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1

Getting to Know Homo erectus  

NSDL National Science Digital Library

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.

Jeffrey H. Schwartz (University of Pittsburgh;)

2004-07-02

2

Natural history ofHomo erectus  

Microsoft Academic Search

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

2003-01-01

3

The taxonomic implications of cranial shape variation in Homo erectus  

Microsoft Academic Search

The taxonomic status of Homo erectus sensu lato has been a source of debate since the early 1980s, when a series of publications suggested that the early African fossils may represent a separate species, H. ergaster. To gain further resolution regarding this debate, 3D geometric morphometric data were used to quantify overall shape variation in the cranial vault within H.

Karen L. Baab

2008-01-01

4

Cranial base morphology and temporal bone pneumatization in Asian Homo erectus  

Microsoft Academic Search

The external morphological features of the temporal bone are used frequently to determine taxonomic affinities of fossils of the genus Homo. Temporal bone pneumatization has been widely studied in great apes and in early hominids. However, this feature is rarely examined in the later hominids, particularly in Asian Homo erectus. We provide a comparative morphological and quantitative analysis of Asian

Antoine Balzeau; Dominique Grimaud-Hervé

2006-01-01

5

A Female Homo erectus Pelvis from Gona, Ethiopia  

E-print Network

accumulation rates in the Busidima Formation narrows the likely age of the fossil to 0.9 to 1.4 Ma (8). To date describe a nearly complete early Pleistocene adult female H. erectus pelvis from the Busidima Formation fossil hom- inid adult pelves are from small-bodied females (such as the 3.2-million

Utrecht, Universiteit

6

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

7

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

NASA Astrophysics Data System (ADS)

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.

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

8

The taxonomic implications of cranial shape variation in Homo erectus Karen L. Baab  

E-print Network

to Homo erectus sensu lato (s.l.). These more recent discoveries from the Caucasus, East Africa, and Asia in the west, to the Caucasus in the north, and China and Java in the east (Right- mire, 1984, 1990, 1998; Bra

Baab, Karen L.

9

Growth processes in teeth distinguish modern humans from Homo erectus and earlier hominins  

Microsoft Academic Search

A modern human-like sequence of dental development, as a proxy for the pace of life history, is regarded as one of the diagnostic hallmarks of our own genus Homo. Brain size, age at first reproduction, lifespan and other life-history traits correlate tightly with dental development. Here we report differences in enamel growth that show the earliest fossils attributed to Homo

Christopher Dean; Meave G. Leakey; Donald Reid; Friedemann Schrenk; Gary T. Schwartz; Christopher Stringer; Alan Walker

2001-01-01

10

Hominid mandibular corpus shape variation and its utility for recognizing species diversity within fossil Homo  

PubMed Central

Mandibular corpora are well represented in the hominin fossil record, yet few studies have rigorously assessed the utility of mandibular corpus morphology for species recognition, particularly with respect to the linear dimensions that are most commonly available. In this study, we explored the extent to which commonly preserved mandibular corpus morphology can be used to: (i) discriminate among extant hominid taxa and (ii) support species designations among fossil specimens assigned to the genus Homo. In the first part of the study, discriminant analysis was used to test for significant differences in mandibular corpus shape at different taxonomic levels (genus, species and subspecies) among extant hominid taxa (i.e. Homo, Pan, Gorilla, Pongo). In the second part of the study, we examined shape variation among fossil mandibles assigned to Homo(including H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster, late African H. erectus, Asian H. erectus, H. heidelbergensis, H. neanderthalensis and H. sapiens). A novel randomization procedure designed for small samples (and using group ‘distinctness values’) was used to determine whether shape variation among the fossils is consistent with conventional taxonomy (or alternatively, whether a priori taxonomic groupings are completely random with respect to mandibular morphology). The randomization of ‘distinctness values’ was also used on the extant samples to assess the ability of the test to recognize known taxa. The discriminant analysis results demonstrated that, even for a relatively modest set of traditional mandibular corpus measurements, we can detect significant differences among extant hominids at the genus and species levels, and, in some cases, also at the subspecies level. Although the randomization of ‘distinctness values’ test is more conservative than discriminant analysis (based on comparisons with extant specimens), we were able to detect at least four distinct groups among the fossil specimens (i.e. H. sapiens, H. heidelbergensis, Asian H. erectus and a combined ‘African Homo’ group consisting of H. habilis sensu stricto, H. rudolfensis, early African H. erectus/H. ergaster and late African H. erectus). These four groups appear to be distinct at a level similar to, or greater than, that of modern hominid species. In addition, the mandibular corpora of H. neanderthalensis could be distinguished from those of ‘African Homo’, although not from those of H. sapiens, H. heidelbergensis, or the Asian H. erectus group. The results suggest that the features most commonly preserved on the hominin mandibular corpus have some taxonomic utility, although they are unlikely to be useful in generating a reliable alpha taxonomy for early African members of the genus Homo. PMID:19094183

Lague, Michael R; Collard, Nicole J; Richmond, Brian G; Wood, Bernard A

2008-01-01

11

Fossil Humankind and Other Anthropoid Primates of China  

Microsoft Academic Search

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.

Xinzhi Wu

2004-01-01

12

Evolution of the Genus Homo  

NASA Astrophysics Data System (ADS)

Definition of the genus Homo is almost as fraught as the definition of Homo sapiens. We look at the evidence for “early Homo,” finding little morphological basis for extending our genus to any of the 2.5-1.6-myr-old fossil forms assigned to “early Homo” or Homo habilis/rudolfensis. We also point to heterogeneity among “early African Homo erectus,” and the lack of apomorphies linking these fossils to the Asian Homo erectus group, a cohesive regional clade that shows some internal variation, including brain size increase over time. The first truly cosmopolitan Homo species is Homo heidelbergensis, known from Africa, Europe, and China following 600 kyr ago. One species sympatric with it included the >500-kyr-old Sima de los Huesos fossils from Spain, clearly distinct from Homo heidelbergensis and the oldest hominids assignable to the clade additionally containing Homo neanderthalensis. This clade also shows evidence of brain size expansion with time; but although Homo neanderthalensis had a large brain, it left no unequivocal evidence of the symbolic consciousness that makes our species unique. Homo sapiens clearly originated in Africa, where it existed as a physical entity before it began (also in that continent) to show the first stirrings of symbolism. Most likely, the biological underpinnings of symbolic consciousness were exaptively acquired in the radical developmental reorganization that gave rise to the highly characteristic osteological structure of Homo sapiens, but lay fallow for tens of thousands of years before being “discovered” by a cultural stimulus, plausibly the invention of language.

Tattersall, Ian; Schwartz, Jeffrey H.

2009-05-01

13

Man the Fat Hunter: The Demise of Homo erectus and the Emergence of a New Hominin Lineage in the Middle Pleistocene (ca. 400 kyr) Levant  

Microsoft Academic Search

The worldwide association of H. erectus with elephants is well documented and so is the preference of humans for fat as a source of energy. We show that rather than a matter of preference, H. erectus in the Levant was dependent on both elephants and fat for his survival. The disappearance of elephants from the Levant some 400 kyr ago

Miki Ben-Dor; Avi Gopher; Israel Hershkovitz; Ran Barkai

2011-01-01

14

Implications of new early Homo fossils from Ileret, east of Lake Turkana, Kenya  

Microsoft Academic Search

Sites in eastern Africa have shed light on the emergence and early evolution of the genus Homo. The best known early hominin species, H.habilis and H.erectus, have often been interpreted as time-successive segments of a single anagenetic evolutionary lineage. The case for this was strengthened by the discovery of small early Pleistocene hominin crania from Dmanisi in Georgia that apparently

F. Spoor; M. G. Leakey; P. N. Gathogo; F. H. Brown; S. C. Antón; I. McDougall; C. Kiarie; F. K. Manthi; L. N. Leakey

2007-01-01

15

Hominid Fossil Record Geology 230: Fossils and Evolution  

E-print Network

,000 yrs? Java man Peking man · H. sapiens: archaic vs. modern #12;Skull of Homo habilis #12;H. rudolfensis of Nariokotome boy #12;The face of Homo erectus #12;Homo erectus from Indonesia, Java Man #12;Homo erectus using skeleton, Germany #12;Homo neadertalensis leading a nomadic existence #12;Neandertals were big-game hunters

Kammer, Thomas

16

Homo floresiensis: a cladistic analysis  

Microsoft Academic Search

The announcement of a new species, Homo floresiensis, a primitive hominin that survived until relatively recent times is an enormous challenge to paradigms of human evolution. Until this announcement, the dominant paradigm stipulated that: 1) only more derived hominins had emerged from Africa, and 2) H. sapiens was the only hominin since the demise of Homo erectus and Homo neanderthalensis. Resistance

Debbie Argue; Mike Morwood; Thomas Sutikna; Jatmiko; E. W. Saptomo

2009-01-01

17

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya.  

PubMed

To address questions regarding the evolutionary origin, radiation and dispersal of the genus Homo, it is crucial to be able to place the occurrence of hominin fossils in a high-resolution chronological framework. The period around 2 Ma (millions of years ago) in eastern Africa is of particular interest as it is at this time that a more substantial fossil record of the genus Homo is first found. Here we combine magnetostratigraphy and strontium (Sr) isotope stratigraphy to improve age control on hominin-bearing upper Burgi (UBU) deposits in Areas 105 and 131 on the Karari Ridge in the eastern Turkana Basin (Kenya). We identify the base of the Olduvai subchron (bC2n) plus a short isolated interval of consistently normal polarity that we interpret to be the Pre-Olduvai event. Combined with precession-forced (~20 kyr [thousands of years]) wet-dry climate cycles resolved by Sr isotope ratios, the magnetostratigraphic data allow us to construct an age model for the UBU deposits. We provide detailed age constraints for 15 hominin fossils from Area 131, showing that key specimens such as cranium KNM-ER 1470, partial face KNM-ER 62000 and mandibles KNM-ER 1482, KNM-ER 1801, and KNM-ER 1802 can be constrained between 1.945 ± 0.004 and 2.058 ± 0.034 Ma, and thus older than previously estimated. The new ages are consistent with a temporal overlap of two species of early Homo that can be distinguished by their facial morphology. Further, our results show that in this time interval, hominins occurred throughout the wet-dry climate cycles, supporting the hypothesis that the lacustrine Turkana Basin was a refugium during regionally dry periods. By establishing the observed first appearance datum of a marine-derived stingray in UBU deposits at 2.058 ± 0.034 Ma, we show that at this time the Turkana Basin was hydrographically connected to the Indian Ocean, facilitating dispersal of fauna between these areas. From a biogeographical perspective, we propose that the Indian Ocean coastal strip should be considered as a possible source area for one or more of the multiple Homo species in the Turkana Basin from over 2 Ma onwards. PMID:24134960

Joordens, Josephine C A; Dupont-Nivet, Guillaume; Feibel, Craig S; Spoor, Fred; Sier, Mark J; van der Lubbe, Jeroen H J L; Nielsen, Trine Kellberg; Knul, Monika V; Davies, Gareth R; Vonhof, Hubert B

2013-12-01

18

Fossil clavicle of a Middle Pleistocene hominid from the Central Narmada Valley, India  

Microsoft Academic Search

The discovery of a Middle Pleistocene hominid clavicle is reported here. This discovery is particularly important because clavicles are hitherto unrepresented in the fossil record of Asia. The Narmada clavicle comes from the Boulder Conglomerate horizon at Hathnora near Hoshangabad in the Central Narmada Valley. This is the same deposit that previously yielded theHomo erectus\\/archaicHomo sapienspartial cranium, which has recently

A. R. Sankhyan

1997-01-01

19

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

NASA Astrophysics Data System (ADS)

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.

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

20

Poor fossil record and major changes around 1 MaBP  

Microsoft Academic Search

The abundance of early fossil humans in African sites ceases at dates around 1.3MaBP; there is almost none until nearly 0.8MaBP.\\u000a Again these are scarce until less than 0.5 Ma. Most of Homo erectus fossils in Java are dated between c.1.3 and 0.70Ma; just\\u000a a few fossil humans are known in Eurasia for this time span. Questions arise on eventual

E. Aguirre

2000-01-01

21

Pressemitteilung Homo floresiensis doch eine eigene Species  

E-print Network

. Wissenschaftler des Senckenberg Center for Human Evolution and Palaeoenvironment der Universität Tübingen kleinwüchsige Population des Homo erectus etabliert? Oder waren es moderne Menschen, die an einer Krankheit Gehirn. Als Ursa- chen kämen zum Beispiel eine Form der Unterfunktion der Schilddrüse oder das Laron

Ould Ahmedou, Mohameden

22

The Sambungmacan 3 Homo erectus Calvaria: A Comparative  

E-print Network

. *Correspondence to: Eric Delson, Department of Vertebrate Paleontology, American Museum of Natural History, New/CUNY, New York 2 Ph.D. Program in Anthropology, CUNY Graduate Center, New York 3 Division of Paleontology, American Museum of Natural History, New York 4 New York Consortium in Evolutionary Primatology, New York

Delson, Eric

23

Robo-Erectus: Team Description 2005  

Microsoft Academic Search

This paper provides a brief description of Robo-Erectus (RE), the humanoid developed in the Advanced Robotics and Intelligent Control Centre of Singapore Polytechnic that will participate in the humanoid league of Ro- boCup 2005. The project to develop a low-cost humanoid platform is presented. The mechanical structure of Robo-Erectus and the evolution of its various mod- els is presented. The

Pik Kong Yue; Changjiu Zhou; Fook Seng Choy; Cher Hwee Tan; Mike Wong; Hong Kee; Richard Ong; Kong Siang; Chin Wooi Ong

2005-01-01

24

Before the Emergence of Homo sapiens: Overview on the Early-to-Middle Pleistocene Fossil Record (with a Proposal about Homo heidelbergensis at the subspecific level)  

PubMed Central

The origin of H. sapiens has deep roots, which include two crucial nodes: (1) the emergence and diffusion of the last common ancestor of later Homo (in the Early Pleistocene) and (2) the tempo and mode of the appearance of distinct evolutionary lineages (in the Middle Pleistocene). The window between 1,000 and 500 thousand years before present appears of crucial importance, including the generation of a new and more encephalised kind of humanity, referred to by many authors as H. heidelbergensis. This species greatly diversified during the Middle Pleistocene up to the formation of new variants (i.e., incipient species) that, eventually, led to the allopatric speciation of H. neanderthalensis and H. sapiens. The special case furnished by the calvarium found near Ceprano (Italy), dated to 430–385?ka, offers the opportunity to investigate this matter from an original perspective. It is proposed to separate the hypodigm of a single, widespread, and polymorphic human taxon of the Middle Pleistocene into distinct subspecies (i.e., incipient species). The ancestral one should be H. heidelbergensis, including specimens such as Ceprano and the mandible from Mauer. PMID:21716742

Manzi, Giorgio

2011-01-01

25

The Origin of Homo  

Microsoft Academic Search

Despite a steady increase in the number and diversity of African Middle Pliocene hominin fossils, paleoanthropolo-gists are\\u000a not now substantially closer to understanding the temporal, geographical or ecological contexts of the origin of the Homo clade than was the case in 1964, when Louis Leakey, Phillip Tobias and John Napier introduced Homo habilis as the earliest species of the human

William H. Kimbel

26

Homo floresiensis: a cladistic analysis.  

PubMed

The announcement of a new species, Homo floresiensis, a primitive hominin that survived until relatively recent times is an enormous challenge to paradigms of human evolution. Until this announcement, the dominant paradigm stipulated that: 1) only more derived hominins had emerged from Africa, and 2) H. sapiens was the only hominin since the demise of Homo erectus and Homo neanderthalensis. Resistance to H. floresiensis has been intense, and debate centers on two sets of competing hypotheses: 1) that it is a primitive hominin, and 2) that it is a modern human, either a pygmoid form or a pathological individual. Despite a range of analytical techniques having been applied to the question, no resolution has been reached. Here, we use cladistic analysis, a tool that has not, until now, been applied to the problem, to establish the phylogenetic position of the species. Our results produce two equally parsimonious phylogenetic trees. The first suggests that H. floresiensis is an early hominin that emerged after Homo rudolfensis (1.86Ma) but before H. habilis (1.66Ma, or after 1.9Ma if the earlier chronology for H. habilis is retained). The second tree indicates H. floresiensis branched after Homo habilis. PMID:19628252

Argue, D; Morwood, M J; Sutikna, T; Jatmiko; Saptomo, E W

2009-11-01

27

Mandibular shape analysis in fossil hominins: Fourier descriptors in norma lateralis.  

PubMed

Biological shape can be defined as the boundary of a form in 2-space (R(2)). An earlier study (Lestrel et al., 2010, HOMO-J. Comp. Hum. Biol.) of the cranial vault found that there were statistically significant differences between each of the three groups: H. erectus, H. heidelbergensis, and H. neanderthalensis compared with H. sapiens. In contrast, there was no statistically significant difference among the first three groups. These results suggest that these three groups may have formed single evolving lineage while H. sapiens represents a separate evolutionary development. The purpose of the current research was to discern if the mandible reflected a similar pattern as the cranial vault data. This study used lateral jpeg images of the mandible. Five fossil samples were used: A. robustus (n=7), H. erectus (n=12), H. heidelbergensis (n=4), H. neanderthalensis (n=22) and H. sapiens (n=61). Each mandible image was pre-processed with Photoshop Elements. Each image was then submitted to a specially written routine that digitized the 84 points along the mandible boundary. Each mandible was fitted with elliptical Fourier functions (EFFs). Procrustes superimposition was imposed to insure minimum shape differences. The mandible results largely mirrored the earlier cranial vault study with one exception. Statistically significant results were obtained for the mandible between the H. erectus and H. neanderthalensis samples in contrast to the earlier cranial vault data. F-tests disclosed that the statistical significance was limited to the anterior symphysis of the mandible. This mosaic pattern may be explained by the reduction in prognathism with the concomitant if rudimentary development of the chin as seen in H. neanderthalensis compared to H. erectus. PMID:23769600

Lestrel, P E; Wolfe, C A; Bodt, A

2013-08-01

28

Fossils  

NSDL National Science Digital Library

Students discover the science of paleontology and the fossilization process. Why should we study fossils? Use your KWL chart to record information you have learned and anything else you want to know about. First read about the fossils of birds and what we learn from them. Then discover the Fossilization Process. Find out if there are still new dinosaurs to be discovered. Watch paleontologists hunt for ...

Tassihj

2009-10-21

29

Fossils  

NSDL National Science Digital Library

Fossils is an activity for grades 1-2 that enables students to apply their interest in dinosaurs to discovering how fossils tell us about our past. As a result of this activity, the students will be able to: tell a friend or parent who a paleontologist is and what he does; explain what a fossil is; explain how we use fossils to learn about the past; and make a fossil using clay, plaster of paris, and some sort of molding object such as a shell, leaf, bone, etc. A suggested extension of this activity is turning it into an archaeological "dig" by burying objects in plaster of paris and then using dull instruments to dig for the "fossils."

1998-01-01

30

Fossils  

NSDL National Science Digital Library

4th Grade Science Standard 4: Students will understand how fossils are formed, where they may be found in Utah, and how they can be used to make inferences. DISCOVERING FOSSILS!!

41

Earliest Homo Sapiens Fossils Discovered in Ethiopia  

NSF Publications Database

... 1 p.m. Eastern NSF PR 03-65 - June 11, 2003 Media contact: Bill Noxon (703) 292-7750 wnoxon@nsf.gov ... images, see: http://www.berkeley.edu/news/ media/hominid/. For photos, contact: David Brill (770 ...

42

Brain size of Homo floresiensis and its evolutionary implications.  

PubMed

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

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

2013-06-01

43

Homo floresiensis and the evolution of the hominin shoulder.  

PubMed

The holotype of Homo floresiensis, diminutive hominins with tiny brains living until 12,000 years ago on the island of Flores, is a partial skeleton (LB1) that includes a partial clavicle (LB1/5) and a nearly complete right humerus (LB1/50). Although the humerus appears fairly modern in most regards, it is remarkable in displaying only 110 degrees of humeral torsion, well below modern human average values. Assuming a modern human shoulder configuration, such a low degree of humeral torsion would result in a lateral set to the elbow. Such an elbow joint would function more nearly in a frontal than in a sagittal plane, and this is certainly not what anyone would have predicted for a tool-making Pleistocene hominin. We argue that Homo floresiensis probably did not have a modern human shoulder configuration: the clavicle was relatively short, and we suggest that the scapula was more protracted, resulting in a glenoid fossa that faced anteriorly rather than laterally. A posteriorly directed humeral head was therefore appropriate for maintaining a normally functioning elbow joint. Similar morphology in the Homo erectus Nariokotome boy (KNM-WT 15000) suggests that this shoulder configuration may represent a transitional stage in pectoral girdle evolution in the human lineage. PMID:17692894

Larson, Susan G; Jungers, William L; Morwood, Michael J; Sutikna, Thomas; Jatmiko; Saptomo, E Wahyu; Due, Rokus Awe; Djubiantono, Tony

2007-12-01

44

The evolution of early Homo: a reply to Scott.  

PubMed

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

Van Arsdale, A P; Wolpoff, M H

2014-03-01

45

Morphology and kinematics of prey capture in the syngnathid fishes Hippocampus erectus and Syngnathus floridae  

Microsoft Academic Search

The mechanism of prey capture in two syngnathid fishes, the lined seahorse Hippocampus erectus (Perry) and the dusky pipefish Syngnathus floridae (Jordan and Gilbert), is described based on anatomical observations and high-speed video recordings (200 and 400 images s?1) of feeding events by four seahorses and three pipefish. The fish were collected near Turkey Point, Florida, U.S.A., in January\\u000a 1994

B. A. Bergert; P. C. Wainwright

1997-01-01

46

Homo Economicus Belief Inhibits Trust  

PubMed Central

As a foundational concept in economics, the homo economicus assumption regards humans as rational and self-interested actors. In contrast, trust requires individuals to believe partners’ benevolence and unselfishness. Thus, the homo economicus belief may inhibit trust. The present three experiments demonstrated that the direct exposure to homo economicus belief can weaken trust. And economic situations like profit calculation can also activate individuals’ homo economicus belief and inhibit their trust. It seems that people’s increasing homo economicus belief may serve as one cause of the worldwide decline of trust. PMID:24146907

Xin, Ziqiang; Liu, Guofang

2013-01-01

47

Homo habilis's humanness: Phillip Tobias as a philosopher.  

PubMed

A detailed, interdisciplinary reading of Phillip Tobias's publications on Homo habilis shows how a philosophical notion of "humanness" has structured his interpretation of the fossils attributed to this species. The role of this notion in his research and its backgrounds in philosophy, disciplinary history, and a widespread mid-20th-century climate of opinion are analyzed and discussed. PMID:23272596

Corbey, Raymond

2012-01-01

48

Additional Evidence for Morpho-Dimensional Tooth Crown Variation in a New Indonesian H. erectus Sample from the Sangiran Dome (Central Java)  

PubMed Central

This contribution reports fifteen human fossil dental remains found during the last two decades in the Sangiran Dome area, in Central Java, Indonesia. Among this sample, only one of the specimens had already been briefly described, with the other fourteen remaining unreported. Seven of the fifteen isolated teeth were found in a secured stratigraphic context in the late Lower-early Middle Pleistocene Kabuh Formation. The remaining elements were surface finds which, based on coincidental sources of information, were inferred as coming from the Kabuh Formation. Mainly constituted of permanent molars, but also including one upper incisor and one upper premolar, this dental sample brings additional evidence for a marked degree of size variation and time-related structural reduction in Javanese H. erectus. This is notably expressed by a significant decrease of the mesiodistal diameter, frequently associated to the reduction or even loss of the lower molar distal cusp (hypoconulid) and to a more square occlusal outline. In addition to the hypoconulid reduction or loss, this new sample also exhibits a low frequency of the occlusal Y-groove pattern, with a dominance of the X and, to a lesser extent, of the+patterns. This combination is rare in the Lower and early Middle Pleistocene paleoanthropological record, including in the early Javanese dental assemblage from the Sangiran Dome. On the other hand, similar dental features are found in Chinese H. erectus and in H. heidelbergensis. As a whole, this new record confirms the complex nature of the intermittent exchanges that occurred between continental and insular Southeast Asia through the Pleistocene. PMID:23843996

Zanolli, Clement

2013-01-01

49

Cranial size variation and lineage diversity in early Pleistocene Homo.  

PubMed

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

Scott, Jeremiah E

2014-03-01

50

Geometric morphometrics and paleoneurology: brain shape evolution in the genus Homo  

Microsoft Academic Search

Paleoneurology concerns the study and analysis of fossil endocasts. Together with cranial capacity and discrete anatomical features, shape can be analysed to consider the spatial relationships between structures and to investigate the endocranial structural system. A sample of endocasts from fossil specimens of the genus Homo has been analysed using traditional metrics and 2D geometric morphometrics based on lateral projections

Emiliano Bruner

2004-01-01

51

Artificial cranial deformation and fossil Australians revisited  

Microsoft Academic Search

Based on cranial characters shared byHomo erectusin Java andHomo sapiensin Australia, Australasia is widely considered the strongest case for a regional origin of modern humans. However, artificial vault deformation has been suggested to be the cause of “archaic” characters such as frontal recession in key fossil Australian crania. We use log–log plots of cranial arc versus chord measurements and we

Susan C. Antón; Karen J. Weinstein

1999-01-01

52

The hominin fossil record: taxa, grades and clades  

Microsoft Academic Search

This paper begins by reviewing the fossil evidence for human evolution. It presents summaries of each of the taxa recognized in a relatively speciose hominin taxonomy. These taxa are grouped in grades, namely possible and probable hominins, archaic hominins, megadont archaic hominins, transitional hominins, pre-modern Homo and anatomically modern Homo . The second part of this contribution considers some of

Bernard Wood; Nicholas Lonergan

2008-01-01

53

The Emergence of Homo sapiens.  

ERIC Educational Resources Information Center

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)

Rensberger, Boyce

1980-01-01

54

The foot of Homo floresiensis  

Microsoft Academic Search

Homo floresiensis is an endemic hominin species that occupied Liang Bua, a limestone cave on Flores in eastern Indonesia, during the Late Pleistocene epoch. The skeleton of the type specimen (LB1) of H.floresiensis includes a relatively complete left foot and parts of the right foot. These feet provide insights into the evolution of bipedalism and, together with the rest of

W. L. Jungers; W. E. H. Harcourt-Smith; R. E. Wunderlich; M. W. Tocheri; S. G. Larson; T. Sutikna; Rhokus Awe Due; M. J. Morwood

2009-01-01

55

First fossil chimpanzee.  

PubMed

There are thousands of fossils of hominins, but no fossil chimpanzee has yet been reported. The chimpanzee (Pan) is the closest living relative to humans. Chimpanzee populations today are confined to wooded West and central Africa, whereas most hominin fossil sites occur in the semi-arid East African Rift Valley. This situation has fuelled speculation regarding causes for the divergence of the human and chimpanzee lineages five to eight million years ago. Some investigators have invoked a shift from wooded to savannah vegetation in East Africa, driven by climate change, to explain the apparent separation between chimpanzee and human ancestral populations and the origin of the unique hominin locomotor adaptation, bipedalism. The Rift Valley itself functions as an obstacle to chimpanzee occupation in some scenarios. Here we report the first fossil chimpanzee. These fossils, from the Kapthurin Formation, Kenya, show that representatives of Pan were present in the East African Rift Valley during the Middle Pleistocene, where they were contemporary with an extinct species of Homo. Habitats suitable for both hominins and chimpanzees were clearly present there during this period, and the Rift Valley did not present an impenetrable barrier to chimpanzee occupation. PMID:16136135

McBrearty, Sally; Jablonski, Nina G

2005-09-01

56

Marquee Fossils  

ERIC Educational Resources Information Center

Professors of an online graduate-level paleontology class developed the concept of marquee fossils--fossils that have one or more unique characteristics that capture the attention and direct observation of students. In the classroom, Marquee fossils integrate the geology, biology, and environmental science involved in the study of fossilized…

Clary, Renee; Wandersee, James

2008-01-01

57

Fossil Fondue  

NSDL National Science Digital Library

To understand how fossils are formed, students model the process of fossilization by making fossils using small toy figures and melted chocolate. They extend their knowledge to the many ways that engineers aid in the study of fossils, including the development of tools and technologies for determining the physical and chemical properties of fossilized organisms, and how those properties tell a story of our changing world.

Integrated Teaching And Learning Program

58

4th Grade Fossils  

NSDL National Science Digital Library

Introduction to Fossils What is a fossil What is a Fossil? Body and Trace Fossils Body and Trace Fossils Life of a Vertebrate fossil Life of a Vertebrate Fossil Finding Fossils Finding Fossils How fossils are found How fossils are formed Age of Fossils Age of Fossils in Sedimentary Rock Fossils found in Utah Fossils found in Utah Where fossils are found in Utah Where fossils are found in Utah Utah County Map Utah County Map ...

Richrigby

2010-01-26

59

Discovering Fossils: Fossil Tools & Resources  

NSDL National Science Digital Library

Fossil enthusiasts Roy Shephard and Luci Algar combined their professional skills in media and education to develop this informative and entertaining website. Designed to be educational and accessible to children, this site presents a wide variety of information about fossils. The site contains a nice collection of images and diagrams; and includes a fossils guide for beginners, information on preparing fossils, a collection of fossil myths, information on ammonites, and more. The site also contains a Games & Activities section for teachers and students, a glossary of fossil terms, a neat diagram depicting the evolution of life on our planet, and even some free fossil desktop images.

60

"Fossil" Forecasting.  

ERIC Educational Resources Information Center

Presents a density study in which students calculate the density of limestone substrate to determine if the specimen contains any fossils. Explains how to make fossils and addresses national standards. (YDS)

Brody, Michael J.; deOnis, Ann

2001-01-01

61

Finding Fossils  

NSDL National Science Digital Library

This OLogy activity serves as a kid-friendly how-to manual about searching for fossils. In Not Just Any Rock Will Do, kids learn that fossils "hide out" in sedimentary rock and see examples of shale and sandstone. Do's and Don'ts for Fossil Hunters gives kids practical tips and a list of fossil-hunting supplies. In Fossils You May Find, there are photos of common invertebrate, vertebrate, and plant fossils to guide kids. Paleontology Clubs and Web Sites lists resources to help kids determine where to hunt for fossils. In Keeping a Field Journal, kids are shown a sample journal entry that points out the types of information they should record.

62

Fossil humans 1 Fossil humans  

E-print Network

Fossil humans 1 Fossil humans All prehistoric skeletal remains of humans which are archeologically, anatomically modern humans. In this sense, the term "humans" is used broadly to mean all primates related of the Neanderthal speci- men in 1856. Fossil human remains have come prin- cipally from Europe, Asia, China, Java

Delson, Eric

63

Fossils 1: Fossils and Dinosaurs  

NSDL National Science Digital Library

This lesson will go beyond naming dinosaurs and give students a broad understanding of how we know about the great beasts. This lesson focuses on what we have learned and can learn from fossils. The follow-up lesson, Dinosaurs Fossils - Uncovering the Facts, explores what information can be discerned by comparing fossils to living organisms.

Science Netlinks;

2001-10-20

64

The status of Homo heidelbergensis (Schoetensack 1908).  

PubMed

The species Homo heidelbergensis is central to many discussions about recent human evolution. For some workers, it was the last common ancestor for the subsequent species Homo sapiens and Homo neanderthalensis; others regard it as only a European form, giving rise to the Neanderthals. Following the impact of recent genomic studies indicating hybridization between modern humans and both Neanderthals and "Denisovans", the status of these as separate taxa is now under discussion. Accordingly, clarifying the status of Homo heidelbergensis is fundamental to the debate about modern human origins. PMID:22718477

Stringer, Chris

2012-05-01

65

Elastic energy storage in the shoulder and the evolution of high-speed throwing in Homo  

PubMed Central

Although some primates, including chimpanzees, throw objects occasionally1,2, only humans regularly throw projectiles with high speed and great accuracy. Darwin noted that humans’ unique throwing abilities, made possible when bipedalism emancipated the arms, enabled foragers to effectively hunt using projectiles3. However, there has been little consideration of the evolution of throwing in the years since Darwin made his observations, in part because of a lack of evidence on when, how, and why hominins evolved the ability to generate high-speed throws4-8. Here, we show using experimental studies of throwers that human throwing capabilities largely result from several derived anatomical features that enable elastic energy storage and release at the shoulder. These features first appear together approximately two million years ago in the species Homo erectus. Given archaeological evidence that suggests hunting activity intensified around this time9, we conclude that selection for throwing in order to hunt likely played an important role in the evolution of the human genus. PMID:23803849

Roach, Neil T.; Venkadesan, Madhusudhan; Rainbow, Michael J.; Lieberman, Daniel E.

2013-01-01

66

Fossil formation  

NSDL National Science Digital Library

The National Science Education Standards Life Science Content Standard mentions that fossils indicate extinct species and contribute to an understanding of evolution and diversity. The Earth and Space Sciences Content Standard tells us they provide clues about past environments. But what is a fossil? How does it form? The processes can be complex. An understanding of fossil formation will enable accurate student conceptions of related science concepts including methods of science in geology, paleontology, and evolution.

University, Staff A.

2008-03-07

67

Fossil Find  

NSDL National Science Digital Library

In this classroom activity, middle school students simulate a "dinosaur dig." The activity opens with background information for teachers about fossils. Working in groups, students excavate fossil sites created in advance by the teacher, or other group of students, and try to reconstruct a chicken skeleton. The activity closes with a two-page student worksheet that directs students to diagram the fossil site and includes probing questions to help them decode their findings.

68

Finding Fossils  

NSDL National Science Digital Library

This activity (located on page 4 of the PDF) is a full inquiry investigation to determine the age of fossils based on where they are discovered. Groups of learners will dig for fossils embedded in a cake of multiple layers, carefully excavating each stratum and eventually preparing a chart from their notes for discussion with the group. The two main lessons from this exercise are that fossils from different layers come from different eras and that multiple interpretations of incomplete fossil evidence are possible. Relates to linked video, DragonflyTV GPS: Baby Dinosaurs.

Twin Cities Public Television, Inc.

2007-01-01

69

Nietzsche's Last Laugh: Ecce Homo as Satire  

Microsoft Academic Search

:Against the many who claim that Nietzsche's Ecce Homo is useless, madness, or merely inscrutable, my close analysis of the philosopher's last original composition reveals that his so-called autobiography actually inhabits an ancient literary form: satire. After establishing how to read this much-maligned book, I argue that Ecce Homo gives us the best example of Nietzsche interpreting his own philosophy,

Nicholas D. More

2011-01-01

70

Nietzsche's Last Laugh: Ecce Homo as Satire  

Microsoft Academic Search

Against the many who claim that Nietzsche's Ecce Homo is useless, madness, or merely inscrutable, my close analysis of the philosopher's last original composition reveals that his so-called autobiography actually inhabits an ancient literary form: satire. After establishing how to read this much-maligned book, I argue that Ecce Homo gives us the best example of Nietzsche interpreting his own philosophy,

Nicholas D. More

2011-01-01

71

Superacid cyclization of homo- and bishomoisoprenoid acids  

Microsoft Academic Search

The superacid cyclization of a number of homo- and bishomoterpenoid acids, the products of which are ?- and d-lactones —important natural compounds or intermediates for the synthesis and manufacture of valuable substances —was investigated. It is shown that the superacid cyclization of homo- and bishomoterpenoid acids to ?- and d-lactones proceeds stereospecifically, chemoselectively, and structurally selectively, is general in character,

P. F. Vlad; N. D. Ungur; V. B. Perutskii

1991-01-01

72

Interactive effects of low water supply and high salt concentration on the growth and dry matter partitioning of Conocarpus erectus seedlings  

Microsoft Academic Search

Effects of low water supply and high salt concentration and their interactions on the growth of Conocarpus erectus seedlings were studied in a pot experiment at the Research and Experiments Station of King Saud University, Riyadh, Saudi Arabia. Water was applied either every other day or every ten days. Sodium chloride dissolved in water at rate either of three g

Loutfy I. El-Juhany; Ibrahim M. Aref

73

Ediacara Fossils  

ERIC Educational Resources Information Center

Now, a research team from Virginia Tech and Nanjing Institute of Geology and Paleontology has discovered uniquely well-preserved fossil forms from 550-million-year-old rocks of the Ediacaran Period. The research appears in the Proceedings of the National Academy of Sciences. The discovery of these unusually preserved fossils reveals unprecedented…

Science Teacher, 2005

2005-01-01

74

Fossil Fuels.  

ERIC Educational Resources Information Center

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…

Crank, Ron

75

Fossil Crinoids  

NASA Astrophysics Data System (ADS)

Crinoids have graced the oceans for more than 500 million years. Among the most attractive fossils, crinoids had a key role in the ecology of marine communities through much of the fossil record, and their remains are prominent rock forming constituents of many limestones. This is the first comprehensive volume to bring together their form and function, classification, evolutionary history, occurrence, preservation and ecology. The main part of the book is devoted to assemblages of intact fossil crinoids, which are described in their geological setting in twenty-three chapters ranging from the Ordovician to the Tertiary. The final chapter deals with living sea lilies and feather stars. The volume is exquisitely illustrated with abundant photographs and line drawings of crinoids from sites around the world. This authoritative account recreates a fascinating picture of fossil crinoids for paleontologists, geologists, evolutionary and marine biologists, ecologists and amateur fossil collectors.

Hess, Hans; Ausich, William I.; Brett, Carlton E.; Simms, Michael J.

1999-10-01

76

Fossil Crinoids  

NASA Astrophysics Data System (ADS)

Crinoids have graced the oceans for more than 500 million years. Among the most attractive fossils, crinoids had a key role in the ecology of marine communities through much of the fossil record, and their remains are prominent rock forming constituents of many limestones. This is the first comprehensive volume to bring together their form and function, classification, evolutionary history, occurrence, preservation and ecology. The main part of the book is devoted to assemblages of intact fossil crinoids, which are described in their geological setting in twenty-three chapters ranging from the Ordovician to the Tertiary. The final chapter deals with living sea lilies and feather stars. The volume is exquisitely illustrated with abundant photographs and line drawings of crinoids from sites around the world. This authoritative account recreates a fascinating picture of fossil crinoids for paleontologists, geologists, evolutionary and marine biologists, ecologists and amateur fossil collectors.

Hess, Hans; Ausich, William I.; Brett, Carlton E.; Simms, Michael J.

2003-01-01

77

Fossil Fuels  

NSDL National Science Digital Library

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.

Project, Iowa P.

2004-01-01

78

Of the animals homo sapiens sapiens (us) have the largest brain/per body weight and the most complex behaviors. It is puzzling as to just what the  

E-print Network

, #12;9.1. THE FOSSIL RECORD ON HOMINIDS 3 making homo sapiens sapiens very recent on the evolutionary been shown to do this. 9.1 The fossil record on hominids How old are humans? This question can 5,000 to 10,000 years ago with the invention of writing and formation of large cities

Ballard, Dana H.

79

Week of Aug. 5, 2002 Vol. 3, No. 15 A D e p a r t m e n t o f E n e r g y / U n i v e r s i t y o f C a l i f o r n i a L a b o r a t o r y  

E-print Network

species is not justified," said White. "This African fossil is so similar to its Asian contemporaries to divergent evolution among Homo erectus -- with the African population most likely evolving into modern Homo Awash was an expansive grassland inhabited by a number of animals, including antelope, elephants

80

Fossils 1: Fossils and Dinosaurs  

NSDL National Science Digital Library

In this lesson, students will understand what can be learned from fossils and in doing so, realize the difference between fact and theory. This lesson is the first of a two-part series on fossils. These lessons will go beyond naming dinosaurs and give students a broad understanding of how we know about the great beasts. They will start to acquire knowledge of the fossil record in preparation for learning about evolution and natural selection, concepts they will study in high school. This particular lesson focuses on what we have learned and can learn from fossils. In the first part, students will discuss what we know about horses. They will then do the same for a Stegosaurus. Another part of the lesson briefly covers how fossils are formed.

81

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.

82

Are Homo sapiens nonsupranuchal fossa and Neanderthal suprainiac fossa convergent traits?  

PubMed

The autapomorphic status of the Neanderthal suprainiac fossa was recently confirmed. This was a result of a detailed analysis of the internal bone composition in the area of the suprainiac depression on Neanderthal and Homo sapiens specimens. However, while anatomical differences between Neanderthal suprainiac fossa and the depression in the inion region of the occipital bone of fossil and recent Homo sapiens have been discussed in detail, the etiology of these structures has not been resolved. In this article, the hypothesis that the Homo sapiens non-supranuchal fossa and the Neanderthal suprainiac fossa both formed to maintain the optimal shape of the occipital plane (to minimize strain on the posterior cranial vault) is tested. First, the variation in the expression of the fossa above inion in the crania of recent Homo sapiens from European, African, and Australian samples was examined, and the degree of structural similarity between these depressions and the Neanderthal suprainiac fossa was assessed. Next, the relationship between the shape of the occipital squama in the midsagittal plane and two particular features (the degree of the occipital torus development and the occurrence of a depression in the inion region that is not the supranuchal fossa) were analyzed. Based on the results, it is suggested that the Homo sapiens non-supranuchal fossa and Neanderthal suprainiac fossa are convergent traits. PMID:21404232

Nowaczewska, Wioletta

2011-04-01

83

Upper Pleistocene Homo sapiens from the Tabon cave (Palawan, The Philippines): description and dating of new discoveries  

Microsoft Academic Search

Among the poor fossil record of Southeast Asian Upper Pleistocene Homo sapiens, the Tabon human remains [12] are frequently cited in the literature despite very scarce published palaeoanthropological data. A recent Filipino-French joint work confirmed the significance of the discoveries made in the 1960s: a frontal bone and two mandibular fragments that have been recently described and dated [9]. Simultaneously,

Florent Détroit; Eusebio Dizon; Christophe Falguères; Sébastien Hameau; Wilfredo Ronquillo; François Sémah

2004-01-01

84

Évolution de la morphologie claviculaire au sein du genre Homo. Conséquences architecturales et fonctionnelles sur la ceinture scapulaire  

Microsoft Academic Search

Evolution of the Clavicular Morphology within the Genus Homo. Architectural and Functional Consequences on the Shoulder Girdle. The clavicle is the less studied shoulder bone from the point of view of comparative anatomy in spite of its importance for the movements of the upper limbs. In this study we have compared the clavicle curvature between extant hominoids and some fossils

Jean-Luc Voisin

2001-01-01

85

1Evolution de la morphologie claviculaire au sein du genre Homo. Consrquences architecturales et fonctionnelles sur la ceinture scapulaire  

Microsoft Academic Search

Evolution of the Clavicular Morphology within the Genus Homo. Architectural and Functional Consequences on the Shoulder Girdle.The clavicle is the less studied shoulder bone from the point of view of comparative anatomy in spite of its importance for the movements of the upper limbs. In this study we have compared the clavicle curva- ture between extant hominoids and some fossils

Jean-Luc Voisin

86

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

PubMed Central

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

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

2007-01-01

87

Remarkable Fossils  

Microsoft Academic Search

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

Thomas Wm. Cowan

1874-01-01

88

Crown size and cusp proportions in Homo antecessor upper first molars. A comment on Quam et al. 2009  

PubMed Central

A recent evaluation of upper first molar (M1) crown size and cusp proportions in the genus Homo (Quam et al. 2009) describes Homo antecessor as maintaining a primitive pattern of cusp proportions, similar to that identified in australopithecines and the earliest members of the genus Homo. These results contrast with those of Gómez-Robles et al. (2007), who described the crown shape in these molars as derived and similar to Neanderthals and European Homo heidelbergensis. The reassessment of these measurements following the same methodology described by Quam et al. (2009) in all the M1s that are currently part of the hypodigm of H. antecessor demonstrates that the fossils from TD6 not only have the same cusp proportions identified in later Homo species, but also a strongly reduced metacone and a large hypocone shared with Middle and Upper Pleistocene members of the Neanderthal lineage. The evolutionary significance of these features should be evaluated in light of the results provided by recently discovered dental, cranial, mandibular, and postcranial H. antecessor fossils. PMID:21208207

Gomez-Robles, Aida; de Castro, Jose Maria Bermudez; Martinon-Torres, Maria; Prado-Simon, Leyre

2011-01-01

89

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

PubMed

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

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

2014-01-01

90

Quaternary fossil fish from the Kibish Formation, Omo Valley, Ethiopia  

Microsoft Academic Search

The late Quaternary Kibish Formation of the Omo Valley, southwestern Ethiopia, preserves environments reflecting a history of fluctuations in the level of nearby Lake Turkana over the past 200,000 years. The Kibish Formation has yielded a diverse mammalian fauna (as well as birds and crocodiles), stone tools, and the oldest anatomically modern Homo sapiens. Fish, the most common vertebrate fossils

Josh Trapani

2008-01-01

91

Fossil Fuels  

NSDL National Science Digital Library

The Department of Energy Web site Fossil Fuels is billed as an energy education site mainly for older kids, but can be enjoyed by adult kids as well. The site gives an introduction to energy, and then a more detailed look at the acquisition and uses of coal, oil, and gas. The good descriptions, illustrations, and animations, along with the frequent questions page and glossary of related terms, combine to give a clear and enlightening overview of the subject.

92

Mandible and Taxonomy of the Earliest European Homo  

Microsoft Academic Search

Although variability of the mandible makes it problematic for taxonomy, the holotypes of three of the oldest European species,\\u000a Home georgicus, H. antecessor, H. heidelbergensis, are mandibles. Moreover, the distinctive validity of these three species cannot be established from these particular mandibles.\\u000a The holotype of H. georgicus is pathological and similar to H. erectus in some important features, while others

P. F. Fabbri

2006-01-01

93

Citrate utilization by homo- and heterofermentative lactobacilli  

Microsoft Academic Search

Citrate utilization by several homo- and heterofermentative lactobacilli was determined in Kempler and McKay and in calcium citrate media. The last medium with glucose permitted best to distinguish citrate-fermenting lactobacilli. Lactobacillus rhamnosus ATCC 11443, Lactobacillus zeae ATCC 15820 and Lactobacillus plantarum ATCC 8014 used citrate as sole energy source, whereas in the other strains, glucose and citrate were cometabolized. Some

R. Medina de Figueroa; F. Alvarez; A. Pesce de Ruiz Holgado; G. Oliver; F. Sesma

2000-01-01

94

Bolkian and Bokian Retardation in Homo Sapiens  

Microsoft Academic Search

Although a low genetic barrier is said to separate humans from apes, Homo sapiens is characterized by striking developmental and anatomical particularities. On the one hand, humans have a very extended life history (retardation). On the other hand, human anatomy shows many instances of both neoteny and hypermorphosis.

Jos Verhulst

1999-01-01

95

Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany.  

PubMed

The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 ± 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

Wagner, Günther A; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falguères, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G Philip

2010-11-16

96

Mud fossils  

USGS Publications Warehouse

At the close of the 18th century, the haze of fantasy and mysticism that tended to obscure the true nature of the Earth was being swept away. Careful studies by scientists showed that rocks had diverse origins. Some rock layers, containing clearly identifiable fossil remains of fish and other forms of aquatic animal and plant life, originally formed in the ocean. Other layers, consisting of sand grains winnowed clean by the pounding surf, obviously formed as beach deposits that marked the shorelines of ancient seas.

1997-01-01

97

Dermatitis and systemic mycosis in lined seahorses Hippocampus erectus associated with a marine-adapted Fusarium solani species complex pathogen.  

PubMed

During a 4 mo epizootic, 100% of 152 lined seahorses Hippocampus erectus in 3 separate groups died while in quarantine following shipment to a public aquarium. Twelve animals with skin depigmentation and ulceration were received by the Aquatic Pathology Service, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA, for diagnostic evaluation. Microscopically, lesions in 11 seahorses included multifocal epithelial necrosis and ulceration associated with 2 to 7 µm diameter, branching, septate fungal hyphae, typically accompanied by deeper infiltration into underlying skeletal muscle. Angioinvasion, with vascular thrombosis and tissue infarction, was a prominent feature in multiple animals. Fungal invasion of one or more internal organs was observed in 4 animals. Hyphae appeared to course freely through tissues and elicited little or no inflammatory response. Fusariosis has been reported sporadically in fish and other aquatic organisms, but identification has often been limited to the genus level based solely on morphologic features. Morphologic characteristics of the fungus isolated from this case were consistent with the Fusarium solani species complex (FSSC), which includes over 50 members that can only be identified definitively using DNA sequence data. A 3-locus typing scheme identified the isolate as a distinct species/haplotype, designated FSSC 12-a, belonging to a specific lineage that appears adapted to aquatic environments and disease in marine animals. Empirical treatment with itraconazole failed to stop mortalities, and subsequent in vitro antifungal susceptibility data explained a lack of clinical efficacy for this agent. Effective treatment in human medicine has similarly been limited by poor susceptibility to several classes of antifungal compounds. PMID:23047188

Salter, Caroline E; O'Donnell, Kerry; Sutton, Deanna A; Marancik, David P; Knowles, Susan; Clauss, Tonya M; Berliner, Aimee L; Camus, Alvin C

2012-10-10

98

Polyenes with maximum HOMO–LUMO gap  

Microsoft Academic Search

On the basis of a variable neighbourhood search with the AutoGraphiX software, it is conjectured that for even numbers of atoms the fully conjugated acyclic ? system of maximum HOMO–LUMO gap is a `comb' in which each vertex of a backbone carries a single pendant edge. Chemically, this represents CnH3n\\/2+2, an ?,?-diene with methylene groups attached at all intermediate positions.

P. W. Fowler; P. Hansen; G. Caporossi; A. Soncini

2001-01-01

99

Melanocortin receptors form constitutive homo- and heterodimers  

Microsoft Academic Search

A significant number of G protein-coupled receptors are shown to form homo- or heterodimers\\/oligomers, and oligomerization of GPCRs may be a quite general phenomenon. We have here explored the possibility that the two closely related human melanocortin receptor 1 (MC1R) and melanocortin receptor 3 (MC3R) form dimers. Using bioluminescence resonance energy transfer (BRET2) we demonstrate that MC1 and MC3Rs form

Ilona Mandrika; Ramona Petrovska; Jarl Wikberg

2005-01-01

100

Comparisons of Early Pleistocene Skulls from East Africa and the Georgian Caucasus: Evidence Bearing on the Origin and Systematics of Genus Homo  

Microsoft Academic Search

A half century ago, when there were fewer fossils (and not so many paleoanthropologists), characterizing the genus Homo was relatively straightforward. In addition to modern humans, Neanderthals could be included, along with other archaics such\\u000a as Broken Hill (now Kabwe) from Zambia and the Ngandong assemblage from Java. Also, it was becoming clear that Atlanthropus from northern Africa, and Pithecanthropus

G. Philip Rightmire; David Lordkipanidze

101

Foramen magnum position variation inPan troglodytes, Plio-Pleistocene hominids, and recentHomo sapiens: Implications for recognizing the earliest hominids  

Microsoft Academic Search

The anteroposterior position of the fora- men magnum distinguishes living Homo sapiens from apes, and has been used as evidence for the hominid status of numerable fossils in the history of human paleontology. Dur- ing the past decade, foramen magnum position has been cited as evidence of the hominid status of Ardipithecus and Sahelanthropus. Specifically, the basion of Ardpithecus is

James C. M. Ahern

2005-01-01

102

Trace Fossils Paleontology  

E-print Network

Trace Fossils Paleontology Geology 331 #12;Freshwater Hardgrounds and Firmgrounds and Shoreface abundant trace fossils, Cruziana Ichnofacies, Ordovician of Wyoming #12;Zoophycos, Miss., KY. Zoophycos clues: Skolithos burrows in Aladdin Sandstone, Black Hills, SD #12;Skolithos trace fossils

Kammer, Thomas

103

Fossil energy review  

SciTech Connect

The Fossil Energy Review provides an update of key events in the Department of Energy's Fossil Energy Program. This issue contains topics relating to: clean coal technology; fossil energy research; and petroleum reserves. (JEF)

Not Available

1989-01-01

104

What Is a Fossil?  

NSDL National Science Digital Library

In this classroom activity, young students explore the differences between bone and trace fossils. The activity opens with background information for teachers about fossils. After describing what a fossil is in their own words, students learn that a fossil is "any evidence of life that is at least 10,000 years old." They then explore the differences between trace and bone fossils by examining pictures. The activity concludes with a student worksheet that challenges them to identify trace and bone fossils.

105

Genome Digging: Insight into the Mitochondrial Genome of Homo  

PubMed Central

Background A fraction of the Neanderthal mitochondrial genome sequence has a similarity with a 5,839-bp nuclear DNA sequence of mitochondrial origin (numt) on the human chromosome 1. This fact has never been interpreted. Although this phenomenon may be attributed to contamination and mosaic assembly of Neanderthal mtDNA from short sequencing reads, we explain the mysterious similarity by integration of this numt (mtAncestor-1) into the nuclear genome of the common ancestor of Neanderthals and modern humans not long before their reproductive split. Principal Findings Exploiting bioinformatics, we uncovered an additional numt (mtAncestor-2) with a high similarity to the Neanderthal mtDNA and indicated that both numts represent almost identical replicas of the mtDNA sequences ancestral to the mitochondrial genomes of Neanderthals and modern humans. In the proteins, encoded by mtDNA, the majority of amino acids distinguishing chimpanzees from humans and Neanderthals were acquired by the ancestral hominins. The overall rate of nonsynonymous evolution in Neanderthal mitochondrial protein-coding genes is not higher than in other lineages. The model incorporating the ancestral hominin mtDNA sequences estimates the average divergence age of the mtDNAs of Neanderthals and modern humans to be 450,000–485,000 years. The mtAncestor-1 and mtAncestor-2 sequences were incorporated into the nuclear genome approximately 620,000 years and 2,885,000 years ago, respectively. Conclusions This study provides the first insight into the evolution of the mitochondrial DNA in hominins ancestral to Neanderthals and humans. We hypothesize that mtAncestor-1 and mtAncestor-2 are likely to be molecular fossils of the mtDNAs of Homo heidelbergensis and a stem Homo lineage. The dN/dS dynamics suggests that the effective population size of extinct hominins was low. However, the hominin lineage ancestral to humans, Neanderthals and H. heidelbergensis, had a larger effective population size and possessed genetic diversity comparable with those of chimpanzee and gorilla. PMID:21151557

Ovchinnikov, Igor V.; Kholina, Olga I.

2010-01-01

106

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

Microsoft Academic Search

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

Antoine Balzeau; Dominique Grimaud-Hervé; Emmanuel Gilissen

2011-01-01

107

Deductions from Fossil Preservtion  

NSDL National Science Digital Library

Students will view fossils, sometimes with supporting illustrations, and answer questions about them via deductive reasoning. The exercise is highly interactive, with the instructor providing hints and helpful questions. The questions concern ways in which fossil preservation reveals information about things like what kind of organism the fossil represents, how that organism lived, and how the fossil came into being.

Stanley, Steven

108

Fossils, Rocks, and Time  

NSDL National Science Digital Library

This on-line book, published by the United States Geological Survey (USGS), discusses the use of fossils in determining the age of rocks. The publication covers how to place events in correct temporal order, a description of the geologic time scale, the use of fossils to indicate rock ages, the law of fossil succession, index fossils, and radioactive dating.

Edwards, Lucy E.; Pojeta Jr., John

1997-06-26

109

The hominin fossil record: taxa, grades and clades  

PubMed Central

This paper begins by reviewing the fossil evidence for human evolution. It presents summaries of each of the taxa recognized in a relatively speciose hominin taxonomy. These taxa are grouped in grades, namely possible and probable hominins, archaic hominins, megadont archaic hominins, transitional hominins, pre-modern Homo and anatomically modern Homo. The second part of this contribution considers some of the controversies that surround hominin taxonomy and systematics. The first is the vexed question of how you tell an early hominin from an early panin, or from taxa belonging to an extinct clade closely related to the Pan-Homo clade. Secondly, we consider how many species should be recognized within the hominin fossil record, and review the philosophies and methods used to identify taxa within the hominin fossil record. Thirdly, we examine how relationships within the hominin clade are investigated, including descriptions of the methods used to break down an integrated structure into tractable analytical units, and then how cladograms are generated and compared. We then review the internal structure of the hominin clade, including the problem of how many subclades should be recognized within the hominin clade, and we examine the reliability of hominin cladistic hypotheses. The last part of the paper reviews the concepts of a genus, including the criteria that should be used for recognizing genera within the hominin clade. PMID:18380861

Wood, Bernard; Lonergan, Nicholas

2008-01-01

110

Postcrania and the specific mate recognition system  

Microsoft Academic Search

The Recognition Concept of Species is examined for its potential usefulness in discriminating speciation events in the hominid\\u000a fossil record. Controversies over species-specific characteristics amongHomo erectus and archaicHomo sapiens have centred on traits of the skull, largely because this element is most commonly preserved. Modern humans have an intuitive\\u000a knowledge of their own Specific Mate Recognition System (SMRS), and therefore

B. M. F. Galdikas; J. B. Duffy; H. Odwak; C. M. Purss; P. Vasey

1993-01-01

111

Transitional Tetrapod Fossil  

NSDL National Science Digital Library

In this video segment from NOVA: Judgment Day: Intelligent Design on Trial, learn about the discovery of a well-preserved transitional fossil and how such transitional fossils support the theory of evolution.

Foundation, Wgbh E.

2007-11-01

112

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya  

E-print Network

. Daviesj , Hubert B. Vonhofj a Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300 RA Leiden of Geosciences, University of Kiel, Ludewig-Meyn-Str. 10, D-24118 Kiel, Germany i Prehistoric Archaeology, Aarhus the Turkana Basin was hydrographically connected to the Indian Ocean, facilitating dispersal of fauna between

Paris-Sud XI, Université de

113

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya  

E-print Network

R. Davies j , Hubert B. Vonhof j a Faculty of Archaeology, Leiden University, P.O. Box 9515, 2300 RA i Prehistoric Archaeology, Aarhus University, Moesgård Allé 20, 8270 Højbjerg, Denmark j Faculty the Turkana Basin was hydrographically connected to the Indian Ocean, facilitating dispersal of fauna between

Utrecht, Universiteit

114

Fun with Fossils  

NSDL National Science Digital Library

Fossils provide a valuable record of the plant and animal life and environmental conditions from millions, even billions of years ago. In this lesson, students create their own fossils, and then use multimedia resources to learn how real fossils form and what scientists can learn from them. They should understand that fossils provide evidence of plants and animals that lived long ago, as well as the environmental conditions at that time. Instructions, a materials list, and links to multimedia resources are provided.

2005-01-01

115

Yawn Contagion and Empathy in Homo sapiens  

PubMed Central

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

Norscia, Ivan; Palagi, Elisabetta

2011-01-01

116

Yawn contagion and empathy in Homo sapiens.  

PubMed

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

Norscia, Ivan; Palagi, Elisabetta

2011-01-01

117

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.

118

The Primate Fossil Record  

Microsoft Academic Search

The Primate Fossil Record is a profusely illustrated, up-to-date, and comprehensive treatment of primate paleontology that captures the complete history of the discovery and interpretation of primate fossils. Each chapter emphasizes three key components of the record of primate evolution: history of discovery, taxonomy of the fossils, and evolution of the adaptive radiations they represent. The volume objectively summarizes the

Walter Carl Hartwig

2002-01-01

119

Is It a Fossil?  

NSDL National Science Digital Library

This formative assessment item is used to uncover students' ideas about fossils before a lesson has begun. Students will determine whether examples are fossils, and what sort of inferences can be made about prior environments because of fossils. This probe is aligned with the National Science Education Standards. Resources are provided along with instructional suggestions.

Fries-Gaither, Jessica

120

Picture Matching Fossils  

NSDL National Science Digital Library

Teaching the students how to picture match fossils and to use the Treatise to find more information. Students are given a wide range of fossils to look at and appropriate material to match their fossil to an image which gives the genus and species name. With that information, the students turn to the Treatise of Invertebrate Paleontology to find upper level taxonomic names.

Rhenberg, Elizabeth

121

Fossil-energy program  

NASA Astrophysics Data System (ADS)

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 combustor for cogeneration, TVA FBC demonstration plant program technical support, PFBC systems analysis, FBC char utilization improvement, fossil fuel applications assessments, performance assurance system support for fossil energy projects, international energy technology, generalized equilibrium models for liquid and gaseous fuel supplies, instrumentations and controls and fossil energy information center.

McNeese, L. E.

1982-01-01

122

Fossils of Kentucky  

NSDL National Science Digital Library

Information on Kentucky fossils is organized by type, age, and region. General fossil facts are given, and there are out-of-print technical reports available at this site. A fossil identification key helps users identify unknown fossils by shape or by descriptive terms. A Geologic and Paleontologic Cookbook offers directions for creating edible models that illustrate prehistoric and other Earth Science concepts (such as trilobite cookies and layer-cake geology). There are links to more K-12 activities and other fossil websites.

123

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

PubMed

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

Kupczik, Kornelius; Hublin, Jean-Jacques

2010-11-01

124

AUSTRALOPITHECUS TO HOMO: Transformations in Body and Mind  

Microsoft Academic Search

? Abstract Significant changes,occurred in human,evolution between,2.5 and 1.8 million years ago. Stone tools first appeared, brains expanded, bodies enlarged, sexual dimorphism in body size decreased, limb proportions changed, cheek teeth reduced in size, and crania began to share more unique features with later Homo. Although the two earliest species of Homo, H. habilis and H. rudolfensis, retained many prim-

Henry M. McHenry; Katherine Coffing

2000-01-01

125

Fossil Mapping of Utah  

NSDL National Science Digital Library

Fossils are evidence of living organisms from the past and are usually preserved in sedimentary rocks. A fossil may be an impression left in sediments, the preserved remains of an organism, or a trace mark showing that an organism once existed. Fossils are usually made from the hard parts of an organism because soft parts decay quickly. Fossils provide clues to Earth's history. They provide evidence that can be used to make inferences about past environments. Fossils can be compared to one another, to living organisms, and to organisms that lived long ago. Students will understand how fossils are formed, where they may be found in Utah, and how they can be used to make inferences. Research locations where fossils are found in Utah and construct a simple fossil map. 4th Grade Utah Core Curriculum, Science Benchmark, Standard 4, Objective 1, UEN TASK Congratulations. You have all become Paleontologists. You study fossils and it is your job to map the fossils of Utah for the State. Students will be divided into 4 groups. Each group will be given a Utah County Map. Each group will focus on one category ...

Ramsey

2009-11-18

126

Fossil Energy Website  

NSDL National Science Digital Library

This site serves as a gathering point for US Department of Energy (USDOE) materials related to fossil energy. Well-organized and easily navigated, the Fossil Energy Website hosts a wealth of resources, including fossil energy news, related USDOE budget information, an events calendar, in-depth explorations of selected issues, speeches and testimony, technical reports, statistics, and an overview of fossil energy-related global activities, among others. Additional resources include regulatory information, a news headlines ticker, a free email update service, related links, and professional notices.

127

Plant Fossil Record  

NSDL National Science Digital Library

The International Organization of Palaeobotany (IOP) manages the Plant Fossil Record (PFR) database. The recently released version of the database, PFR2.2, offers descriptive details of most plant fossil genera and modern genera with fossil species. Based on "the scientific literature ... or museum collections," the database is organized into five sections: Genera (references for plant fossil genera published mostly before 1985), Descriptions (containing descriptive details of "the type specimens of more than 10,000 extinct plant genera"), Taxonomy (an "informal system of vascular plant classification" based on published schemes), Occurrences (distribution information and references), and Palaeo Maps.

128

Evidence of Evolution I. Fossils and the fossil record  

E-print Network

1 Evidence of Evolution I. Fossils and the fossil record · "First and foremost among the databases deposited in those Eras. #12;2 Why is the fossil record incomplete? · fossilization - "lucky accidents · conditions needed for fossilization ­ Rapid burial ­ Hard parts ­ Process unlikely in tropical regions http://www.pbs.org/wgbh/evolution

Dever, Jennifer A.

129

Evidence of Evolution I. Fossils and the fossil record  

E-print Network

Evidence of Evolution #12;I. Fossils and the fossil record � "First and foremost among in the rocks deposited in those Eras. #12;#12;Why is the fossil record incomplete? � fossilization - "lucky the step-by-step transition to becoming a tetrapod Origin of higher taxa recorded in the fossil record: 1

Dever, Jennifer A.

130

Restoring Fossil Creek  

ERIC Educational Resources Information Center

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…

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

2004-01-01

131

"It's Alive!" Fossil Activity  

NSDL National Science Digital Library

The first lab activity for the course is called "PaleontologyâPast, Present, and Future". In addition to discussing several documents related to present and future research directions in the field, students review a brief timeline of the historical development of paleontology as a science. Then they get their first opportunity to work directly with fossils. Students are presented with a set of fossil specimens in boxes (with no identifying labels). Each student selects one fossil of their own. They are asked to make and record very close, detailed observations of the specimen, and to sketch the fossil. Then they are told to "think like it's 1600." Someone has brought this object, taken out of the local rocks, for the student to investigate. The student must write a "proof" that this fossil was obviously once alive, and is not just an interesting mineral or rock formation. They can use their observations, compare the specimen to other objects with which they're familiar, resort to pure logic, or apply any other avenue of argumentation they think will help make their case. Note: In the next lab, on fossil preservation and taphonomy, the students revisit their fossil specimen, and determine its mode of preservation. Indeed, the student's "pet fossil" could be used throughout the course to illustrate various components of the course content.

Yacobucci, Peg

132

Becoming a Fossil  

NSDL National Science Digital Library

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.

2005-01-01

133

Sustainable Fossil Fuels  

Microsoft Academic Search

More and more people believe we must quickly wean ourselves from fossil fuels - oil, natural gas and coal - to save the planet from environmental catastrophe, wars and economic collapse. Professor Jaccard argues that this view is misguided. We have the technological capability to use fossil fuels without emitting climate-threatening greenhouse gases or other pollutants. The transition from conventional

Mark Jaccard

134

Fossil Dig Site  

NSDL National Science Digital Library

In this activity (located on page 5 of PDF), learners work in groups to create dig sites for display. Learners arrange dry, uncooked pasta "bones" to resemble dinosaur fossils on a foam tray of wet soil. Use this activity to introduce learners to dinosaur anatomy, dig sites, fossils, and paleontology in general.

Museum, Chicago C.

2011-01-01

135

Dinosaur Footprints & Fossils  

NSDL National Science Digital Library

In this activity, early learners simulate fossil prints in play dough or clay. Using plastic dinosaur feet to make footprints on their âmudâ (much as dinosaurs walked around their habitat) and harvest items (leaves, corn, twigs, acorns) to make impressions, learners simulate fossil prints. This resource includes open-ended discussion questions to encourage reflection.

Omsi

2004-01-01

136

Fossil energy program  

NASA Astrophysics Data System (ADS)

Research and development programs in support of the increased utilization of coal and other fossil fuel alternatives as sources of clean energy are reported. The following projects are reported: 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 combustor for cogeneration, TVA FBC demonstration plant program technical support, PFBC systems analysis, FBC char utilization improvement, fossil fuel applications assessments, performance assurance system support for fossil energy projects, international energy technology, generalized equilibrium models for liquid and gaseous fuel supplies, analysis of coal production, and fossil energy information center.

McNeese, L. E.

1981-12-01

137

Fossil Identification Project  

NSDL National Science Digital Library

Students attend a class fieldtrip where over five locations across Tennessee representing three different geological time periods (Ordovician, Devonian, and Cretaceous) are visited. The students are required to collect 20 different taxa (5 of which must be unique to each student) and then using the knowledge they have gained in labs identify their taxa to species level. They must make a powerpoint presentation summarizing the paleocological and paleoclimatological information gained about each locality through the collection of the fossil taxa. The activity helps familiarize students with the geology of Tennessee and field collection of fossils in addition to lab identification of fossils.

Lobegeier, Melissa

138

The evolution and development of cranial form in Homo sapiens  

E-print Network

the origin of modern human cranial form. In terms of pattern, AMHS crania are uniquely characterized by twoThe evolution and development of cranial form in Homo sapiens Daniel E. Lieberman* , Brandeis M. Mc of the ontogeny of these autapo- morphies indicates that the developmental changes that led to modern human

Lieberman, Daniel E.

139

Unsolved Problems in Comparing Brain Sizes in Homo Sapiens  

Microsoft Academic Search

When brain size is compared across taxonomic levels, there is a clear relation between body parameters and brain size. It is generally stated that the correlation between brain size and body parameters becomes very small at the species level (Aboitiz, 1996), but this is not the case for Homo sapiens where there is a strong correlation between brain size and

M. Peters; L. Jäncke; J. F. Staiger; G. Schlaug; Y. Huang; H. Steinmetzi

1998-01-01

140

The costal skeleton of Homo antecessor: preliminary results  

Microsoft Academic Search

The Lower Pleistocene TD6 level at the Gran Dolina site in the Sierra de Atapuerca (Burgos, Spain) has yielded nine ribs that represent a minimum of three individuals of the species, Homo antecessor. We present a detailed morphological and metric study of these costal elements, including the siding and anatomical position of all of the rib remains. The adult or

Asier Gómez-Olivencia; José Miguel Carretero; Carlos Lorenzo; Juan Luis Arsuaga; José María Bermúdez de Castro; Eudald Carbonell

2010-01-01

141

Fossil Systematic Description Project  

NSDL National Science Digital Library

Students describe an unknown vertebrate fossil (or fossils, if multiple specimens are necessary for identification). This exercise is the culmination of their lab studies in the morphology of the vertebrate skeleton and requires them to integrate their ability to describe the morphology with research into the literature on their assigned animal. Students also become familiar with presentation of research through writing a formal scientific paper in the style of a particular journal.

Hopkins, Samantha

142

Dinosaur Trace Fossils  

NSDL National Science Digital Library

Anthony J. Martin, Senior Lecturer at Emory University, provides this interesting Website on dinosaur trace fossils -- namely tracks, trails, burrows, borings, gnawings, eggs, nests, gizzard stones, and dung of dinosaurs. The site offers a brief overview followed by illustrated descriptions of particular trace fossil types: Tracks and Trackways, Eggs and Nests, Tooth Marks, Gastroliths, and Coprolites. A series of links points users to further information, and a bibliography on Vertebrate Ichnology provides additional readings (through 1997).

Martin, Anthony J.

143

Silurian Fossils from New Zealand  

Microsoft Academic Search

IN spite of its relatively small land area, New Zealand contains a remarkably complete fossil record. Up to the present the Carboniferous and the Silurian have been the only two Phanerozoic geological periods not known to be represented by fossils. The apparent absence of Silurian fossils has been considered strange because upper Ordovician and lower Devonian fossils are present in

R. A. Cooper

1970-01-01

144

Fossil Simulation in the Classroom  

ERIC Educational Resources Information Center

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)

Hoehn, Robert G.

1977-01-01

145

Flexible Serial Response Learning by Pigeons (Columba livia) and Humans (Homo sapiens)  

E-print Network

Flexible Serial Response Learning by Pigeons (Columba livia) and Humans (Homo sapiens) Walter T to each target was measured. Pigeons (Columba livia) and humans (Homo sapiens) both showed response time

Herbranson, Wally

146

The first experimental approach to probing frontier orbitals and HOMO–LUMO gap in bent metallocenes  

Microsoft Academic Search

Combination of optical and electrochemical methods provided first experimental estimate of both HOMO and LUMO relative energies and HOMO–LUMO gap in organometallic ?-complexes. Energies of redox and optical HOMO-to-LUMO electron transitions in (?-L)2MX2 (Ti, Zr, Hf) linearly correlate viz. ELMCT??Eredox,Eem(0–0)??Eredox. Replacement of Cl? with Me? ?-ligands increases the HOMO–LUMO gap, predominantly, by destabilization introduced in the LUMO via Me-ligands; that

Galina V. Loukova

2002-01-01

147

The Gran Dolina-TD6 Human Fossil Remains and the Origin of Neanderthals  

Microsoft Academic Search

\\u000a We present a revision of the main features withphylogenetic interest observed in the human fossil remains recovered from the\\u000a Aurora Stratum of the TD6 level, Gran Dolina site (Sierra de Atapuerca, Spain) that have been assigned to Homo antecessor. Our aim is to test the hypothesis of a possible relationship between this species and the European Middle and early Late

José María Bermúdez Castro; María Martinón-Torres; Aida Gómez-Robles; Ann Margvelashvili; Juan Luis Arsuaga; José Miguel Carretero; Ignacio Martinez; Susana Sarmiento

148

A Virtual Museum of Fossils  

NSDL National Science Digital Library

This collection of fossils contains 300 fossils of vertebrates and invertebrates and casts of fossils from national museums, universities and private collections. For each geologic time period, the website provides ancient world configurations, important ancient world physiographic features, ancient world locations where the fossils were found, and a comprehensive table with thumbnails of all fossils in the collection. A separate page is devoted to each specimen where multiple high resolution photographs are displayed. Reference skeletal reconstructions are shown where available from the literature.

Chatelain, Edward; Barnbaum, Cecilia

2002-05-01

149

Fossil turbulence revisited  

E-print Network

A theory of fossil turbulence presented in the 11th Liege Colloquium on Marine turbulence is "revisited" in the 29th Liege Colloquium "Marine Turbulence Revisited". The Gibson (1980) theory applied universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as it is constrained and fossilized by buoyancy forces. Towed oceanic microstructure measurements of Schedvin (1979) confirmed the predicted universal constants. Universal constants, spectra, hydrodynamic phase diagrams (HPDs) and other predictions of the theory have been reconfirmed by a wide variety of field and laboratory observations. Fossil turbulence theory has many applications; for example, in marine biology, laboratory and field measurements suggest phytoplankton species with different swimming abilities adjust their growth strategies differently by pattern recognition of several days of turbulence-fossil-turbulence dissipation and persistence times above threshold values, signaling a developing surface layer sea change. In cosmology, self-gravitational structure masses are interpreted as fossils of primordial hydrodynamic states.

Carl H. Gibson

1999-04-19

150

The Fossil Episode ?  

E-print Network

We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an inital pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form expressions for this price increase. Our calibration leads to a price increase of 40 % if capital and labor are allowed to move to the biocarbon sector. Otherwise, the price increase is much higher. We also use the model to analyze the consequences of restrictions on using biocarbon as fuel. We show that such restrictions can lead to a substantially slower global warming due to an endogenous slowdown of fossil fuel extraction. This version: Dec 4, 2012. We are greatful for comments from Per Krusell and Rick van der Ploeg as

John Hassler; Hans-werner Sinn

151

Decomposition Mechanism Studies of Energetic Molecules Using HOMO and LUMO Orbital Energy Driven Molecular Dynamics  

Microsoft Academic Search

In this paper, we present decomposition mechanism studies of energetic molecules using HOMO and LUMO orbital energy gap driven molecular dynamics (MD) method. Under frozen orbital approximation, this is an `electronic excitation' MD, where electrons is excited from HOMO to LUMO orbitals Meanwhile, the HOMO and LUMO orbital energy gap is taken as a biasing potential to accelerate chemical reactions,

Yanhua Dong; Yanfeng Song; Hakima Abou-Rachid

2009-01-01

152

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.

153

What is a Fossil?  

NSDL National Science Digital Library

In this activity about dinosaurs, learners explore how and why fossils form. First, learners are introduced to dinosaur fossils by reading the book "Bones, Bones, Dinosaur Bones" by Byron Barton. Then, learners make impressions in clay using a seashell, pennies, dinosaur teeth and other items. Next, learners make dinosaur tracks in the clay as they "walk" plastic models across the soft clay. Learners also use sponges pre-cut in the shape of dinosaur feet to make more tracks. This activity is featured on page 29 of the "Dinosphere" unit of study for K-2 learners.

Crosslin, Rick; Fortney, Mary; Indianapolis, The C.

2004-01-01

154

Fossil Fuels: Capstone  

NSDL National Science Digital Library

This lesson summarizes our dependency upon fossil fuels, pointing out that there are very few aspects of our daily life that are not impacted by their use. The discussion centers around whether these fuels could be replaced and makes the point that there is a significant percentage of them which is used to manufacture products and is not simply burned for energy. The lesson includes an activity in which students use an online calculator to estimate how much of each fossil fuel they are responsible for consuming each year.

Pratte, John

155

The infrared HOMO–LUMO gap of germanium clusters  

Microsoft Academic Search

The electronic structures of germanium cluster (Gen; n=4–32) were studied by using photoelectron spectroscopy (PES) for Gen?, GenF?, and GenCl?. The halogen atom doping method enables us to determine the HOMO–LUMO gap of the corresponding neutral Gen cluster to be 0.8–1.0 eV around n=30. This result implies that the Gen cluster itself never emits visible emissions.

Y. Negishi; H. Kawamata; F. Hayakawa; A. Nakajima; K. Kaya

1998-01-01

156

Homo floresiensis and the evolution of the hominin shoulder  

Microsoft Academic Search

The holotype of Homo floresiensis, diminutive hominins with tiny brains living until 12,000 years ago on the island of Flores, is a partial skeleton (LB1) that includes a partial clavicle (LB1\\/5) and a nearly complete right humerus (LB1\\/50). Although the humerus appears fairly modern in most regards, it is remarkable in displaying only 110° of humeral torsion, well below modern

Susan G. Larson; William L. Jungers; Michael J. Morwood; Thomas Sutikna; Jatmiko; E. Wahyu Saptomo; Rokus Awe Due; Tony Djubiantono

2007-01-01

157

Fossilization of Acidophilic Microorganisms  

Microsoft Academic Search

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

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

2010-01-01

158

Fossil-energy  

NASA Astrophysics Data System (ADS)

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.

1981-08-01

159

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.

160

Therapod Fossil Hunt Dispatch  

NSDL National Science Digital Library

This online article reports on the finding of a dromaeosaur fossil, the best specimen to date to show that feathers existed long before modern birds and flight. The research was a collaboration between the American Museum of Natural History and the Geological Museum of China.

161

Hydrogen and fossil fuels  

Microsoft Academic Search

A technological forecast is attempted of how fossil fuels will fare during the period of build-up of the hydrogen energy economy. If the latter is inevitable many might expect their death. However, they will probably always be needed as a source of chemicals, and arguments are given for the thesis that synthetic methane will remain a useful fuel even after

J. Rothstein

1995-01-01

162

Fossils and Minerals  

NSDL National Science Digital Library

This site from the Black Hills Institute features information about different types of fossils, minerals, meteorites, and geology in general. Each topic has a brief description, with links to a more detailed explanation. Various samples and books are abailable for purchase on the site.

Research, Inc. B.

163

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?

164

Rethinking Fossil Fuels  

NSDL National Science Digital Library

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.

James Hansen (NASA Goddard Institute for Space Studies;)

2008-09-09

165

Advanced fossil energy utilization  

SciTech Connect

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.

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

2010-01-01

166

Homo sapiens, Homo neanderthalensis and the Denisova specimen: New insights on their evolutionary histories using whole-genome comparisons  

PubMed Central

After a brief review of the most recent findings in the study of human evolution, an extensive comparison of the complete genomes of our nearest relative, the chimpanzee (Pan troglodytes), of extant Homo sapiens, archaic Homo neanderthalensis and the Denisova specimen were made. The focus was on non-synonymous mutations, which consequently had an impact on protein levels and these changes were classified according to degree of effect. A total of 10,447 non-synonymous substitutions were found in which the derived allele is fixed or nearly fixed in humans as compared to chimpanzee. Their most frequent location was on chromosome 21. Their presence was then searched in the two archaic genomes. Mutations in 381 genes would imply radical amino acid changes, with a fraction of these related to olfaction and other important physiological processes. Eight new alleles were identified in the Neanderthal and/or Denisova genetic pools. Four others, possibly affecting cognition, occured both in the sapiens and two other archaic genomes. The selective sweep that gave rise to Homo sapiens could, therefore, have initiated before the modern/archaic human divergence. PMID:23413113

Paixao-Cortes, Vanessa Rodrigues; Viscardi, Lucas Henrique; Salzano, Francisco Mauro; Hunemeier, Tabita; Bortolini, Maria Catira

2012-01-01

167

Sustainability of Fossil Fuels  

NASA Astrophysics Data System (ADS)

For a sustainable world economy, energy is a bottleneck. Energy is at the basis of a modern, technological society, but unlike materials it cannot be recycled. Energy or more precisely "negentropy" (the opposite of entropy) is always consumed. Thus, one either accepts the use of large but finite resources or must stay within the limits imposed by dilute but self-renewing resources like sunlight. The challenge of sustainable energy is exacerbated by likely growth in world energy demand due to increased population and increased wealth. Most of the world still has to undergo the transition to a wealthy, stable society with the near zero population growth that characterizes a modern industrial society. This represents a huge unmet demand. If ten billion people were to consume energy like North Americans do today, world energy demand would be ten times higher. In addition, technological advances while often improving energy efficiency tend to raise energy demand by offering more opportunity for consumption. Energy consumption still increases at close to the 2.3% per year that would lead to a tenfold increase over the course of the next century. Meeting future energy demands while phasing out fossil fuels appears extremely difficult. Instead, the world needs sustainable or nearly sustainable fossil fuels. I propose the following definition of sustainable under which fossil fuels would well qualify: The use of a technology or resource is sustainable if the intended and unintended consequences will not force its abandonment within a reasonable planning horizon. Of course sustainable technologies must not be limited by resource depletion but this is only one of many concerns. Environmental impacts, excessive land use, and other constraints can equally limit the use of a technology and thus render it unsustainable. In the foreseeable future, fossil fuels are not limited by resource depletion. However, environmental concerns based on climate change and other environmental effects of injecting excess carbon into the environment need to be eliminated before fossil fuels can be considered sustainable. Sustainable fossil fuel use would likely rely on abundant, low-grade hydrocarbons like coal, tar, and shale. It would require a closed cycle approach in which carbon is extracted from the ground, processed for its energy content, and returned into safe and stable sinks for permanent disposal. Such sequestration technologies already exist and more advanced approaches that could maintain access to fossil energy for centuries are on the drawing boards. I will review these options and outline a pathway towards a zero emission fossil fuel based economy that could provide energy at prices comparable to those of today for several centuries. A successful implementation will depend not only on technological advances but also on the development of economic institutions that allow one to pay for the required carbon management. If done correctly the markets will decide whether renewable energy, or sustainable fossil energy provides a better choice.

Lackner, K. S.

2002-05-01

168

Centering on Fossils and Dinosaurs.  

ERIC Educational Resources Information Center

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)

Coble, Charles R.; McCall, Gregory K.

1986-01-01

169

Biodiversity of the Fossil Record  

E-print Network

: Forams #12;Protista: Radiolarians #12;#12;Fossil Sponge, note the spicules #12;Archaeocyathid in crossBiodiversity of the Fossil Record Geology 331, Paleontology #12;Linnean Classification: Example stromatolites produced by cyanobacteria, Sharks Bay, Australia Cambrian, NY #12;Fossil bacteria 2BY old from

Kammer, Thomas

170

The largest fossil rodent  

PubMed Central

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

Rinderknecht, Andres; Blanco, R. Ernesto

2008-01-01

171

The Unknown Fossil Report  

NSDL National Science Digital Library

This project challenges the students ingenuity, creativity, and resourcefulness! They each receive a fossil of unknown identity (general geographic locality may be given, e.g., I-55 south of St. Louis, MO). The specimen is described in as much detail as possible. Their report should include taxonomic classification (as complete as they can), age, paleoecology, Earth history, and other interpretations they can infer. Identification may require library work, Internet search, etc.

Reams, Max

172

Bibliography of Fossil Vertebrates  

NSDL National Science Digital Library

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.

1997-01-01

173

Fossil fish studies  

E-print Network

histologically unsuited for fossilization in the black-shale depo- sitional environment (i.e., it was probably not composed of the same type of calcified cartilage as were other chondrichthyans in the environ- ment). Skull material from two species of edestids... have recently been reported from the Lower Triassic of Wapiti Lake, British Columbia (Schaeffer & Mangus, 1976), whereas Edestus is unknown from rocks later than Per- mian in age. REFERENCES Bradley, F. H., 1870, Geology of Vermillion County: Geol...

Chorn, John; Reavis, E. A.; Stewart, J. D.; Whetstone, K. N.

1978-02-17

174

Fossil crinoid studies  

E-print Network

THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS November 15, 1974 Paper 73 FOSSIL CRINOID STUDIES' ROGER K. PABIAN and HARRELL L. STRIMPLE University of Nebraska, Lincoln; University of Iowa, Iowa City CONTENTS PAGE PART I. MISCELLANEOUS..., NEBRASKA 31 PART 4. BIOMETRICAL STUDY OF THE MORPHOLOGY AND DEVELOPMENT OF A NLW SPECIES OF TERPNOCRINUS STRIMPLE AND MOORE, PENNSYLVANIAN, NEBRASKA 38 REFERENCES (Pans 1-4) 52 ADDENDUM 53 ' Manuscript received February 21, 1974. 2 The University...

Pabian, R. K.; Strimple, H. L.

1974-11-15

175

Fossil crinoid studies  

E-print Network

THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS October 1, 1969 Paper 42 FOSSIL CRINOID STUDIES HARRELL L. STRIMPLE, C. O. LEVORSON, MICHAEL R. MCGINNIS, RAYMOND C. MooRE, and AMEL PRIEST CONTENTS PAGE PART 1. NEW LECANOCRINID FROM... PENNSYLVANIAN OF OKLAHOMA (Harrell L. Strimple, with Addendum by Raymond C. Moore) 1 PART 2. UPPER PENNSYLVANIAN ANOBASICRINID FROM NEW MEXICO (Harrell L. Strimple) 8 PART 3. PENNSYLVANIAN CRINOIDS FROM OHIO AND OKLAHOMA (Harrell L. Strimple) 11 PART 4...

Strimple, H. L.; Levorson, C. O.; McGinnis, M. R.; Moore, R. C.; Priest, A.

1969-10-01

176

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.

177

Homo and Hetero-Assembly of Inorganic Nanoparticles  

NASA Astrophysics Data System (ADS)

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.

Resetco, Cristina

178

Interpreting Fossil Assemblages  

NSDL National Science Digital Library

Students are provided several fossiliferous samples to analyze in detail. I provide more than they need to snalyze so everyone in the class can be working. I give a range of specimens of different geologic ages, diversities, abundances, taxonomic compositions, depositional environments and taphonomic grades. The goal is for the students to identify all of the different fossil types to the lowest taxonomic level. I provide some that are well preserved and some that are highly fragmented making identification difficult. Next, students are tasked with assigning an age range of the sample by combining the age ranges of individual taxa, and make taphonomic descriptions and paleoecological analyses.

Boyer, Diana

179

An Enlarged Parietal Foramen in the Late Archaic Xujiayao 11 Neurocranium from Northern China, and Rare Anomalies among Pleistocene Homo  

PubMed Central

We report here a neurocranial abnormality previously undescribed in Pleistocene human fossils, an enlarged parietal foramen (EPF) in the early Late Pleistocene Xujiayao 11 parietal bones from the Xujiayao (Houjiayao) site, northern China. Xujiayao 11 is a pair of partial posteromedial parietal bones from an adult. It exhibits thick cranial vault bones, arachnoid granulations, a deviated posterior sagittal suture, and a unilateral (right) parietal lacuna with a posteriorly-directed and enlarged endocranial vascular sulcus. Differential diagnosis indicates that the perforation is a congenital defect, an enlarged parietal foramen, commonly associated with cerebral venous and cranial vault anomalies. It was not lethal given the individual’s age-at-death, but it may have been associated with secondary neurological deficiencies. The fossil constitutes the oldest evidence in human evolution of this very rare condition (a single enlarged parietal foramen). In combination with developmental and degenerative abnormalities in other Pleistocene human remains, it suggests demographic and survival patterns among Pleistocene Homo that led to an elevated frequency of conditions unknown or rare among recent humans. PMID:23527224

Xing, Song

2013-01-01

180

Unearthing Important Fossils  

NSDL National Science Digital Library

Over the past several weeks, a flurry of dinosaur and other fossil discoveries have reached the mainstream news. From the two 530-million-year-old fish-like creatures that could be the earliest known vertebrates found in China, to the bones of two dinosaurs in Madagascar that may be the oldest dinosaurs ever found, to the "60-ton giraffe-like creature" (3) found in Oklahoma (called Sauroposeidon proteles, or "thunder lizard"), paleontologists are immersed in discovery. The significance of the first discovery is triggering excitement among paleontologists, worldwide. In particular, the discovery of the two "fish-like" fossils in China (to be published in this week's journal Nature) indicates that fish (i.e., vertebrates) evolved much earlier than previously thought and that "the rates of evolution in the oceans during the Cambrian period must have been exceptionally fast" (1). This week's In The News discusses some of the recently unveiled discoveries and provides background information and resources on vertebrate paleontology.

Payne, Laura X.

181

Fossil Microorganisms in Archaean  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

182

The influence of mass, volume and density on the frequency of recovery of fossil hominid hand and wrist bones  

Microsoft Academic Search

A study of the mass, volume and density of each of the wrist and hand bones of male and female human skeletons was undertaken.\\u000a It was found that the mass and volume (i.e. size) of the bones are well correlated with the relative frequencies of preservation\\u000a ofAustralopithecus and earlyHomo wrist and hand bones from fossil hominid sites in Africa. In

D. E. Ricklan

1986-01-01

183

The Homo Cyber Sapiens, the Robot Homonidus Intelligens, and the  

E-print Network

. The examination of the fossil record has shown that biological evolution exhibits periods of relative stability, it ap­ parently does not stop. Indeed, the anthropological record shows important continuing evolutions of years of evolution [7]. The hominid line split only 5 million years ago from the chimpanzee line

Steels, Luc

184

Fossils 2: Uncovering the Facts  

NSDL National Science Digital Library

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.

Science Netlinks;

2001-10-20

185

Learning from the Fossil Record  

NSDL National Science Digital Library

Another interesting and helpful resource from the University of California Berkeley Museum of Paleontology is the Learning from the Fossil Record Web site. Educators will find a list of over twenty fossil related classroom activities presented by different authors with titles such as Building a Topographic Model, Determining the Age Of Rocks and Fossils, Fossilization and Adaptation, the Dinosaur Body Structure, Microfossils, and other interesting subjects. The detailed descriptions include everything needed to complete the individual exercises including background information, procedures, and downloads. The unique collection should be a helpful addition to any junior high or high school science curriculum.

1996-01-01

186

Fossils 2: Uncovering the Facts  

NSDL National Science Digital Library

This lesson is the second in a two-part series on fossils. It explores the information that can be discerned by comparing fossils to living organisms. Students explore fossils and are responsible for using what they have learned to do their own extrapolating. Students conduct an interview with the remains of a Protoceratops. In preparation for the interview, they brainstorm the questions for which they would like answers and then narrow their questions to those that can really be answered by studying the Protoceratops fossils.

187

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

PubMed Central

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

Brighton, Henry; Gigerenzer, Gerd

2012-01-01

188

Cranial integration in Homo: singular warps analysis of the midsagittal plane in ontogeny and evolution  

Microsoft Academic Search

This study addresses some enduring issues of ontogenetic and evolutionary integration in the form of the hominid cranium. Our sample consists of 38 crania: 20 modern adult Homo sapiens, 14 subadult H. sapiens, and four archaic Homo. All specimens were CT-scanned except for two infant H. sapiens, who were imaged by MR instead. For each specimen 84 landmarks and semilandmarks

Fred L. Bookstein; Philipp Gunz; Philipp Mitterœcker; Hermann Prossinger; Katrin Schæfer; Horst Seidler

2003-01-01

189

STRUCTURES INTERNES CLAVICULAIRES CHEZ PAN, GORILLA ET HOMO. MTHODE D'ANALYSE ET RSULTATS PRLIMINAIRES  

E-print Network

STRUCTURES INTERNES CLAVICULAIRES CHEZ PAN, GORILLA ET HOMO. MÃ?THODE D'ANALYSE ET RÃ?SULTATS PRÃ?LIMINAIRES INTERNAL STRUCTURES OF THE CLAVICLE IN PAN, GORILLA AND HOMO. METHOD OF ANALYSIS AND PRELIMINARY density bone structure superior to that of gorillas and humans. For a quarter of chimpanzees

Paris-Sud XI, Université de

190

Substituting fossil fuels with biomass  

Microsoft Academic Search

Replacing fossil fuels with sustainably-produced biomass reduces net CO2 emissions. We express the efficiency of this substitution in reduced emissions per unit of used land or biomass. The substitution costs are calculated as the cost difference between a continued use of fossil fuels at current prices and a use of biomass. The biomass technologies are assumed to be implemented when

Leif Gustavsson; Per Svenningsson

1996-01-01

191

Fossil Cetacea (whales) in the  

Microsoft Academic Search

The fossil whale Aetiocetus, first described from Oregon Coast Range exposures of the Oligocene Yaquina Formation in Lincoln County, could be one of the specimens most important to the evolutionary study of Cetacea. The origin of M ysticeti or baleen (whale-bone) whales is obscured by their poor mid-Tertiary fossil record. The recovery of Aetiocetus remains in Marion County, Oregon, is

1983-01-01

192

Speciation in the fossil record  

Microsoft Academic Search

It is easy to claim that the fossil record says nothing about speciation because the biological species concept (which relies on interbreeding) cannot be applied to it and genetic studies cannot be carried out on it. However, fossilized organisms are often preserved in sufficient abundance for populations of intergrading morphs to be recognized, which, by analogy with modern populations, are

Michael J. Benton; Paul N. Pearson

2001-01-01

193

Life of a Vertebrate Fossil  

NSDL National Science Digital Library

Unless you have a very large research grant, it can be difficult to find fossil bones. Fortunately, this very fine online learning module from the Smithsonian's Natural History Museum can help both young and old to learn about locating fossil bones, among other things. Through this multimedia feature created by the History Museum's department of paleobiology, visitors will learn what paleontologists do in each stage in the life of a vertebrate fossil. With the assistance of short video clips, interactive diagrams, and photographs, visitors will learn about how fossils are prepared for examination and how scientists unravel the stories of these paleontological finds. Finally, visitors will also learn how fossils are stored and preserved.

194

Life of a Vertebrate Fossil  

NSDL National Science Digital Library

Unless you have a very large research grant, it can be difficult to find fossil bones. Fortunately, this very fine online learning module from the Smithsonian's Natural History Museum can help both young and old to learn about locating fossil bones, among other things. Through this multimedia feature created by the History Museum's department of paleobiology, visitors will learn what paleontologists do in each stage in the life of a vertebrate fossil. With the assistance of short video clips, interactive diagrams, and photographs, visitors will learn about how fossils are prepared for examination and how scientists unravel the stories of these paleontological finds. Finally, visitors will also learn how fossils are stored and preserved.

2007-09-21

195

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

PubMed

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

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

2014-09-01

196

Fossil fuel furnace reactor  

DOEpatents

A fossil fuel furnace reactor is provided for simulating a continuous processing plant with a batch reactor. An internal reaction vessel contains a batch of shale oil, with the vessel having a relatively thin wall thickness for a heat transfer rate effective to simulate a process temperature history in the selected continuous processing plant. A heater jacket is disposed about the reactor vessel and defines a number of independent controllable temperature zones axially spaced along the reaction vessel. Each temperature zone can be energized to simulate a time-temperature history of process material through the continuous plant. A pressure vessel contains both the heater jacket and the reaction vessel at an operating pressure functionally selected to simulate the continuous processing plant. The process yield from the oil shale may be used as feedback information to software simulating operation of the continuous plant to provide operating parameters, i.e., temperature profiles, ambient atmosphere, operating pressure, material feed rates, etc., for simulation in the batch reactor.

Parkinson, William J. (Los Alamos, NM)

1987-01-01

197

FOSSIL2 energy policy model documentation: FOSSIL2 documentation  

SciTech Connect

This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume III lists the model equations and a one line definition for equations, in a short, readable format.

None

1980-10-01

198

Fossil records of volcanism  

NASA Astrophysics Data System (ADS)

Greenland glacial ice contains a fossil record of volcanic emissions transported in the stratosphere. C. V. Hammer, H. B. Clausen and W. Dansgaard (Nature, 288, 230, 1980) and M. W. Herron (Journal of Geophysical Research, 87, 3052, 1982) noted peaks of relatively high acidity in the Greenland glacial stratigraphic record that are assumed to be due to precipitation of sulfuric acid aerosols after major volcanic eruptions. R. B. Stothers and M. R. Rampino of the Goddard Institute for Space Studies in New York recently did a search of historical records and found an unexpected correlation of European volcano activity in the period 1500 B.C. to A.D. 1500 with dated acid maxima in Greenland ice (Science, 222, 411-412, 1983).Stothers and Rampino's soon-to-be-reported search (Journal of Geophysical Research, in press) included examination of “about one quarter of a million pages of modern English test” (Science). In their analysis they took into account the statistical uncertainty of the icecore dates and the time lags that would be expected to delay the arrival of acid rain from distant European volcano sources. Of course the problem of the analysis is that whereas there are extensive records of European volcanos, there is precious little information on volcano activity that must have occurred during the same period in the western Pacific and in the western hemisphere. Beginning with the volcano in Thera, Greece, set at about 1450 B.C. (the volcano date having been determined from “archeology and legend”) and its Greenland ice acid peak date set at about 1390 B.C. (± 50, by radiocarbon methods), Stothers and Rampino correlate historical data through Vesuvius (217-216 B.C), Etna (44 B.C.), and others. There seems to be an acid peak to correlate in each instance in the data of Hammer et al.

Bell, Peter M.

199

The legacy of fossil fuels.  

PubMed

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30?Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. PMID:21290608

Armaroli, Nicola; Balzani, Vincenzo

2011-03-01

200

Getting Into the Fossil Record  

NSDL National Science Digital Library

This computer activity provides a basic understanding of what a fossil is and the factors involved in becoming part of the fossil record. It is organized as an informational tour in two sections: one for middle school and one for high school. Students move at a self-selected pace by progressing and answering questions. A teacher's guide contains all necessary instructions as well as lesson plans, handouts, and assessment tools.

Johnson, Jennifer; Lindstrom, Kirsten

201

Is schizophrenia the price that Homo sapiens pays for language?  

PubMed

The dichotomy between schizophrenia and manic-depressive illness is, as E. Kraepelin suspected, flawed; no unequivocal separation can be achieved. There are no categories of psychosis, but only continua of variation. However, the definition of nuclear symptoms by K. Schneider reveals the fundamental characteristics of the core syndrome--it is independent of the environment and constant in incidence across populations that have been separated for thousands of years. The associated genetic variation must be as old as Homo sapiens and represent a component of diversity that crosses the population as a whole. The fecundity disadvantage that accompanies the syndrome requires a balance in a substantial and universal advantage; this advantage, it is proposed, is the speciation characteristic of language; language and psychosis have a common evolutionary origin. Language, it is suggested, originated in a critical change on the sex chromosomes (the 'speciation event'--the genetic change that defined the species) occurring in East Africa between 100 and 250 thousand years ago that allowed the two hemispheres to develop with a degree of independence. Language can be understood as bi-hemispheric with one component function--a linear output sequence--confined to the dominant hemisphere--and a second--parallel distributed sampling occurring mainly in the non-dominant hemisphere. This mechanism provides an account of the generativity of language. The significance of nuclear symptoms is that these reflect a breakdown of bi-hemispheric coordination of language, perhaps specifically of the process of 'indexicalisation' (the distinction between 'I' and 'you') of self- versus other-generated references. Nuclear symptoms can be described as 'language at the end of its tether'; the phenomena and population characteristics of the nuclear syndrome of schizophrenia thus yield clues to the origin of the species. PMID:9468348

Crow, T J

1997-12-19

202

The First Humans: A Summary Perspective on the Origin and Early Evolution of the Genus Homo  

Microsoft Academic Search

Origin, adaptation and diversity are eternal themes in human evolution. These issues are equally timeless with respect to\\u000a our own lineage. Human paleontologists continue to grapple with questions surrounding the origin and early evolution of our\\u000a own genus. How do we identify the earliest members the genus Homo? How many species of Homo were there in the Pliocene and Pleistocene,

Frederick E. Grine; John G. Fleagle

203

Travels with the Fossil Hunters  

NASA Astrophysics Data System (ADS)

Whether dodging bullets in West Africa, or rabid dogs in Pakistan, surviving yak-butter tea in Tibet, or eating raw fish in China, the life of a globe-trotting fossil hunter is often hazardous and always filled with surprises. Travels with the Fossil Hunters lets readers share the wonder, joys of discovery, and excitement of these intrepid scientists. Packed with more than 100 beautiful, full-color photographs, the volume takes readers on twelve expeditions to remote parts of the world in search of diverse fossil remains, from those of dinosaurs to human ancestors. Each expedition by paleontologists from London's Natural History Museum reveals the problems and challenges of working in extreme conditions, from the deserts of the Sahara and Yemen to the frozen wastes of Antarctica, from the mountains of India to the forests of Latvia. Along the way they also describe the paleontology and geology of the countries they visit and the scientific reasons for their expeditions. With a foreword from Sir David Attenborough and an introduction from Richard Fortey, this fascinating book will appeal to amateur and professional fossil hunters alike and to readers interested in accounts of exotic locales. Peter Whybrow is a research scientist at the Natural History Museum, London. His research interests include Arabian Miocene vertebrates, paleoclimates, paleogeography, and biotic diversity. He is senior editor with A. Hill of Fossil Vertebrates of Arabia (Yale University Press, New Haven, 1999).

Whybrow, Peter J.

2000-04-01

204

A Galactic Fossil  

NASA Astrophysics Data System (ADS)

How old are the oldest stars? Using ESO's VLT, astronomers recently measured the age of a star located in our Galaxy. The star, a real fossil, is found to be 13.2 billion years old, not very far from the 13.7 billion years age of the Universe. The star, HE 1523-0901, was clearly born at the dawn of time. "Surprisingly, it is very hard to pin down the age of a star", the lead author of the paper reporting the results, Anna Frebel, explains. "This requires measuring very precisely the abundance of the radioactive elements thorium or uranium, a feat only the largest telescopes such as ESO's VLT can achieve." ESO PR Photo 23a/07 ESO PR Photo 23a/07 The 'Cosmic Clock' This technique is analogous to the carbon-14 dating method that has been so successful in archaeology over time spans of up to a few tens of thousands of years. In astronomy, however, this technique must obviously be applied to vastly longer timescales. For the method to work well, the right choice of radioactive isotope is critical. Unlike other, stable elements that formed at the same time, the abundance of a radioactive (unstable) isotope decreases all the time. The faster the decay, the less there will be left of the radioactive isotope after a certain time, so the greater will be the abundance difference when compared to a stable isotope, and the more accurate is the resulting age. Yet, for the clock to remain useful, the radioactive element must not decay too fast - there must still be enough left of it to allow an accurate measurement, even after several billion years. "Actual age measurements are restricted to the very rare objects that display huge amounts of the radioactive elements thorium or uranium," says Norbert Christlieb, co-author of the report. ESO PR Photo 23b/07 ESO PR Photo 23b/07 Uranium Line in the Spectrum of an Old Star Large amounts of these elements have been found in the star HE 1523-0901, an old, relatively bright star that was discovered within the Hamburg/ESO survey [1]. The star was then observed with UVES on the Very Large Telescope (VLT) for a total of 7.5 hours. A high quality spectrum was obtained that could never have been achieved without the combination of the large collecting power Kueyen, one of the individual 8.2-m Unit Telescopes of the VLT, and the extremely good sensitivity of UVES in the ultraviolet spectral region, where the lines from the elements are observed. For the first time, the age dating involved both radioactive elements in combination with the three other neutron-capture elements europium, osmium, and iridium. "Until now, it has not been possible to measure more than a single cosmic clock for a star. Now, however, we have managed to make six measurements in this one star", says Frebel. Ever since the star was born, these "clocks" have ticked away over the eons, unaffected by the turbulent history of the Milky Way. They now read 13.2 billion years. The Universe being 13.7 billion years old, this star clearly formed very early in the life of our own Galaxy, which must also formed very soon after the Big Bang. More Information This research is reported in a paper published in the 10 May issue of the Astrophysical Journal ("Discovery of HE 1523-0901, a Strongly r-Process Enhanced Metal-Poor Star with Detected Uranium", by A. Frebel et al.). The team includes Anna Frebel (McDonald Observatory, Texas) and John E. Norris (The Australian National University), Norbert Christlieb (Uppsala University, Sweden, and Hamburg Observatory, Germany), Christopher Thom (University of Chicago, USA, and Swinburne University of Technlogy, Australia), Timothy C. Beers (Michigan State University, USA), Jaehyon Rhee (Center for Space Astrophysics, Yonsei University, Korea, and Caltech, USA).

2007-05-01

205

Fossils: Observing, Making and Learning  

NSDL National Science Digital Library

In this activity, learners explore how casts of fossilized bones are created and used to learn about dinosaurs. Learners make observations, draw diagrams and share their findings. Learners also make clay molds to create plaster copies of real fossils. Then, learners consider how animals' and dinosaurs' body parts were used for protection, hunting, eating, etc. This activity is featured on pp.11-13 (part of a lesson that begins on p.7) of the "Dinosphere" unit of study for grades 3-5.

Crosslin, Rick; Fortney, Mary; Indianapolis, The C.

2004-01-01

206

Oldest Fossil Basidiomycete Clamp Connections  

E-print Network

- gia 81:622–626 Pirozynski KA (1976) Fossil fungi. Annu Rev Phytopathol 14:237–246 Poinar GO, Brown AE (2003) A non-gilled hymenomycete in Cretaceous amber. Mycol Res 107:763–768 Poinar GO, Singer R (1990) Upper Eocene gilled mushroom from the Dominican... Basin (France) #2; Basidiomycota #2; Chert #2; Fossil fungi #2; Mississippian Introduction Molecular clock estimates have been used to suggest that the first Basidiomycota occurred during the Paleozoic, some 500 million years (Ma) ago (Berbee and Taylor...

Krings, Michael; Dotzler, Nora; Galtier, Jean; Taylor, Thomas N.

2011-01-01

207

FOSSIL2 energy policy model documentation: FOSSIL2 documentation  

SciTech Connect

This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume II provides the model equations with each of their variables defined, while Volume III lists the equations, and a one line definition for equations, in a shorter, more readable format.

None

1980-10-01

208

Uncovering Visitor Conceptions of Fossils and the Fossil Record  

Microsoft Academic Search

One of the common features of any natural history museum is its fossil collection. A visitor's prior knowledge of and experience with these prehistoric objects is expected to greatly influence how visitors make sense of these iconic displays. For this study, over 150 visitors to two natural history museums in Southern California were interviewed to find out what they knew

James Kisiel; Jeanine Ancelet

2009-01-01

209

The future of fossil fuels  

Microsoft Academic Search

With today's energy technology, the world faces a stark choice between economic growth and a healthy environment. The accumulation of CO2 in the atmosphere must stop, while energy services to a growing world population striving for a high standard of living must improve. New technologies must eliminate CO2 emissions. Only carbon capture and storage can maintain access to fossil carbon

Klaus Lackner

2007-01-01

210

Progress of Fossil Fuel Science  

Microsoft Academic Search

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

M. F. Demirbas

2007-01-01

211

Synthetic soup ground trace fossils  

NSDL National Science Digital Library

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

Cowan, Clint

212

Corrosion in fossil fuel systems  

Microsoft Academic Search

The overall aim of the symposium was to present, in a concise form, the types of corrosion problems of current intense interest in fossil fuel systems, and their relationships to the specific process parameters. In addition, papers were sought which would illustrate how basic understanding of corrosion mechanisms, developed in well-controlled, clean systems, has been used to formulate approaches to

1983-01-01

213

Theory of fossil magnetic field  

E-print Network

Theory of fossil magnetic field is based on the observations, analytical estimations and numerical simulations of magnetic flux evolution during star formation in the magnetized cores of molecular clouds. Basic goals, main features of the theory and manifestations of MHD effects in young stellar objects are discussed.

Dudorov, Alexander E

2014-01-01

214

Mitochondrial genomes as living 'fossils'.  

PubMed

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

Small, Ian

2013-01-01

215

Hagerman Fossil Beds National Monument  

NSDL National Science Digital Library

This National Park Service website offers descriptions of: the animal fossils found at this park, including the extinct Hagerman horse; the geology of the park which is mostly floodplain sediments of primarily silty clays; and the geological, hydrological, and hydrostratigraphical aspects of a landslide model. There are photos of park landslides, prehistoric projectile points, and the historical Oregon Trail.

216

Fossil Reptiles of Great Britain  

E-print Network

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 series of volumes will review the current state of knowledge of the key earth-science sites in Great

Benton, Michael

217

Synthesis and GABAA receptor activity of A-homo analogues of neuroactive steroids.  

PubMed

A procedure is described for the preparation of A-homo-5-pregnenes via an acid catalyzed rearrangement of cyclopropylcarbinols assisted by microwave irradiation. 3alpha-Hydroxy and 4alpha-hydroxy-A-homo-5-pregnen-20-one, analogues of the neuroactive steroid allopregnanolone, were obtained by means of a regioselective epoxidation of a double bond in the expanded A-ring, using a fructose-derived chiral ketone as catalyst and oxone as oxidant. Although both these compounds were marginally active in inhibiting TBPS binding to GABA(A) receptors, 3beta-hydroxy-A-homo-5-pregnen-20-one was almost as active as allopregnanolone. Reduction of the double bond of the latter compound resulted in a ten fold loss of activity. PMID:20417993

Dansey, María V; Di Chenna, Pablo H; Veleiro, Adriana S; Kristofíková, Zdena; Chodounska, Hana; Kasal, Alexander; Burton, Gerardo

2010-07-01

218

JiTT - Ethics of Fossil Collecting  

NSDL National Science Digital Library

1) What do you think it means for a fossil resource to be "abused"? 2) What's the issue with fossil hunting on federal land (such as National Parks)? Explain what your interpretation of the conflict ...

Guertin, Laura

219

Identifying Fossils: Exploring the Mississippi River Bluffs  

NSDL National Science Digital Library

This activity is a geology lab where students learn about fossils found in sedimentary rocks and show their understanding by writing a literary nonfiction paper from the perspective of one of those fossils.

220

Fossilization and Adaptation Activities in Paleontology  

NSDL National Science Digital Library

This activity introduces students to the concepts of time, past life, and fossils. After completing these exercises students will be able to evaluate the importance of fossils to our knowledge of past life, identify conditions necessary for fossilization, construct a possible scenario for formation of fossils, understand how organisms are adapted to their environments, and understand the relationships of modern and ancient communities with their environments.

Breithaupt, Brent

221

Hunting Invertebrate Fossils in the Classroom  

NSDL National Science Digital Library

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.

Garbisch, Jon

222

Respiratory Mechanisms and the Metazoan Fossil Record  

Microsoft Academic Search

THE fossil record sheds little light on the problem of metazoan origins. Most of the major metazoan phyla appear in the fossil record in the Cambrian but no ancestral organisms have been found in the Precambrian, although suitable non-metamorphosed Precambrian rocks exist1. The oldest known metazoan fossils (latest Precambrian) are those from the Ediacara formation, Australia2. These fossils represent soft-bodied

Rudolf A. Raff

1970-01-01

223

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

NASA Astrophysics Data System (ADS)

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.

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

2010-11-01

224

Organism Population and Organic Fossil Fuels  

Microsoft Academic Search

Organic fossil fuels are from sedimentary basin and the basin is a huge crude reactor, which should be a grand canonical ensemble. Formation and occurrence of organic fossil fuels should be treated with the principle of thermodynamics of non-equilibrium. In the basin, the distribution of organic fossil fuels is in accord with the distribution types of kerogen and the sedimentary

Jin Jun; Hou Chuangye; Wang Haoping

2007-01-01

225

A surprise inside a T. Rex fossil  

NSDL National Science Digital Library

When scientists looked inside the leg bone of a recently discovered Tyrannosaurus rex fossil, they found something they weren't expecting. Typically, only the hard parts of an animal, like the bones, are preserved as fossils. This T. rex fossil, however, contained some beautifully preserved soft tissue inside the bone, where the marrow once was.

American Association for the Advancement of Science (AAAS;)

2005-03-24

226

Evidence of Evolution the fossil record  

E-print Network

1 Evidence of Evolution the fossil record · spotty - more complete in some regions than others to becoming a tetrapod Origin of higher taxa recorded in the fossil record: 1) tetrapod evolution #12;4 Transitional species ­ 1st true frog: Vierealla, 190 mya 2) Frog evolution in the fossil record: Dinosaurs

Dever, Jennifer A.

227

Expected Anomalies in the Fossil Record  

Microsoft Academic Search

The problem of intermediates in the fossil record has been frequently discussed ever since Darwin. The extent of `gaps' (missing transitional stages) has been used to argue against gradual evolution from a common ancestor. Traditionally, gaps have often been explained by the improbability of fossilization and the discontinuous selection of found fossils. Here we take an analytical approach and demonstrate

Mareike Fischer; Mike Steel

2007-01-01

228

Advanced Fossil Energy Technologies: Current reports  

Microsoft Academic Search

Advanced Fossil Energy Technologies (FET) is designed to keep fossil energy researchers informed of the latest scientific and technical reports in their area. The publication announces all DOE-sponsored reports and patent applications in the subject scope of fossil energy that have been received and processed into the Energy Data Base (EDB) in a two-week period prior to the publication date

Tamura

1988-01-01

229

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere literature on the atmospheric lifetime of fossil fuel CO2 and its impact on climate, and we present initial

Matsumoto, Katsumi

230

Looking at Fossils in New Ways  

ERIC Educational Resources Information Center

Existing fossils could be studied from a different prospective with the use of new methods of analysis for gathering more information. The new techniques of studying fossils binds the new and the old techniques and information and provides another way to look at fossils.

Flannery, Maura C.

2005-01-01

231

Cretaceous Fossils: Plants Quick Identification Gallery  

NSDL National Science Digital Library

This site forms a component of the CretaceousFossils.com page providing detailed information and high resolution photos of Cretaceous plants. The site supplies a practical, visual resource designed to facilitate identification of plant fossils from the Cretaceous Period. Educators and students alike may find this site and its links useful for viewing, identifying and downloading photos of exceptionally preserved fossil plant specimens.

Keith, Minor; Cretaceousfossils.com

232

Fossil Collection and Museum Curation  

NSDL National Science Digital Library

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.

Boyer, Diana

233

Further fossil cephalopods from Jamaica  

Microsoft Academic Search

Fossil cephalopods are rare in the Antillean region. A deformed conch of a kossmaticeratid ammonite,Pseudokossmaticerasl sp., from the Maastrichtian of the Blue Mountain Inlier is the first ammonite from southeastern Jamaica. This tentative systematic\\u000a assignment is in agreement with the age otherwise assigned to these rocks.Cimomia sp. cf.C. vaughani (Gardner) is a hercoglossid nautiloid from the Lower-Middle Eocene Chapelton Formation

Stephen K. Donovan; Grenville Draper

2001-01-01

234

Extinction and the fossil record  

NASA Technical Reports Server (NTRS)

The author examines evidence of mass extinctions in the fossil record and searches for reasons for such large extinctions. Five major mass extinctions eliminated at least 40 percent of animal genera in the oceans and from 65 to 95 percent of ocean species. Questions include the occurrence of gradual or catastrophic extinctions, causes, environment, the capacity of a perturbation to cause extinctions each time it happens, and the possibility and identification of complex events leading to a mass extinction.

Sepkoski, J. J. Jr; Sepkoski JJ, ,. J. r. (Principal Investigator)

1994-01-01

235

The Early Eukaryotic Fossil Record  

Microsoft Academic Search

The Precambrian era records the evolution of the domain Eucarya. Although the taxonomy of fossils is often impossible to resolve\\u000a beyond the level of domain, their morphology and chemistry indicate the evolution of major biological innovations. The late\\u000a Archean record for eukaryotes is limited to trace amounts of biomarkers. Morphological evidence appears in late Paleoproterozoic\\u000a and early Mesoproterozoic (1800–1300 Ma)

Emmanuelle J. Javaux

236

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

E-print Network

have yielded fossil vertebrates, ranging in age from the Ordovician to the Pleistocene. The currentThe 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

Benton, Michael

237

Turbulence and diffusion: fossil turbulence  

E-print Network

Fossil turbulence processes are central to turbulence, turbulent mixing, and turbulent diffusion in the ocean and atmosphere, in astrophysics and cosmology, and in most other natural flows. George Gamov suggested in 1954 that galaxies might be fossils of primordial turbulence produced by the Big Bang. John Woods showed that breaking internal waves on horizontal dye sheets in the interior of the stratified ocean form highly persistent remnants of these turbulent events, which he called fossil turbulence. The dark mixing paradox of the ocean refers to undetected mixing that must exist somewhere to explain why oceanic scalar fields like temperature and salinity are so well mixed, just as the dark matter paradox of galaxies refers to undetected matter that must exist to explain why rotating galaxies don't fly apart by centrifugal forces. Both paradoxes result from sampling techniques that fail to account for the extreme intermittency of random variables involved in self-similar, nonlinear, cascades over a wide range of scales; turbulent vorticity for dark mixing, and accreting small-planetary-mass MACHO number density for dark matter.

Carl H. Gibson

2000-03-10

238

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

E-print Network

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

Paris-Sud XI, Université de

239

Relationship of Cranial Robusticity to Cranial Form, Geography and Climate in Homo sapiens  

E-print Network

Sciences, Stony Brook University Medical Center, Stony Brook, NY 11794 2 Department of Human Evolution, Max ABSTRACT Variation in cranial robusticity among modern human populations is widely acknowledged in modern humans are also used as diagnostic characters to distin- guish among Homo taxa and to reconstruct

Baab, Karen L.

240

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

E-print Network

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

Lummaa, Virpi

241

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

ERIC Educational Resources Information Center

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…

Poti, Patrizia; Hayashi, Misato; Matsuzawa, Tetsuro

2009-01-01

242

Determination of the chemical potential and HOMO\\/LUMO orbitals in density purification methods  

Microsoft Academic Search

Several density purification methods have been proposed to achieve linear scaling in Hartree–Fock and Kohn–Sham calculations. However, only the density is found, while in the traditional diagonalization method the orbitals are also obtained. This could be seen as a drawback as in many cases one would like at least the HOMO and LUMO orbitals and their orbital energies. In this

Emanuel H. Rubensson; Hans Jørgen Aa. Jensen

2006-01-01

243

Basis set effects on relative energies and HOMO–LUMO energy gaps of fullerene C 36  

Microsoft Academic Search

Fifteen C36 isomers were examined to determine the influence that the quality of basis sets has on the geometry parameters, the relative stability and HOMO–LUMO energy gaps of fullerene isomers calculated with density functional theory. It is worthwhile to note that the geometry parameters of all C36 isomers are insensitive to basis sets. On the other hand, one set of

Kyoung Hoon Kim; Young-Kyu Han; Jaehoon Jung

2005-01-01

244

Biradicaloid character of phenalenyl-based aromatic compounds with a small HOMO–LUMO gap  

Microsoft Academic Search

Biradicaloid character of three Kekulé aromatic compounds containing two phenalenyl moieties is discussed on the basis of the theoretical and experimental results. DFT calculation of the compounds reveals a small HOMO–LUMO gap with a large spatial overlap between them, leading to a singlet biradical character in a ground state and an excited triplet biradical state with a small ?ES–T. Singlet

Takashi Kubo; Maki Sakamoto; Kazuhiro Nakasuji

2005-01-01

245

Implicit and Explicit Category Learning by Macaques (Macaca mulatta) and Humans (Homo sapiens)  

E-print Network

Implicit and Explicit Category Learning by Macaques (Macaca mulatta) and Humans (Homo sapiens) J theoretical perspective differentiates in humans an explicit, rule-based system of category learning from. Humans and macaques learned categories composed of sine-wave gratings that varied across trials in bar

Indiana University

246

Greater Emphasis on Female Attractiveness in Homo sapiens: A Revised Solution to an Old Evolutionary Riddle  

Microsoft Academic Search

Substantial evidence from psychology and cross-cultural anthropology supports a general rule of greater emphasis on female physical attractiveness in Homo sapiens. As sensed by Darwin (1871) and clarified by Trivers (1972), generally higher female parental investment is a key determinant of a common pattern of sexual selection in which male animals are more competitive, more eager sexually and more conspicuous

Jonathan Gottschall

247

L’architecture de l’épaule au sein du genre Homo : nouvelles interprétations  

Microsoft Academic Search

The morphology of human clavicles can be estimated by projecting them on two perpendicular planes in order to assess the shapes of their cranial and dorsal primary curvatures. In cranial view no differences in curvature appear within the genus Homo, which means the different species had similar arms elevation capacity, especially in protraction. On the contrary, in dorsal view two

Jean-Luc Voisin

2010-01-01

248

Teaching Paleontology: Fascinating Fossils (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

This National Park Service (NPS) educational website contains a presentation for upper-elementary students about fossils and how they form. Detailed photos and illustrations discuss fossil types such as petrification or permineralization, carbon fossils, trace fossils, casts and molds, pseudofossils and index fossils. This slide show indicates how these different fossil types form and are preserved, and in which National Park areas they are found. The parks mentioned included John Day Fossil Beds, Petrified Forest, Agate Fossil Beds, Florissant Fossil Beds, and Hagerman Fossil Beds.

Monument, Florissant F.

1999-12-17

249

Fossil energy biotechnology: A research needs assessment  

NASA Astrophysics Data System (ADS)

The Office of Program Analysis of the U.S. Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation's fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

1993-11-01

250

Layered Fossil Parfait: Deeper is Older  

NSDL National Science Digital Library

In this activity, learners explore dinosaur fossils by making an edible treat. First, learners read "Dinosaur Bones" by Aliki to examine how fossils are formed. Then, the educator sifts through the class garbage to demonstrate that the deeper something is buried the older it may be. Next, learners make a layered dinosaur fossil model using candy and other treats. This activity is featured on page 30 of the "Dinosphere" unit of study for K-2 learners.

Crosslin, Rick; Fortney, Mary; Indianapolis, The C.

2004-01-01

251

Teaching Through Trade Books: Fascinating Fossil Finds  

NSDL National Science Digital Library

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.

Royce, Chrstine A.

2004-10-01

252

Biased versus unbiased randomness in homo-polymers and copolymers of amino acids in the prebiotic world.  

PubMed

The polymerization of amino acids under anhydrous prebiotic conditions was first studied several decades ago. Here we use a stochastic model stressing the relevant role of the polarity of amino acids in the formation of oligopeptides in a prebiotic milieu. Our goal is to outline the predominance of co-polypeptides over homo-polypeptides, resulting not only from the randomness, but also from polarity properties of amino acids. Our results conclude that there was a higher probability of the formation of co-polypeptides than of homo-polymers. Besides, we may hypothesize that the former would have a more ample spectrum of possible chemical functions than homo-polypeptides. PMID:23128064

Mosqueira, Fernando G; Negron, Alicia; Ramos, Sergio; Polanco, Carlos

2012-01-01

253

Proposing Explanations for Fossil Footprints  

NSDL National Science Digital Library

This activity will allow students to observe and interpret fossil footprint evidence. From the evidence, they are asked to construct defensible hypotheses or explanations for events that took place in the geological past. Students will be asked to propose explanations and make predictions based on evidence, recognize and analyze alternative explanations and predictions, understand that scientific explanations are subject to change as new evidence becomes available, and understand that scientific explanations must meet certain criteria. Students learn that scientific explanations must be consistent with experimental and observational evidence, should also be logical, respect the rules of evidence, be open to criticism, report methods and procedures, and make knowledge public. The site contains all of the information and instructions needed to complete the activity.

254

Fossil fuel biodegradation: laboratory studies.  

PubMed

Biodegradation of the polycyclic aromatic hydrocarbons of creosote by undefined bacterial cultures was shown to be accompanied by the accumulation of neutral and acidic oxidation products. Formation of a number of identified neutral products is accounted for by demonstration of anomalous actions of an arene dioxygenase on the benzylic methylene and methylene carbons of napthenoaromatic hydrocarbons. Both neutral and acidic water-soluble fractions are also formed when various mixed bacterial cultures degrade weathered crude oil. While constituents of these fractions are not yet identified, the neutral materials have been shown to be toxic to developing embryos of invertebrates. These observations are discussed in relation to chemical and toxicological assessments of biodegradation of the complex chemical mixtures of fossil fuels. PMID:8565917

Chapman, P J; Shelton, M; Grifoll, M; Selifonov, S

1995-06-01

255

Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules.  

PubMed

A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (Rudberg 2012 J. Phys.: Condens. Matter 24 072202) has demonstrated vanishing HOMO-LUMO gaps for these systems, which is generally attributed to the treatment of exchange in the functional used. The present work shows that the vanishing gap is, in fact, an electrostatic artefact of the method used to prepare the system. Practical solutions for ensuring the gap is maintained when the system size is increased are demonstrated. This work has important implications for the use of large-scale density-functional theory in biomolecular systems, particularly in the simulation of photoemission, optical absorption and electronic transport, all of which depend critically on differences between energies of molecular orbitals. PMID:23470878

Lever, Greg; Cole, Daniel J; Hine, Nicholas D M; Haynes, Peter D; Payne, Mike C

2013-04-17

256

Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules  

E-print Network

A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (E. Rudberg, J. Phys.: Condens. Mat. 2012, 24, 072202) has demonstrated vanishing HOMO-LUMO gaps for these systems, which is generally attributed to the treatment of exchange in the functional used. The present work shows that the vanishing gap is, in fact, an electrostatic artefact of the method used to prepare the system. Practical solutions for ensuring the gap is maintained when the system size is increased are demonstrated. This work has important implications for the use of large-scale density-functional theory in biomolecular systems, particularly in the simulation of photoemission, optical absorption and electronic transport, all of which depend critically on differences between energies of molecular orbitals.

Greg Lever; Daniel J Cole; Nicholas D M Hine; Peter D Haynes; Mike C Payne

2013-02-19

257

Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules  

E-print Network

A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (E. Rudberg, J. Phys.: Condens. Mat. 2012, 24, 072202) has demonstrated vanishing HOMO-LUMO gaps for these systems, which is generally attributed to the treatment of exchange in the functional used. The present work shows that the vanishing gap is, in fact, an electrostatic artefact of the method used to prepare the system. Practical solutions for ensuring the gap is maintained when the system size is increased are demonstrated. This work has important implications for the use of large-scale density-functional theory in biomolecular systems, particularly in the simulation of photoemission, optical absorption and electronic transport, all of which depend critically on differences between energies of molecular orbitals.

Lever, Greg; Hine, Nicholas D M; Haynes, Peter D; Payne, Mike C

2013-01-01

258

Size-dependent HOMO-LUMO gap oscillation of carbon nanotube with a finite length  

Microsoft Academic Search

The electronic structure of carbon nanotube(5, 5) with a finite length, is studied on the basis of Hückel molecular orbital method. HOMO-LUMO gap oscillates and decreases as the length l of tube increases, where l is the number of cis-polyene rings of the circumference of carbon nanotube. For tube(5,5, l) without a cap the gap vanishes at l = 3n

Tohru Sato; Motoki Tanaka; Tokio Yamabe

1999-01-01

259

Unoccupied orbital energies of 1,4-benzenedithiol and the HOMO–LUMO gap  

Microsoft Academic Search

The energies of the temporary anion states of 1,4-benzenedithiol (BDT) are determined by electron scattering and compared with those computed by density functional theory (DFT) and Hartree–Fock (HF) methods. Using semi-empirical scalings derived from the ionization energies and electron affinities of a series of phenyl–ethynyl compounds, we compute the HOMO–LUMO energy gap of BDT. We show that without such scalings

A. M. Scheer; G. A. Gallup; P. D. Burrow

2008-01-01

260

Geometry-based Computation of Symmetric Homo-oligomeric Protein Complexes  

Microsoft Academic Search

The need to engineer novel therapeutics and functional materials is driving the in-silico design of molecular complexes. This paper proposes a method to compute symmetric homo-oligomeric protein complexes when the structure of the replicated protein monomer is known and rigid. The relationship between the structure of a protein and its biological function brings the in-silico determina- tion of protein structures

Christopher Miles; Brian Olson; Amarda Shehu

261

New approaches toward the synthesis of (D-homo) steroid skeletons using Mukaiyama reactions  

Microsoft Academic Search

New, short, and flexible procedures have been developed for syntheses of steroid and D-homo steroid skeletons. A Mukaiyama reaction between the silyl enol ether of 6-methoxytetralone and 2-methyl-2-cyclopentenone or carvone, with transfer of the silyl group to the receiving enone, gave a second silyl enol ether. Addition of a carbocation, generated under Lewis acid conditions from 3-methoxy-2-butenol, 3-ethoxy-3-phenyl-2-propenol or 3-methoxy-2-propenol

Florence C. E. Sarabèr; Alexander Baranovsky; Ben J. M. Jansen; Maarten A. Posthumus; Aede de Groot

2006-01-01

262

Cranial integration in Homo: singular warps analysis of the midsagittal plane in ontogeny and evolution.  

PubMed

This study addresses some enduring issues of ontogenetic and evolutionary integration in the form of the hominid cranium. Our sample consists of 38 crania: 20 modern adult Homo sapiens, 14 sub-adult H. sapiens, and four archaic Homo. All specimens were CT-scanned except for two infant H. sapiens, who were imaged by MR instead. For each specimen 84 landmarks and semi-landmarks were located on the midsagittal plane and converted to Procrustes shape coordinates. Integration was quantified by the method of singular warps, a new geometric-statistical approach to visualizing correlations among regions. The two classic patterns of integration, evolutionary and ontogenetic, were jointly explored by comparing analyses of overlapping subsamples that span ranges of different hypothetical factors. Evolutionary integration is expressed in the subsample of 24 adult Homo, and ontogenetic integration in the subsample of 34 H. sapiens. In this data set, vault, cranial base, and face show striking and localized patterns of covariation over ontogeny, similar but not identical to the patterns seen over evolution. The principal differences between ontogeny and phylogeny pertain to the cranial base. There is also a component of cranial length to height ratio not reducible to either process. Our methodology allows a separation of these independent processes (and their impact on cranial shape) that conventional methods have not found. PMID:12662941

Bookstein, Fred L; Gunz, Philipp; Mitteroecker, Philipp; Prossinger, Hermann; Schaefer, Katrin; Seidler, Horst

2003-02-01

263

ANALISIS SIFAT FOTOSENSITIVITAS SENYAWA ANTIBAKTERI TURUNAN FLUOROKUINOLON BERDASARKAN DATA TRANSISI ELEKTRONIK DAN SELISIH ENERGI ORBITAL HOMO-LUMO PHOTOSENSITIVITY ANALYSIS OF FLUOROQUINOLONE ANTIBACTERIAL COMPOUNDS BASED ON ELECTRONIC TRANSITIONS DATA AND HOMO-LUMO ENERGY BAND GAP  

Microsoft Academic Search

INTISARI Telah dilakukan analisis sifat fotosensitivitas dari senyawa antibakteri fluorokuinolon berdasarkan karakteristik spektra elektronik dan selisih energi HOMO-LUMO. Perhitungan spektra elektronik dilakukan menggunakan metode semiempirik ZINDO\\/s untuk mengetahui sifat fotosensitivitasnya pada daerah ultraviolet (?=200-400 nm) untuk molekul pada fasa gas dalam bentuk ion zwitter-nya. Perhitungan selisih energi HOMO-LUMO dilakukan untuk memprediksikan kekuatan fotosensitivitas dari senyawa antibakteri tersebut. Kedua proses perhitungan

Iqmal Tahir; Faiz El Makky; Harno Dwi Pranowo; Karna Wijaya

264

Using extant morphological variation to understand fossil  

E-print Network

among populations in two living clades -- the New World tamarins (genus Saguinus) and the African greatUsing 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

Ackermann, Rebecca Rogers

265

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

E-print Network

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide David Archer,1 Michael Eby,2 Victor Brovkin,3 released from combustion of fossil fuels equilibrates among the various carbon reservoirs of the atmosphere 0084-6597/09/0530-0117$20.00 Key Words climate, warming, ocean chemistry, carbon cycle Abstract CO2

Scherer, Norbert F.

266

Silica-replaced fossils through the Phanerozoic  

Microsoft Academic Search

A systematic survey of 1863 papers on macrobenthic assemblages reveals that an average of 21% of published Paleozoic papers concern silicified fossils, but that average drops to just 4% for post-Paleozoic papers. During the Paleozoic, silicified fossil occurrences do not significantly correlate with the amount of shelf chert, outcrop area, time, duration of geologic intervals, or carbonate rock volume. This

Jennifer K. Schubert; David L. Kidder; Douglas H. Erwin

1997-01-01

267

Silica-replaced fossils through the Phanerozoic  

NASA Astrophysics Data System (ADS)

A systematic survey of 1863 papers on macrobenthic assemblages reveals that an average of 21% of published Paleozoic papers concern silicified fossils, but that average drops to just 4% for post-Paleozoic papers. During the Paleozoic, silicified fossil occurrences do not significantly correlate with the amount of shelf chert, outcrop area, time, duration of geologic intervals, or carbonate rock volume. This substantial drop in numbers of silicified fossils coincides temporally with increased importance of aragonite faunas following the end-Permian extinctions. However, qualitative measurements of secular changes in abundance and diversity of siliceous sponges are consistent not only with the post-Paleozoic decline in fossil silicification, but also with fluctuations in the amount of silicified fossils throughout the Paleozoic. The facies distribution of silicified fossils in the Permian of West Texas also suggests that the distribution of silicified fossils may reflect the occurrence of siliceous sponges. The decline in silicified fossils after the Permian may be related to a concomitant rise in offshore bedded chert deposition and movement of the locus of biogenic silica formation from nearshore to offshore regions beginning in the Triassic, rather than with the expansion of diatoms in the Cretaceous.

Schubert, Jennifer K.; Kidder, David L.; Erwin, Douglas H.

1997-11-01

268

Fossil Fuels, Stock Externalities, and Backstop Technology  

Microsoft Academic Search

The Hotelling exhaustible resource model is extended to include stock pollution and nonpolluting backstop technology. It is shown that an optimal energy consumption strategy typically includes a regime in which the two energy sources are consumed simultaneously. Along this regime, fossil fuel consumption decreases and backstop consumption increases. Together, fossil fuel and backstop consumption may form eleven optimal regime combinations.

Olli Tahvonen

1997-01-01

269

Fossil ovipositions of dragonflies: Review and interpretation  

Microsoft Academic Search

The paper deals with the stratigraphic range and morphology of fossil formations on plants interpreted as insect ovipositions.\\u000a Our analysis of the insect fossil record has shown that the endophytic ovipositions probably belong to the Kennedyina and\\u000a Triadophlebiina (in the Paleozoic and Lower Mesozoic) and to the Calopterygina (in the Upper Mesozoic and Cenozoic).

D. V. Vasilenko; A. P. Rasnitsyn

2007-01-01

270

Evolution of the biosphere and fossil fuels  

Microsoft Academic Search

The effect of fundamental events in biological evolution on the scale of fossil-fuel accumulation from the historical aspect is considered. Four main stages in the establishment of the ancient biospheres are recognized: pro-, proto-, neoto-, and acmeobiospheres. The hypothesis is based on especially favorable conditions for the formation of oil and fossil fuels during late Archean and early Proterozoic time.

N. V. Lopatin

1980-01-01

271

The original colours of fossil beetles  

PubMed Central

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

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

2012-01-01

272

Accuracy of Fossils and Dating Methods  

NSDL National Science Digital Library

The issue-focused, peer-reviewed article asserts that fossil dating is accurate because the method follows strict scientific guidelines: the age of rocks around a fossil can be considered, mathematical calculations are used, the state of decay, carbon-14, and isotopes figure in calculations, and tree of life relationships often help sort the dates.

Michael Benton (University of Bristol, UK;)

2001-01-01

273

Do alternative energy sources displace fossil fuels?  

NASA Astrophysics Data System (ADS)

A fundamental, generally implicit, assumption of the Intergovernmental Panel on Climate Change reports and many energy analysts is that each unit of energy supplied by non-fossil-fuel sources takes the place of a unit of energy supplied by fossil-fuel sources. However, owing to the complexity of economic systems and human behaviour, it is often the case that changes aimed at reducing one type of resource consumption, either through improvements in efficiency of use or by developing substitutes, do not lead to the intended outcome when net effects are considered. Here, I show that the average pattern across most nations of the world over the past fifty years is one where each unit of total national energy use from non-fossil-fuel sources displaced less than one-quarter of a unit of fossil-fuel energy use and, focusing specifically on electricity, each unit of electricity generated by non-fossil-fuel sources displaced less than one-tenth of a unit of fossil-fuel-generated electricity. These results challenge conventional thinking in that they indicate that suppressing the use of fossil fuel will require changes other than simply technical ones such as expanding non-fossil-fuel energy production.

York, Richard

2012-06-01

274

The fossil record of callitrichine primates Introduction  

E-print Network

The fossil record of callitrichine primates Introduction The ctiscovery offossils pertaining developed from horizontal comparisons against what is now a rapidly improving fossil record to the evolution of the cattitrichine New L2:ortd monke\\ s is a recognized objective of current field work and has

Rosenberger, Alfred H.

275

Creature Features - Showcase of Living Fossils  

NSDL National Science Digital Library

This activity is a side project that students work on through the organismal portion of a course in paleobiology/paleontology. Students present on the lifestyle, habitat, and behavior of "living fossil" groups. The activity ties the fossil record to the modern living world and allows students to engage with ideas of evolutionary stasis, taphonomy, and functional morphology.

Sunderlin, David

276

Book reviews Just looking at fossils  

E-print Network

on human evolution based on fossils is one example of this pattern. There are groups of organisms, however of interest is Hydrozoa. There is very little in the fossil record with regard to animals of this group, so I and less clear-cut. Hybridization can lead to the merging of species that, then, can split again, leading

Tullberg, Birgitta

277

56 SCIENCE SCOPE Fossil sharks: Learning  

E-print Network

, 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

Bermingham, Eldredge

278

Fossil Fuel Emission Verification Modeling at LLNL  

Microsoft Academic Search

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

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

2009-01-01

279

The Microbial Origin of Fossil Fuels  

Microsoft Academic Search

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

Guy Ourisson; Pierre Albrecht; Michel Rohmer

1984-01-01

280

John Day Fossil Beds National Monument  

NSDL National Science Digital Library

This National Park Service website offers an education section which includes: programs for visiting school groups involving the geological and evolutionary processes of the park, working with fossil casts, and other fossil activities; a list of classroom materials to send for (some have cost) including a horse fossil study kit, a general fossil kit, a teacher packet, and a videotape on the paleontology work at the park and evolution of the horse; and a list of teacher workshops in Oregon. There are species lists for vertebrate and plant fossils, diagrams of the major geologic formations and illustrations of different paleobiomes, species lists for existing flora and fauna, and a fire management plan. Regional and park history is covered as well as the history of the Chinookan, Sahaptian, Shoshonean, and Salishan Indians of Eastern Oregon. There is also information for planning a visit to the park.

281

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

NSDL National Science Digital Library

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.

2008-10-06

282

The future of fossil fuels  

NASA Astrophysics Data System (ADS)

With today's energy technology, the world faces a stark choice between economic growth and a healthy environment. The accumulation of CO2 in the atmosphere must stop, while energy services to a growing world population striving for a high standard of living must improve. New technologies must eliminate CO2 emissions. Only carbon capture and storage can maintain access to fossil carbon reserves that by themselves could satisfy energy demand for centuries. Technologies for CO2 capture at power plants and other large sources already exist. A new generation of efficient, clean power plants could capture its CO2 and deliver it for underground injection or mineral sequestration. However, the remaining CO2 emissions from distributed sources are too large to be ignored. Either hydrogen or electricity need to substitute for carbonaceous energy carriers, or CO2 emissions must be balanced out by capturing an equivalent amount of carbon from the environment. Biomass growth offers one such option; direct capture of CO2 from the air provides another. Carbon capture and storage technologies can close the anthropogenic carbon cycle and, thus, provide one possible avenue to a world that is not limited by energy constraints.

Lackner, Klaus

2007-03-01

283

Systematics of some enigmatic "fossils"  

NSDL National Science Digital Library

Students are given sets of different shaped fasteners (staples, paper clips, tacks, etc.) and work with the instructor through a guided exercise in which they construct a character matrix and cladogram depicting the phylogeny of the "organisms". Students are then divided into small groups; each group receives a set of various shapes/colors of pasta. (The sets are all the same.) Each group must decide how many species are present in their sample (considering the potential for ontogenetic and sexual variation within species), choose and define characters for a cladistic analysis, and construct a character matrix. The instructor runs the matrices through cladistic analysis software, and the following week the students receive the results from analysis of each group's data. The class then discusses the effects of species definition, character choice, etc. on phylogenetic hypotheses. The activity allows students to directly confront issues of identifying and distinguishing morphological species. Conflicting results obtained by different groups analyzing the same data set drive home the complicated nature of character choice and definition in construction of a character matrix for cladistic analysis, and underscore the fact that individual cladograms represent phylogenetic hypotheses subject to modification by further analysis. (This last point becomes necessary background as students encounter different/competing hypotheses of phylogenetic relationships during study of fossil invertebrates.)

Tumarkin-Deratzian, Allison

284

Clean Fossil Energy Conversion Processes  

NASA Astrophysics Data System (ADS)

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.

Fan, L.-S.

2007-03-01

285

Fossil oak galls preserve ancient multitrophic interactions  

PubMed Central

Trace fossils of insect feeding have contributed substantially to our understanding of the evolution of insect–plant interactions. The most complex phenotypes of herbivory are galls, whose diagnostic morphologies often allow the identification of the gall inducer. Although fossil insect-induced galls over 300?Myr old are known, most are two-dimensional impressions lacking adequate morphological detail either for the precise identification of the causer or for detection of the communities of specialist parasitoids and inquilines inhabiting modern plant galls. Here, we describe the first evidence for such multitrophic associations in Pleistocene fossil galls from the Eemian interglacial (130?000–115?000 years ago) of The Netherlands. The exceptionally well-preserved fossils can be attributed to extant species of Andricus gallwasps (Hymenoptera: Cynipidae) galling oaks (Quercus), and provide the first fossil evidence of gall attack by herbivorous inquiline gallwasps. Furthermore, phylogenetic placement of one fossil in a lineage showing obligate host plant alternation implies the presence of a second oak species, Quercus cerris, currently unknown from Eemian fossils in northwestern Europe. This contrasts with the southern European native range of Q. cerris in the current interglacial and suggests that gallwasp invasions following human planting of Q. cerris in northern Europe may represent a return to preglacial distribution limits. PMID:18559323

Stone, Graham N; van der Ham, Raymond W.J.M; Brewer, Jan G

2008-01-01

286

Fossil oak galls preserve ancient multitrophic interactions.  

PubMed

Trace fossils of insect feeding have contributed substantially to our understanding of the evolution of insect-plant interactions. The most complex phenotypes of herbivory are galls, whose diagnostic morphologies often allow the identification of the gall inducer. Although fossil insect-induced galls over 300Myr old are known, most are two-dimensional impressions lacking adequate morphological detail either for the precise identification of the causer or for detection of the communities of specialist parasitoids and inquilines inhabiting modern plant galls. Here, we describe the first evidence for such multitrophic associations in Pleistocene fossil galls from the Eemian interglacial (130000-115000 years ago) of The Netherlands. The exceptionally well-preserved fossils can be attributed to extant species of Andricus gallwasps (Hymenoptera: Cynipidae) galling oaks (Quercus), and provide the first fossil evidence of gall attack by herbivorous inquiline gallwasps. Furthermore, phylogenetic placement of one fossil in a lineage showing obligate host plant alternation implies the presence of a second oak species, Quercus cerris, currently unknown from Eemian fossils in northwestern Europe. This contrasts with the southern European native range of Q. cerris in the current interglacial and suggests that gallwasp invasions following human planting of Q. cerris in northern Europe may represent a return to preglacial distribution limits. PMID:18559323

Stone, Graham N; van der Ham, Raymond W J M; Brewer, Jan G

2008-10-01

287

The Fossil Record of the Peronosporomycetes (Oomycota)  

E-print Network

. Petsamomyces, a new genus of organic-walled microfossils from the coal-bearing deposits of the Early Proterozoic, Kola Peninsula. Paleontol J 40: 465–475, doi:10.1134/S0031030106050017 Berry EW. 1916. Remarkable fossil fungi. Mycologia 8:73– 79, doi:10... to the Peronosporomycetes are discussed briefly and an explanation is provided as to why the fossil record of this group has remained inconsistent. In recent years there have been several new reports of fossil peronosporomycetes based on structurally preserved oogonium...

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

2011-01-01

288

An Indoor Fossil/Archeological Dig  

NSDL National Science Digital Library

In this activity, students will participate in a simulated fossil hunt or archeological excavation. Working in groups, they will excavate fossils or artifacts buried in a container and tag, number and label, and record the position and details of each object encountered. They will make site sketches as each layer is removed. When all the objects have been found, and all the information obtained, the group can compose a field report on the dig site that makes some inferences about the conditions that existed at the time the fossil/artifact was buried. A student worksheet is provided.

2011-06-24

289

Physiological and life history strategies of a fossil large mammal in a resource-limited environment  

PubMed Central

Because of their physiological and life history characteristics, mammals exploit adaptive zones unavailable to ectothermic reptiles. Yet, they perform best in energy-rich environments because their high and constant growth rates and their sustained levels of resting metabolism require continuous resource supply. In resource-limited ecosystems such as islands, therefore, reptiles frequently displace mammals because their slow and flexible growth rates and low metabolic rates permit them to operate effectively with low energy flow. An apparent contradiction of this general principle is the long-term persistence of certain fossil large mammals on energy-poor Mediterranean islands. The purpose of the present study is to uncover the developmental and physiological strategies that allowed fossil large mammals to cope with the low levels of resource supply that characterize insular ecosystems. Long-bone histology of Myotragus, a Plio-Pleistocene bovid from the Balearic Islands, reveals lamellar-zonal tissue throughout the cortex, a trait exclusive to ectothermic reptiles. The bone microstructure indicates that Myotragus grew unlike any other mammal but similar to crocodiles at slow and flexible rates, ceased growth periodically, and attained somatic maturity extremely late by ?12 years. This developmental pattern denotes that Myotragus, much like extant reptiles, synchronized its metabolic requirements with fluctuating resource levels. Our results suggest that developmental and physiological plasticity was crucial to the survival of this and, perhaps, other large mammals on resource-limited Mediterranean Islands, yet it eventually led to their extinction through a major predator, Homo sapiens. PMID:19918076

Kohler, Meike; Moya-Sola, Salvador

2009-01-01

290

Spitzer Digs Up Galactic Fossil  

NASA Technical Reports Server (NTRS)

[figure removed for brevity, see original site] Figure 1

[figure removed for brevity, see original site] Figure 2

This false-color image taken by NASA's Spitzer Space Telescope shows a globular cluster previously hidden in the dusty plane of our Milky Way galaxy. Globular clusters are compact bundles of old stars that date back to the birth of our galaxy, 13 or so billion years ago. Astronomers use these galactic 'fossils' as tools for studying the age and formation of the Milky Way.

Most clusters orbit around the center of the galaxy well above its dust-enshrouded disc, or plane, while making brief, repeated passes through the plane that each last about a million years. Spitzer, with infrared eyes that can see into the dusty galactic plane, first spotted the newfound cluster during its current pass. A visible-light image (inset of Figure 1) shows only a dark patch of sky.

The red streak behind the core of the cluster is a dust cloud, which may indicate the cluster's interaction with the Milky Way. Alternatively, this cloud may lie coincidentally along Spitzer's line of sight.

Follow-up observations with the University of Wyoming Infrared Observatory helped set the distance of the new cluster at about 9,000 light-years from Earth - closer than most clusters - and set the mass at the equivalent of 300,000 Suns. The cluster's apparent size, as viewed from Earth, is comparable to a grain of rice held at arm's length. It is located in the constellation Aquila.

Astronomers believe that this cluster may be one of the last in our galaxy to be uncovered.

This image composite was taken on April 21, 2004, by Spitzer's infrared array camera. It is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

Galactic Fossil Found Behind Curtain of Dust In Figure 2, the image mosaic shows the same patch of sky in various wavelengths of light. While the visible-light image (left) shows a dark sky speckled with stars, infrared images (middle and right), reveal a never-before-seen bundle of stars, called a globular cluster. The left panel is from the California Institute of Technology's Digitized Sky Survey; the middle panel includes images from the NASA-funded Two Micron All-Sky Survey and the University of Wyoming Infrared Observatory (circle inset); and the right panel is from NASA's Spitzer Space Telescope.

The Two Micron All-Sky Survey false-color image was obtained using near-infrared wavelengths ranging from 1.3 to 2.2 microns. The University of Wyoming Observatory false-color image was captured on July 31, 2004, at wavelengths ranging from 1.2 to 2.2 microns. The Spitzer false-color image composite was taken on April 21, 2004, by its infrared array camera. It is composed of images obtained at four mid-infrared wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red).

2004-01-01

291

Asymmetric phase-transfer catalysis with homo- and heterochiral quaternary ammonium salts: a theoretical study.  

PubMed

A thorough theoretical study of phase-transfer quaternary ammonium catalysts designed by the Maruoka group has been performed in an attempt to gain better understanding of the properties and catalytic behavior of the homo- and heterochiral forms of these systems. The conformationally flexible analogue is found to easily undergo interconversion from the homo- to the heterochiral form driven by the higher thermodynamic stability of the heterochiral isomer and resulting in alternation in catalytic behavior. Theoretical calculations of (1)H NMR spectra of the two isomers for different model systems are in good agreement with the experimental data, allowing us to conclude that the upfield shift of signals for the benzylic protons in the heterochiral form could be explained by an increase in the shielding effect of the aromatic parts of the system around these protons due to the conformational changes. By applying the automated transition state (TS) search procedure for the alkylation of glycine derivatives catalyzed by the homo-/heterochiral form of a conformationally rigid analogue, we were able to locate more than 40 configurations of the TS structures. In brief, the homochiral form was theoretically confirmed to catalyze the formation of the predominant R-product, while for the heterochiral form the catalytic activity is found to depend on two factors: (i) formation of a tight ion pair between the catalyst and the glycine derivative, which results in a decrease in the reaction rate, in agreement with the experimental data, and formation of only the R-product, and (ii) the possibility that the reaction occurs without the initial formation of the ion pair or after its dissociation, in which case the formation of an S-product is predominant. The combined effects of both factors would explain the lower reaction rate and the poor enantioselectivity observed experimentally for the heterochiral form. PMID:24720781

Petrova, Galina P; Li, Hai-Bei; Maruoka, Keiji; Morokuma, Keiji

2014-05-15

292

Early Pleistocene 40Ar/39Ar ages for Bapang Formation hominins, Central Jawa, Indonesia  

PubMed Central

The Sangiran dome is the primary stratigraphic window for the Plio-Pleistocene deposits of the Solo basin of Central Jawa. The dome has yielded nearly 80 Homo erectus fossils, around 50 of which have known findspots. With a hornblende 40Ar/39Ar plateau age of 1.66 ± 0.04 mega-annum (Ma) reportedly associated with two fossils [Swisher, C.C., III, Curtis, G. H., Jacob, T., Getty, A. G., Suprijo, A. & Widiasmoro (1994) Science 263, 1118–1121), the dome offers evidence that early Homo dispersed to East Asia during the earliest Pleistocene. Unfortunately, the hornblende pumice was sampled at Jokotingkir Hill, a central locality with complex lithostratigraphic deformation and dubious specimen provenance. To address the antiquity of Sangiran H. erectus more systematically, we investigate the sedimentary framework and hornblende 40Ar/39Ar age for volcanic deposits in the southeast quadrant of the dome. In this sector, Bapang (Kabuh) sediments have their largest exposure, least deformation, and most complete tephrostratigraphy. At five locations, we identify a sequence of sedimentary cycles in which H. erectus fossils are associated with epiclastic pumice. From sampled pumice, eight hornblende separates produced 40Ar/39Ar plateau ages ranging from 1.51 ± 0.08 Ma at the Bapang/Sangiran Formation contact, to 1.02 ± 0.06 Ma, at a point above the hominin-bearing sequence. The chronological sequence of 40Ar/39Ar ages follows stratigraphic order across the southeast quadrant. An intermediate level yielding four nearly complete crania has an age of about 1.25 Ma. PMID:11309488

Larick, Roy; Ciochon, Russell L.; Zaim, Yahdi; Sudijono; Suminto; Rizal, Yan; Aziz, Fachroel; Reagan, Mark; Heizler, Matthew

2001-01-01

293

Fossil Energy Perspective on Global Climate Change.  

National Technical Information Service (NTIS)

This report discusses global climates change from a fossil energy power generation perspective. As such, it highlights the substantial uncertainties that underlie the forecasts of GHG emissions, GHG concentrations, and climate change--forecasts that some ...

1990-01-01

294

Capturing and Storing Fossil-Fuel Carbon  

NASA Astrophysics Data System (ADS)

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 fuel, presumably hydrogen, that is produced from fossil fuels in large-scale facilities in conjunction with CO2 capture, and 2) the storage of CO2 in geological formations, especially deep saline aquifers. Modeling and analysis has not yet identified any showstoppers. Hydrogen production from fossil fuels at refineries and ammonia plants is already fully commercial, as is injection of CO2 into oil reservoirs. Under development are hydrogen vehicles powered by internal combustion engines and by fuel cells. Carbon capture and storage appears to have the potential to play a major role in global environmental management.

Keith, David

2002-03-01

295

Evolution of the biosphere and fossil fuels  

SciTech Connect

The effect of fundamental events in biological evolution on the scale of fossil-fuel accumulation from the historical aspect is considered. Four main stages in the establishment of the ancient biospheres are recognized: pro-, proto-, neoto-, and acmeobiospheres. The hypothesis is based on especially favorable conditions for the formation of oil and fossil fuels during late Archean and early Proterozoic time. Their composition did not vary appreciably. During the Phanerozoic Eon, when the development of a mature biosphere reached its apogee, the explosion-like increase in complexity of the organic world changed the relationships of a number of fossil fuels and their evolutionary history in a radical way. This led to manifold differentiation within each type of fossil fuel.

Lopatin, N.V.

1980-10-01

296

Paleobiogeography: The relevance of fossils to biogeography  

E-print Network

of a variety of congruent phenomena, not just vicariance. The important role that extinction plays in influencing apparent biogeographic patterns among modern and fossil groups suggests that this is another area ripe for new methodological developments....

Lieberman, Bruce S.

2003-01-01

297

Hybrid solar-fossil fuel power generation  

E-print Network

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 ...

Sheu, Elysia J. (Elysia Ja-Zeng)

2012-01-01

298

Stable Isotopic Analyses of Laetoli Fossil Herbivores  

Microsoft Academic Search

\\u000a In order to further refine early hominin paleoecology at Laetoli, over 500 specimens of fossil enamel and ostrich eggshell\\u000a fragments collected from the Laetolil Beds and the Upper Ndolanya Beds were analyzed isotopically. The goal was to develop\\u000a a high-resolution spatio-temporal framework for identifying and characterizing foraging patterns of mammalian herbivore lineages\\u000a and fossil ostriches that could be used to

John D. Kingston

299

On the Nature of Fossil Galaxy Groups  

Microsoft Academic Search

We present a new sample of 25 fossil groups (FGs) at z<0.1. Both the global properties of FGs (e.g. X-ray luminosity) as well as the photometric properties (i.e. isophotal shape parameter, a4) and spectroscopic parameters (e.g. the alpha-enhancement) of their first-ranked ellipticals are consistent with those of bright ellipticals located in non-fossil systems. This result favors a scenario where FGs

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

2010-01-01

300

Global Completeness of the Bat Fossil Record  

Microsoft Academic Search

Bats are unique among mammals in their use of powered flight and their widespread capacity for laryngeal echolocation. Understanding\\u000a how and when these and other abilities evolved could be improved by examining the bat fossil record. However, the fossil record\\u000a of bats is commonly believed to be very poor. Quantitative analyses of this record have rarely been attempted, so it

Thomas P. Eiting; Gregg F. Gunnell

2009-01-01

301

Fossil record and ecology of Nyssa (Cornaceae)  

Microsoft Academic Search

The fossil record ofNyssa is critically reviewed on the basis of reports of fruits, wood, and leaves from numerous localities in the Northern Hemisphere.\\u000a Commonly overlooked features of fruit stone morphology, particularly the placement of vascular bundles relative to the surface\\u000a ribs, are used in grouping the fossil fruits and relating them to modern taxa. Aspects of the ecology of

Richard H. Eyde

1997-01-01

302

Quantifying Fossil Fuel CO 2 over Europe  

Microsoft Academic Search

Europe is responsible for more than 25% of global fossil fuel CO2 emissions (Marland et al. 2006), and these emissions account for about 30–50% of the observed CO2 variability in this region (see Sect. 4.2.1). To balance greenhouse gases over Europe, therefore, also requires quantification\\u000a of CO2 emissions from fossil fuel (i.e. coal, oil and natural gas) burning. Reliable continuous

Ingeborg Levin; Ute Karstens

303

Adventures in Paleontology: 36 Classroom Fossil Activities  

NSDL National Science Digital Library

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.

Slesnick, Irwin; Hansen, Thor

2006-01-01

304

Fossil group origins. IV. Characterization of the sample and observational properties of fossil systems  

NASA Astrophysics Data System (ADS)

Context. Virialized halos grow by the accretion of smaller ones in the cold dark matter scenario. The rate of accretion depends on the different properties of the host halo. Those halos for which this accretion rate was very fast and efficient resulted in systems dominated by a central galaxy surrounded by smaller galaxies that were at least two magnitudes fainter. These galaxy systems are called fossil systems, and they can be the fossil relics of ancient galaxy structures. Aims: We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Methods: Deep r-band images were obtained with the 2.5-m Isaac Newton Telescope and Nordic Optic Telescope. Optical spectroscopic observations were performed at the 3.5-m Telescopio Nazionale Galileo for ~1200 galaxies. This new dataset was completed with Sloan Digital Sky Survey Data Release 7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies (?m12) and the first and fourth ranked galaxies (?m14) within 0.5 R200. We consider fossil systems to be those with ?m12 ? 2 mag or ?m14 ? 2.5 mag within the errors. Results: We find that 15 candidates turned out to be fossil systems. Their observational properties agree with those of non-fossil systems. Both follow the same correlations, but the fossil systems are always extreme cases. In particular, they host the brightest central galaxies, and the fraction of total galaxy light enclosed in the brightest group galaxy is larger in fossil than in non-fossil systems. Finally, we confirm the existence of genuine fossil clusters. Conclusions: Combining our results with others in the literature, we favor the merging scenario in which fossil systems formed from mergers of L? galaxies. The large magnitude gap is a consequence of the extreme merger ratio within fossil systems and therefore it is an evolutionary effect. Moreover, we suggest that at least one fossil group candidate in our sample could represent a transitional fossil stage. This system could have been a fossil in the past, but not now owing to the recent accretion of another group of galaxies.

Zarattini, S.; Barrena, R.; Girardi, M.; Castro-Rodriguez, N.; Boschin, W.; Aguerri, J. A. L.; Méndez-Abreu, J.; Sánchez-Janssen, R.; Catalán-Torrecilla, C.; Corsini, E. M.; del Burgo, C.; D'Onghia, E.; Herrera-Ruiz, N.; Iglesias-Páramo, J.; Jimenez Bailon, E.; Lozada Muoz, M.; Napolitano, N.; Vilchez, J. M.

2014-05-01

305

Tuning of the HOMO-LUMO gap of donor-substituted symmetrical and unsymmetrical benzothiadiazoles.  

PubMed

This article reports the design and synthesis of donor-substituted symmetrical and unsymmetrical benzothiadiazoles (BTDs) of 5-12 type D-?-A-D, D1-?-A-D2, D1-A1-A2-D2, D-A1-A2-D and D-A1-A2-A1-D by Ullmann, Suzuki and cycloaddition-retroelectrocyclization reactions. The photophysical, electrochemical and computational properties were studied and show substantial donor-acceptor interaction. Their single photon absorption show strong charge transfer bands in the near-infrared (NIR) region and the electrochemical reduction show multiple reduction waves. The optical HOMO-LUMO gap of BTDs 5-12 was found to be a function of the number and nature of the acceptors. Computational studies reveal that strong cyano-based acceptors, dicyanoquinodimethane (DCNQ) and tetracyanobutadiene (TCBD) lower the LUMO level in BTDs 7-12, which results in a low HOMO-LUMO gap compared to acetylene linked BTDs 5 and 6. The BTDs with carbazole and single TCBD and DCNQ acceptors show better thermal stability. PMID:24940822

Misra, Rajneesh; Gautam, Prabhat

2014-08-01

306

Relationship between cusp size and occlusal wear pattern in Neanderthal and Homo sapiens first maxillary molars.  

PubMed

Tooth wear studies in mammals have highlighted the relationship between wear facets (attritional areas produced during occlusion by the contact between opposing teeth) and physical properties of the ingested food. However, little is known about the influence of tooth morphology on the formation of occlusal wear facets. We analyzed the occlusal wear patterns of first maxillary molars (M(1) s) in Neanderthals, early Homo sapiens, and contemporary modern humans. We applied a virtual method to analyze wear facets on the crown surface of three-dimensional digital models. Absolute and relative wear facet areas are compared with cusp area and cusp height. Although the development of wear facets partially follows the cusp pattern, the results obtained from the between-group comparisons do not reflect the cusp size differences characterizing these groups. In particular, the wear facets developed along the slopes of the most discriminate cusp between Neanderthals and Homo sapiens (hypocone) do not display any significant difference. Moreover, no correlations have been found between cusp size and wear facet areas (with the exception of the modern sample) and between cusp height and wear facet areas. Our results suggest that cusp size is only weakly related to the formation of the occlusal wear facets. Other factors, such as, diet, food processing, environmental abrasiveness, and nondietary habits are probably more important for the development and enlargement of wear facets, corroborating the hypotheses suggested from previous dental wear studies. PMID:21337711

Fiorenza, Luca; Benazzi, Stefano; Viola, Bence; Kullmer, Ottmar; Schrenk, Friedemann

2011-03-01

307

Multistage system for deep desulfurization of fossil fuels  

Microsoft Academic Search

A method is described for the deep desulfurization of a liquid fossil fuel, comprising the steps of: (a) subjecting the liquid fossil fuel to hydrodesulfurization (HDS) whereby the liquid fossil fuel is depleted of forms of sulfur susceptible to removal by HDS but is not depleted of forms of sulfur refractory to HDS; (b) contacting the liquid fossil fuel with

Monticello

1993-01-01

308

Origin of Life on Earth: The Precambrian Fossil  

E-print Network

eukaryotes · 2.0-3.5 BY ­ formation of BIF's, stromatolites common · 3.5 BY ­ oldest probable fossilsOrigin of Life on Earth: The Precambrian Fossil Record Geology 230 Fossils and Evolution #12;Time · 4.0 BY ­ oldest rocks of sedimentary origin #12;Fossil Evidence · 3.8 BY ago: small carbon compound

Kammer, Thomas

309

The properties of fossil groups of galaxies  

NASA Astrophysics Data System (ADS)

Numerical simulations as well as optical and X-ray observations over the last few years have shown that poor groups of galaxies can evolve to what is called a fossil group. Dynamical friction as the driving process leads to the coalescence of individual galaxies in ordinary poor groups leaving behind nothing more than a central, massive elliptical galaxy supposed to contain the merger history of the whole group. Due to merging timescales for less-massive galaxies and gas cooling timescales of the X-ray intragroup medium exceeding a Hubble time, a surrounding faint-galaxy population having survived this galactic cannibalism as well as an extended X-ray halo similar to that found in ordinary groups, is expected. Recent studies suggest that fossil groups are very abundant and could be the progenitors of brightest cluster galaxies (BCGs) in the centers of rich galaxy clusters. However, only a few objects are known to the literature. This article aims to summarize the results of observational fossil group research over the last few years and presents ongoing work by the authors. Complementary to previous research, the SDSS and RASS surveys have been cross-correlated to identify new fossil structures yielding 34 newly detected fossil group candidates. Observations with ISIS at the 4.2 m William Herschel Telescope on La Palma have been carried out to study the stellar populations of the central ellipticals of 6 fossil groups. In addition multi-object spectroscopy with VLTs VIMOS has been performed to study the shape of the OLF of one fossil system.

Eigenthaler, P.; Zeilinger, W. W.

2009-12-01

310

Ancient Hunters and Their Modern Representatives : William Sollas’s (1849–1936) Anthropology from Disappointed Bridge to Trunkless Tree and the Instrumentalisation of Racial Conflict  

Microsoft Academic Search

During the first decades of the 20th century, many anthropologists who had previously adhered to a linear view of human evolution, from an ape via Pithecanthropus erectus(today Homo erectus) and Neanderthal to modern humans, began to change their outlook. A shift towards a branching model of human evolution began to take hold. Among the scientific factors motivating this trend was

Marianne Sommer

2005-01-01

311

A Fossil Hunt Tells the Age of Sediments  

NSDL National Science Digital Library

In this activity, students will identify an assemblage of fossils, determine their age, evaluate the fossil population, and make some inferences about the ancient environment in which they existed. The discovery aspect of this exercise is that all of the fossils the students will find existed together in only one time period. The environment of these fossils, a fresh water lake, is ascertained from using the fossil guidebook. A student worksheet and discussion questions are provided.

2005-10-06

312

IGM heating in fossil galaxy groups  

NASA Astrophysics Data System (ADS)

We study intergalactic medium (IGM) heating in a sample of five fossil galaxy groups by using their radio properties at 610 MHz and 1.4 GHz. The power by radio jets introducing mechanical heating for the sampled objects is not sufficient enough to suppress the cooling flow. Therefore, we discussed shock-, vortex heating, and conduction as alternative heating processes. Further, the 1.4 GHz and 610 MHz radio luminosities of fossil groups are compared to a sample of normal galaxy groups of the same brightest group galaxies (BGGs), stellar mass, and total group stellar mass, quantified using the K-band luminosity. It appears that the fossil BGGs are under luminous at 1.4 GHz and 610 MHz for a given BGG stellar mass and luminosity, in comparison to a general population of the groups. In addition, we explore how the bolometric radio luminosity of fossil sample depends on clusters and groups characteristics. Using the HIghest X-ray FLUx Galaxy Cluster Sample (HIFLUGCS) as a control sample we found that the large-scale behaviours of fossil galaxy groups are consistent with their relaxed and virialized nature.

Miraghaei, H.; Khosroshahi, H. G.; Klöckner, H.-R.; Ponman, T. J.; Jetha, N. N.; Raychaudhury, S.

2014-10-01

313

Eumetazoan fossils in terminal proterozoic phosphorites?  

PubMed

Phosphatic sedimentary rocks preserve a record of early animal life different from and complementary to that provided by Ediacaran fossils in terminal Proterozoic sandstones and shales. Phosphorites of the Doushantuo Formation, South China, contain eggs, egg cases, and stereoblastulae that document animals of unspecified phylogenetic position; small fossils containing putative spicules may specifically record the presence of sponges. Microfossils recently interpreted as the preserved gastrulae of cnidarian and bilaterian metazoans can alternatively be interpreted as conventional algal cysts and/or egg cases modified by diagenetic processes known to have had a pervasive influence on Doushantuo phosphorites. Regardless of this interpretation, evidence for Doushantuo eumetazoans is provided by millimeter-scale tubes that display tabulation and apical budding characteristic of some Cnidaria, especially the extinct tabulates. Like some Ediacaran remains, these small, benthic, colonial fossils may represent stem-group eumetazoans or stem-group cnidarians that lived in the late Proterozoic ocean. PMID:11095754

Xiao, S; Yuan, X; Knoll, A H

2000-12-01

314

On The Nature of Fossil Galaxy Groups  

E-print Network

We present a new sample of 25 fossil groups (FGs) at z fossil systems. Both the global properties of FGs (e.g. X-ray luminosity) as well as the photometric properties (i.e. isophotal shape parameter, a4) and spectroscopic parameters (e.g. the alpha-enhancement) of their first-ranked ellipticals are consistent with those of the control sample. This result favors a scenario where FGs are not a distinct class of systems, but rather a common phase in the life of galaxy groups. We also find no evidence for an evolutionary sequence explaining the formation of galaxies in fossil systems through the merging of galaxies in compact groups.

La Barbera, F; De la Rosa, I G; Sorrentino, G; Gal, R R; Kohl-Moreira, J L

2009-01-01

315

Fossil evidence of the zygomycetous fungi.  

PubMed

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

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

2013-06-01

316

John Day Fossil Beds National Monument  

NSDL National Science Digital Library

Millions of years ago, central Oregon was a hotbed of volcanic activity. Curious geologists and others can learn about the John Day Fossil Beds National Monument on this most excellent Flash-enabled online tour. After "flying" in overhead to the site, visitors can learn about the 40 million year history of the site that would later become the John Day Fossil Beds. The next area of the site is titled "The Present Unlocks the Past" and it includes an exploration of the evolution of the horse in prehistoric Oregon, along with offering access into the daily life of a working paleontologist. In the interactive feature "Whose skull is whose?", visitors will get the change to compare the skulls of ancient animals with those of their modern analogs. After that, visitors can get a better sense of the current state of affairs in the fossil beds by looking over a thirteen-image slideshow of this gorgeous section of Oregon.

317

Ontogeny of australopithecines and early Homo: evidence from cranial capacity and dental eruption  

Microsoft Academic Search

The relationship between cranial capacity and age of eruption of the mandibular first permanent molar is examined in modern anthropoid primates and used to infer age of eruption in fossil hominids. In developing and evaluating the predictive model, emphasis is placed on (i) distinguishing among cranial capacity, brain weight and brain volume as measures of brain size; (ii) selection of

Richard J. Smith; Patrick J. Gannon; B. Holly Smith

1995-01-01

318

Solar hydrogen: Moving beyond fossil fuels  

SciTech Connect

The prospect of using hydrogen from water as a substitute for oil and other fossil fuels has moved from the realm of dream to distinct possibility. What has made hydrogen worth reconsidering now are recent dramatic developments in photovoltaic (PV) cells that directly convert sunlight into electricity. This book discusses the advantages of a hydrogen-based economy and how such a system could be implemented. Contents include: Needed - a low-polluting alternative to fossil fuels (emerging fossil fuel crisis and the prospects for PV hydrogen derived using thin-film solar cells); Photovoltaic power comes of age (amorphous silicon solar cell and implications for the future of photovoltaic power); Designing a PV hydrogen energy system (finding sites, designing the PV electricity production system, electrolytic production of hydrogen, hydrogen storage, compression and transmission, and cost of delivered hydrogen); How PV compares to other synthetic fuels (nuclear electrolytic hydrogen, electrolytic hydrogen from other renewable sources, biomass-derived fluid fuels, synthetic fossil fuels, and hydrogen safety); How PV hydrogen could replace oil (transportation fuel, automobile fuel and environmental problems and alternative synthetic fuels); Breaking into markets for gaseous fuels (residential heating, industrial cogeneration and as chemical feedstocks); An evolutionary path to the PV hydrogen economy (chemical markets, transportation fuel, residential space and water heating, and parallels with the development of PV electricity); and A policy agenda (policies for reducing the external social costs of fossil fuels, for promoting improved energy end-use efficiency, and for promoting PV hydrogen development). It would take many decades to complete the transition to a PV hydrogen economy, but since the dangers of over dependence on fossil fuels and the benefits of switching to PV hydrogen are so great, policy strategies for hastening the transition warrant high priority.

Ogden, J.M.; Williams, R.H.

1989-01-01

319

Fossils, Genes and The Origin of Organs  

SciTech Connect

A toolkit of experimental and comparative biology can be applied to understand the great transformations in the history of life. Expeditionary paleontology can be used to target key nodes of the tree of life for which new fossils can provide insights into major morphological transformations. These fossils often have intermediate conditions that allow extant creatures to be compared in new ways. The tools of developmental genetics can then be used to explore these new comparisons to understand the genetic basis for macroevolutionary change. These different approaches can be used to predict new discoveries and this is only possible because of the empirical content of the tree of life.

Shubin, Neil (University of Chicago) [University of Chicago

2011-04-20

320

Microbial Fossils Detected in Desert Varnish  

NASA Technical Reports Server (NTRS)

Mars Global Surveyor Thermal Emission Spectrometer data indicate regions with significant levels of hematite (_Fe2O3). Fe-oxides, like hematite, can form as aqueous mineral precipitates and as such may preserve microscopic fossils or other biosignatures. Several potential terrestrial analogues to martian hematite like hydrothermal vents have preserved microfossils. Microbial fossilization in Fe-oxides is often a function of biomineralization. For example, goethite (FeO2H) encrustation of fungal mycelia from the mid-Tertiary preserved fungal morphologies such that their genera could be determined.

Flood, B. E.; Allen, C.; Longazo, T.

2003-01-01

321

On The Nature of Fossil Galaxy Groups  

Microsoft Academic Search

We present a new sample of 25 fossil groups (FGs) at z < 0.1, along with a\\u000acontrol sample of seventeen bright ellipticals located in non-fossil systems.\\u000aBoth the global properties of FGs (e.g. X-ray luminosity) as well as the\\u000aphotometric properties (i.e. isophotal shape parameter, a4) and spectroscopic\\u000aparameters (e.g. the alpha-enhancement) of their first-ranked ellipticals are\\u000aconsistent with

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

2009-01-01

322

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.

323

Fossil generation restructuring in the Ukraine  

SciTech Connect

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).

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

1996-12-31

324

Who Was Helping? The Scope for Female Cooperative Breeding in Early Homo  

PubMed Central

Derived aspects of our human life history, such as short interbirth intervals and altricial newborns, have been attributed to male provisioning of nutrient-rich meat within monogamous relationships. However, many primatologists and anthropologists have questioned the relative importance of pair-bonding and biparental care, pointing to evidence that cooperative breeding better characterizes human reproductive and child-care relationships. We present a mathematical model with empirically-informed parameter ranges showing that natural selection favors cooperation among mothers over a wide range of conditions. In contrast, our analysis provides a far more narrow range of support for selection favoring male coalition-based monogamy over more promiscuous independent males, suggesting that provisioning within monogamous relationships may fall short of explaining the evolution of Homo life history. Rather, broader cooperative networks within and between the sexes provide the primary basis for our unique life history. PMID:24367605

Bell, Adrian Viliami; Hinde, Katie; Newson, Lesley

2013-01-01

325

Salivary apyrases of Triatoma infestans are assembled into homo-oligomers  

PubMed Central

Apyrase activity is present in the saliva of haematophagous arthropods. It is related to blood-feeding because of the apyrase ability to hydrolyse ADP, a key component of platelet aggregation. Five apyrases with apparent molecular masses of 88, 82, 79, 68 and 67 kDa were identified in the saliva of the vector of Chagas disease, Triatoma infestans. The large size observed during purification of these enzymes suggested oligomerization. In the present study, we confirmed, using gel-filtration and analytical ultracentrifugation, the presence of apyrase oligomers with molecular masses of 200 kDa in the saliva. Electrophoretic analyses showed that disulphide bonds were involved in homo-oligomerization. In addition, heterogeneity in disulphide bonds and in pI was detected, with the pI ranging from 4.9 to 5.4. The present study gives the first insights into the quaternary structure of soluble apyrases. PMID:16542158

Faudry, Eric; Santana, Jaime M.; Ebel, Christine; Vernet, Thierry; Teixeira, Antonio R. L.

2006-01-01

326

Female condition influences preferences for sexual dimorphism in faces of male humans (Homo sapiens).  

PubMed

In some species, female condition correlates positively with preferences for male secondary sexual traits. Women's preferences for sexually dimorphic characteristics in male faces (facial masculinity) have recently been reported to covary with self-reported attractiveness. As women's attractiveness has been proposed to signal reproductive condition, the findings in human (Homo sapiens) and other species may reflect similar processes. The current study investigated whether the covariation between condition and preferences for masculinity would generalize to 2 further measures of female attractiveness: other-rated facial attractiveness and waist-to-hip ratio (WHR). Women with high (unattractive) WHR and/or relatively low other-rated facial attractiveness preferred more "feminine" male faces when choosing faces for a long-term relationship than when choosing for a short-term relationship, possibly reflecting diverse tactics in female mate choice. PMID:14498802

Penton-Voak, I S; Little, A C; Jones, B C; Burt, D M; Tiddeman, B P; Perrett, D I

2003-09-01

327

Earliest evidence for the structure of Homo sapiens populations in Africa  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

328

Azole Affinity of Sterol 14?-Demethylase (CYP51) Enzymes from Candida albicans and Homo sapiens  

PubMed Central

Candida albicans CYP51 (CaCYP51) (Erg11), full-length Homo sapiens CYP51 (HsCYP51), and truncated ?60HsCYP51 were expressed in Escherichia coli and purified to homogeneity. CaCYP51 and both HsCYP51 enzymes bound lanosterol (Ks, 14 to 18 ?M) and catalyzed the 14?-demethylation of lanosterol using Homo sapiens cytochrome P450 reductase and NADPH as redox partners. Both HsCYP51 enzymes bound clotrimazole, itraconazole, and ketoconazole tightly (dissociation constants [Kds], 42 to 131 nM) but bound fluconazole (Kd, ?30,500 nM) and voriconazole (Kd, ?2,300 nM) weakly, whereas CaCYP51 bound all five medical azole drugs tightly (Kds, 10 to 56 nM). Selectivity for CaCYP51 over HsCYP51 ranged from 2-fold (clotrimazole) to 540-fold (fluconazole) among the medical azoles. In contrast, selectivity for CaCYP51 over ?60HsCYP51 with agricultural azoles ranged from 3-fold (tebuconazole) to 9-fold (propiconazole). Prothioconazole bound extremely weakly to CaCYP51 and ?60HsCYP51, producing atypical type I UV-visible difference spectra (Kds, 6,100 and 910 nM, respectively), indicating that binding was not accomplished through direct coordination with the heme ferric ion. Prothioconazole-desthio (the intracellular derivative of prothioconazole) bound tightly to both CaCYP51 and ?60HsCYP51 (Kd, ?40 nM). These differences in binding affinities were reflected in the observed 50% inhibitory concentration (IC50) values, which were 9- to 2,000-fold higher for ?60HsCYP51 than for CaCYP51, with the exception of tebuconazole, which strongly inhibited both CYP51 enzymes. In contrast, prothioconazole weakly inhibited CaCYP51 (IC50, ?150 ?M) and did not significantly inhibit ?60HsCYP51. PMID:23274672

Warrilow, Andrew G.; Parker, Josie E.; Kelly, Diane E.

2013-01-01

329

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

PubMed

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

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

2014-08-01

330

Nonlinear Socio-Ecological Dynamics and First Principles ofCollective Choice Behavior of ``Homo Socialis"  

NASA Astrophysics Data System (ADS)

Socio-ecological dynamics emerged from the field of Mathematical SocialSciences and opened up avenues for re-examination of classical problems of collective behavior in Social and Spatial sciences. The ``engine" of this collective behavior is the subjective mental evaluation of level of utilities in the future, presenting sets of composite socio-economic-temporal-locational advantages. These dynamics present new laws of collective multi-population behavior which are the meso-level counterparts of the utility optimization individual behavior. The central core of the socio-ecological choice dynamics includes the following first principle of the collective choice behavior of ``Homo Socialis" based on the existence of ``collective consciousness": the choice behavior of ``Homo Socialis" is a collective meso-level choice behavior such that the relative changes in choice frequencies depend on the distribution of innovation alternatives between adopters of innovations. The mathematical basis of the Socio-Ecological Dynamics includes two complementary analytical approaches both based on the use of computer modeling as a theoretical and simulation tool. First approach is the ``continuous approach" --- the systems of ordinary and partial differential equations reflecting the continuous time Volterra ecological formalism in a form of antagonistic and/or cooperative collective hyper-games between different sub-sets of choice alternatives. Second approach is the ``discrete approach" --- systems of difference equations presenting a new branch of the non-linear discrete dynamics --- the Discrete Relative m-population/n-innovations Socio-Spatial Dynamics (Dendrinos and Sonis, 1990). The generalization of the Volterra formalism leads further to the meso-level variational principle of collective choice behavior determining the balance between the resulting cumulative social spatio-temporal interactions among the population of adopters susceptible to the choice alternatives and the cumulative equalization of the power of elites supporting different choice alternatives. This balance governs the dynamic innovation choice process and constitutes the dynamic meso-level counterpart of the micro-economic individual utility maximization principle.

Sonis, M.

331

Zinc finger protein 131 inhibits estrogen signaling by suppressing estrogen receptor {alpha} homo-dimerization  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer ZNF131 directly interacts with ER{alpha}. Black-Right-Pointing-Pointer The binding affinity of ZNF131 to ER{alpha} increases upon E2 stimulation. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Black-Right-Pointing-Pointer ZNF131 inhibits ER{alpha}-dimerization and E2-induced breast cancer cell proliferation. Black-Right-Pointing-Pointer ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor. -- Abstract: Steroid hormone estrogen elicits various physiological functions, many of which are mediated through two structurally and functionally distinct estrogen receptors, ER{alpha} and ER{beta}. The functional role of zinc finger protein 131 (ZNF131) is poorly understood, but it is assumed to possess transcriptional regulation activity due to the presence of a DNA binding motif. A few recent reports, including ours, revealed that ZNF131 acts as a negative regulator of ER{alpha} and that SUMO modification potentiates the negative effect of ZNF131 on estrogen signaling. However, its molecular mechanism for ER{alpha} inhibition has not been elucidated in detail. Here, we demonstrate that ZNF131 directly interacts with ER{alpha}, which consequently inhibits ER{alpha}-mediated trans-activation by suppressing its homo-dimerization. Moreover, we show that the C-terminal region of ZNF131 containing the SUMOylation site is necessary for its inhibition of estrogen signaling. Taken together, these data suggest that ZNF131 inhibits estrogen signaling by acting as an ER{alpha}-co-repressor.

Oh, Yohan [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)] [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Chung, Kwang Chul, E-mail: kchung@yonsei.ac.kr [Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

2013-01-04

332

"Small size" in the Philippine human fossil record: is it meaningful for a better understanding of the evolutionary history of the negritos?  

PubMed

"Pygmy populations" are recognized in several places over the world, especially in Western Africa and in Southeast Asia (Philippine "negritos," for instance). Broadly defined as "small-bodied Homo sapiens" (compared with neighboring populations), their origins and the nature of the processes involved in the maintenance of their phenotype over time are highly debated. Major results have been recently obtained from population genetics on present-day negrito populations, but their evolutionary history remains largely unresolved. We present and discuss the Upper Pleistocene human remains recovered from Tabon Cave and Callao Cave in the Philippines, which are potentially highly relevant to these research questions. Human fossils have been recovered in large numbers from Tabon Cave (Palawan Island) but mainly from reworked and mixed sediments from several archaeological layers. We review and synthesize the long and meticulous collaborative work done on the archives left from the 1960s excavations and on the field. The results demonstrate the long history of human occupations in the cave, since at least ~30,000 BP. The examination of the Tabon human remains shows a large variability: large and robust for one part of the sample, and small and gracile for the other part. The latter would fit quite comfortably within the range of variation of Philippine negritos. Farther north, on Luzon Island, the human third metatarsal recently recovered from Callao Cave and dated to ~66,000 BP is now the oldest direct evidence of human presence in the Philippines. Previous data show that, compared with H. sapiens (including Philippine negritos), this bone presents a very small size and several unusual morphological characteristics. We present a new analytical approach using three-dimensional geometric morphometrics for comparing the Callao fossil to a wide array of extant Asian mammals, including nonhuman primates and H. sapiens. The results demonstrate that the shape of the Callao metatarsal is definitely closer to humans than to any other groups. The fossil clearly belongs to the genus Homo; however, it remains at the margin of the variation range of H. sapiens. Because of its great antiquity and the presence of another diminutive species of the genus Homo in the Wallace area during this time period (H. floresiensis), we discuss here in detail the affinities and potential relatedness of the Callao fossil with negritos that are found today on Luzon Island. PMID:24297220

Détroit, Florent; Corny, Julien; Dizon, Eusebio Z; Mijares, Armand S

2013-01-01

333

Origin of Symbolic Cognition 99 An Evolutionary Framework for the Acquisition of Symbolic Cognition by Homo sapiens  

E-print Network

. This observation may undermine claims for "adaptedness" in modern human behaviors. Keywords: Human Evolution., 2007) that New Caledonian crows share with humans and chimpanzees the ability to form and use stick by Homo sapiens Ian Tattersall American Museum of Natural History Human beings are unique

Cook, Robert

334

The Road to Homo sapien sapien: Genetic Evidences Tell Us Stories about the Origin and Evolution of Modern Human  

Microsoft Academic Search

Human Beings, the common name of Homo sapien sapien, is regarded as the lord of the earth, at least by themselves. Now they are trying to look deep into their own history, that is, the evolutionary history of their own. In this review, we first look back on the history of development of theory of evolution, which leads to the

Chen Yi-Lun

335

Field-mapping and petrographic analysis of volcanoes surrounding the Lake Natron Homo sapiens footprint site, northern Tanzania  

Microsoft Academic Search

The Lake Natron Homo sapiens footprint site is located in northern Tanzania along the East African Rift escarpment. The site is positioned south of Lake Natron within an ephemeral channel of the Engare Sero River. The hominid footprints are preserved in a tuff, which originated from one of the volcanic centers surrounding the site. Two large volcanoes in the surrounding

S. M. Hewitt; B. Zimmer; C. Liutkus; S. K. Carmichael; K. McGinnis

2010-01-01

336

Molecular biology of Homo sapiens: Abstracts of papers presented at the 51st Cold Spring Harbor symposium on quantitative biology  

SciTech Connect

This volume contains abstracts of papers presented at the 51st Cold Springs Harbor Symposium on Quantitative Biology. The topic for this meeting was the ''Molecular Biology of Homo sapiens.'' Sessions were entitled Human Gene Map, Human Cancer Genes, Genetic Diagnosis, Human Evolution, Drugs Made Off Human Genes, Receptors, and Gene Therapy. (DT)

Watson, J.D.; Siniscalco, M.

1986-01-01

337

Impact of AMS 14C determinations on considerations of the antiquity of Homo sapiens in the western hemisphere  

Microsoft Academic Search

The ability of AMS facilities to obtain direct 14C determinations on milligram amounts of organic extracts of bone has significantly advanced efforts to reexamine the validity of the dating evidence for a number of allegedly Pleistocene Homo sapiens skeletons from the Western Hemisphere previously assigned ages of from about 20000 to 70000 years. AMS 14C analysis has indicated that four

R. E. Taylor; Louis A. Payen; Peter J. Slota

1984-01-01

338

Topological factors governing the HOMO-LUMO band gap of the density of states of periodic hydrocarbon polymer networks  

Microsoft Academic Search

The band structures and density of states of 77 infintely large conjugated hydrocarbon polymer networks are calculated with HMO. A general rule for predicting whether the HOMO-LUMO band gap is zero or non-zero is proposed for an arbitrary hydrocarbon polymer network with periodic structure. The effects of bond alternation and of conjugate branching are discussed. Molecular design of high spin

Ying-Duo Gao; Hitomi Kumazaki; Junko Terai; Kanako Chida; Haruo Hosoya

1993-01-01

339

a Molecular Model Potential Study of the Homo-Lumo Gap in a Low-Dimensional Crystal  

Microsoft Academic Search

We study the effect of some crystal vibrations on the electron distribution and the gap HOMO-LUMO in a linear chain of atoms where, the valence electrons move in a model potential constructed by combining atromic boxes. It is found that at the turning points, these two levels collapse together for a chain with an even number of atoms while for

Jorge Ricardo Letelier; Alejandro Toro-Labbé; Ying-Nan Chiu

1999-01-01

340

Ab initio molecular dynamics simulations with a HOMO–LUMO gap biasing potential to accelerate rare reaction events  

Microsoft Academic Search

A method for promoting reaction events in ab initio molecular dynamics simulations that is explicitly based on the electronic structure is developed. The technique uses a bias potential that is added to the regular potential and is constructed from the HOMO–LUMO gap of the system. This bias potential is tested along predetermined reaction coordinates and through molecular dynamics simulations for

Nicholas J. Mosey; Anguang Hu; Tom K. Woo

2003-01-01

341

Variation in enamel thickness within the genus Homo Tanya M. Smith a,b,*, Anthony J. Olejniczak b  

E-print Network

Variation in enamel thickness within the genus Homo Tanya M. Smith a,b,*, Anthony J. Olejniczak b Available online 22 February 2012 Keywords: Human evolution Hominin tooth structure Dental morphology Early as having thick molar enamel, one of very few dental traits that distinguish hominins from living African

Smith, Tanya M.

342

An interesting new fossil dragonfly (Anisoptera: Libellulidae: \\  

Microsoft Academic Search

Summary A new dragonfly species, Parabrachydiplax miocenica n. gen. n. sp. (Anisoptera: Libelluli- dae), is described from the early Middle Miocene of Heggbach in southern Germany. The holotype was collected by the priest J. PROBST in 1865 and represents the earliest record of fossil insect remains from the Upper Freshwater Molasse of Baden-Württemberg. The phylo- genetic position of this new

Volker J. Sach

343

Fossil Energy Materials Program conference proceedings  

SciTech Connect

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)

Judkins, R.R. (comp.)

1987-08-01

344

Synthetic Trace Fossils using mechanical bugs  

NSDL National Science Digital Library

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.

Cowan, Clint

345

Fossil names dedicated to Erik Flügel  

Microsoft Academic Search

There are 3 genera and at least 19 species names of fossils, attributed to calcareous algae, sponges, hydrozoans, corals, ammonites, gastropods, foraminifers, and radiolarians that have been dedicated to Erik Flügel. These are listed with their original diagnosis or description and re-illustrations of the holotypes.

Baba Senowbari-Daryan

2005-01-01

346

GEOL 204: The Fossil Record Team Project  

E-print Network

the scope of the project: the history of paleontology; the societal aspects of paleontology Possible Topics--Picking a Topic: Your task is to research, record, and present information concerning a topic of paleontological (by no means an exhaustive list!): Particular Major Events in the History of Life: Archean Fossils

Holtz Jr., Thomas R.

347

Fossil fuels, the greenhouse effect and photovoltaics  

Microsoft Academic Search

The dependence of widespread use of photovoltaics to generate electricity on the cost of competing forms of energy is examined. The likely rise in the cost of fossil fuels and their role in the contamination of the global environment are discussed. The depletion of oil reserves and changes in the global climate are highlighted. The role of photovoltaics in future

D. E. Carlson

1989-01-01

348

Learning about Fossil Formation by Classroom Simulation.  

ERIC Educational Resources Information Center

Activities in which students build their own simulations of fossils, using seashells, chicken bones, toy dinosaurs, or leaves as models and plaster of paris, sand, mud, clay, or a mixture of gravel and clay as a matrix are presented. Curriculum extensions are included. (KR)

Schlenker, Richard M.; Yoshida, Sarah J.

1991-01-01

349

Fossil birds of the Kibish Formation  

Microsoft Academic Search

The Kibish Formation has yielded a small collection of bird fossils, which are identified here as belonging to five species in four different families: Pelecanidae (pelicans), Anhingidae (darters), Ardeidae (herons) and Phasianidae (gamefowl). Two species of pelicans are identified: Pelecanus cf. P. onocrotalus, and P. aff. P. rufescens. The darter is referrable to Anhinga melanogaster. The heron is identifiable as Ardea

Antoine Louchart

2008-01-01

350

Globular Clusters as Fossils of Galaxy Formation  

Microsoft Academic Search

The globular clusters in the halos of large galaxies like our own are almost certainly fossil remnants of the early star-forming subsystems from which these galaxies were built. The ages of the halo clusters in our Galaxy indicate a prolonged period of galaxy building lasting at least several Gyr, and their masses indicate that they were formed in very massive

Richard B. Larson

351

Globular Clusters as Fossils of Galaxy Formation  

Microsoft Academic Search

The globular clusters in the halos of large galaxies like our own are almost certainly fossil remnants of the early star-forming subsystems from which these galaxies were built. The ages of the halo clusters in our Galaxy indicate a prolonged period of galaxy building lasting at least several Gyr, and their masses indicate that they were formed in very massive

Richard B. Larson

1996-01-01

352

Cuticle Analysis of Living and Fossil Metasequoia  

Microsoft Academic Search

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

Qin Leng

353

Fossil fuels supplies modeling and research  

SciTech Connect

The fossil fuel supplies modeling and research effort focuses on models for US Strategic Petroleum Reserve (SPR) planning and management. Topics covered included new SPR oil valuation models, updating models for SPR risk analysis, and fill-draw planning. Another task in this program area is the development of advanced computational tools for three-dimensional seismic analysis.

Leiby, P.N.

1996-06-01

354

The Proterozoic Fossil Record of Heterotrophic Eukaryotes  

E-print Network

not by heterotrophs but by algae. Most of the fossils that can be assigned to a modern clade are algal (red), is interpreted as an alga (Han and Runnegar, 1992; Schneider et al., 2002). The presence of red algae in rocks diversity, in fact, autotrophy, which characterizes the algae and land plants, appears to be a derived

Porter, Susannah

355

New era for fossil power plant simulators  

Microsoft Academic Search

At a time when the utility industry is focusing on products and services that can enhance competitiveness, affordable fossil plant simulators are a welcome technology. In just a few years, these simulators have progressed from being an expensive tool that few utilities could afford to being a technology that many utilities feel they can`t do without. Offering a variety of

Hoffman

1995-01-01

356

On the fossil record of the Gekkota.  

PubMed

Gekkota is often interpreted as sister to all remaining squamates, exclusive of dibamids, or as sister to Autarchoglossa. It is the only diverse lineage of primarily nocturnal lizards and includes some of the smallest amniotes. The skeleton of geckos has often been interpreted as paedomorphic and/or "primitive" but these lizards also display a wide range of structural specializations of the postcranium, including modifications associated with both scansorial locomotion and limb reduction. Although the concept of "Gekkota" has been variously applied by different authors, we here apply a rigorous apomorphy based definition, recent advances in gekkotan morphology and phylogenetics, and diverse comparative material to provide a comprehensive assessment of 28 known pre-Quaternary geckos, updating the last such review, published three decades ago. Fossils evaluated include both sedimentary fossils and amber-embedded specimens. Known Cretaceous geckos are exclusively Asian and exhibit character combinations not seen in any living forms. Cenozoic gekkotans derive from sites around the world, although Europe is especially well represented. Paleogene geckos are largely known from disarticulated remains and show similarities to Sphaerodactylidae and Diplodactylidae, although resemblances may be plesiomorphic in some cases. Many Neogene gekkotans are referable to living families or even genera, but their geographic occurrences are often extralimital to those of modern groups, as is consistent with paleoclimatic conditions. The phylogenetic placement of fossil gekkotans has important repercusions for timetree calibration, but at present only a small number of fossils can be confidently assigned to even family level groupings, limiting their utility in this regard. PMID:24482344

Daza, Juan D; Bauer, Aaron M; Snively, Eric D

2014-03-01

357

The Future of the Fossil Record  

Microsoft Academic Search

The fossil record provides a powerful basis for analyzing the controlling factors and impact of biological evolution over a wide range of temporal and spatial scales and in the context of an evolving Earth. An increasingly interdisciplinary paleontology has begun to formulate the next generation of questions, drawing on a wealth of new data, and on methodological advances ranging from

David Jablonski

1999-01-01

358

Realistic ocean energy alternatives to fossil fuels  

Microsoft Academic Search

The US Commission on Ocean Policy endorsed the Administrations complete dependence on fossil fuels as the primary energy source for the nation. Two very significant alternatives were rejected or neglected. The first alternative was sea based semi submerged nuclear power plant ships deployed in a line paralleling the coastline of the United States. The US has developed and deployed hundreds

John Piña Craven

2005-01-01

359

From fossil fuels to renewable energies  

Microsoft Academic Search

This paper describes the model of an industrial society based on fossil fuels whose supply decreases and the society is forced to develop alternative energy sources. It is conceived as an abstract model that captures the basic aspect of such a change, but in a simple and schematic way. Despite this, most of the important dynamics of this problem are

Margarita Mediavilla; Luis Javier Miguel; Carlos de Castro

360

Replacement of fossil fuels by hydrogen  

Microsoft Academic Search

The replacement of fossil fuels by solar hydrogen plantations is considered. A model is proposed in which ten plantation families, situated in suitable deserted zones of the world after the year 2000, would generate enough electrical energy to produce solar cells and materials for the construction of ten new plantations within a decade. The technological growth process for identical solar

R. Dahlberg

1982-01-01

361

Changing pattern of fossil fuel COâ emissions  

Microsoft Academic Search

Calculations of global COâ emissions using fossil fuel production data have demonstrated that the annual emissions rate grew at a rate of 4.5% per year before 1973 and about half that rate after 1973. However, in projecting future emissions, fuel consumption rather than production data should be considered. World population and economic growth (and hence energy demand) are not the

R. M. Rotty; G. Marland; N. Treat

1984-01-01

362

From Fossils to Facts to Stories.  

ERIC Educational Resources Information Center

Eight steps are outlined for presenting a combined science/language experience unit to primary students, in which the children observe and discuss a phenomenon and dictate a group report. Sample projects with fossils, magnets, and air pressure are described. (SJL)

Hungerford, Harold R.; Steinruck, Yvonne Siv

1978-01-01

363

Fossilized gravitational wave relic and primordial clocks  

NASA Astrophysics Data System (ADS)

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.

Brahma, Suddhasattwa; Nelson, Elliot; Shandera, Sarah

2014-01-01

364

Solid modeling of fossil small mammal teeth  

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

365

Mass Extinctions in the Marine Fossil Record  

Microsoft Academic Search

A new compilation of fossil data on invertebrate and vertebrate families indicates that four mass extinctions in the marine realm are statistically distinct from background extinction levels. These four occurred late in the Ordovician, Permian, Triassic, and Cretaceous periods. A fifth extinction event in the Devonian stands out from the background but is not statistically significant in these data. Background

David M. Raup; J. John Sepkoski

1982-01-01

366

IGM Heating in Fossil Galaxy Groups  

E-print Network

We study intergalactic medium (IGM) heating in a sample of five fossil galaxy groups by using their radio properties at 610 MHz and 1.4 GHz. The power by radio jets introducing mechanical heating for the sampled objects is not sufficient enough to suppress the cooling flow. Therefore, we discussed shock-, vortex heating, and conduction as alternative heating processes. Further, the 1.4 GHz and 610 MHz radio luminosities of fossil groups are compared to a sample of normal galaxy groups of the same radio brightest (BGGs), stellar mass, and total group stellar mass, quantified using the $K$-band luminosity. It appears that the fossil BGGs are under luminous at 1.4 GHz and 610 MHz for a given BGG stellar mass and luminosity, in comparison to a general population of the groups. In addition, we explore how the bolometric radio luminosity of fossil sample depends on clusters and groups characteristics. Using the HIghest X-ray FLUx Galaxy Cluster Sample (HIFLUGCS) as a control sample we found that the large-scale beh...

Miraghaei, H; Klöckner, H -R; Ponman, T J; Jetha, N N; Raychaudhury, S

2014-01-01

367

Precambrian Fossils (?) near Elliot Lake, Ontario.  

PubMed

Complex structures in Upper Huronian (Lower Proterozoic) quartzite north of Lake Huron are interpreted as probable metazoan fossils aged between 2 and 2.5 x 10(9) years. They are preserved as sand casts in the form of curved spindles having inclined lateral corrugations, axial marking, and apparent bilateral symmetry. PMID:17730739

Hofmann, H J

1967-04-28

368

Thermal dissolution of solid fossil fuels  

SciTech Connect

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.

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

2007-10-15

369

The Fascinating Story of Fossil Fuels  

ERIC Educational Resources Information Center

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)

Asimov, Isaac

1973-01-01

370

Solar hydrogen: Moving beyond fossil fuels  

Microsoft Academic Search

The prospect of using hydrogen from water as a substitute for oil and other fossil fuels has moved from the realm of dream to distinct possibility. What has made hydrogen worth reconsidering now are recent dramatic developments in photovoltaic (PV) cells that directly convert sunlight into electricity. This book discusses the advantages of a hydrogen-based economy and how such a

J. M. Ogden; R. H. Williams

1989-01-01

371

Fossil Cores In The Kepler Data  

NASA Astrophysics Data System (ADS)

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.

Jackson, Brian

372

Status and perspectives of fossil power generation  

Microsoft Academic Search

According to forecasts made by the World Energy Conference and other organizations, fossil fuels such as coal, oil and natural gas will be, in the foreseeable future, our main source for power generation. It is, therefore, very important to use these non-renewable resources with great care and utilize them only in highly efficient plants. This not only conserves our limited

Bert Rukes; Robert Taud

2004-01-01

373

Mapping fossil and non-fossil systems out to their virial radii  

NASA Astrophysics Data System (ADS)

As the largest gravitational bound systems in the Universe, galaxy clusters are very valuable cosmological probes. Among them, fossil systems are supposed to be more evolved and relaxed while non-fossil systems are more disturbed and dynamically younger. With high quality Suzaku and Chandra observations, we studied the gas properties such as entropy, pressure, and baryon fraction profiles as well as their azimuthal variations out to the virial radii of a typical fossil system RXJ1159+5531 and a typical non-fossil system MKW4. The comparison of these two systems allows us to put constraints on the role played by non-gravitational processes and the evolution of galaxy clusters.

Su, Y.; Buote, D.; White, R.; Gastaldello, F.; Irwin, J.

2014-07-01

374

Middle pleistocene humans from africa  

Microsoft Academic Search

Patterns of human evolution in the Middle Pleistocene remain poorly understood. There is general consensus that by the onset\\u000a of this time period, populations ofHomo erectus were dispersed from Africa into Eurasia, including the Far East. In the western part of this range (perhaps in Africa),Homo erectus then produced a daughter lineage exhibiting more advanced characters of the face, braincase

G. P. Rightmire

2000-01-01

375

Probable Carbonate Fossilization Processes Within Dead Sea Microbial Remains  

NASA Technical Reports Server (NTRS)

Microbial fossilization processes in the Dead Sea is primarily associated with the calcium cation. The putative fossilized microbes do not represent the reported living microbial population. Additional information is contained in the original extended abstract.

Morris, P. A.; Wentworth, S. J.; Thomas-Keprta, K. L.; Allen, C. C.; McKay, D. S.

2001-01-01

376

A new fossil silverfish (Zygentoma: Insecta) in Mesozoic Burmese amber  

Microsoft Academic Search

Two fossil silverfish preserved in Burmese amber (dated from the Cretaceous: Upper Albian, 100–110 MY) are described in the new genus and species Burmalepisma cretacicum (Lepismatidae: Lepismatinae). The fossil species is characterized mainly by its chaetotaxy.

Luis F. Mendes; George O. Poinar

2008-01-01

377

Fossil Record Accurately Reflects Recent Flowering of Marine Biodiversity  

NSF Publications Database

... H. Richard Lane (703) 292-8550 hlane@nsf.gov Fossil Record Accurately Reflects Recent Flowering of ... reading produced by the inconsistencies of the fossil record, says a team of paleontologists led by ...

378

Azole affinity of sterol 14?-demethylase (CYP51) enzymes from Candida albicans and Homo sapiens.  

PubMed

Candida albicans CYP51 (CaCYP51) (Erg11), full-length Homo sapiens CYP51 (HsCYP51), and truncated ?60HsCYP51 were expressed in Escherichia coli and purified to homogeneity. CaCYP51 and both HsCYP51 enzymes bound lanosterol (K(s), 14 to 18 ?M) and catalyzed the 14?-demethylation of lanosterol using Homo sapiens cytochrome P450 reductase and NADPH as redox partners. Both HsCYP51 enzymes bound clotrimazole, itraconazole, and ketoconazole tightly (dissociation constants [K(d)s], 42 to 131 nM) but bound fluconazole (K(d), ~30,500 nM) and voriconazole (K(d), ~2,300 nM) weakly, whereas CaCYP51 bound all five medical azole drugs tightly (K(d)s, 10 to 56 nM). Selectivity for CaCYP51 over HsCYP51 ranged from 2-fold (clotrimazole) to 540-fold (fluconazole) among the medical azoles. In contrast, selectivity for CaCYP51 over ?60HsCYP51 with agricultural azoles ranged from 3-fold (tebuconazole) to 9-fold (propiconazole). Prothioconazole bound extremely weakly to CaCYP51 and ?60HsCYP51, producing atypical type I UV-visible difference spectra (K(d)s, 6,100 and 910 nM, respectively), indicating that binding was not accomplished through direct coordination with the heme ferric ion. Prothioconazole-desthio (the intracellular derivative of prothioconazole) bound tightly to both CaCYP51 and ?60HsCYP51 (K(d), ~40 nM). These differences in binding affinities were reflected in the observed 50% inhibitory concentration (IC(50)) values, which were 9- to 2,000-fold higher for ?60HsCYP51 than for CaCYP51, with the exception of tebuconazole, which strongly inhibited both CYP51 enzymes. In contrast, prothioconazole weakly inhibited CaCYP51 (IC(50), ~150 ?M) and did not significantly inhibit ?60HsCYP51. PMID:23274672

Warrilow, Andrew G; Parker, Josie E; Kelly, Diane E; Kelly, Steven L

2013-03-01

379

New wrist bones of Homo floresiensis from Liang Bua (Flores, Indonesia).  

PubMed

The carpals from the Homo floresiensis type specimen (LB1) lack features that compose the shared, derived complex of the radial side of the wrist in Neandertals and modern humans. This paper comprises a description and three-dimensional morphometric analysis of new carpals from at least one other individual at Liang Bua attributed to H. floresiensis: a right capitate and two hamates. The new capitate is smaller than that of LB1 but is nearly identical in morphology. As with capitates from extant apes, species of Australopithecus, and LB1, the newly described capitate displays a deeply-excavated nonarticular area along its radial aspect, a scaphoid facet that extends into a J-hook articulation on the neck, and a more radially-oriented second metacarpal facet; it also lacks an enlarged palmarly-positioned trapezoid facet. Because there is no accommodation for the derived, palmarly blocky trapezoid that characterizes Homo sapiens and Neandertals, this individual most likely had a plesiomorphically wedge-shaped trapezoid (like LB1). Morphometric analyses confirm the close similarity of the new capitate and that of LB1, and are consistent with previous findings of an overall primitive articular geometry. In general, hamate morphology is more conserved across hominins, and the H. floresiensis specimens fall at the far edge of the range of variation for H. sapiens in a number of metrics. However, the hamate of H. floresiensis is exceptionally small and exhibits a relatively long, stout hamulus lacking the oval-shaped cross-section characteristic of human and Neandertal hamuli (variably present in australopiths). Documentation of a second individual with primitive carpal anatomy from Liang Bua, along with further analysis of trapezoid scaling relative to the capitate in LB1, refutes claims that the wrist of the type specimen represents a modern human with pathology. In total, the carpal anatomy of H. floresiensis supports the hypothesis that the lineage leading to the evolution of this species originated prior to the cladogenetic event that gave rise to modern humans and Neandertals. PMID:23290261

Orr, Caley M; Tocheri, Matthew W; Burnett, Scott E; Awe, Rokus Due; Saptomo, E Wahyu; Sutikna, Thomas; Jatmiko; Wasisto, Sri; Morwood, Michael J; Jungers, William L

2013-02-01

380

FOSSIL ANTHROPOIDS OF THE r y ALEMCAMBRIDGE INDIA  

E-print Network

; . ~ 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

Boyer, Edmond

381

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

E-print Network

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 (GrieRESEARCH PAPER The first fossil record of Polyrhachis (Hymenoptera: Formicidae: Formicinae) from

Villemant, Claire

382

Three new fossil landbirds from the early Paleogene of Denmark  

Microsoft Academic Search

Well-preserved remains of fossil modern birds are rare, especially from the earliest stages of their evolution. In this paper we describe three new fossil specimens that can be referred to two of the major clades of extant 'landbirds', namely Apodiformes ('swifts') and Coliiformes ('mousebirds'). Because the fossils presented here are from the earliest tertiary of Denmark, they represent some of

GARETH J. DYKE; DAVID M. WATERHOUSE; ANETTE V. KRISTOFFERSEN

2004-01-01

383

Evolution of Marine Invertebrates and the Burgess Shale Fossils  

E-print Network

Evolution of Marine Invertebrates and the Burgess Shale Fossils Geology 331, Paleontology #12;Marshall, 2006 #12;Halkierids, which produced some of the small, shelly fossils of the Early Cambrian #12;More examples of small shelly fossils from the Early Cambrian. Scale bars are 0.1 mm. #12;#12;#12;The

Kammer, Thomas

384

Carbon Capture by Fossil Fuel Power Plants: An Economic Analysis  

E-print Network

Carbon Capture by Fossil Fuel Power Plants: An Economic Analysis ¨Ozge I¸slegen Graduate School excellent research assistance. #12;Carbon Capture by Fossil Fuel Power Plants: An Economic Analysis Abstract: For fossil fuel power plants to be built in the future, carbon capture and storage (CCS) technologies offer

Silver, Whendee

385

EDIACARAN AND CAMBRIAN INDEX FOSSILS FROM SONORA, MEXICO  

E-print Network

Formation near Pitiquito, Sonora, Mexico, and new occurrences of the Neoproterozoic index fossil Cloudina are reported from the underlying La Cie´- nega Formation. Considered together, these fossils constrainEDIACARAN AND CAMBRIAN INDEX FOSSILS FROM SONORA, MEXICO by FRANCISCO SOUR-TOVAR*, JAMES W

Hagadorn, Whitey

386

Geology, Formation and Fossils of the Connecticut Valley  

Microsoft Academic Search

Fossils and fossil footprints allow geologists to learn not only of the geological formation of a certain region, but also of the biodiversity of plant and animal life. The abundant fossil footprints of Connecticut Valley allow us to glimpse at life about two hundred million years ago. Connecticut, during this time period, was characterized by the lush tropical forests as

Naila Eisa; Lorenzo Bellard

387

The star formation histories of fossil group galaxies  

Microsoft Academic Search

A comparison is carried out among the star formation histories of early-type\\u000agalaxies (ETG) in fossil groups, clusters and low density environments.\\u000aAlthough they show similar evolutionary histories, a significant fraction of\\u000athe fossils are younger than their counterparts, suggesting that fossils can be\\u000aprecursors of the isolated ETGs.

Ignacio G. de la Rosa; Robert N. Proctor; Claudia Mendes de Oliveira; Duncan A. Forbes; Roberto Cid Fernandes; Abilio Mateus

2009-01-01

388

The star formation histories of fossil group galaxies  

E-print Network

A comparison is carried out among the star formation histories of early-type galaxies (ETG) in fossil groups, clusters and low density environments. Although they show similar evolutionary histories, a significant fraction of the fossils are younger than their counterparts, suggesting that fossils can be precursors of the isolated ETGs.

De la Rosa, I G; de Oliveira, C Mendes; Forbes, D A; Fernandes, R Cid; Mateus, A

2009-01-01

389

New form of information from T. rex and Mastodon fossils  

NSDL National Science Digital Library

After discovering a giant T. rex leg bone fossil in Montana, back in 2003, a team of scientists had a problem: It wouldn't fit in their helicopter. When they broke the fossil open in order to fit the pieces inside, this led to a shocking discovery. Some of the dinosaur's soft tissues such as blood vessels were still present inside the fossil.

American Association for the Advancement of Science (AAAS;)

2007-04-12

390

Genomic Fossils Calibrate the Long-Term Evolution of Hepadnaviruses  

E-print Network

Because most extant viruses mutate rapidly and lack a true fossil record, their deep evolution and longGenomic Fossils Calibrate the Long-Term Evolution of Hepadnaviruses Cle�ment Gilbert*, Ce-term vertical inheritance. Such endogenous viruses are highly valuable as they provide a molecular fossil record

Feschotte, Cedric

391

RESEARCH LETTERS 161 The Fossil Record of Cretaceous  

E-print Network

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

Benton, Michael

392

Advanced research and technology development fossil energy materials program  

Microsoft Academic Search

The Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program is a multifaceted materials research and development program sponsored by the Office of Fossil Energy of the U.S. Department of Energy. The program is administered by the Office of Technical Coordination. In 1979, the Office of Fossil Energy assigned responsibilities for this program to the DOE Oak

R. R. Judkins; R. A. Bradley

1988-01-01

393

Advanced Research and Technology Development Fossil Energy Materials Program  

Microsoft Academic Search

The Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program is a multifaceted materials research and development program sponsored by the Office of Fossil Energy of the US Department of Energy. The program is administered by the Office of Technical Coordination. In 1979, the Office of Fossil Energy assigned responsibilities for this program to the DOE Oak

R. R. Judkins; R. A. Bradley

1987-01-01

394

Can Fossil Carbon Fuel the 21st Century?  

Microsoft Academic Search

Fossil fuels, despite their drawbacks, have been fueling the world economy for the last two centuries. They have proven abundant, easy to use, and low in cost. Contrary to common belief, fossil fuels are not likely to run out any time soon. For the foreseeable future, fossil fuels may continue to be the most cost-effective energy resource, even as concerns

Klaus S. Lackner

2002-01-01

395

Yankee Ticket Prices and Fossil Fuels 10 April 2008  

E-print Network

Yankee Ticket Prices and Fossil Fuels 10 April 2008 When I was young, Yankee Stadium had ~70 attention to this practice is that fossil fuel moguls are intent on hoodwinking the entire planet with an analogous scheme. The basic trick is this: fossil fuel reserves are overstated. Government "energy

Hansen, James E.

396

METHODS TO REDUCE THE DEPENDENCE ON FOSSIL FUEL  

Microsoft Academic Search

SUMMARY The wealth level in the world is directly connected with energy use. Currently, fossil fuels provide the bulk of that energy. By definition, the availability of fossil fuel is finite. Moreover, there are strong indications that the CO2 emissions resulting from fossil fuel use have an effect on climates. Therefore, energy-efficient technologies and the use of sustainable energy should

Jacob Klimstra

397

Constraints of fossil fuels depletion on global warming projections  

Microsoft Academic Search

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO2 concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained

Luca Chiari; Antonio Zecca

2011-01-01

398

Status of Fossil Energy Resources: A Global Perspective  

Microsoft Academic Search

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

M. Balat

2007-01-01

399

Structural coloration in a fossil feather  

PubMed Central

Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs. PMID:19710052

Vinther, Jakob; Briggs, Derek E. G.; Clarke, Julia; Mayr, Gerald; Prum, Richard O.

2010-01-01

400

Structural coloration in a fossil feather.  

PubMed

Investigation of feathers from the famous Middle Eocene Messel Oil Shale near Darmstadt, Germany shows that they are preserved as arrays of fossilized melanosomes, the surrounding beta-keratin having degraded. The majority of feathers are preserved as aligned rod-shaped eumelanosomes. In some, however, the barbules of the open pennaceous, distal portion of the feather vane are preserved as a continuous external layer of closely packed melanosomes enclosing loosely aligned melanosomes. This arrangement is similar to the single thin-film nanostructure that generates an iridescent, structurally coloured sheen on the surface of black feathers in many lineages of living birds. This is, to our knowledge, the first evidence of preservation of a colour-producing nanostructure in a fossil feather and confirms the potential for determining colour differences in ancient birds and other dinosaurs. PMID:19710052

Vinther, Jakob; Briggs, Derek E G; Clarke, Julia; Mayr, Gerald; Prum, Richard O

2010-02-23

401

Determining Age of Rocks and Fossils  

NSDL National Science Digital Library

This activity will help students to have a better understanding of the basic principles used to determine the age of rocks and fossils. It consists of several parts: to have students determine relative age of a geologically complex area, to familiarize students with the concept of half-life in radioactive decay, to have students see that individual runs of statistical processes are less predictable than the average of many runs, and to demonstrate how the rate of radioactive decay and the buildup of the resulting decay product is used in radiometric dating of rocks. Students learn to use the principles of determining relative age to show how ages of rocks and fossils can be narrowed even if they cannot be dated radiometrically.

Mckinney, Frank

402

Diatoms: a fossil fuel of the future.  

PubMed

Long-term global climate change, caused by burning petroleum and other fossil fuels, has motivated an urgent need to develop renewable, carbon-neutral, economically viable alternatives to displace petroleum using existing infrastructure. Algal feedstocks are promising candidate replacements as a 'drop-in' fuel. Here, we focus on a specific algal taxon, diatoms, to become the fossil fuel of the future. We summarize past attempts to obtain suitable diatom strains, propose future directions for their genetic manipulation, and offer biotechnological pathways to improve yield. We calculate that the yields obtained by using diatoms as a production platform are theoretically sufficient to satisfy the total oil consumption of the US, using between 3 and 5% of its land area. PMID:24529448

Levitan, Orly; Dinamarca, Jorge; Hochman, Gal; Falkowski, Paul G

2014-03-01

403

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

NASA Astrophysics Data System (ADS)

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.

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

2008-03-01

404

Identifying Fossil Bacteria in Martian Materials  

NASA Technical Reports Server (NTRS)

Within the next decade, robotic missions are going to Mars with the search for evidence for extant and extinct life as at least one of the mission objectives. Moreover, the first Martian samples will be returned to Earth in 2008. It is therefore imperative that we can be certain that we can identify life in Martian rocks. In this paper we will not be discussing extant life but will concentrate on fossil life.

Westall, F.; McKay, D. S.; Gibson, E. K., Jr.

1999-01-01

405

Precambrian ``fossil'' Vermiforma is a tectograph  

SciTech Connect

Vermiforma antiqua Cloud 1976, once celebrated as the earliest animal fossil of the US, is actually a tectonic artifact. The main argument is that the congruence and equal orientation of multiple patterns on the same bedding plane are incompatible with swaying worm bodies of worm burrows. As shown by analog and numerical simulations, these structures can be explained as tracks of particles that broke out from the base of an overlying turbidite and became rolled between beds during bed-to-bed shearing.

Seilacher, A.; Meschede, M.; Bolton, E.W.; Luginsland, H.

2000-03-01

406

The First Turbulence and First Fossil Turbulence  

Microsoft Academic Search

A model is proposed connecting turbulence, fossil turbulence and the big-bang origin of the universe. While details are incomplete, the model is consistent with our knowledge of these processes and is supported by observations. Turbulence arises in a hot big-bang quantum gravitational dynamics scenario at Planck scales. Chaotic, eddy-like motions produce an exothermic Planck particle cascade from 10-35 m at

Carl H. Gibson

2004-01-01

407

Atmospheric Lifetime of Fossil Fuel Carbon Dioxide  

Microsoft Academic Search

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

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

408

Fossil evidence of the zygomycetous fungi  

E-print Network

Neoproterozoic shale, Canada (cour- tesy N.J. Butterfield). — b, c. Microfossils resembling mucoralean columellae; Lower Devonian Rhynie chert, Scotland. — d, e. Winfrenatia reticulata, Lower Devonian Rhynie chert, Scotland; d. thallus; e. hyphal net enclosing... orifice that is surrounded by a con- spicuous collar-like structure. The proximal end of the collar appears irregular, suggesting that it may have been mechani- cally separated. The fossils are morphologically quite similar to columellae seen in members...

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

2013-02-18

409

The Fossil Starburst in M82  

Microsoft Academic Search

We present high-resolution HST imaging in the optical (WFPC2) and near-infrared (NICMOS) of a disk region 1 kpc northeast of the starburst core in the nearby galaxy M82. This region, M82 ``B,'' has been suspected to be a fossil starburst site in which an intense episode of star formation occurred over 100 Myr ago, and our new observations confirm this

Richard de Grijs; Robert W. O'Connell; John S. Gallagher III

2001-01-01

410

Oral Presentation of a Fossil Group  

NSDL National Science Digital Library

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.

Reams, Max

411

Coupled evolutionary rates and the fossil record  

Microsoft Academic Search

A model for speciation is given in which a taxon’s phenotypic variation and concomitant variation in fitness are related to\\u000a gradients within the environment. Phenotypic expressions within the population are shown to undergo abrupt transitions as\\u000a a result of discontinuous fitness-functions. Evidence for rapid and abrupt phenotypic variation is explored by analyses of\\u000a speciation (= origination) rates within the fossil

Karl J. Niklas

1978-01-01

412

Adaptation, plant evolution, and the fossil record  

NASA Technical Reports Server (NTRS)

The importance of adaptation in determining patterns of evolution has become an important focus of debate in evolutionary biology. As it pertains to paleobotany, the issue is whether or not adaptive evolution mediated by natural selection is sufficient to explain the stratigraphic distributions of taxa and character states observed in the plant fossil record. One means of addressing this question is the functional evaluation of stratigraphic series of plant organs set in the context of paleoenvironmental change and temporal patterns of floral composition within environments. For certain organ systems, quantitative estimates of biophysical performance can be made on the basis of structures preserved in the fossil record. Performance estimates for plants separated in time or space can be compared directly. Implicit in different hypotheses of the forces that shape the evolutionary record (e.g. adaptation, mass extinction, rapid environmental change, chance) are predictions about stratigraphic and paleoenvironmental trends in the efficacy of functional performance. Existing data suggest that following the evolution of a significant structural innovation, adaptation for improved functional performance can be a major determinant of evolutionary changes in plants; however, there are structural and development limits to functional improvement, and once these are reached, the structure in question may no longer figure strongly in selection until and unless a new innovation evolves. The Silurian-Devonian paleobotanical record is consistent with the hypothesis that the succession of lowland floodplain dominants preserved in the fossil record of this interval was determined principally by the repeated evolution of new taxa that rose to ecological importance because of competitive advantages conferred by improved biophysical performance. This does not seem to be equally true for Carboniferous-Jurassic dominants of swamp and lowland floodplain environments. In these cases, environmental disruption appears to have been a major factor in shaping the fossil record. This does not mean that continuing adaptation was not important during this interval, but it may indicate that adaptive evolution was strongest in environments other than those best represented in the paleobotanical record.

Knoll, A. H.; Niklas, K. J.

1987-01-01

413

Non-Retroviral Fossils in Vertebrate Genomes  

PubMed Central

Although no physical fossils of viruses have been found, retroviruses are known to leave their molecular fossils in the genomes of their hosts, the so-called endogenous retroviral elements. These have provided us with important information about retroviruses in the past and their co-evolution with their hosts. On the other hand, because non-retroviral viruses were considered not to leave such fossils, even the existence of prehistoric non-retroviral viruses has been enigmatic. Recently, we discovered that elements derived from ancient bornaviruses, non-segmented, negative strand RNA viruses, are found in the genomes of several mammalian species, including humans. In addition, at approximately the same time, several endogenous elements of RNA viruses, DNA viruses and reverse-transcribing DNA viruses have been independently reported, which revealed that non-retroviral viruses have played significant roles in the evolution of their hosts and provided novel insights into virology and cell biology. Here we review non-retroviral virus-like elements in vertebrate genomes, non-retroviral integration and the knowledge obtained from these endogenous non-retroviral virus-like elements. PMID:22069518

Horie, Masayuki; Tomonaga, Keizo

2011-01-01

414

Spatial Bias in the Marine Fossil Record  

PubMed Central

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

Vilhena, Daril A.; Smith, Andrew B.

2013-01-01

415

Fossil avian eggshell preserves ancient DNA  

PubMed Central

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

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

416

Replacement of fossil fuels by hydrogen  

NASA Astrophysics Data System (ADS)

The replacement of fossil fuels by solar hydrogen plantations is considered. A model is proposed in which ten plantation families, situated in suitable deserted zones of the world after the year 2000, would generate enough electrical energy to produce solar cells and materials for the construction of ten new plantations within a decade. The technological growth process for identical solar plantation units could be completed about 50 years after construction of the first plantation. All ten plantation families would, by using their electrical energy for the electrolysis of water, generate an amount of hydrogen per year which is four to five times the energy of the world's present annual consumption of oil. This concept envisions the global replacement of fossil fuels by hydrogen within a period consistent with the remaining time span of fossil fuel availability. Storage and transportation of hydrogen would be economical, and the energy produced would not present any environmental problems. Advantages with respect to gains in international cooperation, world peace, and world economy are also discussed.

Dahlberg, R.

417

Proceedings: 1991 Fossil power plant construction conference  

SciTech Connect

EPRI's Second International Conference on Fossil Plant Construction was held in Washington, DC on September 18-20 1991. The conference was attended by approximately 150 people representing 30 utilities, and many independent power producers, architect engineering companies, and equipment suppliers. The conference covered recent developments in fossil plant construction. This proceedings includes papers from the following sessions: Challenges for New Capacity and Construction; Recent Construction Experience on Fossil Projects; Recent Experience on Special Projects; IPP and Cogeneration Project Experience; Planning and Development; Modularization and Construction Technology; Management Challenges; Applications of Computer Technologies; Planning and Development; Retrofit and Special Projects; and Construction Experience and Lessons Learned. Papers and discussions in the sessions led to the following conclusions from the conference: (1) Increasing competitive demands on major users of electric energy, growing environmental restrictions, and changing competitive conditions in the electric industry require continued development of new management approaches and technologies to improve quality, cost, and schedule on future projects. (2) Many new techniques and technologies are available to assist in meeting performance and environmental challenges for new facilities and in improving design and construction; their successful use on completed projects demonstrated the benefits. (3) transfer and effective use of new technologies on future projects remains a major opportunity for electric generation projects.

Tatum, C.B. (ed.)(Stanford Univ., CA (United States))

1992-12-01

418

Regulation of the transcription factor Ets-1 by DNA-mediated homo-dimerization.  

PubMed

The function of the Ets-1 transcription factor is regulated by two regions that flank its DNA-binding domain. A previously established mechanism for auto-inhibition of monomeric Ets-1 on DNA response elements with a single ETS-binding site, however, has not been observed for the stromelysin-1 promoter containing two palindromic ETS-binding sites. We present the structure of Ets-1 on this promoter element, revealing a ternary complex in which protein homo-dimerization is mediated by the specific arrangement of the two ETS-binding sites. In this complex, the N-terminal-flanking region is required for ternary protein-DNA assembly. Ets-1 variants, in which residues from this region are mutated, loose the ability for DNA-mediated dimerization and stromelysin-1 promoter transactivation. Thus, our data unravel the molecular basis for relief of auto-inhibition and the ability of Ets-1 to function as a facultative dimeric transcription factor on this site. Our findings may also explain previous data of Ets-1 function in the context of heterologous transcription factors, thus providing a molecular model that could also be valid for Ets-1 regulation by hetero-oligomeric assembly. PMID:18566588

Lamber, Ekaterina P; Vanhille, Laurent; Textor, Larissa C; Kachalova, Galina S; Sieweke, Michael H; Wilmanns, Matthias

2008-07-23

419

Regulation of the transcription factor Ets-1 by DNA-mediated homo-dimerization  

PubMed Central

The function of the Ets-1 transcription factor is regulated by two regions that flank its DNA-binding domain. A previously established mechanism for auto-inhibition of monomeric Ets-1 on DNA response elements with a single ETS-binding site, however, has not been observed for the stromelysin-1 promoter containing two palindromic ETS-binding sites. We present the structure of Ets-1 on this promoter element, revealing a ternary complex in which protein homo-dimerization is mediated by the specific arrangement of the two ETS-binding sites. In this complex, the N-terminal-flanking region is required for ternary protein–DNA assembly. Ets-1 variants, in which residues from this region are mutated, loose the ability for DNA-mediated dimerization and stromelysin-1 promoter transactivation. Thus, our data unravel the molecular basis for relief of auto-inhibition and the ability of Ets-1 to function as a facultative dimeric transcription factor on this site. Our findings may also explain previous data of Ets-1 function in the context of heterologous transcription factors, thus providing a molecular model that could also be valid for Ets-1 regulation by hetero-oligomeric assembly. PMID:18566588

Lamber, Ekaterina P; Vanhille, Laurent; Textor, Larissa C; Kachalova, Galina S; Sieweke, Michael H; Wilmanns, Matthias

2008-01-01

420

Morphology of the nasal capsule of primates-with special reference to daubentonia and homo.  

PubMed

Primitive mammals are considered macrosmatic. They have very large and complicated nasal capsules, nasal cavities with extensive olfactory epithelia, and relatively large olfactory bulbs. The complicated structures of the nasal capsule follow a relatively conservative "bauplan," which is normally easy to see in earlier fetal stages; especially in altricial taxa it differentiates well into postnatal life. As anteriormost part of the chondrocranium, the nasal capsule is at first cartilaginous. Most of it ossifies endochondrally, but "appositional bone" ("Zuwachsknochen") is also common. Many fetal structures become resorbed. Together, all surviving bone structures form the ethmoid bone, but cartilages of the external nose and of the vomeronasal complex can persist throughout life. We describe in detail the anatomy of Daubentonia madagascariensis based on a fetal stage (41 mm HL) and an adult skull was analyzed by µCT. We found that the nasal capsule of this species is by far the most complicated one of all extant Primates. We also describe older fetuses of Homo sapiens (35 and 63 mm HL) as representative of a derived primate. The most significant feature of man-and probably of all anthropoids-is the complete loss of the recessus frontoturbinalis and its associated structures. It can be demonstrated that the evolutionary reductions within the primate nasal capsule mainly affect those structures associated with olfaction, whereas cartilages that are important for the biomechanics of the facial skull of the fetus persist. Anat Rec, 297:1985-2006, 2014. © 2014 Wiley Periodicals, Inc. PMID:25312360

Maier, Wolfgang; Ruf, Irina

2014-11-01

421

Computational study of gold-catalyzed homo- and cross-coupling reactions.  

PubMed

The role of gold as the organizing metal in homo- and cross-coupling reactions is explored in this paper combining DFT calculations with QTAIM, NBO, and the energetic span model analysis. For the gold(III) complex 7, a key intermediate in the experimental oxidative coupling scheme by Zhang et al., we describe the mechanisms corresponding to a cross-coupling after transmetalation with boron compounds and to a homocoupling after transmetalation with the original gold(I) complex 6, a new example of dual role of this metal in homogeneous catalysis. We predict for the first path a two-step transmetalation with a low energy rate-limiting step characterized by a four-center transition structure, where fluorine plays an essential role, followed by a reductive elimination where the C-C bond formation is coupled to the departure of fluorine from the gold center. The homocoupling path follows a similar mechanism, with a two-step transmetalation with interesting changes in bonding around the Au(I) center and a rate-limiting reductive elimination. Our findings on the competition between mechanisms, and the effect of ligands and solvent, agree with the experimental results and provide new insights into the mechanism of gold-catalyzed cross-coupling reactions. PMID:23597253

Nieto Faza, Olalla; Silva López, Carlos

2013-05-17

422

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

PubMed

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

Elanthiraiyan, M; Jayasudha, B; Arivazhagan, M

2015-01-01

423

Calix[n]imidazolium as a new class of positively charged homo-calix compounds  

PubMed Central

Macrocycles based on neutral calixarenes and calixpyrroles have been extensively explored for ion binding, molecular assembly and related applications. Given that only these two types of calix compounds and their analogs are available, the introduction of new forms of widely usable calix macrocycles is an outstanding challenge. Here we report the quadruply/quintuply charged imidazole-based homo-calix compounds, calix[4/5]imidazolium. The noncovalent (C-H)+/?+-anion interactions of the imidazolium rings with anions inside and outside the cone are the stabilizing factors for crystal packing, resulting in self-assembled arrays of cone-shaped calix-imidazolium molecules. Calix[4]imidazolium senses fluoride selectively even in aqueous solutions. Calix[5]imidazolium recognizes neutral fullerenes through ?+–? interactions and makes them soluble in water, which could be useful in fullerene chemistry. Not only derivatization and ring expansion of calix[n]imidazolium, but also their utilization in ionic liquids, carbene chemistry and nanographite/graphene exfoliation could be exploited. PMID:23653209

Chun, Young; Jiten Singh, N; Hwang, In-Chul; Woo Lee, Jung; Yu, Seong Uk; Kim, Kwang S

2013-01-01

424

Pathophysiology of GPCR Homo- and Heterodimerization: Special Emphasis on Somatostatin Receptors  

PubMed Central

G-protein coupled receptors (GPCRs) are cell surface proteins responsible for translating >80% of extracellular reception to intracellular signals. The extracellular information in the form of neurotransmitters, peptides, ions, odorants etc is converted to intracellular signals via a wide variety of effector molecules activating distinct downstream signaling pathways. All GPCRs share common structural features including an extracellular N-terminal, seven-transmembrane domains (TMs) linked by extracellular/intracellular loops and the C-terminal tail. Recent studies have shown that most GPCRs function as dimers (homo- and/or heterodimers) or even higher order of oligomers. Protein-protein interaction among GPCRs and other receptor proteins play a critical role in the modulation of receptor pharmacology and functions. Although ~50% of the current drugs available in the market target GPCRs, still many GPCRs remain unexplored as potential therapeutic targets, opening immense possibility to discover the role of GPCRs in pathophysiological conditions. This review explores the existing information and future possibilities of GPCRs as tools in clinical pharmacology and is specifically focused for the role of somatostatin receptors (SSTRs) in pathophysiology of diseases and as the potential candidate for drug discovery. PMID:24281555

Somvanshi, Rishi K.; Kumar, Ujendra

2012-01-01

425

Allostery at G Protein-Coupled Receptor Homo- and Heteromers: Uncharted Pharmacological Landscapes  

PubMed Central

For many years seven transmembrane domain G protein-coupled receptors (GPCRs) were thought to exist and function exclusively as monomeric units. However, evidence both from native cells and heterologous expression systems has demonstrated that GPCRs can both traffic and signal within higher-order complexes. As for other protein-protein interactions, conformational changes in one polypeptide, including those resulting from binding of pharmacological ligands, have the capacity to alter the conformation and therefore the response of the interacting protein(s), a process known as allosterism. For GPCRs, allosterism across homo- or heteromers, whether dimers or higher-order oligomers, represents an additional topographical landscape that must now be considered pharmacologically. Such effects may offer the opportunity for novel therapeutic approaches. Allosterism at GPCR heteromers is particularly exciting in that it offers additional scope to provide receptor subtype selectivity and tissue specificity as well as fine-tuning of receptor signal strength. Herein, we introduce the concept of allosterism at both GPCR homomers and heteromers and discuss the various questions that must be addressed before significant advances can be made in drug discovery at these GPCR complexes. PMID:21079041

Smith, Nicola J.

2010-01-01

426

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

PubMed

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

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

2014-06-01

427

Novel Telechelic Polymer Hydrogels using Homo and Hetero-combinations of End-blocks  

NASA Astrophysics Data System (ADS)

The last two decades have seen telechelic triblock polymers support increasing number of applications as stabilizers and flow modifiers in fields as varied as pharmaceutics, paints and oil recovery. Mainly consisting of a solvophilic mid-block end-capped with solvophobic blocks, their use as flow altering additives stems from their ability to form gels comprising hydrophobic junctions, with hydrophilic blocks bridging these junctions. Previous studies have shown that the chemical nature of the end-block has a direct bearing on the morphology of the gel, which in turn affects its macroscopic properties. We have conducted an examination of this relationship using a variety of techniques including cryogenic scanning electron microscopy (cryo-SEM), small angle neutron scattering (SANS) and rheology. Using homo and hetero-combinations of poly(1,2-butadiene) and poly(perfluoropropylene oxide) as hydrophobic end-blocks with poly(ethylene oxide) as the hydrophilic mid-block, we have demonstrated that the hydrogels obtained are distinct in morphology and physical properties. The study seeks to highlight the importance of controlling end-blocks in triblock polymers as a potential tool towards manipulating the physical properties of gels.

Taribagil, Rajiv R.; Hillmyer, Marc A.; Lodge, Timothy P.

2010-03-01

428

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

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

429

Yukon gold mine yields ancient horse fossil 700,000yearold fossil discovered in Yukon permafrost yields genome world record.  

E-print Network

Yukon gold mine yields ancient horse fossil 700,000yearold fossil discovered in Yukon permafrost an unusually large horse fossil in the Yukon permafrost, he knew it was important. Now, in a new study visiting Yukon placer gold mining exposures to understand the permafrost and the ice age environments

Machel, Hans

430

Emissions Scenarios and Fossil-fuel Peaking  

NASA Astrophysics Data System (ADS)

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.

Brecha, R.

2008-12-01

431

Age and metallicity gradients in fossil ellipticals  

NASA Astrophysics Data System (ADS)

Context. Fossil galaxy groups are speculated to be old and highly evolved systems of galaxies that formed early in the universe and had enough time to deplete their L? galaxies through successive mergers of member galaxies, building up one massive central elliptical, but retaining the group X-ray halo. Aims: Considering that fossils are the remnants of mergers in ordinary groups, the merger history of the progenitor group is expected to be imprinted in the fossil central galaxy (FCG). We present for the first time radial gradients of single-stellar population (SSP) ages and metallicites in a sample of FCGs to constrain their formation scenario. We also measure line-strength gradients for the strongest absorption features in these galaxies. Methods: We took deep spectra with the long-slit spectrograph ISIS at the William Herschel Telescope (WHT) for six FCGs. The obtained spectra are fit with Pegase HR SSP models within the full-spectrum fitting package ULySS yielding SSP ages and metallicities of the stellar populations. We measure radial gradients of SSP ages and metallicities along the major axes. Lick indices are measured for the strongest absorption features to determine line-strength gradients and compare with the full-spectrum fitting results. Results: Our sample comprises some of the most massive galaxies in the universe exhibiting an average central velocity dispersion of ?0 = 271 ± 28 km s-1. Metallicity gradients are throughout negative with comparatively flat slopes of ?[Fe/H] = -0.19 ± 0.08 while age gradients are found to be insignificant (?age = 0.00 ± 0.05). All FCGs lie on the fundamental plane, suggesting that they are virialised systems. We find that gradient strengths and central metallicities are similar to those found in cluster ellipticals of similar mass. Conclusions: The comparatively flat metallicity gradients with respect to those predicted by monolithic collapse (?Z = -0.5) suggest that fossils are indeed the result of multiple major mergers. Hence we conclude that fossils are not "failed groups" that formed with a top-heavy luminosity function. The low scatter of gradient slopes suggests a similar merging history for all galaxies in our sample. Figures 3 and 4 are available in electronic form at http://www.aanda.orgReduced spectra are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/553/A99

Eigenthaler, P.; Zeilinger, W. W.

2013-05-01

432

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

Microsoft Academic Search

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

V. Balachandran; A. Lakshmi; A. Janaki

433

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

SciTech Connect

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.

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

1993-12-01

434

Out of Africa: new hypotheses and evidence for the dispersal of Homo sapiens along the Indian Ocean rim.  

PubMed

The dispersal of Homo sapiens out of Africa is a significant topic in human evolutionary studies. Most investigators agree that our species arose in Africa and subsequently spread out to occupy much of Eurasia. Researchers have argued that populations expanded along the Indian Ocean rim at ca 60,000 years ago during a single rapid dispersal event, probably employing a coastal route towards Australasia. Archaeologists have been relatively silent about the movement and expansion of human populations in terrestrial environments along the Indian Ocean rim, although it is clear that Homo sapiens reached Australia by ca 45,000 years ago. Here, we synthesize and document current genetic and archaeological evidence from two major landmasses, the Arabian peninsula and the Indian subcontinent, regions that have been underplayed in the story of out of Africa dispersals. We suggest that modern humans were present in Arabia and South Asia earlier than currently believed, and probably coincident with the presence of Homo sapiens in the Levant between ca 130 and 70,000 years ago. We show that climatic and environmental fluctuations during the Late Pleistocene would have had significant demographic effects on Arabian and South Asian populations, though indigenous populations would have responded in different ways. Based on a review of the current genetic, archaeological and environmental data, we indicate that demographic patterns in Arabia and South Asia are more interesting and complex than surmised to date. PMID:20334598

Petraglia, Michael D; Haslam, Michael; Fuller, Dorian Q; Boivin, Nicole; Clarkson, Chris

2010-06-01

435

Abstracts: Eighth Annual Conference on Fossil Energy Materials. Fossil Energy Program  

SciTech Connect

Abstracts are presented for about 40 papers. The Fossil Energy Advanced Research and Technology Development Materials program is an integrated materials research activity of the fossil energy coal program, whose objective is to conduct R and D for all advanced coal conversion and utilization technologies. The program is aimed at understanding materials behavior in coal system environments and the development of new materials for improving plant operations and reliability. A generic approach is used for addressing multiple coal technologies; for example, the hot-gas particulate filter development is applicable to pressurized fluidized bed combustion, integrated coal gasification combined-cycle, coal combustion, and indirectly fired combined-cycle systems.

Not Available

1994-07-01

436

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

NASA Technical Reports Server (NTRS)

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.

Williams, J. R.

1974-01-01

437

Homo- and heteropolymetallic 3-(2-pyridyl)pyrazolate manganese and rhenium complexes.  

PubMed

fac-[MBr(CO)3(pypzH)] (M = Mn, Re; pypzH = (3-(2-pyridyl)pyrazole) complexes are prepared from fac-[MBr(CO)3(NCMe)2] and pypzH. The result of their deprotonation depends on the metallic substrate: the rhenium complex affords cleanly the bimetallic compound [fac-{Re(CO)3(?(2)-pypz)}]2 (?(2)-pypz = ?(2)-3-(2-pyridyl-?(1)N)pyrazolate-2?(1)N), which was crystallographically characterized, whereas a similar manganese complex was not detected. When two equivalents of pyridylpyrazolate are used, polymetallic species [fac-M(CO)3(?(2)-pypz)(?(3)-pypz)M'] (?(3)-pypz = ?(3)-3-(2-pyridyl-?(1)N)pyrazolate-1?(2)N,N:2?(1)N:; M = Mn, M' = Li, Na, K; M = Re, M' = Na) are obtained. The crystal structures of the manganese carbonylate complexes were determined. The lithium complex is a monomer containing one manganese and one lithium atom, whereas the sodium and potassium complexes are dimers and reveal an unprecedented coordination mode for the bridging 3-(2-pyridyl)pyrazolate ligand, where the nitrogen of the pyridyl fragment and the nitrogen-1 of pyrazolate are chelated to manganese atoms, and each nitrogen-2 of pyrazolate is coordinated to two alkaline atoms. The polymetallic carbonylate complexes are unstable in solution and evolve spontaneously to [fac-{Re(CO)3(?(2)-pypz)}]2 or to the trimetallic paramagnetic species [Mn(II)(?(2)-pypz)2{fac-{Mn(I)(CO)3(?(2)-pypz)}2}]. The related complex cis-[MnCl2(pypzH)2] was also synthesized and structurally characterized. The electrochemical behavior of the new homo- and heteropolymetallic 3-(2-pyridyl)pyrazolate complexes has been studied and details of their redox properties are reported. PMID:24452527

Arroyo, Marta; Gómez-Iglesias, Patricia; Antón, Noelia; García-Rodríguez, Raúl; Alegria, Elisabete C B A; Pombeiro, Armando J L; Miguel, Daniel; Villafañe, Fernando

2014-03-14

438

Homo floresiensis and the late Pleistocene environments of eastern Indonesia: defining the nature of the relationship  

NASA Astrophysics Data System (ADS)

Evidence from Liang Bua, a limestone cave on the island of Flores in East Indonesia, provides a unique opportunity to explore the long term relationship between hominins and their environment. Occupation deposits at the site span ˜95 ka and contain abundant stone artefacts, well preserved faunal remains and evidence for an endemic species of hominin: Homo floresiensis. Work at the site included detailed geomorphological and environmental analysis, which has enabled comparisons to be drawn between changes in the occupational intensity in the cave, using stone tool and faunal counts, and changes in the environmental conditions, using the characteristics of the sedimentary layers in the cave and speleothem records. These comparisons demonstrate that H. floresiensis endured rapidly fluctuating environmental conditions over the last ˜100 ka, which influenced the geomorphological processes in the cave and their occupational conditions. The intensity of occupation in the cave changed significantly between 95 and 17 ka, with peaks in occupation occurring at 100-95, 74-61 and 18-17 ka. These correlate with episodes of channel formation and erosion in the cave, which in turn correspond with high rainfall, thick soils and high bio-productivity outside. In contrast, periods of low occupational intensity correlate with reduced channel activity and pooling associated with drier periods from 94 to 75 and 36 to 19 ka. This apparent link between intensity of hominin use of the cave and the general conditions outside relates to the expansion and contraction of the rainforest and the ability of H. floresiensis to adapt to habitat changes. This interpretation implies that these diminutive hominins were able to survive abrupt and prolonged environmental changes by changing their favoured occupation sites. These data provide the basis for a model of human-environment interactions on the island of Flores. With the addition of extra data from other sites on Flores, this model will provide a greater understanding of H. floresiensis as a unique human species.

Westaway, K. E.; Morwood, M. J.; Sutikna, T.; Moore, M. W.; Rokus, A. D.; van den Bergh, G. D.; Roberts, R. G.; Saptomo, E. W.

2009-12-01

439

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

440

Radiation history of fossil meteorites from Sweden  

NASA Astrophysics Data System (ADS)

We present the results of the analysis of the data obtained by Heck et al. (2004; 2008) regarding the contents of 4He and 20,21,22Ne and the exposure age of chromite grains recovered from fossil meteorites (L-chondrites) found in marine limestone—mid-Ordovician sediments—in the Thorsberg and Gullhogen quarries of southern Sweden. It has been shown that the increase of the content of noble gases in the chromite grains (by 1-2 orders of magnitude) and their exposure age with a decreasing mass of the samples (by approximately an order of magnitude) can be caused by an increase of the portion of small grains and by their poor preservation in the samples of small mass. The revealed relationships, as well as the fact that practically all fossil meteorites were found in a small area (˜6000 m2), can be explained by the following assumption: a meteorite shower, caused by a single meteorite, fell ˜470 Myr; this occurred less than 0.2 Myr after the catastrophic destruction of the L-chondrite parent body. The time of this fall corresponds to that of the formation of the oldest sedimentation stratum, containing the meteorite fragments, in the Thorsberg quarry. Meteorite fragments in the younger strata are most likely the result of the subsequent redeposition that occurred in a shallow sea, when the sediment mass was forming. In this case, to explain the distribution of fossil meteorites in the mid-Ordovician sediments in Sweden, there is no necessity to hypothesize that an intense flux of meteorites was falling onto the Earth over the course of ˜1-2 Myr about 470 million years ago.

Alexeev, V. A.

2010-08-01

441

An unusual mechanism for HOMO-LUMO gap narrowing in a minimal near-IR dye generated by the deprotonation of bis(dicyanomethylene)indan  

NASA Astrophysics Data System (ADS)

A minimal near-IR (NIR) dye with the lower molecular-weight than 250 is produced by the deprotonation of 1,3-bis(dicyanomethylene)indan. Despite the small ?-conjugation system, the anionic dye shows light absorption and fluorescence in the red to near infra-red region. This Letter reports on the unusual mechanism for HOMO-LUMO gap narrowing for the NIR dye. Density functional theory (DFT) analyses show the molecular-orbital transition from the LUMO+1 to HOMO by the deprotonation, which significantly reduces the HOMO-LUMO gap. Time-dependent DFT and group-theory analyses well explain the electronic-excitation properties. This is a new mechanism for reducing a HOMO-LUMO gap without extending ?-conjugation systems.

Fujisawa, Jun-ichi

2014-07-01

442

Recent Developments in Biodesulfurization of Fossil Fuels  

NASA Astrophysics Data System (ADS)

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.

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

443

Earth's early fossil record: Why not look for similar fossils on Mars?  

NASA Technical Reports Server (NTRS)

The oldest evidence of life on Earth is discussed with attention being given to the structure and formation of stromatolites and microfossils. Fossilization of microbes in calcium carbonate or chert media is discussed. In searching for fossil remains on Mars, some lessons learned from the study of Earth's earliest fossil record can be applied. Certain sedimentary rock types and sedimentary rock configurations should be targeted for investigation and returned by the Martian rover and ultimately by human explorers. Domical, columnar to wavy laminated stratiform sedimentary rocks that resemble stromatolites should be actively sought. Limestone, other carbonates, and chert are the favored lithology. Being macroscopic, stromatolites might be recognized by an intelligent unmanned rover. In addition, black, waxy chert with conchoidal fracture should be sought. Chert is by far the preferred lithology for the preservation of microbes and chemical fossils. Even under optimal geological conditions (little or no metamorphism or tectonic alteration, excellent outcrops, and good black chert) and using experienced field biogeologists, the chances of finding well preserved microbial remains in chert are very low.

Awramik, Stanley M.

1989-01-01

444

Energy information Guide. Vol. III. Fossil Fuels. [1151 references to fossil fuels  

Microsoft Academic Search

Volume III of the series covers fossil fuels in general and petroleum, natural gas, and coal in particular. The listings include dictionaries, encyclopedias, handbooks and manuals, directories, statistical sources, indexes, abstracts, atlases, bibliographies, and electronic data bases. By using this guide, the researcher can gain both a quick reference source and a long-range perspective on his line of inquiry. The

1984-01-01

445

Species longevity in North American fossil mammals.  

PubMed

Species longevity in the fossil record is related to many paleoecological variables and is important to macroevolutionary studies, yet there are very few reliable data on average species durations in Cenozoic fossil mammals. Many of the online databases (such as the Paleobiology Database) use only genera of North American Cenozoic mammals and there are severe problems because key groups (e.g. camels, oreodonts, pronghorns and proboscideans) have no reliable updated taxonomy, with many invalid genera and species and/or many undescribed genera and species. Most of the published datasets yield species duration estimates of approximately 2.3-4.3 Myr for larger mammals, with small mammals tending to have shorter species durations. My own compilation of all the valid species durations in families with updated taxonomy (39 families, containing 431 genera and 998 species, averaging 2.3 species per genus) yields a mean duration of 3.21 Myr for larger mammals. This breaks down to 4.10-4.39 Myr for artiodactyls, 3.14-3.31 Myr for perissodactyls and 2.63-2.95 Myr for carnivorous mammals (carnivorans plus creodonts). These averages are based on a much larger, more robust dataset than most previous estimates, so they should be more reliable for any studies that need species longevity to be accurately estimated. PMID:25236413

Prothero, Donald R

2014-08-01

446

Shotgun microbial profiling of fossil remains.  

PubMed

Millions to billions of DNA sequences can now be generated from ancient skeletal remains thanks to the massive throughput of next-generation sequencing platforms. Except in cases of exceptional endogenous DNA preservation, most of the sequences isolated from fossil material do not originate from the specimen of interest, but instead reflect environmental organisms that colonized the specimen after death. Here, we characterize the microbial diversity recovered from seven c. 200- to 13 000-year-old horse bones collected from northern Siberia. We use a robust, taxonomy-based assignment approach to identify the microorganisms present in ancient DNA extracts and quantify their relative abundance. Our results suggest that molecular preservation niches exist within ancient samples that can potentially be used to characterize the environments from which the remains are recovered. In addition, microbial community profiling of the seven specimens revealed site-specific environmental signatures. These microbial communities appear to comprise mainly organisms that colonized the fossils recently. Our approach significantly extends the amount of useful data that can be recovered from ancient specimens using a shotgun sequencing approach. In future, it may be possible to correlate, for example, the accumulation of postmortem DNA damage with the presence and/or abundance of particular microbes. PMID:24612293

Der Sarkissian, C; Ermini, L; Jónsson, H; Alekseev, A N; Crubezy, E; Shapiro, B; Orlando, L

2014-04-01

447

Tiny Fossil Sheds Light on Mammalian Evolution  

NSDL National Science Digital Library

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.

De Nie, Michael W.

2001-01-01

448

Multistage system for deep desulfurization of fossil fuels  

SciTech Connect

A method is described for the deep desulfurization of a liquid fossil fuel, comprising the steps of: (a) subjecting the liquid fossil fuel to hydrodesulfurization (HDS) whereby the liquid fossil fuel is depleted of forms of sulfur susceptible to removal by HDS but is not depleted of forms of sulfur refractory to HDS; (b) contacting the liquid fossil fuel with an effective amount of a biocatalyst comprising one or more microorganisms capable of converting HDS-refractory organic sulfur into water-soluble inorganic sulfur; (c) incubating the liquid fossil fuel with said biocatalyst under conditions sufficient for the conversion of a substantial amount of the HDS-refractory organic sulfur into water-soluble inorganic sulfur; and (d) separating the products of the incubation of step (c), the products including: (i) deeply desulfurized liquid fossil fuel, and (ii) water-soluble inorganic sulfur.

Monticello, D.J.

1993-08-03

449

Fossil energy biotechnology: A research needs assessment. Final report  

SciTech Connect

The Office of Program Analysis of the US Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation`s fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and, (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

Not Available

1993-11-01

450

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

Microsoft Academic Search

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

Christopher J. Lepre; Dennis V. Kent

2010-01-01

451

The reconstruction of fossil planation surface in China  

Microsoft Academic Search

On the basis of results of relative subjects, the fossil planation surface has been discussed by the authors from the point\\u000a of geomorphologic view. The discussion contents included the characteristic information, research methods, paleotopography\\u000a (gradient and altitude) and other problems about fossil planation surface. The recognition and reconstruction of fossil planation\\u000a surface mainly rely on the following characteristic information: (i)

Jinliang Feng; Zhijiu Cui

2002-01-01

452

The Macroeconomic Transition to a Fossil-Fuel-Free Economy  

Microsoft Academic Search

In this paper I discuss causes and consequences of transition toward a fossil-fuel-free economy. In the long run, fossil fuel's finiteness will cause a rise in their prices and are expected to lead economies to the employment of renewable-energy sources, as an alternative to the fossil fuel currently at use. I therefore developed a general equilibrium model which makes possible

Sagi Dagan

453

We Can Use Fossils to Learn about Paleoecology  

NSDL National Science Digital Library

This site explains how to use evidence from fossils to understand the ecology of ancient organisms. Fossils provide clues and together abiotic and biotic factors combine to form complete ecosystems, each with its own unique ecology and history. Predator and prey relationships and dispersal are used as examples to show how fossils can also tell us about biotic factors, such as what organisms are present and how they interact. The site shows how fossils tell many stories about past ecology and that these stories may be about climate, changing environments, and interactions between organisms.

454

Rates of speciation in the fossil record  

NASA Technical Reports Server (NTRS)

Data from palaeontology and biodiversity suggest that the global biota should produce an average of three new species per year. However, the fossil record shows large variation around this mean. Rates of origination have declined through the Phanerozoic. This appears to have been largely a function of sorting among higher taxa (especially classes), which exhibit characteristic rates of speciation (and extinction) that differ among them by nearly an order of magnitude. Secular decline of origination rates is hardly constant, however; many positive deviations reflect accelerated speciation during rebounds from mass extinctions. There has also been general decline in rates of speciation within major taxa through their histories, although rates have tended to remain higher among members in tropical regions. Finally, pulses of speciation appear sometimes to be associated with climate change, although moderate oscillations of climate do not necessarily promote speciation despite forcing changes in species' geographical ranges.

Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

1998-01-01

455

Fossil birds of the Kibish Formation.  

PubMed

The Kibish Formation has yielded a small collection of bird fossils, which are identified here as belonging to five species in four different families: Pelecanidae (pelicans), Anhingidae (darters), Ardeidae (herons) and Phasianidae (gamefowl). Two species of pelicans are identified: Pelecanus cf. P. onocrotalus, and P. aff. P. rufescens. The darter is referrable to Anhinga melanogaster. The heron is identifiable as Ardea sp., and the gamefowl as Numidinae indet. (guineafowl). Pelecanus cf. P. onocrotalus is represented by, among other remains, a well-preserved partial skull. Four of the birds are thus referrable to extant taxa that provide some paleoenvironmental clues for Member I of the Kibish Formation. The two species of pelican, the darter, and the heron indicate the presence of local freshwater bodies, a lake or a slow river, supporting resources of fish. The guineafowl is poorly informative ecologically, but probably excludes the notion that the local terrestrial landscape was treeless. PMID:18656245

Louchart, Antoine; Haile-Selassie, Y; Vignaud, P; Likius, A; Brunet, M

2008-09-01

456

FAST FOSSIL ROTATION OF NEUTRON STAR CORES  

SciTech Connect

It is argued that the superfluid core of a neutron star super-rotates relative to the crust, because stratification prevents the core from responding to the electromagnetic braking torque, until the relevant dissipative (viscous or Eddington-Sweet) timescale, which can exceed {approx}10{sup 3} yr and is much longer than the Ekman timescale, has elapsed. Hence, in some young pulsars, the rotation of the core today is a fossil record of its rotation at birth, provided that magnetic crust-core coupling is inhibited, e.g., by buoyancy, field-line topology, or the presence of uncondensed neutral components in the superfluid. Persistent core super-rotation alters our picture of neutron stars in several ways, allowing for magnetic field generation by ongoing dynamo action and enhanced gravitational wave emission from hydrodynamic instabilities.

Melatos, A., E-mail: amelatos@unimelb.edu.au [School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia)

2012-12-10

457

Rates of speciation in the fossil record.  

PubMed Central

Data from palaeontology and biodiversity suggest that the global biota should produce an average of three new species per year. However, the fossil record shows large variation around this mean. Rates of origination have declined through the Phanerozoic. This appears to have been largely a function of sorting among higher taxa (especially classes), which exhibit characteristic rates of speciation (and extinction) that differ among them by nearly an order of magnitude. Secular decline of origination rates is hardly constant, however; many positive deviations reflect accelerated speciation during rebounds from mass extinctions. There has also been general decline in rates of speciation within major taxa through their histories, although rates have tended to remain higher among members in tropical regions. Finally, pulses of speciation appear sometimes to be associated with climate change, although moderate oscillations of climate do not necessarily promote speciation despite forcing changes in species' geographical ranges. PMID:11541734

Sepkoski, J J

1998-01-01

458

The future of oil: unconventional fossil fuels.  

PubMed

Unconventional fossil hydrocarbons fall into two categories: resource plays and conversion-sourced hydrocarbons. Resource plays involve the production of accumulations of solid, liquid or gaseous hydro-carbons that have been generated over geological time from organic matter in source rocks. The character of these hydrocarbons may have been modified subsequently, especially in the case of solids and extra-heavy liquids. These unconventional hydrocarbons therefore comprise accumulations of hydrocarbons that are trapped in an unconventional manner and/or whose economic exploitation requires complex and technically advanced production methods. This review focuses primarily on unconventional liquid hydro-carbons. The future potential of unconventional gas, especially shale gas, is also discussed, as it is revolutionizing the energy outlook in North America and elsewhere. PMID:24298078

Chew, Kenneth J

2014-01-13

459

Homo-D-lactic acid production from mixed sugars using xylose-assimilating operon-integrated Lactobacillus plantarum.  

PubMed

In order to achieve efficient D-lactic acid fermentation from a mixture of xylose and glucose, the xylose-assimilating xylAB operon from Lactobacillus pentosus (PXylAB) was introduced into an L-lactate dehydrogenase gene (ldhL1)-deficient Lactobacillus plantarum (?ldhL1-xpk1::tkt-?xpk2) strain in which the phosphoketolase 1 gene (xpk1) was replaced with the transketolase gene (tkt) from Lactococcus lactis, and the phosphoketolase 2 (xpk2) gene was deleted. Two copies of xylAB introduced into the genome significantly improved the xylose fermentation ability, raising it to the same level as that of ?ldhL1-xpk1::tkt-?xpk2 harboring a xylAB operon-expressing plasmid. Using the two-copy xylAB integrated strain, successful homo-D-lactic acid production was achieved from a mixture of 25 g/l xylose and 75 g/l glucose without carbon catabolite repression. After 36-h cultivation, 74.2 g/l of lactic acid was produced with a high yield (0.78 g per gram of consumed sugar) and an optical purity of D-lactic acid of 99.5%. Finally, we successfully demonstrated homo-D-lactic acid fermentation from a mixture of three kinds of sugar: glucose, xylose, and arabinose. This is the first report that describes homo-D-lactic acid fermentation from mixed sugars without carbon catabolite repression using the xylose-assimilating pathway integrated into lactic acid bacteria. PMID:21643702

Yoshida, Shogo; Okano, Kenji; Tanaka, Tsutomu; Ogino, Chiaki; Kondo, Akihiko

2011-10-01

460

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

PubMed Central

Summary 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

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

2012-01-01

461

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

NASA Astrophysics Data System (ADS)

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.

Goncharova, Iryna

2014-01-01

462

The eukaryotic fossil record in deep time  

NASA Astrophysics Data System (ADS)

Eukaryotic organisms are defining constituents of the Phanerozoic biosphere, but they also extend well back into the Proterozoic record, primarily in the form of microscopic body fossils. Criteria for identifying pre-Ediacaran eukaryotes include large cell size, morphologically complex cell walls and/or the recognition of diagnostically eukaryotic cell division patterns. The oldest unambiguous eukaryote currently on record is an acanthomorphic acritarch (Tappania) from the Palaeoproterozoic Semri Group of central India. Older candidate eukaryotes are difficult to distinguish from giant bacteria, prokaryotic colonies or diagenetic artefacts. In younger Meso- and Neoproterozoic strata, the challenge is to recognize particular grades and clades of eukaryotes, and to document their macro-evolutionary expression. Distinctive unicellular forms include mid-Neoproterozoic testate amoebae and phosphate biomineralizing 'scale-microfossils' comparable to an extant green alga. There is also a significant record of seaweeds, possible fungi and problematica from this interval, documenting multiple independent experiments in eukaryotic multicellularity. Taxonomically resolved forms include a bangiacean red alga and probable vaucheriacean chromalveolate algae from the late Mesoproterozoic, and populations of hydrodictyacean and siphonocladalean green algae of mid Neoproterozoic age. Despite this phylogenetic breadth, however, or arguments from molecular clocks, there is no convincing evidence for pre-Ediacaran metazoans or metaphytes. The conspicuously incomplete nature of the Proterozoic record makes it difficult to resolve larger-scale ecological and evolutionary patterns. Even so, both body fossils and biomarker data point to a pre-Ediacaran biosphere dominated overwhelming by prokaryotes. Contemporaneous eukaryotes appear to be limited to conspicuously shallow water environments, and exhibit fundamentally lower levels of morphological diversity and evolutionary turnover than their Phanerozoic counterparts. I will argue here that this fundamental change of state was driven by the early Ediacaran appearance of Eumetazoa, a uniquely complex clade of heterotrophic eukaryotes that redefined how the planet worked.

Butterfield, N.

2011-12-01

463

Cytochrome c-mediated oxidation of hydroethidine and mito-hydroethidine in mitochondria: Identification of homo- and heterodimers  

Microsoft Academic Search

Here we report that ferricytochrome c (cyt c3+) induces oxidation of hydroethidine (HE) and mitochondria-targeted hydroethidine (Mito-HE or MitoSOX Red) forming highly characteristic homo- and heterodimeric products. Using an HPLC-electrochemical (EC) method, several products were detected from cyt c3+-catalyzed oxidation of HE and Mito-HE and characterized by mass spectrometry and NMR techniques as follows: homodimers (HE-HE, E+-E+, Mito-HE-Mito-HE, and Mito-E+-Mito-E+)

Jacek Zielonka; Satish Srinivasan; Micael Hardy; Olivier Ouari; Marcos Lopez; Jeannette Vasquez-Vivar; Narayan G. Avadhani; B. Kalyanaraman

2008-01-01

464

Circumacenes versus periacenes: HOMO-LUMO gap and transition from nonmagnetic to magnetic ground state with size  

SciTech Connect

Circumacenes and periacenes as zigzag-edged nanographenes differ only in that circumacenes have one extra benzene ring on each of the two armchair sides. Using first principles density functional theory, we show that this slight difference in the boundary shape dramatically affects the critical size at which the open-shell antiferromagnetic state supersedes the closed-shell nonmagnetic state as the ground state. We correlate this critical size to the decreasing HOMO-LUMO gap with the molecular size and discuss implications of the critical size for experimental syntheses of circumacenes and periacenes.

Jiang, Deen [ORNL; Dai, Sheng [ORNL

2008-01-01

465

NMR characterisation of a triple stranded complex formed by homo-purine and homo-pyrimidine DNA strands at 1:1 molar ratio and acidic pH.  

PubMed Central

Homo-purine (d-TGAGGAAAGAAGGT) and homo-pyrimidine (d-CTCCTTTCTTCC) oligomers have been designed such that they are complementary in parallel orientation. When mixed in a 1:1 molar ratio, the system adopts an antiparallel duplex at neutral pH with three mismatched base pairs. On lowering the pH below 5.5, a new complex is formed. The NMR results show the coexistence of a intermolecular pyrimidine.purine:pyrimidine DNA triplex and a single stranded oligopurine at this pH. The triplex is stabilized by five T.A:T, four C+.G:C and two mismatched triads, namely, C+.G-T and T.A-C. This triplex is further stabilized by a Hoogsteen C+.G base-pair on one end. Temperature dependence of the imino proton resonances reveals that the triplex dissociates directly into single strands around 55 degrees C, without duplex intermediates. Parallel duplexes are not formed under any of the conditions employed in this study. PMID:7479074

Bhaumik, S R; Chary, K V; Govil, G; Liu, K; Miles, H T

1995-01-01

466

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

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

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

2011-09-01

467

World fossil fuel subsidies and global carbon emissions  

Microsoft Academic Search

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

Bjorn Larsen; Anwar Shah

1992-01-01

468

ORIGINAL PAPER New fossil ants in French Cretaceous amber  

E-print Network

ORIGINAL PAPER New fossil ants in French Cretaceous amber (Hymenoptera: Formicidae) Vincent history and basal relationships. In this paper, a new sphecomyrmine ant, allied to the Burmese amber genus workers remarkably preserved in a single piece of Early Cenoma- nian French amber. The new fossils provide

Villemant, Claire

469

Ichnotaxonomic assessment of Mazon Creek area trace fossils, Illinois, USA  

E-print Network

Macroneuropteris) 49 Body Fossils 50 Discussion 52 Ichnotaxa 52 Behavior 52 Ichnofacies 53 Comparative Ichnotaxonomy 55 Summary 64 Conclusions... of this study is to determine the ichnotaxonomy of trace fossils on or in concretions and in shales from the Francis Creek Shale Member (FCSM) of the Middle Pennsylvanian Carbondale Formation in northern Illinois. This study will also identify behavioral...

LoBue, David J.

2010-08-12

470

Field Project: Fossil Collection, Identification, and Report Writing  

NSDL National Science Digital Library

The primary purposes of this exercise are to assemble a collection of fossils in the field, to gain experience in fossil identification, to interpret the mode of life and environment in which the organisms lived, and to present this in a written format . This exercise is designed to sharpen the observational skills that are steadily developed during lab and integrate them with lecture concepts.

Leslie, Steve

471

Dictyodoru and associated trace fossils from the Palaeozoic of Thuringia  

E-print Network

Carboniferous Bordenschiefer. Trace fossils of the Late Ordovician Hauptquarzit The Hauptquarzit is datedDictyodoru and associated trace fossils from the Palaeozoic of Thuringia MICHAEL J. BENTON Bcnton. 15, pp. 115-132. Oslo. ISSN 00?4-1164. Dicryudora occurs in the Huupryuurrif (Late Ordovician; D

Benton, Michael

472

PALEOZOIC TRACE FOSSILS FROM THE KUFRA BASIN, LIBYA  

E-print Network

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 of Cru- ziana and Arthrophym from the Cambro-Ordovician in the Kufra Basin. Elsewhere, the Cambro

Benton, Michael

473

Introduction The use of carbonate fossils for palaeothermom-  

E-print Network

Introduction The use of carbonate fossils for palaeothermom- etry as derived from stable isotope young fossils (such as those from the Cenozoic era) with obviously unaltered original skeletal STABLE ISOTOPE EVIDENCE FOR DIAGENESIS OF THE ORDOVICIAN COURTOWN AND TRAMORE LIMESTONES, SOUTH-EASTERN IRELAND

Patterson, William P.

474

Trace Fossil Evidence for Late Ordovician Animals on Land  

Microsoft Academic Search

Fossil burrows within newly recognized buried soils in the Late Ordovician Juniata Formation, near Potters Mills in central Pennsylvania, represent the oldest reported nonmarine trace fossils. They are thought to have been an original part of the soil because their greater density toward the top of the paleosols corresponds with mineralogical, microstructural, and chemical changes attributed to ancient weathering and

Gregory J. Retallack; Carolyn R. Feakes

1987-01-01

475

Microalgal and terrestrial transport biofuels to displace fossil fuels  

Microsoft Academic Search

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

Lucas Reijnders

2009-01-01

476

Changing Concepts of the Nature and Significance of Fossils.  

ERIC Educational Resources Information Center

Provides information on early written accounts of fossils and contrasts historical phases regarding their organic or inorganic origin. Topic areas discussed include the deluge as a stimulant to geological investigation, stratigraphic sequences and earth history, extinction, faunal succession and organic evolution, and fossil evidence of…

Gregory, Joseph T.

1984-01-01

477

Geochemical controls on vanadium accumulation in fossil fuels  

Microsoft Academic Search

High vanadium contents in petroleum and other fossil fuels have been attributed to organic-matter type, organisms, volcanic emanations, diffusion of sea water, and epigenetic enrichment. However, these factors are inadequate to account for the high abundance of vanadium in some fossil fuels and the paucity in others. By examining vanadium deposits in sedimentary rocks with sparse organic matter, constraints are

G. N. Breit; R. B. Wanty

1989-01-01

478

Situ mining of fossil fuel containing inorganic matrices  

Microsoft Academic Search

A process is claimed for recovering underground fossil fuel deposits retained in an inorganic matrix wherein the deposit is contacted with an aqueous medium of anaerobic microorganisms for a time sufficient to produce particles of the deposit containing both the organic fossil fuel and inorganic matrix of a size capable of forming a slurry with the aqueous medium for pumping

S. Ghosh; D. L. Klass

1980-01-01

479

Optimization of Fossil Fuel Sources: An Exergy Approach  

Microsoft Academic Search

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

Ü. Çamdali; V. ?. Ed?ger

2007-01-01

480

Situ mining of fossil fuel containing inorganic matrices  

Microsoft Academic Search

A process for recovering underground fossil fuel deposits retained in an inorganic matrix wherein the deposit is contacted with an aqueous medium of anaerobic microorganisms for a time sufficient to produce particles of the deposit containing both the organic fossil fuel and inorganic matrix of a size capable of forming a slurry with the aqueous medium for pumping to the

S. Ghosh; D. L. Klas

1978-01-01

481

Fossil microorganisms and formation of Early Precambrian weathering crusts  

Microsoft Academic Search

Weathering crusts are the only reliable evidences of continental conditions existence, and often are the only source of information about exogenous processes and subsequently about conditions under which the development of biosphere occurred. Complex of diverse fossil microorganisms was discovered in result of electronic-microscope investigations. Chemical composition of discovered fossils is identical to that of the host rocks and is

M. M. Astafieva; A. Yu. Rozanov; A. B. Vrevsky; N. A. Alfimova; V. A. Matrenichev; R. B. Hoover

2009-01-01

482

Reducing Fossil Carbon Emissions and Building Environmental Awareness at  

E-print Network

Reducing Fossil Carbon Emissions and Building Environmental Awareness at Dartmouth College Summary: Environmental Analysis and Policy Formation during the spring 2004 term. We were dealt the charge: "Identify selected the mission: "To reduce Dartmouth College's fossil carbon emissions." We believe this mission

483

Fossil Energy Fuel Cell Wayne Surdoval, SECA Coordinator  

E-print Network

Fossil Energy Fuel Cell Program Wayne Surdoval, SECA Coordinator June 3, 2003 SECA Fuel Processing National Energy Technology Laboratory Office of Fossil Energy #12;Strategic Center for Natural Gas Formation. · Coke formation ­ High molecular weight and aromatics result in more C- deposit. ­ Catalyst

484

THE EARLIEST KNOWN FOSSIL ANT (FIRST SOUTHERN HEMISPHERE MESOZOIC RECORD)  

E-print Network

THE EARLIEST KNOWN FOSSIL ANT (FIRST SOUTHERN HEMISPHERE MESOZOIC RECORD) (HYMENOPTERA: FORMICIDAE are scarce in Cretaceous deposits. Sphecomyrma freyi Wilson & Brown (1967) was the first fossil ant assigned.S.A. (Magothy Formation). This formation was at the time referred to the lower part of the Upper Cretaceous

Villemant, Claire

485

Problematic fossils in the late Neoproterozoic Wonoka Formation, South Australia  

Microsoft Academic Search

Complex biogenic structures are described from the upper Wonoka Formation (late Neoproterozoic) of the Adelaide ‘Geosyncline’, South Australia. The structures are preserved within silty limestones and calcareous siltstones as dark bedding plane markings defining branching arrays of parallel, elongate, curved elements. The fossils bear at least a superficial resemblance to the putative trace fossil Palaeopascichnus, normally preserved in siliciclastic sediments,

Peter W. Haines

2000-01-01

486

Transitional fossil earwigs - a missing link in Dermaptera evolution  

Microsoft Academic Search

BACKGROUND: The Dermaptera belongs to a group of winged insects of uncertain relationship within Polyneoptera, which has expanded anal region and adds numerous anal veins in the hind wing. Evolutional history and origin of Dermaptera have been in contention. RESULTS: In this paper, we report two new fossil earwigs in a new family of Bellodermatidae fam. nov. The fossils were

Jingxia Zhao; Yunyun Zhao; Chungkun Shih; Dong Ren; Yongjie Wang

2010-01-01

487

The star formation histories of fossil group galaxies  

Microsoft Academic Search

A comparison is carried out among the star formation histories of early-type galaxies in fossil groups, clusters and low density environments. Although they show similar evolutionary histories, a significant fraction of the fossils are younger than their counterparts, suggesting that they can be precursors of the isolated ETG galaxies.

Ignacio G. de la Rosa; Robert N. Proctor; Claudia Mendes de Oliveira; Duncan A. Forbes; Roberto Cid Fernandes; Abilio Mateus

2010-01-01

488

The X-Ray Structure of Old, Fossil Galaxy Groups  

Microsoft Academic Search

A class of `fossil' groups has been discovered. Most L* galaxies in these groups have merged into a normal, relaxed, giant elliptical galaxy. Fossil groups thus appear to be very old. They represent an end-point of galaxy merging and may be the evolutionary link between compact groups and giant elliptical galaxies. We propose an ACIS study of these old groups

Laurence Jones

2000-01-01

489

Fossil weevils (Coleoptera: Curculionidae) from latitude 85°S Antarctica  

Microsoft Academic Search

Two species of fossil listroderine weevils (Coleoptera: Curculionidae: Rhytirhinini: Listroderina) are reported from the Meyer Desert Formation at a locality on the Beardmore Glacier in the Transantarctic Mountains about 500 km from the South Pole. Associated fossils include wood, leaves and pollen of Nothofagus, stems and leaves of several species of mosses, achenes of Ranunculus, shells of freshwater molluscs and

Allan C. Ashworth; Guillermo Kuschel

2003-01-01

490

Where is the Fossil Evidence for Gondwanan Crayfish?  

Microsoft Academic Search

Crayfish body- and ichnofossils recently reported from Lower Permian and Lower Triassic strata of Antarctica have been reinterpreted to be the body fossils of euthycarcinoid arthropods and the burrows of small- to large-sized therapsids (mammal-like reptiles). The earliest fossil evidence of crayfish presence and activity in continental deposits is still from the Laurasian continents of Pangea. This evidence is in

Stephen T. Hasiotis

2002-01-01

491

Fuzzy intelligent system for the operation of fossil power plants  

Microsoft Academic Search

In artificial intelligence applications in large-scale industry, such as fossil fuel power plants, the knowledge about the process comes from an expert's experience, and is generally expressed in a vague and fuzzy way, using ill-defined linguistic terms. This paper presents a fuzzy intelligent system to assist an operator of fossil power plants. The approach is characterized as a fuzzy diagnostic

G. Arroyo-Figueroa; L. E. Sucar; A. Villavicencio

2000-01-01

492

Absolute measures of the completeness of the fossil record  

Microsoft Academic Search

Measuring the completeness of the fossil record is essential to understanding evolution over long timescales, particularly when comparing evolutionary patterns among biological groups with different preservational properties. Completeness measures have been presented for various groups based on gaps in the stratigraphic ranges of fossil taxa, and on hypothetical lineages implied by estimated evolutionary trees. Here we present and compare quantitative,

Mike Foote; J. John Sepkoski

1999-01-01

493

Special Creation and the Fossil Record: The Central Fallacy.  

ERIC Educational Resources Information Center

Fossil records are used to point out two major flaws in the scientific creationist theory: (1) factual evidence does not support the theory, and (2) the creationists' own characterization of the fossil record contradicts their theory. Claims that creationists avoid discussing specifics about their model because of weaknesses. (DC)

Miller, Kenneth R.

1982-01-01