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1

Vertical structuring of gigantic jets  

NASA Astrophysics Data System (ADS)

Gigantic Jets (GJs) are initiated deep inside the thundercloud as intracloud discharges whose upward-directed leaders manage to escape through the thundercloud top and propagate up to the ionosphere. The speed at which leaders propagate is limited by the air heating of every newly formed leader section, rate of which is slower at upper altitudes in the Earth's atmosphere. Despite the expected deceleration of an upward-directed leader, GJs are observed to accelerate as they approach the ionosphere. In this letter, we discuss the dependence of the leader speed on current density in the leader stem, and we propose a simple time-dynamic model for GJ propagation that includes the effects of the expansion of the streamer zone adjacent to the leader head. We propose that the GJ acceleration is a consequence of its vertical structuring and, therefore, can be used to trace the transition altitude between the leader and streamer zone sections of GJs.

Silva, Caitano L.; Pasko, Victor P.

2013-06-01

2

Pituitary Gigantism: A Case Report  

PubMed Central

Objective: To present a rare case of gigantism. Case Report: A 25-year-old lady presented with increased statural growth and enlarged body parts noticed since the age of 14 years, primary amenorrhea, and frontal headache for the last 2 years. She has also been suffering from non-inflammatory low back pain with progressive kyphosis and pain in the knees, ankles, and elbows for the last 5 years. There was no history of visual disturbance, vomiting, galactorrhoea, cold intolerance. She had no siblings. Family history was non-contributory. Blood pressure was normal. Height 221 cm, weight 138 kg, body mass index (BMI)28. There was coarsening of facial features along with frontal bossing and prognathism, large hands and feet, and small goitre. Patient had severe kyphosis and osteoarthritis of knees. Confrontation perimetry suggested bitemporal hemianopia. Breast and pubic hair were of Tanner stage 1. Serum insulin like growth factor-1 (IGF1) was 703 ng/ml with all glucose suppressedgrowth hormone (GH)values of >40 ng/ml. Prolactin was 174 ng/ml. Basal serum Lutenising Hormone (LH), follicle stimulating Hormone (FSH) was low. Oral glucose tolerance test (OGTT), liver and renal function tests, basal cortisol and thyroid profile, Calcium, phosphorus and Intact Parathyroid hormone (iPTH) were normal. Computed tomographyscan of brain showed large pituitary macroadenoma. Automated perimetry confirmed bitemporal hemianopia. A diagnosis of gigantism due to GH secreting pituitary macroadenoma with hypogonadotrophichypogonadism was made. Debulking pituitary surgery followed by somatostatin analogue therapy with gonadal steroid replacement had been planned, but the patient refused further treatment. PMID:23565401

Bhattacharjee, Rana; Roy, Ajitesh; Goswami, Soumik; Selvan, Chitra; Chakraborty, Partha P.; Ghosh, Sujoy; Biswas, Dibakar; Dasgupta, Ranen; Mukhopadhyay, Satinath; Chowdhury, Subhankar

2012-01-01

3

Gigantic cannibals driving a whole-lake trophic cascade  

E-print Network

Gigantic cannibals driving a whole-lake trophic cascade Lennart Persson* , Andre´ M. De Roos population from a dominance of stunted individuals to a dominance of gigantic cannibals among adult. The presence of the phase with gigantic cannibals depends critically on the energy they extract from

Roos, André M. de

4

Evolution of Gigantism in Amphiumid Salamanders  

PubMed Central

The Amphiumidae contains three species of elongate, permanently aquatic salamanders with four diminutive limbs that append one, two, or three toes. Two of the species, Amphiuma means and A. tridactylum, are among the largest salamanders in the world, reaching lengths of more than one meter, whereas the third species (A. pholeter), extinct amphiumids, and closely related salamander families are relatively small. Amphiuma means and A. tridactylum are widespread species and live in a wide range of lowland aquatic habitats on the Coastal Plain of the southeastern United States, whereas A. pholeter is restricted to very specialized organic muck habitats and is syntopic with A. means. Here we present analyses of sequences of mitochondrial and nuclear loci from across the distribution of the three taxa to assess lineage diversity, relationships, and relative timing of divergence in amphiumid salamanders. In addition we analyze the evolution of gigantism in the clade. Our analyses indicate three lineages that have diverged since the late Miocene, that correspond to the three currently recognized species, but the two gigantic species are not each other's closest relatives. Given that the most closely related salamander families and fossil amphiumids from the Upper Cretaceous and Paleocene are relatively small, our results suggest at least two extreme changes in body size within the Amphuimidae. Gigantic body size either evolved once as the ancestral condition of modern amphiumas, with a subsequent strong size reduction in A. pholeter, or gigantism independently evolved twice in the modern species, A. means and A. tridactylum. These patterns are concordant with differences in habitat breadth and range size among lineages, and have implications for reproductive isolation and diversification of amphiumid salamanders. PMID:19461997

Bonett, Ronald M.; Chippindale, Paul T.; Moler, Paul E.; Van Devender, R. Wayne; Wake, David B.

2009-01-01

5

A Case of Sotos Syndrome (Cerebral Gigantism) and Psychosis  

Microsoft Academic Search

Sotos syndrome, or cerebral gigantism, is a syndrome of accelerated growth during early childhood, and a number of craniofacial and other physical abnormalities are commonly present. Behavioral and psychiatric manifestations of the disorder include attention deficits, aggressiveness, and social inhibition. The authors describe a case of psychosis that developed in a patient with Sotos syndrome.

Michael T. Compton; Marc Celentana; Brian Price; Andrew C. Furman

2004-01-01

6

Gigantism and comparative life-history parameters of tyrannosaurid dinosaurs  

Microsoft Academic Search

How evolutionary changes in body size are brought about by variance in developmental timing and\\/or growth rates (also known as heterochrony) is a topic of considerable interest in evolutionary biology. In particular, extreme size change leading to gigantism occurred within the dinosaurs on multiple occasions. Whether this change was brought about by accelerated growth, delayed maturity or a combination of

Gregory M. Erickson; Peter J. Makovicky; Philip J. Currie; Mark A. Norell; Scott A. Yerby; Christopher A. Brochu

2004-01-01

7

Twin Explosions In Gigantic Dusty Potato Crisp  

NASA Astrophysics Data System (ADS)

ESO's Very Large Telescope, equipped with the multi-mode FORS instrument, took an image of NGC 3190, a galaxy so distorted that astronomers gave it two names. And as if to prove them right, in 2002 it fired off, almost simultaneously, two stellar explosions, a very rare event. This beautiful edge-on spiral galaxy with tightly wound arms and a warped shape that makes it resemble a gigantic potato crisp lies in the constellation Leo ('the Lion') [1] and is approximately 70 million light years away. It is the dominant member of a small group of galaxies known as Hickson 44, named after the Canadian astronomer, Paul Hickson. In addition to NGC 3190 [2], Hickson 44 consists of one elliptical and two spiral galaxies. These are, however, slightly out of the field of view and therefore not visible here. ESO PR Photo 17/06 ESO PR Photo 17/06 The Spiral Galaxy NGC 3190 In 1982, Hickson published a catalogue of over 400 galaxies found in compact, physically-related groups of typically 4 to 5 galaxies per group (see the image of Robert's Quartet in ESO PR Photo 34/05 as another example). Such compact groups allow astronomers to study how galaxies dynamically affect each other, and help them test current ideas on how galaxies form. One idea is that compact groups of galaxies, such as Hickson 44, merge to form a giant elliptical galaxy, such as NGC 1316 (see ESO PR 17/00). Indeed, signs of tidal interactions are visible in the twisted dust lane of NGC 3190. This distortion initially misled astronomers into assigning a separate name for the southwestern side, NGC 3189, although NGC 3190 is the favoured designation. NGC 3190 has an 'Active Galactic Nucleus', and as such, the bright, compact nucleus is thought to host a supermassive black hole. In March 2002, a new supernova (SN 2002bo) was found in between the 'V' of the dust lanes in the southeastern part of NGC 3190. It was discovered independently by the Brazilian and Japanese amateur astronomers, Paulo Cacella and Yoji Hirose. SN 2002bo was caught almost two weeks before reaching its maximum brightness, allowing astronomers to study its evolution. It has been the subject of intense monitoring by a world-wide network of telescopes. The conclusion was that SN 2002bo is a rather unusual Type Ia supernova [3]. The image presented here was taken in March 2003, i.e. about a year after the maximum of the supernova which is 50 times fainter on the image than a year before. While observing SN 2002bo in May 2002, a group of Italian astronomers discovered another supernova, SN 2002cv, on the other side of NGC 3190. Two supernovae of this type appearing nearly simultaneously in the same galaxy is a rare event, as normally astronomers expect only one such event per century in a galaxy. SN 2002cv was best visible at infrared wavelengths as it was superimposed on the dust lane of NGC 3190, and therefore hidden by a large quantity of dust. In fact, this supernova holds the record for the most obscured Type Ia event. The image was obtained with a total exposure time of 14 minutes only. Yet, with the amazing power of the Very Large Telescope, it reveals a large zoo of galaxies of varying morphologies. How many can you find? A high resolution image and its caption is available on this page.

2006-05-01

8

A gigantic feathered dinosaur from the lower cretaceous of China.  

PubMed

Numerous feathered dinosaur specimens have recently been recovered from the Middle-Upper Jurassic and Lower Cretaceous deposits of northeastern China, but most of them represent small animals. Here we report the discovery of a gigantic new basal tyrannosauroid, Yutyrannus huali gen. et sp. nov., based on three nearly complete skeletons representing two distinct ontogenetic stages from the Lower Cretaceous Yixian Formation of Liaoning Province, China. Y. huali shares some features, particularly of the cranium, with derived tyrannosauroids, but is similar to other basal tyrannosauroids in possessing a three-fingered manus and a typical theropod pes. Morphometric analysis suggests that Y. huali differed from tyrannosaurids in its growth strategy. Most significantly, Y. huali bears long filamentous feathers, thus providing direct evidence for the presence of extensively feathered gigantic dinosaurs and offering new insights into early feather evolution. PMID:22481363

Xu, Xing; Wang, Kebai; Zhang, Ke; Ma, Qingyu; Xing, Lida; Sullivan, Corwin; Hu, Dongyu; Cheng, Shuqing; Wang, Shuo

2012-04-01

9

Page 1 of 45 Gigantism among Late Jurassic limulids: new ichnological evidence from  

E-print Network

Page 1 of 45 Accepted M anuscript 1 Gigantism among Late Jurassic limulids: new ichnological was discovered in Upper Jurassic limestones from the Causses Basin (Causse M�jean, Loz�re, France gigantic horseshoe crabs in the Jurassic of Western Europe, thus casting doubt on the postulated increase

10

Discharge processes, electric field, and electron energy in ISUAL-recorded gigantic jets  

Microsoft Academic Search

This article reports the first high time resolution measurements of gigantic jets from the Imager of Sprites and Upper Atmospheric Lightning (ISUAL) experiment. The velocity of the upward propagating fully developed jet stage of the gigantic jets was ?107 m s?1, which is similar to that observed for downward sprite streamers. Analysis of spectral ratios for the fully developed jet

Cheng-Ling Kuo; J. K. Chou; L. Y. Tsai; A. B. Chen; H. T. Su; R. R. Hsu; S. A. Cummer; H. U. Frey; S. B. Mende; Y. Takahashi; L. C. Lee

2009-01-01

11

Methyleugenol in Ocimum basilicum L. Cv. genovese gigante.  

PubMed

Ocimum basilicum cv. Genovese Gigante is the basil cultivar used the most in the production of a typical Italian sauce called pesto. The aromatic composition of plants at different growth stages was determined. Plants from different areas of northwestern Italy were analyzed at 4 and 6 weeks after sowing and showed methyleugenol and eugenol as the main components. The content of these compounds was correlated with plant height rather than plant age. Particularly, methyleugenol was predominant in plants up to 10 cm in height, whereas eugenol was prevalent in taller plants. These results are important in the evaluation of risk to human health posed by dietary ingestion of methyleugenol contained in pesto. PMID:11170620

Miele, M; Dondero, R; Ciarallo, G; Mazzei, M

2001-01-01

12

Gigantism caused by growth hormone secreting pituitary adenoma.  

PubMed

Gigantism indicates excessive secretion of growth hormones (GH) during childhood when open epiphyseal growth plates allow for excessive linear growth. Case one involved a 14.7-year-old boy presented with extreme tall stature. His random serum GH level was 38.4 ng/mL, and failure of GH suppression was noted during an oral glucose tolerance test (OGTT; nadir serum GH, 22.7 ng/mL). Magnetic resonance imaging (MRI) of the brain revealed a 12-mm-sized pituitary adenoma. Transsphenoidal surgery was performed and a pituitary adenoma displaying positive immunohistochemical staining for GH was reported. Pituitary MRI scan was performed 4 months after surgery and showed recurrence/residual tumor. Medical treatment with a long-acting somatostatin analogue for six months was unsuccessful. As a result, secondary surgery was performed. Three months after reoperation, the GH level was 0.2 ng/mL and insulin-like growth factor 1 was 205 ng/mL. Case two involved a 14.9-year-old boy, who was referred to our department for his tall stature. His basal GH level was 9.3 ng/mL, and failure of GH suppression was reported during OGTT (nadir GH, 9.0 ng/mL). Pituitary MRI showed a 6-mm-sized pituitary adenoma. Surgery was done and histopathological examination demonstrated a pituitary adenoma with positive staining for GH. Three months after surgery, the GH level was 0.2 ng/mL and nadir GH during OGTT was less than 0.1 ng/mL. Pituitary MRI scans showed no residual tumor. We present two cases of gigantism caused by a GH-secreting pituitary adenoma with clinical and microscopic findings. PMID:25077093

Rhee, Noorisaem; Jeong, Kumi; Yang, Eun Mi; Kim, Chan Jong

2014-06-01

13

Rare examples of early VLF events observed in association with ISUAL-detected gigantic jets  

NASA Astrophysics Data System (ADS)

We examine narrowband VLF observations and investigate the association of early VLF perturbations with gigantic jets recorded by the Imager of Sprites and Upper Atmospheric Lightnings (ISUAL) instrument aboard FORMOSAT-2. From its inception in 2004 to April 2013, the ISUAL instrument has recorded 90 gigantic jets using a triggered camera. Stanford VLF receivers located around the world are used to detect perturbations to VLF transmitter signals associated with lightning. While nine gigantic jet events occurred within 100 km of a VLF transmitter-receiver great circle path, only four early VLF events were detected in association with three ISUAL gigantic jets. One of these is a moderate event of 0.4 dB amplitude change, and the others are very small. The recovery time of these events are less than a couple of minutes and so do not constitute the "long recovery" early VLF events that have been postulated to be associated with gigantic jets. We speculate on possible explanations for the lack of other events on monitored paths, including a lack of significant ionization produced in the D region ionosphere by the gigantic jet event, weak transmitter signals recorded by the receivers, or mode effects on transmitter paths.

Marshall, R. A.; Adachi, T.; Hsu, R.-R.; Chen, A. B.

2014-01-01

14

An Evolutionary Cascade Model for Sauropod Dinosaur Gigantism - Overview, Update and Tests  

PubMed Central

Sauropod dinosaurs are a group of herbivorous dinosaurs which exceeded all other terrestrial vertebrates in mean and maximal body size. Sauropod dinosaurs were also the most successful and long-lived herbivorous tetrapod clade, but no abiological factors such as global environmental parameters conducive to their gigantism can be identified. These facts justify major efforts by evolutionary biologists and paleontologists to understand sauropods as living animals and to explain their evolutionary success and uniquely gigantic body size. Contributions to this research program have come from many fields and can be synthesized into a biological evolutionary cascade model of sauropod dinosaur gigantism (sauropod gigantism ECM). This review focuses on the sauropod gigantism ECM, providing an updated version based on the contributions to the PLoS ONE sauropod gigantism collection and on other very recent published evidence. The model consist of five separate evolutionary cascades (Reproduction, Feeding, Head and neck, Avian-style lung, and Metabolism). Each cascade starts with observed or inferred basal traits that either may be plesiomorphic or derived at the level of Sauropoda. Each trait confers hypothetical selective advantages which permit the evolution of the next trait. Feedback loops in the ECM consist of selective advantages originating from traits higher in the cascades but affecting lower traits. All cascades end in the trait Very high body mass. Each cascade is linked to at least one other cascade. Important plesiomorphic traits of sauropod dinosaurs that entered the model were ovipary as well as no mastication of food. Important evolutionary innovations (derived traits) were an avian-style respiratory system and an elevated basal metabolic rate. Comparison with other tetrapod lineages identifies factors limiting body size. PMID:24205267

Sander, P. Martin

2013-01-01

15

Biology of the sauropod dinosaurs: the evolution of gigantism  

PubMed Central

The herbivorous sauropod dinosaurs of the Jurassic and Cretaceous periods were the largest terrestrial animals ever, surpassing the largest herbivorous mammals by an order of magnitude in body mass. Several evolutionary lineages among Sauropoda produced giants with body masses in excess of 50 metric tonnes by conservative estimates. With body mass increase driven by the selective advantages of large body size, animal lineages will increase in body size until they reach the limit determined by the interplay of bauplan, biology, and resource availability. There is no evidence, however, that resource availability and global physicochemical parameters were different enough in the Mesozoic to have led to sauropod gigantism. We review the biology of sauropod dinosaurs in detail and posit that sauropod gigantism was made possible by a specific combination of plesiomorphic characters (phylogenetic heritage) and evolutionary innovations at different levels which triggered a remarkable evolutionary cascade. Of these key innovations, the most important probably was the very long neck, the most conspicuous feature of the sauropod bauplan. Compared to other herbivores, the long neck allowed more efficient food uptake than in other large herbivores by covering a much larger feeding envelope and making food accessible that was out of the reach of other herbivores. Sauropods thus must have been able to take up more energy from their environment than other herbivores. The long neck, in turn, could only evolve because of the small head and the extensive pneumatization of the sauropod axial skeleton, lightening the neck. The small head was possible because food was ingested without mastication. Both mastication and a gastric mill would have limited food uptake rate. Scaling relationships between gastrointestinal tract size and basal metabolic rate (BMR) suggest that sauropods compensated for the lack of particle reduction with long retention times, even at high uptake rates. The extensive pneumatization of the axial skeleton resulted from the evolution of an avian-style respiratory system, presumably at the base of Saurischia. An avian-style respiratory system would also have lowered the cost of breathing, reduced specific gravity, and may have been important in removing excess body heat. Another crucial innovation inherited from basal dinosaurs was a high BMR. This is required for fueling the high growth rate necessary for a multi-tonne animal to survive to reproductive maturity. The retention of the plesiomorphic oviparous mode of reproduction appears to have been critical as well, allowing much faster population recovery than in megaherbivore mammals. Sauropods produced numerous but small offspring each season while land mammals show a negative correlation of reproductive output to body size. This permitted lower population densities in sauropods than in megaherbivore mammals but larger individuals. Our work on sauropod dinosaurs thus informs us about evolutionary limits to body size in other groups of herbivorous terrestrial tetrapods. Ectothermic reptiles are strongly limited by their low BMR, remaining small. Mammals are limited by their extensive mastication and their vivipary, while ornithsichian dinosaurs were only limited by their extensive mastication, having greater average body sizes than mammals. PMID:21251189

Sander, P Martin; Christian, Andreas; Clauss, Marcus; Fechner, Regina; Gee, Carole T; Griebeler, Eva-Maria; Gunga, Hanns-Christian; Hummel, Jurgen; Mallison, Heinrich; Perry, Steven F; Preuschoft, Holger; Rauhut, Oliver W M; Remes, Kristian; Tutken, Thomas; Wings, Oliver; Witzel, Ulrich

2011-01-01

16

Genomic gigantism: DNA loss is slow in mountain grasshoppers.  

PubMed

Several studies have shown DNA loss to be inversely correlated with genome size in animals. These studies include a comparison between Drosophila and the cricket, Laupala, but there has been no assessment of DNA loss in insects with very large genomes. Podisma pedestris, the brown mountain grasshopper, has a genome over 100 times as large as that of Drosophila and 10 times as large as that of Laupala. We used 58 paralogous nuclear pseudogenes of mitochondrial origin to study the characteristics of insertion, deletion, and point substitution in P. pedestris and Italopodisma. In animals, these pseudogenes are "dead on arrival"; they are abundant in many different eukaryotes, and their mitochondrial origin simplifies the identification of point substitutions accumulated in nuclear pseudogene lineages. There appears to be a mononucleotide repeat within the 643-bp pseudogene sequence studied that acts as a strong hot spot for insertions or deletions (indels). Because the data for other insect species did not contain such an unusual region, hot spots were excluded from species comparisons. The rate of DNA loss relative to point substitution appears to be considerably and significantly lower in the grasshoppers studied than in Drosophila or Laupala. This suggests that the inverse correlation between genome size and the rate of DNA loss can be extended to comparisons between insects with large or gigantic genomes (i.e., Laupala and Podisma). The low rate of DNA loss implies that in grasshoppers, the accumulation of point mutations is a more potent force for obscuring ancient pseudogenes than their loss through indel accumulation, whereas the reverse is true for Drosophila. The main factor contributing to the difference in the rates of DNA loss estimated for grasshoppers, crickets, and Drosophila appears to be deletion size. Large deletions are relatively rare in Podisma and Italopodisma. PMID:11158383

Bensasson, D; Petrov, D A; Zhang, D X; Hartl, D L; Hewitt, G M

2001-02-01

17

Lightning development associated with two negative gigantic jets Gaopeng Lu,1  

E-print Network

Lightning development associated with two negative gigantic jets Gaopeng Lu,1 Steven A. Cummer,1 very highfrequency (VHF) lightning mapping networks that the associated lightning character- istics intracloud lightning with upper level channels attempting to exit the cloud, and then produced the upward

Cummer, Steven A.

18

Radar and lightning analyses of gigantic jet-producing storms Tiffany C. Meyer,1,2  

E-print Network

Radar and lightning analyses of gigantic jet-producing storms Tiffany C. Meyer,1,2 Timothy J. Lang range of very high frequency lightning mapping networks. All six were within range of operational radars and two-dimensional lightning network coverage: five within the National Lightning Detection Network

Rutledge, Steven

19

Linker Chains of the Gigantic Hemoglobin of the Earthworm Lumbricus terrestris: Primary Structures of  

E-print Network

Linker Chains of the Gigantic Hemoglobin of the Earthworm Lumbricus terrestris: Primary Structures Brian T. Chait,2 and Austen F. Riggs1* 1 Section of Neurobiology, School of Biological Sciences, and Institute of Cellular and Molecular Biology, University of Texas, Austin, Texas 2 Laboratory for Mass

Riggs, Austen

20

Multiinstrumental observations of a positive gigantic jet produced by a winter thunderstorm in Europe  

E-print Network

Multiinstrumental observations of a positive gigantic jet produced by a winter thunderstorm was short at 120­160 ms. This is the first documented GJ which emerged from a maritime winter thunderstorm and winter thunderstorms in the Mediterranean. During the trailing jet phase of the GJ, a sprite with halo

Cummer, Steven A.

21

Oxygen hypothesis of polar gigantism not supported by performance of Antarctic  

E-print Network

, Antarctica. Individual sea spiders were forced into activity and their performance was measured at different. Keywords: sea spider; oxygen; polar gigantism; temperature; Antarctica; symmorphosis 1. INTRODUCTION by one or more latitude-associated factors. Postulated factors include changes in food availability

Moran, Amy L.

22

Modeling of thundercloud screening charges: Implications for blue and gigantic jets  

Microsoft Academic Search

A two-dimensional axisymmetric model of charge relaxation in the conducting atmosphere is used in conjunction with a probabilistic lightning model to demonstrate how realistic cloud electrodynamics lead to the development of blue and gigantic jets. The model accounts for time-dependent conduction currents and screening charges formed under the influence of the thundercloud charge sources. Particular attention is given to numerical

Jeremy A. Riousset; Victor P. Pasko; Paul R. Krehbiel; William Rison; Mark A. Stanley

2010-01-01

23

Observations of Seven Blue/Gigantic Jets above One Storm over the Atlantic Ocean  

NASA Astrophysics Data System (ADS)

Blue/gigantic jets are electrical discharges developing from thundercloud tops and propagating to the upper atmosphere [e.g., Pasko et al., Nature, 416, 152, 2002; Su et al., Nature, 423, 973, 2003]. Not just producing an impressive display, gigantic jets establish a direct path of electrical contact between the upper troposphere and the lower ionosphere, capable of transferring a large amount of charge between them [Cummer et al., Nat. Geosci., 2, 617, 2009]. It has been suggested that they may play an important role in the earth's electrical environment [e. g., Pasko, Nature, 423, 927, 2003]. Upward discharges from thunderstorms like blue/gigantic jets are believed to originate from lightning leaders escaping from thunderclouds when the cloud's charges of different polarities are not balanced [Krehbiel et al., Nat. Geosci., 1, 233, 2008; Riousset et al., JGR, 115, A00E10, 2010]. On the evening of August 2, 2013, 4 gigantic jets, 2 blue jets and 1 blue starter were recorded within 26 min above a storm over the Atlantic Ocean by a low light level camera from the campus of Florida Institute of Technology. The events were also captured by two all-sky cameras: one again from the Florida Tech campus and the other from a nearby location. According to the NLDN data, positive intra-cloud flashes preceded all events except one gigantic jet. The distance between the observation site to the locations of the NLDN lightning discharges varies from 77 to 82 km. Optical signatures of intra-cloud discharge activities accompanied the events are clearly visible in the videos. The duration of each jet varies from about 300 ms to 1.2 s, and the 1.2 s duration is probably the longest that has been reported to date for jets. Rebrightening of gigantic jet structures occurs for at least two of the events. The upper terminal altitude of the 4 gigantic jets is greater than 76-81 km, the 2 blue jets reach about 48 and 51 km altitude, respectively, and the blue starter reaches 24 km altitude. The altitude of cloud tops varies from 14 to 20 km. All events exhibit a tree-like structure and develop in an impulsive manner. Similar to other observations of gigantic jets, bright beads appear at the tops of the gigantic jets. The impulsive upward propagation of the jets together with the positive polarity of the preceding intra-cloud discharges suggests that the jets originate from upward propagating negative leaders initiated inside the thundercloud. All events propagate upward from the top of the cloud nearly vertically except for one event that develops in a slanted direction, about twenty three degrees from the vertical. With only a few branches, the three blue jet/starter events display a structure very similar to a cloud-to-ground lightning stroke. Our observations support the unified view of the upward discharges from thunderclouds advanced by Krehbiel et al. [2008] and Riousset et al. [2010]. In this talk, we discuss the video observations of the events and the associated radio signatures in detail.

Liu, N.; Spiva, N.; Dwyer, J. R.; Rassoul, H.; Free, D. L.; Cummer, S. A.

2013-12-01

24

Cope's Rule and Romer's theory: patterns of diversity and gigantism in eurypterids and Palaeozoic vertebrates  

PubMed Central

Gigantism is widespread among Palaeozoic arthropods, yet causal mechanisms, particularly the role of (abiotic) environmental factors versus (biotic) competition, remain unknown. The eurypterids (Arthropoda: Chelicerata) include the largest arthropods; gigantic predatory pterygotids (Eurypterina) during the Siluro-Devonian and bizarre sweep-feeding hibbertopterids (Stylonurina) from the Carboniferous to end-Permian. Analysis of family-level originations and extinctions among eurypterids and Palaeozoic vertebrates show that the diversity of Eurypterina waned during the Devonian, while the Placodermi radiated, yet Stylonurina remained relatively unaffected; adopting a sweep-feeding strategy they maintained their large body size by avoiding competition, and persisted throughout the Late Palaeozoic while the predatory nektonic Eurypterina (including the giant pterygotids) declined during the Devonian, possibly out-competed by other predators including jawed vertebrates. PMID:19828493

Lamsdell, James C.; Braddy, Simon J.

2010-01-01

25

Gigantic Cosmic Corkscrew Reveals New Details About Mysterious Microquasar  

NASA Astrophysics Data System (ADS)

Making an extra effort to image a faint, gigantic corkscrew traced by fast protons and electrons shot out from a mysterious microquasar paid off for a pair of astrophysicists who gained new insights into the beast's inner workings and also resolved a longstanding dispute over the object's distance. Microquasar SS 433 VLA Image of Microquasar SS 433 CREDIT: Blundell & Bowler, NRAO/AUI/NSF (Click on Image for Larger Version) The astrophysicists used the National Science Foundation's Very Large Array (VLA) radio telescope to capture the faintest details yet seen in the plasma jets emerging from the microquasar SS 433, an object once dubbed the "enigma of the century." As a result, they have changed scientists' understanding of the jets and settled the controversy over its distance "beyond all reasonable doubt," they said. SS 433 is a neutron star or black hole orbited by a "normal" companion star. The powerful gravity of the neutron star or black hole draws material from the stellar wind of its companion into an accretion disk of material tightly circling the dense central object prior to being pulled onto it. This disk propels jets of fast protons and electrons outward from its poles at about a quarter of the speed of light. The disk in SS 433 wobbles like a child's top, causing its jets to trace a corkscrew in the sky every 162 days. The new VLA study indicates that the speed of the ejected particles varies over time, contrary to the traditional model for SS 433. "We found that the actual speed varies between 24 percent to 28 percent of light speed, as opposed to staying constant," said Katherine Blundell, of the University of Oxford in the United Kingdom. "Amazingly, the jets going in both directions change their speeds simultaneously, producing identical speeds in both directions at any given time," Blundell added. Blundell worked with Michael Bowler, also of Oxford. The scientists' findings have been accepted by the Astrophysical Journal Letters. SS 433 New VLA Image of SS 433: Red-and-Blue Line Shows Path of Constant-Speed Jets. Note Poor Match of Path to Image. CREDIT: Blundell & Bowler, NRAO/AUI/NSF SS 433 Same Image, With Colored Beads Representing Particle Ejections at Different Speeds. Particle Path Now Matches. CREDIT: Blundell & Bowler, NRAO/AUI/NSF Click Here for Page of Full-Sized Graphics The new VLA image shows two full turns of the jets' corkscrew on both sides of the core. Analyzing the image showed that if material came from the core at a constant speed, the jet paths would not accurately match the details of the image. "By simulating ejections at varying speeds, we were able to produce an exact match to the observed structure," Blundell explained. The scientists first did their match to one of the jets. "We then were stunned to see that the varying speeds that matched the structure of one jet also exactly reproduced the other jet's path," Blundell said. Matching the speeds in the two jets reproduced the observed structure even allowing for the fact that, because one jet is moving more nearly away from us than the other, it takes light longer to reach us from it, she added. The astrophysicists speculate that the changes in ejection speed may be caused by changes in the rate at which material is transferred from the companion star onto the accretion disk. The detailed new VLA image also allowed the astrophysicists to determine that SS 433 is nearly 18,000 light-years distant from Earth. Earlier estimates had the object, in the constellation Aquila, as near as 10,000 light-years. An accurate distance, the scientists said, now allows them to better determine the age of the shell of debris blown out by the supernova explosion that created the dense, compact object in the microquasar. Knowing the distance accurately also allows them to measure the actual brightness of the microquasar's components, and this, they said, improves their understanding of the physical processes at work in the system. The breakthrough image was made us

2004-10-01

26

Birmingham Mid-Head Resection Hip Arthroplasty in a Young Man with Gigantism  

Microsoft Academic Search

The Birmingham Mid-Head Resection (Smith & Nephew Ltd, Warwick, United Kingdom) arthroplasty is a new bone-conserving procedure that, like hip resurfacing, is used in younger, active patients. We present the case of a young man with Sotos syndrome (cerebral gigantism) with associated extraordinary stature (height, 2.16 m; weight, 157 kg) who underwent Birmingham Mid-Head Resection arthroplasty. The large stature of

Michael T. Murphy; Mark P. Shillington; Damon R. Mogridge; Simon F. Journeaux

27

Starvation reveals the cause of infection-induced castration and gigantism  

PubMed Central

Parasites often induce life-history changes in their hosts. In many cases, these infection-induced life-history changes are driven by changes in the pattern of energy allocation and utilization within the host. Because these processes will affect both host and parasite fitness, it can be challenging to determine who benefits from them. Determining the causes and consequences of infection-induced life-history changes requires the ability to experimentally manipulate life history and a framework for connecting life history to host and parasite fitness. Here, we combine a novel starvation manipulation with energy budget models to provide new insights into castration and gigantism in the Daphnia magnaPasteuria ramosa hostparasite system. Our results show that starvation primarily affects investment in reproduction, and increasing starvation stress reduces gigantism and parasite fitness without affecting castration. These results are consistent with an energetic structure where the parasite uses growth energy as a resource. This finding gives us new understanding of the role of castration and gigantism in this system, and how life-history variation will affect infection outcome and epidemiological dynamics. The approach of combining targeted life-history manipulations with energy budget models can be adapted to understand life-history changes in other disease systems. PMID:25143034

Cressler, Clayton E.; Nelson, William A.; Day, Troy; McCauley, Edward

2014-01-01

28

The small but clear gravity signal above the natural cave 'Grotta Gigante' (Trieste, Italy)  

NASA Astrophysics Data System (ADS)

Gravity observations are a powerful means for detecting underground mass changes. The Italian and Slovenian Karst has a number of explored caves, several are also touristic due to their size (e.g. Grotta Gigante in Italy; Skocjianske Jame and Postojnska Jama in Slovenia). Just a few years ago another big cave was discovered by chance close to Trieste when drilling a tunnel for a motor-highway, which shows that more caves are expected to be discovered in coming years. We have acquired the gravity field above the Grotta Gigante cave, a cave roughly 100 m high and 200 m long with a traditional spring-gravity meter (Lacoste&Romberg) and height measurements made with GPS and total station. The GPS was made with two different teams and processing algorithms, to cross-check accuracy and error estimate. Some stations had to be surveyed with a classical instrument due to the vegetation which concealed the satellite positioning signal. Here we present the results of the positioning acquisitions and the gravity field. The cave produces a signal of 1.5 mGal, with a clear elongated concentric symmetry. The survey shows that a systematic coverage of the Karst would have the benefit to recover the position of all of the greater existing caves. This will have a large impact on civil and environmental purposes, since it will for example allow to plan the urban development at a safety distance from subsurface caves.

Braitenberg, Carla; Sampietro, Daniele; Zuliani, David; Barbagallo, Alfio; Fabris, Paolo; Fabbri, Julius; Rossi, Lorenzo; Handi Mansi, Ahmed

2014-05-01

29

GaAs-oxide interface states - Gigantic photoionization via Auger-like process  

NASA Technical Reports Server (NTRS)

Spectral and transient responses of photostimulated current in MOS structures were employed for the study of GaAs-anodic oxide interface states. Discrete deep traps at 0.7 and 0.85 eV below the conduction band were found with concentrations of 5 x 10 to the 12th/sq cm and 7 x 10 to the 11th/sq cm, respectively. These traps coincide with interface states induced on clean GaAs surfaces by oxygen and/or metal adatoms (submonolayer coverage). In contrast to surfaces with low oxygen coverage, the GaAs-thick oxide interfaces exhibited a high density (about 10 to the 14th/sq cm) of shallow donors and acceptors. Photoexcitation of these donor-acceptor pairs led to a gigantic photoionization of deep interface states with rates 1000 times greater than direct transitions into the conduction band. The gigantic photoionization is explained on the basis of energy transfer from excited donor-acceptor pairs to deep states.

Lagowski, J.; Kazior, T. E.; Gatos, H. C.; Walukiewicz, W.; Siejka, J.

1981-01-01

30

Are sick individuals weak competitors? Competitive ability of snails parasitized by a gigantism-inducing trematode.  

PubMed

Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability. PMID:24205383

Seppl, Otto; Karvonen, Anssi; Kuosa, Marja; Haataja, Maarit; Jokela, Jukka

2013-01-01

31

Are Sick Individuals Weak Competitors? Competitive Ability of Snails Parasitized by a Gigantism-Inducing Trematode  

PubMed Central

Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability. PMID:24205383

Seppala, Otto; Karvonen, Anssi; Kuosa, Marja; Haataja, Maarit; Jokela, Jukka

2013-01-01

32

Gigantic optical magneto-electric effect in CuB2O4  

NASA Astrophysics Data System (ADS)

It has been recognized since 1960s that magneto-electric (ME) materials may also show an optical magneto-electric (OME) effect showing up as a change in optical absorption with reversal of the propagating direction of light. The OME effect is an interesting object of scientific research and provides possibilities for applications. However, the changes in absorption coefficient ever discovered were very small (less than 0.2 %). We present a gigantic OME effect in a noncentrosymmetric weak ferromagnet CuB2O4, in which the absorption coefficient changes by a factor of three with reversal of a very weak magnetic field of 300 Oe. This magnitude of OME effect enables us to observe it by a CCD camera with linearly polarized near-infrared and visible light. Spectroscopic study and comparison of OME effect with magnetization indicate an important role of canted antiferromagnetic spin ordering and local symmetry of a square Cu^2+ site. The gigantic OME effect can be applicable to optical devices like magnetic switching of color in the future.

Saito, Mitsuru; Taniguchi, Kouji; Arima, Takahisa

2008-03-01

33

One-pot versus sequential reactions in the self-assembly of gigantic nanoscale polyoxotungstates.  

PubMed

By using a new type of lacunary tungstoselenite {Se(2)W(29)O(103)} (1), which contains a "defect" pentagonal {W(W)(4)} unit, we explored the assembly of clusters using this building block and demonstrate how this unit can give rise to gigantic nanomolecular species, using both a "one-pot" and "stepwise" synthetic assembly approach. Specifically, exploration of the one-pot synthetic parameter space lead to the discovery of {Co(2.5)(W(3.5)O(14))(SeW(9)O(33))(Se(2)W(30)O(107))} (2), {CoWO(H(2)O)(3)(Se(2)W(26)O(85))(Se(3)W(30)O(107))(2)} (3), and {Ni(2)W(2)O(2)Cl(H(2)O)(3)(Se(2)W(29)O(103)) (Se(3)W(30)O(107))(2)} (4), effectively demonstrating the potential of the {Se(2)W(29)} based building blocks, which was further extended by the isolation of a range of 3d transition metal doped tetramer family derivatives: {M(2)W(n)O(m)(H(2)O)(m)(Se(2)W(29)O(102))(4)} (M = Mn, Co, Ni or Zn, n = 2, m = 4; M = Cu, n = 3, m = 5) (5-9). To contrast the 'one-pot' approach, an optimized stepwise self-assembly investigation utilizing 1 as a precursor was performed showing that the high nuclearity clusters can condense in a more controllable way allowing the tetrameric clusters (5-8) to be synthesized with higher yield, but it was also shown that 1 can be used to construct a gigantic {W(174)} hexameric-cluster {Cu(9)Cl(3)(H(2)O)(18)(Se(2)W(29)O(102))(6)} (10). Further, 1 can also dimerize to {(Se(2)W(30)O(105))(2)} (11) by addition of extra tungstate under similar conditions. All the clusters were characterized by single-crystal X-ray crystallography, chemical analysis, infrared spectroscopy, thermogravimetric analysis, and electrospray ionization mass spectrometry, which remarkably showed that all the clusters, even the largest cluster, 10 (?50 kD), could be observed as the intact cluster demonstrating the extraordinary potential of this approach to construct robust gigantic nanoscale polyoxotungstates. PMID:23244039

Gao, Jing; Yan, Jun; Beeg, Sebastian; Long, De-Liang; Cronin, Leroy

2013-02-01

34

A gigantic, exceptionally complete titanosaurian sauropod dinosaur from southern Patagonia, Argentina.  

PubMed

Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death. PMID:25186586

Lacovara, Kenneth J; Lamanna, Matthew C; Ibiricu, Lucio M; Poole, Jason C; Schroeter, Elena R; Ullmann, Paul V; Voegele, Kristyn K; Boles, Zachary M; Carter, Aja M; Fowler, Emma K; Egerton, Victoria M; Moyer, Alison E; Coughenour, Christopher L; Schein, Jason P; Harris, Jerald D; Martnez, Rubn D; Novas, Fernando E

2014-01-01

35

Methyleugenol and eugenol variation in Ocimum basilicum cv. Genovese gigante grown in greenhouse and in vitro.  

PubMed

The variation of the two main aromatic compounds in Ocimum basilicum cv Genovese Gigante grown in greenhouse and "in vitro" was analyzed. The content of methyleugenol and eugenol was correlated to the plants' height rather than to the plants' age and the growth site. Particularly, methyleugenol was prevalent in plants up to 6.5 cm, as plants grew it was replaced by eugenol that was dominant in taller plants. Analysis of basil 20 cm in height showed that methyleugenol is prevalently localized in the low part while eugenol is prevalent in the upper part of the plant. Moreover, a chronic and acute toxicity of methyleugenol was evidentiated in an assay using chicken embryos. PMID:11822201

Miele, M; Ledda, B; Falugi, C; Mazzei, M

2001-01-01

36

[What can the physician do when faced with the gigantic puzzle of abuse?].  

PubMed

The entire subject of abuse can be compared to a gigantic puzzle were patients as well as their physicians get lost. The goal of this article is first to find a common definition to all acts of abuse and then to subdivide them into three distinct categories: sexual, physical, and emotional abuse. The treating physician should realize that victims of abuse, after the passage of time, will eventually fall sick and consult a doctor for physical or/and psychological symptoms which are the result of the past abuse. Most of the time, these patients will not speak spontaneously of the abuse, either because they have not understood the cause/effect relation, or because the abuse feels unspeakable. It is therefore necessary for the doctor to know how to detect abuse through symptomatology, how to help these patients reveal their secret, how to listen with a non-judgemental ear, and how to propose appropriate treatment. PMID:19999625

Gauthier, Cornelia

2009-01-01

37

Gigantic Optical Magnetoelectric Effect in CuB2O4  

NASA Astrophysics Data System (ADS)

Although it has been well known that materials in which both space inversion and time reversal symmetries are broken can host optical magneto-electric effect, i.e., change in optical constants with the reversal of propagating direction of light, the largest change in absorption ever reported on this effect was 0.2%. Here we show that optical absorption in noncentrosymmetric weak ferromagnetic material CuB2O4 changes by more than 100% with reversal of a low magnetic field of 300 Oe. The gigantic optical magneto-electric effect is ascribed to the canted antiferromagnetic spin ordering of square-coordinated Cu2+ sites, where the local inversion is slightly broken.

Saito, Mitsuru; Taniguchi, Kouji; Arima, Taka-hisa

2008-01-01

38

Can Oxygen Set Thermal Limits in an Insect and Drive Gigantism?  

PubMed Central

Background Thermal limits may arise through a mismatch between oxygen supply and demand in a range of animal taxa. Whilst this oxygen limitation hypothesis is supported by data from a range of marine fish and invertebrates, its generality remains contentious. In particular, it is unclear whether oxygen limitation determines thermal extremes in tracheated arthropods, where oxygen limitation may be unlikely due to the efficiency and plasticity of tracheal systems in supplying oxygen directly to metabolically active tissues. Although terrestrial taxa with open tracheal systems may not be prone to oxygen limitation, species may be affected during other life-history stages, particularly if these rely on diffusion into closed tracheal systems. Furthermore, a central role for oxygen limitation in insects is envisaged within a parallel line of research focussing on insect gigantism in the late Palaeozoic. Methodology/Principal Findings Here we examine thermal maxima in the aquatic life stages of an insect at normoxia, hypoxia (14 kPa) and hyperoxia (36 kPa). We demonstrate that upper thermal limits do indeed respond to external oxygen supply in the aquatic life stages of the stonefly Dinocras cephalotes, suggesting that the critical thermal limits of such aquatic larvae are set by oxygen limitation. This could result from impeded oxygen delivery, or limited oxygen regulatory capacity, both of which have implications for our understanding of the limits to insect body size and how these are influenced by atmospheric oxygen levels. Conclusions/Significance These findings extend the generality of the hypothesis of oxygen limitation of thermal tolerance, suggest that oxygen constraints on body size may be stronger in aquatic environments, and that oxygen toxicity may have actively selected for gigantism in the aquatic stages of Carboniferous arthropods. PMID:21818347

Verberk, Wilco C. E. P.; Bilton, David T.

2011-01-01

39

A Gray-purple Mass on the Floor of the Mouth: Gigantic Mucogingival Pyogenic Granuloma in a Teenage Patient  

PubMed Central

Pyogenic granuloma is defined as a benign neoplasm of vascular phenotype. This case describes the clinical and histopathological features of a gigantic mucogingival pyogenic granuloma, in a 14-year-old healthy black boy. This exophytic gray-purple mass, related to a toothpick injury, had more than twelve-month evolution on the anterior mandible involving lingual area besides to the floor of the mouth pressing the right salivary duct. Conservative excision was performed, followed by uncomplicated healing with no recurrence in two years. The histopathological examination reported a pyogenic granuloma (lobular capillary haemangioma). The authors provide a discussion of the presurgical differential diagnosis of the lesion. This case report presents an extremely uncommon location of a gigantic pyogenic granuloma, involving mucogingival complex and affecting the salivary outflow. This clinical manuscript may shed light on the controversies about possible mechanisms inducing oral pyogenic granuloma. PMID:24987485

Brunet-LLobet, Lluis; Miranda-Rius, Jaume; Lahor-Soler, Eduard; Mrina, Ombeni; Nadal, Alfons

2014-01-01

40

GaAs-oxide interface states - A gigantic photoionization effect and its implications to the origin of these states  

NASA Technical Reports Server (NTRS)

Gigantic photoionization was discovered on GaAs-oxide interfaces leading to the discharge of deep surface states with rates exceeding 1000 times those of photoionization transitions to the conduction band. It exhibits a peak similar to acceptor-donor transitions and is explained as due to energy transfer from photo-excited donor-acceptor pairs to deep surface states. This new process indicates the presence of significant concentrations of shallow donor and acceptor levels not recognized in previous interface models.

Lagowski, J.; Walukiewicz, W.; Kazior, T. E.; Gatos, H. C.; Siejka, J.

1981-01-01

41

Gravity combined with laser-scan in Grotta Gigante: a benchmark cave for gravity studies  

NASA Astrophysics Data System (ADS)

Laser scanning has become one of the most important topographic techniques in the last decades, due to its ability to reconstruct complex surfaces with high resolution and precision and due to its fast acquisition time. Recently a laser-scan survey has been acquired (Fingolo et al., 2011) in the "Grotta Gigante" cave near Trieste, Italy, the biggest cave worldwide according to the Guinness Awards. In this paper this survey is used to obtain a 3D discretization of the cave with prisms. Then through this new model, with the densities derived from campaign measurements, the exact gravimetric effect of the structure was computed (Nagy et al., 2000) and compared with the gravity observation at the surface. The transition from the cloud of laser-scan points to the prism model was carried out by different computer elaborations; first of all the reduction of the data density through an averaging process that allows to pass from over 10000 points/m2 to less than 10points/m2. Then the whole dataset was filtered from the outliers by the means of a simple quadratic surface that fit the data (Turner, 1999). The reduced data points should be divided into the 2 surfaces of top and bottom, that are used to define the prisms. This step was performed using the local regression method (Loess) to calculate a surface located halfway between top and bottom points. Once the top and bottom interfaces were obtained it was possible to get the final prism representation and calculate the gravity signal. The observed Bouguer field is explained very well by our model and the residuals are used to evaluate possible secondary caves. The final prism model together with the gravity database on surface and inside the cave form a perfect benchmark to test forward and inverse potential field algorithms. References Fingolo M., Facco L., Ceccato A., Breganze C., Paganini P., Cezza M., Grotta Gigante di Trieste. Tra realt virtuale e rilievi 3D ad alta risoluzione, Veneto Geologi, 75, pp.21-25, 2011 Nagy D., Papp G., Benedek J., The gravitational potential and its derivatives for the prism, Journal of Geodesy, 74 (7-8), pp. 552-560, 2000 Turner D. A., Anderson I. J., Mason J. C., Cox M. G., An algorithm for fitting an ellipsoid to data, CiteseerXBeta, http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.36.2773 , 1999

Pivetta, Tommaso; Braitenberg, Carla

2014-05-01

42

Discovery of gigantic molecular nanostructures using a flow reaction array as a search engine  

NASA Astrophysics Data System (ADS)

The discovery of gigantic molecular nanostructures like coordination and polyoxometalate clusters is extremely time-consuming since a vast combinatorial space needs to be searched, and even a systematic and exhaustive exploration of the available synthetic parameters relies on a great deal of serendipity. Here we present a synthetic methodology that combines a flow reaction array and algorithmic control to give a chemical real-space search engine leading to the discovery and isolation of a range of new molecular nanoclusters based on [Mo2O2S2]2+-based building blocks with either fourfold (C4) or fivefold (C5) symmetry templates and linkers. This engine leads us to isolate six new nanoscale cluster compounds: 1, {Mo10(C5)}; 2, {Mo14(C4)4(C5)2}; 3, {Mo60(C4)10}; 4, {Mo48(C4)6}; 5, {Mo34(C4)4}; 6, {Mo18(C4)9}; in only 200 automated experiments from a parameter space spanning ~5 million possible combinations.

Zang, Hong-Ying; de La Oliva, Andreu Ruiz; Miras, Haralampos N.; Long, De-Liang; McBurney, Roy T.; Cronin, Leroy

2014-04-01

43

Lower limb gigantism, lymphedema, and painful varicosities following a thigh vascular access graft.  

PubMed

Prosthetic arteriovenous grafts (AVGs) are associated with greater morbidity than autogenous arteriovenous fistulas (AVFs), but their use is indicated when AVF formation is not possible. This report adds to the literature a case of lower limb gigantism, painful varicosities, and lymphedema following long-term use of AVG in the upper thigh. The patient's past medical history included renal transplantation on the same side well before the AVG was inserted and right leg deep vein thrombosis. Suspicion of AVG thrombosis was excluded by Doppler ultrasound, which demonstrated an access flow of 1700?mL/min. A computed tomography (CT) scan of the abdomen and pelvis did not identify the cause of her symptoms. Whereas functional incompetence of the iliac vein valve might be responsible for the varicosities, the extent of hypertrophy in this case raises the suspicion of lymphatic blockage possibly secondary to groin dissection undertaken at the time of graft insertion, in addition to the previous dissection at the time of transplantation. This case highlights the need for minimal groin dissection during AVG insertion, particularly in patients with a history of previous abdominopelvic surgery. PMID:24467313

Thompson, Michael; Mathuram Thiyagarajan, Umasankar; Akoh, Jacob A

2014-07-01

44

Discovery of gigantic molecular nanostructures using a flow reaction array as a search engine  

PubMed Central

The discovery of gigantic molecular nanostructures like coordination and polyoxometalate clusters is extremely time-consuming since a vast combinatorial space needs to be searched, and even a systematic and exhaustive exploration of the available synthetic parameters relies on a great deal of serendipity. Here we present a synthetic methodology that combines a flow reaction array and algorithmic control to give a chemical real-space search engine leading to the discovery and isolation of a range of new molecular nanoclusters based on [Mo2O2S2]2+-based building blocks with either fourfold (C4) or fivefold (C5) symmetry templates and linkers. This engine leads us to isolate six new nanoscale cluster compounds: 1, {Mo10(C5)}; 2, {Mo14(C4)4(C5)2}; 3, {Mo60(C4)10}; 4, {Mo48(C4)6}; 5, {Mo34(C4)4}; 6, {Mo18(C4)9}; in only 200 automated experiments from a parameter space spanning ~5 million possible combinations. PMID:24770632

Zang, Hong-Ying; de la Oliva, Andreu Ruiz; Miras, Haralampos N.; Long, De-Liang; McBurney, Roy T.; Cronin, Leroy

2014-01-01

45

Discovery of gigantic molecular nanostructures using a flow reaction array as a search engine.  

PubMed

The discovery of gigantic molecular nanostructures like coordination and polyoxometalate clusters is extremely time-consuming since a vast combinatorial space needs to be searched, and even a systematic and exhaustive exploration of the available synthetic parameters relies on a great deal of serendipity. Here we present a synthetic methodology that combines a flow reaction array and algorithmic control to give a chemical 'real-space' search engine leading to the discovery and isolation of a range of new molecular nanoclusters based on [Mo(2)O(2)S(2)](2+)-based building blocks with either fourfold (C4) or fivefold (C5) symmetry templates and linkers. This engine leads us to isolate six new nanoscale cluster compounds: 1, {Mo(10)(C5)}; 2, {Mo(14)(C4)4(C5)2}; 3, {Mo(60)(C4)10}; 4, {Mo(48)(C4)6}; 5, {Mo(34)(C4)4}; 6, {Mo(18)(C4)9}; in only 200 automated experiments from a parameter space spanning ~5 million possible combinations. PMID:24770632

Zang, Hong-Ying; de la Oliva, Andreu Ruiz; Miras, Haralampos N; Long, De-Liang; McBurney, Roy T; Cronin, Leroy

2014-01-01

46

Change in the immunophenotype of a somatotroph adenoma resulting in gigantism  

PubMed Central

Background: Examining the pathologic progression of a pituitary adenoma from the point of a prepubescent child to an adult with gigantism affords us an opportunity to consider why patients may develop secretory or functioning tumors and raises questions about whether therapeutic interventions and surveillance strategies could be made to avoid irreversible phenotypic changes. Case Description: A patient underwent a sublabial transsphenoidal resection for a clinically non-functioning macroadenoma in 1999. He underwent radiation treatment and was transiently given growth hormone (GH) supplementation as an adolescent. His growth rapidly traversed several percentiles and he was found to have elevated GH levels. The patient became symptomatic and was taken for a second neurosurgical procedure. Pathology and immunohistochemical staining demonstrated a significantly higher proportion of somatotroph cells and dense granularity; he was diagnosed with a functional somatotroph adenoma. Conclusions: While it is likely that the described observations reflect the manifestations of a functional somatotroph adenoma in development, it is possible that pubertal growth, GH supplementation, its removal, or radiation therapy contributed to the described endocrine and pathologic changes.

Thawani, Jayesh P.; Bailey, Robert L.; Burns, Carrie M.; Lee, John Y. K.

2014-01-01

47

Gigantic solitary fibrous tumour of extra-peritoneal space. A case report and review of the literature.  

PubMed

Solitary fibrous tumour (SFT) is a rare soft tissue tumour which belongs to fibroblastic/myofibroblastic group of tumours. The most often it appears in pleura, also in pericardium, internal organs, peritoneum and extraperitoenal space. SFT was first described as a new type of pleura's tumour by Klemperer and Rabin in 1931. The histogenesis of SFT's has been discussed for years suggesting its mesothelial origin. Recently, SFT has been classified as a mesenchymal fibroblastic tumour. We report a very rare case of 71-year old man suffering from gigantic solitary fibrous tumour of extraperitoneal space who underwent curative surgery in the Department of General, Gastroenterological and Oncologic Surgery in 2011. PMID:25222582

Guzel, Tomasz; D?browski, Bohdan; Mazurkiewicz, Micha?; Makiewicz, Marcin; Krasno?bski, Ireneusz W

2014-07-01

48

Gigantic transverse x-ray magnetic circular dichroism in ultrathin Co in Au/Co/Au(001)  

NASA Astrophysics Data System (ADS)

Transverse-geometry x-ray magnetic circular dichroism (TXMCD) measurements on Au/Co-staircase/Au(001) reveal the orbital origin of intrinsic in-plane magnetic anisotropy A gigantic TXMCD was successfully observed at the Co L3,2 edges for Co thickness (tC0) in the 2-monolayer regime. A TXMCD-sum-rule analysis shows a remarkable enhancement of an orbital-moment anisotropy (?morb) and of an in-plane magnetic dipole moment (m||T). Both ?morb and m||T exhibit close similarity in tCo dependence, reflecting the in-plane magnetic anisotropy These observations evidence that extremely strong, intrinsic, in-plane magnetic anisotropy originates from the anisotropic orbital part of the wave function, dominating the dipole-dipole-interaction-derived, extrinsic, in-plane magnetic anisotropy.

Koide, T.; Mamiya, K.; Asakura, D.; Osatune, Y.; Fujimori, A.; Suzuki, Y.; Katayama, T.; Yuasa, S.

2014-04-01

49

Predation as the primary selective force in recurrent evolution of gigantism in Poecilozonites land snails in Quaternary Bermuda  

PubMed Central

During the last half million years, pulses of gigantism in the anagenetic lineage of land snails of the subgenus Poecilozonites on Bermuda were correlated with glacial periods when lower sea level resulted in an island nearly an order of magnitude larger than at present. During those periods, the island was colonized by large vertebrate predators that created selection pressure for large size and rapid growth in the snails. Extreme reduction in land area from rising seas, along with changes in ecological conditions at the onset of interglacial episodes, marked extinction events for large predators, after which snails reverted to much smaller size. The giant snails were identical in morphology during the last two glacials when the predators included a large flightless rail Rallus recessus (marine isotope stages (MIS) 4-2) and a crane Grus latipes and a duck Anas pachysceles (MIS 6). In a preceding glacial period (MIS 10), when the fauna also included the tortoise Hesperotestudo bermudae, the snails were not only large, but the shells were much thicker, presumably to prevent crushing by tortoises. Evolution of Poecilozonites provides an outstanding example of dramatic morphological change in response to environmental pressures in the absence of cladogenesis. PMID:20554560

Olson, Storrs L.; Hearty, Paul J.

2010-01-01

50

Herbivory and Body Size: Allometries of Diet Quality and Gastrointestinal Physiology, and Implications for Herbivore Ecology and Dinosaur Gigantism  

PubMed Central

Digestive physiology has played a prominent role in explanations for terrestrial herbivore body size evolution and size-driven diversification and niche differentiation. This is based on the association of increasing body mass (BM) with diets of lower quality, and with putative mechanisms by which a higher BM could translate into a higher digestive efficiency. Such concepts, however, often do not match empirical data. Here, we review concepts and data on terrestrial herbivore BM, diet quality, digestive physiology and metabolism, and in doing so give examples for problems in using allometric analyses and extrapolations. A digestive advantage of larger BM is not corroborated by conceptual or empirical approaches. We suggest that explanatory models should shift from physiological to ecological scenarios based on the association of forage quality and biomass availability, and the association between BM and feeding selectivity. These associations mostly (but not exclusively) allow large herbivores to use low quality forage only, whereas they allow small herbivores the use of any forage they can physically manage. Examples of small herbivores able to subsist on lower quality diets are rare but exist. We speculate that this could be explained by evolutionary adaptations to the ecological opportunity of selective feeding in smaller animals, rather than by a physiologic or metabolic necessity linked to BM. For gigantic herbivores such as sauropod dinosaurs, other factors than digestive physiology appear more promising candidates to explain evolutionary drives towards extreme BM. PMID:24204552

Clauss, Marcus; Steuer, Patrick; Muller, Dennis W. H.; Codron, Daryl; Hummel, Jurgen

2013-01-01

51

Magnetic control of crystal chirality and gigantic magneto-chiral effect in CuB2O4  

NASA Astrophysics Data System (ADS)

The possibility of a magnetic-field control of the chirality of matter has been debated since 19th century, because of its importance in the problem of homochirality. However, the difference of symmetry between magnetic fields and chirality implies that it would be impossible to induce chirality by a magnetic field alone. Here, we report the successful induction of crystal chirality in a noncentrosymmetric canted antiferromagnet, CuB2O4, by the application of a low-intensity static magnetic field[1]. The chirality is reversed by a 90-degree rotation of the direction of the magnetic field. This is the first successful magnetic control of chirality to the best of our knowledge. The induction of chirality by a magnetic field gives rise to a gigantic enhancement of magneto-chiral dichroism in this material. The magnitude of the effect is larger by three orders than the previous reports. The extraordinary enhancement allows us to design new magneto-optical devices. [1] M. Saito et al., Phys. Rev. Lett. 101 117402 (2008).

Saito, Mitsuru; Ishikawa, Kenta; Taniguchi, Kouji; Arima, Taka-Hisa

2009-03-01

52

Nanoscale assemblies of gigantic molecular {Mo154}-rings: (dimethyldioctadecylammonium)20[Mo154O462H8(H2O)70].  

PubMed

Clusters based on the mixed-valence gigantic inorganic ring [Mo154O462H14(H2O)70]14- ({Mo154}-ring) and dimethyldioctadecylammonium (DODA) were combined to form novel molecular assemblies of an inorganic-organic hybrid molecular system as Langmuir-Blodgett (LB) and cast films. (DODA)20[Mo154O462H8(H2O)70] (2) was prepared by cation exchange and was characterized by a combination of thermogravimetry, IR, UV-vis-NIR, 1H NMR, and XRD measurements. The salt 2 was soluble in common organic solvents, and the chemical stability of {Mo154}-ring encapsulated by DODA cationic surfactants in CHCl3 was found to be higher than that of the "native" sodium salt of the {Mo154}-ring in H2O. Uniform spherical vesicle-like molecular assemblies of (DODA)20[Mo154O462H8(H2O)70] were observed in dilute THF, whose average diameter of 95 nm and a normalized variance of 5.7% were confirmed by a X-ray small-angle scattering. Deposition of 2 as a cast film showed circular domains with a typical diameter of approximately 100 nm, indicating possible similarities between solution and surface-deposited structures. The resulting LB films of salt 2 were transferred from an acidic buffer subphase with pH = 1.5 onto mica, giving a two-dimensional film surface with a unity transfer ratio. Further, the electronic absorption spectra of the LB multilayer were consistent with the classic type II mixed-valence MoV/MoVI electronic state well know for molybdenum blue {Mo154}-ring systems, and it appears that on the surface the plane of the {Mo154}-ring is approximately parallel to the substrate surface, as indicated by polarized electronic spectra, while the alkyl chains of DODA were relatively normal to the substrate surface. Therefore, the layer between the {Mo154}-rings and DODA cations was alternately stacked along the direction of film propagation. Finally, it was found that the surface morphology of the cast and LB films was determined by the molecular assembly of (DODA)20[Mo154O462H8(H2O)70] in solution and the air-water interface, respectively. PMID:18041852

Akutagawa, Tomoyuki; Jin, Reina; Tunashima, Ryo; Noro, Shin-Ichiro; Cronin, Leroy; Nakamura, Takayoshi

2008-01-01

53

[Gigantic nasal tumor].  

PubMed

A space-occupying lesion, which had been growing on the external surface of the nose of a 57-year-old man for 5 years was considered to most likely be an angiofibroma after surgical removal and histological examination, but the final clinical diagnosis was clearly a rhinophyma. This discrepancy is relevant for surgical treatment, because the vessel-rich tumor tended to substantial intraoperative bleeding. PMID:19183915

Lehnerdt, G; Oztrk, E; Grabellus, F

2009-04-01

54

No More Gigantism  

ERIC Educational Resources Information Center

The food situation in India is critical. It requires the development of both land and water resources, both of which are largely untapped. Ground water is one undeveloped resource that can help alleviate the irrigation problems facing agriculture. More efficient utilization could free millions of hectares of land for cultivation. (MA)

Vohra, B. B.

1975-01-01

55

Vulvo-perineal reconstruction with a reverse sensitive rectus abdominis salvage flap in a multirecurrent anal carcinoma.  

PubMed

Reconstructive options after vulvectomy is preferably performed using fasciocutaneous flaps. If the defect is very large, the use of vertical rectus abdominis myocutaneous (VRAM) flap is recommended. We report a case of a patient affected by multirecurrent anal carcinoma, treated by chemotherapy, radiotherapy and surgery several times, until an extended abdominoperineal resection of Miles was performed. Since other surgical options were no more available, a primary reverse VRAM flap reconstruction was harvested, together with an end-to-end nerve anastomosis between the cutaneous ramus of the 8th intercostal nerve and the superior branch of the pudendal nerve to achieve sensibility. Encouraging results, without actual recurrence of the disease, were obtained. PMID:19631598

Di Benedetto, Giovanni; Siquini, Walter; Bertani, Aldo; Grassetti, Luca

2010-02-01

56

Dynamics of streamer-to-leader transition at reduced air densities and its implications for propagation of lightning leaders and gigantic jets  

NASA Astrophysics Data System (ADS)

In this paper we present modeling studies of air heating by electrical discharges in a wide range of pressures. The developed model is capable of quantifying the different contributions for heating of air at the particle level and rigorously accounts for the vibration-dissociation-vibration coupling. The model is validated by calculating the breakdown times of short air gaps and comparing to available experimental data. Detailed discussion on the role of electron detachment in the development of the thermal-ionizational instability that triggers the spark development in short air gaps is presented. The dynamics of fast heating by quenching of excited electronic states is discussed and the scaling of its main channels with ambient air density is quantified. The developed model is employed to study the streamer-to-leader transition process and to obtain its scaling with ambient air density. Streamer-to-leader transition is the name given to a sequence of events occurring in a thin plasma channel through which a relatively strong current is forced through, culminating in heating of ambient gas and increase of the electrical conductivity of the channel. This process occurs during the inception of leaders (from sharp metallic structures, from hydrometeors inside the thundercloud, or in virgin air) and during their propagation (at the leader head or during the growth of a space leader). The development of a thermal-ionizational instability that culminates in the leader formation and propagation is characterized by a change in air ionization mechanism from electron impact to associative ionization and by contraction of the plasma channel. The introduced methodology for estimation of leader speeds shows that the propagation of a leader is limited by the air heating of every newly formed leader section. It is demonstrated that the streamer-to-leader transition time has an inverse-squared dependence on the ambient air density at near-ground pressures, in agreement with similarity laws for Joule heating in a streamer channel. Model results indicate that a deviation from this similarity scaling occurs at very low air densities, where the rate of electronic power deposition is balanced by the channel expansion, and air heating from quenching of excited electronic states is very inefficient. These findings place a limit on the maximum altitude at which a hot and highly conducting lightning leader channel can be formed in the Earth's atmosphere, result which is important for understating of the gigantic jet (GJ) discharges between thundercloud tops and the lower ionosphere. Simulations of leader speeds at GJ altitudes demonstrate that initial speeds of GJs are consistent with the leader propagation mechanism. The simulation of a GJ, escaping upward from a thundercloud top, shows that the lengthening of the leader streamer zone, in a medium of exponentially decreasing air density, determines the existence of an altitude at which the streamer zones of GJs become so long that they dynamically extend (jump) all the way to the ionosphere.

Silva, Caitano L.; Pasko, Victor P.

2013-12-01

57

[Reconstruction with skin flaps of the posterior aspect of the thighs after total pelvic evisceration with removal of vulvo-perineal soft tissues in recurrent vulvar squamous carcinoma].  

PubMed

We report of a case of a fortythree years old women affected by squamous cell cancer of the vulva (T3N0M0). Despite curative treatment (radical vulvectomy with bilateral inguinal and femoral lymphadenectomy), after 41 months she had a local recurrence, retreated with surgery and radiotherapy; another recurrence, after 29 months was treated with chemotherapy, without results. Because of local diffusion with infiltration of the urethra and anus, the patient was submitted to demolitive operation (total pelvic evisceratio, excision of pelvic and perineal soft tissues and reconstruction with rotating skin flaps of the posterior face of the thighs). After two years of follow up, the patient is alive without evidence of disease. PMID:16437992

Rinaldi, M; Cormio, G; Bucaria, V; Di Tonno, P; Marino, F; Altomare, D F

2005-01-01

58

Bill & Melinda Gates Foundation der konservative Gigant  

Microsoft Academic Search

\\u000a Es gibt keine private Stiftung, die in den vergangenen Jahren mehr Aufsehen erregt hat als die von Bill Gates und seiner Frau\\u000a Melinda. Das liegt zum einen daran, dass das Vermgen des reichsten Manns der Welt dahintersteht das des Mitgrnders des\\u000a Softwareriesen Microsoft, William H. Gates III, genannt Bill. Die jngste Liste der Superreichen, die jhrlich vom Wirtschaftsmagazin\\u000a Forbes

Norbert Kuls

59

Cerebral gigantism (Sotos syndrome). Compiled data of 22 cases  

Microsoft Academic Search

An in depth study on growth, bone age, cranial CT scans and plasma somatomedin activity (SM-act) was made of 22 children with Sotos syndrome. In addition to the known characteristics of the syndrome, thin and brittle nails were found in three adolescent patients. The mean body stature, expressed as standard deviation score, increased from 2.22.8 in the 1st year of

J. M. Wit; F. A. Beemer; P. G. Barth; J. W. E. Oorthuys; P. F. Dijkstra; J. L. Van den Brande; N. J. Leschot

1985-01-01

60

Gigantism in unique biogenic magnetite at the Paleocene-Eocene Thermal Maximum  

PubMed Central

We report the discovery of exceptionally large biogenic magnetite crystals in clay-rich sediments spanning the PaleoceneEocene Thermal Maximum (PETM) in a borehole at Ancora, NJ. Aside from previously described abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite up to 4 ?m long and hexaoctahedral prisms up to 1.4 ?m long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition, lattice perfection, and oxygen isotopes consistent with an aquatic origin. Electron holography indicates single-domain magnetization despite their large crystal size. We suggest that the development of a thick suboxic zone with high iron bioavailabilitya product of dramatic changes in weathering and sedimentation patterns driven by severe global warmingdrove diversification of magnetite-forming organisms, likely including eukaryotes. PMID:18936486

Schumann, Dirk; Raub, Timothy D.; Kopp, Robert E.; Guerquin-Kern, Jean-Luc; Wu, Ting-Di; Rouiller, Isabelle; Smirnov, Aleksey V.; Sears, S. Kelly; Lucken, Uwe; Tikoo, Sonia M.; Hesse, Reinhard; Kirschvink, Joseph L.; Vali, Hojatollah

2008-01-01

61

Occurrence of gigantic biogenic magnetite during the Paleocene-Eocene Thermal Maximum  

NASA Astrophysics Data System (ADS)

The Paleocene-Eocene Thermal Maximum (PETM) is one of the most severe climatic events of the Cenozoic Era. A massive injection of light carbon into the oceans and atmosphere over a few thousand of years triggered drastic perturbation of Earth's climate resulting in abrupt global warming of ~5-9oC [Sluijs et al., 2007] that persisted for ~180,000 years. This episode is marked by the diversification and radiation of terrestrial plants and mammals while in the marine realm numerous deep-sea benthic foraminifera species disappeared and new forms evolved. Sediments deposited during the PETM are clay-rich and contain distinct evidence of these climatic changes. Kopp et al., (2007) and Lippert & Zachos (2007) report an extraordinary magnetofossil Lagersttte' in lowermost Eocene kaolinite-rich clay sediments deposited at subtropical paleolatitude in the Atlantic Coastal Plain of New Jersey, USA. Magnetofossils are magnetic particles produced most abundantly by magnetotactic bacteria. Kopp et al. (2007) and Lippert & Zachos (2007) used ferromagnetic resonance (FMR) spectroscopy, other rock magnetic methods, and transmission electron microscopy (TEM) of magnetic separates to characterize sediments from boreholes at Ancora (ODP Leg 174AX) and Wilson Lake, NJ, respectively. These sediments contain abundant ~40- to 300-nm cuboidal, elongate-prismatic and bullet-shaped magnetofossils, sometimes arranged in short chains, resembling crystals in living magnetotactic bacteria. Despite the scarcity of intact magnetofossil chains, the asymmetry ratios of the FMR spectra reflects a profusion of elongate single domain (SD) crystals and/or chains. Here we address both conundrums by reporting the discovery from these same sediments of exceptionally large and novel biogenic magnetite crystals unlike any previously reported from living organisms or from sediments. Aside from abundant bacterial magnetofossils, electron microscopy reveals novel spearhead-like and spindle-like magnetite crystals up to 4 ?m long (eight times larger than magnetite produced by magnetotactic bacteria) and elongated hexaoctahedra up to 1.4 ?m long. Similar to magnetite produced by magnetotactic bacteria, these single-crystal particles exhibit chemical composition and lattice perfection consistent with a biogenic origin. The oxygen isotopic composition of indiviual particles supports a low temperature aquatic origin. Electron holography indicates single-domain magnetization despite the large crystal size. In a few cases, we observed apparently intact, tip-outward spherical assemblages of spearhead-like particles that possibly represent the preserved original biological arrangement of these crystals in a hitherto unknown magnetite producing organism. The discovery of these exceptionally large biogenic magnetite crystals that possibly represent the remains of a new microorganism that appeared and disappeared with the PETM sheds some light upon the ecological response to biogeochemical changes that occurred during this warming event. The abundance of fossil magnetotactic bacteria on the Atlantic Coastal Plain during the PETM could be explained by enhanced production, enhanced preservation, or both. The presence of novel magnetofossils, however, argues that changes in growth conditions are a major part of the explanation. Considering that other bacterial magnetofossils are present (although less abundant) and well-preserved in sediments below and above the PETM clay, as well as in a sand lens within the PETM clay [Kopp et al., 2007], suggests that the new magnetofossils are unlikely to be a preservation artefact. We conclude, therefore, that the development of a thick suboxic zone with high iron bioavailability - a product of dramatic changes in weathering and sedimentation patterns driven by severe global warming - resulted in diversification of magnetite-forming organisms, likely including eukaryotes. In this study we extended the search for these new magnetofossils [Schumann et al. 2008] to other PETM locations of the Atlantic margin and to a possible modern

Schumann, D.; Raub, T. D.; Kopp, R. E.; Guerquin-Kern, J. L.; Wu, T. D.; Rouiller, I.; Smirnov, A. V.; Sears, S. K.; Lcken, U.; Tikoo, S. M.; Hesse, R.; Kirschvink, J. L.; Vali, H.

2009-04-01

62

Gigantic Internal Magnetic Fields in Nanosize Semiconductor Quantum Dots and Their Effect on Dark Exciton Recombintion  

Microsoft Academic Search

The interaction of electron and hole spins with the spins of paramagnetic centers and the atomic nuclei is usually negligibly weak in bulk semiconductors because it is a contact interaction. However, in nanosize quantum dots this interaction, proportional to the square of the electron and hole wave functions at the nuclear or paramagnetic center position, grows dramatically, as the inverse

Al. L. Efros; M. Rosen; M. Nirmal; M. G. Bawendi

1996-01-01

63

Gigantic Internal Magnetic Fields in Nanosize Semiconductor Quantum Dots and Their Effect on Dark Exciton Recombintion  

NASA Astrophysics Data System (ADS)

The interaction of electron and hole spins with the spins of paramagnetic centers and the atomic nuclei is usually negligibly weak in bulk semiconductors because it is a contact interaction. However, in nanosize quantum dots this interaction, proportional to the square of the electron and hole wave functions at the nuclear or paramagnetic center position, grows dramatically, as the inverse of the volume of the quantum dot. As a result fluctuations of the effective random magnetic field of the nuclei acting on the electron spin can reach several Tesla, and in a crystal with a paramagnetic center this field can be several hundred Tesla. This field may be responsible for the radiative recombination of the optically forbidden Dark Exciton and for the temperature dependent Stokes shift observed in CdSe quantum dots in the 1.4 to 15 K region. Conversely, the electron and hole spins strongly affect the spins of the nuclei and paramagnetic defects as the inverse cube of the dot radius. This should lead to their coalignment and to a large NMR Knight shift in optically excited quantum dots.

Efros, Al. L.; Rosen, M.; Nirmal, M.; Bawendi, M. G.

1996-03-01

64

Sudden pressure increase in magma reservoir triggered by gigantic lava-dome collapse on Montserrat  

NSDL National Science Digital Library

Dilatometers recorded pressure changes within the Soufrière Hills Volcano's magma chamber during the 13 July 2003 collapse of its� lava dome. Strain data was evaluated to determine the depth of the pressure source. Results suggest an ellipsoidal magma chamber source at a depth of roughly six kilometers and an average radius of about one kilometer. The observed increase in pressure was consistent with the magma containing pressurized bubbles that expanded when the ambient pressure was reduced.

Al., Voight E.; Agu

65

Radar and lightning analyses of gigantic jet-producing storms Tiffany C. Meyer,1,2  

E-print Network

) and intracloud (IC) lightning, as well as the more uncommon transient luminous events (TLEs)--plays a role a cloud top of roughly 16 km [Pasko et al., 2002]. In July 2002, low-light-level cameras in Kenting. The likely parent thunderstorm was a high-precipitation supercell clus- ter with radar echo tops of at least

Cummer, Steven A.

66

Gigantism in unique biogenic magnetite at the PaleoceneEocene Thermal Maximum  

E-print Network

and International Affairs, Princeton University, 210 Guyot Hall, Princeton, NJ 08544; eImagerie Inte´grative de la-crystal particles exhibit chemical composition, lattice per- fection, and oxygen isotopes consistent with an aquatic suggest that the development of a thick suboxic zone with high iron bioavailability--a product of dramatic

67

Discovery of the Largest Orbweaving Spider Species: The Evolution of Gigantism in Nephila  

PubMed Central

Background More than 41,000 spider species are known with about 400500 added each year, but for some well-known groups, such as the giant golden orbweavers, Nephila, the last valid described species dates from the 19th century. Nephila are renowned for being the largest web-spinning spiders, making the largest orb webs, and are model organisms for the study of extreme sexual size dimorphism (SSD) and sexual biology. Here, we report on the discovery of a new, giant Nephila species from Africa and Madagascar, and review size evolution and SSD in Nephilidae. Methodology We formally describe N. komaci sp. nov., the largest web spinning species known, and place the species in phylogenetic context to reconstruct the evolution of mean size (via squared change parsimony). We then test female and male mean size correlation using phylogenetically independent contrasts, and simulate nephilid body size evolution using Monte Carlo statistics. Conclusions Nephila females increased in size almost monotonically to establish a mostly African clade of true giants. In contrast, Nephila male size is effectively decoupled and hovers around values roughly one fifth of female size. Although N. komaci females are the largest Nephila yet discovered, the males are also large and thus their SSD is not exceptional. PMID:19844575

Kuntner, Matjaz; Coddington, Jonathan A.

2009-01-01

68

Gigantism in honeybees: Apis cerana queens reared in mixed-species colonies  

NASA Astrophysics Data System (ADS)

The development of animals depends on both genetic and environmental effects to a varying extent. Their relative influences can be evaluated in the social insects by raising the intracolonial diversity to an extreme in nests consisting of workers from more than one species. In this study, we studied the effects of mixed honeybee colonies of Apis mellifera and Apis cerana on the rearing of grafted queen larvae of A. cerana. A. mellifera sealed worker brood was introduced into A. cerana colonies and on emergence, the adults were accepted. Then, A. cerana larvae were grafted for queen rearing into two of these mixed-species colonies. Similarly, A. cerana larvae and A. mellifera larvae were also grafted conspecifically as controls. The success rate of A. cerana queen rearing in the test colonies was 64.5%, surpassing all previous attempts at interspecific queen rearing. After emergence, all virgin queens obtained from the three groups ( N=90) were measured morphometrically. The A. cerana queens from the mixed-species colonies differed significantly in size and pigmentation from the A. cerana control queens and closely approximated the A. mellifera queens. It is inferred that these changes in the A. cerana queens reared in the mixed-species colonies can be attributed to feeding by heterospecific nurse bees and/or chemical differences in royal jelly. Our data show a strong impact of environment on the development of queens. The results further suggest that in honeybees the cues for brood recognition can be learned by heterospecific workers after eclosion, thereby providing a novel analogy to slave making in ants.

Tan, Ken; Hepburn, H. R.; He, Shaoyu; Radloff, S. E.; Neumann, P.; Fang, Xiang

2006-07-01

69

The Pulp gigantic geode (Almera, Spain): geology, metal pollution, microclimatology, and conservation  

NASA Astrophysics Data System (ADS)

The discovery of the giant Geode of Pulp (Almera, Spain) was considered as an important highlight in the geological heritage of Spain. Projects developed for their conservation were immediately initiated with legal figures of protection and tourist projects. The Geode has a tourist interest, which must be tempered by environmental restrictions limiting the public visits. First results demonstrate that a continuous visit of two or three people for more than 10 min provokes the appearance of condensation and risks corrosion of the gypsum crystals. In addition, the electron microprobe analyses confirms (1) the hydrothermal phases of iron-manganese in carbonated host rock; (2) the presence of sulphides with Fe-Zn-Pb-Ag-Sb-Cu-Hg-As-Te-Se; and (3) Ba, Ca, and Sr sulphates with mercury traces. The present proposal to label the geode and the mining environment as geological-natural heritage is feasible, although any tourist adaptation must not permit visits to the geode indoor and Hg levels must be controlled.

Fernndez-Corts, ngel; Calaforra, Jos Mara; Garca-Guinea, Javier

2006-07-01

70

The Architecture The universe resembles an unfathomably large honeycomb. Gigantic galaxy clusters occupy  

E-print Network

an expansive gas atmosphere (red). #12;TEXT HELMUT HORNUNG Photos:MPIforExtraterrestrialPhysics(leftpage);MPAGarching�VirgoCollaboration(left),NASA with bright splotches. The American space agency NASA published the photo, composed of individual shots taken the bright lights on the NASA images follow the contours of the continents, galaxy clusters trace

71

Gigantic swelling of inorganic layered materials: a bridge to molecularly thin two-dimensional nanosheets.  

PubMed

Platy microcrystals of a typical layered material, protonated titanate, have been shown to undergo an enormous degree of swelling in aqueous solutions of various amines, including tertiary amines, quaternary ammonium hydroxides, and primary amines. Introducing these solutions expanded the crystal gallery height by up to ~100-fold. Through systematic analysis, we determined that ammonium ion intercalation is predominantly affected by the acid-base equilibrium and that the degree of swelling or inflow of H2O is controlled by the osmotic pressure balance between the gallery and the solution environment, both of which are relatively independent of electrolyte identity but substantially dependent on molarity. In solutions of tertiary amines and quaternary ammonium hydroxides, the uptake of ammonium ions increases nearly linearly with increasing external concentration before reaching a saturation plateau, i.e., ~40% relative to the cation-exchange capacity of the crystals used. The only exception is tetrabutylammonium ions, which yield a lower saturation value, ~30%, owing to steric effects. The swelling behaviors in some primary amine solutions differ as a result of the effect of attractive forces between amine solute molecules on the solution osmotic pressure. Although the swelling is essentially colligative in nature, the stability of the resultant swollen structure is heavily dependent on the chemical nature of the guest ions. Intercalated ions of higher polarity and smaller size help stabilize the swollen structure, whereas ions of lower polarity and larger size lead readily to exfoliation. The insight gained from this study sheds new light on both the incorporation of guest molecules into a gallery of layered structures in general and the exfoliation of materials into elementary single-layer nanosheets. PMID:24635385

Geng, Fengxia; Ma, Renzhi; Ebina, Yasuo; Yamauchi, Yusuke; Miyamoto, Nobuyoshi; Sasaki, Takayoshi

2014-04-01

72

Dopamine-deprived striatal GABAergic interneurons burst and generate repetitive gigantic IPSCs in medium spiny neurons.  

PubMed

Striatal GABAergic microcircuits modulate cortical responses and movement execution in part by controlling the activity of medium spiny neurons (MSNs). How this is altered by chronic dopamine depletion, such as in Parkinson's disease, is not presently understood. We now report that, in dopamine-depleted slices of the striatum, MSNs generate giant spontaneous postsynaptic GABAergic currents (single or in bursts at 60 Hz) interspersed with silent episodes, rather than the continuous, low-frequency GABAergic drive (5 Hz) observed in control MSNs. This shift was observed in one-half of the MSN population, including both "D(1)-negative" and "D(1)-positive" MSNs. Single GABA and NMDA channel recordings revealed that the resting membrane potential and reversal potential of GABA were similar in control and dopamine-depleted MSNs, and depolarizing, but not excitatory, actions of GABA were observed. Glutamatergic and cholinergic antagonists did not block the GABAergic oscillations, suggesting that they were generated by GABAergic neurons. In support of this, cell-attached recordings revealed that a subpopulation of intrastriatal GABAergic interneurons generated bursts of spikes in dopamine-deprived conditions. This subpopulation included low-threshold spike interneurons but not fast-spiking interneurons, cholinergic interneurons, or MSNs. Therefore, a population of local GABAergic interneurons shifts from tonic to oscillatory mode when dopamine deprived and gives rise to spontaneous repetitive giant GABAergic currents in one-half the MSNs. We suggest that this may in turn alter integration of cortical signals by MSNs. PMID:19535589

Dehorter, Nathalie; Guigoni, Celine; Lopez, Catherine; Hirsch, June; Eusebio, Alexandre; Ben-Ari, Yehezkel; Hammond, Constance

2009-06-17

73

Hard magnetic ferrite with a gigantic coercivity and high frequency millimetre wave rotation  

PubMed Central

Magnetic ferrites such as Fe3O4 and Fe2O3 are extensively used in a range of applications because they are inexpensive and chemically stable. Here we show that rhodium-substituted ?-Fe2O3, ?-RhxFe2?xO3 nanomagnets prepared by a nanoscale chemical synthesis using mesoporous silica as a template, exhibit a huge coercive field (Hc) of 27 kOe at room temperature. Furthermore, a crystallographically oriented sample recorded an Hc value of 31 kOe, which is the largest value among metal-oxide-based magnets and is comparable to those of rare-earth magnets. In addition, ?-RhxFe2?xO3 shows high frequency millimetre wave absorption up to 209 GHz. ?-Rh0.14Fe1.86O3 exhibits a rotation of the polarization plane of the propagated millimetre wave at 220 GHz, which is one of the promising carrier frequencies (the window of air) for millimetre wave wireless communications. PMID:22948817

Namai, Asuka; Yoshikiyo, Marie; Yamada, Kana; Sakurai, Shunsuke; Goto, Takashi; Yoshida, Takayuki; Miyazaki, Tatsuro; Nakajima, Makoto; Suemoto, Tohru; Tokoro, Hiroko; Ohkoshi, Shin-ichi

2012-01-01

74

ecCNO Solar Neutrinos: A Challenge for Gigantic Ultra-Pure Liquid Scintillator Detectors  

E-print Network

Neutrinos produced in the Sun by electron capture reactions on $^{13}{\\rm N}$, $^{15}{\\rm O}$ and $^{17}{\\rm F}$, to which we refer as ecCNO neutrinos, are not usually considered in solar neutrino analysis since the expected fluxes are extremely low. The experimental determination of this sub-dominant component of the solar neutrino flux is very difficult but could be rewarding since it provides a determination of the metallic content of the solar core and, moreover, probes the solar neutrino survival probability in the transition region at $E_\

Villante, F L

2014-01-01

75

Unigas readies for motor fuel surge with supplies from gigantic plant  

SciTech Connect

Nestled away a short distance from the smog and congestion of Mexico City is a sprawling LP-gas plant from which 72 million gallons of propane are shipped annually. Boasting a storage capacity of 865,000 gal. in 19 tanks, this plant is believed to possess the largest total reserve capacity of any such facility south of the border and in all of Latin America. This paper reports on a tour of the Unigas plant in Ixhuatepec, hosted by general director Carlos Venegas Baeza, which provides insight into three major areas: the operations and plans of one of the largest LP-gas companies in Mexico, the booming market in carburetion, and most noteworthy, the technologically advanced safety/security system that has been installed at this point.

Not Available

1992-10-01

76

Evolution of Gigantism in Amphiumid Salamanders Ronald M. Bonett1,2  

E-print Network

Amphibia Tree of Life grant to DBW (DEB- EF- 0334939), and was performed on instruments funded, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared in generating ecological and genetic divergence, and has been a primary axis of change during the radiation

Wake, David B.

77

Glassy Protein Dynamics and Gigantic Solvent Reorganization Energy of Plastocyanin David N. LeBard and Dmitry V. Matyushov*  

E-print Network

while met- alloproteins deposited in mitochondrial membranes and photo- synthetic units serve as redox in synthetic redox systems with a copper ion serving as the redox site because of large structural changes upon

Matyushov, Dmitry

78

A Gigantic Sarcopterygian (Tetrapodomorph Lobe-Finned Fish) from the Upper Devonian of Gondwana (Eden, New South Wales, Australia)  

PubMed Central

Edenopteron keithcrooki gen. et sp. nov. is described from the Famennian Worange Point Formation; the holotype is amongst the largest tristichopterids and sarcopterygians documented by semi-articulated remains from the Devonian Period. The new taxon has dentary fangs and premaxillary tusks, features assumed to be derived for large Northern Hemisphere tristichopterids (Eusthenodon, Hyneria, Langlieria). It resembles Eusthenodon in ornament, but is distinguished by longer proportions of the parietal compared to the post-parietal shield, and numerous differences in shape and proportions of other bones. Several characters (accessory vomers in the palate, submandibulars overlapping ventral jaw margin, scales ornamented with widely-spaced deep grooves) are recorded only in tristichopterids from East Gondwana (Australia-Antarctica). On this evidence Edenopteron gen. nov. is placed in an endemic Gondwanan subfamily Mandageriinae within the Tristichopteridae; it differs from the nominal genotype Mandageria in its larger size, less pointed skull, shape of the orbits and other skull characters. The hypothesis that tristichopterids evolved in Laurussia and later dispersed into Gondwana, and a derived subgroup of large Late Devonian genera dispersed from Gondwana, is inconsistent with the evidence of the new taxon. Using oldest fossil and most primitive clade criteria the most recent phylogeny resolves South China and Gondwana as areas of origin for all tetrapodomorphs. The immediate outgroup to tristichopterids remains unresolved either Spodichthys from Greenland as recently proposed, or Marsdenichthys from Gondwana, earlier suggested to be the sister group to all tristichopterids. Both taxa combine two characters that do not co-occur in other tetrapodomorphs (extratemporal bone in the skull; non-cosmoid round scales with an internal boss). Recently both primitive and derived tristichopterids have been discovered in the late Middle Devonian of both hemispheres, implying extensive ghost lineages within the group. Resolving their phylogeny and biogeography will depend on a comprehensive new phylogenetic analysis. PMID:23483884

Young, Ben; Dunstone, Robert L.; Senden, Timothy J.; Young, Gavin C.

2013-01-01

79

Espectroscopa del triplete del CaII de gigantes rojas del campo de la Nube Menor de Magallanes  

NASA Astrophysics Data System (ADS)

Using spectra obtained with the VLT (Chile), we determined the metallic- ity of 360 red giant field stars surrounding 15 Small Magellanic Cloud (SMC) star clusters previously studied by us. Using this information, as well as that available for 13 other previously studied fields and for our 15 clusters, we found no evidence of metallicity gradient in the SMC. Besides, we observed a clear tendency for the field stars to be more metal-poor than the corresponding cluster they surround. FULL TEXT IN SPANISH

Parisi, M. C.; Geisler, D.; Grocholski, A. J.; Clari, J. J.; Sarajedini, A.

80

Metal/nanowire contacts, quantum confinement, and their roles in the generation of new, gigantic actions in nanowire transistors.  

PubMed

A distinctly new route for the design, modeling and electrical behavior of very short-channel (5-10nm in channel length) nanowire field-effect transistors (FETs) has been presented. Essential elements of the approach entail a drain current determined by thermionic emission, but not by carrier mobility in the channel of the transistor. Abasic understanding of the fundamental physics and the concepts of Schottky-barrier-based design for the proposed route have been described. Quantum confinement in the nanowire channel together with Schottky barrier tailing and temperature-dependent fluctuations of applied biases has been taken into account for the development of the model. Both current-voltage characteristics and transconductance of FETs have been studied. The calculated results are in near-quantitative agreement with the available experiments. Measured data show very diverse (e.g., exponential, linear, saturating, and non-linear non-exponential non-saturating) nanowire transistor characteristics. The model explains these characteristics well and reveals a number of new transistor actions. It highlights the impacts of quantum confinement and Schottky contacts for these new transistor actions. It also quantifies the significant enhancement of the drain-source current and transconductance. With new findings thus achieved, suggestions for the realization of very high-performance, small-diameter (preferably 2nm), small-Schottky-barrier-height, high-operating temperature, ultra-short-channel-length, nanowire transistors have been made. Optimized design of these transistors has been suggested. And the range (in terms of device and technological parameters) of the proposed model has been elucidated. PMID:24129340

Mohammad, S Noor

2013-11-15

81

GEOPHYSICAL RESEARCH LETTERS, VOL. 40, 33153319, doi:10.1002/grl.50596, 2013 Vertical structuring of gigantic jets  

E-print Network

in the leader stem, and we propose a simple time- dynamic model for GJ propagation that includes the effects- derstorm cell 200 km away from the observation site. Pasko et al. [2002] have estimated the bright portions with the ionosphere, and the trailing jet cor- responding to the lower part of the GJ that decays slower than other

Pasko, Victor

82

Investigation of Initiation of Gigantic Jets connecting Thunderclouds to the Ionosphere Lizhu Tong, Kenichi Nanbu, and Hiroshi Fukunishi 1)  

E-print Network

, the triggering conditions of streamer formation in laboratory situations are extended to form a criterion;2 formation in laboratory situations. The estimated initiation heights are in agreement with the observations The charge structure of thunderclouds has been studied extensively for many years. MacGorman and Rust (1998

Paris-Sud XI, Université de

83

The Solar System Linked to a Gigantic Interstellar Cloud, During 500 Myr: Implications for a Galactic Theory of Terrestrial Catatrophism  

NASA Astrophysics Data System (ADS)

The local galactic environment within 1 Kpc of the Sun comprises a massive, expanding ring of interstellar matter associated with star-forming molecular clouds and a group of relatively young OB stars known as Gould's Belt. This structure is likely the result of the disintegration of a formerly bound supercloud. Gould's belt is a discrete system that forms part of the so-called Orion or local arm, which is thought to be a material interarm. branch or spur. Another characteristic of the solar neighborhood is the existence of at least three superclusters near the Sun: (1) Sirius, (2) Pleiades, and (3) Hyades. The central thesis of this paper is that Gould's Belt, the local arm and the superclusters were formed in different epochs within a supercloud of about 2x107 Solar masses and about 500 pc of radius that has been being decelerated for a long period of time. The stars of the older generations, i.e. the Sirius supercluster whose age is around 500 Myr, tend to conserve the kinematics of the pre-braking phase of the supercloud, while the gas and early stars complexes reflect the recent kinematics, resulting from the braking process. We calculated back in time the epicyclic galactic orbits of the Sirius supercluster and the supercloud, starting from their current state as initial conditions and having into account the action of a friction force on the gas. From the condition that the Sirius supercluster and the supercloud shared the same orbits before the separation of gas and stars due to the braking of the gas, we determined the model's free parameters. The main evidence supporting our hypothesis is that the supercloud's track derived from the model coincides with a large 'tunnel' in the distribution of local interstellar matter, toward the galactic longitude of about 240 deg. An interesting prediction of the model is that the Sun has been gravitationally bound to the supercloud, rotating in sense contrary to the supercloud's rotation. With the values obtained for the model's parameters, we calculated the Sun's orbit with respect to the supercloud's gravitational center, for the last 100 Myr; time in which the braking force acted on the supercloud. A plausible explanation for the capture of the Sun by the supercloud is that while the Sun was passing through an extended concentration of gas, around 500 Myr ago, this gas was suddenly accelerated and organized into a supercloud, making the difference between the supercloud's barycenter velocity and the Sun velocity relative to Regional Standard of Rest lower than the escape velocity. This explains why the Sun current velocity of about 11 km/s with respect to LSR is significantly lower than the average of 60 km/s typical for similar G-type stars in the Galaxy. Additional information is contained in the original extended abstract.

Olano, C. A.

2000-01-01

84

The Solar System Linked to a Gigantic Interstellar Cloud, During 500 Myr: Implications for a Galactic Theory of Terrestrial Catatrophism  

Microsoft Academic Search

The local galactic environment within 1 Kpc of the Sun comprises a massive, expanding ring of interstellar matter associated with star-forming molecular clouds and a group of relatively young OB stars known as Gould's Belt. This structure is likely the result of the disintegration of a formerly bound supercloud. Gould's belt is a discrete system that forms part of the

C. A. Olano

2000-01-01

85

Tunneled modified lotus petal flap for surgical reconstruction of severe introital stenosis after radical vulvectomy  

PubMed Central

INTRODUCTION We presented the anatomical, functional and aesthetic results achieved with lotus petal flap in case of introital stenosis as a results of inadequate primary plastic reconstruction. We discussed the potential advantages of lotus petal flap compared to others vulvar reconstructive techniques. PRESENTATION OF CASE We report a case of a 44-years old woman presenting a severe introital stenosis following radical surgery for vulvar cancer. She could not have a normal sexual activity life because the narrow scarred introitus resulting after primary closure of a large vulvar defect. The patient comes to our attention after three years from primary surgery. Once the scar was removed we performed a vulvoperineal reconstruction with bilateral tunneled lotus petal flaps. DISCUSSION Lotus petal flap is a safe, easy and quick technique, has a good functional and cosmetic results in this young woman, and represents an optimal alternative solution for plastic reconstruction in case of severe introital stenosis after primary closure of large vulvoperineal defect. CONCLUSION Tunneled lotus petal flaps represents a feasible, attractive and versatile surgical reconstructive technique that can be easily performed after surgical treatment of vulvoperineal neoplasms. PMID:22534648

Buda, Alessandro; Confalonieri, Pier Luigi; Rovati, Luca Carlo Vittorio; Signorelli, Mauro; Del Bene, Massimo

2012-01-01

86

Partial characterization of 5?-nucleotidase from giant squid (Dosidicus gigas) mantle Caracterizacin parcial de la enzima 5?-nucleotidasa del manto de calamar gigante (Dosidicus gigas)  

Microsoft Academic Search

The most important cephalopod resource in the northwestern area of Mexico is the jumbo squid whose postmortem biochemical behavior has been studied in detail. Adenosine triphosphate (ATP) degradation in this organism is different than the other species because of the fast degradation of adenosine monophosphate (AMP) metabolite in mantle. In this research, AMP deaminase from jumbo squid mantle was partially

R. Pacheco-Aguilar; V. M. Ocano-Higuera; J. M. Ezquerra-Brauer; F. J. Castillo-Yaez; G. Garca-Snchez; E. Marquez-Rios

2010-01-01

87

Subcutaneous photophores in the jumbo squid Dosidicus gigas (d'Orbigny, 1835) (Cephalopoda: Ommastrephidae) Fotforos subcutneos en el calamar gigante Dosidicus gigas (d'Orbigny, 1835) (Cephalopoda: Ommastrephidae)  

Microsoft Academic Search

Resumen.- En Dosidicus gigas se observaron pequeas inclusiones de color amarillo plido embebidas a distintas profundidades en el msculo del manto, las que corresponden a fotforos. A nivel histolgico los fotforos estn formados por un tejido fotogenerador, que se tie de color naranja intenso con tincin tricrmica de Mallory y un tejido vacuolar, que lo rodea y penetra en ste,

Karin B. Lohrmann

2008-01-01

88

The electromagnetic Ram action of the plasma focus as a paradigm for the generation of cosmic rays and the gigantic jets in active galaxies  

NASA Astrophysics Data System (ADS)

Recent measurements of the energy spectrum of the plasma-focus-generated deuteron beam yield as spectrum of the form N(E)=(approx.) E to the -2.7 for 1MeV E 13 MeV. Other measurements show that the beta 1 electron beam which is generated simultaneously with the deuteron beam is interrupted into segments of spacing 25ps and duration approximately 4ps. A stuttering-electro-magnetic-ram (ser) model of the plasma focus in proposed which is similar to Raudorf's electronic ram which produces a similar spectrum for an electron beam for 1Mev E 10MeV. It is proposed that the cosmic ray spectrum and the giganic galactic jets are both generated by ser action near the centers of active galaxies.

Bostick, W. H.; Nardi, V.

1985-08-01

89

Replacement of wheat bran with spineless cactus (Opuntia ficus indica Mill cv Gigante) and urea in the diets of Holstein x Gyr heifers.  

PubMed

The aim of this study was to evaluate the replacement effect of wheat bran with spineless cactus and urea in heifers. Twenty-four heifers with an average initial weight of 185??13kg were used in this experiment. Four levels of spineless cactus corrected with urea and ammonium sulfate (9:1) were studied: 0, 33, 66, and 100% replacement with wheat bran. Samples of feed, orts, and feces were analyzed to estimate the intake and digestibility of dry matter (DM) and nutrients. Indigestible neutral detergent fiber was used as an internal marker. The experiment was conducted in a completely randomized design. Dry matter, neutral detergent fiber, and total digestible nutrient intake demonstrated a quadratic effect (P?

de Figueiredo Monteiro, Carolina Corra; Silva de Melo, Airon Aparecido; Ferreira, Marcelo Andrade; de Souza Campos, Jos Mauricio; Rodrigues Souza, Julyana Sena; Dos Santos Silva, Evannielly Thuanny; de Paula Xavier de Andrade, Rafael; da Silva, Emmanuelle Cordeiro

2014-10-01

90

From Ally McBeal to Sbado GiganteContributions of Television Viewing to the Gender Role Attitudes of Latino Adolescents  

Microsoft Academic Search

Although previous findings indicate that frequent television viewing is associated with holdingmore stereo typical attitudes aboutgender, no studies have examinedthis connection among Latino youth, who are frequent viewers of both English- and Spanish-language programming. The present study attempted to rectify this situation by examining connections between exposure to this content, viewer involvement, and the gender role beliefs of Latino adolescents.

Roco Rivadeneyra; L. Monique Ward

2005-01-01

91

Three-dimensional computer analysis of white shark jaw mechanics: how hard can a great white bite?  

E-print Network

, CA, USA Keywords finite element analysis; bite force; Carcharodon carcharias; megalodon in the gigantic fossil species Carcharodon megalodon. However, jaw adductor-generated force in Carcharodon appears predatory fish. Its gigantic, whale- eating relative, Carcharodon megalodon, was arguably the most

Summers, Adam P.

92

CARACTERIZACIN PARCIAL DEL COLGENO EXTRADO A PARTIR DEL MANTO, ALETA Y TENTCULOS DE CALAMAR GIGANTE (Dosidicus gigas) PARTIAL CHARACTERIZATION OF COLLAGEN FROM MANTLE, FIN, AND ARMS OF JUMBO SQUID (Dosidicus gigas)  

Microsoft Academic Search

In Dosidicus gigas or jumbo squid, collagen plays an important role in squid swimming mechanisms. Scarce information is available on collagen. The content as well some physical and chemical properties of pepsin-soluble (PSC) and insoluble collagen (IC) were compared in mantle, arm, and fin from adult fresh jumbo squid. The total collagen content and SDS-electrophoresis profile were different in each

W. Torres-Arreola; R. Pacheco-Aguilar; R. R. Sotelo-Mundo; O. Rouzaud-Sndez; J. M. Ezquerra-Brauer

2008-01-01

93

Variabilidad en la estructura poblacional del calamar gigante (Dosidicus gigas) en Santa Rosala, regin central del Golfo de California Variability in the population structure of jumbo squid (Dosidicus gigas) in Santa Rosala, central Gulf of California  

Microsoft Academic Search

This study describes the population structure of jumbo squid (Dosidicus gigas) in the area of Santa Rosala (central Gulf of California) during the years 2003 and 2004, and analyzes the interannual variability in the size structure over a wider time period, 1996-2004 (except 2000-2002). The results revealed clear differences in the size structure and sexual maturity of males and females

G Bazzino; C Salinas-Zavala; U Markaida

2007-01-01

94

Produccin y evaluacin funcional de un concentrado proteico de calamar gigante (Dosidicus gigas) obtenido mediante disolucin alcalina Production and functional evaluation of a protein concentrate from giant squid (Dosidicus gigas) obtained by alkaline dissolution  

Microsoft Academic Search

A protein concentrate from jumbo squid (Dosidicus gigas) was produced under alkaline conditions. Solubility, recovery of proteins, electrophoretic profile, as well as changes in the pattern of solubility of proteins recovered were determined. In the gels, its capability (functionaltechnological) was evaluated in terms of texture profile analysis, folding test, water holding capacity, and color attributes. The alkaline treatment promoted the

G. Dihort-Garcia; V. M. Ocano-Higuera; J. M. Ezquerra-Brauer; M. E. Lugo-Sanchez; R. Pacheco-Aguilar; S. M. Barrales-Heredia; E. Marquez-Rios

2011-01-01

95

Parameterization of a B3LYP specific correction for non-covalent interactions and basis set superposition error on a gigantic dataset of CCSD(T) quality non-covalent interaction energies  

PubMed Central

A vast number of non-covalent interaction energies at the counterpoise corrected CCSD(T) level have been collected from the literature to build a diverse new dataset. The whole dataset, which consists of 2027 CCSD(T) energies, includes most of the published data at this level. A large subset of the data was then used to train a novel, B3LYP specific, empirical correction scheme for non-covalent interactions and basis set superposition error (abbreviated as B3LYP-MM). Results obtained with our new correction scheme were directly compared to benchmark results obtained with B3LYP-D31 and M06-2X2 (two popular density functions designed specifically to accurately model non-covalent interactions). For non-covalent complexes dominated by dispersion or dipole-dipole interactions all three tested methods give accurate results with the medium size aug-cc-pVDZ36 basis set with MUEs of 0.27 (B3LYP-MM), 0.32 (B3LYP-D3) and 0.47 kcal/mol (M06-2X) (with explicit counterpoise corrections). These results validate both B3LYP-D3 and M06-2X for interactions of this type using a much larger data set than was presented in prior work. However, our new dispersion correction scheme shows some clear advantages for dispersion and dipole-dipole dominated complexes with the small LACVP* basis set, which is very popular in use due to its low associated computational cost: The MUE for B3LYP-MM with the LACVP* basis set for this subset of complexes (without explicit counterpoise corrections) is only 0.28 kcal/mol, compared to 0.65 kcal/mol for M06-2X or 1.16 kcal/mol for B3LYP-D3. Additionally, our new correction scheme also shows major improvements in accuracy for hydrogen-bonded systems and for systems involving ionic interactions, for example cation-? interactions. Compared to B3LYP-D3 and M06-2X, we also find that our new B3LYP-MM correction scheme gives results of higher or equal accuracy for a large dataset of conformer energies of di- and tripeptides, sugars, and cysteine. PMID:22058661

Schneebeli, Severin T.; Bochevarov, Arteum D.; Friesner, Richard A.

2011-01-01

96

unknown title  

E-print Network

Observations were made on gigantism and albinism in the giant snail, Archachatina marginata. Gigantic snails were initially about twice the size of normal snails of same age. However this growth superiority of gigantic snails apparently slowed down with age. Albinism in the snails was expressed in form of creamy-white bodies instead of the normally brownish colour. Albino snails however retained normal shell colouration. All offspring of these albinos maintained these same characteristics. There was no difference in mortality rates of albino and normal snails. Gigantism and albinism have serious implications for commercial snail farming.

Archachatina Marginata Swainson; Peter Ugochukwu

97

WHAT WE CAN SEE AND MEASURE MAKES UP 4 PERCENT OF THE UNIVERSE. 96 PERCENT LIES IN THE DARK. The Science Magazine of the Max Planck Society 1.2013  

E-print Network

explodes or a black hole ejects gigantic gas clouds from the core of a distant galaxy. These aggressive converting this quartet into a quintet. H.E.S.S. II is the name of the new dish, which our picture shows resembles an unfathomably large honeycomb. Gigantic galaxy clusters occupy the nodes of the waxy walls

Falge, Eva

98

Development of the giant-axon sheaths in larval lobsters, Homarus americanus Daniel K. Hartline 1,2  

E-print Network

membrane and hence increase conduction speed. Benthic-living adult lobsters utilize axonal gigantism decapod shrimp utilize a combination of axonal gigantism and myelination 4,5 . The more exposed life) sections were taken, double-stained with uranyl acetate and lead citrate, and photographed in a LEO912 EF

Hartline, Daniel K.

99

Effect of lyophilized jumbo squid (Dosidicus gigas) fin and mantle muscle on dough properties and bread baking performance of commercial wheat flour Efecto de aleta y msculo de manto de calamar gigante (Dosidicus gigas) liofilizado sobre las propiedades de la masa y la calidad panadera de una harina de trigo comercial  

Microsoft Academic Search

The effect of 25 and 50 g\\/kg of lyophilized jumbo squid (Dosidicus gigas) fin (JSF) and mantle muscle (JSM) on dough properties and baking performance of wheat flour were studied. Dough maximum resistance (Rmax), extensibility, deformation work (Area, 45-min resting time), baking performance, loaf volume, and acceptability were evaluated. JSF (25 g\\/kg) almost tripled (P ? 0.05) Rmax compared to

J. C. Ramirez-Suarez; A. R. Islas-Rubio; L. C. Montoya-Ballesteros; M. C. Granados-Nevarez; F. Vzquez-Lara; R. Pacheco-Aguilar; M. E. Lugo-Snchez

2012-01-01

100

EFECTO DE LA CALIDAD DEL AGUA Y TAMAO DE PARTCULA EN LA PRODUCCIN DE QUITOSANO A PARTIR DE ?-QUITINA EXTRADA DE DESPERDICIOS DE CALAMAR GIGANTE (Dosidicus gigas) EFFECT OF WATER QUALITY AND PARTICLE SIZE ON THE PRODUCTION OF CHITOSAN FROM ?-CHITIN ISOLATED FROM JUMBO SQUID PROCESSING WASTES (Dosidicus gigas)  

Microsoft Academic Search

Jumbo squid wastes represent an important source of ?-chitin, which recently has been studied for its properties and potential applications. ?-chitin is characterized for chains in parallel fashion with weaker intermolecular interactions than ?-chitin. Therefore ?-chitin is more soluble in common solvents as well as it display higher reactivity for deacetylation and chemical modification than ?-chitin. Preparation of ?-chitin was

Z. Rocha-Pino; K. Shirai; L. Arias; H. Vzquez-Torres

2008-01-01

101

Validacin histolgica de los estadios de madurez gondica de las hembras de calamar gigante (Dosidicus gigas) en el Golfo de California, Mxico Histological validation of the gonadal maturation stages of female jumbo squid (Dosidicus gigas) in the Gulf of California, Mexico  

Microsoft Academic Search

The oocyte structure of jumbo squid (Dosidicus gigas) female gonads was analyzed to validate morphochromatic sexual maturation stages based on a six-phase scale. Samples were obtained fortnightly from the Santa Rosala area, Baja California Sur, from June 2001 to November 2002. Histological preparations were obtained from each gonad to count the number of oocytes at each level of development. The

JG Daz-Uribe; A Hernndez-Herrera; E Morales-Bojrquez; S Martnez-Aguilar; MC Surez-Higuera; A Hernndez-Lpez

2006-01-01

102

TEMPERATURAS DEL GOLFO DE CALIFORNIA DURANTE MAYO Y JUNIO DE 1996 Y SU RELACIN CON LAS CAPTURAS DE CALAMAR GIGANTE (Dosidicus gigas D'ORBIGNY, 1835) WATER TEMPERATURES IN THE GULF OF CALIFORNIA IN MAY AND JUNE 1996 AND THEIR RELATION TO THE CAPTURE OF GIANT SQUID ( Dosidicus gigas D'ORBIGNY, 1835)  

Microsoft Academic Search

The relation between water temperature and the capture of giant squid in the Gulf of California was analyzed. Data were collected in May and June 1996 at 60 stations. Each fishing session lasted 30 minutes, and an average of 100 organisms per 0.5 0.5 square were caught. The hypothesis was that if

S. C. Mar

2000-01-01

103

Estimacin estocstica de la capturabilidad y el reclutamiento del calamar gigante Dosidicus gigas (D'Orbigny, 1835) del Golfo de California, Mxico Stochastic estimation of the catchability and recruitment of the jumbo squid Dosidicus gigas (D'Orbigny, 1835) from the Gulf of California, Mexico  

Microsoft Academic Search

In this paper a depletion model with two different approaches (stochastic and deterministic) was analyzed, in order to compare the observation error hypothesis in the catch-per-unit effort (CPUE) data, and the process error in the model, as well as its effect on the recruitment and catchability estimates in the jumbo squid fishery from the Gulf of California, Mexico. Results showed

Enrique Morales-Bojrquez; Manuel O. Nevrez-Martnez

2002-01-01

104

Growth Disorders  

MedlinePLUS

... gigantism in children, where their bones and their body grow too much. In adults, it can cause acromegaly, which makes the hands, feet and face larger than normal. Possible treatments include surgery to remove the tumor, medicines, and radiation therapy.

105

Errancies of Desire: Subjectivity, Difference, and Proximity in Transnational Film and Literature  

E-print Network

of displays of sex and violence in the media. The generalmedia (5-6) but it was also misinterpreted as the act of a sexmedia. Additionally, the widely held perception of the Black males gigantic sex

Messier, Vartan Patrick

2011-01-01

106

Pressure variation of Rashba spin splitting toward topological transition in the polar semiconductor BiTeI  

E-print Network

BiTeI is a polar semiconductor with gigantic Rashba spin-split bands in bulk. We have investigated the effect of pressure on the electronic structure of this material via magnetotransport. Periods of Shubunikovde Haas ...

Ideue, T.

107

Astrophysics: A burst of new ideas  

E-print Network

Gigantic cosmological gamma-ray bursts have fallen into a dichotomy of long and short bursts, each with a very different origin. The discovery of an oddball burst calls for a rethink of that classification.

Bing Zhang

2006-12-21

108

Fermi discovers giant bubbles in Milky Way  

NASA Video Gallery

Using data from NASA's Fermi Gamma-ray Space Telescope, scientists have recently discovered a gigantic, mysterious structure in our galaxy. This feature looks like a pair of bubbles extending above...

109

Super Hero, Japanese Style  

E-print Network

Broadcast Transcript: Super Sentai is a long-running Japanese TV series about regular humans who destroy bad guys using nothing but their color-coded uniforms, excellent martial arts skills and, you know, totally advanced weapons and gigantic...

Hacker, Randi

2013-10-02

110

Sacsinopathies: sacsin-related ataxia.  

PubMed

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) was originally found among inhabitants of the Charlevoix-Saguenay region of northeastern Quebec in Canada. This disease is a neurodegenerative disorder characterized by early-onset spastic ataxia, dysarthria, nystagmus, distal muscle wasting, finger and foot deformities, and retinal hypermyelination. The principal neuropathology comprises atrophy of the upper vermis and the loss of Purkinje cells in the cerebellum. The SACS gene was originally reported to consist of a single gigantic exon spanning 12.8 kb with an 11.5-kb open reading frame (ORF), and to encode the protein sacsin. Recently, eight exons upstream from the original gigantic one, however, have been found, and the new ORF has elongated to 13.7 kb. To date, at least 28 mutations have been found in Quebec and non-Quebec patients including ones in Italy, Japan, Spain, Tunisia, and Turkey, and ARSACS thus shows a worldwide occurrence. Although most of the mutations reported have been in the gigantic exon, the genotype is now expanding upstream from this gigantic exon. Therefore, the new exons upstream of the gigantic one should be analyzed when a case is clinically compatible with ARSACS, even without any mutation in the gigantic exon. Although Quebec patients show a homogeneous phenotype, non-Quebec patients exhibit some atypical clinical features, as follows: slightly later onset than that in Quebec patients, absence of retinal hypermyelination, intellectual impairment, and lack of spasticity. Thus, since ARSACS shows the clinical diversity, the SACS gene should be analyzed not only in typical cases as Quebec patients but also in atypical cases as non-Quebec patients. As more SACS mutations are identified worldwide, the clinical spectrum of 'sacsinopathies' will expand, and a finer genotype-phenotype correlation study will become possible and shed light on the molecular mechanism underlying ARSACS. PMID:17853117

Takiyama, Yoshihisa

2007-01-01

111

Shake It up  

ERIC Educational Resources Information Center

If scientists know where earthquakes are most likely to occur, then architects and engineers can design safer buildings for such areas and potentially prevent some of the devastating aftereffects. Engineers have met this challenge through the design and use of gigantic shake tables to evaluate the stability of various structures. In this 45-minute

Gilstrap, Tatiana; Sheldon, Peter; Schimmoeller, Peggy

2010-01-01

112

PREFACE: 1982 International Conference on Plasma Physics  

Microsoft Academic Search

Invited Papers: The Physics of Hot Plasmas During the last decade a dramatic evolution of plasma physics has occurred. Not only have gigantic fusion plasma machines been planned, and are now being built, and elaborate spaceships and antenna systems been constructed to explore remote parts of the cosmos; new observations have revealed fascinating structures in space, ranging from pulsar plasmas

Hans Wilhelmsson

1982-01-01

113

The King-Kong Effects: Improving Sensation of Walking in VR with Visual and Tactile Vibrations at each Step  

E-print Network

Kong Effects are inspired by special effects in movies in which the incoming of a gigantic creature targeting the immersion of a user walking in a 3D virtual scene. Index Terms: I.3.7 [Computer Graphics to the VR. Indeed, breathtaking special effects have become common in Hollywood movies to make

Paris-Sud XI, Université de

114

The King-Kong Effects: Improving sensation of walking in VR with visual and tactile vibrations at each step  

Microsoft Academic Search

In this paper we present novel sensory feedbacks named King-Kong Effects to enhance the sensation of walking in virtual environments. King Kong Effects are inspired by special effects in movies in which the incoming of a gigantic creature is suggested by adding visual vibrations\\/pulses to the camera at each of its steps. In this paper, we propose to add artificial

Leo Terziman; Maud Marchal; Franck Multon; Bruno Arnaldi; Anatole Lecuyer

2012-01-01

115

Gazl ecek Sektr ve Gazoz Pazar ndaki KOB ler in Ni Pazarlamas na Bir rnek  

Microsoft Academic Search

Small and Medium-Sized Enterprises (SME) rarely find themselves in distress like the ones do in carbonated beverages market. The reasons for that may be the market dominance of a few gigantic firms in terms of control and market share, and the disability of resource-limited SMEs in responding to market needs due to the competitive structure of the industry. In this

Canan AY; Sinan NARDALI; Burak KARTAL

116

Introduction The Sun is a mass of incandescent gas  

E-print Network

and isotopic compositions, we can analyze actual pieces of stars in the laboratory, using mass spectrometersChapter 1 Introduction The Sun is a mass of incandescent gas A gigantic nuclear furnace Building hydrogen into helium At a temperature of millions of degrees They Might be Giants We are stardust Joni

Nittler, Larry R.

117

Rock "n" Roll Presidents on Mount Rushmore. Second Grade Activity. Schools of California Online Resources for Education (SCORE): Connecting California's Classrooms to the World.  

ERIC Educational Resources Information Center

A historian, Doane Robinson, and a sculptor, Gutzon Borglum, worked together to build a gigantic monument in South Dakota that honored four of the greatest U.S. presidents: George Washington, Abraham Lincoln, Theodore Roosevelt, and Thomas Jefferson. Robinson and Borglum wanted the monument to represent U.S. ideals. To celebrate the anniversary of

Sawyer, Debbie

118

Molecular Clouds, Star Formation and Galactic Structure.  

ERIC Educational Resources Information Center

Radio observations show that the gigantic clouds of molecules where stars are born are distributed in various ways in spiral galaxies, perhaps accounting for the variation in their optical appearance. Research studies and findings in this area are reported and discussed. (JN)

Scoville, Nick; Young, Judith S.

1984-01-01

119

11/26/12 4:27 PMCoal mine fossils: Paleontology shows us past climate change. -Slate Magazine Page 1 of 4http://www.slate.com/articles/health_and_science/coal/2012/11/coal_mine_fossils_paleontology_shows_us_past_climate_change.single.html  

E-print Network

, the largest snake to ever live, devouring a crocodile, on display at Grand Central Terminal in New York. Photo by Michael Loccisano/Getty Images. Mining for Gigantic Fossil Snakes The most valuable thing in a coal mine the fossil record of an entire tropical ecosystem as it existed 58 million years ago. By looking

Montañez, Isabel Patricia

120

ORIGINAL PAPER Hans Egger Ewald Bru ckl  

E-print Network

of ash material, which makes it one of the largest basaltic pyroclastic eruptions in geological his- toryORIGINAL PAPER Hans Egger ? Ewald Bru¨ ckl Gigantic volcanic eruptions and climatic change calculated the total eruption volume of this series as 21,000 km3 , which occurred in 600,000 years. The most

Brückl, Ewald

121

The Story of Semco: The Company that Humanized Work  

ERIC Educational Resources Information Center

This article examines and analyzes Semco, a company that changed the way it viewed and treated its workers for the better. It is the contention of Semco's CEO, that at most large corporations "everyone is part of a gigantic, impersonal machine, and it is impossible to feel motivated when you feel you are just another cog. Human nature demands

Vanderburg, David

2004-01-01

122

Menander's Theophoroumene between Greece and Rome  

Microsoft Academic Search

This article identifies and discusses a fragmentary fresco (Ufficio Scavi di Pompei 20545), which is of interest to scholars of both ancient drama and music. This panel, which reproduces an excerpt of the climactic scene of Menander's Theophoroumene, provides new and early evidence for the process of manipulation of the Early-Hellenistic archetype of this illustration. In particular, the gigantic pipe

Sebastiana Nervegna

2010-01-01

123

Menander's Theophoroumene between Greece and Rome  

Microsoft Academic Search

:This article identifies and discusses a fragmentary fresco (Ufficio Scavi di Pompei 20545), which is of interest to scholars of both ancient drama and music. This panel, which reproduces an excerpt of the climactic scene of Menander's Theophoroumene, provides new and early evidence for the process of manipulation of the Early-Hellenistic archetype of this illustration. In particular, the gigantic pipe

Sebastiana Nervegna

2010-01-01

124

The Ink of the Cuttlefish  

Microsoft Academic Search

WITH reference to the interesting account in NATURE, vol. ix. p. 332, of a gigantic Cephalopod captured in American waters, and of a still larger one, which attacked the boat belonging to some fishermen near Newfoundland, by twining its arms round the vessel, and which, having had two of those arms cut off by the fishermen, moved off, ``ejecting a

W. R. Hughes

1874-01-01

125

The Sumatran earthquake impact on Earth Rotation from satellite gravimetric measurements  

E-print Network

the gigantic Sumatra Earthquake of December 26, 2004. Our approach is based upon the geoid height variations shift contradicts that one derived from seismic model. Keywords : Earth rotation Sumatra Earthquake on 2004 December 26 at 00h 58min 51s UTC, about 200 km from the western coast of northern Sumatra

126

Riding the Dinosaur Wave.  

ERIC Educational Resources Information Center

As his geology students' specialized knowledge of the Mesozoic era increased, a high school teacher realized he needed a way to showcase their work. The Mesozoic Resource Center's biggest hit was a walk-through diorama showing how life might have been during each of three Mesozoic periods. Highlights included two gigantic student-built dinosaur

Girod, Mark

1998-01-01

127

Gender, Education and Child Labour: A Sociological Perspective  

ERIC Educational Resources Information Center

In all societies, boys and girls are assigned different societal roles and experience different perspectives of life as a result of their being male or female. Such differences have a gigantic impact on their lives. The importance of gender perspective is very important in understanding the convolution of child labour. Gender, as opposed to sex,

Bhat, Bilal Ahmad

2010-01-01

128

Coral Reefs: A Gallery Program, Grades 7-12.  

ERIC Educational Resources Information Center

Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy

National Aquarium in Baltimore, MD. Dept. of Education.

129

The Experience of External Studies. Occasional Papers No. 4.  

ERIC Educational Resources Information Center

This document brings together four invited papers by external students who have graduated from Riverina College: (1) "The External Student: One Profile" (Christine Del Gigante); (2) "Managing Life as a External Student" (Robert Landow); (3) "The Computerised Student" (John Chant); and (4) "The Right to Study" (Coral Davidson). Topics covered

Riverina Coll. of Advanced Education, Wagga Wagga, New South Wales (Australia).

130

The evolution of planktivory in sharks and rays. Supervisor: Dr Charlie Underwood (Birkbeck Earth Sciences)  

E-print Network

The evolution of planktivory in sharks and rays. Supervisor: Dr Charlie Underwood (Birkbeck Earth Sciences) Large to gigantic plankton feeding sharks and rays are found throughout the world's oceans with subordinate chondrichthyans (sharks and rays). In contrast, planktivory has evolved several times amongst

Crawford, Ian

131

J. Parasitol., 89(3), 2003, pp. 458463 American Society of Parasitologists 2003  

E-print Network

. To decouple size variation from many correlated effects of age and to test for parasite-induced gigantism, laboratory experiments standardized snail size­age-at-infection, exposure history, inoculating dose, and duration of infection. The positive relationship between size and prevalence was eliminated

Graham, Andrea L.

132

THE PRINCETON FIELD GUIDE TO  

E-print Network

. Introduction History of Discovery and Research 00 What Is a Dinosaur? 00 Dating Dinosaurs 00 The Evolution, Feathers, and Color 00 Respiration and Circulation 00 Digestive Tracts 00 Senses 00 Vocalization 00 Disease Energetics 00 Gigantism 00 Mesozoic Oxygen 00 The Evolution--and Loss--of Avian Flight 00 Dinosaur Safari 00

Landweber, Laura

133

Mathematics in Use: Suspension Bridges.  

ERIC Educational Resources Information Center

Reviews the mathematics utilized in the design and construction of suspension bridges, in general, then illustrates these mathematical concepts by examining data associated with the Mackinac Bridge, which connects the two peninsulas of Michigan. Emphasizes the strong interest factor these gigantic structures have for students by attaching a sense

Ginther, John L.

1992-01-01

134

Landslide disaster avoidance: learning from Leyte  

Microsoft Academic Search

On 17 February 2006 a gigantic rockslide triggered a debris avalanche that overran the barangay Guinsaugon, St. Bernard in Southern Leyte Province, Philippines, burying 154 victims, with 990 missing including 246 school children. Even with satellite imagery, GIS-based landslide susceptibility modelling and real-time meteorological and seismic data analysis, scientific prediction of every potentially fatal landslide is not possible in most

T. R. Davies

2006-01-01

135

The Quaternary vegetation and landscape evolution of Novaya Zemlya in the light of palynological records  

Microsoft Academic Search

The paper presents the results of paleoenvironmental (pollen) investigations of Novaya Zemlya throughout all the Quaternary, including Eopleistocene, Pleistocene and Holocene. Clear evidence of continuity between the modern flora and paleofloras confirms the lack of sharp and continuous interruptions in the vegetation development in high latitudes as well as the absence of gigantic ice sheets in the Eastern Arctic. During

Leonid Serebryanny; Eugeniya Malyasova

1998-01-01

136

Man, Controller of the Universe  

NASA Astrophysics Data System (ADS)

The Man, Controller of the Universe painted by the renowned Mexican artist Diego Rivera in the gigantic mural of the Palace of Fine Arts in Mexico City is overlooked by a telescope. We acknowledge this instrument as the Plaskett Telescope at the Dominion Astrophysical Observatory in Victoria, Canada.

Olowin, R. P.

2011-06-01

137

New pelomedusoid turtles from the late Palaeocene Cerrejn Formation of Colombia and their implications for phylogeny and body size evolution  

Microsoft Academic Search

Pelomedusoides comprises five moderate-sized extant genera with an entirely Southern Hemisphere distribution, but the fossil record of these turtles reveals a great diversity of extinct taxa, documents several instances of gigantism, and indicates a complex palaeobiogeographical history for the clade. Here, we report new pelomedusoid turtle fossils from the late Palaeocene Cerrejn Formation of Colombia. The most complete of these

Edwin A. Cadena; Daniel T. Ksepka; Carlos A. Jaramillo; Jonathan I. Bloch

2012-01-01

138

Steal Nerves -a medical mystery thriller -  

E-print Network

. You can match me? You can match me? Jesus. Give me a chance to prove it. You'd just is a bit of a pr* *oblem: it is a good plan, but it does require some trauma. And of the right sort in an unintended halo. The cinereous hair upon the gigantic head is a good deal mo* *re plausible than it's real

Bringsjord, Selmer

139

Computer-Guided, Population-Based Screening System for Growth Disorders (CrescNet) and On-Line Generation of Normative Data for Growth and Development  

Microsoft Academic Search

The mean age at which the diagnosis of growth disorders such as Turners syndrome, growth hormone (GH) deficiency or true GH-dependent gigantism is established is still rather late in many countries around the world. In addition, the question of secular trends in a given population and the rate at which childhood obesity is increasing in industrialized countries make it mandatory

W. Kiess; R. Gausche; A. Keller; J. Burmeister; H. Willgerodt; E. Keller

2001-01-01

140

Renal cell carcinoma in a patient with Beckwith-Wiedemann syndrome  

Microsoft Academic Search

We report the case of a patient with Beckwith-Wiedemann syndrome (BWS) who developed renal cell carcinoma (RCC). At birth, this patient presented with macroglossia, diastasis recti, mild gigantism, hepatomegaly and hypoglycemia, and the diagnosis of BWS was made. At 22 months, an intrapelvic rhabdomyosarcoma was detected and resected. At 37 months, computed tomography (CT) demonstrated a small mass with high

T. Yamaguchi; T. Fukuda; M. Uetani; K. Hayashi; N. Kurosaki; H. Maeda; T. Matsumoto; H. Miyake

1996-01-01

141

The Early History of Automated Dedicated to the memory of Hao Wang  

E-print Network

Chapter 1 The Early History of Automated Deduction Dedicated to the memory of Hao Wang Martin Davis Publishers B.V. All rights reserved #12; #12; The Early History of Automated Deduction 5 With the ready the rules of inference in all possible directions was sure to lead to a gigantic combinatorial explosion

Mohri, Mehryar

142

\\  

Microsoft Academic Search

Amazon Rainforest is endowed with a wide range of natural resources. Ancestral com- munities depended on the forest for their livelihoods and displayed a good repertoire of imaginative forms of resource management, adapted to climate extremes in temperature and rainfall. From the midst of the 1900's, however, the Amazon Rainforest became a labour safety valve, perceived as a gigantic reserve

Isabel Maria Madaleno

2008-01-01

143

Neural fibrolipoma of the foot.  

PubMed

Neural fibrolipoma is a benign tumor comprised of hypertrophied fibrofatty tissue with intermixed nerve tissue. We present the case of a neural fibrolipoma of the foot that underwent above-ankle amputation and review the characteristic features of this unique form of localized gigantism. PMID:12886159

Ly, Justin Q; Bui-Mansfield, Liem T; SanDiego, Jerry W; Beaman, Nancy A; Ficke, James R

2003-01-01

144

Kuba, Kids, and an Airport: How One Community Celebrates Art and Imagination.  

ERIC Educational Resources Information Center

Describes "The Kuba Project: An Exhibit of Gigantic Proportions" in which high school students learned about the Kuba people of the Congo and created monumental ceramic works of art. Explains that the student artwork was exhibited at the Phoenix Sky Harbor International Airport in Phoenix (Arizona) as part of the Sky Harbor Art Program. (CMK)

Eller, Lennee; Grigsby, Eugene, Jr.

2003-01-01

145

Latinas in College: "Contra Viento y Marea" (Against Winds and Tides)  

ERIC Educational Resources Information Center

With the rapid demographic changes in the United States in general and in the state of Kansas in particular, educational institutions are challenged with a gigantic task: to educate a very diverse population with multifaceted linguistic and cultural backgrounds, needs, and challenges that is growing exponentially. To illustrate this demographic

Diaz De Sabates, Gabriela

2007-01-01

146

On heavy dustfall observed with explosive sandstorms in Chongwon-Chongju, Korea in 2002  

Microsoft Academic Search

Continuous monitoring of sand and duststorms (SD) and associated heavy dustfall (HD) is made in Korea. In particular, accurate measurements of atmospheric dust loadings have been carried out with the tapered element oscillating microbalance method, and satellite detection of dust clouds is included in the analysis. In 2002, we found three gigantic dust clouds that moved over the Korean Peninsula,

Yong-seung Chung; Hak-sung Kim; Jugder Dulama; Joyce Harris

2003-01-01

147

Air-density-dependent model for analysis of air heating associated with streamers, leaders, and transient luminous events  

Microsoft Academic Search

Blue and gigantic jets are transient luminous events in the middle atmosphere that form when conventional lightning leaders escape upward from the thundercloud. The conditions in the Earth's atmosphere (i.e., air density, reduced electric field, etc.) leading to conversion of hot leader channels driven by thermal ionization near cloud tops to nonthermal streamer forms observed at higher altitudes are not

Jeremy A. Riousset; Victor P. Pasko; Anne Bourdon

2010-01-01

148

The proteus syndrome  

Microsoft Academic Search

Four boys are described with partial gigantism of the hands and\\/or feet, pigmented nevi, hemihypertrophy, subcutaneous hamartomatous tumors and macrocephaly, and\\/or other skull anomalies. Three of these patients showed an accelerated growth in their first years of life. Two suffered from cystiform pulmonary abnormalities. The children showed normal mental development with the exception of one with traumatic brain damage. Parental

H.-R. Wiedemann; G. R. Burgio; P. Aldenhoff; J. Kunze; H. J. Kaufmann; E. Schirg

1983-01-01

149

Using the Structure of HTML Documents to Improve Retrieval  

Microsoft Academic Search

The World Wide Web (WWW) is a gigantic information resource, which is growing daily. As more and more data are added to the WWW, it is becoming increasingly difficult to effectively locate useful information from this environment. In this paper, we propose a method for making use of the structures and hyperlinks of HTML documents to improve the effectiveness of

Michal Cutler; Yungming Shih; Weiyi Meng

1997-01-01

150

Automated GUI Test Coverage Analysis Using GA  

Microsoft Academic Search

A Graphical User Interface (GUI) is a graphical front-end to a software system. A GUI contains graphical objects with certain distinct values which can be used to determine the state of the GUI at any time. Software developing organizations always desire to test the software thoroughly to get maximum confidence about its quality. But this requires gigantic effort to test

Abdul Rauf; Sajid Anwar; M. Arfan Jaffer; Arshad Ali Shahid

2010-01-01

151

Developments in South American Squid Fisheries  

E-print Network

Developments in South American Squid Fisheries Marcelo Juanico is with the Museo Nacional deI., 1975). Up to now squids have been only a minor and scarce resource in the Chilean fisheries, recorded gigante," Humboldt squid) with a man- tle length of up to I m and a weight of 35 kg. It is fished mainly

152

Bacteria can sprout webs of electrical wiring that transform the soil into a geological  

E-print Network

that this is what allows electrons to move through the system. He thinks the microbes probably shed electrons b17305; 2007). The wires allow the bacteria to get rid of electrons generated during metabolism, transporting them to distant `electron dumps'. The earth beneath our feet might act as a gigantic circuit built

Lovley, Derek

153

Creating Efficiencies in Last Mile Delivery through Workforce  

E-print Network

What opportunities are there beyond reducing cost? · Researchers are exploring customer service issues UNIVERSITY CHICAGO QUINLAN SCHOOL OF BUSINESS 44 Does workforce management matter and what does it cost. As Hugh Gigante of Appian notes, `If we tell a customer that it costs them $100 a day to keep the same

Bustamante, Fabián E.

154

On the negative selection and the danger theory inspired security for heterogeneous networks  

Microsoft Academic Search

Aspirations for a boundless communication paradigm for future generation networks have changed the conventional way of looking at network security. With such a vision, security techniques should not only be securing local end-users but also be protecting entire networks from malicious adversaries. Unfortunately, providing security protection for such gigantic networks is a very challenging task. Based on the analogous relationships

Fazirulhisyam Hashim; KUMUDU S. MUNASINGHE; Abbas Jamalipour

2012-01-01

155

Scientific Research  

Microsoft Academic Search

DURING the last century every branch of scientific research has undergone gigantic strides towards perfection Great credit is due, ay, even in greater proportions than is given, to those talented minds, who, although on every hand impeded by obstacles, have successfully overcome every difficulty, and solved problems which excite the wonder and admiration of the universe. Within the limits in

C. H. W. Biggs

1870-01-01

156

Methods of Mathematical and Computational Physics for Industry, Science, and Technology  

Microsoft Academic Search

Many industrial problems provide scientists with important and challenging problems that need to be solved today rather than tomorrow. The key role of mathematical physics, modelling, and computational methodologies in addressing such problems continues to increase. Science has never been exogenous to applied research. Gigantic ships and steam engines, repeating catapult of Dionysius and the Antikythera `computer' invented around 80BC

Roderick V N Melnik; Frands Voss

2006-01-01

157

Global distributions and occurrence rates of transient luminous events Alfred B. Chen,1,2  

E-print Network

Global distributions and occurrence rates of transient luminous events Alfred B. Chen,1,2 Cheng report the global transient luminous event (TLE) distributions and rates based on the Imager of Sprites winter. From July 2004 to June 2007, ISUAL recorded 5,434 elves, 633 sprites, 657 halos, and 13 gigantic

California at Berkeley, University of

158

Science 101: If an insect grows to human size, will it have superhuman strength?  

NSDL National Science Digital Library

If insects grew to gigantic proportions, could they take over the world with their super-strength? To find and understand the answer, you have to understand a bit of basic geometry and how it applies to all kinds of organisms of different sizes.

Robertson, William C.

2006-04-01

159

Search Encyclopedia Home | About Us | Fun & Travel | Study Aids | More Links | Contact Us | Sponsors Advanced Search  

E-print Network

. It is a 215-foot addition to the bleachers, which becomes, in about 12 seconds, a 250-ton pile of twisted the 140-high bleachers fall to the ground and become a gigantic mass of twisted metal. Mike Lude stated he/18/2007http://www.historylink.org/essays/output.cfm?file_id=2947 #12;like having a new offspring and having

Sniadecki, Nathan J.

160

A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum  

Microsoft Academic Search

BackgroundThe origin of sauropod dinosaurs is one of the major landmarks of dinosaur evolution but is still poorly understood. This drastic transformation involved major skeletal modifications, including a shift from the small and gracile condition of primitive sauropodomorphs to the gigantic and quadrupedal condition of sauropods. Recent findings in the Late TriassicEarly Jurassic of Gondwana provide critical evidence to understand

Diego Pol; Alberto Garrido; Ignacio A. Cerda; Andrew Allen Farke

2011-01-01

161

The Pleistocene serpent Wonambi and the early evolution of snakes  

Microsoft Academic Search

The Madtsoiidae were medium sized to gigantic snakes with a fossil record extending from the mid-Cretaceous to the Pleistocene, and spanning Europe, Africa, Madagascar, South America and Australia. This widely distributed group survived for about 90 million years (70% of known ophidian history), and potentially provides important insights into the origin and early evolution of snakes. However, madtsoiids are known

John D. Scanlon; Michael S. Y. Lee

2000-01-01

162

J. Zoo/., Lond (2000) 251, 369-375 2000 The Zoological Society of London Printed in the United Kingdom The relationship of neonate mass and incubation temperature  

E-print Network

of animals, ectothermic and endothermic, invertebrate and vertebrate, microscopic and gigantic. We begin) and endotherms (birds and mammals) in terms of degree-days. The similar nature of these relationships allows us either as a function of temperature (as with ectotherms) or size (as with endotherms), with differences

Gillooly, Jamie

163

DNA, RNA , and protein  

NSDL National Science Digital Library

Have you ever wondered why you look like your mother while your brother looks like your grandfather? Consult life's gigantic book of information! This resource contains an illustrated interactive explanation of RNA, DNA, and proteins. This resource is appropriate for all users as it provides useful background information to enhance STEM teaching and learning for all. Copyright 2005 EDC

E-Museum, Nobel

2001-01-01

164

636 nature physics | VOL 6 | SEPTEMBER 2010 | www.nature.com/naturephysics research highlights  

E-print Network

Collider, the Compact Muon Solenoid (CMS) is set to make important discoveries at the frontiers of particle gigantic black holes in galaxies far from our own, and it is unlikely that nuclei could have travelled through the galaxy reproduces the observed effect. The model suggests that it is the more effective

Loss, Daniel

165

Urano y sus dos satlites irregulares recientemente descubiertos  

NASA Astrophysics Data System (ADS)

Hasta hace poco tiempo, Urano era el nico de los Planetas Gigantes que no posea satlites irregulares. Esto lo diferenciaba del resto de los planetas Gigantes, al igual que la peculiar oblicuidad de su eje de spin. La gran inclinacin de su eje de rotacin se debe probablemente a una colisin que sufri el planeta con otro embrin planetario al final del proceso de formacin. Esta colisin habra desligado satlites exteriores preexistentes del planeta. Recientemente se han descubierto dos satlites irregulares de Urano, lo que introduce algunas nuevas cotas y condiciones en el escenario de la "Hiptesis de la Gran Colisin" . Los satlites irregulares de Urano tuvieron que ser capturados en una etapa posterior a la del escenario de la Gran Colisin, de no ser as, hubieran sido eyectados del sistema por el impulso impartido con ese gran impacto. En este trabajo, se discuten los posibles mecanismos de captura de los satlites irregulares y se presenta un nuevo posible mecanismo para dicha captura.

Parisi, M. G.; Brunini, A.

166

Micropulsos  

NASA Astrophysics Data System (ADS)

Existen dos mecanismos posibles de producir en las estrellas, los pulsos trmicos. Uno de ellos ocurre cuando en el interior estelar hay ms de una capa, las cuales son fuente de energa nuclear, con diferentes composiciones. Cuando se aproximan entre s, y si estas tienen un rango muy diferente de temperatura para la quema de los ncleos, pueden disparar un flash de liberacin de energa. Este es el caso de los pulsos trmicos en la rama gigante asinttica (AGB). El otro mecanismo ocurre cuando en el interior estelar hay una capa lo suficientemente delgada, la cual se vuelve trmicamente inestable y es capaz de disparar una corrida trmica, este es el caso de los micropulsos en la rama gigante (GB). Se muestran los resultados durante los micropulsos, para el rango de masas en el cual estos ocurren (alrededor de las 3 M?).

Panei, J. A.; Benvenuto, O. G.

167

Transcription of the dystrophin gene in human muscle and non-muscle tissues  

Microsoft Academic Search

The gene that is defective in patients with Duchenne and Becker muscular dystrophy consists of about 60 short exons scattered along a gigantic DNA region that spans some 2 megabase pairs1,2. The encoded protein, dystrophin, was recently characterized as a component of muscle intracellular membranes of low abundance3,4. The dystrophin messenger RNA is difficult to study in both normal and

Jamel Chelly; Jean-Claude Kaplan; Pascal Maire; Sophie Gautron; Axel Kahn

1988-01-01

168

Women Workers of France  

Microsoft Academic Search

There is more than a sentimental side to the story of how the women of Franceand for that matter the women of every nation engaged in the gigantic conflicthave enlisted their services in the numerous industrial and civic activities heretofore engaged in by men only. There is involved the all-important question of labor readjustment after the war. And this becomes

Martin Wells

1916-01-01

169

An Atypical Case of Pityriasis Rosea Gigantea after Influenza Vaccination  

PubMed Central

Pityriasis rosea is a common erythematosquamous eruption, typically presenting along the cleavage lines of the skin. A wide spectrum of atypical manifestations may challenge even the most experienced physician. Here we report a rare case of a suberythrodermic pityriasis rosea with gigantic plaques after an influenza vaccination, and we discuss the possible triggers of atypical manifestations of such a common dermatological disease in the setting of an altered immunity. PMID:24847250

Papakostas, Dimitrios; Stavropoulos, Panagiotis G.; Papafragkaki, Dafni; Grigoraki, Ekaterini; Avgerinou, Georgia; Antoniou, Christina

2014-01-01

170

Promises and challenges in solid-state lighting  

Microsoft Academic Search

Lighting technologies based on semiconductor light-emitting diodes (LEDs) offer unprecedented promises that include three major benefits: (i) Gigantic energy savings enabled by efficient conversion of electrical energy to optical energy; (ii) Substantial positive contributions to sustainability through reduced emissions of global-warming gases, acid-rain gases, and toxic substances such as mercury; and (iii) The creation of new paradigms in lighting driven

Fred Schubert

2010-01-01

171

Age of Carcharodon megalodon?  

Microsoft Academic Search

MAURICE Lariche1 states that the teeth of the gigantic extinct shark, Carcharodon megalodon, found on the bottom of modern oceans belong to the Pleistocene period. The report of the Challenger Expedition2 states that some shark teeth from the same station were covered with a layer of manganese dioxide-one slightly, another deeply. Among them at Station 281, depth 2,385 fathoms, South

W. Tschernezky

1959-01-01

172

A case of a giant cystic lymphangioma mimicking acute appendicitis  

PubMed Central

Cystic lymphangiomas are rare tumours that can mimic various causes of acute abdomen including appendicitis. They exhibit variations in two characteristics on presentation: they can arise from a wide range of organs including various intra-abdominal structures and they can have a wide variation in size on presentation. We report a case of a gigantic cystic lymphangioma presenting as an acute abdomen closely mimicking acute appendicitis and we conduct a review of the relevant literature. PMID:22524917

Eisawi, A; Otter, M; Asha, M; Al-Temimi, A

2012-01-01

173

Cold Nuclear Fusion Induced by Controlled Out-Diffusion of Deuterons in Palladium  

Microsoft Academic Search

A gigantic neutron burst of (1--2) 106 n\\/s has been detected from deuterated Pd plates with heterostructures set in a vacuum chamber. An explosive release of D2 gas, biaxial bending of all the samples, and excess heat evolution were also observed at the same time. It has been concluded that these phenomena are caused by the cooperative production of D

Eiichi Yamaguchi; Takashi Nishioka

1990-01-01

174

The soilair exchange characteristics of total gaseous mercury from a large-scale municipal landfill area  

Microsoft Academic Search

The cycle of mercury (Hg) from a gigantic landfill area (area ?2.72km2) was investigated by conducting micrometeorological measurements of its exchange rates across soilair boundary during the spring season of 2000. Based on this field campaign, we attempted to provide various insights into the Hg exchange processes, especially with respect to the decoupling of the mixed signatures of complex source

Ki-Hyun Kim; Min-Young Kim; Gangwoong Lee

2001-01-01

175

Damage from the Great East Japan Earthquake and Tsunami - A quick report  

Microsoft Academic Search

The Tohoku region, Northeast Japan, was hit by a gigantic earthquake which occurred in the Pacific close to Tohoku, and subsequently\\u000a by a giant tsunami. These hazards have caused huge damage on the eastern coast Japan. The earthquakes magnitude was 9.0,\\u000a the strongest ever recorded in Japan. The tsunami was also historical as its run-up height reached over 39m. As

Nobuo Mimura; Kazuya Yasuhara; Seiki Kawagoe; Hiromune Yokoki; So Kazama

2011-01-01

176

Correlation between development of the marginal basin system of the NW Pacific and uplift of the Tibet Plateau  

Microsoft Academic Search

The Java-Makassar-Sulu-Celebes Seas, South China Sea (together with the East China Sea), Japan Sea, Okhotsk Sea and Bering Sea basins, exhibit the typical geometry of dextral, transtensional basins and constitute a gigantic, linked dextral and transtensional rift system (e.g., Xu et al. 1996, 2000). The basin system resulted from a large amount (>1000 km) of northward motion of East Eurasia

J. Xu; T. K. Kelty; Z. Ben-Avraham

2010-01-01

177

Em 2053 teremos desvendado todos os mistrios do crebro? Conseguiremos conhe-  

E-print Network

dos projetos internacionais que es- tão a ser desenvolvidos em território nacional. Energia solar de cento da energia que ire mos utilizar será solar. Coisas como novos com- bustíveis, dessalinização da absor- ção de energia solar a partir dessa espécie de lupas gigantes que são os concentradores de al

Instituto de Sistemas e Robotica

178

Renal cell carcinoma in a patient with Beckwith-Wiedemann syndrome.  

PubMed

We report the case of a patient with Beckwith-Wiedemann syndrome (BWS) who developed renal cell carcinoma (RCC). At birth, this patient presented with macroglossia, diastasis recti, mild gigantism, hepatomegaly and hypoglycemia, and the diagnosis of BWS was made. At 22 months, an intrapelvic rhabdomyosarcoma was detected and resected. At 37 months, computed tomography (CT) demonstrated a small mass with high attenuation in the right kidney, which was surgically confirmed to be RCC. PMID:8657457

Yamaguchi, T; Fukuda, T; Uetani, M; Hayashi, K; Kurosaki, N; Maeda, H; Matsumoto, T; Miyake, H

1996-01-01

179

Neuropsychiatric aspects of Sotos syndrome. A review and two case illustrations  

Microsoft Academic Search

Sotos syndrome, also known as cerebral gigantism, is a rare growth disorder first described by Sotos and colleagues in 1964.\\u000a Since then, a majority of the literature pertaining to Sotos syndrome has focussed on the medical aspects of the syndrome,\\u000a while neuropsychiatric issues have been given little attention. The present article presents a review of the current knowledge\\u000a concerning neuropsychiatric

S. E. Mouridsen; M.-B. Hansen

2002-01-01

180

Crystallographic Observation of Dynamic Gas Adsorption Sites and Thermal Expansion in a Breathable Fluorous Metal?Organic Framework  

SciTech Connect

Playing accordion: Cooling a single crystal of a microporous fluorous metal-organic framework under ambient atmosphere leads to very large breathing upon gas adsorption, during which multiple N2 molecules are filled into channels and cages (see picture). While the framework exhibits remarkable positive thermal expansion under vacuum, a gigantic apparent negative thermal expansion takes place when the crystal is exposed to N2 at ambient pressure.

Yang, Chi [University of North Texas; Wang, Xiaoping [ORNL; Omary, Mohammad A [University of North Texas

2009-01-01

181

Giant idiopathic pulmonary artery aneurysm: an interesting incidental finding.  

PubMed

Idiopathic pulmonary artery aneurysm is a rare condition. This type of aneurysm can be presented with noncardiac symptoms or even asymptomatic. We report a 73-year-old man with a gigantic idiopathic pulmonary artery aneurysm which was referred to our unit for his kidney problems. During his workup we incidentally found the aneurysm by an abnormal chest-X ray and auscultation. Our further evaluations revealed a 9.8?cm aneurysm in transthoracic echocardiography. PMID:24744953

Fazlinejad, Afsoon; Vojdanparast, Mohammad; Jafarzadeh Esfehani, Reza; Moosavi, Sahar Sadat; Jalali, Parisa

2014-01-01

182

Giant Idiopathic Pulmonary Artery Aneurysm: An Interesting Incidental Finding  

PubMed Central

Idiopathic pulmonary artery aneurysm is a rare condition. This type of aneurysm can be presented with noncardiac symptoms or even asymptomatic. We report a 73-year-old man with a gigantic idiopathic pulmonary artery aneurysm which was referred to our unit for his kidney problems. During his workup we incidentally found the aneurysm by an abnormal chest-X ray and auscultation. Our further evaluations revealed a 9.8?cm aneurysm in transthoracic echocardiography. PMID:24744953

Fazlinejad, Afsoon; Vojdanparast, Mohammad; Jafarzadeh Esfehani, Reza; Moosavi, Sahar Sadat; Jalali, Parisa

2014-01-01

183

Treatment of macroglossia in Beckwith-Wiedemann syndrome.  

PubMed

A case of macroglossia caused by Beckwith Wiedemann syndrome is reported. Beckwith-Wiedemann Syndrome is an overgrowth disorder characterized by a constellation of congenital anomalies. The most common manifestations are omphalocele, macroglossia, gigantism, and visceromegaly. When the tongue reaches a huge dimension, clinical symptoms are represented by dysphagia, alterations in speech, difficulty in chewing, obstruction of the upper airways, and psychologic consequences derived from the patient's physical appearance. The authors describe the surgical strategy performed in the reported case. PMID:16633192

Clauser, Luigi; Tieghi, Riccardo; Polito, Jessica

2006-03-01

184

Taking the Long View: Panoramic Photographs 1851-1991  

NSDL National Science Digital Library

Taking the Long View contains thousands of images that are at least twice as long as they are wide, creating the impression of a panoramic view. They depict many aspects of life in the US and selected foreign countries. The collection's emphasis is on cityscapes and group portraits. Images can be browsed by subject, author, or location, or searched, and are available as large thumbnails, very large jpegs, and gigantic high resolution tifs.

1997-01-01

185

The effect of diet and reproductive maturity on the growth and reproduction of Helisoma anceps (Pulmonata) infected by Halipegus occidualis (Trematoda).  

PubMed

Inhibition of snail reproductive activity by larval trematodes often results in increased growth of the snail, termed gigantism, during which the snail is hypothesized to allocate excess energy normally used for reproduction to somatic growth. Using the planorbid snail Helisoma anceps and the hemiurid trematode Halipegus occidualis, this hypothesis was examined by raising snails on low and high quality diets under 3 infection conditions: uninfected (UNI) and infected prior to (IPR) and after (IAR) reproductive maturity. Snails exhibited gigantism as an increase in wet mass only in the IPR condition on a high quality diet; snails in the IAR condition were not significantly different in size from UNI controls. Throughout the experiment, snails raised on a high quality diet were larger than those on the low quality diet, regardless of infection status, primarily because of increased growth rates prior to the onset of reproduction. Egg production by UNI snails on the high quality diet was 20 times higher than snails on the low diet, even though diet quality only differed by a factor of 4, and infected snails (both IPR and IAR) showed significantly reduced reproductive activity compared to UNI controls. The number of cercariae shed by each snail on a daily basis was not significantly different between IPR and IAR conditions when each diet quality was examined separately; more cercariae were produced by snails raised on the high quality diet. The prevalence of infection at the end of the experiment was lowest among snails raised on the low quality diet, suggesting the diet, i.e., energy intake, influences the loss of infections. Snail mortality did not differ among the various treatment conditions. These data suggest that gigantism is dependent upon snail reproductive maturity at the time of infection and food quality, and comparison to growth rates and fecundity data from previous field studies indicates that H. anceps in the field are probably protein deprived. Gigantism does not appear to be adaptive for the snail because survival was not increased, or for the parasite because cercariae production was the same for snails exhibiting gigantism or not. These results also stress the need for caution when examining the fecundity and growth rates of both uninfected and infected snails in the laboratory, especially when comparing these data to other laboratory or field studies. PMID:9057703

Keas, B E; Esch, G W

1997-02-01

186

Animus  

E-print Network

, after the last bell, at the Wharton tomb?he tried to kiss her. He was tall and pleasingly disheveled. His skin was strangely dark for a white person, a kind of dusky yellow color. His face was far worse than hers. His hands were gigantic and hot... someone where my suitcase had gone. The man at the front desk had long blonde hair and a handsome frown. I asked him if he had seen the case. I explained that it had belonged to my mother, who is dead. He said, I know the one. He pulled it from...

Hall, Emily Edna

2008-06-18

187

Theory of magneto-optical effects in helical multiferroic materials via toroidal magnon excitation  

NASA Astrophysics Data System (ADS)

We investigate dynamical magnetoelectric effect owing to Nambu-Goldstone magnon resonance in helical multiferroic materials. Using the spin wave expansion, we analyzed magneto- and electroactive modes in the J1-J2 Heisenberg model through the spin-current mechanism. Under external magnetic field, the Nambu-Goldstone magnons accompany dynamical toroidal moments, i.e., toroidal magnons, and their resonant absorption shows anomalous features such as nonreciprocal directional dichroism and natural circular dichroism. The estimation indicates that such effects are gigantic in helical magnets.

Miyahara, S.; Furukawa, N.

2014-05-01

188

Molarization of Mandibular Second Premolar  

PubMed Central

ABSTRACT Macrodontia (megadontia, megalodontia, mac rodontism) is a rare shape anomaly that has been used to describe dental gigantism. Mandibular second premolars show an elevated variability of crown morphology, as are its eruptive potential and final position in the dental arch. To date, only eight cases of isolated macrodontia of second premolars have been reported in the literature. This case report presents clinical and radiographic findings of unusual and rare case of isolated unilateral molarization of left mandibular second premolar. How to cite this article: Mangla N, Khinda VIS, Kallar S, Brar GS. Molarization of Mandibular Second Premolar. Int J Clin Pediatr Dent 2014;7(2):137-139. PMID:25356014

Singh Khinda, Vineet Inder; Kallar, Shiminder; Singh Brar, Gurlal

2014-01-01

189

Electric-Field Control of Solitons in a Ferroelectric Organic Charge-Transfer Salt  

NASA Astrophysics Data System (ADS)

The role of solitons in transport, dielectric, and magnetic properties has been revealed for the quasi-one-dimensional organic charge-transfer salt, TTF-QBrCl3 [tetrathiafulvalene (TTF)-2-bromo-3,5,6-trichloro-p-benzoquinone (QBrCl3)]. The material was found to be ferroelectric and hence the solitons should be located at the boundary of the segments with opposite electric polarization. This feature enabled the electric-field control of soliton density and hence the clear-cut detection of soliton contributions. The gigantic dielectric response in the ferroelectric phase is ascribed to the dynamical bound and creeping motions of spinless solitons.

Kagawa, F.; Horiuchi, S.; Matsui, H.; Kumai, R.; Onose, Y.; Hasegawa, T.; Tokura, Y.

2010-06-01

190

Controls on size and occurrence of the largest sub-aerial landslide on Earth: Seymareh (Saidmarreh) landslide, Zagros fold-thrust belt, Iran  

NASA Astrophysics Data System (ADS)

Gigantic (> 1 Gm3) landslides are high-magnitude, low-frequency extremes of mass movements. They are important factors in topographic evolution and hazard in mountain regions due to their magnitude. However, few examples exist for study because of their infrequency. Consequently, controls on the location and size gigantic landslides remain poorly understood. Re-examination of the Seymareh (Saidmarreh) rock avalanche, Zagros fold-thrust belt, shows it to be the largest sub-aerial landslide on Earth (initial failure volume 38 Gm3), thus representing the upper magnitude limit for terrestrial landslides. Detailed examination of the source area (including orbital remote sensing, geotechnical investigation and structural mapping) provides new insights into controls on the size and mobility of gigantic landslides. The gigantic Early Holocene rockslide initiated on the northeast limb of Kabir Kuh, the largest anticline in the Zagros fold-thrust belt, and involved the simultaneous failure of a rock mass measuring 15 km along strike. The rockslide transformed into a rock avalanche that ran-out 19.0 km, filling two adjacent valleys and overtopping an intervening low mountain ridge. The failure involved 220 m of competent jointed limestone (Asmari Formation) underlain by 580 m of weaker mudrock-dominated units. Geologic structure, geomechanical strength and topography of the source slope strongly controlled failure initiation. Extreme landslide dimensions resulted in part from extensive uniform pre-failure stability, produced by structural and topographic features related to the large scale of the Kabir Kuh anticline. High continuity bedding planes determined the large lateral extent along strike. Bedding normal joints, the breached nature of the anticline and fluvial undercutting at the slope toe accommodated expansive lateral, headscarp and toe release, respectively, necessary for extensive failure. Geomechanically weak units at depth aided the penetration of the failure surface into the source slope while low bedding dip (ca. 19) allowed kinematic freedom of a particularly thick sequence to move downslope. Prevention of gradual rockmass removal by smaller-magnitude, more frequent denudation ensured its preservation for later simultaneous failure. The overall failure surface (11) cut across weaker beds and finally breached the Asmari carapace by break-out at the base of the source slope. Relative relief of the source slope on Kabir Kuh was modest (1350 m on average) indicating that uniform structural and topographic conditions along strike, shallow bedding dips, and the geomechnical properties of the source rock mass were more important in determining the magnitude of the landslide that forms the upper magnitude limit for subaerial landslides.

Roberts, N. J.; Evans, S. G.

2009-12-01

191

Magnetization-induced second harmonic generation in a polar ferromagnet.  

PubMed

Second harmonic generation (SHG) induced by spontaneous magnetization has been investigated for a polar ferromagnetic crystal of GaFeO3. The Kerr rotation of the second harmonic light becomes gigantic with decreasing temperature below the magnetic transition temperature (approximately =205 K), e.g., as large as 73 degrees at 100 K. The magnetic domains can be visualized by using that large nonlinear Kerr rotation. The spectrum of the magnetization-induced SHG as measured indicates the two-photon resonant electronic process on a Fe3+ ion in the crystal. PMID:14995401

Ogawa, Y; Kaneko, Y; He, J P; Yu, X Z; Arima, T; Tokura, Y

2004-01-30

192

Magnetization-Induced Second Harmonic Generation in a Polar Ferromagnet  

NASA Astrophysics Data System (ADS)

Second harmonic generation (SHG) induced by spontaneous magnetization has been investigated for a polar ferromagnetic crystal of GaFeO3. The Kerr rotation of the second harmonic light becomes gigantic with decreasing temperature below the magnetic transition temperature (?205 K), e.g., as large as 73 at 100K. The magnetic domains can be visualized by using that large nonlinear Kerr rotation. The spectrum of the magnetization-induced SHG as measured indicates the two-photon resonant electronic process on a Fe3+ ion in the crystal.

Ogawa, Y.; Kaneko, Y.; He, J. P.; Yu, X. Z.; Arima, T.; Tokura, Y.

2004-01-01

193

Black Smokers  

NSDL National Science Digital Library

This webpage contains a brief introduction to the discovery of hydrothermal systems and black smokers. Within the webpage are links to information on gigantic tube worms, polychaete worms, oceans, and extreme environments. This site also provides a list of hydrothermal systems, relevant links to organizations, laboratories and observatories, WebQuests, and other websites with further information on hydrothermal systems. As part of the Environmental Literacy Council site, this webpage also contains links to other resources with environmental content, including air climate, land, water, ecosystems, energy, food, and environment and society.

2009-07-01

194

The Final Proceedings of the DOE/NASA Solar Power Satellite Program Review  

NASA Technical Reports Server (NTRS)

The solar power satellite (SPS) concept defined as 'placing gigantic satellites in geosynchronous orbit to capture sunlight, changing the energy into an appropriate form for transmission to Earth, and introducing the energy into the electric power grid' is evaluated in terms of costs and benefits. The concept development and evaluation program is reviewed in four general areas: systems definition; environmental; societal; and comparative assessments. Specific factors addressed include: transportation, construction in space, methods of conversion of sunlight into energy, transmission to Earth, maintenance in orbit and decommissioning of satellites; environmental, political, and economic effects; and comparison of SPS to other forms of power generation, both terrestrial and in space.

1980-01-01

195

Giant Lipoma of Posterior Cervical Region  

PubMed Central

Lipomas are the slow growing soft tissue tumors of benign nature. They commonly grow on torso and extremities but may also develop in head and neck region. Rarely lipomas can grow to acquire gigantic proportions, turning into an entity termed as giant lipoma. Such lipomas are entitled to immediate attention as they have a relatively high malignant potential. We report a rare case of giant cervical lipoma in an elderly gentleman, followed by a brief discussion on diagnosis and management of the disorder. PMID:25349767

Kumar, Lovekesh; Karande, Snehal K.; Kolhe, Yuvraj

2014-01-01

196

Theoretical Study of Piezo-phototronic Nano-LEDs.  

PubMed

Two-dimensional finite-element simulation of the piezo-phototronic effect in p-n-junction-based devices is carried out for the first time. A charge channel can be induced at the p-n junction interface when strain is applied, given the n-side is a piezoelectric semiconductor and the p-type side is non-piezoelectric semiconductor. This provides the first simulated evidence supporting the previously suggested mechanism responsible for the experimentally observed gigantic change of light-emission efficiency in piezo-phototronic light-emitting devices. PMID:25205535

Liu, Ying; Niu, Simiao; Yang, Qing; Klein, Benjamin D B; Zhou, Yu Sheng; Wang, Zhong Lin

2014-11-01

197

La Thuile 2014: Theoretical premises to neutrino round table  

E-print Network

This talk, dedicated to the memory of G. Giacomelli, introduced the round table on neutrinos held in February 2014. The topics selected for the discussion are: 1) the neutrinoless double beta decay rate (interpretation in terms of light neutrinos, nuclear uncertainties); 2) the physics in the gigantic water Cherenkov detectors (proton decay, atmospheric neutrinos); 3) the study of neutrino oscillations (mass hierarchy and CP violation; other neutrino states); 4) the neutrino astronomy at low and high energies (solar, supernova, cosmic neutrinos). The importance of an active interplay between theory and experiment is highlighted.

Vissani, Francesco

2014-01-01

198

Slimeware: engineering devices with slime mold.  

PubMed

The plasmodium of the acellular slime mold Physarum polycephalum is a gigantic single cell visible to the unaided eye. The cell shows a rich spectrum of behavioral patterns in response to environmental conditions. In a series of simple experiments we demonstrate how to make computing, sensing, and actuating devices from the slime mold. We show how to program living slime mold machines by configurations of repelling and attracting gradients and demonstrate the workability of the living machines on tasks of computational geometry, logic, and arithmetic. PMID:23834592

Adamatzky, Andrew

2013-01-01

199

Probing membrane potential with nonlinear optics.  

PubMed Central

The nonlinear optical phenomenon of second harmonic generation is shown to have intrinsic sensitivity to the voltage across a biological membrane. Our results demonstrate that this second order nonlinear optical process can be used to monitor membrane voltage with excellent signal to noise and other crucial advantages. These advantages suggest extensive use of this novel approach as an important new tool in elucidating membrane potential changes in biological systems. For this first demonstration of the effect we use a chiral styryl dye which exhibits gigantic second harmonic signals. Possible mechanisms of the voltage dependence of the second harmonic signal are discussed. PMID:8218895

Bouevitch, O; Lewis, A; Pinevsky, I; Wuskell, J P; Loew, L M

1993-01-01

200

Anomalous increase of the thermal emf in epitaxial graphene on size-quantized films  

NASA Astrophysics Data System (ADS)

The thermoelectric effect in epitaxial graphene formed on the surface of a size-quantized metal film is examined in the context of a Davydov model. An approach based on the Kubo formula for the conductivity and differential thermal emf is used. It is shown that because of size quantization, near the edges of the energy levels the thermal emf of epitaxial graphene increases to gigantic values of 200 ?V/K, or almost a factor of seven greater than the emf of isolated graphene (about 30 ?V/K).

Alisultanov, Z. Z.; Mirzegasanova, N. A.

2014-05-01

201

[Tall stature: some classical syndromes].  

PubMed

We describe the findings of XYY syndrome in the setting of encountering an individual with this particular condition in the endocrinology clinic. XYY syndrome is a relatively frequent if unfamiliar condition, which is characterized by taller than average height. The extra Y chromosome may play a role in determining the height of these individuals. From this case, a differential diagnosis of tall stature is outlined, in addition to a description of the principal syndromes associated with gigantism. These primarily include Klinefelter syndrome, Marfan syndrome, androgen resistance and growth hormone excess. These various entities are described from the point of view of their symptomatology, biology, pathophysiology and therapeutic characteristics. PMID:17020230

Gusbin, N; Verloes, A; Daly, A; Beckers, A

2006-01-01

202

Large meteorite impacts: The K/T model  

NASA Technical Reports Server (NTRS)

The Cretaceous/Tertiary (K/T) boundary event represents probably the largest meteorite impact known on Earth. It is the only impact event conclusively linked to a worldwide mass extinction, a reflection of its gigantic scale and global influence. Until recently, the impact crater was not definitively located and only the distal ejecta of this impact was available for study. However, detailed investigations of this ejecta's mineralogy, geochemistry, microstratigraphy, and textures have allowed its modes of ejection and dispersal to be modeled without benefit of a source crater of known size and location.

Bohor, B. F.

1992-01-01

203

Bolometers in magnetic field: Use of NTD Ge sensors  

NASA Astrophysics Data System (ADS)

In this paper we report about the properties of Neutron Transmutation Doped (NTD) Ge in magnetic fields, focusing on the electrical conduction properties and magnetoresistance, in view of a use as sensors for bolometers in magnetic field. Samples of two different doping density were studied in magnetic field up to 5 T and temperature down to 65 mK. NTD sensors show a reproducible gigantic magnetoresistance that leads to an enhancement of their sensitivity to temperature variations. We discuss preliminarily the possible use of NTD sensors in magnetic field in particle detector developments, in particular for the KATRIN experiment.

Pasca, E.; Barucci, M.; Giuliani, A.; Olivieri, E.; Risegari, L.; Ventura, G.

2007-06-01

204

Magnetic Control of Crystal Chirality and the Existence of a Large Magneto-Optical Dichroism Effect in CuB{sub 2}O{sub 4}  

SciTech Connect

The possibility of a magnetic field controlling the chirality of matter has been debated for a long time. Here, we report the successful induction of chirality in the noncentrosymmetric canted antiferromagnet, CuB{sub 2}O{sub 4}, by application of a low intensity static magnetic field. The chirality is reversed by a 90 deg. rotation of the direction of the magnetic field. The induction of chirality by a magnetic field gives rise to a gigantic enhancement of magnetochiral dichroism in this material. The ability to switch handedness in combination with this large magnetochiral optical effect allows us to design new optical devices such as a magnetically controllable isolator.

Saito, M.; Ishikawa, K.; Taniguchi, K.; Arima, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan)

2008-09-12

205

Magnetic Control of Crystal Chirality and the Existence of a Large Magneto-Optical Dichroism Effect in CuB2O4  

NASA Astrophysics Data System (ADS)

The possibility of a magnetic field controlling the chirality of matter has been debated for a long time. Here, we report the successful induction of chirality in the noncentrosymmetric canted antiferromagnet, CuB2O4, by application of a low intensity static magnetic field. The chirality is reversed by a 90 rotation of the direction of the magnetic field. The induction of chirality by a magnetic field gives rise to a gigantic enhancement of magnetochiral dichroism in this material. The ability to switch handedness in combination with this large magnetochiral optical effect allows us to design new optical devices such as a magnetically controllable isolator.

Saito, M.; Ishikawa, K.; Taniguchi, K.; Arima, T.

2008-09-01

206

REVIEWS OF TOPICAL PROBLEMS: Birth and life of massive black holes  

NASA Astrophysics Data System (ADS)

The problems of massive black holes in galactic nuclei of different types are reviewed. The dynamical evolution of compact star systems ends naturally in a gigantic concentrated mass of gas, containing an admixture of surviving stars, that unavoidably collapses into a black hole. The subsequent joint evolution of the remnant star system with a massive black hole at the center leads either to the phenomenon of a bright central source in the nuclei of active galaxies and quasars or to the opposite case of a "dead" frozen black hole in the nucleus of a normal galaxy.

Dokuchaev, V. I.

1991-06-01

207

Geological and Hydrodynamical Examination of the Bathyal Tsunamigenic Origin of Miocene Conglomerates in Chita Peninsula, Central Japan  

NASA Astrophysics Data System (ADS)

A conglomerate appears on a rocky coast called "Tsubutega-ura Coast", located on the southwestern coast near the southern tip of the Chita Peninsula, Aichi Prefecture, central Japan. The conglomerate belongs to Miocene sedimentary rocks termed the Morozaki Group. The conglomerate includes meter-scale boulders, indicating that it was formed by an extraordinary event. In the geological investigation, we observed that the conglomerate shows alternate changes of paleocurrent directions between seaward and landward. This feature is supposed to be formed by tsunami currents. In the hydrodynamical investigation, we obtained following results: (1) the lowest limit of a current velocity to move a boulder of about 3 m in diameter would be about 2-3 m/s, (2) the speed of tsunami currents reproduced by tsunami simulation exceeds 3 m/s at 300 m in depth when the tsunami is generated by a gigantic earthquake with magnitude 9.0 or more, (3) the transport distance of the boulder would be several hundred meters to several kilometers by one tsunami event caused by a gigantic earthquake. We conclude that tsunamis best explain the formation of the conglomerate deposited in upper bathyal environments about 200-400 m depth, both from geological and hydrodynamical viewpoints.

Tachibana, Toru; Tsuji, Yoshinobu

2011-06-01

208

Chromosome evolution with naked eye: Palindromic context of the life origin  

NASA Astrophysics Data System (ADS)

Based on the representation of the DNA sequence as a two-dimensional (2D) plane walk, we consider the problem of identification and comparison of functional and structural organizations of chromosomes of different organisms. According to the characteristic design of 2D walks we identify telomere sites, palindromes of various sizes and complexity, areas of ribosomal RNA, transposons, as well as diverse satellite sequences. As an interesting result of the application of the 2D walk method, a new duplicated gigantic palindrome in the X human chromosome is detected. A schematic mechanism leading to the formation of such a duplicated palindrome is proposed. Analysis of a large number of the different genomes shows that some chromosomes (or their fragments) of various species appear as imperfect gigantic palindromes, which are disintegrated by many inversions and the mutation drift on different scales. A spread occurrence of these types of sequences in the numerous chromosomes allows us to develop a new insight of some accepted points of the genome evolution in the prebiotic phase.

Larionov, Sergei; Loskutov, Alexander; Ryadchenko, Eugeny

2008-03-01

209

The Climatic Observatory of the Karst (O.C.C.), a scientific facility within an important tourist framework  

NASA Astrophysics Data System (ADS)

The Climatic Observatory of the Karst, officially inaugurated on 2nd October, 2008, is born in the same place of the historical headquarter of the Borgo Grotta Gigante Meteorological Office, which was set up in 1966 and has been officially operating since 1st January, 1967. The meteorological facilities and the weather office are located on the premises of the visitor centre of "Grotta Gigante, which is a very popular karstic cave of Trieste, visited each year by at least 70k people. The privileged position induced the promoters of this initiative to think about an integrated meteorological multilanguages system for the visitors. This system provides in real time weather forecasts and meteorological data and, at the same time, general tourist information as well. The synergic cooperation of various Scientific Organizations, which are involved in climatic research at the Borgo Grotta Gigante Climatic Observatory of the Karst, makes possible the realization of this project: "E.Boegan Cave Commission of S.A.G. (the administrative body); ARPA-OSMER, the Friuli Venezia-Giulia Meteorological Observatory of the Regional Agency of the Environmental Protection, (which manages the automatic station, broadcasts and publishes data in real time and forecasts in the visitors waiting room); C.N.R.-I.S.M.A.R., the Marine Science Institute in Trieste of the National Research Council of Italy (which manages and maintains mechanical instruments, publishes data and carries out checks, files data and publishes reports); U.M.F.V.G., the Friuli Venezia Giulia Meteorological Union (which is involved in scientific dissemination activity and web sharing of information); the Environmental and Public Works Section and Water Service of the Friuli Venezia Giulia Region (water resources monitoring). Moreover one of the main characteristic of the Observatory, also because of didactic reasons, is to maintain the traditional mechanical-analogue part of data collection, carried out by observers, alongside the electronic sensors. This factor is essential for the continuity and the homogeneity of historical series and it distinguishes the observatory from a normal weather station. The data collected is published annually in the "Osservazioni meteoriche" magazine, a publication edited by CGEB as a supplement to the scientific journal "Atti e memorie", which is sent to various Public Authorities, Scientific Organizations, libraries and anyone who applies for it.

Colucci, R. R.; Micheletti, S.; Fabbo, R.

2009-09-01

210

Visualizing a Complete Siphoviridae Member by Single-Particle Electron Microscopy: the Structure of Lactococcal Phage TP901-1  

PubMed Central

Tailed phages are genome delivery machines exhibiting unequaled efficiency acquired over more than 3 billion years of evolution. Siphophages from the P335 and 936 families infect the Gram-positive bacterium Lactococcus lactis using receptor-binding proteins anchored to the host adsorption apparatus (baseplate). Crystallographic and electron microscopy (EM) studies have shed light on the distinct adsorption strategies used by phages of these two families, suggesting that they might also rely on different infection mechanisms. Here, we report electron microscopy reconstructions of the whole phage TP901-1 (P335 species) and propose a composite EM model of this gigantic molecular machine. Our results suggest conservation of structural proteins among tailed phages and add to the growing body of evidence pointing to a common evolutionary origin for these virions. Finally, we propose that host adsorption apparatus architectures have evolved in correlation with the nature of the receptors used during infection. PMID:23135714

Bebeacua, Cecilia; Lai, Livia; Vegge, Christina Skovgaard; Br?ndsted, Lone; van Heel, Marin

2013-01-01

211

3DScapeCS: application of three dimensional, parallel, dynamic network visualization in Cytoscape  

PubMed Central

Background The exponential growth of gigantic biological data from various sources, such as protein-protein interaction (PPI), genome sequences scaffolding, Mass spectrometry (MS) molecular networking and metabolic flux, demands an efficient way for better visualization and interpretation beyond the conventional, two-dimensional visualization tools. Results We developed a 3D Cytoscape Client/Server (3DScapeCS) plugin, which adopted Cytoscape in interpreting different types of data, and UbiGraph for three-dimensional visualization. The extra dimension is useful in accommodating, visualizing, and distinguishing large-scale networks with multiple crossed connections in five case studies. Conclusions Evaluation on several experimental data using 3DScapeCS and its special features, including multilevel graph layout, time-course data animation, and parallel visualization has proven its usefulness in visualizing complex data and help to make insightful conclusions. PMID:24225050

2013-01-01

212

Mass extinctions and cosmic collisions - A lunar test  

NASA Astrophysics Data System (ADS)

The possibility has been considered that some or all major mass extinctions in the geologic record of earth are caused by the collision of massive, cosmic objects. Thus, it has been proposed that the unusual concentration of siderophile elements in strata at which the boundary between the Cretaceous (K) and Tertiary (T) geologic time periods has been placed must represent the remnants of a gigantic meteorite. However, a large 65-m.y.-old crater which could have been the result of the impact of this meteorite is not presently known on earth. One approach to evaluate the merits of the collisional hypothesis considered is based on the study of the probability of collision between a cosmic object of a suitable size and the earth. As moon and earth were subject to the same bombardment history and the preservation of craters on the moon is much better than on earth, a consideration of the lunar cratering record may provide crucial information.

Horz, F.

213

Mechanism of enhanced optical second-harmonic generation in the conducting pyrochlore-type Pb2Ir2O7-x oxide compound.  

PubMed

The structural, electronic, and optical properties of pyrochlore-type Pb(2)Ir(2)O(6)O(0.55)('), which is a metal without spatial inversion symmetry at room temperature, were investigated. Structural analysis revealed that the structural distortion relevant to the breakdown of the inversion symmetry is dominated by the Pb-O' network but is very small in the Ir-O network. At the same time, gigantic second-harmonic generation signals were observed, which can only occur if the local environment of the Ir 5d electrons features broken inversion symmetry. First-principles electronic structure calculations reveal that the underlying mechanism for this phenomenon is the induction of the noncentrosymmetricity in the Ir 5d bands by the strong hybridization with O' 2p orbitals. Our results stimulate theoretical study of inversion-broken iridates, where exotic quantum states such as a topological insulator and Dirac semimetal are anticipated. PMID:23683242

Hirata, Yasuyuki; Nakajima, Makoto; Nomura, Yusuke; Tajima, Hiroyuki; Matsushita, Yoshitaka; Asoh, Keiko; Kiuchi, Yoko; Eguiluz, Adolfo G; Arita, Ryotaro; Suemoto, Tohru; Ohgushi, Kenya

2013-05-01

214

Acinic Cell Carcinoma of Minor Salivary Gland of the Base of Tongue That Required Reconstructive Surgery  

PubMed Central

Acinic cell carcinoma of minor salivary gland of the base of tongue is very rare. Squamous cell carcinoma is the most common tumor in the base of tongue. We present a patient with gigantic acinic cell carcinoma of the base of tongue. This patient required emergency tracheotomy before surgery, because he had dyspnea when he came to our hospital. We removed this tumor by pull-through method and performed reconstructive surgery using a rectus abdominis myocutaneous flap. It was a case that to preserved movement of the tongue and swallowing function by keeping lingual arteries and hypoglossal nerves. This case was an extremely rare case of ACC of the base of tongue that required reconstructive surgery. PMID:23304595

Wada, Kota; Watanabe, Subaru; Ando, Yuji; Seino, Yoichi; Moriyama, Hiroshi

2012-01-01

215

Lead in ancient Rome's city waters  

PubMed Central

It is now universally accepted that utilization of lead for domestic purposes and water distribution presents a major health hazard. The ancient Roman world was unaware of these risks. How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown. Lead isotopes in sediments from the harbor of Imperial Rome register the presence of a strong anthropogenic component during the beginning of the Common Era and the Early Middle Ages. They demonstrate that the lead pipes of the water distribution system increased Pb contents in drinking water of the capital city by up to two orders of magnitude over the natural background. The Pb isotope record shows that the discontinuities in the pollution of the Tiber by lead are intimately entwined with the major issues affecting Late Antique Rome and its water distribution system. PMID:24753588

Delile, Hugo; Blichert-Toft, Janne; Goiran, Jean-Philippe; Keay, Simon; Albarede, Francis

2014-01-01

216

Extrinsic spin Hall effect from first principles.  

PubMed

We present an ab initio description of the spin Hall effect in metals. Our approach is based on density functional theory in the framework of a fully relativistic Korringa-Kohn-Rostoker method and the solution of a linearized Boltzmann equation including the scattering-in term (vertex corrections). The skew scattering mechanism at substitutional impurities is considered. Spin-orbit coupling in the host as well as at the impurity atom and the influence of spin-flip processes are fully taken into account. A sign change of the spin Hall effect in Cu and Au hosts is obtained as a function of the impurity atom, and even light elements like Li can cause a strong effect. It is shown that the gigantic spin Hall effect in Au can be caused by skew scattering at C and N impurities which are typical contaminations in a vacuum chamber. PMID:20482194

Gradhand, Martin; Fedorov, Dmitry V; Zahn, Peter; Mertig, Ingrid

2010-05-01

217

MoMA: The Changing of the Avant-Garde  

NSDL National Science Digital Library

This Web exhibition from MoMA presents a history of modern utopian and visionary architecture, using architectural drawings donated to the museum by the Howard Gilman Foundation in 2000. The drawings date from the late 1950s to the 1970s. The main menu is two spheres, Megastructures (larger, public buildings and complexes) and Postmodern Roots (smaller buildings, retail and houses), from which users can select names to view particular projects. Each project consists of two to four drawings and explanatory text, with larger views of all the drawings available. An interesting example under Megastructures is Superstudio, a group of five Italian architects who, in the 1960s, created a set of purely theoretical drawing that impose gigantic, white, grid-patterned structures on natural landscapes such as rivers, ocean coastlines, and the Alps. Megastructures give way to Postmodern Roots in the 1960s, where drawings of projects by Robert Venturi, Michael Graves, James Stirling, Rem Koolhaas, and others can be seen.

2002-01-01

218

The aerodynamics of Argentavis, the world's largest flying bird from the Miocene of Argentina.  

PubMed

We calculate the flight performance of the gigantic volant bird Argentavis magnificens from the upper Miocene ( approximately 6 million years ago) of Argentina using a computer simulation model. Argentavis was probably too large (mass approximately 70 kg) to be capable of continuous flapping flight or standing takeoff under its own muscle power. Like extant condors and vultures, Argentavis would have extracted energy from the atmosphere for flight, relying on thermals present on the Argentinean pampas to provide power for soaring, and it probably used slope soaring over the windward slopes of the Andes. It was an excellent glider, with a gliding angle close to 3 degrees and a cruising speed of 67 kph. Argentavis could take off by running downhill, or by launching from a perch to pick up flight speed. Other means of takeoff remain problematic. PMID:17609382

Chatterjee, Sankar; Templin, R Jack; Campbell, Kenneth E

2007-07-24

219

Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet  

NASA Astrophysics Data System (ADS)

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a pitch of 4 ?m on a surface of GaFeO3 crystal and used the diffracted light as a probe. Optical ME modulation signal for Bragg spot of the order n=1 becomes gigantic in the photon energy 1--4 eV and reaches 1--2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than three orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead a new route for the practical use of the optical ME effect.

Kida, N.; Kaneko, Y.; He, J. P.; Matsubara, M.; Sato, H.; Arima, T.; Akoh, H.; Tokura, Y.

2006-03-01

220

Enhanced Optical Magnetoelectric Effect in a Patterned Polar Ferrimagnet  

NASA Astrophysics Data System (ADS)

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4?m on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1 4 eV and reaches 1 2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect.

Kida, N.; Kaneko, Y.; He, J. P.; Matsubara, M.; Sato, H.; Arima, T.; Akoh, H.; Tokura, Y.

2006-04-01

221

Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet.  

PubMed

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4 microm on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1-4 eV and reaches 1-2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect. PMID:16712266

Kida, N; Kaneko, Y; He, J P; Matsubara, M; Sato, H; Arima, T; Akoh, H; Tokura, Y

2006-04-28

222

Pressure variation of Rashba spin splitting toward topological transition in the polar semiconductor BiTeI  

NASA Astrophysics Data System (ADS)

BiTeI is a polar semiconductor with gigantic Rashba spin-split bands in bulk. We have investigated the effect of pressure on the electronic structure of this material via magnetotransport. Periods of Shubunikov-de Haas (SdH) oscillations originating from the spin-split outer Fermi surface and inner Fermi surface show disparate responses to pressure, while the carrier number derived from the Hall effect is unchanged with pressure. The associated parameters which characterize the spin-split band structure are strongly dependent on pressure, reflecting the pressure-induced band deformation. We find the SdH oscillations and transport response are consistent with the theoretically proposed pressure-induced band deformation leading to a topological phase transition. Our analysis suggests the critical pressure for the quantum phase transition near Pc=3.5 GPa.

Ideue, T.; Checkelsky, J. G.; Bahramy, M. S.; Murakawa, H.; Kaneko, Y.; Nagaosa, N.; Tokura, Y.

2014-10-01

223

How can you sail in outer space?  

NSDL National Science Digital Library

Can a spaceship save on fuel by sailing in space? This riddle asks students how such a feat could be accomplished. A paragraph and video clip on a clue page sum up two girls' investigation into one possible solution. The girls knew that air is absent in space, so they set out to see if a fan would move a sail in a vacuum chamber. When students select the correct answer from the riddle's three answer choices, a brief video plays that describes how sunlight can exert enough force to propel spacecraft equipped with solar sails (thin, gigantic mirrors). The video explains why this technique can work in space but not on Earth. A text version of the riddle is available.

Television, Twin C.

2004-01-01

224

Crossing the line: increasing body size in a trans-Wallacean lizard radiation (Cyrtodactylus, Gekkota).  

PubMed

The region between the Asian and Australian continental plates (Wallacea) demarcates the transition between two differentiated regional biotas. Despite this striking pattern, some terrestrial lineages have successfully traversed the marine barriers of Wallacea and subsequently diversified in newly colonized regions. The hypothesis that these dispersals between biogeographic realms are correlated with detectable shifts in evolutionary trajectory has however rarely been tested. Here, we analyse the evolution of body size in a widespread and exceptionally diverse group of gekkotan lizards (Cyrtodactylus), and show that a clade that has dispersed eastwards and radiated in the Australopapuan region appears to have significantly expanded its body size 'envelope' and repeatedly evolved gigantism. This pattern suggests that the biotic composition of the proto-Papuan Archipelago provided a permissive environment in which new colonists were released from evolutionary constraints operating to the west of Wallacea. PMID:25296929

Oliver, Paul M; Skipwith, Phillip; Lee, Michael S Y

2014-10-01

225

Chandra X-Ray Observatory Image of Cassiopeia A  

NASA Technical Reports Server (NTRS)

This is an extraordinary first image from the Chandra X-Ray Observatory (CXO), the supernova remnant Cassiopeia A, tracing the aftermath of a gigantic stellar explosion in such sturning detail that scientists can see evidence of what may be a neutron star or black hole near the center. The red, green, and blue regions in this image of the supernova remnant Cassiopeia A show where the intensity of low, medium, and high energy X-rays, respectively, is greatest. The red material on the left outer edge is enriched in iron, whereas the bright greenish white region on the low left is enriched in silicon and sulfur. In the blue region on the right edge, low and medium energy X-rays have been filtered out by a cloud of dust and gas in the remnant . The image was made with the CXO's Advanced Charged-Coupled Device (CCD) Imaging Spectrometer (ACIS). Photo credit: NASA/CXC/SAO/Rutgers/J.Hughes

1999-01-01

226

Angiomyolipoma of the Thoracic Wall: An Extremely Rare Diagnostic Challenge  

PubMed Central

Extrarenal angiomyolipoma (AML) is an extremely uncommon lesion, accounting for less than 9% of all angiomyolipomas. We present a previously unreported case of a rarely located gigantic extrarenal angiomyolipoma at the posterolateral chest wall of a 35-year-old woman. Clinically, the lesion had all the characteristics of a benign tumor, being soft in palpation, painless, and growing in size in a slow rate. Histologically, the lesion consisted of convoluted thick-walled blood vessels without an elastic layer, interlacing fascicles of smooth muscle, and mature adipose tissue, features consistent with an angiomyolipoma. The mass was surgically removed, without any postoperative complications, and the patient has an uneventful postoperative course. Signs of local recurrence have not been observed. The purpose of this brief report is to point out the necessity of including angiomyolipoma in the differential diagnosis of adipose layer lesions.

Gemenetzis, Georgios; Kostidou, Eleni; Goula, Kalliroi; Smyrniotis, Vassilios; Arkadopoulos, Nikolaos

2014-01-01

227

Clinical Manifestations and Diagnosis of Acromegaly  

PubMed Central

Acromegaly and gigantism are due to excess GH production, usually as a result of a pituitary adenoma. The incidence of acromegaly is 5 cases per million per year and the prevalence is 60 cases per million. Clinical manifestations in each patient depend on the levels of GH and IGF-I, age, tumor size, and the delay in diagnosis. Manifestations of acromegaly are varied and include acral and soft tissue overgrowth, joint pain, diabetes mellitus, hypertension, and heart and respiratory failure. Acromegaly is a disabling disease that is associated with increased morbidity and reduced life expectancy. The diagnosis is based primarily on clinical features and confirmed by measuring GH levels after oral glucose loading and the estimation of IGF-I. It has been suggested that the rate of mortality in patients with acromegaly is correlated with the degree of control of GH. Adequately treated, the relative mortality risk can be markedly reduced towards normal. PMID:22518126

Lugo, Gloria; Pena, Lara; Cordido, Fernando

2012-01-01

228

Probing the extreme wind confinement of the most magnetic O star with COS spectroscopy  

NASA Astrophysics Data System (ADS)

We propose to obtain phase-resolved UV spectroscopy of the recently discovered magnetic O star NGC 1624-2, which has the strongest magnetic field ever detected in a O-star, by an order of magnitude. We will use the strength and variability of the UV resonance line profiles to diagnose the density, velocity, and ionization structure of NGC 1624-2's enormous magnetosphere that results from entrapment of its stellar wind by its strong, nearly dipolar magnetic field. With this gigantic magnetosphere, NGC 1624-2 represents a new regime of extreme wind confinement that will constrain models of magnetized winds and their surface mass flux properties. A detailed understanding of such winds is necessary to study the rotational braking history of magnetic O-stars, which can shed new light on the fundamental origin of magnetism in massive, hot stars.

Petit, Veronique

2014-10-01

229

Assessing dinosaur growth patterns: a microscopic revolution.  

PubMed

Some of the longest standing questions in dinosaur paleontology pertain to their development. Did dinosaurs grow at slow rates similar to extant reptiles or rapidly similar to living birds and mammals? How did some forms attain gigantic proportions? Conversely, how did birds (avian dinosaurs) become miniaturized? New data on dinosaur longevity garnered from bone microstructure (i.e. osteohistology) are making it possible to assess basic life-history parameters of the dinosaurs such as growth rates and timing of developmental events. Analyses of these data in an evolutionary context are enabling the identification of developmental patterns that lead to size changes within the Dinosauria. Furthermore, this rich new database is providing inroads for studying individual and population biology. All in all, paleohistological research is proving to be the most promising avenue towards gaining a comprehensive understanding of dinosaur biology. PMID:16701457

Erickson, Gregory M

2005-12-01

230

Magnetic biasing of a ferroelectric hysteresis loop in a multiferroic orthoferrite.  

PubMed

In a multiferroic orthoferrite Dy0.7Tb0.3FeO3, which shows electric-field-(E-)driven magnetization (M) reversal due to a tight clamping between polarization (P) and M, a gigantic effect of magnetic-field (H) biasing on P-E hysteresis loops is observed in the case of rapid E sweeping. The magnitude of the bias E field can be controlled by varying the magnitude of H, and its sign can be reversed by changing the sign of H or the relative clamping direction between P and M. The origin of this unconventional biasing effect is ascribed to the difference in the Zeeman energy between the +P and -P states coupled with the M states with opposite sign. PMID:24484164

Tokunaga, Y; Taguchi, Y; Arima, T; Tokura, Y

2014-01-24

231

Zelda and company - Petrogenesis of sulfide-rich Fremdlinge and constraints on solar nebula processes  

NASA Technical Reports Server (NTRS)

A detailed petrographic and chemical study of Zelda (a gigantic sulfide-rich Fremdling from the Allende Ca-rich inclusion, CAI, Egg 6) and its contact with the host was conducted using analytical SEM and electron-microprobe techniques, and the results were compared with those obtained on other sulfide-rich and oxide-rich Fremdlinge. Strong evidence is presented that Zelda, a type-example of sulfide-rich Fremdlinge, has been formed from a preexisting Ur-Fremdling, similar by composition to Willy, by closed-system sulfidization of magnetite and metal. At least two different sulfidization mechanisms appear to have occurred in altering Fremdlinge: one producing compositionally homogeneous equigranular objects such as Zelda, the other producing compositionally and texturally heterogeneous objects.

Armstrong, John T.; Hutcheon, Ian D.; Wasserburg, G. J.

1987-01-01

232

Turnaround in cyclic cosmology.  

PubMed

It is speculated how dark energy in a brane world can help reconcile an infinitely cyclic cosmology with the second law of thermodynamics. A cyclic model is described, in which dark energy with w<-1 equation of state leads to a turnaround at a time, extremely shortly before the would-be big rip, at which both volume and entropy of our Universe decrease by a gigantic factor, while very many independent similarly small contracting universes are spawned. The entropy of our model decreases almost to zero at turnaround but increases for the remainder of the cycle by a vanishingly small amount during contraction, empty of matter, then by a large factor during inflationary expansion. PMID:17359014

Baum, Lauris; Frampton, Paul H

2007-02-16

233

Quantifying volcanic ash dispersal and impact of the Campanian Ignimbrite super-eruption  

NASA Astrophysics Data System (ADS)

We apply a novel computational approach to assess, for the first time, volcanic ash dispersal during the Campanian Ignimbrite (Italy) super-eruption providing insights into eruption dynamics and the impact of this gigantic event. The method uses a 3D time-dependent computational ash dispersion model, a set of wind fields, and more than 100 thickness measurements of the CI tephra deposit. Results reveal that the CI eruption dispersed 250-300 km3 of ash over 3.7 million km2. The injection of such a large quantity of ash (and volatiles) into the atmosphere would have caused a volcanic winter during the Heinrich Event 4, the coldest and driest climatic episode of the Last Glacial period. Fluorine-bearing leachate from the volcanic ash and acid rain would have further affected food sources and severely impacted Late Middle-Early Upper Paleolithic groups in Southern and Eastern Europe.

Costa, A.; Folch, A.; Macedonio, G.; Giaccio, B.; Isaia, R.; Smith, V. C.

2012-05-01

234

The aerodynamics of Argentavis, the world's largest flying bird from the Miocene of Argentina  

PubMed Central

We calculate the flight performance of the gigantic volant bird Argentavis magnificens from the upper Miocene (?6 million years ago) of Argentina using a computer simulation model. Argentavis was probably too large (mass ?70 kg) to be capable of continuous flapping flight or standing takeoff under its own muscle power. Like extant condors and vultures, Argentavis would have extracted energy from the atmosphere for flight, relying on thermals present on the Argentinean pampas to provide power for soaring, and it probably used slope soaring over the windward slopes of the Andes. It was an excellent glider, with a gliding angle close to 3 and a cruising speed of 67 kph. Argentavis could take off by running downhill, or by launching from a perch to pick up flight speed. Other means of takeoff remain problematic. PMID:17609382

Chatterjee, Sankar; Templin, R. Jack; Campbell, Kenneth E.

2007-01-01

235

Massive granular cell ameloblastoma with dural extension and atypical morphology.  

PubMed

Ameloblastomas are rare histologically benign, locally aggressive tumors arising from the oral ectoderm that occasionally reach a gigantic size. Giant ameloblastomas are a rarity these days with the advent of panoramic radiography in routine dental practice. Furthermore, the granular cell variant is an uncommon histological subtype of ameloblastoma where the central stellate reticulum like cells in tumor follicles is replaced by granular cells. Although granular cell ameloblastoma (GCA) is considered to be a destructive tumor with a high recurrence rate, the significance of granular cells in predicting its biologic behavior is debatable. However, we present a rare case of giant GCA of remarkable histomorphology showing extensive craniofacial involvement and dural extension that rendered a good prognosis following treatment. PMID:25395775

Raghunath, Vandana; Rath, Rachna; Kamal, Firoz; Misra, Satya Ranjan

2014-10-01

236

?Li-loaded directionally sensitive anti-neutrino detector for possible geo-neutrinographic imaging applications.  

PubMed

Despite the latent and unique benefits of imaging uranium and thorium's distribution in the earth's interior, previously proposed experimental techniques used to identify the incoming geo-neutrino's direction are not applicable to practical imaging due to the high miss-identification in a neutrino's track reconstruction. After performing experimental studies and Monte-Carlo simulations, we confirmed that a significant improvement is possible in neutrino tracking identification with a (6)Li-loaded neutrino detector. For possible imaging applications, we also explore the feasibility of producing geo-neutrinographic images of gigantic magmatic reservoirs and deep structure in the mantle. We anticipate and plan to apply these newly designed detectors to radiographic imaging of the Earth's interior, monitoring of nuclear reactors, and tracking astrophysical sources of neutrinos. PMID:24759616

Tanaka, H K M; Watanabe, H

2014-01-01

237

Massive granular cell ameloblastoma with dural extension and atypical morphology  

PubMed Central

Ameloblastomas are rare histologically benign, locally aggressive tumors arising from the oral ectoderm that occasionally reach a gigantic size. Giant ameloblastomas are a rarity these days with the advent of panoramic radiography in routine dental practice. Furthermore, the granular cell variant is an uncommon histological subtype of ameloblastoma where the central stellate reticulum like cells in tumor follicles is replaced by granular cells. Although granular cell ameloblastoma (GCA) is considered to be a destructive tumor with a high recurrence rate, the significance of granular cells in predicting its biologic behavior is debatable. However, we present a rare case of giant GCA of remarkable histomorphology showing extensive craniofacial involvement and dural extension that rendered a good prognosis following treatment.

Raghunath, Vandana; Rath, Rachna; Kamal, Firoz; Misra, Satya Ranjan

2014-01-01

238

On the fate of pumice rafts formed during the 2012 Havre submarine eruption  

PubMed Central

Pumice rafts are floating mobile accumulations of low-density pumice clasts generated by silicic volcanic eruptions. Pumice in rafts can drift for years, become waterlogged and sink, or become stranded on shorelines. Here we show that the pumice raft formed by the impressive, deep submarine eruption of the Havre caldera volcano (Southwest Pacific) in July 2012 can be mapped by satellite imagery augmented by sailing crew observations. Far from coastal interference, the eruption produced a single >400?km2 raft in 1 day, thus initiating a gigantic, high-precision, natural experiment relevant to both modern and prehistoric oceanic surface dispersal dynamics. Observed raft dispersal can be accurately reproduced by simulating drift and dispersal patterns using currents from an eddy-resolving ocean model hindcast. For future eruptions that produce potentially hazardous pumice rafts, our technique allows real-time forecasts of dispersal routes, in addition to inference of ash/pumice deposit distribution in the deep ocean. PMID:24755668

Jutzeler, Martin; Marsh, Robert; Carey, Rebecca J.; White, James D. L.; Talling, Peter J.; Karlstrom, Leif

2014-01-01

239

Dinosaur body temperatures determined from isotopic (C-?O) ordering in fossil biominerals.  

PubMed

The nature of the physiology and thermal regulation of the nonavian dinosaurs is the subject of debate. Previously, arguments have been made for both endothermic and ectothermic metabolisms on the basis of differing methodologies. We used clumped isotope thermometry to determine body temperatures from the fossilized teeth of large Jurassic sauropods. Our data indicate body temperatures of 36 to 38C, which are similar to those of most modern mammals. This temperature range is 4 to 7C lower than predicted by a model that showed scaling of dinosaur body temperature with mass, which could indicate that sauropods had mechanisms to prevent excessively high body temperatures being reached because of their gigantic size. PMID:21700837

Eagle, Robert A; Ttken, Thomas; Martin, Taylor S; Tripati, Aradhna K; Fricke, Henry C; Connely, Melissa; Cifelli, Richard L; Eiler, John M

2011-07-22

240

Petroleum, alcohol, and energy substitution in Brazil: Theoretical and empirical issues  

SciTech Connect

As in other Latin American nations, the petroleum industry has always been surrounded by controversy in Brazil. Issues related to exploration, exploitation, and import of crude have received special attention by Brazilian decision makers. In the past decade, an additional relevant issue was brought into play by the oil crisis. An import substitution program for energy was implemented by the development of alternative indigenous energy sources. Among these sources, sugarcane was viewed as a reliable renewable resource for the production of fuel alcohol and, very recently, of electricity. Brazil engaged in a gigantic program of fuel substitution, which is now facing severe problems due to the fall of petroleum prices. This study analyzes the recent energy import substitution program in Brazil, specifically concentrating on microeconomic and environmental aspects of fuel substitution.

Biller, D.

1991-01-01

241

A clinically novel AIP mutation in a patient with a very large, apparently sporadic somatotrope adenoma  

PubMed Central

Summary Heterozygous germline inactivating mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene lead to pituitary adenomas that most frequently present in the setting of familial isolated pituitary adenoma syndrome, usually as somatotropinomas and prolactinomas. More recently, they have been found in a significant percentage of young patients presenting with pituitary macroadenoma without any apparent family history. We describe the case of a 19-year-old man who presented with a gigantic somatotropinoma. His family history was negative. His peripheral DNA showed a heterozygous AIP mutation (p.I13N), while tumor tissue only had the mutated allele, showing loss of heterozygosity (LOH) and suggesting that the mutation caused the disease. Learning points AIP mutations may be observed in sporadic somatotrope adenomas occurring in young patients.LOH is a strong indicator that an AIP variant is disease causing.Somatotrope adenomas in carriers of AIP mutations are generally larger and more difficult to cure. PMID:25136448

Daly, Adrian F; Quinones-Hinojosa, Alfredo; Thiry, Albert; Beckers, Albert

2014-01-01

242

Introduction to Plasma Dynamo, Reconnection and Shocks  

SciTech Connect

In our plasma universe, most of what we can observe is composed of ionized gas, or plasma. This plasma is a conducting fluid, which advects magnetic fields when it flows. Magnetic structure occurs from the smallest planetary to the largest cosmic scales. We introduce at a basic level some interesting features of non linear magnetohydrodynamics (MHD). For example, in our plasma universe, dynamo creates magnetic fields from gravitationally driven flow energy in an electrically conducting medium, and conversely magnetic reconnection annihilates magnetic field and accelerates particles. Shocks occur when flows move faster than the local velocity (sonic or Alfven speed) for the propagation of information. Both reconnection and shocks can accelerate particles, perhaps to gigantic energies, for example as observed with 10{sup 20} eV cosmic rays.

Intrator, Thomas P. [Los Alamos National Laboratory

2012-08-30

243

Familial Dandy-Walker malformation and leukodystrophy.  

PubMed

We report the first familial cases with two different types of posterior fossa cystic malformation and a leukodystrophic-like aspect on cerebral magnetic resonance imaging (MRI). The girl and her brother had severe encephalopathy, marked hypotonia, absent deep tendon reflexes, macrocrania, gigantism, and dysmorphic face and extremities. The girl had generalized seizures. The boy had unilateral cataract and bilateral optic atrophy. The parents were first cousins, suggesting autosomal recessive transmission. MRI showed Dandy-Walker variant in the girl, with cerebellar vermis hypoplasia and expansion of the cisterna magna, which communicated with the fourth ventricle. Her brother had mega cisterna magna communicating with the fourth ventricle and a normal cerebellum. The 2 children had abnormally high signal in the supratentorial white matter. Visual and auditory evoked potentials revealed prolonged latencies. Motor and sensory conduction velocities were normal. Muscle and nerve biopsies were normal. Metabolic exploration demonstrated no abnormality. PMID:9258968

Humbertclaude, V T; Coubes, P A; Leboucq, N; Echenne, B B

1997-05-01

244

6Li-loaded directionally sensitive anti-neutrino detector for possible geo-neutrinographic imaging applications  

PubMed Central

Despite the latent and unique benefits of imaging uranium and thorium's distribution in the earth's interior, previously proposed experimental techniques used to identify the incoming geo-neutrino's direction are not applicable to practical imaging due to the high miss-identification in a neutrino's track reconstruction. After performing experimental studies and Monte-Carlo simulations, we confirmed that a significant improvement is possible in neutrino tracking identification with a 6Li-loaded neutrino detector. For possible imaging applications, we also explore the feasibility of producing geo-neutrinographic images of gigantic magmatic reservoirs and deep structure in the mantle. We anticipate and plan to apply these newly designed detectors to radiographic imaging of the Earth's interior, monitoring of nuclear reactors, and tracking astrophysical sources of neutrinos. PMID:24759616

Tanaka, H. K. M.; Watanabe, H.

2014-01-01

245

Abundncias espectroscpicas de simbiticas amarelas  

NASA Astrophysics Data System (ADS)

Este trabalho consiste no estudo de uma amostra de estrelas simbiticas amarelas cujas componentes frias apresentam tipos espectrais G ou K. Uma amostra de 20 estrelas foi usada, o que corresponde ao conjunto completo de estrelas simbiticas amarelas visveis no hemisfrio sul presentes no catlogo de Belczynski et al (2000 A&A Suppl. 146, 407). Os espectros estelares foram obtidos por observaes usando os telescpios de 1,6 m do LNA e 1,52 m do ESO e os dados fornecidos pelo satlite IUE (International Ultraviolet Explorer) e posteriormente reduzidos no IAG. Os fluxos das linhas medidas de cada espectro foram calibrados em fluxo (com as correes de avermelhamento baseados no trabalho de Pacheco e Costa 1992, A&A 257, 619), e os parmetros fsicos (temperatura e densidade eletrnica) das nebulosas que envolvem os sistemas simbiticos determinados, usando-se fluxos medidos de OIII e NII da parte visvel do espectro. Para a determinao das razes de abundncias de C/N e O/N aplicou-se o mtodo de Nussbaumer et al. (1988, A&A 198, 179). As razes de abundncias foram derivadas das linhas de emisso (NIV, CIV, OIII, NIII e CIII) dos espectros IUE. Numa ltima fase plotou-se o diagrama C/N-O/N onde comparou-se a abundncia qumica das simbiticas amarelas obtidas neste trabalho com as de gigantes normais. Os resultados mostram abundncias compatveis com aquelas derivadas para nebulosas planetrias do bojo, indicando que o material nebular originado das gigantes vermelhas de cada sistema, e no da fonte quente. (FAPESP, CNPq)

Calbo, S. R.; Costa, R. D. D.

2003-08-01

246

Earliest Example of a Giant Monitor Lizard (Varanus, Varanidae, Squamata)  

PubMed Central

Background Varanidae is a clade of tiny (<20 mm pre-caudal length [PCL]) to giant (>600 mm PCL) lizards first appearing in the Cretaceous. True monitor lizards (Varanus) are known from diagnostic remains beginning in the early Miocene (Varanus rusingensis), although extremely fragmentary remains have been suggested as indicating earlier Varanus. The paleobiogeographic history of Varanus and timing for origin of its gigantism remain uncertain. Methodology/Principal Findings A new Varanus from the Mytilini Formation (Turolian, Miocene) of Samos, Greece is described. The holotype consists of a partial skull roof, right side of a braincase, partial posterior mandible, fragment of clavicle, and parts of six vertebrae. A cladistic analysis including 83 taxa coded for 5733 molecular and 489 morphological characters (71 previously unincluded) demonstrates that the new fossil is a nested member of an otherwise exclusively East Asian Varanus clade. The new species is the earliest-known giant (>600 mm PCL) terrestrial lizard. Importantly, this species co-existed with a diverse continental mammalian fauna. Conclusions/Significance The new monitor is larger (longer) than 99% of known fossil and living lizards. Varanus includes, by far, the largest limbed squamates today. The only extant non-snake squamates that approach monitors in maximum size are the glass-snake Pseudopus and the worm-lizard Amphisbaena. Mosasauroids were larger, but exclusively marine, and occurred only during the Late Cretaceous. Large, extant, non-Varanus, lizards are limbless and/or largely isolated from mammalian competitors. By contrast, our new Varanus achieved gigantism in a continental environment populated by diverse eutherian mammal competitors. PMID:22900001

Conrad, Jack L.; Balcarcel, Ana M.; Mehling, Carl M.

2012-01-01

247

Physical characteristics of TLEs inferred from ISUAL observations (Invited)  

NASA Astrophysics Data System (ADS)

ISUAL/FORMOSAT-2 is the first satellite mission for the long term survey of upper atmospheric transient luminous phenomena/events (TLEs). The payload consists of three sensor packages including an intensified CCD imager, a six-channel spectrophotometer and a dual-band array photometer. Hence ISUAL experiment could provide information to understand the spatial and the temporal evolutions of TLEs. In this presentation, we will review the important findings of the ISUAL mission in the first five years of operation; mainly on the electric field of sprites streamers [Pasko, 2004; Kuo et al., 2005; Liu et al., 2006; Adachi et al., 2006; Liu et al, 2010; Celestin and Pasko, 2010], the FUV emissions of elves [Mende et al., 2005; Chang et al., 2010], the luminous and electric properties of gigantic jets [Su et al., 2005; Kuo et al., 2009; Chou et al., 2010], and the high-altitude sprite current and the lightning continuing current [Cummer et al, 2006; Adachi et al, 2009]. ISUAL has carried out 762 nm-filtered, 557.7 nm-filtered and 427.8 nm-filtered imager campaigns, besides the regular 1PN2 emission survey. For the 762 nm-filtered imager campaign, a weak but detectable O2 Atmospheric band emission (~1 kR) was predicted based on a plasma chemistry model [Sentman et al., 2008], and the image data may have confirmed the existence of this band emission. While, no significant 557.7 nm emissions were detected from the ISUAL recorded elves. In the 427.8 nm campaign, altitudinal ionization profile of sprites was inferred. The ionization structure of elves and the leader structure of gigantic jets will also be discussed.

Kuo, C.; Chen, A. B.; Su, H.; Hsu, R.; Frey, H. U.; Mende, S. B.; Takahashi, Y.; Lee, L.

2010-12-01

248

Abundncia qumica de simbiticas na direo do bojo galctico  

NASA Astrophysics Data System (ADS)

O estudo da distribuio de metalicidades de gigantes K no Bojo indica um largo intervalo com valores entre 0.1 a 10 vezes o valor solar. As razes elementais Ca/Fe, Si/Fe, Mg/Fe so tpicas de estrelas do halo, apontando para um processo rpido de enriquecimento, via estrelas masssivas (SN's tipo II). No entanto, este cenrio no combina com os resultados derivados de nebulosas planetrias do bojo tais como os de Ratag et al. (1992, A&A,255,270), Cuisinier et al.(2000, A&A,353, 543), Escudero e Costa (2001, A&A,380, 300),que obtm abundncias anlogas s do disco. Neste cenrio, o estudo de estrelas simbiticas possibilita uma abordagem particularmente apropriada para o problema das abundncias qumicas de estrelas de massa intermediria em estgios avanados da evoluao estelar. Apresentamos aqui os resultados da determinaco das abundncias do grupo do CNO numa extensa amostra de simbiticas do bojo. Alis, com a disponibilidade de espectros no visvel determinamos tambm abundncias de Ar, Ne, S e He, fundamentais para analisar os processos de enriquecimento qumico ocorridos ao longo da evoluo estelar, bem como a evoluo qumica do meio interestelar. Com os espectros UV do satelite IUE obtivemos abundncias de C, necessrias no estudo da evoluo dos sistemas. As relaoes C/N-O/N mostram que o material nebular produto do vento da componente gigante e no dos eventos de nova que s vezes acontecem nestes sistemas, como foi mostrado por Nussbaumer et al (1988,A&A,198,179). As abundncias de Ar, S, Ne e O so compativeis com resultados de fontes no disco e bojo, seguindo o gradiente proposto por muitos autores na literatura a partir de diferentes objetos como cefeidas, nebulosas planetrias e ans G. (CAPES,FAPESP,CNPq)

Luna, G. J. M.; Costa, R. D. D.

2003-08-01

249

Atmospheric oxygen concentration controls the size history of foraminifers  

NASA Astrophysics Data System (ADS)

Body size correlates with numerous physiological traits and thus influences organism fitness. However, long-term controls on size evolution remain poorly understood because few datasets spans sufficiently long intervals. One proposed controlling factor is variation in atmospheric oxygen, which is widely argued to have influenced size evolution in numerous taxa, notably gigantism in arthropods during the late Paleozoic. In this study, we compiled a comprehensive genus- and species-level size database of foraminifers (marine protists) to enable an extensive analysis of factors influencing size evolution. Foraminifers are an ideal study group because they are present in all Phanerozoic periods and have been diverse and abundant in shallow-marine habitats since Devonian time. We observe significant correlation between foraminiferan size and atmospheric oxygen concentration in foraminifers as a whole and in half of the major subclades. Larger size is associated with higher oxygen concentrations, as predicted by simple physiological models based on changes in the ratio of surface area to volume. Because the oxygen content ocean waters is controlled in part by atmospheric pO2, we interpret the association between foraminiferan size and pO2 to result from a direct physiological effect of oxygen availability. Atmospheric oxygen concentration predicts foraminiferan size better than six other Phanerozoic time series (pCO2, sea level, number of named geological formations, ?18O, ?13C, 87Sr/86Sr), further suggesting the correlation between oxygen and size does not occur simply through some common geological cause that influences many aspects of Earth system history. These findings support the hypothesis that widespread Permo-Carboniferous gigantism was enabled by high pO2 and suggest that oxygen availability has been among the most important influences on size evolution through Phanerozoic time.

Payne, J.; Jost, A. B.; Ouyang, X.; Skotheim, J. M.; Wang, S. C.

2010-12-01

250

Dinmica y crecimiento de los granos de polvo en la nebulosa protoplanetaria  

NASA Astrophysics Data System (ADS)

En el escenario estndar de la formacin planetaria, los planetesimales (cuerpos de tamao kilomtrico) crecen a partir de granos de polvo, similares a los interestelares, embebidos en un disco gaseoso denominado nebulosa protoplanetaria. Durante esta etapa, los movimientos del gas pueden tener gran influencia en la dinmica y el crecimiento de los granos de polvo, dado que el flujo kepleriano del gas frena el movimiento de los mismos haciendo que caigan hacia el Sol, y la turbulencia inhibe la inestabilidad gravitacional de la capa de polvo. Aunque se acepta que los planetesimales fueron los elementos constituyentes de los planetas, todava se desconoce cmo se produjo la formacin de los mismos. Por esta razn, en los estudios ms recientes, existe un renovado inters por comprender mejor la evolucin de la capa de polvo inmersa en el disco gaseoso de la Nebulosa. El gas que fluye en el disco puede engendrar estructuras carentes de simetra axial, como por ejemplo ondas espirales y vrtices, a partir de gran variedad de mecanismos de excitacin e inestabilidad. En 1995, Barge y Sommeria pusieron de manifiesto que la existencia de vrtices gaseosos persistentes en la nebulosa solar tendra importantes consecuencias sobre la formacin de los planetesimales y el posterior crecimiento de los planetas gigantes. La investigacin desarrollada en esta Tesis analiza la relacin entre el polvo y el gas debida al acoplamiento por friccin dinmica entre ambos; en concreto, se estudia el efecto del flujo medio del gas sobre la dinmica de las partculas de polvo. El primer objetivo es investigar en profundidad los procesos de captura y crecimiento de los granos de polvo dentro de un vrtice y su posible relevancia en cuanto a la formacin de los planetesimales. El segundo objetivo es la exploracin de los efectos de ondas espirales propagndose en el disco gaseoso sobre la dinmica y el crecimiento de las partculas. La presencia de lneas de corriente no circulares perturba significativamente el movimiento de las partculas alrededor del Sol e incrementa su vida media en la Nebulosa. El flujo medio del gas se modela de forma simple, analizndose la dinmica y el crecimiento de las partculas mediante simulaciones numricas. Al incrementarse la vida media y la densidad superficial de las partculas slidas, los mecanismos de confinamiento derivados de la presencia de vrtices y ondas espirales actuan sobre el material slido de la Nebulosa (mediante agregacin colisional o inestabilidades gravitacionales) de manera mucho ms eficiente que la previamente considerada. Esto ofrece nuevas posibilidades para la formacin de planetesimales y ncleos de planetas gigantes, y puede explicar la formacin rpida de planetas extrasolares gigantes. Adems, esta Tesis analiza la respuesta de las partculas, en un disco protoplanetario con un radio de 100 UA en torno a una estrella de tipo solar, al campo gravitatorio derivado de la presencia de dos estrellas compaeras ligadas en una rbita relativamente elongada (300-1600 UA). Para llevar a cabo este anlisis, se han realizado una serie de simulaciones numricas de configuraciones jerrquicas coplanares utilizando un programa FORTRAN que integra directamente las ecuaciones del movimiento con el objeto de modelar la presencia de las fuerzas gravitacionales y viscosas. El disco protoplanetario masivo se encuentra en torno a una de las componentes de la binaria. La evolucin temporal del subdisco de polvo depende directamente de la naturaleza (directa o retrgrada) de la revolucin relativa de la compaera estelar, y de la temperatura y la masa del disco circunestelar.

de La Fuente Marcos, Carlos

2001-06-01

251

Body Size Evolution in Insular Speckled Rattlesnakes (Viperidae: Crotalus mitchellii)  

PubMed Central

Background Speckled rattlesnakes (Crotalus mitchellii) inhabit multiple islands off the coast of Baja California, Mexico. Two of the 14 known insular populations have been recognized as subspecies based primarily on body size divergence from putative mainland ancestral populations; however, a survey of body size variation from other islands occupied by these snakes has not been previously reported. We examined body size variation between island and mainland speckled rattlesnakes, and the relationship between body size and various island physical variables among 12 island populations. We also examined relative head size among giant, dwarfed, and mainland speckled rattlesnakes to determine whether allometric differences conformed to predictions of gape size (and indirectly body size) evolving in response to shifts in prey size. Methodology/Principal Findings Insular speckled rattlesnakes show considerable variation in body size when compared to mainland source subspecies. In addition to previously known instances of gigantism on ngel de la Guarda and dwarfism on El Muerto, various degrees of body size decrease have occurred frequently in this taxon, with dwarfed rattlesnakes occurring mostly on small, recently isolated, land-bridge islands. Regression models using the Akaike information criterion (AIC) showed that mean SVL of insular populations was most strongly correlated with island area, suggesting the influence of selection for different body size optima for islands of different size. Allometric differences in head size of giant and dwarf rattlesnakes revealed patterns consistent with shifts to larger and smaller prey, respectively. Conclusions/Significance Our data provide the first example of a clear relationship between body size and island area in a squamate reptile species; among vertebrates this pattern has been previously documented in few insular mammals. This finding suggests that selection for body size is influenced by changes in community dynamics that are related to graded differences in area over what are otherwise similar bioclimatic conditions. We hypothesize that in this system shifts to larger prey, episodic saturation and depression of primary prey density, and predator release may have led to insular gigantism, and that shifts to smaller prey and increased reproductive efficiency in the presence of intense intraspecific competition may have led to insular dwarfism. PMID:20209105

Meik, Jesse M.; Lawing, A. Michelle; Pires-daSilva, Andre

2010-01-01

252

Analysis of impulse signals with Hylaty ELF station  

NASA Astrophysics Data System (ADS)

Lighting discharges generate electromagnetic field pulses that propagate in the Earth-ionosphere waveguide. The attenuation in the ELF range is so small that the pulses originating from strong atmospheric discharges can be observed even several thousand kilometers away from the individual discharge. The recorded waveform depends on the discharge process, the Earth-ionosphere waveguide properties on the source-receiver path, and the transfer function of the receiver. If the distance from the source is known, an inverse method can be used for reconstructing the current moment waveform and the charge moment of the discharge. In order to reconstruct the source parameters from the recorded signal a reliable model of the radio wave propagation in the Earth-ionosphere waveguide as well as practical signal processing techniques are necessary. We present two methods, both based on analytical formulas. The first method allows for fast calculation of the charge moment of relatively short atmospheric discharges. It is based on peak amplitude measurement of the recorded magnetic component of the ELF EM field and it takes into account the receiver characteristics. The second method, called "inverse channel method" allows reconstructing the complete current moment waveform of strong atmospheric discharges that exhibit the continuing current phase, such as Gigantic Jets and Sprites. The method makes it possible to fully remove from the observed waveform the distortions related to the receiver's impulse response as well as the influence of the Earth-ionosphere propagation channel. Our ELF station is equipped with two magnetic antennas for Bx and By components measurement in the 0.03 to 55 Hz frequency range. ELF Data recording is carried out since 1993, with continuous data acquisition since 2005. The station features low noise level and precise timing. It is battery powered and located in the sparsely populated area, far from major electric power lines, which results in high quality signal recordings and allows for precise calculations of the charge moments of upward discharges and strong cloud-to-ground discharges originating from distant sources. The same data is used for Schumann resonance observation. We demonstrate the use of our methods based on recent recordings from the Hylaty ELF station. We include examples of GJ (Gigantic Jet) and TGF (Terrestrial Gamma-ray Flash) related discharges.

Kulak, A.; Mlynarczyk, J.; Ostrowski, M.; Kubisz, J.; Michalec, A.

2012-04-01

253

Compass roses on the Book of Navigation ( Kitab-? Bahriye): Declination data source for geomagnetic field models  

NASA Astrophysics Data System (ADS)

The Earth is surrounded by a geomagnetic field that is generated by dynamo processes in the core like a gigantic magnet. The Earth's geomagnetic field shifts with time and location. There has been a comprehensive effort for modelling the geomagnetic field of the Earth at regional and global scales by several researchers in the recent decades. The magnetic data from historical sources have a great importance in geomagnetic field modelling. The declination was the first measured geomagnetic field element with the early use of compasses for navigation. In this study the declination values estimated from compass roses drawn on the Book of Navigation ( Kitab-? Bahriye) that are georeferenced by an artificial neural network are compared to the declination values based on the geomagnetic field models CALS3K.3 and SCHA.DIF.3K. The results show that the compass roses drawn on the portolan charts of Kitab-? Bahriye can be used as declination data sources for regional or global geomagnetic field models.

Yilmaz, Ibrahim; Gullu, Mevlut; Yilmaz, Mustafa; Dereli, Mehmet A.

2010-10-01

254

Human growth hormone and prolactin secreting pituitary adenomas analyzed by in situ hybridization.  

PubMed Central

Acidophilic pituitary adenomas commonly produce growth hormone (GH) or prolactin (PRL), according to studies employing immunohistochemical and ultrastructural methods. To examine this question, in situ hybridization with oligonucleotide probes was done on routinely processed tissues received in the pathology laboratory to analyze for the presence of GH and PRL messenger RNA (mRNA) in 4 normal pituitaries, 10 prolactinomas, and 16 GH-secreting adenomas. Most acidophilic cells in normal pituitaries expressed either GH or PRL hormone and the respective mRNAs, but GH mRNA and PRL hormone were also detected in some of the same cells. Patients with a clinical diagnosis of prolactinoma had cells with only PRL mRNA in their tumors, while most (14 of 16) patients with a clinical diagnosis of acromegaly or gigantism had both GH and PRL mRNAs in their tumors. The GH adenomas varied in these studies. In situ hybridization was helpful in characterizing the adenoma from a patient with acromegaly who had immunoreactive PRL, but no immunoreactive GH in the resected tumor; in situ hybridization analysis revealed mRNAs for both GH and PRL in the same tumor cells. Our findings indicate that pituitary adenomas from patients with acromegaly commonly express PRL mRNA. It is concluded that in situ hybridization provides new information about the clinical biology and the histopathologic classification of pituitary adenomas. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:2466405

Lloyd, R. V.; Cano, M.; Chandler, W. F.; Barkan, A. L.; Horvath, E.; Kovacs, K.

1989-01-01

255

On longitudinal bone growth, short stature, and related matters: insights about cartilage physiology from the Utah paradigm.  

PubMed

Precursor cell division in growing cartilage determines human height, the lengths of the spine and limb bones, the alignment of joints, spines and limbs, and the ratio of spinal length to limb length. That division also helps to determine the sizes and shapes of joints, apophyses and epiphyses. Ideas about what controls those facts are changing. To former views, in which mainly genetic and humoral factors controlled them, the Utah paradigm of skeletal physiology adds long-overlooked biomechanical including muscular factors. These three kinds of factors would collaborate in controlling the precursor cell division that determines the above skeletal features. Problems with that control clearly cause or help to cause many clinical disorders. Examples include short stature, gigantism, premature and delayed skeletal maturation, some changes in fracture patterns associated with puberty, joint malalignments, congenital hip dysplasia, scoliosis, limb torsions, the ball-and-socket ankle, and some skeletal abnormalities in Marfan's syndrome and the osteochondrodystrophies. The physiology such things depend on has matured sufficiently to justify a review for pediatricians, endocrinologists and other clinical specialists, and many basic scientists. PMID:11393568

Frost, H M; Schnau, E

2001-05-01

256

What big eyes you have: the ecological role of giant pterygotid eurypterids.  

PubMed

Eurypterids are a group of extinct chelicerates that ranged for over 200 Myr from the Ordovician to the Permian. Gigantism is common in the group; about 50% of families include taxa over 0.8 m in length. Among these were the pterygotids (Pterygotidae), which reached lengths of over 2 m and were the largest arthropods that ever lived. They have been interpreted as highly mobile visual predators on the basis of their large size, enlarged, robust chelicerae and forward-facing compound eyes. Here, we test this interpretation by reconstructing the visual capability of Acutiramus cummingsi (Pterygotidae) and comparing it with that of the smaller Eurypterus sp. (Eurypteridae), which lacked enlarged chelicerae, and other arthropods of similar geologic age. In A. cummingsi, there is no area of lenses differentiated to provide increased visual acuity, and the interommatidial angles (IOA) do not fall within the range of high-level modern arthropod predators. Our results show that the visual acuity of A. cummingsi is poor compared with that of co-occurring Eurypterus sp. The ecological role of pterygotids may have been as predators on thin-shelled and soft-bodied prey, perhaps in low-light conditions or at night. PMID:25009243

Anderson, Ross P; McCoy, Victoria E; McNamara, Maria E; Briggs, Derek E G

2014-07-01

257

A Phororhacoid bird from the Eocene of Africa  

NASA Astrophysics Data System (ADS)

The bird fossil record is globally scarce in Africa. The early Tertiary evolution of terrestrial birds is virtually unknown in that continent. Here, we report on a femur of a large terrestrial new genus discovered from the early or early middle Eocene (between 52 and 46 Ma) of south-western Algeria. This femur shows all the morphological features of the Phororhacoidea, the so-called Terror Birds. Most of the phororhacoids were indeed large, or even gigantic, flightless predators or scavengers with no close modern analogs. It is likely that this extinct group originated in South America, where they are known from the late Paleocene to the late Pleistocene (59 to 0.01 Ma). The presence of a phororhacoid bird in Africa cannot be explained by a vicariant mechanism because these birds first appeared in South America well after the onset of the mid-Cretaceous Gondwana break up (100 million years old). Here, we propose two hypotheses to account for this occurrence, either an early dispersal of small members of this group, which were still able of a limited flight, or a transoceanic migration of flightless birds from South America to Africa during the Paleocene or earliest Eocene. Paleogeographic reconstructions of the South Atlantic Ocean suggest the existence of several islands of considerable size between South America and Africa during the early Tertiary, which could have helped a transatlantic dispersal of phororhacoids.

Mourer-Chauvir, Ccile; Tabuce, Rodolphe; Mahboubi, M'hammed; Adaci, Mohammed; Bensalah, Mustapha

2011-10-01

258

Origin of marginal basins of the NW Pacific and their plate tectonic reconstructions  

NASA Astrophysics Data System (ADS)

Geometry of basins can indicate their tectonic origin whether they are small or large. The basins of Bohai Gulf, South China Sea, East China Sea, Japan Sea, Andaman Sea, Okhotsk Sea and Bering Sea have typical geometry of dextral pull-apart. The Java, Makassar, Celebes and Sulu Seas basins together with grabens in Borneo also comprise a local dextral, transform-margin type basin system similar to the central and southern parts of the Shanxi Basin in geometry. The overall configuration of the Philippine Sea resembles a typical sinistral transpressional "pop-up" structure. These marginal basins except the Philippine Sea basin generally have similar (or compatible) rift history in the Cenozoic, but there do be some differences in the rifting history between major basins or their sub-basins due to local differences in tectonic settings. Rifting kinematics of each of these marginal basins can be explained by dextral pull-apart or transtension. These marginal basins except the Philippine Sea basin constitute a gigantic linked, dextral pull-apart basin system.

Xu, Junyuan; Ben-Avraham, Zvi; Kelty, Tom; Yu, Ho-Shing

2014-03-01

259

Transcending the replacement paradigm of solid-state lighting.  

PubMed

The field of photonics starts with the efficient generation of light. The generation of efficient yet highly controllable light can indeed be accomplished with light-emitting diodes (LEDs), which are, in principle, capable of generating white light with a 20 times greater efficiency than conventional light bulbs. Deployed on a global scale to replace conventional sources, such solid-state light sources will result in enormous benefits that, over a period of 10 years, include (1) gigantic energy savings of 1.9 x 1020 joule, (2) a very substantial reduction in global-warming CO2 emissions, (3) a strong reduction in the emission of pollutants such as acid-rain-causing SO2, mercury (Hg), and uranium (U), and (4) financial savings exceeding a trillion (10(12)) US$. These benefits can be accomplished by the "replacement paradigm" in which conventional light sources are replaced by more energy efficient, more durable, and non-toxic light sources. However, it will be shown that solid-state light sources can go beyond the replacement paradigm, by providing new capabilities including the control of spectrum, color temperature, polarization, temporal modulation, and spatial emission pattern. We will show that such future, "smart" light sources, can harness the huge potential of LEDs by offering multi-dimensional controllability that will enhance the functionality and performance of light sources in a wide range of applications. These applications include optical microscopy, imaging, display technologies, communications, networking, and transportation systems. PMID:19104616

Kim, Jong Kyu; Schubert, E Fred

2008-12-22

260

Morphogenetic Mechanisms in the Cyclic Regeneration of Hair Follicles and Deer Antlers from Stem Cells  

PubMed Central

We have made comparisons between hair follicles (HFs) and antler units (AUs)two seemingly unrelated mammalian organs. HFs are tiny and concealed within skin, whereas AUs are gigantic and grown externally for visual display. However, these two organs share some striking similarities. Both consist of permanent and cyclic/temporary components and undergo stem-cell-based organogenesis and cyclic regeneration. Stem cells of both organs reside in the permanent part and the growth centres are located in the temporary part of each respective organ. Organogenesis and regeneration of both organs depend on epithelial-mesenchymal interactions. Establishment of these interactions requires stem cells and reactive/niche cells (dermal papilla cells for HFs and epidermal cells for AUs) to be juxtaposed, which is achieved through destruction of the cyclic part to bring the reactive cells into close proximity to the respective stem cell niche. Developments of HFs and AUs are regulated by similar endocrine (particularly testosterone) and paracrine (particularly IGF1) factors. Interestingly, these two organs come to interplay during antlerogenesis. In conclusion, we believe that investigators from the fields of both HF and AU biology could greatly benefit from a comprehensive comparison between these two organs. PMID:24383056

Li, Chunyi; McMahon, Chris

2013-01-01

261

Crustal structure of Shatsky Rise from joint refraction and reflection seismic tomography  

NASA Astrophysics Data System (ADS)

Shatsky Rise in the western Pacific is one of a few gigantic oceanic plateaus in the world, with a surface area of 4.8 105~km2 (about the same size as California). In contrast to other large oceanic plateaus formed during the Cretaceous Quite Period, Shatsky Rise formed during the frequent reversals of magnetic polarity, allowing its tectonic environment to be resolved in detail. It was formed at a rapidly spreading ridge-ridge-ridge triple junction, so the effect of lithospheric lid on magma migration is expected to be minimal, thereby facilitating the petrological interpretation of its seismic structure in terms of parental mantle processes. In the summer of 2010, a seismic refraction survey combined with multichannel seismic profiling was conducted across Shatsky Rise. Twenty eight ocean-bottom seismometers were deployed along two crossing perpendicular lines, and all of the instruments were recovered successfully, yielding a large volume of high-quality wide-angle refraction and reflection data, with the source-receiver distance often exceeding 200~km. In this contribution, we present the P-wave velocity structure of the Shatsky Rise crust, which is constructed by joint refraction and reflection travel time tomography, and also discuss its implications for the origin of Shatsky Rise.

Korenaga, J.; Sager, W. W.

2011-12-01

262

Wafer-scale metasurface for total power absorption, local field enhancement and single molecule Raman spectroscopy  

NASA Astrophysics Data System (ADS)

The ability to detect molecules at low concentrations is highly desired for applications that range from basic science to healthcare. Considerable interest also exists for ultrathin materials with high optical absorption, e.g. for microbolometers and thermal emitters. Metal nanostructures present opportunities to achieve both purposes. Metal nanoparticles can generate gigantic field enhancements, sufficient for the Raman spectroscopy of single molecules. Thin layers containing metal nanostructures (``metasurfaces'') can achieve near-total power absorption at visible and near-infrared wavelengths. Thus far, however, both aims (i.e. single molecule Raman and total power absorption) have only been achieved using metal nanostructures produced by techniques (high resolution lithography or colloidal synthesis) that are complex and/or difficult to implement over large areas. Here, we demonstrate a metasurface that achieves the near-perfect absorption of visible-wavelength light and enables the Raman spectroscopy of single molecules. Our metasurface is fabricated using thin film depositions, and is of unprecedented (wafer-scale) extent.

Wang, Dongxing; Zhu, Wenqi; Best, Michael D.; Camden, Jon P.; Crozier, Kenneth B.

2013-10-01

263

Sex-specific effects of a parasite evolving in a female-biased host population  

PubMed Central

Background Males and females differ in many ways and might present different opportunities and challenges to their parasites. In the same way that parasites adapt to the most common host type, they may adapt to the characteristics of the host sex they encounter most often. To explore this hypothesis, we characterized host sex-specific effects of the parasite Pasteuria ramosa, a bacterium evolving in naturally, strongly, female-biased populations of its host Daphnia magna. Results We show that the parasite proliferates more successfully in female hosts than in male hosts, even though males and females are genetically identical. In addition, when exposure occurred when hosts expressed a sexual dimorphism, females were more infected. In both host sexes, the parasite causes a similar reduction in longevity and leads to some level of castration. However, only in females does parasite-induced castration result in the gigantism that increases the carrying capacity for the proliferating parasite. Conclusions We show that mature male and female Daphnia represent different environments and reveal one parasite-induced symptom (host castration), which leads to increased carrying capacity for parasite proliferation in female but not male hosts. We propose that parasite induced host castration is a property of parasites that evolved as an adaptation to specifically exploit female hosts. PMID:23249484

2012-01-01

264

Norwegian petroleum resources with focus on challenges and opportunities in the Barents Sea  

SciTech Connect

The Norwegian Continental Shelf can be subdivided into 3 different petroleum provinces: (1) the North Sea, (2) the Norwegian Sea including the Jan Mayen ridge, and (3) the Barents Sea including the islands of Svalbard. The majority of the fields and discoveries and most of the resources are located in the mature North Sea Basin. Significant resources are however also discovered in the Norwegian Sea and the Barents Sea. 39 fields are in production or decided to be developed while 3 fields are closed down. Approximately 70% of the discovered resources are located in these fields, of which some are gigantic in size (Statfjord, Ekofisk, Gullfaks, Oseberg, Troll and Snorre). Most of the remaining discoveries (134) are smaller in size and approximately 2/3 of the resources are gas. According to a recent study carried out by the Norwegian Petroleum Directorate the expected undiscovered Norwegian Petroleum Resources are assessed to be on the order of 3,5 billion Sm{sup 3} o.e. with a level of uncertainty ranging from 2 to 6 billion Sm{sup 3} o.e. 40% of the undiscovered petroleum resources are expected to be found as oil. These are the perspectives of the Norwegian Petroleum Resources. The resources of the Barents Sea is included in this perspective. The significance of the Barents Sea resources is not particularly important in the short-medium term perspective, but will be important in the longer perspective.

Aamodt, F.R. [Norwegian Petroleum Directorate, Stavanger (Norway). Exploration Branch

1995-12-31

265

A New Azhdarchid Pterosaur from the Late Cretaceous of the Transylvanian Basin, Romania: Implications for Azhdarchid Diversity and Distribution  

PubMed Central

We describe a new taxon of medium-sized (wing span ca. 3 m) azhdarchid pterosaur from the Upper Cretaceous Transylvanian Basin (Sebe? Formation) of Romania. This specimen is the most complete European azhdarchid yet reported, comprising a partially articulated series of vertebrae and associated forelimb bones. The new taxon is most similar to the Central Asian Azhdarcho lancicollis Nessov but possesses a suite of autapomorphies in its vertebrae that include the relative proportions of cervicals three and four and the presence of elongated prezygapophyseal pedicles. The new taxon is interesting in that it lived contemporaneously with gigantic forms, comparable in size to the famous Romanian Hatzegopteryx thambema. The presence of two distinct azhdarchid size classes in a continental depositional environment further strengthens suggestions that these pterosaurs were strongly linked to terrestrial floodplain and wooded environments. To support this discussion, we outline the geological context and taphonomy of our new specimen and place it in context with other known records for this widespread and important Late Cretaceous pterosaurian lineage. PMID:23382886

Vremir, Matyas; Kellner, Alexander W. A.; Naish, Darren; Dyke, Gareth J.

2013-01-01

266

Advances in Plastic Surgery  

PubMed Central

Recent progress in plastic surgery has been rapid and many new techniques have been developed. Reconstructive procedures have been advanced by a better understanding of the anatomy of the blood supply to skin and muscle, with the subsequent development of the use of axial flaps, musculocutaneous flaps and neurosensory flaps. Burn treatment has advanced greatly, making it possible to successfully treat larger and more complicated burns. The development of microsurgery has made possible free-flap transfer and replantation of amputated parts. Advances in surgical procedures on the hands include a realization that primary repair of lacerated tendons and nerves will give good results. Replacement joints have been developed that can be used in hands for joints destroyed by arthritis or trauma. Craniofacial surgery is a new field of endeavor in plastic surgery, involving new techniques that can be used to treat exophthalmos of Graves' disease and the facial deformities resulting from gigantism and acromegaly. Head and neck procedures have advanced, with the emphasis on immediate reconstruction using new flaps. Techniques for treating cleft lip and palate have been refined. Encouraging results have been reported in the treatment of nevus flammeus with argon lasers. In aesthetic surgical procedures, the aim is for safety and consistent long-lasting results. Improved understanding of the physiology and treatment of radionecrosis has evolved. PMID:7072237

McDonald, Harold D.; Vasconez, Luis O.

1982-01-01

267

Compressed Baryonic Matter: from Nuclei to Pulsars  

E-print Network

Our world is wonderful because of the negligible baryonic part although unknown dark matter and dark energy dominate the Universe. Those nuclei in the daily life are forbidden to fuse by compression due to the Coulomb repulse, nevertheless, it is usually unexpected in extraterrestrial extreme-environments: the gravity in a core of massive evolved star is so strong that all the other forces (including the Coulomb one) could be neglected. Compressed baryonic matter is then produced after supernova, manifesting itself as pulsar-like stars observed. The study of this compressed baryonic matter can not only be meaningful in fundamental physics (e.g., the elementary color interaction at low-energy scale, testing gravity theories, detecting nano-Hertz background gravitational waves), but has also profound implications in engineering applications (including time standard and navigation), and additionally, is focused by Chinese advanced telescopes, either terrestrial or in space. Historically, in 1930s, L. Landau speculated that dense matter at supra-nuclear density in stellar cores could be considered as gigantic nuclei (the prototype of standard model of neutron star), however, we address that the residual compact object of supernova could be of condensed matter of quark clusters. The idea that pulsars are quark-cluster stars was not ruled out during the last decade, and we are expecting to test further by future powerful facilities. (in Chinese)

Renxin Xu

2013-10-12

268

Rb-Sr, Sm-Nd, K-Ca, O, and H isotopic study of Cretaceous-Tertiary boundary sediments, Caravaca, Spain Evidence for an oceanic impact site  

NASA Astrophysics Data System (ADS)

The results of isotopic and trace-element-abundance analyses of Ir-enriched Cretaceous-Tertiary-boundary clay sediments from Caravaca, Spain, and of adjacent carbonate and marl layers, are presented. Acetic-acid and HCl leachates and residues were analyzed by isotope dilution to determine K, Rb, Sr, Sm, and Nd concentrations and Sr-87/Sr-86 and Nd-143/Nd-144 ratios. The stable isotope ratios delta-D, delta-(C-13), and delta-(0-18) were also determined. The results are presented in tables and graphs and compared with published data on the Caravaca sediments and on samples from other locations. The boundary clay is found to be distinguished from the adjacent layers by its isotopic ratios and to be of mainly terrestrial, lithospheric (deeper than 3-km) origin. Although submarine-weathering effects are evident and difficult to quantify, the degree of variation in Ni, Ir, Sr, and REE concentrations is considered too large to be attributed to postdepositional processes alone. These findings are seen as evidence for the ocean impact of a large single asteroid producing a worldwide blanket of ejecta, a large injection of water vapor into the atmosphere, and perhaps a gigantic tsunami, at the end of the Cretaceous period.

Depaolo, D. J.; Kyte, F. T.; Marshall, B. D.; O'Neil, J. R.; Smit, J.

1983-09-01

269

Wafer-scale metasurface for total power absorption, local field enhancement and single molecule Raman spectroscopy  

PubMed Central

The ability to detect molecules at low concentrations is highly desired for applications that range from basic science to healthcare. Considerable interest also exists for ultrathin materials with high optical absorption, e.g. for microbolometers and thermal emitters. Metal nanostructures present opportunities to achieve both purposes. Metal nanoparticles can generate gigantic field enhancements, sufficient for the Raman spectroscopy of single molecules. Thin layers containing metal nanostructures (metasurfaces) can achieve near-total power absorption at visible and near-infrared wavelengths. Thus far, however, both aims (i.e. single molecule Raman and total power absorption) have only been achieved using metal nanostructures produced by techniques (high resolution lithography or colloidal synthesis) that are complex and/or difficult to implement over large areas. Here, we demonstrate a metasurface that achieves the near-perfect absorption of visible-wavelength light and enables the Raman spectroscopy of single molecules. Our metasurface is fabricated using thin film depositions, and is of unprecedented (wafer-scale) extent. PMID:24091825

Wang, Dongxing; Zhu, Wenqi; Best, Michael D.; Camden, Jon P.; Crozier, Kenneth B.

2013-01-01

270

The changing pace of insular life: 5000 years of microevolution in the Orkney vole (microtus arvalis orcadensis).  

PubMed

Island evolution may be expected to involve fast initial morphological divergence followed by stasis. We tested this model using the dental phenotype of modern and ancient common voles (Microtus arvalis), introduced onto the Orkney archipelago (Scotland) from continental Europe some 5000 years ago. First, we investigated phenotypic divergence of Orkney and continental European populations and assessed climatic influences. Second, phenotypic differentiation among Orkney populations was tested against geography, time, and neutral genetic patterns. Finally, we examined evolutionary change along a time series for the Orkney Mainland. Molar gigantism and anterior-lobe hypertrophy evolved rapidly in Orkney voles following introduction, without any transitional forms detected. Founder events and adaptation appear to explain this initial rapid evolution. Idiosyncrasy in dental features among different island populations of Orkney voles is also likely the result of local founder events following Neolithic translocation around the archipelago. However, against our initial expectations, a second marked phenotypic shift occurred between the 4th and 12th centuries AD, associated with increased pastoral farming and introduction of competitors (mice and rats) and terrestrial predators (foxes and cats). These results indicate that human agency can generate a more complex pattern of morphological evolution than might be expected in island rodents. PMID:24957579

Cucchi, Thomas; Barnett, Ross; Martnkov, Natlia; Renaud, Sabrina; Renvois, Elodie; Evin, Allowen; Sheridan, Alison; Mainland, Ingrid; Wickham-Jones, Caroline; Tougard, Christelle; Qur, Jean Pierre; Pascal, Michel; Pascal, Marine; Heckel, Gerald; O'Higgins, Paul; Searle, Jeremy B; Dobney, Keith M

2014-10-01

271

Genome evolution by matrix algorithms: cellular automata approach to population genetics.  

PubMed

Mammalian genomes are replete with millions of polymorphic sites, among which those genetic variants that are colocated on the same chromosome and exist close to one another form blocks of closely linked mutations known as haplotypes. The linkage within haplotypes is constantly disrupted due to meiotic recombination events. Whole ensembles of such numerous haplotypes are subjected to evolutionary pressure, where mutations influence each other and should be considered as a whole entity-a gigantic matrix, unique for each individual genome. This idea was implemented into a computational approach, named Genome Evolution by Matrix Algorithms (GEMA) to model genomic changes taking into account all mutations in a population. GEMA has been tested for modeling of entire human chromosomes. The program can precisely mimic real biological processes that have influence on genome evolution such as: 1) Authentic arrangements of genes and functional genomic elements, 2) frequencies of various types of mutations in different nucleotide contexts, and 3) nonrandom distribution of meiotic recombination events along chromosomes. Computer modeling with GEMA has demonstrated that the number of meiotic recombination events per gamete is among the most crucial factors influencing population fitness. In humans, these recombinations create a gamete genome consisting on an average of 48 pieces of corresponding parental chromosomes. Such highly mosaic gamete structure allows preserving fitness of population under the intense influx of novel mutations (40 per individual) even when the number of mutations with deleterious effects is up to ten times more abundant than those with beneficial effects. PMID:24723728

Qiu, Shuhao; McSweeny, Andrew; Choulet, Samuel; Saha-Mandal, Arnab; Fedorova, Larisa; Fedorov, Alexei

2014-04-01

272

Protection of Cities from Small Rockets, Missiles, Projectiles and Mortar Shells  

E-print Network

The authors suggest a low cost closed AB-Dome, which may protect small cities such as Sederot from rockets, mortar shells, chemical and biological weapons. The offered AB-Dome is also very useful in peacetime because it protects the city from outside weather (violent storms, hail) and creates a fine climate within the Dome. The roughly hemispherical AB-Dome is a gigantic inflated thin transparent film, located at altitude up to 1 - 5 kilometers, which converts the city into a closed-loop air system. The film may be armored with a basalt or steel grille or cloth pocket-retained stones that destroy (by collision or detonation) incoming rockets, shells and other projectiles. Such an AB-Dome would even protect the city in case of a third-party nuclear war involving temporary poisoning of the Earth atmosphere by radioactive dust. The building of the offered dome is easy; the film spreads on the ground, the fan engines turn on and the cover rises to the needed altitude and is supported there by a small internal ove...

Bolonkin, Alexander

2008-01-01

273

Two sun-like superflare stars rotating as slow as the Sun*  

NASA Astrophysics Data System (ADS)

We report on the results of high dispersion spectroscopy of two "superflare stars," KIC 9766237 and KIC 9944137 with Subaru/HDS. Superflare stars are G-type main sequence stars, but show gigantic flares compared to the Sun, which have recently been discovered in the data obtained with the Kepler spacecraft. Though most of these stars are thought to have a rotation period shorter than 10 d on the basis of photometric variabilities, the two targets of the present paper are estimated to have rotation periods of 21.8 d and 25.3 d. Our spectroscopic results clarified that these stars have stellar parameters similar to those of the Sun in terms of the effective temperature, surface gravity, and metallicity. The projected rotational velocities derived by us are consistent with the photometric rotation period, indicating a fairly high inclination angle. The average strength of the magnetic field on the surface of these stars are estimated to be 1-20 G, by using the absorption line of Ca II 8542. We could not detect any hint of binarity in our spectra, although more data are needed to firmly rule out the presence of an unseen low-mass companion. These results claim that the spectroscopic properties of these superflare stars are very close to those of the Sun, and support the hypothesis that the Sun might cause a superflare.

Nogami, Daisaku; Notsu, Yuta; Honda, Satoshi; Maehara, Hiroyuki; Notsu, Shota; Shibayama, Takuya; Shibata, Kazunari

2014-04-01

274

Interplay between superconductivity and magnetism in Fe(1-x)Pd(x)Te.  

PubMed

The attractive/repulsive relationship between superconductivity and magnetic ordering has fascinated the condensed matter physics community for a century. In the early days, magnetic impurities doped into a superconductor were found to quickly suppress superconductivity. Later, a variety of systems, such as cuprates, heavy fermions, and Fe pnictides, showed superconductivity in a narrow region near the border to antiferromagnetism (AFM) as a function of pressure or doping. However, the coexistence of superconductivity and ferromagnetic (FM) or AFM ordering is found in a few compounds [RRh4B4 (R = Nd, Sm, Tm, Er), R'Mo6X8 (R' = Tb, Dy, Er, Ho, and X = S, Se), UMGe (M = Ge, Rh, Co), CeCoIn5, EuFe2(As(1-x)P(x))2, etc.], providing evidence for their compatibility. Here, we present a third situation, where superconductivity coexists with FM and near the border of AFM in Fe(1-x)Pd(x)Te. The doping of Pd for Fe gradually suppresses the first-order AFM ordering at temperature T(N/S), and turns into short-range AFM correlation with a characteristic peak in magnetic susceptibility at T'(N). Superconductivity sets in when T'(N) reaches zero. However, there is a gigantic ferromagnetic dome imposed in the superconducting-AFM (short-range) cross-over regime. Such a system is ideal for studying the interplay between superconductivity and two types of magnetic (FM and AFM) interactions. PMID:23690601

Karki, Amar B; Garlea, V Ovidiu; Custelcean, Radu; Stadler, Shane; Plummer, E W; Jin, Rongying

2013-06-01

275

Wireless wearable controller for upper-limb neuroprosthesis.  

PubMed

The objective of this project was to develop a wireless, wearable joint angle transducer to enable proportional control of an upper-limb neuroprosthesis by wrist position. Implanted neuroprostheses use functional electrical stimulation to provide hand grasp to individuals with tetraplegia. Wrist position is advantageous for control because it augments the tenodesis grasp and can be implemented bilaterally. Recently developed, fully implantable multichannel stimulators are battery-powered and use wireless telemetry to control stimulator outputs. An external wrist controller was designed for command signal acquisition for people with cervical-level spinal cord injury to control this implantable stimulator. The wearable controller, which uses gigantic magnetoresistive sensing techniques to measure wrist position, is worn on the forearm. A small dime-sized magnet is fixed to the back of the hand. Results indicate that the device is a feasible control method for an upper-limb neuroprosthesis and could be reduced to a small "wristwatch" size for cosmesis and easy donning. PMID:19533538

Wheeler, Christa A; Peckham, P Hunter

2009-01-01

276

When Did Carcharocles megalodon Become Extinct? A New Analysis of the Fossil Record.  

PubMed

Carcharocles megalodon ("Megalodon") is the largest shark that ever lived. Based on its distribution, dental morphology, and associated fauna, it has been suggested that this species was a cosmopolitan apex predator that fed on marine mammals from the middle Miocene to the Pliocene (15.9-2.6 Ma). Prevailing theory suggests that the extinction of apex predators affects ecosystem dynamics. Accordingly, knowing the time of extinction of C. megalodon is a fundamental step towards understanding the effects of such an event in ancient communities. However, the time of extinction of this important species has never been quantitatively assessed. Here, we synthesize the most recent records of C. megalodon from the literature and scientific collections and infer the date of its extinction by making a novel use of the Optimal Linear Estimation (OLE) model. Our results suggest that C. megalodon went extinct around 2.6 Ma. Furthermore, when contrasting our results with known ecological and macroevolutionary trends in marine mammals, it became evident that the modern composition and function of modern gigantic filter-feeding whales was established after the extinction of C. megalodon. Consequently, the study of the time of extinction of C. megalodon provides the basis to improve our understanding of the responses of marine species to the removal of apex predators, presenting a deep-time perspective for the conservation of modern ecosystems. PMID:25338197

Pimiento, Catalina; Clements, Christopher F

2014-01-01

277

El proyecto AUGER  

NASA Astrophysics Data System (ADS)

Hace ya ms de 30 aos en Volcano Ranch, EE.UU., un extenso chubasco csmico (ECC) fue detectado con energa en exceso de 1020 eV. Desde entonces, observatorios ubicados en Haverah Park del Reino Unido, Yakutsk de Rusia, AGASA de Japn y Dugway de EE.UU. tambin han observado ECC con energas mayores que 1020 eV. Poco se sabe de dichos rayos, y en particular cul es la naturaleza del primario, de dnde provienen, y cmo son acelerados, pero su naturaleza ultrarelativista excluye la mayora de las respuestas dejando slo algunas plausibles de ser investigadas experimentalmente. Grupos de cientficos de 20 pases estn trabajando con el fin de construir dos arreglos de detectores gigantes, uno en cada hemisferio a lo largo de 3000 km2 c/u. Dichas dimensiones son necesarias debido al flujo estimado de 1 rayo csmico/centuria/km2/sr. La sede del Observatorio del Sur es la Argentina. El proyecto fue nombrado Pierre Auger en conmemoracin del clebre fsico francs que detect por primera vez chubascos csmicos en 1938. El proyecto focaliza su inters en rayos csmicos con energas mayores que 1020 eV.

Etchegoyen, A.

278

Galaxy Mass Assembly with VLT & HST and lessons for E-ELT/MOSAIC  

E-print Network

The fraction of distant disks and mergers is still debated, while 3D-spectroscopy is revolutionizing the field. However its limited spatial resolution imposes a complimentary HST imagery and a robust analysis procedure. When applied to observations of IMAGES galaxies at z=0.4-0.8, it reveals that half of the spiral progenitors were in a merger phase, 6 billion year ago. The excellent correspondence between methodologically-based classifications of morphologies and kinematics definitively probes a violent origin of disk galaxies as proposed by Hammer et al. (2005). Examination of nearby galaxy outskirts reveals fossil imprints of such ancient merger events, under the form of well organized stellar streams. Perhaps our neighbor, M31, is the best illustration of an ancient merger, which modeling in 2010 leads to predict the gigantic plane of satellites discovered by Ibata et al. (2013). There are still a lot of discoveries to be done until the ELT era, which will open an avenue for detailed and accurate 3D-spect...

Hammer, F; Puech, M

2014-01-01

279

Polar correlations and defect-induced ferroelectricity in cryogenic KTaO3  

NASA Astrophysics Data System (ADS)

KTaO3 is an incipient ferroelectric material with an extrapolated transition temperature below 0 K. It contains a small number of "unavoidable defects" which are randomly distributed. Some of these defects are polar and their interaction leads to macroscopic coherent polar structures at low temperatures. In this article it is shown that freezing of local defect dipoles coincides with elastic stiffening and damping of ultrasonic waves in KTaO3. The elastic freezing anomalies are accompanied by stepwise increases of piezoelectricity, forming a thermal polar staircase below ca. 120 K and a gigantic enhancement below 50 K. A small spontaneous polarization also emerges below this temperature, gradually increasing to a value of 0.045 ? C cm -2 at 5 K with increasing coherency of defect dipoles. The orientation of this spontaneous polarization depends on a weak strain-induced anisotropy of the macroscopic sample. Defect-induced ferroelectricity, as demonstrated for KTaO3, may be a possible way forward to develop functional device materials based on the switching of coherently interacting defects.

Aktas, Oktay; Crossley, Sam; Carpenter, Michael A.; Salje, Ekhard K. H.

2014-10-01

280

The effect of albumin fusion structure on the production and bioactivity of the somatostatin-28 fusion protein in Pichia pastoris.  

PubMed

Somatostatin, a natural inhibitor of growth hormone (GH), and its analogs have been used in clinical settings for the treatment of acromegaly, gigantism, thyrotropinoma, and other carcinoid syndromes. However, natural somatostatin is limited for clinical usage because of its short half-life in vivo. Albumin fusion technology was used to construct long-acting fusion proteins and Pichia pastoris was used as an expression system. Three fusion proteins (SS28)(2)-HSA, (SS28)(3)-HSA, and HSA-(SS28)(2), were constructed with different fusion copies of somatostatin-28 and fusion orientations. The expression level of (SS28)(3)-HSA was much lower than (SS28)(2)-HSA and HSA-(SS28)(2) due to the additional fusion of the somatostatin-28 molecule. MALDI-TOF mass spectrometry revealed that severe degradation occurred in the fermentation process. Similar to the standard, somatostatin-14, all three fusion proteins were able to inhibit GH secretion in blood, with (SS28)(2)-HSA being the most effective one. A pharmacokinetics study showed that (SS28)(2)-HSA had a prolonged half-life of 2 h. These results showed that increasing the number of small protein copies fused to HSA may not be a suitable method for improving protein bioactivity. PMID:24752560

Ding, Yuedi; Fan, Jun; Li, Wenxin; Peng, Ying; Yang, Runlin; Deng, Lili; Fu, Qiang

2014-06-01

281

Noachian Faulting: What Do Faults Tell Us About the Tectonic History of Tharsis?  

NASA Technical Reports Server (NTRS)

The western hemisphere of Mars is dominated by the formation of Tharsis, which is an enormous high-standing region (roughly 25% of the surface area of the planet) capped by volcanics, including the solar system's largest shield volcanoes. Tharsis is surrounded by an enormous radiating system of grabens and a circumferential system of wrinkle ridges that extends over the entire western hemisphere of Mars. This region is perhaps the largest and most long lived tectonic and volcanic province of any of the terrestrial planets with a well-preserved history of magmatic-driven activity that began in the Noachian and has lasted throughout Martian geologic time. Tharsis and the surrounding regions comprise numerous components, including volcanic constructs of varying sizes and extensive lava flow fields, large igneous plateaus, fault and ridge systems of varying extent and relative age of formation, gigantic outflow channel systems, vast system of canyons, and local and regional centers of tectonic activity. Many of these centers are interpreted to be the result of magmatic-related activity, including uplift, faulting, dike emplacement, volcanism, and local hydrothermal activity. Below we present a summary of our work for Tharsis focusing primarily on the earliest stage of development, the Noachian period. Here we hone in on the early centers and how they relate to the early development of the Tharsis Magmatic Complex (TMC).

Anderson, R. C.; Dohm, J. M.

2001-01-01

282

Perspectives for a neutrino program based on the upgrades of the CERN accelerator complex  

E-print Network

In this paper, we discuss the possibilities offered to neutrino physics by the upgrades of the CERN accelerator complex. Emphasis is on the physics reach of a medium $\\gamma$ (350-580) $\\beta$-beam that fully exploits the improvements in the CERN accelerator complex for the luminosity/energy upgrade of the LHC. We show that, this design not only profits of the ongoing efforts for the upgrades of the LHC, but also leverage out the existing infrastructures of the LNGS underground laboratory. Furthermore, given the involved high neutrino energies, above 1 GeV, a non-magnetized iron detector could efficiently exploit the neutrino beam. We show that the performance of this complex for what concerns the discovery of the CP violation in the leptonic sector, in case $\\theta_{13}$ is discovered by Phase I experiments, is comparable with the current baseline design based on a gigantic water Cherenkov at Frejus. Furthermore, this complex has also some sensitivity to the neutrino mass hierarchy.

A. Donini; E. Fernandez; P. Migliozzi; S. Rigolin; L. Scotto Lavina; T. Tabarelli de Fatis; F. Terranova

2005-11-10

283

Identification of old tidal dwarfs near early-type galaxies from deep imaging and HI observations  

E-print Network

It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group disks of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still poorly constrained by observations. As part of deep optical and HI surveys with the CFHT MegaCam camera and Westerbork Synthesis Radio Telescope made within the ATLAS3D project, and follow-up spectroscopic observations with the Gemini-North telescope, we have discovered old TDG candidates around several early-type galaxies. At least one of them has an oxygen abundance close to solar, as expected for a tidal origin. This confirmed pre-enriched object is located within the gigantic, but very low surface brightness, tidal tail that emanates from the elliptical galaxy, NGC 5557. An age of 4 Gyr estimated from its SED fitting makes it the oldest securely identified TDG ever found so far. We investigated the structural and gaseous properties of the TDG and of a companion located in...

Duc, Pierre-Alain; McDermid, Richard M; Cuillandre, Jean-Charles; Serra, Paolo; Bournaud, Frdric; Cappellari, Michele; Emsellem, Eric

2014-01-01

284

Interplay between superconductivity and magnetism in Fe1?xPdxTe  

PubMed Central

The attractive/repulsive relationship between superconductivity and magnetic ordering has fascinated the condensed matter physics community for a century. In the early days, magnetic impurities doped into a superconductor were found to quickly suppress superconductivity. Later, a variety of systems, such as cuprates, heavy fermions, and Fe pnictides, showed superconductivity in a narrow region near the border to antiferromagnetism (AFM) as a function of pressure or doping. However, the coexistence of superconductivity and ferromagnetic (FM) or AFM ordering is found in a few compounds [RRh4B4 (R = Nd, Sm, Tm, Er), R?Mo6X8 (R? = Tb, Dy, Er, Ho, and X = S, Se), UMGe (M = Ge, Rh, Co), CeCoIn5, EuFe2(As1?xPx)2, etc.], providing evidence for their compatibility. Here, we present a third situation, where superconductivity coexists with FM and near the border of AFM in Fe1?xPdxTe. The doping of Pd for Fe gradually suppresses the first-order AFM ordering at temperature TN/S, and turns into short-range AFM correlation with a characteristic peak in magnetic susceptibility at T?N. Superconductivity sets in when T?N reaches zero. However, there is a gigantic ferromagnetic dome imposed in the superconducting-AFM (short-range) cross-over regime. Such a system is ideal for studying the interplay between superconductivity and two types of magnetic (FM and AFM) interactions. PMID:23690601

Karki, Amar B.; Garlea, V. Ovidiu; Custelcean, Radu; Stadler, Shane; Plummer, E. W.; Jin, Rongying

2013-01-01

285

Thermal expansion anomaly regulated by entropy.  

PubMed

Thermal expansion, defined as the temperature dependence of volume under constant pressure, is a common phenomenon in nature and originates from anharmonic lattice dynamics. However, it has been poorly understood how thermal expansion can show anomalies such as colossal positive, zero, or negative thermal expansion (CPTE, ZTE, or NTE), especially in quantitative terms. Here we show that changes in configurational entropy due to metastable micro(scopic)states can lead to quantitative prediction of these anomalies. We integrate the Maxwell relation, statistic mechanics, and first-principles calculations to demonstrate that when the entropy is increased by pressure, NTE occurs such as in Invar alloy (Fe3Pt, for example), silicon, ice, and water, and when the entropy is decreased dramatically by pressure, CPTE is expected such as in anti-Invar cerium, ice and water. Our findings provide a theoretic framework to understand and predict a broad range of anomalies in nature in addition to thermal expansion, which may include gigantic electrocaloric and electromechanical responses, anomalously reduced thermal conductivity, and spin distributions. PMID:25391631

Liu, Zi-Kui; Wang, Yi; Shang, ShunLi

2014-01-01

286

Two Sun-like Superflare Stars Rotating as Slow as the Sun  

E-print Network

We report on the results of high dispersion spectroscopy of two `superflare stars', KIC 9766237, and KIC 9944137 with Subaru/HDS. Superflare stars are G-type main sequence stars, but show gigantic flares compared to the Sun, which have been recently discovered in the data obtained with the Kepler spacecraft. Though most of these stars are thought to have a rotation period shorter than 10 days on the basis of photometric variabilities, the two targets of the present paper are estimated to have a rotation period of 21.8 d, and 25.3 d. Our spectroscopic results clarified that these stars have stellar parameters similar to those of the Sun in terms of the effective temperature, surface gravity, and metallicity. The projected rotational velocities derived by us are consistent with the photometric rotation period, indicating a fairy high inclination angle. The average strength of the magnetic field on the surface of these stars are estimated to be 1-20 G, by using the absorption line of Ca II 8542. We could not det...

Nogami, Daisaku; Honda, Satoshi; Maehara, Hiroyuki; Notsu, Shota; Shibayama, Takuya; Shibata, Kazunari

2014-01-01

287

Saving a life but losing the patient.  

PubMed

Gregor Samsa awakes to find himself transformed into a gigantic bug. The creature's inchoate flailing leads Gregor's sister to conclude that Gregor is no more, having been replaced by a brute beast lacking any vestige of human understanding. Sadly, real cases of brain injury and disease can lead to psychological metamorphoses so profound that we cannot easily think that the survivor is the person we knew. I argue that there can be cases in which statements like, "It's just not Gregor anymore," are not merely figures of speech. With this in mind, I consider three possible results of saving a biological life: (1) ordinary cases where saving the life will save the person, with strong duties to save the life; (2) cases where the intervention needed to save the life will replace the person, with strong duties not to save the life; (3) cases in which it is indeterminate whether the person will be saved or replaced. How should we think about indeterminate cases? Impersonal ethical considerations miss the point, while standard person-affecting considerations are inapplicable. I suggest turning attention away from survival towards a richer focus on what I call "personal concern." I show how considerations of personal concern, unlike those of self-interest, need not be tied to survival and how this allows personal concern to provide a basis for ethically substantive discussion of cases where saving a life might result in losing the patient. PMID:24293085

Greene, Mark

2013-12-01

288

Genome Evolution by Matrix Algorithms: Cellular Automata Approach to Population Genetics  

PubMed Central

Mammalian genomes are replete with millions of polymorphic sites, among which those genetic variants that are colocated on the same chromosome and exist close to one another form blocks of closely linked mutations known as haplotypes. The linkage within haplotypes is constantly disrupted due to meiotic recombination events. Whole ensembles of such numerous haplotypes are subjected to evolutionary pressure, where mutations influence each other and should be considered as a whole entitya gigantic matrix, unique for each individual genome. This idea was implemented into a computational approach, named Genome Evolution by Matrix Algorithms (GEMA) to model genomic changes taking into account all mutations in a population. GEMA has been tested for modeling of entire human chromosomes. The program can precisely mimic real biological processes that have influence on genome evolution such as: 1) Authentic arrangements of genes and functional genomic elements, 2) frequencies of various types of mutations in different nucleotide contexts, and 3) nonrandom distribution of meiotic recombination events along chromosomes. Computer modeling with GEMA has demonstrated that the number of meiotic recombination events per gamete is among the most crucial factors influencing population fitness. In humans, these recombinations create a gamete genome consisting on an average of 48 pieces of corresponding parental chromosomes. Such highly mosaic gamete structure allows preserving fitness of population under the intense influx of novel mutations (40 per individual) even when the number of mutations with deleterious effects is up to ten times more abundant than those with beneficial effects. PMID:24723728

Qiu, Shuhao; McSweeny, Andrew; Choulet, Samuel; Saha-Mandal, Arnab; Fedorova, Larisa; Fedorov, Alexei

2014-01-01

289

Promises and challenges in solid-state lighting  

NASA Astrophysics Data System (ADS)

Lighting technologies based on semiconductor light-emitting diodes (LEDs) offer unprecedented promises that include three major benefits: (i) Gigantic energy savings enabled by efficient conversion of electrical energy to optical energy; (ii) Substantial positive contributions to sustainability through reduced emissions of global-warming gases, acid-rain gases, and toxic substances such as mercury; and (iii) The creation of new paradigms in lighting driven by the unique controllability of solid-state lighting sources. Due to the powerful nature of these benefits, the transition from conventional lighting sources to solid-state lighting is virtually assured. This presentation will illustrate the new world of lighting and illustrate the pervasive changes to be expected in lighting, displays, communications, and biotechnology. The presentation will also address the formidable challenges that must be addressed to continue the further advancement of solid-state lighting technology. These challenges offer opportunities for research and innovation. Specific challenges include light management, carrier transport, and optical design. We will present some innovative approaches in order to solve known technical challenges faced by solid-state lighting. These approaches include the demonstration and use of new optical thin-film materials with a continuously tunable refractive index. These approaches also include the use of polarization-matched structures that reduce the polarization fields in GaInN LEDs and the hotly debated efficiency droop, that is, the decreasing LED efficiency at high currents.

Schubert, Fred

2010-03-01

290

A vision of the environmental and occupational noise pollution in Malaysia.  

PubMed

Environmental noise remains a complex and fragmented interplay between industrialization, population growth, technological developments, and the living environment. Next to the circulatory diseases and cancer, noise pollution has been cited as the third epidemic cause of psychological and physiological disorders internationally. A reliable and firm relationship between the cumulative health implications with the traffic annoyance and occupational noise has been established. This agenda has called for an integrated, coordinated, and participatory approach to the reliable protection of noise interference. Despite several fragmented policies, legislation and global efforts have been addressed; the noise pollution complaints have been traditionally neglected in developing countries, especially in Malaysia. This paper was undertaken to postulate an initial platform to address the dynamic pressures, gigantic challenges, and tremendous impacts of noise pollution scenario in Malaysia. The emphasis is speculated on the traffic interference and assessment of industrial and occupational noise. The fundamental importance of noise monitoring and modeling is proposed. Additionally, the confronting conservation program and control measure for noise pollution control are laconically elucidated. PMID:25387540

Yuen, Foo Keng

2014-01-01

291

Giant spin-driven ferroelectric polarization in TbMnO3 under high pressure.  

PubMed

The recent research on multiferroics has provided solid evidence that the breaking of inversion symmetry by spin order can induce ferroelectric polarization P. This type of multiferroics, called spin-driven ferroelectrics, often show a gigantic change in P on application of a magnetic field B. However, their polarization (<~0.1??C?cm(-2)) is much smaller than that in conventional ferroelectrics (typically several to several tens of ?C?cm(-2)). Here we show that the application of external pressure to a representative spin-driven ferroelectric, TbMnO3, causes a flop of P and leads to the highest P (?1.0??C?cm(-2)) among spin-driven ferroelectrics ever reported. We explain this behaviour in terms of a pressure-induced magnetoelectric phase transition, based on the results of density functional simulations. In the high-pressure phase, the application of B further enhances P over 1.8??C?cm(-2). This value is nearly an order of magnitude larger than those ever reported in spin-driven ferroelectrics. PMID:25215855

Aoyama, T; Yamauchi, K; Iyama, A; Picozzi, S; Shimizu, K; Kimura, T

2014-01-01

292

Giant spin-driven ferroelectric polarization in TbMnO3 under high pressure  

NASA Astrophysics Data System (ADS)

The recent research on multiferroics has provided solid evidence that the breaking of inversion symmetry by spin order can induce ferroelectric polarization P. This type of multiferroics, called spin-driven ferroelectrics, often show a gigantic change in P on application of a magnetic field B. However, their polarization (<~0.1??C?cm?2) is much smaller than that in conventional ferroelectrics (typically several to several tens of ?C?cm?2). Here we show that the application of external pressure to a representative spin-driven ferroelectric, TbMnO3, causes a flop of P and leads to the highest P (?1.0??C?cm?2) among spin-driven ferroelectrics ever reported. We explain this behaviour in terms of a pressure-induced magnetoelectric phase transition, based on the results of density functional simulations. In the high-pressure phase, the application of B further enhances P over 1.8??C?cm?2. This value is nearly an order of magnitude larger than those ever reported in spin-driven ferroelectrics.

Aoyama, T.; Yamauchi, K.; Iyama, A.; Picozzi, S.; Shimizu, K.; Kimura, T.

2014-09-01

293

Environmental and biotic controls on the evolutionary history of insect body size.  

PubMed

Giant insects, with wingspans as large as 70 cm, ruled the Carboniferous and Permian skies. Gigantism has been linked to hyperoxic conditions because oxygen concentration is a key physiological control on body size, particularly in groups like flying insects that have high metabolic oxygen demands. Here we show, using a dataset of more than 10,500 fossil insect wing lengths, that size tracked atmospheric oxygen concentrations only for the first 150 Myr of insect evolution. The data are best explained by a model relating maximum size to atmospheric environmental oxygen concentration (pO(2)) until the end of the Jurassic, and then at constant sizes, independent of oxygen fluctuations, during the Cretaceous and, at a smaller size, the Cenozoic. Maximum insect size decreased even as atmospheric pO(2) rose in the Early Cretaceous following the evolution and radiation of early birds, particularly as birds acquired adaptations that allowed more agile flight. A further decrease in maximum size during the Cenozoic may relate to the evolution of bats, the Cretaceous mass extinction, or further specialization of flying birds. The decoupling of insect size and atmospheric pO(2) coincident with the radiation of birds suggests that biotic interactions, such as predation and competition, superseded oxygen as the most important constraint on maximum body size of the largest insects. PMID:22665762

Clapham, Matthew E; Karr, Jered A

2012-07-01

294

Energy allocation patterns in Biomphalaria alexandrina snails in response to cadmium exposure and Schistosoma mansoni infection.  

PubMed

This study was aimed to investigate the effects of both parasitism and environmental stress on the growth, reproduction, and survival of Biomphalaria alexandrina snails. Resource allocation strategies may be influenced by both biotic and abiotic factors. Using the planorbid snail B. alexandrina and Schistosoma mansoni, this hypothesis was examined by raising snails fed the same diet under two stressors (infection and Cd exposure). The snails divided into four groups, uninfected, infected, Cd-exposed uninfected, and Cd-exposed infected snails. Egg production, growth, and survival of the snails were monitored over a 9-week period postinfection. Inhibition of snail reproductive activity by parasitism results in increased snail growth in the first week postinfection, termed gigantism, during which the snail is hypothesized to allocate excess energy normally used for reproduction to somatic growth. Infection status and Cd exposure had significant effects on snail growth and reproduction. The infected and Cd-exposed infected snails exhibiting reduced survival relative to snails of other treatments. It was found that parasite development influenced by Cd exposure. Results of this study suggest that energy allocation patterns are context-dependent in B. alexandrina snails, influenced by infection and Cd exposure. PMID:16256110

Ibrahim, Mohamed Moussa

2006-01-01

295

Ferroelectricity with Ferromagnetic Moment in Orthoferrites  

NASA Astrophysics Data System (ADS)

Exotic multiferroics with gigantic magnetoelectric (ME) coupling have recently been attracting broad interests from the viewpoints of both fundamental physics and possible technological application to next-generation spintronic devices. To attain a strong ME coupling, it would be preferable that the ferroelectric order is induced by the magnetic order. Nevertheless, the magnetically induced ferroelectric state with the spontaneous ferromagnetic moment is still quite rare apart from a few conical-spin multiferroics. To further explore multiferroic materials with both the strong ME coupling and spontaneous magnetization, we focused on materials with magnetic structures other than conical structure. In this talk we present that the most orthodox perovskite ferrite systems DyFeO3 and GdFeO3 have ``ferromagnetic-ferroelectric,'' i.e., genuinely multiferroic states in which weak ferromagnetic moment is induced by Dzyaloshinskii-Moriya interaction working on Fe spins and electric polarization originates from the striction due to symmetric exchange interaction between Fe and Dy (Gd) spins [1] [2]. Both materials showed large electric polarization (>0.1 ?C/cm^2) and strong ME coupling. In addition, we succeeded in mutual control of magnetization and polarization with electric- and magnetic-fields in GdFeO3, and attributed the controllability to novel, composite domain wall structure. [4pt] [1] Y. Tokunaga et al., Phys. Rev. Lett. 101, 097205 (2008). [0pt] [2] Y. Tokunaga et al., Nature Mater. 8, 558 (2009).

Tokunaga, Yusuke

2010-03-01

296

Origin and evolution of marginal basins of the NW Pacific: Diffuse-plate tectonic reconstructions  

E-print Network

Formation of the gigantic linked dextral pull-apart basin system in the NW Pacific is due to NNE- to ENE-ward motion of east Eurasia. This mainly was a response to the Indo-Asia collision which started about 50 Ma ago. The displacement of east Eurasia can be estimated using three aspects: (1) the magnitude of pull-apart of the dextral pull-apart basin system, (2) paleomagnetic data from eastern Eurasia and the region around the Arctic, and (3) the shortening deficits in the Large Tibetan Plateau. All the three aspects indicate that there was a large amount (about 1200 km) of northward motion of the South China block and compatible movements of other blocks in eastern Eurasia during the rifting period of the basin system. Such large motion of the eastern Eurasia region contradicts any traditional rigid plate tectonic reconstruction, but agrees with the more recent concepts of non-rigidity of both continental and oceanic lithosphere over geological times. Based on these estimates, the method developed for resto...

Xu, Junyuan; Ben-Avraham, Zvi; Yu, Ho-Shing

2012-01-01

297

Intercontinental dispersal of giant thermophilic ants across the Arctic during early Eocene hyperthermals  

PubMed Central

Early Eocene land bridges allowed numerous plant and animal species to cross between Europe and North America via the Arctic. While many species suited to prevailing cool Arctic climates would have been able to cross throughout much of this period, others would have found dispersal opportunities only during limited intervals when their requirements for higher temperatures were met. Here, we present Titanomyrma lubei gen. et sp. nov. from Wyoming, USA, a new giant (greater than 5 cm long) formiciine ant from the early Eocene (approx. 49.5 Ma) Green River Formation. We show that the extinct ant subfamily Formiciinae is only known from localities with an estimated mean annual temperature of about 20C or greater, consistent with the tropical ranges of almost all of the largest living ant species. This is, to our knowledge, the first known formiciine of gigantic size in the Western Hemisphere and the first reported cross-Arctic dispersal by a thermophilic insect group. This implies intercontinental migration during one or more brief high-temperature episodes (hyperthermals) sometime between the latest Palaeocene establishment of intercontinental land connections and the presence of giant formiciines in Europe and North America by the early middle Eocene. PMID:21543354

Archibald, S. Bruce; Johnson, Kirk R.; Mathewes, Rolf W.; Greenwood, David R.

2011-01-01

298

Thermal Expansion Anomaly Regulated by Entropy  

PubMed Central

Thermal expansion, defined as the temperature dependence of volume under constant pressure, is a common phenomenon in nature and originates from anharmonic lattice dynamics. However, it has been poorly understood how thermal expansion can show anomalies such as colossal positive, zero, or negative thermal expansion (CPTE, ZTE, or NTE), especially in quantitative terms. Here we show that changes in configurational entropy due to metastable micro(scopic)states can lead to quantitative prediction of these anomalies. We integrate the Maxwell relation, statistic mechanics, and first-principles calculations to demonstrate that when the entropy is increased by pressure, NTE occurs such as in Invar alloy (Fe3Pt, for example), silicon, ice, and water, and when the entropy is decreased dramatically by pressure, CPTE is expected such as in anti-Invar cerium, ice and water. Our findings provide a theoretic framework to understand and predict a broad range of anomalies in nature in addition to thermal expansion, which may include gigantic electrocaloric and electromechanical responses, anomalously reduced thermal conductivity, and spin distributions. PMID:25391631

Liu, Zi-Kui; Wang, Yi; Shang, ShunLi

2014-01-01

299

[Mitral valve repair in a patient with giant left atrial myxoma;report of a case].  

PubMed

In patients with left atrial myxoma, mitral valve regurgitation is often encountered. However, preoperative assessment of the mitral valve is difficult in cases with giant left atrial myxoma occupying the left atrial cavity. We experienced a patient with giant left atrial myxoma who underwent tumor excision and mitral valve repair. A 40-year-old woman was transferred to the emergency room due to respiratory failure. On admission, her hemodynamic status was unstable and percutaneous cardiopulmonary support was immediately started. Transesophageal echocardiography was performed, which showed giant left atrial tumor with the pedicle on the atrial septum with mitral valve regurgitation, but the severity of regurgitation was unclear. After excision of left atrial myxoma with atrial septum, the mitral valve was examined. The anterior leaflet( A3 scallop) prolapse due to a torn chordae was found. The mitral valve was repaired with leaflet resection and prosthetic ring annuloplasty. Postoperative course was uneventful and postoperative echocardiography showed no residual mitral valve regurgitation. The mitral valve should be carefully inspected intraoperatively after resection of left atrial myxoma, especially when the tumor is gigantic. PMID:25201370

Iizuka, Hirofumi; Aoki, Atushi; Omoto, Tadashi; Maruta, Kazuto; Sakurai, Sigeru; Kawaura, Hiromasa

2014-09-01

300

Revolutionising landscapes: Hydroelectricity and the heavy industrialisation of society and environment in the Comte de Beauharnois, 1927--1948  

NASA Astrophysics Data System (ADS)

This dissertation analyses the rapid industrialisation of the rural Comte de Beauharnois and the adjacent stretch of the Fleuve Saint-Laurent owing to the construction, between 1929 and 1948, of a gigantic canal for hydroelectricity production and navigation by an electricity corporation called the Beauharnois Light Heat and Power (BLH&P). Using principally the archives of the BLH&P---especially its complaints files and its rich photographic record---this thesis argues that this process exemplifies the finance capitalist reorganisation of the society and ecosystems of the Canadian province of Quebec from the 19th century to the Great Depression. In keeping with recent work in environmental history, the transformation of rural landscapes and a river for heavy industry is described as an important dimension of a revolution in modes of production. More specifically, I argue that, in the case under study, the finance-capitalist reorganisation of Quebec revolved around two central and explicit projects, one social and the other environmental: the grouping of most individuals in an industrial working class without control over the means of production and the reorganisation of rural landscapes into reservoirs of modern energy and industrial natural resources.

Pelletier, Louis-Raphael

301

DNA Viruses: The Really Big Ones (Giruses)  

PubMed Central

Viruses with genomes greater than 300 kb and up to 1200 kb are being discovered with increasing frequency. These large viruses (often called giruses) can encode up to 900 proteins and also many tRNAs. Consequently, these viruses have more protein-encoding genes than many bacteria, and the concept of small particle/small genome that once defined viruses is no longer valid. Giruses infect bacteria and animals although most of the recently discovered ones infect protists. Thus, genome gigantism is not restricted to a specific host or phylogenetic clade. To date, most of the giruses are associated with aqueous environments. Many of these large viruses (phycodnaviruses and Mimiviruses) probably have a common evolutionary ancestor with the poxviruses, iridoviruses, asfarviruses, ascoviruses, and a recently discovered Marseillevirus. One issue that is perhaps not appreciated by the microbiology community is that large viruses, even ones classified in the same family, can differ significantly in morphology, lifestyle, and genome structure. This review focuses on some of these differences rather than provides extensive details about individual viruses. PMID:20690825

Van Etten, James L.; Lane, Leslie C.; Dunigan, David D.

2010-01-01

302

The Influence of Extremely Large Solar Proton Events in a Changing Stratosphere. Stratospheric Influence of Solar Proton Events  

NASA Technical Reports Server (NTRS)

Two periods of extremely large solar proton events (SPEs) occurred in the past thirty years, which forced significant long-term polar stratospheric changes. The August 2-10, 1972 and October 19-27, 1989 SPEs happened in stratospheres that were quite different chemically. The stratospheric chlorine levels were relatively small in 1972 (approximately 1.2 ppbv) and were fairly substantial in 1989 at about (approximately 3 ppbv). Although these SPEs produced both HO(x) and NO(y) constituents in the mesosphere and stratosphere, only the NO(y) constituents had lifetimes long enough to affect ozone for several months to years past the events. Our recently improved two-dimensional chemistry and transport atmospheric model was used to compute the effects of these gigantic SPEs in a changing stratosphere. Significant upper stratospheric ozone depletions > 10% are computed to last for a few months past these SPEs. The long-lived SPE-produced NO(y) constituents were transported to lower levels during winter after these huge SPEs and caused impacts in the middle and lower stratosphere. During periods of high halogen loading these impacts resulted in interference with the chlorine and bromine loss cycles for ozone destruction. The chemical state of the atmosphere, including the stratospheric sulfate aerosol density, substantially affected the predicted stratospheric influence of these extremely large SPEs.

Jackman, Charles H.; Fleming, Eric L.; Vitt, Francis M.

1999-01-01

303

Micromechanics of the pericellular matrix  

NASA Astrophysics Data System (ADS)

In recent years, much attention has been directed towards the properties and activities of the cell surface. In particular, the coupling of the membrane to the underlying protein polymer network called the actin cortex plays an important role in many events. The other side of the cell surface is less studied, although it too has a bound polymer network comprised of gigantic cross-linked polysaccharides (sugars). Called the pericellular matrix (PCM), it is associated with many cells including fibroblasts, chondrocytes, endothelial and smooth muscle cells. Its thickness can vary from 10's of nanometers to 10 microns and it is associated with adhesion dependent events like migration and mitosis. Biologists often hypothesize that its viscoelastic properties are responsible for the modulation of cell adhesion activities. To investigate this proposal, we measure the PCM's viscoelasticity using microrheology and probe the sharpness of its edge and its mesh size. The elastic modulus of the PCM under different condition is determined, and we characterize the long, elastic cables that can be pulled from the PCM. These results are compared with an externally reconstituted model PCM on the cell surface.

Curtis, J. E.; Boehm, H.; Schmitz, C. H. J.; Spatz, J. P.

2006-03-01

304

External threats: the dilemma of resource management on the Colorado River in Grand Canyon National park, USA  

NASA Astrophysics Data System (ADS)

The United States Congress established Grand Canyon National Park in 1919 to preserve for posterity the outstanding natural attributes of the canyon cut by the Colorado River. In some cases National Park Service attempts to maintain Grand Canyon's natural environment have been thwarted by activities outside the park. One of the most obvious external threats is Glen Canyon Dam, only 26 km upstream from the park boundary. Constructed in 1963, this gigantic dam has greatly altered the physicochemical and biological characteristics of 446 km of the Colorado River in Grand Canyon National Park. The river's aquatic ecosystem has been greatly modified through the loss of indigenous species and the addition of numerous exotics. We consider this an exotic ecosystem. The riparian ecosystem has been less modified, with addition of a few exotics and no loss of nativesthis we consider a naturalized ecosystem. The great dilemma now faced by park managers is that, after 20 years of managing resources along a river controlled by Glen Canyon Dam, the Bureau of Reclamation has proposed major changes in operational procedures for the dam. Scientists and managers from the National Park Service, Bureau of Reclamation, and cooperating federal and state resource management agencies are using a systems analysis approach to examine the impacts of various Colorado River flow regimes on aquatic, riparian, and recreational parameters in the park. This approach will help in the development of management alternatives designed to permit the most efficient use of that river's natural resources without their destruction.

Johnson, R. Roy; Carothers, Steven W.

1987-01-01

305

When Did Carcharocles megalodon Become Extinct? A New Analysis of the Fossil Record  

PubMed Central

Carcharocles megalodon (Megalodon) is the largest shark that ever lived. Based on its distribution, dental morphology, and associated fauna, it has been suggested that this species was a cosmopolitan apex predator that fed on marine mammals from the middle Miocene to the Pliocene (15.92.6 Ma). Prevailing theory suggests that the extinction of apex predators affects ecosystem dynamics. Accordingly, knowing the time of extinction of C. megalodon is a fundamental step towards understanding the effects of such an event in ancient communities. However, the time of extinction of this important species has never been quantitatively assessed. Here, we synthesize the most recent records of C. megalodon from the literature and scientific collections and infer the date of its extinction by making a novel use of the Optimal Linear Estimation (OLE) model. Our results suggest that C. megalodon went extinct around 2.6 Ma. Furthermore, when contrasting our results with known ecological and macroevolutionary trends in marine mammals, it became evident that the modern composition and function of modern gigantic filter-feeding whales was established after the extinction of C. megalodon. Consequently, the study of the time of extinction of C. megalodon provides the basis to improve our understanding of the responses of marine species to the removal of apex predators, presenting a deep-time perspective for the conservation of modern ecosystems. PMID:25338197

Pimiento, Catalina; Clements, Christopher F.

2014-01-01

306

Northwestern Tharsis Latent Outflow Activity Mars  

NASA Technical Reports Server (NTRS)

Previously defined outflow channels, which are indicated by relict landforms similar to those observed on Earth, signify ancient catastrophic flood events on Mars. These conspicuous geomorphic features are some of the most remarkable yet profound discoveries made by geologists to date. These outflow channels, which debouched tremendous volumes of water into topographic lows such as Chryse, Utopia, Elysium, and Hellas Planitiae, may represent the beginning of warmer and wetter climatic periods unlike the present-day cold and dry Mars. In addition to the previously identified outflow channels, observations permitted by the newly acquired Mars Orbiter Laser Altimeter (MOLA) data have revealed a system of gigantic valleys, referred to as the northwestern slope valleys (NSV), that are located to the northwest of a huge shield volcano, Arsia Mons, western hemisphere of Mars. These features generally correspond spatially to gravity lows similar to the easternmost, circum-Chryse outflow channel systems. Geologic investigations of the Tharsis region suggest that the large valley system pre-dates the construction of Arsia Mons and its extensive associated lava flows of mainly Late Hesperian and Amazonian age and coincides stratigraphically with the early development of the circum-Chryse outflow channel systems that debouch into Chryse Planitia. This newly identified system, the NSV, potentially signifies the largest flood event(s) ever recorded for the solar system. Additional information is contained in original extended abstract.

Dohm, J. M.; Anderson, R. C.; Baker, V. R.; Ferris, J. C.; Hare, T. M.; Strom, R. G.; Rudd, L.; Rice, J. W., Jr.; Scott, D. H.

2000-01-01

307

[Fiberoptic nasal intubation in a patient with huge laryngeal cyst].  

PubMed

Huge laryngeal cyst is rare, but may cause difficulty or inability in tracheal intubation during induction of general anesthesia. A 69-year-old patient was scheduled for laryngomicroscopic cystectomy. In this patient, we examined two methods of oro-tracheal intubation either with rigid laryngoscopy or flexible fiberscopy using transnasal fiberoptic monitoring. Direct laryngoscopy failed to expose the epiglottis because of large cyst being fragile and easy to bleed. And even oral fiberscopy intubation was also difficult since a large mass hindered acquiring a suitable view. However, trans-nasal fiberscopy monitoring could guide the oro-tracheal fiber into the trachea for intubation. When an anesthesiologist can predict the abnormality of epiglottis, this combination might be recommended for difficult airway and intubation. Postoperative respiratory management under intubating state was necessary because of bleeding, airway edema, and deviation of the larynx after tumor resection. We reported anesthetic management of a patient with epiglottis gigantic cyst occupying the laryngopharyngeal airway. It is a rare tumor leading to difficulty of induction of anesthesia and necessitating postoperative intubated respiratory care. PMID:11510074

Matsumoto, K

2001-07-01

308

On heavy dustfall observed with explosive sandstorms in Chongwon-Chongju, Korea in 2002  

NASA Astrophysics Data System (ADS)

Continuous monitoring of sand and duststorms (SD) and associated heavy dustfall (HD) is made in Korea. In particular, accurate measurements of atmospheric dust loadings have been carried out with the tapered element oscillating microbalance method, and satellite detection of dust clouds is included in the analysis. In 2002, we found three gigantic dust clouds that moved over the Korean Peninsula, and associated HD occurred with PM10 values of 1106-3006 ?g m -3. In Beijing, China much higher concentrations were recorded, while in SW Japan measured values were up to 986 ?g m -3. Two SD occurred in March and April, while the third one occurred unusually in November. During the year, there were nine cases of reddish-brown sand with 18 dusty days. The intensity of HD was extraordinary for the recent decade. It was observed that with invading SD, the higher the PM10 values the lower the PM2.5 loadings. Also, variations of visibility were more depending on PM2.5 variations than PM10 values. It is shown that satellite detection is a useful technique in monitoring SD and HD.

Chung, Yong-seung; Kim, Hak-sung; Dulam, Jugder; Harris, Joyce

309

Ultrafast observation of critical nematic fluctuations and giant magnetoelastic coupling in iron pnictides.  

PubMed

Many of the iron pnictides have strongly anisotropic normal-state characteristics, important for the exotic magnetic and superconducting behaviour these materials exhibit. Yet, the origin of the observed anisotropy is unclear. Electronically driven nematicity has been suggested, but distinguishing this as an independent degree of freedom from magnetic and structural orders is difficult, as these couple together to break the same tetragonal symmetry. Here we use time-resolved polarimetry to reveal critical nematic fluctuations in unstrained Ba(Fe1-xCox)2As2. The femtosecond anisotropic response, which arises from the two-fold in-plane anisotropy of the complex refractive index, displays a characteristic two-step recovery absent in the isotropic response. The fast recovery appears only in the magnetically ordered state, whereas the slow one persists in the paramagnetic phase with a critical divergence approaching the structural transition temperature. The dynamics also reveal a gigantic magnetoelastic coupling that far exceeds electron-spin and electron-phonon couplings, opposite to conventional magnetic metals. PMID:24499997

Patz, Aaron; Li, Tianqi; Ran, Sheng; Fernandes, Rafael M; Schmalian, Joerg; Bud'ko, Sergey L; Canfield, Paul C; Perakis, Ilias E; Wang, Jigang

2014-01-01

310

Fast, comprehensive online two-dimensional high performance liquid chromatography through the use of high temperature ultra-fast gradient elution reversed-phase liquid chromatography.  

PubMed

A new approach to high speed, comprehensive online dual gradient elution 2DLC (LCxLC) based on the use of ultra-fast, high temperature gradient elution reversed phase chromatography is described. Entirely conventional gradient elution instrumentation and columns are assembled in a system which develops a total peak capacity of about 900 in 25 min; this is equivalent to roughly one peak/2 s. Each second dimension gradient is done in a cycle time of 21 s and the peak retention times measured for a set of twenty six indole-3-acetic acid (IAA) derivatives are reproducible to 0.2 s. Each peak eluting from the first dimension column is sampled at least twice across its width, as the corresponding peaks on the second dimension column appear in two or three consecutive second dimension chromatograms, clearly indicating that there is little loss in the resolution gained in the first dimension separation. Application to the separation of the low molecular weight components of wild-type and mutant maize seedlings indicates the presence of about 100 peaks on a timescale of 25 min. Compelling illustrations of the analytical potential of fast, high temperature 2DLC are evident in the clear presence of nine distinct peaks in a single second dimension chromatogram from a single quite narrow first dimension peak, and the great power of 2DLC to solve the "analytic dynamic range" problem inherent in the measurement of small peaks that are neighbors to a gigantic peak. PMID:16720027

Stoll, Dwight R; Cohen, Jerry D; Carr, Peter W

2006-07-28

311

Bone histology of the titanosaur Lirainosaurus astibiae (Dinosauria: Sauropoda) from the Latest Cretaceous of Spain  

NASA Astrophysics Data System (ADS)

The titanosaur Lirainosaurus astibiae is the only sauropod species known from the Late Cretaceous of the Iberian Peninsula. Lirainosaurus did not reach a gigantic body size and is one of the smallest sauropods discovered to date. Histological analysis of Lirainosaurus bones, focused on diaphyseal transverse sections of appendicular elements, reveals that Lirainosaurus did not exhibit the osseous microstructure typical for large sauropods, but is comparable with that of the coeval titanosaurs Alamosaurus sanjuanensis, Ampelosaurus atacis, and Magyarosaurus dacus, and also shares histological traits with other small to medium-sized sauropodomorph dinosaurs. Lirainosaurus limb bones exhibit a laminar fibrolamellar bone microstructure interrupted by growth marks, fully obliterated in adulthood by intense secondary remodeling processes which tend to replace completely the primary cortex. Lirainosaurus attained smaller sizes than typical sauropods reducing the rate of primary periosteal osteogenesis and developing an extensive secondary remodeling well before the adult size was reached. Histological organization of Lirainosaurus long bones is more mature than observed in basal neosauropods at similar ontogenetic stage, documenting a case of peramorphosis by pre-displacement. This heterochronic growth would be a reversal of the accelerated pattern of bone deposition typical for the sauropod lineage.

Company, Julio

2011-01-01

312

Bone histology of the titanosaur Lirainosaurus astibiae (Dinosauria: Sauropoda) from the Latest Cretaceous of Spain.  

PubMed

The titanosaur Lirainosaurus astibiae is the only sauropod species known from the Late Cretaceous of the Iberian Peninsula. Lirainosaurus did not reach a gigantic body size and is one of the smallest sauropods discovered to date. Histological analysis of Lirainosaurus bones, focused on diaphyseal transverse sections of appendicular elements, reveals that Lirainosaurus did not exhibit the osseous microstructure typical for large sauropods, but is comparable with that of the coeval titanosaurs Alamosaurus sanjuanensis, Ampelosaurus atacis, and Magyarosaurus dacus, and also shares histological traits with other small to medium-sized sauropodomorph dinosaurs. Lirainosaurus limb bones exhibit a laminar fibrolamellar bone microstructure interrupted by growth marks, fully obliterated in adulthood by intense secondary remodeling processes which tend to replace completely the primary cortex. Lirainosaurus attained smaller sizes than typical sauropods reducing the rate of primary periosteal osteogenesis and developing an extensive secondary remodeling well before the adult size was reached. Histological organization of Lirainosaurus long bones is more mature than observed in basal neosauropods at similar ontogenetic stage, documenting a case of peramorphosis by pre-displacement. This heterochronic growth would be a reversal of the accelerated pattern of bone deposition typical for the sauropod lineage. PMID:21120450

Company, Julio

2011-01-01

313

Low-field magnetoelectric effect at room temperature  

NASA Astrophysics Data System (ADS)

The discoveries of gigantic ferroelectric polarization in BiFeO3 (ref. 1) and ferroelectricity accompanied by a magnetic order in TbMnO3 (ref. 2) have renewed interest in research on magnetoelectric multiferroics, materials in which magnetic and ferroelectric orders coexist, from both fundamental and technological points of view. Among several different types of magnetoelectric multiferroic, magnetically induced ferroelectrics in which ferroelectricity is induced by complex magnetic orders, such as spiral orders, exhibit giant magnetoelectric effects, remarkable changes in electric polarization in response to a magnetic field. Many magnetically induced ferroelectrics showing the magnetoelectric effects have been found in the past several years. From a practical point of view, however, their magnetoelectric effects are useless because they operate only far below room temperature (for example, 28K in TbMnO3 (ref. 2) and 230K in CuO (ref. 11)). Furthermore, in most of them, the operating magnetic field is an order of tesla that is too high for practical applications. Here we report materials, Z-type hexaferrites, overcoming these problems on magnetically induced ferroelectrics. The best magnetoelectric properties were obtained for Sr3Co2Fe24O41 ceramics sintered in oxygen, which exhibit a low-field magnetoelectric effect at room temperature. Our result represents an important step towards practical device applications using the magnetoelectric effects.

Kitagawa, Yutaro; Hiraoka, Yuji; Honda, Takashi; Ishikura, Taishi; Nakamura, Hiroyuki; Kimura, Tsuyoshi

2010-10-01

314

X-raying Chemical Evolution and Galaxy Formation in The Antennae  

E-print Network

We present the integrated 411 ks {\\it Chandra} ACIS-S exposure of the Antennae galaxies (NGC 4038/39). Besides a rich population of point-like sources, this spectacular image reveals a spatially and spectrally complex hot diffuse gaseous component. For the first time we detect intense line emission from Fe, Ne, Mg and Si in The Antennae, and obtain a detailed picture of spatially varied metal abundances in the hot interstellar medium (ISM) of a galaxy. In certain regions, the abundances of $\\alpha$-elements may be many times solar, while the Fe abundance is sub-solar or near-solar. The differences in the local metal enrichment of the hot ISM may be related to the local star formation rates and to the degree of confinement of the enriched hot ISM. We also report large-scale gaseous features, including two gigantic, $\\sim$10-kpc-scale `loops' extending to the South of the merging disks, and a low-surface-brightness hot halo, extending out to $\\sim$18 kpc. These features may be related to superwinds from the starburst in The Antennae or result from the merger hydrodynamics. Their long cooling times suggest that they may persist to form the hot X-ray halo of the emerging elliptical galaxy.

G. Fabbiano; A. Baldi; A. R. King; T. J. Ponman; J. Raymond; A. Read; A. Rots; Francois Schweizer; A. Zezas

2004-01-13

315

Chemical control of downy mildew on lettuce and basil under greenhouse.  

PubMed

Eight experimental trials were carried out during 2007 and 2008 to evaluate the efficacy of different fungicides against downy mildew of lettuce (Bremia lactucae) and basil (Peronospora belbahrii) under greenhouse conditions, at temperatures ranging from 19 to 24 degrees C. The mixture fluopicolide (fungicide belonging to the + propamocarb hydrochloride (fungicide belonging to the new chemical class of acyl-picolides) was compared with metalaxyl m + copper, zoxamide + mancozeb, iprovalicarb + Cu, fenamidone + fosetyl-Al and azoxystrobin. Two treatments were carried out at 8-12 day interval on lettuce and basil. The artificial inoculation of B. lactucae on lettuce (cv Cobham Green) and P. belbahrii. on basil (cv Genovese gigante) was carried out by using 1 x 10(5) CFU/ml 24 h after the first treatment. In the presence of a medium-high disease severity, all fungicides tested in these trials were effective against downy mildew on lettuce and basil as the other fungicides already available. The importance of the availability of a number of different chemicals to control downy mildews is discussed. PMID:20222581

Gullino, M L; Gilardi, G; Garibaldi, A

2009-01-01

316

The Revival of White Holes as Small Bangs  

E-print Network

Black holes are extremely dense and compact objects from which light cannot escape. There is an overall consensus that black holes exist and many astronomical objects are identified with black holes. White holes were understood as the exact time reversal of black holes, therefore they should continuously throw away material. It is accepted, however, that a persistent ejection of mass leads to gravitational pressure, the formation of a black hole and thus to the "death of while holes". So far, no astronomical source has been successfully tagged a white hole. The only known white hole is the Big Bang which was instantaneous rather than continuous or long-lasting. We thus suggest that the emergence of a white hole, which we name a 'Small Bang', is spontaneous - all the matter is ejected at a single pulse. Unlike black holes, white holes cannot be continuously observed rather their effect can only be detected around the event itself. Gamma ray bursts are the most energetic explosions in the universe. Long gamma-ray bursts were connected with supernova eruptions. There is a new group of gamma-ray bursts, which are relatively close to Earth, but surprisingly lack any supernova emission. We propose identifying these bursts with white holes. White holes seem like the best explanation of gamma-ray bursts that appear in voids. We also predict the detection of rare gigantic gamma-ray bursts with energies much higher than typically observed.

Alon Retter; Shlomo Heller

2011-05-13

317

Earth after the Moon-forming Impact  

NASA Astrophysics Data System (ADS)

The Hadean Earth is widely and enduringly pictured as a world of exuberant volcanism, exploding meteors, huge craters, infernal heat, and billowing sulfurous steams; i.e., a world of fire and brimstone punctuated with blows to the head. In the background the Moon looms gigantic in the sky. The popular image has given it a name that celebrates our mythic roots. A hot early Earth is an inevitable consequence of accretion. The Moon-forming impact ensured that Earth as we know it emerged from a fog of silicate vapor. The impact separated the volatiles from the silicates. It took 100 years to condense and rain out the bulk of the vaporized silicates, although relatively volatile elements may have remained present in the atmosphere throughout the magma ocena stage. The magma ocean lasted 2 Myr, its lifetime prolonged by tidal heating and thermal blanketing by a thick CO2-rich steam atmosphere. Water oceans condensed quickly after the mantle solidified, but for some 10-100 Myr the surface would have stayed warm ( 500 K) until the CO2 was removed into the mantle. Thereafter the faint young Sun suggests that a lifeless Earth would always have been evolving toward a bitterly cold ice world, but the cooling trend was frequently interrupted by volcanic or impact induced thaws. This work was funded by NASA's Exobiology and Astrobiology Programs.

Zahnle, Kevin

2006-09-01

318

An Improved Distance Matrix Computation Algorithm for Multicore Clusters  

PubMed Central

Distance matrix has diverse usage in different research areas. Its computation is typically an essential task in most bioinformatics applications, especially in multiple sequence alignment. The gigantic explosion of biological sequence databases leads to an urgent need for accelerating these computations. DistVect algorithm was introduced in the paper of Al-Neama et al. (in press) to present a recent approach for vectorizing distance matrix computing. It showed an efficient performance in both sequential and parallel computing. However, the multicore cluster systems, which are available now, with their scalability and performance/cost ratio, meet the need for more powerful and efficient performance. This paper proposes DistVect1 as highly efficient parallel vectorized algorithm with high performance for computing distance matrix, addressed to multicore clusters. It reformulates DistVect1 vectorized algorithm in terms of clusters primitives. It deduces an efficient approach of partitioning and scheduling computations, convenient to this type of architecture. Implementations employ potential of both MPI and OpenMP libraries. Experimental results show that the proposed method performs improvement of around 3-fold speedup upon SSE2. Further it also achieves speedups more than 9 orders of magnitude compared to the publicly available parallel implementation utilized in ClustalW-MPI. PMID:25013779

Al-Neama, Mohammed W.; Reda, Naglaa M.; Ghaleb, Fayed F. M.

2014-01-01

319

Quantifying distal dispersal and impact of volcanic ash from super-eruptions: an application to Campanian Ignimbrite  

NASA Astrophysics Data System (ADS)

Distal and ultra-distal volcanic ash dispersal during a super-eruption was reconstructed for the first time, providing insights into eruption dynamics and the impact of these gigantic events. A novel computational methodology was applied to the ash fallout of the Campanian Ignimbrite (CI), the most powerful volcanic eruption in Europe in the last 200 kyrs. The method uses a 3D time-dependent computational ash dispersion model, an ensemble of wind fields, and hundreds of thickness observations of the CI tephra deposit. Results reveal that 250-300 km3 of fallout material was produced during the eruption, blanketing a region of ~3.7 million km2 with more than 5 mm of fine ash. The model also indicates that the column height was ~37-40 km, and the eruption lasted 2-4 days. The eruption would have caused a volcanic winter within the coldest and driest Heinrich event. Fluorine-bearing leachate from the volcanic ash and acid rain would have further affected food sources and severely impacted Late Middle Paleolithic groups in Southern and Eastern Europe.

Costa, A.; Folch, A.; Macedonio, G.; Giaccio, B.; Isaia, R.; Smith, V. C.

2012-04-01

320

Design of PREVENCION: a population-based study of cardiovascular disease in Peru.  

PubMed

Latin America is undergoing the epidemiologic transition that occurred earlier in developed countries, and is likely to face a gigantic epidemic of heart disease in the next few years unless urgent action is taken. The first essential component of any effective cardiovascular disease (CVD) control program is to establish reliable estimates of cardiovascular disease-related morbidity and mortality. However, such data from population-based studies in Latin America are still lacking. In this paper, we present the design and operation of PREVENCION (Estudio Peruano de Prevalencia de Enfermedades Cardiovasculares, for Peruvian Study of the Prevalence of Cardiovascular diseases). PREVENCION is an ongoing population-based study on a representative sample of the civilian non-institutionalized population of the second largest city in Peru. Its population is comparable to the rest of the Peruvian urban population and closely resembles other Latin American populations in countries such as Bolivia and Ecuador. Our study will contribute to the enormous task of understanding and preventing CVD in Latin America. PMID:16243113

Medina-Lezama, Josefina; Chirinos, Julio A; Zea Daz, Humberto; Morey, Oscar; Bolanos, Juan F; Munoz-Atahualpa, Edgar; Chirinos-Pacheco, Julio

2005-11-01

321

Earth After the Moon Forming Impact  

NASA Technical Reports Server (NTRS)

The Hadean Earth is widely and enduringly pictured as a world of exuberant volcanism, exploding meteors, huge craters, infernal heat, and billowing sulfurous steams; i.e., a world of fire and brimstone punctuated with blows to the head. In the background the Moon looms gigantic in the sky. The popular image has given it a name that celebrates our mythic roots. A hot early Earth is an inevitable consequence of accretion. The Moon-forming impact ensured that Earth as we know it emerged from a fog of silicate vapor. The impact separated the volatiles from the silicates. It took -100 years to condense and rain out the bulk of the vaporized silicates, although relatively volatile elements may have remained present in the atmosphere throughout the magma ocena stage. The magma ocean lasted approx. 2 Myr, its lifetime prolonged by tidal heating and thermal blanketing by a thick (CO2-rich steam atmosphere. Water oceans condensed quickly after the mantle solidified, but for some 10-100 Myr the surface would have stayed warm (approx. 500 K) until the CO2 was removed into the mantle. Thereafter the faint young Sun suggests that a lifeless Earth would always have been evolving toward a bitterly cold ice world, but the cooling trend was frequently interrupted by volcanic or impact induced thaws.

Zahnle, Kevin

2006-01-01

322

AB Blanket for Cities (for continual pleasant weather and protection from chemical, biological and radioactive weapons)  

E-print Network

In a series of previous articles (see references) the author offered to cover a city or other important large installations or subregions by a transparent thin film supported by a small additional air overpressure under the form of an AB Dome. The building of a gigantic inflatable AB Dome over an empty flat surface is not difficult. However, if we want to cover a city, garden, forest or other obstacle course we cannot easily deploy the thin film over building or trees. In this article is suggested a new method which solves this problem. The idea is to design a double film blanket filled by light gas (for example, methane, hydrogen, or helium). Sections of this AB Blanket are lighter then air and fly in atmosphere. They can be made on a flat area (serving as an assembly area) and delivered by dirigible or helicopter to station at altitude over the city. Here they connect to the already assembled AB Blanket subassemblies, cover the city in an AB Dome and protect it from bad weather, chemical, biological and rad...

Bolonkin, Alexander

2009-01-01

323

AB Blanket for Cities (for continual pleasant weather and protection from chemical, biological and radioactive weapons)  

E-print Network

In a series of previous articles (see references) the author offered to cover a city or other important large installations or subregions by a transparent thin film supported by a small additional air overpressure under the form of an AB Dome. The building of a gigantic inflatable AB Dome over an empty flat surface is not difficult. However, if we want to cover a city, garden, forest or other obstacle course we cannot easily deploy the thin film over building or trees. In this article is suggested a new method which solves this problem. The idea is to design a double film blanket filled by light gas (for example, methane, hydrogen, or helium). Sections of this AB Blanket are lighter then air and fly in atmosphere. They can be made on a flat area (serving as an assembly area) and delivered by dirigible or helicopter to station at altitude over the city. Here they connect to the already assembled AB Blanket subassemblies, cover the city in an AB Dome and protect it from bad weather, chemical, biological and radioactive fallout or particulates. After finish of dome building the light gas can be changed by air. Two projects for Manhattan (NY, USA) and Moscow (Russia) are targets for a sample computation.

Alexander Bolonkin

2009-02-04

324

The evolutionary physiology of animal flight: paleobiological and present perspectives.  

PubMed

Recent geophysical analyses suggest the presence of a late Paleozoic oxygen pulse beginning in the late Devonian and continuing through to the late Carboniferous. During this period, plant terrestrialization and global carbon deposition resulted in a dramatic increase in atmospheric oxygen levels, ultimately yielding concentrations potentially as high as 35% relative to the contemporary value of 21%. Such hyperoxia of the late Paleozoic atmosphere may have physiologically facilitated the initial evolution of insect flight metabolism. Widespread gigantism in late Paleozoic insects and other arthropods is also consistent with enhanced oxygen flux within diffusion-limited tracheal systems. Because total atmospheric pressure increases with increased oxygen partial pressure, concurrently hyperdense conditions would have augmented aerodynamic force production in early forms of flying insects. By the late Permian, evolution of decompositional microbial and fungal communities, together with disequilibrium in rates of carbon deposition, gradually reduced oxygen concentrations to values possibly as low as 15%. The disappearance of giant insects by the end of the Permian is consistent with extinction of these taxa for reasons of asphyxiation on a geological time scale. As with winged insects, the multiple historical origins of vertebrate flight in the late Jurassic and Cretaceous correlate temporally with periods of elevated atmospheric oxygen. Much discussion of flight performance in Archaeopteryx assumes a contemporary atmospheric composition. Elevated oxygen levels in the mid- to late Mesozoic would, however, have facilitated aerodynamic force production and enhanced muscle power output for ancestral birds, as well as for precursors to bats and pterosaurs. PMID:10845087

Dudley, R

2000-01-01

325

Giant blocks in the South Kona landslide, Hawaii  

USGS Publications Warehouse

A large field of blocky sea-floor hills, up to 10km long and 500 high, are gigantic slide blocks derived from the west flank of Mauna Loa volcano on the island of Hawaii. These megablocks are embedded in the toe of the south Kona landslide, which extends ~80km seaward from the present coastline to depths of nearly 5km. A 10-15km-wide belt of numerous, smaller, 1-3 km-long slide blocks separates the area of giant blocks from two submarine benches at depths of 2600 and 3700m depth that terminate seaward 20 to 30km from the shoreline. Similar giant blocks are found on several other major submarine Hawaiian landslides, including those north of Oahu and Molokai, but the South Kona blocks are the first to be examined in detail using high-resolution bathymetry, dredging, and submersible diving. Dredging of two of the giant blocks brought up pillowed tholeiitic lava. Megablocks were carried by a late Pleistocene giant landslide 40-80km west from the ancestral shoreline of Mauna Loa volcano before growth of the midslope benches by later slump movement. -from Authors

Moore, J.G.; Bryan, W.B.; Beeson, M.H.; Normark, W.R.

1995-01-01

326

Structural Control of Giant Rock Avalanches in Argentina  

NSDL National Science Digital Library

Jigsaw version: To prepare, students do background reading on landslides and rock avalanches and read the introductory portion of Hermanns and Strecker's 1999 article on rock avalanches in Argentina. In class, students receive data (assembled from figures in the article) on bedrock geology and physiography, as well as stereonets showing orientations of prominent joint sets, bedding, and foliations in the bedrock. Their task is to answer the question of why gigantic rock avalanches occur is some places but not others in this part of Argentina. Each student receives one of four possible data sets and works with a team to analyze the data and solve the problem for the team's area. Each team member must then individually explain his/her analysis to a group of three other students, one from each of the other teams, and the group then compares the four locations for similarities and differences. The activity gives students practice in interpreting geologic maps, using stereonets, and peer teaching. The activity also connects structural geology to another geoscience discipline.Short case example version: This is an abbreviated version of the jigsaw activity described above and focuses on only one of the rock avalanche areas.

Tewksbury, Barb

327

ADELE sensitivity to high-energy radiation from transient luminous events during the Hurricane and Severe Storm Sentinels campaigns  

NASA Astrophysics Data System (ADS)

In the summers of 2013 and 2014, UCSC will fly the Airborne Detector for Energetic Lightning Emissions (ADELE) instrument on board one of the Global Hawk aircraft of the NASA Hurricane and Severe Storm Sentinels (HS3) campaign over storms in the Atlantic. In addition to Terrestrial Gamma-ray Flashes (TGFs), which have been observed at gamma-ray energies by satellites such as RHESSI and FERMI, ADELE will also search for high-energy radiation from Transient Luminous Events (TLEs, i.e. elves, gigantic jets, blue jets, sprites, and sprite halos). High-energy radiation is plausible as a byproduct of stepped leaders in jets, streamers in sprites, and acceleration of electrons in the electromagnetic pulse (EMP) that produces elves. Because ADELE will fly at low altitudes, the intensity of radiation from these events could be orders of magnitude higher at ADELE than at satellites in low earth orbit. We will consider the high energy spectra that might be produced by TLEs and estimate to what extent these phenomena can be observed by ADELE on HS3.

Bowers, G.; Smith, D. M.; Dwyer, J. R.; Cummer, S. A.; Martinez-Mckinney, F.; Kelley, N. A.; Harris, C. B.; Buzbee, P.

2012-12-01

328

No evidence for directional evolution of body mass in herbivorous theropod dinosaurs  

PubMed Central

The correlation between large body size and digestive efficiency has been hypothesized to have driven trends of increasing mass in herbivorous clades by means of directional selection. Yet, to date, few studies have investigated this relationship from a phylogenetic perspective, and none, to our knowledge, with regard to trophic shifts. Here, we reconstruct body mass in the three major subclades of non-avian theropod dinosaurs whose ecomorphology is correlated with extrinsic evidence of at least facultative herbivory in the fossil recordall of which also achieve relative gigantism (more than 3000 kg). Ordinary least-squares regressions on natural log-transformed mean mass recover significant correlations between increasing mass and geological time. However, tests for directional evolution in body mass find no support for a phylogenetic trend, instead favouring passive models of trait evolution. Cross-correlation of sympatric taxa from five localities in Asia reveals that environmental influences such as differential habitat sampling and/or taphonomic filtering affect the preserved record of dinosaurian body mass in the Cretaceous. Our results are congruent with studies documenting that behavioural and/or ecological factors may mitigate the benefit of increasing mass in extant taxa, and suggest that the hypothesis can be extrapolated to herbivorous lineages across geological time scales. PMID:23193135

Zanno, Lindsay E.; Makovicky, Peter J.

2013-01-01

329

Giant lizards occupied herbivorous mammalian ecospace during the Paleogene greenhouse in Southeast Asia  

PubMed Central

Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered with a diverse mammal assemblage from the late middle Eocene Pondaung Formation of Myanmar, which provides a historical test of factors controlling body size in herbivorous squamates. We infer a predominately herbivorous feeding ecology for the new acrodontan based on dental anatomy, phylogenetic relationships and body size. Ranking body masses for Pondaung Formation vertebrates indicates that the lizard occupied a size niche among the larger herbivores and was larger than most carnivorous mammals. Paleotemperature estimates of Pondaung Formation environments based on the body size of the new lizard are approximately 25C higher than modern. These results indicate that competitive exclusion and predation by mammals did not restrict body size evolution in these herbivorous squamates, and elevated temperatures relative to modern climates during the Paleogene greenhouse may have resulted in the evolution of gigantism through elevated poikilothermic metabolic rates and in response to increases in floral productivity. PMID:23740779

Head, Jason J.; Gunnell, Gregg F.; Holroyd, Patricia A.; Hutchison, J. Howard; Ciochon, Russell L.

2013-01-01

330

New Indivisible Planetary Science Paradigm  

E-print Network

I present here a new, indivisible planetary science paradigm, a wholly self-consistent vision of the nature of matter in the Solar System, and dynamics and energy sources of planets. Massive-core planets formed by condensing and raining-out from within giant gaseous protoplanets at high pressures and high temperatures. Earth's complete condensation included a 300 Earth-mass gigantic gas/ice shell that compressed the rocky kernel to about 66% of Earth's present diameter. T-Tauri eruptions stripped the gases away from the inner planets and stripped a portion of Mercury's incompletely condensed protoplanet, and transported it to the region between Mars and Jupiter where it fused with in-falling oxidized condensate from the outer regions of the Solar System and formed the parent matter of ordinary chondrite meteorites, the main-Belt asteroids, and veneer for the inner planets, especially Mars. In response to decompression-driven planetary volume increases, cracks form to increase surface area and mountain ranges ...

Herndon, J Marvin

2013-01-01

331

New Indivisible Planetary Science Paradigm  

E-print Network

I present here a new, indivisible planetary science paradigm, a wholly self-consistent vision of the nature of matter in the Solar System, and dynamics and energy sources of planets. Massive-core planets formed by condensing and raining-out from within giant gaseous protoplanets at high pressures and high temperatures. Earth's complete condensation included a 300 Earth-mass gigantic gas/ice shell that compressed the rocky kernel to about 66% of Earth's present diameter. T-Tauri eruptions stripped the gases away from the inner planets and stripped a portion of Mercury's incompletely condensed protoplanet, and transported it to the region between Mars and Jupiter where it fused with in-falling oxidized condensate from the outer regions of the Solar System and formed the parent matter of ordinary chondrite meteorites, the main-Belt asteroids, and veneer for the inner planets, especially Mars. In response to decompression-driven planetary volume increases, cracks form to increase surface area and mountain ranges characterized by folding form to accommodate changes in curvature. The differences between the inner planets are primarily the consequence of different degrees of protoplanetary compression. The internal composition of Mercury is calculated by analogy with the Earth. The rationale is provided for Mars potentially having a greater subsurface water reservoir capacity than before realized.

J. Marvin Herndon

2013-06-17

332

3D reconstruction of the source and scale of buried young flood channels on Mars.  

PubMed

Outflow channels on Mars are interpreted as the product of gigantic floods due to the catastrophic eruption of groundwater that may also have initiated episodes of climate change. Marte Vallis, the largest of the young martian outflow channels (<500 million years old), is embayed by lava flows that hinder detailed studies and comparisons with older channel systems. Understanding Marte Vallis is essential to our assessment of recent Mars hydrologic activity during a period otherwise considered to be cold and dry. Using data from the Shallow Radar sounder on the Mars Reconnaissance Orbiter, we present a three-dimensional (3D) reconstruction of buried channels on Mars and provide estimates of paleohydrologic parameters. Our work shows that Cerberus Fossae provided the waters that carved Marte Vallis, and it extended an additional 180 kilometers to the east before the emplacement of the younger lava flows. We identified two stages of channel incision and determined that channel depths were more than twice those of previous estimates. PMID:23470730

Morgan, Gareth A; Campbell, Bruce A; Carter, Lynn M; Plaut, Jeffrey J; Phillips, Roger J

2013-05-01

333

Control of Regional and Global Weather  

E-print Network

Author suggests and researches a new revolutionary idea for regional and global weather control. He offers to cover cities, bad regions of country, full country or a continent by a thin closed film with control clarity located at a top limit of the Earth troposphere (4 - 6 km). The film is supported at altitude by small additional atmospheric pressure and connected to ground by thin cables. It is known, the troposphere defines the Earth weather. Authors show this closed dome allows to do a full control of the weather in a given region (the day is always fine, the rain is only in night, no strong wind). The average Earth (white cloudy) reflectance equal 0.3 - 0.5. That means the Earth losses about 0.3 - 0.5 of a solar energy. The dome controls the clarity of film and converts the cold regions to subtropics and creates the hot deserts, desolate wildernesses to the prosperous regions with temperate climate. That is a realistic and the cheapest method of the weather control in the Earth at the current time. Key words: Global weather control, gigantic film dome, converting a cold region to subtropics, converting desolate wilderness to a prosperous region.

Alexander Bolonkin

2007-01-09

334

The Atlas-3D project - IX. The merger origin of a fast and a slow rotating Early-Type Galaxy revealed with deep optical imaging: first results  

E-print Network

The mass assembly of galaxies leaves imprints in their outskirts, such as shells and tidal tails. The frequency and properties of such fine structures depend on the main acting mechanisms - secular evolution, minor or major mergers - and on the age of the last substantial accretion event. We use this to constrain the mass assembly history of two apparently relaxed nearby Early-Type Galaxies (ETGs) selected from the Atlas-3D sample, NGC 680 and NGC 5557. Our ultra deep optical images obtained with MegaCam on the Canada-France-Hawaii Telescope reach 29 mag/arcsec^2 in the g-band. They reveal very low-surface brightness (LSB) filamentary structures around these ellipticals. Among them, a gigantic 160 kpc long tail East of NGC 5557 hosts gas-rich star-forming objects. NGC 680 exhibits two major diffuse plumes apparently connected to extended HI tails, as well as a series of arcs and shells. Comparing the outer stellar and gaseous morphology of the two ellipticals with that predicted from models of colliding galax...

Duc, Pierre-Alain; Serra, Paolo; Michel-Dansac, Leo; Ferriere, Etienne; Alatalo, Katherine; Blitz, Leo; Bois, Maxime; Bournaud, Frederic; Bureau, Martin; Cappellari, Michele; Davies, Roger L; Davis, Timothy A; de Zeeuw, P T; Emsellem, Eric; Khochfar, Sadegh; Krajnovic, Davor; Kuntschner, Harald; Lablanche, Pierre-Yves; McDermid, Richard M; Morganti, Raffaella; Naab, Thorsten; Oosterloo, Tom; Sarzi, Marc; Scott, Nicholas; Weijmans, Anne-Marie; Young, Lisa M

2011-01-01

335

Unforecasted earthquake and forgotten tsunamis: Lessons from 2011 Tohoku event  

NASA Astrophysics Data System (ADS)

The 11 March Tohoku earthquake was the largest (M~9) earthquake in Japan's history. Historical data indicated that large (M<8) earthquakes have repeated in Miyagi-oki since 1793 with an average recurrence interval of 37 years. Because the most recent event occurred in 1978, the probability of an earthquake in the next 30 years was forecasted as 99 %, the highest number of such a long-term forecast around Japan. The March event, however, was not a characteristic type as repeated in the last few centuries, but the size and spatial extent far exceeded the forecast. Very few seismologists anticipated such a gigantic earthquake would occur around Japan. The March earthquake caused about 20,000 fatalities, mostly from its tsunami. Such devastating tsunami was not the first one in Japan. The Sanriku coast, a sawtooth-shaped submerging coast of northern Tohoku, has suffered from damaging tsunamis in the last century. The 1960 Chilean tsunami was about 3 to 5 m high, and caused about 120 fatalities. The 1933 Sanriku tsunami caused up to 20 m tsunami and about 3,000 fatalities. The 1896 Sanriku tsunami caused more than 30 m tsunami with 22,000 fatalities. The 2011 tsunami heights and fatalities were roughly comparable to those from the 1896 tsunami. To the south of Sanriku coast around Sendai, the coastlines are simpler and characterized by flat plains. While the above historic tsunamis were not high on Sendai plain, a historical document and recent geological studies of tsunami deposits have shown that AD 869 Jogan tsunami caused several km of tsunami inundation and a thousand fatalities, very similar to the 2011 tsunami. However, tsunami hazard maps were constructed for the characteristic earthquake with high probability. On March 11, the tsunami warning message was issued by Japan Meteorological Agency (JMA) within 3 minutes of the earthquake. The rupture process of the giant earthquake took a few minutes to complete, hence the estimated earthquake size for the tsunami warning was underestimated. The tsunami arrival time and coastal heights calculated for an earthquake of M 7.9 were announced with tsunami warning message. When a few meters of tsunami was detected on offshore tsunami gauges, JMA upgraded the tsunami warning level, but this information did not reach all the coastal residents particularly at heavily damaged area. The March earthquake and tsunami disaster left many lessons. (1) the long-term forecast should consider prehistoric paleoseismological data, even if historical data for centuries are available, (2) tsunami hazard maps may need to be prepared for infrequent gigantic earthquakes as well as more frequent smaller-sized earthquakes, (3) the past tsunami disaster must be remembered and transmitted to next generation, and (4) upgrading tsunami warning level in emergency situation is rather difficult.

Satake, K.

2011-12-01

336

Transregional lineament of Central Asia, its magmatism, metallogeny and seismicity  

NASA Astrophysics Data System (ADS)

The analysis of the place and role of such large fault as Central Kyzylkum, North Nurata and South Ferghana, Atbashin, which were regarded earlier as separate independent structures led us to the idea that they are parts of a single global structure. We suggest that it should be called "Transregional lineament of Central Asia". Transregional lineament of Central Asia is multisutured long-term, and in the nodal points of some parts it is complicated by deep fault zones of Anti Tien-Shan trend.There are large gold ore deposits (Muruntau, Kokpatas, Kumtor) in the intersection of some of these faults. Within the lineament there are 4 mafite - ultramafite associations of different age, that are presented as isolated or combined blocks, zones and regions. The most ancient is ophiolite one (I association). Best of all it is developed in Sultanuvais and Northern Tamdytau, Uzbekistan. The second, rift association of this belt is picrite-gabbro-diabase-alkali-olivine-basalt is widespread within the belt (northern Bukantau, northern Nuratau, northern slope of the Altay ridge).The third association is peridotite-gabbroic. It is represented by the Tebinbulak intrusive of Sultanuvais. Coverings, small stocks, dikes and explosion tubes formed by potassic mafite-ultramafites ore related to much later inter-plate (P-T) occurrences of mafite-ultramafite magmatism (IY association). On Kyrgyzstan's territory the studied lineament is observed as a system of regional deep faults -Atbashi-Inylchek and Southern Ferghana, with which the ophiolite ultramafite-mafite formation is associated. The rocks have the traces of tectonic movements, which can be the ground to regard them as protrusions. Tectonically, the vast territory of Mongolia is divided into two large blocks: northern and southern. This part of the lineament called Transmongolian. This part is week studied-a special investigation was only carried out in its western part - Bulgan fault. Thus, in the presence of linear-stretched sublatitudinal metallogenic belts within the area of the studied transregional lineament in the Central Asian region, the most prospective ore deposits'assemblages are located in the intersection of these belts as deep faults of meridional, north-eastern and north-western trend. The following deposits are situated in such intersection zones: the largest in Eurasia Muruntau gold deposit, a large deposit Kumtor, Kyrgyzstan; and the gigantic class deposit - Ashi in China.Anomalously increased heat flow density (HFD) values both Muruntau deposit (according to our data- up to 85 mW/m2), and for Kumtor deposit (according to E.A.Ljubimova data - up to 130 mW/m2 ) indicate the deep character of dislocations. Interpretation of seismic observations revealed a transregional zone with the width of up to 80 km in the upper part of Kyzylkums crust. The strip is located in the relief of Moho surface, and is discordant to the general trend of premesozoic structures. Abrupt variations of the Moho boundary with vertical movement of up to 10 km are observed in the eastern end of the Issyk-Kul valley and at the boundary of Northern and Middle Tien Shan, along the Nikolaev line. In conclusion we'd like to note that such structures are well-known in American, Australian and other continents.They are recognized as deep structures and served as channels for the heat energy, magmas and fluids to come out of the core and mantle of the Earth. In this connection, activity of these structures are accompanied by the presence of various magamatic, endogenous as well as gigantic ore deposits.

Sidorova, I.

2004-12-01

337

Types and Evolution of Gas Hydrate System along the Tectonically Active Zones of the Western Pacific: Nankai Trough vs. Eastern Margin of Japan Sea  

NASA Astrophysics Data System (ADS)

A series of sea-going surveys of marine gas hydrates around Japan Islands for more than a decade has revealed characteristic and contrasting features and evolution of gas hydrate system between the Nankai subduction zone and the Joetsu Basin of Japan Sea. Gas hydrate of the Nankai trough largely occurs as pore-filling type, laterally extending in turbidites. Methane is depleted in C-13, mostly derived from microbial brake-down of organic matters. Strong and continuous BSRs occur at around 270 mbsf, corresponding to the base of gas hydrate stability (BGHS). Furthermore, double BSRs with weak reflector (BSR-2) 20-30 m below BSR appear in uplifting knolls. BSR-2 is explained as a relic BSR, which coincides with BGHS. Combination effects of uplifting of gas hydrate bearing sediments and sea-level fall are likely to have caused shoaling of BGHS and BSRs, dissociation of gas hydrate between old and new BRSs, and further accumulation of gas hydrates above BSR. Thus the recycling of methane at BGHS triggered by glacial sea level fall contributed for the development of subsurface gas hydrate deposits. Joetsu basin is located on a newly formed convergent boundary between Eurasia and Philippine Sea Plates. Well-defined circular pockmarks with ca.500 m in diameter develop on the folded and faulted Umitaka spur and Joetsu knoll in the basin. A number of circular swells and mounds, 200-500 m in diameter, have been also recognized nearby the pockmarks. Thus the Umitaka spur and perhaps Joetsu knoll are characterized by rough topography of pockmarks and mounds. Methane of plumes and gas hydrate originates in deep-seated thermogenic gases with relatively heavy carbon. 3D seismic profiles clearly depict gas chimney structures below pockmark-mound zones, and gigantic methane plumes stand on the mounds not in the pockmarks. Pockmarks are often considered as vent holes, however, those of the Joestu Basin are quite. BSRs occur at about 150 mbsr, corresponding to very high heat flow, and are widely distributed throughout the area, while no double BSRs are observed. BSRs within gas chimneys are very strong and often exhibit pull-up structure. A number of piston corers have recovered chunks of massive gas hydrate from the mounds. ROV dives observed gas hydrates exposed atop the mounds. Furthermore, electric ocean floor survey has revealed that sediments below the pockmark-mound zones were not conductive. These lines of evidence suggest that the mounds are more-or-less composed of or at least contain significant amounts of methane. Sea-level fall during the last glacial, 120 m in Japan Sea, should have caused instability of gas hydrate, in particular, those within pockmarks. Pull-up structures within the chimney seem to support the model that the mounds are gas hydrate dome and the pockmark, probably a relic hydrate mound. Glacial sea level fall should have caused massive dissociation of subsurface methane hydrate as in case of the Nankai trough. However the methane from the dissociation of massive hydrate in the chimney should escape to seawater to form a crater-like depression pockmarks. Considering active venting, gigantic plumes, inferred violent venting and perhaps floating of massive gas hydrates, gas hydrate deposits are to be formed during warmer, high-sea level periods, and episodic dissociation and massive emission of methane to ocean/atmosphere system.

Matsumoto, R.; Tomaru, H.; Takeuchi, L.; Hiruta, A.; Ishizaki, O.; Aoyama, C.; Machiyama, H.; Goto, T.

2007-12-01

338

Rare normal faulting earthquake induced by subduction megaquake: example from 2011 Tohoku-oki earthquake  

NASA Astrophysics Data System (ADS)

A month after March 11 gigantic M9.0 Tohoku-oki earthquake, M7.0 intraplate earthquake occurred at a depth of 5 km on April 11 beneath coastal area of near Iwaki city, Fukushima prefecture. Focal mechanism of the mainshock indicates that this earthquake is a normal faulting event. Based on field reconnaissance and LIDAR mapping by Geospatial Information Authority of Japan, we recognized coseismic surface ruptures, presumably associated with the main shock. Coseismic surface ruptures extend NNW for about 11 km in a right-stepping en echelon manner. Geomorphic expressions of these ruptures commonly include WWS-facing normal fault scarps and/or drape fold scarp with open cracks on their crests, on the hanging wall sides of steeply west-dipping normal fault planes subparallel to Cretaceous metamorphic rocks. Highest topographic scarp height is about 2.3 m. In this study we introduce preliminary results of a trenching survey across the coseismic surface ruptures at Shionohira site, to resolve timing of paleoseismic events along the Shionohira fault. Trench excavations were carried out at two sites (Ichinokura and Shionohira sites) in Iwaki, Fukushima. At Shionohira site a 2-m-deep trench was excavated across the coseismic fault scarp emerged on the alluvial plain on the eastern flank of the Abukuma Mountains. On the trench walls we observed pairs of steeply dipping normal faults that deform Neogene to Paleogene conglomerates and unconformably overlying, late Quaternary to Holocene fluvial units. Sense of fault slip observed on the trench walls (large dip-slip with small sinistral component) is consistent with that estimated from coseismic surface ruptures. Fault throw estimated from separation of piercing points on lower Unit I and vertical structural relief on folded upper Unit I is consistent with topographic height of the coseismic fault scarp at the trench site. In contrast, vertical separation of Unit II, unconformably overlain by Unit I, is measured as about 1.5 m, twice as large as coseismic vertical component of slip, indicative of penultimate seismic event prior to the 2011 earthquake. Abrupt thickening of overlying Unit I may also suggest preexisting topographic relief prior to its deposition. Radiocarbon dating of charred materials included in event horizons and tephrostratigraphy at two sites indicate that penultimate event prior to the 2011 event might occurred at about 40 ka. This normal fault earthquake is in contrast to compressional or neutral stress regimes in Tohoku region before the 2011 megaquake and rarity of the normal faulting earthquake inferred from these paleoseismic studies may reflect its mechanical relation to the gigantic megathrust earthquakes, such as unusual, enhanced extensional stress on the hangingwall block induced by mainshock and/or postseismic creep after the M~9 earthquake.

Ishiyama, T.; Sugito, N.; Echigo, T.; Sato, H.; Suzuki, T.

2012-04-01

339

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA Electronic-Theater 2002. Spectacular Visualizations of our Blue Marble  

NASA Technical Reports Server (NTRS)

Spectacular Visualizations of our Blue Marble The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to the 2002 Winter Olympic Stadium Site of the Olympic Opening and Closing Ceremonies in Salt Lake City. Fly in and through Olympic Alpine Venues using 1 m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies including hurricanes & "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including new 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we communicate science. (In cooperation with the American Museum of Natural History in NYC). See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers of Newsweek, TIME, National Geographic, Popular Science & on National & International Network TV. New computer software tools allow us to roam & zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See vertexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nicola Nina climate changes. See the city lights, fishing fleets, gas flares and biomass burning of the Earth at night observed by the "night-vision" DMSP military satellite.

Hasler, A. F.; Starr, David (Technical Monitor)

2002-01-01

340

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA Electronic Theater 2002  

NASA Technical Reports Server (NTRS)

The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to the 2002 Winter Olympic Stadium Site of the Olympic Opening and Closing Ceremonies in Salt Lake City. Fly in and through Olympic Alpine Venues using 1 m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies including hurricanes and "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including new 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we communicate science. (In cooperation with the American Museum of Natural History in NYC) See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers of Newsweek, TIME, National Geographic, Popular Science and on National and International Network TV. New computer software tools allow us to roam and zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds. data. Spectacular new visualizations of the global atmosphere and oceans are shown. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP military satellite.

Haser, Fritz; Starr, David (Technical Monitor)

2002-01-01

341

The Liang Bua faunal remains: a 95k.yr. sequence from Flores, East Indonesia.  

PubMed

Excavations at Liang Bua, a limestone cave on the island of Flores, East Indonesia, have yielded a well-dated archaeological and faunal sequence spanning the last 95k.yr., major climatic fluctuations, and two human species -H. floresiensis from 95 to 17k.yr.(1), and modern humans from 11k.yr. to the present. The faunal assemblage comprises well-preserved mammal, bird, reptile and mollusc remains, including examples of island gigantism in small mammals and the dwarfing of large taxa. Together with evidence from Early-Middle Pleistocene sites in the Soa Basin, it confirms the long-term isolation, impoverishment, and phylogenetic continuity of the Flores faunal community. The accumulation of Stegodon and Komodo dragon remains at the site in the Pleistocene is attributed to Homo floresiensis, while predatory birds, including an extinct species of owl, were largely responsible for the accumulation of the small vertebrates. The disappearance from the sequence of the two large-bodied, endemic mammals, Stegodon florensis insularis and Homo floresiensis, was associated with a volcanic eruption at 17 ka and precedes the earliest evidence for modern humans, who initiated use of mollusc and shell working, and began to introduce a range of exotic animals to the island. Faunal introductions during the Holocene included the Sulawesi warty pig (Sus celebensis) at about 7ka, followed by the Eurasian pig (Sus scrofa), Long-tailed macaque, Javanese porcupine, and Masked palm civet at about 4ka, and cattle, deer, and horse - possibly by the Portuguese within historic times. The Holocene sequence at the site also documents local faunal extinctions - a result of accelerating human population growth, habitat loss, and over-exploitation. PMID:19058833

van den Bergh, G D; Meijer, H J M; Due Awe, Rokhus; Morwood, M J; Szab, K; van den Hoek Ostende, L W; Sutikna, T; Saptomo, E W; Piper, P J; Dobney, K M

2009-11-01

342

Underlying mechanisms of transient luminous events: a review  

NASA Astrophysics Data System (ADS)

Transient luminous events (TLEs) occasionally observed above a strong thunderstorm system have been the subject of a great deal of research during recent years. The main goal of this review is to introduce readers to recent theories of electrodynamics processes associated with TLEs. We examine the simplest versions of these theories in order to make their physics as transparent as possible. The study is begun with the conventional mechanism for air breakdown at stratospheric and mesospheric altitudes. An electron impact ionization and dissociative attachment to neutrals are discussed. A streamer size and mobility of electrons as a function of altitude in the atmosphere are estimated on the basis of similarity law. An alternative mechanism of air breakdown, runaway electron mechanism, is discussed. In this section we focus on a runaway breakdown field, characteristic length to increase avalanche of runaway electrons and on the role played by fast seed electrons in generation of the runaway breakdown. An effect of thunderclouds charge distribution on initiation of blue jets and gigantic jets is examined. A model in which the blue jet is treated as upward-propagating positive leader with a streamer zone/corona on the top is discussed. Sprite models based on streamer-like mechanism of air breakdown in the presence of atmospheric conductivity are reviewed. To analyze conditions for sprite generation, thunderstorm electric field arising just after positive cloud-to-ground stroke is compared with the thresholds for propagation of positively/negatively charged streamers and with runway breakdown. Our own estimate of tendril's length at the bottom of sprite is obtained to demonstrate that the runaway breakdown can trigger the streamer formation. In conclusion we discuss physical mechanisms of VLF (very low frequency) and ELF (extremely low frequency) phenomena associated with sprites.

Surkov, V. V.; Hayakawa, M.

2012-08-01

343

Investigating onychophoran gas exchange and water balance as a means to inform current controversies in arthropod physiology.  

PubMed

Several controversies currently dominate the fields of arthropod metabolic rate, gas exchange and water balance, including the extent to which modulation of gas exchange reduces water loss, the origins of discontinuous gas exchange, the relationship between metabolic rate and life-history strategies, and the causes of Palaeozoic gigantism. In all of these areas, repeated calls have been made for the investigation of groups that might most inform the debates, especially of taxa in key phylogenetic positions. Here we respond to this call by investigating metabolic rate, respiratory water loss and critical oxygen partial pressure (Pc) in the onychophoran Peripatopsis capensis, a member of a group basal to the arthropods, and by synthesizing the available data on the Onychophora. The rate of carbon dioxide release (VCO2) at 20 degrees C in P. capensis is 0.043 ml CO2 h(-1), in keeping with other onychophoran species; suggesting that low metabolic rates in some arthropod groups are derived. Continuous gas exchange suggests that more complex gas exchange patterns are also derived. Total water loss in P. capensis is 57 mg H2O h(-1) at 20 degrees C, similar to modern estimates for another onychophoran species. High relative respiratory water loss rates ( approximately 34%; estimated using a regression technique) suggest that the basal condition in arthropods may be a high respiratory water loss rate. Relatively high Pc values (5-10% O2) suggest that substantial safety margins in insects are also a derived condition. Curling behaviour in P. capensis appears to be a strategy to lower energetic costs when resting, and the concomitant depression of water loss is a proximate consequence of this behaviour. PMID:18805813

Clusella-Trullas, Susana; Chown, Steven L

2008-10-01

344

Fluorescence advantages with microscopic spatiotemporal control  

PubMed Central

We present a clever design concept of using femtosecond laser pulses in microscopy by selective excitation or de-excitation of one fluorophore over the other overlapping one. Using either a simple pair of femtosecond pulses with variable delay or using a train of laser pulses at 20-50 Giga-Hertz excitation, we show controlled fluorescence excitation or suppression of one of the fluorophores with respect to the other through wave-packet interference, an effect that prevails even after the fluorophore coherence timescale. Such an approach can be used both under the single-photon excitation as well as in the multi-photon excitation conditions resulting in effective higher spatial resolution. Such high spatial resolution advantage with broadband-pulsed excitation is of immense benefit to multi-photon microscopy and can also be an effective detection scheme for trapped nanoparticles with near-infrared light. Such sub-diffraction limit trapping of nanoparticles is challenging and a two-photon fluorescence diagnostics allows a direct observation of a single nanoparticle in a femtosecond high-repetition rate laser trap, which promises new directions to spectroscopy at the single molecule level in solution. The gigantic peak power of femtosecond laser pulses at high repetition rate, even at low average powers, provide huge instantaneous gradient force that most effectively result in a stable optical trap for spatial control at sub-diffraction limit. Such studies have also enabled us to explore simultaneous control of internal and external degrees of freedom that require coupling of various control parameters to result in spatiotemporal control, which promises to be a versatile tool for the microscopic world. PMID:23814447

Goswami, Debabrata; Roy, Debjit; De, Arijit K.

2013-01-01

345

New insights into regional tectonics of the Indochina Peninsula inferred from Lower-Middle Jurassic paleomagnetic data of the Sibumasu Terrane  

NASA Astrophysics Data System (ADS)

The post-Jurassic occurrence of differential tectonic rotation between the Indochina and South Sundaland blocks remains an issue to be properly investigated. New paleomagnetic study is used here to find the role of Sibumasu Terrane in this rotation, which is located between a clockwise rotated Indochina Block and a counter-clockwise rotated South Sundaland Block. For this purpose, lower to middle Jurassic red sandstones of the Umphang Group in the Sibumasu Terrane were sampled at 21 sites in the Ratchaburi area (13.6E, 99.6E), Thailand. Stepwise thermal demagnetization by 680 C unblocked a pre-folding characteristic remanent magnetization. A mean direction of this component at 100% unfolding is Ds = 348.5, Is = 24.7, ?95 = 10.5, k = 10.7, N = 20, corresponding to an Early-Middle Jurassic pole of ? = 78.6N, ? = 10.6E (A95 = 9.3). Comparison of this direction with those reported from other localities of the Umphang Group (Kalaw, Mae Sot and North Trang Syncline localities) reveal variable declinations (between 348.5 and 44.7) for the Sibumasu Terrane. We ascribe this variation to differential tectonic deformation in the Sibumasu Terrane, as reflected from sinusoidal shaped structural features in the study area. The presence of such features in the granitic rocks indicates the occurrences of deformational activities after their intrusion, which took place in the period between 130 Ma and 51 Ma. The Sibumasu Terrane behaved as an independent fragment at a time when Indochina was undergoing a clockwise rotation and southward displacement, as a result of extrusion tectonics after the gigantic India-Asia collision. Taking into consideration a westerly deflected declination (D = 342.8) from the West Trang area in Peninsular Thailand, a counterclockwise rotation of 15 is estimated for the Sibumasu Terrane, as a result of continuous northward indentation of the Australian Plate into South Sundaland Block.

Fujiwara, Katsuya P.; Zaman, Haider; Surinkum, Adichat; Chaiwong, Nikhom; Fujihara, Makoto; Ahn, Hyeon-Seon; Otofuji, Yo-ichiro

2014-11-01

346

Muzzle of South American Pleistocene ground sloths (Xenarthra, Tardigrada).  

PubMed

Sloths are among the most characteristic elements of the Cainozoic of South America and are represented, during the Pleistocene, by approximately nine genera of gigantic ground sloths (Megatheriidae and Mylodontidae). A few contributions have described their masticatory apparatus, but almost no attention has been paid to the reconstruction of the muzzle, an important feature to consider in relation to food intake, and particularly relevant in sloths because of the edentulous nature of the muzzle and its varied morphology. The relationship between dietary habits and shape and width of the muzzle is well documented in living herbivores and has been considered an important feature for the inference of alimentary styles in fossils, providing an interesting methodological tool that deserves to be considered for xenarthrans. The goal of this study was to examine models of food intake by reconstructing the appearance and shape of the muzzle in five species of Pleistocene ground sloths (Megatherium americanum, Glossotherium robustum, Lestodon armatus, Mylodon darwini, and Scelidotherium leptocephalum) using reconstructions of the nasal cartilages and facial muscles involved in food intake. The preservation of the nasal septum, and the scars for muscular attachment in the rostral part of the skulls, allow making a conservative reconstruction of muzzle anatomy in fossil sloths. Wide-muzzled ground sloths (Glossotherium and Lestodon) had a square, nonprehensile upper lip and were mostly bulk-feeders. The lips, coupled with the tongue, were used to pull out grass and herbaceous plants. Narrow-muzzled sloths (Mylodon, Scelidotherium, and Megatherium) had a cone-shaped and prehensile lip and were mixed or selective feeders. The prehensile lip was used to select particular plants or plant parts. PMID:16315216

Bargo, M Susana; Toledo, Nstor; Vizcano, Sergio F

2006-02-01

347

Multiple episodes of fluid flow in the SW Barents Sea (Loppa High) evidenced by gas flares, pockmarks and gas hydrate accumulation  

NASA Astrophysics Data System (ADS)

Gas and gas hydrates have gained considerable attention in the last 20 yr due to their possible impact on global climate change from methane escalations. Our study area, the SW Barents Sea, is unique in its evolution due to the effect of glaciations which removed thick layers of sediment from the seabed. Unloading due to erosion and deglaciation resulted in opening of pre-existing faults and creation of new ones, facilitating fluid migration and eventually escape into the water from the subsurface. Expressions of hydrocarbon gas accumulation and fluid flow such as gas hydrates and pockmarks are widely distributed in the Barents Sea. Several gas flares, some of them 200 m high in echograms, occur along a segment of the Ringvassy Loppa Fault Complex, indicating open fractures and active fluid flow. Observation of gas flares along regional fault complexes outside pockmark regions indicates that present gas escape occurs along faults only. The pockmark formation and gas flares belong to different episodes of fluid flow. The pockmarks are absent outside soft sediment depocentres indicating that their existence is related to the presence of recording medium. The thin sediment cover in pockmarks and their penetration down into glaciomarine sediments indicate that they formed after deposition of these sediments and that fluid escape was active to the very recent past. Methane hydrate stability zone (MHSZ) modelling shows that after the last glacial maximum 18 000-20 000 14C years ago, the MHSZ has thinned from 600 m to zero in most parts of the SW Barents Sea. The fluid expulsion probably happened after retreat of the glaciers causing release of methane from dissociation of methane hydrates through fluid escape processes which lasted until recently. Bottom simulating reflectors (BSR) observed are probably due to structure II hydrates formed from gas containing higher order hydrocarbon components such as ethane, propane, etc. along with methane. The study area falls close to the new gigantic oil discoveries, Skrugard and Havis, and north of the Snhvit hydrocarbon field.

Chand, S.; Thorsnes, T.; Rise, L.; Brunstad, H.; Stoddart, D.; Be, R.; Lgstad, P.; Svolsbru, T.

2012-05-01

348

Multiple step growth of single crystalline rutile nanorods with the assistance of self-assembled monolayer for dye sensitized solar cells.  

PubMed

A novel multiple step growth (MSG) process has been developed to synthesize rutile nanorods (NRs) on fluorine-doped tin oxide (FTO) glass with the assistance of a self-assembled monolayer (SAM) aiming to increase the internal surface area of the 1D materials for dye sensitized solar cell (DSSC) applications. The experimental result reveals that the SAM layer can be selectively decomposed at the tip of the nanorod, namely the rutile (001) surface, due to the anisotropic photocatalytic property of the rutile. The remaining SAM layer on the side-wall of the NRs remains intact and serves as water repellent which prevents the radial growth of the NRs during the next step hydrothermal synthesis; therefore, the spacing between the NRs and the porosity of the NR array can be retained after additional growth cycles. On the other hand, introduction of a middle layer formed via TiCl4 solution treatment before the next growth cycle is found to be an effective way to control the diameters of the newly grown NRs. The performance of DSSC made from the rutile NRs grown using the MSG technique has been examined, and it is significantly affected by the internal surfaces of the NRs. Furthermore, the MSG combined with NR etching treatment by acid at low temperature (150 C) leads to a significant enhancement in the solar cell performance. The gigantic wettability difference of the NRs before and after the SAM treatment as well as the MSG method could be adapted to prepare superhydrophobic and superhydrophilic nanostructured patterns for other applications. PMID:24033252

Yang, Mengjin; Neupane, Suman; Wang, Xuewen; He, Jin; Li, Wenzhi; Pala, Nezih

2013-10-01

349

Hellbender Genome Sequences Shed Light on Genomic Expansion at the Base of Crown Salamanders  

PubMed Central

Among animals, genome sizes range from 20 Mb to 130 Gb, with 380-fold variation across vertebrates. Most of the largest vertebrate genomes are found in salamanders, an amphibian clade of 660 species. Thus, salamanders are an important system for studying causes and consequences of genomic gigantism. Previously, we showed that plethodontid salamander genomes accumulate higher levels of long terminal repeat (LTR) retrotransposons than do other vertebrates, although the evolutionary origins of such sequences remained unexplored. We also showed that some salamanders in the family Plethodontidae have relatively slow rates of DNA loss through small insertions and deletions. Here, we present new data from Cryptobranchus alleganiensis, the hellbender. Cryptobranchus and Plethodontidae span the basal phylogenetic split within salamanders; thus, analyses incorporating these taxa can shed light on the genome of the ancestral crown salamander lineage, which underwent expansion. We show that high levels of LTR retrotransposons likely characterize all crown salamanders, suggesting that disproportionate expansion of this transposable element (TE) class contributed to genomic expansion. Phylogenetic and age distribution analyses of salamander LTR retrotransposons indicate that salamanders high TE levels reflect persistence and diversification of ancestral TEs rather than horizontal transfer events. Finally, we show that relatively slow DNA loss rates through small indels likely characterize all crown salamanders, suggesting that a decreased DNA loss rate contributed to genomic expansion at the clades base. Our identification of shared genomic features across phylogenetically distant salamanders is a first step toward identifying the evolutionary processes underlying accumulation and persistence of high levels of repetitive sequence in salamander genomes. PMID:24958463

Sun, Cheng; Mueller, Rachel Lockridge

2014-01-01

350

Late Palaeozoic to Triassic evolution of the Turan and Scythian platforms: The pre-history of the Palaeo-Tethyan closure  

NASA Astrophysics Data System (ADS)

A number of en chelon-arranged, southwest-facing arc fragments of Palaeozoic to Jurassic ages, sandwiched between two fairly straight east-northeast trending boundaries, constitute the basement of the Scythian and the Turan platforms located between the Laurasian and Tethyside units. They have until now largely escaped detection owing to extensive Jurassic and younger cover and the inaccessibility of the subsurface data to the international geological community. These units are separated from one another by linear/gently-curved faults of great length and steep dip. Those that are exposed show evidence of strike-slip motion. The arc units originally constituted parts of a single "Silk Road Arc" located somewhere south of the present-day central Asia for much of the Palaeozoic, although by the late Carboniferous they had been united into a continental margin arc south of the Tarim basin and equivalent units to the west and east. They were stacked into their present places in northern Afghanistan, Turkmenistan, Caucasus and the northern Black Sea by large-scale, right-lateral strike-slip coastwise transport along arc-slicing and arc-shaving strike-slip faults in the Triassic and medial Jurassic simultaneously with the subductive elimination of Palaeo-Tethys. This gigantic dextral zone ("the Silk Road transpression") was a trans-Eurasian structure and was active simultaneously with another, similar system, the Gornostaev keirogen and greatly distorted Eurasia. The late Palaeozoic to Jurassic internal deformation of the Dniepr-Donets aulacogen was also a part of the dextral strain in southern Europe. When the emplacement of the Scythian and Turan units was completed, the elimination of Palaeo-Tethys had also ended and Neo-Tethyan arcs were constructed atop their ruins, mostly across their southern parts. The western end of the great dextral zone that emplaced the Turan and Scythian units horsetails just east of north Dobrudja and a small component goes along the Tornquist-Teisseyre lineament.

Natal'in, Boris A.; ?engr, A. M. Cell

2005-08-01

351

The giant bite of a new raptorial sperm whale from the Miocene epoch of Peru.  

PubMed

The modern giant sperm whale Physeter macrocephalus, one of the largest known predators, preys upon cephalopods at great depths. Lacking a functional upper dentition, it relies on suction for catching its prey; in contrast, several smaller Miocene sperm whales (Physeteroidea) have been interpreted as raptorial (versus suction) feeders, analogous to the modern killer whale Orcinus orca. Whereas very large physeteroid teeth have been discovered in various Miocene localities, associated diagnostic cranial remains have not been found so far. Here we report the discovery of a new giant sperm whale from the Middle Miocene of Peru (approximately 12-13 million years ago), Leviathan melvillei, described on the basis of a skull with teeth and mandible. With a 3-m-long head, very large upper and lower teeth (maximum diameter and length of 12 cm and greater than 36 cm, respectively), robust jaws and a temporal fossa considerably larger than in Physeter, this stem physeteroid represents one of the largest raptorial predators and, to our knowledge, the biggest tetrapod bite ever found. The appearance of gigantic raptorial sperm whales in the fossil record coincides with a phase of diversification and size-range increase of the baleen-bearing mysticetes in the Miocene. We propose that Leviathan fed mostly on high-energy content medium-size baleen whales. As a top predator, together with the contemporaneous giant shark Carcharocles megalodon, it probably had a profound impact on the structuring of Miocene marine communities. The development of a vast supracranial basin in Leviathan, extending on the rostrum as in Physeter, might indicate the presence of an enlarged spermaceti organ in the former that is not associated with deep diving or obligatory suction feeding. PMID:20596020

Lambert, Olivier; Bianucci, Giovanni; Post, Klaas; de Muizon, Christian; Salas-Gismondi, Rodolfo; Urbina, Mario; Reumer, Jelle

2010-07-01

352

Reproductive Biology and Its Impact on Body Size: Comparative Analysis of Mammalian, Avian and Dinosaurian Reproduction  

PubMed Central

Janis and Carrano (1992) suggested that large dinosaurs might have faced a lower risk of extinction under ecological changes than similar-sized mammals because large dinosaurs had a higher potential reproductive output than similar-sized mammals (JC hypothesis). First, we tested the assumption underlying the JC hypothesis. We therefore analysed the potential reproductive output (reflected in clutch/litter size and annual offspring number) of extant terrestrial mammals and birds (as dinosaur analogs) and of extinct dinosaurs. With the exception of rodents, the differences in the reproductive output of similar-sized birds and mammals proposed by Janis and Carrano (1992) existed even at the level of single orders. Fossil dinosaur clutches were larger than litters of similar-sized mammals, and dinosaur clutch sizes were comparable to those of similar-sized birds. Because the extinction risk of extant species often correlates with a low reproductive output, the latter difference suggests a lower risk of population extinction in dinosaurs than in mammals. Second, we present a very simple, mathematical model that demonstrates the advantage of a high reproductive output underlying the JC hypothesis. It predicts that a species with a high reproductive output that usually faces very high juvenile mortalities will benefit more strongly in terms of population size from reduced juvenile mortalities (e.g., resulting from a stochastic reduction in population size) than a species with a low reproductive output that usually comprises low juvenile mortalities. Based on our results, we suggest that reproductive strategy could have contributed to the evolution of the exceptional gigantism seen in dinosaurs that does not exist in extant terrestrial mammals. Large dinosaurs, e.g., the sauropods, may have easily sustained populations of very large-bodied species over evolutionary time. PMID:22194835

Werner, Jan; Griebeler, Eva Maria

2011-01-01

353

Postseismic deformations following the Sumatra-Andaman earthquake in SE Asia during three and half years  

NASA Astrophysics Data System (ADS)

Since the occurrence of the 2004 Sumatra-Andaman earthquake (Mw9.2), the Sumatra-Andaman Subduction zone has attracted geophysicists' attention. We have been carrying on CGPS observation in Thailand and Myanmar to detect postseismic deformation following this gigantic event. Since CGPS on land is not enough to clarify the detailed image of postseismic deformation, we also make InSAR analyses in Andaman and Phuket Islands. On September 12, 2007, another Mw8.4 event occurred SW off Sumatra. We report deformations observed with GPS and SAR including co- and postseismic deformation following this event. We have analyzed CGPS data up to the end of 2007 and detected postseismic displacements all over the Indochina peninsula. Phuket, which suffered from about 26cm coseismic displacement, has shifted by ~26cm southwestward till July, 2007. Postseismic transient is clearly recognized and already exceeds coseismic movements at remote sites such as Bangkok and Chiang Mai in Thailand. We try to invert observed postseismic displacement and estimate distribution of afterslip using Yabuki and Matsu'ura's(1992) scheme. Afterslip may have rapidly decayed in and around the source region of the Nias earthquake and beneath the Andaman Islands, while it still continues beneath the northern tip of Sumatra and Nicobar Island. This result implies spatial variation in frictional property on the plate interface. Our GPS sites are located in far field and the afterslip distribution obtained above does not have enough resolution in the depth direction. In order to examine near-field displacement, we also process 3 ALOS/PALSAR images acquired during Jun.19, 2007 and May 6, 2008, in Andaman Islands in order detect postseismic transient. The result shows a negative line-of-sight displacement in the southern part, which is consistent with CGPS observation by Paul et al.(2007). This movement can be simulated by an afterslip on a shallow part of the plate interface.

Hashimoto, M.; Fukushima, Y.; Katagi, T.; Hashizume, M.; Satomura, M.; Wu, P.; Ishii, M.; Kato, T.; Fukuda, Y.

2009-04-01

354

The evolving science of detection of 'blood doping'.  

PubMed

Blood doping practices in sports have been around for at least half a century and will likely remain for several years to come. The main reason for the various forms of blood doping to be common is that they are easy to perform, and the effects on exercise performance are gigantic. Yet another reason for blood doping to be a popular illicit practice is that detection is difficult. For autologous blood transfusions, for example, no direct test exists, and the direct testing of misuse with recombinant human erythropoietin (rhEpo) has proven very difficult despite a test exists. Future blood doping practice will likely include the stabilization of the transcription factor hypoxia-inducible factor which leads to an increased endogenous erythropoietin synthesis. It seems unrealistic to develop specific test against such drugs (and the copies hereof originating from illegal laboratories). In an attempt to detect and limit blood doping, the World Anti-Doping Agency (WADA) has launched the Athlete Biological Passport where indirect markers for all types of blood doping are evaluated on an individual level. The approach seemed promising, but a recent publication demonstrates the system to be incapable of detecting even a single subject as 'suspicious' while treated with rhEpo for 10-12 weeks. Sad to say, the hope that the 2012 London Olympics should be cleaner in regard to blood doping seems faint. We propose that WADA strengthens the quality and capacities of the National Anti-Doping Agencies and that they work more efficiently with the international sports federations in an attempt to limit blood doping. PMID:22225538

Lundby, Carsten; Robach, Paul; Saltin, Bengt

2012-03-01

355

New Insights into Non-Avian Dinosaur Reproduction and Their Evolutionary and Ecological Implications: Linking Fossil Evidence to Allometries of Extant Close Relatives  

PubMed Central

It has been hypothesized that a high reproductive output contributes to the unique gigantism in large dinosaur taxa. In order to infer more information on dinosaur reproduction, we established allometries between body mass and different reproductive traits (egg mass, clutch mass, annual clutch mass) for extant phylogenetic brackets (birds, crocodiles and tortoises) of extinct non-avian dinosaurs. Allometries were applied to nine non-avian dinosaur taxa (theropods, hadrosaurs, and sauropodomorphs) for which fossil estimates on relevant traits are currently available. We found that the reproductive traits of most dinosaurs conformed to similar-sized or scaled-up extant reptiles or birds. The reproductive traits of theropods, which are considered more bird-like, were indeed consistent with birds, while the traits of sauropodomorphs conformed better to reptiles. Reproductive traits of hadrosaurs corresponded to both reptiles and birds. Excluding Massospondyluscarinatus, all dinosaurs studied had an intermediary egg to body mass relationship to reptiles and birds. In contrast, dinosaur clutch masses fitted with either the masses predicted from allometries of birds (theropods) or to the masses of reptiles (all other taxa). Theropods studied had probably one clutch per year. For sauropodomorphs and hadrosaurs, more than one clutch per year was predicted. Contrary to current hypotheses, large dinosaurs did not have exceptionally high annual egg numbers (AEN). Independent of the extant model, the estimated dinosaur AEN did not exceed 850 eggs (75,000 kg sauropod) for any of the taxa studied. This estimated maximum is probably an overestimation due to unrealistic assumptions. According to most AEN estimations, the dinosaurs studied laid less than 200 eggs per year. Only some AEN estimates obtained for medium to large sized sauropods were higher (200-400 eggs). Our results provide new (testable) hypotheses, especially for reproductive traits that are insufficiently documented or lacking from the fossil record. This contributes to the understanding of their evolution. PMID:23991160

Werner, Jan; Griebeler, Eva Maria

2013-01-01

356

China's battle to save the environment.  

PubMed

By the year 2000 a Great Green Wall of forests may be crossing the country from northwest to northeast, a total of 53 million hectares of green protection from encroaching deserts and erosion, stretching through 12 provinces to increase the nation's forest cover, which now stands at a mere 12.7% of China's territory. Soils have been degraded to a critical level only within the past 150 years. At present, about one-sixth of the total land is affected by erosion. In 1988 more than 11 million hectares of farmland, one-tenth of the total sown acreage, suffered from severe drought. Another 7.5 million hectares of crops were flooded, and grain output has been dropping steadily. China is now importing more than 1 billion tons of food staples to feed its population. In all big cities including the capital Beijing, sulphur dioxide and dust levels in the atmosphere surpass the norm set by the State. The most seriously polluted city in China is Benxi, situated in Liaoning Province, which contains some 420 factories. Shanghai has become a preview of what is in store for many Chinese cities unless urgent anti-pollution measures are designed and implemented. Much of the city's municipal and industrial wastes are simply flushed untreated into rivers and shallow coastal waters. Some 34 billion tons of municipal and industrial wastes are flushed into China's rivers and streams every year. A highly lauded forest farm in Sichuan Province credits afforestation with increased precipitation in the dry season, reduced soil erosion, and a halt to the flooding of some 10 rivers in the region. Many of China's 32,000 species of higher plants are endangered; and similarly, many of the nation's 2200 species of birds and animals, like the giant panda, are threatened with extinction. The country's gigantic population remains the key problem as well as the key to its solution. PMID:12291351

Nash, N

1989-01-01

357

Familial Isolated Pituitary Adenomas (FIPA) and the Pituitary Adenoma Predisposition due to Mutations in the Aryl Hydrocarbon Receptor Interacting Protein (AIP) Gene  

PubMed Central

Pituitary adenomas are one of the most frequent intracranial tumors and occur with a prevalence of approximately 1:1000 in the developed world. Pituitary adenomas have a serious disease burden, and their management involves neurosurgery, biological therapies, and radiotherapy. Early diagnosis of pituitary tumors while they are smaller may help increase cure rates. Few genetic predictors of pituitary adenoma development exist. Recent years have seen two separate, complimentary advances in inherited pituitary tumor research. The clinical condition of familial isolated pituitary adenomas (FIPA) has been described, which encompasses the familial occurrence of isolated pituitary adenomas outside of the setting of syndromic conditions like multiple endocrine neoplasia type 1 and Carney complex. FIPA families comprise approximately 2% of pituitary adenomas and represent a clinical entity with homogeneous or heterogeneous pituitary adenoma types occurring within the same kindred. The aryl hydrocarbon receptor interacting protein (AIP) gene has been identified as causing a pituitary adenoma predisposition of variable penetrance that accounts for 20% of FIPA families. Germline AIP mutations have been shown to associate with the occurrence of large pituitary adenomas that occur at a young age, predominantly in children/adolescents and young adults. AIP mutations are usually associated with somatotropinomas, but prolactinomas, nonfunctioning pituitary adenomas, Cushing disease, and other infrequent clinical adenoma types can also occur. Gigantism is a particular feature of AIP mutations and occurs in more than one third of affected somatotropinoma patients. Study of pituitary adenoma patients with AIP mutations has demonstrated that these cases raise clinical challenges to successful treatment. Extensive research on the biology of AIP and new advances in mouse Aip knockout models demonstrate multiple pathways by which AIP may contribute to tumorigenesis. This review assesses the current clinical and therapeutic characteristics of more than 200 FIPA families and addresses research findings among AIP mutation-bearing patients in different populations with pituitary adenomas. PMID:23371967

Aaltonen, Lauri A.; Daly, Adrian F.

2013-01-01

358

Cometary Knots Around A Dying Star  

NASA Technical Reports Server (NTRS)

These gigantic, tadpole-shaped objects are probably the result of a dying star's last gasps. Dubbed 'cometary knots' because their glowing heads and gossamer tails resemble comets, the gaseous objects probably were formed during a star's final stages of life. Hubble astronomer C. Robert O'Dell and graduate student Kerry P. Handron of Rice University in Houston, Texas discovered thousands of these knots with the Hubble Space Telescope while exploring the Helix nebula, the closest planetary nebula to Earth at 450 light-years away in the constellation Aquarius. Although ground-based telescopes have revealed such objects, astronomers have never seen so many of them. The most visible knots all lie along the inner edge of the doomed star's ring, trillions of miles away from the star's nucleus. Although these gaseous knots appear small, they're actually huge. Each gaseous head is at least twice the size of our solar system; each tail stretches for 100 billion miles, about 1,000 times the distance between the Earth and the Sun. Astronomers theorize that the doomed star spews hot, lower-density gas from its surface, which collides with cooler, higher-density gas that had been ejected 10,000 years before. The crash fragments the smooth cloud surrounding the star into smaller, denser finger-like droplets, like dripping paint. This image was taken in August, 1994 with Hubble's Wide Field Planetary Camera 2. The red light depicts nitrogen emission ([NII] 6584A); green, hydrogen (H-alpha, 6563A); and blue, oxygen (5007A).

1994-01-01

359

Testing for intraspecific postzygotic isolation between cryptic lineages of Pseudacris crucifer.  

PubMed

Phenotypically cryptic lineages appear common in nature, yet little is known about the mechanisms that initiate and/or maintain barriers to gene flow, or how secondary contact between them might influence evolutionary trajectories. The consequences of such contact between diverging lineages depend on hybrid fitness, highlighting the potential for postzygotic isolating barriers to play a role in the origins of biological species. Previous research shows that two cryptic, deeply diverged intraspecific mitochondrial lineages of a North American chorus frog, the spring peeper (Pseudacris crucifer), meet in secondary contact in Southwestern Ontario, Canada. Our study quantified hatching success, tadpole survival, size at metamorphosis, and development time for experimentally generated pure lineage and hybrid tadpoles. Results suggest that lineages differ in tadpole survival and that F1 hybrids may have equal fitness and higher than average mass at metamorphosis compared with pure parental crosses. These findings imply hybrid early life viability may not be the pivotal reproductive isolation barrier helping to maintain lineage boundaries. However, we observed instances of tadpole gigantism, failure to metamorphose, and bent tails in some tadpoles from hybrid families. We also speculate and provide some evidence that apparent advantages or similarities of hybrids compared with pure lineage tadpoles may disappear when tadpoles are raised with competitors of different genetic makeup. This pilot study implies that ecological context and consideration of extrinsic factors may be a key to revealing mechanisms causing negative hybrid fitness during early life stages, a provocative avenue for future investigations on barriers to gene flow among these intraspecific lineages. PMID:24363891

Stewart, Kathryn A; Lougheed, Stephen C

2013-11-01

360

Escape of volatiles from Venus  

NASA Astrophysics Data System (ADS)

A model for describing the loss of atmosphere in Venus in the geologic time is presented. The amount of volatiles degassed from Venus in 4.6 Ga is in the order of 286.9 Terrestrial Atmospheric Masses (TAM) (1 TAM = 5.28x1018 kg). If the drag of the solar wind acted since the birth of Venus, 4.6 Ga ago, a minimum limit of the amount of atmosphere lost by the planet is 6.76 TAM. The current atmosphere of Venus has 88.44 TAM of mass. The sum of the lost and the current atmosphere is 95.2 TAM. This result is 191.7 TAM smaller than the estimation of the mass degassed in all the history of Venus. Then we have a deficit of 191.7 TAM of volatiles on Venus. It is well known that the surface of Venus is geologically young (? 500 Ma) In all this period the model predicts that Venus lost, by the solar wind, only 0.08 TAM of atmosphere. From this we can assume that the deficit of volatiles is due to events that occur before that time or perhaps at that time. It is possible to speculate that the resurfacing of Venus, the massive loss of volatiles, and a change from prograde to retrograde rotation of the planet occur at the same time and could be produced by a gigantic impact with a planetary-size body. In this catastrophic event the angular momentum of the planet could change from the original (possibly prograde) to the current one, all the surface of Venus could be melt producing a resurfacing and the water and part of the CO2 in the atmosphere could be ejected to space.

Durand-Manterola, H. J.

361

West-Antarctic Ice Streams: Analog to Ice Flow in Channels on Mars  

NASA Technical Reports Server (NTRS)

Sounding of the sea floor in front of the Ross Ice Shelf in Antarctica recently revealed large persistent patterns of longitudinal megaflutes and drumlinoid forms, which are interpreted to have formed at the base of ice streams during the list glacial advance. The flutes bear remarkable resemblance to longitudinal grooves and highly elongated streamlined islands found on the floors of some large martian channels, called outflow channels. ln addition, other similarities exist between Antarctic ice streams and outflow channels. Ice streams are 30 to 80 km wide and hundreds of kilometers long, as are the martian channels. Ice stream beds are below sea level. Floors of many martian outflow channels lie below martian datum, which may have been close to or below past martian sea levels. The Antarctic ice stream bed gradient is flat and locally may go uphill, and surface slopes are exceptionally low. So are gradients of martian channels. The depth to the bed in ice streams is 1 to 1.5 km. At bankful stage, the depth of the fluid in outflow channels would have been 1 to 2 km. These similarities suggest that the martian outflow channels, whose origin is commonly attributed to gigantic catastrophic floods, were locally filled by ice that left a conspicuous morphologic imprint. Unlike the West-Antarctic-ice streams, which discharge ice from an ice sheet, ice in the martian channels came from water erupting from the ground. In the cold martian environment, this water, if of moderate volume, would eventually freeze. Thus it may have formed icings on springs, ice dams and jams on constrictions in the channel path, or frozen pools. Given sufficient thickness and downhill surface gradient, these ice masses would have moved; and given the right conditions, they could have moved like Antarctic ice streams.

Lucchitta, B. K.

1997-01-01

362

The evolution of high energy accelerators  

SciTech Connect

Accelerators have been devised and built for two reasons: In the first place, by physicists who needed high energy particles in order to have a means to explore the interactions between particles that probe the fundamental elementary forces of nature. And conversely, sometimes accelerator builders produce new machines for higher energy than ever before just because it can be done, and then challenge potential users to make new discoveries with the new means at hand. These two approaches or motivations have gone hand in hand. This lecture traces how high energy particle accelerators have grown from tools used for esoteric small-scale experiments to the gigantic projects of today. So far all the really high-energy machines built and planned in the world--except the SLC--have been ring accelerators and storage rings using the strong-focusing method. But this method has not removed the energy limit, it has only pushed it higher. It would seem unlikely that one can go beyond the Large Hadron Collider (LHC)--but in fact a workshop was held in Sicily in November 1991, concerned with the question of extrapolating to 100 TeV. Other acceleration and beam-forming methods are now being discussed--collective fields, laser acceleration, wake-field accelerators etc., all aimed primarily at making linear colliders possible and more attractive than with present radiofrequency methods. So far it is not entirely clear which of these schemes will dominate particle physics in the future--maybe something that has not been thought of as yet.

Courant, E.D.

1994-08-01

363

Patterns of the Up-Down State in normal and epileptic mice  

PubMed Central

Goal_of this manuscript is to investigate whether changes that exist in epileptic brain generating spontaneous seizures are reflected in the pattern of the Up-Down state recorded from the neocortex and dentate gyrus. Experiments were carried out on naive and epileptic mice under urethane anesthesia. Local field potentials were recorded with chronically implanted microelectrodes and single unit activity was recorded with glass microelectrodes. Recorded neurons were labeled by neurobiotine and identified later as granular cells or interneurons in histological sections. The following major features differentiate the pattern of Up-Down State in epilepsy from normal. 1) The duration of Up and Down phases is significantly longer. 2) Recovery of network excitability after termination of the Up phase is longer. 3) UP-spikes occur during the Up phase, which transiently interrupt the development of the normal electrographic pattern of Up phase. Our data provide evidence that UP-spikes result from gigantic EPSPs generated in response to afferent activity. UP-spikes in the neocortex and dentate gyrus occur in close temporal relationship indicating the existence of direct or indirect pathological functional connections between these areas. Changes in the duration of UP- and Down phases as well increased time of recovery of excitability of epileptic brain after termination of Up phase suggest alterations in the homeostatic properties of neuronal network in epileptic brain. We suggest that the existence of UP-spikes in epileptic brain may be an additional electrographic pattern indicating epileptogenicity. Unraveling the neuronal substrates of UP-spikes may further improve our understanding of the mechanisms of epilepsy. PMID:22960310

Bragin, Anatol; Benassi, Simone K.; Engel, Jerome

2012-01-01

364

Earthquake calamity warning from space station: orbital dynamics coupling geology mantle convection  

NASA Astrophysics Data System (ADS)

It is not surprising that the earthquakes happened among clashing tectonic plate boundaries where numerous earthquake stations exist. Then, why do we need more? The significance of Sichuan and Tongshan earthquakes of China is a wakeup call that major earthquakes of logarithmic Richter scales beyond 7 could happen exactly within a single tectonic plate surprisingly. Thus, the previous border surveillance is broadened to areas coverage. Judging the success of archival survey of NASA with the gravitational potential by Liu et al., we review a unified earthquakes theory covering both the peripheral and the central plate in this paper, so that we can take seriously the need of a comprehensive global surveillance of natural calamity in the Space. The earth surface crust, like a kitchen kettle lid, covers tightly the melted mantle rock layer, like a pea soup cooking in the kettle. Given the time they will all become bubbling, rattling & shaking, known as the Bernard instability. This instability is ubiquitous for any liquid state matter being heated from below, if and only if it has a real positive thermal expansion coefficient. Likewise, the earth mantle is being cooked from below by an enormously hot fireball of the size of a moon. The heat comes from the radioactive decay confined within the core over eon's age. Due to the enormous gravitation attraction being always real positive and additive, the inner core is bifurcated into 2 regimes, a heat-melted liquid metal regime, where the earth magnetic field is produced and predicted by Faraday induction law. And further inside there exists a tightly squeezed solid metal ball regime, due to the gigantic weight compression, as confirmed by sonar experiments. The complexity of earth Bernard instability is due to the extra rotational Coriolis force that makes the up-down thermal convection side-way, creating the mass imbalance and permitting in-situ measurements feasible at a distance.

Szu, Harold H.; Liu, Han-Shou

2009-04-01

365

Prevalence and Risk Factors for Depressive Reaction among Resident Survivors after the Tsunami following the Great East Japan Earthquake, March 11, 2011  

PubMed Central

Objectives The Great East Japan Earthquake caused a gigantic tsunami which devastated coastal areas of northern Japan on 11 March 2011. Despite the large number of resident survivors who continued to reside in their damaged houses on the second or upper floors, research on the mental health of these individuals has been limited. This study explored the prevalence of depressive reaction and risk factors for depressive reaction among these resident survivors. Methods A cross-sectional household health support needs screening was conducted for resident survivors in Higashi-Matsushima city, Miyagi prefecture, two to four months after the tsunami. The health interview that was conducted including mental status, assessed by the Patient Health Questionnaire-2 (PHQ-2). Results Of 5,454 respondents, 8.1% had depressive reaction. After adjustment by the number of weeks from the tsunami and the mortality rate at each respondent's place of residence, depressive reaction was significantly associated with house flooding below or above the ground floor (odds ratios of 1.92, 2.36, respectively), the unavailability of gas supply (odds ratio, 1.67), being female (odds ratio, 1.47), middle aged or elderly (odds ratios of 2.41, 2.42, respectively), regular intake of psychotropic medicine(s) since before the tsunami (odds ratio, 2.53) and the presence of one to five or more than six cohabiters (odds ratios of 0.61, 0.52, respectively). Conclusions The results suggest a considerable psychological burden (depressive reaction) following the tsunami among resident survivors. Special supports for families with psychiatric problems need to be considered among resident survivors. Restoration of lifeline utilities and the strengthening of social ties of persons living alone may help prevent depressive reaction among resident survivors after a tsunami. PMID:25279563

Matsubara, Chieko; Murakami, Hitoshi; Imai, Koubun; Mizoue, Tetsuya; Akashi, Hidechika; Miyoshi, Chiaki; Nakasa, Tamotsu

2014-01-01

366

Visions of Our Planet's Atmosphere, Land and Oceans Electronic-Theater 2001  

NASA Technical Reports Server (NTRS)

The NASA/NOAA/AMS Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to Fredericton New Brunswick. Drop in on the Kennedy Space Center and Park City Utah, site of the 2002 Olympics using 1 m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and International global satellite weather movies including hurricanes & tornadoes. See the latest spectacular images from NASA/NOAA and Canadian remote sensing missions like Terra GOES, TRMM, SeaWiFS, Landsat 7, and Radarsat that are visualized & explained. See how High Definition Television (HDTV) is revolutionizing the way we communicate science in cooperation with the American Museum of Natural History in NYC. See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. New visualization tools allow us to roam & zoom through massive global images eg Landsat tours of the US, Africa, & New Zealand showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See massive dust storms sweeping across Africa. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. The demonstration is interactively driven by a SGI Onyx II Graphics Supercomputer with four CPUs, 8 Gigabytes of RAM and Terabyte of disk. With multiple projectors on a giant screen. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP military satellite.

Hasler, A. F.; Einaudi, Franco (Technical Monitor)

2001-01-01

367

Automated Analysis of Planktic Foraminifers Part I: Application to Macroevolution and Climate Change  

NASA Astrophysics Data System (ADS)

Size and shape data of microfossils are tedious to gather manually but are efficiently obtained electronically. Using automated microscopy (see Part II, Bollmann et al., this volume) we have collected digitized images and extracted size information of >1.6 million foraminiferal tests in globally distributed Holocene and Cenozoic samples. In the Holocene the maximum sizes and maximum abundances co-occur under similar "optimum" environmental conditions. Total assemblage test sizes show a strong correlation with surface water temperature and stratification: they increase from high to low latitudes and show deviations from this general relationship towards smaller sizes in frontal systems and upwelling areas. Cenozoic size changes in planktic foraminiferal assemblages were pronounced in low latitude and minor in high latitude areas. The global size record reveals the following major features: (a) a dramatic size decrease at the K/T-boundary, followed by (b) an interval of "dwarfs" (Paleocene - late Eocene), (c) a transition period from the late Eocene to the mid-Miocene, when low-latitude assemblages started evolving towards larger size, and (d) an interval of growth to gigantism in tropical and subtropical assemblages from mid-Miocene to Recent. Comparisons with proxy data show that low latitude planktic foraminiferal size increases are positively correlated to polar cooling. We infer that cooling of deep-waters led to enhanced stratification of surface waters and thus to increases in number and stability of ecological niches into which species could evolve. Whether these processes affected all species or only some awaits size analyses of single taxa (see Part III, Schiebel et al., this volume). The observed macroevolutionary size increase of planktic foraminifers in the Cenozoic seems largely abiotically driven.

Schmidt, D. N.; Thierstein, H. R.; Bollmann, J.

2003-04-01

368

Mechanical Analysis of Feeding Behavior in the Extinct "Terror Bird" Andalgalornis steulleti (Gruiformes: Phorusrhacidae)  

PubMed Central

The South American phorusrhacid bird radiation comprised at least 18 species of small to gigantic terrestrial predators for which there are no close modern analogs. Here we perform functional analyses of the skull of the medium-sized (?40 kg) patagornithine phorusrhacid Andalgalornis steulleti (upper Miocenelower Pliocene, Andalgal Formation, Catamarca, Argentina) to assess its mechanical performance in a comparative context. Based on computed tomographic (CT) scanning and morphological analysis, the skull of Andalgalornis steulleti is interpreted as showing features reflecting loss of intracranial immobility. Discrete anatomical attributes permitting such cranial kinesis are widespread phorusrhacids outgroups, but this is the first clear evidence of loss of cranial kinesis in a gruiform bird and may be among the best documented cases among all birds. This apomorphic loss is interpreted as an adaptation for enhanced craniofacial rigidity, particularly with regard to sagittal loading. We apply a Finite Element approach to a three-dimensional (3D) model of the skull. Based on regression analysis we estimate the bite force of Andalgalornis at the bill tip to be 133 N. Relative to results obtained from Finite Element Analysis of one of its closest living relatives (seriema) and a large predatory bird (eagle), the phorusrhacid's skull shows relatively high stress under lateral loadings, but low stress where force is applied dorsoventrally (sagittally) and in pullback simulations. Given the relative weakness of the skull mediolaterally, it seems unlikely that Andalgalornis engaged in potentially risky behaviors that involved subduing large, struggling prey with its beak. We suggest that it either consumed smaller prey that could be killed and consumed more safely (e.g., swallowed whole) or that it used multiple well-targeted sagittal strikes with the beak in a repetitive attack-and-retreat strategy. PMID:20805872

Degrange, Federico J.; Tambussi, Claudia P.; Moreno, Karen; Witmer, Lawrence M.; Wroe, Stephen

2010-01-01

369

Nitrogen in Solar System Minor Bodies: Delivery Pathways to Primeval Earth  

NASA Astrophysics Data System (ADS)

Oxygen isotope data point towards enstatite and ordinary chondrites as presumable building blocks of primordial Earth. Nitrogen was incorporated as nitrides to these first building blocks and was outgassed in the early stages of chemical segregation. However, giant impacts with planetesimals played an important role in partially eroding the atmosphere of Earth, and promoting thermal escape of diverse components. As a consequence, the Earth's atmospheric composition could have been subjected to important changes along the eons. A last, and probably less massive, delivery of volatiles took place at the time of a gigantic cataclysm known as Late Heavy Bombardment. During a short interval roughly between 3.9 and 3.8 Gyr ago, a gravitational migration inwards of Jupiter and Saturn occurred, that perturbed hundreds of small bodies rich in water, ammonia, methane and organic compounds that were stored until then in the outer regions. Current atmospheric signatures suggest that by that mechanism a continuous shower of outer-disk primordial components enriched the volatile inventory of terrestrial planets. The relevance of such contribution is still debated, but significant progress has been made in the last decades from the study of undifferentiated bodies. Consequently, planetary scattering of undifferentiated bodies delivered to Earth a significant fraction of minerals, and light elements that could have played a key role in the volatile enrichment the terrestrial crust. I suggest some unexplored pathways to allow a safe delivery of organics to Earth's surface, following recent evidence on meteoroid fragmentation, fireball spectra and Antarctic micrometeorite discoveries. Recent compositional studies of asteroids, comets and meteorites corroborate the need of having more precise data on the abundance and isotopic ratios of N in these minor bodies. Future space missions to primitive bodies like Rosetta, OSIRIS-Rex, Hayabusa II, or Marco Polo-R could help us to complete the big picture, and this chapter tries to compile our present knowledge of its delivery to Earth along the eons.

Trigo-Rodrguez, Josep M.

370

Phase transition transistors based on strongly-correlated materials  

NASA Astrophysics Data System (ADS)

The field-effect transistor (FET) provides electrical switching functions through linear control of the number of charges at a channel surface by external voltage. Controlling electronic phases of condensed matters in a FET geometry has long been a central issue of physical science. In particular, FET based on a strongly correlated material, namely ``Mott transistor,'' has attracted considerable interest, because it potentially provides gigantic and diverse electronic responses due to a strong interplay between charge, spin, orbital and lattice. We have investigated electric-field effects on such materials aiming at novel physical phenomena and electronic functions originating from strong correlation effects. Here we demonstrate electrical switching of bulk state of matter over the first-order metal-insulator transition [1]. We fabricated FETs based on VO2 with use of a recently developed electric-double-layer transistor technique, and found that the electrostatically induced carriers at a channel surface drive all preexisting localized carriers of 10^22 cm-3 even inside a bulk to motion, leading to bulk carrier delocalization beyond the electrostatic screening length. This non-local switching of bulk phases is achieved with just around 1 V, and moreover, a novel non-volatile memory like character emerges in a voltage-sweep measurement. These observations are apparently distinct from those of conventional FETs based on band insulators, capturing the essential feature of collective interactions in strongly correlated materials. This work was done in collaboration with K. Shibuya, D. Okuyama, T. Hatano, S. Ono, M. Kawasaki, Y. Iwasa, and Y. Tokura. [4pt] [1] M. Nakano et al., Nature 487, 459 (2012).

Nakano, Masaki

2013-03-01

371

Evolution of High Tooth Replacement Rates in Sauropod Dinosaurs  

PubMed Central

Background Tooth replacement rate can be calculated in extinct animals by counting incremental lines of deposition in tooth dentin. Calculating this rate in several taxa allows for the study of the evolution of tooth replacement rate. Sauropod dinosaurs, the largest terrestrial animals that ever evolved, exhibited a diversity of tooth sizes and shapes, but little is known about their tooth replacement rates. Methodology/Principal Findings We present tooth replacement rate, formation time, crown volume, total dentition volume, and enamel thickness for two coexisting but distantly related and morphologically disparate sauropod dinosaurs Camarasaurus and Diplodocus. Individual tooth formation time was determined by counting daily incremental lines in dentin. Tooth replacement rate is calculated as the difference between the number of days recorded in successive replacement teeth. Each tooth family in Camarasaurus has a maximum of three replacement teeth, whereas each Diplodocus tooth family has up to five. Tooth formation times are about 1.7 times longer in Camarasaurus than in Diplodocus (315 vs. 185 days). Average tooth replacement rate in Camarasaurus is about one tooth every 62 days versus about one tooth every 35 days in Diplodocus. Despite slower tooth replacement rates in Camarasaurus, the volumetric rate of Camarasaurus tooth replacement is 10 times faster than in Diplodocus because of its substantially greater tooth volumes. A novel method to estimate replacement rate was developed and applied to several other sauropodomorphs that we were not able to thin section. Conclusions/Significance Differences in tooth replacement rate among sauropodomorphs likely reflect disparate feeding strategies and/or food choices, which would have facilitated the coexistence of these gigantic herbivores in one ecosystem. Early neosauropods are characterized by high tooth replacement rates (despite their large tooth size), and derived titanosaurs and diplodocoids independently evolved the highest known tooth replacement rates among archosaurs. PMID:23874921

Smith, Kathlyn M.; Fisher, Daniel C.; Wilson, Jeffrey A.

2013-01-01

372

A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum  

PubMed Central

Background The origin of sauropod dinosaurs is one of the major landmarks of dinosaur evolution but is still poorly understood. This drastic transformation involved major skeletal modifications, including a shift from the small and gracile condition of primitive sauropodomorphs to the gigantic and quadrupedal condition of sauropods. Recent findings in the Late TriassicEarly Jurassic of Gondwana provide critical evidence to understand the origin and early evolution of sauropods. Methodology/Principal Findings A new sauropodomorph dinosaur, Leonerasaurus taquetrensis gen. et sp. nov., is described from the Las Leoneras Formation of Central Patagonia (Argentina). The new taxon is diagnosed by the presence of anterior unserrated teeth with a low spoon-shaped crown, amphicoelous and acamerate vertebral centra, four sacral vertebrae, and humeral deltopectoral crest low and medially deflected along its distal half. The phylogenetic analysis depicts Leonerasaurus as one of the closest outgroups of Sauropoda, being the sister taxon of a clade of large bodied taxa composed of Melanorosaurus and Sauropoda. Conclusions/Significance The dental and postcranial anatomy of Leonerasaurus supports its close affinities with basal sauropods. Despite the small size and plesiomorphic skeletal anatomy of Leonerasaurus, the four vertebrae that compose its sacrum resemble that of the large-bodied primitive sauropods. This shows that the appearance of the sauropod-type of sacrum predated the marked increase in body size that characterizes the origins of sauropods, rejecting a causal explanation and evolutionary linkage between this sacral configuration and body size. Alternative phylogenetic placements of Leonerasaurus as a basal anchisaurian imply a convergent acquisition of the sauropod-type sacrum in the new small-bodied taxon, also rejecting an evolutionary dependence of sacral configuration and body size in sauropodomorphs. This and other recent discoveries are showing that the characteristic sauropod body plan evolved gradually, with a step-wise pattern of character appearance. PMID:21298087

Pol, Diego; Garrido, Alberto; Cerda, Ignacio A.

2011-01-01

373

Identification of old tidal dwarfs near early-type galaxies from deep imaging and H I observations  

NASA Astrophysics Data System (ADS)

It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group discs of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still poorly constrained by observations. As part of deep optical and H I surveys with the Canada-France-Hawaii Telescope (CFHT) MegaCam camera and Westerbork Synthesis Radio Telescope made within the ATLAS3D project, and follow-up spectroscopic observations with the Gemini-North telescope, we have discovered old TDG candidates around several early-type galaxies. At least one of them has an oxygen abundance close to solar, as expected for a tidal origin. This confirmed pre-enriched object is located within the gigantic, but very low surface brightness, tidal tail that emanates from the elliptical galaxy, NGC 5557. An age of 4 Gyr estimated from its SED fitting makes it the oldest securely identified TDG ever found so far. We investigated the structural and gaseous properties of the TDG and of a companion located in the same collisional debris, and thus most likely of tidal origin as well. Despite several Gyr of evolution close to their parent galaxies, they kept a large gas reservoir. Their central surface brightness is low and their effective radius much larger than that of typical dwarf galaxies of the same mass. This possibly provides us with criteria to identify tidal objects which can be more easily checked than the traditional ones requiring deep spectroscopic observations. In view of the above, we discuss the survival time of TDGs and question the tidal origin of the DoSs.

Duc, Pierre-Alain; Paudel, Sanjaya; McDermid, Richard M.; Cuillandre, Jean-Charles; Serra, Paolo; Bournaud, Frdric; Cappellari, Michele; Emsellem, Eric

2014-05-01

374

Clinical applications of somatostatin analogs for growth hormone-secreting pituitary adenomas  

PubMed Central

Excessive growth hormone (GH) is usually secreted by GH-secreting pituitary adenomas and causes gigantism in juveniles or acromegaly in adults. The clinical complications involving cardiovascular, respiratory, and metabolic systems lead to elevated morbidity in acromegaly. Control of serum GH and insulin-like growth factor (IGF) 1 hypersecretion by surgery or pharmacotherapy can decrease morbidity. Current pharmacotherapy includes somatostatin analogs (SAs) and GH receptor antagonist; the former consists of lanreotide Autogel (ATG) and octreotide long-acting release (LAR), and the latter refers to pegvisomant. As primary medical therapy, lanreotide ATG and octreotide LAR can be supplied in a long-lasting formulation to achieve biochemical control of GH and IGF-1 by subcutaneous injection every 46 weeks. Lanreotide ATG and octreotide LAR provide an effective medical treatment, whether as a primary or secondary therapy, for the treatment of GH-secreting pituitary adenoma; however, to maximize benefits with the least cost, several points should be emphasized before the application of SAs. A comprehensive assessment, especially of the observation of clinical predictors and preselection of SA treatment, should be completed in advance. A treatment process lasting at least 3 months should be implemented to achieve a long-term stable blood concentration. More satisfactory surgical outcomes for noninvasive macroadenomas treated with presurgical SA may be achieved, although controversy of such adjuvant therapy exists. Combination of SA and pegvisomant or cabergoline shows advantages in some specific cases. Thus, an individual treatment program should be established for each patient under a full evaluation of the risks and benefits. PMID:24421637

Wang, Ji-wen; Li, Ying; Mao, Zhi-gang; Hu, Bin; Jiang, Xiao-bing; Song, Bing-bing; Wang, Xin; Zhu, Yong-hong; Wang, Hai-jun

2014-01-01

375

Protection of Cities from Small Rockets, Missiles, Projectiles and Mortar Shells  

E-print Network

The authors suggest a low cost closed AB-Dome, which may protect small cities such as Sederot from rockets, mortar shells, chemical and biological weapons. The offered AB-Dome is also very useful in peacetime because it protects the city from outside weather (violent storms, hail) and creates a fine climate within the Dome. The roughly hemispherical AB-Dome is a gigantic inflated thin transparent film, located at altitude up to 1 - 5 kilometers, which converts the city into a closed-loop air system. The film may be armored with a basalt or steel grille or cloth pocket-retained stones that destroy (by collision or detonation) incoming rockets, shells and other projectiles. Such an AB-Dome would even protect the city in case of a third-party nuclear war involving temporary poisoning of the Earth atmosphere by radioactive dust. The building of the offered dome is easy; the film spreads on the ground, the fan engines turn on and the cover rises to the needed altitude and is supported there by a small internal overpressure. The offered method is cheaper by thousands of times than protection of a city by current anti-rocket systems. The AB-Dome may be also used (height is up to 1-5 and more kilometers) for TV, communication, long distance location, tourism, suspended high speed and altitude windmills (energy), illumination and entertainment (projected messages and pictures). The authors developed the theory of AB-Dome, made estimations, computations and computed a typical project. Discussion and results are at the end of the article.

Alexander Bolonkin; Joseph Friedlander

2008-02-03

376

Extreme plasticity in life-history strategy allows a migratory predator (jumbo squid) to cope with a changing climate.  

PubMed

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55cm mantle length) in 1-1.5years and have supported a major commercial fishery in the Guaymas Basin during the last 20years. An El Nio event in 2009-2010, was accompanied by a collapse of this fishery, and squid in the region showed major changes in the distribution and life-history strategy. Large squid abandoned seasonal coastal-shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Nio by tidal upwelling and a well-mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010 to 2012, small squid were abundant and matured at an unusually small mantle-length (<30cm) and young age (approximately 6months). Juvenile squid thus appeared to respond to El Nio with an alternative life-history trajectory in which gigantism and high fecundity in normally productive coastal-shelf habitats were traded for accelerated reproduction at small size in an offshore environment. Both small and large mature squid, were present in the Salsipuedes Basin during 2011, indicating that both life- history strategies can coexist. Hydro-acoustic data, reveal that squid biomass in this study area nearly doubled between 2010 and 2011, primarily due to a large increase in small squid that were not susceptible to the fishery. Such a climate-driven switch in size-at-maturity may allow D. gigas to rapidly adapt to and cope with El Nio. This ability is likely to be an important factor in conjunction with longerterm climate-change and the potential ecological impacts of this invasive predator on marine ecosystems. PMID:23505049

Hoving, Henk-Jan T; Gilly, William F; Markaida, Unai; Benoit-Bird, Kelly J; -Brown, Zachary W; Daniel, Patrick; Field, John C; Parassenti, Liz; Liu, Bilin; Campos, Bernardita

2013-07-01

377

Thermal and electrical conductivity of iron at Earth's core conditions.  

PubMed

The Earth acts as a gigantic heat engine driven by the decay of radiogenic isotopes and slow cooling, which gives rise to plate tectonics, volcanoes and mountain building. Another key product is the geomagnetic field, generated in the liquid iron core by a dynamo running on heat released by cooling and freezing (as the solid inner core grows), and on chemical convection (due to light elements expelled from the liquid on freezing). The power supplied to the geodynamo, measured by the heat flux across the core-mantle boundary (CMB), places constraints on Earth's evolution. Estimates of CMB heat flux depend on properties of iron mixtures under the extreme pressure and temperature conditions in the core, most critically on the thermal and electrical conductivities. These quantities remain poorly known because of inherent experimental and theoretical difficulties. Here we use density functional theory to compute these conductivities in liquid iron mixtures at core conditions from first principles--unlike previous estimates, which relied on extrapolations. The mixtures of iron, oxygen, sulphur and silicon are taken from earlier work and fit the seismologically determined core density and inner-core boundary density jump. We find both conductivities to be two to three times higher than estimates in current use. The changes are so large that core thermal histories and power requirements need to be reassessed. New estimates indicate that the adiabatic heat flux is 15 to 16 terawatts at the CMB, higher than present estimates of CMB heat flux based on mantle convection; the top of the core must be thermally stratified and any convection in the upper core must be driven by chemical convection against the adverse thermal buoyancy or lateral variations in CMB heat flow. Power for the geodynamo is greatly restricted, and future models of mantle evolution will need to incorporate a high CMB heat flux and explain the recent formation of the inner core. PMID:22495307

Pozzo, Monica; Davies, Chris; Gubbins, David; Alf, Dario

2012-05-17

378

The 1994 EUROMET collection of micrometeorites at Cap-Prudhomme, Antarctica  

NASA Astrophysics Data System (ADS)

Advance funding from IFRTP (Institut Francais pour la Recherche et pour la Technique Polaire) for micrometeorite collection at Cap-Prudhomme has allowed construction of a new micrometeorite 'factory,' conceived to greatly reduce contamination of the ultraclean ice by our activities. The potential problems include fly ash, rust grains, fuel spills 'sticking to the shoes,' and trace elements from the plasticizers used in plastic tubing. In the new factory, intended to produce and then cycle 10-15 tons of melt ice water per day, all parts exposed to water were replaced by either stainless steel or teflon. After examination with a microscope and their transfer into teflon and or glass vials, all samples were frozen the day of their collection. The factory operated from December 15, 1993, through February 6, 1994. Problems included injuries as well as very bad weather conditions, characterized by both the heaviest snow falls observed and unexpected gusts from a blizzard. Also, several new components of the factory did not function properly under the extreme conditions of Antarctica. Our major objective was to obtain the 'cleanest' and 'purest' 25-50 microns micrometeorites ever collected in Antarctica, for comparison with stratospheric Interplanetary Dust Particles (IDPs). We could not fulfill this premise, but we recovered the best 100-400-micron-size fraction of 'giant' micrometeorites ever collected on Earth. Our 26 daily collections are listed,refering to an 'index of quality.' Aliquots of these daily collections will be distributed to major institutions in Austria, England, the U.S.A., and Japan, to be preserved for future generations. The Antarctica ice sheet is truly a gigantic, ultraclean, and inexhaustible micrometeorite collector, but it is very tricky to recover 'ultraclean' micrometeorites from it.

Maurette, M.; Immel, G.; Engrand, C.; Kurat, G.; Pillinger, C. T.

1994-07-01

379

MHD numerical simulations of Perseus A: formation of filaments and magnetic loops  

NASA Astrophysics Data System (ADS)

The Perseus Cluster (A426) is the brightest cluster of galaxies observed in X-rays in the sky and its giant central galaxy (NGC1275) hosts the extended double radio source 3C84. There is a spectacular H-alpha nebulosity surrounding NGC1275 with loops and filaments that are probably magnetized and extend over 100 kpc. The continuous blowing of bubbles leading to the propagation of shock fronts is also evident and more recently, outflow and infall velocities of several 1000 km/s have been detected associated to the surrounding filaments. We here present preliminary results of 2.5D MHD simulations of the Perseus cluster central region assuming that the production of the outflow structures and loops that arise from the surface of NGC1275 are due to turbulent injection triggered by recent star formation and SNe activity in the galaxy. This is in turn, probably induced by a continuous gas infall from the satellite galaxies around NGC1275. Our simulations which include both, the turbulent gas outflow and gas infall from the surroundings, have revealed a continuous formation of the observed features, like the filaments, the gigantic magnetic loops and weak shock fronts that propagate into the ICM medium with the observed velocities of 1000-5000 km/s. After 10 Myr, a nearly steady state is established between the outflow material emerging from the central galaxy and the inflow gas from the surrounds. The outflow activity seems to retard the cannibalism action of the central galaxy over the surrounding galaxies. This result may have important implications over the evolution of the whole cluster as it seems to indicate that the SF and SNe production that are induced by the cannibalism may help to decelerate the later due to turbulence and outflow production. These results also offer important clues to the hot halo formation in the center of the cluster and in the suppression of cooling flows.

Falceta-Gonalves, Diego; de Gouveia dal Pino, E. M.; Gallagher, J.; Lazarian, A.

2009-04-01

380

The potential for crustal resources on Mars  

NASA Technical Reports Server (NTRS)

Martian resources pose not only an interesting scientific challenge but also have immense astronautical significance because of their ability to enhance mission efficiency, lower launch and program costs, and stimulate the development of large Mars surface facilities. Although much terrestrial mineralization is associated with plate tectonics and Mars apparently possesses a thick, stationary lithosphere, the presence of crustal swells, rifting, volcanism, and abundant volatiles indicates that a number of sedimentary, hydrothermal, dry-magma mineral concentration processes may have operated on Mars. For example, in Colorado Plateau-style (roll-front) deposits, uranium precipitation is localized by redox variations in groundwater. Also, evaporites (either in salt pans or even interstitially in pore spaces) might concentrate Cl, Li, and K. Many Martian impact craters have been modified by volcanism and probably have been affected by rising magma bodies interacting with ground ice or water. Such conditions might produce hydrothermal circulations and element concentrations. If the high sulfur content found by the Viking landers typifies Martian abundances, sulfide ore bodies may have been formed locally. Mineral-rich Africa seems to share many volcanic and tectonic characteristics with portions of Mars and may suggest Mars' potential mineral wealth. For example, the rifts of Valles Marineris are similar to the rifts in east Africa, and may both result from a large mantle plume rising from the interior and disrupting the surface. The gigantic Bushveld complex of South Africa, an ancient layered igneous intrusion that contains ores of chromium and Pt-group metals, illustrates the sort of dry-magma processes that also could have formed local element concentrations on Mars, especially early in the planet's history when heat flow was higher.

Cordell, Bruce M.; Gillett, Stephen L.

1991-01-01

381

The evolving science of detection of 'blood doping'  

PubMed Central

Blood doping practices in sports have been around for at least half a century and will likely remain for several years to come. The main reason for the various forms of blood doping to be common is that they are easy to perform, and the effects on exercise performance are gigantic. Yet another reason for blood doping to be a popular illicit practice is that detection is difficult. For autologous blood transfusions, for example, no direct test exists, and the direct testing of misuse with recombinant human erythropoietin (rhEpo) has proven very difficult despite a test exists. Future blood doping practice will likely include the stabilization of the transcription factor hypoxia-inducible factor which leads to an increased endogenous erythropoietin synthesis. It seems unrealistic to develop specific test against such drugs (and the copies hereof originating from illegal laboratories). In an attempt to detect and limit blood doping, the World Anti-Doping Agency (WADA) has launched the Athlete Biological Passport where indirect markers for all types of blood doping are evaluated on an individual level. The approach seemed promising, but a recent publication demonstrates the system to be incapable of detecting even a single subject as suspicious while treated with rhEpo for 1012 weeks. Sad to say, the hope that the 2012 London Olympics should be cleaner in regard to blood doping seems faint. We propose that WADA strengthens the quality and capacities of the National Anti-Doping Agencies and that they work more efficiently with the international sports federations in an attempt to limit blood doping. PMID:22225538

Lundby, Carsten; Robach, Paul; Saltin, Bengt

2012-01-01

382

Contributions of Nimbus 7 TOMS Data to Volcanic Study and Hazard Mitigation  

NASA Technical Reports Server (NTRS)

Nimbus TOMS data have led to advancements among many volcano-related scientific disciplines, from the initial ability to quantify SO2 clouds leading to derivations of eruptive S budgets and fluxes, to tracking of individual clouds, assessing global volcanism and atmospheric impacts. Some of the major aspects of TOMS-related research, listed below, will be reviewed and updated: (1) Measurement of volcanic SO2 clouds: Nimbus TOMS observed over 100 individual SO2 clouds during its mission lifetime; large explosive eruptions are now routinely and reliably measured by satellite. (2) Eruption processes: quantification of SO2 emissions have allowed assessments of eruption sulfur budgets, the evaluation of "excess" sulfur, and inferences of H2S emissions. (3) Detection of ash: TOMS data are now used to detect volcanic particulates in the atmosphere, providing complementary analyses to infrared methods of detection. Paired TOMS and AVHRR studies have provided invaluable information on volcanic cloud compositions and processes. (4) Cloud tracking and hazard mitigation: volcanic clouds can be considered gigantic tracers in the atmosphere, and studies of the fates of these clouds have led to new knowledge of their physical and chemical dispersion in the atmosphere for predictive models. (5) Global trends: the long term data set has provided researchers an unparalleled record of explosive volcanism, and forms a key component in assessing annual to decadal trends in global S emissions. (6) Atmospheric impacts: TOMS data have been linked to independent records of atmospheric change, in order to compare cause and effect processes following a massive injection of SO2 into the atmosphere. (7) Future TOMS instruments and applications: Nimbus TOMS has given way to new satellite platforms, with several wavelength and resolution modifications. New efforts to launch a geostationary TOMS could provide unprecedented observations of volcanic activity.

Krueger, Arlin J.; Bluth, G. J. S.; Schaefer, S. A.

1998-01-01

383

Perched brine plumes above salt domes and dewatering of geopressured sediments  

NASA Astrophysics Data System (ADS)

Previous studies have shown that there is a brine plume with more than 160 g l -1 total dissolved solids (TDS) in the subsurface, perched above Welsh Salt Dome in South Louisiana. The occurrence of this plume has been postulated to be due to the expulsion of geopressured fluids up a fault on the flank of Welsh Dome. The process that resulted in formation of the anomalous brine plume near Welsh Dome is of importance because hydrocarbon production is approximately coincident with the brine plume in map plan, although in cross-sections, the brine plume actually occurs a few hundred meters above hydrocarbon production zones. Using a variable density groundwater flow model, SUTRA, we tested the hypothesis that a pulse of fluid flow up the fault could result in brine formation near the top of the dome. When the permeability of the geopressured zone was very low in our simulations, brine formation in the hydropressured zone occurred entirely by brine-density flow and flow was downward along the fault flanking the dome. Above a certain threshold permeability for the geopressured zone, between 10 -7 darcy and 10 -5 darcy in the vertical direction, geopressured fluids were forced up the fault and brine formation occurred above the dome rather than on the flank. Brines can theoretically form above salt domes in very short geologic times (10 -1 Ma) by expulsion of waters from the geopressured zone below, but the fluid effluxes required are gigantic and appear to be unsustainable over large time intervals such as 10 Ma.

Ranganathan, V.; Hanor, J. S.

1989-09-01

384

Earth after the Moon-forming Impact  

NASA Technical Reports Server (NTRS)

The Hadean Earth is widely and enduringly pictured as a world of exuberant volcanism, exploding meteors, huge craters, infernal heat, and billowing sulfurous steams; i.e., a world of fire and brimstone punctuated with blows to the head. In the background the Moon looms gigantic in the sky. The popular image has given it a name that celebrates our mythic roots. A hot early Earth is an inevitable consequence of accretion. The Moon-forming impact ensured that Earth as we know it emerged from a fog of silicate vapor. The impact separated the volatiles from the silicates. It took approx. 100 years to condense and rain out the bulk of the vaporized silicates, although relatively volatile elements may have remained present in the atmosphere throughout the magma ocena stage. The magma ocean lasted approx. 2 Myr, its lifetime prolonged by tidal heating and thermal blanketing by a thick CO2-rich steam atmosphere. Water oceans condensed quickly after the mantle solidified, but for some 10-100 Myr the surface would have stayed warm (approx. 500 K) until the CO2 was removed into the mantle. Thereafter the faint young Sun suggests that a lifeless Earth would always have been evolving toward a bitterly cold ice world, but the cooling trend was fiequently interrupted by volcanic or impact induced thaws. A cartoon history of water, temperature, and carbon dioxide in the aftermath of the moon-formining-impact is shown. How long it stays hot depends on how long it takes to scrub the C02 out of the atmosphere.

Zahnle, K. J.

2006-01-01

385

Rhodolith Beds Are Major CaCO3 Bio-Factories in the Tropical South West Atlantic  

PubMed Central

Rhodoliths are nodules of non-geniculate coralline algae that occur in shallow waters (<150 m depth) subjected to episodic disturbance. Rhodolith beds stand with kelp beds, seagrass meadows, and coralline algal reefs as one of the world's four largest macrophyte-dominated benthic communities. Geographic distribution of rhodolith beds is discontinuous, with large concentrations off Japan, Australia and the Gulf of California, as well as in the Mediterranean, North Atlantic, eastern Caribbean and Brazil. Although there are major gaps in terms of seabed habitat mapping, the largest rhodolith beds are purported to occur off Brazil, where these communities are recorded across a wide latitudinal range (2N - 27S). To quantify their extent, we carried out an inter-reefal seabed habitat survey on the Abrolhos Shelf (1650? - 1945?S) off eastern Brazil, and confirmed the most expansive and contiguous rhodolith bed in the world, covering about 20,900 km2. Distribution, extent, composition and structure of this bed were assessed with side scan sonar, remotely operated vehicles, and SCUBA. The mean rate of CaCO3 production was estimated from in situ growth assays at 1.07 kg m?2 yr?1, with a total production rate of 0.025 Gt yr?1, comparable to those of the world's largest biogenic CaCO3 deposits. These gigantic rhodolith beds, of areal extent equivalent to the Great Barrier Reef, Australia, are a critical, yet poorly understood component of the tropical South Atlantic Ocean. Based on the relatively high vulnerability of coralline algae to ocean acidification, these beds are likely to experience a profound restructuring in the coming decades. PMID:22536356

Amado-Filho, Gilberto M.; Moura, Rodrigo L.; Bastos, Alex C.; Salgado, Leonardo T.; Sumida, Paulo Y.; Guth, Arthur Z.; Francini-Filho, Ronaldo B.; Pereira-Filho, Guilherme H.; Abrantes, Douglas P.; Brasileiro, Poliana S.; Bahia, Ricardo G.; Leal, Rachel N.; Kaufman, Les; Kleypas, Joanie A.; Farina, Marcos; Thompson, Fabiano L.

2012-01-01

386

Inferences of Diplodocoid (Sauropoda: Dinosauria) Feeding Behavior from Snout Shape and Microwear Analyses  

PubMed Central

Background As gigantic herbivores, sauropod dinosaurs were among the most important members of Mesozoic communities. Understanding their ecology is fundamental to developing a complete picture of Jurassic and Cretaceous food webs. One group of sauropods in particular, Diplodocoidea, has long been a source of debate with regard to what and how they ate. Because of their long lineage duration (Late Jurassic-Late Cretaceous) and cosmopolitan distribution, diplodocoids formed important parts of multiple ecosystems. Additionally, fortuitous preservation of a large proportion of cranial elements makes them an ideal clade in which to examine feeding behavior. Methodology/Principal Findings Hypotheses of various browsing behaviors (selective and nonselective browsing at ground-height, mid-height, or in the upper canopy) were examined using snout shape (square vs. round) and dental microwear. The square snouts, large proportion of pits, and fine subparallel scratches in Apatosaurus, Diplodocus, Nigersaurus, and Rebbachisaurus suggest ground-height nonselective browsing; the narrow snouts of Dicraeosaurus, Suuwassea, and Tornieria and the coarse scratches and gouges on the teeth of Dicraeosaurus suggest mid-height selective browsing in those taxa. Comparison with outgroups (Camarasaurus and Brachiosaurus) reinforces the inferences of ground- and mid-height browsing and the existence of both non-selective and selective browsing behaviors in diplodocoids. Conclusions/Significance These results reaffirm previous work suggesting the presence of diverse feeding strategies in sauropods and provide solid evidence for two different feeding behaviors in Diplodocoidea. These feeding behaviors can subsequently be tied to paleoecology, such that non-selective, ground-height behaviors are restricted to open, savanna-type environments. Selective browsing behaviors are known from multiple sauropod clades and were practiced in multiple environments. PMID:21494685

Whitlock, John A.

2011-01-01

387

REVIEWS OF TOPICAL PROBLEMS Rotational explosion mechanism for collapsing supernovae and the two-stage neutrino signal from supernova 1987A in the Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

The two-stage (double) signal produced by the outburst of the close supernova (SN) in the Large Magellanic Cloud, which started on and involved two neutrino signals during the night of 23 February 1987 UT, is theoretically interpreted in terms of a scenario of rotationally exploding collapsing SNs, to whose class the outburst undoubtedly belongs. This scenario consists of a set of hydrodynamic and kinetic models in which key results are obtained by numerically solving non-one-dimensional and nonstationary problems. Of vital importance in this context is the inclusion of rotation effects, their role being particularly significant precisely in terms of the question of the transformation of the original collapse of the presupernova iron core to the explosion of the SN shell, with an energy release on a familiar scale of 1051 erg. The collapse in itself leads to the birth of neutron stars (black holes) emitting neutrino and gravitational radiation signals of gigantic intensity, whose total energy significantly (by a factor of hundreds) exceeds the above-cited SN burst energy. The proposed rotational scenario is described briefly by artificially dividing it into three (or four) characteristic stages. This division is dictated by the physical meaning of the chain of events a rotating iron core of a sufficiently massive (more than 10M) star triggers when it collapses. An attempt is made to quantitatively describe the properties of the associated neutrino and gravitational radiations. The review highlights the interpretation of the two-stage neutrino signal from SN 1987A, a problem which, given the present status of theoretical astrophysics, cannot, in the author's view, be solved without including rotation effects.

Imshennik, Vladimir S.

2011-02-01

388

Possibility of unlimited shear displacement due to sliding-surface-liquefaction of MH gasification and long runout submarine landslides  

NASA Astrophysics Data System (ADS)

Recent studies on the mechanism of occurrence of large scale submarine landslides focuses mostly on the generation of excess pore pressure due to rapid sedimentation rate in certain environment, rather than gasification of methane hydrates (MH), although MH gasification could contribute to the landslides in the transgresssion period. However, at the 1896 Meiji Sanriku-oki Earthquake which caused serious tsunami disaster in the Tohoku region of Japan, there are witnesses of large-scale flame which were of possibly ejected dissolved methane hydrates (MH) from sea floor. We employed the stress-controlled undrained ring shear apparatuses have been developed at Disaster Prevention Research Institute, Kyoto University to reproduce shear behavior of the dry sand-dry ice mixture under constant normal stress and shear speed control tests using the latest ring shear apparatus. Tested sample was mixture of silica sands and dry-ice pellets (frozen carbon-dioxide). Those mixtures are often used for studying the mechanism of the methane hydrates in laboratories because no explosion protection facility is required. Through three series of tests, we obtained following results. (1) Rate Effect: The samples were tested under stepped shear speed ranging from 0.02 cm/s to 10 cm/s. The obtained excess pore-pressure ratio relationship, which is defined as the ratio of excess pore air pressure to initial effective stress, These results clearly shows positive speed dependency, especially for 1 cm/s and 10 cm/s. This phenomenon could be explained by the "sliding surface liquefaction." (2) Difference between internal and external friction: Based on the published observation of the sliding surface and the BSR, the sliding surface can be generated in the boundary of the MH layer. Tests to compare the internal friction and external friction between sand layers reveals that the behaviour of the both conditions have no significant difference. (3) Shear behaviour under cyclic loading condition: Above-mentioned sliding-surface-liquefaction in the sand - dry ice mixture supports the possibility of similar accelerating and unlimited displacement in the sand-MH mixture or boundaries between MH and sand layer induced by certain strong ground motion under sea floor. To simulate the earthquake-induced submarine landslides due to gasification of MH, authors applied the simple sine-curve cyclic loading to the sand-dry ice sample. After certain number of cyclic loading, sliding surface liquefaction appeared. When the mobilized shear resistance reduced by such excess pore pressure becomes smaller than the shear stress, accelerating behavior and unlimited shear displacement could be expected. Thus, MH still has high possibility to cause gigantic submarine landslides under certain strong earthquake condition.

Tsukui, A.; Fukuoka, H.; Yamasaki, S.

2012-04-01

389

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA Electronic Theater 2002  

NASA Technical Reports Server (NTRS)

The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to the Olympic Medals Plaza, the new Gateway Center, and the University of Utah Stadium Site of the Olympic Opening and Closing Ceremonies in Salt Lake City. Fly in and through the Park City, and Snow Basin sites of the 2002 Winter Olympic Alpine Venues using 1 m IKONOS "Spy Satellite" data. See the four seasons of the Wasatch Front as observed by Landsat 7 at 15m resolution and watch the trees turn color in the Fall, snow come and go in the mountains and the reservoirs freeze and melt. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies Including hurricanes & "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including new 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we communicate science. (In cooperation with the American Museum of Natural History in NYC) See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers Of Newsweek, TIME, National Geographic, Popular Science & on National & International Network TV. New computer software. tools allow us to roam & zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See vertexes and currents in the global oceans that bring up the nutrients to feed tin) algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and biomass burning of the Earth at night observed by the "night-vision" DMSP military satellite. The demonstration is interactively driven by a SGI Octane Graphics Supercomputer with two CPUs, 4 Gigabytes of RAM and 0.5 Terabyte of disk using two projectors across a super sized panoramic 48 foot screen. In addition new HDTV technology will be demonstrated from a portable computer server.

Hasler, A. F.; Starr, David (Technical Monitor)

2002-01-01

390

TYPE IIn SUPERNOVA SN 2010jl: OPTICAL OBSERVATIONS FOR OVER 500 DAYS AFTER EXPLOSION  

SciTech Connect

We present extensive optical observations of a Type IIn supernova (SN IIn) 2010jl for the first 1.5 years after its discovery. The UBVRI light curves demonstrated an interesting two-stage evolution during the nebular phase, which almost flatten out after about 90 days from the optical maximum. SN 2010jl has one of the highest intrinsic H{alpha} luminosities ever recorded for an SN IIn, especially at late phase, suggesting a strong interaction of SN ejecta with the dense circumstellar material (CSM) ejected by the progenitor. This is also indicated by the remarkably strong Balmer lines persisting in the optical spectra. One interesting spectral evolution about SN 2010jl is the appearance of asymmetry of the Balmer lines. These lines can be well decomposed into a narrow component and an intermediate-width component. The intermediate-width component showed a steady increase in both strength and blueshift with time until t {approx} 400 days after maximum, but it became less blueshifted at t {approx} 500 days, when the line profile appeared relatively symmetric again. Owing to the fact that a pure reddening effect will lead to a sudden decline of the light curves and a progressive blueshift of the spectral lines, we therefore propose that the asymmetric profiles of H lines seen in SN 2010jl are unlikely due to the extinction by newly formed dust inside the ejecta, contrary to the explanation by some early studies. Based on a simple CSM-interaction model, we speculate that the progenitor of SN 2010jl may suffer a gigantic mass loss ({approx}30-50 M{sub Sun }) a few decades before explosion. Considering a slow-moving stellar wind (e.g., {approx}28 km s{sup -1}) inferred for the preexisting, dense CSM shell and the extremely high mass-loss rate (1-2 M{sub Sun} yr{sup -1}), we suggest that the progenitor of SN 2010jl might have experienced a red supergiant stage and may explode finally as a post-red supergiant star with an initial mass above 30-40 M{sub Sun }.

Zhang Tianmeng; Wu Chao; Zhai Meng; Wu Hong; Fan Zhou; Zou Hu; Zhou Xu; Ma Jun [National Astronomical Observatories of China, Chinese Academy of Sciences, Beijing 100012 (China); Wang Xiaofeng; Chen Juncheng; Chen Jia; Liu Qin; Huang Fang; Liang Jide; Zhao Xulin [Physics Department and Tsinghua Center for Astrophysics (THCA), Tsinghua University, Beijing 100084 (China); Lin Lin [Center for Astrophysics, University of Science and Technology of China, No. 96, JinZhai Road Baohe District, Hefei, Anhui 230026 (China); Wang Min [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210008 (China); Dennefeld, Michel [Institut d'Astrophysique de Paris, and University Pierre et Marie Curie (Paris 6) (France); Zhang Jujia, E-mail: armengjade@gmail.com, E-mail: wang_xf@mail.tsinghua.edu.cn [Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

2012-11-01

391

Lymnaea palustris and Lymnaea fuscus are potential but uncommon intermediate hosts of Fasciola hepatica in Sweden  

PubMed Central

Background Lymnaea palustris and L. fuscus are members of the European stagnicolines (Gastropoda: Lymnaeidae). The role of stagnicolines in transmission of Fasciola hepatica has been often proposed. To assess the possible relationship between these two stagnicolines and F. hepatica in Sweden, field monitoring in parallel with experimental infections of L. palustris and L. fuscus were conducted. Methods Stagnicoline snails were collected and identified on pastures grazed by either sheep or cattle on four farms suffering from fasciolosis in Sweden during 20112012. Field-collected L. palustris and L. fuscus were examined for F. hepatica DNA by PCR. In the laboratory, different age groups of L. palustris, L. fuscus and G. truncatula were each exposed to two F. hepatica miracidia and main infection characteristics were obtained. Results One field-collected L. palustris (out of n?=?668) contained F. hepatica as determined by PCR. On the other hand, stagnicolines artificially exposed to F. hepatica miracidia resulted in successful infection with fully differentiated cercariae, but only in juvenile snails (size, 12mm at exposure) and with a prevalence of 51% and 13% in L. palustris and L. fuscus, respectively. In contrast, 90% of juvenile (size, 12mm) and 92% of preadult G. truncatula (size, ? 2-4mm), respectively, were successfully infected. Delayed, reduced and/or no spontaneous cercarial shedding was observed in the two stagnicolines when compared to G. truncatula. However, at snail dissection most cercariae from L. fuscus and L. palustris were able to encyst similarly to those from G. truncatula. Conclusion Both L. fuscus and L. palustris can sustain larval development of F. hepatica but with an apparent level of age resistance. The finding of a single F. hepatica positive specimen of L. palustris, together with infection characteristics from the experimental infection, suggest that L. palustris is a more suitable snail vector of F. hepatica than L. fuscus. The reduced growth observed in both stagnicolines was contrary to the parasitic gigantism theory. Overall, it seems that the epidemiological role of L. palustris in transmission of F. hepatica in Sweden is likely to be much lower than for G. truncatula. PMID:23985077

2013-01-01

392

Attitude Determination and Control Systems  

NASA Technical Reports Server (NTRS)

In the year 1900, Galveston, Texas, was a bustling community of approximately 40,000 people. The former capital of the Republic of Texas remained a trade center for the state and was one of the largest cotton ports in the United States. On September 8 of that year, however, a powerful hurricane struck Galveston island, tearing the Weather Bureau wind gauge away as the winds exceeded 100 mph and bringing a storm surge that flooded the entire city. The worst natural disaster in United States history even today the hurricane caused the deaths of between 6000 and 8000 people. Critical in the events that led to such a terrible loss of life was the lack of precise knowledge of the strength of the storm before it hit. In 2008, Hurricane Ike, the third costliest hurricane ever to hit the United States coast, traveled through the Gulf of Mexico. Ike was gigantic, and the devastation in its path included the Turk and Caicos Islands, Haiti, and huge swaths of the coast of the Gulf of Mexico. Once again, Galveston, now a city of nearly 60,000, took the direct hit as Ike came ashore. Almost 200 people in the Caribbean and the United States lost their lives; a tragedy to be sure, but far less deadly than the 1900 storm. This time, people were prepared, having received excellent warning from the GOES satellite network. The Geostationary Operational Environmental Satellites have been a continuous monitor of the world's weather since 1975, and they have since been joined by other Earth-observing satellites. This weather surveillance to which so many now owe their lives is possible in part because of the ability to point accurately and steadily at the Earth below. The importance of accurately pointing spacecraft to our daily lives is pervasive, yet somehow escapes the notice of most people. But the example of the lives saved from Hurricane Ike as compared to the 1900 storm is something no one should ignore. In this section, we will summarize the processes and technologies used in designing and operating spacecraft pointing (i.e. attitude) systems.

Starin, Scott R.; Eterno, John

2011-01-01

393

Observational evidence for intermediate-mass black holes: ultra-luminous X-ray sources  

NASA Astrophysics Data System (ADS)

Ultra-luminous compact X-ray sources (ULXs; Makishima et al. 2000) are promising candidates for intermediate-mass black holes. This candidacy comes in the first place from their high X-ray luminosities reaching 10(39.5-40.5) erg/s, corresponding to the Eddington limits for 20-200 M[sun] black holes. Although ULXs could be normal stellar-mass black holes with highly super-Eddington and/ or anisotropic X-ray emission (e.g., King 2002), this possibility is considered rather low because of the absence of such abnormally luminous states among known Galactic and Magellanic black-hole binaries (BHB). Although ULXs exhibit rather complex spectral behavior, they are typically found in either multi-color-disk type spectral state, or in power-law type one. The former state of ULXs may be distinguished from the standard-disk state of Galactic/Magellanic BHBs, by the rather high disk temperature (Makishima et al. 200) of ULXs and apparent non-constancy of their inner-disk radii (Mizuno et al. 2001). Observations with the CCD camera (XIS) onboard Suzaku launched in 2005 July, as well as the XMM-Newton EPIC (e.g., Foschini et al. 2005; Tsunoda et al. 2006), suggest that the multi-color-disk type spectra are in reality emitted by slim disks (Watarai et al. 2001), which may form around black holes under super-critical accretion rate (but the luminosity remaining only slightly super-Eddington; Kubota and Makishima 2004; Abe et al. 2005). The Hard X-ray Detector onboard Suzaku is providing useful upper limits on the 15-50 keV emission from a few ULXs. It is intriguing that a fair fraction of ULXs are surrounded by optical line-emitting nebulae (Pakull 2004). In X-rays as well, some ULXs may be accompanied by thin-thermal spectral components (e.g., Miyaji et al. 2001). This possibility is reinforced by the Suzaku XIS data, and archival XMM-Newton data. These optical and X-ray results suggest that each ULX is surrounded by a gigantic hot plasma bubble, which could be interpreted as a remnant of the explosion which produced the IMBH.

Makishima, Kazuo

2007-04-01

394

?Nd in Seawater Records Ocean Temperature Changes with a Time Delay  

NASA Astrophysics Data System (ADS)

The quaternary era is characterized by large glacial-interglacial cycles responsible for perturbations both in the global oceanic circulation and in the continental rainfalls, inducing changes in the discharge of rivers. The Bengal Gulf, with its gigantic sedimentary fan made of the sediments eroded from the Himalayas and carried away by the Ganges and the Brahmaputra, offers a case study for these changes. Gourlan et al., [2010] tackled the relations between the Himalayan erosion, the Indian Monsoon and the marine sedimentary records. Making use of the short residence time of Neodymium (? 1000 years) compared to the time of global ocean mixing (3000 years), they determined the ancient seawater neodymium isotopic ratio (expressed in the usual ?Nd) recorded in the coatings and carbonates fractions of marine sediments from ODP Site 758 during the last 800 ka, and showed similar variations between ?18O and the ?Nd seawater. These co-variations were related to changes in the outflow of Ganga-Brahmaputra-Meghna (GBM) reaching the sea-surface at ODP site 758 during Glacial-Interglacial periods, themselves related to the ice-sheet growth/ decay and the tropical hydrological cycle. Here we focus on the precise quantification of time delays between the co-variations of ?18O and ?Nd seawater. The high frequency of sampling allows for a precise data interpolation of both series. We use a correlation technique to derive time delays for the dataset taken as a whole. The two datasets are filtered around periods of interest (44 ky and 100 ky), and the procedure is renewed. Despite strong limitations due to data scarcity and variable sampling frequency, we show that the ?Nd seawater curve is delayed by 2300300 y for the 44 ky frequency and by 7800300 y for the 100 ky frequency. The shift remains the same over the entire last 800 ky. This suggests that the seawater composition changes after the change in temperature as recorded by ?18O. In addition, the difference in delay between the 100 ky and 44 ky cycles could be related to the amplitude of the temperature change

Gourlan, A. T.; Chauvel, C.; Voisin, C.

2012-04-01

395

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA Electronic Theater 2002  

NASA Technical Reports Server (NTRS)

The NASA/NOAA Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to the Olympic Medals Plaza, the new Gateway Center, and the University of Utah Stadium Site of the Olympic Opening and Closing Ceremonies in Salt Lake City. Fly in and through the Park City, and Snow Basin sites of the 2002 Winter Olympic Alpine Venues using 1 m IKONOS "Spy Satellite" data. See the four seasons of the Wasatch Front as observed by Landsat 7 at 15m resolution and watch the trees turn color in the Fall, snow come and go in the mountains and the reservoirs freeze and melt. Go back to the early weather satellite images from the 1960s and see them contrasted with the latest US and international global satellite weather movies including hurricanes & "tornadoes". See the latest visualizations of spectacular images from NASA/NOAA remote sensing missions like Terra, GOES, TRMM, SeaWiFS, Landsat 7 including new 1 - min GOES rapid scan image sequences of Nov 9th 2001 Midwest tornadic thunderstorms and have them explained. See how High-Definition Television (HDTV) is revolutionizing the way we communicate science. (In cooperation with the American Museum of Natural History in NYC) See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on the covers of Newsweek, TIME, National Geographic, Popular Science & on National & International Network TV. New computer software tools allow us to roam & zoom through massive global images e.g. Landsat tours of the US, and Africa, showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP military satellite. The demonstration is interactively driven by a SGI Octane Graphics Supercomputer with two CPUs, 4 Gigabytes of RAM and 0.5 Terabyte of disk using two projectors across a super sized panoramic 48 foot screen. In addition new HDTV technology will be demonstrated from a portable computer server.

Hasler, A. F.; Starr, David (Technical Monitor)

2001-01-01

396

Acromegaly resolution after traumatic brain injury: a case report  

PubMed Central

Introduction Anterior hypopituitarism is a common complication of head trauma, with a prevalence of 30% to 70% among long-term survivors. This is a much higher frequency than previously thought and suggests that most cases of post-traumatic hypopituitarism remain undiagnosed and untreated. Symptoms of hypopituitarism are very unspecific and very similar to those in traumatic brain injury patients in general, which makes hypopituitarism difficult to diagnose. The factors that predict the likelihood of developing hypopituitarism following traumatic brain injury remain poorly understood. The incidence of a specific hormone deficiency is variable, with growth hormone deficiency reported in 18% to 23% of cases. Case presentation A 23-year-old Hispanic man with a 2-year history of hypertension and diabetes presented with severe closed-head trauma producing diffuse axonal injury, subarachnoid hemorrhage and a brain concussion. A computed tomography scan showed a pituitary macroadenoma. The patient has clinical features of acromegaly and gigantism without other pituitary hyperfunctional manifestations or mass effect syndrome. A short-term post-traumatic laboratory test showed high levels of insulin like growth factor 1 and growth hormone, which are compatible with a growth hormoneproducing pituitary tumor. At the third month post-trauma, the patients levels of insulin like growth factor 1 had decreased to low normal levels, with basal low levels of growth hormone. A glucose tolerance test completely suppressed the growth hormone, which confirmed resolution of acromegaly. An insulin tolerance test showed lack of stimulation of growth hormone and cortisol, demonstrating hypopituitarism of both axes. Conclusion Even though hypopituitarism is a frequent complication of traumatic brain injury, there are no reports in the literature, to the best of my knowledge, of patients with hyperfunctional pituitary adenomas, such as growth hormoneproducing adenoma, that resolved after head trauma. A clear protocol has not yet been established to identify which patients should be screened for hypopituitarism. Predictive factors that might determine the likelihood of developing post-traumatic hypopituitarism have not been clearly established, but there is no evidence of the presence of pituitary adenomas as a risk factor in otherwise healthy patients. PMID:25182385

2014-01-01

397

Olivine in the Southern Isidis Basin  

NASA Technical Reports Server (NTRS)

The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) took this observation of the transition region between Libya Montes and the Isidis Basin on Mars at 17:16 UTC (12:16 p.m. EST) on January 2, 2007, near 3.6 degrees north latitude, 84.1 degrees east longitude. The image was taken in 544 colors covering 0.36-3.92 micrometers, and shows features as small as 18 meters (60 feet) across. The image is about 11 kilometers (7 miles) wide at its narrowest point.

The Isidis Basin resulted from of a gigantic impact on the surface of Mars early in the planet's history. The southern rim, where this target is located, is a region of complex geology and part of the planetary dichotomy boundary that separates the older southern highlands from the lower, younger northern plains. The image on the left was constructed from three visible wavelengths (RGB: 0.71, 0.60, 0.53 microns) and is a close approximation of how the surface would appear to the human eye. The image on the right was constructed from three infrared wavelengths (RGB: 2.49, 1.52, 1.08 microns) chosen to highlight variations in the mineralogy of the area. Of interest is that features in this image not only differ in color, but also in texture and morphology. The gray areas absorb similarly at all wavelengths used in this image, but display absorptions at other wavelengths related to the iron- and magesium-rich mineral pyroxene. The reddest areas absorb strongly at the wavelengths used for green and blue, which is attributable to another iron- and magesium-rich mineral, olivine. The brownish areas show subdued mineral absorptions and could represent some type of mixture between the other two materials. The presence of the mineral olivine is particularly interesting because olivine easily weathers to other minerals; thus, its presence indicates either the lack of weathering in this region or relatively recent exposure.

CRISM's mission: Find the spectral fingerprints of aqueous and hydrothermal deposits and map the geology, composition and stratigraphy of surface features. The instrument will also watch the seasonal variations in Martian dust and ice aerosols, and water content in surface materials -- leading to new understanding of the climate.

The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) is one of six science instruments on NASA's Mars Reconnaissance Orbiter. Led by The Johns Hopkins University Applied Physics Laboratory, the CRISM team includes expertise from universities, government agencies and small businesses in the United States and abroad.

2007-01-01

398

Deformations Associated With Large Interplate Earthquakes Along the Sumatra-Andaman Subduction Zone  

NASA Astrophysics Data System (ADS)

Since the occurrence of the 2004 Sumatra-Andaman earthquake (Mw9.2), the Sumatra-Andaman Subduction zone has attracted geophysicists' attention. We have been carrying on CGPS observation in Thailand and Myanmar to detect postseismic deformation following this gigantic event. Since CGPS on land is not enough to clarify the detailed image of postseismic deformation, we also make InSAR analyses in Andaman and Phuket Islands. On September 12, 2007, another Mw8.4 event occurred SW off Sumatra. We report deformations observed with GPS and SAR including co- and postseismic deformation following this event. We have analyzed CGPS data up to the end of 2007 and detected postseismic displacements all over the Indochina peninsula. Phuket, which suffered from about 26cm coseismic displacement, has shifted by 26cm southwestward till July, 2007. Postseismic transient is clearly recognized and already exceeds coseismic movements at remote sites such as Bangkok and Chiang Mai in Thailand. We processed ALOS/PALSAR data in Andaman and Phuket islands. No remarkable deformation is found in Andaman and Phuket Islands, since the operation period of ALOS/PALSAR is not long enough and the wavelength of postseismic deformation may be much longer than the swath. We try to synthesize the postseismic displacement using a 3-D viscoelastic FEM model. Its results imply that viscoelastic relaxation in mantle with a typical mantle viscosity may play an important role for the observed postseismic transients except during the first six month. An extremely low viscosity is not required beneath the Andaman Sea, though this back arc is now actively opening. Coseismic motion following the 2007 Sumatra event is detected north of Benkgulu on the coast of southern Sumatra with InSAR. The largest LOS displacement of about 35cm is observed 100km NW of Bengkulu. Coseismic westward displacements of 3.5cm from the 2007 Sumatra event are also observed at Singapore, whose epicentral distance is about 700km, with CGPS. The observed fringe can be simulated by a plane fault model gently dipping northeastward with a 10m slip. On the other hand, the maximum of postseismic LOS displacement is shifted about 50km south from the coseismic maximum and significant fringes are more localized than the coseismic ones. The shift and localization of fringe are difficult to understand with an afterslip on deeper extension of coseismic fault plane. There is a slight disturbance in fringes along the Sumatran fault in the coseismic image, although it might be a topographic error. We will continue monitoring crustal deformations in the Sumatra-Andaman subduction zone with GPS and InSAR in order to reveal stress transfer.

Hashimoto, M.; Fukushima, Y.; Katagi, T.; Hashizume, M.; Satomura, M.; Wu, P.; Kato, T.

2008-12-01

399

Tvashtar in Motion  

NASA Technical Reports Server (NTRS)

This five-frame sequence of New Horizons images captures the giant plume from Io's Tvashtar volcano. Snapped by the probe's Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Jupiter earlier this year, this first-ever 'movie' of an Io plume clearly shows motion in the cloud of volcanic debris, which extends 330 kilometers (200 miles) above the moon's surface. Only the upper part of the plume is visible from this vantage point -- the plume's source is 130 kilometers (80 miles) below the edge of Io's disk, on the far side of the moon.

The appearance and motion of the plume is remarkably similar to an ornamental fountain on Earth, replicated on a gigantic scale. The knots and filaments that allow us to track the plume's motion are still mysterious, but this movie is likely to help scientists understand their origin, as well as provide unique information on the plume dynamics.

Io's hyperactive nature is emphasized by the fact that two other volcanic plumes are also visible off the edge of Io's disk: Masubi at the 7 o'clock position, and a very faint plume, possibly from the volcano Zal, at the 10 o'clock position. Jupiter illuminates the night side of Io, and the most prominent feature visible on the disk is the dark horseshoe shape of the volcano Loki, likely an enormous lava lake. Boosaule Mons, which at 18 kilometers (11 miles) is the highest mountain on Io and one of the highest mountains in the solar system, pokes above the edge of the disk on the right side.

The five images were obtained over an 8-minute span, with two minutes between frames, from 23:50 to 23:58 Universal Time on March 1, 2007. Io was 3.8 million kilometers (2.4 million miles) from New Horizons; the image is centered at Io coordinates 0 degrees north, 342 degrees west.

The pictures were part of a sequence designed to look at Jupiter's rings, but planners included Io in the sequence because the moon was passing behind Jupiter's rings at the time.

2007-01-01

400

Energetic runaway electrons emitted from streamers  

NASA Astrophysics Data System (ADS)

Streamers are filamentary plasmas, which are driven by highly nonlinear space charge waves. In tips of streamers, intense electric fields are produced, and the generation of runaway electrons in these discharges has been identified and discussed in the literature for more than two decades [Babich, Sov. Phys. Dokl., 263, 76, 1982, and references therein]. It has been proposed that with total potential differences on the order of tens of MV available in streamer zones of lightning leaders, during a highly transient negative corona flash stage of the development of negative stepped leader, electrons with energies 2-8 keV ejected from streamer tips near the leader head can be further accelerated to energies of hundreds of keV and possibly to several tens of MeV [Moss et al., JGR, 111, A02307, 2006]. It has been proposed that these energetic electrons may be responsible, through the bremsstrahlung process, for the generation of hard X-rays observed from ground and satellites [e.g., Fishman et al., Science, 264, 1313, 1994; Inan et al., GRL, 23, 1017, 1996; Moore et al., GRL, 28, 2141, 2001; Dwyer et al., GRL, 32, L01803, 2005; Smith et al., Science, 307, 1085, 2005; Cummer et al., GRL, 32, L08811, 2005; and references therein]. The current observations and theories of transient luminous events occurring above cloud tops and termed blue and gigantic jets are converging towards a clear connection between jet discharges and streamer zones of lightning leaders [Krehbiel et al., Nature Geosci., 1, 233, 2008; and references therein] and it has been suggested that the thermal runaway electron process operating in leaders may contribute to production of terrestrial gamma ray flashes from the jet discharges [Moss et al., 2006]. In the present work, we combine our recently developed Monte Carlo code simulating the propagation of electrons in air with energies varying from sub-eV to MeV [Celestin and Pasko, CEDAR Workshop, Boulder, CO, W2 ECCR245, 20-25 June, 2010] with streamer fluid models [e.g., Bourdon et al., PSST, 16, 656, 2007] in order to demonstrate the strong impact of the ambient conditions and dynamical features of the streamer discharges on the emission of high energy electrons eventually leading to X-ray emissions. We describe a mechanism in which electrons with energies 10 times higher than those obtained in [Moss et al., 2006] are ejected from tips of streamers and are directly capable of further acceleration in streamer zone of negative leaders.

Celestin, S. J.; Pasko, V. P.

2010-12-01

401

Crustal deformation of Miyakejima volcano, Japan since the eruption of 2000 using dense GPS campaign observation  

NASA Astrophysics Data System (ADS)

Miyakejima is an active volcanic Island located about 175 km south of Tokyo, Japan. Miyakejima volcano erupted approximately every 20 years in the past 100 years. The latest eruptive activities since 2000 was different from those of the last 100 years, in that the activities included a caldera formation for the first time in 2500 years and gigantic volcanic gas emission that forced islander to evacuate over four and half years. In 2000, a dense GPS observation campaign had detected the magma intrusion in detail (e.g., Irwan et al., 2003; Murase et al., 2006). However, this campaign observation ceased from 2002 to 2010 because a large amount of volcanic gas prevented from entering to the island. Since 2011, we restarted the campaign observation by the dense GPS network, and examined the ongoing magma accumulation process beneath Miyakejima volcano to get insights about the future activity. In this analysis, we combined the data of our campaign observations, the data of the University Union in 2000, and the GEONET data. The observation data were analyzed by RTK-LIB (Takasu et al., 2007) using GPS precise ephemeris from IGS. We estimated the locations and volumes of the pressure sources beneth Miyakejima using an elevation-modified Mogi model (Fukui et al., 2003) and open crack model (Okada, 1992) during the two periods (2000 ~ 2012 and 2011 ~ 2012). We used the software of Magnetic and Geodetic data Computer Analysis Program for Volcano (MaGCAP-V) (Fukui et al., 2010), and estimated the source parameters by trial and error. During 2000 and 2012, a contracting spherical source and contracting dyke were estimated beneath the caldera and at the southwestern part of the island, respectively. In contrast, during 2011 and 2012, an spherical inflation source was estimated a few km beneath the caldera. This result suggest that Miyakejima is now storing new magma for the next eruption. Geospatial Information Authority of Japan (GSI) (2011) suggested that the inflation started since 2006. We will also carry out the GPS observation this autmn, and will present the result during 2012-2013.

Fukui, M.; Matsushima, T.; Oikawa, J.; Watanabe, A.; Okuda, T.; Ozawa, T.; Kohno, Y.; Miyagi, Y.

2013-12-01

402

Massive Dissociation of Subsurface Gas Hydrates and Collapse of Gas Hydrate Mounds during the LGM in the Eastern Margin of Japan Sea: Evidence from Benthic Forams and U/Th ages of Authigenic Carbonates  

NASA Astrophysics Data System (ADS)

A number of gigantic methane plumes, ca. 600 m high, and massive blocks of gas hydrate, ca. 0.5 m x 1.0 m, have been observed on the Umitaka spur and Joetsu knoll, eastern margin of Japan Sea. Large pockmarks and mounds, ca. 0.5 km in diameter, develop on the spur and knoll. The mounds exhibit rough morphological features characterized by small valleys of 5m wide, steep cliffs, crater-like depressions of 10 m in diameter, and scattered carbonate nodules and crusts of various size and shape with occasional gas hydrate blocks and veins and gas venting. To the contrary, pockmarks are inactive, partly filled by well-stratified mud without any indication of gas venting. 2D and 3D seismic surveys have recognized widely distributed BSRs at around 150 mbsf over the spur and knoll. Seismic profiles delineated deep gas chimney structures below the pockmarks and mounds. Unusual pull-up structures within gas chimneys indicate massive accumulation of gas hydrate. All these findings are likely to suggest that massive hydrate deposits both in gas chimneys at depths and hydrate mounds on the spur and knoll were collapsed and floated up to the sea surface, leaving big holes (= pockmarks) on the seafloor. Quantitative analysis of foraminiferal assemblage has revealed that the well laminated, burrow-free 17 to 22 ka sediments are substantially barren for benthic forams but for unusual species which has been believed to survive under high methane environments. Shells of such a few benthic formas from around 20 ka sediments are anomalously depleted in C-13. U-Th ages of authigenic carbonates of CH4-induced carbonate nodules and crusts are likely to center around 20 ka. Above line of evidences all suggest that gas hydrate system was collapsed and methane fluxes were enhanced during the last glacial maximum (LGM), presumably due to low stand of sea level and pressure release. Broken gas hydrate blocks are expected to float up to the sea surface to supply significant amount of methane to atmosphere. The amount of methane emitted from a single hydrate mound is estimated to be at least ~0.1 Tcf CH4.

Matsumoto, R.; Takeuchi, E.; Sanno, R.

2008-12-01

403

The distribution of an illustrated timeline wall chart and teacher's guide of 20th century physics  

SciTech Connect

The American Physical Society's part of its centennial celebration in March of 1999 decided to develop a timeline wall chart on the history of 20th century physics. This resulted in eleven consecutive posters, which when mounted side by side, create a 23-foot mural. The timeline exhibits and describes the millstones of physics in images and words. The timeline functions as a chronology, a work of art, a permanent open textbook, and a gigantic photo album covering a hundred years in the life of the community of physicists and the existence of the American Physical Society. Each of the eleven posters begins with a brief essay that places a major scientific achievement of the decade in its historical context. Large portraits of the essays' subjects include youthful photographs of Marie Curie, Albert Einstein, and Richard Feynman among others, to help put a face on science. Below the essays, a total of over 130 individual discoveries and inventions, explained in dated text boxes with accompanying images, form the backbone of the timeline. For ease of comprehension, this wealth of material is organized into five color-coded story lines the stretch horizontally across the hundred years of the 20th century. The five story lines are: Cosmic Scale, relate the story of astrophysics and cosmology; Human Scale, refers to the physics of the more familiar distances from the global to the microscopic; Atomic Scale, focuses on the submicroscopic world of atoms, nuclei and quarks; Living World, chronicles the interaction of physics with biology and medicine; Technology, traces the applications of physic to everyday living. Woven into the bottom border of the timeline are period images of significant works of art, architecture, and technological artifacts such as telephones, automobiles, aircraft, computers, and appliances. The last poster, covering the years since 1995, differs from the others. Its essay concerns the prospect for physics into the next century, and is illustrated with pictures of promising award winning high school students who, it is hoped, will be the leading researchers of physics in the decades ahead. Appropriately the last entries in the timeline are not achievements but open questions to be answered in the future.

Schwartz, Brian

2000-12-26

404

Mass Ejection from Old and Young Stars and the Sun  

NASA Astrophysics Data System (ADS)

RESUMEN. Para poder explicar: 1) la enorme cantidad de perdida de masa y la baja velocidad asint5tica de las estrellas gigantes de o, y 2) los flujos de masa observados en protoestrellas, se sugiere un modelo para Ia perdida de masa, en donde se usa un flujo de ondas de Alfvencomo un mecanismo de aceleraci6n para los vientos de estrellas de tipo y vientos en protoestrellas. Se estudian los mecanismos de disipaci5n de las ondas de Alfven: los amortiguamientos no lineal, de superficie reso- nante y turbulento. En nuestro modelo se usa una divergente A(r) = A(R0) (r/r0)5 (donde A(r) es el area a una distancia radial r, y (A(r)/r2)max/(A(ro)/r02 - 10). Tambien se sugiere un modelo para una de hoyo coronal en el Sol. Se muestra que para satisfacer los datos observacionales en el Sol, tomando en cuenta la deposici6n del momento de las ondas de Alfven sobre el viento, se necesita: (a) una divergencia lenta en un hoyo coronal hasta una altura de 0.01 - 0.1 R seguido de (b) una divergencia rap ida de hasta una altura aproximada de 1 R . ABSTRACT: In order to explain (1) a large mass-loss rate and a small asymptotic flow speed of late-type giant stars and (2) the observed protostellar mass outflows, we suggest a model for mass loss, where we use a flux of Alfven waves as a mechanism of acceleration for late-type giant star winds and protostellar winds. We study the Alfven wave dissipation mechanisms: nonlinear damping, resonant surface damping, and turbulent damping. In our model we use a diverging geometry A(r) = A(r0) (r I r )S (where A(r) is the cross sectional area of the geometry at a radial distance r, and(A(r) I r2)max/(A(r0)/r02) = 10). We also suggest a model for a coronal hole geometry in the sun. We show that in order to satisfy the observational data of the sun, taking into account Alfven wave momentum deposition in the wind, we need: (a) a slow divergence in a coronal hole up t6 a height of 0.01 - 0.1 followed by (b) a rapid divergence up to a height of approximately 1 Re Key : '? #TICS - STARS-LATE TYPE - STARS- LOSS

Jatenco-Pereira, V.; Opher, R.

1990-11-01

405

Population education for social betterment.  

PubMed

In India primary education has increased 3 times in the last 30 years. Over this same period middle school education has increased 4 times, higher secondary education 5 times, and university level education over 6 times. The number of universities alone increased from 19 in 1950 to 118 by 1981. The inconsistencies brought about by rapid population growth may be judged by the fact that while the number of institutions and the enrollment of students has expanded beyond measure, the number of illiterate persons has risen from 386 million in 1971 to 446 million in 1981. Clearly, education is vital for human resource development. In political terms, human resource development prepares a population for adult participation in political processes. From social and cultural perspectives, the development of human resources helps people to lead fuller and richer lives. Population means people, and people need food, clothing, homes, education, transportation, health services, and jobs. As long as a country's resources can satisfy the essential needs of its population, there is no population problem. If the population grows faster than the rate at which the basic needs of each individual can be met, the buildup of such a situation produces a crisis of gigantic dimensions. To meet basic requirements, India needs to provide annually an additional 12 million tons of foodgrains, 188 million meters of cloth, 2.5 million houses, along with schools, teachers, and jobs over and above what is currently available. Another need is for fresh air, pure water, and space to live in. The question is how is this need to be met when the earth is a finite sphere. What will happen when the world's 3.5 billion people double into a staggering 7 billion by the end of the 20th century. It is because of this concern for family well being and the betterment of human resources that the Family Planning Association of India has since 1969 undertaken innovative pilot programs in popultion education for the younger generation, for teachers, social workers, and other concerned groups. The government of India promotes population education for school and out-of-school youths through the 5-year national population education project for schools and through the adult education project for out-of-school youth. PMID:12311993

Mukhi, S

1983-01-26

406

The propagation of the shock wave from a strong explosion in a plane-parallel stratified medium: the Kompaneets approximation  

NASA Astrophysics Data System (ADS)

Context: Using certain simplifications, Kompaneets derived a partial differential equation that states the local geometrical and kinematical conditions that each surface element of a shock wave, created by a point blast in a stratified gaseous medium, must satisfy. Kompaneets could solve his equation analytically for the case of a wave propagating in an exponentially stratified medium, obtaining the form of the shock front at progressive evolutionary stages. Complete analytical solutions of the Kompaneets equation for shock wave motion in further plane-parallel stratified media were not found, except for radially stratified media. Aims: We aim to analytically solve the Kompaneets equation for the motion of a shock wave in different plane-parallel stratified media that can reflect a wide variety of astrophysical contexts. We were particularly interested in solving the Kompaneets equation for a strong explosion in the interstellar medium of the Galactic disk, in which, due to intense winds and explosions of stars, gigantic gaseous structures known as superbubbles and supershells are formed. Methods: Using the Kompaneets approximation, we derived a pair of equations that we call adapted Kompaneets equations, that govern the propagation of a shock wave in a stratified medium and that permit us to obtain solutions in parametric form. The solutions provided by the system of adapted Kompaneets equations are equivalent to those of the Kompaneets equation. We solved the adapted Kompaneets equations for shock wave propagation in a generic stratified medium by means of a power-series method. Results: Using the series solution for a shock wave in a generic medium, we obtained the series solutions for four specific media whose respective density distributions in the direction perpendicular to the stratification plane are of an exponential, power-law type (one with exponent k=-1 and the other with k =-2) and a quadratic hyperbolic-secant. From these series solutions, we deduced exact solutions for the four media in terms of elemental functions. The exact solution for shock wave propagation in a medium of quadratic hyperbolic-secant density distribution is very appropriate to describe the growth of superbubbles in the Galactic disk. Member of the Carrera del Investigador Cientfico del CONICET, Argentina.

Olano, C. A.

2009-11-01

407

Electronic-Theater 2001: Visions of Our Planet's Atmosphere, Land and Oceans  

NASA Technical Reports Server (NTRS)

The NASA/NOAA/AMS Electronic Theater presents Earth science observations and visualizations in a historical perspective. Fly in from outer space to Wisconsin, Madison and the Monona Terrace Center. Drop in on the Kennedy Space Center and Park City Utah, site of the 2002 Olympics using I m IKONOS "Spy Satellite" data. Go back to the early weather satellite images from the 1960s pioneered by UW. Scientists and see them contrasted with the latest US and International global satellite weather movies including hurricanes & tornadoes. See the latest spectacular images from NASA/NOAA remote sensing missions like Terra GOES, TRMM, SeaWiFS, Landsat 7 that are visualized & explained. See how High Definition Television (HDTV) is revolutionizing the way we communicate science in cooperation with the American Museum of Natural History in NYC. See dust storms in Africa and smoke plumes from fires in Mexico. See visualizations featured on Newsweek, TIME, National Geographic, Popular Science covers & National & International Network TV. New visualization tools allow us to roam & zoom through massive global images eg Landsat tours of the US, Africa, & New Zealand showing desert and mountain geology as well as seasonal changes in vegetation. See animations of the polar ice packs and the motion of gigantic Antarctic Icebergs from SeaWinds data. Spectacular new visualizations of the global atmosphere & oceans are shown. See massive dust storms sweeping across Africa. See vortices and currents in the global oceans that bring up the nutrients to feed tiny plankton and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nina/La Nina climate changes. The demonstration is interactively driven by a SGI Onyx 11 Graphics Supercomputer with four CPUs, 8 Gigabytes of RAM and Terabyte of disk. With five projectors on a giant IMAX sized 18 x 72 ft screen. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "nightvision" DMSP military satellite.

Hasler, Authur; Starr, David OC. (Technical Monitor)

2001-01-01

408

Maximum Earthquake Magnitude Assessments by Japanese Government Committees (Invited)  

NASA Astrophysics Data System (ADS)

The 2011 Tohoku earthquake (M 9.0) was the largest earthquake in Japanese history and such a gigantic earthquake was not foreseen around Japan. After the 2011 disaster, various government committees in Japan have discussed and assessed the maximum credible earthquake size around Japan, but their values vary without definite consensus. I will review them with earthquakes along the Nankai Trough as an example. The Central Disaster Management Council, under Cabinet Office, set up a policy for the future tsunami disaster mitigation. The possible future tsunamis are classified into two levels: L1 and L2. The L2 tsunamis are the largest possible tsunamis with low frequency of occurrence, for which saving people's lives is the first priority with soft measures such as tsunami hazard maps, evacuation facilities or disaster education. The L1 tsunamis are expected to occur more frequently, typically once in a few decades, for which hard countermeasures such as breakwater must be prepared. The assessments of L1 and L2 events are left to local governments. The CDMC also assigned M 9.1 as the maximum size of earthquake along the Nankai trough, then computed the ground shaking and tsunami inundation for several scenario earthquakes. The estimated loss is about ten times the 2011 disaster, with maximum casualties of 320,000 and economic loss of 2 trillion dollars. The Headquarters of Earthquake Research Promotion, under MEXT, was set up after the 1995 Kobe earthquake and has made long-term forecast of large earthquakes and published national seismic hazard maps. The future probability of earthquake occurrence, for example in the next 30 years, was calculated from the past data of large earthquakes, on the basis of characteristic earthquake model. The HERP recently revised the long-term forecast of Naknai trough earthquake; while the 30 year probability (60 - 70 %) is similar to the previous estimate, they noted the size can be M 8 to 9, considering the variability of past earthquakes. The Nuclear Regulation Authority, established in 2012, makes independent decisions based on the latest scientific knowledge. They assigned maximum credible earthquake magnitude of 9.6 for Nankai an Ryukyu troughs, 9.6 for Kuirl-Japan trench, and 9.2 for Izu-Bonin trench.

Satake, K.

2013-12-01

409

The Impossible cave in the Classical Karst  

NASA Astrophysics Data System (ADS)

The Impossible Cave has been discovered, near Trieste (Classical Karst, northern Italy) in the year 2004 during road construction and up to today has been explored for more than 3 km. This cave opens in Paleocene - Eocene pure limestones, similarly to the ones situated in Rosandra Valley (placed a few hundreds meters from the entrance of this cave) that is the better developed cave system in the Karst of Trieste. In the area where the Impossible Cave has been found, the calcareous strata form a knee fold and overtrusts the marly arenaceous strata of the Eocene Flysch of Trieste with a large NW-SE fault. The cave is situated approximately 500 m from the contact between the limestones and the Flysch. The large galleries that form the Impossible Cave are better developed in an E-W general direction but that is the result of an alternate conditioning by dinaric and anti-dinaric structures; in the other side, the smaller galleries are orientated NW-SE, parallel to Flysch and limestones contact and to the direction of the strata. The most particular feature of the Impossible Cave is the great underground karst forms development, which is better represented by a large cavern that for size is close to the one of the Grotta Gigante that is the bigger tourist cave worldwide. A peculiar aspect of the Impossible Cave is that the surface where the cave has been discovered is characterized by the absence of well developed dolines or sinkholes and the classical karst morphologies are very few or poorly developed. On the surface it is impossible to recognize the main structural features which interest the rock massif; however, hypogean voids show clearly that structural rock mass trim is the main factor which due the speleogenesis. In the mean time the Impossible Cave differs from theoretical cave models for the Classical Karst and that's the reason of the nickname of impossible. By comparing it to the main caves in the areas it seems developed in a direction and at an altitude not related to the previously known hydrogeological evolution of this region. Explorations of this cave have indicated that signs of the Messinian crisis are not found or limited to few caverns that in the terminal parts have sub vertical walls; different structural features drove the formation of main and secondary galleries and it probably occurred at different times.

Cucchi, F.; Boschin, W.; Visintin, L.; Zini, L.

2009-04-01

410

Optimization of flow modeling in fractured media with discrete fracture network via percolation theory  

NASA Astrophysics Data System (ADS)

Fractured media are very heterogeneous systems where occur complex physical and chemical processes to model. One of the possible approaches to conceptualize this type of massifs is the Discrete Fracture Network (DFN). Donado et al., modeled flow and transport in a granitic batholith based on this approach and found good fitting with hydraulic and tracer tests, but the computational cost was excessive due to a gigantic amount of elements to model. We present in this work a methodology based on percolation theory for reducing the number of elements and in consequence, to reduce the bandwidth of the conductance matrix and the execution time of each network. DFN poses as an excellent representation of all the set of fractures of the media, but not all the fractures of the media are part of the conductive network. Percolation theory is used to identify which nodes or fractures are not conductive, based on the occupation probability or percolation threshold. In a fractured system, connectivity determines the flow pattern in the fractured rock mass. This volume of fluid is driven through connection paths formed by the fractures, when the permeability of the rock is negligible compared to the fractures. In a population of distributed fractures, each of this that has no intersection with any connected fracture do not contribute to generate a flow field. This algorithm also permits us to erase these elements however they are water conducting and hence, refine even more the backbone of the network. We used 100 different generations of DFN that were optimized in this study using percolation theory. In each of the networks calibrate hydrodynamic parameters as hydraulic conductivity and specific storage coefficient, for each of the five families of fractures, yielding a total of 10 parameters to estimate, at each generation. Since the effects of the distribution of fault orientation changes the value of the percolation threshold, but not the universal laws of classical percolation theory, the latter is applicable to such networks. Under these conditions, percolation theory permit us to reduced the number of elements (90% in average) that form clusters of the 100 DFNs, preserving the so-called backbone. In this way the calibration runs in these networks changed from several hours to just a second obtaining much better results.

Donado-Garzon, L. D.; Pardo, Y.

2013-12-01

411

Larger than life: billboard communication in Southeast Asia.  

PubMed

Billboards are widely used in Southeast Asia, and especially in Malaysia, Singapore, Indonesia, and Thailand, for delivering persuasive political and commercial messages and for advertising the cinema. Billboards are a cost effective way of communicating with all segments of society including illiterate persons, poor people who cannot afford television sets and radios, rural populations, and diverse ethnic and linguistic groups. Billboards are a form of applied art and are used to deliver temporary messages. Each country has its own billboard traditions and styles, and within each country, commercial, cinema, and political boards also have their own styles. In Indonesia and Thailand, almost all billboards are hand painted and gigantic in size. The paintings are highly realistic and detailed. In Thailand billboards are produced in large studios employing many artists, and the boards cost about US$9.00/square meter or more. The Four Art Studio in Bankok produces commercial boards in Renaissance, Impressionistic, Pop, and Op art styles. Both Indonesia and Thailand were early centers of artistic and cultural influence in Asia, and each country has highly developed art traditions. In Indonesia, the Japanese occupation led to the development of propaganda and nationalistic art. After independence nationalistic art was developed still further. At the present time, socialist-realistism predominates as an art style, and large air brushed political billboards are prominantly displayed throughout the country. In Malaysia and Singapore billboards are small in size. Most of the boards, except those used to advertise the cinema, are printed rather than painted. Neither country has a strong tradition of art. Realism is not stressed in their fine arts nor in their art training. The lack of a realistic art tradition probably accounts for the emphasis placed on printed billboards. Cinema boards are painted but they are not produced by applied artists and are generally mediocre in quality. Political boards in Malaysia generally contain only verbal messages. In Singapore there are few political billboards. In Japan billboards are also widely used. They are sophisticated and usually printed with advanced technological methods. An innovative form of billboard, a 20 meter audiovisual screen, is appearing more and more frequently in Japanese cities. PMID:12339664

Barnard, B

1983-01-01

412

Particle versus density models in spark formation: X-rays from pulled fronts?  

NASA Astrophysics Data System (ADS)

Streamer discharges govern the early stages of sparks and lightning, of spark-like phenomena in water, oil, and semiconductors, in industrial corona reactors, or in gigantic sprite discharges above thunderclouds [1,2]. Thunderstorms recently have been found to emit terrestrial gamma-ray flashes or X-rays towards satellites and towards the ground. These emissions might be explained by particle models of ``pulled'' streamer ionization fronts. In general, the growing discharge channel has an inner structure with multiple scales [1-3]. While the largest part of this channel can be treated in a density approximation for the electrons and ions, the dynamics of the ionization front is that of a pulled front; it is determined in the leading edge where the density approach eventually breaks down. We therefore investigate a realistic MC particle model for the motion of single electrons in a discharge in pure nitrogen. The particle model not only incorporates particle fluctuations, but also shows that the electron energies are systematically larger in the leading edge of the front than in the corresponding density model, and that the ionization level behind the front is higher as well, while the front velocity hardly changes [3]. These effects increase with increasing applied electric field and might actually cause the recently observed X-ray emission from lightning through rare very energetic runaway electrons in the tail of the distribution. Comparing the leading edge of the particle front with a linear particle avalanche, the avalanche shows the same mean density gradient and energy overshoot in its leading edge as the nonlinear front; hence the pulled front concept in this sense applies to discrete particle models as well [3]. This gives a key to understanding the above effects through analytical approximations and to develop efficient numerical methods coupling particle and density models in space.[1] U. Ebert et al., Plasma Sources Sci. Techn. 15, S118 (2006) (arXiv:physics/0604023).[2] Streamers, sprites, leaders, lightning: From micro- to macroscales, workshop in Oct. 2007: http://www.lorentzcenter.nl/lc/web/2007/265/info.php3?wsid=265; and cluster issue in J. Phys. D in fall 2008; organizers/editors: U. Ebert and D.D. Sentman.[3] C. Li et al., J. Appl. Phys. 101, 123305 (2007) (arXiv:physics/0702129).

Ebert, Ute

2008-03-01

413