in extreme environments. Here, we review these tools as applied in one of the most polyextreme habitats known on our planet, namely, deep hypersaline anoxic basins (DHABs, located at ca. 3000–3500 m depth in the Eastern Mediterranean Sea. Molecular gene signatures amplified from environmental DHAB samples identified a high degree of genetic novelty, as well as distinct communities in the DHABs. Canonical correspondence analyses provided strong evidence that salinity, ion composition, and anoxia were the strongest selection factors shaping protistan community structures, largely preventing cross-colonization among the individual basins. Thus, each investigated basin represents a unique habitat (“isolated islands of evolution”, making DHABs ideal model sites to test evolutionary hypotheses. Fluorescence in situ hybridization assays using specifically designed probes revealed that the obtained genetic signatures indeed originated from indigenous polyextremophiles. Electron microscopy imaging revealed unknown ciliates densely covered with prokaryote ectosymbionts, which may enable adaptations of eukaryotes to DHAB conditions. The research reviewed here significantly advanced our knowledge on polyextremophile eukaryotes, which are excellent models for a number of biological research areas, including ecology, diversity, biotechnology, evolutionary research, physiology, and astrobiology.

  9. Gnomons in Ancient China

    Science.gov (United States)

    Li, Geng

    Gnomon shadow measurement was one of the most fundamental astronomical observations in ancient China. It was crucial for calendar making, which constituted an important aspect of imperial governance. A painted stick discovered from a prehistoric (2300 BC) astronomical site of Taosi (see Chap. 201, "Taosi Observatory", 10.1007/978-1-4614-6141-8_215") is the oldest gnomon known of China. From second century BC onward, gnomon shadow measurements have been essential part of calendrical practice. Various historical measurements are discussed in this chapter.

  10. Climate and Ancient Societies

    DEFF Research Database (Denmark)

    Climate, and human responses to it, have a strongly interconnected relationship. This when climate change occurs, the result of either natural or human causes, societies should react and adapt to these. But do they? If so, what is the nature of that change, and are the responses positive...... or negative for the long-term survival of social groups? In this volume, scholars from diverse disciplines including archaeology, geology and climate sciences explore scientific and material evidence for climate changes in the past, their causes, their effects on ancient societies and how those societies...

  11. Mathematics in ancient Greece

    CERN Document Server

    Dantzig, Tobias

    2006-01-01

    More than a history of mathematics, this lively book traces mathematical ideas and processes to their sources, stressing the methods used by the masters of the ancient world. Author Tobias Dantzig portrays the human story behind mathematics, showing how flashes of insight in the minds of certain gifted individuals helped mathematics take enormous forward strides. Dantzig demonstrates how the Greeks organized their precursors' melange of geometric maxims into an elegantly abstract deductive system. He also explains the ways in which some of the famous mathematical brainteasers of antiquity led

  12. Exploring Ancient Skies A Survey of Ancient and Cultural Astronomy

    CERN Document Server

    Kelley, David H

    2011-01-01

    Exploring Ancient Skies brings together the methods of archaeology and the insights of modern astronomy to explore the science of astronomy as it was practiced in various cultures prior to the invention of the telescope. The book reviews an enormous and growing body of literature on the cultures of the ancient Mediterranean, the Far East, and the New World (particularly Mesoamerica), putting the ancient astronomical materials into their archaeological and cultural contexts. The authors begin with an overview of the field and proceed to essential aspects of naked-eye astronomy, followed by an examination of specific cultures. The book concludes by taking into account the purposes of ancient astronomy: astrology, navigation, calendar regulation, and (not least) the understanding of our place and role in the universe. Skies are recreated to display critical events as they would have appeared to ancient observers—events such as the supernova of 1054 A.D., the "lion horoscope," and the Star of Bethlehem. Explori...

  13. Ancient celtic horns

    Science.gov (United States)

    Campbell, Murray

    2002-11-01

    There is considerable evidence from iconographic and documentary sources that musical lip-reed instruments were important in the early celtic communities of Scotland and Ireland. In recent years several studies have been undertaken with the aim of gaining a better understanding of the musical nature of these ancient horns, and of their place in the life and culture of the time. A valuable source of tangible evidence is to be found in the archaeological remains deposited across Scotland and the whole of Ireland. A project is now under way, under the auspices of the Kilmartin House Trust and the general direction of John Purser, which has brought together an international team of musicians, craftsmen, archaeologists, musicologists and physicists with the aim of analyzing ancient musical artifacts, reconstructing some of the original instruments, and analyzing the sounds they produce. This paper describes acoustical studies carried out on a number of recent reconstructions of wooden and bronze instruments, and discusses the role of acoustics in this type of investigation. [Work supported by Sciart and EPSRC.

  14. Anoxic survival potential of bivalves: (arte)facts.

    Science.gov (United States)

    de Zwaan, Albertus; Babarro, Jose M F; Monari, Marta; Cattani, Otello

    2002-03-01

    The anoxic survival time of the bivalves Chamelea gallina, Cerastoderma edule and Scapharca inaequivalvis from two different ecosystems and differing anoxia tolerances was studied in static (closed) and flow-through systems. The antibiotics chloramphenicol, penicillin and polymyxin were added, and molybdate (specific inhibitor of the process of sulfate reduction). Survival in (near) anoxic seawater of Chamelea was studied in a static system by comparing untreated seawater with autoclaved seawater and untreated clams with clams incubated in well-aerated seawater, containing the broad-spectrum antibiotic chloramphenicol, prior to the anoxic survival test. With untreated clams and natural seawater (median mortality time 2.4 days) a decrease in pH and exponential accumulation of sulfide and ammonium was observed in the anoxic medium, indicating excessive growth of (sulfate reducing) bacteria. In sterilized seawater LT50 (2.1 days) was not significantly different and again considerable amounts of ammonium and sulfide accumulated. However, pre-treatment of clams with chloramphenicol resulted in an increase of LT50 (11.0 days) by approximately fivefold. Accumulation of ammonium and sulfide was retarded, but was finally even stronger than in the medium containing untreated clams. Median mortality times were 2.5 and 2.4 days for Chamelea and 2.7 and 2.9 days for Cerastoderma for static and flow-through incubations, respectively. Addition of chloramphenicol increased strongly survival time in both systems with corresponding values of 11.0 and 16.3 days for Chamelea, and 6.4 and 6.5 days for Cerastoderma. LT50 of Scapharca in anoxic seawater was 14.4 days. Chloramphenicol and penicillin increased median survival time to 28.5 and 28.7 days, respectively, whereas polymyxin displayed no effect (LT50=13.6 days). Molybdate added to artificial sulfate free seawater blocked biotic sulfide formation, but did not improve survival time (LT50=13.7 days). Overall the results indicate

  15. Administrative Ecology

    Science.gov (United States)

    McGarity, Augustus C., III; Maulding, Wanda

    2007-01-01

    This article discusses how all four facets of administrative ecology help dispel the claims about the "impossibility" of the superintendency. These are personal ecology, professional ecology, organizational ecology, and community ecology. Using today's superintendency as an administrative platform, current literature describes a preponderance of…

  16. Authenticity in ancient DNA studies

    DEFF Research Database (Denmark)

    Gilbert, M Thomas P; Willerslev, Eske

    2006-01-01

    Ancient DNA studies represent a powerful tool that can be used to obtain genetic insights into the past. However, despite the publication of large numbers of apparently successful ancient DNA studies, a number of problems exist with the field that are often ignored. Therefore, questions exist as ...

  17. Tamil merchant in ancient Mesopotamia.

    Directory of Open Access Journals (Sweden)

    Malliya Gounder Palanichamy

    Full Text Available Recent analyses of ancient Mesopotamian mitochondrial genomes have suggested a genetic link between the Indian subcontinent and Mesopotamian civilization. There is no consensus on the origin of the ancient Mesopotamians. They may be descendants of migrants, who founded regional Mesopotamian groups like that of Terqa or they may be merchants who were involved in trans Mesopotamia trade. To identify the Indian source population showing linkage to the ancient Mesopotamians, we screened a total of 15,751 mitochondrial DNAs (11,432 from the literature and 4,319 from this study representing all major populations of India. Our results although suggest that south India (Tamil Nadu and northeast India served as the source of the ancient Mesopotamian mtDNA gene pool, mtDNA of these ancient Mesopotamians probably contributed by Tamil merchants who were involved in the Indo-Roman trade.

  18. Tamil merchant in ancient Mesopotamia.

    Science.gov (United States)

    Palanichamy, Malliya Gounder; Mitra, Bikash; Debnath, Monojit; Agrawal, Suraksha; Chaudhuri, Tapas Kumar; Zhang, Ya-Ping

    2014-01-01

    Recent analyses of ancient Mesopotamian mitochondrial genomes have suggested a genetic link between the Indian subcontinent and Mesopotamian civilization. There is no consensus on the origin of the ancient Mesopotamians. They may be descendants of migrants, who founded regional Mesopotamian groups like that of Terqa or they may be merchants who were involved in trans Mesopotamia trade. To identify the Indian source population showing linkage to the ancient Mesopotamians, we screened a total of 15,751 mitochondrial DNAs (11,432 from the literature and 4,319 from this study) representing all major populations of India. Our results although suggest that south India (Tamil Nadu) and northeast India served as the source of the ancient Mesopotamian mtDNA gene pool, mtDNA of these ancient Mesopotamians probably contributed by Tamil merchants who were involved in the Indo-Roman trade. PMID:25299580

  19. Studies on protozoa in ancient remains - A Review

    Directory of Open Access Journals (Sweden)

    Liesbeth Frías

    2013-02-01

    Full Text Available Paleoparasitological research has made important contributions to the understanding of parasite evolution and ecology. Although parasitic protozoa exhibit a worldwide distribution, recovering these organisms from an archaeological context is still exceptional and relies on the availability and distribution of evidence, the ecology of infectious diseases and adequate detection techniques. Here, we present a review of the findings related to protozoa in ancient remains, with an emphasis on their geographical distribution in the past and the methodologies used for their retrieval. The development of more sensitive detection methods has increased the number of identified parasitic species, promising interesting insights from research in the future.

  20. Ancient Chinese Sundials

    Science.gov (United States)

    Deng, Kehui

    Timekeeping was essential in the agricultural society of ancient China. The use of sundials for timekeeping was associated with the use of the gnomon, which had its origin in remote antiquity. This chapter studies three sundials (guiyi 晷仪) from the Qin and Han dynasties, the shorter shadow plane sundial (duanying ping yi 短影平仪) invented by Yuan Chong in the Sui Dynasty, and the sundial chart (guiyingtu 晷影图) invented by Zeng Minxing in the Southern Song dynasty. This chapter also introduces Guo Shoujing's hemispherical sundial (yang yi 仰仪). A circular stone sundial discovered at the Small Wild Goose Pagoda in Xi'an is also mentioned. It is dated from the Sui and Tang dynasties. A brief survey of sundials from the Qing dynasty shows various types of sundials.

  1. Characterization of Ancient Tripitaka

    Science.gov (United States)

    Gong, Y. X.; Geng, L.; Gong, D. C.

    2015-08-01

    Tripitaka is the world's most comprehensive version of Buddhist sutra. There are limited numbers of Tripitaka currently preserved, most of them present various patterns of degradation. As little is known about the materials and crafts used in Tripitaka, it appeared necessary to identify them, and to further define adapted conservation treatment. In this work, a study concerning the paper source and dyestuff of the Tripitaka from approximate 16th century was carried out using fiber analysis and thin-layer chromatography (TLC). The results proved that the papers were mainly made from hemp or bark of mulberry tree, and indigo was used for colorizing the paper. At the end, we provide with suggestions for protecting and restoring the ancient Tripitaka.

  2. A new particulate Mn-Fe-P-shuttle at the redoxcline of anoxic basins

    Science.gov (United States)

    Dellwig, Olaf; Leipe, Thomas; März, Christian; Glockzin, Michael; Pollehne, Falk; Schnetger, Bernhard; Yakushev, Evgeniy V.; Böttcher, Michael E.; Brumsack, Hans-Jürgen

    2010-12-01

    . When entering sulfidic waters MnO x particles are progressively reduced leading to an increasing relative abundance of Fe- and P-rich particles. In deeper parts of the water column these particles are also reductively dissolved, thereby releasing Fe 2+ and phosphate to the water column. This Mn-Fe-P-shuttle likely affects phosphate transport throughout the water column and thus impacts primary production at least over longer time scales. Furthermore, the particulate Mn-Fe-P-shuttle must have played an important role for the cycling of P and certain trace metals in ancient ocean basins, e.g., during certain periods of Cretaceous black shale formation and should be considered in future mass balances and modeling approaches dealing with oxic/anoxic interfaces of aquatic ecosystems.

  3. Biogeochemical Cycle of Methanol in Anoxic Deep-Sea Sediments

    Science.gov (United States)

    Yanagawa, Katsunori; Tani, Atsushi; Yamamoto, Naoya; Hachikubo, Akihiro; Kano, Akihiro; Matsumoto, Ryo; Suzuki, Yohey

    2016-01-01

    The biological flux and lifetime of methanol in anoxic marine sediments are largely unknown. We herein reported, for the first time, quantitative methanol removal rates in subsurface sediments. Anaerobic incubation experiments with radiotracers showed high rates of microbial methanol consumption. Notably, methanol oxidation to CO2 surpassed methanol assimilation and methanogenesis from CO2/H2 and methanol. Nevertheless, a significant decrease in methanol was not observed after the incubation, and this was attributed to the microbial production of methanol in parallel with its consumption. These results suggest that microbial reactions play an important role in the sources and sinks of methanol in subseafloor sediments. PMID:27301420

  4. Abiotic redox reactions of antimony and plutonium under anoxic conditions

    OpenAIRE

    Kirsch, Regina,

    2012-01-01

    Redox reactions of Sb(V) and Sb(III) with mackinawite (FeS) and of aqueous Pu(III) and Pu(V) with various Fe(II)-bearing minerals and Fe(III)-oxides have been investigated under anoxic conditions. X-ray absorption spectroscopy was used to analyze oxidation state and local coordination environment of Sb and Pu associated with the solid phase. After reaction with mackinawite, chukanovite and magnetite, PuO2, Pu(III) or mixtures of the two oxidation states were observed. On magnetite, a tridenta...

  5. Ancient human microbiomes

    OpenAIRE

    Warinner, Christina; Speller, Camilla; Collins, Matthew J.; Lewis, Cecil M.

    2015-01-01

    Very recently, we discovered a vast new microbial self: the human microbiome. Our native microbiota interface with our biology and culture to influence our health, behavior, and quality of life, and yet we know very little about their origin, evolution, or ecology. With the advent of industrialization, globalization, and modern sanitation, it is intuitive that we have changed our relationship with microbes, but we have little information about the ancestral state of our microbiome, and theref...

  6. Astronomy in the Ancient Caucasus

    Science.gov (United States)

    Simonia, Irakli; Jijelava, Badri

    This chapter discusses the role of recurrent heavenly phenomena in the formation of ancient cultural traditions. Artifacts bearing witness to astronomical and calendrical practices in the ancient Caucasus are described and we analyze the significance of the "boats of the sun" petroglyphs at Gobustan in Azerbaijan, the solar station at Abuli in Georgia, and the "sky dial" at Carahunge in Armenia. Similarities and differences between the ancient cultures of the region are discussed. Finally, we present the results of the latest field research and new facts and hypotheses.

  7. The Ancient Egyptian Demonology Project

    OpenAIRE

    Weber, Felicitas

    2016-01-01

    “The Ancient Egyptian Demonology Project: Second Millennium BCE” was intended and funded as a three-year project (2013-2016) to explore the world of Ancient Egyptian demons in the 2nd millennium BC. It intends to create a classification and ontology of benevolent and malevolent demons. Whereas ancient Egyptians did not use a specific term denoting “demons”, liminal beings known from various other cultures such as δαίμονες, ghosts, angels, Mischwesen, genies, etc., were nevertheless described ...

  8. Did the ancient Egyptians migrate to ancient Nigeria?

    OpenAIRE

    Jock M. Agai

    2014-01-01

    Literatures concerning the history of West African peoples published from 1900 to 1970 debate�the possible migrations of the Egyptians into West Africa. Writers like Samuel Johnson and�Lucas Olumide believe that the ancient Egyptians penetrated through ancient Nigeria but Leo�Frobenius and Geoffrey Parrinder frowned at this opinion. Using the works of these early�20th century writers of West African history together with a Yoruba legend which teaches�about the origin of their earliest ancesto...

  9. [Ancient Egyptian Odontology].

    Science.gov (United States)

    Berghult, B

    1999-01-01

    In ancient Egypt during the reign of Pharaoh Djoser, circa 2650 BC, the Step Pyramid was constructed by Imhotep. He was later worshiped as the God of Medicine. One of his contemporaries was the powerful writer Hesy who is reproduced on a panel showing a rebus of a swallow, a tusk and an arrow. He is therefore looked upon as being the first depicted odontologist. The art of writing begun in Egypt in about 3100 BC and the medical texts we know from different papyri were copied with hieratic signs around 1900-1100 BC. One of the most famous is the Papyrus Ebers. It was purchased by professor Ebers on a research travel to Luxor in 1873. Two years later a beautiful facsimile in color was published and the best translation came in 1958 in German. The text includes 870 remedies and some of them are related to teeth and oral troubles like pain in the mouth, gingivitis, periodontitis and cavities in the teeth. The most common oral pain was probably pulpitis caused by extreme attrition due to the high consumption of bread contaminated with soil and/or quern minerals. Another text is the Papyrus Edwin Smith with four surgical cases of dental interest. The "toothworms" that were presumed to bring about decayed teeth have not been identified in the medical texts. It was not until 1889 W.D. Miller presented a scientific explanation that cavities were caused by bacteria. In spite of extensive research only a few evidence of prosthetic and invasive treatments have been found and these dental artifacts have probably been made post mortem. Some of the 150 identified doctors were associated with treatments of disorders of the mouth. The stele of Seneb from Sa'is during the 26th dynasty of Psamtik, 664-525 BC, shows a young man who probably was a dental healer well known to Pharaoh and his court. Clement of Alexandria mentions circa 200 AD that the written knowledge of the old Egyptians was gathered in 42 collections of papyri. Number 37-42 contained the medical writings. The

  10. Radical Ecological Democracy: Escaping India's globalization trap

    OpenAIRE

    Ashish Kothari

    2009-01-01

    The global economic and ecological crises can be seen as an opportunity to fundamentally question our paths of ‘development’, and move towards ideologies, policies, and practices of ecological sustainability and social equity. India in its current globalizing form, presents a vivid picture of unsustainability. But, Ashish Kothari proposes that in its ancient and new ideologies and its myriad grassroots experiments in alternatives, it could also be the harbinger of revolutionary changes in the...

  11. Anoxic radiation protection of bacterial spores in suspension

    International Nuclear Information System (INIS)

    Several compounds (nine alcohols, sodium formate, and CO2 gas) have been tested for an ability to alter the anoxic radiation sensitivity of Bacillus megaterium spores, irradiated in suspension. Some of the additives protected (allyl alcohol, ethanol, glycerol, methanol, 1-propanol, 2-propanol, sodium formate and CO2); some did not (1-amyl alcohol, benzyl alcohol, and t-butanol). A correlation exists between anoxic radiation protection and the ability of the additive to react with a water-derived radical and form a radical at the α-hydroxy position. Only those additives that form a radical at this site showed an ability to protect. As a test of the relevance of this correlation between radiation protection and the formation of an α-hydroxy radical, OH competition experiments were run between methanol and t-amyl alcohol. These results showed that methanol partially loses its ability to protect when the competition for OH favors t-amyl alcohol about 4.3:1. These initial results suggest that the correlation is significant, although the exact mechanisms for protection are not known

  12. H2 cycling and microbial bioenergetics in anoxic sediments

    Science.gov (United States)

    Hoehler, Tori M.; DeVincenzi, Donald (Technical Monitor)

    2001-01-01

    The simple biochemistry of H2 is central to a large number of microbial processes, affecting the interaction of organisms with each other and with the environment. In anoxic sediments, the great majority of microbial redox processes involve H2 as a reactant, product, or potential by-product, and the thermodynamics of these processes are thus highly sensitive to fluctuations in environmental H2 concentrations. In turn, H2 concentrations are controlled by the activity of H2-consuming microorganisms, which efficiently utilize this substrate down to levels which correspond to their bioenergetic limitations. Consequently, any environmental change which impacts the thermodynamics of H2-consuming organisms is mirrored by a corresponding change in H2 concentrations. This phenomenon is illustrated in anoxic sediments from Cape Lookout Bight, NC, USA: H2 concentrations are controlled by a suite of environmental parameters (e.g., temperature, sulfate concentrations) in a fashion which can be quantitatively described by a simple thermodynamic model. These findings allow us to calculate the apparent minimum quantity of biologically useful energy in situ. We find that sulfate reducing bacteria are not active at energy yields below -18 kJ per mole sulfate, while methanogenic archaea exhibit a minimum close to -10 kJ per mole methane.

  13. Ancient and Current Chaos Theories

    Directory of Open Access Journals (Sweden)

    Güngör Gündüz

    2006-07-01

    Full Text Available Chaos theories developed in the last three decades have made very important contributions to our understanding of dynamical systems and natural phenomena. The meaning of chaos in the current theories and in the past is somewhat different from each other. In this work, the properties of dynamical systems and the evolution of chaotic systems were discussed in terms of the views of ancient philosophers. The meaning of chaos in Anaximenes’ philosophy and its role in the Ancient natural philosophy has been discussed in relation to other natural philosophers such as of Anaximander, Parmenides, Heraclitus, Empedocles, Leucippus (i.e. atomists and Aristotle. In addition, the fundamental concepts of statistical mechanics and the current chaos theories were discussed in relation to the views in Ancient natural philosophy. The roots of the scientific concepts such as randomness, autocatalysis, nonlinear growth, information, pattern, etc. in the Ancient natural philosophy were investigated.

  14. Ancient Astronomical Monuments of Athens

    Science.gov (United States)

    Theodossiou, E.; Manimanis, V. N.

    2010-07-01

    In this work, four ancient monuments of astronomical significance found in Athens and still kept in the same city in good condition are presented. The first one is the conical sundial on the southern slope of the Acropolis. The second one is the Tower of the Winds and its vertical sundials in the Roman Forum of Athens, a small octagonal marble tower with sundials on all 8 of its sides, plus a water-clock inside the tower. The third monument-instrument is the ancient clepsydra of Athens, one of the findings from the Ancient Agora of Athens, a unique water-clock dated from 400 B.C. Finally, the fourth one is the carved ancient Athenian calendar over the main entrance of the small Byzantine temple of the 8th Century, St. Eleftherios, located to the south of the temple of the Annunciation of Virgin Mary, the modern Cathedral of the city of Athens.

  15. Anoxic monimolimnia: Nutrients devious feeders or bombs ready to explode?

    Science.gov (United States)

    Gianni, Areti; Zacharias, Ierotheos

    2015-04-01

    Coastal regions are under strong human influence and its environmental impact is reflected into their water quality. Oligotrophic estuaries and coastal systems have changed in mesotrophic and/or eutrophic, shown an increase in toxic algal blooms, hypoxic/anoxic events, and massive mortalities of many aquatic and benthic organisms. In strongly stratified and productive water basins, bottom water dissolved oxygen is depleted due to the excessive organic matter decomposition in these depths. Distribution and recycling of nutrients in their water column is inextricably dependent on oxygenation and redox conditions. Bottom water anoxia accelerates PO43-, NH4+ and H2S recycling and accumulation from organic matter decomposition. The anoxic, H2S, PO43- and NH4+ rich bottom water constitutes a toxic layer, threatening the balance of the entire ecosystem. In permanently stratified water basins, storm events could result in stratification destruction and water column total mixing. The turnover brings large amounts of H2S to the surface resulting in low levels of oxygen and massive fish kills. PO43- and NH4+ are released to the interface and surface waters promoting algal blooms. Μore organic matter is produced fueling anoxia. The arising question is, whether the balance of an anoxic water ecosystem is under the threat of its hypolimnetic nutrient and sulfide load, only in the case of storm events and water column total mixing. In polymictic water basins it is clear that the accumulated, in the bottom layer, nutrients will supply surface waters, after the pycnocline overturn. Besides this mechanism of basins' water quality degradation is nowadays recognized as one of the biggest obstacles in eutrophic environments management and restoration efforts. The role of internal load, in permanently stratified water basins, is not so clear. In the present study the impact of storm events on water column stability and bottom water anoxia of meromictic coastal basins, is investigated

  16. Effect of a Jurassic oceanic anoxic event on belemnite ecology and evolution

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Thibault, Nicolas Rudolph; Ruhl, Micha;

    2014-01-01

    ocean anoxia driven by anthropogenic release of greenhouse gases. Potential consequences of this anthropogenic forcing can be approximated by studying analog environmental perturbations in the past such as the T-OAE. Here we present to our knowledge the first organic carbon isotope record derived from...

  17. Reconstructing ancient genomes and epigenomes

    DEFF Research Database (Denmark)

    Orlando, Ludovic Antoine Alexandre; Gilbert, M. Thomas P.; Willerslev, Eske

    2015-01-01

    DNA studies have now progressed to whole-genome sequencing for an increasing number of ancient individuals and extinct species, as well as to epigenomic characterization. Such advances have enabled the sequencing of specimens of up to 1 million years old, which, owing to their extensive DNA damage and...... contamination, were previously not amenable to genetic analyses. In this Review, we discuss these varied technical challenges and solutions for sequencing ancient genomes and epigenomes....

  18. Orthopedic surgery in ancient Egypt

    OpenAIRE

    Blomstedt, Patric

    2014-01-01

    Background — Ancient Egypt might be considered the cradle of medicine. The modern literature is, however, sometimes rather too enthusiastic regarding the procedures that are attributed an Egyptian origin. I briefly present and analyze the claims regarding orthopedic surgery in Egypt, what was actually done by the Egyptians, and what may have been incorrectly ascribed to them. Methods — I reviewed the original sources and also the modern literature regarding surgery in ancient Egypt, concentra...

  19. Hedera helix L. and damages in Tlos Ancient City

    Directory of Open Access Journals (Sweden)

    Elinç, Z.K.

    2013-03-01

    Full Text Available There are various plant types in Tlos Ancient City of Fethiye district in the Province of Mugla, a city where different residential ruins of Lycia Civilization starting from Classical Age until Byzantine Period. Tlos is an important city in West-Lycia and is situated right on the control point of Lycia Way. Hedera helix L. is one of the plants living in this area, which attracts the attention as it mostly harms the ancient ruins. One of the most important reasons why Hedera helix L. is growing commonly in this region is the perfect ecological circumstances for the growth of this plant of the location where this ancient city is situated in. Additionally the fact that the ruins of the city are left on their fate, is another perfect circumstance for the Hedera helix L. to grow. Climbing or creeping stems of Hedera helix L. stick easily to the objects it touches and encircle them. Due to this characteristic, the walls of the ancient city are covered by this plant. Nevertheless, Hedera helix L. does not only harm the ancient constructions and natural rocks but also woody plants. The harm caused by dried out or cut Hedera helix L. are more than the harm caused by them when they were untouched. The subject of this study is to prove the shape and level of the harm caused by Hedera helix L. on ancient ruins of Tlos. At the same time, this study will underline the fighting methods against Hedera helix L. by comparing similar studies in other countries. Knowledge collected after this study will offer an insight into the excavation and restoration studies undertaken in all Mediterranean countries.

  20. Did the ancient Egyptians migrate to ancient Nigeria?

    Directory of Open Access Journals (Sweden)

    Jock M. Agai

    2014-01-01

    Full Text Available Literatures concerning the history of West African peoples published from 1900 to 1970 debate�the possible migrations of the Egyptians into West Africa. Writers like Samuel Johnson and�Lucas Olumide believe that the ancient Egyptians penetrated through ancient Nigeria but Leo�Frobenius and Geoffrey Parrinder frowned at this opinion. Using the works of these early�20th century writers of West African history together with a Yoruba legend which teaches�about the origin of their earliest ancestor(s, this researcher investigates the theories that the�ancient Egyptians had contact with the ancient Nigerians and particularly with the Yorubas.Intradisciplinary and/or interdisciplinary implications: There is an existing ideology�amongst the Yorubas and other writers of Yoruba history that the original ancestors of�the Yorubas originated in ancient Egypt hence there was migration between Egypt and�Yorubaland. This researcher contends that even if there was migration between Egypt and�Nigeria, such migration did not take place during the predynastic and dynastic period as�speculated by some scholars. The subject is open for further research.

  1. Bruxism Associated with Anoxic Encephalopathy: Successful Treatment with Baclofen

    Directory of Open Access Journals (Sweden)

    A. Bruce Janati

    2013-01-01

    Full Text Available Introduction. Bruxism is a movement disorder characterized by grinding and clenching of the teeth. Etiology of bruxism can be divided into three groups: psychosocial factors, peripheral factors, and pathophysiological factors. Methods. The clinical investigation was conducted at King Khaled Hospital in Hail, Saudi Arabia, in 2012. Results. A 16-year-old Saudi female was brought to the hospital in a comatose state and with generalized convulsive seizures secondary to acute anoxic encephalopathy. In the third week of hospitalization, while still in a state of akinetic mutism, she developed incessant bruxism which responded favorably to a GABA receptor agonist (baclofen. Conclusion. Our data support the hypothesis that bruxism emanates from imbalance or dysregulation of the neurotransmitter system. Larger scale studies will be needed to confirm this hypothesis.

  2. Anoxic Activated Sludge Monitoring with Combined Nitrate and Titrimetric Measurements

    DEFF Research Database (Denmark)

    Petersen, B.; Gernaey, Krist; Vanrolleghem, P.A.

    2002-01-01

    An experimental procedure for anoxic activated sludge monitoring with combined nitrate and titrimetric measurements is proposed and evaluated successfully with two known carbon sources, (-)acetate and dextrose. For nitrate measurements an ion-selective nitrate electrode is applied to allow for...... frequent measurements, and thereby the possibility for detailed determination of the denitrification biokinetics. An internal nitrate electrode calibration is implemented in the experiments to avoid the often-encountered electrode drift problem. It was observed that the best experimental design was with...... the carbon source in excess, since excess nitrate provoked nitrite build-up thereby complicating the data interpretation. A conceptual model could quantitatively describe the experimental observations and thus link the experimentally measured proton production with the consumption of electron acceptor...

  3. Diagenetic isotope effects in an anoxic marine sediment

    International Nuclear Information System (INIS)

    The carbon isotope effects associated with the remineralization of organic matter in the anoxic sediments of Cape Lookout Bight, NC, have been investigated. Total organic carbon δ13C profiles and an isotopic mass balance of the diagenetic products, σCO2 and methane, indicate that the initial step in the breakdown of the organic matter, i.e. the transformation of biopolymeric material to biomonomers, does not express a significant isotope effect. Intramolecular δ13C measurements of the diagenetic intermediate, acetate indicates that large isotope effects (5-10 per-thousand) occur during the biosynthesis of that compound. Downcore δ13C variations in the acetate appear to be related to fractionations associated with methanogenesis. The fractionation factor for the conversion of the acetate methyl group to methane has been estimated to be 1.02 from the porewater profiles

  4. Molybdenum drawdown during Cretaceous Oceanic Anoxic Event 2

    Science.gov (United States)

    Goldberg, Tatiana; Poulton, Simon W.; Wagner, Thomas; Kolonic, Sadat F.; Rehkämper, Mark

    2016-04-01

    During the Cretaceous greenhouse, episodes of widespread ocean deoxygenation were associated with globally occurring events of black shale deposition. Possibly the most pronounced of these oceanic anoxic events (OAE's) was the Cenomanian-Turonian OAE2 (∼94 Ma). However, although certain redox sensitive trace metals tend to be preferentially sequestered in sediments deposited under anoxic conditions, with Mo drawdown being specifically prone to euxinic settings, these elements are generally somewhat depleted in sediments deposited during OAE2. To understand the driving factors responsible for this depleted trace metal drawdown, we have studied a low latitude section from the proto-North Atlantic Ocean (Tarfaya S57), where existing biomarker and iron-sulphur data point to a dominantly euxinic water column, with periodic transitions to ferruginous (Fe-rich) water column conditions. We utilise a variety of redox proxies (Fe-speciation, redox sensitive trace metals and Mo isotopes), which, in combination, allows us to evaluate the detailed nature of ocean redox conditions and hence controls on trace metal drawdown. The results suggest that seawater δ98Mo values may have ranged between ∼0.6 and 1.1‰ during OAE2, likely connected to changes in the local Mo reservoir as a consequence of low and probably heterogeneous concentrations of Mo in the ocean. The very low Mo/TOC ratios at Tarfaya and elsewhere in the proto-North Atlantic may support a model in which deep-water circulation was partially restricted within and between the North Atlantic and other ocean basins. We propose that the combination of a low and possibly heterogeneous δ98Mo of seawater Mo, together with low Mo/TOC ratios, points to a large decrease in the global oceanic Mo reservoir during OAE2, reflecting a major global scale increase in Mo drawdown under persistent euxinic conditions.

  5. An open ocean record of the Toarcian oceanic anoxic event

    Directory of Open Access Journals (Sweden)

    D. R. Gröcke

    2011-11-01

    Full Text Available Oceanic anoxic events were time intervals in the Mesozoic characterized by widespread distribution of marine organic matter-rich sediments (black shales and significant perturbations in the global carbon cycle. These perturbations are globally recorded in sediments as carbon isotope excursions irrespective of lithology and depositional environment. During the early Toarcian, black shales were deposited on the epi- and pericontinental shelves of Pangaea, and these sedimentary rocks are associated with a pronounced (ca. 7 ‰ negative (organic carbon isotope excursion (CIE which is thought to be the result of a major perturbation in the global carbon cycle. For this reason, the lower Toarcian is thought to represent an oceanic anoxic event (the T-OAE. If the T-OAE was indeed a global event, an isotopic expression of this event should be found beyond the epi- and pericontinental Pangaean localities. To address this issue, the carbon isotope composition of organic matter (δ13Corg of lower Toarcian organic matter-rich cherts from Japan, deposited in the open Panthalassa Ocean, was analysed. The results show the presence of a major (>6 ‰ negative excursion in δ13Corg that, based on radiolarian biostratigraphy, is a correlative of the lower Toarcian negative CIE known from Pangaean epi- and pericontinental strata. A smaller negative excursion in δ13Corg (ca. 2 ‰ is recognized lower in the studied succession. This excursion may, within the current biostratigraphic resolution, represent the excursion recorded in European epicontinental successions close to the Pliensbachian/Toarcian boundary. These results from the open ocean realm suggest, in conjunction with other previously published datasets, that these Early Jurassic carbon cycle perturbations affected the active global reservoirs of the exchangeable carbon cycle (deep marine, shallow marine, atmospheric.

  6. Ancient DNA in Greece. Problems and prospects

    International Nuclear Information System (INIS)

    The promise associated with early 'ancient DNA' results has not been translated into routine techniques of value to archaeologists. The reasons for this are partly technical - ancient DNA analysis is an extremely difficult technique - and partly practical - ancient DNA analysis is often an 'after thought' to an archaeological project. In this paper ancient human DNA analysis is briefly reviewed paying particular attention to specimens originating from Greek archaeological contexts. Problems commonly encountered during ancient DNA research are summarised and recommendations for future strategies in the application of ancient DNA in archaeology are proposed. (author)

  7. Night blindness and ancient remedy

    Directory of Open Access Journals (Sweden)

    H.A. Hajar Al Binali

    2014-01-01

    Full Text Available The aim of this article is to briefly review the history of night blindness and its treatment from ancient times until the present. The old Egyptians, the Babylonians, the Greeks and the Arabs used animal liver for treatment and successfully cured the disease. The author had the opportunity to observe the application of the old remedy to a patient. Now we know what the ancients did not know, that night blindness is caused by Vitamin A deficiency and the animal liver is the store house for Vitamin A.

  8. Tuberculosis in ancient times

    Directory of Open Access Journals (Sweden)

    Louise Cilliers

    2008-09-01

    Full Text Available In spite of an array of effective antibiotics, tuberculosis is still very common in developing countries where overcrowding, malnutrition and poor hygienic conditions prevail. Over the past 30 years associated HIV infection has worsened the situation by increasing the infection rate and mortality of tuberculosis. Of those diseases caused by a single organism only HIV causes more deaths internationally than tuberculosis. The tubercle bacillus probably first infected man in Neolithic times, and then via infected cattle, but the causative Mycobacteriacea have been in existence for 300 million years. Droplet infection is the most common way of acquiring tuberculosis, although ingestion (e.g. of infected cows’ milk may occur. Tuberculosis probably originated in Africa. The earliest path gnomonic evidence of human tuberculosis in man was found in osteo-archaeological findings of bone tuberculosis (Pott’s disease of the spine in the skeleton of anEgyptian priest from the 21st Dynasty (approximately 1 000 BC. Suggestive but not conclusiveevidence of tuberculotic lesions had been found in even earlier skeletons from Egypt and Europe. Medical hieroglyphics from ancient Egypt are silent on the disease, which could be tuberculosis,as do early Indian and Chinese writings. The Old Testament refers to the disease schachapeth, translated as phthisis in the Greek Septuagint. Although the Bible is not specific about this condition, tuberculosis is still called schachapeth in modern Hebrew. In pre-Hippocratic Greece Homer did not mention phthisis, a word meaning non-specific wasting of the body. However. Alexander of Tralles (6th century BC seemed to narrow the concept down to a specific disease, and in the Hippocratic Corpus (5th-4th centuries BC phthisis can be recognised as tuberculosis. It was predominantly a respiratory disease commonly seen and considered to be caused by an imbalance of bodily humours. It was commonest in autumn, winter and spring

  9. Understanding Malaria: Fighting an Ancient Scourge

    Science.gov (United States)

    Understanding Malaria Fighting an Ancient Scourge U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Allergy and Infectious Diseases Understanding Malaria Fighting an Ancient Scourge U.S. DEPARTMENT OF HEALTH ...

  10. Acupuncture: From Ancient Practice to Modern Science

    Science.gov (United States)

    ... Section CAM Acupuncture From Ancient Practice to Modern Science Past Issues / Winter 2009 Table of Contents For ... of Progress / Acupuncture From Ancient Practice to Modern Science / Low Back Pain and CAM / Time to Talk / ...

  11. Arctic Ocean circulation during the anoxic Eocene Azolla event

    Science.gov (United States)

    Speelman, Eveline; Sinninghe Damsté, Jaap; März, Christian; Brumsack, Hans; Reichart, Gert-Jan

    2010-05-01

    The Azolla interval, as encountered in Eocene sediments from the Arctic Ocean, is characterized by organic rich sediments ( 4wt% Corg). In general, high levels of organic matter may be caused by increased productivity, i.e. extensive growth of Azolla, and/or enhanced preservation of organic matter, or a combination of both. Anoxic (bottom) water conditions, expanded oxygen minimum zones, or increased sedimentation rates all potentially increase organic matter preservation. According to plate tectonic, bathymetric, and paleogeographic reconstructions, the Arctic Ocean was a virtually isolated shallow basin, with one possible deeper connection to the Nordic Seas represented by a still shallow Fram Strait (Jakobsson et al., 2007), hampering ventilation of the Arctic Basin. During the Azolla interval surface waters freshened, while at the same time bottom waters appear to have remained saline, indicating that the Arctic was highly stratified. The restricted ventilation and stratification in concert with ongoing export of organic matter most likely resulted in the development of anoxic conditions in the lower part of the water column. Whereas the excess precipitation over evaporation maintained the freshwater lid, sustained input of Nordic Sea water is needed to keep the deeper waters saline. To which degree the Arctic Ocean exchanged with the Nordic Seas is, however, still largely unknown. Here we present a high-resolution trace metal record (ICP-MS and ICP-OES) for the expanded Early/Middle Eocene section capturing the Azolla interval from Integrated Ocean Drilling Program (IODP) Expedition 302 (ACEX) drilled on the Lomonosov Ridge, central Arctic Ocean. Euxinic conditions throughout the interval resulted in the efficient removal of redox sensitive trace metals from the water column. Using the sedimentary trace metal record we also constrained circulation in the Arctic Ocean by assessing the relative importance of trace metal input sources (i.e. fluvial, eolian, and

  12. Metabolic ecology.

    Science.gov (United States)

    Humphries, Murray M; McCann, Kevin S

    2014-01-01

    Ecological theory that is grounded in metabolic currencies and constraints offers the potential to link ecological outcomes to biophysical processes across multiple scales of organization. The metabolic theory of ecology (MTE) has emphasized the potential for metabolism to serve as a unified theory of ecology, while focusing primarily on the size and temperature dependence of whole-organism metabolic rates. Generalizing metabolic ecology requires extending beyond prediction and application of standardized metabolic rates to theory focused on how energy moves through ecological systems. A bibliometric and network analysis of recent metabolic ecology literature reveals a research network characterized by major clusters focused on MTE, foraging theory, bioenergetics, trophic status, and generalized patterns and predictions. This generalized research network, which we refer to as metabolic ecology, can be considered to include the scaling, temperature and stoichiometric models forming the core of MTE, as well as bioenergetic equations, foraging theory, life-history allocation models, consumer-resource equations, food web theory and energy-based macroecology models that are frequently employed in ecological literature. We conclude with six points we believe to be important to the advancement and integration of metabolic ecology, including nomination of a second fundamental equation, complementary to the first fundamental equation offered by the MTE. PMID:24028511

  13. The eye and its diseases in Ancient Egypt

    DEFF Research Database (Denmark)

    Andersen, S. Ry

    1997-01-01

    Ophthalmology, History of ophthalmology, eyes in the Ancient Egypt, eye disease in Ancient Egypt, porotic hyperostosis, mummification......Ophthalmology, History of ophthalmology, eyes in the Ancient Egypt, eye disease in Ancient Egypt, porotic hyperostosis, mummification...

  14. MRI demonstration of cortical laminar necrosis and delayed white matter injury in anoxic encephalopathy

    International Nuclear Information System (INIS)

    We performed serial radiological examinations on a patient with anoxic encephalopathy. In the early term after the anoxic insult, T1-weighted MRI revealed high signal intensity area distributed laminarly in the cerebral cortex and diffusely in the putamen, which were thought to refect the cortical necrosis and necrosis in the putamen. Single photon emission computed tomography using I-123 isopropylamphetamine showed persistent hypoperfusion in the arterial watershed zones. T2-weighted MRI performed several months after the anoxic episode revealed diffuse high-intensity lesions in the arterial watershed zones. These delayed-onset white matter lesions continued to extend over several months. (orig.)

  15. Massive expansion of marine archaea during a mid-Cretaceous oceanic anoxic event

    DEFF Research Database (Denmark)

    Kuypers, M.M.M.; Blokker, P.; Erbacher, J.;

    2001-01-01

    Biogeochemical and stable carbon isotopic analysis of black-shale sequences deposited during an Albian oceanic anoxic event (∼112 million years ago) indicate that up to 80 weight percent of sedimentary organic carbon is derived from marine, nonthermophilic archaea. The carbon-13 content of archaeal...... molecular fossils indicates that these archaea were living chemoautotrophically. Their massive expansion may have been a response to the strong stratification of the ocean during this anoxic event. Indeed, the sedimentary record of archaeal membrane lipids suggests that this anoxic event marks a time in...... Earth history at which certain hyperthermophilic archaea adapted to low-temperature environments....

  16. Hydrolysis of particulate substrate by activated sludge under aerobic, anoxic and anaerobic conditions

    DEFF Research Database (Denmark)

    Henze, Mogens; Mladenovski, C.

    1991-01-01

    An investigation of hydrolysis of particulate organic substrate by activated sludge has been made. Raw municipal wastewater was used as substrate. It was mixed with activated sludge from a high loaded activated sludge plant with pure oxygen aeration. During 4 days batch experiments under aerobic......, anoxic and anaerobic conditions, the hydrolysis was following through the production of ammonia. The hydrolysis rate of nitrogeneous compounds is significantly affected by the electron donor available. The rate is high under aerobic conditions, medium under anaerobic conditions and low under anoxic...... conditions. The ratio between the hydrolysis rates under aerobic and under anoxic conditions are very similar to the respiration rates measured as electron equivalents....

  17. A comparative study of phosphate sorption in lowland soils under oxic and anoxic conditions

    DEFF Research Database (Denmark)

    Heiberg, Lisa; Pedersen, Thomas Vils; Jensen, Henning S.; Kjærgaard, Charlotte; Hansen, Hans Christian Bruun

    2010-01-01

    soils was compared with oxic conditions to assess the potential of lowland soils to function as traps for Pi when flooded with drainage water. Batch sorption experiments were performed on seven minerogenic soils. Sorption to the anoxic soils was conducted after anoxic incubation, resulting in reduction...... FeII phosphates may have caused the higher sorption capacities. Use of maximum sorption capacity (Smax) is therefore misleading as a measure of Pi sorption at low Psol concentrations. The results demonstrate that none of the strongly anoxic soils, irrespective of the initial FeIII oxide content, the...

  18. Understanding Oceanic Anoxic Events: An Integrated Geochemical Approach

    Science.gov (United States)

    Cohen, A. S.; Coe, A. L.; Kemp, D. B.; Pearce, C. R.

    2007-12-01

    Discrete intervals of widespread organic carbon accumulation, termed Oceanic Anoxic Events (OAEs), occurred at a few relatively brief intervals during the Mesozoic. Recent studies have shown that these events took place at the same time as other substantial environmental changes that included global warming, ocean acidification, and unusually high levels of species extinctions. However, many factors relating to the behaviour of the Earth System during OAEs remain unclear. These include: The primary driving mechanism(s) - was there one common mechanism or were OAEs the result of different processes; the spatial and temporal extent of seawater anoxia during OAEs; the precise effects on marine and terrestrial biota; variations in atmospheric CO2 and global temperature; and the mechanism and timescale of Earth's recovery process. The records of environmental change during OAEs are best preserved in marine deposits, with continental shelf sections being particularly well studied. The combined use of geochemical, sedimentological and palaeontological observations indicates a complex interplay of factors. Significant advances in our understanding of OAEs have taken place in the last decade or so using new geochemical and isotopic proxies and a high- resolution, multidisciplinary approach. For example, Sr- and Os-isotope data indicate that rates of chemical weathering increased markedly during the Toarcian (Early Jurassic) OAE, whilst Mo-isotope data suggest that the areal extent of seawater anoxia fluctuated during the OAE despite the persistence of euxinic conditions in some regions. The pattern of Mo-isotope data for the Toarcian contrasts strongly with new Mo-isotope results from the Kimmeridge Clay Formation (Late Jurassic), when anoxic conditions were confined to European epicontinental seas and were likely to have resulted from very different primary causes. Cyclostratigraphic analysis has been used to provide a temporal framework for the timescale of OAEs at sub

  19. An open marine record of the Toarcian oceanic anoxic event

    Directory of Open Access Journals (Sweden)

    D. R. Gröcke

    2011-04-01

    Full Text Available Oceanic anoxic events were time intervals in the Mesozoic characterized by widespread distribution of marine organic-rich sediments (black shales and significant perturbations in the global carbon cycle. The expression of these perturbations is globally recorded in sediments as excursions in the carbon isotope record irrespective of lithology or depositional environment. During the Early Toarcian, black shales were deposited on the epi- and peri-continental shelves of Pangaea and these sedimentary rocks are associated with a pronounced (ca. 7‰ negative (organic carbon isotope excursion (CIE which is thought to be the result of a major perturbation in the global carbon cycle. For this reason, the Early Toarcian is thought to represent an oceanic anoxic event (the T-OAE. Associated with this event, there were pronounced perturbations in global weathering rates and seawater temperatures. Although it is commonly asserted that the T-OAE is a global event and that the distribution of black shales is likewise global, an isotopic and/or organic-rich expression of this event has as yet only been recognized on epi- and peri-continental Pangaean localities. To address this issue, the carbon isotope composition of organic matter (δ13Corg of Early Toarcian cherts from Japan that were deposited in the open Panthalassa Ocean was analysed. The results show the presence of a major (>6‰ negative excursion in δ13Corg that, based on radiolarian biostratigraphy, is a correlative of the Early Toarcian negative CIE known from European epicontinental strata. Furthermore, a secondary ca. −2‰ excursion in δ13Corg is also recognized lower in the studied succession that, within the current biostratigraphical resolution, is likely to represent the excursion that occurs close to the Pliensbachian/Toarcian boundary and which is also recorded in European epicontinental successions

  20. Diversity and Population status of Bats in Pilikuttuwa ancient cave temple in the Gampaha District, Sri Lanka

    OpenAIRE

    T. G. Tharaka Kusuminda; W. G. M. Edirisinghe; Ranil P. Nanayakkara; Nilantha Vishvanath

    2013-01-01

    Due to two unique specializations - echolocation and flight, bats have become one of the most successful groups of extant mammals in the world. Pilikuttuwa rajamaha viharaya, an ancient meditation monastery complex is a one of best places for bats which gives protection in Sri Lanka. In the present study, we evaluate the species diversity and population status of bats in Pilikuttuwa ancient meditation monastery complex with regard to their roosting ecology. Six species of bats including Tapho...

  1. Ancient medicine--a review.

    Science.gov (United States)

    Zuskin, Eugenija; Lipozencić, Jasna; Pucarin-Cvetković, Jasna; Mustajbegović, Jadranka; Schachter, Neil; Mucić-Pucić, Branka; Neralić-Meniga, Inja

    2008-01-01

    Different aspects of medicine and/or healing in several societies are presented. In the ancient times as well as today medicine has been closely related to magic, science and religion. Various ancient societies and cultures had developed different views of medicine. It was believed that a human being has two bodies: a visible body that belongs to the earth and an invisible body of heaven. In the earliest prehistoric days, a different kind of medicine was practiced in countries such as Egypt, Greece, Rome, Mesopotamia, India, Tibet, China, and others. In those countries, "medicine people" practiced medicine from the magic to modern physical practices. Medicine was magical and mythological, and diseases were attributed mostly to the supernatural forces. The foundation of modern medicine can be traced back to ancient Greeks. Tibetan culture, for instance, even today, combines spiritual and practical medicine. Chinese medicine developed as a concept of yin and yang, acupuncture and acupressure, and it has even been used in the modern medicine. During medieval Europe, major universities and medical schools were established. In the ancient time, before hospitals had developed, patients were treated mostly in temples. PMID:18812066

  2. Wisdom of an Ancient City

    Institute of Scientific and Technical Information of China (English)

    GE JIANXIONG

    2010-01-01

    @@ The famous painting,Along the River During Qingming Festival,impresses visitors at the China Pavilion not iust because of the animated figures in the electronic version of the painting but because it shows a prosperous view of Kaifeng,capital of the Northern Song Dynasty (960-1127).It also showcases the wisdom of city planning in ancient China.

  3. The ancient art of memory.

    Science.gov (United States)

    Hobson, Allan

    2013-12-01

    Revision of Freud's theory requires a new way of seeking dream meaning. With the idea of elaborative encoding, Sue Llewellyn has provided a method of dream interpretation that takes into account both modern sleep science and the ancient art of memory. Her synthesis is elegant and compelling. But is her hypothesis testable? PMID:24304762

  4. Discovering the Ancient Temperate Rainforest.

    Science.gov (United States)

    Lindsay, Anne

    1997-01-01

    Two activities for grades 3 through 8 explore species adaptation and forestry issues in the North American rainforests. In one activity, students create imaginary species of plants or animals that are adapted for life in an ancient temperate rainforest. In the second activity, students role play groups affected by plans to log an area of the…

  5. Ecological Economics

    OpenAIRE

    Martínez Alier, Joan

    2001-01-01

    Ecological economics is a relatively new interdisciplinary field concerned with the relationship between economic systems and the biological and physical world. This article covers the following topics: A discussion of views on whether ecological economics is just a field or approach within economics or a new ÒtransdisciplinaryÓ field in its own right; Origin of the name of the field; Core common principles of ecological economics; Comparison with environmental economics; Applications; Histor...

  6. Predictive isotopic biogeochemistry: hydrocarbons from anoxic marine basins

    Science.gov (United States)

    Freeman, K. H.; Wakeham, S. G.; Hayes, J. M.

    1994-01-01

    Carbon isotopic compositions were determined for individual hydrocarbons in water column and sediment samples from the Cariaco Trench and Black Sea. In order to identify hydrocarbons derived from phytoplankton, the isotopic compositions expected for biomass of autotrophic organisms living in surface waters of both localities were calculated based on the concentrations of CO2(aq) and the isotopic compositions of dissolved inorganic carbon. These calculated values are compared to measured delta values for particulate organic carbon and for individual hydrocarbon compounds. Specifically, we find that lycopane is probably derived from phytoplankton and that diploptene is derived from the lipids of chemoautotrophs living above the oxic/anoxic boundary. Three acyclic isoprenoids that have been considered markers for methanogens, pentamethyleicosane and two hydrogenated squalenes, have different delta values and apparently do not derive from a common source. Based on the concentration profiles and isotopic compositions, the C31 and C33 n-alkanes and n-alkenes have a similar source, and both may have a planktonic origin. If so, previously assigned terrestrial origins of organic matter in some Black Sea sediments may be erroneous.

  7. Sulfide Oxidation in the Anoxic Black-Sea Chemocline

    DEFF Research Database (Denmark)

    JØRGENSEN, BB; FOSSING, H.; WIRSEN, CO; JANNASCH, HW

    1991-01-01

    The depth distributions of O2 and H2S and of the activity of chemical or bacterial sulfide oxidation were studied in the chemocline of the central Black Sea. Relative to measurements from earlier studies, the sulfide zone had moved upwards by 20-50 m and was now (May 1988) situated at a depth of 81...... per day, occurred in anoxic water at the top of the sulfide zone concurrent with the highest rates of dark CO2 assimilation. The main soluble oxidized products of sulfide were thiosulfate (68-82%) and sulfate. Indirect evidence was presented for the formation of elemental sulfur which accumulated to a...... that the measured H2S oxidation rates were 4-fold higher than could be explained by the downward flux of organic carbon and too high to balance the availability of electron acceptors such as oxidized iron or manganese. A nitrate maximum at the lower boundary of the O2 zone did not extend down to the...

  8. Radioanalytical studies of anthropogenic radionuclides in an anoxic fjord

    International Nuclear Information System (INIS)

    The vertical distribution of 239+240Pu, 238Pu, 241Am, 99Tc, 137Cs and 134Cs has been studied in the permanently super-anoxic Framvaren fjord in southern Norway. The adjacent Helvik fjord (slightly below 14 m depth) was studied with the respect to the same radionuclides as a comparison for their distribution and levels during more normal conditions. Th was studied in both fjords as a representative for actinides in oxidation state +4. Vertical distribution of Pu, Am and Th in Framvaren all show increased concentration with depth. Complex formation with DOC is believed to be the main course for this behaviour. Increasing 232Th with depth in sediment indicate possible remobilization of this element from the sediments. The limited water exchange between the two fjords is illustrated by the low 238Pu/239+240Pu ratio and the higher 134Cs/137Cs ratio in Framvaren fjord. Concentration of 99Tc in Framvaren is also lower than compared to Helvik fjord. Concentration of 99Tc in Helvik and Framvaren fjord is approximately constant with depth

  9. Microbial Community of a Hydrothermal Mud Vent Underneath the Deep-Sea Anoxic Brine Lake Urania (Eastern Mediterranean)

    Science.gov (United States)

    Yakimov, Michail M.; Giuliano, Laura; Cappello, Simone; Denaro, Renata; Golyshin, Peter N.

    2007-04-01

    The composition of a metabolically active prokaryotic community thriving in hydrothermal mud fluids of the deep-sea hypersaline anoxic Western Urania Basin was characterized using rRNA-based phylogenetic analysis of a clone library. The physiologically active prokaryotic assemblage in this extreme environment showed a great genetic diversity. Most members of the microbial community appeared to be affiliated to yet uncultured organisms from similar ecosystems, i.e., deep-sea hypersaline basins and hydrothermal vents. The bacterial clone library was dominated by phylotypes affiliated with the epsilon- Proteobacteria subdivision recognized as an ecologically significant group of bacteria inhabiting deep-sea hydrothermal environments. Almost 18% of all bacterial clones were related to delta- Proteobacteria, suggesting that sulfate reduction is one of the dominant metabolic processes occurring in warm mud fluids. The remaining bacterial phylotypes were related to alpha- and beta- Proteobacteria, Actinobacteria, Bacteroides, Deinococcus-Thermus, KB1 and OP-11 candidate divisions. Moreover, a novel monophyletic clade, deeply branched with unaffiliated 16S rDNA clones was also retrieved from deep-sea sediments and halocline of Urania Basin. Archaeal diversity was much lower and detected phylotypes included organisms affiliated exclusively with the Euryarchaeota. More than 96% of the archaeal clones belonged to the MSBL-1 candidate order recently found in hypersaline anoxic environments, such as endoevaporitic microbial mats, Mediterranean deep-sea mud volcanoes and anoxic basins. Two phylotypes, represented by single clones were related to uncultured groups DHVE-1 and ANME-1. Thus, the hydrothermal mud of hypersaline Urania Basin seems to contain new microbial diversity. The prokaryotic community was significantly different from that occurring in the upper layers of the Urania Basin since 60% of all bacterial and 40% of all archaeal phylotypes were obtained only from mud

  10. ENANTIOSELECTIVE MICROBIAL TRANSFORMATION OF THE PHENYLPYRAZOLE INSECTICIDE FIPRONIL IN ANOXIC SEDIMENTS

    Science.gov (United States)

    Fipronil, a chiral insecticide, was biotransformed initially to fipronil sulfide in anoxic sediment slurries following a short lag period. Sediment slurries characterized as either sulfidogenic or methanogenic transformed fipronil with half-lives of approximately 35 and 40 days, ...

  11. Anoxic biodegradation of petroleum hydrocarbons in saline media using denitrifier biogranules.

    Science.gov (United States)

    Moussavi, Gholamreza; Shekoohiyan, Sakine; Naddafi, Kazem

    2016-07-01

    The total petroleum hydrocarbons (TPH) biodegradation was examined using biogranules at different initial TPH concentration and contact time under anoxic condition in saline media. The circular compact biogranules having the average diameter between 2 and 3mm were composed of a dense population of Bacillus spp. capable of biodegrading TPH under anoxic condition in saline media were formed in first step of the study. The biogranules could biodegrade over 99% of the TPH at initial concentration up to 2g/L at the contact time of 22h under anoxic condition in saline media. The maximum TPH biodegradation rate of 2.6 gTPH/gbiomass.d could be obtained at initial TPH concentration of 10g/L. Accordingly, the anoxic biogranulation is a possible and promising technique for high-rate biodegradation of petroleum hydrocarbons in saline media. PMID:26990939

  12. Factors affecting biological denitrifying dephosphatation in anaerobic/anoxic/aerobic sequencing batch reactor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study was conducted to verify and discuss the denitrifying dephosphatation under different levels of nitrate concentration and retention time of anoxic/aerobic process in a Sequencing Batch Reactor ( SBR ).The results of tests demonstrated that there were two kinds of phosphorus-accumulating organisms (PAOs) in the biological excess phosphorus removal (BEPR) system. One was non-DNPAOs that could only use oxygen as terminal electron acceptors, the other was denitrifying PAOs (DNPAOs) that could use both nitrate and oxygen as terminal electron acceptors. Phosphorus uptake efficiency could be attained under anoxic period ranging from 28.7%-96.7% in an anacrobic/anoxic/aerobic system. Experimental results showed that nitrate concentration and retention time of anoxic/aerobic process were the key factors affecting the course of denitrifying dephosphatation.

  13. Jurassic carbonate microfacies, sea-level changes and the Toarcian anoxic event in the Tethys Himalaya (South Tibet)

    Science.gov (United States)

    Han, Zhong; Hu, Xiumian; Garzanti, Eduardo

    2016-04-01

    Detailed microfacies analysis of carbonate rocks from the Tingri and Nyalam areas of South Tibet allowed us to reconstruct the evolution of sedimentary environments during the Early to Middle Jurassic. Based on texture, sedimentary structure, grain composition and fossil content of about 500 thin sections, 17 microfacies overall were identified, and three evolutionary stages were defined. Stage 1 (Rhaetian?-lower Sinemurian Zhamure Formation) was characterized by siliciclastic and mixed siliciclastic-carbonate sedimentation on a barrier shore environment, stage 2 (upper Sinemurian-Pliensbachian Pupuga Formation) by high-energy grainstones with rich benthic faunas thriving on a carbonate platform, and stage 3 (Toarcian-lower Bajocian Nieniexiongla Formation) by low-energy mudstones intercalated with frequent storm layers on a carbonate ramp. Besides, Carbon isotope analyses (δ13Ccarb and δ13Corg) were performed on the late Pliensbachian-early Toarcian interval, and the organic matter recorded a pronounced stepped negative excursion -4.5‰ corresponding to characteristics of the early Toarcian oceanic anoxic event globally, which began just below the stage 2-stage 3 facies shifting boundary. The comparison between the Tethys Himalaya (South Tibet) and the tropical/subtropical zones of the Western Tethys and Panthalassa was carried out to discuss the factors controlling sedimentary evolution. The change from stage 1 to stage 2 was possibly induced by sea-level rise, when the Tibetan Tethys Himalaya was located at tropical/subtropical latitudes in suitable climatic and ecological conditions for carbonate sedimentation. The abrupt change from stage 2 to stage 3 is interpreted as a consequence of the early Toarcian oceanic anoxic event, accompanied by obvious carbon-isotope negative excursion and sea-level rise. The failed recovery from the carbonate crisis in the early Bajocian, with continuing deposition on a low-energy carbonate ramp, is ascribed to the tectonic

  14. Iron metabolism in anoxic environments at near neutral pH

    OpenAIRE

    Straub, Kristina Lotte; Benz, Marcus; Schink, Bernhard

    2001-01-01

    Anaerobic dissimilatory ferric iron-reducing and ferrous iron-oxidizing bacteria gain energy through reduction or oxidation of iron minerals and presumably play an important role in catalyzing iron transformations in anoxic environments. Numerous ferric iron-reducing bacteria have been isolated from a great diversity of anoxic environments, including sediments, soils, deep terrestrial subsurfaces, and hot springs. In contrast, only few ferrous iron-oxidizing bacteria are known so far. At neut...

  15. Technetium diffusion in clay-based materials under oxic and anoxic conditions

    International Nuclear Information System (INIS)

    Diffusion coefficients were determined for Tc in compacted clay-based materials in both anoxic and oxic environments. The soils were saturated with a synthetic groundwater solution; the principle ions in solution were CA2+, Na+ and Cl-. Anoxic conditions were established by conducting the experiments in low-O2 glove box and by mixing 0.5 wt% powdered Fe with the soils. Under anoxic conditions, apparent diffusion coefficients, Da, were 2/s for Tc in compacted backfill material (a 1:3 mix by dry mass of Lake Agassiz clay and crushed granite aggregate). Distribution coefficients, Kd, for Tc on Lake Agassiz clay and backfill material in anoxic environments were back-calculated from Da values. Based on the Kd values, Tc strongly sorbs on Lake Agassiz clay and backfill under anoxic conditions. Effective diffusion coefficients De, for Tc of 10, 16 and 110 μm2/s were measured in oxic Avonlea bentonite, Lake Agassiz clay and illite-smectite, respectively, at a clay dry bulk density of ∼ 1.2 Mg/m3; the corresponding Da values were 55, 48 and 75 μm2/s. Since anoxic conditions are expected in a disposal vault excavated deep in granitic rock in the Canadian Shield, the results suggest the migration of Tc through the backfill will be relatively slow. (author) 23 refs., 9 tabs., 4 figs

  16. Environmental health and hygiene in ancient India: an appraisal.

    Science.gov (United States)

    Pushpangadan, P; Sharma, J; Kaur, J

    1987-07-01

    The ancient Indians were the custodians of a highly evolved civilization with great awareness on the decisive importance as well as the vulnerability of man's natural environment. The ancient Indians sages and Rishis had considered human environment from the point of view of physical, chemical, biological and social process that influences directly or indirectly the health and well - being of the human kind. Their approach towards life was very comprehensive, highly integrated with the environment and, therefore, was ecologically sound and sustainable. It was aimed at promoting a peaceful coexistence with all the living organisms as well as a fuller harmony with the physical environment. The ancient masters tactfully implemented much of their value oriented teachings through certain rituals, taboos and totems and made the people to observe it as spiritual duty; the violation of which was feared an antispiritual. This approach had its astonishing impact and the people accepted these value oriented practices as a way of life and which in course of time became traditions for ages ensuring peaceful coexistence of human kind with other living organisms as well as with the physical environment. But with the advent of modern civilization most of these value oriented traditions are being either lost or discarded. The disappearance or disregard for such time tested environmental conservation or preservation oriented traditions had begun to show its detrimental effect on the life supporting system. PMID:22557580

  17. Psychiatric Thoughts in Ancient India

    Directory of Open Access Journals (Sweden)

    Ravi Abhyankar

    2015-01-01

    Full Text Available A review of the literature regarding psychiatric thoughts in ancient India is attempted. Besides interesting reading, many of the concepts are still relevant and can be used in day-to-day practice especially towards healthy and happy living. Certain concepts are surprisingly contemporary and valid today. They can be used in psychotherapy and counselling and for promoting mental health. However, the description and classification of mental illness is not in tune with modern psychiatry.

  18. ANCIENT BREAD STAMPS FROM JORDAN

    OpenAIRE

    Kakish, Randa

    2014-01-01

    Marking bread was an old practice performed in different parts of the old world. It was done for religious, magical, economic and identification purposes. Bread stamps differ from other groups of stamps. Accordingly, the aim of this article is to identify such stamps, displayed or stored, in a number of Jordanian Archaeological Museums. A col-lection of twelve ancient bread stamps were identified and studied. Two of the stamps were of unknown provenance while the others came from al-Shuneh, D...

  19. Ancient Technology in Contemporary Surgery

    OpenAIRE

    Buck, Bruce A.

    1982-01-01

    Archaeologists have shown that ancient man developed the ability to produce cutting blades of an extreme degree of sharpness from volcanic glass. The finest of these prismatic blades were produced in Mesoamerica about 2,500 years ago. The technique of production of these blades was rediscovered 12 years ago by Dr. Don Crabtree, who suggested possible uses for the blades in modern surgery. Blades produced by Dr. Crabtree have been used in experimental microsurgery with excellent results. Anima...

  20. Biological Nutrient Removal in a Full Scale Anoxic/Anaerobic/Aerobic/Pre-anoxic-MBR Plant for Low C/N Ratio Municipal Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    胡香; 谢丽; 张善发; 杨殿海

    2014-01-01

    A novel full scale modified A2O (anoxic/anaerobic/aerobic/pre-anoxic)-membrane bioreactor (MBR) plant combined with the step feed strategy was operated to improve the biological nutrient removal (BNR) from low C/N ratio municipal wastewater in Southern China. Transformation of organic carbon, nitrogen and phosphorus, and membrane fouling were investigated. Experimental results for over four months demonstrated good efficiencies for chemical oxygen demand (COD) and 4NH+-N removal, with average values higher than 84.5%and 98.1%, re-spectively. A relatively higher total nitrogen (TN) removal efficiency (52.1%) was also obtained at low C/N ratio of 3.82, contributed by the configuration modification (anoxic zone before anaerobic zone) and the step feed with a distribution ratio of 1︰1. Addition of sodium acetate into the anoxic zone as the external carbon source, with a theoretical amount of 31.3 mg COD per liter in influent, enhanced denitrification and the TN removal efficiency in-creased to 74.9%. Moreover, the total phosphate (TP) removal efficiency increased by 18.0%. It is suggested that the external carbon source is needed to improve the BNR performance in treating low C/N ratio municipal waste-water in the modified A2O-MBR process.

  1. An investigation into the ancient abortion laws: comparing ancient Persia with ancient Greece and Rome.

    Science.gov (United States)

    Yarmohammadi, Hassan; Zargaran, Arman; Vatanpour, Azadeh; Abedini, Ehsan; Adhami, Siamak

    2013-01-01

    Since the dawn of medicine, medical rights and ethics have always been one of mankind's concerns. In any civilisation, attention paid to medical laws and ethics depends on the progress of human values and the advancement of medical science. The history of various civilisations teaches that each had its own views on medical ethics, but most had something in common. Ancient civilisations such as Greece, Rome, or Assyria did not consider the foetus to be alive and therefore to have human rights. In contrast, ancient Persians valued the foetus as a living person equal to others. Accordingly, they brought laws against abortion, even in cases of sexual abuse. Furthermore, abortion was considered to be a murder and punishments were meted out to the mother, father, and the person performing it. PMID:24304111

  2. The challenge of proving the existence of metazoan life in permanently anoxic deep-sea sediments.

    Science.gov (United States)

    Danovaro, Roberto; Gambi, Cristina; Dell'Anno, Antonio; Corinaldesi, Cinzia; Pusceddu, Antonio; Neves, Ricardo Cardoso; Kristensen, Reinhardt Møbjerg

    2016-01-01

    The demonstration of the existence of metazoan life in absence of free oxygen is one of the most fascinating and difficult challenges in biology. Danovaro et al. (2010) discovered three new species of the Phylum Loricifera, living in the anoxic sediments of the L'Atalante, a deep-hypersaline anoxic basin of the Mediterranean Sea. Multiple and independent analyses based on staining, incorporation of radiolabeled substrates, CellTracker Green incorporation experiments and ultra-structure analyses, allowed Danovaro et al. (2010) to conclude that these animals were able to spend their entire life cycle under anoxic conditions. Bernhard et al. (2015) investigated the same basin. Due to technical difficulties in sampling operations, they could not collect samples from the permanently anoxic sediment, and sampled only the redoxcline portion of the L'Atalante basin. They found ten individuals of Loricifera and provided alternative interpretations of the results of Danovaro et al. (2010). Here we analyze these interpretations, and present additional evidence indicating that the Loricifera encountered in the anoxic basin L'Atalante were actually alive at the time of sampling. We also discuss the reliability of different methodologies and approaches in providing evidence of metazoans living in anoxic conditions, paving the way for future investigations.This paper is a response to Bernhard JM, Morrison CR, Pape E, Beaudoin DJ, Todaro MA, Pachiadaki MG, Kormas KAr, Edgcomb VG. 2015. Metazoans of redoxcline sediments in Mediterranean deep-sea hypersaline anoxic basins. BMC Biology 2015 13:105.See research article at http://bmcbiol.biomedcentral.com/articles/10.1186/s12915-015-0213-6. PMID:27267928

  3. Ecological Modernization

    NARCIS (Netherlands)

    Mol, A.P.J.

    2006-01-01

    The Encyclopedia of Globalization provides a thorough understanding of the theoretical underpinnings of globalization as well as the various historical and analytical interpretations. Consisting of over 400 entries, coverage includes key cultural, ecological, economic, geographical, historical, poli

  4. Community Ecology

    CERN Document Server

    1988-01-01

    This book presents the proceedings of a workshop on community ecology organized at Davis, in April, 1986, sponsored by the Sloan Foundation. There have been several recent symposia on community ecology (Strong et. al., 1984, Diamond and Case, 1987) which have covered a wide range of topics. The goal of the workshop at Davis was more narrow: to explore the role of scale in developing a theoretical approach to understanding communities. There are a number of aspects of scale that enter into attempts to understand ecological communities. One of the most basic is organizational scale. Should community ecology proceed by building up from population biology? This question and its ramifications are stressed throughout the book and explored in the first chapter by Simon Levin. Notions of scale have long been important in understanding physical systems. Thus, in understanding the interactions of organisms with their physical environment, questions of scale become paramount. These more physical questions illustrate the...

  5. Performance evaluation of a novel anaerobic-anoxic sludge blanket reactor for biological nutrient removal treating municipal wastewater.

    Science.gov (United States)

    Díez-Montero, Rubén; De Florio, Loredana; González-Viar, Marta; Herrero, María; Tejero, Iñaki

    2016-06-01

    A novel anaerobic-anoxic sludge blanket reactor, AnoxAn, unifies the non-aerated zones of the biological nutrient removal treatment train in a single upflow reactor, aimed at achieving high compactness and efficiency. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. This contribution presents the performance evaluation of the novel reactor in the removal of organic matter and nutrients from municipal wastewater, coupled with an aerobic hybrid MBR. The overall system achieved total nitrogen and phosphorus removal with average efficiencies of 75% and 89%, respectively. Separate anoxic and anaerobic conditions were maintained in AnoxAn, allowing anaerobic phosphate release and nearly complete anoxic denitrification in the single reactor operating with an HRT of 4.2h. Biomass was retained in the reactor achieving TSS concentration up to 10gL(-1) and partial hydrolysis of influent particulate organic matter. PMID:26970922

  6. Ecological shortage

    International Nuclear Information System (INIS)

    The Meadows study (Limits to Growth) has made the environmental problem popular, but it has reduced the ecological problem to one of population and raw materials, leaving the conditions of social organisation and developmental policy out of consideration. This means that in spite of the repeated moral appeals, developing countries are left to their natural fate while fear and resignation are spread in the industrial nations. The present study tries to contradict this trend in consideration of interdependences in ecological development. (orig.)

  7. Steel corrosion in anoxic mediums with high chloride concentrations

    International Nuclear Information System (INIS)

    Carbon steels are widely used in contact with chloride containing mediums, however most of the literature reports corrosion problems in solutions in contact with air, for example, sea water. There are other applications where the steel is in contact with freshwater in the absence of oxygen as is the case with materials for nuclear repositories or in petroleum production. These mediums can have varied composition but their corrosivity is usually related to the concentration of chlorides. There are no systematic studies in the literature about the influence of high chloride concentrations on the speed of steel corrosion for carbon steels in the absence of oxygen. Some work has been done using Raman and XPS spectroscopy, but these techniques have been carried out ex situ in samples submitted to the action of high chloride concentrations. This results in the appearance of corrosion products on the metal surface due to the oxidation of the surface from exposure to air before and during the use of these techniques, generating confusing and uncertain data. The lack of reliable data is due to the difficulty of applying these techniques in situ under very low oxygen conditions (less than 10 ppb) without allowing any air into the system. Since there are no studies in the literature about the influence of high concentrations of chloride on the corrosion speed of carbon steels in the absence of oxygen, this work aims to generate experimental data to evaluate the influence of high concentrations of this anion on the corrosion speed of steel under anoxic conditions. The corrosivity of each solution was evaluated using electrochemical techniques such as corrosion potential, corrosion speed, anodic and cathodic polarization curves, cyclic voltammetries and electrochemical impedance spectroscopy to study the oxidation-reduction processes that occur with specific temperature, pH and chloride concentration conditions. Concentrated solutions of sodium chloride (50,000, 100,000 and 180

  8. Public Library Systems in Ancient South India

    OpenAIRE

    Raman Nair, R.

    1991-01-01

    The paper puts forward and substantiates the view that the concept of free public library service goes back to ancient times. Governments of those days were aware of their responsibility to provide to all citizens free information service. The study observes with reference to ancient Indian records that educational facilities and libraries were accessible to people of Ancient India without any discrimination based on economic status, caste, religion or geographical boundaries. Scholars handl...

  9. The Ancient Greece's roots of Olimpism

    Directory of Open Access Journals (Sweden)

    Bubka Sergej Nazarovich

    2011-10-01

    Full Text Available The paper focused on the phenomena of sport in Ancient Greece along with history, traditions, religion, education, culture and art. Economic and political conditions are analysed which promote or hamper development of Olympic Games in Ancient Greece. Exceptional stability of Ancient Olympic games during more than eleven centuries are noted as well as their influence on the life of Greek polices of those days. Hellenistic period needs of individual consideration.

  10. Aiding the Interpretation of Ancient Documents

    DEFF Research Database (Denmark)

    Roued-Cunliffe, Henriette

    tool it is important first to comprehend the interpretation process involved in reading ancient documents. This is not a linear process but rather a recursive process where the scholar moves between different levels of reading, such as ‘understanding the meaning of a character’ or ‘understanding......How can Decision Support System (DSS) software aid the interpretation process involved in the reading of ancient documents? This paper discusses the development of a DSS prototype for the reading of ancient texts. In this context the term ‘ancient documents’ is used to describe mainly Greek...

  11. The History and Practice of Ancient Astronomy

    CERN Document Server

    Evans, James

    1998-01-01

    The History and Practice of Ancient Astronomy combines new scholarship with hands-on science to bring readers into direct contact with the work of ancient astronomers. While tracing ideas from ancient Babylon to sixteenth-century Europe, the book places its greatest emphasis on the Greek period, when astronomers developed the geometric and philosophical ideas that have determined the subsequent character of Western astronomy. The author approaches this history through the concrete details of ancient astronomical practice. Carefully organized and generously illustrated, the book can teach reade

  12. Re-inventing ancient human DNA

    OpenAIRE

    Knapp, Michael; Lalueza-Fox, Carles; Hofreiter, M.

    2015-01-01

    For a long time, the analysis of ancient human DNA represented one of the most controversial disciplines in an already controversial field of research. Scepticism in this field was only matched by the long-lasting controversy over the authenticity of ancient pathogen DNA. This ambiguous view on ancient human DNA had a dichotomous root. On the one hand, the interest in ancient human DNA is great because such studies touch on the history and evolution of our own species. On the other hand, beca...

  13. Biosolids reduction by the oxic-settling-anoxic process: Impact of sludge interchange rate.

    Science.gov (United States)

    Semblante, Galilee U; Hai, Faisal I; Bustamante, Heriberto; Guevara, Nelly; Price, William E; Nghiem, Long D

    2016-06-01

    The impact of sludge interchange rate (SIR) on sludge reduction by oxic-settling-anoxic (OSA) process was investigated. The sludge yield of an OSA system (a sequencing batch reactor, SBR, integrated with external anoxic reactors) was compared to that of a control (an SBR attached to a single-pass aerobic digester). SIR (%) is the percentage by volume of sludge returned from the external reactor into the main bioreactor of the OSA, and was varied from 0% to 22%. OSA achieved greater sludge reduction when fed with unsettled sewage (sCOD=113mg/L) rather than settled sewage (sCOD=60mg/L). The SIR of 11% resulted in the highest OSA performance. At the optimum SIR, higher volatile solids destruction and nitrification/denitrification (i.e., conversion of destroyed volatile solids into inert forms) were observed in the external anoxic and intermittently aerated (i.e., aerobic/anoxic) reactors, respectively. Denitrification in the aerobic/anoxic reactor was inefficient without SIR. Effluent quality and sludge settleability of the main SBR were unaffected by SIR. PMID:26810193

  14. Nitrification and aerobic denitrification in anoxic-aerobic sequencing batch reactor.

    Science.gov (United States)

    Alzate Marin, Juan C; Caravelli, Alejandro H; Zaritzky, Noemí E

    2016-01-01

    The aim of this study was to evaluate the feasibility of achieving nitrogen (N) removal using a lab-scale sequencing batch reactor (SBR) exposed to anoxic/aerobic (AN/OX) phases, focusing to achieve aerobic denitrification. This process will minimize emissions of N2O greenhouse gas. The effects of different operating parameters on the reactor performance were studied: cycle duration, AN/OX ratio, pH, dissolved oxygen concentration (DOC), and organic load. The highest inorganic N removal (NiR), close to 70%, was obtained at pH=7.5, low organic load (440mgCOD/(Lday)) and high aeration given by 12h cycle, AN/OX ratio=0.5:1.0 and DOC higher than 4.0mgO2/L. Nitrification followed by high-rate aerobic denitrification took place during the aerobic phase. Aerobic denitrification could be attributed to Tetrad-forming organisms (TFOs) with phenotype of glycogen accumulating organisms using polyhydroxyalkanoate and/or glycogen storage. The proposed AN/OX system constitutes an eco-friendly N removal process providing N2 as the end product. PMID:26512862

  15. A Modified Oxidation Ditch with Additional Internal Anoxic Zones for Enhanced Biological Nutrient Removal

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; YANG Dianhai; XU Li; SHEN Changming

    2013-01-01

    A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally,aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process.Under all experimental conditions,the anaerobic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency.The effluent NH+4-N,total nitrogen(TN),PO34--P and total phosphorus(TP)contents were 1.2 mg·L-1,13 mg·L-1,0.3 mg·L-1 and 0.4 mg·L-1,respectively,all met the discharge standards in China.The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%.The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification.It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones,which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source.However,an excess internal recycle would cause nitrite to accumulate in the system.This seems to be harmful to biological phosphorus removal.

  16. Positive role of nitrite as electron acceptor on anoxic denitrifying phosphorus removal process

    Institute of Scientific and Technical Information of China (English)

    HUANG RongXin; LI Dong; LI XiangKun; BAO LinLin; JIANG AnXi; ZHANG Jie

    2007-01-01

    Literatures revealed that the electron acceptor-nitrite could be inhibitory or toxic in the denitrifying phosphorus removal process.Batch test experiments were used to investigate the inhibitory effect during the anoxic condition.The inoculated activated sludge was taken from a continuous double- sludge denitrifying phosphorus and nitrogen removal system.Nitrite was added at the anoxic stage.One time injection and sequencing batch injection were carried on in the denitrifying dephosphorus procedure.The results indicated that the nitrite concentration higher than 30 mg/L would inhibit the anoxic phosphate uptake severely, and the threshold inhibitory concentration was dependent on the characteristics of the activated sludge and the operating conditions; instead, lower than the inhibitory concentration would not be detrimental to anoxic phosphorus uptake, and it could act as good electron acceptor for the anoxic phosphate accumulated.Positive effects performed during the denitrifying biological dephosphorus all the time.The utility of nitrite as good electron acceptor would provide a new feasible way in the denitrifying phosphorus process.

  17. Chinese Ancient Football with Romanticism

    Institute of Scientific and Technical Information of China (English)

    江凌; 李晓勤

    2004-01-01

    Like other traditional Chinese sports, the ancient Chinese football, which used to be called “cuju”, has some differences from several sports in western countries concerning cultural and hamanist purport as well as metal aspiration, although it was similar with modern football to some extent, such as a leather-made ball with a bladder, rectangle sports ground, referee, goal and certain competitiveness. The author tries to talk about such difference in cultural and humanist purport as well as mental aspiration by making a comparison between “cuju” and modern football.

  18. Ancient Indian Leaps into Mathematics

    CERN Document Server

    Yadav, B S

    2011-01-01

    This book presents contributions of mathematicians covering topics from ancient India, placing them in the broader context of the history of mathematics. Although the translations of some Sanskrit mathematical texts are available in the literature, Indian contributions are rarely presented in major Western historical works. Yet some of the well-known and universally-accepted discoveries from India, including the concept of zero and the decimal representation of numbers, have made lasting contributions to the foundation of modern mathematics. Through a systematic approach, this book examines th

  19. Traditional ecological knowledge among transhumant pastoralists in Mediterranean Spain

    OpenAIRE

    Elisa Oteros-Rozas; Ricardo Ontillera-Sánchez; Pau Sanosa; Erik Gómez-Baggethun; Victoria Reyes-García; José A. González

    2013-01-01

    Mobility is a millenary human strategy to deal with environmental change. An outstanding example of mobility is transhumance, an ancient pastoralist practice consisting of the seasonal migration of livestock between ecological regions following peaks in pasture productivity. The maintenance of transhumance depends partly on the preservation of related traditional ecological knowledge (TEK). We (a) identified and characterized social groups that hold transhumance-related TEK, (b) analyzed tren...

  20. Diversity and three-dimensional structures of the alpha Mcr of the methanogenic Archaea from the anoxic region of Tucuruí Lake, in Eastern Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Priscila Bessa Santana

    2012-01-01

    Full Text Available Methanogenic archaeans are organisms of considerable ecological and biotechnological interest that produce methane through a restricted metabolic pathway, which culminates in the reaction catalyzed by the Methyl-coenzyme M reductase (Mcr enzyme, and results in the release of methane. Using a metagenomic approach, the gene of the a subunit of mcr (mcrα was isolated from sediment sample from an anoxic zone, rich in decomposing organic material, obtained from the Tucuruí hydroelectric dam reservoir in eastern Brazilian Amazonia. The partial nucleotide sequences obtained were 83 to 95% similar to those available in databases, indicating a low diversity of archaeans in the reservoir. Two orders were identified -the Methanomicrobiales, and a unique Operational Taxonomic Unit (OTU forming a clade with the Methanosarcinales according to low bootstrap values. Homology modeling was used to determine the three-dimensional (3D structures, for this the partial nucleotide sequence of the mcrα were isolated and translated on their partial amino acid sequences. The 3D structures of the archaean mcrα observed in the present study varied little, and presented approximately 70% identity in comparison with the mcrα of Methanopyrus klanderi. The results demonstrated that the community of methanogenic archaeans of the anoxic C1 region of the Tucurui reservoir is relatively homogeneous.

  1. [Ancient history of Indian pharmacy].

    Science.gov (United States)

    Okuda, Jun; Natsume, Yohko

    2010-01-01

    The study of the ancient history of Indian medicine has recently been revived due to the publication of polyglot translations. However, little is known of ancient Indian pharmacy. Archaeological evidence suggests the Indus people lived a settled life approximately in 2500 B.C. Their cities were enjoying the cleanest and most hygienic daily life with elaborate civic sanitation systems. The whole conception shows a remarkable concern for health. Then, the early Aryans invaded India about 1500 B.C. and the Vedic age started. The Rgveda texts contain the hymns for Soma and those for herbs. The term Ayurveda (i.e., science of life) is found in some old versions of both Ramāyana and Mahābhārata and in the Atharvaveda. Suśruta had the credit of making a breakthrough in the field of surgery. The Ayurveda, a work on internal medicine, gives the following transmission of sages: Brahmā-->Daksa-->Prajāpati-->Aśivinau-->Indra-->Caraka. On the other hand, the Suśruta-samhitā, which deals mainly with surgical medicine, explains it as follows; Indra-->Dhanvantari-->Suśruta Both Caraka and Suśruta were medical doctors as well as pharmacists, so they studied more than 1000 herbs thoroughly. The Ayurveda had been used by his devotees for medical purposes. It eventually spread over Asia with the advanced evolution of Buddhism. PMID:21032887

  2. Influence of an oxic settling anoxic system on biomass yield, protozoa and filamentous bacteria.

    Science.gov (United States)

    Rodriguez-Perez, Santiago; Fermoso, Fernando G

    2016-01-01

    An oxic settling anoxic system coupled with an activated sludge process has been studied to reduce sewage sludge production. The reduction of sludge yield, excess sludge production and active biomass yield were 51.7%, 52.9% and 67.1%, respectively, compared with the control system. The oxic reactor of the oxic settling anoxic system, even with a lower active biomass concentration than the oxic reactor of control system, showed a higher metabolic activity in their active biomass. Diversity and crawling ciliates group have been shown as promising bioindicators of active biomass yield reduction. The identification of floc-forming bacteria in the control system suggested that oxic settling anoxic system will improve settling properties compared to a Conventional Activated Sludge process. PMID:26479432

  3. Batroxobin Against Anoxic Damage of Rat Hippocampal Neurons in Culture: Morphological Changes and Hsp70 Expression

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Batroxobin,the thrombin-like enzyme,is used for therapeutic defibrination. We have found that batroxobin has good therapeutic effect in ischemic reperfusion rats and clinical practices in vivo. But we have not studied the neuroprotective effect of batroxobin on anoxic hippocampal neurons in vitro. The purpose of this study was to obtain further information on the mechanism of the batroxobin-induced neuroprotection and examine the neuroprotective effect on neurons exposed to anoxia. The effect of batroxobin on anoxic damages in cultured hippocampal neurons of neonatal rats was investigated by using morphological changes and heat shock protein 70Kd (Hsp70) immunoreactive expression as indicators. The results indicate that batroxobin, besides its defibrination, may have a direct neuroprotective effect on anoxic damage of hippocampal neurons.

  4. Information Ecology

    DEFF Research Database (Denmark)

    Christiansen, Ellen Tove

    2006-01-01

    The paper describes a pedagogical didactical paradigm for teaching student-designers how to deal with context issues. Form/context-relationships are conceptualized as information ecologies and described as behavioral settings using a key concept developed by social psychologist R.A. Baker in the...... 1960ties, and chosen here because it integrates cultural and psychological trajectories in a theory of living settings. The pedagogical-didactical paradigm comprises three distinct information ecologies, named after their intended outcome: the problem-setting, the exploration-setting, and the fit......-setting. It is specified how context issues can be treated within each of these information ecologies. The paper concludes by discussing the outcome of applying this paradigm with respect to the student-designers’ competence as reflective practitioners....

  5. Survival and Recovery of Methanotrophic Bacteria Starved Under Oxic and Anoxic Conditions

    Science.gov (United States)

    Roslev, Peter; King, Gary M.

    1994-01-01

    The effects of carbon deprivation on survival of methanotrophic bacteria were compared in cultures incubated in the presence and absence of oxygen in the starvation medium. Survival and recovery of the examined methanotrophs were generally highest for cultures starved under anoxic conditions as indicated by poststarvation measurements of methane oxidation, tetrazolium salt reduction, plate counts, and protein synthesis. Methylosinus trichosporium OB3b survived up to 6 weeks of carbon deprivation under anoxic conditions while maintaining a physiological state that allowed relatively rapid (hours) methane oxidation after substrate addition. A small fraction of cells starved under oxic and anoxic conditions (4 and 10%, respectively) survived more than 10 weeks but required several days for recovery on plates and in liquid medium. A non-spore-forming methanotroph, strain WP 12, displayed 36 to 118% of its initial methane oxidation capacity after 5 days of carbon deprivation. Oxidation rates varied with growth history prior to the experiments as well as with starvation conditions. Strain WP 12 starved under anoxic conditions showed up to 90% higher methane oxidation activity and 46% higher protein production after starvation than did cultures starved under oxic conditions. Only minor changes in biomass and niorpholow were seen for methanotrophic bacteria starved tinder anoxic conditions. In contrast, starvation under oxic conditions resulted in morphology changes and an initial 28 to 35% loss of cell protein. These data suggest that methanotrophic bacteria can survin,e carbon deprivation under anoxic conditions by using maintenance energy derived Solelyr from an anaerobic endogenous metabolism. This capability could partly explain a significant potential for methane oxidation in environments not continuously, supporting aerobic methanotrophic growth.

  6. ECOLOGICAL EDUCATION

    Directory of Open Access Journals (Sweden)

    GABRIELA GYONGY MIHUT

    2011-04-01

    Full Text Available While in most emerging and developing countries, the population has a lower ecological footprint in the developed countries have a larger footprint.There is also an alarming contrast between a person perception of her liability for damages to its environment and its actual size. These misconceptions may have their source in the absence of awareness of risks from climate change, culture or religion.The purpose of this study is to analyze the situation at the international and Romanian level and to draw attention on the necessity of un ecological education.

  7. Political ecology

    International Nuclear Information System (INIS)

    Using facts and examples, this didactically structures textbook gives an insight into the extent and consequences of the damage to the environment, with the subjects - fundamentals of ecology; - population and food problems; - the energy problem; - economic growth; scarcity of resources, recycling; - ground, water, and air pollution, - city and traffic problems; - work protection and medical care; - political alternatives and 'soft technologies'. The analysis of the political and economic reasons is combined with social and technical alternatives from which demands to be made and measures to be taken can be derived for individuals, citizens' interest groups, political groups and trade unions. Teaching models intend to help teachers to work on specific problems of ecology. (orig.)

  8. Multiple facets of anoxic metabolism and hydrogen production in the unicellular green alga Chlamydomonas reinhardtii.

    Science.gov (United States)

    Grossman, Arthur R; Catalanotti, Claudia; Yang, Wenqiang; Dubini, Alexandra; Magneschi, Leonardo; Subramanian, Venkataramanan; Posewitz, Matthew C; Seibert, Michael

    2011-04-01

    Many microbes in the soil environment experience micro-oxic or anoxic conditions for much of the late afternoon and night, which inhibit or prevent respiratory metabolism. To sustain the production of energy and maintain vital cellular processes during the night, organisms have developed numerous pathways for fermentative metabolism. This review discusses fermentation pathways identified for the soil-dwelling model alga Chlamydomonas reinhardtii, its ability to produce molecular hydrogen under anoxic conditions through the activity of hydrogenases, and the molecular flexibility associated with fermentative metabolism that has only recently been revealed through the analysis of specific mutant strains. PMID:21563367

  9. Decomposition of algal lipids in clay-enriched marine sediment under oxic and anoxic conditions

    Institute of Scientific and Technical Information of China (English)

    吕冬伟; 宋茜; 王旭晨

    2010-01-01

    A series of laboratory incubation experiments were conducted to examine the decomposition of algal organic matter in clay-enriched marine sediment under oxic and anoxic conditions.During the 245-day incubation period,changes in the concentrations of TOC,major algal fatty acid components (14:0,16:0,16:1,18:1 and 20:5),and n-alkanes (C16-C23) were quantified in the samples.Our results indicate that the organic matters were degraded more rapidly in oxic than anoxic conditions.Adsorption of fatty acids onto cla...

  10. Attitudes Toward Deviant Sex in Ancient Mesopotamia

    Science.gov (United States)

    Bullough, Vern L.

    1971-01-01

    The article concludes that the whole question of sexual life in ancient Mesopotamia is difficult to reconstruct and fraught with many uncertainties. Nevertheless, it seems certain that the ancient Mesopotamians had fewer prohibitions against sex than our own civilization, and regarded as acceptable many practices which later societies condemned.…

  11. The Idea of Ancient Greek Philosophy

    Institute of Scientific and Technical Information of China (English)

    苏雪

    2016-01-01

    As the source of western philosophy, ancient Greek philosophy had a profound influence on western philosophy. Ancient philosophers were hard to reach a consensus on the existence of all the things in the world. They tried to grasp the profound understanding of the world, which is the clue of the history of philosophy.

  12. Women--Sex Objects in Ancient Egypt.

    Science.gov (United States)

    Mutimer, Brian T. P.

    Although it has been said that the women in Ancient Egypt enjoyed a reasonable state of social and professional equality with men, this paper presents an alternate theory--that women were second-class citizens whose physical prowess was secondary to their role as sex objects. It appears that men and women in Ancient Egypt often participated in the…

  13. An ancient rangefinder for teaching surveying methods

    OpenAIRE

    Sparavigna, Amelia Carolina

    2012-01-01

    Rangefinders are instruments used for ballistics and for surveying in general. Here we propose a discussion of some of them, ranging from the ancient Rome to the modern methods. Using an ancient roman artefact as a model, we can pre-pare a rangefinder at no cost for teaching surveying methods to students of engineering and military schools

  14. Mechanisms in ancient Chinese books with illustrations

    CERN Document Server

    Hsiao, Kuo-Hung

    2014-01-01

    This book presents a unique approach for studying mechanisms and machines with drawings that were depicted unclearly in ancient Chinese books. The historical, cultural and technical backgrounds of the mechanisms are explained, and various mechanisms described and illustrated in ancient books are introduced. By utilizing the idea for the conceptual design of modern mechanisms, all feasible designs of ancient mechanisms with uncertain members and joints that meet the technical standards of the subjects’ time periods are synthesized systematically. Ancient Chinese crossbows (the original crossbow and repeating crossbows), textile mechanisms (silk-reeling mechanism, spinning mechanisms, and looms), and many other artisan's tool mechanisms are used as illustrated examples.  Such an approach provides a logical method for the reconstruction designs of ancient mechanisms with uncertain structures. It also provides an innovative direction for researchers to further identify the original structures of mechanisms...

  15. Structural recognition of ancient Chinese ideographic characters

    Institute of Scientific and Technical Information of China (English)

    Li Ning; Chen Dan

    2014-01-01

    Ancient Chinese characters, typically the ideographic characters on bones and bronze before Shang Dynasty (16th—11th century B.C.), are valuable culture legacy of history. However the recognition of Ancient Chinese characters has been the task of paleography experts for long. With the help of modern computer technique, everyone can expect to be able to recognize the characters and understand the ancient inscriptions. This research is aimed to help people recognize and understand those ancient Chinese characters by combining Chinese paleography theory and computer information processing technology. Based on the analysis of ancient character features, a method for structural character recognition is proposed. The important characteristics of strokes and basic components or radicals used in recognition are introduced in detail. A system was implemented based on above method to show the effectiveness of the method.

  16. Hurdles in investigating UVB damage in the putative ancient asexual Darwinula stevensoni (Ostracoda, Crustacea)

    OpenAIRE

    Van den Broecke, Lynn; Vanfleteren, Jacques; Martens, Koen; SCHON, Isa

    2013-01-01

    Ostracoda or mussel-shrimps are small, bivalved Crustacea. Because of their excellent fossil record and their broad variety of reproductive modes, ostracods are of great interest as a model group in ecological and evolutionary research. Here, we investigated damage and repair from one of the most important biological mutagens, namely UVB radiation, in the putative ancient asexual ostracod Darwinula stevensoni from Belgium. We applied three different methods: the Polymerase Inhibition (PI) ass...

  17. Ecology, Microbial

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, Allan

    2009-03-19

    Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

  18. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  19. Phloem flow and sugar transport in Ricinus communis L. is inhibited under anoxic conditions of shoot or roots

    NARCIS (Netherlands)

    Peuke, A.D.; Gessler, A.; Trumbore, S.; Windt, C.W.; Homan, N.; Gerkema, E.; As, van H.

    2015-01-01

    Anoxic conditions should hamper the transport of sugar in the phloem, as this is an active process. The canopy is a carbohydrate source and the roots are carbohydrate sinks.By fumigating the shoot with N2 or flooding the rhizosphere, anoxic conditions in the source or sink, respectively, were induce

  20. Ancient and modern environmental DNA

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Winther; Overballe-Petersen, Søren; Ermini, Luca;

    2015-01-01

    DNA obtained from environmental samples such as sediments, ice or water (environmental DNA, eDNA), represents an important source of information on past and present biodiversity. It has revealed an ancient forest in Greenland, extended by several thousand years the survival dates for mainland...... woolly mammoth in Alaska, and pushed back the dates for spruce survival in Scandinavian ice-free refugia during the last glaciation. More recently, eDNA was used to uncover the past 50 000 years of vegetation history in the Arctic, revealing massive vegetation turnover at the Pleistocene....../Holocene transition, with implications for the extinction of megafauna. Furthermore, eDNA can reflect the biodiversity of extant flora and fauna, both qualitatively and quantitatively, allowing detection of rare species. As such, trace studies of plant and vertebrate DNA in the environment have revolutionized our...

  1. Archimedes: Accelerator Reveals Ancient Text

    International Nuclear Information System (INIS)

    Archimedes (287-212 BC), who is famous for shouting 'Eureka' (I found it) is considered one of the most brilliant thinkers of all times. The 10th-century parchment document known as the 'Archimedes Palimpsest' is the unique source for two of the great Greek's treatises. Some of the writings, hidden under gold forgeries, have recently been revealed at the Stanford Synchrotron Radiation Laboratory at SLAC. An intense x-ray beam produced in a particle accelerator causes the iron in original ink, which has been partly erased and covered, to send out a fluorescence glow. A detector records the signal and a digital image showing the ancient writings is produced. Please join us in this fascinating journey of a 1,000-year-old parchment from its origin in the Mediterranean city of Constantinople to a particle accelerator in Menlo Park.

  2. Ancient Acupuncture Literature on Apoplexy

    Institute of Scientific and Technical Information of China (English)

    XU Yi-zeng; BI Zhen; Xiao Yuan-chun

    2003-01-01

    This paper reviews twenty-eight Chinese medicine books with complete prescriptions prior to the Qing Dynasty, and analyzes the characteristics of acupoint selection and needling manipulations from the perspective of apoplectic symptoms. It is concluded that,in ancient times, apoplexy is often treated on the basis of its symptoms and a great number of acupoints are employed; hemiplegia is mainly treated by the acupoints of the Large Intestine Meridian and Gallbladder Meridian,with two key acupoints; coma is mainly treated by first-aid acupoints and qi-supplementing acupoints, with seven key acupoints; wry mouth and convulsion are mainly treated by the local acupoints; as for needling manipulations, moxibustion with moxa cones is principally used, while needling is less used.

  3. Modified aluminosilicates as low-cost sorbents of As(III) from anoxic groundwater

    Czech Academy of Sciences Publication Activity Database

    Doušová, B.; Fuitová, L.; Grygar, Tomáš; Machovič, Vladimír; Koloušek, D.; Herzogová, L.; Lhotka, M.

    2009-01-01

    Roč. 165, 1-3 (2009), s. 134-140. ISSN 0304-3894 Grant ostatní: GA AV ČR(CZ) IAA401250701 Institutional research plan: CEZ:AV0Z40320502; CEZ:AV0Z30460519 Keywords : arsenic * anoxic groundwater * decontamination Subject RIV: CA - Inorganic Chemistry Impact factor: 4.144, year: 2009

  4. A euxinic southern North Atlantic Ocean during the Cenomanian/Turonian oceanic anoxic event

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Koster, J.

    1998-01-01

    During mid-Cretaceous times large amounts of organic carbon (Corg) became sequestered in black shales', possibly due to oceanic anoxic events' characterized by the development of an extended oxygen minimum zone (OMZ). Here, we provide the first direct evidence for an open ocean OMZ in the Cenomani

  5. Gradual and sustained carbon dioxide release during Aptian Oceanic Anoxic Event 1a

    Science.gov (United States)

    Naafs, B. D. A.; Castro, J. M.; de Gea, G. A.; Quijano, M. L.; Schmidt, D. N.; Pancost, R. D.

    2016-02-01

    During the Aptian Oceanic Anoxic Event 1a, about 120 million years ago, black shales were deposited in all the main ocean basins. The event was also associated with elevated sea surface temperatures and a calcification crisis in calcareous nannoplankton. These environmental changes have been attributed to variations in atmospheric CO2 concentrations, but the evolution of the carbon cycle during this event is poorly constrained. Here we present records of atmospheric CO2 concentrations across Oceanic Anoxic Event 1a derived from bulk and compound-specific δ13C from marine rock outcrops in southern Spain and Tunisia. We find that CO2 concentrations doubled in two steps during the oceanic anoxic event and remained above background values for approximately 1.5-2 million years before declining. The rise of CO2 concentrations occurred over several tens to hundreds of thousand years, and thus was unlikely to have resulted in any prolonged surface ocean acidification, suggesting that CO2 emissions were not the primary cause of the nannoplankton calcification crisis. We find that the period of elevated CO2 concentrations coincides with a shift in the oceanic osmium-isotope inventory associated with emplacement of the Ontong Java Plateau flood basalts, and conclude that sustained volcanic outgassing was the primary source of carbon dioxide during Oceanic Anoxic Event 1a.

  6. Methane oxidizing bacteria at the oxic-anoxic interface : taxon-specific activity and resilience

    OpenAIRE

    Reim, Andreas

    2013-01-01

    The methanotrophic bacteria are the only known biological sink for the third most important greenhouse gas methane, performing an important ecosystem function influencing global climate change. In the soil surface layer of water logged soils aerobic methanotrophs thrive at the oxic-anoxic interface attenuating the amount of potentially emitted methane. The highly diverse methanotroph community is shaping the interface characterize...

  7. Anoxic survival of Macoma balthica: the effect of antibiotics, molybdate and sulphide

    NARCIS (Netherlands)

    De Zwaan, A.; Schaub, B.; Babarro, J.M.F.

    2001-01-01

    In anoxic semi-closed systems, the survival time of the clam Macoma balthica was compared to clams which were incubated in the presence of several antibiotics (chloramphenicol, 5- oxytetracycline hydrochloride, penicillin, streptomycin. a mix of penicillin and streptomycin and a mix of chloramphenic

  8. Study of control strategy and simulation in anoxic-oxic nitrogen removal process

    Institute of Scientific and Technical Information of China (English)

    PENG Yong-zhen; WANG Zhi-hui; WANG Shu-ying

    2005-01-01

    The control strategy and simulation of external carbon addition were specially studied in an anoxic-oxic(A/O) process with low carbon: nitrogen(C/N) domestic wastewater. The control strategy aimed to adjust the flow rate of external carbon dosage to the anoxic zone, thus the concentration of nitrate plus nitrite( NOx -N) in the anoxic zone was kept closed to the set point. The relationship was studied between the NOx-N concentration in the anoxic zone(SNo) and the dosage of external carbon, and the results showed that the removal efficiency of the total nitrogen(TN) could not be largely improved by double dosage of carbon source when SNO reached about 2mg/L. Through keeping SNO at the level of about 2 mg/L, the demand of effluent quality could be met and the carbon dosage could be optimized. Based on the Activated Sludge Model No. 1 (ASM No. 1 ), a simplified mathematical model of external carbon dosage was developed. Simulation results showed that PI controller and feed-forward PI controller both had good dynamic response and steady precision. And feed-forward PI controller had better control effects due to its consideration of influent disturbances.

  9. The effect of anoxic treatment on the larvae of six species of dermestids (Coleoptera)

    DEFF Research Database (Denmark)

    Bergh, J.E.; Hansen, L.S.; Jensen, K.M.V.; Nielsen, Per Væggemose

    2003-01-01

    Based on surveys of species of museum pest insects commonly found in Finland, Norway, Denmark and Sweden, six species were selected for a study of the effect of exposure to anoxic treatment on the larval stage. An oxygen level of 0.3% (the rest, nitrogen) was applied and lethal exposure times wer...

  10. Anoxic N-2 fluxes from freshwater sediments in the absence of oxidized nitrogen compounds.

    NARCIS (Netherlands)

    Luijn, F.; Boers, P.C.M.; Lijklema, L.

    1998-01-01

    From anoxic incubated freshwater sediments, initially without inorganic nitrogen compounds in the overlying water, remarkable and unexpected N2 fluxes were estimated. N2 leakage from the atmosphere and oxygen leakage followed by nitrification and denitrification, two possible causes, were thoroughly

  11. Enrichment of denitrifying glycogen-accumulating organisms in anaerobic/anoxic activated sludge system.

    Science.gov (United States)

    Zeng, Raymond J; Yuan, Zhiguo; Keller, Jürg

    2003-02-20

    Denitrifying glycogen-accumulating organisms (DGAO) were successfully enriched in a lab-scale sequencing batch reactor (SBR) running with anaerobic/anoxic cycles and acetate feeding during the anaerobic period. Acetate was completely taken up anaerobically, which was accompanied by the consumption of glycogen and the production of poly-beta-hydroxy-alkanoates (PHA). In the subsequent anoxic stage, nitrate or nitrite was utilized as electron acceptor for the oxidation of PHA, resulting in glycogen replenishment and cell growth. The above phenotype showed by the enrichment culture demonstrates the existence of DGAO. Further, it was found that the anaerobic behavior of DGAO could be predicted well by the anaerobic GAO model of Filipe et al. (2001) and Zeng et al. (2002a). The final product of denitrification during anoxic stage was mainly nitrous oxide (N(2)O) rather than N(2). The data strongly suggests that N(2)O production may be caused by the inhibition of nitrous oxide reductase by an elevated level of nitrite accumulated during denitrification. The existence of these organisms is a concern in biological nutrient removal systems that typically have an anaerobic/anoxic/aerobic reactor sequence since they are potential competitors to the polyphosphate-accumulating organisms. PMID:12491525

  12. Electrophysiological Correlates of Deficient Encoding in a Case of Post-Anoxic Amnesia

    Science.gov (United States)

    Lehmann, Sandra; Morand, Stephanie; James, Clara; Schnider, Armin

    2007-01-01

    Little is known about the initial stages of information processing in amnesia as compared to normal memory. In this study, we used electrical spatiotemporal mapping to compare cortical activation during encoding and recognition in a 56-year-old patient with severe, chronic post-anoxic amnesia and an age-matched control group. Event-related…

  13. ENVIRONMENTAL FACTORS INFLUENCING METHANOGENESIS IN A SHALLOW ANOXIC AQUIFER: A FIELD AND LABORATORY STUDY

    Science.gov (United States)

    The environmental factors influencing methanogenesis in a shallow anoxic aquifer were probed in a combined field and laboratory study. Field data collected over a year revealed that in situ rates of methane production were depressed in winter and elevated in summer. Over the same...

  14. Open Questions on the Origin of Life at Anoxic Geothermal Fields

    Science.gov (United States)

    Mulkidjanian, Armen Y.; Bychkov, Andrew Yu.; Dibrova, Daria V.; Galperin, Michael Y.; Koonin, Eugene V.

    2012-10-01

    We have recently reconstructed the `hatcheries' of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells (Mulkidjanian et al. Proc Natl Acad Sci U S A 109:E821-830, 2012). These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K+, Zn2+, Mn2+, and phosphate. Thus, protocells must have evolved in habitats with a high K+/Na+ ratio and relatively high concentrations of Zn, Mn and phosphorous compounds. Geochemical reconstruction shows that the ionic composition conducive to the origin of cells could not have existed in marine settings but is compatible with emissions of vapor-dominated zones of inland geothermal systems. Under an anoxic, CO2-dominated atmosphere, the ionic composition of pools of cool, condensed vapor at anoxic geothermal fields would resemble the internal milieu of modern cells. Such pools would be lined with porous silicate minerals mixed with metal sulfides and enriched in K+ ions and phosphorous compounds. Here we address some questions that have appeared in print after the publication of our anoxic geothermal field scenario. We argue that anoxic geothermal fields, which were identified as likely cradles of life by using a top-down approach and phylogenomics analysis, could provide geochemical conditions similar to those which were suggested as most conducive for the emergence of life by the chemists who pursuit the complementary bottom-up strategy.

  15. Factors involved in the (near) anoxic survival time of Cerastoderma edule: associated bacteria vs. endogenous fuel

    NARCIS (Netherlands)

    Babarro, J.M.F.; De Zwaan, A.

    2001-01-01

    The effect of several antibiotics, molybdate and hydrogen sulfide was tested on anoxic tolerance of the cockle Cerastoderma edule, as well as utilisation of glycogen. The aim was to evaluate the role of fuel depletion and growth of bacteria as a cause of mortality. The exponential increase of sulfid

  16. Ecological macroeconomics

    DEFF Research Database (Denmark)

    Røpke, Inge

    2013-01-01

    of the economy could go hand in hand with increased employment. These ideas were not reflected much in actual policies, and – despite some green elements – the subsequent economic upturn was driven first of all by consumption, and in several affluent countries, fueled by credit expansion. The current revival...... on how to reconcile environmental and social concerns. Based on this broad variety of pieces in a jigsaw puzzle, a new ecological macroeconomics is emerging, but the contours are still vague. This chapter seeks to outline some of this topography and to add a few pieces of its own by highlighting the need...... to shift resources from consumption to investment and describing the role of consumer-citizens in such a change. The chapter starts by identifying the problems and challenges for an ecological macroeconomics. The next section outlines some of the shortcomings of traditional macroeconomics...

  17. ECOLOGICAL EDUCATION

    OpenAIRE

    GABRIELA GYONGY MIHUT

    2011-01-01

    While in most emerging and developing countries, the population has a lower ecological footprint in the developed countries have a larger footprint.There is also an alarming contrast between a person perception of her liability for damages to its environment and its actual size. These misconceptions may have their source in the absence of awareness of risks from climate change, culture or religion.The purpose of this study is to analyze the situation at the international and Romanian level an...

  18. Geologically ancient DNA: fact or artefact?

    DEFF Research Database (Denmark)

    Hebsgaard, Martin Bay; Phillips, Matthew J.; Willerslev, Eske

    2005-01-01

    Studies continue to report ancient DNA sequences and viable microbial cells that are many millions of years old. In this paper we evaluate some of the most extravagant claims of geologically ancient DNA. We conclude that although exciting, the reports suffer from inadequate experimental setup and...... insufficient authentication of results. Consequently, it remains doubtful whether amplifiable DNA sequences and viable bacteria can survive over geological timescales. To enhance the credibility of future studies and assist in discarding false-positive results, we propose a rigorous set of authentication...... criteria for work with geologically ancient DNA....

  19. Terrestrial ecology

    International Nuclear Information System (INIS)

    The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems

  20. Accounting And Forms Of Accountability In Ancient Civilizations: Mesopotamia And Ancient Egypt

    OpenAIRE

    SALVADOR CARMONA

    2005-01-01

    The aim of this paper is to identify the relevance and implications of ancient accounting practices to the contemporary theorizing of accounting. The paper provides a synthesis of the literature on ancient accounting particularly in relation to issues of human accountability, identifies its major achievements and outlines some of the key challenges facing researchers. We argue that far from being an idiosyncratic research field of marginal interest, research in ancient accounting is a rich an...

  1. AN INTERESTING CASE OF ANCIENT SCHWANNOMA

    Directory of Open Access Journals (Sweden)

    Binu

    2015-01-01

    Full Text Available INTRODUCTION : Schwannoma is a common benign tumour of nerve sheath. Degenerating type of schwannoma is called ancient schwannoma. Ancient schwannomas of scalp are rare and are often misdiagnosed as sebaceous cyst or dermoid cyst. CASE REPORT : We present a thirty two year old male presented with scalp swel ling of eight years duration. X - ray showed no intracranial extension. He underwent excision of the tumour and histopathology was reported as ancient schwannoma. DISCUSSION : Histopathologically , ancient schwannomas charecterised by cellular Antoni type A ar eas and less cellular Antoni type - B areas. 9 th , 7 th , 11 th , 5 th and 4 th cranial nerves are often affected and may be associated with multiple neuro fibramatosis (Von - Recklinghausen’s disease. Impact : Case is presented for its rarity and possible pre - operative misdiagnosis

  2. Genetic Diversity among Ancient Nordic Populations

    DEFF Research Database (Denmark)

    Melchior, Linea; Lynnerup, Niels; Siegismund, Hans R;

    2010-01-01

    locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the...... ancient Danes (average 13%) than among extant Danes and Scandinavians ( approximately 2.5%) as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic...... samples (4,200 YBP, Bell Beaker culture) that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP) was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for...

  3. Faience: the ceramic technology of ancient Egypt

    OpenAIRE

    Sparavigna, Amelia Carolina

    2012-01-01

    Faiences are ancient Egyptian ceramic materials, considered as "high-tech" products. The paper discussed the method by which the faiences were produced and the application of SEM and Raman spectroscopy to their analysis

  4. NIMI TANTRA (Opthalmology of Ancient India)

    OpenAIRE

    Ramachandran, C.K.

    1984-01-01

    The art of opthalmology was well developed in ancient India and was known as Nimi Tantra. In this paper the author presents the main features of Nimi Tantra an authoritative treatises written by Nimi, a prominent opthalmologist of his time.

  5. Ancient Magnetic Reversals: Clues to the Geodynamo.

    Science.gov (United States)

    Hoffman, Kenneth A.

    1988-01-01

    Discusses the question posed by some that the earth's magnetic field may reverse. States that rocks magnetized by ancient fields may offer clues to the underlying reversal mechanism in the earth's core. (TW)

  6. Rethinking the Ancient Sulfur Cycle

    Science.gov (United States)

    Fike, David A.; Bradley, Alexander S.; Rose, Catherine V.

    2015-05-01

    The sulfur biogeochemical cycle integrates the metabolic activity of multiple microbial pathways (e.g., sulfate reduction, disproportionation, and sulfide oxidation) along with abiotic reactions and geological processes that cycle sulfur through various reservoirs. The sulfur cycle impacts the global carbon cycle and climate primarily through the remineralization of organic carbon. Over geological timescales, cycling of sulfur is closely tied to the redox state of Earth's exosphere through the burial of oxidized (sulfate) and reduced (sulfide) sulfur species in marine sediments. Biological sulfur cycling is associated with isotopic fractionations that can be used to trace the fluxes through various metabolic pathways. The resulting isotopic data provide insights into sulfur cycling in both modern and ancient environments via isotopic signatures in sedimentary sulfate and sulfide phases. Here, we review the deep-time δ34S record of marine sulfates and sulfides in light of recent advances in understanding how isotopic signatures are generated by microbial activity, how these signatures are encoded in marine sediments, and how they may be altered following deposition. The resulting picture shows a sulfur cycle intimately coupled to ambient carbon cycling, where sulfur isotopic records preserved in sedimentary rocks are critically dependent on sedimentological and geochemical conditions (e.g., iron availability) during deposition.

  7. Ancient Admixture in Human History

    Science.gov (United States)

    Patterson, Nick; Moorjani, Priya; Luo, Yontao; Mallick, Swapan; Rohland, Nadin; Zhan, Yiping; Genschoreck, Teri; Webster, Teresa; Reich, David

    2012-01-01

    Population mixture is an important process in biology. We present a suite of methods for learning about population mixtures, implemented in a software package called ADMIXTOOLS, that support formal tests for whether mixture occurred and make it possible to infer proportions and dates of mixture. We also describe the development of a new single nucleotide polymorphism (SNP) array consisting of 629,433 sites with clearly documented ascertainment that was specifically designed for population genetic analyses and that we genotyped in 934 individuals from 53 diverse populations. To illustrate the methods, we give a number of examples that provide new insights about the history of human admixture. The most striking finding is a clear signal of admixture into northern Europe, with one ancestral population related to present-day Basques and Sardinians and the other related to present-day populations of northeast Asia and the Americas. This likely reflects a history of admixture between Neolithic migrants and the indigenous Mesolithic population of Europe, consistent with recent analyses of ancient bones from Sweden and the sequencing of the genome of the Tyrolean “Iceman.” PMID:22960212

  8. Ancient history of flatfish research

    Science.gov (United States)

    Berghahn, Rüdiger; Bennema, Floris Pieter

    2013-01-01

    Owing to both their special appearance and behavior flatfish have attracted the special attention of people since ages. The first records of humans having been in touch with flatfish date back to the Stone Age about 15,000 years B.C. Detailed descriptions were already given in the classical antiquity and were taken up 1400 years later in the Renaissance by the first ichthyologists, encyclopédists, and also by practical men. This was more than 200 years before a number of common flatfish species were given their scientific names by Linnaeus in 1758. Besides morphology, remarkable and sometimes amusing naturalistic observations and figures are bequeathed. Ancient history of flatfish research is still a wide and open array. Examples are presented how the yield of information and interpretation from these times increases with interdisciplinary cooperation including archeologists, zoologists, ichthyologists, historians, art historians, fisheries and fishery biologist. The timeline of this contribution ends with the start of modern fishery research at the end of the 19th century in the course of the rapidly increasing exploitation of fish stocks.

  9. The Language of Ancient Greek Philological Texts

    OpenAIRE

    Brigita Kukjalko

    2011-01-01

    Annotation to the Doctoral Thesis by Brigita Aleksejeva: The Language of Ancient Greek Philological Texts An Ancient Greek philological text often combined the research of various language-related issues, which are nowadays studied by separate branches of linguistics – such as orthography, phonology, morphology, lexicology, syntax, and stylistics. The language of these texts differs from that of the fictional and non-theoretical texts of the period: since they represent the origins of the ...

  10. Radiocarbon dating of ancient Japanese documents

    International Nuclear Information System (INIS)

    History is a reconstruction of past human activity, evidence of which is remained in the form of documents or relics. For the reconstruction of historic period, the radiocarbon dating of ancient documents provides important information. Although radiocarbon age is converted into calendar age with the calibration curve, the calibrated radiocarbon age is still different from the historical age when the document was written. The difference is known as 'old wood effect' for wooden cultural property. The discrepancy becomes more serious problem for recent sample which requires more accurate age determination. Using Tandetron accelerator mass spectrometer at Nagoya University, we have measured radiocarbon ages of Japanese ancient documents, sutras and printed books written dates of which are clarified from the paleographic standpoint. The purpose is to clarify the relation between calibrated radiocarbon age and historical age of ancient Japanese document by AMS radiocarbon dating. This paper reports 23 radiocarbon ages of ancient Japanese documents, sutras and printed books. The calibrated radiocarbon ages are in good agreement with the corresponding historical ages. It was shown by radiocarbon dating of the ancient documents that Japanese paper has little gap by 'old wood effect'; accordingly, ancient Japanese paper is a suitable sample for radiocarbon dating of recent historic period. (author)

  11. Reassembling ecologies

    OpenAIRE

    Justesen, Lise; Mouritsen, Jan; Tryggestad, Kjell

    2011-01-01

    In its general form, stakeholder theory posits an extension of the ecology. It claims that there are other stakes and interests than those posited by shareholder value theory (Freeman et al. 2004; Jensen and Sandström 2011), and some stakeholder theory proponents argue that the natural environment is also to be considered as a stakeholder (Driscoll and Starik 2004; Norton 2007). It is a positive claim – there are more stakes and interests – and a moral one – we should look towards more intere...

  12. Ancient bacteria in permafrost soils fact or artefact? Considerations in recovering microbial DNA from geological ancient settings

    Science.gov (United States)

    Willerslev, E.

    2003-04-01

    Several recent reports claim that prokaryotic genetic sequences or viable cultures can survive for millions of years in geological settings. If substantiated, these findings could fundamentally alter views about bacterial physiology, ecology and evolution. However, both the culturing of microbes and the amplification of ancient DNA molecules from fossil remains are beset with difficulties. First, theoretical and empirical studies have shown that small DNA fragments (100 200 bp) do not survive in the geosphere for more than 104 years in temperate environments and 105 years in colder ones due to hydrolytic and oxidative damage. Therefore, the revivals of dormant bacteria with no active DNA repair from remains hundreds of thousands to millions of years old is, from a theoretical point, expected to be difficult, if not impossible. Second, the no specificity of the media used to culture micro organisms, as well as the great sensitivity of PCR, makes the risk of contamination with contemporary ubiquitous microbial cells and exogenous DNA molecules extremely high. Contamination poses risks at all stages of sample processing (e.g.) within the samples themselves, in the chemical reagents, on laboratory disposables or through the air. The high risk of contamination strongly suggests the need for standardized procedures within the field such as independent replication of results. This criterion of authenticity has not yet been full field in any of the studies claiming million year old microbial cultures or DNA. In order to tests the long-term survival of ancient bacteria DNA a study on permafrost was conducted using ancient DNA precautions, controls and criteria. Permafrost must be considered among the most promising environments for long term DNA survival due to its constant low temperatures (-10C to 12C Siberian or 20C Antarctica) and high cell numbers (107). We found that bacteria DNA could reproducibly be obtained from samples dated up to 300-400,000 years B.P. but not

  13. Ecological Economics

    Science.gov (United States)

    Common, Michael; Stagl, Sigrid

    2005-10-01

    Taking as its starting point the interdependence of the economy and the natural environment, this book provides a comprehensive introduction to the emerging field of ecological economics. The authors, who have written extensively on the economics of sustainability, build on insights from both mainstream economics and ecological sciences. Part I explores the interdependence of the modern economy and its environment, while Part II focuses mainly on the economy and on economics. Part III looks at how national governments set policy targets and the instruments used to pursue those targets. Part IV examines international trade and institutions, and two major global threats to sustainability - climate change and biodiversity loss. Assuming no prior knowledge of economics, this textbook is well suited for use on interdisciplinary environmental science and management courses. It has extensive student-friendly features including discussion questions and exercises, keyword highlighting, real-world illustrations, further reading and website addresses. A comprehensive introduction to a developing field which will interest students from science, economics and management backgrounds A global approach to the problems of sustainability and sustainable development, issues which are increasingly prominent in political debate and policy making Filled with student-friendly features including focus areas for each chapter, keyword highlighting, real-world illustrations, discussion questions and exercises, further reading and website addresses

  14. Community composition of ammonia-oxidizing archaea from surface and anoxic depths of oceanic oxygen minimum zones

    Directory of Open Access Journals (Sweden)

    Xuefeng ePeng

    2013-07-01

    Full Text Available Ammonia-oxidizing archaea (AOA have been reported at high abundance in much of the global ocean, even in environments, such as pelagic oxygen minimum zones (OMZs, where conditions seem unlikely to support aerobic ammonium oxidation. Due to the lack of information on any potential alternative metabolism of AOA, the AOA community composition might be expected to differ between oxic and anoxic environments, indicating some difference in ecology and/or physiology of the AOA assemblage. This hypothesis was tested by evaluating AOA community composition using a functional gene microarray that targets the ammonia monooxygenase gene subunit A (amoA. The relationship between environmental parameters and the biogeography of the Arabian Sea and the Eastern Tropical South Pacific (ETSP AOA assemblages was investigated using principal component analysis (PCA and redundancy analysis (RDA. In both the Arabian Sea and the ETSP, AOA communities within the core of the OMZ were not significantly different from those inhabiting the oxygenated surface waters above the OMZ. The AOA communities in the Arabian Sea were significantly different from those in the ETSP. In both oceans, the abundance of archaeal amoA gene in the core of the OMZ was higher than that in the surface waters. Our results indicate that AOA communities are distinguished by their geographic origin. RDA suggested that temperature was the main factor that correlated with the differences between the AOA communities from the Arabian Sea and those from the ETSP. Physicochemical properties that characterized the different environments of the OMZ and surface waters played a less important role, than did geography, in shaping the AOA community composition.

  15. Geochemical characterization and miospore biochronostratigraphy of the Frasnian anoxic event in the Parnaiba basin, Northeast Brazil

    International Nuclear Information System (INIS)

    Radioactive shales of Frasnian age in the Parnaiba Basin present high concentrations of organic matter. They correspond to a condensed section related to the Devonian maximum marine transgression. Combined geochemical, palynological and clay mineral data point out to a dominant algal contribution in the composition of the organic matter, as well as to anoxic depositional settings. This radioactive shale interval corresponds to the onset of a long-lasting, global anoxic event which was to be intensified in the Late Frasnian, and thus can be regarded as a marker for chronostratigraphic correlations. It includes the main source rocks of Devonian age in the Palaeozoic basins of north Brazil, and therefore represents a target of potential interest for hydrocarbon exploration. (authors). 16 refs., 10 figs., 1 tab., 17 photos

  16. Algae after dark: mechanisms to cope with anoxic/hypoxic conditions.

    Science.gov (United States)

    Yang, Wenqiang; Catalanotti, Claudia; Wittkopp, Tyler M; Posewitz, Matthew C; Grossman, Arthur R

    2015-05-01

    Chlamydomonas reinhardtii is a unicellular, soil-dwelling (and aquatic) green alga that has significant metabolic flexibility for balancing redox equivalents and generating ATP when it experiences hypoxic/anoxic conditions. The diversity of pathways available to ferment sugars is often revealed in mutants in which the activities of specific branches of fermentative metabolism have been eliminated; compensatory pathways that have little activity in parental strains under standard laboratory fermentative conditions are often activated. The ways in which these pathways are regulated and integrated have not been extensively explored. In this review, we primarily discuss the intricacies of dark anoxic metabolism in Chlamydomonas, but also discuss aspects of dark oxic metabolism, the utilization of acetate, and the relatively uncharacterized but critical interactions that link chloroplastic and mitochondrial metabolic networks. PMID:25752440

  17. Anoxic carbon degradation in Arctic sediments: Microbial transformations of complex substrates

    DEFF Research Database (Denmark)

    Arnosti, Carol; Finke, Niko; Larsen, Ole;

    2005-01-01

    Complex substrates are degraded in anoxic sediments by the concerted activities of diverse microbial communities. To explore the effects of substrate complexity on carbon transformations in permanently cold anoxic sediments, four substrates—Spirulina cells, Isochrysis cells, and soluble high...... of carbon degradation diverged, with an additional 43%, 32%, 33%, and 8% of Isochrysis, Iso-Ex, Spirulina, and Spir-Ex carbon respired to CO2 over the next 750 h of incubation. Somewhat surprisingly, the soluble, carbohydrate-rich extracts did not prove to be more labile substrates than the whole...... cells from which they were derived. Although Spirulina and Iso-Ex differed in physical and chemical characteristics (solid/soluble, C/N ratio, lipid and carbohydrate content), nearly identical quantities of carbon were respired to CO2. In contrast, only 15% of Spir-Ex carbon was respired, despite the...

  18. Identification of ancient Olea europaea L. and Cornus mas L. seeds by DNA barcoding.

    Science.gov (United States)

    Gismondi, Angelo; Rolfo, Mario Federico; Leonardi, Donatella; Rickards, Olga; Canini, Antonella

    2012-07-01

    The analysis of ancient DNA (aDNA) provides archaeologists and anthropologists with innovative, scientific and accurate data to study and understand the past. In this work, ancient seeds, found in the "Mora Cavorso" archaeological site (Latium, Central Italy), were analyzed to increase information about Italian Neolithic populations (plant use, agriculture, diet, trades, customs and ecology). We performed morphological and genetic techniques to identify fossil botanical species. In particular, this study also suggests and emphasizes the use of DNA barcode method for ancient plant sample analysis. Scanning electron microscope (SEM) observations showed seed compact structure and irregular surface but they did not permit a precise nor empirical classification: so, a molecular approach was necessary. DNA was extracted from ancient seeds and then it was used, as template, for PCR amplifications of standardized barcode genes. Although aDNA could be highly degraded by the time, successful PCR products were obtained, sequenced and compared to nucleotide sequence databases. Positive outcomes (supported by morphological comparison with modern seeds, geographical distribution and historical data) indicated that seeds could be identified as belonging to two plant species: Olea europaea L. and Cornus mas L. PMID:22847014

  19. Biogenic nitrogen gas production at the oxic-anoxic interface in the Cariaco Basin, Venezuela

    Directory of Open Access Journals (Sweden)

    E. Montes

    2012-08-01

    Full Text Available Excess nitrogen gas (excess N2 was measured in samples collected at six locations in the eastern and western sub-basins of the Cariaco Basin, Venezuela, in September 2008 (non-upwelling conditions and March 2009 (upwelling conditions. During both sampling periods, excess N2 concentrations were below detection in surface waters, increasing to ~22 μmol N kg−1 at the oxic-anoxic interface ([O2] < ~ 4 μmol N kg−1, ~250 m. Below the oxic-anoxic interface (300–400 m, the average concentration of excess N2 was 24.7 ± 1.9 μmol N kg−1 in September 2008 and 27.5 ± 2.0 μmol N kg−1 in March 2009, i.e., excess N2 concentrations within this depth interval were ~ 3 μmol N kg−1 higher (p < 0.001 during the upwelling season compared to the non-upwelling period. These results suggest that N-loss in the Cariaco Basin may vary seasonally in response to changes in the flux of sinking particulate organic matter. We attribute the increase in excess N2 concentrations, or N-loss, observed during upwelling to: (1 higher availability of fixed nitrogen derived from suspended and sinking particles at the oxic-anoxic interface and/or (2 enhanced ventilation at the oxic-anoxic interface during upwelling.

  20. Biogenic nitrogen gas production at the oxic–anoxic interface in the Cariaco Basin, Venezuela

    Directory of Open Access Journals (Sweden)

    E. Montes

    2013-01-01

    Full Text Available Excess nitrogen gas (N2xs was measured in samples collected at six locations in the eastern and western sub-basins of the Cariaco Basin, Venezuela, in September 2008 (non-upwelling conditions and March 2009 (upwelling conditions. During both sampling periods, N2xs concentrations were below detection in surface waters, increasing to ~ 22 μmol N kg−1 at the oxic–anoxic interface ([O2] < ~ 4 μmol kg−1, ~ 250 m. Below the oxic–anoxic interface (300–400 m, the average concentration of N2xs was 24.7 ± 1.9 μmol N kg−1 in September 2008 and 27.5 ± 2.0 μmol N kg−1 in March 2009, i.e., N2xs concentrations within this depth interval were ~ 3 μmol N kg−1 higher (p < 0.001 during the upwelling season compared to the non-upwelling period. These results suggest that N-loss in the Cariaco Basin may vary seasonally in response to changes in the flux of sinking particulate organic matter. We attribute the increase in N2xs concentrations, or N-loss, observed during upwelling to: (1 higher availability of fixed nitrogen derived from suspended and sinking particles at the oxic–anoxic interface and/or (2 enhanced ventilation at the oxic–anoxic interface during upwelling.

  1. Biogenic nitrogen gas production at the oxic-anoxic interface in the Cariaco Basin, Venezuela

    OpenAIRE

    Montes, E.(Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain); Altabet, M.A.; F. E. Muller-Karger; Scranton, M. I.; R. C. Thunell; Benitez-Nelson, C.; L. Lorenzoni; Astor, Y. M.

    2012-01-01

    Excess nitrogen gas (excess N2) was measured in samples collected at six locations in the eastern and western sub-basins of the Cariaco Basin, Venezuela, in September 2008 (non-upwelling conditions) and March 2009 (upwelling conditions). During both sampling periods, excess N2 concentrations were below detection in surface waters, increasing to ~22 μmol N kg−1 at the oxic-anoxic interface ([O...

  2. Survival and Recovery of Methanotrophic Bacteria Starved under Oxic and Anoxic Conditions †

    OpenAIRE

    Roslev, Peter; King, Gary M.

    1994-01-01

    The effects of carbon deprivation on survival of methanotrophic bacteria were compared in cultures incubated in the presence and absence of oxygen in the starvation medium. Survival and recovery of the examined methanotrophs were generally highest for cultures starved under anoxic conditions as indicated by poststarvation measurements of methane oxidation, tetrazolium salt reduction, plate counts, and protein synthesis. Methylosinus trichosporium OB3b survived up to 6 weeks of carbon deprivat...

  3. Small-world Characteristics of EEG Patterns in Post-Anoxic Encephalopathy

    OpenAIRE

    MartijnBeudel; JocemHBoersma; MarleenC.Tjepkema-Cloostermans

    2014-01-01

    Post-Anoxic Encephalopathy (PAE) has a heterogenous outcome which is difficult to predict. At present, it is possible to predict poor outcome using somatosensory evoked potentials (SSEP) in only a minority of the patients at an early stage. In addition, it remains difficult to predict good outcome at an early stage. Network architecture, as can be quantified with continuous electroencephalography (cEEG), may serve as a candidate measure for predicting neurological outcome. Here we explore whe...

  4. Small-World Characteristics of EEG Patterns in Post-Anoxic Encephalopathy

    OpenAIRE

    Beudel, Martijn; Tjepkema-Cloostermans, Marleen C; Boersma, Jochem H.; van Putten, Michel J. A. M.

    2014-01-01

    Post-anoxic encephalopathy (PAE) has a heterogenous outcome which is difficult to predict. At present, it is possible to predict poor outcome using somatosensory evoked potentials in only a minority of the patients at an early stage. In addition, it remains difficult to predict good outcome at an early stage. Network architecture, as can be quantified with continuous electroencephalography (cEEG), may serve as a candidate measure for predicting neurological outcome. Here, we explore whether c...

  5. Dense bottom gravity currents and their impact on pelagic methanotrophy at oxic/anoxic transition zones

    Science.gov (United States)

    Schmale, Oliver; Krause, Srefan; Holtermann, Peter; Power Guerra, Nicole C.; Umlauf, Lars

    2016-04-01

    Interfaces between oxic and anoxic water bodies represent distinct zones in which the activity of specially adapted microbes often controls biogeochemical transformations. Anoxic basins as the Black Sea, the Cariaco Basin, and the Baltic Sea represent ideal locations to examine these processes, the involved microorganisms, and the influence of their metabolism on the turnover of different substances. Taking the Baltic Sea as an example, it is shown here that turbulent mixing of sulfidic and oxic waters may have a strong impact on microbially-mediated transformations. Direct evidence for these processes was derived from observations of methane oxidizing bacteria (MOB), their activity, and turbulence inside a sharp redox interface, freshly generated by a large-scale intrusion of oxic waters into the sulfidic deep layers of the central Baltic Sea (Gotland Basin). Based on detailed turbulence measurements, different mixing regimes along the basin slope were defined in our study to characterize the effect of turbulent mixing on MOB abundances and methanotrophic activities. We found that methane oxidation rates inside the oxic/anoxic transition zone at the shallow entrance of the basin were five times higher compared to the weakly turbulent redoxcline region in the deep interior of the basin. We propose that high mixing rates in the entrance and the close vicinity of two oxic/anoxic transition zones increased the flux of oxygen and methane into the transition zone, and consequently stimulated the growth of the MOB population and their activity. In contrast, low mixing rates in the stagnant interior of the basin reduced the flux of these gases into the transition zone, explaining the relatively small MOB population size and low methane turnover rates observed in the center of the basin.

  6. Organic geochemistry of the early Toarcian oceanic anoxic event in Hawsker Bottoms, Yorkshire, England

    OpenAIRE

    Trabucho-Alexandre, J.; French, Katherine L.; Sepulveda, Julio; Grocke, D. R.; Summons, Roger Everett

    2013-01-01

    A comprehensive organic geochemical investigation of the Hawsker Bottoms outcrop section in Yorkshire, England has provided new insights about environmental conditions leading into and during the Toarcian oceanic anoxic event (T-OAE; ~183 Ma). Rock-Eval and molecular analyses demonstrate that the section is uniformly within the early oil window. Hydrogen index (HI), organic petrography, polycyclic aromatic hydrocarbon (PAH) distributions, and tricyclic terpane ratios mark a shift to a lower r...

  7. Open Questions on the Origin of Life at Anoxic Geothermal Fields

    OpenAIRE

    Mulkidjanian, Armen Y; Bychkov, Andrew Yu.; Dibrova, Daria V.; Michael Y. Galperin; Koonin, Eugene V

    2012-01-01

    We have recently reconstructed the ‘hatcheries’ of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells (Mulkidjanian et al.: Origin of first cells at terrestrial, anoxic geothermal fields. Proc Natl Acad Sci USA 2012, 109:E821–830). These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K+, Zn2+, Mn2+, a...

  8. Recycling and burial of phosphorus in sediments of an anoxic fjord-the By Fjord, western Sweden

    DEFF Research Database (Denmark)

    Viktorsson, Lena; Kononets, Mikhail; Roos, Per;

    2013-01-01

    water. The water in the basin is exchanged only every 3 to 5 years and the water below sill level is anoxic or sulfidic between water renewals. Five sites were examined in the By Fjord; three shallow sites above the sill level with oxic bottom waters and two deeper sites with anoxic bottom waters....... Contents of sediment organic carbon, total nitrogen and organic phosphorus were higher at deep stations when compared to shallow ones, whereas the contents of sediment inorganic phosphorus was higher at shallow than at deep stations both in surficial and buried sediment. One shallow oxic site and one deep...... fluxes from sediments with anoxic overlying water (1.25-2.26 mmol m(-2) d(-1)). The DIP flux increased with increasing flux of dissolved inorganic carbon (DIC) not only at anoxic but also at oxic bottoms, which is different from observations in brackish water environments. The average ratio between the...

  9. Daugava hydroenergy and ecology

    International Nuclear Information System (INIS)

    Daugava is forth largest river in Baltic sea basin and largest river of Latvia. Like Danube in Central Europe, Daugava is the river of Baltic civilization. Many folk songs, tales an myths we can read about this river in Latvian, Russian, Polish. There are the roots of Latvian culture. From ancient times Daugava is known as the 'ebonite river' Eridanus, Rubon, Wein, Dvina. From 5 century A. C. Daugava is a well know vikings water magistral from North to South. In 1939 was built first hydro electric power station, in 1965, second, in 1974, third on this river and was created Daugava damn system. Productivity from fishing falls down 2000 times, pollution was reason, why in 1987 building of forth Daugava HES was stopped. About future of Daugava hydro electric power stations damn system future Latvian society have discussions until this time. Ecological problem No. 1 on Daugava is pollution, because Daugava is the main resource of fresh water for 70% of Latvian population. Problem No. 2 is connected with safety of banks of Baltic sea, because 24 million t sand Daugava leaves on the bottom of artificial dames, not on sea cost. Problem No. 3 is loosing of recreative function of river and Daugava landscapes. Problem No. 4 - lack of Daugava monitoring system. In 1989, when after catastrophe on Belorussia chemical concern in Novopolock river was polluted wit 5 tons of cyanide. Latvia get know about it only after observing of death fishes in our territory. Other problem is Ignalina nuclear power plant in Lithuania - 30 km from banks of Daugava. What to do? One possibilities is destroying of damns, but it is unreal. Now in Latvia are founded Found of Daugava, which unite all self-governments, which are settled near the river. Fund of Daugava, supported by State, have a special recreative programme. Ministry of Environment of Latvia are working on Daugava monitoring system introducing. There are some plans together with Scandinavian countries to built new water cleaning

  10. Ecological Ethics

    International Nuclear Information System (INIS)

    Deborah Oughton started with a view of the work in progress by the ICRP TG 94 on ethics, from the historical context and the principles-based ethics in RP, to continue with an overview of the ethical theories and with the main area of elaboration which concerns the common values, to conclude with considerations about the implementation in different area such as biomedicine, nuclear safety and workers, ecological aspects, and environmental health and society. By reading again the ICRP and IAEA publications on the ethical aspects in the protection of environment from the effects of ionizing radiation, the presentation covers the various and different cultures within the history of environmental ethics, the perception of Nature and the theories of environmental ethics, in particular by focusing on anthropocentrism, biocentrism and ecocentrism, as philosophical worldwide views, and on conservation, biodiversity, sustainability, environmental justice and human dignity, as primary principles of environmental protection. The influence of western Christianity, with a view of man dominating over every creeping thing on earth, and of the non-western ideas, the human perception of Nature has been analyzed and discussed to conclude that, in reality then, the anthropocentrism, biocentrism and ecocentrism, as reflected in many cultures and religions, they all support the need to protect the environment and to recognise and preserve the diversity. Three challenges were then discussed in the presentation: the ecosystem approach and ecological economics, for example in the case of Fukushima by asking what is the economic cost of marine contamination; the ecosystem changes with attention to what harms, as in the case of the environment in the contaminated areas around Chernobyl; and the environmental consequences of remediation, which can be considered a source of controversy for environmental ethics and policy

  11. Biological nutrient removal in a sequencing batch reactor operated as oxic/anoxic/extended-idle regime.

    Science.gov (United States)

    Li, Xiao-ming; Chen, Hong-bo; Yang, Qi; Wang, Dong-bo; Luo, Kun; Zeng, Guang-ming

    2014-06-01

    Previous researches have demonstrated that biological phosphorus removal from wastewater could be induced by oxic/extended-idle (O/EI) regime. In this study, an anoxic period was introduced after the aeration to realize biological nutrient removal. High nitrite accumulation ratio and polyhydroxyalkanoates biosynthesis were obtained in the aeration and biological nutrient removal could be well achieved in oxic/anoxic/extended-idle (O/A/EI) regime for the wastewater used. In addition, nitrogen and phosphorus removal performance in O/A/EI regime was compared with that in conventional anaerobic/anoxic/aerobic (A(2)/O) and O/EI processes. The results showed that O/A/EI regime exhibited higher nitrogen and phosphorus removal than A(2)/O and O/EI processes. More ammonium oxidizing bacteria and polyphosphate accumulating organisms and less glycogen accumulating organisms containing in the biomass might be the principal reason for the better nitrogen and phosphorus removal in O/A/EI regime. Furthermore, biological nutrient removal with O/A/EI regime was demonstrated with municipal wastewater. The average TN, SOP and COD removal efficiencies were 93%, 95% and 87%, respectively. PMID:24393562

  12. Humic substances as fully regenerable electron acceptors in recurrently anoxic environments

    Science.gov (United States)

    Klüpfel, Laura; Piepenbrock, Annette; Kappler, Andreas; Sander, Michael

    2014-03-01

    Humic substances form through the degradation of microbial and plant precursors, and make up a significant fraction of natural organic matter in terrestrial and aquatic environments. Humic substances are redox-active and can act as terminal electron acceptors in anaerobic microbial respiration. Reduced humic substances may become re-oxidized during aeration of temporarily anoxic systems, such as wetlands, sediments and many soils. If the transfer of electrons from anaerobic respiration through humic substances to oxygen is sustained over many redox cycles, it may competitively suppress electron transfer to carbon dioxide, and thereby lower the formation of methane in temporarily anoxic systems. Here, we monitor changes in the redox states of four chemically distinct dissolved humic substances over successive cycles of reduction by the bacterium Shewanella oneidensis MR-1 and oxidation by oxygen, in a series of laboratory experiments. We show that electron transfer to and from these substances is fully reversible and sustainable over successive redox cycles. We suggest that redox cycling of humic substances may largely suppress methane production in temporarily anoxic systems.

  13. Small sewage treatment system with an anaerobic-anoxic-aerobic combined biofilter.

    Science.gov (United States)

    Park, S M; Jun, H B; Hong, S P; Kwon, J C

    2003-01-01

    The objective of this study was to investigate a small sewage treatment system that could improve nitrogen and BOD5 removal efficiency as well as generate less solid using an anaerobic-anoxic-aerobic biofiltration system. Wastewater temperature was in the range of 14-25 degrees C, and hydraulic residual times were 12 h for each reactor. The upflow anaerobic digester equipped with anoxic filter was fed with both raw sewage and recycled effluent from the aerobic filter to induce denitrification and solid reduction simultaneously. In the subsequent aerobic filter, residual organic carbon and ammonia might be oxidized and finally nitrate formed. In the anaerobic reactor, about 71% of influent TCOD was removed by sedimentation of the un-filterable COD at the recycle ratio of 300%. Another 20% of influent TCOD was removed in the anoxic filter by denitrification of the recycled nitrate. After 100 days operation, solid reduction and nitrification efficiency were about 30% and 95%, respectively. Overall removal efficiencies of COD and total nitrogen (T-N) were above 94% and 70% at the recycle ratio of 300%, respectively. Total wasted solid from the system after 100 days operation was about 316 g, which was only 44% of the solid generated from a controlled activated sludge system operated at sludge retention time of 8 days. PMID:14753539

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

    International Nuclear Information System (INIS)

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

  15. The Ancient Martian Climate System

    Science.gov (United States)

    Haberle, Robert M.

    2014-01-01

    Today Mars is a cold, dry, desert planet. The atmosphere is thin and liquid water is not stable. But there is evidence that very early in its history it was warmer and wetter. Since Mariner 9 first detected fluvial features on its ancient terrains researchers have been trying to understand what climatic conditions could have permitted liquid water to flow on the surface. Though the evidence is compelling, the problem is not yet solved. The main issue is coping with the faint young sun. During the period when warmer conditions prevailed 3.5-3.8 Gy the sun's luminosity was approximately 25% less than it is today. How can we explain the presence of liquid water on the surface of Mars under such conditions? A similar problem exists for Earth, which would have frozen over under a faint sun even though the evidence suggests otherwise. Attempts to solve the "Faint Young Sun Paradox" rely on greenhouse warming from an atmosphere with a different mass and composition than we see today. This is true for both Mars and Earth. However, it is not a straightforward solution. Any greenhouse theory must (a) produce the warming and rainfall needed, (b) have a plausible source for the gases required, (c) be sustainable, and (d) explain how the atmosphere evolved to its present state. These are challenging requirements and judging from the literature they have yet to be met. In this talk I will review the large and growing body of work on the early Mars climate system. I will take a holistic approach that involves many disciplines since our goal is to present an integrated view that touches on each of the requirements listed in the preceding paragraph. I will begin with the observational evidence, which comes from the geology, mineralogy, and isotopic data. Each of the data sets presents a consistent picture of a warmer and wetter past with a thicker atmosphere. How much warmer and wetter and how much thicker is a matter of debate, but conditions then were certainly different than

  16. The Vindolanda Tablets and the Ancient Economy

    DEFF Research Database (Denmark)

    Evers, Kasper Grønlund

    model is outlined which takes into account the different economic behaviours revealed by the tablets and attempts to fit them together into one coherent, economic system, whilst also relating the activities to questions of scale in the ancient economy; moreover, the conclusions drawn in the study are......, the aim is to investigate how best to comprehend the economic system attested at Vindolanda and to consider the wider implications for studies of the ancient economy in general. This is accomplished by a three-step approach: first, the nature of the Vindolandan evidence is assessed, and the state of...... research on both studies of the ancient economy and the economy of early Roman Britain is accounted for, so as to highlight the value of the Vindolanda Tablets and lay the ground for the interpretations which follow. Secondly, the economic activities attested by the tablets are analysed in terms of market...

  17. PIXE analysis on an ancient scroll sample

    International Nuclear Information System (INIS)

    For years, scientists have developed several new techniques to read texts of Herculaneum scrolls without destroying them. Recently, the use of a custom built high-resolution CT scanner was proposed to scan and then virtually unroll the scrolls for reading. Identification of any unique chemical signatures in the ancient ink would allow better calibration of the CT scanner to improve the chances of resolving the ink from the burned papyrus background. To support this effort, we carried out one pilot study to see whether the composition of the ink can be obtained from an ancient scroll sample using PIXE technique. PIXE data were collected and analyzed in two different regions of the ancient scroll sample (ink and blank regions). This preliminary work shows that elemental distributions from the ink used in this scroll mainly contained Al, Fe and Ti as well as minor trace amounts of Cr, Cu and Zn. (author)

  18. The ancient Chinese notes on hydrogeology

    Science.gov (United States)

    Zhou, Yu; Zwahlen, François; Wang, Yanxin

    2011-08-01

    The ancient Chinese notes on hydrogeology are summarized and interpreted, along with records of some related matters, like groundwater exploration and utilization, karst springs, water circulation, water conservation and saline-land transformation, mine drainage, and environmental hydrogeology. The report focuses only on the earliest recorded notes, mostly up until the Han Dynasty (206 BC - AD 25). Besides the references cited, the discussion in this report is based mainly on archaeological material, the preserved written classic literature, and some assumptions and/or conclusions that have been handed down in legends to later ages. Although most material relates to ancient China, the lessons learned may have practical significance worldwide. Compared to other contemporary parts of the world, ancient China, without doubt, took the lead in the field of groundwater hydrology. The great achievements and experience of the Chinese ancestors should provide motivation and inspiration for hydrogeologists to carry out their scientific research and exploration passionately and actively.

  19. Twins in Ancient Greece: a synopsis.

    Science.gov (United States)

    Malamitsi-Puchner, Ariadne

    2016-01-01

    This brief outline associates twins with several aspects of life in Ancient Greece. In Greek mythology twins caused ambivalent reactions and were believed to have ambivalent feelings for each other. Very often, they were viewed as the representatives of the dualistic nature of the universe. Heteropaternal superfecundation, which dominates in ancient myths, explains on one hand, the god-like qualities and, on the other hand, the mortal nature of many twins. An assumption is presented that legends referring to twins might reflect the territorial expansions of Ancient Greeks in Northern Mediterranean, around the Black Sea, in Asia Minor, as well as North East Africa. In conclusion, in Greek antiquity, twins have been used as transitional figures between myth and reality. PMID:26135766

  20. Did the ancient egyptians discover Algol?

    Science.gov (United States)

    Jetsu, L.; Porceddu, S.; Porceddu, S.; Lyytinen, J.; Kajatkari, P.; Markkanen, T.; Toivari-Viitala, J.

    2013-02-01

    Fabritius discovered the first variable star, Mira, in 1596. Holwarda determined the 11 months period of Mira in 1638. Montanari discovered the next variable star, Algol, in 1669. Its period, 2.867 days, was determined by Goodricke (178). Algol was associated with demon-like creatures, "Gorgon" in ancient Greek and "ghoul" in ancient Arab mythology. This indicates that its variability was discovered much before 1669 (Wilk 1996), but this mythological evidence is ambiguous (Davis 1975). For thousands of years, the Ancient Egyptian Scribes (AES) observed stars for timekeeping in a region, where there are nearly 300 clear nights a year. We discovered a significant periodicity of 2.850 days in their calendar for lucky and unlucky days dated to 1224 BC, "the Cairo Calendar". Several astrophysical and astronomical tests supported our conclusion that this was the period of Algol three millennia ago. The "ghoulish habits" of Algol could explain this 0.017 days period increase (Battersby 2012).

  1. The ancient lunar crust, Apollo 17 region

    Science.gov (United States)

    James, O. B.

    1992-01-01

    The Apollo 17 highland collection is dominated by fragment-laden melt rocks, generally thought to represent impact melt from the Serenitatis basin-forming impact. Fortunately for our understanding of the lunar crust, the melt rocks contain unmelted clasts of preexisting rocks. Similar ancient rocks are also found in the regolith; most are probably clasts eroded out of melt rocks. The ancient rocks can be divided into groups by age, composition, and history. Oldest are plutonic igneous rocks, representing the magmatic components of the ancient crust. The younger are granulitic breccias, which are thoroughly recrystallized rocks of diverse parentages. The youngest are KREEPy basalts and felsites, products of relatively evolved magmas. Some characteristics of each group are given.

  2. Iron corrosion in an anoxic soil: Comparison between thermodynamic modelling and ferrous archaeological artefacts characterised along with the local in situ geochemical conditions

    International Nuclear Information System (INIS)

    Graphical abstract: Eh/pH diagram based on the in situ conditions measured on the archaeological site of Glinet (France, 16th century). Display Omitted Research highlights: → Long-term corrosion behaviour of ferrous archaeological artefacts in anoxic media. → Use of thermodynamic modelling to correlate the corrosion products to the environmental data. → Thermodynamic data for carbonate phases from the rosasite group (chukanovite). - Abstract: This article is part of an ongoing study on the long-term corrosion behaviour of ferrous archaeological artefacts. The aim of this study is to correlate the corrosion products formed on ancient artefacts in an anoxic medium to the environmental data using thermodynamic modelling. For this purpose, measurement campaigns have been conducted on the archaeological site of Glinet (16th century, High Normandy (Seine-Maritime), France) where the evolution of the pore water chemistry has been recorded for a period of one year. Three evolution steps have been distinguished after the oxidizing perturbation which was induced by the piezometers installation. The first step was related to an oxidizing environment in which pore water was in equilibrium with a Fe(III) precipitated phase: ferrihydrite (FeOOH.0.4 H2O). The second step was considered as an intermediate step and Fe speciation had evolved; equilibrium was achieved between ferrihydrite and a Fe(II) carbonate phase: siderite (Fe(II)CO3). The last step of the evolution was related to a reducing stage where pore water was in equilibrium with magnetite (Fe3(II,III)O4) and with chukanovite (Fe2(II)(OH)2CO3). As these phases were present in the corrosion layers formed on the archaeological samples, it is possible to conclude that the thermodynamic approach was helpful in developing a better understanding of the effect of geochemical conditions on the composition and mineralogy of the corrosion products formed on archaeological artefacts. This work could be used as a reference for

  3. Craniofacial plasticity in ancient Peru.

    Science.gov (United States)

    Stone, Jessica H; Chew, Kristen; Ross, Ann H; Verano, John W

    2015-01-01

    Numerous studies have utilized craniometric data to explore the roles of genetic diversity and environment in human cranial shape variation. Peru is a particularly interesting region to examine cranial variation due to the wide variety of high and low altitude ecological zones, which in combination with rugged terrain have created isolated populations with vastly different physiological adaptations. This study examines seven samples from throughout Peru in an effort to understand the contributions of environmental adaptation and genetic relatedness to craniofacial variation at a regional scale. Morphological variation was investigated using a canonical discriminant analysis and Mahalanobis D(2) analysis. Results indicate that all groups are significantly different from one another with the closest relationship between Yauyos and Jahuay, two sites that are located geographically close in central Peru but in very different ecozones. The relationship between latitude/longitude and face shape was also examined with a spatial autocorrelation analysis (Moran's I) using ArcMap and show that there is significant spatial patterning for facial measures and geographic location suggesting that there is an association between biological variation and geographic location. PMID:25807293

  4. Sound Ecologies

    Directory of Open Access Journals (Sweden)

    Michelle Duffy

    2010-02-01

    Full Text Available Discussions about what constitutes ‘the rural’ invariably focus on notions of spatial location – of inhabiting spaces apart from that of the metropolitan. Deeply embedded in our images of what it means to be Australian, nonetheless our intellectual framing of ‘the rural’ as something outback and beyond has significant implications for our relations with these spaces. The relatively recent phenomenon of sea- and tree-changes has struck many unawares, and not simply because a good latté is so hard to find. Although a frivolous remark, such an apparent lack does shift our focus to a bodily scale of the rural; how is rural place re/made through our experiences of it? This article originates out of on-going research that explores the practice of listening and sound and the ways in which the body can draw attention to the intuitive, emotional, and psychoanalytical processes of subjectivity and place-making. Drawing on Nigel Thrift’s concept of an ecology of place, I suggest that contemporary heightened concerns with regards to loss and lack in rural Australia has led to a nascent emotional economy – one in which individual and intimate connections to the rural require a rethinking of how we live community and belonging. In such a terrain, what does it mean to be rural?

  5. Symmetries in Images on Ancient Seals

    CERN Document Server

    Sparavigna, Amelia

    2008-01-01

    In this paper, we discuss the presence of symmetries in images engraved on ancient seals, in particular on stamp seals. Mainly used to secure the containers from tampering and for owner's identification, these objects appeared during the 5th millennium BC in Mesopotamia. Usually the seals were engraved with simple images, suitable to communicate an immediate information. Rotational symmetries are already displayed by the most ancient stamp seals, whose images reach a quasi-perfect symmetry in their small circular or ovoid spaces. Bilateral symmetries are quite common in Egyptian scarab seals.

  6. Ancient neurilemmoma: A rare oral tumor

    Directory of Open Access Journals (Sweden)

    J Muruganandhan

    2013-01-01

    Full Text Available Neurilemmomas are benign tumors of neural origin composed of Schwann cell proliferation in characteristic patterns. Ancient neurilemmomas are usually longstanding growths that exhibit degenerative features that could be mistaken for malignancy. They are extremely rare in the oral cavity and present in older individuals of long duration. The authors report a case of ancient neurilemmoma in a young patient with short duration of growth. This unique case presented with remarkable histopathological features with respect to vascularity and atypia associated with degenerative change. It is essential to not mistake these features as malignant transformation so as to avoid radical procedures.

  7. The TL dating of ancient porcelain

    International Nuclear Information System (INIS)

    The age determination of ancient porcelain using the pre-dose technique in TL dating was reported. The variation of beta dose with depth below the surface of the porcelain slice, the thermal activation characteristic (TAC) for 110 degree C peak, the measurement of paleodose and the estimation of annual dose were studied. The results show that this technique is suitable for authenticity testing of ancient porcelain, but both accuracy and precision for porcelain dating are worse than those for pottery, because porcelain differs from pottery on composition, structure and firing temperature. Besides, some complicated factors in the pre-dose technique would be the possible cause of the greater errors

  8. Records of solar eclipse observations in ancient China

    Science.gov (United States)

    Han, Yanben; Qiao, Qiyuan

    2009-11-01

    Like ancient people at other places of the world, the ancient Chinese lived in awe of the Sun. As they felt solar eclipses extremely significant events, they closely observed the occurrence of solar eclipse. Ancient astronomers further realized very early that solar eclipses were one of the important astronomical phenomena to revise and improve the ancient calendar. Interestingly, ancient emperors regarded solar eclipses as warnings from heaven that might affect the stability of their throne. Consequently, observing and recording solar eclipses became official, which dated far back to ancient China when numerous relevant descriptions were recorded in historical books. These records contribute substantially to China as an ancient civilization, as well as to the research of the long-term variation of the rotation rate of the Earth during >2000 years before the 17th century. This paper briefly reviews the perception, observations and recording of solar eclipses by ancient Chinese astronomers.

  9. Is our Future Written in the Geological Record of Oceanic Anoxic Events? The Calcareous Nannoplankton Perspective (Invited)

    Science.gov (United States)

    Erba, E.

    2013-12-01

    The topical emergence of climate change as a crucial issue for society and governments has urged the understanding of the future state of the planet within the context of increasing carbon dioxide concentrations. In the near future, the ocean's uptake of CO2 is expected to rapidly decline because of surface warming, increased vertical stratification, and slowed thermohaline circulation. The Anthropocene CO2 emissions are inferred to be the cause of global warming and alteration of ocean chemistry, triggering unknown responses of marine biota in terms of extinction, innovation and/or temporary adaptations. During the Mesozoic under excess CO2 and greenhouse conditions, the ocean became depleted of oxygen, promoting the burial of massive amounts of organic matter. These episodes are named Oceanic Anoxic Events (OAEs) and might provide guidance as to the response of marine biota to massive CO2 releases and how and at what rate pre-perturbation conditions are eventually restored. After over three decades of research on OAEs, an impressive amount of data has been generated: there is a general consensus on the role of Large Igneous Provinces (LIPs) inducing CO2 increases, greenhouse climate and profound variations in chemical, physical and trophic characteristics of the ocean. OAEs can be studied to decipher the complexity of drivers and of responses within and among different organisms to CO2 pulses, extreme warmth, weathering changes, ocean fertilization and acidification to add the long-term and large-scale prospective to investigations on current, very-short-term and local responses. In Jurassic and Cretaceous oceans, coccolithophores were already a most efficient carbonate-forming group and OAEs offer the opportunity of characterizing variations in their abundance, diversity, and morphology to trace ecological affinities and adaptations to oceanic ecosystem perturbations. We quantitatively investigated the Toarcian OAE, the early Aptian OAE1a and the latest

  10. Watermarking ancient documents based on wavelet packets

    Science.gov (United States)

    Maatouk, Med Neji; Jedidi, Ola; Essoukri Ben Amara, Najoua

    2009-01-01

    The ancient documents present an important part of our individual and collective memory. In addition to their preservation, the digitization of these documents may offer users a great number of services like remote look-up and browsing rare documents. However, the documents, digitally formed, are likely to be modified or pirated. Therefore, we need to develop techniques of protecting images stemming from ancient documents. Watermarking figures to be one of the promising solutions. Nevertheless, the performance of watermarking procedure depends on being neither too robust nor too invisible. Thus, choosing the insertion field or mode as well as the carrier points of the signature is decisive. We propose in this work a method of watermarking images stemming from ancient documents based on wavelet packet decomposition. The insertion is carried out into the maximum amplitude ratio being in the best base of decomposition, which is determined beforehand according to a criterion on entropy. This work is part of a project of digitizing ancient documents in cooperation with the National Library of Tunis (BNT).

  11. Microscopical Examination of Ancient Silver Coins

    International Nuclear Information System (INIS)

    The microstructure of three silver coins of the IIId century B.C. from the Illyrian king Monounios, the ancient Greek city of Dyrrachion and of Korkyra was studied with XRF and microscopy. From this investigation it turned out that these coins have different chemical composition and microstructure that imply different minting method

  12. LD Students and the Ancient Mariner.

    Science.gov (United States)

    Cohen, Barbara L.

    1988-01-01

    Synectics, the making of analogies, was used with learning disabled high school seniors to provide them with a creative process that aids in developing a deeper understanding of literature. After studying Coleridge's "Rime of the Ancient Mariner," the students completed a six-step process and produced a short writing assignment. (VW)

  13. Fast neutron activation analysis of ancient mirror

    International Nuclear Information System (INIS)

    About fifty specimens of ancient Chinese bronze mirror from various dynasties are analysed by fast neutron radiated from neutron generator. The contents of copper, tin and lead in the mirror are listed in this paper. Experimental method and measurement equipment are described too

  14. Mitochondrial phylogenomics of modern and ancient equids

    DEFF Research Database (Denmark)

    Vilstrup, Julia T; Seguin-Orlando, Andaine; Stiller, Mathias; Ginolhac, Aurelien; Raghavan, Maanasa; Nielsen, Sandra C A; Weinstock, Jacobo; Froese, Duane; Vasiliev, Sergei K; Ovodov, Nikolai D; Clary, Joel; Helgen, Kristofer M; Fleischer, Robert C; Cooper, Alan; Shapiro, Beth; Orlando, Ludovic Antoine Alexandre

    2013-01-01

    sequences from all seven extant lineages within the genus Equus. Bayesian and Maximum Likelihood phylogenetic inference confirms that zebras are monophyletic within the genus, and the Plains and Grevy's zebras form a well-supported monophyletic group. Using ancient DNA techniques, we further characterize...

  15. Ancient science in a digital age.

    Science.gov (United States)

    Lehoux, Daryn

    2013-03-01

    Technology is rapidly changing our understanding of ancient science. New methods of visualization are bringing to light important texts we could not previously read; changes in online publishing are allowing unprecedented access to difficult-to-find materials; and online mapping tools are offering new pictures of lost spaces, connectivities, and physical objects. PMID:23789512

  16. Unlocking the Mysteries of Ancient Egypt.

    Science.gov (United States)

    Riechers, Maggie

    1995-01-01

    Describes the work of Egyptologist William Murnane who is recording the ritual scenes and inscriptions of a great columned hall from the days of the pharaohs. The 134 columns, covered with divine imagery and hieroglyphic inscriptions represent an unpublished religious text. Briefly discusses ancient Egyptian culture. Includes several photographs…

  17. Moessbauer effect study of ancient Egyptian pottery

    International Nuclear Information System (INIS)

    Moessbauer spectroscopy was used in examining ancient Egyptian pottery. From the values of Moessbauer parameters and the differences for the individual samples, conclusions could be drawn as to the temperature of baking and the kind of clay used in various archaeological periods. (A.K.)

  18. Defining Astrology in Ancient and Classical History

    Science.gov (United States)

    Campion, Nicholas

    2015-05-01

    Astrology in the ancient and classical worlds can be partly defined by its role, and partly by the way in which scholars spoke about it. The problem is complicated by the fact that the word is Greek - it has no Babylonian or Egyptian cognates - and even in Greece it was interchangeable with its cousin, 'astronomy'. Yet if we are to understand the role of the sky, stars and planets in culture, debates about the nature of ancient astrology, by both classical and modern scholars, must be taken into account. This talk will consider modern scholars' typologies of ancient astrology, together with ancient debates from Cicero in the 1st century BC, to Plotinus (204/5-270 AD) and Isidore of Seville (c. 560 - 4 April 636). It will consider the implications for our understanding of astronomy's role in culture, and conclude that in the classical period astrology may be best understood through its diversity and allegiance to competing philosophies, and that its functions were therefore similarly varied.

  19. A Roman Dodecahedron as an ancient rangefinder

    OpenAIRE

    Sparavigna, Amelia Carolina

    2012-01-01

    Rangefinders are instruments used for ballistics and for surveying in general. I report about some of them, ranging from the ancient Rome to modern methods. In particular, I am discussing the use of Roman Dodecahedra, bronze artifacts of gallo-roman origin, for measuring distance

  20. Precursors of Vocational Psychology in Ancient Civilizations.

    Science.gov (United States)

    Dumont, Frank; Carson, Andrew D.

    1995-01-01

    Examines philosophical theories produced by two ancient civilizations (Eastern Mediterranean and Chinese) for applications to an applied psychology of work. Includes analysis of Egyptians, Semites, and Greeks, with a special emphasis on Plato. Suggests that many basic elements of vocational psychology were present during the first millennium B.C.…

  1. The Roots of Science in Ancient China.

    Science.gov (United States)

    Fisher, Arthur

    1982-01-01

    A 45-year-old research project (culminating in the multivolume "Science and Civilization in China") is examining major scientific innovations in ancient China and attempting to explain why, although the Chinese gained a technological edge in the past, they did not make the forward leap into modern science. (JN)

  2. Planetary science: Traces of ancient lunar water

    Science.gov (United States)

    Hauri, Erik H.

    2013-03-01

    The presence of water in lunar volcanic rocks has been attributed to delivery after the Moon formed. Water detected in rocks from the ancient lunar highlands suggests that the Moon already contained water early in its history, and poses more challenges for the giant impact theory of Moon formation.

  3. A probabilistic model of Ancient Egyptian writing

    OpenAIRE

    Nederhof, Mark Jan; Rahman, Fahrurrozi

    2015-01-01

    This article investigates a probabilistic model to describe how signs form words in Ancient Egyptian writing. This applies to both hieroglyphic and hieratic texts. The model uses an intermediate layer of sign functions. Experiments are concerned with finding the most likely sequence of sign functions that relates a given sequence of signs and a given sequence of phonemes. Postprint

  4. Ancient Pyramids Help Students Learn Math Concepts

    Science.gov (United States)

    Smith, Courtney D.; Stump, Amanda M.; Lazaros, Edward J.

    2010-01-01

    This article presents an activity that allows students to use mathematics and critical-thinking skills to emulate processes used by the ancient Egyptians to prepare the site for the Pyramids of Giza. To accomplish this, they use three different methods. First, they create a square using only simple technological tools that were available to the…

  5. Discovering the Ancient Maya from Space

    Science.gov (United States)

    Sever, T. L.

    2008-01-01

    The Pet6n region of northern Guatemala contains some of the most significant Mayan archeological sites in Latin America. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper, IKONOS, and QuickBird satellite, and airborne STAR-3i and AIRSAR radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as sites, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the bajos, which are seasonally flooded swamps that cover over 40% of the land surface. Through the use of various airborne and satellite sensor systems we have been able to detect and map ancient causeways, temples, reservoirs, and land forms, and locate these features on the ground through GPS technology. Recently, we have discovered that there is a strong relationship between a tropical forest vegetation signature in satellite imagery and the location of archeological sites. We believe that the use of limestone and lime plasters in ancient Maya construction affects the moisture, nutrition, and plant species of the surface vegetation. We have mapped these vegetation signatures in the imagery and verified through field survey that they are indicative of archeological sites. Through the use of remote sensing and GIS technology it is possible to identify unrecorded archeological features in a dense tropical forest environment and monitor these cultural features for their protection.

  6. Characteristics of mortars from ancient bridges

    Czech Academy of Sciences Publication Activity Database

    Frankeová, Dita; Slížková, Zuzana; Drdácký, Miloš

    Vol. 7. Dordrecht : Springer, 2012 - (Válek, J.; Hughes, J.; Groot, J.), s. 165-174 ISBN 978-94-007-4634-3 R&D Projects: GA ČR(CZ) GA103/09/2067; GA MŠk(CZ) LA09008 Institutional support: RVO:68378297 Keywords : mortars * ancient bridges * analytical methods Subject RIV: AL - Art, Architecture, Cultural Heritage

  7. Internal load management in eutrophic, anoxic environments. The role of natural zeolite.

    Science.gov (United States)

    Gianni, Areti; Zacharias, Ierotheos

    2015-04-01

    During the last decades, the increase of the nutrient and organic load inflows in the coastal zone increased the number of the anoxic environments. Inputs' control constitutes one of the basic practices for the eutrophic/anoxic aquatic ecosystems management. However, the induced changes at the ecosystem characteristics resulting from the trophic state alteration, and anoxic conditions prevalence, render the ecosystem's restoration difficult if not impossible. Bottom water anoxia accelerates PO43-, NH4+ and S2- recycling and accumulation from organic matter decomposition. This, toxic layer is a permanent menace for the balance of the entire ecosystem, as it can supply PO43-, NH4+ and S2- to the surface layers altering their qualitative character and threatening the welfare of fishes and other aquatic organisms. Having as objective the water basins' internal load control and based on practices are used in eutrophic environments' restoration, this study is referred to the role of the natural zeolite in eutrophic/anoxic ecosystems management. For the first time are presented, results from S2- removal experiments using the zeolitic mineral mordenite, [(Na2, Ca, K2)4 (H2O)28] [Al8Si40O96]. Four different sets of experiments were conducted, in order to examine zeolite's removal capacity of S2- in aquatic solutions, under a wide range of physicochemical parameters. More specific: a) the effect of initial pH on the removal process, b) the removal process kinetics, c) the removal process isotherms and d) the effect of salinity on the removal process were studied. Natural zeolite has the ability to neutralize the pH of aqueous solutions, thus all the experiments were practically performed at pH 7. Initially sulfides concentration range from 1 to 10mg/l. Zeolite's removal capability appeared to be directly depended on the S2- initial concentration. For initial concentration of 1mg/l, the removal rate reached up to 90% after 24h. The maximum zeolite removal capacity was

  8. Outreach Testing of Ancient Astronomy

    Science.gov (United States)

    Sanmartin, J. R. S.; Blanco, M. B. M.

    2015-10-01

    fundamental quantity being given by half the difference between solar distances to vertical at winter and summer solstices, with value about 23.5°. Day and year periods greatly differing by about 2 ½ orders of magnitude, 1 day against 365 days, helps students to correctly visualize and interpret the experimental measurements. Since the gnomon serves to observe at night the moon shadow too, students can also determine the inclination of the lunar orbital plane, as about 5 degrees away from the ecliptic, thus explaining why eclipses are infrequent. Independently, earth taking longer between spring and fall equinoxes than from fall to spring (the solar anomaly), as again verified by the students, was explained in ancient Greek science, which posited orbits universally as circles or their combination, by introducing the eccentric circle, with earth placed some distance away from the orbital centre when considering the relative motion of the sun, which would be closer to the earth in winter. In a sense, this can be seen as hint and approximation of the elliptic orbit proposed by Kepler many centuries later. EPSC Abstracts Vol. 10, EPSC2015-40, 2015 European Planetary Science Congress 2015 c Author(s) 2015 EPSC European Planetary Science Congress Secondly, by observing lunar phases and eclipses from the ground, students could also determine, following Aristarchus of Samos in the 3rd century BC, 4 length ratios involving moon and sun distances to earth, and radii of all three, moon, sun, and earth. The angular width of the moon could be first determined with simplest optical devices as about half a degree; this yields the ratio between moon diameter 2RM and distance DM to earth. Next, eclipses of sun prove its angular width, and thus ratio 2RS/DS, similar to the lunar one, though the relatively high lunar orbital eccentricity, 0.055, does result in not quite a full eclipse if at lunar apogee. Further, at a half-moon phase, when the angle sun-moon-earth is a right one, the angle

  9. Outreach Testing of Ancient Astronomy

    Science.gov (United States)

    Sanmartin, J. R. S.; Blanco, M. B. M.

    2015-10-01

    fundamental quantity being given by half the difference between solar distances to vertical at winter and summer solstices, with value about 23.5°. Day and year periods greatly differing by about 2 ½ orders of magnitude, 1 day against 365 days, helps students to correctly visualize and interpret the experimental measurements. Since the gnomon serves to observe at night the moon shadow too, students can also determine the inclination of the lunar orbital plane, as about 5 degrees away from the ecliptic, thus explaining why eclipses are infrequent. Independently, earth taking longer between spring and fall equinoxes than from fall to spring (the solar anomaly), as again verified by the students, was explained in ancient Greek science, which posited orbits universally as circles or their combination, by introducing the eccentric circle, with earth placed some distance away from the orbital centre when considering the relative motion of the sun, which would be closer to the earth in winter. In a sense, this can be seen as hint and approximation of the elliptic orbit proposed by Kepler many centuries later. EPSC Abstracts Vol. 10, EPSC2015-40, 2015 European Planetary Science Congress 2015 c Author(s) 2015 EPSC European Planetary Science Congress Secondly, by observing lunar phases and eclipses from the ground, students could also determine, following Aristarchus of Samos in the 3rd century BC, 4 length ratios involving moon and sun distances to earth, and radii of all three, moon, sun, and earth. The angular width of the moon could be first determined with simplest optical devices as about half a degree; this yields the ratio between moon diameter 2RM and distance DM to earth. Next, eclipses of sun prove its angular width, and thus ratio 2RS/DS, similar to the lunar one, though the relatively high lunar orbital eccentricity, 0.055, does result in not quite a full eclipse if at lunar apogee. Further, at a half-moon phase, when the angle sun-moon-earth is a right one, the angle

  10. The Ancient Kemetic Roots of Library and Information Science.

    Science.gov (United States)

    Zulu, Itibari M.

    This paper argues that the ancient people of Kemet (Egypt), "the black land," built and operated the first major libraries and institutions of higher education in the world. Topics of discussion include the Ancient Egyptians as an African people; a chronology of Ancient Kemet; literature in Kemet; a history of Egyptian Librarianship; the…

  11. [Construction and evaluation of an engineered bacterial strain for producing lipopeptide under anoxic conditions].

    Science.gov (United States)

    Liang, Xiao-long; Zhao, Feng; Shi, Rong-jiu; Ban, Yun-he; Zhou, Ji-dong; Han, Si-qin; Zhang, Ying

    2015-08-01

    Biosurfactant-facilitated oil recovery is one of the most important aspects of microbial enhanced oil recovery (MEOR). However, the biosurfactant production by biosurfactant-producing microorganisms, most of which are aerobes, is severely suppressed due to the in-situ anoxic conditions within oil reservoirs. In this research, we successfully engineered a strain JD-3, which could grow rapidly and produce lipopeptide under anoxic conditions, by protoplast confusion using a Bacillus amyloliquefaciens strain BQ-2 which produces biosurfactant aerobically, and a facultative anaerobic Pseudomonas stutzeri strain DQ-1 as parent strains. The alignment of 16S rDNA sequence (99% similarity) and comparisons of cell colony morphology showed that fusant JD-3 was closer to the parental strain B. amyloliquefaciens BQ-2. The surface tension of culture broth of fusant JD-3, after 36-hour cultivation under anaerobic conditions, decreased from initially 63.0 to 32.5 mN · m(-1). The results of thin layer chromatography and infrared spectrum analysis demonstrated that the biosurfactant produced by JD-3 was lipopeptide. The surface-active lipopeptide had a low critical micelle concentration (CMC) of 90 mg · L(-1) and presented a good ability to emulsify various hydrocarbons such as crude oil, liquid paraffin, and kerosene. Strain JD-3 could utilize peptone as nitrogen source and sucrose, glucose, glycerin or other common organics as carbon sources for anaerobic lipopeptide synthesis. The subculture of fusant JD-3 showed a stable lipopeptide-producing ability even after ten serial passages. All these results indicated that fusant JD-3 holds a great potential to microbially enhance oil recovery under anoxic conditions. PMID:26685621

  12. An anoxic, Fe(II)-rich, U-poor ocean 3.46 billion years ago

    Science.gov (United States)

    Li, Weiqiang; Czaja, Andrew D.; Van Kranendonk, Martin J.; Beard, Brian L.; Roden, Eric E.; Johnson, Clark M.

    2013-11-01

    The oxidation state of the atmosphere and oceans on the early Earth remains controversial. Although it is accepted by many workers that the Archean atmosphere and ocean were anoxic, hematite in the 3.46 billion-year-old (Ga) Marble Bar Chert (MBC) from Pilbara Craton, NW Australia has figured prominently in arguments that the Paleoarchean atmosphere and ocean was fully oxygenated. In this study, we report the Fe isotope compositions and U concentrations of the MBC, and show that the samples have extreme heavy Fe isotope enrichment, where δ56Fe values range between +1.5‰ and +2.6‰, the highest δ56Fe values for bulk samples yet reported. The high δ56Fe values of the MBC require very low levels of oxidation and, in addition, point to a Paleoarchean ocean that had high aqueous Fe(II) contents. A dispersion/reaction model indicates that O2 contents in the photic zone of the ocean were less than 10-3 μM, which suggests that the ocean was essentially anoxic. An independent test of anoxic conditions is provided by U-Th-Pb isotope systematics, which show that U contents in the Paleoarchean ocean were likely below 0.02 ppb, two orders-of-magnitude lower than the modern ocean. Collectively, the Fe and U data indicate a reduced, Fe(II)-rich, U-poor environment in the Archean oceans at 3.46 billion years ago. Given the evidence for photosynthetic communities provided by broadly coeval stromatolites, these results suggests that an important photosynthetic pathway in the Paleoarchean oceans may have been anoxygenic photosynthetic Fe(II) oxidation.

  13. Balancing Acts Between Ancient and Modern Cities: The Ancient Greek Cities Project of C. A. Doxiadis

    OpenAIRE

    Zarmakoupi, Mantha

    2015-01-01

    This paper examines the inception and development of the Ancient Greek Cities (AGC) research project (1963–77) of Constantinos A. Doxiadis and addresses the novelty of its methodological approach to the study of classical urbanism. With the AGC project, Doxiadis launched a comprehensive study of the ancient Greek built environment to provide an overview of the factors involved in its shaping. The project produced 24 published volumes — the first two laying out the historical and methodologica...

  14. Ancient Egypt in our Cultural Heritage?

    Directory of Open Access Journals (Sweden)

    Vera Vasiljević

    2016-02-01

    Full Text Available Inspiration derived from ancient Egypt is usually expressed through the Egyptian motifs in arts and popular culture of the 19th and 20th centuries, as well as through the non-scientific interpretations of the culture, very much based upon the Renaissance ones. The number and variety of material and non-material traces of this fascination are most expressed in the countries where, along with the early support for the institutional development of Egyptology, there existed economically potent educated middle classes (Western and Central Europe, USA, but may also be traced elsewhere. The public fascination by ancient Egypt has not ceased by the times of foundation of Egyptology, marked by the decipherment of the hieroglyphic script in 1822. Until the end of the 20th century Egyptologists have rarely dealt with the prelude to their discipline, limiting their interest to the critical approach to ancient sources and to noting the attempts to interpret the hieroglyphic script and the function of pyramids. However, the rising importance of the reception studies in other disciplines raised the interest of Egyptologists for the "fascination of Egypt", thus changing the status of various modes of expressing "Egyptomania" – they have thus become a part of the cultural heritage, registered, documented, preserved and studied. The research of this kind is only beginning in Serbia. The line of inquiry enhances the knowledge of the scope, manifestations and roles of the interest in Egypt, not limited by the national or political borders. On the other hand, the existence of the cultural heritage similar to the wider European view of ancient Egypt – short remarks by Jerotej Račanin, Kandor by Atanasije Stojković, the usage of architectural motifs derived from Egypt, the emergence of small private collections, to mention several early examples – all show that the research into the reception of ancient Egypt may contribute to the knowledge about the history

  15. Genetic diversity among ancient Nordic populations.

    Directory of Open Access Journals (Sweden)

    Linea Melchior

    Full Text Available Using established criteria for work with fossil DNA we have analysed mitochondrial DNA from 92 individuals from 18 locations in Denmark ranging in time from the Mesolithic to the Medieval Age. Unequivocal assignment of mtDNA haplotypes was possible for 56 of the ancient individuals; however, the success rate varied substantially between sites; the highest rates were obtained with untouched, freshly excavated material, whereas heavy handling, archeological preservation and storage for many years influenced the ability to obtain authentic endogenic DNA. While the nucleotide diversity at two locations was similar to that among extant Danes, the diversity at four sites was considerably higher. This supports previous observations for ancient Britons. The overall occurrence of haplogroups did not deviate from extant Scandinavians, however, haplogroup I was significantly more frequent among the ancient Danes (average 13% than among extant Danes and Scandinavians (approximately 2.5% as well as among other ancient population samples reported. Haplogroup I could therefore have been an ancient Southern Scandinavian type "diluted" by later immigration events. Interestingly, the two Neolithic samples (4,200 YBP, Bell Beaker culture that were typed were haplogroup U4 and U5a, respectively, and the single Bronze Age sample (3,300-3,500 YBP was haplogroup U4. These two haplogroups have been associated with the Mesolithic populations of Central and Northern Europe. Therefore, at least for Southern Scandinavia, our findings do not support a possible replacement of a haplogroup U dominated hunter-gatherer population by a more haplogroup diverse Neolithic Culture.

  16. Diverse methane concentrations in anoxic brines and underlying sediments, eastern Mediterranean Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Karisiddaiah, S.M.

    of the brines are extremely high, 2692]103 nM at 3493m, and are 20 times higher than the Bannock Basin values. Thus, based on available physical pro"les (oxygen, temperature and salinity) of water masses in these brines, the approximate boundary of the brine... Atlantis II (mer Rouge). Oceanologica Acta 13, 187}197. Boldrin, A., Rabitti, S., 1990. Hydrography of the brines in the Bannock and Tyro anoxic basins (Eastern Mediterranean). Marine Chemistry 31, 21}33. Camerlenghi, A., Cita, M.B., Hieke, W., Ricchuito, T...

  17. Biogenic nitrogen gas production at the oxic–anoxic interface in the Cariaco Basin, Venezuela

    OpenAIRE

    Montes, E.(Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain); Altabet, M.A.; F. E. Muller-Karger; Scranton, M. I.; R. C. Thunell; Benitez-Nelson, C.; L. Lorenzoni; Astor, Y. M.

    2013-01-01

    Excess nitrogen gas (N2xs) was measured in samples collected at six locations in the eastern and western sub-basins of the Cariaco Basin, Venezuela, in September 2008 (non-upwelling conditions) and March 2009 (upwelling conditions). During both sampling periods, N2xs concentrations were below detection in surface waters, increasing to ~ 22 μmol N kg−1 at the oxic–anoxic interface...

  18. PROGRESSIVE VENTILATION OF THE OCEANS - POTENTIAL FOR RETURN TO ANOXIC CONDITIONS IN THE POST-PALEOZOIC

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, Pat; Berry, William B.N.

    1980-09-01

    After the ventilation of the residual anoxic layer in the late Paleozoic (Berry and Wilde, 1978) a return to ephemeral anoxic conditions in the ocean is suggested by anoxic sediments found in the Mesozoic cores of the deep-sea drilling program (Schlanger and Jenkyns 1977, and Theide and Van Andel 1977). A preliminary physical oceanographic model is presented to explain the development of oxygen depleted layers in mid-waters below the surface wind-mixed layer during non-glacial climates. The model shows the range of temperature, salinity and density values for hypothetical water masses for two climatically related oceanographic situations: Case A where bottom waters are formed at mid-latitudes at the surface salinity maxima, and Case B where bottom waters are produced at high latitudes but not by sea-ice formation as in the modern ocean. The hypothetical water masses are characterized by examples from the modern ocean and extrapolation to non-glacial times is made by eliminating water masses produced by or influenced by sea-ice formation in modern glacial times. The state of oxidation is made by plotting the model water masses on an oxygen saturation diagram and comparing the relative oxygen capacity with modern conditions of zonal organic productivity. The model indicates for Case A (high latitude temperatures above 5°C) two oxygen, depleted layers in the equatorial regions (1) from about 200m to the depth of completed oxidation of surface material separated by an oxygenated zone to (2) a deep depleted zone along the base of the pycnocline at 2900 M. The deep depleted zone extends along the Case A pycnocline polarward toward the high latitude productivity maximum. For case B with a pycnocline at about 1500m the deep anoxic layer is not sustained. Considerations of density only, suggest that neutral stratification and the potential for overturn is enhanced for climates transitional between Case A and Case B where the density contrast between major water masses

  19. Normoxic and anoxic metabolism of Nicotiana tabacum transformants lacking root nitrate reductase

    OpenAIRE

    Stoimenova, Maria

    2002-01-01

    The aim of this work was to find out whether and how nitrate reduction in roots would facilitate survival of hypoxic and anoxic (flooding)-phases. For that purpose, we compared the response of roots of hydroponically grown tobacco wildtype (Nicotiana tabacum cv. Gatersleben) and of a transformant (LNR-H) with no nitrate reductase (NR) in the roots but almost normal NR in leaves (based on a nia2-double mutant). As an additional control we used occasionally a 35S-transformant of the same nia2-d...

  20. Dysoxic/anoxic episodes in the Aptian-Albian (Early Cretaceous)

    Science.gov (United States)

    Bralower, Timothy J.; Sliter, William V.; Arthur, Michael A.; Leckie, R. Mark; Allard, David; Schlanger, Seymour O.

    New biostratigraphic data suggest, for the first time, that the long Aptian-Albian Oceanic Anoxic Event was marked by at least three distinct, relatively brief episodes of widespread dysoxia/anoxia which interrupted generally oxygenated conditions. The high-resolution, integrated foraminiferal and nannofossil biostratigraphy derived here allows recognition of an apparently ocean-wide dysoxic/anoxic episode in the early Aptian (Globigerinelloides blowi foraminiferal Zone, Chiastozygus litterarius nannofossil Zone, Conusphaera rothii nannofossil Subzone, shortly after magnetic Chron CMO). Equally widespread, but distributionally patchier dysoxic/anoxic episodes occurred in the early Albian (Hedbergella planispira foraminiferal Zone, Prediscosphaera columnata nannofossil Zone, subzone NC8B) and early late Albian (Biticinella breggiensis foraminiferal Zone, Axopodorhabdus albianus nannofossil Zone, subzone NC9B). These episodes can be best recognized in highly carbonaceous sediments deposited in epicontinental basins, now exposed on land, including the lower Aptian "Livello Selli" of the Italian Apennines, the lower Albian "Niveau Paquier" of the Fosse Vocontienne, France, and the lower upper Albian Toolebuc Formation of the Eromanga Basin, Queensland, Australia. Our data indicate that these horizons correlate at the nannofossil subzonal level to carbonaceous intervals in DSDP/ODP sites which were deposited in pelagic and hemipelagic oceanic settings. Although none of these episodes is associated with major biotic extinctions, they are characterized by changes, of variable magnitude, in the community structure of planktonic foraminifera, which commonly consist of a low-diversity assemblage of opportunistic taxa or are entirely absent. Nannofossil taxa in these horizons do not change as radically, but in some sites show marked nearshore affinities or, in other sequences, are possibly replaced by other phytoplankton. Dissolution events cannot be entirely ruled out as a

  1. Jellyfish Lake, Palau: early diagenesis of organic matter in sediments of an anoxic marine lake

    Science.gov (United States)

    Orem, W.H.; Burnett, W.C.; Landing, W.M.; Lyons, W.B.; Showers, W.

    1991-01-01

    The major postdepositional change in the sedimentary organic matter is carbohydrate biodegradation. Lignin and aliphatic substances are preserved in the sediments. Dissolved organic matter in pore waters is primarily composed of carbohydrates, reflecting the degradation of sedimentary carbohydrates. Rate constants for organic carbon degradation and sulfate reduction in sediments of the lake are about 10?? lower than in other anoxic sediments. This may reflect the vascular plant source and partly degraded nature of the organic matter reaching the sediments of the lake. -from Authors

  2. Arsenic in an alkaline AMD treatment sludge: Characterization and stability under prolonged anoxic conditions

    International Nuclear Information System (INIS)

    Lime treatment of acid mine drainage (AMD) generates large volumes of neutralization sludge that are often stored under water covers. The sludge consists mainly of calcite, gypsum and a widespread ferrihydrite-like Fe phase with several associated species of metal(loid) contaminants. The long-term stability of metal(loid)s in this chemically ill-defined material remains unknown. In this study, the stability and speciation of As in AMD sludge subjected to prolonged anoxic conditions is determined. The total As concentration in the sludge is 300 mg kg-1. In the laboratory, three distinct water cover treatments were imposed on the sludge to induce different redox conditions (100%N2, 100%N2 + glucose, 95%N2:5%H2). These treatments were compared against a control of oxidized, water-saturated sludge. Electron micro-probe (EMP) analysis and spatially resolved synchrotron X-ray fluorescence (SXRF) results indicate that As is dominantly associated with Fe in the sludge. In all treatments and throughout the experiment, measured concentrations of dissolved As were less than 5 μg L-1. Dissolved Mn concentration in the N2 + glucose treatment increased significantly compared to other treatments. Manganese and As K-edge X-ray absorption near edge structure spectroscopy (XANES) analyses showed that Mn was the redox-active element in the solid-phase, while As was stable. Arsenic(V) was still the dominant species in all water-covered sludges after 9 months of anoxic treatments. In contrast, Mn(IV) in the original sludge was partially reduced into Mn(II) in all water-covered sludges. The effect was most pronounced in the N2 + glucose treatment, suggesting microbial reduction. Micro-scale SXRF and XANES analysis of the treated sludge showed that Mn(II) accumulated in areas already enriched in Fe and As. Overall, the study shows that AMD sludges remain stable under prolonged anoxic conditions. External sources of chemical reductants or soluble C were needed to induce lower redox state

  3. Denitrification in an anoxic rotating biological contactor under two carbon/nitrogen ratios

    OpenAIRE

    Cortez, Susana; Teixeira, P; Oliveira, Rosário; Mota, M.

    2008-01-01

    The aim of the present work was to compare the performance of an anoxic bench-scale rotating biological contactor (RBC), in terms of the denitrification process, applied to treat synthetic wastewater under two carbon/nitrogen (C/N) molar ratios (1.5 and 3). The average removal efficiency in terms of nitrogen-nitrate was of about 90.4% at a C/N=1.5 lowering to 73.7% at a C/N=3. Considering carbon-acetate removal an overall efficiency of 82.0% and 63.6% was attained at a C/N rati...

  4. Hydrolysis and degradation of filtrated organic particulates in a biofilm reactor under anoxic and aerobic conditions

    DEFF Research Database (Denmark)

    Janning, K.F.; Mesterton, K.; Harremoës, P.

    1997-01-01

    carbon to the bulk liquid was observed as an indication of hydrolysis taking place. The second experiment was designed as a series of on-line OUR batch experiments in a biofilm reactor with recirculation, in order to investigate further the degradation of particulate organic matter. After the biofilm had......Two experiments were performed in order to investigate the anoxic and the aerobic degradation of filtrated organic matter in a biofilter. In submerged lab: scale reactors with Biocarbone media as filter material, accumulated particulate organic matter from pre-settled wastewater served as the only...

  5. Traditional Ecological Knowledge among transhumant pastoralists in Mediterranean Spain: learning for adaptation to global change

    OpenAIRE

    Oteros Rozas, E.; Ontillera-Sánchez, R.; Sanosa, P.; Gómez-Baggethun, E.; Reyes-García, V.; González, J. A.

    2013-01-01

    Mobility is a millenary human strategy to deal with environmental change. An outstanding example of mobility is transhumance, an ancient pastoralist practice consisting of the seasonal migration of livestock between ecological regions following peaks in pasture productivity. The maintenance of transhumance depends partly on the preservation of related traditional ecological knowledge (TEK). We (a) identified and characterized social groups that hold transhumance-related TEK, (b) analyzed tren...

  6. Evaluation of metal partitioning and mobility in a sulfidic mine tailing pile under oxic and anoxic conditions.

    Science.gov (United States)

    Pinto, Patricio X; Al-Abed, Souhail R; Holder, Christopher; Reisman, David J

    2014-07-01

    Mining-influenced water emanating from mine tailings and potentially contaminating surface water and groundwater is one of the most important environmental issues linked to the mining industry. In this study, two subsets of Callahan Mine tailings (mainly comprised of silicates, sulfides, and carbonates) were collected using sealed containers, which allowed keeping the samples under anoxic conditions during transportation and storage. Among the potential contaminants, in spite of high concentrations of Cu, Mn, Pb, and Zn present in the solid mine tailings, only small amounts of Mn and Zn were found in the overlying pore water. The samples were subjected to leaching tests at different reduction-oxidation (redox) conditions to compare metal and S mobilization under oxic and anoxic conditions. It was observed that Cd, Cu, Mn, Pb, S, and Zn were mobilized at higher rates under oxic conditions, while Fe was mobilized at a higher rate under anoxic conditions in comparable constant pH experiments. These results suggest that metal mobilization is significantly impacted by redox conditions. When anoxic metal mobilization assessment is required, it is recommended to always maintain anoxic conditions because oxygen exposure may affect metal mobilization. A sequential extraction performed under oxic conditions revealed that most of the metals in the samples were associated with the sulfidic fraction and that the labile fraction was associated with Mn and moderate amounts of Pb and Zn. PMID:24747936

  7. Accumulation of fossil fuels and metallic minerals in active and ancient rift lakes

    Science.gov (United States)

    Robbins, E.I.

    1983-01-01

    A study of active and ancient rift systems around the world suggests that accumulations of fossil fuels and metallic minerals are related to the interactions of processes that form rift valleys with those that take place in and around rift lakes. The deposition of the precursors of petroleum, gas, oil shale, coal, phosphate, barite, Cu-Pb-Zn sulfides, and uranium begins with erosion of uplifted areas, and the consequent input of abundant nutrients and solute loads into swamps and tectonic lakes. Hot springs and volcanism add other nutrients and solutes. The resulting high biological productivity creates oxidized/reduced interfaces, and anoxic and H2S-rich bottom waters which preserves metal-bearing organic tissues and horizons. In the depositional phases, the fine-grained lake deposits are in contact with coarse-grained beach, delta, river, talus, and alluvial fan deposits. Earthquake-induced turbidites also are common coarse-grained deposits of rift lakes. Postdepositional processes in rifts include high heat flow and a resulting concentration of the organic and metallic components that were dispersed throughout the lakebeds. Postdepositional faulting brings organic- and metal-rich sourcebeds in contact with coarse-grained host and reservoir rocks. A suite of potentially economic deposits is therefore a characteristic of rift valleys. ?? 1983.

  8. Ecological palaeoecology: a missing link between ecology and evolution

    Directory of Open Access Journals (Sweden)

    Rull, V.

    2014-12-01

    Full Text Available Palaeoecology is more than a palaeoenvironmental discipline; it is a science that is well-suited for supplying the empirical evidence necessary to test ecological hypotheses and contributes to our understanding of the interface of ecology and evolution. A critical time frame in palaeoecology is the often-overlooked Q-time dimension (centuries to millennia, which tends to be the most appropriate time dimension to examine ecology–evolution interactions. This paper discusses these topics from a conceptual perspective and provides examples of the contributions of palaeoecology to the study of ecology–evolution interactions. It also admonishes researchers about the threats of overlooking palaeoecology. Specifically, this paper argues that the neglect of palaeoecology may result in the loss of empirical support for ecology and its interactions with evolution as DNA-based phylogenetic and phylogeographic studies become more and more prevalent. The main concepts discussed are the time continuum, the notion of ecological palaeoecology and the empirical nature of palaeoecology in the face of more hypothetical approaches. More practically speaking, several examples are provided that highlight the utility of ecological palaeoecology for understanding a variety of processes, including ecological succession, community– environment equilibria, community assembly, biotic responses to environmental change, speciation and extinction, and biodiversity conservation. The ecology–evolution interface is analysed using two processes in which these disciplines interact intensively: ecological succession and long-range migration. This work concludes that both ecological palaeoecology (including ancient DNA records and DNA-based phylogenetics and phylogeography are needed to better understand the biosphere ecologically and the processes occurring at the ecology–evolution interface.La paleoecología es más que una disciplina ambiental, ya que proporciona las

  9. Zooplankton diversity and distribution in a deep and anoxic Mediterranean coastal lake

    Directory of Open Access Journals (Sweden)

    G. KEHAYIAS

    2013-04-01

    Full Text Available The variation of the smaller size fraction of zooplankton was investigated during a two-year period in a brackish deep and anoxic coastal lake of western Greece (Aitoliko, along with the specific environmental characteristics of this ecosystem. The zooplanktonic community comprised a relatively small number of taxa and it was dominated by brackish-water calanoid copepods (Paracartia latisetosa, Calanipeda aquaedulcis and in certain periods by rotifers and tintinnids. The zooplankton abundance showed an increase in the warmer period starting from late spring and reached maximum values in July. In the well oxygenated surface layer, temperature was the most important parameter influencing the seasonal cycles of all groups. In contrast, the oxygen depletion a few meters under the surface affected the vertical distribution of most of the zooplankton groups, which were found restricted in the surface layer especially from spring until autumn. Only the meroplanktonic larvae of polychaetes presented increased proportions in the deeper layers. Salinity has not significantly influenced the zooplanktonic assemblages. The results point out the degraded status of the Aitoliko basin where the hypoxic/anoxic layers resulted to a high portion of dead organic material identified as copepod carcasses, and underlines the necessity of monitoring of this ecosystem.

  10. Phosphorus, carbon and nitrogen enrichment during sedimentation in a seasonally anoxic lake (Lake Lugano, Switzerland

    Directory of Open Access Journals (Sweden)

    Kurt W. Hanselmann

    2002-08-01

    Full Text Available Sedimentation fluxes of major nutrients are investigated during 1996 and 1997 at three different depths and two locations in eutrophic southern basin of Lake Lugano (Switzerland. Horizontal differences between the two sites are on the order of 10-40% (but can exceed 50%, whereas differences related to interannual oscillations range between 5 and 24%. Particulate organic carbon (POC and nitrogen (PN fluxes show a constant increase of 5-20% from the upper to the bottom trap. This tendency remains more or less constant during the year. On the contrary, particulate phosphorus (PP shows a seasonal variation, with higher accumulation rates from the I to the III trap in autumn and winter which can exceed +1200%. This phenomenon is due to the interaction between the dissolved phosphorus (DP and the iron(oxihydroxides (Fe(OH3 near the oxycline. Fe(OH3 precipitates at the iron redox boundary, scavenging DP. This enrichment flux increases together with the development of the anoxic benthic layer. The efficiency of the iron redox layer in trapping upward diffusing P is related to the concentration of dissolved iron in the anoxic hypolimnion. In Lake Lugano the two considered sites present major difference of iron concentration, and this difference is reflected in the P sedimentation fluxes. The exposition of an additional sedimentation trap above the maximal oxycline height has allowed to gain insight into this phenomenon.

  11. Effects of extracellular polymeric substances on granulation of anoxic sludge in sequencing batch reactor.

    Science.gov (United States)

    Wang, Binbin; Liu, Shunlian; Zhao, Hongmei; Zhang, Xinyan; Peng, Dangcong

    2012-01-01

    Variations of extracellular polymeric substances (EPS) and its components with sludge granulation were examined in a lab-scale sequencing batch reactor (SBR) which was fed with sodium nitrate and sodium acetate. Ultrasonication plus cation exchange resin (CER) were used as the EPS extraction method. Results showed that after approximately 90 d cultivation, the sludge in the reactor was almost granulated. The content of extracellular polysaccharides increased from 10.36 mg/g-VSS (volatile suspended solids) at start-up with flocculent sludge to 23.18 mg/g-VSS at 91 d with matured granular sludge, while the content of extracellular proteins were almost unchanged. Polysaccharides were the major components of EPS in anoxic granular sludge, accounting for about 70.6-79.0%, while proteins and DNA accounted for about 16.5-18.9% and 4.6-9.9%, respectively. It is proposed that EPS play a positive role in anoxic sludge granulation and polysaccharides might be strongly involved in aggregation of flocs into granules. PMID:22744684

  12. Perils of categorical thinking: "Oxic/anoxic" conceptual model in environmental remediation

    Science.gov (United States)

    Bradley, Paul M.

    2012-01-01

    Given ambient atmospheric oxygen concentrations of about 21 percent (by volume), the lower limit for reliable quantitation of dissolved oxygen concentrations in groundwater samples is in the range of 0.1–0.5 mg/L. Frameworks for assessing in situ redox condition are often applied using a simple two-category (oxic/anoxic) model of oxygen condition. The "oxic" category defines the environmental range in which dissolved oxygen concentrations are clearly expected to impact contaminant biodegradation, either by supporting aerobic biodegradation of electron-donor contaminants like petroleum hydrocarbons or by inhibiting anaerobic biodegradation of electron-acceptor contaminants like chloroethenes. The tendency to label the second category "anoxic" leads to an invalid assumption that oxygen is insignificant when, in fact, the dissolved oxygen concentration is less than detection but otherwise unknown. Expressing dissolved oxygen concentrations as numbers of molecules per volume, dissolved oxygen concentrations that fall below the 0.1 mg/L field detection limit range from 1 to 1017 molecules/L. In light of recent demonstrations of substantial oxygen-linked biodegradation of chloroethene contaminants at dissolved oxygen concentrations well below the 0.1–0.5 mg/L field detection limit, characterizing "less than detection" oxygen concentrations as "insignificant" is invalid.

  13. Methane production and simultaneous sulphate reduction in anoxic, salt marsh sediments

    Science.gov (United States)

    Oremland, R.S.; Marsh, L.M.; Polcin, S.

    1982-01-01

    It has been generally believed that sulphate reduction precludes methane generation during diagenesis of anoxic sediments1,2. Because most biogenic methane formed in nature is thought to derive either from acetate cleavage or by hydrogen reduction of carbon dioxide3-6, the removal of these compounds by the energetically more efficient sulphate-reducing bacteria can impose a substrate limitation on methanogenic bacteria 7-9. However, two known species of methanogens, Methanosarcina barkeri and Methanococcus mazei, can grow on and produce methane from methanol and methylated amines10-13. In addition, these compounds stimulate methane production by bacterial enrichments from the rumen11,14 and aquatic muds13,14. Methanol can enter anaerobic food webs through bacterial degradation of lignins15 or pectin16, and methylated amines can be produced either from decomposition of substances like choline, creatine and betaine13,14 or by bacterial reduction of trimethylamine oxide17, a common metabolite and excretory product of marine animals. However, the relative importance of methanol and methylated amines as precursors of methane in sediments has not been previously examined. We now report that methanol and trimethylamine are important substrates for methanogenic bacteria in salt marsh sediments and that these compounds may account for the bulk of methane produced therein. Furthermore, because these compounds do not stimulate sulphate reduction, methanogenesis and sulphate reduction can operate concurrently in sulphate-containing anoxic sediments. ?? 1982 Nature Publishing Group.

  14. Determination of the nitrous oxide emission potential of deammonification under anoxic conditions.

    Science.gov (United States)

    Schneider, Y; Beier, M; Rosenwinkel, K-H

    2011-12-01

    Various studies have been performed to determine nitrous oxide (N2O) emissions from conventional biological nitrogen removal processes in wastewater treatment like nitrification and denitrification in the main stream. However, with respect to the overall emissions of a wastewater treatment plant, part-stream treatment for high-strength wastewater (e.g., sludge liquor) is also expected to hold a significant emission potential because of high concentrations and extreme boundary conditions. This paper presents results from a laboratory-scale study on nitrous oxide production by biomass from a deammonification process (nitritation + anammox) under anoxic conditions. It was discovered that N2O formation results from incomplete endogenous denitrification rather than anammox and is dependent on substrate availability. Based on direct measurements of the dissolved N2O concentrations in a sequencing batch reactor, the dynamic behavior of N2O production is characterized in more detail. The results show that, during anoxic conditions, the N2O emission potential of deammonification is significantly lower than from conventional denitrification. PMID:22368962

  15. Integrative approach to delineate natural attenuation of chlorinated benzenes in anoxic aquifers

    International Nuclear Information System (INIS)

    Biodegradation of chlorobenzenes was assessed at an anoxic aquifer by combining hydrogeochemistry and stable isotope analyses. In situ microcosm analysis evidenced microbial assimilation of chlorobenzene (MCB) derived carbon and laboratory investigations asserted mineralization of MCB at low rates. Sequential dehalogenation of chlorinated benzenes may affect the isotope signature of single chlorobenzene species due to simultaneous depletion and enrichment of 13C, which complicates the evaluation of degradation. Therefore, the compound-specific isotope analysis was interpreted based on an isotope balance. The enrichment of the cumulative isotope composition of all chlorobenzenes indicated in situ biodegradation. Additionally, the relationship between hydrogeochemistry and degradation activity was investigated by principal component analysis underlining variable hydrogeochemical conditions associated with degradation activity at the plume scale. Although the complexity of the field site did not allow straightforward assessment of natural attenuation processes, the application of an integrative approach appeared relevant to characterize the in situ biodegradation potential. - Lines of evidence for in situ biodegradation of chlorinated benzenes in an anoxic aquifer by combining hydrogeochemical and stable isotope data with multivariate statistics.

  16. Nitrogen and phosphorus removal in pilot-scale anaerobic-anoxic oxidation ditch system

    Institute of Scientific and Technical Information of China (English)

    PENG Yongzhen; HOU Hongxun; WANG Shuying; CUI Youwei; Zhiguo Yuan

    2008-01-01

    To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal(SNDPR),a whole course of SNDPR damage and recovery was studied in a pilot-scale,anaerobicanoxic oxidation ditch(OD),where the volumes of anaerobic zone,anoxic zone,and ditches zone of the OD system were 7,21,and 280L,respectively.The reactor was fed with municipal wastewater with a flow rate of 336 L/d.The concept of simultaneous nitrification and denitrification (SND)rate(rSND) was put forward to quantify SND.The results indicate that:(1)high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase,total nitrogen (TN) and total phosphate(TP) removal rates were 80%and 85%,respectively;(2)when the system was aerated excessively,the stability of SND was damaged,and rSND dropped from 80% to 20%or less;(3)the natural logarithm of the ratio of NOx to MJ4+ in the effluent had a linear correlation to oxidation-reduction potential (ORP);(4)when NO3- was less than 6 mg/L.high phosphorus removal efficiency could be achieved;(5)denitrifying phosphorus removal (DNPR) could take place in the anaerobic-anoxic OD system.The major innovation was that the SND rate was devised and quantified.

  17. Anoxic biodegradation of dimethyl phthalate (DMP) by activated sludge cultures under nitrate-reducing conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and wastewaters. Dimethyl phthalate (DMP) biodegradation by activated sludge cultures under nitrate-reducing conditions was investigated. Under one optimized condition, DMP was biodegraded from 102.20 mg/L to undetectable level in 56 h under anoxic conditions and its reaction fitted well with the first-order kinetics. Using the high-performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC-MS) analysis, mono-methyl phthalate (MMP) and phthalic acid (PA) were detected as the major intermediates of DMP biodegradation. When combined with the determination of chemical oxygen demand (CODCr) removal capacity and pH, DMP was found to be mineralized completely under anoxic conditions. The biodegradation pathway was proposed as DMP → MMP → PA → … → CO2 + H2O.The molar ratio of DMP to nitrate consumed was found to be 9.0:1, which agrees well with the theoretical stoichiometric values of DMP biodegradation by nitrate-reducing bacteria. The results of the non-linear simulation showed that the optimum pH and temperature for the degradation were 7.56 and 31.4℃, respectively.

  18. Anoxic sediments off Central Peru record interannual to multidecadal changes of climate and upwelling ecosystem during the last two centuries

    Directory of Open Access Journals (Sweden)

    D. Gutiérrez

    2006-01-01

    Full Text Available High-resolution paleo-environmental and paleo-ecological archives in laminated sequences are present in selected areas from the upper continental Peruvian margin within the oxygen minimum zone. We present initial results of a multidisciplinary study (the PALEOPECES project that aims to reconstruct environmental and ecosystem variability during the past 200 years from high-resolution records. We report chronology development, sediment structure, elemental, organic, and mineralogical compositions of a box core collected at 300 m depth off Pisco, central Peru. An average sedimentation rate of 2.2 mm y-1 was estimated from downcore excess 210Pb activities for the last 100-150 years. Extending this rate further downcore indicates that a slump located at 52 cm depth from the top of the core can be correlated with a large tsunami that struck the coast of central Peru in 1746. X-ray analyses reveal laminated structures composed of couplets of light and dark laminae. Observations under polarized microscope show that light laminae are dominated by more dense, detrital and terrigenous material, while dark laminae are less dense with greater concentrations of amorphous biogenic silica. Downcore variations in dry bulk density and X-ray radioscopy of gray level show similar patterns, including a major shift at 34 cm depth (ca. mid-nineteenth century. A finely laminated sequence, which may include annual varves, is present between 34 cm depth and the slump layer. Sediment characteristics of the sequence suggest increased seasonality of terrigenous versus biogenous sedimentation during the corresponding period. In addition to a mid-nineteenth century change and considerable multidecadal variability in TOC, there is a positive trend in the past 50 years. Mineralogical analyses from a Fourier Transformed Infrared Spectroscopy (FTIR of the upper core covering the last 25 years, indicate higher concentrations of the mineral fraction (quartz, feldspar, kaolinite and

  19. Climate change, social unrest and dynastic transition in ancient China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dian; JIM Chiyung; LIN Chusheng; HE Yuanqing; LEE Fung

    2005-01-01

    The evident connection between human evolution and climatic changes has been concurred by scientists. Although many people are trying to forecast the impacts of climatic changes on our future society, there are not any studies to quantitatively scrutinize the interrelation between climatic changes and social developments by using historical data. In line with this knowledge gap, this study adopted a scientific approach to compare the paleoclimatic records with the historical data of wars, social unrests, and dynastic transitions in China spanned from the late Tang to Qing Dynasties. Results showed that war frequency in cold phases was much higher than that in mild phases. Besides, 70%-80% of war peaks and most of the dynastic transitions and nationwide social unrests in China took place in cold phases. This phenomenon could be attributed to the diminishing thermal energy input in cold phases resulting in the fall of land-productivity and hence, the deficiency of livelihood resources across society. Accompanied with certain social circumstances, this kind of ecological stress was transformed into wars and social unrests, followed by dynastic transitions in most of the cases. By closer examination, it was even found that war frequency was negatively correlated with temperature anomaly series. As land carrying capacities vary from one climatic zone to another, the magnitude of war- temperature association also differed among different geographic regions. It is suggested that climatic change was one of the most important factors in determining the dynastic cycle and alternation of war and peace in ancient China.

  20. Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary

    Science.gov (United States)

    Almathen, Faisal; Charruau, Pauline; Mohandesan, Elmira; Mwacharo, Joram M.; Orozco-terWengel, Pablo; Pitt, Daniel; Abdussamad, Abdussamad M.; Uerpmann, Margarethe; Uerpmann, Hans-Peter; De Cupere, Bea; Magee, Peter; Alnaqeeb, Majed A.; Salim, Bashir; Raziq, Abdul; Dessie, Tadelle; Abdelhadi, Omer M.; Banabazi, Mohammad H.; Al-Eknah, Marzook; Walzer, Chris; Faye, Bernard; Hofreiter, Michael; Peters, Joris; Hanotte, Olivier

    2016-01-01

    Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species’ range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the “restocking from the wild” hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments. PMID:27162355

  1. Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary.

    Science.gov (United States)

    Almathen, Faisal; Charruau, Pauline; Mohandesan, Elmira; Mwacharo, Joram M; Orozco-terWengel, Pablo; Pitt, Daniel; Abdussamad, Abdussamad M; Uerpmann, Margarethe; Uerpmann, Hans-Peter; De Cupere, Bea; Magee, Peter; Alnaqeeb, Majed A; Salim, Bashir; Raziq, Abdul; Dessie, Tadelle; Abdelhadi, Omer M; Banabazi, Mohammad H; Al-Eknah, Marzook; Walzer, Chris; Faye, Bernard; Hofreiter, Michael; Peters, Joris; Hanotte, Olivier; Burger, Pamela A

    2016-06-14

    Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species' range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the "restocking from the wild" hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments. PMID:27162355

  2. Thermal and spectroscopic analysis of ancient potteries

    International Nuclear Information System (INIS)

    The present work is focused on the characterization study of ancient pottery shreds excavated recently from Sembiankandiyur in India. The study is intended to identify the firing temperature, firing conditions and morphology of the ancient pottery samples. The samples were analyzed using FTIR, XRD and TG-DTA. FTIR and XRD studies were used in mineralogical characterization of potteries. The firing temperature and conditions were interpreted by studying the difference in mineral composition in the samples using FTIR and XRD. TG-DTA is considered the complementary technique to elucidate the firing temperature from the thermal characteristic reactions such as dehydration, decomposition and transformations of minerals in the course of controlled firing of the samples. The results showed that all the samples fired in a oxidizing condition and firing temperature also inferred.(authors)

  3. Environmental Conditions in a Carpathian Deep Sea Basin During the Period Preceding Oceanic Anoxic Event 2 - A Case Study from the Skole Nappe

    Directory of Open Access Journals (Sweden)

    Bąk Krzysztof

    2015-01-01

    Full Text Available Hemipelagic green clayey shales and thin muddy turbidites accumulated in a deep sea environment below the CCD in the Skole Basin, a part of the Outer Carpathian realm, during the Middle Cenomanian. The hemipelagites contain numerous radiolarians, associated with deep-water agglutinated foraminifera. These sediments accumulated under mesotrophic conditions with limited oxygen concentration. Short-term periodic anoxia also occurred during that time. Muddy turbidity currents caused deposition of siliciclastic and biogenic material, including calcareous foramini-fers and numerous sponge spicules. The preservation and diversity of the spicules suggests that they originate from disarticulation of moderately diversified sponge assemblages, which lived predominantly in the neritic-bathyal zone. Analyses of radiolarian ecological groups and pellets reflect the water column properties during the sedimentation of green shales. At that time, surface and also intermediate waters were oxygenated enough and sufficiently rich in nutri-ents to enable plankton production. Numerous, uncompacted pellets with nearly pristine radiolarian skeletons inside show that pelletization was the main factor of radiolarian flux into the deep basin floor. Partly dissolved skeletons indicate that waters in the Skole Basin were undersaturated in relation to silica content. Oxygen content might have been depleted in the deeper part of the water column causing periodic anoxic conditions which prevent rapid bacterial degra-dation of the pellets during their fall to the sea floor.

  4. Macroculture, Athletics and Democracy in ancient Greece

    OpenAIRE

    Economou, Emmanouel/Marios/Lazaros; Kyriazis, Nicholas

    2012-01-01

    In the present essay we examine whether and how sports affected the emergence of democracy as a political phenomenon in Classical Greece. To achieve this we introduce in a model the concept of macroculture as a complex of mutually supporting values, norms and beliefs in various areas of human activity, like athletics, war, politics, etc. Then, we proceed through a historical review on the history of sports in Ancient Greece and we investigate various aspects of how and under which terms athle...

  5. Ancient Egypt in our Cultural Heritage?

    OpenAIRE

    Vera Vasiljević

    2016-01-01

    Inspiration derived from ancient Egypt is usually expressed through the Egyptian motifs in arts and popular culture of the 19th and 20th centuries, as well as through the non-scientific interpretations of the culture, very much based upon the Renaissance ones. The number and variety of material and non-material traces of this fascination are most expressed in the countries where, along with the early support for the institutional development of Egyptology, there existed economically potent ed...

  6. Science in the Study of Ancient Egypt

    OpenAIRE

    Zakrzewski, Sonia; Shortland, Andrew; Rowland, Joanne

    2016-01-01

    Egyptology has been dominated by the large quantity of written and pictorial material available. This amazing archaeology has opened up a wonderful view of the ancient Egyptian world. The importance of hieroglyphics and texts, and their interpretation, has led to other areas of archaeology playing much less prominence in the study of Egypt. Perhaps most notable in this is relative lack of the application of analytical science to answer Egyptian questions. This problem has been compounded by d...

  7. Chemistry Progress and Civilization in Ancient China

    Institute of Scientific and Technical Information of China (English)

    JIANG Yu-Qian; RUAN Shu-Xiang; TANG Shan; SHUAI Zhi-Gang

    2011-01-01

    @@ During the 6,000 years of Chinese civilization, chemistry has played an essential role.The bronzed chime bells of the Warring States Period (475-221 BC) unearthed in Hubei Province shows not only the excellence in musical instruments in ancient China, but also the technological advances in metallurgy.Chinese alchemy was not originated from the quest to turn common metals to gold, instead, it was for searching medicines for longevity of human beings, mostly practised by Taoists.

  8. Parallel OCR for Ancient Greek Critical Editions

    OpenAIRE

    Del Grosso, Angelo; Boschetti, Federico

    2012-01-01

    This project is focused on the parallelization of OCR processes applied to Ancient Greek critical editions. Two experiments have been performed. The first experiment is related to parameters differently tuned on the nodes of the grid, in order to identify the best combination that improves the accuracy of the recognition. The second experiment concerns the application of OCR with the best parameters on sample pages by a divide et impera strategy. Results related to the performances of the par...

  9. HTLV-1: ancient virus, new challenges

    OpenAIRE

    Marzieh Rahimzadegan; Farshid Abedi; Seyed Abodolrahim Rezaei; Reza Ghadimi

    2014-01-01

    Human T-lymphotropic virus (HTLV-1) is an ancient pathogen for human being but arising and recognized recently. The routes of transmission are vertical (mainly by breastfeeding), unsafe sexual contacts and through contaminated blood components specially in whom need frequent and repeated blood transfusions such as permanent anemia due to blood loss in hemophilia and major thalassemia. Patients who should undergo hemodialysis in their lifelong are another instance for increased risk of HTLV-1 ...

  10. Influence of wastewater composition on nutrient removal behaviors in the new anaerobic–anoxic/nitrifying/induced crystallization process

    OpenAIRE

    Shi, Jing; Xiwu LU; Yu, Ran; Gu, Qian; Zhou, Yi

    2013-01-01

    In this study, the new anaerobic–anoxic/nitrifying/induced crystallization (A2N–IC) system was compared with anaerobic-anoxic/nitrifying (A2N) process to investigate nutrient removal performance under different influent COD and ammonia concentrations. Ammonia and COD removal rates were very stable in both processes, which were maintained at 84.9% and 86.6% when the influent ammonia varied from 30 mg L−1 to 45 mg L−1 and COD ranged from 250 mg L−1 to 300 mg L−1. The effluent phosphorus always ...

  11. Simultaneous Organics and Nutrients Removal from Domestic Wastewater in a Combined Cylindrical Anoxic/Aerobic Moving Bed Biofilm Reactor

    OpenAIRE

    Husham T. Ibrahim; He Qiang; Wisaam S. Al-Rekabi

    2014-01-01

    The aim of present study was to design and construct an continuous up-flow pilot scale Moving Bed Biofilm Reactor (MBBR) which is consists of combined cylindrical Anoxic/Aerobic MBBR in nested form with anoxic/aerobic volume ratio equal to 0.16 to treated 4 m3 /days of domestic wastewater in Chongqing city at Southwest China. The treatment must be satisfactory to meet with grade B of discharge standard of pollutants for municipal wastewater treatment plant in China (GB/T18918-2002). Kaldnes (...

  12. Forest Fire Ecology.

    Science.gov (United States)

    Zucca, Carol; And Others

    1995-01-01

    Presents a model that integrates high school science with the needs of the local scientific community. Describes how a high school ecology class conducted scientific research in fire ecology that benefited the students and a state park forest ecologist. (MKR)

  13. Methodology and general ecology

    Czech Academy of Sciences Publication Activity Database

    Brandl, Zdeněk

    Vol. Chapter 1. Leiden : Backhuys Publishers, 2002 - (Fernando, C.), s. 1-21 ISBN 90-5782-117-6 Institutional research plan: CEZ:AV0Z6017912 Keywords : zooplankton * ecology * methods Subject RIV: EH - Ecology, Behaviour

  14. EcologicOther_ELT

    Data.gov (United States)

    Vermont Center for Geographic Information — The EcologicOther_ELT (Ecological Land Type) data layer was developed by the Green Mountain National Forest in the early 1980's from aerial photography. Using...

  15. Oxygen as Intermediate in Anoxic Environments: Nitrite-Dependent Methane Oxidation and Beyond

    Science.gov (United States)

    Ettwig, K. F.

    2014-12-01

    In recent years the known diversity of hydrocarbon activation mechanisms under anaerobic conditions has been extended by intra-aerobic denitrification, a process in which oxygen is derived from NO and used for substrate activation. For two phylogenetically unrelated bacterial species, the freshwater NC10 phylum bacterium Methylomirabilis oxyfera [1] and the marine γ-proteobacterial strain HdN1 [2] it has been shown that, under anoxic conditions with nitrate and/or nitrite, mono-oxygenases are used for methane and hexadecane oxidation, respectively. No degradation was observed with nitrous oxide (N2O) only. In the anaerobic methanotroph M. oxyfera, which lacks apparent nitrous oxide reductase in its genome, substrate activation in the presence of nitrite was directly associated with both O2 and N2 formation. These findings strongly argue for the role of nitric oxide (NO), or an oxygen species derived from it, in the activation reaction of methane. Although intracellular oxygen generation has been experimentally documented and elegantly explains the utilization of 'aerobic' pathways under anoxic conditions, research about the underlying molecular mechanism has just started. The proposed candidate enzymes for oxygen (or possibly another another reactive intermediate) production from NO, an NO dismutase (NOD) [3], related to quinol-dependent NO reductases (qNORs), is present and highly expressed in both M. oxyfera and strain HdN1. Besides that, several recently sequenced species from the Cytophaga-Flavobacterium-Bacteroides group harbor Nod/Nor genes, but experimential evidence is needed to show if these have NOD activity, are unusual but functional qNORs, or represent transition states between the two. Additionally, for several anaerobic hydrocarbon-degrading organisms the biochemical mechanism of substrate activation has not been elucidated yet: whereas signature genes of anaerobic degradation are missing, monooxygenase genes are present. Also these microorganisms

  16. Artificial mouth opening fosters anoxic conditions that kill small estuarine fish

    Science.gov (United States)

    Becker, Alistair; Laurenson, Laurie J. B.; Bishop, Kylie

    2009-05-01

    Fish kills are not uncommon within estuaries in many regions of the world. In seasonally open systems, which are common in temperate areas, they are often associated with mouth openings. Such a kill occurred in July 2005 in the Surrey Estuary following a closed mouth period of seven months resulting in the loss of many thousands of fish. At the time the fish community within the estuary was under investigation which provided comprehensive data of this population prior to the kill. Monthly water quality monitoring was also being conducted prior to the kill and also carried out on a daily basis following the mouth opening. The Surrey was stratified during the closed mouth phase, isolated waters below the halocline had stagnated and become anoxic. As a result only waters above the halocline contained oxygen concentrations capable of sustaining most fish. It appears that if a mouth opening happens under low flow conditions, a shearing effect occurs within the water column where surface waters flow out to sea leaving deeper waters behind. This resulted in only anoxic waters being present for in excess of six days and was responsible for the fish kill. Fish sampling of the Surrey Estuary was conducted three and six months following the kill and those data were compared to that collected in the 12 months prior to the event. Three months after the kill few fish were collected within the estuary and included marine opportunists near the mouth and estuarine resident species in the far upper reaches of the system. However six months following the kill large numbers of estuarine resident species were collected throughout the Surrey Estuary. As many species were euryhaline, it is believed that some individuals migrated into freshwater reaches of the Surrey to escape the anoxic conditions within the estuary. As conditions improved they recolonised the Surrey Estuary. The high fecundity and rapid growth of these small, short lived species probably aided in their re

  17. A2O工艺缺氧生物磷去除%Anoxic Biological Phosphorus Uptake in A2O Process

    Institute of Scientific and Technical Information of China (English)

    王晓莲; 王淑莹; 彭永臻

    2005-01-01

    A lab-scale anaerobic-anoxic-oxic (A2O) process used to treat a synthetic brewage wastewater was investigated. The objectives of the study were to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal and enhance the denitrifying phosphorus removal in A2O bioreactors. Sludge analysis confirmed that the average anoxic P uptake accounted for approximately 70% the total amount of P uptake, and the ratio of anoxic P uptake rate to aerobic P uptake rate was 69%. In addition, nitrate concentration in the anoxic phase and different organic substrate introduced into the anaerobic phase had significant effect on the anoxic P uptake. Compared with conventional A2O processes, good removal efficiencies of COD, phosphorus, ammonia and total nitrogen (92.3%, 95.5%, 96% and 79.5%, respectively) could be achieved in the anoxic P uptake system, and aeration energy consumption was saved 25%. By controlling the nitrate recirculation flow in the anoxic zone, anoxic P uptake could be enhanced, which solved the competition for organic substrates among poly-P organisms and denitrifiers successfully under the COD limiting conditions. Therefore, in wastewater treatment plants the control system should be applied according to the practical situation to optimize the operation.

  18. Quantification of ecological debt

    International Nuclear Information System (INIS)

    The discussion about ecological debt is important keeping in mind historical foreign trade, where natural resources exploitation and primary production exported didn't assessment the ecological damage or the environmental values of the interchange. This essay shows the debate of ecological debt on greenhouse emission, enterprise environmental debit, unequal international trade, toxic waste export, and bio piracy; in order to present the necessity of a new ecological and equitable world economy

  19. Ecological, Pedagogical, Public Rhetoric

    Science.gov (United States)

    Rivers, Nathaniel A.; Weber, Ryan P.

    2011-01-01

    Public rhetoric pedagogy can benefit from an ecological perspective that sees change as advocated not through a single document but through multiple mundane and monumental texts. This article summarizes various approaches to rhetorical ecology, offers an ecological read of the Montgomery bus boycotts, and concludes with pedagogical insights on a…

  20. Hydrothermal synthesis of oxygen functionalized S-P codoped g-C3N4 nanorods with outstanding visible light activity under anoxic conditions.

    Science.gov (United States)

    Hu, Shaozheng; Ma, Lin; Xie, Ying; Li, Fayun; Fan, Zhiping; Wang, Fei; Wang, Qiong; Wang, Yanjuan; Kang, Xiaoxue; Wu, Guang

    2015-12-28

    Extending the application of photocatalytic oxidation technology to the anoxic removal of organic pollutants that exist under some oxygen-free conditions is attractive but challenging. In this study, oxygen functionalized S-P codoped g-C3N4 nanorods with outstanding visible light activity under anoxic conditions are synthesized using a hydrothermal post-treatment. S and P codoping inhibits the crystal growth of graphitic carbon nitride, enhances the SBET, decreases the band gap energy, and increases the separation efficiency of photogenerated electrons and holes, which increases the anoxic photocatalytic RhB degradation constant by approximately 6.5 times. Oxygen functionalization not only increases the adsorption ability of graphitic carbon nitride but also captures the photogenerated electrons to produce photogenerated holes for RhB degradation under anoxic conditions, leading to a doubling of the RhB degradation constant. This study provides new insight into the design and fabrication of anoxic photocatalysts. PMID:26571403

  1. A study on provenance relation between Jiaotanxia ancient Guan porcelain and Qingliangsi ancient Ru porcelain by NAA

    International Nuclear Information System (INIS)

    11 samples of ancient Chinese Ru porcelain from Qingliangsi kiln, 23 samples of ancient Chinese Guan porcelain from Jiaotanxia kiln and 4 samples of modern archaized Guan porcelain were obtained to determine the contents of elements in each of them by neutron activation analysis (NAA). The NAA data were further analyzed using fuzzy cluster analysis to obtain the fuzzy cluster trend diagrams for the bodies' samples and the glazes samples respectively. The analysis shows that the raw material origins of the Jiaotanxia ancient Chinese Guan porcelain bodies samples are very concentrated; those of the Qingliangsi ancient Chinese Ru porcelain bodies samples are a little dispersed; those of ancient Chinese Guan porcelain glazes samples are relatively concentrated; those of ancient Chinese Ru porcelain glazes samples are dispersed; and the origins of the raw material of ancient Chinese Guan porcelain glazes samples are obviously different from those of ancient Chinese Ru porcelain glazes samples. The bodies samples and glazes samples of Jiaotanxia ancient Chinese Guan porcelain and those of Qingliangsi ancient Chinese Ru porcelain have some difference but can be compared with each other. (authors)

  2. Minding the Ecological Body: Neuropsychoanalysis and Ecopsychoanalysis

    Directory of Open Access Journals (Sweden)

    JosephDodds

    2013-03-01

    Full Text Available Neuropsychoanalysis explores experimentally and theoretically the philosophically ancient discussion of the relation of mind and body, and seems well placed to overcome the problem of a 'mindless' neuroscience and a 'brainless' psychology and psychotherapy, especially when combined with a greater awareness that the body itself, not only the brain, provides the material substrate for the emergent phenomenon we call mind. However, the mind-brain-body is itself situated within a complex ecological world, interacting with other mind-brain-bodies and the 'non-human environment'. This occurs both synchronically and diachronically as the organism and its environment (living and nonliving interact in highly complex often nonlinear ways. Psychoanalysis can do much to help unmask the anxieties, deficits, conflicts, phantasies and defences crucial in understanding the human dimension of the ecological crisis. Yet, psychoanalysis still largely remains not only a 'psychology without biology', which neuropsychoanalysis seeks to remedy, but also a 'psychology without ecology'. Ecopsychoanalysis (Dodds & Jordan 2012 is a new transdisciplinary approach drawing on a range of fields such as psychoanalysis, psychology, ecology, philosophy, science, complexity theory, aesthetics, and the humanities. It attempts to play with what each approach has to offer in the sense of a heterogeneous assemblage of ideas and processes, mirroring the interlocking complexity, chaos and turbulence of nature itself. By emphasizing the way the mind-brain-body studied by neuropsychoanalysis is embedded in wider social and ecological networks, ecopsychoanalysis can help open up the relevance of neuropsychoanalysis to wider fields of study, including those who are concerned with what E.O. Wilson (2003 called 'the future of life’.

  3. Microscopic and Spectroscopic Characterisation of Waterlogged Archaeological Softwood from Anoxic Environments

    DEFF Research Database (Denmark)

    Pedersen, Nanna Bjerregaard

    waterlogged sites and solely decayed by erosion bacteria to refine the understanding of the residual wood structure left after degradation. This was done not only to improve the ability to develop suitable and cost effective conservations treatments but also to improve the understanding of anaerobic decay...... mechanisms acting on plant biomass in waterlogged anoxic environment.Morphological analyses showed typical erosion bacteria decay patterns in the residual wood structure. Decay resistance of some cell types and cell wall compartments in preference to others is most likely explained not only by elevated...... lower than to levels higher than native S2 layer concentrations. The residual material showed strong depletion of carbohydrates. The chemical composition of the lignin in the residual material was similar to the sound waterlogged S2 layer. However, an initial size exclusion chromatography analysis...

  4. Integrative approach to delineate natural attenuation of chlorinated benzenes in anoxic aquifers.

    Science.gov (United States)

    Stelzer, Nicole; Imfeld, Gwenaël; Thullner, Martin; Lehmann, Jürgen; Poser, Alexander; Richnow, Hans-H; Nijenhuis, Ivonne

    2009-06-01

    Biodegradation of chlorobenzenes was assessed at an anoxic aquifer by combining hydrogeochemistry and stable isotope analyses. In situ microcosm analysis evidenced microbial assimilation of chlorobenzene (MCB) derived carbon and laboratory investigations asserted mineralization of MCB at low rates. Sequential dehalogenation of chlorinated benzenes may affect the isotope signature of single chlorobenzene species due to simultaneous depletion and enrichment of (13)C, which complicates the evaluation of degradation. Therefore, the compound-specific isotope analysis was interpreted based on an isotope balance. The enrichment of the cumulative isotope composition of all chlorobenzenes indicated in situ biodegradation. Additionally, the relationship between hydrogeochemistry and degradation activity was investigated by principal component analysis underlining variable hydrogeochemical conditions associated with degradation activity at the plume scale. Although the complexity of the field site did not allow straightforward assessment of natural attenuation processes, the application of an integrative approach appeared relevant to characterize the in situ biodegradation potential. PMID:19250727

  5. Reduction of Biological Sludge Production Applying an Alternating Oxic/anoxic Process in Water Line.

    Science.gov (United States)

    Eusebi, Anna Laura; Panigutti, Maximiliano; Battistoni, Paolo

    2016-06-01

    Alternating oxic/anoxic process, applied for the main objective of the improvement of nitrogen performances, was studied in terms of secondary effect of biomass reduction. The process was carried out in one real water resource recovery facility and the data were compared with the previous conventional period when a conventional process was adopted. The main mechanism of the process for the sludge minimization is recognized in the metabolic uncoupling. In fact, an increase of the specific oxygen uptake rate in the biological reactor was recorded stimulated by the change of the oxidation reduction potential environment. Moreover, the heterotrophic growth yield was measured equal to 0.385 kgVSS/kgCOD. The global percentage of reduction was tested with the mass balance of solids. The process is able to decrease the observed sludge yield up to 20%. The specific energy consumption was evaluated. PMID:27225780

  6. A Membrane De-Oxygenator for the Study of Anoxic Processes

    DEFF Research Database (Denmark)

    Arcangeli, Jean-Pierre; Arvin, Erik

    1995-01-01

    A membrane reactor for the elimination of oxygen in an anoxic medium for microbial growth has been studied. The reactor consists of a reservoir containing a solution of sulfite and cobalt salt where silicone tubing, through which the medium flows, is immersed. Silicone is highly permeable to gases......, so oxygen diffuses through the silicone membrane and is absorbed in the sulfite solution. The maximum oxygen removal rate was 1.1 g m−2 d−1 at 15°C. The advantage of this de-oxygenator is its low cost and the ease with which it can be handled. A calculation method is discussed in relation to the...... design of the membrane de-oxygenator....

  7. Determination of U oxidation state in anoxic (N2) aqueous solutions. Method development and testing

    International Nuclear Information System (INIS)

    The report describes the development and testing of a method for determining uranium oxidation state in aqueous solutions in inert (N2) atmosphere. The method included the separation of the tetravalent and hexavalent states by anion-exchange chromatography in HCl medium, followed by analysis of the uranium contents of each of the fractions by ICP-MS. The tests of the study demonstrated the suitability of the method for analysing the oxidation states of uranium at the low concentrations representative for U solubilities in anoxic groundwater. Additionally, the results obtained give some information on the redox state of the aqueous solutions in inert (N2) atmosphere. Obviously, the trace oxygen content in the atmosphere of the box is enough to cause slightly oxidizing conditions for uranium in the absence of reducing agents (e.g. H2, iron). (10 refs.)

  8. An Unusual Case of Asystole following Penetrating Neck Trauma and Anoxic Brain Injury

    Directory of Open Access Journals (Sweden)

    Matthew Nayor

    2011-01-01

    Full Text Available Bradycardia and transient asystole are well-described sequelae of a myriad of neurologic insults, ranging from focal to generalized injuries. Increased vagal tone also predisposes many individuals, particularly adolescents, to transient neurally mediated bradyarrhythmia. However, prolonged periods of sinus arrest without junctional or ventricular escape are quite rare, even after significant neurologic injury. We describe the case of a 17-year-old man who presented with anoxic brain injury secondary to hemorrhagic shock from a stab wound to the neck. His recovery was complicated by prolonged periods of sinus arrest and asystole, lasting over 60 seconds per episode. This case illustrates that sustained asystolic episodes may occur following significant neurologic injury, and may continue to recur even months after an initial insult. Pacemaker implantation for such patients should be strongly considered.

  9. Exposure of an anoxic and contaminated canal sediment: Mobility of metal(loid)s

    International Nuclear Information System (INIS)

    A derelict canal contains an estimated 9800 tonnes of anoxic sediment with highly elevated concentrations of trace elements. Lack of maintenance, reduced water levels and vegetation colonization threaten the stability of pollutants by removing existing waterlogged reduced conditions. A column leaching study of the sediment under increasingly oxidized conditions showed reductions in As mobility but increased heavy metal concentrations. In a reduced state, As mobility was higher (as a consequence of enhanced Fe and organic carbon solubility) whilst heavy metal concentrations in leachates were lower (due to markedly higher pH). Over 10 contiguous wetting and drying cycles, the consequences were profound; all trace elements were continuously leached with enhanced flushing of Fe, As, Zn and Cu. This raises concern over possible mobilization of pollutants to the wider environment, including groundwater. Options for management to stabilize contaminants are discussed that point to the importance of limiting water flow through the sediment. - Wetting and drying enhance contaminant mobility in an urban canal sediment.

  10. Ischemic-anoxic insults in children leading to iron accumulation in the basal ganglia: MR findings

    International Nuclear Information System (INIS)

    The MR imaging appearances of normal brain iron distribution and increased iron deposition in several degenerative disorders have been previously reported. The authors describe the MR imaging findings (0.3-T imaging system) in three children, aged 2-6 years, with previous ischemic-anoxic events and subsequent resuscitations. On T2- weighted images (repetition time/echo time [msec] = 2,000/84) areas of decreased signal intensity were seen that involved the basal ganglia (three patients) and adjacent white matter (two patients), consistent with iron deposition; areas of hyperintensity were seen in the periventricular and/or subcortical white matter. These findings suggest that abnormal levels of iron accumulate in the basal ganglia after peripheral ischemic damage

  11. Photocatalytic decomposition of humic acids in anoxic aqueous solutions producing hydrogen, oxygen and light hydrocarbons.

    Science.gov (United States)

    Klauson, Deniss; Budarnaja, Olga; Beltran, Ignacio Castellanos; Krichevskaya, Marina; Preis, Sergei

    2014-01-01

    Photocatalytic water splitting for hydrogen and oxygen production requires sacrificial electron donors, for example, organic compounds. Titanium dioxide catalysts doped with platinum, cobalt, tungsten, copper and iron were experimentally tested for the production of hydrogen, oxygen and low molecular weight hydrocarbons from aqueous solutions of humic substances (HS). Platinum-doped catalyst showed the best results in hydrogen generation, also producing methane, ethene and ethane, whereas the best oxygen production was exhibited by P25, followed by copper--and cobalt-containing photocatalysts. Iron-containing photocatalyst produced carbon monoxide as a major product. HS undergoing anoxic photocatalytic degradation produce hydrogen with minor hydrocarbons, and/or oxygen. It appears that better hydrogen yield is achieved when direct HS splitting takes place, as opposed to HS acting as electron donors for water splitting. PMID:25145176

  12. Methane production from bicarbonate and acetate in an anoxic marine sediment

    Science.gov (United States)

    Crill, P. M.; Martens, C. S.

    1986-01-01

    Methane production from C-14 labeled bicarbonate and acetate was measured over the top 28 cm of anoxic Cape Lookout Bight sediments during the summer of 1983. The depth distribution and magnitude of summed radioisotopically determined rates compare well with previous measurements of total methane production and the sediment-water methane flux. Methane production from CO2 reduction and acetate fermentation accounts for greater than 80 percent of the total production rate and sediment-water flux. Methane production from bicarbonate was found to occur in all depth intervals sampled except those in the top 2 cm, whereas significant methane production from acetate only occurred at depths below 10 cm where sulfate was exhausted. Acetate provided 20 to 29 percent of the measured methane production integrated over the top 30 cm of the sediments.

  13. Energetic Constraints on H-2-Dependent Terminal Electron Accepting Processes in Anoxic Environments

    DEFF Research Database (Denmark)

    Heimann, Axel Colin; Jakobsen, Rasmus; Blodau, C.

    2010-01-01

    Microbially mediated terminal electron accepting processes (TEAPs) to a large extent control the fate of redox reactive elements and associated reactions in anoxic soils, sediments, and aquifers. This review focuses on thermodynamic controls and regulation of H-2-dependent TEAPs, case studies...... and sulfate reduction are under direct thermodynamic control in soils and sediments and generally approach theoretical minimum energy thresholds. If H-2 concentrations are lowered by thermodynamically more potent TEAPs, these processes are inhibited. This principle is also valid for TEAPS providing more free...... energy, such as denitrification and arsenate reduction, but electron donor concentration cannot be lowered so that the processes reach theoretical energy thresholds. Thermodynamics and kinetics have been integrated by combining traditional descriptions of microbial kinetics with the equilibrium constant...

  14. Vasoactivity of hydrogen sulfide in normoxic and anoxic turtles (Trachemys scripta)

    DEFF Research Database (Denmark)

    Stecyk, Jonathan A.W.; Jensen, Nini Skovgaard; Nilsson, Göran E.;

    2010-01-01

    Systemic vascular resistance (Rsys) of freshwater turtles increases substantially during anoxia, but the underlying mechanisms are not fully understood. We investigated whether hydrogen sulfide (H2S), an endogenously produced metabolite believed to be an O2 sensor/transducer of vasomotor tone......, contributes to the increased Rsys of anoxic red-eared slider turtles (Trachemys scripta). Vascular infusion of the H2S donor NaHS in anesthetized turtles at 21°C and fully recovered normoxic turtles at 5°C and 21°C revealed H2S to be a potent vasoconstrictor of the systemic circulation. Likewise, wire...... myography of isolated turtle mesenteric and pulmonary arteries demonstrated H2S to mediate an anoxia-induced constriction. Intriguingly, however, NaHS did not exert vasoconstrictory effects during anoxia (6 h at 21°C; 14 days at 5°C) when plasma H2S concentration, estimated from the colorimetric measurement...

  15. Six years' practical experience with aerobic/anoxic deammonification in biofilm systems.

    Science.gov (United States)

    Hippen, A; Helmer, C; Kunst, S; Rosenwinkel, K H; Seyfried, C F

    2001-01-01

    Nitrogen elimination through autotrophic micro-organisms is currently in the focus of research projects on the treatment of wastewater with high nitrogen contents, for instance to be able to develop and fix dimensioning parameters for purposeful application. In fact, several industrial plants have already shown for some years that the steady operation of nitrogen elimination without carbon demand is possible. Due to the low growth rates of the participating micro-organisms, these processes can be found in particular in biofilm systems, which also allow for the simultaneous running of the two basic processes. In the following, we will discuss on the basis of the operation results of industrial and pilot-scale plants the operation stability of the aerobic/anoxic deammonification, and explain which experiences are available in particular for conversion in biofilm systems. PMID:11548011

  16. The carbon isotope biogeochemistry of methane production in anoxic sediments. 1: Field observations

    Science.gov (United States)

    Blair, Neal E.; Boehme, Susan E.; Carter, W. Dale, Jr.

    1993-01-01

    The natural abundance C-13/C-12 ratio of methane from anoxic marine and freshwater sediments in temperate climates varies seasonally. Carbon isotopic measurements of the methanogenic precursors, acetate and dissolved inorganic carbon, from the marine sediments of Cape Lookout Bight, North Carolina were used to determine the sources of the seasonal variations at that site. Movement of the methanogenic zone over an isotopic gradient within the dissolved CO2 pool appears to be the dominant control of the methane C-13/C-12 ratio from February to June. The onset of acetoclastic methane-production is a second important controlling process during mid-summer. An apparent temperature dependence on the fractionation factor for CO2-reduction may have a significant influence on the isotopic composition of methane throughout the year.

  17. Design and development of an ancient Chinese document recognition system

    Science.gov (United States)

    Peng, Liangrui; Xiu, Pingping; Ding, Xiaoqing

    2003-12-01

    The digitization of ancient Chinese documents presents new challenges to OCR (Optical Character Recognition) research field due to the large character set of ancient Chinese characters, variant font types, and versatile document layout styles, as these documents are historical reflections to the thousands of years of Chinese civilization. After analyzing the general characteristics of ancient Chinese documents, we present a solution for recognition of ancient Chinese documents with regular font-types and layout-styles. Based on the previous work on multilingual OCR in TH-OCR system, we focus on the design and development of two key technologies which include character recognition and page segmentation. Experimental results show that the developed character recognition kernel of 19,635 Chinese characters outperforms our original traditional Chinese recognition kernel; Benchmarked test on printed ancient Chinese books proves that the proposed system is effective for regular ancient Chinese documents.

  18. Role of soil geochemical and microbiological components on selenium behaviour in oxic and anoxic conditions

    International Nuclear Information System (INIS)

    Selenium (Se) is naturally present in the environment. Se is essential for living organisms at trace concentrations, but it becomes rapidly toxic with their increases. The 79Se radioactive isotopes of Se, is found in nuclear wastes that may be buried in deep geological formations. In soil, Se exists in many forms and its mobility is affected by the redox potential and microbial activity. Very few studies have focused on Se behaviour at trace concentration. We have tried to distinguish the major abiotic geochemical and microbiological processes involved in the fate of trace selenite (Se(IV)) in a soil. The study was based on batch incubation in oxic or anoxic conditions of slurry suspension artificially contaminated with Se (IV) to 0.4 mg Se.kg-1 dry soil. The incubation involved sterilized and non-sterile soil samples with or without organic amendment to stimulate microbial activities. For each incubation, we followed the distribution of Se between solid, liquid and gaseous phases as well as the geochemical evolution of the solution, the composition of the atmosphere gas bottles and the soil microflora. The results showed that Se was relatively few mobile in the soil studied. Geochemical processes played a major role in controlling the Se mobility. Over time, some abiotic transformations in the solid phase contributed to increase the Se immobilisation. The microbiological processes contributed to this increase in the solid phase. Moreover, in oxic as in anoxic conditions, some microbial processes were responsible, to a lesser extent, for a dispersion of Se in the atmosphere by the production of volatile compounds. (author)

  19. Effect of Cretaceous oceanic anoxic events on the evolutionary trend of planktonic foraminifera

    Science.gov (United States)

    Kuroyanagi, A.; Ozaki, K.; Kawahata, H.

    2014-12-01

    It is widely thought that oceanic redox state is essential for the evolutionary history of life on the earth, and "anoxic events" have been proposed as one of the causal mechanisms for mass extinctions. During mid-Cretaceous, widely known as the extremely warm period, oceanic anoxic events (OAEs) occurred several times and they would have caused a substantial impact on the biosphere. Planktonic foraminifera are marine planktons with calcite tests and their productions constitute ~30-80% of the modern deep-marine calcite budget, thus they play an important role in the global carbon cycle. Previous study reported that planktonic foraminifera displayed the high turnover (extinction and speciation) rate at or near the major OAEs. However, the impact of Cretaceous OAEs on the evolutionary trend of planktonic foraminifera remains obscure. In this study, we investigated the role of spatiotemporal extent of anoxia on the evolutionary trend of planktonic foraminifera by assessing the extinction/speciation rate of planktonic foraminifera around Cretaceous OAEs. The number of foraminiferal species increased across the OAE1a and then showed a peak after this episode. Around OAE2, several planktonic foraminifera species became extinct and several speciated, however, long-term trends in foraminiferal evolution showed no drastic changes near the event. Therefore these results suggest that the ocean surface environment at OAEs would not have a direct effect on foraminiferal extinction/speciation. This interpretation is reinforced when considering the recent culturing results, which demonstrate that modern planktonic foraminifera have a high tolerance to extremely low dissolved oxygen levels than expected. Accumulating geochemical data also suggest a spatial heterogeneity of oceanic anoxia/euxinia during OAE2. These results lead us to conclude that Cretaceous OAEs would not directly related to planktonic foraminiferal extinction due to regional distribution of anoxia/euxinia.

  20. Experimental Study on Anoxic/Oxic Bioreactor and Constructed Wetland for Rural Domestic Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    John Leju Celestino Ladu

    2014-01-01

    Full Text Available This study examined the removal of nutrients from the domestic wastewater through the application of integrated anoxic/oxic (A/O bio-reactor and constructed wetland system. Influent and effluent samples were collected from the system and experimented for Chemical Oxygen Demand (COD, NH4+-N, NO3--N and TP in the laboratory. Different Hydraulic Retention Time (HRT and recycle ratios were applied in the reactor to evaluate their influence on removal efficiency of nutrients. The temperature was controlled between 20 to 24°C and pH ranges was 7.6-8.1. The result revealed average COD removal efficiencies of 47, 68, 74, 83 and 85% at HRT of 1.5, 4, 2, 3 and 5 h. The average removal of NH4+-N was 60.3, 63.0, 64.4, 71 and 91.8 % operated with HRT of 2, 3, 5, 1.5 and 4 h, respectively. The average removal of NO3- -N was 92, 94, 95 and 97% run with HRT of 2, 1.5, 3, 5 and 4 h, respectively. The average removal of TP was 78, 85, 88 and 89% operated with HRT of 5, 3, 2 and 1 h. This system removed up to 74.1, 94.4 and 85% of NH4+-N, NO3- -N and TP with proper pH control using external source of alkalinity. The result showed the optimum recycle ratio of 3. The results obtained attest that, the integrated anoxic/oxic bioreactor and constructed wetland is feasible and efficient for wastewater treatment.

  1. Timing and evolution of ocean anoxic event during Early Cambrian in south China

    Science.gov (United States)

    Yang, J.; Jiang, S.; Pi, D.; Ling, H.

    2008-12-01

    The Precambrian/Cambrian (PC-C) interval is one of the most interesting intervals in the evolution of life because of the sudden diversification of animals with mineralized skeletons, known as "Cambrian Explosion". The Yangtze Platform in south China is one of the best occurrences that can provide excellent insights into the palaeo-environmental and biological changes across the PC-C boundary. Our study show that the ocean anoxia were widespread during the Early Cambrian period, however, the start of this anoxic event was not from the PC-C boundary (i.e., 542 Ma), but some 7 Ma later (~535 Ma) when the Niutitang Formation black rock series (black phosphorite, chert, and black shale) deposited along a thousand kilometer long NEE zone in the transitional facies in the Yangtze Platform, while the major Cambrian radiation (Changjiang fauna) took place during 521-511 Ma. During the Niutitang period, the depositional environment of the Early Cambrian sedimentary sequence in south China have evolved from an initial oxic/dysoxic to a major anoxic/euxinic environment, and then back to dysoxic/oxic environment. A Ni-Mo sulfide layer occurred in the lower part of the Niutitang black shales which contains extremely enrichments of many metals, and can serve as a marker layer in south China when the depositional environment turned into euxinic condition. Re-Os isotope study of the sulfide ores and host black shales show an age of 535 Ma. Initial Os isotopic compositions, Mo isotopic compositions, and rare earth elements and Pt group element geochemistry suggest involvement of submarine hydrothermal fluids during the metal enrichments in black shale.

  2. Biological Phosphorus Release and Uptake Under Alternating Anaerobic and Anoxic Conditions In a Fixed-Film Reactor

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens; Strube, Rune

    1994-01-01

    Biological phosphorus removal was investigated in a fixed-film reactor with alternating anaerobic and anoxic conditions. The tests showed that biological phosphorus removal can be obtained in a fixed-film reactor with nitrate as oxidising agent. In the anaerobic period, 0.52 mg of PO4-P was...

  3. Simultaneous organic carbon and nitrogen removal in an anoxic-oxic activated sludge system under various operating conditions.

    Science.gov (United States)

    Rasool, Kashif; Ahn, Dae Hee; Lee, Dae Sung

    2014-06-01

    This study investigated a bench-scale anoxic-oxic activated sludge system for integrated removal of COD and nitrogen. The experimental unit includes four chambers and continuous feeding in first chamber without recycle of nitrified liquid from aerobic to anoxic chamber unlike the conventional anoxic-oxic process. Recycled excessive sludge was used for the purpose of recycling nitrified mixed liquor. Synthetic wastewater with average loading rates of 0.53 kg COD/m(3)/d and 0.067 kg NH4(+)-N/m(3)/d was fed to the reactor system at hydraulic residence times (HRT) of 24 and 18 h. The results of 100 days operation showed high removal efficiencies of organic matter of about 97% as total COD and more than 99% removal of ammonia-nitrogen. In anoxic-oxic operation phase, total inorganic nitrogen (TIN) removal was about 66% by pre-denitrification. Moreover, the solid liquid separation through final clarifier was excellent without any suspended solid in the effluent. PMID:24768910

  4. Transport and removal of viruses in saturated sand columns under oxic and anoxic conditions--Potential implications for groundwater protection.

    Science.gov (United States)

    Frohnert, Anne; Apelt, Susann; Klitzke, Sondra; Chorus, Ingrid; Szewzyk, Regine; Selinka, Hans-Christoph

    2014-11-01

    To protect groundwater as a drinking water resource from microbiological contamination, protection zones are installed. While travelling through these zones, concentrations of potential pathogens should decline to levels that pose no risks to human health. Removal of viruses during subsurface passage is influenced by physicochemical conditions, such as oxygen concentration, which also affects virus survival. The aim of our study was to evaluate the effect of redox conditions on the removal of viruses during sand filtration. Experiments in glass columns filled with medium-grained sand were conducted to investigate virus removal in the presence and absence of dissolved oxygen. Bacteriophages MS2 and PhiX174, as surrogates for human enteric viruses were spiked in pulsed or in continuous mode and pumped through the columns at a filter velocity of about 1m/d. Virus breakthrough curves were analyzed by calculating total viral elimination and fitted using one-dimensional transport models (CXTFIT and HYDRUS-1D). While short-term experiments with pulsed virus application showed only small differences with regard to virus removal under oxic and anoxic conditions, a long-term experiment with continuous dosing revealed a clearly lower elimination of viruses under anoxic conditions. These findings suggest that less inactivation and less adsorption of viruses in anoxic environments affect their removal. Therefore, in risk assessment studies aimed to secure drinking water resources from viral contamination and optimization of protection zones, the oxic and anoxic conditions in the subsurface should also be considered. PMID:25024100

  5. Application of nitrate to enhance biodegradation of gasoline components in soil by indigenous microorganisms under anoxic condition.

    Science.gov (United States)

    Yang, Su-Cai; Song, Yun; Wang, Dong; Wei, Wen-Xia; Yang, Yan; Men, Bin; Li, Jia-Bin

    2016-01-01

    Anaerobic/anoxic biodegradation of hydrocarbons offers an attractive approach to the removal of these compounds from polluted environments such as aquifers, aquatic sediments, submerged soils and subsurface soils. The application of nitrate was investigated to accelerate the degradation of gasoline components such as mono-aromatic hydrocarbons and total petroleum hydrocarbons (TPH) in soil by indigenous microorganisms under anoxic condition. The addition of nitrate had little effect on the degradation of mono-aromatic hydrocarbons m- & p-xylene, o-xylene, sec-butylbenzene and 1,2,4-trimethylbenzene, but facilitated the degradation of TPH (C6-C12) and mono-aromatic hydrocarbons toluene and ethylbenzene markedly. Furthermore, the more nitrate added, the higher the percentage of toluene, ethylbenzene and TPH (C6-C12) degraded after 180 days of anoxic incubation. Microorganisms capable of degrading toluene, ethylbenzene and TPH (C6-C12) with nitrate as the electron acceptor under anaerobic/anoxic condition are composed predominantly of Alpha-, Beta-, Gamma- or Delta-proteobacteria. Beta- and Gamma-proteobacteria were the main components of indigenous microorganisms, and accounted for 83-100% of the total amount of indigenous microorganisms in soil used in this study. Furthermore, the total amount of indigenous microorganisms increased with nitrate added. The addition of nitrate stimulated the growth of indigenous microorganisms, and therefore facilitated the degradation of toluene, ethylbenzene and TPH (C6-C12). PMID:26508265

  6. Genome sequence of Halorhabdus tiamatea, the first archaeon isolated from a deep-sea anoxic brine lake.

    KAUST Repository

    Antunes, Andre

    2011-09-01

    We present the draft genome of Halorhabdus tiamatea, the first member of the Archaea ever isolated from a deep-sea anoxic brine. Genome comparison with Halorhabdus utahensis revealed some striking differences, including a marked increase in genes associated with transmembrane transport and putative genes for a trehalose synthase and a lactate dehydrogenase.

  7. Sorption and diffusion of radionuclides (C, Tc, U, Pu, Np) in rock samples under oxic and anoxic conditions

    International Nuclear Information System (INIS)

    Interactions of redox sensitive elements with common Finnish rocks were studied in the laboratory under oxic and anoxic conditions. Sorption and diffusion of technetium, uranium, plutonium and neptunium were studied in drill cores of granites and gneiss. Also carbon was studied under oxic conditions. Cylindrical drill core cup samples and plane surfaces sawed from drill cores were exposed for periods from six to eighteen months to synthetic ground water to which Tc-99, U-233, Pu-236, Np-237 or C-14 as H14CO3- had been added. Synthetic granitic ground water was used in all experiments. In comparative studies for uranium also carbonate rich synthetic bentonite water was used under anoxic conditions. Technetium, uranium and neptunium were transported effectively under both oxic and anoxic conditions. Transported species of these elements were found throughout the rock matrices investigated. The measured apparent diffusivities for neptinium under oxic conditions were 2.7 x 1014- m2/S for tonalite and 3.0 x 10-13 m2/S for rapakivi granite. The range of Da-values for neptunium under anoxic conditions was (1.4-9.6) x 10-14 m2/S. For uranium the range of Da-values under oxic conditions was (3.6-5.7) x 10-14 m2/S; under anoxic conditions it was (1.1-4.3) x 10-14 m2/S in granite ground water and (1.8-5.3) x 10-14 m2/S in bentonite water. The ranges of measured Da-values for technetium varied 1.8x10-15-2.3x10-13 m2/S under oxic conditions and 2.3x10-15-2.3x10-14 m2/S under anoxic conditions. The migration of plutonium was slow in all samples. The range of measured apparent diffusivities of plutonium under oxic conditions was from 2.7x10-15 to 2.4x10-14 m2/S. Under anoxic conditions the measured Da-values were 2.7x10-15 m2/S for rapakivi granite and 3.5x10-15 m2/S for tonalite

  8. Improving access to endogenous DNA in ancient bones and teeth

    OpenAIRE

    Damgaard, Peter B.; Ashot Margaryan; Hannes Schroeder; Ludovic Orlando; Eske Willerslev; Allentoft, Morten E.

    2015-01-01

    Poor DNA preservation is the most limiting factor in ancient genomic research. In the majority of ancient bones and teeth, endogenous DNA molecules represent a minor fraction of the whole DNA extract, rendering shot-gun sequencing inefficient for obtaining genomic data. Based on ancient human bone samples from temperate and tropical environments, we show that an EDTA-based enzymatic ‘pre-digestion’ of powdered bone increases the proportion of endogenous DNA several fold. By performing the pre...

  9. Advances in structural mechanics of Chinese ancient architectures

    Institute of Scientific and Technical Information of China (English)

    Maohong YU; Yoshiya ODA; Dongping FANG; Junhai ZHAO

    2008-01-01

    Chinese ancient architectures are valuable heritage of ancient culture of China. Many historical building have been preserved up to now. The researches on the structural mechanics of ancient architectures show the different aspects of structure and mechanics. Systematical studies on the structural mechanics of ancient architectures have been carried out at Xi'an Jiaotong University since 1982. It is related with the need of repair of some national preservation relics in Xi'an. These studies include: 1) Ancient wooden structures including three national preservation relics Arrow Tower at North City Gate, City Tower at East City Gate, and Baogao Temple in Ningbao, Zhejiang province. 2) Ancient tall masonry building, the Big Goose Pagoda and Small Goose Pagoda in Xi'an. 3) Mechanical characteristics of ancient soil under foundation and city wall; the influence of caves in and under the ancient City Wall on the stability of the wall. 4) The typical Chinese ancient building at the center of city: the Bell Tower and Drum tower. 5) The behavior of Dou-Gong and Joggle joint of Chinese ancient wooden structure. 6) The mechanical behavior of ancient soils under complex stress state. A new systematical strength theory, the unified strength theory, is used to analyze the stability of ancient city wall in Xi'an and foundation of tall pagoda built in Tang dynasty. These researches also concern differential settlements of Arrow Tower and resistance to earthquake of these historical architecture heritages. Some other studies are also introduced. This paper gives a summary of these researches. Preservation and research are nowadays an essential requirement for the famous monuments, buildings, towers and others. Our society is more and more conscious of this necessity, which involves increasing activities of restoration, and then sometimes also of repair, mechanical strengthening and seismic retrofitting. Many historical buildings have in fact problems of structural strength and

  10. Piracy in the Ancient World: from Minos to Mohammed

    OpenAIRE

    P.C. de Souza

    1992-01-01

    This thesis is an historical analysis of the phenomenon of piracy in the ancient world from the Bronze Age to the Arab conquests. It is based on detailed examination and discussion of the ancient sources. There is a short introduction (Part One) which establishes the scope of the enquiry, defines the subject and surveys modern scholarly literature. Part Two (The Image of Ancient Piracy) consists of a study of the Greek and Latin vocabulary for piracy, and six separate studie...

  11. Unriddling of ancient-medieval culture by PIXE

    International Nuclear Information System (INIS)

    Some examples are given for unriddling of ancient-medieval culture by PIXE. Effectiveness of PIXE to analyze art and archaeological objects is also explained. Objects employed here are 1) red, yellow, blue and white pigments painted on sun-dried bricks excavated in Egypt, 2) ancient glass beads used in the Near East, 3) South American mummy hair, 4) ancient slag excavated from Kansai-district, Japan 5) ink used by Galileo Galilei and 6) Renaissance style enameled gold jewelry. (author)

  12. Connecting Philosophy of Ancient Egyptians to Modern Thinking

    OpenAIRE

    Aminuddin Hassan; Nurul A.A.K. Anuar; Norhasni Z. Abiddin

    2012-01-01

    Problem statement: Associating any knowledge from ancient Egyptians to modern civilization and thinking was important and had its own value. The process of understanding knowledge related to ancient Egyptians is actually based on the nature of philosophical thought. Approach: In the discussion of ancient Egypt philosophy, it is important to look at it from the perspectives of the four branches of philosophy; metaphysics, epistemology, axiology and logic. Metaphysics has two elements, which ar...

  13. Study on Prohibitions of Ancient Chinese Costumes in Black Series

    OpenAIRE

    Xiaomeng Qu

    2013-01-01

    China is a historical country with extensive and profound civilization, in which the Chinese Costume has always been a brilliant feature. Black series occupies an important position in the color institution of ancient Chinese Costumes. The prohibition on black series costumes also has a significant meaning in ancient China. By discussing prohibitions related to black series in ancient Chinese costume institution, this paper studied two typical colors used by people of different classes as the...

  14. Geography, Writing System and History of Ancient Civilizations

    OpenAIRE

    Mo, Pak-Hung

    2013-01-01

    We find an undiscovered effect of geography on the choices of writing system in ancient civilizations that in turn drive their courses of historical evolution. The fates of the ancient civilizations were predetermined by the causation spirals generated by the writing system chosen by their ancient ancestors. Understanding the mechanism can enlighten our present political choices that in turn determine the future course of humankind evolution. It can also inspire us about the clue to build an ...

  15. Re-discovering ancient wheat varieties as functional foods

    OpenAIRE

    Cooper, Raymond

    2015-01-01

    With the gluten-free food market worth almost $1.6 bn in 2011, there is every reason for renewed interest in ancient grains. This resurgent interest is expressed in re-discovering ancient varieties as functional foods. In particular, people affected by celiac disease have to avoid all gluten in their diet and several ancient grains may offer an important alternative.

  16. Philosophy of ecology

    CERN Document Server

    Brown, Bryson; Peacock, Kent A

    2011-01-01

    The most pressing problems facing humanity today - over-population, energy shortages, climate change, soil erosion, species extinctions, the risk of epidemic disease, the threat of warfare that could destroy all the hard-won gains of civilization, and even the recent fibrillations of the stock market - are all ecological or have a large ecological component. in this volume philosophers turn their attention to understanding the science of ecology and its huge implications for the human project. To get the application of ecology to policy or other practical concerns right, humanity needs a clear and disinterested philosophical understanding of ecology which can help identify the practical lessons of science. Conversely, the urgent practical demands humanity faces today cannot help but direct scientific and philosophical investigation toward the basis of those ecological challenges that threaten human survival. This book will help to fuel the timely renaissance of interest in philosophy of ecology that is now oc...

  17. Ancient iron and lead isotope analysis

    International Nuclear Information System (INIS)

    Full text: Little work has been published to date on the subject of lead isotope analysis of ancient iron artefacts. That which has suffers from a lack of understanding of the nature of ancient iron, and of the behavior of lead in relation to iron oxides. This paper examines data from a lead isotope study of 12th-10th Century B.C.E. iron artefacts from Israel and Palestine, and iron ores from these and surrounding areas, focusing on the issues of iron corrosion and lead contamination. The data shows that experimentally produced bloomery iron contains very little lead (less than O. 1 ppm), with most lead in the ore being reduced in the smelting process and lost to the slag. This low quantity of lead raises the question of contamination in samples which have been corroding whilst buried, in this case, for 3000 years. It is proposed that useful lead isotope data may be obtained where analysis of hydrated iron oxides in particular is avoided, as they commonly make up the outer layers of recovered ancient iron objects, formed in direct association with surrounding soil and rock. Lead contamination of these porous oxides- is a constantly observed feature of the material, and the affinity of lead for such oxides is well documented. Where there exists uncorroded iron (a rare event), or where there exists a core of magnetite beneath the outer hydrated oxide layers, it may be possible to obtain useful lead isotope data, which reflect the isotopic composition of the metal as it emerged from the furnace in antiquity. A magnetic separation process and washing in cold 7M HCl are proposed as means of removing contaminated hydrated iron oxides from this more useful material in the laboratory, prior to lead isotope analysis

  18. CASE REPORT: Giant Retroperitoneal Presacral Ancient Schwannoma

    Directory of Open Access Journals (Sweden)

    Al-Jiffry, B.O1, 2; Othman,B.S2; Hatem, M1

    2013-01-01

    Full Text Available Summary: Ancient schwannoma, is a rare variant of schwannoma with characterization of degenerative changes and diffuse hypercellularity. Retroperitoneal presacral form is often found incidentally, because they present with vague symptoms or symptomless. Schwannoma occurring in this area occasionally presents with enormous dimensions, known as a giant schwannoma. The tumor removal is a surgical challenge due to the difficult approach and abundant vascularity. In this report we describe a 61 –year old female presented to ER with vaginal bleeding and lower abdominal pain. The case diagnosed on clinical, CT and MRI findings to be a fibroma of the left ovary. Exploration by the gynecology team revealed a huge retroperitoneal presacral tumor compressing the left external iliac vessels and displacing the left ureter; they took a biopsy and closed the abdomen. Histopathological result was benign schwannoma. The patient were referred to our hospital (Al Hada Armed Forces Hospital, Taif, Saudi Arabia to be managed from postoperative DVT when her family asked our department of surgery for further management and signed a high risk consent. We explored the case after insertion of IVC filter and ureteric catheter. A 20x20 cm mass was thoroughly dissected and resected with part of sacrum. The final histopathological result was benign nerve sheath tumor with features consistent with degenerated (ancient schwannoma and the tumor was completely resected. The patient was discharged from the hospital without complications and follow up for three years revealed no recurrence. The clinical, radiological, and pathological features of this disease are discussed in this report. To conclude, retroperitoneal giant ancient schwannomas are a rare variant of the benign schwannoma and often present as unrecognized slow growing masses. Keep in mind potentially severe bleeding and neurological deficit risk of surgical intervention without away from oncologic principle

  19. Simultaneous Organics and Nutrients Removal from Domestic Wastewater in a Combined Cylindrical Anoxic/Aerobic Moving Bed Biofilm Reactor

    Directory of Open Access Journals (Sweden)

    Husham T. Ibrahim

    2014-03-01

    Full Text Available The aim of present study was to design and construct an continuous up-flow pilot scale Moving Bed Biofilm Reactor (MBBR which is consists of combined cylindrical Anoxic/Aerobic MBBR in nested form with anoxic/aerobic volume ratio equal to 0.16 to treated 4 m3 /days of domestic wastewater in Chongqing city at Southwest China. The treatment must be satisfactory to meet with grade B of discharge standard of pollutants for municipal wastewater treatment plant in China (GB/T18918-2002. Kaldnes (K1 media was used as a carrier in both reactors at a media fill ratio equal to 50%. The reactors was operated under the Anoxic/Oxic (An/O process which must meet stringent TN limits without sludge returning into the system and only an internal recycling was performed from aerobic to anoxic reactor. After developing the biofilm on the media, reactor was operated at 3 different Hydraulic Residence Time (HRT ranging from 4.95 to 8.25 h. During operation the internal recycle ratio to eliminate nitrogen compounds were 100% of inflow rate and the average Dissolved Oxygen concentration (DO in aerobic and anoxic MBBRs were 4.49 and 0.16 mg/L, respectively. The obtained results showed that the HRT of 6.2 h was suitable for simultaneous removal of COD, NH4+-N, TN and TP. In this HRT the average removal efficiencies were 93.15, 98.06, 71.67 and 90.88% for COD, NH4+-N, TN and TP, respectively.

  20. Conserved intron positions in ancient protein modules

    Directory of Open Access Journals (Sweden)

    de Roos Albert DG

    2007-02-01

    Full Text Available Abstract Background The timing of the origin of introns is of crucial importance for an understanding of early genome architecture. The Exon theory of genes proposed a role for introns in the formation of multi-exon proteins by exon shuffling and predicts the presence of conserved splice sites in ancient genes. In this study, large-scale analysis of potential conserved splice sites was performed using an intron-exon database (ExInt derived from GenBank. Results A set of conserved intron positions was found by matching identical splice sites sequences from distantly-related eukaryotic kingdoms. Most amino acid sequences with conserved introns were homologous to consensus sequences of functional domains from conserved proteins including kinases, phosphatases, small GTPases, transporters and matrix proteins. These included ancient proteins that originated before the eukaryote-prokaryote split, for instance the catalytic domain of protein phosphatase 2A where a total of eleven conserved introns were found. Using an experimental setup in which the relation between a splice site and the ancientness of its surrounding sequence could be studied, it was found that the presence of an intron was positively correlated to the ancientness of its surrounding sequence. Intron phase conservation was linked to the conservation of the gene sequence and not to the splice site sequence itself. However, no apparent differences in phase distribution were found between introns in conserved versus non-conserved sequences. Conclusion The data confirm an origin of introns deep in the eukaryotic branch and is in concordance with the presence of introns in the first functional protein modules in an 'Exon theory of genes' scenario. A model is proposed in which shuffling of primordial short exonic sequences led to the formation of the first functional protein modules, in line with hypotheses that see the formation of introns integral to the origins of genome evolution

  1. On Borders: From Ancient to Postmodern Times

    Science.gov (United States)

    Bellezza, G.

    2013-11-01

    The article deals with the evolution of the concept of borders between human groups and with its slow evolution from the initial no men's land zones to the ideal single-dimension linear borders. In ancient times the first borders were natural, such as mountain ranges or large rivers until, with the development of Geodesy, astronomical borders based on meridians and parallels became a favourite natural base. Actually, Modern States adopted these to fix limits in unknown conquered territories. The postmodern thought led give more importance to cultural borders until, in the most recent times, is becoming rather impossible to fix borders in the virtual cyberspace.

  2. Human Nature Evil in Ancient Western Literature

    Institute of Scientific and Technical Information of China (English)

    张茜

    2015-01-01

    Whether man is good or evil by nature is a constant topic tophilosophers and writers. Is a man born virtuous or evil? What onearth is human nature? Is the origin of human nature kind or wicked?People have been debating over this topic for centuries. Theseseemingly simple questions have perplexed those Great Minds forthousands of years in European countries and are the constant themesof literary works as well. The problem of human nature is the deepestof the issues regarding human beings which have long been underdiscussion since ancient time.

  3. The Charm of An Ancient Southern City

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    AN artistic narrow bridge winds into a place of pavilions, terraces and open halls, all under the pleasant shade of green trees. This is Mist-Water Pavilion Park in Gantang Lake in the city of Jiujiang, Jiangxi Province. When you stand here in the quiet and elegant historic garden and look out over the water on all four sides, you can’t help but think of the ancient war that took place on this very spot 1,700 years ago. During the Three Kingdoms Period (220-280), this was

  4. Buried Alive: Microbes from Ancient Halite.

    Science.gov (United States)

    Jaakkola, Salla T; Ravantti, Janne J; Oksanen, Hanna M; Bamford, Dennis H

    2016-02-01

    Halite is one of the most extreme environments to support life. From the drought of the Atacama Desert to salt deposits up to Permian in age and 2000 meters in burial depth, live microbes have been found. Because halite is geologically stable and impermeable to ground water, the microbes allegedly have a syndepositional origin, making them the oldest organisms known to live on Earth. Recently, our understanding of the microbial diversity inside halite has broadened, and the first genome sequences of ancient halite-buried microbes are now available. The secrets behind prolonged survival in salt are also starting to be revealed. PMID:26796472

  5. Ancient Egypt, Sacred Science, and Transatlantic Romanticism

    OpenAIRE

    Redd, Marques Jerard

    2011-01-01

    Ancient Egyptian culture has been a powerful influence on a major tradition of English literature that runs from Edmund Spenser's The Faerie Queene (1596), one of whose major iconographic centers is the temple of Isis, to John Crowley's four-volume novel Ægypt (2007). My dissertation focuses on the Romantic period - the midpoint of this trajectory - because it is an extremely intense moment of this influence. In addition to the visions of Egypt presented in the Bible, Greco-Roman writers, a...

  6. PIXE analysis of ancient Chinese Changsha porcelain

    Energy Technology Data Exchange (ETDEWEB)

    Lin, E.K.; Yu, Y.C.; Wang, C.W.; Liu, T.Y.; Wu, C.M.; Chen, K.M.; Lin, S.S

    1999-04-02

    In this work, proton induced X-ray emission (PIXE) method was applied for the analysis of ancient Chinese Changsha porcelain produced in the Tang dynasty (AD 618-907). A collection of glazed potsherds was obtained in the complex of the famous kiln site at Tongguan, Changsha city, Hunan province. Studies of elemental composition were carried out on ten selected Changsha potsherds. Minor and trace elements such as Ti, Mn, Fe, Co, Cu, Rb, Sr, and Zr in the material of the porcelain glaze were determined. Variation of these elements from sample to sample was investigated. Details of results are presented and discussed.

  7. The Ancient Maya Landscape from Space

    Science.gov (United States)

    Sever, T.; Arnold, James E. (Technical Monitor)

    1999-01-01

    The Peten, once inhabited by a population of several million before the collapse of the ancient Maya in the 10th and 11th centuries, is being repopulated toward its former demographic peak. Environmental dynamics, however, impose severe constraints to further development. Current practices in subsistence, commercial agriculture, and cattle raising are causing rapid deforestation resulting in the destruction of environmental and archeological resources. The use of remote sensing and Geographic Information Systems (GIS) technology is a cost-effective methodology for addressing issues in Maya archeology as well as monitoring the environmental impacts being experienced by the current population.

  8. An ancient greek pain remedy for athletes

    DEFF Research Database (Denmark)

    Bartels, Else M.; Swaddling, Judith; Harrison, Adrian Paul

    2006-01-01

    While Hippocratic writings make no reference to the actual Olympics, there is frequent mention of diet, exercise, and the treatment of injuries sustained by the athletic participants. Indeed, Galen in his Composition of Medicines gives details of a remedy prescribed for the relief of pains and...... swellings, which was reserved for use by the winners of Olympic events, the so-called "Fuscum Olympionico inscriptum"-(ointment) entitled "dark Olympic victor's". In a time when the Olympic games have recently returned to their homeland, we examine the potential efficacy of this ancient remedy in terms of...

  9. Food, dietetics and nutrition in ancient India.

    Science.gov (United States)

    Manyam, B V

    1995-01-01

    In pre-agricultural era, entire mankind consumed meat as early man was a hunter. Possibly he ate from plants sources which grew in the wilderness. With the advent of agriculture as an outcome of civilization, man acquired the ability to cultivate what he wanted, as by now he was influenced to some extent by the selection of the food that he wanted to eat. All this ultimately led to him taking to vegeterianism, which probably did not occur until approximately 1500 B.C. It is tried in this study to examine the concept of nutrition, balanced diet, appetite, food etiquette, food sanitation and food poisoning etc. in ancient India. PMID:11618846

  10. Study of ancient pottery from Slovakia

    International Nuclear Information System (INIS)

    Ancient pottery samples collected from south-west Slovakia were studied through subjective observation and by Moessbauer spectroscopy. This method is convenient for determining the provenance and the manufacture of pottery. Transformations, induced by firing the clay and characterized by Moessbauer spectroscopy, give valuable information regarding the manufacture as, for instance, the final temperature of firing in it. The relative abundance of Fe2+ and Fe3+ determines the atmosphere used to fire a pottery. It has been found that the determination of the firing atmosphere obtained through the subjective observation is in good agreement with that obtained using Moessbauer spectroscopy. An unfired and fired clay was also investigated. (orig.)

  11. Fossil avian eggshell preserves ancient DNA

    DEFF Research Database (Denmark)

    Oskam, Charlotte L; Haile, James; McLay, Emma;

    2010-01-01

    Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful......, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has...

  12. Origin of Chinese ancient glasses——study on the earliest Chinese ancient glasses

    Institute of Scientific and Technical Information of China (English)

    GAN Fuxi; CHENG Huansheng; LI Qinghui

    2006-01-01

    The earliest Chinese ancient glasses before the West Han Dynasty (200 BC) from different regions are studied. The glass samples were unearthed from Hunan, Hubei, Yunnan, Sichuan, Guizhou, Guangdong and Xinjiang of China. The chemical composition of these glasses samples is analyzed by proton induced X-ray emission (PIXE) technique, energy dispersive X-ray fluorescence (EDXRF) method and inductively coupled plasma atomic emission spectrometry (ICP-AES). It is shown that the glass chemical compositions belong to barium-lead silicate BaO-PbO-SiO2, potash soda lime silicate K2O (Na2O)-CaO-SiO2 (K2O/Na2O>1), soda potash lime silicate Na2O (K2O)-CaO-SiO2 (K2O/Na2O<1) and potash silicate K2O-SiO2 glass systems, respectively. The origins of the earliest Chinese ancient glasses are discussed from the archaeological and historical points of view. These four types of Chinese ancient glasses were all made in Chinese territory using local raw materials. The glass preparation technology was related to the Chinese ancient bronze metallurgy and proto-porcelain glaze technology. The glass technology relationship between the East and the West is analyzed at the same time.

  13. Diversity and Population status of Bats in Pilikuttuwa ancient cave temple in the Gampaha District, Sri Lanka

    Directory of Open Access Journals (Sweden)

    T. G. Tharaka Kusuminda

    2013-12-01

    Full Text Available Due to two unique specializations - echolocation and flight, bats have become one of the most successful groups of extant mammals in the world. Pilikuttuwa rajamaha viharaya, an ancient meditation monastery complex is a one of best places for bats which gives protection in Sri Lanka. In the present study, we evaluate the species diversity and population status of bats in Pilikuttuwa ancient meditation monastery complex with regard to their roosting ecology. Six species of bats including Taphozous melanopogon, Rhinolophus beddomei, Rhinolophus rouxii, Hipposideros galeritus, Hipposideros speoris and Megaderma spasma were recorded with the following conservation status, four in Vulnerable and two in Least Concerned. Taphozous melanopogon was the most abundant, and had the largest population with the widest distribution at the study site. A Natural predator of bats, Paradoxurus hermaphoditus was recorded in one roosting site.

  14. Nuclear analytical methods on ancient Thai rice

    International Nuclear Information System (INIS)

    For more than half of humanity, rice is life. Rice is a grain which has shaped the history, culture, diet and economy of billions of people in Asia. In Thailand, it is the essence of life. Archaeological evidence revealed that rice had been planted in northeastern area of Thailand more than 5,500 years ago which is earlier than in China and India. The ancient rice grains were found in various archaeological sites in Thailand such as Nakhon Nayok, Suphan Buri and Prachin Buri Provinces. In this work, the ancient black rice from Nakhon Nayok Province was elementally analyzed using scanning electron microscope coupled with energy dispersive X-ray fluorescence spectroscopy, proton induced X-ray emission spectroscopy and micro-beam energy dispersive X-ray fluorescence spectroscopy. Infrared (IR) spectroscopy was also used to study the chemical composition and bio-molecular structure. The grains were oblique in shape with a rough surface. Three major elements (Si, Ca and Al) and other trace elements were detected. The IR spectra provided some information about the presence of molecular bonds. (author)

  15. Mitochondrial DNA analysis of ancient Peruvian highlanders.

    Science.gov (United States)

    Shinoda, Ken-ichi; Adachi, Noboru; Guillen, Sonia; Shimada, Izumi

    2006-09-01

    Ancient DNA recovered from 57 individuals excavated by Hiram Bingham at the rural communities of Paucarcancha, Patallacta, and Huata near the famed Inca royal estate and ritual site of Machu Picchu was analyzed by polymerase chain reaction, and the results were compared with ancient and modern DNA from various Central Andean areas to test their hypothesized indigenous highland origins. The control and coding regions of the mitochondrial DNA (mtDNA) of 35 individuals in this group were sequenced, and the haplogroups of each individual were determined. The frequency data for the haplogroups of these samples show clear proximity to those of modern Quechua and Aymara populations in the Peruvian and Bolivian highlands, and contrast with those of pre-Hispanic individuals of the north coast of Peru that we defined previously. Our study suggests a strong genetic affinity between sampled late pre-Hispanic individuals and modern Andean highlanders. A previous analysis of the Machu Picchu osteological collection suggests that the residents there were a mixed group of natives from various coastal and highland regions relocated by the Inca state for varied purposes. Overall, our study indicates that the sampled individuals from Paucarcancha and Patallacta were indigenous highlanders who provided supportive roles for nearby Machu Picchu. PMID:16485299

  16. Sample Return from Ancient Hydrothermal Springs

    Science.gov (United States)

    Allen, Carlton C.; Oehler, Dorothy Z.

    2008-01-01

    Hydrothermal spring deposits on Mars would make excellent candidates for sample return. Molecular phylogeny suggests that that life on Earth may have arisen in hydrothermal settings [1-3], and on Mars, such settings not only would have supplied energy-rich waters in which martian life may have evolved [4-7] but also would have provided warm, liquid water to martian life forms as the climate became colder and drier [8]. Since silica, sulfates, and clays associated with hydrothermal settings are known to preserve geochemical and morphological remains of ancient terrestrial life [9-11], such settings on Mars might similarly preserve evidence of martian life. Finally, because formation of hydrothermal springs includes surface and subsurface processes, martian spring deposits would offer the potential to assess astrobiological potential and hydrological history in a variety of settings, including surface mineralized terraces, associated stream deposits, and subsurface environments where organic remains may have been well protected from oxidation. Previous attempts to identify martian spring deposits from orbit have been general or limited by resolution of available data [12-14]. However, new satellite imagery from HiRISE has a resolution of 28 cm/pixel, and based on these new data, we have interpreted several features in Vernal Crater, Arabia Terra as ancient hydrothermal springs [15, 16].

  17. Ancient and Medieval Earth in Armenia

    Science.gov (United States)

    Farmanyan, S. V.

    2015-07-01

    Humankind has always sought to recognize the nature of various sky related phenomena and tried to give them explanations. The purpose of this study is to identify ancient Armenians' pantheistic and cosmological perceptions, world view, notions and beliefs related to the Earth. The paper focuses on the structure of the Earth and many other phenomena of nature that have always been on a major influence on ancient Armenians thinking. In this paper we have compared the term Earth in 31 languages. By discussing and comparing Universe structure in various regional traditions, myths, folk songs and phraseological units we very often came across to "Seven Heavens" (Seven heavens is a part of religious cosmology found in many major religions such as Islam, Judaism, Hinduism and Christianity (namely Catholicism) and "Seven Earths". Armenians in their turn divided Earth and Heavens into seven layers. And in science too, both the Earth and the Heavens have 7 layers. The Seven Heavens refer to the layers of our atmosphere. The Seven Earths refer to the layers of the Earth (from core to crust), as well as seven continents. We conclude that the perception of celestial objects varies from culture to culture and preastronomy had a significant impact on humankind, particularly on cultural diversities.

  18. Acoustical measurements in ancient Roman theatres

    Science.gov (United States)

    Farnetani, Andrea; Fausti, Patrizio; Pompoli, Roberto; Prodi, Nicola

    2001-05-01

    The Greek and Roman theatres are among the most precious and spectacular items of cultural heritage in the Mediterranean countries. The theatres are famous not only for their impressive architecture, but also for the acoustic qualities. For this reason it is important to consider these theatres as an acoustical heritage and to study their sound field. Within the activities of the ERATO (identification Evaluation and Revival of the Acoustical heritage of ancient Theatres and Odea) project, acoustical measurements were taken in well-preserved ancient Roman theatres at Aspendos (Turkey) and Jerash (Jordan). Roman theatres have an impressive stage building that forms a back wall in the orchestra area, and it was found that, from the analysis of the acoustical parameters, the reverberation time (e.g., 1.7 s at middle frequencies in the theatre of Aspendos) is quite long compared not only with other open-space theatres but also with closed spaces. Contrary to modern halls the clarity is high and this fact, together with a low sound level in most of the seats, gives the sound field a unique character.

  19. Fine-scale ecological and economic assessment of climate change on olive in the Mediterranean Basin reveals winners and losers

    OpenAIRE

    Ponti, Luigi; Gutierrez, Andrew Paul; Ruti, Paolo Michele; Dell’Aquila, Alessandro

    2014-01-01

    Inability to determine reliably the direction and magnitude of change in natural and agro-ecosystems due to climate change poses considerable challenge to their management. Olive is an ancient ubiquitous crop having considerable ecological and socioeconomic importance in the Mediterranean Basin. We assess the ecological and economic impact of projected 1.8 °C climate warming on olive and its obligate pest, the olive fly. This level of climate warming will have varying impact on olive yield an...

  20. Reconstruction Of Ancient Microbial Biodiversity And Metabolism From Fossil Travertine

    Science.gov (United States)

    Asangba, A. E.; Dong, Y.; Lindo, J.; Malhi, R. S.; Foubert, A.; Swennen, R.; Ozkul, M.; Fouke, B. W.

    2013-12-01

    Abstract: A virtually unexplored frontier in the study of life in extreme environments is the extraction of genetic and environmental information directly from microbes entombed in calcium carbonate (CaCO3) crystals in the geological record. An environmental metagenomic study has been initiated to systematically track the fate of microbial gene sequences, lipids and other 'biomarkers' during the fossilization and diagenesis of Pleistocene terrestrial hot-spring travertine in Yellowstone National Park and the Pamukkale region of Turkey. The Mammoth Hot Springs corridor of Yellowstone contains thermal springs (73oC) that are actively and rapidly (mm's/day) precipitating travertine, as well as a complete time-series of travertine deposits that extend back to the Pleistocene (~33 ka). Comparative samples have been collected from quarries in the Denizli Basin (700-900 ka). The goal is to quantitatively track the preservation of these biomolecules through geological time, across specific sequences of down-flow travertine depositional facies and use this information to accurately reconstruct the identity, activity and ecology of the ancient microbes and their hot-spring environments. Analyses are being conducted of biomarkers extracted from bulk rock (cm's in diameter) as well as micro-drilled samples (μm in diameter). Each travertine sample is first being quantitatively screened (optically and geochemically) to determine the extent and fabric of water-rock alteration. Biomass has been successfully extracted from 10 μm-diameter fluid inclusions in primary crystals, as well as inter-crystalline deposits, and is undergoing metagenomic sequencing.

  1. Theorizing "Ecological Communication"

    OpenAIRE

    Mathur, Piyush

    2003-01-01

    In this dissertation, I make a theoretical exploration into the mass communication of ecological issues, a phenomenon bound to become increasingly important through the on-going dual process of economic-cum-ecological globalization and information revolution. Such an exploration is warranted, first, because, despite the highly visible coexistence of global warming and the digital divide on the same world-stage, sociohumanistic research generally has continued to focus on ecology and (mass) c...

  2. Germination ecology in orchids

    OpenAIRE

    TĚŠITELOVÁ, Tamara

    2009-01-01

    Germination ecology of four Epipactis species (E. albensis, E. atrorubens, E. helleborine, E. purpurata) was studied. Habitat preferences of adult plants were analyzed using phytosociological relevés from the Czech Phytosociological Database. A field experiment was carried out to determine course of germination of Epipactis seeds sown in different habitat types. Relationship between ecological preferences and germination ecology, and spatial aspects of seed dispersal and seedling recruitment ...

  3. Development of Ecological Buildings

    Directory of Open Access Journals (Sweden)

    Andrius Keizikas

    2011-04-01

    Full Text Available The article presents research on ecological buildings and their influence on the constructional sphere. The aim of the paper is to reveal the essence of ecological architecture showing substantial progress and its potential to stimulate architectural and technological growth. The article also describes relations between the ideas of ecological buildings and the ‘passive house’ concepts and aspects of development as well as describes the possibilities of improving building sustainability and energy efficiency. Article in Lithuanian

  4. The ecological economics: An ecological economics

    International Nuclear Information System (INIS)

    Ecological Economics arise as a scientific discipline aimed to integrate concepts of economics, ecology, thermodynamics, ethic and other natural and social sciences in order to incorporate a biophysical and integrated perspective of the inter dependences between economies and environment, from a plural conception and a methodology beyond disciplines. Ecological Economics studies the black box of economic processes usually excluded of the traditional economics: thermodynamics and ecology. Although it is relatively a new field of study, it has been strengthening its theoretical framework with scientific basis and analytic principles that lead to its identification as a new discipline that show a whole new paradigm. The scope of this article is to show the conceptual and methodological bases, the main founders, approaches and central debates of this new discipline. This brief introduction is a preamble to the papers of the meeting Ecological Economics: a perspective for Colombia included in this number, that took place on September 22 - 27 of 2007, at the National University of Colombia at Bogota. During tree days national and international experts, professors, researchers, workers of environmental sector and people interested on environmental issues joined together to know the conceptual and methodological achievements reached of this discipline; as well as to analyse and evaluate the environmental problems of the country, from the systemic, interdisciplinary and general perspective that it promotes

  5. A new look at old bread: ancient Egyptian baking

    Directory of Open Access Journals (Sweden)

    Delwen Samuel

    1999-11-01

    Full Text Available Despite abundant archaeological, pictorial and textual evidence of ancient Egyptian life and death, we have little detailed information about the staple diet of most of the population. Now experimental work by a postdoctoral Wellcome Research Fellow in Bioarchaeology at the Institute is revealing how the ancient Egyptians made their daily bread.

  6. A new look at old bread: ancient Egyptian baking

    OpenAIRE

    Delwen Samuel

    1999-01-01

    Despite abundant archaeological, pictorial and textual evidence of ancient Egyptian life and death, we have little detailed information about the staple diet of most of the population. Now experimental work by a postdoctoral Wellcome Research Fellow in Bioarchaeology at the Institute is revealing how the ancient Egyptians made their daily bread.

  7. A modern appraisal of ancient Etruscan herbal practices

    DEFF Research Database (Denmark)

    Harrison, Adrian Paul; Bartels, E.M.

    2006-01-01

    that the "Etruscan Herbal" contains such plants as valerian and henbane, which with regard to their hypnotic and delirium-easing effects, respectively, may have been used in a more ritual and magical way by ancient herbalists and societies throughout the ancient Mediterranean. Without a doubt though, the application...

  8. An Ancient Inca Tax and Metallurgy in Peru

    Science.gov (United States)

    Journal of Chemical Education, 2007

    2007-01-01

    The discovery of ancient Inca tax rulers and other metallurgical objects in Peru show that the ancient civilizations of the country smelted metals. The analysis shows that the smelters in Peru switched from the production of copper to silver after a tax was imposed on them by the Inca rulers.

  9. Evolution of Management Thought in the Ancient Times.

    Science.gov (United States)

    Sharma, C. L.

    This paper argues that although systematic management thought is a distinctly modern development, the writings of ancient scholars and records of ancient rulers infer that they understood the rudiments of management principles and concepts. To support this thesis, the author reviews the evidence of management practices and concepts in various…

  10. Deep sequencing of RNA from ancient maize kernels

    DEFF Research Database (Denmark)

    Fordyce, Sarah Louise; Avila Arcos, Maria del Carmen; Rasmussen, Morten;

    2013-01-01

    The characterization of biomolecules from ancient samples can shed otherwise unobtainable insights into the past. Despite the fundamental role of transcriptomal change in evolution, the potential of ancient RNA remains unexploited - perhaps due to dogma associated with the fragility of RNA. We...

  11. Design a Book: A Quest in Ancient Egypt

    Science.gov (United States)

    Cooper, David

    2005-01-01

    This article describes a classroom project that combines creative writing, basic book design, and social studies content. During this project, the authors' seventh grade students research a variety of ancient Egyptian archaeological sites while reviewing course material from a unit of study on ancient Egypt, practice project management skills…

  12. Trade routes and communication pattern of ancient Orissa

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.; Patnaik, S.K.

    attempt has been made for the study of the trade routes and communication pattern of ancient Orissa. Thus an attempt is made to trace out the trade routes and communication pattern of ancient Orissa in the light of available archaeological and literary...

  13. Dynamics in artifact ecologies

    DEFF Research Database (Denmark)

    Bødker, Susanne; Klokmose, Clemens Nylandsted

    2012-01-01

    We increasingly interact with multiple interactive artifacts with overlapping capabilities during our daily activities. It has previously been shown that the use of an interactive artifact cannot be understood in isolation, but artifacts must be understood as part of an artifact ecology, where...... artifacts influence the use of others. Understanding this interplay becomes more and more essential for interaction design as our artifact ecologies grow. This paper continues a recent discourse on artifact ecologies. Through interviews with iPhone users, we demonstrate that relationships between artifacts...... in artifact ecologies cannot be understood as static, instead they evolve dynamically over time. We provide activity theory-based concepts to explain these dynamics....

  14. Production of class a biosolids with anoxic low dose alkaline treatment and odor management

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Orf, M.M.; Brewster, J.; Oleszkiewicz, J.; Reimers, R.S.; Lagasse, P.; Amy, B.; Glindemann, D.

    2003-07-01

    The feasibility of full-scale anoxic disinfection of dewatered and digested sludge from Winnipeg, Manitoba with low lime doses and lagoon fly ash was investigated to determine if a class A product could be produced. Lime doses of 50g, 100g, and 200g per kg of biosolids (dry) were used along with fly ash doses of 500g. 1000g. and 1500g per kg of biosolids (dry). The mixed product was buried in eight-10 cubic meter trenches at the West End Water Pollution Control Center In Winnipeg. The trenches were backfilled with dirt and trapped to simulate anoxic conditions. Sampling cages were packed with the mixed product and pathogens non-indigenous to Winnipeg's biosolids. The cages were buried amongst the mixed biosolids in the trench. The non-indigenous pathogens spiked in the laboratory were the helminth Ascaris suum and the enteric virus reovirus. Samples were removed at days 12, 40, 69, 291, and 356 and were tested for the presence of fecal Coliform, Clostridium perfringens spores, Ascaris suum eggs, and reovirus. The pH, total solids, and free ammonia content of the mixed product were also determined for each sample. Odor was quantified for samples at both 291 and 356 days. Fecal Coliform bacteria and reovirus were completely inactivated for doses as low as 100g lime per kg biosolids (dry) and 50g lime + 500g fly ash per kg biosolids (dry). Spores of the bacteria C. perfringens experienced a 4-log reduction when treated with 100g lime per kg biosolids and a 5-log reduction when treated with doses as low as 50g lime + 500g fly ash per kg biosolids (dry) after 69 days. Ascaris eggs were completely inactivated in 5 gram packets for all treatments involving 100g lime per kg biosolids (dry) after 69 days. Class A pathogen requirements were met for all treatments involving a lime dose of at least 100g per kg biosolids. The odor potential from the produced biosolids is also assessed. (author)

  15. Mitochondrial DNA analysis of ancient Sampula population in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The archaeological site of Sampula cemetery was located about 14 km to the southwest of the Luo County in Xinjiang Khotan, China, belonging to the ancient Yutian kingdom. 14C analysis showed that this cemetery was used from 217 B.C. to 283 A.D.Ancient DNA was analyzed by 364 bp of the mitochondrial DNA hypervariable region Ⅰ (mtDNA HVR-Ⅰ), and by six restriction fragment length polymorphism (RFLP) sites of mtDNA coding region. We successfully extracted and sequenced intact stretches of maternally inherited mtDNA from 13 out of 16 ancient Sampula samples. The analysis of mtDNA haplogroup distribution showed that the ancient Sampula was a complex population with both European and Asian characteristics. Median joining network of U3 sub-haplogroup and multi-dimensional scaling analysis all showed that the ancient Sampula had maternal relationship with Ossetian and Iranian.

  16. Exploring Ancient Skies An Encyclopedic Survey of Archaeoastronomy

    CERN Document Server

    Kelley, David H

    2005-01-01

    Exploring Ancient Skies brings together the methods of archaeology and the insights of modern astronomy to explore the science of astronomy as it was practiced in various cultures prior to the invention of the telescope. The book reviews an enormous and growing body of literature on the cultures of the ancient Mediterranean, the Far East, and the New World (particularly Mesoamerica), putting the ancient astronomical materials into their archaeological and cultural contexts. The authors begin with an overview of the field and proceed to essential aspects of naked-eye astronomy, followed by an examination of specific cultures. The book concludes by taking into account the purposes of ancient astronomy: astrology, navigation, calendar regulation, and (not least) the understanding of our place and role in the universe. Skies are recreated to display critical events as they would have appeared to ancient observers - events such as the supernova of 1054, the 'lion horoscope' or the 'Star of Bethlehem.' Exploring An...

  17. Mapping The Ancient Maya Landscape From Space

    Science.gov (United States)

    Sever, Tom; Arnold, James E. (Technical Monitor)

    2002-01-01

    The Peten region of northern Guatemala is one of the last places on earth where major archeological sites remain to be discovered. It was in this region that the Maya civilization began, flourished, and abruptly disappeared. Remote sensing technology is helping to locate and map ancient Maya sites that are threatened today by accelerating deforestation and looting. Thematic Mapper and IKONOS satellite and airborne Star3-I radar data, combined with Global Positioning System (GPS) technology, are successfully detecting ancient Maya features such as cities, roadways, canals, and water reservoirs. Satellite imagery is also being used to map the bajos, which are seasonally flooded swamps that cover over 40% of the land surface. The use of bajos for farming has been a source of debate within the professional community for many years. But the recent detection and verification of cultural features within the bajo system by our research team are providing conclusive evidence that the ancient Maya had adapted well to wetland environments from the earliest times and utilized them until the time of the Maya collapse. The use of the bajos for farming is also an important resource for the future of the current inhabitants who are experiencing rapid population growth. Remote sensing imagery is also demonstrating that in the Preclassic period (600 BC- AD 250), the Maya had already achieved a high organizational level as evidenced by the construction of massive temples and an elaborate inter-connecting roadway system. Although they experienced several setbacks such as droughts and hurricanes, the Maya nevertheless managed the delicate forest ecosystem successfully for several centuries. However, around AD 800, something happened to the Maya to cause their rapid decline and eventual disappearance from the region. The evidence indicates that at this time there was increased climatic dryness, extensive deforestation, overpopulation, and widespread warfare. This raises a question that

  18. Cosmologies of the ancient Mediterranean world

    Directory of Open Access Journals (Sweden)

    John T. Fitzgerald

    2013-06-01

    Full Text Available Cosmology is concerned with the order of the universe and seeks to provide an account, not only of that order, but also of the mind or reason behind it. In antiquity, the cosmos was usually understood religiously, such that the cosmologies of the ancient Mediterranean world were either religious in nature or constituted a reaction to a religiously conceived understanding of the structures of the universe. The oldest form in which ancient cosmologies occur is myth, which, owing to its elasticity as a form, enabled them to be appropriated, adapted and used by different groups. In addition, different cosmologies co-existed within the same ancient culture, each having an authoritative status. This article provides an introductory overview of these cosmological myths and argues that a comparative approach is the most fruitful way to study them. Emphasis is given to certain prominent cosmological topics, including theogony (the genesis of the divine or the relationship of the divine to the cosmos, cosmogony (the genesis of the cosmos, and anthropogony (the origin of humans within the cosmos. Although these myths vary greatly in terms of content and how they envision the origin of the cosmos, many of them depict death as part of the structure of the universe.Kosmologie het te doen met die orde van die heelal en wil rekenskap gee van hierdie orde en ook van die bewussyn daaragter. In die antieke tyd is die kosmos gewoonlik godsdienstig verstaan, met die gevolg dat die kosmologieë van die antieke Mediterreense wêreld óf ’n godsdienstige aard gehad het óf bestaan het uit ’n reaksie op ’n godsdienstig-geskepte begrip van die strukture van die heelal. Mites was die oudste vorm waarin antieke kosmologieë voorkom wat vanweë hulle plooibaarheid dit bewerk het dat hierdie kosmologieë deur verskillende groepe toegeëien, aangepas en gebruik kon word. Hierbenewens het verskillende kosmologieë in die antieke kultuur langs mekaar bestaan – elkeen

  19. Mackinawite and greigite in ancient alkaline hydrothermal chimneys: Identifying potential key catalysts for emergent life

    Science.gov (United States)

    White, Lauren M.; Bhartia, Rohit; Stucky, Galen D.; Kanik, Isik; Russell, Michael J.

    2015-11-01

    One model for the emergence of life posits that ancient, low temperature, submarine alkaline hydrothermal vents, partly composed of iron-sulfides, were capable of catalyzing the synthesis of prebiotic organic molecules from CO2, H2 and CH4. Specifically, hydrothermal mackinawite (FeIIS) and greigite (FeIIFeIII2S4) have been highlighted in previous studies as analogs of the active centers of hydrogenase, ferredoxin, acetyl coenzyme-A synthase and carbon monoxide dehydrogenase featured in the biochemistry of certain autotrophic prokaryotes that occupy the base of the evolutionary tree. Despite the proposed importance of iron sulfide minerals and clusters in the synthesis of abiotic organic molecules, the mechanisms for the formation of these sulfides from solution and their preservation under the anoxic and low temperature (below 100 °C) conditions expected in off-axis submarine alkaline vent systems is not well understood (Bourdoiseau et al., 2011; Rickard and Luther, 2007). To rectify this, single hydrothermal chimneys were precipitated using a unique apparatus to simulate growth at hydrothermal vents of moderate temperature under supposed Hadean ocean-bottom conditions. Iron sulfide phases were observed through Raman spectroscopy at growth temperatures ranging from 40° to 80 °C. Fe(III)-containing mackinawite is confirmed to be present with mackinawite and greigite, supporting an FeIII-mackinawite intermediate mechanism for the transformation of mackinawite to greigite below 100 °C. Raman spectroscopy of the chimneys revealed a maximum yield of greigite at 75 °C. These results suggest abiotic production of catalytically active mackinawite and greigite are possible under early Earth hydrothermal conditions as well as on other wet, rocky worlds geochemically similar to the Earth.

  20. Studies in Continuity and Change: A Comparative Study of the Mother Goddess in Ancient India and Ancient Egypt.

    Science.gov (United States)

    Hardiman, W. J.

    Visiting the Temple of Kali in Calcutta, India, one understands the importance of an Afro-centric methodology in describing the complex nature of the Mother Goddess in ancient India. Discoveries of ancient female figurines indicate an early Indian concept of the female role in the creation of civilization and culture and of the notion of the…

  1. Radiocarbon dating of ancient Japanese calligraphy sheets. Checks with ancient documents of known age and its application to kohitsugire calligraphies

    International Nuclear Information System (INIS)

    Radiocarbon ages of ancient documents, sutras and books of known age were measured by AMS. The calibrated radiocarbon ages corresponded to the years in which they were written. The result shows that Japanese paper is suitable for radiocarbon dating. Radiocarbon dating on ancient calligraphies of unknown age clarified their historical ages and academic value. (author)

  2. Ancient DNA from lake sediments: Bridging the gap between paleoecology and genetics

    Directory of Open Access Journals (Sweden)

    Lumibao Candice Y

    2011-01-01

    Full Text Available Abstract Background Quaternary plant ecology in much of the world has historically relied on morphological identification of macro- and microfossils from sediments of small freshwater lakes. Here, we report new protocols that reliably yield DNA sequence data from Holocene plant macrofossils and bulk lake sediment used to infer ecological change. This will allow changes in census populations, estimated from fossils and associated sediment, to be directly associated with population genetic changes. Results We successfully sequenced DNA from 64 samples (out of 126 comprised of bulk sediment and seeds, leaf fragments, budscales, and samaras extracted from Holocene lake sediments in the western Great Lakes region of North America. Overall, DNA yields were low. However, we were able to reliably amplify samples with as few as 10 copies of a short cpDNA fragment with little detectable PCR inhibition. Our success rate was highest for sediments Conclusions An ability to extract ancient DNA from Holocene sediments potentially allows exciting new insights into the genetic consequences of long-term environmental change. The low DNA copy numbers we found in fossil material and the discovery of multiple sequence variants from single macrofossil extractions highlight the need for careful experimental and laboratory protocols. Further application of these protocols should lead to better understanding of the ecological and evolutionary consequences of environmental change.

  3. Ancient climate change, antifreeze, and the evolutionary diversification of Antarctic fishes.

    Science.gov (United States)

    Near, Thomas J; Dornburg, Alex; Kuhn, Kristen L; Eastman, Joseph T; Pennington, Jillian N; Patarnello, Tomaso; Zane, Lorenzo; Fernández, Daniel A; Jones, Christopher D

    2012-02-28

    The Southern Ocean around Antarctica is among the most rapidly warming regions on Earth, but has experienced episodic climate change during the past 40 million years. It remains unclear how ancient periods of climate change have shaped Antarctic biodiversity. The origin of antifreeze glycoproteins (AFGPs) in Antarctic notothenioid fishes has become a classic example of how the evolution of a key innovation in response to climate change can drive adaptive radiation. By using a time-calibrated molecular phylogeny of notothenioids and reconstructed paleoclimate, we demonstrate that the origin of AFGP occurred between 42 and 22 Ma, which includes a period of global cooling approximately 35 Ma. However, the most species-rich lineages diversified and evolved significant ecological differences at least 10 million years after the origin of AFGPs, during a second cooling event in the Late Miocene (11.6-5.3 Ma). This pattern indicates that AFGP was not the sole trigger of the notothenioid adaptive radiation. Instead, the bulk of the species richness and ecological diversity originated during the Late Miocene and into the Early Pliocene, a time coincident with the origin of polar conditions and increased ice activity in the Southern Ocean. Our results challenge the current understanding of the evolution of Antarctic notothenioids suggesting that the ecological opportunity that underlies this adaptive radiation is not linked to a single trait, but rather to a combination of freeze avoidance offered by AFGPs and subsequent exploitation of new habitats and open niches created by increased glacial and ice sheet activity. PMID:22331888

  4. Ancient Forests and the Tree-Ring Reconstruction of Past Climate (Ancient Forests and Dendroclimatology)

    Energy Technology Data Exchange (ETDEWEB)

    Stahle, David (Tree-Ring Laboratory, University of Arkansas)

    2003-02-12

    The original presettlement forests of North America have been dramatically altered, but thousands of unmolested ancient forests survive on remote or noncommercial terrain, including dry-site eastern hardwoods such as chestnut oak and post oak, the pinyon-juniper woodlands of the semiarid West, oak woodlands of California and in northeast Mexico, and the boreal forests of Canada and Alaska. Long tree-ring chronologies derived from these ancient forest remnants provide irreplaceable archives of environmental variability which are crucial for evaluating present and future change. Temperature sensitive tree -ring chronologies from cold treeline environments place 20th century warming into long historical perspective, and moisture sensitive tree-ring chronologies provide analogs to the decadal moisture regimes of the 20th century. These tree-ring data suggests that the 16th century megadrought was the most severe-sustained drought to impact North America in 1500 years, and had huge environmental and social impacts at the dawn of European settlement.

  5. Ancient bacteria show evidence of DNA repair

    DEFF Research Database (Denmark)

    Johnson, Sarah Stewart; Hebsgaard, Martin B; Christensen, Torben R;

    2007-01-01

    geological timescales. There has been no direct evidence in ancient microbes for the most likely mechanism, active DNA repair, or for the metabolic activity necessary to sustain it. In this paper, we couple PCR and enzymatic treatment of DNA with direct respiration measurements to investigate long...... this long-term survival is closely tied to cellular metabolic activity and DNA repair that over time proves to be superior to dormancy as a mechanism in sustaining bacteria viability.......-term survival of bacteria sealed in frozen conditions for up to one million years. Our results show evidence of bacterial survival in samples up to half a million years in age, making this the oldest independently authenticated DNA to date obtained from viable cells. Additionally, we find strong evidence that...

  6. Ancient asteroids enriched in refractory inclusions.

    Science.gov (United States)

    Sunshine, J M; Connolly, H C; McCoy, T J; Bus, S J; La Croix, L M

    2008-04-25

    Calcium- and aluminum-rich inclusions (CAIs) occur in all classes of chondritic meteorites and contain refractory minerals predicted to be the first condensates from the solar nebula. Near-infrared spectra of CAIs have strong 2-micrometer absorptions, attributed to iron oxide-bearing aluminous spinel. Similar absorptions are present in the telescopic spectra of several asteroids; modeling indicates that these contain approximately 30 +/- 10% CAIs (two to three times that of any meteorite). Survival of these undifferentiated, large (50- to 100-kilometer diameter) CAI-rich bodies suggests that they may have formed before the injection of radiogenic 26Al into the solar system. They have also experienced only modest post-accretionary alteration. Thus, these asteroids have higher concentrations of CAI material, appear less altered, and are more ancient than any known sample in our meteorite collection, making them prime candidates for sample return. PMID:18356491

  7. Hydraulic performance of an ancient Spanish watermill

    Energy Technology Data Exchange (ETDEWEB)

    Pujol, Toni; Sola, Jordi; Montoro, Lino; Pelegri, Marc [Area de Mecanica de Fluids, Departament d' Enginyeria Mecanica i de la Construccio Industrial, Universitat de Girona, Campus Montilivi, 17071 Girona, Catalonia (Spain)

    2010-02-15

    Here we analyze the hydraulic performance of an ancient Spanish horizontal watermill. Previous studies of similar devices have focused on qualitative descriptions of their technical functioning, providing efficiency curves based on two-dimensional analytical approximations. In contrast, here we perform three-dimensional computational fluid dynamics (CFD) simulations that allow us to obtain quantitative values for both the hydraulic torque and the power. The results here found reveal how previous studies clearly overestimated the efficiency of these devices. Finally, we make use of the capabilities of CFDs by investigating the performance of a modified blade profile. The new design here proposed successfully increases the energy efficiency (up to 44%) in comparison with the classical one. (author)

  8. Trace elements in ancient ceramics: Pt.4

    International Nuclear Information System (INIS)

    In the last period of Tong Dynasty, Jingdezhen began its production of ceramics. During the Song Dynasty, the ceramic industry greatly developed and produced fine white ware at Hutian. In the Yuan Dynastry, Hutian became the centre of production making the world famous blue and white wares. Here are reported results of analyses of ancient porcelians of Hutian in Jiangdezhen by reactor neutron activation analysis. The results show that the patterns of eight rare earth elements are apparently different for products in different periods, indicating that methods for producing ceramics or kinds of clay used were different. The contents of some other trace elements such as hafnium, tantalum, thorium and uranium show the same regularity in difference of composition also

  9. Phobias in Poetry: Coleridge's Ancient Mariner.

    Science.gov (United States)

    Singh, Satendra; Khetarpal, Abha

    2012-04-01

    The Rime of the Ancient Mariner was written by Coleridge and is a classic poetry about retribution, punishment, guilt, and curse. Religious beliefs and delusions can arise from neurologic lesions and anomalous experiences, suggesting that at least some religious beliefs can be pathological. Looking at the poem through the psychiatric and psychological domain, the symbolism, the narration and the entire setting of the poem represents Post Traumatic Stress Disorder. Mariner's reactions are beautifully portrayed from the psychoanalytic point of view and the literary piece shows claustrophobia, stygiophobia, dikephobia, and poinephobia. The mental stress of a person under a crisis situation has remarkably been evoked in this poem. This incredible piece of art expresses how the realization of divine love within oneself has the power to heal pain and suffer. PMID:23162202

  10. Recognition of dementia in ancient China.

    Science.gov (United States)

    Liu, Jia; Wang, Lu-Ning; Tian, Jin-Zhou

    2012-12-01

    A search of previous records in the literatures was done to summarize the opinions for dementia in ancient China. The earliest description of dementia was traced in the Yellow emperor's internal classic, a book written 2000 years ago. Hua Tuo (AD 140-208) in Han Dynasty first denominated "dementia" in the book, Hua Tuo Shen Yi Mi Zhuan. The pathogenesis of dementia could be generalized as the insufficiency of Qi, a flowing energy; the stagnation of phlegm, a harmful liquid substance in the body; and the blood stasis, which were also regarded as therapeutic targets. Therefore, we can conclude that dementia has been recognized and investigated in traditional Chinese medicine, which is definitely before the industrial civilization era. PMID:22835605

  11. Unknown ancient Greek ophthalmological instruments and equipment.

    Science.gov (United States)

    Lascaratos, J; Marketos, S

    1997-01-01

    Discoveries of some ancient medical instruments and equipment found in the Hellenic world have been published in magazines of general interest and in a rare Greek medical journal, yet none caught the attention of ophthalmologists. Among these instruments are two forms of the famous 'Kenteterion', dating from the Hellenistic period, used for the couching of cataract. These were found on the island of Milos in the last century. Two magnifying lenses of the Archaic period from the recent Cretan excavations gave us the opportunity to discuss the problem of their medical use. The two drop-bottles from the excavations on Cyprus and at Tanagra, which are also described, seem to be of medical, and possible ophthalmological, use. PMID:9657298

  12. The Ancient Evolutionary History of Polyomaviruses.

    Science.gov (United States)

    Buck, Christopher B; Van Doorslaer, Koenraad; Peretti, Alberto; Geoghegan, Eileen M; Tisza, Michael J; An, Ping; Katz, Joshua P; Pipas, James M; McBride, Alison A; Camus, Alvin C; McDermott, Alexa J; Dill, Jennifer A; Delwart, Eric; Ng, Terry F F; Farkas, Kata; Austin, Charlotte; Kraberger, Simona; Davison, William; Pastrana, Diana V; Varsani, Arvind

    2016-04-01

    Polyomaviruses are a family of DNA tumor viruses that are known to infect mammals and birds. To investigate the deeper evolutionary history of the family, we used a combination of viral metagenomics, bioinformatics, and structural modeling approaches to identify and characterize polyomavirus sequences associated with fish and arthropods. Analyses drawing upon the divergent new sequences indicate that polyomaviruses have been gradually co-evolving with their animal hosts for at least half a billion years. Phylogenetic analyses of individual polyomavirus genes suggest that some modern polyomavirus species arose after ancient recombination events involving distantly related polyomavirus lineages. The improved evolutionary model provides a useful platform for developing a more accurate taxonomic classification system for the viral family Polyomaviridae. PMID:27093155

  13. Panorama of ancient metazoan macromolecular complexes.

    Science.gov (United States)

    Wan, Cuihong; Borgeson, Blake; Phanse, Sadhna; Tu, Fan; Drew, Kevin; Clark, Greg; Xiong, Xuejian; Kagan, Olga; Kwan, Julian; Bezginov, Alexandr; Chessman, Kyle; Pal, Swati; Cromar, Graham; Papoulas, Ophelia; Ni, Zuyao; Boutz, Daniel R; Stoilova, Snejana; Havugimana, Pierre C; Guo, Xinghua; Malty, Ramy H; Sarov, Mihail; Greenblatt, Jack; Babu, Mohan; Derry, W Brent; Tillier, Elisabeth R; Wallingford, John B; Parkinson, John; Marcotte, Edward M; Emili, Andrew

    2015-09-17

    Macromolecular complexes are essential to conserved biological processes, but their prevalence across animals is unclear. By combining extensive biochemical fractionation with quantitative mass spectrometry, here we directly examined the composition of soluble multiprotein complexes among diverse metazoan models. Using an integrative approach, we generated a draft conservation map consisting of more than one million putative high-confidence co-complex interactions for species with fully sequenced genomes that encompasses functional modules present broadly across all extant animals. Clustering reveals a spectrum of conservation, ranging from ancient eukaryotic assemblies that have probably served cellular housekeeping roles for at least one billion years, ancestral complexes that have accrued contemporary components, and rarer metazoan innovations linked to multicellularity. We validated these projections by independent co-fractionation experiments in evolutionarily distant species, affinity purification and functional analyses. The comprehensiveness, centrality and modularity of these reconstructed interactomes reflect their fundamental mechanistic importance and adaptive value to animal cell systems. PMID:26344197

  14. The pecked cross symbol in ancient mesoamerica.

    Science.gov (United States)

    Aveni, A F; Hartung, H; Buckingham, B

    1978-10-20

    Attention is directed to a design, possibly of Teotihuacan origin, carved both in rock and in the floors of ceremonial buildings throughout ancient Mesoamerica. Consisting generally of a double circular pattern centered on a set of orthogonal axes, the so-called pecked cross or quartered circle figure is shown to exhibit a remarkable consistency in appearance throughout its 29 reported locations, thus suggesting that it was not perfunctory. The metric properties of the symbols gleaned from field surveys are delineated, and several interpretations of their possible functions are discussed. These symbols may have been intended as astronomical orientational devices, surveyor's bench marks, calendars, or ritual games. Evidence is presented which implies that more than one and perhaps all of these functions were employed simultaneously, a view which is shown to be consistent with the cosmological attitude of the pre-Columbian people. PMID:17817633

  15. The Ancient Evolutionary History of Polyomaviruses

    Science.gov (United States)

    Buck, Christopher B.; Van Doorslaer, Koenraad; Peretti, Alberto; Geoghegan, Eileen M.; Tisza, Michael J.; An, Ping; Katz, Joshua P.; Pipas, James M.; McBride, Alison A.; Camus, Alvin C.; McDermott, Alexa J.; Dill, Jennifer A.; Delwart, Eric; Ng, Terry F. F.; Farkas, Kata; Austin, Charlotte; Kraberger, Simona; Davison, William; Pastrana, Diana V.; Varsani, Arvind

    2016-01-01

    Polyomaviruses are a family of DNA tumor viruses that are known to infect mammals and birds. To investigate the deeper evolutionary history of the family, we used a combination of viral metagenomics, bioinformatics, and structural modeling approaches to identify and characterize polyomavirus sequences associated with fish and arthropods. Analyses drawing upon the divergent new sequences indicate that polyomaviruses have been gradually co-evolving with their animal hosts for at least half a billion years. Phylogenetic analyses of individual polyomavirus genes suggest that some modern polyomavirus species arose after ancient recombination events involving distantly related polyomavirus lineages. The improved evolutionary model provides a useful platform for developing a more accurate taxonomic classification system for the viral family Polyomaviridae. PMID:27093155

  16. Copper tracing to determine the micrometric electronic properties of a thick ferrous corrosion layer formed in an anoxic medium

    International Nuclear Information System (INIS)

    Highlights: → Corrosion mechanisms in anoxic carbonated media. → Cu2+/Cu(0) tracing. → Determination of the electronic properties of the corrosion layer. → Decoupling of the cathodic and anodic reactions. - Abstract: In anoxic carbonated environments, the corrosion layer formed on iron is composed of magnetite and ferrous carbonates with different distributions, influencing the electronic properties of the whole layer. This study aims at determining at a micrometric scale the electronic properties of such corrosion layers, with a reaction tracing based on the use of the Cu2+/Cu(0) redox couple. Experiments reveal that the electrons formed at the metallic interface are available everywhere in the pores of a thick corrosion layer. This result is of importance to elucidate the corrosion mechanisms because it implies a decoupling of the anodic and the cathodic reactions.

  17. Biological Phosphorus Release and Uptake Under Alternating Anaerobic and Anoxic Conditions In a Fixed-Film Reactor

    DEFF Research Database (Denmark)

    Kerrn-Jespersen, Jens Peter; Henze, Mogens; Strube, Rune

    1994-01-01

    Biological phosphorus removal was investigated in a fixed-film reactor with alternating anaerobic and anoxic conditions. The tests showed that biological phosphorus removal can be obtained in a fixed-film reactor with nitrate as oxidising agent. In the anaerobic period, 0.52 mg of PO4-P...... was released per mg of acetate taken up on an average. In the anoxic period, 2.0 mg of PO4-P was taken up per mg of NO3-N reduced on an average. The relationship between potassium released and phosphate released in the anaerobic phase was determined to be 0.37 mg K/mg P, while the relationship between...

  18. [Medicine in ancient Mesopotamia - part 2].

    Science.gov (United States)

    Martins E Silva, J

    2010-01-01

    The second part embraces exclusively the main characteristics of the medicine in Ancient Mesopotamia, in its main facets: concept of disease, healers and practice. The disease was considered a divine punishment or resultant from a malign influence. Insofar, the medicine began by being preventive, by the use of appropriate amulets or by offerings or sacrifices intending to pacify those malign forces. The treatment of the generality of the diseases privileged the expulsion of those spirits and malign influences from the patient body, purifying it, which was done by the specific intervention of a approximately shipu (clergymanexorcist); not having results, the treatment was continued by the asû (practical healer) that appealed to a group of physical manipulations, limited surgical acts and the administration or application of prescriptions, resultants of the mixture of organic and inorganic substances. In case of failing, the patients (as well as common healthy individuals or rule leaders) could fall back upon a priest diviner (bârû) that, by examination of the organs of an animal especially sacrificed for, would give a final decision about the disease or the future. Besides this more occult facet, nourished in religious faiths and in the magic, the medicine of Ancient Mesopotamia included rational knowledge, certainly as the result of systematic patients observation and semiotic interpretation. From those observations and knowledge referred to the Sumerian period, carefully logged, refined and transmitted to the following generations, it was built a valuable group of texts with the description of symptoms, signs, diagnosis and prognostic of the most common diseases, still identifiable in the present. PMID:20353716

  19. Archaeal remains dominate marine organic matter from the early Albian oceanic anoxic event 1b

    DEFF Research Database (Denmark)

    Kuypers, M.M.M.; Blokker, P.; Hopmans, E.C.;

    2002-01-01

    The sources for both soluble and insoluble organic matter of the early Albian (∼112 Myr) oceanic anoxic event (OAE) 1b black shales of the Ocean Drilling Program (ODP) site 1049C (North Atlantic Ocean off the coast of Florida) and the Ravel section of the Southeast France Basin (SEFB) were...... C/C ratios was used to estimate that up to ∼40% of the organic matter of the SEFB and up to ∼80% of the organic matter of ODP site 1049C preserved in the black shales is derived from archaea. Furthermore, it is shown that, even though there are apparent similarities (high organic carbon (OC) content......, distinct lamination, C-enrichment of OC) between the black shales of OAE1b and the Cenomanian/Turonian (∼94 Myr) OAE, the origin of the organic matter (archaeal versus phytoplanktonic) and causes for C-enrichment of OC are completely different. © 2002 Elsevier Science B.V. All rights reserved....

  20. Electricity generation by anaerobic bacteria and anoxic sediments from hypersaline soda lakes

    Science.gov (United States)

    Miller, L.G.; Oremland, R.S.

    2008-01-01

    Anaerobic bacteria and anoxic sediments from soda lakes produced electricity in microbial fuel cells (MFCs). No electricity was generated in the absence of bacterial metabolism. Arsenate respiring bacteria isolated from moderately hypersaline Mono Lake (Bacillus selenitireducens), and salt-saturated Searles Lake, CA (strain SLAS-1) oxidized lactate using arsenate as the electron acceptor. However, these cultures grew equally well without added arsenate using the MFC anode as their electron acceptor, and in the process oxidized lactate more efficiently. The decrease in electricity generation by consumption of added alternative electron acceptors (i.e. arsenate) which competed with the anode for available electrons proved to be a useful indicator of microbial activity and hence life in the fuel cells. Shaken sediment slurries from these two lakes also generated electricity, with or without added lactate. Hydrogen added to sediment slurries was consumed but did not stimulate electricity production. Finally, electricity was generated in statically incubated "intact" sediment cores from these lakes. More power was produced in sediment from Mono Lake than from Searles Lake, however microbial fuel cells could detect low levels of metabolism operating under moderate and extreme conditions of salt stress. ?? 2008 US Government.

  1. An oligarchic microbial assemblage in the anoxic bottom waters of a volcanic subglacial lake.

    Science.gov (United States)

    Gaidos, Eric; Marteinsson, Viggo; Thorsteinsson, Thorsteinn; Jóhannesson, Tomas; Rúnarsson, Arni Rafn; Stefansson, Andri; Glazer, Brian; Lanoil, Brian; Skidmore, Mark; Han, Sukkyun; Miller, Mary; Rusch, Antje; Foo, Wilson

    2009-04-01

    In 2006, we sampled the anoxic bottom waters of a volcanic lake beneath the Vatnajökull ice cap (Iceland). The sample contained 5 x 10(5) cells per ml, and whole-cell fluorescent in situ hybridization (FISH) and PCR with domain-specific probes showed these to be essentially all bacteria, with no detectable archaea. Pyrosequencing of the V6 hypervariable region of the 16S ribosomal RNA gene, Sanger sequencing of a clone library and FISH-based enumeration of four major phylotypes revealed that the assemblage was dominated by a few groups of putative chemotrophic bacteria whose closest cultivated relatives use sulfide, sulfur or hydrogen as electron donors, and oxygen, sulfate or CO(2) as electron acceptors. Hundreds of other phylotypes are present at lower abundance in our V6 tag libraries and a rarefaction analysis indicates that sampling did not reach saturation, but FISH data limit the remaining biome to water and oxygenated glacial meltwater. PMID:19092861

  2. Influence of green waste compost on azimsulfuron dissipation and soil functions under oxic and anoxic conditions.

    Science.gov (United States)

    García-Jaramillo, M; Cox, L; Hermosín, M C; Cerli, C; Kalbitz, K

    2016-04-15

    Concerns have been raised over the sustainability of intensive rice cultivation, where the use of chemical fertilizers and pesticides has been associated with numerous environmental problems. The objective of this study was to test the effect of the herbicide azimsulfuron on important soil functions as affected by amendment with a byproduct of the olive oil industry. Soil was collected from a Mediterranean rice field. Part of it was amended with alperujo compost (AC). Amended and unamended soils were incubated for 43days in presence or not of azimsulfuron, under anoxic-flooded (AF) and oxic-unflooded (OU) conditions. We monitored the dissipation of the herbicide azimsulfuron, C mineralization, soil microbial biomass (SMB) and dissolved organic carbon (DOC) content and its nature. Under AF conditions, the application of compost produced an increase in the dissipation of the herbicide (up to 12.4%). It was related with the higher DOC content, 4 times higher than under OU conditions. Though increases in carbon turnover (under AF and OU conditions) and reduction of SMBC after herbicide application (only under AF conditions) were observed, the differences were not statistically significant. The application of this organic amendment is presented as an efficient management strategy to increase C turnover in agricultural soils and reduce some of the negative effects derived from the application of azimsulfuron under flooded conditions. PMID:26849340

  3. Counting clonogenic assays from normoxic and anoxic irradiation experiments manually or by using densitometric software

    International Nuclear Information System (INIS)

    The clonogenic assay is the method of choice to determine cell reproductive death after in vitro irradiation treatment. Traditionally, colony quantification has been performed by manual counting, a very laborious, time-consuming and rather subjective task. In this study, we compared manual counting by two skilled investigators with automated counting using the freely available ClonoCounter program. Five human tumour cell lines were irradiated under normoxia (21% O2) or anoxia (2), after 24 h or 6 h anoxic preincubation. Colonies were quantified manually or using the ClonoCounter software. A positive correlation between the absolute number of colonies counted manually and automatically was shown. Though there was a general trend of underpredicting the absolute number of cell colonies when counting automatically, survival curves were very similar, and in none of the cell lines were significant differences in radiobiological parameters such as mean inactivation dose, surviving fraction at 2 Gy and oxygen enhancement ratio detected. Our results suggest that the ClonoCounter provides sufficient reliability to be implemented for counting human tumour colonies in in vitro irradiation experiments. In contrast to several previously reported computer-aided colony-counting methods, it is a freely available program, requiring only minimal instrument costs. (note)

  4. Modeling simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater.

    Science.gov (United States)

    Mendes, Carlos; Esquerre, Karla; Queiroz, Luciano Matos

    2016-07-15

    This paper presents a mathematical model based on the Anaerobic Digestion Model No. 1 (ADM1) to simulate the effects of nitrate concentration and hydraulic retention time (HRT) on the simultaneous carbon and nitrogen removal (SCNR) in anaerobic/anoxic reactor treating domestic wastewater. The model was calibrated using previously published experimental data obtained from anaerobic batch tests for different COD/ [Formula: see text] ratios. Model simulations were performed to predict the SCNR in a completely mixed reactor (CSTR) operating under mesophilic conditions (35 °C). Six different scenarios were evaluated to investigate the performance of the SCNR based on typical influent characteristics of domestic wastewater. The variables analyzed were chemical oxygen demand (COD) removal, nitrate concentration, methane production, nitrogen gas, volatile fatty acids (VFA) concentration, pH and percentage of COD used by the denitrifying and methanogenic microorganisms. The HRT was decreased stepwise from 15 to 4 h. The results indicate that Scenario (S5) with a COD/ [Formula: see text] ratio equal to 10 and an HRT equal to 15 h ensures the occurrence of the stable SCNR. Furthermore, the accumulation of denitrification intermediates and a significant reduction in the biogas production when the organic matter is limited was verified. PMID:27088208

  5. Experimental study of the nickel solubility in groundwater and cement water under anoxic conditions

    International Nuclear Information System (INIS)

    According to the safety analysis of decommissioning waste from the Olkiluoto Nuclear Power Plant, 59Ni and 94Nb are dominant in the dose rates in the decommissioning waste after 6.5·104 years. The estimated solubility limit of Ni used in the analysis was based on both geochemical modeling and experimental results. However, the estimated solubility limit was associated with considerable uncertainties. In order for the safety analysis to be conservative, it was necessary to use values that clearly exceeded those obtained from the modeling and experiments. The same solubility limits were used for cement water and groundwater. The main objective of the work was to determine the solubility of Ni in groundwater and cement water under anoxic conditions. The experiments were carried out under CO2(g)-free N2 at ambient temperature using NiCl2 solutions spiked with 63Ni. The Ni concentration was determined from the 63Ni activity using liquid scintillation counting. The waters used consisted of two groundwaters from Olkiluoto, Finland, and two cement-conditioned waters. The latter were obtained by equilibrating the groundwaters with crushed and sieved cement. The nickel solubility in each of the four types of water was determined by using the over-saturation method

  6. Prognostically important EEG coma patterns in diffuse anoxic and traumatic encephalopathies in adults.

    Science.gov (United States)

    Synek, V M

    1988-04-01

    Because of the paucity in the English literature of a detailed and universally accepted EEG grading scale relating to survival after diffuse traumatic and anoxic brain insults, prognostically oriented EEG patterns including recently described abnormalities are presented and discussed. The significance of these patterns may also apply in cases of coma of other etiologies, which can present morphologically similar features. EEG patterns have been classified into five major grades based on an internationally accepted scale. Individual patterns have been more clearly defined on the basis of the morphology of dominant activities, their distribution, persistence, and reactivity to external stimulation. Favorable outcome with survival seems to occur with both grade 1 and the "reactive type" of grade 2 abnormalities, with preservation of normal sleep features, and with frontal monorhythmic delta activity. Prognostically uncertain patterns are "nonreactive" grade 2 abnormalities, diffuse delta activity with grade 3 abnormality, and the "reactive type of alpha pattern coma." The following patterns are suggested to be prognostically malignant if persistent: grade 3 abnormality with small amplitude, diffuse, irregular delta activity; grade 4 ("burst suppression pattern"), in particular when epileptiform discharges are present and with "low-output EEG"; and grade 5 ("isoelectric EEG"). Fatal outcome is also common with the "nonreactive type of alpha pattern coma" and the recently reported "theta pattern coma." These patterns are presented in the illustrations. It is intended that this more detailed subdivision will promote understanding between electroencephalographers using visual EEG assessment in cases of coma. PMID:3074973

  7. Alternate anoxic/aerobic operation for nitrogen removal in a membrane bioreactor for municipal wastewater treatment.

    Science.gov (United States)

    Guglielmi, G; Andreottola, G

    2011-01-01

    A large pilot-scale membrane bioreactor (MBR) with a conventional denitrification/nitrification scheme for municipal wastewater treatment has been run for one year under two different aeration strategies in the oxidation/nitrification compartment. During the first five months air supply was provided according to the dissolved-oxygen set-point and the system run as a conventional predenitrification MBR; then, an intermittent aeration strategy based on effluent ammonia nitrogen was adopted in the aerobic compartment in order to assess the impact on process performances in terms of N and P removal, energy consumption and sludge reduction. The experimental inferences show a significant improvement of the effluent quality as COD and total nitrogen, both due to a better utilization of the denitrification potential which is a function of the available electron donor (biodegradable COD) and electron acceptor (nitric nitrogen); particularly, nitrogen removal increased from 67% to 75%. At the same time, a more effective biological phosphorus removal was observed as a consequence of better selection of denitrifying phosphorus accumulating organisms (dPAO). The longer duration of anoxic phases also reflected in a lower excess sludge production (12% decrease) compared with the standard pre-denitrification operation and in a decrease of energy consumption for oxygen supply (about 50%). PMID:22335118

  8. Environmental magnetism of the Toarcian Oceanic Anoxic Event at Peniche (Portugal)

    Science.gov (United States)

    Font, Eric; Vitor Duarte, Luis; Adatte, Thierry; Mirão, José

    2016-04-01

    The Pliensbachian-Toarcian section of Peniche has been recently selected as the global stratotype section and point for this time interval. It represents one of the best examples of the record of the oceanic anoxic event (OAE) in the world. Here we conducted a detailed a magnetostratigraphic and environmental study in order to improve the time-scale calibration and to provide new magnetic markers for period of oceanic anoxia recorded in marine sediments. Our results show that the magnetic signal is carried by very low coercive magnetic minerals and exhibit unstable and unreliable data for magnetostratigraphic investigation. In counterpart, bulk magnetic properties (magnetic susceptibility, isothermal remanent magnetization curves, etc) coupled to Scanning Electron Microscopy (SEM) show a striking negative correlation with carbonate content and 13DC previously published in the literature. Particularly, the most pronounced negative C isotopic composition of the OAE interval correlates with high magnetic susceptibility values. SEM-EDS analysis show that the strata featured by high MS values contain ubiquitous pyrite and greigite framboids. These insights provide new markers to identify the magnetic signature of OAE in the marine record. Funded by IDL (FCT UID/GEO/50019/2013)

  9. Effect of substrate availability on nitrous oxide production by deammonification processes under anoxic conditions.

    Science.gov (United States)

    Schneider, Yvonne; Beier, Maike; Rosenwinkel, Karl-Heinz

    2012-05-01

    Due to its high global warming potential, nitrous oxide (N(2)O) emissions from wastewater treatment processes have recently received a high degree of attention. Nevertheless, there is still a lack of information regarding the microbiological processes leading to N(2)O production. In this study, two lab-scale sequencing batch reactors were operated with deammonification biomass to investigate the role of denitrification and the influence of substrate availability regarding N(2)O formation during the anoxic phase of deammonification. Three different operational phases were established: within the first phase conversion by anammox was favoured and after a transition phase, denitrification activity was promoted. Low nitrous oxide production was observed during stable operation aiming for anammox conversion. Pulsed inflow of the wastewater containing ammonium (NH(4)(+)) and nitrite (NO(2)(-)) led to increased N(2)O production rates. Within the period of denitrification as dominating nitrogen conversion process, the nitrous oxide concentration level was higher during continuous inflow conditions, but the reaction to pulsed inflow was less pronounced. The results indicated that denitrification was responsible for N(2)O formation from the deammonification biomass. Operational settings to achieve suppression of denitrification processes to a large extend were deducted from the results of the experiments. PMID:22296600

  10. Pathway of nitrous oxide consumption in isolated Pseudomonas stutzeri strains under anoxic and oxic conditions.

    Science.gov (United States)

    Desloover, Joachim; Roobroeck, Dries; Heylen, Kim; Puig, Sebastià; Boeckx, Pascal; Verstraete, Willy; Boon, Nico

    2014-10-01

    The microbial consumption of nitrous oxide (N2O) has gained great interest since it was revealed that this process could mitigate the greenhouse effect of N2O. The consumption of N2O results from its reduction to dinitrogen gas (N2) as part of the denitrification process. However, there is ongoing debate regarding an alternative pathway, namely reduction of N2O to NH4(+), or assimilatory N2O consumption. To date, this pathway is poorly investigated and lacks unambiguous evidence. Enrichment of denitrifying activated sludge using a mineral nitrogen-free medium rendered a mixed culture capable of anoxic and oxic N2O consumption. Dilution plating, isolation and deoxyribonucleic acid fingerprinting identified a collection of Pseudomonas stutzeri strains as dominant N2O consumers in both anaerobic and aerobic enrichments. A detailed isotope tracing experiment with a Pseudomonas stutzeri isolate showed that consumption of N2O via assimilatory reduction to NH4(+) was absent. Conversely, respiratory N2O reduction was directly coupled to N2 fixation. PMID:24447520

  11. Carbonate platform evidence of ocean acidification at the onset of the early Toarcian oceanic anoxic event

    Science.gov (United States)

    Trecalli, Alberto; Spangenberg, Jorge; Adatte, Thierry; Föllmi, Karl B.; Parente, Mariano

    2012-12-01

    The early Toarcian oceanic anoxic event (Early Jurassic;˜183 Myr ago) is associated with one of the largest negative carbon isotope excursion (CIE) in the whole Phanerozoic (3-7‰). Estimates of the magnitude and rate of CO2 injection in the ocean-atmosphere system are compatible with a scenario of ocean acidification. Many carbonate platforms drowned in the Pliensbachian, well before the early Toarcian event. In this paper we test the hypothesis of surface water ocean acidification by presenting data from a resilient carbonate platform: the Apennine Carbonate Platform of southern Italy. The studied sections document a dramatic shift of the carbonate factory from massive biocalcification to chemical precipitation. Lithiotis bivalves and calcareous algae (Palaeodasycladus mediterraneus), which were the most prolific carbonate producers of Pliensbachian carbonate platforms, disappear during the first phase of the early Toarcian CIE, before the most depleted values are reached. We discuss the local versus supraregional significance of this shift and propose a scenario involving abrupt decline of carbonate saturation, forced by CO2 release at the beginning of the early Toarcian CIE, followed by a calcification overshoot, driven by the recovery of ocean alkalinity. Attribution of the demise of carbonate platform hypercalcifiers to ocean acidification is supported by palaeophysiology and reinforced by experimental data on the detrimental effects of ocean acidification on recent shellfishes and calcareous algae.

  12. Nutrient removal and phosphorus recovery performances of a novel anaerobic-anoxic/nitrifying/induced crystallization process.

    Science.gov (United States)

    Shi, Jing; Lu, Xiwu; Yu, Ran; Zhu, Wentao

    2012-10-01

    An anaerobic-anoxic/nitrifying (A(2)N) two sludge process coupled with induced crystallization (IC) called A(2)N-IC process was developed for wastewater nutrient removal and phosphorus recovery. The performances of A(2)N-IC process in comparison with A(2)N process at different COD to phosphorus (COD/P) feeding ratios were investigated. The results indicated that A(2)N-IC achieved not only high and stable nutrient removal but also phosphorus recovery. Calcium phosphorus crystals were formed in the crystallization reactor in A(2)N-IC. Moreover, the incorporation of chemical induced crystallization improved biological phosphorus removal. In A(2)N-IC process, phosphorus removal efficiency was consistently maintained at 99.2%, whereas in A(2)N it decreased from 93.0% to 65.7% with the decrease of feeding COD/P ratio. The COD and ammonia removal efficiencies were regardless of feeding COD/P ratio in the two processes. PMID:22858484

  13. A pore water study of plutonium in a seasonally anoxic lake

    International Nuclear Information System (INIS)

    Data are presented on the distribution of sup(239,240)Pu in the pore waters of two cores taken from a seasonally anoxic lake. The pore water sup(239,240)Pu profile exhibits a subsurface activity maximum of 230 +- 30 μBq kg-1 in the 3-6 cm interval in June, as compared to an activity of 5 +- 3 μBq kg-1 in the overlying water. The pore water sup(239,240)Pu profile in June follows the solid phase distribution pattern of sup(239,240)Pu and also the pore water distributions of Fe and Mn. Under more reducing conditions in August, pore water sup(239,240)Pu activities drop off to undetectable levels at all depths. This rapid change in the pore water sup(239,240)Pu activity reflects the dynamic nature of Pu diagenesis in these sediments. Potential diffusional fluxes of sup(239,240)Pu into the lake's hypolimnion in June are calculated to be on the order of 2.5 μBq cm-2 y-1. This flux would not be significant in altering the solid phase sup(239,240)Pu inventory (2.8 x 104 μBq cm-2). (author)

  14. Dissolved organic matter in anoxic pore waters from Mangrove Lake, Bermuda

    Science.gov (United States)

    Orem, W.H.; Hatcher, P.G.; Spiker, E. C.; Szeverenyi, N.M.; Maciel, G.E.

    1986-01-01

    Dissolved organic matter and dissolved inorganic chemical species in anoxic pore water from Mangrove Lake, Bermuda sediments were studied to evaluate the role of pore water in the early diagenesis of organic matter. Dissolved sulphate, titration alkalinity, phosphate, and ammonia concentration versus depth profiles were typical of many nearshore clastic sediments and indicated sulphate reduction in the upper 100 cm of sediment. The dissolved organic matter in the pore water was made up predominantly of large molecules, was concentrated from large quantities of pore water by using ultrafiltration and was extensively tudied by using elemental and stable carbon isotope analysis and high-resolution, solid state 13C nuclear magnetic resonance and infrared spectroscopy. The results indicate that this material has a predominantly polysaccharide-like structure and in addition contains a large amount of oxygen-containing functional groups (e.g., carboxyl groups). The 13C nulcear magnetic resonance spectra of the high-molecular-weight dissolved organic matter resemble those of the organic matter in the surface sediments of Mangrove Lake. We propose that this high-molecular-weight organic matter in pore waters represents the partially degraded, labile organic components of the sedimentary organic matter and that pore waters serve as a conduit for removal of these labile organic components from the sediments. The more refractory components are, thus, selectively preserved in the sediments as humic substances (primarily humin). ?? 1986.

  15. Changes in calcareous nannoplankton calcification during the latest Cenomanian Oceanic Anoxic Event 2 and similarity with other Cretaceous Oceanic Anoxic Events

    Science.gov (United States)

    Faucher, Giulia; Erba, Elisabetta; Bottini, Cinzia

    2016-04-01

    The Cenomanian has been characterized by greenhouse climate conditions and profound environmental perturbations, including the latest Cenomanian Oceanic Anoxic Event 2 (OAE 2), an episode of widespread organic matter burial in oxygen-depleted oceans. OAE 2 is thought to be related to the emplacement of the Caribbean Plateau which probably introduced in the atmosphere a large amount of CO2 with consequent impact on biota, climate and ocean chemistry. The perturbation of the carbon cycle is reflected in the carbon isotopic record that evidences a positive shift at the OAE 2 onset and subsequent C-isotopic peaks. The aim of this study is the identification of possible changes in coccolith size/shape as a response to paleoenvironmental perturbations associated with OAE 2. Biometric analyses were performed on selected coccolith species (Biscutum constans, Discorhabdus rotatorius, Watznaueria barnesiae and Zeugrabdothus erectus) from five sections spanning the Cenomanian-Turonian boundary interval including OAE 2. The study provided evidence for size fluctuations and dwarfism of B. constans, Z. erectus and D. rotatorius during OAE 2, followed by a recovery at the end of the event. On the contrary, W. barnesiae displays constant sizes through the event. High-resolution investigations showed that B. constans follows the same size trends in all the analysed sections with i) a decrease in size at the OAE 2 onset where an increase in pCO2 is observed, ii) a partial increase in size back to pre-OAE 2 values around the first δ13C peak (peak A), where a decrease in pCO2 concentration is reconstructed iii) and a subsequent more expressed decrease in size reaching minimum values around the δ13C peak B where trace metal abundance has been identified. Small specimens are present till the end of OAE 2 and only after δ13C peak D a partial recovery in size is observed. Nannoplankton dwarfism is here interpreted as forced by rapidly increasing pCO2 during the formation of the

  16. Ecological production certification and the consumer ecological wants evolution

    OpenAIRE

    Chaikin, O.

    2013-01-01

    Article deals with the problem of modern tendency of the consumers ecological wants evolution development. The place of ecological certification in consumer evolutionary ecological want satisfaction under sustainable development condition bounds have been researched

  17. Terrestrial Ecology Guide.

    Science.gov (United States)

    Morrison, James W., Ed.; Hall, James A., Ed.

    This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…

  18. Audubon Ecology Study Program.

    Science.gov (United States)

    National Audubon Society, New York, NY.

    The materials in the set include a student reader "The Story of Ecology," a leaders' guide, and a large, pictorial wall chart. The student reader is divided into 10 units relating to a definition of ecology, the sun and life, air and the water cycle, major divisions of the earth, plants and food chains, distribution of plants and animals,…

  19. Ecological analyses and applications

    International Nuclear Information System (INIS)

    Progress is reported on the following: assessment of nuclear power plants; ecological analysis of uranium mining, milling, and fuel fabrication; environmental impact statements concerning uranium enrichment facilities; site evaluations for storage of radioactive wastes; ecological analysis of geothermal energy development; enhanced oil recovery; environmental monitoring plan for modular integrated utility systems; and fossil energy environmental project

  20. Biosemiotics and ecological monitoring

    DEFF Research Database (Denmark)

    Bruni, Luis Emilio

    2001-01-01

    the qualitative and relational aspects that can only be grasped by considering the semiotic networks operative in complex ecological and cultural systems. In this paper, it is suggested that a biosemiotic approach to ecology may prove useful for the modelling process, which in turn will allow the...

  1. Island Ecology in Bermuda.

    Science.gov (United States)

    Wulff, Barry L.; And Others

    1981-01-01

    Reports on an island ecology course offered by Eastern Connecticut State College providing opportunities for students to study the ecology and natural history of organisms found in a variety of subtropical habitats in Bermuda. Explains student selection criteria, trip preparation, evaluation criteria, daily programs, and habitats studied on the…

  2. Long-term performance and fouling analysis of full-scale direct nanofiltration (NF) installations treating anoxic groundwater

    KAUST Repository

    Beyer, Florian

    2014-10-01

    Long-term performance and fouling behavior of four full-scale nanofiltration (NF) plants, treating anoxic groundwater at 80% recovery for drinking water production, were characterized and compared with oxic NF and reverse osmosis systems. Plant operating times varied between 6 and 10 years and pretreatment was limited to 10μm pore size cartridge filtration and antiscalant dosage (2-2.5mgL-1) only. Membrane performance parameters normalized pressure drop (NPD), normalized specific water permeability (Kw) and salt retention generally were found stable over extended periods of operation (>6 months). Standard acid-base cleanings (once per year or less) were found to be sufficient to maintain satisfying operation during direct NF of the described iron rich (≤8.4mgL-1) anoxic groundwaters. Extensive autopsies of eight NF membrane elements, which had been in service since the plant startup (6-10 years), were performed to characterize and quantify the material accumulated in the membrane elements. Investigations using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), total organic carbon (TOC) and adenosine triphosphate (ATP) measurements revealed a complex mixture of organic, biological and inorganic materials. The fouling layers that developed during half to one year of operation without chemical cleaning were very thin (<2. μm). Most bio(organic) accumulates were found in the lead elements of the installations while inorganic precipitates/deposits (aluminosilicates and iron(II)sulfides) were found in all autopsied membrane elements. The high solubility of reduced metal ions and the very slow biofilm development under anoxic conditions prevented rapid fouling during direct NF of the studied groundwaters. When compared to oxic NF and RO systems in general (e.g. aerated ground waters or surface waters), the operation and performance of the described anoxic installations (with minimal pretreatment) can be described as very stable. © 2014

  3. Consumption of Methane and CO_2 by Methanotrophic Microbial Mats from Gas Seeps of the Anoxic Black Sea

    OpenAIRE

    Treude, Tina; Orphan, Victoria; Knittel, Katrin; Gieseke, Armin; House, Christopher H.; Boetius, Antje

    2007-01-01

    The deep anoxic shelf of the northwestern Black Sea has numerous gas seeps, which are populated by methanotrophic microbial mats in and above the seafloor. Above the seafloor, the mats can form tall reef-like structures composed of porous carbonate and microbial biomass. Here, we investigated the spatial patterns of CH_4 and CO_2 assimilation in relation to the distribution of ANME groups and their associated bacteria in mat samples obtained from the surface of a large reef structure. A combi...

  4. High sea-surface temperatures during the early Aptian Oceanic Anoxic Event 1a in the Boreal Realm

    OpenAIRE

    J. Mutterlose; Bottini, C.; Schouten, S.; Sinninghe Damsté, J.S.

    2014-01-01

    The early Aptian was characterized by the widespread occurrence of anoxia in the oceans, known as Oceanic Anoxic Event (OAE) 1a. Intense degassing from submarine volcanic plateaus presumably resulted in high atmospheric CO2 concentrations, culminating in greenhouse conditions. OAE 1a can, therefore, be considered as a past “natural experiment” important to understand the future evolution of our climate. Paleotemperature estimates for OAE 1a are, however, predominantly based on bulk oxygen iso...

  5. Seasonal dynamics of ammonia/ammonium-oxidizing prokaryotes in oxic and anoxic wetland sediments of subtropical coastal mangrove

    OpenAIRE

    Wang, Yong-Feng; Feng, Yao-Yu; Ma, Xiaojun; Gu, Ji-Dong

    2012-01-01

    Mangrove wetlands are an important ecosystem in tropical and subtropical regions, and the sediments may contain both oxic and anoxic zones. In this study, ammonia/ammonium-oxidizing prokaryotes (AOPs) in yellow and black sediments with vegetation and non-vegetated sediments in a mangrove wetland of subtropical Hong Kong were investigated in winter and summer. The phylogenetic diversity of anammox bacterial 16S rRNA genes and archaeal and bacterial amoA genes (encoding ammonia monooxygenase al...

  6. Assimilation of Cellulose-Derived Carbon by Microeukaryotes in Oxic and Anoxic Slurries of an Aerated Soil

    OpenAIRE

    Chatzinotas, Antonis; Schellenberger, Stefanie; Glaser, Karin; Kolb, Steffen

    2013-01-01

    Soil microeukaryotes may trophically benefit from plant biopolymers. However, carbon transfer from cellulose into soil microeukaryotes has not been demonstrated so far. Microeukaryotes assimilating cellulose-derived carbon in oxic and anoxic soil slurries were therefore examined by rRNA-based stable-isotope probing. Bacteriovorous flagellates and ciliates and, likely, mixotrophic algae and saprotrophic fungi incorporated carbon from supplemental [U-13C]cellulose under oxic conditions. A previ...

  7. Determination of major and minor constituents in anoxic thermal brines of deep sandstone aquifers in Northern Germany

    OpenAIRE

    Michael Kühn; C. Niewöhner; M. Isenbeck-Schröter; Hans-Martin Schulz;  

    1998-01-01

    The common process of low energy geothermal exploitation is the doublet of production- and reinjection borehole. The quality of water reinjected into a elastic reservoir is essential for the reliability of an injection well. In order to estimate precipitation reactions it is necessary to obtain extensive reliable analysis data of the water for the use of thermodynamic modelling. For thermal anoxic brines, the analysis of major and especially minor ion content is difficult because of matrix ef...

  8. Half saturation constants for nitrate and nitrite by in-sewer anoxic transformations of wastewater organic matter

    DEFF Research Database (Denmark)

    Abdul-Talib, Suhaimi; Hvitved-Jacobsen, Thorkild; Vollertsen, Jes;

    2001-01-01

     significant breakthrough and progress have been made in the study of the kinetics of microbial transformation in sewers under aerobic and under changing aerobic/anaerobic conditions. Fundamental knowledge on anoxic kinetics of wastewater is still lacking, so it is not now possible to apply...... experiments conducted on 7 different wastewater samples were found to be 0.76 gNO3.N/m3 and 0.33 gNO2-N/m3 respectively....

  9. The Denitrifying Biological Phosphorus Removal Performance in Anaerobic/Anoxic Sequencing Batch Reactor: The Effect of Carbon Source

    OpenAIRE

    Gürtekin, Engin; Nusret ŞEKERDAĞ

    2015-01-01

    In this study, the effect of carbon source on denitrifying biological phosphorus removal performance in acetate and glucose fed two anaerobic/anoxic sequencinq batch reactor (SBR) was investigated. Glucose and acetate were used as the substrates. In acetate and glucose fed reactors, the COD (Chemical Oxygen Demand) removal efficiencies were 91,90% and PO4-P removal efficiencies were 87,51% respectively. These results shows that the phosphorus removal efficiency is lower in glucose fed reactor.

  10. The anoxic stress conditions explored at the nanoscale by atomic force microscopy in highly eutrophic and sulfidic marine lake

    Science.gov (United States)

    Marguš, M.; Morales-Reyes, I.; Bura-Nakić, E.; Batina, N.; Ciglenečki, I.

    2015-10-01

    Marine Rogoznica lake (RL), an eutrophic and euxinic environment situated at the eastern Adriatic coast was used as a natural laboratory to test the application of atomic force microscopy (AFM) in combination with the electrochemical and high temperature catalytic oxidation (HTCO) measurements for characterization of water column organic matter (OM) and reduced sulfur species (RSS) in relation to seasonal changes of environmental conditions. Water column of RL was explored at the nanoscale by the AFM during the anoxic holomictic event (S1, October 2011) and stratified winter (S2, January 2012) and spring (S3, May 2012) conditions in the oxic and anoxic water samples. Obtained results from the AFM uphold the electrochemical and HTCO measurements, indicating significant difference in the present type of OM during the holomictic, anoxic stress conditions in comparison to the samples collected during the stratification period. Differences in the OM type were discussed in line with the physical and biological processes that occurred in RL during sampling: mixing processes characterized by fast turnover of water layers and biological activity characterized by low (January 2012) and high (May 2012) primary production of diatoms and zooplankton grazing activities.

  11. Nitrogen reduction in wastewater treatment using different anox-circulation flow rates and ethanol as a carbon source.

    Science.gov (United States)

    Poutiainen, H; Laitinen, S; Pradhan, S; Pessi, M; Heinonen-Tanski, H

    2010-05-01

    We studied the optimization of nitrogen reduction from municipal wastewater in a laboratory-scale modified Ludzack-Ettinger activated sludge wastewater treatment plant (WWTP). The unit consisted of primary denitrification, secondary nitrification, a sludge clarifier and a post-denitrification unit. The process simulates the Kuopio WWTP, which provided the influent utilized. We describe the effect of varying anox-circulation schemes on the nitrogen removal efficiency. We further compare the denitrification efficiencies of ethanol and methanol applied in the post-denitrification unit, and compare the properties and costs of these chemicals as carbon sources. Maximum efficiency of total nitrogen removal (70.8%) was obtained with 256% anox-circulation. The process was, however, not very sensitive, as a wide range of 150-400% of anox-circulations gave good results for nitrogen reduction. The unit achieved high BOD, and COD reductions of wastewater also when nitrogen reduction was moderate. The addition of 40 mg/L/day of ethanol to the post-denitrification tank meant that the nitrate-levels of effluent could be controlled to below 10 mg/L of nitrate nitrogen. Methanol and ethanol were equally effective for denitrification. The use of ethanol instead of methanol could reduce treatment costs by 30% to 0.02 E/m3 of treated wastewater according to 2008 market prices. PMID:20540423

  12. Assessment of Ecological Importance and Anthropogenic Change of Subaquatic Springs in Ancient Lake Ohrid

    OpenAIRE

    Jordanoska, Biljana; Stafilov, Trajče; Wüest, Alfred Johny

    2013-01-01

    Apart from their contribution in the water balance of Lake Ohrid, Republic of Macedonia, subaquatic springs are also expected to affect the water quality. A simple experiment was developed and applied to subaquatic spring in Kališta region (south-east of Kališta village, in the north-western part of the Lake) and at the spring at Veli Dab (eastern side of the Lake) based on physicochemical spring water properties. Different sampling methods were established with the aim of uncovering a more s...

  13. Fungal palaeodiversity revealed using high-throughput metabarcoding of ancient DNA from arctic permafrost

    DEFF Research Database (Denmark)

    Bellemain, E.; Davey, M.L.; Kauserud, H.;

    2013-01-01

    The taxonomic and ecological diversity of ancient fungal communities was assessed by combining next generation sequencing and metabarcoding of DNA preserved in permafrost. Twenty-six sediment samples dated 16000-32000 radiocarbon years old from two localities in Siberia were analysed for fungal ITS....... We detected 75 fungal OTUs from 21 orders representing three phyla, although rarefaction analyses suggested that the full diversity was not recovered despite generating an average of 6677±3811 (mean±SD) sequences per sample and that preservation bias likely has considerable effect on the recovered...... DNA. Most OTUs (75.4%) represented ascomycetes. Due to insufficient sequencing depth, DNA degradation and putative preservation biases in our samples, the recovered taxa probably do not represent the complete historic fungal community, and it is difficult to determine whether the fungal communities...

  14. Preservation of an ancient passive maker in Kurdish language

    Directory of Open Access Journals (Sweden)

    كريمي دوستان ، ویسی كريمي دوستان ، ویسی

    2009-01-01

    Full Text Available The existence of passive makers in Kurdish language, similar to that of ancient Iranian languages can be very helpful in linguistic studies, language change and finding the nature of passive structures in modern Iranian languages such as Persian. The writers of this article have found a passive maker in Kurdish language and its dialects such as Sorani, Ardalani, Kalhori, Ilami and Horami that like ancient Iranian languages is added to the verb root to form passive structures. This morpheme in Kurdish language appears as /ya/ and /ya^/ which is similar to /ya/ in ancient Iranian languages.

  15. Retroperitoneal ancient schwannoma: Review of clinico-radiological features

    International Nuclear Information System (INIS)

    A case is reported here of an ancient schwannoma in the retroperitoneum. The findings of abdominal ultrasound and CT in a patient with a retroperitoneal ancient schwannoma are presented, and the clinical and radiological features of this unusual tumour are reviewed. The presence of a large, well-delineated complex cystic mass in the deep soft tissues should raise the possibility of an ancient schwannoma. It is important to recognize these tumours as benign with excellent prognosis so as to avoid unnecessary radical surgery. Copyright (1998) Blackwell Science Pty Ltd

  16. Pathogens and host immunity in the ancient human oral cavity

    DEFF Research Database (Denmark)

    Warinner, Christina; Rodrigues, João F Matias; Vyas, Rounak;

    2014-01-01

    Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral...... cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction...... calculus permits the simultaneous investigation of pathogen activity, host immunity and diet, thereby extending direct investigation of common diseases into the human evolutionary past....

  17. Some notes on medical liability in ancient times.

    Science.gov (United States)

    Somville, F J M P; Broos, P L O; Van Hee, R

    2010-01-01

    Already in ancient times did medical liability occupy mankind. Various civilizations did give their own interpretation on the subject and proposed solutions. Original writings are rare and articles concerning ancient medical liability equally are hard to find. The only relatively trustworthy sources are of legal nature and find their origin in Greek philosophy and Roman Law. At a later stage, Arabic philosophers gave a renewed view on the statements of these previous civilizations and added their own way of thinking. All these influences still reflect in our modern western way of medical acting. Some of these ancient customs concerning medical liability will be discussed in this article. PMID:20690537

  18. Ferrous archaeological analogues for the understanding of the multi-secular corrosion mechanisms in an anoxic environment

    International Nuclear Information System (INIS)

    Understanding the long term corrosion mechanisms of iron in an anoxic environment is essential in the field of the radioactive waste storage. In France, it is planned to store high level nuclear wastes in a multi-barrier system containing a glassy matrix surrounded by a stainless steel container, embedded in a low-carbon steel over-container. This system would be placed in a deep geological repository, which would impose anoxic conditions. As it must be efficient for a period of several thousands of years, one should understand the alteration mechanisms that are expected to occur in such a long time. To this purpose, a specific approach is developed on ferrous archaeological analogues with thick corrosion layer formed in natural conditions. In this study, the corrosion mechanisms have been assessed by examining nails aged of 400 years coming from the archaeological site of Glinet, selected as a reference site. The first point was a fine characterisation of the entire corrosion system metal / corrosion products / medium, through the use of coupled multi-scale analytical tools. The first results showed that the samples were corroded in an anoxic calco-carbonated environment. Moreover, the coupling of X-ray micro-diffraction, Raman microspectroscopy and dispersive energy spectroscopy has enabled to identify three corrosion systems composed of iron carbonates, siderite and chukanovite, and magnetite. Depending on the phase's layout in the system, the electronic resistance of the corrosion layers has been established, from resistive to conductive. In a second stage, re-corroding experiments in laboratory were performed. Firstly, the electrochemical behaviour of the corrosion system has shown that water reduction at the metallic interface is negligible. Furthermore, reaction tracing with copper and deuterium has allowed identifying the electron consumptions sites mainly localised on the external part, and the precipitation sites on the internal part of the corrosion

  19. Education in ecology

    International Nuclear Information System (INIS)

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

  20. Quantifying Ancient Maya Land Use Legacy Effects on Contemporary Rainforest Canopy Structure

    Directory of Open Access Journals (Sweden)

    Jessica N. Hightower

    2014-11-01

    Full Text Available Human land use legacies have significant and long-lasting ecological impacts across landscapes. Investigating ancient (>400 years legacy effects can be problematic due to the difficulty in detecting specific, historic land uses, especially those hidden beneath dense canopies. Caracol, the largest (~200 km2 Maya archaeological site in Belize, was abandoned ca. A.D. 900, leaving behind myriad structures, causeways, and an extensive network of agricultural terraces that persist beneath the architecturally complex tropical forest canopy. Airborne LiDAR enables the detection of these below-canopy archaeological features while simultaneously providing a detailed record of the aboveground 3-dimensional canopy organization, which is indicative of a forest’s ecological function. Here, this remote sensing technology is used to determine the effects of ancient land use legacies on contemporary forest structure. Canopy morphology was assessed by extracting LiDAR point clouds (0.25 ha plots from LiDAR-identified terraced (n = 150 and non-terraced (n = 150 areas on low (0°–10°, medium (10°–20°, and high (>20° slopes. We calculated the average canopy height, canopy openness, and vertical diversity from the LiDAR returns, with topographic features (i.e., slope, elevation, and aspect as covariates. Using a PerMANOVA procedure, we determined that forests growing on agricultural terraces exhibited significantly different canopy structure from those growing on non-terraced land. Terraces appear to mediate the effect of slope, resulting in less structural variation between slope and non-sloped land and yielding taller, more closed, more vertically diverse forests. These human land uses abandoned >1000 years ago continue to impact contemporary tropical rainforests having implications related to arboreal habitat and carbon storage.

  1. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also means that more algorithm based methods, e.g. ordination techniques and boosted regression tress, will not be......This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement and...

  2. Quantitative plant ecology

    DEFF Research Database (Denmark)

    Damgaard, Christian

    2014-01-01

    This e-book is written in the Wolfram' CDF format (download free CDF player from Wolfram.com) The objective of this e-book is to introduce the population ecological concepts for measuring and predicting the ecological success of plant species. This will be done by focusing on the measurement and...... statistical modelling of plant species abundance and the relevant ecological processes that control species abundance. The focus on statistical modelling and likelihood function based methods also means that more algorithm based methods, e.g. ordination techniques and boosted regression tress, will not be...

  3. Massive Expansion of Marine Archaea During The Early Albian Oceanic Anoxic Event 1B

    Science.gov (United States)

    Kuypers, M. M.; Kuypers, M. M.; Blokker, P.; Erbacher, J.; Kinkel, H.; Pancost, R. D.; Pancost, R. D.; Schouten, S.; Sinninghe Damsté, J. S.

    2001-12-01

    Oceanic anoxic events (OAEs), periods of globally enhanced burial of organic matter (OM) in the marine realm, played an important role in the mid-Cretaceous `greenhouse climate' by effectively reducing atmospheric carbon dioxide concentrations. It is generally believed that these OAEs were caused either by decreased remineralisation or increased production of phytoplanktonic OM. Here we show that enhanced organic carbon (OC) burial during the early Albian OAE1b (~112 My) was caused by a different process. Combined biogeochemical and stable carbon isotopic analyses indicate that black shales from this period contain up to 80% of OC derived from archaea. Archaea-derived isoprenoidal tetraether membrane lipids and free and macromolecularly bound isoprenoid alkanes are abundantly present in these black shales. More specifically the presence of certain ether lipids (cyclic biphytane tetraethers) indicates representatives of the pelagic archaea. To the best of our knowledge this is the earliest fossil evidence for marine planktonic archaea, extending their geological record by more than 60 million years. The diversity of archaeal lipids recovered from the OAE1b black shales suggests that they derive from a multitude of archaeal species. However, the specific 13C enrichment of all such lipids indicates a common `heavy' (13C-rich) carbon source for the archaea and/or a common pathway of carbon-fixation with a reduced 13C fractionation effect compared to the Calvin cycle used by algae, cyanobacteria and higher plants. The large differences (up to 12%) in 13C/12C ratios between the algal biomarkers and the much more abundant archaeal molecular fossils suggest that the latter were not living heterotrophically on photoautotrophic biomass. It seems likely that the archaea present during OAE1b used a chemical energy source (possibly ammonium) for carbon fixation since photoautotrophy within the domain of the Archaea is restricted to only a few species from hypersaline

  4. [Medicine in ancient Mesopotamia--part 1].

    Science.gov (United States)

    Martins E Silva, J

    2009-01-01

    The present work summarizes the more elucidating aspects on the foundations and the practice of the medicine in Antique Mesopotamia, since the invention of the writing, more than 5000 thousand years ago, and the beginning of our era. The first part of the article includes a brief perspective about the political and social evolution that characterized those archaic civilizations, as well as the inventions and knowledge further used by the following Humanity's generations. Most of what is known on the subject, as well as the history and political-social events that occurred in the region during that remote epoch, resulted of the laborious decoding of about half a million small clay plates or fragments with text engravings in cuneiform characters that were discovered since the middle of the XIX century in the ruins of the main cities of the Babylonian and Assyrian empires. The second part embraces exclusively the main characteristics of the medicine in Ancient Mesopotamia, in its main facets: concept of disease, healers and practice. The disease was considered a divine punishment or resultant from a malign influence. In that base, the medicine began by being preventive, by the use of appropriate amulets, or by offerings or sacrifices intending to pacify those malign forces. The treatment of the generality of the diseases privileged the expulsion of those spirits and malign influences from the patient body, purifying it, which was done by the specific intervention of an ãshipu (clergyman-exorcist); not having results, the treatment was continued by the asû (practical healer) that appealed to a group of physical manipulations, limited surgical acts and the administration or application of prescriptions, resultants of the mixture of organic and inorganic substances. In case of failing, the patients (as well as individuals or rein leaders) could fall back upon a priest diviner (bârû) who, by examination of the organs of an animal especially sacrificed for the effect

  5. Influence of microorganisms on the oxidation state distribution of multivalent actinides under anoxic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald Timothy [Los Alamos National Laboratory; Borkowski, Marian [Los Alamos National Laboratory; Lucchini, Jean - Francois [Los Alamos National Laboratory; Ams, David [Los Alamos National Laboratory; Richmann, M. K. [Los Alamos National Laboratory; Khaing, H. [Los Alamos National Laboratory; Swanson, J. S. [Los Alamos National Laboratory

    2010-12-10

    The fate and potential mobility of multivalent actinides in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium, uranium and neptunium are the near-surface multivalent contaminants of concern and are also key contaminants for the deep geologic disposal of nuclear waste. Their mobility is highly dependent on their redox distribution at their contamination source as well as along their potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. Under anoxic conditions, indirect and direct bioreduction mechanisms exist that promote the prevalence of lower-valent species for multivalent actinides. Oxidation-state-specific biosorption is also an important consideration for long-term migration and can influence oxidation state distribution. Results of ongoing studies to explore and establish the oxidation-state specific interactions of soil bacteria (metal reducers and sulfate reducers) as well as halo-tolerant bacteria and Archaea for uranium, neptunium and plutonium will be presented. Enzymatic reduction is a key process in the bioreduction of plutonium and uranium, but co-enzymatic processes predominate in neptunium systems. Strong sorptive interactions can occur for most actinide oxidation states but are likely a factor in the stabilization of lower-valent species when more than one oxidation state can persist under anaerobic microbiologically-active conditions. These results for microbiologically active systems are interpreted in the context of their overall importance in defining the potential migration of multivalent actinides in the subsurface.

  6. Differential modification of oxic and anoxic components of radiation damage in Bacillus megaterium spores by caffeine

    International Nuclear Information System (INIS)

    Studies were carried out on the effect of caffeine on the X-irradiation sensitivity of B. megaterium spores with the following results: Caffeine exerts a concentration-dependent modifying action on oxygen-dependent components of X-ray-induced damage in B. megaterium spore suspensions causing an 'over-O2 effect' at about 1 x 10-4 mol dm-3, and as the concentration is increased to 1 10-3 mol dm-3 or above, a small but consistent protection is seen. In the absence of O2, at a wide range of concentrations (8.5 x 10-5 to 1 x 10-1 mol dm-3), caffeine enhances the inactivation constant, k, from 1.17 to about 1.50 kGy-1. Both ethanol and t-butanol (5 x 10-2 mol dm-3) remove the 'over O2-effect' produced by 1 x 10-4 mol dm-3 caffeine in O2; such an effect, however, is not accompanied by reduction in the H2O2 concentrations in the spore suspensions. Ethanol prevents caffeine-induced anoxic sensitization, as well as H2O2 buildup. t-BuOH has no influence on either the low dose part of the log fraction survival curve or on the H2O2 yield in the spore suspensions. Caffeine reacts with radiation-induced e-sub(aq) and radicalOH with rate constants of 1.5 x 1010 and 6.9 x 109 dm3 mol-1 s-1, respectively. (author)

  7. Denitrification coupled with methane anoxic oxidation and microbial community involved identification

    Directory of Open Access Journals (Sweden)

    Renata Medici Frayne Cuba

    2011-02-01

    Full Text Available In this work, the biological denitrification associated with anoxic oxidation of methane and the microbial diversity involved were studied. Kinetic tests for nitrate (NO3- and nitrite (NO2- removal and methane uptake were carried out in 100 mL batch reactors incubated in a shaker (40 rpm at 30 ºC. Denitrificant/methanotrophic biomass was taken from a laboratory scale reactor fed with synthetic nitrified substrates (40 mgN L-1 of NO3- and subsequently NO2- and methane as carbon source. Results obtained from nitrate removal followed a first order reaction, presenting a kinetic apparent constant (kNO3 of 0.0577±0.0057d-1. Two notable points of the denitrification rate (0.12gNO3--N g-1 AVS d-1 and 0.07gNO3--N g-1 AVS d-1 were observed in the beginning and on the seventh day of operation. When nitrite was added as an electron acceptor, denitrification rates were improved, presenting an apparent kinetic constant (kNO2 of 0.0722±0.0044d-1, a maximum denitrification rate of 0.6gNO2--N g-1AVS d-1, and minimum denitrification rate of 0.1gNO2--N g-1AVS d-1 at the beginning and end of the test, respectively. Endogenous material supporting denitrification and methane concentration dissolved in the substrate was discarded from the control experiments in the absence of methane and seed, respectively. Methylomonas sp. was identified in the reactors fed with nitrate and nitrite as well as uncultured bacterium.

  8. Anoxic growth of Ensifer meliloti 1021 by N2O-reduction, a potential mitigation strategy

    Science.gov (United States)

    Bueno, Emilio; Mania, Daniel; Frostegard, Ǻsa; Bedmar, Eulogio J.; Bakken, Lars R.; Delgado, Maria J.

    2015-01-01

    Denitrification in agricultural soils is a major source of N2O. Legume crops enhance N2O emission by providing N-rich residues, thereby stimulating denitrification, both by free-living denitrifying bacteria and by the symbiont (rhizobium) within the nodules. However, there are limited data concerning N2O production and consumption by endosymbiotic bacteria associated with legume crops. It has been reported that the alfalfa endosymbiont Ensifer meliloti strain 1021, despite possessing and expressing the complete set of denitrification enzymes, is unable to grow via nitrate respiration under anoxic conditions. In the present study, we have demonstrated by using a robotized incubation system that this bacterium is able to grow through anaerobic respiration of N2O to N2. N2O reductase (N2OR) activity was not dependent on the presence of nitrogen oxyanions or NO, thus the expression could be induced by oxygen depletion alone. When incubated at pH 6, E. meliloti was unable to reduce N2O, corroborating previous observations found in both, extracted soil bacteria and Paracoccus denitrificans pure cultures, where expression of functional N2O reductase is difficult at low pH. Furthermore, the presence in the medium of highly reduced C-substrates, such as butyrate, negatively affected N2OR activity. The emission of N2O from soils can be lowered if legumes plants are inoculated with rhizobial strains overexpressing N2O reductase. This study demonstrates that strains like E. meliloti 1021, which do not produce N2O but are able to reduce the N2O emitted by other organisms, could act as even better N2O sinks. PMID:26074913

  9. Small-world Characteristics of EEG Patterns in Post-Anoxic Encephalopathy

    Directory of Open Access Journals (Sweden)

    Martijn eBeudel

    2014-06-01

    Full Text Available Post-Anoxic Encephalopathy (PAE has a heterogenous outcome which is difficult to predict. At present, it is possible to predict poor outcome using somatosensory evoked potentials (SSEP in only a minority of the patients at an early stage. In addition, it remains difficult to predict good outcome at an early stage. Network architecture, as can be quantified with continuous electroencephalography (cEEG, may serve as a candidate measure for predicting neurological outcome. Here we explore whether cEEG monitoring can be used to detect the integrity of neural network architecture in patients with PAE after cardiac arrest. From 56 patients with PAE treated with mild therapeutic hypothermia (MTH, 19-channel cEEG data was recorded starting as soon as possible after cardiac arrest. Adjacency matrices of shared frequencies between 1 and 25 Hz of the EEG channels were obtained using Fourier transformations. Number of network nodes and connections, clustering coefficient (C, average path length (L and small-world index (SWI were derived. Outcome was quantified by the best Cerebral Performance Category (CPC-score within 6 months. Compared to non-survivors, survivors showed significantly more nodes and connections. L was significantly higher and C and SWI were significantly lower in the survivor group than in the non-survivor group. The number of nodes, connections and the L negatively correlated with the CPC-score. C and SWI correlated positively with the CPC-score. The combination of number of nodes, connections, C and L showed the most significant difference and correlation between survivors and non-survivors and CPC-score. Our data might implicate that non-survivors have insufficient distribution and differentiation of neural activity for regaining normal brain function. These network differences, already present during hypothermia, might be further developed as early prognostic markers. The predictive values are however still inferior to current practice

  10. Small-world characteristics of EEG patterns in post-anoxic encephalopathy.

    Science.gov (United States)

    Beudel, Martijn; Tjepkema-Cloostermans, Marleen C; Boersma, Jochem H; van Putten, Michel J A M

    2014-01-01

    Post-anoxic encephalopathy (PAE) has a heterogenous outcome which is difficult to predict. At present, it is possible to predict poor outcome using somatosensory evoked potentials in only a minority of the patients at an early stage. In addition, it remains difficult to predict good outcome at an early stage. Network architecture, as can be quantified with continuous electroencephalography (cEEG), may serve as a candidate measure for predicting neurological outcome. Here, we explore whether cEEG monitoring can be used to detect the integrity of neural network architecture in patients with PAE after cardiac arrest. From 56 patients with PAE treated with mild therapeutic hypothermia, 19-channel cEEG data were recorded starting as soon as possible after cardiac arrest. Adjacency matrices of shared frequencies between 1 and 25 Hz of the EEG channels were obtained using Fourier transformations. Number of network nodes and connections, clustering coefficient (C), average path length (L), and small-world index (SWI) were derived. Outcome was quantified by the best cerebral performance category (CPC)-score within 6 months. Compared to non-survivors, survivors showed significantly more nodes and connections. L was significantly higher and C and SWI were significantly lower in the survivor group than in the non-survivor group. The number of nodes, connections, and the L were negatively correlated with the CPC-score. C and SWI correlated positively with the CPC-score. The combination of number of nodes, connections, C, and L showed the most significant difference and correlation between survivors and non-survivors and CPC-score. Our data might implicate that non-survivors have insufficient distribution and differentiation of neural activity for regaining normal brain function. These network differences, already present during hypothermia, might be further developed as early prognostic markers. The predictive values are however still inferior to current practice parameters

  11. Impact of free ammonia on anammox rates (anoxic ammonium oxidation) in a moving bed biofilm reactor.

    Science.gov (United States)

    Jaroszynski, L W; Cicek, N; Sparling, R; Oleszkiewicz, J A

    2012-06-01

    Using a bench scale moving bed bioreactor (MBBR), the effect of free ammonia (FA, NH(3), the un-ionized form of ammonium NH(4)(+)) concentration on anoxic ammonium oxidation (anammox) was evaluated based on the volumetric nitrogen removal rate (NRR). Although, a detailed microbial analysis was not conducted, the major NRR observed was assumed to be by anammox, based on the nitrogen conversion ratios of nitrite to ammonium and nitrate to ammonium. Since the concentration of free ammonia as a proportion of the total ammonia concentration is pH-dependent, the impact of changing the operating pH from 6.9 to 8.2, was investigated under constant nitrogen loading conditions during continuous reactor operation. Furthermore, the effect of sudden nitrogen load changes was investigated under constant pH conditions. Batch tests were conducted to determine the immediate response of the anammox consortium to shifts in pH and FA concentrations. It was found that FA was inhibiting NRR at concentrations exceeding 2 mg N L(-1). In the pH range 7-8, the decrease in anammox activity was independent of pH and related only to the concentration of FA. Nitrite concentrations of up to 120 mg N L(-1) did not negatively affect NRR for up to 3.5 h. It was concluded that a stable NRR in a moving bed biofilm reactor depended on maintaining FA concentrations below 2 mg N L(-1) when the pH was maintained between 7 and 8. PMID:22483855

  12. Nitrogen polishing in a fully anoxic anammox MBBR treating mainstream nitritation-denitritation effluent.

    Science.gov (United States)

    Regmi, Pusker; Holgate, Becky; Miller, Mark W; Park, Hongkeun; Chandran, Kartik; Wett, Bernhard; Murthy, Sudhir; Bott, Charles B

    2016-03-01

    As nitrogen discharge limits are becoming more stringent, short-cut nitrogen systems and tertiary nitrogen polishing steps are gaining popularity. For partial nitritation or nitritation-denitritation systems, anaerobic ammonia oxidation (anammox) polishing may be feasible to remove residual ammonia and nitrite from the effluent. Nitrogen polishing of mainstream nitritation-denitritation system effluent via anammox was studied at 25°C in a fully anoxic moving bed bioreactor (MBBR) (V = 0.45 m(3) ) over 385 days. Unlike other anammox based processes, a very fast startup of anammox MBBR was demonstrated, despite nitrite limited feeding conditions (influent nitrite = 0.7 ± 0.59 mgN/L, ammonia = 6.13 ± 2.86 mgN/L, nitrate = 3.41 ± 1.92 mgN/L). The nitrogen removal performance was very stable within a wide range of nitrogen inputs. Anammox bacteria (AMX) activity up to 1 gN/m(2) /d was observed which is comparable to other biofilm-based systems. It is generally believed that nitrate production limits nitrogen removal through AMX metabolism. However, in this study, anammox MBBR demonstrated ammonia, nitrite, and nitrate removal at limited chemical oxygen demand (COD) availability. AMX and heterotrophs contributed to 0.68 ± 0.17 and 0.32 ± 0.17 of TIN removal, respectively. It was speculated that nitrogen removal might be aided by denitratation which could be due to heterotrophs or the recently discovered ability for AMX to use short-chain fatty acids to reduce nitrate to nitrite. This study demonstrates the feasibility of anammox nitrogen polishing in an MBBR is possible for nitritation-denitration systems. PMID:26333200

  13. Reproductive tactics of male bearded goby (Sufflogobius bibarbatus) in anoxic and hypoxic waters

    Science.gov (United States)

    Seivåg, Maria Larsen; Salvanes, Anne Gro Vea; Utne-Palm, Anne Christine; Kjesbu, Olav Si'gurd

    2016-03-01

    The bearded goby (Sufflogobius bibarbatus), a key species in the northern Benguela Upwelling Ecosystem, tolerates extremely low levels of oxygen. Yet little is known about how its reproduction is affected by these harsh living conditions. The distribution patterns of alternative reproductive tactics of male bearded goby across the continental shelf off Namibia were investigated. Histology and stereology were for the first time used to validate macroscopic maturity development by estimating volume fraction of the different stages of spermatogenesis using "Delesse principle", an approach so far for teleosts barely used in studies on testes but applied in advanced oocyte estimation. The macroscopic scale appeared suitable for the purpose, and the prevalence of territorial and sneaker tactics could therefore be documented. The sneakers had relative large testes and small seminal vesicles (SV), with the opposite being the case for the territorials. A third, numerous category with intermediate sized testes and SV was also recognized with unclear underlying tactical rationale, although regression analyses indicated similar investment in testes weight in relation to somatic weight as for the territorials. Low oxygen levels were the most important factor limiting spawning activity in territorial males. Our data suggested the existence of a spawning site on the outer shelf of the central Namibian shelf where the bottom water is hypoxic (oxygen saturation of 6.2-6.7%) while the anoxic middle shelf area (oxygen saturation of 1.7-2.9%) appeared to show too low oxygen levels for spawning to take place. Hence, significant parts of this large shelf area appear unsuited for successful reproduction of the bearded goby, in particular for nest building by the territorials.

  14. Cadmium-isotopic evidence for increasing primary productivity during the Late Permian anoxic event

    Science.gov (United States)

    Georgiev, Svetoslav V.; Horner, Tristan J.; Stein, Holly J.; Hannah, Judith L.; Bingen, Bernard; Rehkämper, Mark

    2015-01-01

    Earth's most extreme extinction event near the end of the Late Permian decimated more than 90% of all extant marine species. Widespread and intensive oceanic anoxia almost certainly contributed to the catastrophe, though the driving mechanisms that sustained such conditions are still debated. Of particular interest is whether water column anoxia was a consequence of a 'stagnant ocean', or if it was controlled by increases in nutrient supply, primary productivity, and subsequent heterotrophic respiration. Testing these competing hypotheses requires deconvolving sedimentary/bottom water redox conditions from changes in surface water productivity in marine sediments. We address this issue by studying marine shales from East Greenland and the mid-Norwegian shelf and combining sedimentary redox proxies with cadmium-isotopic analyses. Sedimentary nitrogen-isotopic data, pyrite framboid analyses, and organic and inorganic shale geochemistry reveal sulfidic conditions with vigorous upwelling, and increasingly anoxic conditions with a strengthening upwelling in the Greenland and Norwegian sections, respectively. Detailed analysis of sedimentary metal budgets illustrates that Cd is primarily associated with organic carbon and records primary geochemical signatures, thus enabling reconstruction of surface water nutrient utilization. Cadmium-isotopic analyses of the authigenic shale fraction released by inverse aqua regia digestion yield an average δ114Cd110 of + 0.15 ± 0.01 ‰ (2 SE, n = 12; rel. NIST SRM 3108), indicative of incomplete surface water nutrient utilization up-section. The constant degree of nutrient utilization combined with strong upwelling requires increasing primary productivity - and not oceanic stagnation - to balance the larger nutrient fluxes to both study sites during the development of the Late Permian water column anoxia. Overall, our data illustrate that if bottom water redox and upwelling can be adequately constrained, Cd-isotopic analyses of

  15. Anoxic Biodegradation of Isosaccharinic Acids at Alkaline pH by Natural Microbial Communities.

    Directory of Open Access Journals (Sweden)

    Simon P Rout

    Full Text Available One design concept for the long-term management of the UK's intermediate level radioactive wastes (ILW is disposal to a cementitious geological disposal facility (GDF. Under the alkaline (10.013.0 anoxic conditions expected within a GDF, cellulosic wastes will undergo chemical hydrolysis. The resulting cellulose degradation products (CDP are dominated by α- and β-isosaccharinic acids (ISA, which present an organic carbon source that may enable subsequent microbial colonisation of a GDF. Microcosms established from neutral, near-surface sediments demonstrated complete ISA degradation under methanogenic conditions up to pH 10.0. Degradation decreased as pH increased, with β-ISA fermentation more heavily influenced than α-ISA. This reduction in degradation rate was accompanied by a shift in microbial population away from organisms related to Clostridium sporosphaeroides to a more diverse Clostridial community. The increase in pH to 10.0 saw an increase in detection of Alcaligenes aquatilis and a dominance of hydrogenotrophic methanogens within the Archaeal population. Methane was generated up to pH 10.0 with acetate accumulation at higher pH values reflecting a reduced detection of acetoclastic methanogens. An increase in pH to 11.0 resulted in the accumulation of ISA, the absence of methanogenesis and the loss of biomass from the system. This study is the first to demonstrate methanogenesis from ISA by near surface microbial communities not previously exposed to these compounds up to and including pH 10.0.

  16. Jellyfish Lake, Palau: Regeneration of C, N, Si, and P in anoxic marine lake sediments

    Science.gov (United States)

    Lyons, W.B.; Lent, R.M.; Burnett, W.C.; Chin, P.; Landing, W.M.; Orem, W.H.; McArthur, J.M.

    1996-01-01

    Sediment cores from Jellyfish Lake were processed under an inert atmosphere and the pore waters extracted and analyzed for the following parameters: pH, titration alkalinity (TA), Cl-, H4SiO4, PO43-, NH4+, Ca2-, Mg2+, SO42-, and H2S. Additionally, in one set of pore-water samples (core 10), the ??13C of the ??CO2 was also determined. The TA, H4SiO4, PO43-, NH4+, and H2S increased with depth in the pore waters above anoxic bottom-water values. H2S values increased to 3.8 ??M. In one case, both H4SiO4 and PO43- concentrations increased to a maximum value and then decreased with depth, suggesting removal into solid phases. The H4SiO4 concentrations are equal to or greater than pore-water values observed in sediments underlying upwelling areas. PO43- concentrations are, in general, lower than pore-water values from terrigenous nearshore areas but higher than nearshore carbonate pore-water values from Florida Bay or Bermuda. The Ca2+, Cl-, and Mg2+: Cl- ratios show slight decreases in the top 15-20 cm, suggesting that authigenic carbonate may be forming. This suggestion is supported by the fact that the pore waters are saturated with respect to CaCO3 due to the very high TAs. The ??13C measurements of the pore-water ??CO2 are from a shorter core. These measurements reach their most negative concentration at 72 cm and then become slightly heavier. This change is accompanied by a decrease in TA, suggesting the onset of methanogenesis at this location in this core.

  17. Anoxic growth of Ensifer meliloti 1021 by N2O-reduction, a potential mitigation strategy

    Directory of Open Access Journals (Sweden)

    Emilio eBueno

    2015-05-01

    Full Text Available Denitrification in agricultural soils is a major source of N2O. Legume crops enhance N2O emission by providing N-rich residues, thereby stimulating denitrification, both by free-living denitrifying bacteria and by the symbiont (rhizobium within the nodules. However, there are limited data concerning N2O production and consumption by endosymbiotic bacteria associated with legume crops. It has been reported that the alfalfa endosymbiont Ensifer meliloti strain 1021, despite possessing and expressing the complete set of denitrification enzymes, is unable to grow via nitrate respiration under anoxic conditions. In the present study, we have demonstrated by using a robotized incubation system that this bacterium is able to grow through anaerobic respiration of N2O to N2. N2O reductase (N2OR activity was not dependent on the presence of nitrogen oxyanions or NO, thus the expression could be induced by oxygen depletion alone. When incubated at pH 6, E. meliloti was unable to reduce N2O, corroborating previous observations found in both, extracted soil bacteria and Paracoccus denitrificans pure cultures, where expression of functional N2O reductase is difficult at low pH. Furthermore, the presence in the medium of highly reduced C-substrates, such as butyrate, negatively affected N2OR activity. The emission of N2O from soils can be lowered if legumes plants are inoculated with rhizobial strains overexpressing N2O reductase. This study demonstrates that strains like E. meliloti 1021, which do not produce N2O but are able to reduce the N2O emitted by other organisms, could act as even better N2O sinks.

  18. Dissolution Behaviour of UO2 in Anoxic Conditions: Comparison of Ca-Bentonite and Boom Clay

    International Nuclear Information System (INIS)

    In order to determine in how far the clay properties influence the dissolution of spent fuel, experiments were carried out with depleted UO2 in the presence of either compacted dry Ca-bentonite with Boom Clay groundwater (KB-BCW) or compacted dry Boom Clay with Boom Clay groundwater (BC-BCW). The leach tests were performed at 25 deg. C in anoxic atmosphere for 2 years. The U concentrations in the clay water were followed during these 2 years, and the amount of U in the clay was determined after 2 years in order to determine the UO2 dissolution rate. The uranium concentration after 0.45 μm filtration was 50 times higher in the Boom Clay with Boom Clay water (2.0 x 10-7 mol.L-1) than in Ca-bentonite with Boom Clay water (6.5 x 10-9 mol.L-1), probably due to colloid formation in the Boom Clay system. Most released uranium was found in the clay. The fraction of uranium, dissolved from the UO2 pellet and found on the clay represents about 42 % of total uranium release in the system BC-BCW and more than 76 % in the system KB-BCW. The higher uranium retention of Boom Clay goes together with a higher dissolution rate. Global dissolution rates were estimated at about 2.0 x 10-2 μg.cm-2.d-1 for the BCBCW system and 3.4 x 10-3 μg.cm-2.d-1 for the KB-BCW system. This is not much lower than for similar tests with spent fuel, reported in literature. (authors)

  19. Stimulation of autotrophic denitrification by intrusions of the Bosporus Plume into the anoxic Black Sea

    Directory of Open Access Journals (Sweden)

    Clara A. Fuchsman

    2012-07-01

    Full Text Available Autotrophic denitrification was measured in the southwestern coastal Black Sea, where the Bosporus Plume injects oxidized chemical species (especially O2 and NO3- into the oxic, suboxic and anoxic layers. Prominent oxygen intrusions caused an overlap of NOx- and sulfide at the same station where autotrophic denitrification activity was detected with incubation experiments. Several bacteria that have been proposed to oxidize sulfide in other low oxygen environments were found in the Black Sea including SUP05, Sulfurimonas, Arcobacter, and BS-GSO2. Comparison of TRFLP profiles from this mixing zone station and the Western Gyre (a station not affected by the Bosporus Plume indicate the greatest relative abundance of Sulfurimonas and Arcobacter at the appropriate depths at the mixing zone station. The autotrophic gammaproteobacterium BS-GSO2 correlated with ammonium fluxes rather than with sulfide fluxes and the maximum in SUP05 peak height was shallower than the depths where autotrophic denitrification was detected. Notably, anammox activity was not detected at the mixing zone station, though low levels of DNA from the anammox bacteria Candidatus Scalindua were present. These results provide evidence for a modified ecosystem with different N2 production pathways in the southwest coastal region compared to that found in the rest of the Black Sea. Moreover, the same Sulfurimonas phylotype (BS139 was previously detected on >30 μm particles in the suboxic zone of the Western Gyre along with DNA of potential sulfate reducers, so it is possible that particle-attached autotrophic denitrification may be an overlooked N2 production pathway in the central Black Sea as well.

  20. Anoxic growth of Ensifer meliloti 1021 by N2O-reduction, a potential mitigation strategy.

    Science.gov (United States)

    Bueno, Emilio; Mania, Daniel; Frostegard, Ǻsa; Bedmar, Eulogio J; Bakken, Lars R; Delgado, Maria J

    2015-01-01

    Denitrification in agricultural soils is a major source of N2O. Legume crops enhance N2O emission by providing N-rich residues, thereby stimulating denitrification, both by free-living denitrifying bacteria and by the symbiont (rhizobium) within the nodules. However, there are limited data concerning N2O production and consumption by endosymbiotic bacteria associated with legume crops. It has been reported that the alfalfa endosymbiont Ensifer meliloti strain 1021, despite possessing and expressing the complete set of denitrification enzymes, is unable to grow via nitrate respiration under anoxic conditions. In the present study, we have demonstrated by using a robotized incubation system that this bacterium is able to grow through anaerobic respiration of N2O to N2. N2O reductase (N2OR) activity was not dependent on the presence of nitrogen oxyanions or NO, thus the expression could be induced by oxygen depletion alone. When incubated at pH 6, E. meliloti was unable to reduce N2O, corroborating previous observations found in both, extracted soil bacteria and Paracoccus denitrificans pure cultures, where expression of functional N2O reductase is difficult at low pH. Furthermore, the presence in the medium of highly reduced C-substrates, such as butyrate, negatively affected N2OR activity. The emission of N2O from soils can be lowered if legumes plants are inoculated with rhizobial strains overexpressing N2O reductase. This study demonstrates that strains like E. meliloti 1021, which do not produce N2O but are able to reduce the N2O emitted by other organisms, could act as even better N2O sinks. PMID:26074913

  1. Cretaceous oceanic anoxic event 2 triggered by a massive magmatic episode.

    Science.gov (United States)

    Turgeon, Steven C; Creaser, Robert A

    2008-07-17

    Oceanic anoxic events (OAEs) were episodes of widespread marine anoxia during which large amounts of organic carbon were buried on the ocean floor under oxygen-deficient bottom waters. OAE2, occurring at the Cenomanian/Turonian boundary (about 93.5 Myr ago), is the most widespread and best defined OAE of the mid-Cretaceous. Although the enhanced burial of organic matter can be explained either through increased primary productivity or enhanced preservation scenarios, the actual trigger mechanism, corresponding closely to the onset of these episodes of increased carbon sequestration, has not been clearly identified. It has been postulated that large-scale magmatic activity initially triggered OAE2 (refs 4, 5), but a direct proxy of magmatism preserved in the sedimentary record coinciding closely with the onset of OAE2 has not yet been found. Here we report seawater osmium isotope ratios in organic-rich sediments from two distant sites. We find that at both study sites the marine osmium isotope record changes abruptly just at or before the onset of OAE2. Using a simple two-component mixing equation, we calculate that over 97 per cent of the total osmium content in contemporaneous seawater at both sites is magmatic in origin, a approximately 30-50-fold increase relative to pre-OAE conditions. Furthermore, the magmatic osmium isotope signal appears slightly before the OAE2-as indicated by carbon isotope ratios-suggesting a time-lag of up to approximately 23 kyr between magmatism and the onset of significant organic carbon burial, which may reflect the reaction time of the global ocean system. Our marine osmium isotope data are indicative of a widespread magmatic pulse at the onset of OAE2, which may have triggered the subsequent deposition of large amounts of organic matter. PMID:18633415

  2. PNAS Plus: Origin of first cells at terrestrial, anoxic geothermal fields

    Science.gov (United States)

    Mulkidjanian, Armen Y.; Bychkov, Andrew Yu.; Dibrova, Daria V.; Galperin, Michael Y.; Koonin, Eugene V.

    2012-04-01

    All cells contain much more potassium, phosphate, and transition metals than modern (or reconstructed primeval) oceans, lakes, or rivers. Cells maintain ion gradients by using sophisticated, energy-dependent membrane enzymes (membrane pumps) that are embedded in elaborate ion-tight membranes. The first cells could possess neither ion-tight membranes nor membrane pumps, so the concentrations of small inorganic molecules and ions within protocells and in their environment would equilibrate. Hence, the ion composition of modern cells might reflect the inorganic ion composition of the habitats of protocells. We attempted to reconstruct the "hatcheries" of the first cells by combining geochemical analysis with phylogenomic scrutiny of the inorganic ion requirements of universal components of modern cells. These ubiquitous, and by inference primordial, proteins and functional systems show affinity to and functional requirement for K+, Zn2+, Mn2+, and phosphate. Thus, protocells must have evolved in habitats with a high K+/Na+ ratio and relatively high concentrations of Zn, Mn, and phosphorous compounds. Geochemical reconstruction shows that the ionic composition conducive to the origin of cells could not have existed in marine settings but is compatible with emissions of vapor-dominated zones of inland geothermal systems. Under the anoxic, CO2-dominated primordial atmosphere, the chemistry of basins at geothermal fields would resemble the internal milieu of modern cells. The precellular stages of evolution might have transpired in shallow ponds of condensed and cooled geothermal vapor that were lined with porous silicate minerals mixed with metal sulfides and enriched in K+, Zn2+, and phosphorous compounds.

  3. Constraining the temporal evolution of a deep hypersaline anoxic basin by 1D geochemical modelling

    Science.gov (United States)

    Goldhammer, Tobias; Aiello, Ivano; Zabel, Matthias

    2014-05-01

    Deep hypersaline anoxic basins (DHABs) are seafloor features of the accretionary prism of the Mediterranean Ridge. They have formed by the dissolution of exhumed shallow Messinian evaporites and subsequent concentration of the ultra-saline solutions in depressions on the seafloor. As an example, the horseshoe-shaped Urania basin is a DHAB south of the Peloponnese peninsula contains one of the most saline (about six times higher than Mediterranean seawater) and sulfidic (up to 15mM) water bodies of the Earth. Furthermore, its deepest part is underlain by a mud volcano that is responsible for the injection of fluid mud beneath the brine lake, with exceptionally sharp chemoclines between water column, brine, and mud layer. We here present a model approach to reconstruct the temporal aspects of the formation, dynamics and persistence of the brine-mud-system in the deep pit of the Urania Basin. Based on data from a sampling campaign with RV Meteor (Cruise M84/1 in February 2011), we set up a one-dimensional geochemical model that integrates diffusion, reaction and advective transport and mixing. Using a set of model preconditions, we aimed to answer (1) which processes are required to maintain the current situation of steep chemical gradients of the brine-mud-system, (2) how fast the current situation could have developed under different scenarios, and (3) how long such extraordinary conditions could have persisted through Earth's history. We further discuss the consequences of the temporal framework for the evolution of prokaryotic life in this extreme habitat.

  4. NF-κB and epigenetic mechanisms as integrative regulators of brain resilience to anoxic stress.

    Science.gov (United States)

    Sarnico, Ilenia; Branca, Caterina; Lanzillotta, Annamaria; Porrini, Vanessa; Benarese, Marina; Spano, Pier Franco; Pizzi, Marina

    2012-10-01

    Brain cells display an amazing ability to respond to several different types of environmental stimuli and integrate this response physiologically. Some of these responses can outlive the original stimulus by days, weeks or even longer. Long-lasting changes in both physiological and pathological conditions occurring in response to external stimuli are almost always mediated by changes in gene expression. To effect these changes, cells have developed an impressive repertoire of signaling systems designed to modulate the activity of numerous transcription factors and epigenetic mechanisms affecting the chromatin structure. Since its initial characterization in the nervous system, NF-κB has shown to respond to multiple signals and elicit pleiotropic activities suggesting that it may play a pivotal role in integration of different types of information within the brain. Ample evidence demonstrates that NF-κB factors are engaged in and necessary for neuronal development and synaptic plasticity, but they also regulate brain response to environmental noxae. By focusing on the complexity of NF-κB transcriptional activity in neuronal cell death, it emerged that the composition of NF-κB active dimers finely tunes the neuronal vulnerability to brain ischemia. Even though we are only beginning to understand the contribution of distinct NF-κB family members to the regulation of gene transcription in the brain, an additional level of regulation of NF-κB activity has emerged as operated by the epigenetic mechanisms modulating histone acetylation. We will discuss NF-κB and epigenetic mechanisms as integrative regulators of brain resilience to anoxic stress and useful drug targets for restoration of brain function. This article is part of a Special Issue entitled: Brain Integration. PMID:22575713

  5. Ecologies of Learning, Ecologies of Creativity

    DEFF Research Database (Denmark)

    Høyrup, Helene

    and further qualified by “Medierådet for børn og unge” [The Media Council for Children and Young Adults]. The purpose of this project, which I am presently advising and researching, is to investigate the learning-enhancing potentials in having local folk libraries and schools cooperate more closely...... in the light of the new Danish school reform. How can different learning institutions contribute to a “joint” ecology of learning? What would the benefits be from this in terms of young people’s literacies? On what theoretical basis can such an ecology and co-creation take place? And what kind of didactics......The subject of this project/paper is the challenges that digital media pose to earlier definitions, divisions and conceptions of learning institutions and their activities. It is argued that, in the light of digital media, the idea of institutional co-creation of learning and literacies needs...

  6. Barcoding the largest animals on Earth: ongoing challenges and molecular solutions in the taxonomic identification of ancient cetaceans.

    Science.gov (United States)

    Speller, Camilla; van den Hurk, Youri; Charpentier, Anne; Rodrigues, Ana; Gardeisen, Armelle; Wilkens, Barbara; McGrath, Krista; Rowsell, Keri; Spindler, Luke; Collins, Matthew; Hofreiter, Michael

    2016-09-01

    Over the last few centuries, many cetacean species have witnessed dramatic global declines due to industrial overharvesting and other anthropogenic influences, and thus are key targets for conservation. Whale bones recovered from archaeological and palaeontological contexts can provide essential baseline information on the past geographical distribution and abundance of species required for developing informed conservation policies. Here we review the challenges with identifying whale bones through traditional anatomical methods, as well as the opportunities provided by new molecular analyses. Through a case study focused on the North Sea, we demonstrate how the utility of this (pre)historic data is currently limited by a lack of accurate taxonomic information for the majority of ancient cetacean remains. We then discuss current opportunities presented by molecular identification methods such as DNA barcoding and collagen peptide mass fingerprinting (zooarchaeology by mass spectrometry), and highlight the importance of molecular identifications in assessing ancient species' distributions through a case study focused on the Mediterranean. We conclude by considering high-throughput molecular approaches such as hybridization capture followed by next-generation sequencing as cost-effective approaches for enhancing the ecological informativeness of these ancient sample sets.This article is part of the themed issue 'From DNA barcodes to biomes'. PMID:27481784

  7. Perspectives of the microbial carbon pump with special references to microbial respiration and ecological efficiency

    Directory of Open Access Journals (Sweden)

    H. Dang

    2014-01-01

    Full Text Available Although respiration consumes fixed carbon and produce CO2, it provides energy for essential biological processes of an ecosystem, including the microbial carbon pump (MCP. In MCP-driving biotransformation of labile DOC to recalcitrant DOC (RDOC, microbial respiration provides the metabolic energy for environmental organic substrate sensing, cellular enzyme syntheses and catalytic processes such as uptake, secretion, modification, fixation and storage of carbon compounds. The MCP efficiency of a heterotrophic microorganism is thus related to its energy production efficiency and hence to its respiration efficiency. Anaerobically respiring microbes usually have lower energy production efficiency and lower energy-dependent carbon transformation efficiency, and consequently lower MCP efficiency at per cell level. This effect is masked by the phenomena that anoxic environments often store more organic matter. Here we point out that organic carbon preservation and RDOC production is different in mechanisms, and anaerobically respiring ecosystems could also have lower MCP ecological efficiency. Typical cases can be found in large river estuarine ecosystems. Due to strong terrigenous input of nutrients and organic matter, estuarine ecosystems usually experience intense heterotrophic respiration processes that rapidly consume dissolved oxygen, potentially producing hypoxic and anoxic zones in the water column. The lowered availability of dissolved oxygen and the excessive supply of nutrients such as nitrate from river input prompt enhanced anaerobic respiration processes. Thus, some nutrients may be consumed by anaerobically respiring heterotrophic microorganisms, instead of being utilized by phytoplankton for carbon fixation and primary production. In this situation, the ecological functioning of the estuarine ecosystem is altered and the ecological efficiency is lowered, as less carbon is fixed and less energy is produced. Ultimately this would have

  8. Resurrecting ancient animal genomes: the extinct moa and more.

    Science.gov (United States)

    Huynen, Leon; Millar, Craig D; Lambert, David M

    2012-08-01

    Recently two developments have had a major impact on the field of ancient DNA (aDNA). First, new advances in DNA sequencing, in combination with improved capture/enrichment methods, have resulted in the recovery of orders of magnitude more DNA sequence data from ancient animals. Second, there has been an increase in the range of tissue types employed in aDNA. Hair in particular has proven to be very successful as a source of DNA because of its low levels of contamination and high level of ancient endogenous DNA. These developments have resulted in significant advances in our understanding of recently extinct animals: namely their evolutionary relationships, physiology, and even behaviour. Hair has been used to recover the first complete ancient nuclear genome, that of the extinct woolly mammoth, which then facilitated the expression and functional analysis of haemoglobins. Finally, we speculate on the consequences of these developments for the possibility of recreating extinct animals. PMID:22674514

  9. Ancestry of modern Europeans: contributions of ancient DNA.

    Science.gov (United States)

    Lacan, Marie; Keyser, Christine; Crubézy, Eric; Ludes, Bertrand

    2013-07-01

    Understanding the peopling history of Europe is crucial to comprehend the origins of modern populations. Of course, the analysis of current genetic data offers several explanations about human migration patterns which occurred on this continent, but it fails to explain precisely the impact of each demographic event. In this context, direct access to the DNA of ancient specimens allows the overcoming of recent demographic phenomena, which probably highly modified the constitution of the current European gene pool. In recent years, several DNA studies have been successfully conducted from ancient human remains thanks to the improvement of molecular techniques. They have brought new fundamental information on the peopling of Europe and allowed us to refine our understanding of European prehistory. In this review, we will detail all the ancient DNA studies performed to date on ancient European DNA from the Middle Paleolithic to the beginning of the protohistoric period. PMID:23052219

  10. A decision support system for the reading of ancient documents

    DEFF Research Database (Denmark)

    Roued-Cunliffe, Henriette

    2011-01-01

    The research presented in this thesis is based in the Humanities discipline of Ancient History and begins by attempting to understand the interpretation process involved in reading ancient documents and how this process can be aided by computer systems such as Decision Support Systems (DSS). The...... thesis balances between the use of IT tools to aid Humanities research and the understanding that Humanities research must involve human beings. It does not attempt to develop a system that can automate the reading of ancient documents. Instead it seeks to demonstrate and develop tools that can support......, by remembering complex reasoning, can aid the process of interpretation that is reading ancient documents. It is based on the idea that the interpretation process goes through a network of interpretation. The network of interpretation illustrates a recursive process where scholars move between...

  11. PIXE study on ancient pottery from Chinese Shanghai area

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H.S. [Institute of Modern Physics, Fudan University, 220 Handan Road, Shanghai 200433 (China)]. E-mail: hscheng@fudan.edu.cn; Zhang, Z.Q. [Institute of Modern Physics, Fudan University, 220 Handan Road, Shanghai 200433 (China); Song, J. [Shanghai Museum, Shanghai 200003 (China); Gao, M.H. [Department of Cultural Relics and Museology, Fudan University, Shanghai 200433 (China); Zhu, D. [Institute of Modern Physics, Fudan University, 220 Handan Road, Shanghai 200433 (China); Lin, J.W. [Institute of Modern Physics, Fudan University, 220 Handan Road, Shanghai 200433 (China); Feng, S.L. [Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918, Beijing 100039 (China)

    2006-08-15

    Shanghai is the largest city in China, and it also has a very long history. Archaeologists have found that six thousand yeas ago, there were ancient people living at Songze, Qingpu County, Shanghai. This paper reports the study of ancient potteries unearthed from the Guangfulin site located at Songjiang, Shanghai. The potteries unearthed from Guangfulin site belonged to two different culture types: the Liangzhu culture type (local culture) and a new culture, which might be derived from elsewhere. PIXE has been used to measure the chemical compositions of samples and factor analysis was used. Experimental results show that the compositions of the pottery from the two phases are different from each other. It means that the raw materials used to make the ancient pottery originate from different places. This results support the idea suggested by archaeologists that a group of ancient people migrated to the Shanghai area from some other place 4000 years ago.

  12. Transmission Electron Microscopy (TEM) investigations of ancient Egyptian cosmetic powders

    Science.gov (United States)

    Deeb, C.; Walter, P.; Castaing, J.; Penhoud, P.; Veyssière, P.

    The processing technologies available during the time of ancient Egypt are of present concern to the field of Archaeology and Egyptology. Materials characterization is the best tool for establishing the processing history of archaeological objects. In this study, transmission electron microscopy (TEM) is used, in addition to other techniques, for phase identification and study of the microstructure and characteristic defect structures in ancient Egyptian cosmetic powders. These powders generally consist of a mix of Pb-containing mineral phases: galena (PbS), cerussite (PbCO3), and phosgenite (Pb2Cl2CO3), among others. Modern materials are fabricated according to recipes found in ancient texts to mimic the processing of ancient times and to compare with the archaeological specimens. In particular, a comparison between the dislocation structures of PbS crystals deformed in the laboratory and PbS from archaeological specimens from the collections of the Louvre Museum is presented .

  13. No rheumatoid arthritis in ancient Egypt: a reappraisal.

    Science.gov (United States)

    Kwiecinski, Jakub; Rothschild, Bruce M

    2016-06-01

    Antiquity of rheumatoid arthritis (RA) remains controversial, and its origins in Americas or in the Old World are disputed. Proponents of the latter frequently refer to RA in ancient Egypt, but validity of those claims has never been examined. Review of all reported RA cases from ancient Egypt revealed that none of them represent real RA, instead being either examples of changing naming conventions or of imprecise diagnostic criteria. Most cases represented osteoarthritis or spondyloarthropathies. Also review of preserved ancient Egyptian medical writings revealed many descriptions of musculoskeletal disorders, but none of them resembled RA. This suggests that RA was absent in ancient Egypt and supports the hypothesis of the New World origin of RA and its subsequent global spread in the last several centuries. PMID:26650735

  14. Ancient Land Routes On The Paximadhi Peninsula, Karystos, Euboea

    Science.gov (United States)

    Keller, D.; Hom, E.

    Recent regional surface surveys have placed more focus on rural investigations, but the means of transport and communication within those rural surroundings has not always received adequate attention. The Southern Euboea Exploration Project has undertaken a new phase of research in the Karystos area with the goal of developing a methodology that allows for a more detailed record of the pre-modern land routes. On the Paximadhi peninsula it was possible to identify numerous fragments of suspected ancient routes dating to the Classical and Hellenistic periods. In the majority of cases these fragments were closely associated with adjacent datable ancient sites. By taking into consideration the evidence recorded during the survey it was sometimes possible to propose the extension of these ancient segments and to theorize the directions, lengths, and purposes of ancient networks.

  15. PIXE study on ancient pottery from Chinese Shanghai area

    International Nuclear Information System (INIS)

    Shanghai is the largest city in China, and it also has a very long history. Archaeologists have found that six thousand yeas ago, there were ancient people living at Songze, Qingpu County, Shanghai. This paper reports the study of ancient potteries unearthed from the Guangfulin site located at Songjiang, Shanghai. The potteries unearthed from Guangfulin site belonged to two different culture types: the Liangzhu culture type (local culture) and a new culture, which might be derived from elsewhere. PIXE has been used to measure the chemical compositions of samples and factor analysis was used. Experimental results show that the compositions of the pottery from the two phases are different from each other. It means that the raw materials used to make the ancient pottery originate from different places. This results support the idea suggested by archaeologists that a group of ancient people migrated to the Shanghai area from some other place 4000 years ago

  16. Deep sequencing of RNA from ancient maize kernels.

    Directory of Open Access Journals (Sweden)

    Sarah L Fordyce

    Full Text Available The characterization of biomolecules from ancient samples can shed otherwise unobtainable insights into the past. Despite the fundamental role of transcriptomal change in evolution, the potential of ancient RNA remains unexploited - perhaps due to dogma associated with the fragility of RNA. We hypothesize that seeds offer a plausible refuge for long-term RNA survival, due to the fundamental role of RNA during seed germination. Using RNA-Seq on cDNA synthesized from nucleic acid extracts, we validate this hypothesis through demonstration of partial transcriptomal recovery from two sources of ancient maize kernels. The results suggest that ancient seed transcriptomics may offer a powerful new tool with which to study plant domestication.

  17. SOIL BIOLOGY AND ECOLOGY

    Science.gov (United States)

    The term "Soil Biology", the study of organism groups living in soil, (plants, lichens, algae, moss, bacteria, fungi, protozoa, nematodes, and arthropods), predates "Soil Ecology", the study of interactions between soil organisms as mediated by the soil physical environment. oil ...

  18. Terrestrial animal ecology

    International Nuclear Information System (INIS)

    The Animal Ecology project is an integral part of the terrestrial ecology program. For convenience, it is reported separately because of the specialized nature of its techniques. It includes studies to characterize faunal populations taxonomically and ecologically and to estimate density and biomass of important mammal, bird, herpetofauna, and invertebrate populations. Extensive studies of small mammal populations conducted in past years are being summarized for open literature publication. Methodology and techniques developed in the animal ecology program are expected to be vital to studies to be initiated under a newly funded 189 entitled Radioecology of Waste Management Zones. These kinds of supportive studies will be needed to determine dietary habits of important animals inhabiting waste management zones, construction of realistic food chain models, and estimating radioactivity doses to biota

  19. Ecological Sections of Minnesota

    Data.gov (United States)

    Minnesota Department of Natural Resources — This coverage provides information for the second level of the Ecological Classification System. The boundaries of the polygons of this coverage were derived from...

  20. The French ecological movement

    International Nuclear Information System (INIS)

    The analysis of the ecological Movement in France is presented: its organisation, its topics, its position with respect to the main political trends. The accent is put in particular on the antinuclear contestation