Sample records for homo erectus fossils

  1. Getting to Know Homo erectus

    NSDL National Science Digital Library

    Jeffrey H. Schwartz (University of Pittsburgh; )

    2004-07-02

    Access to the article is free, however registration and sign-in are required. Europe and Asia have yielded a number of hominid fossils from the period 1 to 0.5 million years ago, but few hominid fossils from this era have been found in Africa. In his Perspective, Schwartz discusses a new hominid fossil find at Olorgesailie in Kenya, and whether it belongs to the species Homo erectus.

  2. Natural history ofHomo erectus

    Microsoft Academic Search

    2003-01-01

    Our view of H. erectus is vastly different today than when Pithecanthropus erectus was described in 1894. Since its synonimization into Homo, views of the species and its distribution have varied from a single, widely dispersed, polytypic species ultimately ancestral to all later Homo, to a derived, regional isolate ultimately marginal to later hominin evolution. A revised chrono- stratigraphic framework

  3. Grandmothering and the evolution of homo erectus.

    PubMed

    O'connell, J F; Hawkes, K; Blurton Jones, N G

    1999-05-01

    Despite recent, compelling challenge, the evolution of Homo erectus is still commonly attributed to big game hunting and/or scavenging and family provisioning by men. Here we use a version of the "grandmother" hypothesis to develop an alternative scenario, that climate-driven adjustments in female foraging and food sharing practices, possibly involving tubers, favored significant changes in ancestral life history, morphology, and ecology leading to the appearance, spread and persistence of H. erectus. Available paleoclimatic, environmental, fossil and archaeological data are consistent with this proposition; avenues for further critical research are readily identified. This argument has important implications for widely-held ideas about the recent evolution of long human lifespans, the prevalence of male philopatry among ancestral hominids, and the catalytic role of big game hunting and scavenging in early human evolution. PMID:10222165

  4. Crown morphology and variation of the lower premolars of Zhoukoudian Homo erectus

    Microsoft Academic Search

    Song Xing; Mi Zhou; Wu Liu

    2009-01-01

    Traditional descriptive observation and advanced geometric morphometric are employed to study the morphological characteristics\\u000a of Zhoukoudian mandibular premolars, and simultaneously with the specimens of Australopithecus, African early Homo, Homo erectus in other areas of Asia except Zhoukoudian, Europe Pleistocene fossil hominins, and recent Chinese (72 P3 and 69 P4 on the whole) being included as comparisons. Results suggest obvious evolutionary

  5. The Sambungmacan 3 Homo erectus Calvaria: A Comparative

    E-print Network

    Delson, Eric

    The Sambungmacan 3 Homo erectus Calvaria: A Comparative Morphometric and Morphological Analysis, Yogyakarta, Indonesia 10 Department of Cell Biology and Anatomy, Mount Sinai School of Medicine, New York. Here we undertake an analysis of its phylogenetic and systematic position using geometric morphometrics

  6. Taxonomic differences in deciduous upper second molar crown outlines of Homo sapiens, Homo neanderthalensis and Homo erectus.

    PubMed

    Bailey, Shara E; Benazzi, Stefano; Souday, Caroline; Astorino, Claudia; Paul, Kathleen; Hublin, Jean-Jacques

    2014-07-01

    A significant number of Middle to Late Pleistocene sites contain primarily (and sometimes only) deciduous teeth (e.g., Grotta del Cavallo, Mezmaiskaya, Blombos). Not surprisingly, there has been a recent renewed interest in deciduous dental variation, especially in the context of distinguishing Homo neanderthalensis and Homo sapiens. Most studies of the deciduous dentition of fossil hominins have focused on standard metrical variation but morphological (non-metric and morphometric) variation also promises to shed light on long standing taxonomic questions. This study examines the taxonomic significance of the crown outline of the deciduous upper second molar through principal components analysis and linear discriminant analysis. We examine whether or not the crown shape of the upper deciduous second molar separates H. neanderthalensis from H. sapiens and explore whether it can be used to correctly assign individuals to taxa. It builds on previous studies by focusing on crown rather than cervical outline and by including a large sample of geographically diverse recent human populations. Our samples include 17 H. neanderthalensis, five early H. sapiens, and 12 Upper Paleolithic H. sapiens. In addition, we include two Homo erectus specimens in order to evaluate the polarity of crown shape differences observed between H. neanderthalensis and H. sapiens. Our results show that crown outline shape discriminates H. sapiens and H. neanderthalensis quite well, but does not do well at distinguishing H. erectus from H. sapiens. We conclude that the crown outline shape observed in H. sapiens is a primitive retention and that the skewed shape observed in H. neanderthalensis is a derived condition. Finally, we explore the phylogenetic implications of the results for the H. erectus molars. PMID:24703186

  7. Early Homo erectus skeleton from west Lake Turkana, Kenya

    Microsoft Academic Search

    Frank Brown; John Harris; Richard Leakey; Alan Walker

    1985-01-01

    The most complete early hominid skeleton ever found was discovered at Nariokotome III, west Lake Turkana, Kenya, and excavated in situ in sediments dated close to 1.6 Myr. The specimen, KNM-WT 15000, is a male Homo erectus that died at 12 +\\/- 1 years of age, as judged by human standards, but was already 1.68 m tall. Although human-like in

  8. Molar crown inner structural organization in Javanese Homo erectus.

    PubMed

    Zanolli, Clément

    2015-01-01

    This contribution investigates the inner organizational pattern (tooth tissue proportions and enamel-dentine junction morphology) of seven Homo erectus permanent molar crowns from the late Lower-early Middle Pleistocene Kabuh Formation of the Sangiran Dome (Central Java, Indonesia). The previous study of their external characteristics confirmed the degree of time-related structural reduction occurred in Javanese H. erectus, and also revealed a combination of nonmetric features which are rare in the Lower and early Middle Pleistocene dental record, but more frequently found in recent humans. In accordance with their outer occlusal morphology, the specimens exhibit a set of derived internal features, such as thick to hyperthick enamel, an incomplete expression of the crest patterns at the enamel-dentine junction (EDJ) level, a sharp EDJ topography. As a whole, these features differ from those expressed in some penecontemporaneous specimens/samples representing African H. erectus/ergaster and H. heidelbergensis, as well as in Neanderthals, but occur in recent human populations. Further research in virtual dental paleoanthropology to be developed at macroregional scale would clarify the polarity and intensity of the intermittent exchanges between continental and insular Southeast Asia around the Lower to Middle Pleistocene boundary, as well as should shed light on the still poorly understood longitudinal evolutionary dynamics across continental Asia. PMID:25209431

  9. Shell tool use by early members of Homo erectus in Sangiran, central Java, Indonesia: cut mark evidence

    Microsoft Academic Search

    Kildo Choi; Dubel Driwantoro

    2007-01-01

    Sangiran has been known as a source of fossil Homo erectus but is better known for the absence of archaeological tools. Cut mark analysis of Pleistocene mammalian fossils documents 18 cut marks inflicted by tools of thick clamshell flakes on two bovid bones created during butchery at the Pucangan Formation in Sangiran between 1.6 and 1.5million years ago. These cut

  10. Ecospaces occupied by Homo erectus and Homo sapiens in insular Southeast Asia in the Pleistocene

    NASA Astrophysics Data System (ADS)

    Hertler, Christine; Haupt, Susanne; Volmer, Rebekka; Bruch, Angela

    2014-05-01

    Hominins migrated to the islands of the Sunda Shelf multiple times. At least two immigration events are evident, an early immigration of Homo erectus in the late Early Pleistocene and a second immigration of Homo sapiens during the Late Pleistocene. Regional environments changed considerably in the Pleistocene. Expansion patterns among hominins are at least co-determined by their ecologies and environmental change. We examine these expansion patterns on the basis of habitat reconstructions. Mammalian communities provide a geographically extensive record and permit to assess hominin ecospaces. Although chronological resolution is low, they represent the most complete record of habitat changes associated with hominin expansion patterns. In order to reconstruct and compare hominin ecospaces on a quantitative scale, we set up a reference sample consisting of mammalian communities of 117 national parks in South Asia and Sub-Saharan Africa. The diversity of such communities is assessed by ecological profiling of specialized herbivore taxa. Moreover, datasets on climate and vegetation correlate with the diversity structure of such specialized herbivore communities. Reconstructing the diversity structure of communities at key sites in Pleistocene Southeast Asia permits to infer features of the climatic and vegetation framework associated with different hominin taxa. Our results show that Homo erectus and Homo sapiens did not occupy similar ecospaces. The ecospace of Homo erectus is characterized by comparatively low diversity among frugivorous and folivorous taxa, while obligate grazers are part of the assemblages. Specialized herbivore communities with such a diversity structure occur at present in East Africa, while they are absent in Southeast Asia. In the reference sample, this type of ecospace corresponds to seasonal wetlands. Although Homo sapiens still inhabits this type of environment in Southeast Asia, his ecospace is wider. Homo sapiens is associated with specialized herbivore communities dominated by frugivorous and folivorous taxa. Specialized herbivore communities with such a diversity structure occur at present in rainforests on the Sunda Shelf.

  11. Dating the Homo erectus bearing travertine from Kocaba? (Denizli, Turkey) at at least 1.1 Ma

    NASA Astrophysics Data System (ADS)

    Lebatard, Anne-Elisabeth; Alçiçek, M. Cihat; Rochette, Pierre; Khatib, Samir; Vialet, Amélie; Boulbes, Nicolas; Bourlès, Didier L.; Demory, François; Guipert, Gaspard; Mayda, Serdar; Titov, Vadim V.; Vidal, Laurence; de Lumley, Henry

    2014-03-01

    Since its discovery within a travertine quarry, the fragmentary cranium of the only known Turkish Homo erectus, the Kocaba? hominid, has led to conflicting biochronological estimations. First estimated to be ˜500 ka old, the partial skull presents a combination of archaic and evolved features that puts it as an intermediate specimen between the Dmanisi fossils (Homo georgicus) and the Chinese Zhoukoudian skulls (Homo erectus) respectively dated to 1.8 to ˜0.8 Ma. Here we present a multidisciplinary study combining sedimentological, paleontological and paleoanthropological observations together with cosmogenic nuclide concentration and paleomagnetic measurements to provide an absolute chronological framework for the Upper fossiliferous Travertine unit where the Kocaba? hominid and fauna were discovered. The 26Al/10Be burial ages determined on pebbles from conglomeratic levels framing the Upper fossiliferous Travertine unit, which exhibits an inverse polarity, constrains its deposition to before the Cobb Mountain sub-chron, that is between 1.22 and ˜1.5 Ma. The alternative match of the normal polarity recorded above the travertine with the Jaramillo subchron (lower limit 1.07 Ma) may also be marginally compatible with cosmogenic nuclides interpretation, thus the proposed minimum age of 1.1 Ma for the end of massive travertine deposition. The actual age of the fossils is likely to be in the 1.1-1.3 Ma range. This absolute date is in close agreement with the paleoanthropological conclusions based on morphometric comparisons implying that Kocaba? hominid belongs to the Homo erectus s.l. group that includes Chinese and African fossils, and is different from Middle and Upper Pleistocene specimens. Furthermore, this date is confirmed by the large mammal assemblage, typical of the late Villafranchian. Because it attests to the antiquity of human occupation of the Anatolian Peninsula and one of the waves of settlements out of Africa, this work challenges the current knowledge of the Homo erectus dispersal over Eurasia.

  12. Mojokerto revisited: evidence for an intermediate pattern of brain growth in Homo erectus.

    PubMed

    O'Connell, Caitlin A; DeSilva, Jeremy M

    2013-08-01

    Brain development in Homo erectus is a subject of great interest, and the infant calvaria from Mojokerto, Indonesia, has featured prominently in these debates. Some researchers have suggested that the pattern of brain development in H. erectus resembled that of non-human apes, while others argue for a more human-like growth pattern. In this study, we retested hypotheses regarding brain ontogeny in H. erectus using new methods (resampling), and data from additional H. erectus crania. Our results reveal that humans achieve 62% (±10%) and chimpanzees 80% (±9%) of their adult endocranial volume by 0.5-1.5 years of age. Using brain mass data, humans achieve on average 65% and chimpanzees 81% of adult size by 0.5-1.5 years. When compared with adult H. erectus crania (n = 9) from Indonesian sites greater than 1.2 million years old, Mojokerto had reached ?70% of its adult cranial capacity. Mojokerto thus falls almost directly between the average growth in humans and chimpanzees, and well within the range of both. We therefore suggest that brain development in H. erectus cannot be dichotomized as either ape-like or human-like; it was H. erectus-like. These data indicate that H. erectus may have had a unique developmental pattern that should be considered as an important step along the continuum of brain ontogeny between apes and humans. PMID:23815827

  13. New dating of the Homo erectus cranium from Lantian (Gongwangling), China.

    PubMed

    Zhu, Zhao-Yu; Dennell, Robin; Huang, Wei-Wen; Wu, Yi; Rao, Zhi-Guo; Qiu, Shi-Fan; Xie, Jiu-Bing; Liu, Wu; Fu, Shu-Qing; Han, Jiang-Wei; Zhou, Hou-Yun; Ou Yang, Ting-Ping; Li, Hua-Mei

    2015-01-01

    The Homo erectus cranium from Gongwangling, Lantian County, Shaanxi Province is the oldest fossil hominin specimen from North China. It was found in 1964 in a layer below the Jaramillo subchron and was attributed to loess (L) L15 in the Chinese loess-palaeosol sequence, with an estimated age of ca. 1.15 Ma (millions of years ago). Here, we demonstrate that there is a stratigraphical hiatus in the Gongwangling section immediately below loess 15, and the cranium in fact lies in palaeosol (S) S22 or S23, the age of which is ca. 1.54-1.65 Ma. Closely spaced palaeomagnetic sampling at two sections at Gongwangling and one at Jiacun, 10 km to the north, indicate that the fossil layer at Gongwangling and a similar fossil horizon at Jiacun were deposited shortly before a short period of normal polarity above the Olduvai subchron. This is attributed to the Gilsa Event that has been dated elsewhere to ca. 1.62 Ma. Our investigations thus demonstrate that the Gongwangling cranium is slightly older than ca. 1.62 Ma, probably ca. 1.63 Ma, and significantly older than previously supposed. This re-dating now makes Gongwangling the second oldest site outside Africa (after Dmanisi) with cranial remains, and causes substantial re-adjustment in the early fossil hominin record in Eurasia. PMID:25456822

  14. An explorative multiproxy approach to characterize the ecospace of Homo erectus at Sangiran (Java, Indonesia)

    NASA Astrophysics Data System (ADS)

    Hertler, Christine; Haupt, Susanne; Lüdecke, Tina; Wirkner, Mathias; Bruch, Angela

    2015-04-01

    Homo erectus inhabited the islands of the Sunda Shelf in the late Early Pleistocene. This is illustrated by an extensive record of hominid specimens stemming from a variety of sites in Java. The hominid locality Sangiran plays a crucial role in studying related environments, because the geological record at the Sangiran dome covers a stratigraphic sequence, unlike any other hominid site in Java. Although the detailed chronology of the localities in Java is still under dispute, it covers the period between the late Early and early Middle Pleistocene. Fossil evidence includes the hominin specimens proper, diverse and evolving vertebrate faunas as well as pollen profiles. We applied a multiproxy approach to analyse and reconstruct features of the Homo erectus ecospace. Preliminary results of our explorative study are introduced in this paper. Based on the pollen record, we reconstructed temperature and precipitation for the major stratigraphic units. Although resulting values are averaging over wide chronological intervals, they illustrate general climatic trends in the late Early and early Middle Pleistocene in accordance with previous studies and the MIS record. The mammalian specimens we selected for this preliminary study possess a more restricted stratigraphic provenience. Our analyses are based on a dental sample of Duboisia santeng from the Koenigswald collection (n=14). The occurrence of the taxon is restricted to 3 layers in the stratigraphy. We reconstructed body mass and inferred diet from mesowear and isotope studies. There is no significant shift in body masses of Duboisia santeng. This result is in accordance with studies from other localities in Java. However, slight shifts in the mesowear signals (mixed feeder with increasingly browsing signal) are confirmed by studies of carbon isotopes. The analysis of oxygen isotopes provides evidence for seasonality which is compared with the signals from the vegetation.

  15. Way out of Africa: Early Pleistocene paleoenvironments inhabited by Homo erectus in Sangiran, Java.

    PubMed

    Bettis, E Arthur; Milius, Adrianne K; Carpenter, Scott J; Larick, Roy; Zaim, Yahdi; Rizal, Yan; Ciochon, Russell L; Tassier-Surine, Stephanie A; Murray, Daniel; Suminto; Bronto, Sutinko

    2009-01-01

    A sequence of paleosols in the Solo Basin, Central Java, Indonesia, documents the local and regional environments present when Homo erectus spread through Southeast Asia during the early Pleistocene. The earliest human immigrants encountered a low-relief lake-margin landscape dominated by moist grasslands with open woodlands in the driest landscape positions. By 1.5 Ma, large streams filled the lake and the landscape became more riverine in nature, with riparian forests, savanna, and open woodland. Paleosol morphology and carbon isotope values of soil organic matter and pedogenic carbonates indicate a long-term shift toward regional drying or increased duration of the annual dry season through the early Pleistocene. This suggests that an annual dry season associated with monsoon conditions was an important aspect of the paleoclimate in which early humans spread from Africa to Southeast Asia. PMID:19007966

  16. Fossil Humankind and Other Anthropoid Primates of China

    Microsoft Academic Search

    Xinzhi Wu

    2004-01-01

    More than 70 sites have yielded human fossils in China. They are attributed to Homo sapiens erectus and Homo sapiens sapiens. The earliest one is possibly about 1.7 Ma. A series of common morphological features, including shovel-shaped incisors and flatness of the face, characterize them. There is a morphological mosaic between H. s. erectus and H. s. sapiens in China.

  17. Landscape development preceding Homo erectus immigration into Central Java, Indonesia: the Sangiran Formation Lower Lahar

    Microsoft Academic Search

    E. Arthur Bettis; Yahdi Zaim; Roy R Larick; Russell L Ciochon; Suminto; Yan Rizal; Mark Reagan; Matthew Heizler

    2004-01-01

    The Sangiran Dome is the primary stratigraphic window for the Solo Basin, a coastal feature on the Pliocene–Pleistocene Sunda subcontinent south margin. In the Dome, the Lower Lahar unit (LLU) is a lahar-type debris flow overlying near-shore marine sediments. The event that emplaced the LLU likely originated from sector collapse on a neighboring volcanic edifice. Freshwater mollusc fossils in the

  18. The first archaic Homo from Taiwan.

    PubMed

    Chang, Chun-Hsiang; Kaifu, Yousuke; Takai, Masanaru; Kono, Reiko T; Grün, Rainer; Matsu'ura, Shuji; Kinsley, Les; Lin, Liang-Kong

    2015-01-01

    Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190-10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region. PMID:25625212

  19. The first archaic Homo from Taiwan

    PubMed Central

    Chang, Chun-Hsiang; Kaifu, Yousuke; Takai, Masanaru; Kono, Reiko T.; Grün, Rainer; Matsu’ura, Shuji; Kinsley, Les; Lin, Liang-Kong

    2015-01-01

    Recent studies of an increasing number of hominin fossils highlight regional and chronological diversities of archaic Homo in the Pleistocene of eastern Asia. However, such a realization is still based on limited geographical occurrences mainly from Indonesia, China and Russian Altai. Here we describe a newly discovered archaic Homo mandible from Taiwan (Penghu 1), which further increases the diversity of Pleistocene Asian hominins. Penghu 1 revealed an unexpectedly late survival (younger than 450 but most likely 190–10 thousand years ago) of robust, apparently primitive dentognathic morphology in the periphery of the continent, which is unknown among the penecontemporaneous fossil records from other regions of Asia except for the mid-Middle Pleistocene Homo from Hexian, Eastern China. Such patterns of geographic trait distribution cannot be simply explained by clinal geographic variation of Homo erectus between northern China and Java, and suggests survival of multiple evolutionary lineages among archaic hominins before the arrival of modern humans in the region. PMID:25625212

  20. Associated ilium and femur from Koobi Fora, Kenya, and postcranial diversity in early Homo.

    PubMed

    Ward, Carol V; Feibel, Craig S; Hammond, Ashley S; Leakey, Louise N; Moffett, Elizabeth A; Plavcan, J Michael; Skinner, Matthew M; Spoor, Fred; Leakey, Meave G

    2015-04-01

    During the evolution of hominins, it is generally accepted that there was a shift in postcranial morphology between Australopithecus and the genus Homo. Given the scarcity of associated remains of early Homo, however, relatively little is known about early Homo postcranial morphology. There are hints of postcranial diversity among species, but our knowledge of the nature and extent of potential differences is limited. Here we present a new associated partial ilium and femur from Koobi Fora, Kenya, dating to 1.9 Ma (millions of years ago) that is clearly attributable to the genus Homo but documents a pattern of morphology not seen in eastern African early Homo erectus. The ilium and proximal femur share distinctive anatomy found only in Homo. However, the geometry of the femoral midshaft and contour of the pelvic inlet do not resemble that of any specimens attributed to H. erectus from eastern Africa. This new fossil confirms the presence of at least two postcranial morphotypes within early Homo, and documents diversity in postcranial morphology among early Homo species that may reflect underlying body form and/or adaptive differences. PMID:25747316

  1. Taxonomic identification of Lower Pleistocene fossil hominins based on distal humeral diaphyseal cross-sectional shape

    PubMed Central

    2015-01-01

    The coexistence of multiple hominin species during the Lower Pleistocene has long presented a challenge for taxonomic attribution of isolated postcrania. Although fossil humeri are well-suited for studies of hominin postcranial variation due to their relative abundance, humeral articular morphology has thus far been of limited value for differentiating Paranthropus from Homo. On the other hand, distal humeral diaphyseal shape has been used to justify such generic distinctions at Swartkrans. The potential utility of humeral diaphyseal shape merits larger-scale quantitative analysis, particularly as it permits the inclusion of fragmentary specimens lacking articular morphology. This study analyzes shape variation of the distal humeral diaphysis among fossil hominins (c. 2-1 Ma) to test the hypothesis that specimens can be divided into distinct morphotypes. Coordinate landmarks were placed on 3D laser scans to quantify cross-sectional shape at a standardized location of the humeral diaphysis (proximal to the olecranon fossa) for a variety of fossil hominins and extant hominids. The fossil sample includes specimens attributed to species based on associated craniodental remains. Mantel tests of matrix correlation were used to assess hypotheses about morphometric relationships among the fossils by comparing empirically-derived Procrustes distance matrices to hypothetical model matrices. Diaphyseal shape variation is consistent with the hypothesis of three distinct morphotypes (Paranthropus, Homo erectus, non-erectus early Homo) in both eastern and southern Africa during the observed time period. Specimens attributed to non-erectus early Homo are unique among hominids with respect to the degree of relative anteroposterior flattening, while H. erectus humeri exhibit morphology more similar to that of modern humans. In both geographic regions, Paranthropus is characterized by a morphology that is intermediate with respect to those morphological features that differentiate the two forms of early Homo. This study demonstrates the utility of the humeral diaphysis for taxonomic identification of isolated postcranial remains and further documents a high degree of postcranial diversity in early Homo.

  2. The Homo habitat niche: using the avian fossil record to depict ecological characteristics of Palaeolithic Eurasian hominins

    NASA Astrophysics Data System (ADS)

    Finlayson, Clive; Carrión, José; Brown, Kimberly; Finlayson, Geraldine; Sánchez-Marco, Antonio; Fa, Darren; Rodríguez-Vidal, Joaquín; Fernández, Santiago; Fierro, Elena; Bernal-Gómez, Marco; Giles-Pacheco, Francisco

    2011-06-01

    Although hardly applied to human palaeoecology, bird fossils offer a unique opportunity for quantitative studies of the hominin habitat. Here we reconstruct the Homo habitat niche across a large area of the Palaearctic, based on a database of avian fauna for Pleistocene sites. Our results reveal a striking association between Homo and habitat mosaics. A mix of open savannah-type woodland, wetlands and rocky habitats emerges as the predominant combination occupied by Homo across a wide geographical area, from the earliest populations of the Lower Palaeolithic to the latest hunter-gatherer communities of the Upper Palaeolithic. This observation is in keeping with the view that such landscapes have had long standing selective value for hominins.

  3. Brief Communication: Shape analysis of the MT 1 proximal articular surface in fossil hominins and shod and unshod Homo.

    PubMed

    Proctor, Daniel J

    2010-12-01

    As a follow-up study to Proctor et al. (Am J Phys Anthropol 135 (2008) 216-224), this study quantifies the first metatarsal proximal articular surface using three-dimensional morphometrics to test for differences in articular surface shape between habitually shod and habitually unshod humans. In addition, differences in shape between Homo, Pan, Gorilla, and Hylobates are compared to the fossil hominin specimens A. L. 333-54, Stw 562, Stw 573 ("Little Foot"), OH 8, SKX 5017, and SK 1813. No difference in surface shape was found between habitually shod and habitually unshod humans. There is a clear quantitative division in articular surface shape between humans and apes that is more pronounced than a previous study by Proctor et al. (Am J Phys Anthropol 135 (2008) 216-224), due to additional landmarks present in this study. The specimen OH 8 is indistinguishable from modern Homo. The fossils A. L. 333-54, Stw 562, and Stw 573 are intermediate in shape between humans and apes. The specimens SKX 5017 and SK 1813 have a more apelike articular surface. When combined with other characteristics, this trait suggests that Paranthropus used a degree of abduction during locomotion that was much less than that in extant apes, but greater than that in Australopithecus, allowing for some small degree of grasping ability. PMID:20925078

  4. Dead Men Telling Tales: Homo Fossils and What to Do With Them

    Microsoft Academic Search

    Ben Jeffares

    2004-01-01

    “Human Paleobiology” is about the use of fossils to determine the adaptations and evolutionary trajectories of human ancestors. At least part of this book’s purpose may be summed up in its title; this is Paleobiology, the study of long dead organisms via their fossils, as opposed to Paleoanthropology, the physical anthropology of dead people. Consequently, this book draws attention to

  5. Disproportionate Cochlear Length in Genus Homo Shows a High Phylogenetic Signal during Apes’ Hearing Evolution

    PubMed Central

    Braga, J.; Loubes, J-M.; Descouens, D.; Dumoncel, J.; Thackeray, J. F.; Kahn, J-L.; de Beer, F.; Riberon, A.; Hoffman, K.; Balaresque, P.; Gilissen, E.

    2015-01-01

    Changes in lifestyles and body weight affected mammal life-history evolution but little is known about how they shaped species’ sensory systems. Since auditory sensitivity impacts communication tasks and environmental acoustic awareness, it may have represented a deciding factor during mammal evolution, including apes. Here, we statistically measure the influence of phylogeny and allometry on the variation of five cochlear morphological features associated with hearing capacities across 22 living and 5 fossil catarrhine species. We find high phylogenetic signals for absolute and relative cochlear length only. Comparisons between fossil cochleae and reconstructed ape ancestral morphotypes show that Australopithecus absolute and relative cochlear lengths are explicable by phylogeny and concordant with the hypothetized ((Pan,Homo),Gorilla) and (Pan,Homo) most recent common ancestors. Conversely, deviations of the Paranthropus oval window area from these most recent common ancestors are not explicable by phylogeny and body weight alone, but suggest instead rapid evolutionary changes (directional selection) of its hearing organ. Premodern (Homo erectus) and modern human cochleae set apart from living non-human catarrhines and australopiths. They show cochlear relative lengths and oval window areas larger than expected for their body mass, two features corresponding to increased low-frequency sensitivity more recent than 2 million years ago. The uniqueness of the “hypertrophied” cochlea in the genus Homo (as opposed to the australopiths) and the significantly high phylogenetic signal of this organ among apes indicate its usefulness to identify homologies and monophyletic groups in the hominid fossil record. PMID:26083484

  6. Dental Evidence for Diets of Early Homo

    Microsoft Academic Search

    Peter S. Ungar; Robert S. Scott

    The evolution of diet in the earliest members of our genus, Homo rudolfensis, H. habilis and H. erectus has received increased attention over the past few years (see Ungar et al., 2006a for review). Many models have been constructed,\\u000a based largely on nutritional studies combined with direct analogy (with living peoples or non-human primates) or on contextual\\u000a evidence, such as

  7. No homo.

    PubMed

    Brown, Joshua R

    2011-01-01

    The phrase no homo arose in hip-hop lyrics of the 1990s as a discourse interjection to negate supposed sexual and gender transgressions. Today the phrase has gained currency beyond hip-hop culture and pervades racial and gender continua. As a result, its increasing prevalence in mainstream speech has caused critics to deplore no homo as outright homophobia. This article describes the origins and scope of no homo. Instead of easily identifying the phrase as homophobic, the article invites readers to examine the phrase as a way of understanding the complexities in gender identification processes along with the linguistic dexterity necessary for survival in certain sociocultural groups. By exploring the macrosociological issues which created and perpetuate the need for no homo, we arrive at a deeper understanding of sexuality, marginalized sexuality, and the (often unspoken) uneasiness with sexual and gendered nonconformity. PMID:21360388

  8. New magnetostratigraphy for the Olduvai Subchron in the Koobi Fora Formation, northwest Kenya, with implications for early Homo

    NASA Astrophysics Data System (ADS)

    Lepre, Christopher J.; Kent, Dennis V.

    2010-02-01

    A problematic magnetostratigraphy for the Koobi Fora Formation has contributed to debates on the evolutionary implications for early hominin fossils. To address this, 50 independent samples distributed over a nearly 63-m-thick interval were collected from the lower-middle KBS Member type section in fossil collection Area 102, northeast Turkana Basin. Characteristic directions obtained by thermal demagnetization define a coherent magnetostratigraphy that is supported by alternating-field studies on 28 sister specimens and the prior tephrochronological framework. Two long polarity intervals were recognized, each 30-40 m in thickness, and interpreted as the upper part of the normal polarity Olduvai Subchron and the overlying reverse polarity Matuyama Chron. The end Olduvai consists of a normal-reverse-normal polarity sequence occurring over a thickness of at least 1 m but perhaps up to 5 m, suggesting that this subchron has a short reverse interval in its uppermost part. Such a fine-scale structure also has been reported from several other sites, like the Pliocene-Pleistocene boundary and point stratotype section at Vrica, Italy, which serves as a basis for formally delimiting three temporally discrete polarity subintervals for the Olduvai Subchron. These paleomagnetic results that place the upper boundary of the Olduvai at ˜ 48 m above the base of the KBS Member, coupled with published radioisotopic dates, firmly secure the age of partial cranium KNM-ER 3733 in the interval 1.78-1.48 Ma, with an interpolated age of ˜ 1.7 Ma, giving this fossil the most unambiguous numerical-age constraints, as compared to the oldest Homo cranial remains from Europe and Asia. Nonetheless, assured placement of the top of the Olduvai Subchron in the KBS Member is not sufficient in the face of other uncertainties to influence conventional interpretations of the timing and direction for the global dispersal of early Homo erectus.

  9. Wild chimpanzee dentition and its implications for assessing life history in immature hominin fossils

    PubMed Central

    Zihlman, Adrienne; Bolter, Debra; Boesch, Christophe

    2004-01-01

    Data from three African field sites on Pan troglodytes demonstrate an unambiguous pattern of a slower growth rate in wild vs. captive chimpanzee populations. A revised dental growth chronology for chimpanzees is similar to estimated timing of Homo erectus and therefore has implications for interpreting life history in hominins. PMID:15243156

  10. Antinociceptive and Anti-Inflammatory Effects of Solvent Extracts of Tagetes erectus Linn ( Asteraceae)

    Microsoft Academic Search

    NV Shinde; KG Kanase

    Purpose: Traditionally, the leaves of Tagetes erectus L. are used in India for the alleviation of pain and inflammation. The objective of this study was to investigate the antinociceptive and anti-inflammatory activities of this plant material in an animal model. Methods: The chloroform, methanol and ether extracts of the leaves of Tagetes erectus L. (family: Asteraceae) were tested against acetic

  11. Cytogenetic and Nuclear DNA Content Characterization of Diploid Bromus erectus and Bromus variegatus

    Microsoft Academic Search

    Metin Tuna; Kenneth P. Vogel; K. Arumuganathan

    2006-01-01

    Bromus erectus Huds. (erect brome) and B. variegatus M. Bieb. are Eurasian Bromus species that have been tentatively identified as potential progenitors of smooth bromegrass (B. inermis Leyss) which is the principal cultivated bromegrass in North America. The objective of this study was to characterize the genome of diploid accessions of B. erectus (2n 5 2x 5 14) and B.

  12. Postcranial evidence from early Homo from Dmanisi, Georgia

    Microsoft Academic Search

    David Lordkipanidze; Tea Jashashvili; Abesalom Vekua; Marcia S. Ponce de León; Christoph P. E. Zollikofer; G. Philip Rightmire; Herman Pontzer; Reid Ferring; Oriol Oms; Martha Tappen; Maia Bukhsianidze; Jordi Agusti; Ralf Kahlke; Gocha Kiladze; Bienvenido Martinez-Navarro; Alexander Mouskhelishvili; Medea Nioradze; Lorenzo Rook

    2007-01-01

    The Plio-Pleistocene site of Dmanisi, Georgia, has yielded a rich fossil and archaeological record documenting an early presence of the genus Homo outside Africa. Although the craniomandibular morphology of early Homo is well known as a result of finds from Dmanisi and African localities, data about its postcranial morphology are still relatively scarce. Here we describe newly excavated postcranial material

  13. A comparative study of frontal bone morphology among Pleistocene hominin fossil groups.

    PubMed

    Athreya, Sheela

    2009-12-01

    Features of the frontal bone that are conventionally used to distinguish among fossil hominin groups were quantitatively examined. Fifty-five fossil crania dating from the early to the late Pleistocene were analyzed. Using a modified pantograph, outlines of the frontal bone were collected along the midsagittal and two parasagittal planes. The profile from nasion to bregma, as well as two profiles above the medial and lateral sections of the orbit, respectively, extending from the orbital margin to the coronal suture were traced. The outlines were measured using Elliptical Fourier Function Analysis (EFFA), which enabled a quantification of aspects of the frontal bone that have historically been described primarily in nonmetric or linear terms. Four measurements were obtained: 1) overall morphology as expressed in the Fourier harmonic amplitudes; 2) maximum projection of the supraorbital torus at three points along the browridge (glabella and the medial and lateral aspects of the torus above the orbit); 3) maximum distance of the frontal squama from the frontal chord, capturing forehead curvature; and 4) nasion-bregma chord length. The results indicate that the midsagittal profile is significantly different among all Pleistocene groups in analyses that include both size and shape, as well as size-adjusted data. Homo erectus is significantly different from the late Pleistocene groups (Neandertals and early modern H. sapiens) in glabellar projection. Anatomically modern humans are significantly different from all other groups in both raw and size-standardized analyses of all three outlines that captured overall morphology, as well as forehead curvature and lateral supraorbital torus prominence, and middle Pleistocene Homo are significantly different in both medial and lateral overall parasagittal form. However, for the majority of analyses there were no significant differences among the Pleistocene archaic groups in supraorbital torus projection, frontal squama curvature, nasion-bregma chord length, or overall frontal bone morphology. PMID:19878968

  14. Brain size of Homo floresiensis and its evolutionary implications

    PubMed Central

    Kubo, Daisuke; Kono, Reiko T.; Kaifu, Yousuke

    2013-01-01

    The extremely small endocranial volume (ECV) of LB1, the type specimen of Homo floresiensis, poses a challenge in our understanding of human brain evolution. Some researchers hypothesize dramatic dwarfing of relative brain size from Homo erectus presumably without significant decrease in intellectual function, whereas others expect a lesser degree of brain diminution from a more primitive, small-brained form of hominin currently undocumented in eastern Asia. However, inconsistency in the published ECVs for LB1 (380–430 cc), unclear human intraspecific brain–body size scaling and other uncertainties have hampered elaborative modelling of its brain size reduction. In this study, we accurately determine the ECV of LB1 using high-resolution micro-CT scan. The ECV of LB1 thus measured, 426 cc, is larger than the commonly cited figure in previous studies (400 cc). Coupled with brain–body size correlation in Homo sapiens calculated based on a sample from 20 worldwide modern human populations, we construct new models of the brain size reduction in the evolution of H. floresiensis. The results show a more significant contribution of scaling effect than previously claimed. PMID:23595271

  15. Biom. Hum. et Anthropol. 2006, 24,3-4, p. 243-255. Granat J., Os hyode et larynx chez Homo OS HYODE ET LARYNX CHEZ HOMO. POSITION ESTIMEE PAR LA BIOMETRIE

    E-print Network

    Paris-Sud XI, Université de

    Biom. Hum. et Anthropol. 2006, 24,3-4, p. 243-255. Granat J., Os hyoïde et larynx chez Homo 243 OS HYOÏDE ET LARYNX CHEZ HOMO. POSITION ESTIMEE PAR LA BIOMETRIE HYOID BONE AND LARYNX IN HOMO. ESTIMATED fossiles, l'estimation de la position de l'os hyoïde, et donc celle du larynx, constitue un paramètre

  16. The evolution of early Homo: a reply to Scott.

    PubMed

    Van Arsdale, A P; Wolpoff, M H

    2014-03-01

    Scott presents a welcome reply to our article, "A single lineage in early Pleistocene Homo" (Van Arsdale and Wolpoff ). However, Scott's reply mischaracterizes and fails to directly address the hypothesis of a single lineage that we test. Additionally, the approach taken by Scott fails to replicate the methods used in our analysis. As Scott himself suggests, our null hypothesis of a single evolving lineage in early Homo remains without refutation. Although many evolutionary scenarios might explain the complex pattern of variation present in the early Homo fossil record, the most parsimonious remains that of a single lineage displaying evolutionary change over time. PMID:24372272

  17. Postcranial evidence from early Homo from Dmanisi, Georgia

    E-print Network

    Pontzer, Herman

    fossil and archaeological record documenting an early presence of the genus Homo outside Africa. Although to a remarkable variation in relief, humidity and vegetational character. The presence of fresh water, University of North Texas, Denton, Texas 76203, USA. 6 Departament de Geologia, Universitat Auto`noma de

  18. Cranial size variation and lineage diversity in early Pleistocene Homo.

    PubMed

    Scott, Jeremiah E

    2014-03-01

    A recent article in this journal concluded that a sample of early Pleistocene hominin crania assigned to genus Homo exhibits a pattern of size variation that is time dependent, with specimens from different time periods being more different from each other, on average, than are specimens from the same time period. The authors of this study argued that such a pattern is not consistent with the presence of multiple lineages within the sample, but rather supports the hypothesis that the fossils represent an anagenetically evolving lineage (i.e., an evolutionary species). However, the multiple-lineage models considered in that study do not reflect the multiple-species alternatives that have been proposed for early Pleistocene Homo. Using simulated data sets, I show that fossil assemblages that contain multiple lineages can exhibit the time-dependent pattern of variation specified for the single-lineage model under certain conditions, particularly when temporal overlap among fossil specimens attributed to the lineages is limited. These results do not reject the single-lineage hypothesis, but they do indicate that rejection of multiple lineages in the early Pleistocene Homo fossil record is premature, and that other sources of variation, such as differences in cranial shape, should be considered. PMID:24588348

  19. Stratigraphic, chronological and behavioural contexts of Pleistocene Homo sapiens from Middle Awash, Ethiopia.

    PubMed

    Clark, J Desmond; Beyene, Yonas; WoldeGabriel, Giday; Hart, William K; Renne, Paul R; Gilbert, Henry; Defleur, Alban; Suwa, Gen; Katoh, Shigehiro; Ludwig, Kenneth R; Boisserie, Jean-Renaud; Asfaw, Berhane; White, Tim D

    2003-06-12

    Clarifying the geographic, environmental and behavioural contexts in which the emergence of anatomically modern Homo sapiens occurred has proved difficult, particularly because Africa lacked adequate geochronological, palaeontological and archaeological evidence. The discovery of anatomically modern Homo sapiens fossils at Herto, Ethiopia, changes this. Here we report on stratigraphically associated Late Middle Pleistocene artefacts and fossils from fluvial and lake margin sandstones of the Upper Herto Member of the Bouri Formation, Middle Awash, Afar Rift, Ethiopia. The fossils and artefacts are dated between 160,000 and 154,000 years ago by precise age determinations using the 40Ar/39Ar method. The archaeological assemblages contain elements of both Acheulean and Middle Stone Age technocomplexes. Associated faunal remains indicate repeated, systematic butchery of hippopotamus carcasses. Contemporary adult and juvenile Homo sapiens fossil crania manifest bone modifications indicative of deliberate mortuary practices. PMID:12802333

  20. Geometric properties and comparative biomechanics of Homo floresiensis mandibles.

    PubMed

    Daegling, David J; Patel, Biren A; Jungers, William L

    2014-03-01

    The hypodigm of Homo floresiensis from the cave of Liang Bua on Flores Island in the archipelago of Indonesia includes two mandibles (LB1/2 and LB6/1). The morphology of their symphyses and corpora has been described as sharing similarities with both australopiths and early Homo despite their Late Pleistocene age. Although detailed morphological comparisons of these mandibles with those of modern and fossil hominin taxa have been made, a functional analysis in the context of masticatory biomechanics has yet to be performed. Utilizing data on cortical bone geometry from computed tomography scans, we compare the mechanical attributes of the LB1 and LB6 mandibles with samples of modern Homo, Pan, Pongo, and Gorilla, as well as fossil samples of Paranthropus robustus, Australopithecus africanus and South African early Homo. Structural stiffness measures were derived from the geometric data to provide relative measures of mandibular corpus strength under hypothesized masticatory loading regimes. These mechanical variables were evaluated relative to bone area, mandibular length and estimates of body size to assess their functional affinities and to test the hypothesis that the Liang Bua mandibles can be described as scaled-down variants of either early hominins or modern humans. Relative to modern hominoids, the H. floresiensis material appears to be relatively strong in terms of rigidity in torsion and transverse bending, but is relatively weak under parasagittal bending. Thus, they are 'robust' relative to modern humans (and comparable with australopiths) under some loads but not others. Neither LB1 nor LB6 can be described simply as 'miniaturized' versions of modern human jaws since mandible length is more or less equivalent in Homo sapiens and H. floresiensis. The mechanical attributes of the Liang Bua mandibles are consistent with previous inferences that masticatory loads were reduced relative to australopiths but remained elevated relative to modern Homo. PMID:24560803

  1. Fossil primates 1 Fossil primates

    E-print Network

    Delson, Eric

    Fossil primates 1 Fossil primates Extinct members of the order of mammals to which humans belong group of living primates. However, the chewing teeth and the locomotor anatomy of these fossil forms). These animals are also known from fossil deposits on Ellesmere Island, in Arctic Canada, which was then covered

  2. In search of Homo economicus.

    PubMed

    Yamagishi, Toshio; Li, Yang; Takagishi, Haruto; Matsumoto, Yoshie; Kiyonari, Toko

    2014-09-01

    Homo economicus, a model for humans in neoclassical economics, is a rational maximizer of self-interest. However, many social scientists regard such a person as a mere imaginary creature. We found that 31 of 446 residents of relatively wealthy Tokyo suburbs met the behavioral definition of Homo economicus. In several rounds of economic games, participants whose behavior was consistent with this model always apportioned the money endowed by the experimenter to themselves, leaving no share for their partners. These participants had high IQs and a deliberative decision style. An additional 39 participants showed a similar disregard for other people's welfare, although they were slightly more altruistic than those in the Homo economicus group. The psychological composition of these quasi-Homo economicus participants was distinct from that of participants in the Homo economicus group. Although participants in the latter group behaved selfishly on the basis of rational calculations, those in the former group made selfish choices impulsively. The implications of these findings concerning the two types of extreme noncooperators are discussed. PMID:25037961

  3. The Emergence of Homo sapiens.

    ERIC Educational Resources Information Center

    Rensberger, Boyce

    1980-01-01

    Describes chronologically the evolution of the human race on earth so as to refute Darwin's theory of descent from animals. Skull fragments from sites around the world suggest at least two possible routes toward the emergence of Homo sapiens sapiens. (Author/SK)

  4. Fossil Excavation

    NSDL National Science Digital Library

    In this activity students excavate their own fossil from a teacher-prepared "rock biscuit". Students chip away the matrix with wooden stirring rods (or sharpened wooden dowels) and glue brushes. In each biscuit is a genuine fossil such as a shark's tooth. The activity is designed to be the culmination of a lesson about fossil collecting, the importance of recording data, and different preparation methods.

  5. The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age

    Microsoft Academic Search

    ChangZhu Jin; WenShi Pan; YingQi Zhang; YanJun Cai; QinQi Xu; ZhiLu Tang; Wei Wang; Yuan Wang; JinYi Liu; DaGong Qin; R. Lawrence Edwards; Hai Cheng

    2009-01-01

    One of the most hotly debated and frontal issues in paleoanthropology focuses on the origins of modern humans. Recently, an\\u000a incomplete hominin mandible with a distinctly weaker mental protuberance than modern human and a great variety of coexisting\\u000a fossil mammals were unearthed from the Homo sapiens Cave of Mulan Mountain, Chongzuo, Guangxi. The mammalian fauna from the Homo sapiens Cave

  6. Fossil Fuels.

    ERIC Educational Resources Information Center

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  7. Fossil spiders.

    PubMed

    Selden, Paul A; Penney, David

    2010-02-01

    Over the last three decades, the fossil record of spiders has increased from being previously biased towards Tertiary ambers and a few dubious earlier records, to one which reveals a much greater diversity in the Mesozoic, with many of the modern families present in that era, and with clearer evidence of the evolutionary history of the group. We here record the history of palaeoarachnology and the major breakthroughs which form the basis of studies on fossil spiders. Understanding the preservation and taphonomic history of spider fossils is crucial to interpretation of fossil spider morphology. We also review the more recent descriptions of fossil spiders and the effect these discoveries have had on the phylogenetic tree of spiders. We discuss some features of the evolutionary history of spiders and present ideas for future work. PMID:19961468

  8. Fossil Fuels

    NSDL National Science Digital Library

    Iowa Public Television. Explore More Project

    2004-01-01

    How much does the United States depend on fossil fuels? This web page, part of a site on the future of energy, introduces students to fossil fuels as an energy source. Here students read about the uses, benefits, and limitations of fossil fuels. There is also information on how these fuels are distributed geographically and how they affect the U.S. economy through supply and demand. Thought-provoking questions afford students opportunities to reflect on what they've read. Articles about clean coal, the national energy policy, and the formation of fossil fuels, together with a fossil fuels fact sheet, are accessible from a sidebar. In addition, five PBS NewsHour links to energy-related stories are included.

  9. Pleistocene soil development and paleoenvironmental dynamics in East Africa: a multidisciplinary study of the Homo-bearing Aalat succession, Dandiero Basin

    NASA Astrophysics Data System (ADS)

    Scarciglia, Fabio; Mercatante, Giuseppe; Donato, Paola; Ghinassi, Massimiliano; Carnevale, Giorgio; Delfino, Massimo; Oms, Oriol; Papini, Mauro; Pavia, Marco; Sani, Federico; Rook, Lorenzo

    2015-04-01

    Pleistocene environmental changes in East Africa, largely documented by deep marine or lacustrine records correlated with inland high-resolution, Homo-bearing stratigraphic successions, have been so far interpreted as a major cause of faunal dispersal and human evolution. However, only few studies focused on reconstruction of paleoenvironmental dynamics from continental successions, given the usually poor continuity and extension of stratigraphic records. In this work we report on a multidisciplinary study of the Early to Middle Pleistocene sedimentary fill of the Dandiero Basin (Eritrean Danakil), a morpho-tectonic depression in the East African Rift System, which represents the only continental stratigraphy including human remains of Homo erectus/ergaster and abundant fossil vertebrates in the northernmost sector of this region. Sedimentological, pedological, volcanological and paleontological investigations were performed on the Aalat section, located in the northern part of the Dandiero Basin, as tools for an integrated reconstruction of the Early-Middle Pleistocene transition in East Africa. This section is almost 300 m thick and records repeated shifts from fluvial to deltaic and lacustrine depositional environments, as a response to local tectonic activity and climate changes. Sedimentary facies distribution and paleocurrent data show that sedimentation was controlled by a NS-trending axial drainage. Some tephra layers were identified both at the bottom and the top of the section, whereas two main fossiliferous layers were detected in its lower part. Terrestrial vertebrate faunas include a typical Early to Middle Pleistocene East African mammalian assemblage, where taxa characterized by strong water dependence prevail. Also the ichthyofauna is consistent with the shallow water fluvio-lacustrine paleobiotopes. High-quality paleomagnetic analyses, integrated with radiometric dating and vertebrate paleontology, allowed to substantiate the chronological constraints of the Aalat section to a time span approximately bracketed between the Jaramillo event (ca. 1.07-0.99 Ma) and the Matuyama-Brunhes magnetic field reversal (ca. 0.78 Ma). High rates of sedimentary aggradation can be estimated around 1 mm/a, coherently with a poor to moderate degree of soil development and evidence of soil truncation by erosion. Physico-chemical, mineralogical, geochemical and micromorphological analyses were carried out on selected soil samples. Weathering and pedogenetic features mainly consist of pedogenic structure, secondary carbonate accumulations (following carbonate leaching) and iron-oxide/hydroxide segregations, promoted by water infiltration under varying drainage conditions and/or seasonal contrast. The complex patterns of some petrocalcic horizons and rare rubified soils testify for occasionally longer geomorphic stability and non-deposition, which were more prone to pedogenesis. Our multidisciplinary study revealed that the Aalat section in the Dandiero Basin represents a promising continental archive of the main paleoenvironmental changes occurred during the Early-Middle Pleistocene transition in East Africa.

  10. Fossil Halls

    NSDL National Science Digital Library

    The American Museum of Natural History is home to the world's largest collection of vertebrate fossils, totaling nearly one million specimens. This Web site offers visitors a virtual visit to the Museum's famed Fossil Halls. It features sections on Cladistics, Vertebrate Evolution, Exhibit Specimens, a collection of 19 biographies of important people in paleontology and Virtual Tours of four of the halls. There is also an elementary school teacher guide to the museum exhibit.

  11. Size, shape, and asymmetry in fossil hominins: The status of the LB1 cranium based on 3D morphometric analyses

    E-print Network

    Baab, Karen L.

    Size, shape, and asymmetry in fossil hominins: The status of the LB1 cranium based on 3D that LB1 best fits predictions for a small specimen of fossil Homo but not for a small modern human extant African ape species. Compared to other fossil specimens, the degree of asymmetry in LB1

  12. Fossil Identification

    NSDL National Science Digital Library

    Connie Soja, Colgate University, csoja@colgate.edu

    This activity asks students to identify examples of types of fossils amongst the exhibits at the Museum of the Earth at the Paleontological Research Institution in Ithaca, New York. Students will build on their understanding of the history of life, paleontology, taphonomy, ichnology, and paleoecologyâespecially reefs.

  13. Remarkable Fossils

    Microsoft Academic Search

    Thomas Wm. Cowan

    1874-01-01

    ONE of the most remarkable collections of Wealden fossils ever seen, was lately on loan for a few days to the exhibition then open at Horsham, and is one that is not to be equalled by any at our public museums in the country. So remarkable is it that I am induced to give you a short description. As you

  14. The Homo Energeticus: maturity, inheritance, identity

    NASA Astrophysics Data System (ADS)

    Mason, Arthur

    2013-03-01

    In this letter, modern society’s intimate bond to the convenience and reliability of delivered energy services results in a form of identification I call the Homo Energeticus. The Homo Energeticus relies upon a mature system of services for achieving an equivalency of status and prestige that is historically similar to the morality of a noble class. I describe the uniqueness of this identity by its imperative for acquiring experience through an invisibility of energy expenditures. In this way, the Homo Energeticus cultivates a highly individualized life whose ambience of perfection, while created personally, is only successful insofar as it conceals energy expenditures in labor and supply.

  15. Earliest evidence of modern human life history in North African early Homo sapiens

    PubMed Central

    Smith, Tanya M.; Tafforeau, Paul; Reid, Donald J.; Grün, Rainer; Eggins, Stephen; Boutakiout, Mohamed; Hublin, Jean-Jacques

    2007-01-01

    Recent developmental studies demonstrate that early fossil hominins possessed shorter growth periods than living humans, implying disparate life histories. Analyses of incremental features in teeth provide an accurate means of assessing the age at death of developing dentitions, facilitating direct comparisons with fossil and modern humans. It is currently unknown when and where the prolonged modern human developmental condition originated. Here, an application of x-ray synchrotron microtomography reveals that an early Homo sapiens juvenile from Morocco dated at 160,000 years before present displays an equivalent degree of tooth development to modern European children at the same age. Crown formation times in the juvenile's macrodont dentition are higher than modern human mean values, whereas root development is accelerated relative to modern humans but is less than living apes and some fossil hominins. The juvenile from Jebel Irhoud is currently the oldest-known member of Homo with a developmental pattern (degree of eruption, developmental stage, and crown formation time) that is more similar to modern H. sapiens than to earlier members of Homo. This study also underscores the continuing importance of North Africa for understanding the origins of human anatomical and behavioral modernity. Corresponding biological and cultural changes may have appeared relatively late in the course of human evolution. PMID:17372199

  16. -Long-term assessment of seed provenance effect on the establishment of Bromus erectus -821 Journal of Vegetation Science 19: 821-830, 2008

    E-print Network

    Stampfli, Andreas

    - Long-term assessment of seed provenance effect on the establishment of Bromus erectus - 821 © IAVS; Opulus Press Uppsala. Long-term assessment of seed provenance effect on the establishment.stampfli@ips.unibe.ch *Corresponding author; E-mail michaela.zeiter@ips.unibe.ch Abstract Questions: Do short-term seed

  17. Describing Fossils

    NSDL National Science Digital Library

    Judy Massare

    Students are given a description of a fossil brachiopod, from the literature, along with a one-page handout describing the basic morphology of brachiopods. Students work independently to make a scale drawing of the fossil described (brachial valve, pedicle valve, anterior view, lateral view). They have access to textbooks (Moore, Laliker & Fisher; Clarkson), the Treatise volume, and the internet to get information on morphological terms. This takes about an hour, after which I display all of the diagrams on the wall along with the photographs from the paper from which the description was extracted. We discuss some of the differences and where problems arose in interpreting the description. I emphasize the importance of an accurate drawing or photograph to accompany a description. Students are then given a different brachiopod specimen and asked to produce a written description (pedicle-valve, brachial valve, anterior view, lateral view) of their fossil similar to the one that they readâi.e. using all of the appropriate terms. They are told that other students will be trying to match their description to their specimen. I collect all of the descriptions, edit them (remove portions that use incorrect terminology or inappropriate), and produce a handout of all of the descriptions. At the next class, students are given the descriptions and asked to match descriptions to specimens. They do this independently outside of class. The specimens are made available in the lab room for several days. I add a couple of 'extra' specimens (without description) so that it is not a process of elimination.

  18. Technical note: virtual reconstruction of KNM-ER 1813 Homo habilis cranium.

    PubMed

    Benazzi, Stefano; Gruppioni, Giorgio; Strait, David S; Hublin, Jean-Jacques

    2014-01-01

    A very limiting factor for paleoanthropological studies is the poor state of preservation of the human fossil record, where fragmentation and deformation are considered normal. Although anatomical information can still be gathered from a distorted fossil, such specimens must typically be excluded from advanced morphological and morphometric analyses, thus reducing the fossil sample size and, ultimately, our knowledge of human evolution. In this contribution we provide the first digital reconstruction of the KNM-ER 1813 Homo habilis cranium. Based on state of-the-art three-dimensional digital modeling and geometric morphometric (GM) methods, the facial portion was aligned to the neurocranium, the overall distortion was removed, and the missing regions were restored. The reconstructed KNM-ER 1813 allows for an adjustment of the anthropometric measurements gathered on the original fossil. It is suitable for further quantitative studies, such as GM analyses focused on skull morphology or for finite element analysis to explore the mechanics of early Homo feeding behavior and diet. PMID:24318950

  19. Body composition in Pan paniscus compared with Homo sapiens has implications for changes during human evolution.

    PubMed

    Zihlman, Adrienne L; Bolter, Debra R

    2015-06-16

    The human body has been shaped by natural selection during the past 4-5 million years. Fossils preserve bones and teeth but lack muscle, skin, fat, and organs. To understand the evolution of the human form, information about both soft and hard tissues of our ancestors is needed. Our closest living relatives of the genus Pan provide the best comparative model to those ancestors. Here, we present data on the body composition of 13 bonobos (Pan paniscus) measured during anatomical dissections and compare the data with Homo sapiens. These comparative data suggest that both females and males (i) increased body fat, (ii) decreased relative muscle mass, (iii) redistributed muscle mass to lower limbs, and (iv) decreased relative mass of skin during human evolution. Comparison of soft tissues between Pan and Homo provides new insights into the function and evolution of body composition. PMID:26034269

  20. A review of early Homo in southern Africa focusing on cranial, mandibular and dental remains, with the description of a new species (Homo gautengensis sp. nov.).

    PubMed

    Curnoe, D

    2010-06-01

    The southern African sample of early Homo is playing an increasingly important role in understanding the origins, diversity and adaptations of the human genus. Yet, the affinities and classification of these remains continue to be in a state of flux. The southern African sample derives from five karstic palaeocave localities and represents more than one-third of the total African sample for this group; sampling an even wider range of anatomical regions than the eastern African collection. Morphological and phenetic comparisons of southern African specimens covering dental, mandibular and cranial remains demonstrate this sample to contain a species distinct from known early Homo taxa. The new species Homo gautengensis sp. nov. is described herein: type specimen Stw 53; Paratypes SE 255, SE 1508, Stw 19b/33, Stw 75-79, Stw 80, Stw 84, Stw 151, SK 15, SK 27, SK 45, SK 847, SKX 257/258, SKX 267/268, SKX 339, SKX 610, SKW 3114 and DNH 70. H. gautengensis is identified from fossils recovered at three palaeocave localities with current best ages spanning approximately 2.0 to 1.26-0.82 million years BP. Thus, H. gautengensis is probably the earliest recognised species in the human genus and its longevity is apparently well in excess of H. habilis. PMID:20466364

  1. Yawn Contagion and Empathy in Homo sapiens

    Microsoft Academic Search

    Ivan Norscia; Elisabetta Palagi

    2011-01-01

    The ability to share others' emotions, or empathy, is crucial for complex social interactions. Clinical, psychological, and neurobiological clues suggest a link between yawn contagion and empathy in humans (Homo sapiens). However, no behavioral evidence has been provided so far. We tested the effect of different variables (e.g., country of origin, sex, yawn characteristics) on yawn contagion by running mixed

  2. Genetics and the making of Homo sapiens

    Microsoft Academic Search

    Sean B. Carroll

    2003-01-01

    Understanding the genetic basis of the physical and behavioural traits that distinguish humans from other primates presents one of the great new challenges in biology. Of the millions of base-pair differences between humans and chimpanzees, which particular changes contributed to the evolution of human features after the separation of the Pan and Homo lineages 5–7 million years ago? How can

  3. Description, new reconstruction, comparative anatomy, and classification of the Sterkfontein Stw 53 cranium, with discussions about the taxonomy of other southern African early Homo remains

    Microsoft Academic Search

    Darren Curnoe; Phillip V. Tobias

    2006-01-01

    Specimen Stw 53 was recovered in 1976 from Member 5 of the Sterkfontein Formation. Since its incomplete initial description and comparison, the partial cranium has figured prominently in discussions about the systematics of early Homo. Despite publication of a preliminary reconstruction in 1985, Stw 53 has yet to be compared comprehensively to other Plio-Pleistocene fossils or assessed systematically. In this

  4. Theropod Fossil Hunt Dispatch

    NSDL National Science Digital Library

    This site outlines the step by step progression as a rare fossil is found, authenticated and identified. Follow along as a paleontologist pursues a well-preserved fossil of Sinosauropteryx, a feathered dromaeosaur. The site is enhanced with several photographs.

  5. Face-to-Fossil

    NSDL National Science Digital Library

    This Web article is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here they meet Deena Soris, who interviews the fossil of a Protoceratops. The more-than-20 questions answered by this dinosaur fossil cover topics such as what were you like when you were alive and how did you become a fossil.

  6. Out of Africa and back again

    Microsoft Academic Search

    R. J. Clarke; J. W. Goethe Universittit

    2000-01-01

    If the genusHomo did indeed originate in Africa, then it must have spread by about 2 m.y. ago into Asia where it is represented at 1.8 m.y.\\u000a ago byHomo erectus fossils. This latter species in turn eventually spread back into Africa, as indicated by the 1.4 m.y. old OH 9 calvaria from\\u000a Olduvai, and into Europe, as indicated by the

  7. Population genomics reveals seahorses (Hippocampus erectus) of the western mid-Atlantic coast to be residents rather than vagrants.

    PubMed

    Boehm, J T; Waldman, John; Robinson, John D; Hickerson, Michael J

    2015-01-01

    Understanding population structure and areas of demographic persistence and transients is critical for effective species management. However, direct observational evidence to address the geographic scale and delineation of ephemeral or persistent populations for many marine fishes is limited. The Lined seahorse (Hippocampus erectus) can be commonly found in three western Atlantic zoogeographic provinces, though inhabitants of the temperate northern Virginia Province are often considered tropical vagrants that only arrive during warm seasons from the southern provinces and perish as temperatures decline. Although genetics can locate regions of historical population persistence and isolation, previous evidence of Virginia Province persistence is only provisional due to limited genetic sampling (i.e., mitochondrial DNA and five nuclear loci). To test alternative hypotheses of historical persistence versus the ephemerality of a northern Virginia Province population we used a RADseq generated dataset consisting of 11,708 single nucleotide polymorphisms (SNP) sampled from individuals collected from the eastern Gulf of Mexico to Long Island, NY. Concordant results from genomic analyses all infer three genetically divergent subpopulations, and strongly support Virginia Province inhabitants as a genetically diverged and a historically persistent ancestral gene pool. These results suggest that individuals that emerge in coastal areas during the warm season can be considered "local" and supports offshore migration during the colder months. This research demonstrates how a large number of genes sampled across a geographical range can capture the diversity of coalescent histories (across loci) while inferring population history. Moreover, these results clearly demonstrate the utility of population genomic data to infer peripheral subpopulation persistence in difficult-to-observe species. PMID:25629166

  8. A re-examination of the human fossil specimen from Ba?ki Petrovac (Serbia).

    PubMed

    Radovi?, Predrag; Lindal, Joshua Allan; Roksandic, Mirjana

    2014-08-01

    A fragmented human calotte was discovered during the early 1950s near Ba?ki Petrovac (Serbia), in association with Palaeolithic stone tools. After its initial publication, the fossil specimen remained largely unknown outside of the Serbian academe and no detailed comparative study has ever been carried out. Since the whereabouts of the fossil itself are currently unknown, and given its potential significance for the Pleistocene human evolution, we re-examine the data published by Živanovi? (1966, 1975). Using the original measurements, mostly taken on the frontal bone, and a wide comparative sample of 68 fossil specimens, the fossil was compared and analyzed by statistical multivariate methods. We also conducted a visual examination of the morphology based on the available photographic material. Our analysis reveals phenetic similarity with Middle Pleistocene archaic Homo from Africa and anatomically modern Homo sapiens. However, the absence of primitive cranial traits in Ba?ki Petrovac indicates a clear modern Homo sapiens designation. Although lost at the moment, there is a chance for the re-discovery of the fossil in the years to come. This would give us an opportunity to acquire absolute dates and to study the specimen in a more detailed manner. PMID:24951407

  9. Fossil-energy program

    Microsoft Academic Search

    L. E. McNeese

    1982-01-01

    The increased utilization of coal and other fossil fuel alternatives as sources of clean energy is reported. The projects reported include: coal conversion development, chemical research and development, materials technology, component development and process evaluation, technical support to major liquefaction, process analysis and engineering evaluations, fossil energy environmental analysis, environmental control technology, coal preparation waste utilization, atmospheric fluidized bed coal

  10. Restoring Fossil Creek

    ERIC Educational Resources Information Center

    Flaccus, Kathleen; Vlieg, Julie; Marks, Jane C.; LeRoy, Carri J.

    2004-01-01

    Fossil Creek had been dammed for the past 90 years, and plans were underway to restore the stream. The creek runs through Central Arizona and flows from the high plateaus to the desert, cutting through the same formations that form the Grand Canyon. This article discusses the Fossil Creek monitoring project. In this project, students and teachers…

  11. Becoming a Fossil

    NSDL National Science Digital Library

    2005-01-01

    This text and accompanying video provide an overview of how fossils are formed and preserved. A video clip from the NOVA television program, 'In Search of Human Origins', shows how the famous early hominid 'Lucy' might have died and been fossiliized, and points out the rare set of circumstances that must occur for an organism to be fossilized. Questions for discussion are included.

  12. Bacteria: Fossil Record

    NSDL National Science Digital Library

    This description of the fossil record of bacteria focuses on one particular group of bacteria, the cyanobacteria or blue-green algae, which have left a fossil record that extends far back into the Precambrian. The oldest cyanobacteria-like fossils known are nearly 3.5 billion years old and are among the oldest fossils currently known. Cyanobacteria are larger than most bacteria and may secrete a thick cell wall. More importantly, cyanobacteria may form large layered structures, called stromatolites (if more or less dome-shaped) or oncolites (if round). The site also refers to pseudomorphs of pyrite and siderite, and a group of bacteria known as endolithic. Two links are available for more information. One provides information on the discovery of possible remains of bacteria-like organisms on a meteorite from Mars and the other has a research report on fossilized filamentous bacteria and other microbes, found in Cretaceous amber.

  13. Palaeopathological and variant conditions of the Homo heidelbergensis type specimen (Mauer, Germany).

    PubMed

    Czarnetzki, A; Jakob, T; Pusch, C M

    2003-04-01

    Although early Homo specimens are now known from a number of African, Asian and European Middle Pleistocene sites, the taxon Homo heidelbergensis was initially introduced for the Mauer jaw recovered in 1907. Fossil hominids from the earlier Middle Pleistocene of Europe are very rare and the Mauer mandible is generally accepted as one of the most ancient, with an age of approximately 700 kyr. A new preparation of the mandible was conducted in 1996 and gave rise to the detailed palaeopathological examination which is presented here. Based on comparative analyses, the extreme breadth of the mandibular ramus and its flat intercondylar incision, in conjunction with the flattening and broadening of the coronoid process tip, results either from an idiosyncratic pattern of the course and insertion of the temporalis muscle on the coronoid process or from the temporalis possessing an accessory head. The incidence of periodontal pocketing, together with a vertical reduction of the alveolar margin to approximately 3.00 mm, and a slight protuberance formed in vicinity of the right M(2)can safely be interpreted as pathognomonic indications of periodontal disease. The short distance between the enamel-dentine junction of the teeth and the horizontal alveolar margins could either be an inherited variant or may result from incipient osteoporosis. In addition, an arthrotic condition with slight osteophytic peripheral exostoses and an arthrolit (i.e. an articular calculus or "joint mouse") on the left condylus articularisand a depression in the medial part of the left mandibular condyle extending into the inferior part of the ramus are present. These features are indicative of a trauma-induced osteochondrosis dissecans. The diagnosis therefore suggests that the observed depression results from a well-healed fracture. This traumatic event illustrates the demanding living conditions endured by humans during the European Middle Pleistocene. The variations and pathological conditions observed in Mauer do not question the mandible's role as type specimen for the taxon Homo heidelbergensis. PMID:12727464

  14. Mandibular molar root morphology in Neanderthals and Late Pleistocene and recent Homo sapiens.

    PubMed

    Kupczik, Kornelius; Hublin, Jean-Jacques

    2010-11-01

    Neanderthals have a distinctive suite of dental features, including large anterior crown and root dimensions and molars with enlarged pulp cavities. Yet, there is little known about variation in molar root morphology in Neanderthals and other recent and fossil members of Homo. Here, we provide the first comprehensive metric analysis of permanent mandibular molar root morphology in Middle and Late Pleistocene Homo neanderthalensis, and Late Pleistocene (Aterian) and recent Homo sapiens. We specifically address the question of whether root form can be used to distinguish between these groups and assess whether any variation in root form can be related to differences in tooth function. We apply a microtomographic imaging approach to visualise and quantify the external and internal dental morphologies of both isolated molars and molars embedded in the mandible (n=127). Univariate and multivariate analyses reveal both similarities (root length and pulp volume) and differences (occurrence of pyramidal roots and dental tissue volume proportion) in molar root morphology among penecontemporaneous Neanderthals and Aterian H. sapiens. In contrast, the molars of recent H. sapiens are markedly smaller than both Pleistocene H. sapiens and Neanderthals, but share with the former the dentine volume reduction and a smaller root-to-crown volume compared with Neanderthals. Furthermore, we found the first molar to have the largest average root surface area in recent H. sapiens and Neanderthals, although in the latter the difference between M(1) and M(2) is small. In contrast, Aterian H. sapiens root surface areas peak at M(2). Since root surface area is linked to masticatory function, this suggests a distinct occlusal loading regime in Neanderthals compared with both recent and Pleistocene H. sapiens. PMID:20719359

  15. Yawn Contagion and Empathy in Homo sapiens

    PubMed Central

    Norscia, Ivan; Palagi, Elisabetta

    2011-01-01

    The ability to share others' emotions, or empathy, is crucial for complex social interactions. Clinical, psychological, and neurobiological clues suggest a link between yawn contagion and empathy in humans (Homo sapiens). However, no behavioral evidence has been provided so far. We tested the effect of different variables (e.g., country of origin, sex, yawn characteristics) on yawn contagion by running mixed models applied to observational data collected over 1 year on adult (>16 years old) human subjects. Only social bonding predicted the occurrence, frequency, and latency of yawn contagion. As with other measures of empathy, the rate of contagion was greatest in response to kin, then friends, then acquaintances, and lastly strangers. Related individuals (r?0.25) showed the greatest contagion, in terms of both occurrence of yawning and frequency of yawns. Strangers and acquaintances showed a longer delay in the yawn response (latency) compared to friends and kin. This outcome suggests that the neuronal activation magnitude related to yawn contagion can differ as a function of subject familiarity. In conclusion, our results demonstrate that yawn contagion is primarily driven by the emotional closeness between individuals and not by other variables, such as gender and nationality. PMID:22163307

  16. Homo- and heterometallic planes, chains and cubanes.

    PubMed

    Meally, Seán T; Taylor, Stephanie M; Brechin, Euan K; Piligkos, Stergios; Jones, Leigh F

    2013-07-28

    The synthesis, structural and magnetic characterisation of a family of homo- and heterometallic complexes constructed with the Schiff base ligands 2-iminomethyl-6-methoxy-phenol (L1H) and 2-imino-6-methoxy-phenol (L2H), are discussed. Members include the heterometallic tetranuclear complexes of general formula [Na2M2(X)2(L1)4(Y)2] (where M = Fe(III), X = (-)OMe, Y = NO3(-) (1) and M = Ni(II), X = N3(-) and Y = MeCN (2)), each possessing a butterfly-like topology. We also report the formation of the heterometallic molecular cage [Na3Ni2(L1)6](ClO4) (3) whose metallic skeleton describes a [rare] trigonal bipyramid, the homometallic 1-D coordination polymer [Mn(L1)2(Cl)]n (4), and the tetranuclear cubane clusters [Mn(III)3Mn(IV)(O)3(OEt)(OAc)3(L1)3] (5) and [Ni4(?3-OMe)4(L2)4(MeOH)4] (6). Dc and ac magnetic susceptibility studies on complexes 5 and 6 reveal S = 9/2 and S = 4 spin ground states. PMID:23739726

  17. Genotype-specific responses of Bromus erectus to elevated CO{sub 2} at different levels of biodiversity and endophyte infection - a field experiment

    SciTech Connect

    Steinger, T.; Groppe, K.; Schmid, B. [Univ. of Basel (Switzerland)]|[Univ. of Zurich (Switzerland)

    1995-06-01

    In 1994 we initiated a long-term field experiment in a calcareous grassland to study the effects of elevated CO{sub 2} on individuals, populations, and communities. Clonal replicates of 54 genotypes of the dominant grass Bromus erectus were grown in communities planted at three levels of biodiversity (5-, 12-, 31-species plots) and exposed to ambient and elevated CO{sub 2}. The same genotypes were also individually grown in tubes within the field plots. Some genotypes were infected by the endophytic fungus Epichloee typhina. Elevated CO{sub 2} had no significant effects on plant growth, however, there was large variation among genotypes in all measured characters. A significant CO{sub 2}-by-genotype interaction was found for leaf length in the competition-free tubes. Infection by the endophyte led to the abortion of all inflorescences but increased vegetative growth, especially under competitive conditions.

  18. Fossil fuels -- future fuels

    SciTech Connect

    NONE

    1998-03-01

    Fossil fuels -- coal, oil, and natural gas -- built America`s historic economic strength. Today, coal supplies more than 55% of the electricity, oil more than 97% of the transportation needs, and natural gas 24% of the primary energy used in the US. Even taking into account increased use of renewable fuels and vastly improved powerplant efficiencies, 90% of national energy needs will still be met by fossil fuels in 2020. If advanced technologies that boost efficiency and environmental performance can be successfully developed and deployed, the US can continue to depend upon its rich resources of fossil fuels.

  19. The saliva microbiome of Pan and Homo

    PubMed Central

    2013-01-01

    Background It is increasingly recognized that the bacteria that live in and on the human body (the microbiome) can play an important role in health and disease. The composition of the microbiome is potentially influenced by both internal factors (such as phylogeny and host physiology) and external factors (such as diet and local environment), and interspecific comparisons can aid in understanding the importance of these factors. Results To gain insights into the relative importance of these factors on saliva microbiome diversity, we here analyze the saliva microbiomes of chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) from two sanctuaries in Africa, and from human workers at each sanctuary. The saliva microbiomes of the two Pan species are more similar to one another, and the saliva microbiomes of the two human groups are more similar to one another, than are the saliva microbiomes of human workers and apes from the same sanctuary. We also looked for the existence of a core microbiome and find no evidence for a taxon-based core saliva microbiome for Homo or Pan. In addition, we studied the saliva microbiome from apes from the Leipzig Zoo, and found an extraordinary diversity in the zoo ape saliva microbiomes that is not found in the saliva microbiomes of the sanctuary animals. Conclusions The greater similarity of the saliva microbiomes of the two Pan species to one another, and of the two human groups to one another, are in accordance with both the phylogenetic relationships of the hosts as well as with host physiology. Moreover, the results from the zoo animals suggest that novel environments can have a large impact on the microbiome, and that microbiome analyses based on captive animals should be viewed with caution as they may not reflect the microbiome of animals in the wild. PMID:24025115

  20. Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85–1.78 Ma

    PubMed Central

    Ferring, Reid; Oms, Oriol; Agustí, Jordi; Berna, Francesco; Nioradze, Medea; Shelia, Teona; Tappen, Martha; Vekua, Abesalom; Zhvania, David; Lordkipanidze, David

    2011-01-01

    The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisi's rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisi's first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85–1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisi's hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisi's first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record. PMID:21646521

  1. Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85-1.78 Ma.

    PubMed

    Ferring, Reid; Oms, Oriol; Agustí, Jordi; Berna, Francesco; Nioradze, Medea; Shelia, Teona; Tappen, Martha; Vekua, Abesalom; Zhvania, David; Lordkipanidze, David

    2011-06-28

    The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisi's rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisi's first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85-1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisi's hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisi's first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record. PMID:21646521

  2. Fossilized Dinosaur Bones

    NSDL National Science Digital Library

    This slide show presents images of dinosaur bones and shows paleotologists at work excavating and preserving these fossils, the best evidence remaining of these long-lost creatures. A background essay and discussion questons are included.

  3. Minerals and Fossils

    NSDL National Science Digital Library

    mineraltown.com

    This site is dedicated to rock and mineral collecting. It contains information for worldwide mineral and fossil collectors with articles, mineral photos, videos, a search engine and free classified ads.

  4. Fossil Age Estimation Model

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2006-01-01

    In this activity (page 1 of the PDF), learners will model how paleontologists estimate the age of fossil discoveries by extracting “fossil” playing cards from newspapers stacked in chronological order. Learners identify the “age” of the card based on the “evidence” (printed date) in the surrounding pages. They then create a data table and graph and analyze their findings. Use this activity to introduce learners to paleontology and geology. Relates to the linked video, DragonflyTV GPS: Dinosaurs.

  5. Fossil Simulation in the Classroom

    ERIC Educational Resources Information Center

    Hoehn, Robert G.

    1977-01-01

    Describes classroom science demonstrations and experiments that simulate the process of fossil formation. Lists materials, procedures and suggestions for successful activities. Includes ten student activities (coral fossils, leaf fossils, leaf scars, carbonization, etc.). Describes a fossil game in which students work in pairs. (CS)

  6. 004118:a0001 Fossil Record

    E-print Network

    Benton, Michael

    004118:a0001 Fossil Record Michael J Benton, University of Bristol, Bristol, UK Fossils life. 004118:s0001 Introduction 004118:p0001 Fossils are the remains of plants and animals that once lived. The common image of a fossil is an ancient shell or bone that has been turned to rock

  7. Patterning of geographic variation in Middle Pleistocene Homo frontal bone morphology.

    PubMed

    Athreya, Sheela

    2006-06-01

    A quantitative assessment of the frontal bone morphology of a sample of Middle Pleistocene hominins was undertaken in order to address questions regarding their population structure and evolutionary history. Outline tracings of the frontal bones of forty-seven fossil crania were obtained, and size-standardized measurements were then computed using an Elliptical Fourier analysis of these tracings. Principal component scores of the Fourier harmonic amplitudes were derived and served as a quantitative representation of the morphology of the frontal bone. Morphological, geographical, and temporal distance matrices were then constructed between each pair of fossils. A partial Mantel matrix correlation test was performed between morphological and geographical distance matrices, controlling for temporal distance, in order to determine if the pattern of geographical differentiation in features of the frontal bone of mid-Pleistocene Homo followed that of an isolation-by-distance model of population structure. The results of the partial Mantel tests indicate that the overall patterning of differentiation in the features of the frontal bone cannot best be explained by a population structure shaped by isolation-by-distance. Additionally, various aspects of the frontal bone quantified here follow different patterns of geographical differentiation, suggesting that a mosaic pattern of evolution holds true for characters within one cranial region and not just for those between regions. PMID:16678885

  8. Species-specific albumin in fossil bones from Orce, Granada, Spain

    Microsoft Academic Search

    J. M. Lowenstein; C. Borja; E. García-Olivares

    1999-01-01

    A skull fragment (VM-0) from Orce, Granada, Spain, dated palaeomagnetically at about 1.6 Myr, is thought by some palaeontologist to be hominid,\\u000a while others maintain it is equid. If hominid, it would be by far the oldest evidence ofHomo in Europe. Immunological studies on residual albumin in this fossil were carried out independently, and with different immunological\\u000a methods, at the

  9. The Fossil Record

    NSDL National Science Digital Library

    Lisa Wu

    This lesson plan is part of the DiscoverySchool.com lesson plan library for grades 9-12. It centers around fossils found in the Burgess Shale in western Canada. Topics include body shapes of fossils found, the movement of organisms from oceans to land, and whether organisms existed that did not fossilize. This part of geologic history began in the Cambrian Sea about 540 million years ago. The resource includes objectives, materials, procedures, discussion questions, evaluation ideas, extensions, suggested readings, and vocabulary. There are videos available to order which complement this lesson, an audio-enhanced vocabulary list, and links to teaching tools for making custom quizzes, worksheets, puzzles and lesson plans.

  10. Science Sampler: Fossil detectives

    NSDL National Science Digital Library

    Virginia Bourdeau

    2006-07-01

    Middle school students are transformed into Fossil detectives as they examine the fossil record and use evidence about paleo-environments to develop an understanding of structure and function in living systems and changes over time in Earths history. In this enrichment activity, students work in teams to research an assigned geologic time period. They determine available habitats, food sources and types (animal, plant; woody, herbaceous, etc.), cover sources, methods of getting food, defense, and reproduction that would allow an animal to live in the assigned paleoenvironment. In culmination of their efforts, students create a diorama to display their findings.

  11. Dinoflagellata: Fossil Record

    NSDL National Science Digital Library

    Information on this page pertains to dinoflagellates, the fossil record of which may extend into the Precambrian. Spherical organic-walled microfossils known as acritarchs, some of which may be dinoflagellate hystrichospheres, first appear in rocks about 1.8 billion years old. Exactly what the acritarchs were is not known with certainty; they probably included a number of clades of eukaryotic algae, and are thus a form taxon, including all those spore-like fossils which have not been conclusively assigned to another group.

  12. Rethinking Fossil Fuels

    NSDL National Science Digital Library

    James Hansen (NASA Goddard Institute for Space Studies; )

    2008-09-09

    Climate change and fossil fuel use are connected. It would serve the world well to: begin a moratorium on coal-fired power plants; explore and use renewable energy; insist on immediate action from world governments; and penalize industries putting excess CO2 into the atmosphere.

  13. Fossil-energy

    NASA Astrophysics Data System (ADS)

    1981-08-01

    Progress in the following areas of fossil energy is reported: physiochemical cleaning and recovery of fine coal; a systematic investigation of the organosulfur components in coal; microstructures of coal; rapid analysis of mineral content in coal; coal blending experiments; performance characteristics of heavy media cyclones using fly ash derived heavy media; briquetting solvent treated coal; and coal preparation and testing.

  14. Fossil Halls: Vertebrate Evolution

    NSDL National Science Digital Library

    Part of a larger virtual tour of the Museum's famed Fossil Halls, this Web site has an interactive cladogram with 20 clickable evolutionary branching points. It shows vertebrate evolution for the following three AMNH halls: Hall of Vertebrate Origins, Hall of Dinosaurs and Hall of Mammals and Their Extinct Relatives.

  15. Fossil Evidence of Bipedalism

    NSDL National Science Digital Library

    2010-03-10

    This video segment adapted from NOVA shows how scientists use the fossil record to trace when early human ancestors and related species began walking on two legs instead of four, and to determine whether they were more apelike or human in appearance.

  16. Fossil Halls: Cladistics

    NSDL National Science Digital Library

    Part of a larger virtual tour of the Museum's famed Fossil Halls, this Web site has an overview explaining the cladistic method of scientific analysis as well as how to read cladograms. It answers the following questions: What is the best way to reconstruct evolutionary history? What is a cladogram? What is an advanced feature? Why use cladistics?

  17. Advanced fossil energy utilization

    SciTech Connect

    Shekhawat, D.; Berry, D.; Spivey, J.; Pennline, H.; Granite, E.

    2010-01-01

    This special issue of Fuel is a selection of papers presented at the symposium ‘Advanced Fossil Energy Utilization’ co-sponsored by the Fuels and Petrochemicals Division and Research and New Technology Committee in the 2009 American Institute of Chemical Engineers (AIChE) Spring National Meeting Tampa, FL, on April 26–30, 2009.

  18. Classification of Fossil Microplankton

    Microsoft Academic Search

    C. Downie; G. L. Williams; W. A. S. SARJEANT

    1961-01-01

    IT is becoming increasingly desirable that a definite decision be made as to whether the fossil organicshelled microplankton (dinoflagellates, hystrichospheres, and genera of presumed microplankton incertae sedis) should be classed, for nomenclatural purposes, in the animal or in the plant kingdom. The dinoflagellates, a group of unicellular organisms some of which contain chlorophyll, are clearly algae, while others contain no

  19. Centering on Fossils and Dinosaurs.

    ERIC Educational Resources Information Center

    Coble, Charles R.; McCall, Gregory K.

    1986-01-01

    Describes a set of 10 activities which introduce mainstreamed junior high school students to concepts relating to fossils and dinosaurs. Provides students with opportunities for learning the concepts of change and adaptation, as well as fossil facts and terminology. (TW)

  20. Synthesis and characterisation of a nematic homo-polyurethane

    Microsoft Academic Search

    Domenico Acierno; Eugenio Amendola; Cosimo Carfagna; Simona Concilio; Pio Iannelli; Loredana Incarnato; Paola Scarfato

    2003-01-01

    The presence of hydrogen bonds in the chemical structure of polymers promotes and stabilises the crystalline phase. For liquid crystalline (LC) polymers, the side insertion of aliphatic units to the mesogenic unit is a suitable artifice to decrease the crystalline stability, without significantly affecting the stability of the LC phases. Here, we report on the synthesis of a LC homo-polyurethane

  1. Fossil energy materials needs assessment

    Microsoft Academic Search

    R. T. King; R. R. Judkins

    1980-01-01

    An assessment of needs for materials of construction for fossil energy systems was prepared by Oak Ridge National Laboratories staff members who conducted a literature search and interviewed various individuals and organizations that are active in the area of fossil energy technology. Critical materials problems associated with fossil energy systems are identified. Background information relative to the various technologies is

  2. The largest fossil rodent

    PubMed Central

    Rinderknecht, Andrés; Blanco, R. Ernesto

    2008-01-01

    The discovery of an exceptionally well-preserved skull permits the description of the new South American fossil species of the rodent, Josephoartigasia monesi sp. nov. (family: Dinomyidae; Rodentia: Hystricognathi: Caviomorpha). This species with estimated body mass of nearly 1000?kg is the largest yet recorded. The skull sheds new light on the anatomy of the extinct giant rodents of the Dinomyidae, which are known mostly from isolated teeth and incomplete mandible remains. The fossil derives from San José Formation, Uruguay, usually assigned to the Pliocene–Pleistocene (4–2?Myr ago), and the proposed palaeoenvironment where this rodent lived was characterized as an estuarine or deltaic system with forest communities. PMID:18198140

  3. Bibliography of Fossil Vertebrates

    NSDL National Science Digital Library

    1997-01-01

    The Society of Vertebrate Paleontology (SVP), one of most reputable American paleontological societies, sponsors this online edition of its Bibliography of Fossil Vertebrates. The database, which currently covers the years 1509-1958 and 1981-1993 with approximately 112,000 references, is searchable by author, subject, taxon, language, editor, and journal book or volume title. A help page with query instructions for the somewhat finicky search engine is provided.

  4. Restoring Fossil Creek

    NSDL National Science Digital Library

    Carri J. LeRoy

    2004-07-01

    As part of an ongoing environmental project and partnership with a local university, high school students monitor changes to Fossil Creek in Arizona. Components of the project include fish behavior studies, responses to fishing, water chemistry measurements, aquatic invertebrate studies, photographic recording, riparian habitat transects, and small mammal trapping transects. The data collected will ultimately provide an invaluable annual record for students, working scientists, and the wider community as changes are monitored over time.

  5. Fossil Halls: Timelines

    NSDL National Science Digital Library

    Part of a larger virtual tour of the Museum's famed Fossil Halls, this Web site allows students to travel back in time to several prehistoric points in the history of Earth. At each, they'll find a fleshed-out portrait of the period's creatures and their environment. The eight periods students will visit, some of which include more than one point-in-time snapshot, are Pleistocene, Miocene, Oligocene, Eocene, Cretaceous, Jurassic, Permian and Devonian Periods.

  6. Schewel and Schipper 1 FOSSIL FREIGHT: HOW MUCH FOSSIL FUEL DOES IT TAKE TO MOVE FOSSIL1

    E-print Network

    Kammen, Daniel M.

    Schewel and Schipper 1 FOSSIL FREIGHT: HOW MUCH FOSSIL FUEL DOES IT TAKE TO MOVE FOSSIL1 FUEL?2 #12;Schewel and Schipper 2 Abstract1 This paper asks as the question: how much fossil fuel does it take to move fossil fuel inside the U.S.? An2 understanding of this "fossil freight", which takes up

  7. ALMA MATER, HOMO SAPIENS II DANILE MEULDERS, SLE O'DORCHAI & NATALIE SIMEU

    E-print Network

    Cerf, Nicolas

    #12;ALMA MATER, HOMO SAPIENS II 2 #12;DANI�LE MEULDERS, SÍLE O'DORCHAI & NATALIE SIMEU 3 Projet de Chances et de l'Enseignement supérieur Alma Mater, Homo Sapiens II « Les inégalités entre femmes et MATER, HOMO SAPIENS II 4 #12;DANI�LE MEULDERS, SÍLE O

  8. Fossilized Dinosaur Teeth Adaptations

    NSDL National Science Digital Library

    Rick Crosslin

    2004-01-01

    In this activity, learners use models of fossilized dinosaur teeth to understand how dinosaur teeth were used. Learners specifically research Tyrannosaurus rex and Triceratops horridus dinosaurs and determine that Triceratops teeth work the way pliers and scissors operate, and T. rex teeth are like sharp knives. Learners match and sort dinosaurs by the type and use of their teeth. This activity is featured on pp.14-18 (part of a lesson that begins on p.7) of the "Dinosphere" unit of study for grades 3-5.

  9. High harmonic spectra contributed by HOMO-1 orbital of aligned CO2 molecules.

    PubMed

    Li, Jiawei; Liu, Peng; Yang, Hua; Song, Liwei; Zhao, Shitong; Lu, Hui; Li, Ruxin; Xu, Zhizhan

    2013-03-25

    We observe the high harmonic generation (HHG) from anti-aligned CO(2) molecules when the on-axis peak of HHG from HOMO-2 orbital disappears. The harmonic emission at anti-alignment can be attributed to the contribution of HOMO-1 orbital. Simulations reproduce these observations and reveal the angular distributions of tunneling ionization from HOMO and HOMO-1 respectively at different intensity. The determination of HOMO-1 orbital contributions in harmonic spectra is important for the tomography imaging of aligned molecules and analysis of the time evolved harmonic emission. PMID:23546143

  10. The frontal bone in the genus Homo: a survey of functional and phylogenetic sources of variation.

    PubMed

    Athreya, Sheela

    2012-01-01

    The frontal bone is a useful aspect of the craniofacial skeleton to study in physical anthropology because it contains several characters considered to be important for both population- and species-level distinctions. These include forehead (frontal squama) inclination and supraorbital morphology. Because it lies at the interface between the anterior neurocranium and the upper face, it is also informative about the evolution of both of these regions of the skull. Previous research on frontal bone morphology can be grouped into two broad categories. One set of studies explored the relationship between craniofacial structure and function in an attempt to explain biological sources of variation in the torus development of various extant primate species, including modern humans. The second group of studies examined geographical and temporal patterns of variation in frontal morphology to make inferences about the phylogenetic relationship relationships among fossil hominin populations in the Pleistocene. This paper offers a review of both phylogenetic and functional studies of variation in frontal bone morphology, and synthesizes them to offer a comprehensive understanding of what the frontal bone can tell us about bio-behavioral and evolutionary differences both among extant and extinct members of the genus Homo. PMID:22781585

  11. Homo- and heterodimerization of APP family members promotes intercellular adhesion

    PubMed Central

    Soba, Peter; Eggert, Simone; Wagner, Katja; Zentgraf, Hanswalter; Siehl, Katjuscha; Kreger, Sylvia; Löwer, Alexander; Langer, Andreas; Merdes, Gunter; Paro, Renato; Masters, Colin L; Müller, Ulrike; Kins, Stefan; Beyreuther, Konrad

    2005-01-01

    The amyloid precursor protein (APP) plays a central role in Alzheimer's disease, but its physiological function and that of its mammalian paralogs, the amyloid precursor-like proteins 1 and 2 (APLPs), is still poorly understood. APP has been proposed to form dimers, a process that could promote cell adhesion via trans-dimerization. We investigated the dimerization and cell adhesion properties of APP/APLPs and provide evidence that all three paralogs are capable of forming homo- and heterocomplexes. Moreover, we show that trans-interaction of APP family proteins promotes cell–cell adhesion in a homo- and heterotypic fashion and that endogenous APLP2 is required for cell–cell adhesion in mouse embryonic fibroblasts. We further demonstrate interaction of all the three APP family members in mouse brain, genetic interdependence, and molecular interaction of APP and APLPs in synaptically enriched membrane compartments. Together, our results provide evidence that homo- and heterocomplexes of APP/APLPs promote trans-cellular adhesion in vivo. PMID:16193067

  12. Fossil plant self assessment

    SciTech Connect

    Bozgo, R.H. [Consolidated Edison Company of New York, Inc., New York, NY (United States); Maguire, B.A. [VPA Corp., Reston, VA (United States)

    1996-07-01

    The increasingly competitive environment of the electric utility business is focusing utilities attention on reducing the cost of electricity generation. By using benchmark indicators, gains are being sought in plant material condition with corresponding improvements in operating efficiency and capacity factor as well as reductions in Operating and Maintenance (O&M) costs. In designing a process for improvement, Consolidated Edison Company of New York, Inc. (Con Edison) plant managers were asked to review and approve objectives and criteria for Fossil Plant Operations. The program methods included optimizing work processes (including material condition, maintenance programs, work control systems, and personnel performance); team building techniques to foster personnel buy-in of the process; and long term cultural change to insure an ongoing continuous improvement process with measurable results. The program begins with a self assessment of each plant based upon the approved Objectives and Criteria. The Criteria and Review Approaches (CRAs) are established by senior management and the review team. The criteria cover Management, Operations, Maintenance, and Support Functions including Technical Support, Training and Qualification, Environmental Compliance, Chemistry, and Safety and Emergency Preparedness. The Assessment is followed by a review of corrective action plans and an interim corrective action review. Annual Assessments are planned to ensure continuous improvement. Emphasis is placed on progress made in maintenance at the fossil stations.

  13. Fossils 2: Uncovering the Facts

    NSDL National Science Digital Library

    Science Netlinks

    2001-10-20

    In Fossils and Dinosaurs, the first lesson of this two lesson series, students learned the differences between facts and ideas that are extrapolated from fossil evidence. This lesson allows students to go through an 'interview' with the remains of a Protoceratops. In preparation for the interview, students first brainstorm the questions they would like answers to, and then narrow their questions to those that can be answered by studying the Protoceratops fossils.

  14. Fossil turbulence and fossil turbulence waves can be dangerous

    E-print Network

    Carl H Gibson

    2012-11-25

    Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any other forces that tend to damp the eddies out. By this definition, turbulence always cascades from small scales where vorticity is created to larger scales where turbulence fossilizes. Fossil turbulence is any perturbation in a hydrophysical field produced by turbulence that persists after the fluid is no longer turbulent at the scale of the perturbation. Fossil turbulence patterns and fossil turbulence waves preserve and propagate energy and information about previous turbulence. Ignorance of fossil turbulence properties can be dangerous. Examples include the Osama bin Laden helicopter crash and the Air France 447 Airbus crash, both unfairly blamed on the pilots. Observations support the proposed definitions, and suggest even direct numerical simulations of turbulence require caution.

  15. The fossil record of cnidarian medusae

    Microsoft Academic Search

    Graham A. Young; James W. Hagadorn

    2010-01-01

    Fossils of cnidarian medusae are extremely rare, although reports of fossil “medusoids,” most of which do not represent medusae, are rather common. Our previous inability to distinguish these fossils has hampered attempts to investigate patterns and processes within the medusozoan fossil record. Here we describe criteria for the recognition of bona fide fossil medusae and use them to assess the

  16. Metric and geometric morphometric analysis of new hominin fossils from Maba (Guangdong, China).

    PubMed

    Xiao, Dongfang; Bae, Christopher J; Shen, Guanjun; Delson, Eric; Jin, Jennie J H; Webb, Nicole M; Qiu, Licheng

    2014-09-01

    We present an analysis of a set of previously unreported hominin fossils from Maba (Guangdong, China), a cave site that is best known for the presence of a partial hominin cranium currently assigned as mid-Pleistocene Homo and that has been traditionally dated to around the Middle-Late Pleistocene transition. A more recent set of Uranium series dates indicate that the Maba travertine may date to >237 ka (thousands of years ago), as opposed to the original U-series date, which placed Maba at 135-129 ka. The fossils under study include five upper first and second molars and a partial left mandible with a socketed m3, all recovered from different parts of the site than the cranium or the dated sediments. The results of our metric and 2D geometric morphometric ('GM') study suggest that the upper first molars are likely from modern humans, suggesting a more recent origin. The upper second molars align more closely with modern humans, though the minimum spanning tree from the 2D GM analysis also connects Maba to Homo neanderthalensis. The patterning in the M2s is not as clear as with the M1s. The m3 and partial mandible are morphometrically intermediate between Holocene modern humans and older Homo sapiens. However, a minimum spanning tree indicates that both the partial mandible and m3 align most closely with Holocene modern humans, and they also may be substantially younger than the cranium. Because questions exist regarding the context and the relationship of the dated travertine with the hominin fossils, we suggest caution is warranted in interpreting the Maba specimens. PMID:25104621

  17. Homo and Hetero-Assembly of Inorganic Nanoparticles

    NASA Astrophysics Data System (ADS)

    Resetco, Cristina

    This thesis describes the synthesis and assembly of metal and semiconductor nanoparticles (NPs). The two research topics include i) hetero-assembly of metal and semiconductor NPs, ii) effect of ionic strength on homo-assembly of gold nanorods (GNRs). First, we present hetero-assembly of GNRs and semiconductor quantum dots (QDs) in a chain using biotin-streptavidin interaction. We synthesized alloyed CdTeSe QDs and modified them with mercaptoundecanoic acid to render them water-soluble and to attach streptavidin. We synthesized GNRs by a seed-mediated method and selectively modified the ends with biotin. Hetero-assembly of QDs and GNRs depended on the size, ligands, and ratio of QDs and GNRs. Second, we controlled the rate of homo-assembly of GNRs by varying the ionic strength of the DMF/water solution. The solubility of polystyrene on the ends of GNRs depended on the ionic strength of the solution, which correlated with the rate of assembly of GNRs into chains.

  18. Dating Fossil Pollen: A Simulation.

    ERIC Educational Resources Information Center

    Sheridan, Philip

    1992-01-01

    Describes a hands-on simulation in which students determine the age of "fossil" pollen samples based on the pollen types present when examined microscopically. Provides instructions for the preparation of pollen slides. (MDH)

  19. A New Skull of Early Homo from Dmanisi, Georgia

    Microsoft Academic Search

    Abesalom Vekua; David Lordkipanidze; G. Philip Rightmire; Jordi Agusti; Reid Ferring; Givi Maisuradze; Alexander Mouskhelishvili; Medea Nioradze; Marcia Ponce de Leon; Martha Tappen; Merab Tvalchrelidze; Christoph Zollikofer

    2002-01-01

    Another hominid skull has been recovered at Dmanisi (Republic of Georgia) from the same strata in which hominid remains have been reported previously. The Dmanisi site dated to ~1.75 million years ago has now produced craniofacial portions of several hominid individuals, along with many well-preserved animal fossils and quantities of stone artifacts. Although there are certain anatomical differences among the

  20. Evaluating the transitional mosaic: frameworks of change from Neanderthals to Homo sapiens in eastern Europe

    NASA Astrophysics Data System (ADS)

    Davies, William; White, Dustin; Lewis, Mark; Stringer, Chris

    2015-06-01

    Defining varying spatial and temporal analytical scales is essential before evaluating the responses of late Neanderthals and early Homo sapiens to Abrupt Environmental Transitions (AETs) and environmental disasters for the period 130-25 ka. Recent advances in addressing the population histories and interactions (using both genetic and archaeological evidence) of Neanderthals and H. sapiens have encouraged consideration of more subtle dynamics of archaeological change. Descriptions of change based on methodologies pioneered some 160 years ago are no longer adequate to explain the patterning we now see in the record. New chronological results, using multiple dating methods, allow us to begin to unpick the spatial and temporal scales of change. Isochronic markers (such as specific volcanic eruptions) can be used to create temporal frameworks (lattices), and results from other dating techniques compared against them. A combination of chronological lattices and direct dating of diagnostic artefacts and human fossils permits us, for the first time, to have greater confidence in connecting human (recent hominin) species and their behavioural responses to environmental conditions, and in quantifying scales of change over time and space (time-transgression). The timing of innovations, particularly those in bone, antler and ivory, can be directly quantified and tested, and used to re-evaluate longstanding models of cultural change. This paper also uses these new chronologies to explore the ecologies of late Neanderthals and early H. sapiens: their population densities, mobilities, resources exploited and possible interactions. Environmental productivity estimates are used to generate new questions of potential population densities and mobilities, and thus the sensitivity of these groups to environmental perturbations. Scales and intensities of effect on environments from natural disasters and AETs (notably Heinrich Events and the Campanian Ignimbrite eruption) are defined as a scale from "proximal" to "distal," with local conditions (topographic shelter or exposure) serving to intensify or mitigate those effects.

  1. Technology Treaties and Fossil-Fuels Extraction

    Microsoft Academic Search

    Jon Strand

    2007-01-01

    We consider some unintended effects of a technology treaty to increase the (stochastic) possibility of developing an energy alternative to fossil fuels which, when available, makes fossil fuels redundant. One implication of such a treaty is to increase the incentives for fossil-fuels producers to extract fossil fuels existing in given quantity more rapidly, under competition when the equilibrium price path

  2. Homo Heuristicus: Less-is-More Effects in Adaptive Cognition

    PubMed Central

    Brighton, Henry; Gigerenzer, Gerd

    2012-01-01

    Heuristics are efficient cognitive processes that ignore information. In contrast to the widely held view that less processing reduces accuracy, the study of heuristics shows that less information, computation, and time can in fact improve accuracy. We discuss some of the major progress made so far, focusing on the discovery of less-is-more effects and the study of the ecological rationality of heuristics which examines in which environments a given strategy succeeds or fails, and why. Homo heuristicus has a biased mind and ignores part of the available information, yet a biased mind can handle uncertainty more efficiently and robustly than an unbiased mind relying on more resource-intensive and general-purpose processing strategies. PMID:23613644

  3. Biom. Hum. et Anthropol. 2004, 22, 3-4, p. 139-161. Granat J., La situation du larynx du genre Homo LA SITUATION DU LARYNX DU GENRE HOMO. DONNEES ANATOMIQUES,

    E-print Network

    Paris-Sud XI, Université de

    Biom. Hum. et Anthropol. 2004, 22, 3-4, p. 139-161. Granat J., La situation du larynx du genre Homo 139 LA SITUATION DU LARYNX DU GENRE HOMO. DONNEES ANATOMIQUES, EMBRYOLOGIQUES ET PHYSIOLOGIQUES THE POSITION OF LARYNX OF HOMO GENUS. ANATOMICAL, EMBRYOLOGICAL AND PHYSIOLOGICAL DATA JEAN GRANAT*, EVELYNE

  4. Comparative 3D quantitative analyses of trapeziometacarpal joint surface curvatures among living catarrhines and fossil hominins.

    PubMed

    Marzke, M W; Tocheri, M W; Steinberg, B; Femiani, J D; Reece, S P; Linscheid, R L; Orr, C M; Marzke, R F

    2010-01-01

    Comparisons of joint surface curvature at the base of the thumb have long been made to discern differences among living and fossil primates in functional capabilities of the hand. However, the complex shape of this joint makes it difficult to quantify differences among taxa. The purpose of this study is to determine whether significant differences in curvature exist among selected catarrhine genera and to compare these genera with hominin fossils in trapeziometacarpal curvature. Two 3D approaches are used to quantify curvatures of the trapezial and metacarpal joint surfaces: (1) stereophotogrammetry with nonuniform rational B-spline (NURBS) calculation of joint curvature to compare modern humans with captive chimpanzees and (2) laser scanning with a quadric-based calculation of curvature to compare modern humans and wild-caught Pan, Gorilla, Pongo, and Papio. Both approaches show that Homo has significantly lower curvature of the joint surfaces than does Pan. The second approach shows that Gorilla has significantly more curvature than modern humans, while Pongo overlaps with humans and African apes. The surfaces in Papio are more cylindrical and flatter than in Homo. Australopithecus afarensis resembles African apes more than modern humans in curvatures, whereas the Homo habilis trapezial metacarpal surface is flatter than in all genera except Papio. Neandertals fall at one end of the modern human range of variation, with smaller dorsovolar curvature. Modern human topography appears to be derived relative to great apes and Australopithecus and contributes to the distinctive human morphology that facilitates forceful precision and power gripping, fundamental to human manipulative activities. PMID:19544574

  5. Geology Fieldnotes: Fossil Butte National Monument, Wyoming

    NSDL National Science Digital Library

    Fossil Butte National Monument preserves a 50-million year old bed of Eocene limestone that contains one of the richest fossil deposits in the world. Site features include park geology information, photographs of fossils, related links, visitor information, multimedia resources, and resources for teaching geology with National Park examples. The park geology section discusses the Monument's geologic history and fossil beds, focusing on the conditions that created the fossil-rich region and on the history of fossil collection in the area. A map of the Monument is also included.

  6. Evolution and the Fossil Record

    E-print Network

    Kammer, Thomas

    .) · Charles Darwin, 1859: The Origin of Species by Natural Selection. #12;Artificial Selection vs. Natural Anatomy of Fossilized organisms #12;Natural Selection · Natural selection, a creative force, is one Selection: Dog breeds produced by artificial selection #12;Natural Selection: Key Points · 3 facts lead

  7. Biological fossil CO 2 mitigation

    Microsoft Academic Search

    Evan Hughes; John R Benemann

    1997-01-01

    Over ten times more CO2 is fixed by plants into biomass, and annually released by decomposers and food chains, than is emitted to the atmosphere due to the burning of fossil fuels. Human activity is already directly and indirectly affecting almost half of the terrestrial biological C cycle. Management of even a small fraction of the biological C cycle would

  8. Fossil Reptiles of Great Britain

    E-print Network

    Benton, Michael

    Fossil Reptiles of Great Britain M.J. Benton and P.S. Spencer Department of Geology, University CONSERVATION REVIEW SERIES The comparatively small land area of Great Britain contains an unrivalled sequence by generations of leading geologists, thus giving Britain a unique status in the development of the science. Many

  9. Fossil Identification and Classification Lab

    NSDL National Science Digital Library

    Ralph Willoughby

    Students pick, sort, box, and identify fossils (mostly mollusks but also bryozoa, arthropods, cnidaria, and annelids) from richly fossiliferous, clastic marine sediment, compile a faunal list,compare the fauna with modern taxa, and make evaluate a paleogeographic model for the taxa found.

  10. Progress of Fossil Fuel Science

    Microsoft Academic Search

    M. F. Demirbas

    2007-01-01

    Coal is the most abundant and widely distributed fossil fuel. More than 45% of the world's electricity is generated from coal, and it is the major fuel for generating electricity worldwide. The known coal reserves in the world are enough for more than 215 years of consumption, while the known oil reserves are only about 39 times of the world's

  11. Fossil/modern mole phylogeny

    NSDL National Science Digital Library

    This study is introduced at the beginning of class, and runs throughout the quarter. Students are first given a paper describing a morphological phylogeny of modern moles. The first few weeks' labs teach the students basic phylogenetic methods and the aspects of skeletal morphology needed to understand the character descriptions. Students in groups of 2 or 3 are assigned a set of characters from a particular region of the skeleton (i.e. humerus, lower teeth, skull, etc.). Those groups are responsible for learning to distinguish those characters on a representative group of modern specimens (for which the character codings are already available in the paper they have) and then coding those characters for a number of fossil taxa. The fossils are either described in papers posted on the course website or are represented by specimens held in the instructor's research lab. Students are responsible for finding time to come in and work with the specimens. The next to last lab of the quarter is concerned with analyzing data within each group, for the class as a whole, for fossil taxa alone, and for fossil and modern taxa. Students then write up the results of their analyses for their term project due at the end of the quarter.

  12. Synthetic soup ground trace fossils

    NSDL National Science Digital Library

    Clint Cowan

    This is a lab exercise where students make synthetic trace fossils (using fishing lures) that was presented as a scientific study: BIOGENIC SEDIMENTARY STRUCTURES PRODUCED BY WORMS IN SOUPY, SOFT MUDS: OBSERVATIONS FROM THE CHATTANOOGA SHALE (UPPER DEVONIAN) AND EXPERIMENTS, by VADEC LOBZA AND JURGEN SCHIEBER, JOURNAL OF SEDIMENTARY RESEARCH, VOL. 69, NO. 5, SEPTEMBER, 1999, P. 1041â1049

  13. Mitochondrial genomes as living 'fossils'.

    PubMed

    Small, Ian

    2013-01-01

    The huge variation between mitochondrial genomes makes untangling their evolutionary histories difficult. Richardson et al. report on the remarkably unaltered 'fossil' genome of the tulip tree, giving us many clues as to how the mitochondrial genomes of flowering plants have evolved over the last 150 million years, and raising questions about how such extraordinary sequence conservation can be maintained. PMID:23587103

  14. Spectroscopic properties, NLO, HOMO-LUMO and NBO of maltol.

    PubMed

    Krishnakumar, V; Barathi, D; Mathammal, R; Balamani, J; Jayamani, N

    2014-01-01

    Maltol (3-hydroxy-2-methyl-4pyrone) is widely known as metal ions chelator with many practical applications in catalysis, medicine and food chemistry. The FTIR and FT-Raman spectra of maltol have been recorded in the region 4000-400 and 4000-50 cm(-1), respectively. The conformational analysis, optimized geometry, frequency and intensity of the vibrational bands of maltol were obtained by the density functional theory (DFT) with complete relaxation in the potential energy surface using 6-31G* basis set. The observed and the calculated frequencies are found to be in good agreement. The (1)H and (13)C NMR spectra have been recorded and (1)H and (13)C nuclear magnetic resonance chemical shifts of the molecule were also calculated using the gauge independent atomic orbital (GIAO) method and their respective linear correlations were obtained. The electronic properties HOMO and LUMO energies were measured. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound were calculated. The Mulliken charges, the values of electric dipole moment (?) of the molecule were computed using DFT calculations. The first order hyperpolarizability (?o) and related properties (?, ?o and ??) of both are calculated using B3LYP/6-31G* method on the finite-field approach. The calculated first hyperpolarizability shows that the molecules are an attractive molecule for future applications in non-linear optics. The intramolecular contacts have been interpreted using Natural Bond Orbital (NBO). PMID:24247097

  15. Hunting Invertebrate Fossils in the Classroom

    NSDL National Science Digital Library

    Jon Garbisch

    This activity is designed to provide a general knowledge about paleontology and its intimate relationship to sedimentary geology. It will introduce the student to fossils with an emphasis on the invertebrate phyla. As a result of this activity students will acquire a general knowledge of fossils and paleontology, be able to identify the major invertebrate groups commonly found in the fossil record, and learn how fossils tell us about the history of the earth.

  16. Book reviews Just looking at fossils

    E-print Network

    Tullberg, Birgitta

    Book reviews Just looking at fossils A review by F. Boero Evolutionary Patterns. Growth, Form and Tempo in the Fossil Record. J. B. Jackson, S. Lidgard, F. McKinney (Eds), 2001. University of Chicago on human evolution based on fossils is one example of this pattern. There are groups of organisms, however

  17. Fossil: A Robust Relational Learner Johannes Furnkranz

    E-print Network

    Fürnkranz, Johannes

    Fossil: A Robust Relational Learner Johannes F¨urnkranz juffi@ai.univie.ac.at Austrian Research in this paper describes Fossil, an ILP system that uses a search heuristic based on statistical correlation, Fossil's stopping criterion depends on a search heuristic that estimates the utility of literals

  18. Using extant morphological variation to understand fossil

    E-print Network

    Ackermann, Rebecca Rogers

    Using extant morphological variation to understand fossil relationships: a cautionary tale Rebecca of insights that are pertinent to how we evaluate relationships among our fossil human ancestors. Here I summarize four such insights. I then use a fossil hominid example to illustrate how our understanding

  19. A New Kind of Economy is Born - Social Decision-Makers Beat the "Homo Economicus"

    E-print Network

    Helbing, Dirk

    2013-01-01

    The Internet and Social Media change our way of decision-making. We are no longer the independent decision makers we used to be. Instead, we have become networked minds, social decision-makers, more than ever before. This has several fundamental implications. First of all, our economic theories must change, and second, our economic institutions must be adapted to support the social decision-maker, the "homo socialis", rather than tailored to the perfect egoist, known as "homo economicus".

  20. PALEOANTHROPOLOGY. Comment on "Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia".

    PubMed

    Hawks, John; de Ruiter, Darryl J; Berger, Lee R

    2015-06-19

    Villmoare et al. (Reports, 20 March 2015, p. 1352) report on a hominin mandible from the Ledi-Geraru research area, Ethiopia, which they claim to be the earliest known representative of the genus Homo. However, certain measurements and observations for Australopithecus sediba mandibles presented are incorrect or are not included in critical aspects of the study. When correctly used, these data demonstrate that specimen LD 350-1 cannot be unequivocally assigned to the genus Homo. PMID:26089505

  1. Sky Luminaries in the Space Orienting Activity of Homo Sapiens in the Middle Palaeolithic

    NASA Astrophysics Data System (ADS)

    Kaurov, E. N.

    Data describing the beginnings of the space orienting activity of Homo sapiens is analysed and systematized: observation of the Pole and the recognition of Ursa Major were used as the basis of the determination of the points of the compass. Data and results from astronomy, history of astronomy, archaeology and palaeoanthropology were used for the reconstruction of the evolution of the space orienting activity of Homo sapiens.

  2. The conservation and use of fossil vertebrate sites: British fossil reptile sites

    E-print Network

    Benton, Michael

    The conservation and use of fossil vertebrate sites: British fossil reptile sites Michael J. Benton and William A. Wimbledon BENTON. M. J. & W. A. WIMBLEDON. 19R5. The conservation and use of fossil vertebrate sites: British fossil reptile sites. Proc. Geol. Ass., 96 (I). 1-0. Over a thousand sites in Britain

  3. Fossil groups of galaxies: Are they groups? Are they fossils?

    NASA Astrophysics Data System (ADS)

    Dupke, Renato de Alencar; Miller, Eric; de Oliveira, Claudia Mendes; Sodre, Laerte; Rykoff, Eli; de Oliveira, Raimundo Lopes; Proctor, Rob

    2010-11-01

    Fossil groups present a puzzle to current theories of structure formation. Despite the low number of bright galaxies, their high velocity dispersions and high TX indicate cluster-like potential wells. Measured concentration parameters seem very high indicating early formation epochs in contradiction with the observed lack of large and well defined cooling cores. There are very few fossil groups with good quality X-ray data and their idiosyncrasies may enhance these apparent contradictions. The standard explanation for their formation suggests that bright galaxies within half the virial radii of these systems were wiped out by cannibalism forming the central galaxy. Since dry mergers, typically invoked to explain the formation of the central galaxies, are not expected to change the IGM energetics significantly, thus not preventing the formation of cooling cores, we investigate the scenario where recent gaseous (wet) mergers formed the central galaxy injecting energy and changing the chemistry of the IGM in fossil groups. We show a test for this scenario using fossil groups with enough X-ray flux in the Chandra X-ray Observatory archive by looking at individual metal abundance ratio distributions near the core. Secondary SN II powered winds would tend to erase the dominance of SN IA ejecta in the core of these systems and would help to erase previously existing cold cores. Strong SN II-powered galactic winds resulting from galaxy merging would be trapped by their deep potential wells reducing the central enhancement of SN Ia/SN II iron mass fraction ratio. The results indicate that there is a decrement in the ratio of SN Ia to SN II iron mass fraction in the central regions of the systems analyzed, varying from 99±1% in the outer regions to 85±2% within the cooling radius (Figure 1) and would inject enough energy into the IGM preventing central gas cooling. The results are consistent with a scenario of later formation epoch for fossil groups, as they are defined, when compared to galaxy clusters and normal groups.

  4. Clustering fossils in solid inflation

    NASA Astrophysics Data System (ADS)

    Akhshik, Mohammad

    2015-05-01

    In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tenor perturbation induces observable clustering fossils in the form of quadrupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar bispectrum for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with the Planck constraints. Specializing to this allowed range of model parameter we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of the scalar perturbations. We argue that the imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

  5. Clustering Fossils in Solid Inflation

    E-print Network

    Akhshik, Mohammad

    2014-01-01

    In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tensor perturbation induces observable clustering fossils in the form of quardupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with Planck constraints. Specializing to this allowed range of model parameter, we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of scalar perturbations. We argue that imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

  6. Clustering Fossils in Solid Inflation

    E-print Network

    Mohammad Akhshik

    2014-09-10

    In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tensor perturbation induces observable clustering fossils in the form of quardupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with Planck constraints. Specializing to this allowed range of model parameter, we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of scalar perturbations. We argue that imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

  7. Scaling relations in fossil galaxy groups

    E-print Network

    Habib G. Khosroshahi; Trevor J. Ponman; Laurence R. Jones

    2007-02-04

    Using Chandra X-ray observations and optical imaging and spectroscopy of a flux-limited sample of 5 fossil groups, supplemented by additional systems from the literature, we provide the first detailed study of the scaling properties of fossils compared to normal groups and clusters. In general, all the fossils we study show regular and symmetric X-ray emission, indicating an absence of recent major group mergers. We confirm that, for a given optical luminosity of the group, fossils are more X-ray luminous than non-fossil groups. Fossils, however, fall comfortably on the conventional L_X-T_X relation of galaxy groups and clusters, suggesting that their X-ray luminosity and their gas temperature are both boosted, arguably, as a result of their early formation. This is supported by other scaling relations including the L_X-sigma and T_X-sigma relations in which fossils show higher X-ray luminosity and temperature for a given group velocity dispersion. We find that mass concentration in fossils is higher than in non-fossil groups and clusters. In addition, the M_X-T_X relation suggests that fossils are hotter, for a given total gravitational mass, both consistent with an early formation epoch for fossils. We show that the mass-to-light ratio in fossils is rather high but not exceptional, compared to galaxy groups and clusters. The entropy of the gas in low mass fossils appears to be systematically lower than that in normal groups, which may explain why the properties of fossils are more consistent with an extension of cluster properties. We conclude that the cuspy potential raises the luminosity and temperature of the IGM in fossils. However, this works in conjunction with lower gas entropy, which may arise from less effective preheating of the gas.

  8. Mitochondrial genomes as living ‘fossils’

    PubMed Central

    2013-01-01

    The huge variation between mitochondrial genomes makes untangling their evolutionary histories difficult. Richardson et al. report on the remarkably unaltered ‘fossil’ genome of the tulip tree, giving us many clues as to how the mitochondrial genomes of flowering plants have evolved over the last 150 million years, and raising questions about how such extraordinary sequence conservation can be maintained. See research article http://www.biomedcentral.com/1741-7007/11/29. PMID:23587103

  9. Dinosaurs: Ancient Fossils, New Discoveries

    NSDL National Science Digital Library

    This Web site, created to complement the Museum's Dinosaurs: Ancient Fossils, New Discoveries exhibit, offers a virtual visit to the Museum, complete with text, photos, video clips, audio interviews, and more and includes much of the information which was in the original exhibit which is now closed. The site includes information on the bio-mechanics of dinosaurs and the reasons behind some of their strange appearances.

  10. Fossil Collection and Museum Curation

    NSDL National Science Digital Library

    Diana Boyer

    Before we go into the field, students are exposed to field collection techniques and appropriate information to collect at the outcrop. This assignment is good for field trips because students each collect 1 or few samples, but spend time on the outcrop measuring a section and collecting associated lithologic and other fossil data if available (locality information, exposure, over and underlying sedimentology, details of host rock, sedimentary structures, assocaited fossils, diversity and abundance, taphonomic condition of fossils, etc). The field locality can be anywhere where there are resaonably well preserved fossils (and should give students an appreciation of museum quality specimens). This allows this exercise to be flexible as field trip localities change. All of the information that they collect in the field will be included in their field notebook that is handed in at the end of the field trip for evaluation. In the lab-I used class time-students are asked to make a detailed sketch of their sample that they can take to the library with them, and a discussion is held as to where to look for information to identify specimens with. Students are given a week (variable depending on the availability of resources, for example if monographs need to be aquired through inter-library loan) to idenitfy their specimen and then asked to catalog them for the museum. They fill out a SUNY Oswego Paleontology Museum card, which they have seen all semester for their sample and are given the option to donate it to the collection or keep it.

  11. Dinosaur Fossils Predict Body Temperatures

    PubMed Central

    Allen, Andrew P; Charnov, Eric L

    2006-01-01

    Perhaps the greatest mystery surrounding dinosaurs concerns whether they were endotherms, ectotherms, or some unique intermediate form. Here we present a model that yields estimates of dinosaur body temperature based on ontogenetic growth trajectories obtained from fossil bones. The model predicts that dinosaur body temperatures increased with body mass from approximately 25 °C at 12 kg to approximately 41 °C at 13,000 kg. The model also successfully predicts observed increases in body temperature with body mass for extant crocodiles. These results provide direct evidence that dinosaurs were reptiles that exhibited inertial homeothermy. PMID:16817695

  12. Evolution and the Fossil Record

    NSDL National Science Digital Library

    Dale Springer

    2007-12-12

    This publication of the American Geological Institute is a non-technical introduction to evolution and aims to help the general public gain a better understanding of one of the fundamental underlying concepts of modern science. Concepts covered include geologic time, change through time, Darwin's theory of evolution, evolution as a mechanism for change, the nature of species, the nature of theory, paleontology, and determination of age. Four case studies highlight examples of evolution from the fossil record to provide a perspective for understanding the evolution of life on Earth.

  13. The fossil record of the Peronosporomycetes (Oomycota).

    PubMed

    Krings, Michael; Taylor, Thomas N; Dotzler, Nora

    2011-01-01

    Evidence of fossil Peronosporomycetes has been slow to accumulate. In this review various fossils historically assigmed to the Peronosporomycets are dicussed briefly and an explanation is provided as to why the fossil record of this grouop has remained inconsistent. In recent year there has been several new reports of fossil peronosporomycetes based on structurally preserved oogonium-antheridium complexes from Derovonian and Carboniferous rocks that demonstrate the existence of these organisms as fossils and refute the long-standing assumption that they are too delicate to be preserved. Among these are serral tyoes characterized by oogonial surface members of the group. To date at last three groups of fossil vascular plants (i.e. lycophytes, ferns and seed ferns) are known to host peronosporomycetes aas endophytes; however only one form has been identified as a parasite. PMID:21289104

  14. Fossil energy program. Summary document

    SciTech Connect

    None

    1980-05-01

    This program summary document presents a comprehensive overview of the research, development, and demonstration (RD and D) activities that will be performed in FY 1981 by the Assistant Secretary for Fossil Energy (ASFE), US Department of Energy (DOE). The ASFE technology programs for the fossil resources of coal, petroleum (including oil shale) and gas have been established with the goal of making substantive contributions to the nation's future supply and efficienty use of energy. On April 29, 1977, the Administration submitted to Congress the National Energy Plan (NEP) and accompanying legislative proposals designed to establish a coherent energy policy structure for the United States. Congress passed the National Energy Act (NEA) on October 15, 1978, which allows implementation of the vital parts of the NEP. The NEP was supplemented by additional energy policy statements culminating in the President's address on July 15, 1979, presenting a program to further reduce dependence on imported petroleum. The passage of the NEA-related energy programs represent specific steps by the Administration and Congress to reorganize, redirect, and clarify the role of the Federal Government in the formulation and execution of national energy policy and programs. The energy technology RD and D prog4rams carried out by ASFE are an important part of the Federal Government's effort to provide the combination and amounts of energy resources needed to ensure national security and continued economic growth.

  15. Teaching Through Trade Books: Fascinating Fossil Finds

    NSDL National Science Digital Library

    Chrstine Anne Royce

    2004-10-01

    This month's Teaching Through Trade Books column engages students in "unearthing" fossils and exploring the processes scientists use in uncovering these fascinating finds and interpreting Earth's past.

  16. Fossilization Processes in Thermal Springs

    NASA Technical Reports Server (NTRS)

    Farmer, Jack D.; Cady, Sherry; Desmarais, David J.; Chang, Sherwood (Technical Monitor)

    1995-01-01

    To create a comparative framework for the study of ancient examples, we have been carrying out parallel studies of the microbial biosedimentology, taphonomy and geochemistry of modem and sub-Recent thermal spring deposits. One goal of the research is the development of integrated litho- and taphofacies models for siliceous and travertline sinters. Thermal springs are regarded as important environments for the origin and early evolution of life on Earth, and we seek to utilize information from the fossil record to reconstruct the evolution of high temperature ecosystems. Microbial contributions to the fabric of thermal spring sinters occur when population growth rates keep pace with, or exceed rates of inorganic precipitation, allowing for the development of continuous biofilms or mats. In siliceous thermal springs, microorganisms are typically entombed while viable. Modes of preservation reflect the balance between rates of organic matter degradation, silica precipitation and secondary infilling. Subaerial sinters are initially quite porous and permeable and at temperatures higher than about 20 C, organic materials are usually degraded prior to secondary infilling of sinter frameworks. Thus, organically-preserved microfossils are rare and fossil information consists of characteristic biofabrics formed by the encrustation and underplating of microbial mat surfaces. This probably accounts for the typically low total organic carbon values observed in thermal spring deposits. In mid-temperature, (approx. 35 - 59 C) ponds and outflows, the surface morphology of tufted Phormidium mats is preserved through mat underplating by thin siliceous: crusts. Microbial taxes lead to clumping of ceils and/or preferred filament orientations that together define higher order composite fabrics in thermal spring stromatolites (e.g. network, coniform, and palisade). At lower temperatures (less than 35 C), Calothrix mats cover shallow terracette pools forming flat carpets or pustular surfaces that produce palisade and "shrub" fabrics, respectively. At finer scales, composite fabrics are seen to consist distinctive associations of microstructures formed by the encrustation of individual cells and filaments. Composite fabrics survive the diagenetic transitions from primary opaline silica to quartz and are known from subaerial thermal spring deposits as old as Lower Carboniferous. However, fossil microorganisms tend to be rare in older deposits, and are usually preserved only where cells or sheaths have been stained by iron oxides. In subaqueous mineralizing springs at lower temperatures, early infilling leads to a more rapid and complete reduction in porosity and permeability. This process, along with the slower rates of microbial degradation at lower temperatures, creates a more favorable situation for organic matter preservation. Application of this taphonomic model to the Rhynie Chert, previously interpreted as subaerial, suggest it was probably deposited in a subaqueous spring setting at lower temperatures.

  17. The Fossil Record Noel A. Heim and Dana H. Geary

    E-print Network

    Heim, Noel A.

    II.9 The Fossil Record Noel A. Heim and Dana H. Geary OUTLINE 1. Fossilization and taphonomy 2. The nature of the fossil record 3. Marine diversity in the Phanerozoic 4. The value of the fossil record The fossil record documents the history of life over the course of the past 3.5 billion years, demonstrates

  18. The Microbial Origin of Fossil Fuels

    Microsoft Academic Search

    Guy Ourisson; Pierre Albrecht; Michel Rohmer

    1984-01-01

    The authors have investigated the genesis of fossil fuels and different kinds of sedimentary deposits by studying the structure of individual fossil compounds in order to deduce the structure of their precursors in living organisms. Analysis revealed unexpected similarities, specifically in the pattern of peaks in gas chromatograms in the Cââ to Cââ region. Thousands of samples taken from all

  19. Fossil fuel usage and the environment

    Microsoft Academic Search

    Klass

    1990-01-01

    The Greenhouse Effect and global warming, ozone formation in the troposphere, ozone destruction in the stratosphere, and acid rain are important environmental issues. The relationship of fossil fuel usage to some of these issues is discussed. Data on fossil fuel consumption and the sources and sinks of carbon dioxide, carbon monoxide, methane, nitrogen and sulfur oxides, and ozone indicate that

  20. Capturing and Storing Fossil-Fuel Carbon

    Microsoft Academic Search

    David Keith

    2002-01-01

    Can the global energy system continue to be dominated by fossil fuels throughout the 21st century without leading to an unacceptable rise in the concentration of atmospheric CO2? Yes, if a substantial fraction of the carbon in the fossil fuels can be captured and stored elsewhere than in the atmosphere. Of critical importance are: 1) the commercialization of a non-carbon

  1. The First Fossil Record of Caecilian Amphibians

    Microsoft Academic Search

    Richard Estes; MARVALEE H. WAKE

    1972-01-01

    THREE groups of amphibians are living today-frogs, salamanders and caecilians. The fossil record of frogs and salamanders is relatively poor1,2, but representatives of most groups have been discovered. For the caecilians, however, no authentic fossils have been recognized, until now. We describe here a single diagnostic vertebra from the Palaeocene of Brazil.

  2. The original colours of fossil beetles.

    PubMed

    McNamara, Maria E; Briggs, Derek E G; Orr, Patrick J; Noh, Heeso; Cao, Hui

    2012-03-22

    Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group. PMID:21957131

  3. 56 SCIENCE SCOPE Fossil sharks: Learning

    E-print Network

    Bermingham, Eldredge

    , that particular area was cov- ered with water. Plate tectonics Scientific evidence indicates that the positions of continents have changed over geologic time as a result of plate tectonics. These Earth move- ments have Fossils tell important stories about plate tectonics. Re- lated fossils are often discovered at varied

  4. HEMATITE AND CALCITE COATINGS ON FOSSIL VERTEBRATES

    Microsoft Academic Search

    HUIMING BAO; PAUL L. KOCH; ROBERT P. HEPPLE

    Hematite coatings are common on vertebrate fossils from Paleocene\\/Eocene paleosol deposits in the Bighorn Basin, Wyoming. In general, hematite coatings are found only on fossils and are limited to soils exhibiting hydromorphic features and moderate maturity. Pet- rographic and isotopic evidence suggests that hematite and micritic calcite formed at nearly the same time in a pedogenic environment, whereas sparry calcite

  5. Derivatives of Black Knight Technology

    NASA Astrophysics Data System (ADS)

    Hill, N.; Wright, D.

    This paper traces the line of descent from Black Knight to Black Arrow, and at the same time looks at various proposed projects, both civil and military, which were to be Black Knight derivatives, but which for one reason or another never saw the light of day. Research in this area is rather akin to anthropological work, tracing fossils from Homo erectus (Black Knight) to Homo sapiens (Black Arrow), knowing that a lot of the fossils found will not be on the direct line of descent, but represent branches that became extinct. This article attempts to cover designs, which, although they never made it to hardware, are none the less interesting technically, or shine light on the evolution of design philosophy.

  6. Adaptive sex ratio variation in pre-industrial human (Homo sapiens) populations?

    E-print Network

    Lummaa, Virpi

    Adaptive sex ratio variation in pre-industrial human (Homo sapiens) populations? Virpi Lummaa-20014 Turku, Finland Sex allocation theory predicts that in a population with a biased operational sex ratio (OSR), parents will increase their ¢tness by adjusting the sex ratio of their progeny towards

  7. Spatial Construction Skills of Chimpanzees ("Pan Troglodytes") and Young Human Children ("Homo Sapiens Sapiens")

    ERIC Educational Resources Information Center

    Poti, Patrizia; Hayashi, Misato; Matsuzawa, Tetsuro

    2009-01-01

    Spatial construction tasks are basic tests of visual-spatial processing. Two studies have assessed spatial construction skills in chimpanzees (Pan troglodytes) and young children (Homo sapiens sapiens) with a block modelling task. Study 1a subjects were three young chimpanzees and five adult chimpanzees. Study 1b subjects were 30 human children…

  8. Robinlin: A novel bioactive homo-monoterpene from Robinia pseudoacacia L. (Fabaceae)

    Microsoft Academic Search

    Feifei Tian; Ching-Jer Chang; John B Grutzner; David E Nichols; Jerry L McLaughlin

    2001-01-01

    A bioactivity-directed fractionation of the ethanolic extracts of Robinia pseudoacacia L. (Fabaceae) afforded robinlin (1), a novel homo-monoterpene. The structure of 1 was elucidated by spectral analyses of the parent compound as well as its derivatives; 1 showed strong bioactivity in the brine shrimp lethality test (BST).

  9. DISTINCTION PHNOTYPIQUE DES CAPRINS HOMO-ET HTROZYGOTES SANS CORNES (1)

    E-print Network

    Paris-Sud XI, Université de

    NOTE DISTINCTION PHÉNOTYPIQUE DES CAPRINS HOMO- ET HÉTÉROZYGOTES SANS CORNES (1) G. RICORDEAU J 48 - Moissac RÉSUMÉ Chez les caprins d'origine alpine portant le gène dominant P d'absence de cornes, même les animaux sans cornes présentent deux protubérances osseuses. Chez les PP, les protubérances

  10. Flicker Noise Characterization and Modeling of Homo and Hetero-Junction III-V Tunnel FETs

    E-print Network

    Yener, Aylin

    Flicker Noise Characterization and Modeling of Homo and Hetero-Junction III-V Tunnel FETs R hetero-junction Tunnel Field Effect Transistors were demonstrated with MOSFET-like high drive currents due to reduction in the effective tunneling barrier (Ebeff) at the hetero- interface. In this work, we

  11. ON THE CONCEPT OF (HOMO)MORPHISM : A KEY NOTION IN THE LEARNING OF ABSTRACT ALGEBRA

    E-print Network

    Paris-Sud XI, Université de

    ON THE CONCEPT OF (HOMO)MORPHISM : A KEY NOTION IN THE LEARNING OF ABSTRACT ALGEBRA Thomas Algebra more accessible. I. INTRODUCTION In our context, Abstract Algebra means the discipline devoted to the study of algebraic structures, according to the new paradigm established after the publication of van

  12. Iron-catalyzed homo-coupling of simple and functionalized arylmagnesium reagents.

    PubMed

    Cahiez, Gérard; Chaboche, Christophe; Mahuteau-Betzer, Florence; Ahr, Mathieu

    2005-05-12

    Iron-catalyzed homo-coupling of simple and functionalized arylmagnesium reagents is described. The reaction is highly chemoselective (CN, COOEt and NO(2) groups are tolerated). The procedure was used to perform intramolecular couplings. This cyclization reaction is the key step of the total synthesis of the N-methylcrinasiadine. PMID:15876025

  13. Summary statistics for fossil spider species taxonomy

    PubMed Central

    Penney, David; Dunlop, Jason A.; Marusik, Yuri M.

    2012-01-01

    Abstract Spiders (Araneae) are one of the most species-rich orders on Earth today, and also have one of the longest geological records of any terrestrial animal groups, as demonstrated by their extensive fossil record. There are currently around 1150 described fossil spider species, representing 2.6% of all described spiders (i.e. extinct and extant). Data for numbers of fossil and living spider taxa described annually (and various other metrics for the fossil taxa) were compiled from current taxonomic catalogues. Data for extant taxa showed a steady linear increase of approximately 500 new species per year over the last decade, reflecting a rather constant research activity in this area by a large number of scientists, which can be expected to continue. The results for fossil species were very different, with peaks of new species descriptions followed by long troughs, indicating minimal new published research activity for most years. This pattern is indicative of short bursts of research by a limited number of authors. Given the frequent discovery of new fossil deposits containing spiders, a wealth of new material coming to light from previously worked deposits, and the application of new imaging techniques in palaeoarachnology that allow us to extract additional data from historical specimens, e.g. X-ray computed tomography, it is important not only to ensure a sustained research activity on fossil spiders (and other arachnids) through training and enthusing the next generation of palaeoarachnologists, but preferably to promote increased research and expertise in this field. PMID:22639535

  14. Clean Fossil Energy Conversion Processes

    NASA Astrophysics Data System (ADS)

    Fan, L.-S.

    2007-03-01

    Absolute and per-capita energy consumption is bound to increase globally, leading to a projected increase in energy requirements of 50% by 2020. The primary source for providing a majority of the energy will continue to be fossil fuels. However, an array of enabling technologies needs to be proven for the realization of a zero emission power, fuel or chemical plants in the near future. Opportunities to develop new processes, driven by the regulatory requirements for the reduction or elimination of gaseous and particulate pollutant abound. This presentation describes the chemistry, reaction mechanisms, reactor design, system engineering, economics, and regulations that surround the utilization of clean coal energy. The presentation will cover the salient features of the fundamental and process aspects of the clean coal technologies in practice as well as in development. These technologies include those for the cleaning of SO2, H2S, NOx, and heavy metals, and separation of CO2 from the flue gas or the syngas. Further, new combustion and gasification processes based on the chemical looping concepts will be illustrated in the context of the looping particle design, process heat integration, energy conversion efficiency, and economics.

  15. Ashfall Fossil Beds State Historical Park

    NSDL National Science Digital Library

    Approximately 12 million years ago, a massive volcano in the southwestern corner of Idaho erupted and spread a tremendous blanket of ash over a large area. Much of this ash settled over the grasslands of northeastern Nebraska. Animals consumed the ash-covered grasses, and eventually they began to perish as a result of consuming this abrasive powder. Eventually these animals and their skeletons became fossilized, and this area is now the Ashfall Fossil Beds State Historical Park. Visitors to the Park's website will be delighted to learn that they can view a range of images and videos from the fossil beds, along with an excellent interactive skeleton map that documents the fossilized remains on site. Also, the "Ashfall Geology" site is uniformly excellent, and it includes aerial views of the site and details about the geological formations in the area. Finally, the "Ashfall Animals" area contains information about the paleontological finds, which include five horse species and a saber-toothed deer.

  16. How a Dinosaur Became a Fossil

    NSDL National Science Digital Library

    WGBH Educational Foundation

    2005-12-17

    This interactive resource adapted from the Museum of Paleontology at the University of California, Berkeley shows how a dinosaur can be buried under sediment after it dies, become a fossil, and then become exposed and discovered by paleontologists.

  17. Hybrid solar-fossil fuel power generation

    E-print Network

    Sheu, Elysia J. (Elysia Ja-Zeng)

    2012-01-01

    In this thesis, a literature review of hybrid solar-fossil fuel power generation is first given with an emphasis on system integration and evaluation. Hybrid systems are defined as those which use solar energy and fuel ...

  18. Method of burning a fossil fuel

    Microsoft Academic Search

    Whelan

    1978-01-01

    A method is disclosed for burning a fossil fuel and air with the emmission of an exhaust gas consisting essentially of atmospheric gases, carbon dioxide and water vapor and essentially free of carbon monoxide, hydrocarbons and nitric oxide, which comprises burning the fossil fuel at a temperature between 1000°C and 1500°C with less than the stoichiometric amount of atmospheric oxygen

  19. Adventures in Paleontology: 36 Classroom Fossil Activities

    NSDL National Science Digital Library

    Irwin Slesnick

    2006-01-01

    Millions of years after vanishing from the Earth, dinosaurs still have the power to stir students' curiosity. Deepen that interest with Adventures in Paleontology, a series of lively hands-on activities especially for middle schoolers. This beautifully illustrated full color book features 36 activities that open students up to a variety of foundational sciences, including biology, geology, chemistry, physics, and astronomy. For example: ? "How Do Fossils Form?" discusses how organisms become fossils and illustrates the concept with activities that simulate fossil-making processes. ? "What Can You Learn From Fossils?" explores what fossils teach about ancient organisms. ? "Mass Extinction and Meteor Collisions With Earth" discusses recently discovered links between meteor and asteroid impacts on Earth and the demise of animals like dinosaurs. Other chapters cover how to tell the age of the Earth; how dinosaurs evolved; and diversity, classification, and taxonomy. The final chapters offer humanistic perspectives on fossils in literature and art. As an attention-grabbing complement to the text, vivid full color illustrations show not just skeletons and animal tracks but also what dinosaurs probably looked like in their natural settings. Handy line drawings guide students through each step of the activities.

  20. Temperature-Dependent Sinusoidal Magnetic Order in the Superconductor HoMo6Se8

    Microsoft Academic Search

    J. W. Lynn; J. A. Gotaas; R. W. Erwin; R. A. Ferrell; J. K. Bhattacharjee; R. N. Shelton; P. Klavins

    1984-01-01

    A magnetic phase transition (TM=0.53 K) to a long-period (~102-Å) magnetic state has been observed via neutron scattering in the superconductor (Tc=5.6 K) HoMo6Se8. The characteristic wave vector qc is strongly temperature dependent even though no higher-order satellites are observed. With use of a Ginzburg-Landau model it is found that the temperature dependence of qc can be explained as due

  1. Enantioselective intramolecular aldehyde ?-alkylation with simple olefins: direct access to homo-ene products.

    PubMed

    Comito, Robert J; Finelli, Fernanda G; MacMillan, David W C

    2013-06-26

    A highly selective method for the synthesis of asymmetrically substituted carbocycles and heterocycles from unactivated aldehyde-olefin precursors has been achieved via enantioselective SOMO-catalysis. Addition of a catalytically generated enamine radical cation across a pendent olefin serves to establish a general asymmetric strategy toward the production of a wide range of formyl-substituted rings with alkene transposition. Conceptually, this novel mechanism allows direct access to "homo-ene"-type products. PMID:23745728

  2. APA PROOFS Implicit and Explicit Category Learning by Macaques (Macaca mulatta) and Humans (Homo sapiens)

    Microsoft Academic Search

    J. David Smith; Matthew J. Crossley; F. Gregory Ashby

    An influential theoretical perspective differentiates in humans an explicit, rule-based system of category learning from an implicit system that slowly associates different regions of perceptual space with different response outputs. This perspective was extended for the 1st time to the category learning of nonhuman primates. Humans (Homo sapiens) and macaques (Macacca mulatta) learned categories composed of sine-wave gratings that varied

  3. Structural and Mechanical Differences between Collagen Homo-and Heterotrimers: Relevance for the Molecular Origin of Brittle Bone Disease

    E-print Network

    Buehler, Markus J.

    Structural and Mechanical Differences between Collagen Homo- and Heterotrimers: Relevance for Computational Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts ABSTRACT Collagen to organisms. Normal type I collagen is a heterotrimer triple-helical molecule consisting of two a-1 chains

  4. Homo sapiens (Cro-magnon and modern human), Chris StringerSite: DNA Interactive (www.dnai.org)

    NSDL National Science Digital Library

    2008-10-06

    Interviewee: Chris Stringer DNAi Location:Applications>Human origins>our family tree>Modern humans: a late arrival Human origins expert Chris Stringer talks about the arrival of Homo sapiens and our possible ancestors.

  5. Application of biochemical interactions in fossil fuels

    SciTech Connect

    Lin, M.S.; Premuzic, E.T.

    1994-12-31

    Certain extreme environments tolerant microorganisms interact with heavy crude oils by means of multiple biochemical reactions, asphaltenes, and bituminous materials. These reactions proceed via pathways which involve characteristic components of oils and coals such as asphaltenes, and in the chemically related constituents found in bituminous coals. These chemical components serve as markers of the interactions between microorganisms and fossil fuels. Studies in which temperature, pressure, and salinity tolerant microorganisms have been allowed to interact with different crude oils and bituminous coals, have shown that biochemically induced changes occur in the distribution of hydrocarbons and in the chemical nature of organometallic and heterocyclic compounds. Such structural chemical rearrangements have direct applications in monitoring the efficiency, the extent, and the chemical nature of the fossil fuels bioconversion. Recent developments of chemical marker applications in the monitoring of fossil fuels bioconversion will be discussed.

  6. Fossil evidence of the zygomycetous fungi.

    PubMed

    Krings, M; Taylor, T N; Dotzler, N

    2013-06-01

    Molecular clock data indicate that the first zygomycetous fungi occurred on Earth during the Precambrian, however, fossil evidence of these organisms has been slow to accumulate. In this paper, the fossil record of the zygomycetous fungi is compiled, with a focus on structurally preserved Carboniferous and Triassic fossils interpreted as zygosporangium-gametangia complexes and resembling those of modern Endogonales. Enigmatic microfossils from the Precambrian to Cenozoic that have variously been interpreted as, or compared to, zygomycetous fungi are also discussed. Among these, the spherical structures collectively termed 'sporocarps' are especially interesting because of their complex investments and abundance in certain Carboniferous and Triassic rocks. Circumstantial evidence suggests that at least some 'sporocarp' types represent mantled zygosporangia. Zygomycetous fungi probably were an important element in terrestrial paleoecosystems at least by the Carboniferous. PMID:24027344

  7. Fossil generation restructuring in the Ukraine

    SciTech Connect

    Galambas, J.W. [Hagler Bailly Consulting, Inc., Boulder, CO (United States)

    1996-12-31

    This paper describes the Ukrainian electrical system as it was in 1991, defines the need for restructuring, outlines the restructuring process, identifies a number of major obstacles that are hindering the implementation of the fossil generation, restructuring process, and points out major problems in the coal procurement system. It describes the visits to several Ukrainian power plants, defines restructuring success to date, makes suggestions for improved restructuring progress, highlights lessons learned, and enlightens the audience on the opportunities of investing in the Ukrainian power generation industry. The primary focus is on the Fossil Generator Advisor task, which was carried out under the direction of Hagler Bailly Consulting, Inc. (Hagler Bailly).

  8. How Do Scientists Find Dinosaur Fossils?

    NSDL National Science Digital Library

    This lesson plan is about the process by which paleontologists locate, excavate, and study dinosaurs. Students will write journal entries pretending they are on a dinosaur dig. They will also make fact sheets about this recently discovered Jobaria dinosaur; place Jobaria into a timeline to indicate the periods in which it lived; visit a website to learn about the steps involved in finding and excavating dinosaur fossils, then list these steps and explain their importance; describe what the bones in an interactive Jobaria skeleton indicate about this dinosaur; and view pictures of a trip teenagers took to look for dinosaur fossils.

  9. "Homo High"

    ERIC Educational Resources Information Center

    Kilman, Carrie

    2010-01-01

    In Chicago's public school system, LGBT students were three times more likely than straight peers to miss school because of threats to their safety, according to 2003 districtwide survey; and students who face regular harassment were more like to drop out. In this article, the author shares her thoughts on the move of Chicago school officials to…

  10. Structure and composition of the Trinil femora: functional and taxonomic implications.

    PubMed

    Ruff, Christopher B; Puymerail, Laurent; Macchiarelli, Roberto; Sipla, Justin; Ciochon, Russell L

    2015-03-01

    The original hominin femur (Femur I) and calotte discovered at Trinil, Java by Eugene Dubois in 1891/1892 played a key role in the early history of human paleontology by purportedly demonstrating the contemporaneity of archaic cranial form with modern human erect (bipedal) posture. On this basis, both specimens were subsequently assigned to Pithecanthropus erectus, later transferred to Homo erectus. However, chronological and phylogenetic links between the two have been questioned from the beginning. Four additional hominin partial femora (Femora II-V) from Trinil were subsequently described but have played a relatively minor part in evolutionary scenarios. Here we present the results of a new analysis of structural and density characteristics of the Trinil femora obtained using computed tomography. Trinil Femur I shows none of the characteristics typical of early Homo femora from elsewhere in Asia or Africa, including a relatively long neck, increased mediolateral bending rigidity of the mid-proximal shaft, or a low position of minimum mediolateral breath on the shaft. In contrast, Femora II-V all demonstrate features that are more consistent with this pattern. In addition, material density distributions within the specimens imply more recent and less complete fossilization of Femur I than Femora II-V. Thus, it is very likely that Trinil Femur I derives from a much more recent time period than the calotte, while the less famous and less complete Femora II-V may represent H. erectus at Trinil. The morphological variation within the Trinil femora can be attributed to broader changes in pelvic morphology occurring within the Homo lineage between the Early and late Middle Pleistocene. PMID:25681015

  11. The late Early Pleistocene human dental remains from Uadi Aalad and Mulhuli-Amo (Buia), Eritrean Danakil: macromorphology and microstructure.

    PubMed

    Zanolli, Clément; Bondioli, Luca; Coppa, Alfredo; Dean, Christopher M; Bayle, Priscilla; Candilio, Francesca; Capuani, Silvia; Dreossi, Diego; Fiore, Ivana; Frayer, David W; Libsekal, Yosief; Mancini, Lucia; Rook, Lorenzo; Medin Tekle, Tsegai; Tuniz, Claudio; Macchiarelli, Roberto

    2014-09-01

    Fieldwork performed during the last 15 years in various Early Pleistocene East African sites has significantly enlarged the fossil record of Homo erectus sensu lato (s.l.). Additional evidence comes from the Danakil Depression of Eritrea, where over 200 late Early to early Middle Pleistocene sites have been identified within a ?1000 m-thick sedimentary succession outcropping in the Dandiero Rift Basin, near Buia. Along with an adult cranium (UA 31), which displays a blend of H. erectus-like and derived morpho-architectural features and three pelvic remains, two isolated permanent incisors (UA 222 and UA 369) have also been recovered from the 1 Ma (millions of years ago) Homo-bearing outcrop of Uadi Aalad. Since 2010, our surveys have expanded to the nearby (4.7 km) site of Mulhuli-Amo (MA). This is a fossiliferous area that has been preliminarily surveyed because of its exceptional concentration of Acheulean stone tools. So far, the site has yielded 10 human remains, including the unworn crown of a lower permanent molar (MA 93). Using diverse analytical tools (including high resolution ?CT and ?MRI), we analysed the external and internal macromorphology and microstructure of the three specimens, and whenever possible compared the results with similar evidence from early Homo, H. erectus s.l., H. antecessor, H. heidelbergensis (from North Africa), Neanderthals and modern humans. We also assessed the UA 369 lower incisor from Uadi Aalad for root completion timing and showed that it compares well with data for root apex closure in modern human populations. PMID:24852385

  12. Solid modeling of fossil small mammal teeth

    NASA Astrophysics Data System (ADS)

    Marschallinger, Robert; Hofmann, Peter; Daxner-Höck, Gudrun; Ketcham, Richard A.

    2011-09-01

    This paper presents an approach to create solid models of fossil small mammal teeth using a combination of microcomputed tomography, object based image analysis and voxel modeling. Small mammal teeth, because of their durability, are widely found in Cenozioc sediments the world over and play a key role in stratigraphy as well as in researching the rapid evolution and the paleogeographic spreading of small mammals. Recent advances in microcomputed tomography make this non-destructive analysis method an ideal data source for high-resolution 3D models of fossil small animal teeth. To derive internally consistent solid models of such fossils from micro-CT imagery, we propose a combination of 3D object based image analysis and solid modeling. Incorporating paleontological expert knowledge in the image processing cycle, object based image analysis yields topologically consistent image stacks classified by the main tooth components—enamel, dentine and pulp. Forwarding these data to a voxel modeling system, they can be quantitatively analyzed in an unprecedented manner: going beyond the possibilities of the state-of-art surface models, solid models are capable of unambiguously portraying the entire object volume—teeth can be peeled by material properties, subvolumes can be extracted and automatically analyzed by Boolean operations. The proposed method, which can be flexibly extended to handle a range of paleontological and geological micro-objects, is demonstrated with two typical fossil small mammal teeth.

  13. The Fascinating Story of Fossil Fuels

    ERIC Educational Resources Information Center

    Asimov, Isaac

    1973-01-01

    How this energy source was created, its meaning to mankind, our drastically reduced supply, and why we cannot wait for nature to make more are considered. Today fossil fuels supply 96 percent of the energy used but we must find alternate energy options if we are to combat the energy crisis. (BL)

  14. Synthetic Trace Fossils using mechanical bugs

    NSDL National Science Digital Library

    Clint Cowan

    This activity is suitable for either an hour-long in class activity or a longer laboratory. It explores trace fossils by creating tracks in various substrates using mechanical bugs (Hexbugs). Students analyze the traces without seeing how they were made, then get to explore the traces by playing with the mechanical bugs that made them and varying the substrate.

  15. 004144:a0001 Fossil Record: Quality

    E-print Network

    Benton, Michael

    of Darwin's On the Origin of Species by Means of Natural Selection provide benchmarks of major changes questioned, and doubts have arisen because of questions of quality. Charles Darwin hoped that, over time partnership with the study of modern organ- isms. See also: Darwin, Charles Robert; Fossil record; History

  16. Name: Section: GEOL 204: The Fossil Record

    E-print Network

    Holtz Jr., Thomas R.

    Mammals (First Floor) · Hall of Ice Age Mammals (First Floor) · Butterflies + Plants: Partners) Mass extinctions are an extremely significant phenomenon in the fossil record. Find a display discussing a major mass extinction (the easiest way to do this is in the Sant Ocean Hall, which deals

  17. Fossil energy program. Progress report, July 1980

    Microsoft Academic Search

    McNeese

    1980-01-01

    This report - the seventy-second of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research

  18. Thermal dissolution of solid fossil fuels

    SciTech Connect

    E.G. Gorlov [Institute for Fossil Fuels, Moscow (Russian Federation)

    2007-10-15

    The use of oil shales and coals in the processes of thermal dissolution is considered. It is shown that thermal dissolution is a mode of liquefaction of solid fossil fuels and can be used both independently and in combination with liquefaction of coals and processing of heavy petroleum residues.

  19. Fossil Cores In The Kepler Data

    NASA Astrophysics Data System (ADS)

    Jackson, Brian

    Most gas giant exoplanets with orbital periods < few days are unstable against tidal decay and may be tidally disrupted before their host stars leave the main sequence. These gas giants probably contain rocky/icy cores, and so their cores will be stranded near their progenitor's Roche limit (few hours orbital period). These fossil cores will evade the Kepler mission's transit search because it is focused on periods > 0.5 days, but finding these fossil cores would provide unprecedented insights into planetary interiors and formation ? e.g., they would be a smoking gun favoring formation of gas giants via core accretion. We propose to search for and characterize fossil cores in the Kepler dataset. We will vet candidates using the Kepler photometry and auxiliary data, collect ground-based spectra of the host stars and radial-velocity (RV) and adaptive optics (AO) data to corroborate candidates. We will also constrain stellar tidal dissipation efficiencies (parameterized by Q) by determining our survey's completeness, elucidating dynamical origins and evolution of exoplanets even if we find no fossil cores. Our preliminary search has already found several dozen candidates, so the proposed survey has a high likelihood of success.

  20. 1985 fossil plant water chemistry symposium: Proceedings

    Microsoft Academic Search

    1986-01-01

    A three day EPRI Symposium devoted to water chemistry, corrosion, and scale control in fossil utility steam cycles was held June 11-13, 1985 in Atlanta, Georgia. The purpose of the Symposium was to review and discuss US and foreign practices, corrosion control requirements for boilers, turbines, and other cycle components, sampling and instrumentation, and problems with cycling units. After the

  1. Fossils of Reionization in the Local Group

    E-print Network

    Nickolay Y. Gnedin; Andrey V. Kravtsov

    2006-01-22

    We use a combination of high-resolution gasdynamics simulations of high-redshift dwarf galaxies and dissipationless simulations of a Milky Way sized halo to estimate the expected abundance and spatial distribution of the dwarf satellite galaxies that formed most of their stars around z~8 and evolved only little since then. Such galaxies can be considered as fossils of the reionization era, and studying their properties could provide a direct window into the early, pre-reionization stages of galaxy formation. We show that 5-15% of the objects existing at z~8 do indeed survive until the present in the MW like environment without significant evolution. This implies that it is plausible that the fossil dwarf galaxies do exist in the Local Group. Because such galaxies form their stellar systems early during the period of active merging and accretion, they should have spheroidal morphology regardless of their current distance from the host galaxy. We show that both the expected luminosity function and spatial distribution of dark matter halos which are likely to host fossil galaxies agree reasonably well with the observed distributions of the luminous (L_V>10^6 Lsun) Local Group fossil candidates near the host galaxy (d300 kpc). We discuss several possible explanations for this discrepancy.

  2. Fossilized gravitational wave relic and primordial clocks

    NASA Astrophysics Data System (ADS)

    Brahma, Suddhasattwa; Nelson, Elliot; Shandera, Sarah

    2014-01-01

    If long-wavelength primordial tensor modes are coupled to short-wavelength scalar modes, the scalar curvature two-point function will have an off-diagonal component. This "fossil" remnant is a signature of a mode coupling that cannot be achieved in single-clock inflation. Any constraint on its presence allows a cross-check of the relationship between the dynamical generation of the fluctuations and the evolution of the inflationary background. We use the example of non—Bunch-Davies initial states for the tensor and scalar modes to demonstrate that physically reasonable fossils, consistent with current data, can be observable in the near future. We illustrate how the fossil off-diagonal power spectrum is a complementary probe to the squeezed limit bispectra of the scalar and tensor sectors individually. We also quantify the relation between the observable signal and the squeezed limit bispectrum for a general scalar-scalar-fossil coupling and note the effect of superhorizon tensor modes on the anisotropy in scalar modes.

  3. Renewable hydrogen production for fossil fuel processing

    Microsoft Academic Search

    Greenbaum

    1994-01-01

    The objective of this mission-oriented research program is the production of renewable hydrogen for fossil fuel processing. This program will build upon promising results that have been obtained in the Chemical Technology Division of Oak Ridge National Laboratory on the utilization of intact microalgae for photosynthetic water splitting. In this process, specially adapted algae are used to perform the light-activated

  4. Fossils: An Ancient Sea in Indiana

    NSDL National Science Digital Library

    2005-10-21

    In this interactive activity from the Children's Museum of Indianapolis, Indiana, examine a piece of the ancient Borden Sea in what is now central Indiana. Explore the types of fossils found there and the clues they offer to ancient life on Earth.

  5. Cuticle Analysis of Living and Fossil Metasequoia

    Microsoft Academic Search

    Qin Leng

    The recent discovery of two distinct cuticle types, Uneven Type and Even Type, within the native population of Metasequoia glyptostroboides Hu et Cheng has prompted re-evaluation of the taxonomic utility of cuticle characters in both living and fossil Metasequoia Miki. The result is a comprehensive review of the existing data and methods used in the past to analyze living and

  6. Fossil Energy Materials Program conference proceedings

    SciTech Connect

    Judkins, R.R. (comp.)

    1987-08-01

    The US Department of Energy Office of Fossil Energy has recognized the need for materials research and development to assure the adequacy of materials of construction for advanced fossil energy systems. The principal responsibility for identifying needed materials research and for establishing a program to address these needs resides within the Office of Technical Coordination. That office has established the Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program to fulfill that responsibility. In addition to the AR and TD Materials Program, which is designed to address in a generic way the materials needs of fossil energy systems, specific materials support activities are also sponsored by the various line organizations such as the Office of Coal Gasification. A conference was held at Oak Ridge, Tennessee on May 19-21, 1987, to present and discuss the results of program activities during the past year. The conference program was organized in accordance with the research thrust areas we have established. These research thrust areas include structural ceramics (particularly fiber-reinforced ceramic composites), corrosion and erosion, and alloy development and mechanical properties. Eighty-six people attended the conference. Papers have been entered individually into EDB and ERA. (LTN)

  7. Identification and molecular cloning Moplaa gene, a homologue of Homo sapiens PLAA, in Magnaporthe oryzae.

    PubMed

    Liu, Xiao-Hong; Zhuang, Fei-Long; Lu, Jian-Ping; Lin, Fu-Cheng

    2011-12-20

    Magnaporthe oryzae has been used as a model fungal pathogen to study the molecular basis of plant-fungus interactions due to its economic and genetic importance. In this study, we identified a novel gene, Moplaa, which is the homologue of Homo sapiens PLAA encoding a phospholipase A(2)-activating protein. Moplaa is conserved in some eukaryotic organisms by multiple alignment analysis. The function of the Moplaa gene was studied using the gene target replacement method. The Moplaa deletion mutant exhibited retarded growth and conidial germination, reduced conidiation, appressorial turgor pressure and pathogenicity to rice CO-39. Reintroduction of the gene restored defects of the Moplaa deletion mutant. PMID:21482087

  8. Fossil Woodwardia virginica Foliage From the Middle Miocene Yakima Canyon

    NSDL National Science Digital Library

    Kathleen B. Pigg (Arizona State University; Department of Plant Biology ADR; POSTAL)

    2004-03-09

    Fossil Woodwardia virginica foliage from the middle Miocene Yakima Canyon flora of central Washington State, USA. Vegetative and fertile features of this fossil are remarkably similar to those of the modern ""Virginia chain fern"" of the Atlantic coastal region, USA.

  9. Pyrromethene dyes (BODIPY) can form ground state homo and hetero dimers: Photophysics and spectral properties

    NASA Astrophysics Data System (ADS)

    Marushchak, Denys; Kalinin, Stanislav; Mikhalyov, Ilya; Gretskaya, Natalia; Johansson, Lennart B.-Å.

    2006-09-01

    Homo and hetero dimerisation of two spectroscopically different BODIPY chromophores was studied, namely, 4,4-difluoro-4-bora-3a,4a-diaza- s-indacene and its 5-styryl-derivative. These exhibit very similar absorption and fluorescence spectral shape, but are mutually shifted by ca. 70 nm. For this reason the former and the latter are referred to as the green and red BODIPY, which here are denoted gB and rB, respectively. Various spectroscopic properties of the rB in different common solvents were determined. The calculated and experimental fluorescence quantum yield is found to be close to 100%, the fluorescence relaxation has a single exponential decay with a lifetime of about 4.5 ns, and the Förster radius for donor-donor energy migration is 67 ± 1 Å. The dimerisation in different solvents was examined by using custom synthesised; mono and bis BODIPY-labelled forms of 1,2- cis-diaminocyclohexane. It is shown that gB and rB can form ground state homo- as well as hetero dimers. The dimers are non-fluorescent, compatible with H-dimers and may act as excitation traps or as acceptors to the corresponding excited monomers.

  10. Pyrromethene dyes (BODIPY) can form ground state homo and hetero dimers: photophysics and spectral properties.

    PubMed

    Marushchak, Denys; Kalinin, Stanislav; Mikhalyov, Ilya; Gretskaya, Natalia; -A Johansson, Lennart B

    2006-09-01

    Homo and hetero dimerisation of two spectroscopically different BODIPY chromophores was studied, namely, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene and its 5-styryl-derivative. These exhibit very similar absorption and fluorescence spectral shape, but are mutually shifted by ca. 70 nm. For this reason the former and the latter are referred to as the green and red BODIPY, which here are denoted gB and rB, respectively. Various spectroscopic properties of the rB in different common solvents were determined. The calculated and experimental fluorescence quantum yield is found to be close to 100%, the fluorescence relaxation has a single exponential decay with a lifetime of about 4.5 ns, and the Förster radius for donor-donor energy migration is 67+/-1A. The dimerisation in different solvents was examined by using custom synthesised; mono and bis BODIPY-labelled forms of 1,2-cis-diaminocyclohexane. It is shown that gB and rB can form ground state homo- as well as hetero dimers. The dimers are non-fluorescent, compatible with H-dimers and may act as excitation traps or as acceptors to the corresponding excited monomers. PMID:16455298

  11. Cranial Embryogeny and Hominin Phylogeny Anne Dambricourt Malass

    E-print Network

    Boyer, Edmond

    . North Africa (Ain El Hanech, Algeria) and South East Asia (Homo erectus child from Modjokerto), also to an oldest geological layer far from 1 km, nevertheless such an association is not in accordance

  12. The International Union of Anthropological and Ethnological Sciences World Congress IUAES

    E-print Network

    Paris-Sud XI, Université de

    World. North Africa (Ain El Hanech, Algeria) and South East Asia (Homo erectus child from Modjokerto belonging to an oldest geological layer far from 1 km, nevertheless such an association is not in accordance

  13. sciencemag.org SCIENCE PHOTOS:WIMLUSTENHOUWER/VUUNIVERSITYAMSTERDAM(2)

    E-print Network

    Napp, Nils

    , vesicular stomatitis virus (VSV). The mar- riage puts the VSV Ebola vaccine on equal footing with another the famous Homo erectus Trinil site on the Indonesian island of Java. The shell comes from an assem- blage

  14. Palaeomagnetic analysis of the Sterkfontein palaeocave deposits: implications for the age of the hominin fossils and stone tool industries.

    PubMed

    Herries, Andy I R; Shaw, John

    2011-05-01

    Palaeomagnetic analysis was conducted on speleothems from Members 1-5 at Sterkfontein Cave, South Africa. Palaeomagnetic analysis of siltstone and speleothem from the bulk of Member 4 indicate a reversed magnetic polarity that dates the deposits and its Australopithecus africanus fossils to between 2.58 and ~2.16 Ma. Further confirmation of this age comes in the form of two short normal polarity events correlated to the Rèunion (~2.16 Ma) and Huckleberry Ridge (~2.05 Ma) events in speleothem capping the bulk of Member 4 and coeval with deposition of the final phase of Member 4, including A. africanus fossil Sts 5. At ~2.16-2.05 Ma, Sts 5 is the youngest representative of A. africanus yet discovered. Palaeomagnetic analysis of the Silberberg Grotto deposits identifies a single short geomagnetic field event in flowstone overlying the StW 573 Australopithecus fossil, which is suggested to represent the Rèunion event at ~2.16 Ma. This further supports the uranium lead age estimates of 2.3-2.2 Ma for the StW 573 fossil. Based on a reversed polarity for the deposits below the skeleton it cannot be older than 2.58 Ma. If StW 573 is considered to be a second species of Australopithecus then this indicates that two species of Australopithecus are present at Sterkfontein between 2.6 and 2.0 Ma. All of the Member 5 deposits date to less than 1.8 Ma based on a comparison of palaeomagnetic, faunal, and electron spin resonance age estimates. The StW 53 fossil bearing infill (M5A) is intermediate in age between Member 4 and the rest of Member 5 (B-C) at around 1.78-1.49 Ma. The rest of Member 5 (B-C) containing Oldowan and Acheulian stone tools and Homo and Paranthropus fossils was deposited gradually between 1.40 and 1.07 Ma, much younger than previously suggested. PMID:21392817

  15. First Fossil Lamprey: A Record from the Pennsylvanian of Illinois

    Microsoft Academic Search

    David Bardack; Rainer Zangerl

    1968-01-01

    A fossil record of lampreys has previously been unknown. A new genus demonstrates the presence of this group in the Pennsylvanian. The body outline, parts of the head skeleton, rasping tongue mechanism, gill basket, and other internal organs are preserved. The fossils are very similar in structure to modern forms. The absence of hagfish characters in the fossil supports the

  16. Hydrogen Related Analytical Studies Office of Fossil Energy and

    E-print Network

    prepared several conceptual designs to produce hydrogen from fossil fuel for EPRI and other private clientsHydrogen Related Analytical Studies Office of Fossil Energy and National Energy TechnologyRelatedAnalyticalStudies ­ 072604 Charter Office of Fossil Energy Describe your group's mission or objectives (group is the part

  17. Fossil Papio Cranium From !Ncumtsa (Koanaka) Hills, Western Ngamiland, Botswana

    E-print Network

    Fossil Papio Cranium From !Ncumtsa (Koanaka) Hills, Western Ngamiland, Botswana Blythe A. Williams cercopithecoid; baboon; Kalahari; Pleistocene ABSTRACT Three fossils, a cranium of Papio, a cer- copithecid crania of Papio are extremely rare in the fossil record outside of South Africa and because

  18. RESEARCH PAPER The first fossil record of Polyrhachis (Hymenoptera: Formicidae

    E-print Network

    Villemant, Claire

    RESEARCH PAPER The first fossil record of Polyrhachis (Hymenoptera: Formicidae: Formicinae) from taxon represents the first occurrence of the genus in the fossil record. The origin and rise of one Á Polyrhachis Á New species Á Miocene Á Fossil ant Kurzfassung Aus dem Obermioza¨n von Kreta (Grie

  19. The quality of the fossil record Michael J. Benton

    E-print Network

    Benton, Michael

    Chapter 4 The quality of the fossil record Michael J. Benton ABSTRACT Ever since the days of Charles Darwin, palaeontologists have been concerned about the quality of the fossil record. New concerns are often twice as old as the oldest fossils, and (2) the discovery that much of the variation in diversity

  20. Correlations in fossil extinction and origination rates through geological time

    E-print Network

    Kirchner, James W.

    Correlations in fossil extinction and origination rates through geological time James W. Kirchner1, implying that the fossil record may be controlled by self-organized criticality or other scale-free internal dynamics of the biosphere. Here we directly test for correlations in the fossil record

  1. FOSSIL ANTHROPOIDS OF THE r y ALEMCAMBRIDGE INDIA

    E-print Network

    Boyer, Edmond

    ; . ~ 1@'· t p t1tCO FOSSIL ANTHROPOIDS OF THE r y ALEMCAMBRIDGE INDIA EXPEDITION Q,F 1935 ? ~ -~~r J FOSSIL ANTHROPOIDS OF THE YALE-CAMBRIDGE INDIA EXPEDITION OF 1935 WILLIAM K. GREGORY MILO .. . .... . .. ... . . . . .. . .. . .... ...... . ..... . .. . ... .. . .. . .. ...... . ,, ·· following 27 1 #12;( FOSSIL ANTHROPOIDS OF THE YALE-CAMBRIDGE INDIA EXPEDITION OF 1935 INTRODUCTION The Yale

  2. SURVEY OF SOCIAL INSECTS IN THE FOSSIL RECORD*

    E-print Network

    Villemant, Claire

    SURVEY OF SOCIAL INSECTS IN THE FOSSIL RECORD* BY LAURIE BURNHAM Museum of Comparative Zoology the fossil record for clues not only on the antiquity of sociality, but also on the nature of these early recognized by Emerson (1955) have a fossil record extending at least as far back as the Tertiary. In 1967

  3. EDIACARAN AND CAMBRIAN INDEX FOSSILS FROM SONORA, MEXICO

    E-print Network

    Hagadorn, Whitey

    EDIACARAN AND CAMBRIAN INDEX FOSSILS FROM SONORA, MEXICO by FRANCISCO SOUR-TOVAR*, JAMES W October 2006 Abstract: The Cambrian index fossil Treptichnus pedum is reported from the Puerto Blanco Formation near Pitiquito, Sonora, Mexico, and new occurrences of the Neoproterozoic index fossil Cloudina

  4. Fossil Groups in the Sloan Digital Sky Survey

    E-print Network

    Walter A. Santos; Claudia Mendes de Oliveira; Laerte Sodré Jr

    2007-08-14

    A search for fossil groups in the Sloan Digital Sky Survey was performed using virtual observatory tools. A cross-match of the positions of all SDSS Luminous Red Galaxies (with r fossil groups. Considering this sample, the estimated space density of fossil systems is $n =(1.0 \\pm 0.6) \\times 10^{-6}$ $h_{50}^3$ Mpc$^{-3}$.

  5. PALEOZOIC TRACE FOSSILS FROM THE KUFRA BASIN, LIBYA

    E-print Network

    Benton, Michael

    PALEOZOIC TRACE FOSSILS FROM THE KUFRA BASIN, LIBYA BRIAN R. TURNER AND MICHAEL J. BENTON trace fossils. The oldest association of Cruzianu,Arthrophycus and Monocraterion comesfrom the Cambro, subsurface data and biostrati- graphic control, correlation between the two areas is uncertain. Body fossils

  6. Reducing Fossil Carbon Emissions and Building Environmental Awareness at

    E-print Network

    Reducing Fossil Carbon Emissions and Building Environmental Awareness at Dartmouth College Summary selected the mission: "To reduce Dartmouth College's fossil carbon emissions." We believe this mission's responsibility to educate others about how it is reducing its fossil carbon emissions and encourage them to do

  7. RESEARCH LETTERS 161 The Fossil Record of Cretaceous

    E-print Network

    Benton, Michael

    RESEARCH LETTERS 161 The Fossil Record of Cretaceous Tetrapods EMMANUEL FARA and MICHAEL J. BENTON­165 The fossil record of the Cretaceous is critical for under- standing the evolution of modern tetrapods. Using a mea- sure of relative completeness of the fossil record--the Sim- ple Completeness Metric (SCM

  8. Fossil Biodiversity: Red Noise Plus Signal

    E-print Network

    Adrian L. Melott; Bruce S. Lieberman

    2006-06-14

    We have examined the Fourier power spectrum as well as the Hurst exponent of extinction, origination, and total biodiversity in the marine fossil record, using a recently improved geologic timescale. We find all of them strongly inconsistent with past claims of self-similarity as well as inconsistent with random walk behavior. Instead, they are dominated by low-frequency power, with approximate f^-2 power over one decade in frequency. The spectrum turns over at about 10^8 y, lending plausibility to connections with galactic dynamics. Even in the background of this low-frequency dominance, a previously noted 62 My biodiversity cycle stands out with better than 99% confidence above the noise level, accounting for about 35% of the total variance in the fossil biodiversity record.

  9. Fossil energy waste management. Technology status report

    SciTech Connect

    Bossart, S.J.; Newman, D.A.

    1995-02-01

    This report describes the current status and recent accomplishments of the Fossil Energy Waste Management (FE WM) projects sponsored by the Morgantown Energy Technology Center (METC) of the US Department of Energy (DOE). The primary goal of the Waste Management Program is to identify and develop optimal strategies to manage solid by-products from advanced coal technologies for the purpose of ensuring the competitiveness of advanced coal technologies as a future energy source. The projects in the Fossil Energy Waste Management Program are divided into three types of activities: Waste Characterization, Disposal Technologies, and Utilization Technologies. This technology status report includes a discussion on barriers to increased use of coal by-products. Also, the major technical and nontechnical challenges currently being addressed by the FE WM program are discussed. A bibliography of 96 citations and a list of project contacts is included if the reader is interested in obtaining additional information about the FE WM program.

  10. Global energy resources. [Review, emphasizing fossil fuels

    Microsoft Academic Search

    Grenon

    1977-01-01

    We are in the somewhat paradoxical situation of having more confidence in the extent of our long- or very long-term energy resources than in our mid-term supply. This is why fossil-energy resources are emphasized in this article; we must rely on them for at least 80 to 90% of our energy supply until the end of the century (as far

  11. Atmospheric Lifetime of Fossil Fuel Carbon Dioxide

    Microsoft Academic Search

    David Archer; Michael Eby; Victor Brovkin; Andy Ridgwell; Long Cao; Uwe Mikolajewicz; Ken Caldeira; Katsumi Matsumoto; Guy Munhoven; Alvaro Montenegro; Kathy Tokos

    2009-01-01

    CO2 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere, the ocean, and the terrestrial biosphere on timescales of a few centuries. However, a sizeable fraction of the CO2 remains in the atmosphere, awaiting a return to the solid earth by much slower weathering processes and deposition of CaCO3. Common measures of the atmospheric

  12. Oral Presentation of a Fossil Group

    NSDL National Science Digital Library

    Max Reams

    Each student chooses a different fossil group that interests him/her and prepares a 10 minute PowerPoint presentation about that group, lavishly illustrated and richly illuminated with fascinating facts! This can be as large a group as a phylum or as small as a species. Powerpoint handouts are given out during the oral presentation. Students must have a concluding slide citing references. The discussion must go beyond what is presented by the professor in lecture.

  13. Spatial Bias in the Marine Fossil Record

    PubMed Central

    Vilhena, Daril A.; Smith, Andrew B.

    2013-01-01

    Inference of past and present global biodiversity requires enough global data to distinguish biological pattern from sampling artifact. Pertinently, many studies have exposed correlated relationships between richness and sampling in the fossil record, and methods to circumvent these biases have been proposed. Yet, these studies often ignore paleobiogeography, which is undeniably a critical component of ancient global diversity. Alarmingly, our global analysis of 481,613 marine fossils spread throughout the Phanerozoic reveals that where localities are and how intensively they have been sampled almost completely determines empirical spatial patterns of richness, suggesting no separation of biological pattern from sampling pattern. To overcome this, we analyze diversity using occurrence records drawn from two discrete paleolatitudinal bands which cover the bulk of the fossil data. After correcting the data for sampling bias, we find that these two bands have similar patterns of richness despite markedly different spatial coverage. Our findings suggest that i) long-term diversity trends result from large-scale tectonic evolution of the planet, ii) short-term diversity trends are region-specific, and iii) paleodiversity studies must constrain their analyses to well-sampled regions to uncover patterns not driven by sampling. PMID:24204570

  14. The Undead: Fossil Galaxy Alive Again

    NASA Astrophysics Data System (ADS)

    Berglund, Kallan; Wilcots, Eric M.

    2015-01-01

    This project investigates the formation and evolution of fossil galaxies, specifically the history of active galactic nucleus (AGN) activity as it relates to galaxy mergers. We used low-frequency radio data from the J-VLA radio telescope's new P-band receivers [300-350MHz] to observe fossil galaxy J171811.93+563956.1 (referenced as FG30) at a red-shift of z=0.114. This galaxy was selected for its strong X-ray emission from the surrounding IGM, because it is indicative of an AGN. After cleaning and calibrating the data using CASA, images were generated to map the intensity of radio emission, revealing that FG30 is nearly a point source and lacks any prominent AGN jets. Analysis of the SDSS optical spectrum of FG30 revealed strong evidence of shocks. We believe that past AGN activity heated the intergalactic medium (IGM) to produce the strong X-ray emission, though the jets have been dormant for long enough that the IGM filled in the regions previously cleared by jets. The density of new material is now causing strong shocks when hit by newly restarted jets. This implies the start of a new epoch of AGN activity for FG30, which was most likely caused by a recent galaxy merger. This observation demonstrates that not all fossil groups have been quiescent, as the dominant theories suggested.*This work was supported by the National Science Foundation's REU program through NSF Award AST-1004881.

  15. Fossil avian eggshell preserves ancient DNA

    PubMed Central

    Oskam, Charlotte L.; Haile, James; McLay, Emma; Rigby, Paul; Allentoft, Morten E.; Olsen, Maia E.; Bengtsson, Camilla; Miller, Gifford H.; Schwenninger, Jean-Luc; Jacomb, Chris; Walter, Richard; Baynes, Alexander; Dortch, Joe; Parker-Pearson, Michael; Gilbert, M. Thomas P.; Holdaway, Richard N.; Willerslev, Eske; Bunce, Michael

    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 isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, 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 approximately 125 times lower bacterial load than bone, making it a highly suitable substrate for high-throughput sequencing approaches. Importantly, the preservation of DNA in Pleistocene eggshell from Australia and Holocene deposits from Madagascar indicates that eggshell is an excellent substrate for the long-term preservation of DNA in warmer climates. The successful recovery of DNA from this substrate has implications in a number of scientific disciplines; most notably archaeology and palaeontology, where genotypes and/or DNA-based species identifications can add significantly to our understanding of diets, environments, past biodiversity and evolutionary processes. PMID:20219731

  16. The mixed dentition and associated skull fragments of a juvenile fossil hominid from Sterkfontein, South Africa.

    PubMed

    Moggi-Cecchi, J; Tobias, P V; Beynon, A D

    1998-08-01

    In April-May 1983, the late A.R. Hughes and his field team recovered more than 40 bone fragments and teeth from a single solution pocket of the Sterkfontein Formation. After preparation and reconstruction by JMC, it was recognised that these fragments represent a single juvenile individual (Stw 151), consisting of more than 40 cranial and dental parts, with mixed dentition. It constitutes the most complete set of jaws and teeth of an early hominid child since the Taung child was recovered in 1924. In this paper, the morphological and metrical features of the individual teeth are described. The other associated skull fragments (right ramus of the mandible, left petrous bone, right glenoid region) are also described. Comparisons are made with other South (and East) African fossil hominids. The beautiful preservation simultaneously of most of the deciduous teeth and of the permanent teeth exposed in their crypts allows an accurate analysis of the developmental sequence. A report on the dental developmental status of this juvenile is presented. On the basis of the microanatomical study of the developing permanent teeth, the estimated age at death is 5.2-5.3 years. Reconstructions of the maxillary and mandibular arcades are also offered. The morphological and metrical features of Stw 151 raise the possibility that it may represent a hominid more derived towards an early Homo condition than the rest of the A. africanus sample from Member 4. PMID:9712475

  17. U Pb dating of fossil enamel from the Swartkrans Pleistocene hominid site, South Africa

    NASA Astrophysics Data System (ADS)

    Balter, Vincent; Blichert-Toft, Janne; Braga, José; Telouk, Philippe; Thackeray, Francis; Albarède, Francis

    2008-03-01

    We demonstrate that young fossil enamel older than the range of the U-series (? 300 ka) can be dated by the U-Pb methods using new models of U and Pb loss and uptake. Contrary to the current hypothesis of U uptake that only considers the adsorption/diffusion mechanism, we here develop a complete time-dependent model which takes gains and losses of the most critical nuclides (238U, 234U, and 230Th) into account, both during chemical (dissolved U) and physical (Th and U ?-recoil) processes. Lead is assumed to be a mixture between two components of common Pb and a radiogenic component; the proportions of these components are calculated from the Pb isotope abundances and U/Pb ratios. We apply this new U-Pb method to bovid enamel from the Swartkrans Cave (Gauteng Province, South Africa). This cave has yielded abundant early Pleistocene hominid remains attributed to Paranthropus and Homo as well as various associated archaeological vestiges. Biochronological comparisons with East Africa have provided age estimates ranging between 1.8 and 1.0 Ma, which, however, remain poorly constrained. After correction for initial 234U disequilibrium and further 238U loss, the U and Pb isotope data yield ages of 1.83 ± 1.38, 1.36 ± 0.29, and 0.83 ± 0.21 Ma for the three stratigraphic units, Members 1, 2, and 3, respectively. We discuss the consequences of these radiometric results for hominid evolution in South Africa.

  18. Patterning of geographic variation in Middle Pleistocene Homo frontal bone morphology

    Microsoft Academic Search

    Sheela Athreya

    2006-01-01

    A quantitative assessment of the frontal bone morphology of a sample of Middle Pleistocene hominins was undertaken in order to address questions regarding their population structure and evolutionary history. Outline tracings of the frontal bones of forty-seven fossil crania were obtained, and size-standardized measurements were then computed using an Elliptical Fourier analysis of these tracings. Principal component scores of the

  19. Early Pleistocene hominid teeth recovered in Mohui cave in Bubing Basin, Guangxi, South China

    Microsoft Academic Search

    Wang Wei; Richard Potts; Hou Yamei; Chen Yunfa; Wu Huaying; Yuan Baoyin; Huang Weiwen

    2005-01-01

    Two hominid teeth recovered in Mohui cave are morphologically distinguished fromAustralopithecus in Africa, but close toHomo erectus in China. These teeth are therefore provisionally assigned toHomo erectus. The associated mammalian fauna includeGigantopithecus blacki, Nestoritherium sp.,Sus xiaozhu, Sus peii andAiluropoda microta, which are typical early Pleistocene taxa in South China. The general characteristics of the Mohui faunal assemblage are\\u000a similar to

  20. A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia

    Microsoft Academic Search

    T. Sutikna; M. J. Morwood; R. P. Soejono; Jatmiko; E. Wayhu Saptomo; Rokus Awe Due; P. Brown

    2004-01-01

    Currently, it is widely accepted that only one hominin genus, Homo, was present in Pleistocene Asia, represented by two species, Homo erectus and Homo sapiens. Both species are characterized by greater brain size, increased body height and smaller teeth relative to Pliocene Australopithecus in Africa. Here we report the discovery, from the Late Pleistocene of Flores, Indonesia, of an adult

  1. Emissions Scenarios and Fossil-fuel Peaking

    NASA Astrophysics Data System (ADS)

    Brecha, R.

    2008-12-01

    Intergovernmental Panel on Climate Change (IPCC) emissions scenarios are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. Built into the assumptions for these scenarios are estimates for ultimately recoverable resources of various fossil fuels. There is a growing chorus of critics who believe that the true extent of recoverable fossil resources is much smaller than the amounts taken as a baseline for the IPCC scenarios. In a climate optimist camp are those who contend that "peak oil" will lead to a switch to renewable energy sources, while others point out that high prices for oil caused by supply limitations could very well lead to a transition to liquid fuels that actually increase total carbon emissions. We examine a third scenario in which high energy prices, which are correlated with increasing infrastructure, exploration and development costs, conspire to limit the potential for making a switch to coal or natural gas for liquid fuels. In addition, the same increasing costs limit the potential for expansion of tar sand and shale oil recovery. In our qualitative model of the energy system, backed by data from short- and medium-term trends, we have a useful way to gain a sense of potential carbon emission bounds. A bound for 21st century emissions is investigated based on two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by "peak oil" adherents, and second, that little is done in the way of climate mitigation policies. If resources, and perhaps more importantly, extraction rates, of fossil fuels are limited compared to assumptions in the emissions scenarios, a situation can arise in which emissions are supply-driven. However, we show that even in this "peak fossil-fuel" limit, carbon emissions are high enough to surpass 550 ppm or 2°C climate protection guardrails. Some indicators are presented that the scenario presented here should not be disregarded, and comparisons are made to the outputs of emission scenarios used for the IPCC reports.

  2. Aestivation in the fossil record: evidence from ichnology.

    PubMed

    Hembree, Daniel I

    2010-01-01

    Aestivation is a physiological and behavioral response to high temperature or low moisture conditions. Therefore, it is typically not considered to be capable of being preserved in the fossil record. However, most aestivating organisms produce a burrow to protect themselves from the harmful environmental conditions that trigger aestivation. These structures can be preserved in the rock record as trace fossils. While trace fossils are abundant in the continental fossil record, few are definitively associated with aestivation. Interpreting aestivation behavior from fossil burrows requires a detailed examination and interpretation of the surrounding sedimentary rocks and comparisons with taxonomically and ecologically similar extant organisms. Currently, only four types of aestivation structures are recognized in the fossil record: Pleistocene earthworm chambers, Devonian to Cretaceous lungfish burrows, Permian lysorophid burrows, and Permian to Triassic dicynodont burrows. The trace fossil evidence suggests that aestivation evolved independently among continental organisms in several clades during the middle to late Paleozoic. PMID:20069413

  3. Fossil Energy Program semiannual progress report, October 1990--March 1991

    SciTech Connect

    Judkins, R.R.

    1992-07-01

    This report covers progress made during the period October 1, 1990, through March 31, 1991, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development. The Fossil, Energy Program organization chart is shown in the appendix. Topics include: alloys, ceramics and composite research and development; corrosion and erosion research; environmental analysis and information systems; coal conversion development; mild gasification product characterization; coal combustion research; strategic petroleum reserve planning and modeling; and coal structure and chemistry.

  4. Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics

    SciTech Connect

    Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.

    1993-12-01

    This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

  5. Earliest evidence for the structure of Homo sapiens populations in Africa

    NASA Astrophysics Data System (ADS)

    Scerri, Eleanor M. L.; Drake, Nick A.; Jennings, Richard; Groucutt, Huw S.

    2014-10-01

    Understanding the structure and variation of Homo sapiens populations in Africa is critical for interpreting multiproxy evidence of their subsequent dispersals into Eurasia. However, there is no consensus on early H. sapiens demographic structure, or its effects on intra-African dispersals. Here, we show how a patchwork of ecological corridors and bottlenecks triggered a successive budding of populations across the Sahara. Using a temporally and spatially explicit palaeoenvironmental model, we found that the Sahara was not uniformly ameliorated between ?130 and 75 thousand years ago (ka), as has been stated. Model integration with multivariate analyses of corresponding stone tools then revealed several spatially defined technological clusters which correlated with distinct palaeobiomes. Similarities between technological clusters were such that they decreased with distance except where connected by palaeohydrological networks. These results indicate that populations at the Eurasian gateway were strongly structured, which has implications for refining the demographic parameters of dispersals out of Africa.

  6. Homo-cysteinyl peptide inhibitors of the L1 metallo-b-lactamase, and SAR as determined by combinatorial library synthesis

    E-print Network

    Geysen, Mario

    Homo-cysteinyl peptide inhibitors of the L1 metallo-b-lactamase, and SAR as determined inhibitors. A combinatorial library of more than 90 homo-cysteinyl peptides was synthesized and screened are ineffective against Zn (II)-dependent MBLs.2 Presently, there is no clinically useful inhibitor for MBLs

  7. Microbial synthesis of functional homo-, random, and block polyhydroxyalkanoates by ?-oxidation deleted Pseudomonas entomophila.

    PubMed

    Li, Shijun; Cai, Longwei; Wu, Linping; Zeng, Guodong; Chen, Jinchun; Wu, Qiong; Chen, Guo-Qiang

    2014-06-01

    Functional polyhydroxyalkanoates (PHAs) allow chemical modifications to widen PHA diversity, promising to increase values of these biodegradable and biocompatible polyesters. Among functional PHAs, unsaturated PHA site chains can be easily grafted to add chemical groups, and to cross-link with other PHA polymer chains. However, it has been very difficult to obtain structurally controllable functional homo-, random, or block PHA. For the first time, a ?-oxidation deleted Pseudomonas entomophila was used to successfully synthesize random copolymers of 3-hydroxydodecanoate (3HDD) and 3-hydroxy-9-decenoate (3H9D). Compositions of the random copolymers P(3HDD-co-3H9D) can be adjusted by ratios of dodecanoic acid (DDA) to 9-decenol (9DEO) fed to the culture of P. entomophila. Homopolymer P3H9D was formed when only 9DEO was added to the culture. Diblock copolymers of P3HDD-b-P3H9D were produced by feeding DDA as the first precursor to form a P3HDD block followed by adding 9DEO as the second precursor to form a second P3H9D block. It was demonstrated that random copolymers P(3HDD-co-3H9D) could be crossed-linked under UV-radiation due to the presence of the unsaturated bonds. Thermal and mechanical characterizations of the above homo-, random, and diblock PHA polymers were conducted. It was found that the diblock polymer P3HDD-b-P3H9D increased at least 2-fold on Young's modulus compared with its random copolymers consisting of similar 3HDD/3H9D ratios. This study demonstrates that PHA functionality could be controlled to meet various requirements. PMID:24830358

  8. Type I phosphatidylinositol 4-phosphate 5-kinase homo- and heterodimerization determines its membrane localization and activity.

    PubMed

    Lacalle, Rosa Ana; de Karam, Juan C; Martínez-Muñoz, Laura; Artetxe, Ibai; Peregil, Rosa M; Sot, Jesús; Rojas, Ana M; Goñi, Félix M; Mellado, Mario; Mañes, Santos

    2015-06-01

    Type I phosphatidylinositol 4-phosphate 5-kinases (PIP5KIs; ?, ?, and ?) are a family of isoenzymes that produce phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] using phosphatidylinositol 4-phosphate as substrate. Their structural homology with the class II lipid kinases [type II phosphatidylinositol 5-phosphate 4-kinase (PIP4KII)] suggests that PIP5KI dimerizes, although this has not been formally demonstrated. Neither the hypothetical structural dimerization determinants nor the functional consequences of dimerization have been studied. Here, we used Förster resonance energy transfer, coprecipitation, and ELISA to show that PIP5KI? forms homo- and heterodimers with PIP5KI?_i2 in vitro and in live human cells. Dimerization appears to be a general phenomenon for PIP5KI isoenzymes because PIP5KI?/PIP5KI? heterodimers were also detected by mass spectrometry. Dimerization was independent of actin cytoskeleton remodeling and was also observed using purified proteins. Mutagenesis studies of PIP5KI? located the dimerization motif at the N terminus, in a region homologous to that implicated in PIP4KII dimerization. PIP5KI? mutants whose dimerization was impaired showed a severe decrease in PI(4,5)P2 production and plasma membrane delocalization, although their association to lipid monolayers was unaltered. Our results identify dimerization as an integral feature of PIP5K proteins and a central determinant of their enzyme activity.-Lacalle, R. A., de Karam, J. C., Martínez-Muñoz, L., Artetxe, I., Peregil, R. M., Sot, J., Rojas, A. M., Goñi, F. M., Mellado, M., Mañes, S. Type I phosphatidylinositol 4-phosphate 5-kinase homo- and heterodimerization determines its membrane localization and activity. PMID:25713054

  9. Construction of a constitutively expressed homo-fermentative pathway in Lactobacillus brevis.

    PubMed

    Guo, Wei; He, Ronglin; Ma, Lijuan; Jia, Wendi; Li, Demao; Chen, Shulin

    2014-08-01

    Lactobacillus brevis is a promising lactic acid producing strain that simultaneously utilizes glucose and xylose from lignocellulosic hydrolysate without carbon catabolic repression and inhibition. The production of by-products acetic acid and ethanol has been the major drawback of this strain. Two genes, pfkA (fructose-6-phosphate kinase [PFK]) and fbaA (fructose-1,6-biphosphate aldolase [FBA]), that encode the key enzymes of the EMP/glycolytic pathway from Lactobacillus rhamnosus, were fused to the downstream of the strong promoter P32 and expressed in L. brevis s3f4 as a strategy to minimize the formation of by-products. By expressing the two enzymes, a homo-fermentative pathway for lactic acid production was constructed. The lactic acid yields achieved from glucose in the transformants were 1.12 and 1.16 mol/mol, which is higher than that of the native strain (0.74 mol/mol). However, the lactic acid yield from xylose in the transformants stayed the same as that of the native strain. Enzyme assay indicated that the activity of the foreign protein FBA in the transformants was much higher than that of the native strains, but was ten times lower than that in L. rhamnosus. This result was consistent with the metabolic flux analysis, which indicated that the conversion efficiency of the expressed PFK and FBA was somewhat low. Less than 20 % of the carbons accumulated in the form of fructose-6-phosphate were converted into glyceraldehyde-3-phosphate (GAP) by the expressed PFK and FBA. Metabolic flux analysis also indicated that the enzyme phosphoketolase (XPK) played an important role in splitting the carbon flow from the pentose phosphate pathway to the phosphoketolase pathway. This study suggested that the lactic acid yield of L. brevis could be improved by constructing a homo-fermentative pathway. PMID:24728715

  10. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 4: Energy from fossil fuels

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    The conversion of fossil-fired power plants now burning oil or gas to burn coal is discussed along with the relaxation of air quality standards and the development of coal gasification processes to insure a continued supply of gas from coal. The location of oil fields, refining areas, natural gas fields, and pipelines in the U.S. is shown. The technologies of modern fossil-fired boilers and gas turbines are defined along with the new technologies of fluid-bed boilers and MHD generators.

  11. PALEOANTHROPOLOGY. Response to Comment on "Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia".

    PubMed

    Villmoare, Brian; Kimbel, William H; Seyoum, Chalachew; Campisano, Christopher J; DiMaggio, Erin; Rowan, John; Braun, David R; Arrowsmith, J Ramon; Reed, Kaye E

    2015-06-19

    Hawks et al. argue that our analysis of Australopithecus sediba mandibles is flawed and that specimen LD 350-1 cannot be distinguished from this, or any other, Australopithecus species. Our reexamination of the evidence confirms that LD 350-1 falls outside of the pattern that A. sediba shares with Australopithecus and thus is reasonably assigned to the genus Homo. PMID:26089506

  12. Yeast fermentation affected by homo- and hetero-fermentative Lactobacilli isolated from fuel ethanol distilleries with sugarcane products as substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antagonism between by yeast and lactobacilli is largely dependent on the initial population of each organism. While homo-fermentative lactobacillus present higher inhibitory effect upon yeast when in equal cell number, in industrial fuel ethanol conditions where high yeast cell densities prevail...

  13. Sensitive detection for coralyne and mercury ions based on homo-A/T DNA by exonuclease signal amplification.

    PubMed

    Huang, Hailiang; Shi, Shuo; Zheng, Xuyue; Yao, Tianming

    2015-09-15

    Based on specific homo-A/T DNA binding properties, a strategy for coralyne and mercury ions detection was realised by exonuclease-aided signal amplification. Coralyne could specifically bind homo-A DNA and protect it from the hydrolysis of exonuclease I. The coralyne-protected DNA was subsequently used as a trigger strand to hydrolyze DNA2 in exonuclease-aided signal amplification process. Thiazole orange was used to quantify the remainder DNA2. Under the optimal condition, the fluorescence intensity was linearly proportional to the concentration of coralyne in the range of 0.2-100nM with a limit of detection (LOD) of 0.31nM, which presented the lowest LOD for coralyne among all reported. With homo-T and Hg(2+) taking the place of homo-A DNA and coralyne, respectively, the system could also be used for Hg(2+) detection. The experiments in real samples also showed good results. This method was label-free, low-cost, easy-operating and highly repeatable for the detection of coralyne and mercury ions. It could also be extended to detect various analytes, such as other metal ions, proteins and small molecules by using appropriate aptamers. PMID:25950941

  14. Tuning microcapsules surface morphology using blends of homo-and copolymers of PLGA and PLGA-PEG

    E-print Network

    Raphael, Elie

    Tuning microcapsules surface morphology using blends of homo- and copolymers of PLGA and PLGA-evaporation technique by varying the percentage of PLGA-PEG copolymer in the formulation. As copolymer percentage environment, since PEG and PLGA moieties are not miscible in the solid state. Introduction Although colloids

  15. Neoproterozoic glaciations and the fossil record

    NASA Astrophysics Data System (ADS)

    Xiao, Shuhai

    Sedimentary, geochronological, and ?13C chemostratigraphic data require that at least three glaciations—the Sturtian, Marinoan, and Gaskiers in geochronological order—occurred in the Neoproterozoic glacial interval (NGI; ca. 750-580 Ma); at least the Gaskiers glaciation has not been demonstrated global in nature. Available radiometric and ?13C chemostratigraphic data also suggest that the fossil-rich Doushantuo Formation may have been deposited after the Marinoan but before the Gaskiers glaciation, thus representing a window between two glaciations. A review of the fossil record under this geochronological framework reveals the following patterns: 1) a broad decline in stromatolites and acritarchs occurred in the Cryogenian (ca. 750-600 Ma); 2) a taxonomically unique assemblage of large acanthomorphic acritarchs occurs between the Marinoan and Gaskiers glaciations; 3) multicellular algae diversified after the Marinoan glaciation, although they evolved earlier; 4) animals, probably in microscopic forms, evolved before the Gaskiers glaciation if not earlier; and 5) post-Gaskiers diversification of complex Ediacaran organisms/animals may have begun in deep-water slope environments and later expanded to shallow-water shelf environments where macrobilaterians and biomineralized animals first appeared. It is hypothesized that 1) the Cryogenian decline in stromatolites and acritarchs may have been causally related to glaciations; and 2) acanthomorphic acritarchs, algae, and animals may have suffered diversity loss related to the Gaskiers glaciation. The fossil record also implies that 1) at least some lineages of different algal clades survived all Neoproterozoic glaciations; and 2) some members of the animal clade survived the Gaskiers glaciation, probably in non-glaciated refiigia.

  16. The youngest Ediacaran fossils from southern Africa.

    PubMed

    Narbonne, G M; Saylor, B Z; Grotzinger, J P

    1997-11-01

    Discovery of fossils of the Ediacara biota near the top of the Spitzkopf Member at farm Swanpunt extends the known range of these remains in Namibia more than 600 m to near the sub-Cambrian unconformity. The fossiliferous beds occur approximately 100 m above a volcanic ash dated at 543 +/- 1 Ma, and thus may be the youngest Proterozoic Ediacara-type fossils reported anywhere in the world. Fossils are preserved within and on the tops of dm-thick beds of storm-deposited sandstone at two stratigraphic levels; the environment is interpreted as open marine, generally calm but with episodic disruptions by storm waves, and probably within the euphotic zone. The presence of Pteridinium carolinaense (St. Jean), which is also known from the classic sections in Ediacara and the White Sea among others, reinforces evidence from geochronology and chemostratigraphy that the Swartpunt section is terminal Neoproterozoic in age. The new genus and species Swartpuntia germsi is a large, multifoliate frond that exhibits at least three quilted petaloids. Macroscopically, Swartpuntia resembles Pteridinium and Ediacara-type fronds such as Charniodiscus traditionally interpreted as Cnidaria, whereas microscopically it exhibits segmentation that is remarkably similar to that of the putative worm Dickinsonia. Combination of diagnostic characters of these supposedly disparate groups in a single species suggests that many species of quilted Ediacaran organisms were more similar to each other than they were to any modern groups, and provides support for the concept of the "Vendobionta" as a late Neoproterozoic group of mainly multifoliate organisms with a distinctive quilted segmentation. PMID:11541433

  17. After the Bell: Beachcombing for fossils

    NSDL National Science Digital Library

    John Craven

    2006-10-01

    If you have ever taken a field trip to a natural history museum or an aquarium, you may have noticed in the gift shop a display of fossil shark teeth that can be as old as 65 million years for sale. Where did these teeth come from? How are the ages of these teeth known? Can I find such teeth on my own and, if so, where? These are questions that people of all ages often ask while marveling at these beautiful relics from eons past, and these are the questions we answer in this month's After the Bell column.

  18. Topological Defects: Fossils from the Early Universe

    E-print Network

    Tanmay Vachaspati

    1998-01-20

    In the context of current particle physics theories, it is quite likely that topological defects may be present in our universe. An observation of these fossils from the early universe would lead to invaluable insight into cosmology and particle physics, while their absence provides important constraints on particle-cosmology model building. I describe recent efforts to address cosmological issues in condensed matter systems such as He-3 and a possible solution to the magnetic monopole problem due to defect interactions. (Invited talk at the 1997 RESCEU Symposium, University of Tokyo.)

  19. Biomarkers and Microbial Fossils In Antarctic Rocks

    NASA Astrophysics Data System (ADS)

    Wierzchos, J.; Ascaso, C.

    Lithobiontic microbial communities living within Antarctic rocks are an example of survival in an extremely cold and dry environment. Any unfavourable change in ex- ternal conditions can result in the death and disappearance of microscopic organisms, and this may be followed by the appearance of trace biomarkers and microbial fossils. The extinction of these microorganisms in some zones of the Ross Desert, probably provoked by the hostile environment, might be considered a good terrestrial analogue of the first stage of the disappearance of possible life on early Mars. Granite samples from maritime Antarctica (Granite Harbour) and sandstone rocks from the continental Ross Desert were collected with the aim of searching for biomarkers and microbial fossils at the microscopic level of observation. To this end, a novel in situ applica- tion of scanning electron microscopy with backscattered electron imaging was com- bined with the simultaneous use of X-ray energy dispersive spectroscopy techniques. Our findings confirm the existence of inorganic biomarkers in the form of physico- chemically bioweathered minerals within the granitic rocks. The presence of Fe-rich diagenetic minerals, such as iron hydroxide nanocrystals and biogenic clays around chasmoendolithic hyphae and bacterial cells was also observed. Others biomarkers, including inorganic deposits such as calcium oxalates and silica accumulations, are clear signs of endolithic microorganism activity. The interior of the sandstone rocks (Ross Desert, Mt. Fleming) reveal the presence of microbial fossils of algae and other endolithic microorganisms. These microbial fossils, detected for the first time within Antarctic rocks, contain well preserved and morphologically distinguishable relics of ultrastructural cytoplasm elements, such as cell walls, chloroplast membranes, and oc- casionally, pyrenoids and traces of organic matter. These structures are similar to those observed in live cells also found in Antarctic rocks. Recognising internal cell struc- tures within fossilised cells is proposed as a new criterion for defining the biogenicity of biomorphs. This type of investigation will prompt the development of research strategies, appropriate in situ techniques and will, particularly, provide experience in the search for traces of past biological activity. These efforts will no doubt shed some light on the possibility of past life on Mars.

  20. Recent Developments in Biodesulfurization of Fossil Fuels

    NASA Astrophysics Data System (ADS)

    Xu, Ping; Feng, Jinhui; Yu, Bo; Li, Fuli; Ma, Cuiqing

    The emission of sulfur oxides can have adverse effects on the environment. Biodesulfurization of fossil fuels is attracting more and more attention because such a bioprocess is environmentally friendly. Some techniques of desulfurization have been used or studied to meet the stricter limitation on sulfur content in China. Recent advances have demonstrated the mechanism and developments for biodesulfurization of gasoline, diesel and crude oils by free cells or immobilized cells. Genetic technology was also used to improve sulfur removal efficiencies. In this review, we summarize recent progress mainly in China on petroleum biodesulfurization.

  1. Recent developments in biodesulfurization of fossil fuels.

    PubMed

    Xu, Ping; Feng, Jinhui; Yu, Bo; Li, Fuli; Ma, Cuiqing

    2009-01-01

    The emission of sulfur oxides can have adverse effects on the environment. Biodesulfurization of fossil fuels is attracting more and more attention because such a bioprocess is environmentally friendly. Some techniques of desulfurization have been used or studied to meet the stricter limitation on sulfur content in China. Recent advances have demonstrated the mechanism and developments for biodesulfurization of gasoline, diesel and crude oils by free cells or immobilized cells. Genetic technology was also used to improve sulfur removal efficiencies. In this review, we summarize recent progress mainly in China on petroleum biodesulfurization. PMID:19475378

  2. Genetic evidence of an early exit of Homo sapiens sapiens from Africa through eastern Africa

    Microsoft Academic Search

    Lluís Quintana-Murci; Ornella Semino; Hans-J. Bandelt; Giuseppe Passarino; Ken McElreavey; A. Silvana Santachiara-Benerecetti

    1999-01-01

    The out-of-Africa scenario has hitherto provided little evidence for the precise route by which modern humans left Africa. Two major routes of dispersal have been hypothesized: one through North Africa into the Levant, documented by fossil remains, and one through Ethiopia along South Asia, for which little, if any, evidence exists. Mitochondrial DNA (mtDNA) can be used to trace maternal

  3. A new interpretation of the bee fossil Melitta willardi Cockerell (Hymenoptera, Melittidae)... 35 A new interpretation of the bee fossil Melitta willardi

    E-print Network

    Rasmont, Pierre

    A new interpretation of the bee fossil Melitta willardi Cockerell (Hymenoptera, Melittidae)... 35 A new interpretation of the bee fossil Melitta willardi Cockerell (Hymenoptera, Melittidae) based interpretation of the bee fossil Melitta willardi Cockerell (Hymenoptera, Melittidae) based on geometric

  4. Federal investment in fossil energy technology

    SciTech Connect

    NONE

    1995-03-01

    On February 21, 1995, during a Congressional hearing on the FY 1996 budget request for the Department of Energy`s Office of Fossil Energy, Congressman David Skaggs of the House Appropriations Committee Subcommittee on the Interior and Related Agencies, requested that Assistant Secretary Patricia Godley submit statements from private companies and others on the value of Federal investments in coal, oil and natural gas technology programs. Specifically, Rep. Skaggs asked for public testimony from private industry and others that would cite examples of technology that has been {open_quotes}brought to market viability or near viability that simply would not have happened if left to private investment decisions alone.{close_quotes} The Department responded with the views of more than 280 industry officials, university professors, and State officials. Most of the responses cited specific technologies or advances that would not have been done, or done as quickly, without Federal investment. Others cited the educational opportunities created as part of Department of Energy-sponsored fossil energy university research. Still others cited improvements in the public knowledge base that have benefitted the private sector.

  5. Tiny Fossil Sheds Light on Mammalian Evolution

    NSDL National Science Digital Library

    de Nie, Michael Willem.

    2001-01-01

    In the most recent issue of Science, a team of American and Chinese scientists announced the discovery of the fossil of a tiny shrew-like creature that lived 195 million years ago, 45 million years before previously discovered mammals. Found in 1985 in Yunnan province, China, the fossil was originally believed to be merely a bone fragment because of its small size. It has now been named Hadrocodium wui, ("Fullhead"), and could possibly be the direct ancestor of all living mammals. Hadrocodium was an insectivore, eating worms and small insects. Though it weighed only two grams (the weight of a paper clip), Hadrocodium had a considerably larger brain than most known mammals from the early Jurassic period. The tiny skull also possesses three other key traits that are characteristic of the transition from mammal-like animals to true mammals: a three-bone middle ear separated from the jaw, matching upper and lower teeth, and a powerful jaw hinge. Readers can begin learning more about this discovery with the Science article. Additional coverage is provided by Discovery news, the BBC, National Geographic, ABC News, and CNN.

  6. Calibrating the Tree of Life: fossils, molecules and evolutionary timescales

    PubMed Central

    Forest, Félix

    2009-01-01

    Background Molecular dating has gained ever-increasing interest since the molecular clock hypothesis was proposed in the 1960s. Molecular dating provides detailed temporal frameworks for divergence events in phylogenetic trees, allowing diverse evolutionary questions to be addressed. The key aspect of the molecular clock hypothesis, namely that differences in DNA or protein sequence between two species are proportional to the time elapsed since they diverged, was soon shown to be untenable. Other approaches were proposed to take into account rate heterogeneity among lineages, but the calibration process, by which relative times are transformed into absolute ages, has received little attention until recently. New methods have now been proposed to resolve potential sources of error associated with the calibration of phylogenetic trees, particularly those involving use of the fossil record. Scope and Conclusions The use of the fossil record as a source of independent information in the calibration process is the main focus of this paper; other sources of calibration information are also discussed. Particularly error-prone aspects of fossil calibration are identified, such as fossil dating, the phylogenetic placement of the fossil and the incompleteness of the fossil record. Methods proposed to tackle one or more of these potential error sources are discussed (e.g. fossil cross-validation, prior distribution of calibration points and confidence intervals on the fossil record). In conclusion, the fossil record remains the most reliable source of information for the calibration of phylogenetic trees, although associated assumptions and potential bias must be taken into account. PMID:19666901

  7. Assessing trace element diffusion models in fossil and sub-fossil bone

    NASA Astrophysics Data System (ADS)

    Suarez, C. A.; Kohn, M. J.

    2012-12-01

    Three different diffusion models have been proposed to explain trace element uptake during fossilization of bone: diffusion-adsorption (DA), diffusion-recrystallization (DR), and double-medium diffusion (DMD). Theoretically, differences in trace element profiles, particularly the rare earth elements (REE) and U, can discriminate among these possibilities. In this study, we tested which model best explains natural samples by analyzing trace element profiles in natural bone using laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS). Fossil bones ranging in age from a few ka to over 100 Ma were analyzed along traverses from the outer cortical edge to the inner marrow cavity margin. Forty major, minor and trace elements were analyzed, notably Ca, P, transition metals, Sr, Ba, REE, U, Th and Pb. Spatial and analytical resolutions were ~10 ?m and ~100 ppb respectively. Many specimens show commonly observed exponential decreases in REE from the outer edge and marrow cavity, with relatively homogeneous U distributions. Yet, most significantly, specimens from American Falls (last interglacial) and Duck Point (last glacial maximum) show distinctive U plateaus adjacent to the outer and inner cortical bone margins. Whereas exponential profiles can be produced by different uptake processes, such plateaus are diagnostic of a DR mechanism. Our work is consistent with recent investigation of trace element diffusivities in modern fresh and deproteinated bone. These studies show similar diffusion rates for REE and U, so the profound disparity in U vs. REE profiles in most fossils cannot result solely from differences in volume diffusion within the context of DA and DMD. Rather, as a recrystallization front propagates into bone, the bone appears to encode changing soil water compositions with earlier vs. later compositions reflected in the bone margin vs. interior. Soil water U concentrations apparently remain nearly fixed during fossilization, whereas REE are rapidly stripped from the surrounding matrix, leading to nearly homogeneous U vs. steep REE profiles. However in our Pleistocene bones (American Falls and Duck Point), changes to U concentrations on the bone margin reveal more complex changes to boundary compositions, and eliminate both DA and DMD (alone) as the dominant mechanisms of trace element uptake. Our work reconciles disparate zoning patterns observed in fossil bone, and simplifies interpretations of soil or sediment water chemistry, but complicates U-series dating of fossils.

  8. Paleoarchean trace fossils in altered volcanic glass

    PubMed Central

    Staudigel, Hubert; Furnes, Harald; DeWit, Maarten

    2015-01-01

    Microbial corrosion textures in volcanic glass from Cenozoic seafloor basalts and the corresponding titanite replacement microtextures in metamorphosed Paleoarchean pillow lavas have been interpreted as evidence for a deep biosphere dating back in time through the earliest periods of preserved life on earth. This interpretation has been recently challenged for Paleoarchean titanite replacement textures based on textural and geochronological data from pillow lavas in the Hooggenoeg Complex of the Barberton Greenstone Belt in South Africa. We use this controversy to explore the strengths and weaknesses of arguments made in support or rejection of the biogenicity interpretation of bioalteration trace fossils in Cenozoic basalt glasses and their putative equivalents in Paleoarchean greenstones. Our analysis suggests that biogenicity cannot be taken for granted for all titanite-based textures in metamorphosed basalt glass, but a cautious and critical evaluation of evidence suggests that biogenicity remains the most likely interpretation for previously described titanite microtextures in Paleoarchean pillow lavas. PMID:26038543

  9. Paleoarchean trace fossils in altered volcanic glass.

    PubMed

    Staudigel, Hubert; Furnes, Harald; DeWit, Maarten

    2015-06-01

    Microbial corrosion textures in volcanic glass from Cenozoic seafloor basalts and the corresponding titanite replacement microtextures in metamorphosed Paleoarchean pillow lavas have been interpreted as evidence for a deep biosphere dating back in time through the earliest periods of preserved life on earth. This interpretation has been recently challenged for Paleoarchean titanite replacement textures based on textural and geochronological data from pillow lavas in the Hooggenoeg Complex of the Barberton Greenstone Belt in South Africa. We use this controversy to explore the strengths and weaknesses of arguments made in support or rejection of the biogenicity interpretation of bioalteration trace fossils in Cenozoic basalt glasses and their putative equivalents in Paleoarchean greenstones. Our analysis suggests that biogenicity cannot be taken for granted for all titanite-based textures in metamorphosed basalt glass, but a cautious and critical evaluation of evidence suggests that biogenicity remains the most likely interpretation for previously described titanite microtextures in Paleoarchean pillow lavas. PMID:26038543

  10. Homo-?-amino acid containing MBP(85–99) analogs alleviate experimental autoimmune encephalomyelitis

    PubMed Central

    Kant, Ravi; Pasi, Shweta; Surolia, Avadhesha

    2015-01-01

    MBP(85–99), an immuno-dominant epitope of myelin basic protein which binds to the major histocompatibility complex haplotype HLA-DR2 is widely implicated in the pathogenesis of multiple sclerosis. J5, an antagonist of MBP(85–99), that blocks the binding of MBP(85–99) to soluble HLA-DR2b much more efficiently than glatiramer acetate (a random copolymer comprising major MHC and T-cell receptor contact residues), was transformed into analogs with superior biological half-lives and antagonistic-activities by substitution of some of its residues with homo-?-amino acids. S18, the best analog obtained ameliorated symptoms of experimental autoimmune encephalomyelitis at least twice more effectively than glatiramer acetate or J5. S18 displayed marked resistance to proteolysis in-vitro; biological impact of which was evident in the form of delayed clinical onset of disease and prolonged therapeutic-benefits. Besides active suppression of MBP(85–99)-reactive CD4+ T-cells in-vitro and in-vivo S18 treatment also generated IL-4 producing CD4+ T-cell clones, through which protective effect could be transferred passively. PMID:25644378

  11. Simulation of Threading Dislocation Images in X-ray Topographs of Silicon Carbide Homo-Epilayers

    SciTech Connect

    Vetter,W.; Tsuchida, H.; Kamata, I.; Dudley, M.

    2005-01-01

    Three types of dislocation are seen in homo-epilayers of SiC grown on 4H-SiC wafers with an 8 degree surface offcut: axial screw dislocations, basal plane dislocations propagated into the epilayer at an 8 degree inclination and threading edge dislocations. These types may be imaged by monochromatic synchrotron X-ray topography in the grazing-incidence reflection geometry using the 11{bar 2}8 reflection. Equations needed to apply the ray-tracing method of computer simulating X-ray topographic defect images in this experimental geometry were derived and used to simulate images of all three. Simulations for axial screw dislocations appear as white circles surrounded by narrow dark rings, and those for basal plane dislocations as linear white streaks, both consistent with experimental topographs. Simulations of the threading edge dislocations showed 4 {micro}m wide white ovals with narrow arcs of dark contrast at their ends, inclined relative to the g vector of the topograph according to the sign of their Burgers vector. These images resembled the experimental topographs inasmuch as was possible at the maximum resolution of X-ray topographs.

  12. Pair-Bonding, Romantic Love, and Evolution: The Curious Case of Homo sapiens.

    PubMed

    Fletcher, Garth J O; Simpson, Jeffry A; Campbell, Lorne; Overall, Nickola C

    2015-01-01

    This article evaluates a thesis containing three interconnected propositions. First, romantic love is a "commitment device" for motivating pair-bonding in humans. Second, pair-bonding facilitated the idiosyncratic life history of hominins, helping to provide the massive investment required to rear children. Third, managing long-term pair bonds (along with family relationships) facilitated the evolution of social intelligence and cooperative skills. We evaluate this thesis by integrating evidence from a broad range of scientific disciplines. First, consistent with the claim that romantic love is an evolved commitment device, our review suggests that it is universal; suppresses mate-search mechanisms; has specific behavioral, hormonal, and neuropsychological signatures; and is linked to better health and survival. Second, we consider challenges to this thesis posed by the existence of arranged marriage, polygyny, divorce, and infidelity. Third, we show how the intimate relationship mind seems to be built to regulate and monitor relationships. Fourth, we review comparative evidence concerning links among mating systems, reproductive biology, and brain size. Finally, we discuss evidence regarding the evolutionary timing of shifts to pair-bonding in hominins. We conclude there is interdisciplinary support for the claim that romantic love and pair-bonding, along with alloparenting, played critical roles in the evolution of Homo sapiens. PMID:25910380

  13. erbB3 Is an Active Tyrosine Kinase Capable of Homo- and Heterointeractions

    PubMed Central

    Steinkamp, Mara P.; Low-Nam, Shalini T.; Yang, Shujie; Lidke, Keith A.; Lidke, Diane S.

    2014-01-01

    Often considered to be a “dead” kinase, erbB3 is implicated in escape from erbB-targeted cancer therapies. Here, heregulin stimulation is shown to markedly upregulate kinase activity in erbB3 immunoprecipitates. Intact, activated erbB3 phosphorylates tyrosine sites in an exogenous peptide substrate, and this activity is abolished by mutagenesis of lysine 723 in the catalytic domain. Enhanced erbB3 kinase activity is linked to heterointeractions with catalytically active erbB2, since it is largely blocked in cells pretreated with lapatinib or pertuzumab. erbB2 activation of erbB3 is not dependent on equal surface levels of these receptors, since it occurs even in erbB3-transfected CHO cells with disproportionally small amounts of erbB2. We tested a model in which transient erbB3/erbB2 heterointeractions set the stage for erbB3 homodimers to be signaling competent. erbB3 homo- and heterodimerization events were captured in real time on live cells using single-particle tracking of quantum dot probes bound to ligand or hemagglutinin tags on recombinant receptors. PMID:24379439

  14. Homo-FRET Imaging Enables Quantification of Protein Cluster Sizes with Subcellular Resolution

    PubMed Central

    Bader, Arjen N.; Hofman, Erik G.; Voortman, Jarno; van Bergen en Henegouwen, Paul M.P.; Gerritsen, Hans C.

    2009-01-01

    Fluorescence-anisotropy-based homo-FRET detection methods can be employed to study clustering of identical proteins in cells. Here, the potential of fluorescence anisotropy microscopy for the quantitative imaging of protein clusters with subcellular resolution is investigated. Steady-state and time-resolved anisotropy detection and both one- and two-photon excitation methods are compared. The methods are evaluated on cells expressing green fluorescent protein (GFP) constructs that contain one or two FK506-binding proteins. This makes it possible to control dimerization and oligomerization of the constructs and yields the experimental relation between anisotropy and cluster size. The results show that, independent of the experimental method, the commonly made assumption of complete depolarization after a single energy transfer step is not valid here. This is due to a nonrandom relative orientation of the fluorescent proteins. Our experiments show that this relative orientation is restricted by interactions between the GFP barrels. We describe how the experimental relation between anisotropy and cluster size can be employed in quantitative cluster size imaging experiments of other GFP fusions. Experiments on glycosylphosphatidylinisotol (GPI)-anchored proteins reveal that GPI forms clusters with an average size of more than two subunits. For epidermal growth factor receptor (EGFR), we observe that ?40% of the unstimulated receptors are present in the plasma membrane as preexisting dimers. Both examples reveal subcellular heterogeneities in cluster size and distribution. PMID:19883605

  15. Molecular structure, vibrational spectroscopy, NBO and HOMO, LUMO studies of o-methoxybenzonitrile.

    PubMed

    Elanthiraiyan, M; Jayasudha, B; Arivazhagan, M

    2015-01-01

    In the present study, the FT-IR and FT-Raman spectra of o-methoxybenzonitrile (O-MBN) have been recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1), respectively. The fundamental modes of vibrational frequencies of O-MBN are assigned. Theoretical information on the optimized geometry, harmonic vibrational frequencies, infrared and Raman intensities were obtained by means of ab initio Hartree-Fock (HF) and density functional theory (DFT) gradient calculations with complete relaxation in the potential energy surface using 6-311++G(d,p) basis set. The vibrational frequencies which were determined experimentally from the spectral data are compared with those obtained theoretically from ab initio and DFT calculations. A close agreement was achieved between the observed and calculated frequencies by refinement of the scale factors. The infrared and Raman spectra were also predicted from the calculated intensities. Thermodynamic properties like entropy, heat capacity, zero point energy, have been calculated for the molecule. The predicted first hyperpolarizability also shows that the molecule might have a reasonably good non-linear optical (NLO) behavior. The calculated HOMO-LUMO energy gap reveals that charge transfer occurs within the molecule. Stability of the molecule arising from hyper conjugative interactions, charge delocalization have been analyzed using natural bond orbitals (NBO) analysis. Unambiguous vibrational assignment of all the fundamentals was made using the total energy distribution (TED). PMID:25058575

  16. Vibronic bands in the HOMO-LUMO excitation of linear polyyne molecules

    NASA Astrophysics Data System (ADS)

    Wakabayashi, Tomonari; Wada, Yoriko; Iwahara, Naoya; Sato, Tohru

    2013-04-01

    Hydrogen-capped linear carbon chain molecules, namely polyynes H(C?C)nH (n>=2), give rise to three excited states in the HOMO-LUMO excitation. Electric dipole transition from the ground state is fully allowed to one of the three excited states, while forbidden for the other two low-lying excited states. In addition to the strong absorption bands in the UV for the allowed transition, the molecules exhibit weak absorption and emission bands in the near UV and visible wavelength regions. The weak features are the vibronic bands in the forbidden transition. In this article, symmetry considerations are presented for the optical transitions in the centrosymmetric linear polyyne molecule. The argument includes Herzberg-Teller expansion for the state mixing induced by nuclear displacements along the normal coordinate of the molecule, intensity borrowing from fully allowed transitions, and inducing vibrational modes excited in the vibronic transition. The vibronic coupling considered here includes off-diagonal matrix elements for second derivatives along the normal coordinate. The vibronic selection rule for the forbidden transition is derived and associated with the transition moment with respect to the molecular axis. Experimental approaches are proposed for the assignment of the observed vibronic bands.

  17. Processing of fluorescence lifetime image using modified phasor approach: homo-FRET from the acceptor.

    PubMed

    Zhou, Yanzhou; Bai, Yulei; Chen, Ci; Dickenson, John M

    2013-07-01

    As the hardware of FLIM technique becomes mature, the most important criterion for FLIM application is the correct interpretation of its data. In this research, first of all, a more orthogonal phasor approach, called as Modified Phasor Approach (MPA), is put forward. It is a way to calculate the lifetime of the complex fluorescent process, and a rule to measure how much the fluorescence process deviates from single exponential decay. Secondly, MPA is used to analysis the time-resolved fluorescence processes of the transfected CHO-K1 Cell lines expressing adenosine receptor A1R tagged by CYP and YFP, measured in the channel of the acceptor. The image of the fluorescence lifetime and the multiplication of the fluorescence lifetime and deviation from single exponential decay reveal the details of the Homo-FRET. In one word, MPA provides the physical meaning in its whole modified phasor space, and broadens the way for the application of the fluorescence lifetime imaging. PMID:23494166

  18. Self-Assembly of Fused Homo-Oligomers to Create Nanotubes

    NASA Astrophysics Data System (ADS)

    Buch, Idit; Tsai, Chung-Jung; Wolfson, Haim J.; Nussinov, Ruth

    The formation of a nanostructure by self-assembly of a peptide or protein building block depends on the ability of the building block to spontaneously assemble into an ordered structure. We first describe a protocol of fusing homo-oligomer proteins with a given three-dimensional (3D) structure to create new building blocks. According to this protocol, a single monomer A that self-assembles with identical copies to create an oligomer A 1 is covalently linked, through a short linker L, to another monomer B that self-assembles with identical copies to create the oligomer B j . The result is a fused monomer A - L - B, which has the ability to self-assemble into a nanostructure (A - L - B) k . We control the self-assembly process of A - L - B by mapping the fused building block onto a planar sheet and wrapping the sheet around a cylinder with the target's dimensions. Finally, we validate the created nanotubes by an optimization procedure. We provide examples of two nanotubes in atomistic model details. One of these has experimental data. In principal, such a protocol should enable the creation of a wide variety of potentially useful protein-based nanotubes with control over their physical and chemical properties.

  19. GaN substrate and GaN homo-epitaxy for LEDs: Progress and challenges

    NASA Astrophysics Data System (ADS)

    Wu, Jie-Jun; Wang, Kun; Yu, Tong-Jun; Zhang, Guo-Yi

    2015-06-01

    After a brief review on the progresses in GaN substrates by ammonothermal method and Na-flux method and hydride vapor phase epitaxy (HVPE) technology, our research results of growing GaN thick layer by a gas flow-modulated HVPE, removing the GaN layer through an efficient self-separation process from sapphire substrate, and modifying the uniformity of multiple wafer growth are presented. The effects of surface morphology and defect behaviors on the GaN homo-epitaxial growth on free standing substrate are also discussed, and followed by the advances of LEDs on GaN substrates and prospects of their applications in solid state lighting. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA032605), the National Key Basic Research and Development Program of China (Grant Nos. 2012CB619304 and 2011CB301904), and the National Natural Science Foundation of China (Grant Nos. 61376012, 61474003, and 61327801).

  20. Implicit and explicit category learning by macaques (Macaca mulatta) and humans (Homo sapiens).

    PubMed

    Smith, J David; Beran, Michael J; Crossley, Matthew J; Boomer, Joseph; Ashby, F Gregory

    2010-01-01

    An influential theoretical perspective differentiates in humans an explicit, rule-based system of category learning from an implicit system that slowly associates different regions of perceptual space with different response outputs. This perspective was extended for the 1st time to the category learning of nonhuman primates. Humans (Homo sapiens) and macaques (Macaca mulatta) learned categories composed of sine-wave gratings that varied across trials in bar width and bar orientation. The categories had either a single-dimensional, rule-based solution or a two-dimensional, information-integration solution. Humans strongly dimensionalized the stimuli and learned the rule-based task far more quickly. Six macaques showed the same performance advantage in the rule-based task. In humans, rule-based category learning is linked to explicit cognition, consciousness, and declarative reports about the contents of cognition. These results demonstrate an empirical continuity between human and nonhuman primate cognition, suggesting that nonhuman primates may have some structural components of humans' capacity for explicit cognition. PMID:20141317

  1. Experimental and theoretical spectroscopic analysis, HOMO-LUMO, and NBO studies of cyanuric chloride

    NASA Astrophysics Data System (ADS)

    Prabhaharan, M.; Prabakaran, A. R.; Srinivasan, S.; Gunasekaran, S.

    2014-06-01

    The vibrational spectral analysis of cyanuric chloride was carried out by using FT-Raman and FT-IR spectra in the range 100-4000 cm-1 and 400-4000 cm-1 respectively. The structure optimization was done and structural characteristics were determined by Density Functional Theory (B3LYP) method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The vibrational wavenumbers have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED). The Natural bonding orbital (NBO) analysis performed to confirm the stability of the molecule arising from hyper conjugation and delocalization. The Mulliken atomic charges were also calculated. The computed HOMO-LUMO energy gap shows that charge transfer occurs within the molecule. The thermodynamic properties at different temperatures have been calculated from the vibrational analysis.

  2. Experimental and theoretical spectroscopic analysis, HOMO-LUMO, and NBO studies of cyanuric chloride.

    PubMed

    Prabhaharan, M; Prabakaran, A R; Srinivasan, S; Gunasekaran, S

    2014-06-01

    The vibrational spectral analysis of cyanuric chloride was carried out by using FT-Raman and FT-IR spectra in the range 100-4000cm(-1) and 400-4000cm(-1) respectively. The structure optimization was done and structural characteristics were determined by Density Functional Theory (B3LYP) method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The vibrational wavenumbers have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. A detailed interpretation of the vibrational spectra of the molecule has been made on the basis of the calculated Potential Energy Distribution (PED). The Natural bonding orbital (NBO) analysis performed to confirm the stability of the molecule arising from hyper conjugation and delocalization. The Mulliken atomic charges were also calculated. The computed HOMO-LUMO energy gap shows that charge transfer occurs within the molecule. The thermodynamic properties at different temperatures have been calculated from the vibrational analysis. PMID:24650880

  3. Homo- and heterofermentative lactobacilli differently affect sugarcane-based fuel ethanol fermentation.

    PubMed

    Basso, Thiago Olitta; Gomes, Fernanda Sgarbosa; Lopes, Mario Lucio; de Amorim, Henrique Vianna; Eggleston, Gillian; Basso, Luiz Carlos

    2014-01-01

    Bacterial contamination during industrial yeast fermentation has serious economic consequences for fuel ethanol producers. In addition to deviating carbon away from ethanol formation, bacterial cells and their metabolites often have a detrimental effect on yeast fermentative performance. The bacterial contaminants are commonly lactic acid bacteria (LAB), comprising both homo- and heterofermentative strains. We have studied the effects of these two different types of bacteria upon yeast fermentative performance, particularly in connection with sugarcane-based fuel ethanol fermentation process. Homofermentative Lactobacillus plantarum was found to be more detrimental to an industrial yeast strain (Saccharomyces cerevisiae CAT-1), when compared with heterofermentative Lactobacillus fermentum, in terms of reduced yeast viability and ethanol formation, presumably due to the higher titres of lactic acid in the growth medium. These effects were only noticed when bacteria and yeast were inoculated in equal cell numbers. However, when simulating industrial fuel ethanol conditions, as conducted in Brazil where high yeast cell densities and short fermentation time prevail, the heterofermentative strain was more deleterious than the homofermentative type, causing lower ethanol yield and out competing yeast cells during cell recycle. Yeast overproduction of glycerol was noticed only in the presence of the heterofermentative bacterium. Since the heterofermentative bacterium was shown to be more deleterious to yeast cells than the homofermentative strain, we believe our findings could stimulate the search for more strain-specific antimicrobial agents to treat bacterial contaminations during industrial ethanol fermentation. PMID:24198118

  4. Blood, bulbs, and bunodonts: on evolutionary ecology and the diets of Ardipithecus, Australopithecus, and early Homo.

    PubMed

    Sayers, Ken; Lovejoy, C Owen

    2014-12-01

    Beginning with Darwin, some have argued that predation on other vertebrates dates to the earliest stages of hominid evolution, and can explain many uniquely human anatomical and behavioral characters. Other recent workers have focused instead on scavenging, or particular plant foods. Foraging theory suggests that inclusion of any food is influenced by its profitability and distribution within the consumer's habitat. The morphology and likely cognitive abilities of Ardipithecus, Australopithecus, and early Homo suggest that while hunting and scavenging occurred, their profitability generally would have been considerably lower than in extant primates and/or modern human hunter-gatherers. On the other hand, early hominid diet modelers should not focus solely on plant foods, as this overlooks standard functional interpretations of the early hominid dentition, their remarkable demographic success, and the wide range of available food types within their likely day ranges. Any dietary model focusing too narrowly on any one food type or foraging strategy must be viewed with caution. We argue that early hominid diet can best be elucidated by consideration of their entire habitat-specific resource base, and by quantifying the potential profitability and abundance of likely available foods. PMID:25510078

  5. DFT studies on vibrational spectra, HOMO-LUMO, NBO and thermodynamic function analysis of cyanuric fluoride

    NASA Astrophysics Data System (ADS)

    Prabhaharan, M.; Prabakaran, A. R.; Gunasekaran, S.; Srinivasan, S.

    2015-02-01

    In this work, the theoretical vibrational spectral characteristics of cyanuric fluoride (C3N3F3) have been investigated and compared with existing experimental results. The density functional theoretical (DFT) computations were performed at the B3LYP level with the basis sets 6-31G(d,p) and 6-311++G(d,p) levels to derive the optimized geometry, vibrational wavenumbers with IR intensities of cyanuric fluoride. In addition, the molecular orbital calculations such as Natural Bond Orbitals (NBOs), HOMO-LUMO energy gap and Mapped molecular Electrostatic Potential (MEP) surfaces were also performed with the same level of DFT. Electronic stability of the compound arising from hyper conjugative interactions and charge delocalization were also investigated based on the natural bond orbital (NBO) analysis. Effective stabilization energy E(2) connected with the interactions of the ? and the lone pair of electrons was determined by the NBO analysis. Mulliken population analysis on atomic charges is also calculated. The thermodynamic properties of the cyanuric fluoride at different temperatures have also been calculated for the range of temperature 50-1000 K.

  6. Vibrational, UV spectra, NBO, first order hyperpolarizability and HOMO-LUMO analysis of carvedilol

    NASA Astrophysics Data System (ADS)

    Swarnalatha, N.; Gunasekaran, S.; Nagarajan, M.; Srinivasan, S.; Sankari, G.; Ramkumaar, G. R.

    2015-02-01

    In this work, we have investigated experimentally and theoretically on the molecular structure, vibrational spectra, UV spectral analysis and NBO studies of cardio-protective drug carvedilol. The FT-Raman and FT-IR spectra for carvedilol in the solid phase have been recorded in the region 4000-100 cm-1 and 4000-400 cm-1 respectively. Theoretical calculations were performed by using density functional theory (DFT) method at B3LYP/6-31G(d,p) and B3LYP/6-31++G(d,p) basis set levels. The harmonic vibrational frequencies, the optimized geometric parameters have been interpreted and compared with the reported experimental values. The complete vibrational assignments were performed on the basis of potential energy distribution (PED) of the vibrational modes. The thermodynamic properties and molecular electrostatic potential surfaces of the molecule were constructed. The electronic absorption spectrum was recorded in the region 400-200 nm and electronic properties such as HOMO and LUMO energies were calculated. The stability of the molecule arising from hyper conjugative interactions and charge delocalization have been analyzed from natural bond orbital (NBO) analysis. The first order hyperpolarizability of the title molecule was also calculated. The photo stability of carvedilol under different storage conditions were analyzed using UV-Vis spectral technique.

  7. Normalization of Complete Genome Characteristics: Application to Evolution from Primitive Organisms to Homo sapiens.

    PubMed

    Sorimachi, Kenji; Okayasu, Teiji; Ohhira, Shuji

    2015-04-01

    Normalized nucleotide and amino acid contents of complete genome sequences can be visualized as radar charts. The shapes of these charts depict the characteristics of an organism's genome. The normalized values calculated from the genome sequence theoretically exclude experimental errors. Further, because normalization is independent of both target size and kind, this procedure is applicable not only to single genes but also to whole genomes, which consist of a huge number of different genes. In this review, we discuss the applications of the normalization of the nucleotide and predicted amino acid contents of complete genomes to the investigation of genome structure and to evolutionary research from primitive organisms to Homo sapiens. Some of the results could never have been obtained from the analysis of individual nucleotide or amino acid sequences but were revealed only after the normalization of nucleotide and amino acid contents was applied to genome research. The discovery that genome structure was homogeneous was obtained only after normalization methods were applied to the nucleotide or predicted amino acid contents of genome sequences. Normalization procedures are also applicable to evolutionary research. Thus, normalization of the contents of whole genomes is a useful procedure that can help to characterize organisms. PMID:26085808

  8. Fossil Leaves and Fossil Leaf n-Alkanes: Reconstructing the First Closed Canopied Rainforests

    NASA Astrophysics Data System (ADS)

    Graham, H. V.; Freeman, K. H.

    2013-12-01

    Although the age and location is disputed, the rise of the first closed-canopy forest is likely linked with the expansion of angiosperms in the late Cretacous or early Cenozoic. The carbon isotope 'canopy effect' reflects the extent of canopy closure, and is well documented in ?13C values of the leaves and leaf lipids in modern forests. To test the extent of canopy closure among the oldest documented angiosperm tropical forests, we analyzed isotopic characteristics of leaf fossils and leaf waxes from the Guaduas and Cerrejón Formations. The Guaduas Fm. (Maastrichtian) contains some of the earliest angiosperm fossils in the Neotropics, and both leaf morphology and pollen records at this site suggest an open-canopy structure. The Cerrejón Fm. (Paleocene) contains what are believed to be the first recorded fossil leaves from a closed-canopy forest. We analyzed the bulk carbon isotope content (?13Cleaf) of 199 fossil leaves, as well as the n-alkane concentration and chain-length distribution, and ?13C of alkanes (?13Clipid) of 73 fossil leaves and adjacent sediment samples. Fossil leaves are dominated by eudicots and include ten modern plant families (Apocynaceae, Bombaceae, Euphorbaceae, Fabaceae, Lauraceae, Malvaceae, Meliaceae, Menispermaceae, Moraceae, Sapotaceae). We interpreted extent of canopy coverage based on the range of ?13Cleaf values. The narrow range of ?13C values in leaves from the Guaduas Fm (2.7‰) is consistent with an open canopy. A significantly wider range in values (6.3‰) suggests a closed-canopy signature for site 0315 of the Cerrejón Fm,. In contrast, at Site 0318, a lacustrine deposit, leaves had a narrow range (3.3‰) in ?13C values, and this is not consistent with a closed-canopy, but is consistent with leaf assemblages from a forest edge. Leaves that accumulate in lake sediments tend to be biased toward plants living at the lake edge, which do not experience closed-canopy conditions, and do not express the isotopic characteristics associated with canopy effect. A biomass flux-weighted model of alkane chain-length distribution and ?13Cleaf indicate n-alkanes extracted from bulk rock are consistent with inputs integrated over time from plants represented by fossil leaves. In a modern rainforest, we found leaf lipid amounts markedly higher in the shaded and moist understory, consistent with studies that show alkanes proffer fungal protection. Shade tolerance is associated with higher plant orders and, consistent with this, literature data for modern plants from 30 plant orders shows alkane production in asterids and rosids is 2 to 3 times greater than in basal angiosperms or gymnosperms. The lower clades tend to contain greater amounts of terpenoids and novel benzylisoquinoline alkaloids, rather than alkanes. For our three fossil floras, alkane abundance is strongly influenced by depositional setting, with preservation best in the lacustrine setting. Within each site, abundance patterns are potentially influenced by both taxonomic affiliation and by canopy structure as measured by ?13Cleaf values, and such relationships shed light on the combined influences of plant evolution, canopy structure and the function of biochemical resources on the geochemical record of the first rainforests.

  9. Storage and release of fossil organic carbon related to weathering of sedimentary rocks

    E-print Network

    Paris-Sud XI, Université de

    Storage and release of fossil organic carbon related to weathering of sedimentary rocks Yoann of various mineral and organic carbon forms. Among these carbon forms, fossil organic carbon (FOC) (i basins; weathering; fossil organic carbon flux; fossil organic carbon storage #12;1. Introduction Fossil

  10. Where are inion and endinion? Variations of the exo- and endocranial morphology of the occipital bone during hominin evolution.

    PubMed

    Balzeau, Antoine; Grimaud-Hervé, Dominique; Gilissen, Emmanuel

    2011-10-01

    The occipital bone is frequently investigated in paleoanthropological studies because it has several features that help to differentiate various fossil hominin species. Among these features is the separation between inion and endinion, which has been proposed to be an autapomorphic trait in (Asian) Homo erectus. Methodologies are developed here to quantify for the first time the location of these anatomical points, and to interpret their variation due to the complex interactions between exocranial and endocranial size and shape of the occipital and nuchal planes, as well as the occipital lobes and cerebellum. On the basis of our analysis, neither 'the separation between inion and endinion' nor 'endinion below inion' can be considered as an autapomorphic trait in H. erectus, since this feature is a condition shared by extant African great apes and fossil hominins. Moreover, our results show that the exo- and endocranial anatomy of the occipital bone differs between hominins (except Paranthropus boisei specimens and KNM-ER 1805) and great apes. For example, chimpanzees and bonobos are characterized by a very high position of inion and their occipital bone shows an antero-posterior compression. However, these features are partly correlated with their small size when compared with hominins. Asian H. erectus specimens have a thick occipital torus, but do not differ from other robust specimens, neither in this feature nor in the analysed exo- and endocranial proportions of the occipital bone. Finally, the apparent brain size reduction during the Late Pleistocene and variation between the sexes in anatomically modern humans (AMH) reflect that specimens with smaller brains have a relatively larger posterior height of the cerebellum. However, this trend is not the sole explanation for the 'vertical shift' of endinion above inion that appears occasionally and exclusively in AMH. PMID:21855115

  11. Quaternary fossil fauna of South Canterbury, South Island, New Zealand

    Microsoft Academic Search

    T. H. Worthy

    1997-01-01

    This study documents the Late Quaternary fossil fauna from 59 fossil sites in the South Canterbury downlands, South Island, New Zealand. Twenty?seven sites were predator accumulations attributed to laughing owls, two were accumulated by falcons, two were swamp sites, and the rest were pitfalls or rockshelter deposits. A total of 60 indigenous species of birds, one bat, three rodents, one

  12. On the Optimum Trend of Fossil Fuel Taxation

    Microsoft Academic Search

    Peter J N Sinclair

    1994-01-01

    The interest rate should fall with global warming. Remedial policy should allow for this endogeneity. In the simplest infinite-horizon model yielding a steady-state, one can derive the trend that an ad valorem fossil fuel tax should take to internalize the externality from emissions. It is negative. If implemented, it would reduce fossil fuel depletion and raise the rates of interest

  13. World fossil fuel subsidies and global carbon emissions

    Microsoft Academic Search

    Bjorn Larsen; Anwar Shah

    1992-01-01

    Larsen and Shah present evidence on the level of fossil fuel subsidies and their implications for carbon dioxide emissions. They conclude that substantial fossil fuel subsidies prevail in a handful of large, carbon-emitting countries. Removing such subsidies could substantially reduce national carbon emissions in some countries. Global carbon emissions could be reduced by 9 percent, assuming no change in world

  14. The buzz on bees: Oldest bee fossil found

    NSDL National Science Digital Library

    American Association for the Advancement of Science (AAAS; )

    2006-10-26

    Scientists reported finding the oldest fossil of a honey bee. It is 100 million years old. This fossil is about 40 millions years older than ones found before. Scientists will use the bee to understand how bees developed over history and how bees contributed to rapid changes in green plants.

  15. Fossil Energy Environmental Project. Annual report, FY 1977

    Microsoft Academic Search

    Braunstein

    1978-01-01

    During the past year the Fossil Energy Environmental Project has provided technical support to the Fossil Energy Program Administration of the Department of Energy (DOE\\/FE) in its coal conversion demonstration program. Work was focused in four principal areas: environmental assessment; guidance to demonstration plant contractors regarding environmental obligations; experimental studies of stored solids from coal conversion; and interactive assistance to

  16. Alternative energy: Can renewable energy sources replace fossil fuels

    Microsoft Academic Search

    1992-01-01

    Fossil fuels have been the prime mover of industrial life for some 200 years. The burning of coal and oil have saved inestimable amounts of time and labor while substantially raising living standards around the world. But many scientists now say the use of fossil fuels, which account for 85% of US energy use, contributes to global warming and could

  17. Fossil evidence for Cretaceous escalation in angiosperm leaf vein evolution

    E-print Network

    Bermingham, Eldredge

    Fossil evidence for Cretaceous escalation in angiosperm leaf vein evolution Taylor S. Feilda,1 plants that dominate modern vegetation possess leaf gas exchange potentials that far exceed those of all. Using vein density (DV) measurements of fossil angiosperm leaves, we show that the leaf hydraulic

  18. Revised version Fossiles molculaires d'intrt microbiologique,

    E-print Network

    Paris-Sud XI, Université de

    Molecular fossils are organic substances occurring in soils, sediments, coals and crude oils. The study nouvelles voies de transformation de l'humus, notamment par la mise au point d'une méthode permettant de of these structurally specific fossils has generated applications among several scientific fields. For instance

  19. Microalgal and terrestrial transport biofuels to displace fossil fuels

    Microsoft Academic Search

    Lucas Reijnders

    2009-01-01

    Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn, sugar beet or wheat and biodiesel from rapeseed. When terrestrial biofuels are to

  20. Teaching Paleontology in the National Parks: What is a Fossil?

    NSDL National Science Digital Library

    This slide show provides an introduction to paleontology for younger students. The slides show a variety of plant and anmal fossils, and are accompanied by a brief written narrative. Paleontologists are shown at work excavating and preparing fossils, and some National Park exhibits and facilities are also depicted. Links to a curriculum guide and to a downloadable Powerpoint version of the show are included.

  1. Fossil Ionized Bubbles Around Dead Quasars During Reionization

    E-print Network

    Steven Furlanetto; Zoltan Haiman; S. Peng Oh

    2008-03-24

    One of the most dramatic signatures of the reionization era may be the enormous ionized bubbles around luminous quasars (with radii reaching ~40 comoving Mpc), which may survive as "fossil'' ionized regions long after their source shuts off. Here we study how the inhomogeneous intergalactic medium (IGM) evolves inside such fossils. The average recombination rate declines rapidly with time, and the brief quasar episode significantly increases the mean free path inside the fossil bubbles. As a result, even a weak ionizing background generated by galaxies inside the fossil can maintain it in a relatively highly and uniformly ionized state. For example, galaxies that would ionize 20-30% of hydrogen in a random patch of the IGM can maintain 80-90% ionization inside the fossil, for a duration much longer than the average recombination time in the IGM. Quasar fossils at zfossils, at z>10 have a weaker galaxy-generated ionizing background and a higher gas density, so they can attain a swiss-cheese topology similar to the rest of the IGM, but with a smaller contrast between the ionized bubbles and the partially neutral regions separating them. Analogous HeIII-fossils should exist around the epoch of HeII/HeIII reionization at z~3, although rapid recombinations inside the HeIII-fossils will be more common. Our model of inhomogeneous recombination also applies to "double reionization'' models and shows that a non-monotonic reionization history is even more unlikely than previously thought.

  2. Constraints on carbon dioxide production from fossil fuel use

    Microsoft Academic Search

    R. M. Rotty; G. Marland

    1980-01-01

    The exponential growth of fossil fuel use over recent decades has resulted in a 4.3% annual increase in the carbon dioxide emitted to the atmosphere. The question addressed here is, when (and to what extent) will constraints limit the use of fossil fuels and the subsequent production of COâ. Three types of possible constraints are discussed: resource constraints, fuel-demand constraints,

  3. Modeling Seasonality in Carbon Dioxide Emissions From Fossil Fuel Consumption

    Microsoft Academic Search

    P. Kishore; K. Igarashi; H. Oikawa; M. Uotome; J. S. Gregg; R. J. Andres

    2004-01-01

    Using United States data, a method is developed to estimate the monthly consumption of solid, liquid and gaseous fossil fuels using monthly sales data to estimate the relative monthly proportions of the total annual national fossil fuel use. These proportions are then used to estimate the total monthly carbon dioxide emissions for each state. From these data, the goal is

  4. International comparison of energy efficiency of fossil power generation

    Microsoft Academic Search

    W. H. J. Graus; M. Voogt; E. Worrell

    2007-01-01

    The purpose of this study is to compare the energy efficiency of fossil-fired power generation for Australia, China, France, Germany, India, Japan, Nordic countries (Denmark, Finland, Sweden and Norway aggregated), South Korea, United Kingdom and Ireland, and United States. Together these countries generate 65% of worldwide fossil power generation. Separate benchmark indicators are calculated for the energy efficiency of natural

  5. Trace fossil preservation and the early evolution of animals

    Microsoft Academic Search

    Sören Jensen; Mary L. Droser; James G. Gehling

    2005-01-01

    The trace fossil record is an important element in discussions of the timing of appearance of bilaterian animals. A conservative approach does not extend this record beyond about 560–555 Ma. Crucial to the utility of trace fossils in detecting early benthic activity is the preservational potential of traces made close to the sediment–water interface. Our studies on the earliest Cambrian

  6. Fossil fuel decarbonization technology for mitigating global warming

    Microsoft Academic Search

    M Steinberg

    1999-01-01

    It has been understood that production of hydrogen from fossil and carbonaceous fuels with reduced CO2 emission to the atmosphere is key to the production of hydrogen-rich fuels for mitigating the CO2 greenhouse gas climate change problem. The conventional methods of hydrogen production from fossil fuels (coal, oil, gas and biomass) include steam reforming and water gas shift mainly of

  7. Strontium in Fossil Bones and the Reconstruction of Food Chains

    Microsoft Academic Search

    Heinrich Toots; M. R. Voorhies

    1965-01-01

    The strontium content of bone is a function of the strontium content of the ingested food. Under favorable conditions of fossilization it can be used for the determination of feeding habits of extinct terrestrial vertebrates. Homogeneous samples of fossil biotic communities are a prerequisite for significant results.

  8. Homo-FRET Based Biosensors and Their Application to Multiplexed Imaging of Signalling Events in Live Cells.

    PubMed

    Warren, Sean C; Margineanu, Anca; Katan, Matilda; Dunsby, Chris; French, Paul M W

    2015-01-01

    Multiplexed imaging of Förster Resonance Energy Transfer (FRET)-based biosensors potentially presents a powerful approach to monitoring the spatio-temporal correlation of signalling pathways within a single live cell. Here, we discuss the potential of homo-FRET based biosensors to facilitate multiplexed imaging. We demonstrate that the homo-FRET between pleckstrin homology domains of Akt (Akt-PH) labelled with mCherry may be used to monitor 3'-phosphoinositide accumulation in live cells and show how global analysis of time resolved fluorescence anisotropy measurements can be used to quantify this accumulation. We further present multiplexed imaging readouts of calcium concentration, using fluorescence lifetime measurements of TN-L15-a CFP/YFP based hetero-FRET calcium biosensor-with 3'-phosphoinositide accumulation. PMID:26133241

  9. Fossil Group Origins. VI. Global X-ray scaling relations of fossil galaxy clusters

    E-print Network

    Kundert, A; D'Onghia, E; Girardi, M; Aguerri, J A L; Barrena, R; Corsini, E M; De Grandi, S; Jiménez-Bailón, E; Lozada-Muñoz, M; Méndez-Abreu, J; Sánchez-Janssen, R; Wilcots, E; Zarattini, S

    2015-01-01

    We present the first pointed X-ray observations of ten candidate fossil galaxy groups and clusters. With these Suzaku observations, we determine global temperatures and bolometric X-ray luminosities of the intracluster medium (ICM) out to $r_{500}$ for six systems in our sample. The remaining four systems show signs of significant contamination from non-ICM sources. For the six objects with successfully determined $r_{500}$ properties, we measure global temperatures between $2.8 \\ \\mathrm{keV} \\leq T_{\\mathrm{X}} \\leq 5.3 \\ \\mathrm{keV}$, bolometric X-ray luminosities of $0.6 \\times 10^{44} \\ \\mathrm{ergs} \\ \\mathrm{s}^{-1} \\leq L_{\\mathrm{X,bol}} \\leq 7.2\\times 10^{44} \\ \\mathrm{ergs} \\ \\mathrm{s}^{-1}$, and estimate masses, as derived from $T_{\\mathrm{X}}$, of $M_{500} \\gtrsim 10^{14} \\ \\mathrm{M}_{\\odot}$. Scaling relations are constructed for an assembled sample of fossil and non-fossil systems using global X-ray luminosities, temperatures, optical luminosities, and velocity dispersions. The fit of the sc...

  10. Sedimentation Studies Reveal a Direct Role of Phosphorylation in Smad3:Smad4 Homo and Hetero-Trimerization †

    Microsoft Academic Search

    John J. Correia; Benoy M. Chacko; Suvana S. Lam; Kai Lin

    2001-01-01

    SMAD proteins are known to oligomerize and hetero-associate during their activation and translocation to the nucleus for transcriptional control. Analytical ultracentrifuge studies on Smad3 and Smad4 protein constructs are presented to clarify the model of homo- and hetero-oligomerization and the role of phosphorylation in the activation process. These constructs all exhibit a tendency to form disulfide cross-linked aggregates, primarily dimers,

  11. Ab initio, DFT, HOMO–LUMO and Natural Bond Orbital analyses of the electronic structure of 2-mercapto-1-methylimidazole

    Microsoft Academic Search

    V. Balachandran; A. Lakshmi; A. Janaki

    The Fourier transform Raman and Fourier transform infrared spectra of 2-mercapto-1-methylimidazole have been recorded. Ab initio and density functional computations of the vibrational spectrum, the molecular geometry, highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energy gaps were studied. On the basis of the comparison between calculated and experimental results and the comparison with related molecules, assignments of the

  12. Fossil-energy program. Progress report for June 1981

    SciTech Connect

    Not Available

    1981-08-01

    This report - the eighty-third of series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology, component development and process evaluation, technical support to major liquefaction projects, process analysis and engineering evaluations, fossil energy environmental analysis, flue gas desulfurization, coal preparation waste utilization, atmospheric fluidized bed coal combustor for cogeneration, TVA FBC demonstration plant program technical support, PFBC systems analysis, fossil fuel applications assessments, performance assurance system support for fossil energy projects, international energy technology assessment, generalized equilibrium models for liquid and gaseous fuel supplies, analyses of coal production goals, and fossil energy information center.

  13. The earliest fossil record of the animals and its significance.

    PubMed

    Budd, Graham E

    2008-04-27

    The fossil record of the earliest animals has been enlivened in recent years by a series of spectacular discoveries, including embryos, from the Ediacaran to the Cambrian, but many issues, not least of dating and interpretation, remain controversial. In particular, aspects of taphonomy of the earliest fossils require careful consideration before pronouncements about their affinities. Nevertheless, a reasonable case can now be made for the extension of the fossil record of at least basal animals (sponges and perhaps cnidarians) to a period of time significantly before the beginning of the Cambrian. The Cambrian explosion itself still seems to represent the arrival of the bilaterians, and many new fossils in recent years have added significant data on the origin of the three major bilaterian clades. Why animals appear so late in the fossil record is still unclear, but the recent trend to embrace rising oxygen levels as being the proximate cause remains unproven and may even involve a degree of circularity. PMID:18192192

  14. The homo-oligomerisation of both Sas-6 and Ana2 is required for efficient centriole assembly in flies

    PubMed Central

    Cottee, Matthew A; Muschalik, Nadine; Johnson, Steven; Leveson, Joanna; Raff, Jordan W; Lea, Susan M

    2015-01-01

    Sas-6 and Ana2/STIL proteins are required for centriole duplication and the homo-oligomerisation properties of Sas-6 help establish the ninefold symmetry of the central cartwheel that initiates centriole assembly. Ana2/STIL proteins are poorly conserved, but they all contain a predicted Central Coiled-Coil Domain (CCCD). Here we show that the Drosophila Ana2 CCCD forms a tetramer, and we solve its structure to 0.8 Å, revealing that it adopts an unusual parallel-coil topology. We also solve the structure of the Drosophila Sas-6 N-terminal domain to 2.9 Å revealing that it forms higher-order oligomers through canonical interactions. Point mutations that perturb Sas-6 or Ana2 homo-oligomerisation in vitro strongly perturb centriole assembly in vivo. Thus, efficient centriole duplication in flies requires the homo-oligomerisation of both Sas-6 and Ana2, and the Ana2 CCCD tetramer structure provides important information on how these proteins might cooperate to form a cartwheel structure. DOI: http://dx.doi.org/10.7554/eLife.07236.001 PMID:26002084

  15. Homo-oligomerization of the Activating Natural Killer Cell Receptor NKp30 Ectodomain Increases Its Binding Affinity for Cellular Ligands*

    PubMed Central

    Herrmann, Julia; Berberich, Hannah; Hartmann, Jessica; Beyer, Steffen; Davies, Karen; Koch, Joachim

    2014-01-01

    The natural cytotoxicity receptors, comprised of three type I membrane proteins NKp30, NKp44, and NKp46, are a unique set of activating proteins expressed mainly on the surface of natural killer (NK) cells. Among these, NKp30 is a major receptor targeting virus-infected cells, malignantly transformed cells, and immature dendritic cells. To date, only few cellular ligands of NKp30 have been discovered, and the molecular details of ligand recognition by NKp30 are poorly understood. Within the current study, we found that the ectodomain of NKp30 forms functional homo-oligomers that mediate high affinity binding to its corresponding cellular ligand B7-H6. Notably, this homo-oligomerization is strongly promoted by the stalk domain of NKp30. Based on these data, we suggest that homo-oligomerization of NKp30 in the plasma membrane of NK cells, which might be favored by IL-2-dependent up-regulation of NKp30 expression, provides a way to improve recognition and lysis of target cells by NK cells. PMID:24275655

  16. Fossils and tFossils and the Rock Cyclehe Rock Cycle The rock cycle explains how one type of rock

    E-print Network

    Cochran-Stafira, D. Liane

    1 Fossils and tFossils and the Rock Cyclehe Rock Cycle h ^ The rock cycle explains how one type of rock can be transformed into another in nature. The Geologic Cycle 3 key events: deposition, uplift geologic time Forms Strata: layers of rock The rock cycle explains how one type of rock can be transformed

  17. CHARACTERIZING MODERN AND FOSSIL GYMNOSPERM EXUDATES USING MICRO-FOURIER TRANSFORM INFRARED SPECTROSCOPY

    E-print Network

    Wolfe, Alexander P.

    CHARACTERIZING MODERN AND FOSSIL GYMNOSPERM EXUDATES USING MICRO-FOURIER TRANSFORM INFRARED spectroscopy have direct implications for the assessment of the fossil potential and the chemotaxonomic interpretation of modern and fossil gymnosperm exudates. Keywords: chemotaxonomy, plant resin, gum, conifers

  18. Wyoming fossils change theories about extinction Casper, Wyoming -Wednesday, March 12, 2003

    E-print Network

    Wilf, Peter

    Wyoming fossils change theories about extinction Casper, Wyoming - Wednesday, March 12, 2003 Marketplace Classifieds Internet Service Subscribe Home > News > Wyoming > Wyoming fossils change theories Regional Lee Newspapers Billings Gazette Wyoming fossils change theories about extinction By DAN WHIPPLE

  19. Functional Inositol 1,4,5-Trisphosphate Receptors Assembled from Concatenated Homo- and Heteromeric Subunits*?

    PubMed Central

    Alzayady, Kamil J.; Wagner, Larry E.; Chandrasekhar, Rahul; Monteagudo, Alina; Godiska, Ronald; Tall, Gregory G.; Joseph, Suresh K.; Yule, David I.

    2013-01-01

    Vertebrate genomes code for three subtypes of inositol 1,4,5-trisphosphate (IP3) receptors (IP3R1, -2, and -3). Individual IP3R monomers are assembled to form homo- and heterotetrameric channels that mediate Ca2+ release from intracellular stores. IP3R subtypes are regulated differentially by IP3, Ca2+, ATP, and various other cellular factors and events. IP3R subtypes are seldom expressed in isolation in individual cell types, and cells often express different complements of IP3R subtypes. When multiple subtypes of IP3R are co-expressed, the subunit composition of channels cannot be specifically defined. Thus, how the subunit composition of heterotetrameric IP3R channels contributes to shaping the spatio-temporal properties of IP3-mediated Ca2+ signals has been difficult to evaluate. To address this question, we created concatenated IP3R linked by short flexible linkers. Dimeric constructs were expressed in DT40–3KO cells, an IP3R null cell line. The dimeric proteins were localized to membranes, ran as intact dimeric proteins on SDS-PAGE, and migrated as an ?1100-kDa band on blue native gels exactly as wild type IP3R. Importantly, IP3R channels formed from concatenated dimers were fully functional as indicated by agonist-induced Ca2+ release. Using single channel “on-nucleus” patch clamp, the channels assembled from homodimers were essentially indistinguishable from those formed by the wild type receptor. However, the activity of channels formed from concatenated IP3R1 and IP3R2 heterodimers was dominated by IP3R2 in terms of the characteristics of regulation by ATP. These studies provide the first insight into the regulation of heterotetrameric IP3R of defined composition. Importantly, the results indicate that the properties of these channels are not simply a blend of those of the constituent IP3R monomers. PMID:23955339

  20. The origins and persistence of Homo floresiensis on Flores: biogeographical and ecological perspectives

    NASA Astrophysics Data System (ADS)

    Dennell, Robin W.; Louys, Julien; O'Regan, Hannah J.; Wilkinson, David M.

    2014-07-01

    The finding of archaeological evidence predating 1 Ma and a small hominin species (Homo floresiensis) on Flores, Indonesia, has stimulated much research on its origins and ancestry. Here we take a different approach and examine two key questions - 1) how did the ancestors of H. floresiensis reach Flores and 2) what are the possibilities for estimating the likelihood of hominin persistence for over 1 million years on a small island? With regard to the first question, on the basis of the biogeography we conclude that the mammalian, avian, and reptilian fauna on Flores arrived from a number of sources including Java, Sulawesi and Sahul. Many of the terrestrial taxa were able to float or swim (e.g. stegodons, giant tortoises and the Komodo dragon), while the rodents and hominins probably accidentally rafted from Sulawesi, following the prevailing currents. The precise route by which hominins arrived on Flores cannot at present be determined, although a route from South Asia through Indochina, Sulawesi and hence Flores is tentatively supported on the basis of zoogeography. With regards to the second question, we find the archaeological record equivocal. A basic energetics model shows that a greater number of small-bodied hominins could persist on Flores than larger-bodied hominins (whether H. floresiensis is a dwarfed species or a descendent of an early small-bodied ancestor is immaterial here), which may in part explain their apparent long-term success. Yet the frequent tsunamis and volcanic eruptions in the region would certainly have affected all the taxa on the island, and at least one turnover event is recorded, when Stegodon sondaari became extinct. The question of the likelihood of persistence may be unanswerable until we know much more about the biology of H. floresiensis.

  1. Spectroscopic properties, NLO, HOMO-LUMO and NBO analysis of 2,5-Lutidine.

    PubMed

    Govindarajan, M; Karabacak, M

    2012-10-01

    In this work, FT-IR and FT-Raman spectra of 2,5-Lutidine (C(7)H(9)N) have been reported in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. Density functional theory (DFT) has been used to calculate the optimized geometrical parameters, atomic charges, vibrational wavenumbers and intensity of the vibrational bands. The vibrational frequencies have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. The structure optimizations and normal coordinate force field calculations are based on HF and B3LYP methods with 6-311++G(d,p) basis set. The complete vibrational assignments of wavenumbers have been made on the basis of potential energy distribution (PED). The results of the calculation shows excellent agreement between experimental and calculated frequencies in B3LYP/6-311++G(d,p) basis set. The optimized geometric parameters were compared with experimental values of 2,5-Lutidine. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken charges and NBOs of the title molecule were also calculated and interpreted. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The dipole moment, linear polarizability and first hyperpolarizability values were also computed. PMID:22722076

  2. Spectroscopic properties, NLO, HOMO-LUMO and NBO analysis of 2,5-Lutidine

    NASA Astrophysics Data System (ADS)

    Govindarajan, M.; Karabacak, M.

    2012-10-01

    In this work, FT-IR and FT-Raman spectra of 2,5-Lutidine (C7H9N) have been reported in the regions 4000-400 cm-1 and 3500-100 cm-1, respectively. Density functional theory (DFT) has been used to calculate the optimized geometrical parameters, atomic charges, vibrational wavenumbers and intensity of the vibrational bands. The vibrational frequencies have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. The structure optimizations and normal coordinate force field calculations are based on HF and B3LYP methods with 6-311++G(d,p) basis set. The complete vibrational assignments of wavenumbers have been made on the basis of potential energy distribution (PED). The results of the calculation shows excellent agreement between experimental and calculated frequencies in B3LYP/6-311++G(d,p) basis set. The optimized geometric parameters were compared with experimental values of 2,5-Lutidine. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken charges and NBOs of the title molecule were also calculated and interpreted. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The dipole moment, linear polarizability and first hyperpolarizability values were also computed.

  3. Seeking Inflation Fossils in the Cosmic Microwave Background

    E-print Network

    Liang Dai; Donghui Jeong; Marc Kamionkowski

    2013-05-12

    If during inflation the inflaton couples to a "fossil" field, some new scalar, vector, or tensor field, it typically induces a scalar-scalar-fossil bispectrum. Even if the fossil field leaves no direct physical trace after inflation, it gives rise to correlations between different Fourier modes of the curvature or, equivalently, a nonzero curvature trispectrum, but without a curvature bispectrum. Here we quantify the effects of a fossil field on the cosmic microwave background (CMB) temperature fluctuations in terms of bipolar spherical harmonics (BiPoSHs). The effects of vector and tensor fossils can be distinguished geometrically from those of scalars through the parity of the BiPoSHs they induce. However, the two-dimensional nature of the CMB sky does not allow vectors to be distinguished geometrically from tensors. We estimate the detectability of a signal in terms of the scalar-scalar-fossil coupling for scalar, vector, and tensor fossils, assuming a local-type coupling. We comment on a divergence that arises in the quadrupolar BiPoSH from the scalar-scalar-tensor correlation in single-field slow-roll inflation.

  4. Radiation exposures due to fossil fuel combustion

    NASA Astrophysics Data System (ADS)

    Beck, Harold L.

    The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external ?-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

  5. Microquasars and ULXs: Fossils of GRB Sources

    E-print Network

    I. F. Mirabel

    2004-05-13

    Gamma-ray bursts (GRBs) of long duration probably result from the core-collapse of massive stars in binary systems. After the collapse of the primary star the binary system may remain bound leaving a microquasar or ULX source as remnant. In this context, microquasars and ULXs are fossils of GRB sources and should contain physical and astrophysical clues on GRB-source progenitors. The identification of the birth place of microquasars and magnetars can provide constrains on the progenitor stars of the compact objects, and the runaway velocities can be used to constrain the energy in the explosion of massive stars that leave neutron stars and black holes. The observations show that the neutron star binaries LS 5039, LSI +61 303 and the low-mass black hole in GRO J1655-40 formed in energetic supernova explosions, whereas the black holes of larger masses (M > 10 Msolar) in Cygnus X-1 and GRS 1915+105 formed promptly or in underluminous supernovae. If the massive star formation in the parent clusters of the microquasar LSI +61 303 and magnetars SGR 1806-20 and SGR 1900+14 was coeval, very massive stars (M > 50 Msolar) may in some cases leave neutron stars rather than black holes. The models of GRB sources of long duration have the same basic ingredients as microquasars and ULXs: compact objects with accretion disks and relativistic jets in binary systems. Therefore, the analogies between microquasars and AGN may be extended to the sources of GRBs.

  6. Fossilized excreta associated to dinosaurs in Brazil

    NASA Astrophysics Data System (ADS)

    Souto, P. R. F.; Fernandes, M. A.

    2015-01-01

    This work provides an updated register of the main occurrences of fossilized excreta (coprolites and urolites) associated with dinosaurs found in the Brazil. The goal is to provide a relevant guide to the interpretation of the environment in the context of Gondwana. In four geographic areas, the excreta are recovered from Cretaceous sedimentary deposits in outcrops of the Bauru and São Luis basins and the Upper Jurassic aeolian deposits of the Parana Basin in the state of São Paulo. The coprolites were analyzed by X-ray diffraction and X-ray fluorescence methods. The results of these analyses reveal compositions that differ from the surrounding matrix, indicating a partial substitution of the organic material due to the feeding habits of the producers. Additionally, we describe the urolite excavations in epirelief and hyporelief, the result of gravitational flow the impact from urine jets on sand. These are associated with ornithopod and theropod dinosaur footprints preserved in the aeolian flagstones of the Botucatu Formation, Parana Basin.

  7. Geology Fieldnotes: Agate Fossil Beds National Monument, Nebraska

    NSDL National Science Digital Library

    Agate Fossil Beds National Monument preserves an important source for 19.2 million year-old Miocene mammal fossils from a chapter of evolution frequently referred to as the "Age of Mammals". Features include information on park geology, maps, photographs, visitor information, and links to related publications. The park geology section discusses the Monument's geologic history and climate, profiles of some of the Miocene mammals found in the deposits, and discusses the history of fossil collecting at the locality. The park map indicates quarry and private property areas within the Monument.

  8. On the Nature of Fossil Galaxy Groups: Are they really fossils ?

    E-print Network

    F. La Barbera; R. R. de Carvalho; I. G. de la Rosa; G. Sorrentino; R. R. Gal; J. L. Kohl-Moreira

    2008-12-15

    We use SDSS-DR4 photometric and spectroscopic data out to redshift z~0.1 combined with ROSAT All Sky Survey X-ray data to produce a sample of twenty-five fossil groups (FGs), defined as bound systems dominated by a single, luminous elliptical galaxy with extended X-ray emission. We examine possible biases introduced by varying the parameters used to define the sample and the main pitfalls are discussed. The spatial density of FGs, estimated via the V/V_ MAX} test, is 2.83 x 10^{-6} h_{75}^3 Mpc^{-3} for L_x > 0.89 x 10^42 h_{75}^-2 erg/s consistent with Vikhlinin et al. (1999), who examined an X-ray overluminous elliptical galaxy sample (OLEG). We compare the general properties of FGs identified here with a sample of bright field ellipticals generated from the same dataset. These two samples show no differences in the distribution of neighboring faint galaxy density excess, distance from the red sequence in the color-magnitude diagram, and structural parameters such as a$_{4}$ and internal color gradients. Furthermore, examination of stellar populations shows that our twenty-five FGs have similar ages, metallicities, and $\\alpha$-enhancement as the bright field ellipticals, undermining the idea that these systems represent fossils of a physical mechanism that occurred at high redshift. Our study reveals no difference between FGs and field ellipticals, suggesting that FGs might not be a distinct family of true fossils, but rather the final stage of mass assembly in the Universe.

  9. Fossil Fuel Emission Verification Modeling at LLNL

    SciTech Connect

    Cameron-Smith, P; Kosovic, B; Guilderson, T; Monache, L D; Bergmann, D

    2009-08-06

    We have an established project at LLNL to develop the tools needed to constrain fossil fuel carbon dioxide emissions using measurements of the carbon-14 isotope in atmospheric samples. In Figure 1 we show the fossil fuel plumes from Los Angeles and San Francisco for two different weather patterns. Obviously, a measurement made at any given location is going to depend on the weather leading up to the measurement. Thus, in order to determine the GHG emissions from some region using in situ measurements of those GHGs, we use state-of-the-art global and regional atmospheric chemistry-transport codes to simulate the plumes: the LLNL-IMPACT model (Rotman et al., 2004) and the WRFCHEM community code (http://www.wrf-model.org/index.php). Both codes can use observed (aka assimilated) meteorology in order to recreate the actual transport that occurred. The measured concentration of each tracer at a particular spatio-temporal location is a linear combination of the plumes from each region at that location (for non-reactive species). The challenge is to calculate the emission strengths for each region that fit the observed concentrations. In general this is difficult because there are errors in the measurements and modeling of the plumes. We solve this inversion problem using the strategy illustrated in Figure 2. The Bayesian Inference step combines the a priori estimates of the emissions, and their uncertainty, for each region with the results of the observations, and their uncertainty, and an ensemble of model predicted plumes for each region, and their uncertainty. The result is the mathematical best estimate of the emissions and their errors. In the case of non-linearities, or if we are using a statistical sampling technique such as a Markov Chain Monte Carlo technique, then the process is iterated until it converges (ie reaches stationarity). For the Bayesian inference we can use both a direct inversion capability, which is fast but requires assumptions of linearity and Gaussianity of errors, or one of several statistical sampling techniques, which are computationally slower but do not require either linearity or Gaussianity (Chow, et al., 2008; Delle Monache, et al., 2008). The emission regions we are using are based on the air-basins defined by the California Air Resources Board (CARB), see Figure 3. The only difference is that we have joined some of the smaller air basins together. The results of a test using 4 days of simulated observations using our ensemble retrieval system are shown in Figure 3 (right). The main source of the variation between the different model configurations arises from the uncertainty in the atmospheric boundary layer parameterization in the WRF model. We are currently developing a capability to constrain the boundary layer height in our carbon-14 work either by weighting the ensemble member results by the accuracy of their boundary layer height (using commercial aircraft observations), or as part of the retrieval process using an ensemble Kalman filter (EnKF) capability.

  10. LRFD vs. ASD; Fossil power plant case study

    SciTech Connect

    Chhabra, S.J.; Lo, A.; Wilbur, M.J. (Sargent and Lundy, Chicago, IL (United States))

    1992-01-01

    Structural steel framing in fossil power plants has been traditionally designed using the Allowable Stress Design (ASD) method. The Load and Resistance Factor Design (LRFD) specification published in 1986, represents the state-of-the-art in structural steel design. The LRFD specification has been adopted by the 1991 Uniform Building Code (UBC) and the 1990 Building Officials and Code Administration (BOCA) code, and is gaining in popularity due to potential material savings. This paper compares the ASD and LRFD of typical structural steel framing in a recently designed fossil power plant. This paper will show that LRFD has a cost advantage over ASD, particularly when the member design is governed by the gravity load combination. Experience in using the LRFD method in fossil power plant design is discussed. Suggestions on the classification of fossil power plant design loads to confirm with the American Institute of Steel Construction (AISC) LRFD specifications are also given.

  11. Research Needs for Finely Resolved Fossil Carbon Emissions

    NASA Astrophysics Data System (ADS)

    Gurney, Kevin; Ansley, William; Mendoza, Daniel; Petron, Gabrielle; Frost, Greg; Gregg, Jay; Fischer, Marc; Pataki, Diane; Ackerman, Kate; Houweling, Sander; Corbin, Kathy; Andres, Robert; Blasing, T. J.

    2007-12-01

    Scientific research on the global carbon cycle has emerged as a high priority in biogeochemistry, climate studies, and global change policy. The emission of carbon dioxide (CO2) from fossil fuel combustion is a dominant driver of the current net carbon fluxes between the land, the oceans, and the atmosphere, and it is a key contributor to the rise in modern radiative forcing. Contrary to a commonly held perception, our quantitative knowledge about these emissions is insufficient to satisfy current scientific and policy needs. A more highly spatially and temporally resolved quantification of the social and economic drivers of fossil fuel combustion, and the resulting CO2 emissions, is essential to supporting scientific and policy progress. In this article, a new community of emissions researchers called the CO2 Fossil Fuel Emission Effort (CO2FFEE) outlines a research agenda to meet the need for improved fossil fuel CO2 emissions information and solicits comment from the scientific community and research agencies.

  12. Optimization of fossil fuel sources: An exergy approach

    SciTech Connect

    Camdali, U. [Development Bank of Turkey, Ankara (Turkey)

    2007-02-15

    We performed linear programming for optimization of fossil fuel supply in 2000 in Turkey. For this, an exergy analysis is made because the second law of thermodynamics takes into account the quality of energy as well as quantity of energy. Our analyses showed that the interfuel substitution between different fossil fuels will lead to a best energy mix of the country. The total retail price of fossil fuels can be lowered to 11.349 billion US$ from 13.012 billion US$ by increasing the domestic production of oil, lignite, and hard coal and by decreasing imports. The remaining demand can be met by natural gas imports. In conclusion, our analysis showed that a reduction of 1.663 billion US$ in fossil fuel cost can be made possible by giving more emphasis on domestic production, particularly of oil, lignite and hard coal.

  13. Proceedings of the fourth annual conference on fossil energy materials

    SciTech Connect

    Judkins, R.R.; Braski, D.N. (comps.)

    1990-08-01

    The Fourth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on may 15--17, 1990. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The work is divided into the following categories: (1) Ceramics, (2) New Alloys, (3) Corrosion and Erosion, and (4) Technology Assessment and Technology Transfer. Individual projects are processed separately for the data bases.

  14. Systematic Palaeontology A fossil sawfly of the genus Athalia (Hymenoptera

    E-print Network

    Wetzel, Andreas

    Systematic Palaeontology A fossil sawfly of the genus Athalia (Hymenoptera: Tenthredinidae) from.crpv.2004.12.001 #12;Keywords: Insects; Basal Hymenoptera; Tenthredinidae; Eocene/Oligocene boundary; Potassic Basin; Altkirch Mots clés : Insectes ; Hymenoptera basique ; Tenthredinidae ; limite Éocène

  15. Status of fossil energy resources: A global perspective

    SciTech Connect

    Balat, M. [SILA Science, Trabzon (Turkey)

    2007-07-01

    This article deals with recently status of global fossil energy sources. Fossil energy sources have been split into three categories: oil,coal, and natural gas. Fossil fuels are highly efficient and cheap. Currently oil is the fastest primary energy source in the world (39% of world energy consumption). Coal will be a major source of energy for the world for the foreseeable future (24% of world energy consumption). In 2030, coal covers 45% of world energy needs. Natural gas is expected to be the fastest growing component of world energy consumption (23% of world energy consumption). Fossil fuel extraction and conversion to usable energy has several environmental impacts. They could be a major contributor to global warming and greenhouse gases and a cause of acid rain; therefore, expensive air pollution controls are required.

  16. Fossil Footprints: How Fast Was That Dinosaur Moving?

    ERIC Educational Resources Information Center

    Caton, Randall; Otts, Charlotte

    1999-01-01

    Describes an activity in which students construct relationships between their leg lengths, stride lengths, and movements in order to estimate the speeds of the dinosaurs that made various fossilized tracks. (WRM)

  17. An Interdisciplinary Approach to Dinosaur Fossils, Morphology, Ethology, and Energetics.

    ERIC Educational Resources Information Center

    Zipko, Stephen J.

    1981-01-01

    Describes an interdisciplinary minicourse on dinosaur fossils, morphology, ethology, and energetics. Suggests and provides examples of hands-on activities for junior high school- through college-level students. (DS)

  18. MUNICIPAL WASTE COMBUSTION ASSESSMENT: FOSSIL FUEL CO-FIRING

    EPA Science Inventory

    The report identifies refuse derived fuel (RDF) processing operations and various RDF types; describes such fossil fuel co-firing techniques as coal fired spreader stokers, pulverized coal wall fired boilers, pulverized coal tangentially fired boilers, and cyclone fired boilers; ...

  19. Structure and spectroscopic studies of homo-and heterometallic complexes of adipic acid dihydrazide.

    PubMed

    Jeragh, Bakir; El-Asmy, Ahmed A

    2014-05-01

    A single crystal of adipic acid dihydrazide, ADH, has been analyzed. Its reaction with Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+), Ag(+), Pd(2+) and/or Pt(2+) gave homometallic and heterometallic complexes which are characterized by partial elemental analysis, spectra (MS, ESR, (1)H NMR, electronic; IR), thermal analysis and magnetic measurements. Some complexes: Zn(0.73)Cu(ADH)Cl4·H2O; Zn(0.71)Hg(0.36)(ADH)Cl4·H2O; Zn(0.65)Cd(0.46)(ADH)Cl4·½H2O; Zn(0.75)Co(0.41)(ADH-2H)Cl2·3H2O; Cd0.85Co0.43(ADH)Cl4·½EtOH were isolated having nonstiochiometric metal ratios. The ligand behaves as a neutral (bidentate or tetradentate) and/or binegative tetradentate. A square-pyramid, square-planar and tetrahedral structures were proposed for the homo Co(II), Cu(II) and Ni(II) complexes, respectively. A similar and different stereochemistry around each metal ion (tetrahedral+tetrahedral; tetrahedral+square-planar; tetrahedral+tetrahedral and/or tetrahedral+octahedral) was suggested for the heterometallic complexes. Some complexes were found highly stable with stability point >240 °C; the most stable is [HgNi(ADH-2H)Cl2]. The presence of diamagnetic atom (Zn, Cd or Hg) reduces the magnetic moments and gave anomalous moments. The degradation steps and the hydrated complexes are confirmed through the TGA study. The order of covalency of [Zn(0.73)Cu(ADH)Cl4]·H2O, [CdCu(ADH)Cl4]·H2O and [HgCu(ADH-2H)Cl2] matches with the size of the second metal (Zn complex>Cd complex>Hg complex). Some heterometallic complexes were found nonstoichiometric through the analysis of their metal content and supported by TGA. PMID:24530707

  20. Geological setting of U.S. fossil fuels.

    USGS Publications Warehouse

    Masters, C.D.; Mast, R.F.

    1987-01-01

    The USA has a special position in terms of fossil fuel development. Not only is it one of the most important nations in terms of resources of oil, gas and coal, but it has also been by far the dominant producer and consumer. In this thorough review of the regional geological environments in which fossil fuels formed in the USA, the authors point to a variety of models of resource occurrence of global interest.-Authors

  1. Carbon monoxide: A quantitative tracer for fossil fuel CO2?

    Microsoft Academic Search

    Ulrike Gamnitzer; Ute Karstens; Bernd Kromer; Rolf E. M. Neubert; Harro A. J. Meijer; Hartwig Schroeder; Ingeborg Levin

    2006-01-01

    Carbon monoxide (CO), carbon dioxide (CO2), and radiocarbon (14CO2) measurements have been made in Heidelberg from 2001 to 2004 in order to determine the regional fossil fuel CO2 component and to investigate the application of CO as a quantitative tracer for fossil fuel CO2 (CO2(foss)). The observations were compared with model estimates simulated with the regional transport model REMO at

  2. Fossil-fuel carbon emission control in irrigated maize production

    Microsoft Academic Search

    B. D. Wind; W. W. Wallender

    1997-01-01

    To evaluate optimal management strategies which reduce fossil-fuel carbon emissions, an idealized gross returns objective function was developed for the production of irrigated maize with the inclusion of a disincetive carbon-taxing term. The gross returns objective function is multivariant and optimized through a gradient search procedure. Carbon emissions emanating from maize production stem from the utilization of fossil-fuel energy on

  3. Large historical changes of fossil-fuel black carbon aerosols

    Microsoft Academic Search

    T. Novakov; V. Ramanathan; J. E. Hansen; T. W. Kirchstetter; M. Sato; J. E. Sinton; J. A. Sathaye

    2002-01-01

    Anthropogenic emissions of fine black carbon (BC) particles, the principal light-absorbing atmospheric aerosol, have varied during the past century in response to changes of fossil-fuel utilization, technology developments, and emission controls. We estimate historical trends of fossil-fuel BC emissions in six regions that represent about two-thirds of present day emissions and extrapolate these to global emissions from 1875 onward. Qualitative

  4. Large historical changes of fossil-fuel black carbon aerosols

    Microsoft Academic Search

    T. Novakov; V. Ramanathan; J. E. Hansen; T. W. Kirchstetter; M. Sato; J. E. Sinton; J. A. Sathaye

    2003-01-01

    Anthropogenic emissions of fine black carbon (BC) particles, the principal light-absorbing atmospheric aerosol, have varied during the past century in response to changes of fossil-fuel utilization, technology developments, and emission controls. We estimate historical trends of fossil-fuel BC emissions in six regions that represent about two-thirds of present day emissions and extrapolate these to global emissions from 1875 onward. Qualitative

  5. Problematic fossils from the Palaeo-Neoproterozoic Vindhyan Supergroup, India

    Microsoft Academic Search

    Purnima Srivastava

    Fossils of the Vindhyan Supergroup exhibit extensive diversity and variable biologic affinities represented by: bacteria,\\u000a cyanobacteria, algae, fungi, acritarchs, metaphytes and metazoans (including members of the Ediacaran Fauna) and ranging from\\u000a less than a micron to almost a metre in size. Besides identified fossils, a number of bizarre morphologies (due to deviation\\u000a of morphology from conventional structures), present in various

  6. Instrumentation and control for fossil-energy processes

    SciTech Connect

    Not Available

    1982-09-01

    The 1982 symposium on instrumentation and control for fossil energy processes was held June 7 through 9, 1982, at Adam's Mark Hotel, Houston, Texas. It was sponsored by the US Department of Energy, Office of Fossil Energy; Argonne National Laboratory; and the Society for Control and Instrumentation of Energy Processes. Fifty-two papers have been entered individually into EDB and ERA; eleven papers had been entered previously from other sources. (LTN)

  7. Carbon dioxide emissions from fossil-fuel use, 1751 1950

    Microsoft Academic Search

    R. J. Andres; D. J. Fielding; G. Marland; T. A. Boden; N. Kumar; A. T. Kearney

    1999-01-01

    Newly compiled energy statistics allow for an estimation of the complete time series of carbon dioxide (CO2) emissions from fossil-fuel use for the years 1751 to the present. The time series begins with 3×106 metric tonnes carbon (C). This initial flux represents the early stages of the fossil-fuel era. The CO2 flux increased exponentially until World War I. The time

  8. Aestivation in the Fossil Record: Evidence from Ichnology

    Microsoft Academic Search

    Daniel I. Hembree

    \\u000a Aestivation is a physiological and behavioral response to high temperature or low moisture conditions. Therefore, it is typically\\u000a not considered to be capable of being preserved in the fossil record. However, most aestivating organisms produce a burrow\\u000a to protect themselves from the harmful environmental conditions that trigger aestivation. These structures can be preserved\\u000a in the rock record as trace fossils.

  9. Fossil Energy Advanced Research and Technology Development Materials Program

    SciTech Connect

    Cole, N.C.; Judkins, R.R. (comps.)

    1992-12-01

    Objective of this materials program is to conduct R and D on materials for fossil energy applications with focus on longer-term and generic needs of the various fossil fuel technologies. The projects are organized according to materials research areas: (1) ceramics, (2) new alloys: iron aluminides, advanced austenitics and chromium niobium alloys, and (3) technology development and transfer. Separate abstracts have been prepared.

  10. ABSTRACTS: Seventh annual conference on fossil energy materials

    SciTech Connect

    Not Available

    1993-06-01

    Objective of the Advanced Research and Technology Development materials program is to conduct R and D on materials for fossil energy applications (coal processing, coal liquefaction, gasification, heat engines and recovery, combustion systems, fuel cells). Research is aimed at better understanding of materials in fossil energy environments and development of new materials for improvement of plant operations and reliability. Abstracts are given of 37 papers on ceramics/composites, intermetallics (iron aluminides, etc.), and advanced austenitics. (DLC)

  11. ABSTRACTS: Seventh annual conference on fossil energy materials

    SciTech Connect

    Not Available

    1993-01-01

    Objective of the Advanced Research and Technology Development materials program is to conduct R and D on materials for fossil energy applications (coal processing, coal liquefaction, gasification, heat engines and recovery, combustion systems, fuel cells). Research is aimed at better understanding of materials in fossil energy environments and development of new materials for improvement of plant operations and reliability. Abstracts are given of 37 papers on ceramics/composites, intermetallics (iron aluminides, etc.), and advanced austenitics. (DLC)

  12. Survival of fossils under extreme shocks induced by hypervelocity impacts.

    PubMed

    Burchell, M J; McDermott, K H; Price, M C; Yolland, L J

    2014-08-28

    Experimental data are shown for survival of fossilized diatoms undergoing shocks in the GPa range. The results were obtained from hypervelocity impact experiments which fired fossilized diatoms frozen in ice into water targets. After the shots, the material recovered from the target water was inspected for diatom fossils. Nine shots were carried out, at speeds from 0.388 to 5.34?km?s(-1), corresponding to mean peak pressures of 0.2-19?GPa. In all cases, fragmented fossilized diatoms were recovered, but both the mean and the maximum fragment size decreased with increasing impact speed and hence peak pressure. Examples of intact diatoms were found after the impacts, even in some of the higher speed shots, but their frequency and size decreased significantly at the higher speeds. This is the first demonstration that fossils can survive and be transferred from projectile to target in hypervelocity impacts, implying that it is possible that, as suggested by other authors, terrestrial rocks ejected from the Earth by giant impacts from space, and which then strike the Moon, may successfully transfer terrestrial fossils to the Moon. PMID:25071234

  13. Adventures in Paleontology: 36 Classroom Fossil Activities (e-book)

    NSDL National Science Digital Library

    Irwin Slesnick

    2006-01-01

    Millions of years after vanishing from the Earth, dinosaurs still have the power to stir students' curiosity. Deepen that interest with Adventures in Paleontology, a series of lively hands-on activities especially for middle schoolers. This beautifully illustrated full color book features 36 activities that open students up to a variety of foundational sciences, including biology, geology, chemistry, physics, and astronomy. For example: ? "How Do Fossils Form?" discusses how organisms become fossils and illustrates the concept with activities that simulate fossil-making processes. ? "What Can You Learn From Fossils?" explores what fossils teach about ancient organisms. ? "Mass Extinction and Meteor Collisions With Earth" discusses recently discovered links between meteor and asteroid impacts on Earth and the demise of animals like dinosaurs. Other chapters cover how to tell the age of the Earth; how dinosaurs evolved; and diversity, classification, and taxonomy. The final chapters offer humanistic perspectives on fossils in literature and art. As an attention-grabbing complement to the text, vivid full color illustrations show not just skeletons and animal tracks but also what dinosaurs probably looked like in their natural settings. Handy line drawings guide students through each step of the activities.

  14. The Fossil Phase in the Life of a Galaxy Group

    E-print Network

    Alexander M. von Benda-Beckmann; Elena D'Onghia; Stefan Gottloeber; Matthias Hoeft; Arman Khalatyan; Anatoly Klypin; Volker Mueller

    2007-10-08

    We investigate the origin and evolution of fossil groups in a concordance LCDM cosmological simulation. We consider haloes with masses between $(1-5)\\times10^{13} \\hMsun$ and study the physical mechanisms that lead to the formation of the large gap in magnitude between the brightest and the second most bright group member, which is typical for these fossil systems. Fossil groups are found to have high dark matter concentrations, which we can relate to their early formation time. The large magnitude-gaps arise after the groups have build up half of their final mass, due to merging of massive group members. We show that the existence of fossil systems is primarily driven by the relatively early infall of massive satellites, and that we do not find a strong environmental dependence for these systems. In addition, we find tentative evidence for fossil group satellites falling in on orbits with typically lower angular momentum, which might lead to a more efficient merger onto the host. We find a population of groups at higher redshifts that go through a ``fossil phase'': a stage where they show a large magnitude-gap, which is terminated by renewed infall from their environment.

  15. Ag(I)-mediated homo and hetero pairs of guanosine and cytidine: monitoring by circular dichroism spectroscopy.

    PubMed

    Goncharova, Iryna

    2014-01-24

    Ag(I)-containing compounds are attractive as antibacterial and antifungal agents. The renewed interest in the application of silver(I) compounds has led to the need for detailed knowledge of the mechanism of their action. One of the possible ways is the coordination of Ag(I) to G-C pairs of DNA, where Ag(+) ions form Ag(I)-mediated base pairs and inhibit the transcription. Herein, a systematic chiroptical study on silver(I)-mediated homo and mixed pairs of the C-G complementary-base derivatives cytidine(C) and 5'-guanosine monophosphate(G) in water is presented. Ag(I)-mediated homo and hetero pairs of G and C and their self-assembled species were studied under two pH levels (7.0 and 10.0) by vibrational (VCD) and electronic circular dichroism(ECD). VCD was used for the first time in this field and showed itself to be a powerful method for obtaining specific structural information in solution. Based on results of the VCD experiments, the different geometries of the homo pairs were proposed under pH 7.0 and 10.0. ECD was used as a diagnostic tool to characterize the studied systems and as a contact point between the previously defined structures of the metal or proton mediated pairs of nucleobases and the systems studied here. On the basis of the obtained data, the formation of the self-assembled species of cytidine with a structure similar to the i-motif structure in DNA was proposed at pH 10.0. PMID:24051294

  16. Ag(I)-mediated homo and hetero pairs of guanosine and cytidine: Monitoring by circular dichroism spectroscopy

    NASA Astrophysics Data System (ADS)

    Goncharova, Iryna

    2014-01-01

    Ag(I)-containing compounds are attractive as antibacterial and antifungal agents. The renewed interest in the application of silver(I) compounds has led to the need for detailed knowledge of the mechanism of their action. One of the possible ways is the coordination of Ag(I) to G-C pairs of DNA, where Ag+ ions form Ag(I)-mediated base pairs and inhibit the transcription. Herein, a systematic chiroptical study on silver(I)-mediated homo and mixed pairs of the C-G complementary-base derivatives cytidine(C) and 5?-guanosine monophosphate(G) in water is presented. Ag(I)-mediated homo and hetero pairs of G and C and their self-assembled species were studied under two pH levels (7.0 and 10.0) by vibrational (VCD) and electronic circular dichroism(ECD). VCD was used for the first time in this field and showed itself to be a powerful method for obtaining specific structural information in solution. Based on results of the VCD experiments, the different geometries of the homo pairs were proposed under pH 7.0 and 10.0. ECD was used as a diagnostic tool to characterize the studied systems and as a contact point between the previously defined structures of the metal or proton mediated pairs of nucleobases and the systems studied here. On the basis of the obtained data, the formation of the self-assembled species of cytidine with a structure similar to the i-motif structure in DNA was proposed at pH 10.0.

  17. Na,K-ATPase ?-subunit cis homo-oligomerization is necessary for epithelial lumen formation in mammalian cells.

    PubMed

    Barwe, Sonali P; Skay, Anna; McSpadden, Ryan; Huynh, Thu P; Langhans, Sigrid A; Inge, Landon J; Rajasekaran, Ayyappan K

    2012-12-01

    Na,K-ATPase is a hetero-oligomer of an ?- and a ?-subunit. The ?-subunit (Na,K-?) possesses the catalytic function, whereas the ?-subunit (Na,K-?) has cell-cell adhesion function and is localized to the apical junctional complex in polarized epithelial cells. Earlier, we identified two distinct conserved motifs on the Na,K-?(1) transmembrane domain that mediate protein-protein interactions: a glycine zipper motif involved in the cis homo-oligomerization of Na,K-?(1) and a heptad repeat motif that is involved in the hetero-oligomeric interaction with Na,K-?(1). We now provide evidence that knockdown of Na,K-?(1) prevents lumen formation and induces activation of extracellular regulated kinases 1 and 2 (ERK1/2) mediated by phosphatidylinositol 3-kinase in MDCK cells grown in three-dimensional collagen cultures. These cells sustained cell proliferation in an ERK1/2-dependent manner and did not show contact inhibition at high cell densities, as revealed by parental MDCK cells. This phenotype could be rescued by wild-type Na,K-?(1) or heptad repeat motif mutant of Na,K-?(1), but not by the glycine zipper motif mutant that abrogates Na,K-?(1) cis homo-oligomerization. These studies suggest that Na,K-?(1) cis homo-oligomerization rather than hetero-oligomerization with Na,K-?(1) is involved in epithelial lumen formation. The relevance of these findings to pre-neoplastic lumen filling in epithelial cancer is discussed. PMID:23077177

  18. Proceedings of the Seventh Annual Conference on Fossil Energy Materials. Fossil Energy AR and TD Materials Program

    SciTech Connect

    Cole, N.C.; Judkins, R.R. [comps.

    1993-07-01

    Objective of the AR&TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The 37 papers are arranged into 3 sessions: ceramics, new alloys/intermetallics, and new alloys/advanced austenitics. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  19. The first fossil owls (Aves: Strigiformes) from the Paleogene of Asia and a review of the fossil record of Strigiformes

    Microsoft Academic Search

    E. N. Kurochkin; G. J. Dyke

    2011-01-01

    The fossil record of owls (Strigiformes) is one of the most extensive among the neornithine birds, yet at the same time largely\\u000a restricted geographically to Europe and North America. Various fossil owls are known from the Paleocene (ca. 60 Ma) to Recent.\\u000a Here we present the first taxonomic description of new species of Paleogene owls from Asia, two new taxa

  20. Le peuplement préhistorique du Maroc : données récentes et problèmes

    Microsoft Academic Search

    André Debénath

    2000-01-01

    Prehistoric colonization of Morocco: recent data and problems. The purpose of this paper is to precise our knowledge of the human colonization of the Atlantic coast of Morocco since the first Homo erectus (Rabat, Casablanca, Salé), to the development of the Neolithic groups. The author emphasises the absence of Homo sapiens neanderthalensis in Morocco and the problems of the Aterian

  1. How We Got Here: Evolutionary Changes in Skull Shape in Humans & Their Ancestors

    ERIC Educational Resources Information Center

    Price, Rebecca M.

    2012-01-01

    This activity uses inquiry to investigate how large changes in shape can evolve from small changes in the timing of development. Students measure skull shape in fetal, infant, juvenile, and adult chimpanzees and compare them to adult skulls of "Homo sapiens," "Homo erectus," and "Australopithecus afarensis." They conclude by re-interpreting their…

  2. Assessing fluctuating odontometric asymmetry among fossil hominin taxa through alternative measures of central tendency: effect of outliers and directional components on reported results.

    PubMed

    Kegley, A D T; Hemingway, J

    2007-01-01

    Preliminary inquires into the distribution and expression of fluctuating odontometric asymmetry (FOA), among selected fossil hominins, have revealed results that may be serviceable within studies that assess, among others, palaeobiological, evolutionary processes and events. Though several intricate statistical applications have aided in the advancement of FOA to the hominin fossil record, little is known regarding the influence of outliers and directional components on reported results. Moreover, most methods employed to test homogeneity among FOA datasets are sensitive to the assumption that underlying samples reflect Gaussian distributions. Because this assumption is often violated, alternative formulations of Levene's test statistic, which have been shown to be robust under non-normality, have been suggested. Unfortunately, previous FOA studies have failed to address their potential. Given this, we considered two areas that may influence interpretations of FOA among fossil hominin studies. Firstly, we assessed distributions of signed data (d(u)) among samples of Australopithecus africanus, Paranthropus robustus and Homo habilis for outliers and directional asymmetry to evaluate their influence on reported heterogeneity. Secondly, in an attempt to decrease the probability of falsely rejecting H(0) due to non-normality, we considered alternative estimates of central tendency for comparisons of FOA. Our study confirms the need for intrinsic scrutiny of data, as the removal of one extreme value within the buccolingual H. habilis sample produced statistically significant outcomes at the sample level, while directional asymmetry was exposed within an expanded buccolingual P. robustus sample. However, though servicing alternative measures of central tendency remains informative, except for the buccolingual P. robustus sample before the correction of directional asymmetry, replacement of the mean was not required herein. Consistent with previous investigations, significant differences between buccolingual values in apposing arcades were unique among A. africanus and P. robustus, with the latter expressing greater FOA overall. Finally, our results strengthen the assertion that the individuals sampled among H. habilis may indicate an episode of developmental compromise where external and/or internal noises are lessened through internal homeostasis. PMID:17254582

  3. Much more human, still image with audioSite: DNA Interactive (www.dnai.org)

    NSDL National Science Digital Library

    2008-10-06

    When we come to this creature, Homo ergaster, or early Homo erectus, known now from Georgia, from a site called Dmanisi, and from Africa, we are with a creature which, in terms of it body shape, is much more human than these earlier forms where the body shape still shows many apelike features. The brain size though is small, maybe only half or two-thirds of the modern brain size, but it's certainly, recognizably for the first time I think, most people would agree this is an early human. And as we come through time, H. erectus certainly evolves, we get H. erectus continuing in the Far East, even perhaps as recently as fifty thousand years ago in Java, but for many of us H. erectus in these regions representing a side branch of human evolution.

  4. Synthesis and spectroscopic studies of homo-binuclear, alkoxo bridged homo- and hetero-tetranuclear metal complexes of a bis-N2O4 Schiff base ligand derived from ethanolamine and macroacyclic tetranaphthaldehyde.

    PubMed

    Karao?lu, Kaan; Baran, Talat; De?irmencio?lu, Ismail; Serbest, Kerim

    2011-09-01

    Three new homo-binuclear Ni(II), Cu(II), Zn(II) complexes (2-4), homo-tetranuclear Cu(II) complex (5), and hetero-tetranuclear Cu(II)-Ni(II) complex (6) of a macroacyclic potentially bis-hexadentate N2O4 Schiff base have been synthesized. The imino-alcohol ligand, H4L was obtained by the condensation of ethanolamine with 2,2'-[2,3-bis(1-formyl-2-naphthyloxymethyl)-but-2-ene-1,4-diyldioxy]bis(naphthalene-1-carbaldehyde). The structures of both the Schiff base and its complexes have been proposed by elemental analyses, spectroscopic data i.e. IR, 1H and 13C NMR, UV-vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The ligand has two similar compartments to bind first primary two metal ions, and acts bi- or tetra-negative, bis-tetradentate forming five membered chelate ring. However, secondary two metal ions (either Cu2+ or Ni2+) are ligated with dianionic oxygen atoms of the alcohol groups and are linked to the 1,10-phenanthroline-nitrogen atoms in the tetranuclear complexes (5 and 6). PMID:21550297

  5. Synthesis and spectroscopic studies of homo-binuclear, alkoxo bridged homo- and hetero-tetranuclear metal complexes of a bis-N 2O 4 Schiff base ligand derived from ethanolamine and macroacyclic tetranaphthaldehyde

    NASA Astrophysics Data System (ADS)

    Karao?lu, Kaan; Baran, Talat; De?irmencio?lu, ?smail; Serbest, Kerim

    2011-09-01

    Three new homo-binuclear Ni(II), Cu(II), Zn(II) complexes ( 2-4), homo-tetranuclear Cu(II) complex ( 5), and hetero-tetranuclear Cu(II)-Ni(II) complex ( 6) of a macroacyclic potentially bis-hexadentate N 2O 4 Schiff base have been synthesized. The imino-alcohol ligand, H 4L was obtained by the condensation of ethanolamine with 2,2'-[2,3-bis(1-formyl-2-naphthyloxymethyl)-but-2-ene-1,4-diyldioxy]bis(naphthalene-1-carbaldehyde). The structures of both the Schiff base and its complexes have been proposed by elemental analyses, spectroscopic data i.e. IR, 1H and 13C NMR, UV-vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The ligand has two similar compartments to bind first primary two metal ions, and acts bi- or tetra-negative, bis-tetradentate forming five membered chelate ring. However, secondary two metal ions (either Cu 2+ or Ni 2+) are ligated with dianionic oxygen atoms of the alcohol groups and are linked to the 1,10-phenanthroline-nitrogen atoms in the tetranuclear complexes ( 5 and 6).

  6. INSTITUTNATIONAL DE L'ENVIRONNEMENTINDUSTRIEL ETDES RISQUES Les impacts des nergies fossiles

    E-print Network

    Boyer, Edmond

    fossiles sur l'environnement Guy Landrieu Ingénieur au Département Évaluation, Modélisation, Analyse des)" #12;INERIS : Les impacts des énergies fossiles sur l'environnement Les impacts des énergies fossiles carbonés fossiles, qui représentent environ 90% de la production commerciale d'énergie dans le monde, ont

  7. Lower Silurian trace fossils and the Eocoelia community in the Tortworth Inlier, SW England

    E-print Network

    Benton, Michael

    Lower Silurian trace fossils and the Eocoelia community in the Tortworth Inlier, SW England Michael J. Benton and Charles Hiscock BENTON, M. J. & HISCOCK, C. 1996. Lower Silurian trace fossils, and associated trace fossils indicate an open-shelf site of deposition for this unit. The trace fossils

  8. Fossilized Biophotonic Nanostructures Reveal the Original Colors of 47-Million-Year-Old Moths

    E-print Network

    Cao, Hui

    Fossilized Biophotonic Nanostructures Reveal the Original Colors of 47-Million-Year-Old Moths Maria data from fossils. Here we report the first example of structurally colored scales in fossil fossilization but are reconstructed based upon preserved ultrastructural detail. The dorsal surface

  9. vol. 164, no. 5 the american naturalist november 2004 Maintenance of Trophic Structure in Fossil Mammal

    E-print Network

    Jernvall, Jukka

    vol. 164, no. 5 the american naturalist november 2004 Maintenance of Trophic Structure in Fossil are difficult to detect in the fossil record, we here used fossil locality coverage to approximate changes environmental change. Ecomor- phological grouping of fossils indicates that herbivore genera have low taxon

  10. Geologic Time and the Fossil Record (title provided or enhanced by cataloger)

    NSDL National Science Digital Library

    This interactive site demonstrates how fossil evidence and the principle of superposition are used to determine the age of rock layers and fossils. It contains several examples of index fossils and how they are used to date events. Geologic changes including continental drift are also related to fossil evidence.

  11. Early Pleistocene third metacarpal from Kenya and the evolution of modern human-like hand morphology.

    PubMed

    Ward, Carol V; Tocheri, Matthew W; Plavcan, J Michael; Brown, Francis H; Manthi, Fredrick Kyalo

    2014-01-01

    Despite discoveries of relatively complete hands from two early hominin species (Ardipithecus ramidus and Australopithecus sediba) and partial hands from another (Australopithecus afarensis), fundamental questions remain about the evolution of human-like hand anatomy and function. These questions are driven by the paucity of hand fossils in the hominin fossil record between 800,000 and 1.8 My old, a time interval well documented for the emergence and subsequent proliferation of Acheulian technology (shaped bifacial stone tools). Modern and Middle to Late Pleistocene humans share a suite of derived features in the thumb, wrist, and radial carpometacarpal joints that is noticeably absent in early hominins. Here we show that one of the most distinctive features of this suite in the Middle Pleistocene to recent human hand, the third metacarpal styloid process, was present ?1.42 Mya in an East African hominin from Kaitio, West Turkana, Kenya. This fossil thus provides the earliest unambiguous evidence for the evolution of a key shared derived characteristic of modern human and Neandertal hand morphology and suggests that the distinctive complex of radial carpometacarpal joint features in the human hand arose early in the evolution of the genus Homo and probably in Homo erectus sensu lato. PMID:24344276

  12. miR-homoHSV of Singapore Grouper Iridovirus (SGIV) Inhibits Expression of the SGIV Pro-apoptotic Factor LITAF and Attenuates Cell Death

    PubMed Central

    Cui, Huachun; Huang, Xiaohong; Qin, Qiwei

    2013-01-01

    Growing evidence demonstrates that various large DNA viruses could encode microRNAs (miRNAs) that regulate host and viral genes to achieve immune evasion. In this study, we report that miR-homoHSV, an miRNA encoded by Singapore grouper iridovirus (SGIV), can attenuate SGIV-induced cell death. Mechanistically, SGIV miR-homoHSV targets SGIV ORF136R, a viral gene that encodes the pro-apoptotic lipopolysaccharide-induced TNF-? (LITAF)-like factor. miR-homoHSV suppressed exogenous and endogenous SGIV LITAF expression, and thus inhibited SGIV LITAF-induced apoptosis. Meanwhile, miR-homoHSV expression was able to attenuate cell death induced by viral infection, presumably facilitating viral replication through the down-regulation of the pro-apoptotic gene SGIV LITAF. Together, our data suggest miR-homoHSV may serve as a feedback regulator of cell death during viral infection. The findings of this study provide a better understanding of SGIV replication and pathogenesis. PMID:24312676

  13. Hawaii energy strategy project 2: Fossil energy review. Task 2: Fossil energy in Hawaii

    SciTech Connect

    Breazeale, K. [ed.; Yamaguchi, N.D.; Keeville, H. [and others

    1993-12-01

    In Task 2, the authors establish a baseline for evaluating energy use in Hawaii, and examine key energy and economic indicators. They provide a detailed look at fossil energy imports by type, current and possible sources of oil, gas and coal, quality considerations, and processing/transformation. They present time series data on petroleum product consumption by end-use sector, though they caution the reader that the data is imperfect. They discuss fuel substitutability to identify those end-use categories that are most easily switched to other fuels. They then define and analyze sequential scenarios of fuel substitution in Hawaii and their impacts on patterns of demand. They also discuss energy security--what it means to Hawaii, what it means to neighboring economies, whether it is possible to achieve energy security. 95 figs., 48 tabs.

  14. Fossil Energy Program Annual Progress Report for April 1, 2002, Through March 31, 2003

    SciTech Connect

    Judkins, RR

    2003-06-19

    The mission of the Fossil Energy Program is to conduct research and development that contribute to the advancement of fossil energy technologies. The Oak Ridge National Laboratory Fossil Energy Program research and development activities, performed for the Department of Energy Assistant Secretary for Fossil Energy, cover the areas of coal, clean coal technology, gas, petroleum, and support to the Strategic Petroleum Reserve. Projects on the ORNL Fossil Energy Program are supported by the U.S. Department of Energy Office of Fossil Energy, the DOE National Energy Technology Laboratory, the DOE Fossil Energy Clean Coal Technology Program, the DOE National Petroleum Technology Office, and the DOE Fossil Energy Office of Strategic Petroleum Reserve. The ORNL Fossil Energy Program shares with DOE Oak Ridge Operations technical management responsibility for all activities on the DOE Fossil Energy Advanced Research Materials Program. The Advanced Research Materials Program includes research at other DOE and government laboratories, at universities, and at industrial organizations.

  15. Fossil AGN jets as ultra high energy particle accelerators

    E-print Network

    Gregory Benford; R. J. Protheroe

    2007-10-14

    Remnants of AGN jets and their surrounding cocoons leave colossal magnetohydrodynamic (MHD) fossil structures storing total energies ~10^{60} erg. The original active galacic nucleus (AGN) may be dead but the fossil will retain its stable configuration resembling the reversed-field pinch (RFP) encountered in laboratory MHD experiments. In an RFP the longitudinal magnetic field changes direction at a critical distance from the axis, leading to magnetic re-connection there, and to slow decay of the large-scale RFP field. We show that this field decay induces large-scale electric fields which can accelerate cosmic rays with an E^{-2} power-law up to ultra-high energies with a cut-off depending on the fossil parameters. The cut-off is expected to be rigidity dependent, implying the observed composition would change from light to heavy close to the cut-off if one or two nearby AGN fossils dominate. Given that several percent of the universe's volume may house such slowly decaying structures, these fossils may even re-energize ultra-high energy cosmic rays from distant/old sources, offsetting the ``GZK-losses'' due to interactions with photons of the cosmic microwave background radiation and giving evidence of otherwise undetectable fossils. In this case the composition would remain light to the highest energies if distant sources or fossils dominated, but otherwise would be mixed. It is hoped the new generation of cosmic ray experiments such as the Pierre Auger Observatory and ultra-high energy neutrino telescopes such as ANITA and lunar Cherenkov experiments will clarify this.

  16. The nature and space density of fossil groups of galaxies

    E-print Network

    L. R. Jones; T. J. Ponman; A. Horton; A. Babul; H. Ebeling; D. J. Burke

    2003-04-14

    We describe the properties of a sample of galaxy groups with very unusual distributions of galaxy luminosities. The most extreme example has an X-ray luminosity similar to that of the Virgo cluster but has a very low richness, with only one galaxy brighter than L*, compared with six in Virgo. That one galaxy, however, is optically more luminous than any galaxy in Virgo and has an optical luminosity as bright as many of the central cD galaxies in rich Abell clusters. The characteristic feature of the fossil groups we study is that most of the light arises from one dominant, central galaxy. We define a fossil system and, based on this definition, construct a small X-ray selected, flux-limited sample of fossil groups with well known selection criteria. We confirm that these systems are indeed groups of galaxies, but dominated by one central luminous giant elliptical galaxy and with few, or no, L* galaxies. We find that fossil systems represent 8%-20% of all systems of the same X-ray luminosity. Fossil groups are at least as numerous as all poor and rich clusters combined, and are thus a possible site for the formation of luminous central cluster galaxies before infall into clusters occurs. The fossil systems in our sample have significantly higher X-ray luminosities than normal groups of similar total optical luminosities (or similar X-ray temperature, where the latter can be measured). These enhanced X-ray luminosities may be due to relatively cool gas in the innermost regions or due to a low central gas entropy. We interpret fossil groups as old, undisturbed systems which have avoided infall into clusters, but where galaxy merging of most of the L* galaxies has occurred. An early formation epoch, before that of most groups, could explain low central gas entropies and high X-ray luminosities.

  17. PCI INSTRUMENT FOR HYDROGENATION STUDIES As we are aware, earth is fast running out of fossil fuels. Additionally, use of fossil fuels

    E-print Network

    Subramaniam, Anandh

    PCI INSTRUMENT FOR HYDROGENATION STUDIES As we are aware, earth is fast running out of fossil fuels. Additionally, use of fossil fuels contributes to pollution and global warming. Solar energy is envisaged

  18. Human CCT4 and CCT5 Chaperonin Subunits Expressed in Escherichia coli Form Biologically Active Homo-oligomers*

    PubMed Central

    Sergeeva, Oksana A.; Chen, Bo; Haase-Pettingell, Cameron; Ludtke, Steven J.; Chiu, Wah; King, Jonathan A.

    2013-01-01

    Chaperonins are a family of chaperones that encapsulate their substrates and assist their folding in an ATP-dependent manner. The ubiquitous eukaryotic chaperonin, TCP-1 ring complex (TRiC), is a hetero-oligomeric complex composed of two rings, each formed from eight different CCT (chaperonin containing TCP-1) subunits. Each CCT subunit may have distinct substrate recognition and ATP hydrolysis properties. We have expressed each human CCT subunit individually in Escherichia coli to investigate whether they form chaperonin-like double ring complexes. CCT4 and CCT5, but not the other six CCT subunits, formed high molecular weight complexes within the E. coli cells that sedimented about 20S in sucrose gradients. When CCT4 and CCT5 were purified, they were both organized as two back-to-back rings of eight subunits each, as seen by negative stain and cryo-electron microscopy. This morphology is consistent with that of the hetero-oligomeric double-ring TRiC purified from bovine testes and HeLa cells. Both CCT4 and CCT5 homo-oligomers hydrolyzed ATP at a rate similar to human TRiC and were active as assayed by luciferase refolding and human ?D-crystallin aggregation suppression and refolding. Thus, both CCT4 and CCT5 homo-oligomers have the property of forming 8-fold double rings absent the other subunits, and these complexes carry out chaperonin reactions without other partner subunits. PMID:23612981

  19. Enumeration of Oligomerization States of Membrane Proteins in Living Cells by Homo-FRET Spectroscopy and Microscopy: Theory and Application

    PubMed Central

    Yeow, Edwin K. L.; Clayton, Andrew H. A.

    2007-01-01

    Protein-protein interactions play a pivotal role in biological signaling networks. It is highly desirable to perform experiments that can directly assess the oligomerization state and degree of oligomerization of biological macromolecules in their native environment. Homo-FRET depends on the inverse sixth power of separation between interacting like fluorophores on the nanometer scale and is therefore sensitive to protein oligomerization. Homo-FRET is normally detected by steady-state or time-resolved fluorescence anisotropy measurements. Here we show by theory and simulation that an examination of the extent of homotransfer as measured by steady-state fluorescence anisotropy as a function of fluorophore labeling (or photodepletion) gives valuable information on the oligomerization state of self-associating proteins. We examine random distributions of monomers, dilute solutions of oligomers, and concentrated solutions of oligomers. The theory is applied to literature data on band 3 protein dimers in membranes, GPI-linked protein trimers in “rafts,” and clustered GFP-tagged epidermal growth factor receptors in cell membranes to illustrate the general utility and applicability of our analytical approach. PMID:17416632

  20. Crystal structure of homo-DNA and nature's choice of pentose over hexose in the genetic system

    SciTech Connect

    Egli, Martin; Pallan, Pradeep S.; Pattanayek, Rekha; Wilds, Christopher J.; Lubini, Paolo; Minasov, George; Dobler, Max; Leumann, Christian J.; Eschenmoser, Albert (Bern); (Vanderbilt); (Scripps); (NWU); (Biographics Laboratory 3R); (Alta)

    2010-03-05

    An experimental rationalization of the structure type encountered in DNA and RNA by systematically investigating the chemical and physical properties of alternative nucleic acids has identified systems with a variety of sugar-phosphate backbones that are capable of Watson-Crick base pairing and in some cases cross-pairing with the natural nucleic acids. The earliest among the model systems tested to date, (4{prime} {yields} 6{prime})-linked oligo(2{prime},3{prime}-dideoxy-{beta}-d-glucopyranosyl)nucleotides or homo-DNA, shows stable self-pairing, but the pairing rules for the four natural bases are not the same as those in DNA. However, a complete interpretation and understanding of the properties of the hexapyranosyl (4{prime} {yields} 6{prime}) family of nucleic acids has been impeded until now by the lack of detailed 3D-structural data. We have determined the crystal structure of a homo-DNA octamer. It reveals a weakly twisted right-handed duplex with a strong inclination between the hexose-phosphate backbones and base-pair axes, and highly irregular values for helical rise and twist at individual base steps. The structure allows a rationalization of the inability of allo-, altro-, and glucopyranosyl-based oligonucleotides to form stable pairing systems.

  1. HS3D, A Dataset of Homo Sapiens Splice Regions, and its Extraction Procedure from a Major Public Database

    NASA Astrophysics Data System (ADS)

    Pollastro, Pasquale; Rampone, Salvatore

    The aim of this work is to describe a cleaning procedure of GenBank data, producing material to train and to assess the prediction accuracy of computational approaches for gene characterization. A procedure (GenBank2HS3D) has been defined, producing a dataset (HS3D - Homo Sapiens Splice Sites Dataset) of Homo Sapiens Splice regions extracted from GenBank (Rel.123 at this time). It selects, from the complete GenBank Primate Division, entries of Human Nuclear DNA according with several assessed criteria; then it extracts exons and introns from these entries (actually 4523 + 3802). Donor and acceptor sites are then extracted as windows of 140 nucleotides around each splice site (3799 + 3799). After discarding windows not including canonical GT-AG junctions (65 + 74), including insufficient data (not enough material for a 140 nucleotide window) (686 + 589), including not AGCT bases (29 + 30), and redundant (218 + 226), the remaining windows (2796 + 2880) are reported in the dataset. Finally, windows of false splice sites are selected by searching canonical GT-AG pairs in not splicing positions (271 937 + 332 296). The false sites in a range +/- 60 from a true splice site are marked as proximal. HS3D, release 1.2 at this time, is available at the Web server of the University of Sannio: http://www.sci.unisannio.it/docenti/rampone/.

  2. Janus Model of The Na,K-ATPase ?-subunit Transmembrane Domain: Distinct Faces Mediate ? /? Assembly and ?-? Homo-Oligomerization

    PubMed Central

    Barwe, Sonali P.; Kim, Sanguk; Rajasekaran, Sigrid A.; Bowie, James U.; Rajasekaran, Ayyappan K.

    2007-01-01

    Summary Na,K-ATPase is a hetero-oligomer of ?- and ?-subunits. The Na,K-ATPase ?-subunit (Na,K-? ) is involved in both the regulation of ion transport activity, and in cell-cell adhesion. By structure prediction and evolutionary analysis, we identified two distinct faces on the Na,K-? transmembrane domain (TMD) that could mediate protein-protein interactions: a glycine zipper motif and a conserved heptad repeat. Here, we show that the heptad repeat face is involved in the hetero-oligomeric interaction of Na,K-? with Na,K-? , and the glycine zipper face is involved in the homo-oligomerization of Na,K-? . Point mutations in the heptad repeat motif reduced Na,K-? binding to Na,K-? , and Na,K-ATPase activity. Na,K-? TMD homo-oligomerized in biological membranes, and mutation of the glycine zipper motif affected oligomerization and cell-cell adhesion. These results provide a structural basis for understanding how Na,K-? links ion transport and cell-cell adhesion. PMID:17078968

  3. A novel actin cytoskeleton-dependent noncaveolar microdomain composed of homo-oligomeric caveolin-2 for activation of insulin signaling.

    PubMed

    Kwon, Hayeong; Lee, Jaewoong; Jeong, Kyuho; Jang, Donghwan; Pak, Yunbae

    2013-10-01

    The role of caveolin-2 (cav-2), independently of caveolin-1 (cav-1) and caveolae, has remained elusive. Our data show that cav-2 exists in the plasma membrane (PM) in cells lacking cav-1 and forms homo-oligomeric complexes. Cav-2 did not interact with cavin-1 and cavin-2 in the PM. Rab6-GTP was required for the microtubule-dependent exocytic transport of cav-2 from the Golgi to the PM independently of cav-1. The cav-2-oligomerized noncaveolar microdomain was unaffected by cholesterol depletion and protected from shearing of silica-coated PM. Activation of insulin receptor (IR) was processed in the microdomain. Actin depolymerization affected the formation and sustenance of cav-2-oligomerized noncaveolar microdomain and attenuated IR recruitment to the microdomain thereby inhibiting IR signaling activation. Cav-2 shRNA stable cells and the cells ectopically expressing an oligomerization domain truncation mutant, cav-2?47-86 exhibited retardation of IR signaling activation via the noncaveolar microdomain. Elevation in status of cav-2 expression rendered the noncaveolar activation of IR signaling in cav-1 down-regulated or/and cholesterol-depleted cells. Our findings reveal a novel homo-oligomeric cav-2 microdomain responsible for regulating activation of IR signaling in the PM. PMID:23665048

  4. Multifuel fossil fired Power Plant combined with off-shore wind

    E-print Network

    Multifuel fossil fired Power Plant combined with off-shore wind Henrik Noppenau ENERGI E2 Denmark Rolls-Royce Trent turbiner Fossile fired boiler 390 0.483 0.499 Gasturbineunit 150 0.575 0.575 Fossile Fossile fired boiler 390 0.483 0.499 Gasturbineunit 225 0.575 0.575 Fossile fired total 615 0.513 0

  5. Can Geothermal Power Replace Fossil Fuels?

    NASA Astrophysics Data System (ADS)

    Klenner, R.; Gosnold, W. D.

    2009-12-01

    Development of geothermal energy in any capacity is a positive step toward a sustainable energy future. The resource is enormous and has the capacity to supply most future demand for electrical power if technology can meet some substantial challenges. Electrical power from geothermal energy has several compelling characteristics: a small footprint, low emissions, continuous availability, and sustainability. However, a common perception of geothermal energy is that it is available only in a few isolated localities and thus cannot contribute significantly to future electrical power needs. This perception neglects the stored thermal energy available everywhere in the upper 10 km of Earth’s crust. We are investigating the potential for power production in oil-producing sedimentary basins where subsurface temperatures are sufficient for intermediate geothermal resources (90 °C -150 °C) at depths greater than 3 km. Existing estimates of geothermal energy stored at depth in sedimentary formations in the U.S. have been based only on a few aquifers and have not included the greater volume of fluids in oil-bearing formations. We reevaluated the accessible geothermal resource base for the north central US and found that including geothermal fluids in oil-producing formations increased the resource estimate by a factor of eight. Preliminary analysis of other basins indicates that the current estimate of thermal energy in the U.S. (100,000 EJ) may be of the order of 400,000 EJ. This is particularly significant due to recent technological advances leading to commercialization of scalable organic Rankine cycle (ORC) engines. Until recently, ORC systems were available only on an at large scale, i.e., 10s of MW, and had efficiencies of about 10 percent. Currently there are at least five manufacturers making scalable ORC systems in the 50 kW to 1 MW range, and at least one system has an efficiency of about 17 percent and is expected to attain an efficiency in the low 20s as it is scaled up to produce power in the MW range. Values needed for these systems are temperatures of 92+ °C and flow rates of 140-1000 gpm. In a detailed analysis of the North Dakota part of the Williston Basin, we used heat flow, bottom-hole temperatures, and measured temperature gradients to calculate the energy contained within specific formations having temperatures in the range of 100 °C to 150 °C. We find that at a 2% recovery factor, approximately 4500 MW/hr can be recovered at depths of 3-4 km. North Dakota currently produces approximately 3100 MW/hr from non-renewable sources such as coal and petroleum. We conclude that the geothermal resource in the Williston Basin could completely replace fossil fuels as an electrical power supply for North Dakota.

  6. FOSSIL SYSTEMS IN THE 400d CLUSTER CATALOG

    SciTech Connect

    Voevodkin, Alexey; Borozdin, Konstantin; Heitmann, Katrin; Habib, Salman [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Vikhlinin, Alexey; Mescheryakov, Alexander; Burenin, Rodion [Space Research Institute (IKI), Profsoyuznaya 84/32, Moscow (Russian Federation); Hornstrup, Allan [National Space Institute, Technical University of Denmark, Juliane Maries Vej 30, 2100 Copenhagen 0 (Denmark)

    2010-01-10

    We report the discovery of seven new fossil systems in the 400d cluster survey. Our search targets nearby, z <= 0.2, and X-ray bright, L{sub X} >= 10{sup 43} erg s{sup -1}, clusters of galaxies. Where available, we measure the optical luminosities from Sloan Digital Sky Survey images, thereby obtaining uniform sets of both X-ray and optical data. Our selection criteria identify 12 fossil systems, out of which five are known from previous studies. While in general agreement with earlier results, our larger sample size allows us to put tighter constraints on the number density of fossil clusters. It has been previously reported that fossil groups are more X-ray bright than other X-ray groups of galaxies for the same optical luminosity. We find, however, that the X-ray brightness of massive fossil systems is consistent with that of the general population of galaxy clusters and follows the same L{sub X} -L{sub opt} scaling relation.

  7. The isolated fossil group RXJ1119.7+2126

    E-print Network

    C. Adami; D. Russeil; F. Durret

    2007-03-13

    Fossil groups are galaxy structures that probably underwent a nearly complete fusion of all intermediate magnitude galaxies into a single large central dominant galaxy. However, the formation and evolution processes of these structures are still not well understood. In order to test this scenario and its implications we studied the fossil group RXJ1119.7+2126, based on available spectroscopy of the galaxies in the low density large scale region around the fossil group and deep B and R band imaging of its close vicinity and three comparison fields. We used spectroscopic data to investigate the degree of isolation of RXJ1119.7+2126 in terms of bright neighbour galaxies. The imaging data were used to derive the color magnitude relation and select faint galaxies statistically belonging to this structure. The structure appears as a very isolated group exhibiting a red sequence in the color magnitude relation with characteristics close to the red sequences already observed for other fossil groups. All these results can be interpreted consistently in the framework of the building up process generally proposed for fossil groups.

  8. Mandibular fossa morphology in the Ngandong and Sambungmacan fossil hominids.

    PubMed

    Durband, Arthur C

    2008-10-01

    There has been debate in recent years concerning the significance of the mandibular fossa morphology in the Ngandong and Sambungmacan hominids. These fossils lack a postglenoid process and their squamotympanic fissure runs along the apex of the fossa for its entire length. This configuration differs from that seen in other fossil and modern humans, which have a prominent postglenoid process and a squamotympanic fissure that takes a more posterior course that does not lie in the apex of the fossa. Some recent studies have suggested that the Ngandong and Sambungmacan hominids are not unique in their expression of these characteristics, and that they can also be found in other fossil crania from Africa and Indonesia. The present study reexamines these morphologies in an effort to better understand their distribution in the hominid fossil record. The results confirm that the lack of a prominent postglenoid process in combination with a squamotympanic fissure that lies wholly in the apex of the mandibular fossa along its entire length is indeed autapomorphic for the Ngandong and Sambungmacan fossils. This finding, in conjunction with work on other nonmetric features in these hominids, suggests that at least two hominid morphs, possibly representing separate species, were present on Java during the Pleistocene. In addition, if this apparent autapomorphy is confirmed, then it is also unlikely that the Ngandong hominids contributed to the gene pool of modern humans. PMID:18521904

  9. Triassic leech cocoon from Antarctica contains fossil bell animal

    PubMed Central

    Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.; Moestrup, Øjvind; Taylor, Edith L.

    2012-01-01

    Our understanding of the evolution of life on Earth is limited by the imperfection of the fossil record. One reason for this imperfect record is that organisms without hard parts, such as bones, shells, and wood, have a very low potential to enter the fossil record. Occasionally, however, exceptional fossil deposits that preserve soft-bodied organisms provide a rare glimpse of the true biodiversity during past periods of Earth history. We here present an extraordinary find of a fossil ciliate that is encased inside the wall layer of a more than 200 Ma leech cocoon from Antarctica. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic “conservation traps” comparable to amber. PMID:23213234

  10. Selective flotation of fossil resin from western coal

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-03-20

    The test program has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.

  11. Synthesis of novel 1,2,3-triazolyl derivatives of pregnane, androstane and D-homoandrostane. Tandem "click" reaction/Cu-catalyzed D-homo rearrangement.

    PubMed

    Kotovshchikov, Yury N; Latyshev, Gennadij V; Lukashev, Nikolay V; Beletskaya, Irina P

    2014-06-14

    Copper-catalyzed 1,3-dipolar cycloaddition has been employed in the reaction of steroidal azides with various terminal alkynes. A number of novel 1,2,3-triazolyl derivatives of pregnane, androstane and D-homoandrostane were obtained in high yield (70-98%). The developed synthetic protocols allowed us to attach the triazolyl moiety to both the side chain and the steroidal backbone directly, despite the steric hindrance exerted by the polycyclic system. The presence of Cu(II) was shown to evoke d-homo rearrangement under mild conditions. A rational choice of the copper precatalyst permitted us to carry out the "click" reaction either along with tandem d-homo rearrangement or in the absence of this process. The tendency of 16-heterosubstituted steroids to undergo D-homo rearrangement under Cu(II) catalysis was studied. PMID:24781658

  12. Synthesis of 2'-deoxy-1'-homo-N-nucleosides with anti-influenza activity by catalytic methyltrioxorhenium (MTO)/H2O2 oxyfunctionalization.

    PubMed

    Saladino, Raffaele; Neri, Veronica; Checconi, Paola; Celestino, Ignacio; Nencioni, Lucia; Palamara, Anna Teresa; Crucianelli, Marcello

    2013-02-11

    This paper describes a new route for the synthesis of 1'-homo-N-nucleoside derivatives by means of either methyltrioxorhenium (MTO) or supported MTO catalysts, with H(2)O(2) as the primary oxidant. Under these selective conditions, the oxyfunctionalization of the heterocyclic ring and the N heteroatom oxidation were operative processes, regardless of the type of substrate used, that is, purine or pyrimidine derivatives. In addition, the oxidation of 1'-homo-N-thionucleosides, showed the occurrence of site-specific oxidative nucleophilic substitutions of the heterocyclic ring. The MTO/H(2)O(2) system showed, in general, high reactivity under both homogeneous and heterogeneous conditions, affording the final products with high conversion values of substrates and from medium to high yields. Many of the novel 1'-homo-N-nucleoside analogues were active against the influenza A virus, without any cytotoxic effects, retaining their activity in both protected and unprotected forms. PMID:23225323

  13. "...I've worked on fossils from Driftwood Canyon for over a decade now, publishing a number of works, based on the fossils, in scientific

    E-print Network

    Archibald, S. Bruce

    "...I've worked on fossils from Driftwood Canyon for over a decade now, publishing a number of works, based on the fossils, in scientific journals. My major interest is in the relationship between disciplines such as paleobotany. Much progress has been made in the last few years, and the fossils

  14. Methodology for assessing the benefits of fossil energy RD and D. Volume II. Advanced fossil energy technology outcome data and technology groups

    Microsoft Academic Search

    S. M. Kohan; B. M. Louks

    1976-01-01

    The information in this two-volume report is organized as follows: in Volume I, entitled Energy Network Charts for Advanced Fossil Energy Technologies, a series of charts is presented showing the applications of advanced fossil energy technologies to the recovery, conversion, or utilization of fossil energy (coal, oil shale, crude oil, and natural gas). In this Volume II, outcome tables are

  15. Functional Diversity of Isoamylase Oligomers: The ISA1 Homo-Oligomer Is Essential for Amylopectin Biosynthesis in Rice Endosperm1[W][OA

    PubMed Central

    Utsumi, Yoshinori; Utsumi, Chikako; Sawada, Takayuki; Fujita, Naoko; Nakamura, Yasunori

    2011-01-01

    Rice (Oryza sativa) endosperm has two isoamylase (ISA) oligomers, ISA1 homo-oligomer and ISA1-ISA2 hetero-oligomer. To examine their contribution to starch synthesis, expression of the ISA1 or ISA2 gene was differently regulated in various transgenic plants. Although suppression of ISA2 gene expression caused the endosperm to have only the homo-oligomer, no significant effects were detected on the starch phenotypes. In contrast, ISA2 overexpression led to endosperm having only the hetero-oligomer, and starch synthesis in the endosperm was drastically impaired, both quantitatively and qualitatively, because the starch was devoid of typical starch features, such as thermal and x-ray diffraction properties, and water-soluble highly branched maltodextrins were accumulated. In the ISA2 overexpressed line, about 60% to 70% of the ISA1-ISA2 hetero-oligomer was bound to starch, while the ISA homo- and hetero-oligomers from the wild type were mostly present in the soluble form at the early milking stage of the endosperm. Detailed analysis of the relative amounts of homo- and hetero-oligomers in various lines also led us to the conclusion that the ISA1 homo-oligomer is essential, but not the ISA1-ISA2 oligomer, for starch production in rice endosperm. The relative amounts of ISA1 and ISA2 proteins were shown to determine the ratio of both oligomers and the stoichiometry of both ISAs in the hetero-oligomer. It was noted when compared with the homo-oligomer that all the hetero-oligomers from rice endosperm and leaf and potato (Solanum tuberosum) tuber were much more stable at 40°C. This study provides substantial data on the structural and functional diversity of ISA oligomers between plant tissues and species. PMID:21436381

  16. Fossil Groups in the Sloan Digital Sky Survey

    NASA Astrophysics Data System (ADS)

    Santos, Walter A.; Mendes de Oliveira, Claudia; Sodré, Laerte, Jr.

    2007-10-01

    A search for fossil groups in the Sloan Digital Sky Survey was performed using virtual observatory tools. A cross-match of the positions of all SDSS luminous red galaxies (with r < 19 and measured spectroscopic redshifts) with sources in the ROSAT All-Sky Survey catalog resulted in a list of elliptical galaxies with extended X-ray emission (with a galaxy/ROSAT-source distance of less than 0.5? in all cases). A search for neighbors of the selected elliptical galaxies within a radius of 0.5 h Mpc was conducted, taking into account the r-band magnitudes and spectroscopic or photometric redshifts of all objects within this area, leading to a sample of 34 candidate fossil groups. Considering this sample, the estimated space density of fossil systems is n = (1.0 ± 0.6) × 10-6 h Mpc-3.

  17. Molecular characterization of some enigmatic Lower Devonian fossils

    NASA Astrophysics Data System (ADS)

    Abbott, Geoffrey D.; Ewbank, Greg; Edwards, Dianne; Wang, Guang-Yu

    1998-04-01

    The coalified remains of three extinct nonvascular Lower Devonian plants ( Prototaxites Dawson, Pachytheca Hooker, and Parka Fleming) have been analysed using flash pyrolysis-gas chromatography-mass spectrometry, FTIR, and 13C solid-state NMR. The affinities of these fossils are unknown and their habitats remain conjectural. Host rock lithology and grain size correlate with the state of morphological and chemical preservation of Prototaxites. The flash pyrolysates of well-preserved Prototaxites and Pachytheca were dominated by aromatic hydrocarbons and alkylphenols. Given their resistance to compression when compared with associated lignified vascular plant fossils, it is possible that Prototaxites and Pachytheca contained an extinct polyphenolic structural biomacromolecule that was a failed experiment during terrestrialization. Precise affinities for the enigmatic fossils Prototaxites, Pachytheca, and Parka are still to be confirmed, although Prototaxites and Pachytheca are chemically distinct from Parka.

  18. Most probable distance between the nucleus and HOMO electron: the latent meaning of atomic radius from the product of chemical hardness and polarizability.

    PubMed

    Szarek, Pawe?; Grochala, Wojciech

    2014-11-01

    The simple relationship between size of an atom, the Pearson hardness, and electronic polarizability is described. The estimated atomic radius correlates well with experimental as well as theoretical covalent radii reported in the literature. Furthermore, the direct connection of atomic radius to HOMO electron density and important notions of conceptual DFT (such as frontier molecular orbitals and Fukui function) has been shown and interpreted. The radial maximum of HOMO density distribution at (??)(1/2) minimizes the system energy. Eventually, the knowledge of the Fukui function of an atom is sufficient to estimate its electronic polarizability, chemical potential, and hardness. PMID:25286065

  19. A new reaction motif: "homo-S(N)2'-like" direct nucleophilic addition to neutral eta(3)-allylmolybdenum complexes. total synthesis of the antimalarial (+)-isofebrifugine.

    PubMed

    Chen, Wenyong; Liebeskind, Lanny S

    2009-09-01

    Charge neutral TpMo(CO)(2)(5-acyloxy-eta(3)-pyranyl) and TpMo(CO)(2)(5-acyloxy-eta(3)-pyridinyl) scaffolds undergo a novel intermolecular "homo-S(N)2'-like" reaction with a variety of carbon nucleophiles. Combined with an annulative demetalation, the homo-S(N)2'-like substitution/annulative demetalation sequence rapidly generates 2,7-dioxabicyclo[4.3.0]nonane and 2-aza-7-oxabicyclo[4.3.0]nonane frameworks in good to excellent yields with high enantiopurity. An enantiocontrolled total synthesis of the antimalarial alkaloid (+)-isofebrifugine was achieved utilizing this reaction cascade. PMID:19678704

  20. A New Reaction Motif: “Homo-SN2?-Like” Direct Nucleophilic Addition to Neutral ?3-Allylmolybdenum Complexes. Total Synthesis of the Antimalarial (+)–Isofebrifugine

    PubMed Central

    Chen, Wenyong; Liebeskind, Lanny S.

    2010-01-01

    Charge neutral TpMo(CO)2(5-acyloxy-?3-pyranyl) and TpMo(CO)2(5-acyloxy-?3-pyridinyl) scaffolds undergo a novel intermolecular “homo-SN2?-like” reaction with a variety of carbon nucleophiles. Combined with an annulative demetalation, the homo-SN2?-like substitution/annulative demetalation sequence rapidly generates 2,7-dioxabicyclo[4.3.0]nonane and 2-aza-7-oxabicyclo[4.3.0]nonane frameworks in good to excellent yields with high enantiopurity. An enantiocontrolled total synthesis of the antimalarial alkaloid (+)-isofebrifugine was achieved utilizing this reaction cascade. PMID:19678704

  1. Phylogeny of the Infraorder Pentatomomorpha Based on Fossil and Extant Morphology, with Description of a New Fossil Family from China

    PubMed Central

    Yao, Yunzhi; Ren, Dong; Rider, David A.; Cai, Wanzhi

    2012-01-01

    Background An extinct new family of Pentatomomorpha, Venicoridae Yao, Ren & Cai fam. nov., with 2 new genera and 2 new species (Venicoris solaris Yao, Ren & Rider gen. & sp. nov. and Clavaticoris zhengi Yao, Ren & Cai gen. & sp. nov.) are described from the Early Cretaceous Yixian Formation in Northeast China. Methodology/Principal Findings A cladistic analysis based on a combination of fossil and extant morphological characters clarified the phylogenetic status of the new family and has allowed the reconstruction of intersuperfamily and interfamily relationships within the Infraorder Pentatomomorpha. The fossil record and diversity of Pentatomomorpha during the Mesozoic is discussed. Conclusions/Significance Pentatomomorpha is a monophyletic group; Aradoidea and the Trichophora are sister groups; these fossils belong to new family, treated as the sister group of remainder of Trichophora; Pentatomoidea is a monophyletic group; Piesmatidae should be separated as a superfamily, Piesmatoidea. Origin time of Pentatomomorpha should be tracked back to the Middle or Early Triassic. PMID:22655038

  2. Ab initio, DFT, HOMO-LUMO and Natural Bond Orbital analyses of the electronic structure of 2-mercapto-1-methylimidazole

    NASA Astrophysics Data System (ADS)

    Balachandran, V.; Lakshmi, A.; Janaki, A.

    2011-12-01

    The Fourier transform Raman and Fourier transform infrared spectra of 2-mercapto-1-methylimidazole have been recorded. Ab initio and density functional computations of the vibrational spectrum, the molecular geometry, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gaps were studied. On the basis of the comparison between calculated and experimental results and the comparison with related molecules, assignments of the fundamental vibrational modes are examined. The observed and simulated spectra were found to be well comparable. The molecular stability and bond strength were investigated by applying the Natural Bond Orbital analysis (NBO). The other molecular properties like Mulliken population analysis, thermodynamic functions and polarizabilities of the title compound have been reported. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecule has been obtained by mapping electron density isosurface with electrostatic potential (ESP).

  3. Exploring homo-FRET to quantify the oligomer stoichiometry of membrane-bound proteins involved in a cooperative partition equilibrium.

    PubMed

    Melo, Ana M; Fedorov, Aleksander; Prieto, Manuel; Coutinho, Ana

    2014-09-14

    The establishment of protein-protein interactions between membrane-bound proteins is associated with several biological functions and dysfunctions. Here, an analytical framework that uses energy homo transfer to directly probe quantitatively the oligomerization state of membrane-bound proteins engaged in a three-state cooperative partition is presented. Briefly, this model assumes that monomeric protein molecules partition into the bilayer surface and reversibly assemble into oligomers with k subunits. A general equation relating the overall steady-state fluorescence anisotropy of the sample to its fractional labeling was derived by considering explicitly that the anisotropy of mixed oligomers containing i-labeled monomers is inversely proportional to the number of labeled subunits per oligomer (Runnels and Scarlata limit). This method was very robust in describing the electrostatic interaction of Alexa Fluor 488 fluorescently labeled lysozyme (Lz-A488) with phosphatidylserine-containing membranes. The pronounced decrease detected in the fluorescence anisotropy of Lz-A488 always correlated with the system reaching a high membrane surface density of the protein (at a low lipid-to-protein (L/P) molar ratio). The occurrence of energy homo transfer-induced fluorescence depolarization was further confirmed by measuring the anisotropy decays of Lz-A488 under these conditions. A global analysis of the steady-state anisotropy data obtained under a wide range of experimental conditions (variable anionic lipid content of the liposomes, L/P molar ratios and protein fractional labeling) confirmed that membrane-bound Lz-A488 assembled into oligomeric complexes, possibly with a stoichiometry of k = 6 ± 1. This study illustrates that even in the presence of a coupled partition-oligomerization equilibrium, steady-state anisotropy measurements provide a simple and reliable tool to monitor the self-assembly of membrane-bound proteins. PMID:24722583

  4. A Geometric Arrangement Algorithm for Structure Determination of Symmetric Protein Homo-oligomers from NOEs and RDCs

    NASA Astrophysics Data System (ADS)

    Martin, Jeffrey W.; Yan, Anthony K.; Bailey-Kellogg, Chris; Zhou, Pei; Donald, Bruce R.

    Nuclear magnetic resonance (NMR) spectroscopy is a primary tool to perform structural studies of proteins in the physiologically-relevant solution-state. Restraints on distances between pairs of nuclei in the protein, derived from the nuclear Overhauser effect (NOE) for example, provide information about the structure of the protein in its folded state. NMR studies of symmetric protein homo-oligomers present a unique challenge. Current techniques can determine whether an NOE restrains a pair of protons across different subunits or within a single subunit, but are unable to determine in which subunits the restrained protons lie. Consequently, it is difficult to assign NOEs to particular pairs of subunits with certainty, thus hindering the structural analysis of the oligomeric state. Hence, computational approaches are needed to address this subunit ambiguity. We reduce the structure determination of protein homo-oligomers with cyclic symmetry to computing geometric arrangements of unions of annuli in a plane. Our algorithm, disco, runs in expected O(n 2) time, where n is the number of distance restraints, and is guaranteed to report the exact set of oligomer structures consistent with ambiguously-assigned inter-subunit distance restraints and orientational restraints from residual dipolar couplings (RDCs). Since the symmetry axis of an oligomeric complex must be parallel to an eigenvector of the alignment tensor of RDCs, we can represent each distance restraint as a union of annuli in a plane encoding the configuration space of the symmetry axis. Oligomeric protein structures with the best restraint satisfaction correspond to faces of the arrangement contained in the greatest number of unions of annuli. We demonstrate our method using two symmetric protein complexes: the trimeric E. coli Diacylglycerol Kinase (DAGK), whose distance restraints possess at least two possible subunit assignments each; and a dimeric mutant of the immunoglobulin-binding domain B1 of streptococcal protein G (GB1) using ambiguous NOEs. In both cases, disco computes oligomer structures with high accuracy.

  5. Molecular structure, vibrational, UV, NMR, hyperpolarizability, NBO and HOMO-LUMO analysis of Pteridine2,4-dione.

    PubMed

    Prabavathi, N; Nilufer, A; Krishnakumar, V

    2012-12-01

    The FTIR and FT-Raman spectra of Pteridine2,4-dione has been recorded in the region 4000-450 and 4000-100 cm(-1), respectively. The tautomeric stability, optimized geometry, frequency and intensity of the vibrational bands of Pteridine2,4-dione were obtained by the density functional theory (DFT) using 6-311++G(d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The (1)H and(13)C NMR spectra chemical shifts of the molecule were also calculated using the gauge independent atomic orbital (GIAO) method. The theoretical UV-Vis spectrum of the compound using CIS method and the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The calculated HOMO and LUMO energies show that charge transfer occurs within molecule. The first order hyperpolarizability (?(0)) of these novel molecular system and related properties (?, ?(0) and ??) of Pteridine2,4-dione are calculated using DFT/6-311++G (d,p) method on the finite-field approach. The Mulliken charges, the values of electric dipole moment (?) of the molecule were computed using DFT calculations. The change in electron density (ED) in the ?(*) antibonding orbitals and stabilization energies E(2) have been calculated by natural bond (NBO) analysis to give clear evidence of stabilization originating in the hyper conjugation of hydrogen-bonded interactions. PMID:23085999

  6. Molecular structure, vibrational, UV, NMR, hyperpolarizability, NBO and HOMO-LUMO analysis of Pteridine2,4-dione

    NASA Astrophysics Data System (ADS)

    Prabavathi, N.; Nilufer, A.; Krishnakumar, V.

    2012-12-01

    The FTIR and FT-Raman spectra of Pteridine2,4-dione has been recorded in the region 4000-450 and 4000-100 cm-1, respectively. The tautomeric stability, optimized geometry, frequency and intensity of the vibrational bands of Pteridine2,4-dione were obtained by the density functional theory (DFT) using 6-311++G(d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The 1H and13C NMR spectra chemical shifts of the molecule were also calculated using the gauge independent atomic orbital (GIAO) method. The theoretical UV-Vis spectrum of the compound using CIS method and the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The calculated HOMO and LUMO energies show that charge transfer occurs within molecule. The first order hyperpolarizability (?0) of these novel molecular system and related properties (?, ?0 and ??) of Pteridine2,4-dione are calculated using DFT/6-311++G (d,p) method on the finite-field approach. The Mulliken charges, the values of electric dipole moment (?) of the molecule were computed using DFT calculations. The change in electron density (ED) in the ?* antibonding orbitals and stabilization energies E(2) have been calculated by natural bond (NBO) analysis to give clear evidence of stabilization originating in the hyper conjugation of hydrogen-bonded interactions.

  7. Zooplankton fecal pellets link fossil fuel and phosphate deposits

    SciTech Connect

    Porter, K.G. (Univ. of Georgia, Athens); Robbins, E.I.

    1981-05-22

    Fossil zooplankton fecal pellets found in thinly bedded marine and lacustrine black shales associated with phosphate, oil, and coal deposits, link the deposition of organic matter and biologically associated minerals with planktonic ecosystems. The black shales were probably formed in the anoxic basins of coastal marine waters, inland seas, and rift valley lakes where high productivity was supported by runoff, upwelling, and outwelling.

  8. Evidence for Evolution from the Vertebrate Fossil Record.

    ERIC Educational Resources Information Center

    Gingerich, Philip D.

    1983-01-01

    Discusses three examples of evolutionary transition in the vertebrate fossil record, considering evolutionary transitions at the species level. Uses archaic squirrel-like Paleocine primates, the earliest primates of modern aspect, as examples. Also reviews new evidence on the origin of whales and their transition from land to sea. (JN)

  9. FOSSIL ROVE BEETLES FROM PLEISTOCENE CALIFORNIA ASPHALT DEPOSITS (COLEÓPTERA: STAPHYLINIDAE)

    Microsoft Academic Search

    IAN MOORE; SCOTT E. MILLER

    Three species of Staphylinidae are known as fossils from Late Pleisto- cene asphalt deposits in California: 1 species oí Aleochara from the Carpin- tería asphalt deposit in Santa Barbara County and 2 species of Philonthus from the McKittrick asphalt deposit in Kern County. No Staphylinid frag- ments identifiable to genus have yet been recovered from the Rancho La Brea asphalt

  10. Changing Biomass, Fossil, and Nuclear Fuel Cycles for Sustainability

    Microsoft Academic Search

    Charles W. Forsberg; Charles W

    2007-01-01

    The energy and chemical industries face two great sustainability challenges: the need to avoid climate change and the need to replace crude oil as the basis of our transport and chemical industries. These challenges can be met by changing and synergistically combining the fossil, biomass, and nuclear fuel cycles.

  11. Biomacromolecules of algae and plants and their fossil analogues

    Microsoft Academic Search

    Jan W. de Leeuw; Gerard J. M. Versteegh; Pim F. van Bergen

    A review of our current understanding of resistant biomacromolecules derived from present and past algae and higher plants is presented. Insight in the nature of recent and fossil macromolecules is strongly hampered by the difficulties in obtaining the material in pure and unaltered form. For the extant material, avoiding artificial condensation and structural alteration as a result of chemical isolation

  12. The State of Play and Future of Fossil Fuels

    Microsoft Academic Search

    Patricia Fry Godley

    1997-01-01

    The economic strength of the United States depends on its use of fossil fuels-coal, oil, and natural gas. Today, more than 85 percent of the nation`s energy comes from boilers, furnaces, and internal combustion engines that rely on these fuels. Coal supplies more than 55 percent of our electricity, oil accounts for more than 99 percent of the fuel used

  13. The Formation of Fossil Fuels - Earth: The Operators' Manual

    NSDL National Science Digital Library

    Geoff Haines-Stiles Productions

    This video from Earth: The Operators' Manual describes how fossil fuels are made, and it compares how long it takes to create coal, oil and natural gas (millions of years), with how fast we're using them (hundreds of years). Narrated by Dr. Richard Alley.

  14. Hydrogen quality from decarbonized fossil fuels to fuel cells

    Microsoft Academic Search

    Brian M. Besancon; Vladimir Hasanov; Raphaëlle Imbault-Lastapis; Robert Benesch; Maria Barrio; Mona J. Mølnvik

    2009-01-01

    Increased focus on curbing carbon dioxide (CO2) emissions and a limited and unstable supply of fossil fuel resources make diversification of energy resources a priority. Hydrogen has emerged as a promising energy vector for solving these issues. However, there are numerous challenges related to production, distribution and end use of hydrogen. Of particular importance is the link between hydrogen purity

  15. Persian EFL Students' Developmental versus Fossilized Prepositional Errors

    ERIC Educational Resources Information Center

    Jalali, Hassan; Shojaei, Mahdiyeh

    2012-01-01

    This study investigated the developmental and fossilized prepositional errors in Persian EFL learners' compositions at three levels of proficiency; participants were divided into lower-intermediate, upper-intermediate, and advanced levels. For each participant, four compositions were collected, and after identifying the prepositional errors for…

  16. Fossil-energy program. Progress report for July 1981

    Microsoft Academic Search

    McNeese

    1981-01-01

    This report - the eighty-fourth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology,

  17. Fossil energy program. Progress report for May 1980

    Microsoft Academic Search

    McNeese

    1980-01-01

    This report - the seventieth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research

  18. Fossil-energy program progress report for September 1981

    Microsoft Academic Search

    McNeese

    1981-01-01

    This report - the eighty-sixth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology,

  19. Fossil energy program. Progress report for June 1980

    Microsoft Academic Search

    McNeese

    1980-01-01

    This report - the seventy-first of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research

  20. Fossil-energy program. Progress report for November 1981

    Microsoft Academic Search

    McNeese

    1982-01-01

    This report - the eighty-seventh of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology,

  1. Fossil energy program progress report for August 1980

    Microsoft Academic Search

    McNeese

    1980-01-01

    This report - the seventy-third of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology,

  2. Fossil-energy program. Progress report for October 1981

    Microsoft Academic Search

    McNeese

    1981-01-01

    This report - the eighty-seventh of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology,

  3. Fossil Energy Program. Progress report for April 1980

    Microsoft Academic Search

    McNeese

    1980-01-01

    This report - the sixty-ninth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research

  4. Fossil energy program progress report for September 1980

    Microsoft Academic Search

    McNeese

    1980-01-01

    This report - the seventy-fourth of a series - is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy. The projects reported this month include those for coal conversion development, chemical research and development, materials technology,

  5. Integrated fossil and molecular data reconstruct bat echolocation

    E-print Network

    Wilkinson, Gerald S.

    Integrated fossil and molecular data reconstruct bat echolocation Mark S. Springer , Emma C innovative features in the evolutionary history of mammals--laryngeal echolocation in bats. Molecular data that microbats are paraphyletic but do not resolve whether laryngeal echolocation evolved indepen- dently

  6. Fossil and Recent Cheilostomata (Bryozoa) from the Ross Sea, Antarctica

    Microsoft Academic Search

    P. J. Hayward; P. D. Taylor

    1984-01-01

    Fifty-six species of cheilostome Bryozoa have been identified in samples from the McMurdo Sound area of the Ross Sea, Antarctica. Material collected alive from beneath the permanent ice sheet, at White Island and Cape Bird, is supplemented by fossil material collected from a coastal moraine deposit at Black Island. The moraine is thought to have formed through the ablation of

  7. Missing fossils, molecular clocks, and the origin of the Melastomataceae.

    PubMed

    Morley, Robert J; Dick, Christopher W

    2003-11-01

    In a recent analysis of the historical biogeography of Melastomataceae, Renner, Clausing, and Meyer (2001; American Journal of Botany 88(7): 1290-1300) rejected the hypothesis of a Gondwana origin. Using a fossil-calibrated chloroplast DNA (ndhF) phylogeny, they placed the early diversification of Melastomataceae in Laurasia at the Paleocene/Eocene boundary (ca. 55 Ma) and suggested that long-distance oceanic dispersals in the Oligocene and Miocene (34 to 5 Ma) account for its range expansion into South America, Africa, and Madagascar. Their critical assumption-that oldest northern mid-latitude melastome fossils reflect tribal ages and their geographic origins-may be erroneous, however, because of the sparse fossil record in the tropics. We show that rates of synonymous nucleotide substitutions derived by the Renner et al. (2001) model are up to three times faster than most published rates. Under a Gondwana-origin model advocated here, which includes dispersals from Africa to Southeast Asia via the "Indian ark" and emphasizes filter rather than either sweepstakes dispersal or strict vicariance, rates of nucleotide substitution fall within the range of published rates. We suggest that biogeographic reconstructions need to consider the paucity of Gondwanan fossils and that frequently overlooked interplate dispersal routes provide alternatives to vicariance, boreotropical dispersal, and long-distance oceanic dispersal as explanations for the amphi-oceanic disjunctions of many tropical rain forest plants. PMID:21653339

  8. Current waterside corrosion concerns in fossil utility steam generators

    Microsoft Academic Search

    F. J. Pocock; A. Banweg

    1983-01-01

    Waterside corrosion of tubing in fossil steam generators is an important consideration to the economical production of steam power. These steam generators are part of a system. The accumulation of preboiler system corrosion product deposits within the boiler along with concentration of chemicals beneath these deposits is the principal mode of waterside tube damage. The deposits are usually very porous

  9. The identification and biogeochemical interpretation of fossil magnetotactic bacteria

    E-print Network

    The identification and biogeochemical interpretation of fossil magnetotactic bacteria Robert E. Available online 14 August 2007. Abstract Magnetotactic bacteria, which most commonly live within the oxic, specifically magnetite or greigite. The crystals cause the bacteria to orient themselves passively with respect

  10. Proceedings of the sixth annual conference on fossil energy materials

    SciTech Connect

    Cole, N.C.; Judkins, R.R. (comps.)

    1992-07-01

    The Sixth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on May 12--14, 1992. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The management of the Program has been decentralized to the DOE Field Office, Oak Ridge with Oak Ridge National Laboratory (ORNL) as the technical support contractor. The research is performed by staff members at ORNL and by a substantial number of researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) ceramics, (2) development and corrosion resistance of iron aluminide, advanced austenitic and chromium-niobium alloys, and (3) technology assessment and technology transfer. This conference is held each year to review the work on all of the projects of the Program. The agenda for the meeting is given in Appendix A, and a list of attendees is presented in Appendix B. ASM International cosponsored the conference, for which we are especially grateful.

  11. Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds

    Microsoft Academic Search

    Fucheng Zhang; Stuart L. Kearns; Patrick J. Orr; Michael J. Benton; Zhonghe Zhou; Diane Johnson; Xing Xu; Xiaolin Wang

    2010-01-01

    Spectacular fossils from the Early Cretaceous Jehol Group of northeastern China have greatly expanded our knowledge of the diversity and palaeobiology of dinosaurs and early birds, and contributed to our understanding of the origin of birds, of flight, and of feathers. Pennaceous (vaned) feathers and integumentary filaments are preserved in birds and non-avian theropod dinosaurs, but little is known of

  12. Fossil Energy Program semiannual progress report, April 1990-- September 1990

    SciTech Connect

    Judkins, R.R.

    1991-09-01

    This report covers progress made during the period April 1, 1990, through September 30, 1990, for research and development projects that contribute to the advancement of various fossil energy technologies. Topics discussed include: ceramics and composite materials R&D, new alloys, corrosion and erosion research, coal conversion development, mild gasification. (VC)

  13. Fossil Energy Program semiannual progress report, April 1990-- September 1990

    SciTech Connect

    Judkins, R.R.

    1991-09-01

    This report covers progress made during the period April 1, 1990, through September 30, 1990, for research and development projects that contribute to the advancement of various fossil energy technologies. Topics discussed include: ceramics and composite materials R D, new alloys, corrosion and erosion research, coal conversion development, mild gasification. (VC)

  14. Sustainability by combining nuclear, fossil, and renewable energy sources

    Microsoft Academic Search

    Charles W. Forsberg

    2008-01-01

    The energy industries face two sustainability challenges: the need to avoid climate change and the need to replace traditional crude oil as the basis of our transport system. Radical changes in our energy system will be required to meet these challenges. These challenges may require tight coupling of different energy sources (nuclear, fossil, and renewable) to produce liquid fuels for

  15. Quantification of large uncertainties in fossil leaf paleoaltimetry

    Microsoft Academic Search

    Daniel J. Peppe; Dana L. Royer; Peter Wilf; Elizabeth A. Kowalski

    2010-01-01

    Estimates of paleoelevation potentially constrain geodynamic models of continental deformation and inform interpretations of landscape and climate evolution. One widely used, paleobotanical approach reconstructs paleoelevation from the difference in estimated atmospheric enthalpy between a known sea level and a targeted, coeval, elevated fossil floral site. Enthalpy is estimated using Climate-Leaf Analysis Multivariate Program (CLAMP) on 31 leaf size and shape

  16. ADVANCED FOSSIL FUEL AND THE ENVIRONMENT: AN EXECUTIVE REPORT

    EPA Science Inventory

    This executive-level report gives an overview of some of the more advanced fossil fuel technologies, including several Chemical Coal Cleaning and Liquid Fuels Cleaning methods. Synthetic fuels, Chemically Active Fluid Beds, and Oil Shale are also considered as viable advanced pro...

  17. New Precambrian fossils from the Arumbera Sandstone, Northern Territory, Australia

    Microsoft Academic Search

    M. F. Glaessner; M. R. Walter

    1975-01-01

    Large fossil structures occurring commonly on certain bedding planes in the Arumbera Sandstone southwest of Alice Springs are described as Arumberia banksi gen. et sp. nov. These structures are interpreted as the remains of cupshaped animals, probably of coelenterate grade, that resemble two genera described from the Nama Group of South-West Africa and one from near Lake Baikal, Siberia.

  18. Fossil slabs attached to unsubducted fragments of the Farallon plate.

    PubMed

    Wang, Yun; Forsyth, Donald W; Rau, Christina J; Carriero, Nina; Schmandt, Brandon; Gaherty, James B; Savage, Brian

    2013-04-01

    As the Pacific-Farallon spreading center approached North America, the Farallon plate fragmented into a number of small plates. Some of the microplate fragments ceased subducting before the spreading center reached the trench. Most tectonic models have assumed that the subducting oceanic slab detached from these microplates close to the trench, but recent seismic tomography studies have revealed a high-velocity anomaly beneath Baja California that appears to be a fossil slab still attached to the Guadalupe and Magdalena microplates. Here, using surface wave tomography, we establish the lateral extent of this fossil slab and show that it is correlated with the distribution of high-Mg andesites thought to derive from partial melting of the subducted oceanic crust. We also reinterpret the high seismic velocity anomaly beneath the southern central valley of California as another fossil slab extending to a depth of 200 km or more that is attached to the former Monterey microplate. The existence of these fossil slabs may force a reexamination of models of the tectonic evolution of western North America over the last 30 My. PMID:23509274

  19. EPRI interim consensus guidelines on fossil plant cycle chemistry

    Microsoft Academic Search

    D. M. Sopocy; A. F. Aschoff; C. C. Stauffer; O. Jonas

    1988-01-01

    The total cost of corrosion in the United States utility system has been estimated to be about $3.5 billion per year, withy the annual cost due to turbine corrosion alone estimated at approximately $600 million. The major corrosion problems of fossil units occur in boiler tubes, superheaters and reheaters, turbines, condensers, and feedwater heaters. Weld cracking of deaerator storage tanks

  20. Interim consensus guidelines on fossil plant cycle chemistry. Final report

    Microsoft Academic Search

    A. F. Aschoff; Y. H. Lee; D. M. Sopocy; O. Jonas

    1986-01-01

    US utilities have been faced with a multitude of water and steam control limits disseminated by various groups and manufacturers. These have provided disparate goals for plant personnel and management in determining the operating limits for their plants. EPRI authorized the preparation of guidelines on fossil plant cycle chemistry as part of a research program, RP2712, with the goal to

  1. Acidophilic Collembola: Living Fossils? Jean-Franois PONGE Musum

    E-print Network

    Paris-Sud XI, Université de

    1 Acidophilic Collembola: Living Fossils? Jean-François PONGE Muséum National d'Histoire Naturelle Collembola, i.e. before the Carboniferous age. At this time soils were poor in nutrients, vegetation conditions were quite similar to those now prevailing in the most acid soils. KEY WORDS Collembola / soil

  2. Discovering Fossils--A Hands-on Lab.

    ERIC Educational Resources Information Center

    Goldstein, Alan

    2002-01-01

    Describes fossil investigations developed and provided by the Falls of the Ohio State Park near Louisville, Kentucky. The Devonian shale beds contain representatives of over 600 species including corals, sponges, brachiopods, mollusks, and echinoderms. Rather than focusing on identification, the activities emphasize the past ecological…

  3. Carbon dioxide emission scenarios: limitations of the fossil fuel resource

    Microsoft Academic Search

    Christopher Vernon; Erica Thompson; Sarah Cornell

    2011-01-01

    Contemporary increases in atmospheric carbon dioxide concentration are in large part the result of anthropogenic carbon dioxide emissions from fossil fuel combustion. Scenario analysis is commonly used to generate projections of future carbon dioxide emissions, the resulting atmospheric concentrations and climate impact. In most scenario modelling published to date, carbon dioxide emission scenarios are based on demand-side (socioeconomic and technology)

  4. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    Microsoft Academic Search

    Robert Joseph Andres; J. S. Gregg; London M Losey; Gregg Marland; Thomas A Boden

    2011-01-01

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950-2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80% of global total emissions. These data were then used in a Monte Carlo approach to

  5. First discovery of fossil Nesolagus (Leporidae, Lagomorpha) from Southeast Asia

    Microsoft Academic Search

    ChangZhu Jin; Yukimitsu Tomida; Yuan Wang; YingQi Zhang

    2010-01-01

    A new leporid species, Nesolagus sinensis sp. nov., is described here representing the only leporid member of the Early Pleistocene Gigantopithecus fauna from Sanhe Cave, Chongzuo, Guangxi, South China and also the first fossil taxon of the Southeast Asian genus Nesolagus. Compared with two extant Nesolagus species from Indonesia and Vietnam and other related leprids, the new species has a

  6. Synergistic Energy Conversion Processes Using Nuclear Energy and Fossil Fuels

    Microsoft Academic Search

    Masao Hori

    2008-01-01

    This paper reviews the methods of producing energy carriers, such as electricity, hydrocarbons and hydrogen, by utilizing both nuclear energy and fossil fuels synergistically. There are many possibilities of new, innovative, synergistic processes, which combine chemical and nuclear systems for efficient, clean and economical production of energy carriers. Besides the individual processes by each energy to produce the energy carriers,

  7. Phantom Land and Ghost Slaves : Humankind's Addiction to Fossil Energy

    Microsoft Academic Search

    John Cairns

    Humankind uses vast amounts of fossil energy accumulated millions of years ago. The rate of use is many orders of magnitude greater than the replacement rate. Peak oil is the most immediate problem, and replacing this rate of energy use with biofuels is problematic. Coal is an alternative but produces more severe environment problems than petroleum and is less suitable

  8. Teacher Overview to Stories from the Fossil Record

    NSDL National Science Digital Library

    This is the teacher resource site for the University of California Museum of Paleontology (UCMP) program "Stories from the Fossil Record". It provides information to aide instructors in implementing the program in a classroom setting. Included are lesson plans, handouts, related activities, and background references. Also included are pre- and post-lesson assessments.

  9. Comparison of financing costs for wind turbine and fossil powerplants

    Microsoft Academic Search

    Edward Kahn

    1995-01-01

    This paper compares the financing costs of wind turbine powerplants with those of fossil powerplants. The goal of this examination is to determine the extent to which these costs differ and what the sources of such differences may be. The discussion is organized in the following fashion. Section 2 introduces basic terminology and concepts from finance, as they apply in

  10. Introduction Fossil fuel combustion by aviation, shipping and road

    E-print Network

    Haak, Hein

    96 Introduction Fossil fuel combustion by aviation, shipping and road traffic contributes about one. The total climate impact of aviation emissions (excluding the uncertain impact on natural clouds of the aviation sector has already been assessed quite extensively, e.g. in the IPCC special Report on Aviation

  11. Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds

    E-print Network

    Benton, Michael

    LETTERS Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds Fucheng Zhang1 greatly expanded our knowledge of the diversity and palaeobiology of dinosaurs and early birds, and con) feathers and integumentary fila- ments are preserved in birds3­5 and non-avian theropod dinosaurs6

  12. Dinosaur Fossils Predict Body Temperatures James F. Gillooly1*

    E-print Network

    Allen, Andrew P.

    Dinosaur Fossils Predict Body Temperatures James F. Gillooly1* , Andrew P. Allen2 , Eric L. Charnov of America Perhaps the greatest mystery surrounding dinosaurs concerns whether they were endotherms, ectotherms, or some unique intermediate form. Here we present a model that yields estimates of dinosaur body

  13. Proceedings of the fifth annual conference on fossil energy materials

    SciTech Connect

    Cole, N.C.; Judkins, R.R.

    1991-09-01

    The Fifth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on May 14--16, 1991. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The management of the Program has been decentralized to the DOE Field Office, Oak Ridge with Oak Ridge National Laboratory (ORNL) as the technical support contractor. The research is performed by staff members at ORNL and by a substantial number of researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) Ceramics, (2) New Alloys, (3) Corrosion and Erosion, and (4) Technology Assessment and Technology Transfer. This conference is held every year to review the work on all of the projects of the Program. The agenda for the meeting is given in Appendix A, and a list of attendees is presented in Appendix B.

  14. ORIGINAL PAPER Symbiont bleaching in fossil planktonic foraminifera

    E-print Network

    ORIGINAL PAPER Symbiont bleaching in fossil planktonic foraminifera Bridget S. Wade Æ Nadia Al planktonic foraminifera and demonstrate that the species Morozovelloides crassatus lost their photosymbiotic Photosymbionts Á Planktonic foraminifera Á Eocene Á Site 1052 Á Carbon isotopes Á Extinction B. S. Wade Á N. Al

  15. Molecules and fossils reveal punctuated diversification in Caribbean “faviid” corals

    PubMed Central

    2012-01-01

    Background Even with well-known sampling biases, the fossil record is key to understanding macro-evolutionary patterns. During the Miocene to Pleistocene in the Caribbean Sea, the fossil record of scleractinian corals shows a remarkable period of rapid diversification followed by massive extinction. Here we combine a time-calibrated molecular phylogeny based on three nuclear introns with an updated fossil stratigraphy to examine patterns of radiation and extinction in Caribbean corals within the traditional family Faviidae. Results Concatenated phylogenetic analysis showed most species of Caribbean faviids were monophyletic, with the exception of two Manicina species. The time-calibrated tree revealed the stem group originated around the closure of the Tethys Sea (17.0?Ma), while the genus Manicina diversified during the Late Miocene (8.20?Ma), when increased sedimentation and productivity may have favored free-living, heterotrophic species. Reef and shallow water specialists, represented by Diploria and Favia, originate at the beginning of the Pliocene (5 – 6?Ma) as the Isthmus of Panama shoaled and regional productivity declined. Conclusions Later origination of the stem group than predicted from the fossil record corroborates the hypothesis of morphological convergence in Diploria and Favia genera. Our data support the rapid evolution of morphological and life-history traits among faviid corals that can be linked to Mio-Pliocene environmental changes. PMID:22831179

  16. Age of Neoproterozoic Bilatarian Body and Trace Fossils, White

    E-print Network

    Age of Neoproterozoic Bilatarian Body and Trace Fossils, White Sea, Russia: Implications-bearing, shallow marine siliciclastic rocks in the Zimnie Gory section of the White Sea region indicates the Flinders Ranges (10, 21) in South Australia and White Sea coast in Russia (22), which account for 60

  17. Surface chemistry control for selective fossil resin flotation

    DOEpatents

    Miller, J.D.; Yi, Y.; Yu, Q.

    1994-06-07

    A froth flotation method is disclosed for separating fine particles of fossil resin by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method. 12 figs.

  18. CARBON DIOXIDE FROM FOSSIL FUELS: ADAPTING TO UNCERTAINTY

    EPA Science Inventory

    The paper discusses the general effect and control of CO2. The world is likely to experience noticeable global warming by the beginning of the next century if high annual growth rates of fossil fuel energy use continue. Only with optimistic assumptions and low growth rates will C...

  19. Illinois' State FossilTullimonstrum gregarium The ancient landscape

    E-print Network

    Cochran-Stafira, D. Liane

    with relatives of modern shrimps, jellyfish, squid, sharks, and other marine animals. Rivers that meandered of a soft-bodied animal like the Tully monster or a jellyfish being preserved as a fossil are very small other marine animals such as jellyfish and shrimp, perhaps piercing their prey with their "teeth

  20. Cadmium-Induced Hydrogen Sulfide Synthesis Is Involved in Cadmium Tolerance in Medicago sativa by Reestablishment of Reduced (Homo)glutathione and Reactive Oxygen Species Homeostases

    PubMed Central

    Cui, Weiti; Chen, Huiping; Zhu, Kaikai; Jin, Qijiang; Xie, Yanjie; Cui, Jin; Xia, Yan; Zhang, Jing; Shen, Wenbiao

    2014-01-01

    Until now, physiological mechanisms and downstream targets responsible for the cadmium (Cd) tolerance mediated by endogenous hydrogen sulfide (H2S) have been elusive. To address this gap, a combination of pharmacological, histochemical, biochemical and molecular approaches was applied. The perturbation of reduced (homo)glutathione homeostasis and increased H2S production as well as the activation of two H2S-synthetic enzymes activities, including L-cysteine desulfhydrase (LCD) and D-cysteine desulfhydrase (DCD), in alfalfa seedling roots were early responses to the exposure of Cd. The application of H2S donor sodium hydrosulfide (NaHS), not only mimicked intracellular H2S production triggered by Cd, but also alleviated Cd toxicity in a H2S-dependent fashion. By contrast, the inhibition of H2S production caused by the application of its synthetic inhibitor blocked NaHS-induced Cd tolerance, and destroyed reduced (homo)glutathione and reactive oxygen species (ROS) homeostases. Above mentioned inhibitory responses were further rescued by exogenously applied glutathione (GSH). Meanwhile, NaHS responses were sensitive to a (homo)glutathione synthetic inhibitor, but reversed by the cotreatment with GSH. The possible involvement of cyclic AMP (cAMP) signaling in NaHS responses was also suggested. In summary, LCD/DCD-mediated H2S might be an important signaling molecule in the enhancement of Cd toxicity in alfalfa seedlings mainly by governing reduced (homo)glutathione and ROS homeostases. PMID:25275379

  1. Full band atomistic modeling of homo-junction InGaAs band-to-band tunneling diodes including band gap narrowing

    E-print Network

    Rommel, Sean

    Full band atomistic modeling of homo-junction InGaAs band-to-band tunneling diodes including band Institute of Physics. Related Articles Degenerate p-doping of InP nanowires for large area tunnel diodes Appl. Phys. Lett. 99, 253105 (2011) Metal-oxide-oxide-metal granular tunnel diodes fabricated

  2. Engineering a Homo-Ethanol Pathway in Escherichia coli: Increased Glycolytic Flux and Levels of Expression of Glycolytic Genes during Xylose Fermentation

    Microsoft Academic Search

    HAN TAO; RAMON GONZALEZ; ALFREDO MARTINEZ; MARIA RODRIGUEZ; L. O. Ingram; J. F. Preston; K. T. Shanmugam

    2001-01-01

    Replacement of the native fermentation pathway in Escherichia coli B with a homo-ethanol pathway from Zymomonas mobilis (pdc and adhB genes) resulted in a 30 to 50% increase in growth rate and glycolytic flux during the anaerobic fermentation of xylose. Gene array analysis was used as a tool to investigate differences in expression levels for the 30 genes involved in

  3. Fossil Groups in the Millennium Simulation. Evolution of the Brightest Galaxies

    E-print Network

    Eugenia Diaz-Gimenez; Hernan Muriel; Claudia Mendes de Oliveira

    2008-09-12

    We create a catalogue of simulated fossil groups and study their properties, in particular the merging histories of their first-ranked galaxies. We compare the simulated fossil group properties with those of both simulated non-fossil and observed fossil groups. Using simulations and a mock galaxy catalogue, we searched for massive ($>$ 5 $\\times$ 10$^{13} h^{-1} {\\cal M}_\\odot$) fossil groups in the Millennium Simulation Galaxy Catalogue. In addition, attempted to identify observed fossil groups in the Sloan Digital Sky Survey Data Release 6 using identical selection criteria. Our predictions on the basis of the simulation data are:(a) fossil groups comprise about 5.5% of the total population of groups/clusters with masses larger than 5 x 10$^{13} h^{-1} {\\cal M}_\\odot$. This fraction is consistent with the fraction of fossil groups identified in the SDSS, after all observational biases have been taken into account; (b) about 88% of the dominant central objects in fossil groups are elliptical galaxies that have a median R-band absolute magnitude of $\\sim -23.5-5 log h$, which is typical of the observed fossil groups known in the literature; (c)first-ranked galaxies of systems with $ {\\cal M} >$ 5 x 10$^{13} h^{-1} {\\cal M}_\\odot$, regardless of whether they are either fossil or non-fossil, are mainly formed by gas-poor mergers; (d) although fossil groups, in general, assembled most of their virial masses at higher redshifts in comparison with non-fossil groups, first-ranked galaxies in fossil groups merged later, i.e. at lower redshifts, compared with their non-fossil-group counterparts. We therefore expect to observe a number of luminous galaxies in the centres of fossil groups that show signs of a recent major merger.

  4. Norwegian carbon taxes and their implication for fossil fuels

    SciTech Connect

    Kaarstad, O. [Principle Research Adviser, Energy and Environment, Trondheim (Norway)

    1995-12-31

    The Scandinavian countries, and in particular Norway and Sweden, have since 1990/91 taxed CO{sub 2}-emissions with carbon tax of about US $150 per ton of CO{sub 2}. One may therefore say that these countries have placed themselves in a role as {open_quotes}carbon tax laboratories{close_quotes}. These very high CO{sub 2}-taxes have been in place for about four years and the first lessons from this experience are reported. In general it would seem as if the taxation mechanism is less efficient than economists have expected. The CO{sub 2}-emissions are increasing in both Norway and Sweden and the stabilization goal to the year 2000 will not be achieved in spite of the high taxation. The fossil fuel industry will have to learn to live with the climate change question which is inherently hostile to fossil fuels. It is argued that a more informed and active participation by the fossil fuel industry is needed in the climate change discussion. In addition the image of fossil fuels will benefit from showing real and potential improvement in the area of greenhouse gas emissions in the whole energy chain from production to combustion. The R&D effort being done into CO{sub 2}-capture and -disposal is creating such an option for the future. It is argued that the image of the entire fossil fuel industry will benefit from the creation of a {open_quotes}CO{sub 2}-free{close_quote} option or vision for oil, gas and coal. A number of examples are shown where today (or in the near future) actual CO{sub 2}-disposal in underground formations are taking place.

  5. Revisiting the Fossil Group Candidates UGC 842 and NGC 6034

    NASA Astrophysics Data System (ADS)

    Lopes de Oliveira, R.; Carrasco, E. R.; Mendes de Oliveira, C.; Bortoletto, D. R.; Cypriano, E.; Sodré, L., Jr.; Lima Neto, G. B.

    2010-01-01

    We present a new insight on NGC 6034 and UGC 842, two groups of galaxies previously reported in the literature as being fossil groups. The study is based on optical photometry and spectroscopy obtained with the CTIO Blanco telescope and Sloan Digital Sky Survey archival data. We find that NGC 6034 is embedded in a large structure, dominated by three rich clusters and other small groups. Its first and next four ranked galaxies have magnitude differences in the r band and projected distances which violate the optical criteria to classify it as a fossil group. We confirm that the UGC 842 group is a fossil group, but with about half the velocity dispersion that is reported in previous works. The velocity distribution of its galaxies reveals the existence of two structures in its line of sight, one with ? v ~ 223 km s-1 and another with ? v ~ 235 km s-1, with a difference in velocity of ~820 km s-1. The main structure is dominated by passive galaxies, while these represent ~60% of the second structure. The X-ray temperature for the intragroup medium of a group with such a velocity dispersion is expected to be kT ~0.5-1 keV, against the observed value of kT ~1.9 keV reported in the literature. This result makes UGC 842 a special case among fossil groups because (1) it represents more likely the interaction between two small groups, which warms the intragroup medium and/or (2) it could constitute evidence that member galaxies lost energy in the process of spiraling toward the group center, and decreased the velocity dispersion of the system. As far as we know, UGC 842 is the first low-mass fossil group studied in detail.

  6. Proceedings of the sixth annual conference on fossil energy materials. Fossil Energy AR and TD Mateials Program

    SciTech Connect

    Cole, N.C.; Judkins, R.R. [comps.

    1992-07-01

    The Sixth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on May 12--14, 1992. The meeting was sponsored by the US Department of Energy`s Office of Fossil Energy through the Advanced Research and Technology Development (AR&TD) Materials Program, and ASM International. The objective of the AR&TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The management of the Program has been decentralized to the DOE Field Office, Oak Ridge with Oak Ridge National Laboratory (ORNL) as the technical support contractor. The research is performed by staff members at ORNL and by a substantial number of researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) ceramics, (2) development and corrosion resistance of iron aluminide, advanced austenitic and chromium-niobium alloys, and (3) technology assessment and technology transfer. This conference is held each year to review the work on all of the projects of the Program. The agenda for the meeting is given in Appendix A, and a list of attendees is presented in Appendix B. ASM International cosponsored the conference, for which we are especially grateful.

  7. Fossil Energy Program Annual Progress Report for the Period April 1, 2000 through March 31, 2001

    SciTech Connect

    Judkins, RR

    2001-06-14

    This report covers progress made at Oak Ridge National Laboratory (ORNL) on research and development projects that contribute to the advancement of fossil energy technologies. Projects on the ORNL Fossil Energy Program are supported by the U.S. Department of Energy (DOE) Office of Fossil Energy, the DOE National Energy Technology Laboratory (NETL), the DOE Fossil Energy Clean Coal Technology (CCT) Program, the DOE National Petroleum Technology Office, and the DOE Fossil Energy Office of Strategic Petroleum Reserve (SPR). The ORNL Fossil Energy Program research and development activities cover the areas of coal, clean coal technology, gas, petroleum, and support to the SPR. An important part of the Fossil Energy Program is technical management of all activities on the DOE Fossil Energy Advanced Research (AR) Materials Program. The AR Materials Program involves research at other DOE and government laboratories, at universities, and at industrial organizations.

  8. Two new fossil species of Cryptocephalus Geoffroy (Coleoptera: Chrysomelidae) from Baltic and Dominican Amber

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two new species of Cryptocephalus Geoffroy (Coleoptera: Chrysomelidae) are described and illustrated from fossil resin: Cryptocephalus groehni sp. nov (Baltic amber) and Cryptocephalus kheelorum sp. nov. (Dominican amber). These are the first described species of Cryptocephalinae from fossil resin. ...

  9. Phylogeny, paleontology, and primates: do incomplete fossils bias the tree of life?

    E-print Network

    Pattinson, David J.; Thompson, Richard S.; Piotrowski, Aleks K.; Asher, Robert J.

    2014-09-19

    Paleontological systematics relies heavily on morphological data that have undergone decay and fossilization. Here, we apply a heuristic means to assess how a fossil's incompleteness detracts from inferring its phylogenetic relationships. We...

  10. Estimates of Fossil Fuel Carbon Dioxide Emissions From Mexico at Monthly Time Intervals

    Microsoft Academic Search

    L. M. Losey; R. J. Andres

    2003-01-01

    Human consumption of fossil fuels has greatly contributed to the rise of carbon dioxide in the Earth's atmosphere. To better understand the global carbon cycle, it is important to identify the major sources of these fossil fuels. Mexico is among the top fifteen nations in the world for producing fossil fuel carbon dioxide emissions. Based on this information and that

  11. Sensitivity of inverted carbon sources and sinks from seasonally and interannual varying fossil fuel emission estimates

    Microsoft Academic Search

    K. R. Gurney; Y. Chen

    2003-01-01

    The possibility of a ?fossil fuel rectifier? is tested using two models (PCTM and MATCH:NCEP) that span the spectrum of vertical trapping and rectification as established in the TransCom 3 Atmospheric Carbon Inversion Intercomparison Experiment. Tests with a pseudo fossil fuel emissions field with varying seasonal amplitude suggests that a fossil fuel rectifier is likely to be a small factor

  12. FTIR Spectroscopic Analysis of Surface Oxidation Reactions During Ozonation of Fossil Resin and Coal

    Microsoft Academic Search

    Q. YU; K. BUKKA; Y. YE; J. D. MILLER

    1992-01-01

    Diffuse and specular reflectance FTIR analysis both fossil resin (resinite) and coal has been carried out to study surface oxidation reactions which occur during the selective flotation of fossil resin from coal by ozone conditioning. It was found from the FTIR spectra that ozonation of both fossil resin and coal causes an increase in the peak intensity associated with stretching

  13. Is paleoanthropology science? Naming new fossils and control of access to them

    Microsoft Academic Search

    Ian Tattersall; Jeffrey H. Schwartz

    2002-01-01

    Progress in paleoanthropology is impeded when new fossil materials are published but unavailable for comparative study, as is too often the case. In this commentary, we review the stages of description and analysis that new fossils must undergo and conclude that it is disingenuous to argue that fossils have not been properly \\

  14. Rare earth element systematics of fossil bone revealed by LA-ICPMS analysis

    E-print Network

    Schöne, Bernd R.

    November 2012 Abstract Intra-bone rare earth element (REE) fractionation trends were studied by LA-ICPMS analysis to put constraints on (1) the mechanisms controlling REE fractionation within fossil bones; (2) the relative timing of REE uptake in various parts of fossil bone and (3) the origin of REE in fossil bones. We

  15. Trace fossils in the Ediacaran–Cambrian transition: Behavioral diversification, ecological turnover and environmental shift

    Microsoft Academic Search

    Adolf Seilacher; Luis A. Buatois; M. Gabriela Mángano

    2005-01-01

    After taxonomic revision, trace fossils show a similarly explosive diversification in the Ediacaran–Cambrian transition as metazoan body fossils. In shallow-marine deposits of Ediacaran age, trace fossils are horizontal, simple and rare, and display feeding strategies related to exploitation of microbial matgrounds. Equally notable is the absence of arthropod tracks and sinusoidal nematode trails. This situation changed in the Early Cambrian,

  16. Rare helical spheroidal fossils from the Doushantuo Lagerstätte: Ediacaran animal embryos come of age?

    Microsoft Academic Search

    Shuhai Xiao; James W. Hagadorn; Chuanming Zhou; Xunlai Yuan

    2007-01-01

    A small quantity of helically coiled spheroidal fossils has been recovered from acid digestion of phosphorite samples from the Ediacaran Doushantuo Formation, South China. These fossils consist of an internal body enclosed in a sculptured envelope that is very similar to that of Doushantuo animal eggs and blastula embryos such as Megasphaera ornata. A hallmark of these fossils is a

  17. Occurrence of fossil organic matter in modern environments: Optical, geochemical and isotopic evidence

    E-print Network

    Paris-Sud XI, Université de

    Occurrence of fossil organic matter in modern environments: Optical, geochemical and isotopic of fossil organic matter (FOM) in the modern environment, and focuses on two experimental watersheds] is characterized by alteration of the FOM, which is difficult to describe because fossil material is mixed

  18. Project EARTH-13-RB1: The early evolution of marine turtles based on exceptional British fossils

    E-print Network

    Henderson, Gideon

    Project EARTH-13-RB1: The early evolution of marine turtles based on exceptional British fossils of marine turtles from two exceptional British fossil faunas ­ and Eocene London Clay and the Early Cretaceous Cambridge Greensand (see Owen & Bell 1849; Hooks 1998). Although abundant fossils are known from

  19. Original article Fossil honey bees and evolution in the genus Apis

    E-print Network

    Paris-Sud XI, Université de

    Original article Fossil honey bees and evolution in the genus Apis (Hymenoptera: Apidae) Michael S well-known fossil honey bee species. Apis henshawi is diagnosed, the holotype described, and a complete the known fossil species and evolution in the genus discussed. No honey bees are known from before

  20. Wing Shape of Four New Bee Fossils (Hymenoptera: Anthophila) Provides Insights to Bee Evolution

    E-print Network

    Rasmont, Pierre

    Wing Shape of Four New Bee Fossils (Hymenoptera: Anthophila) Provides Insights to Bee Evolution by a dearth of available fossils needed to determine the timing and tempo of their diversification, as well as episodes of extinction. Here we describe four new compression fossils of bees from three different deposits

  1. INTEGR. COMP. BIOL., 43:127136 (2003) A Fungal Analog for Newfoundland Ediacaran Fossils?1

    E-print Network

    Hagadorn, Whitey

    2003-01-01

    127 INTEGR. COMP. BIOL., 43:127­136 (2003) A Fungal Analog for Newfoundland Ediacaran Fossils?1 SYNOPSIS. We propose that some of the more conspicuous Ediacaran fossils from the Avalon Peninsula, and appears to show growth zonations similar to modern mycelia. Other fossils from this deposit exhibit

  2. Conical fossils from the Lower Cambrian of Eastern California BEN WAGGONER1

    E-print Network

    Hagadorn, Whitey

    Conical fossils from the Lower Cambrian of Eastern California BEN WAGGONER1 BEN WAGGONER1 BEN@amherst.edu Two new cone-shaped fossils from Lower Cambrian strata of eastern California are described is a large tubular fossil characterized by a cen- tral keel and a sigmoid shape. Although it resembles

  3. GEOLOGY, March 2011 259 The stratigraphic distribution of fossils reflects a combina-

    E-print Network

    Heim, Noel A.

    GEOLOGY, March 2011 259 ABSTRACT The stratigraphic distribution of fossils reflects a combina- tion of physical and biological factors. Although many studies have addressed the distribution of fossils the distribution of fossils within longer duration sedimentary succes- sions covering broad geographic regions

  4. Rocks and clocks: calibrating the Tree of Life using fossils and molecules

    E-print Network

    Sorenson, Michael

    Rocks and clocks: calibrating the Tree of Life using fossils and molecules Philip C.J. Donoghue of the available fossils and careful consideration of molecular tree methods: rocks and clocks together questions in macroevolution. The evolving relationship between rocks and clocks Classically, the fossil

  5. Testing the fossil record: Sampling proxies and scaling in the British TriassicJurassic

    E-print Network

    Benton, Michael

    Testing the fossil record: Sampling proxies and scaling in the British Triassic­Jurassic Alexander March 2014 Available online 30 March 2014 Keywords: Palaeodiversity Fossil record Sampling Proxy Triassic Jurassic The quality of the fossil record varies immensely across taxa, geographic regions

  6. 2007-No54-BoilingPoint Health and Greenhouse Gas Impacts of Biomass and Fossil Fuel

    E-print Network

    Kammen, Daniel M.

    2007-No54-BoilingPoint Theme Health and Greenhouse Gas Impacts of Biomass and Fossil Fuel Energy of fossil-fuel energy systems. These scenarios are analysed for various environmental and health impacts from fossil fuels and other energy sources reported by IEA []. In all of these countries except Kenya

  7. Probability That a Fossil Absent from a Sample Is Also Absent from the Paleolandscape

    E-print Network

    Probability That a Fossil Absent from a Sample Is Also Absent from the Paleolandscape Robert S are the same as each midden in a paired sample is constructed; and (3) the probability of fossilization is zero of stratigraphic sampling such as macrofossils from sediment cores or fossils from biostrati- graphic units. © 2000

  8. Source: 24 Hours Edmonton | KEVIN MAIMANN | 29 Jun 2012 ANCIENT FOSSIL DISCOVERED

    E-print Network

    Machel, Hans

    Source: 24 Hours Edmonton | KEVIN MAIMANN | 29 Jun 2012 ANCIENT FOSSIL DISCOVERED University. Geologists Ernesto Pecoits and Natalie Aubet found fossilized tracks in Uruguay they believe was left behind-microbiologist at the university, co-authored the study published Thursday in the journal Science. He said the fossils have been

  9. 464 Fossil humans and 1014% H with 25% S and the remainder oc-

    E-print Network

    Delson, Eric

    464 Fossil humans and 10­14% H with 2­5% S and the remainder oc- curring as N ( of the fossil fuels is the heating value of the fuel, which is mea- sured as the amount of heat energy produced (eds.), Fossil Fuels Utilization: En- vironmental Concerns, 1986; R. A. Meyers (ed.), Coal Handbook

  10. ELEVATED FOSSIL CORAL DEPOSITS IN THE HAWAIIAN ISLANDS: A MEASURE OF ISLAND UPLIFT IN THE QUATERNARY

    E-print Network

    Luther, Douglas S.

    ELEVATED FOSSIL CORAL DEPOSITS IN THE HAWAIIAN ISLANDS: A MEASURE OF ISLAND UPLIFT Gary McMurtry Johanna Resig #12;ABSTRACT The origin of emerged marine fossils in the Hawaiian Islands waves swept up to 326 m on Lanai and neighboring islands depositing marine fossils 105 ka; (3

  11. LET US PREY: SIMULATIONS OF GRAZING TRACES IN THE FOSSIL RECORD

    E-print Network

    Plotnick, Roy E.

    LET US PREY: SIMULATIONS OF GRAZING TRACES IN THE FOSSIL RECORD Roy E. Plotnick and Karen Koy, IL, 60607 Tel. +1 312-996-2111, E-mail: plotnick@uic.edu, kkoy@uic.edu Abstract Trace fossils basic behavior. Changes in the occurrence of trace fossil types over time, in particular during

  12. The Astrophysical Journal, ???, ???, 2009 January Testing Formation Mechanisms and Ages of Fossil Groups of

    E-print Network

    Dupke, Renato A.

    The Astrophysical Journal, ???, ???, 2009 January Testing Formation Mechanisms and Ages of Fossil, 05508-090, São Paulo. Brazil Abstract Fossil groups are X-ray bright galaxy systems that present parameters measured in the few fossil groups with enough X-ray counts, and also by the large magnitude gap

  13. e have discovered a fossil of a higher fly (Diptera: Cyclorrhapha) from

    E-print Network

    Thompson, F. Christian

    W e have discovered a fossil of a higher fly (Diptera: Cyclorrhapha) from Antarctica, a finding been available until now to test his hypothesis. The fossil has several features that enable us. The characteristics of the fossil enable it to be assigned to one of the more highly derived clades (Schizo- phora

  14. The fossil record of early tetrapods: Worker effort and the end-Permian mass extinction

    E-print Network

    Benton, Michael

    The fossil record of early tetrapods: Worker effort and the end-Permian mass extinction EMMA L.E., and Benton, M.J. 2010. The fossil record of early tetrapods: Worker effort and the end-Permian mass of the fossil record of early tetrapods (Tetrapoda, minus Lissamphibia and Amniota) because of their key role

  15. ESTRELLICHNUS JACARNSIS NOV. IGEN., NOV. ISP. -A LARGE RADIAL TRACE FOSSIL

    E-print Network

    Wetzel, Andreas

    ESTRELLICHNUS JACARNSIS NOV. IGEN., NOV. ISP. - A LARGE RADIAL TRACE FOSSIL FROM EOCENE FLYSCH jacaensis nov. igen., nov. isp.- a large radial trace fossil from Eocene flysch (Hecho Group, northern Spain radial trace fossil preserved as hypichnial semi- reliefs. It occurs in Eocene f]ysch deposits

  16. Calibrated chronograms, fossils, outgroup relationships, and root priors: re-examining the historical

    E-print Network

    Sytsma, Kenneth J.

    Calibrated chronograms, fossils, outgroup relationships, and root priors: re transcribed spacers (ITS). Their study presented a set of new fossils within the order, generated a chronogram for Geraniales and other rosid orders using fossil-based priors on five nodes, demonstrated an Eocene radiation

  17. Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California

    E-print Network

    Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California Estimates from the Combustion of Fossil Fuels in California" and augmentation to contract number 05 Dioxide Emission Estimates from the Combustion of Fossil Fuels in California" and augmentation to contract

  18. The Astrophysical Journal, ???, ???, 2008 November Testing the Formation Mechanisms of Fossil Groups

    E-print Network

    Dupke, Renato A.

    The Astrophysical Journal, ???, ???, 2008 November Testing the Formation Mechanisms of Fossil of Michigan, Ann Arbor 2 IAG, USP. Rua do Matao 1226, Sao Paulo. Brazil Abstract Fossil groups are X the high concentration parameters measured in the few fossil groups with enough X-ray counts, and also

  19. Ediacaran fossils from the Innerelv Member (late Proterozoic) of the Tanafjorden area, northeastern Finnmark

    E-print Network

    Farmer, Jack D.

    Ediacaran fossils from the Innerelv Member (late Proterozoic) of the Tanafjorden area, northeastern Finnmark, northern Norway. The fossil assemblage is dominated by discoidal which share certain affinities with the cosmopolitan genera. and However, our specimens differ from these and other discoidal Ediacaran fossils

  20. C H A P T E R Basal euarthropod development: a fossil-based

    E-print Network

    C H A P T E R Basal euarthropod development: a fossil-based perspective Nigel C. Hughes, Joachim T is bridged by a number of fossils known primarily from rocks some to million years old (e.g. Fuxianhuia, Chengjiangocaris, Shankouia, see Figure .; cf. Waloszek et al. ). These centimetre-scale fossil animals illuminate