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1

ExtraTerrestrial Intelligence  

E-print Network

SETI Search for ExtraTerrestrial Intelligence I know perfectly well that at this moment the whole, The Madwoman of Chaillot #12;Options Passive SETI: Listen Active SETI: Transmit #12;Search Strategies Suppose you find a civilization. You want to communicate. How? #12;Search Strategies There are two issues: A

Walter, Frederick M.

2

SETI [Search for ExtraTerrestrial Intelligence  

Microsoft Academic Search

Some critics of the Search for Extra-Terrestrial Intelligence (SETI) like to bolster their arguments with what they call the Fermi Paradox. Legend has it that one day at Los Alamos, shortly after the Alamogordo test (when the first atomic bomb was exploded in the desert about 50 miles northwest of this town on July 16, 1945), Enrico Fermi abruptly broke

B. M. Oliver

1994-01-01

3

SETI: Search for ExtraTerrestrial Intelligence  

E-print Network

SETI: Search for ExtraTerrestrial Intelligence I know perfectly well that at this moment the whole, The Madwoman of Chaillot #12;Search Strategies Suppose you find a civilization. You want to communicate. How? #12;Options Passive SETI: Listen Active SETI: Transmit #12;Search Strategies There are two issues: A

Walter, Frederick M.

4

Terrestrial Planet Formation in Extra-Solar Planetary Systems  

E-print Network

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called "planetary embryos". Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their feeding zones and the amount of radial mixing that occurs. The main factors that influence terrestrial planet formation are the mass and surface density profile of the disk, and the perturbations from giant planets and binary companions if they exist. Simple accretion models predicts that low-mass stars should form small, dry planets in their habitable zones. The migration of a giant planet through a disk of rocky bodies does not completely impede terrestrial planet growth. Rather, "hot Jupiter" systems are likely to also contain exterior, very water-rich Earth-like planets, and also "hot Earths", very close-in rocky planets. Roughly one third of the known systems of extra-solar (giant) planets could allow a terrestrial planet to form in the habitable zone.

Sean N. Raymond

2008-01-16

5

The Terrestrial Planets Large Bodies  

E-print Network

: Greenhouse Effect: Solar heating & atmospheric cooling balance Helps determine if H2O is liquid, ice atmosphere. May have had early oceans that evaporated resulting in a Runaway Greenhouse Effect. Gravity elements. #12;The evolution of Terrestrial Planet atmospheres is driven by three primary effects

Gaudi, B. Scott

6

The use of extra-terrestrial oceans to test ocean acoustics students  

E-print Network

The use of extra-terrestrial oceans to test ocean acoustics students T. G. Leightona) Institute of Sound and Vibration Research, University of Southampton, Highfield, Southampton, SO17 1BJ, United of extra-terrestrial oceans offers the opportunities to set examination questions for which students

Sóbester, András

7

A Review of Extra-Terrestrial Mining Robot Concepts  

NASA Technical Reports Server (NTRS)

Outer space contains a vast amount of resources that offer virtually unlimited wealth to the humans that can access and use them for commercial purposes. One of the key technologies for harvesting these resources is robotic mining of regolith, minerals, ices and metals. The harsh environment and vast distances create challenges that are handled best by robotic machines working in collaboration with human explorers. Humans will benefit from the resources that will be mined by robots. They will visit outposts and mining camps as required for exploration, commerce and scientific research, but a continuous presence is most likely to be provided by robotic mining machines that are remotely controlled by humans. There have been a variety of extra-terrestrial robotic mining concepts proposed over the last 100 years and this paper will attempt to summarize and review concepts in the public domain (government, industry and academia) to serve as an informational resource for future mining robot developers and operators. The challenges associated with these concepts will be discussed and feasibility will be assessed. Future needs associated with commercial efforts will also be investigated.

Mueller, Robert P.; Van Susante, Paul J.

2011-01-01

8

A Review of Extra-Terrestrial Mining Concepts  

NASA Technical Reports Server (NTRS)

Outer space contains a vast amount of resources that offer virtually unlimited wealth to the humans that can access and use them for commercial purposes. One of the key technologies for harvesting these resources is robotic mining of regolith, minerals, ices and metals. The harsh environment and vast distances create challenges that are handled best by robotic machines working in collaboration with human explorers. Humans will benefit from the resources that will be mined by robots. They will visit outposts and mining camps as required for exploration, commerce and scientific research, but a continuous presence is most likely to be provided by robotic mining machines that are remotely controlled by humans. There have been a variety of extra-terrestrial robotic mining concepts proposed over the last 40 years and this paper will attempt to summarize and review concepts in the public domain (government, industry and academia) to serve as an informational resource for future mining robot developers and operators. The challenges associated with these concepts will be discussed and feasibility will be assessed. Future needs associated with commercial efforts will also be investigated.

Mueller, R. P.; van Susante, P. J.

2012-01-01

9

(Astro)Physics 343 Lecture # 14: the Search for ExtraTerrestrial Intelligence  

E-print Network

(Astro)Physics 343 Lecture # 14: the Search for ExtraTerrestrial Intelligence #12 about astrobiology guide our choice of search strategy. #12; What astrobiology encompasses astronomy and detection of extraterrestrial life. Location inspired by Drake's first SETI experiment. Participants

Baker, Andrew J.

10

Search for Extra-Terrestrial Intelligence The following is from The Sixth Book of Mathematical Games from Sci-  

E-print Network

Search for Extra-Terrestrial Intelligence The following is from The Sixth Book of Mathematical Games from Sci- entific American by Martin Gardner. Suppose you want to send a message to extra-terrestrials, American Mathematical Monthly 105 (1998) 640­650.) The following proposed message to extraterrestrials

Lee, Carl

11

Physics 343 Lecture # 14: the Search for ExtraTerrestrial Intelligence  

E-print Network

Physics 343 Lecture # 14: the Search for ExtraTerrestrial Intelligence and galactic collisions about astrobiology guide our choice of search strategy. #12; Quantifying our ignorance... UC Santa scientists met in Green Bank, WV to discuss the prospect for existence and detection of extraterrestrial

Baker, Andrew J.

12

Extra-terrestrial igneous granites and related rocks: A review of their occurrence and petrogenesis  

NASA Astrophysics Data System (ADS)

The telluric planets and the asteroid belt display the same internal structure with a metallic inner core and a silicate outer shell. Experimental data and petrological evidence in silicate systems show that granite can be produced by extreme igneous differentiation through various types of igneous processes. On Moon, 4.4-3.9 Ga granite clasts display dry mineral assemblages. They correspond to at least 8 discrete intrusive events. Large K/Ca enrichment and low REE abundances in granite relative to KREEP are consistent with silicate liquid immiscibility, a process observed in melt inclusions within olivine of lunar basalts and in lunar meteorites. Steep-sided domes identified by remote sensing can represent intrusive or extrusive felsic formations. On Mars, black-and-white rhythmic layers observed on the Tharsis rise along the flanks of the peripheral scarps of the Tharsis Montes giant volcanoes suggest the possible eruption of felsic pyroclastites. Though no true granites were found so far in the Martian SNC meteorites, felsic glasses and mesostases were identified and a component close to terrestrial continental (granitic) crust is inferred from trace element and isotope systematics. Venus has suffered extensive volcanic resurfacing, whereas folded and faulted areas resemble terrestrial continents. Near large shield volcanoes, with dominant basaltic compositions, steep-sided domes have been interpreted as non-degassed silicic extrusions. The hypothesis of a granitic component is "tantalising". Extra-terrestrial granite is frequently found as clasts and mesostases in asteroidal meteorites. Porphyritic textures, with alkali feldspar crystals up to several centimetres in size, were observed in silicate enclaves within iron meteorites. In the chondrite clan, polymict breccias can contain granitic clasts, whose provenance is debated. One clast from the Adzhi-Bogdo meteorite yields a 4.53 0.03 Ga Pb-Pb age, making it the oldest known granite in the solar system. The vast majority of granitic materials recognised so far in the extra-terrestrial record are characterised by ferroan A-type compositions, characterised by high to very high K2O and medium CaO contents, sodic varieties being exceedingly rare. Textural evidence of graphic quartz-alkali feldspar intergrowths within crystallised products suggests that they are igneous in origin and crystallised quickly from a liquid. In water-depleted to water-free environments, fluorine and chlorine can play significant roles, as their effects on liquidus temperatures and crystallising assemblages are nearly identical to those of water. The distribution of alkalis and alkaline earths cannot be related only to extensive crystal fractionation, but is likely induced by supplementary silicate liquid immiscibility. Medium-temperature silicate liquid immiscibility is well known as a mode of differentiation in experimental petrology studies at very low pressures on systems dominated by Fe, Ti, K, and P as major elements. The ultimate question is, therefore, not whether granite (s.l.) occurs in any given planetary body, but if sufficient volumes of granitic materials could have been produced to constitute stable continental nuclei.

Bonin, Bernard

2012-11-01

13

Topographic-driven instabilities in terrestrial bodies  

NASA Astrophysics Data System (ADS)

Models of internal planetary fluid layers (core flows, subsurface oceans) commonly assume that these fluid envelopes have a spherical shape. This approximation however entails a serious restriction from the fluid dynamics point of view. Indeed, in the presence of mechanical forcings (precession, libration, nutation or tides) due to gravitational interaction with orbiting partners, boundary topography (e.g. of the core-mantle boundary) may excite flow instabilities and space-filling turbulence. These phenomena may affect heat transport and dissipation at the main order. Here, we focus on instabilities driven by longitudinal libration. Using a suite of theoretical tools and numerical simulations, we are able to discern a parameter range for which instability may be excited. We thereby consider deformations of different azimuthal order. This study gives the first numerical evidence of the tripolar instability. Furthermore, we explore the non-linear regime and investigate the amplitude as well as the dissipation of the saturated instability. Indeed, these two quantities control the torques on the solid layers and the thermal transport. Furthermore, based on this results, we address the issue of magnetic field generation associated with these flows (by induction or by dynamo process). This instability mechanism applies to both synchronized as non-synchronized bodies. As such, our results show that a tripolar instability might be present in various terrestrial bodies (Early Moon, Gallilean moons, asteroids, etc.), where it could participate in dynamo action. Simulation of a libration-driven tripolar instability in a deformed spherical fluid layer: snapshot of the velocity magnitude, where a complex 3D flow pattern is established.

Vantieghem, S.; Cebron, D.; Herreman, W.; Lacaze, L.

2013-12-01

14

The weak force and SETH: The search for Extra-Terrestrial Homochirality  

SciTech Connect

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality{emdash}SETH. Homochirality is probably a pre-condition for life, so a chiral influence may be required to get life started. We explain how the weak force mediated by the {ital Z}{sup 0} boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how the resulting small excess of the more stable enantiomer may be amplified to homochirality. Titan and comets are good places to test for emerging pre-biotic homochirality, while on Mars there may be traces of homochirality as a relic of extinct life. Our calculations of the PVED show that the natural L-amino acids are indeed more stable than their enantiomers, as are several key D-sugars and right-hand helical DNA. Thiosubstituted DNA analogues show particularly large PVEDs. L-quartz is also more stable than D-quartz, and we believe that further crystal counts should be carried out to establish whether reported excesses of L quartz are real. Finding extra-terrestrial molecules of the same hand as on Earth would lend support to the universal chiral influence of the weak force. We describe a novel miniaturized space polarimeter, called the SETH Cigar, which we hope to use to detect optical rotation on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. Even if we do not find the same hand as on Earth, finding extra-terrestrial optical rotation would be of enormous importance as it would still be the homochiral signature of life. {copyright} {ital 1996 American Institute of Physics.}

MacDermott, A.J. [Department of Chemistry, University of Cambridge Lensfield Road, Cambridge CB2 1EW (United Kingdom)

1996-07-01

15

Montana Evidence for Extra-Terrestrial Impact Event That Caused Ice-Age Mammal Die- Off  

NASA Astrophysics Data System (ADS)

Evidence has been found in Montana for an extra-terrestrial impact event previously documented in the States of AZ, NM, NC, and SC and in Alberta and Manitoba. A mammoth fossil site dated at 11.5 ka (C14) before present (BP) was described in 1969 as the last mammoth occurrence in Montana. The mammoth remains were found in an organic-rich layer--a black mat. The black mat contains abundant charcoal (evidence for forest fire), black carbon glass foam, plant material deposited in a pond, and unrusted iron micro-meteorites. SEM photos of iron micro-meteorites reveal fusion crusts, flow lines, and micro-impact craters--direct evidence for an extra- terrestrial origin. One 140 ?m long micro-meteorite is 96 wt.% Fe and 4% Mn. Another is 71% Fe and 29% Ti. Mammoth tusks contain rusty pits, consistent with iron micro-meteorites that were embedded and then rusted out. A sample of carbon glass in the black mat contains 62% C, 22% O, 6% Fe, 4% Ca, 4% Si, and 2% Al. At the Indian Creek Archeological Site near Townsend, MT below the cultural layers and below a 11.2 ka (C14) volcanic ash layer there are individual glass bubbles about 1 mm in diameter with micro-impact craters. The size distribution of these micro-craters resembles the size distribution of lunar craters, but at a vastly different scale. The glass contains 53% C, 33% O, 6% Ca, 4% Si, 2% Al, 1% Mg, and 0.6% K. The carbon glass and micro-meteorites suggest a comet rather a meteorite origin for the extra-terrestrial material.

Baker, D. W.; Miranda, P. J.; Gibbs, K. E.

2008-05-01

16

The game of active search for extra-terrestrial intelligence: breaking the `Great Silence'  

NASA Astrophysics Data System (ADS)

The search for extra-terrestrial intelligence (SETI) has been performed principally as a one-way survey, listening of radio frequencies across the Milky Way and other galaxies. However, scientists have engaged in an active messaging only rarely. This suggests the simple rationale that if other civilizations exist and take a similar approach to ours, namely listening but not broadcasting, the result is a silent universe. A simple game theoretical model, the prisoner's dilemma, explains this situation: each player (civilization) can passively search (defect), or actively search and broadcast (cooperate). In order to maximize the payoff (or, equivalently, minimize the risks) the best strategy is not to broadcast. In fact, the active search has been opposed on the basis that it might be dangerous to expose ourselves. However, most of these ideas have not been based on objective arguments, and ignore accounting of the possible gains and losses. Thus, the question stands: should we perform an active search? I develop a game-theoretical framework where civilizations can be of different types, and explicitly apply it to a situation where societies are either interested in establishing a two-way communication or belligerent and in urge to exploit ours. The framework gives a quantitative solution (a mixed-strategy), which is how frequent we should perform the active SETI. This frequency is roughly proportional to the inverse of the risk, and can be extremely small. However, given the immense amount of stars being scanned, it supports active SETI. The model is compared with simulations, and the possible actions are evaluated through the San Marino scale, measuring the risks of messaging.

de Vladar, Harold P.

2013-01-01

17

Examining predator-prey body size, trophic level and body mass across marine and terrestrial mammals.  

PubMed

Predator-prey relationships and trophic levels are indicators of community structure, and are important for monitoring ecosystem changes. Mammals colonized the marine environment on seven separate occasions, which resulted in differences in species' physiology, morphology and behaviour. It is likely that these changes have had a major effect upon predator-prey relationships and trophic position; however, the effect of environment is yet to be clarified. We compiled a dataset, based on the literature, to explore the relationship between body mass, trophic level and predator-prey ratio across terrestrial (n = 51) and marine (n = 56) mammals. We did not find the expected positive relationship between trophic level and body mass, but we did find that marine carnivores sit 1.3 trophic levels higher than terrestrial carnivores. Also, marine mammals are largely carnivorous and have significantly larger predator-prey ratios compared with their terrestrial counterparts. We propose that primary productivity, and its availability, is important for mammalian trophic structure and body size. Also, energy flow and community structure in the marine environment are influenced by differences in energy efficiency and increased food web stability. Enhancing our knowledge of feeding ecology in mammals has the potential to provide insights into the structure and functioning of marine and terrestrial communities. PMID:25377460

Tucker, Marlee A; Rogers, Tracey L

2014-12-22

18

Extra!  

NSDL National Science Digital Library

The national media watch group Fairness & Accuracy in Reporting (FAIR) was started in 1986 in order to "invigorate the First Amendment by advocating for greater diversity in the press and by scrutinizing media practices that marginalize public interest, minority and dissenting viewpoints." As part of this work, FAIR publishes Extra!, which is a monthly magazine of well-documented media criticism and commentary. The first issue was published in June 1987, and this website gives interested parties access to many of the articles that have been published over the past twenty-plus years. The magazine receives no money from advertisers or underwriters, and as such, they are able to offer less biased, objective commentary on many of key media issues. Recent articles from Extra! have included a critical assessment of PBS's flagship news show "NewsHour" and an assessment of the Sonny Bono Copyright Term Extension Act, which deals with copyright extensions on books, movies, and so on. Visitors can also browse their "Back Issues" here and sign up for their email list.

19

Estimating terrestrial amphibian pesticide body burden through dermal exposure.  

PubMed

Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active ingredients through contact with contaminated soil: imidacloprid (logKow=0.57), atrazine (logKow=2.5), triadimefon (logKow=3.0), fipronil (logKow=4.11) or pendimethalin (logKow=5.18). All amphibians had measurable body burdens at the end of the exposure in concentrations ranging from 0.019 to 14.562?g/g across the pesticides tested. Atrazine produced the greatest body burdens and bioconcentration factors, but fipronil was more permeable to amphibian skin when application rate was considered. Soil partition coefficient and water solubility were much better predictors of pesticide body burden, bioconcentration factor, and skin permeability than logKow. Dermal uptake data can be used to improve risk estimates of pesticide exposure among amphibians as non-target organisms. PMID:25063914

Van Meter, Robin J; Glinski, Donna A; Hong, Tao; Cyterski, Mike; Henderson, W Matthew; Purucker, S Thomas

2014-10-01

20

Extra Low-Frequency Terrestrial Radio-Wave Field Calculations with the Zonal Harmonics Series  

Microsoft Academic Search

Use of the zonal harmonics series for calculating the terrestrial wave guide fields directly is described. The analysis is extended to include radio waves propagating into sea water or below the earth's surface. A sample calculation of ELF radio waves is analyzed into a direct wave and a wave that has traveled the circumference of the earth. The location of

J. Ralph Johler; Richard L. Lewis

1969-01-01

21

Estimating terrestrial amphibian pesticide body burden through dermal exposure  

EPA Science Inventory

Dermal exposure presents a potentially significant but understudied route for pesticide uptake in terrestrial amphibians. Our study measured dermal uptake of pesticides of varying hydrophobicity (logKow) in frogs. Amphibians were indirectly exposed to one of five pesticide active...

22

Strategic considerations in SETI, and a microwave approach. [Search for ExtraTerrestrial Intelligence  

NASA Technical Reports Server (NTRS)

Plausible options in the search for extraterrestrial intelligence (SETI), and the need to reserve a suitable portion of the EM (microwave) spectrum for SETI research, are discussed. Reasons for selection of a portion of the spectrum, specifically the 'water hole' near 1.5 GHz in the terrestrial microwave window (1-25 GHz), are presented, and competition with various emitters for that band (existing satellite downlink transmissions) is discussed. SETI search policies and options are summarized in a table. Speculative considerations guiding initial phases of the SETI pursuit are discussed.

Seeger, C. L.

1977-01-01

23

First stage identification of syntactic elements in an extra-terrestrial signal  

NASA Astrophysics Data System (ADS)

By investigating the generic attributes of a representative set of terrestrial languages at varying levels of abstraction, it is our endeavour to try and isolate elements of the signal universe, which are computationally tractable for its detection and structural decipherment. Ultimately, our aim is to contribute in some way to the understanding of what 'languageness' actually is. This paper describes algorithms and software developed to characterise and detect generic intelligent language-like features in an input signal, using natural language learning techniques: looking for characteristic statistical "language-signatures" in test corpora. As a first step towards such species-independent language-detection, we present a suite of programs to analyse digital representations of a range of data, and use the results to extrapolate whether or not there are language-like structures which distinguish this data from other sources, such as music, images, and white noise.

Elliott, John

2011-02-01

24

Beyond Earth: How extra-terrestrial volcanism stretches our definition of a volcano  

Microsoft Academic Search

Volcanism is a fundamental geologic process that has affected every solid body in the solar system and, presumably, in other solar systems as well. As we explore other worlds, we come across signs of active and past volcanism, some in unexpected places. Volcanism in extraterrestrial worlds can be much different from the examples we see on Earth, but the similarities

R. Lopes

2007-01-01

25

Unconventional phases of the alternating-spin Heisenberg chain with extra three-body exchange terms  

NASA Astrophysics Data System (ADS)

The Heisenberg chain with alternating site spins (S,?) = (1, 1/2) defines a realistic prototype model admitting extra isotropic three-body exchange terms which drive the chain into exotic quantum phases. In this paper, we focus on the non-magnetic part of the phase diagram. Based on numerical density-matrix renormalization group and exact-diagonalization calculations, we demonstrate that the nearest-neighbor three-body interaction stabilizes (i) a critical spin liquid phase described by two Gaussian conformal theories as well as (ii) a critical nematic-like phase characterized by dominant quadrupolar S-spin fluctuations. The emergence of these phases reflects some specific features of the three-body terms such as the promotion of local collinear spin configurations and the enhanced tendency towards nearest- neighbor clustering of the spins.

Ivanov, N. B.; Schnack, J.

2014-12-01

26

Terrestrial Soft-Bodied Protists and Other Microorganisms in Triassic Amber  

Microsoft Academic Search

Protozoa, cyanobacteria, sheathed algae, sheathed fungi, germinating pollen or spores, and fungal spores have been found in amber 220 to 230 million years old. Many of these microorganisms can be assigned to present-day groups. This discovery of terrestrial, soft-bodied protists that can be referred to modern groups indicates that morphological evolution is very gradual in many protists and that both

George O. Poinar Jr.; Benjamin M. Waggoner; Ulf-Christian Bauer

1993-01-01

27

Impact seismology on terrestrial planets and Small bodies (Invited)  

NASA Astrophysics Data System (ADS)

On planetary bodies without atmosphere (e.g. the Moon, Jovian satellites, small bodies) or a planet with a weak atmosphere such as Mars, impacts of meteoroids are high potential seismic sources. During the Apollo seismic experiment on the Moon, impacts related seismic events were used to constrain the crustal structure, including estimates of lateral variations. (Chenet et al, EPSL, 2006) Moreover, the location and time of present-day lunar surface impacts with masses larger than about 1 kg can now be determined, as impacts generate light flashes observed from Earth with modest telescopes. The location of larger impacts (> 100 kg) can also be detected by High Resolution Optical Orbital cameras. As soon as they are located by these non-seismic methods, impacts become the only seismic sources that can be used by a single seismic station on a planet for inverting the interior structure. We review and present in this paper the main characteristics of the seismic source generated by an impact, in both amplitude and cutoff frequency, and compare these signals to shallow moonquakes as detected by Apollo. We focus on the largest impacts on the Moon, and show that they have a relatively low frequency cutoff frequency (< 1 Hz) associated with the shock wave generated during the impact. Both this cutoff frequency and the amplitude of the seismic wave allow us to constrain the mass and velocity of the impactor (Gudkova et al, Icarus, 2010, Kawamura et al, 2010). We then present mass-frequency models of impacts on the Moon from Apollo observations, and extrapolate these models to other planets and planetary bodies (Mars, Jovian satellites and small bodies). This allow us to constrain not only the expected amplitude of the micro-seismic noise associated with continuous impacts on airless planets (called the meteoritic hum, Lognonn et al, 2009) but also the expected detection frequency of impacts on future seismological missions, such as Moon missions (e.g. SELENE2, ILN, Lunette) or Mars missions (e.g. GEMS, NF or MarsNext). By using statistical simulation, the expected resolution in the seismic velocities models resulting from these future missions can be computed, and we illustrate this for the Moon (Yamada et al., 2010). We finally present and discuss new or exotic challenges such as impact seismology on small bodies or in-situ detection of the electromagnetic signals associated with impacts.

Lognonne, P.; Gagnepain-Beyneix, J.; Le Feuvre, M.; Gudkova, T.; Kawamura, T.; Garcia, R. F.; Johnson, C. L.; Yamada, R.; Weber, R. C.; Blitz, C.

2010-12-01

28

A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods  

PubMed Central

Background Body size is intimately related to the physiology and ecology of an organism. Therefore, accurate and consistent body mass estimates are essential for inferring numerous aspects of paleobiology in extinct taxa, and investigating large-scale evolutionary and ecological patterns in the history of life. Scaling relationships between skeletal measurements and body mass in birds and mammals are commonly used to predict body mass in extinct members of these crown clades, but the applicability of these models for predicting mass in more distantly related stem taxa, such as non-avian dinosaurs and non-mammalian synapsids, has been criticized on biomechanical grounds. Here we test the major criticisms of scaling methods for estimating body mass using an extensive dataset of mammalian and non-avian reptilian species derived from individual skeletons with live weights. Results Significant differences in the limb scaling of mammals and reptiles are noted in comparisons of limb proportions and limb length to body mass. Remarkably, however, the relationship between proximal (stylopodial) limb bone circumference and body mass is highly conserved in extant terrestrial mammals and reptiles, in spite of their disparate limb postures, gaits, and phylogenetic histories. As a result, we are able to conclusively reject the main criticisms of scaling methods that question the applicability of a universal scaling equation for estimating body mass in distantly related taxa. Conclusions The conserved nature of the relationship between stylopodial circumference and body mass suggests that the minimum diaphyseal circumference of the major weight-bearing bones is only weakly influenced by the varied forces exerted on the limbs (that is, compression or torsion) and most strongly related to the mass of the animal. Our results, therefore, provide a much-needed, robust, phylogenetically corrected framework for accurate and consistent estimation of body mass in extinct terrestrial quadrupeds, which is important for a wide range of paleobiological studies (including growth rates, metabolism, and energetics) and meta-analyses of body size evolution. PMID:22781121

2012-01-01

29

Terrestrial soft-bodied protists and other microorganisms in triassic amber.  

PubMed

Protozoa, cyanobacteria, sheathed algae, sheathed fungi, germinating pollen or spores, and fungal spores have been found in amber 220 to 230 million years old. Many of these microorganisms can be assigned to present-day groups. This discovery of terrestrial, soft-bodied protists that can be referred to modern groups indicates that morphological evolution is very gradual in many protists and that both structural and probably functional stasis extend back at least to the Upper Triassic period. PMID:17790989

Poinar, G O; Waggoner, B M; Bauer, U C

1993-01-01

30

Mechanical selfstabilization, a working hypothesis for the study of the evolution of body proportions in terrestrial mammals?  

E-print Network

proportions in terrestrial mammals? Rémi Hackert a,b, Nadja Schilling a , Martin S. Fischer a a Institut für and muculoskeletal systems and the environment. However the musculo skeletal systems of some terrestrial mammals locomotion body proportion running quadruped mammals. 1 hal-00365982,version1-5Mar2009 Author manuscript

Paris-Sud XI, Université de

31

Terrestrial impact craters: Their spatial and temporal distribution and impacting bodies  

Microsoft Academic Search

The terrestrial impact record contains currently ~145 structures and includes the morphological crater types observed on the other terrestrial planets. It has, however, been severely modified by terrestrial geologic processes and is biased towards young ( 200 Ma) and large ( 20 km) impact structures on relatively well-studied cratonic areas. Nevertheless, the ground-truth data available from terrestrial impact structures have

Richard A. F. Grieve; Lauri J. Pesonen

1996-01-01

32

Body mass estimation in xenarthra: a predictive equation suitable for all quadrupedal terrestrial placentals?  

PubMed

The Magnorder Xenarthra includes strange extinct groups, like glyptodonts, similar to large armadillos, and ground sloths, terrestrial relatives of the extant tree sloths. They have created considerable paleobiological interest in the last decades; however, the ecology of most of these species is still controversial or unknown. The body mass estimation of extinct species has great importance for paleobiological reconstructions. The commonest way to estimate body mass from fossils is through linear regression. However, if the studied species does not have similar extant relatives, the allometric pattern described by the regression could differ from those shown by the extinct group. That is the case for glyptodonts and ground sloths. Thus, stepwise multiple regression were developed including extant xenarthrans (their taxonomic relatives) and ungulates (their size and ecological relatives). Cases were weighted to maximize the taxonomic evenness. Twenty-eight equations were obtained. The distribution of the percent of prediction error (%PE) was analyzed between taxonomic groups (Perissodactyla, Artiodactyla, and Xenarthra) and size groups (0-20 kg, 20-300 kg, and more than 300 kg). To assess the predictive power of the functions, equations were applied to species not included in the regression development [test set cross validation, (TSCV)]. Only five equations had a homogeneous %PE between the aforementioned groups. These were applied to five extinct species. A mean body mass of 80 kg was estimated for Propalaehoplophorus australis (Cingulata: Glyptodontidae), 594 kg for Scelidotherium leptocephalum (Phyllophaga: Mylodontidae), and 3,550.7 kg for Lestodon armatus (Phyllophaga: Mylodontidae). The high scatter of the body mass estimations obtained for Catonyx tarijensis (Phyllophaga: Mylodontidae) and Thalassocnus natans (Phyllophaga: Megatheriidae), probably due to different specializations, prevented us from predicting its body mass. Surprisingly, although obtained from ungulates and xenarthrans, these five selected equations were also able to predict the body mass of species from groups as different as rodents, carnivores, hyracoideans, or tubulidentates. This result suggests the presence of a complex common allometric pattern for all quadrupedal placentals. PMID:18655156

De Esteban-Trivigno, Soledad; Mendoza, Manuel; De Renzi, Miquel

2008-10-01

33

Body mass explains characteristic scales of habitat selection in terrestrial mammals  

PubMed Central

Niche theory in its various forms is based on those environmental factors that permit species persistence, but less work has focused on defining the extent, or size, of a species environment: the area that explains a species presence at a point in space. We proposed that this habitat extent is identifiable from a characteristic scale of habitat selection, the spatial scale at which habitat best explains species occurrence. We hypothesized that this scale is predicted by body size. We tested this hypothesis on 12 sympatric terrestrial mammal species in the Canadian Rocky Mountains. For each species, habitat models varied across the 20 spatial scales tested. For six species, we found a characteristic scale; this scale was explained by species body mass in a quadratic relationship. Habitat measured at large scales best-predicted habitat selection in both large and small species, and small scales predict habitat extent in medium-sized species. The relationship between body size and habitat selection scale implies evolutionary adaptation to landscape heterogeneity as the driver of scale-dependent habitat selection. PMID:22393519

Fisher, Jason T; Anholt, Brad; Volpe, John P

2011-01-01

34

BODY HYDRATION AND HAEMOLYMPH OSMOLALITY AFFECT FEEDING AND ITS NEURAL CORRELATE IN THE TERRESTRIAL GASTROPOD, UMAX MAXIMUS  

Microsoft Academic Search

SUMMARY 1. When terrestrial slugs (Limax maximus) are dehydrated to 6570 % of their initial body weight (IBW) their feeding responsiveness is greatly decreased. 2. There is a 90 % decrease in feeding responsiveness when slugs are injected with hyperosmotic mannitol solution that raises the haemolymph osmolality to that of slugs dehydrated to 65-70 % IBW (i.e. 200 mosmolkg\\

CURTIS B. PHIFER; DAVID J. PRIOR

35

Dynamics of the terrestrial planets from a large number of N-body simulations  

NASA Astrophysics Data System (ADS)

The agglomeration of planetary embryos and planetesimals was the final stage of terrestrial planet formation. This process is modeled using N-body accretion simulations, whose outcomes are tested by comparing to observed physical and chemical Solar System properties. The outcomes of these simulations are stochastic, leading to a wide range of results, which makes it difficult at times to identify the full range of possible outcomes for a given dynamic environment. We ran fifty high-resolution simulations each with Jupiter and Saturn on circular or eccentric orbits, whereas most previous studies ran an order of magnitude fewer. This allows us to better quantify the probabilities of matching various observables, including low probability events such as Mars formation, and to search for correlations between properties. We produce many good Earth analogues, which provide information about the mass evolution and provenance of the building blocks of the Earth. Most observables are weakly correlated or uncorrelated, implying that individual evolutionary stages may reflect how the system evolved even if models do not reproduce all of the Solar System's properties at the end. Thus individual N-body simulations may be used to study the chemistry of planetary accretion as particular accretion pathways may be representative of a given dynamic scenario even if that simulation fails to reproduce many of the other observed traits of the Solar System.

Fischer, Rebecca A.; Ciesla, Fred J.

2014-04-01

36

Phase diagram of the alternating-spin Heisenberg chain with extra isotropic three-body exchange interactions  

NASA Astrophysics Data System (ADS)

For the time being isotropic three-body exchange interactions are scarcely explored and mostly used as a tool for constructing various exactly solvable one-dimensional models, although, generally speaking, such competing terms in generic Heisenberg spin systems can be expected to support specific quantum effects and phases. The Heisenberg chain constructed from alternating S = 1 and ? = 1/2 site spins defines a realistic prototype model admitting extra three-body exchange terms. Based on numerical density-matrix renormalization group (DMRG) and exact diagonalization (ED) calculations, we demonstrate that the additional isotropic three-body terms stabilize a variety of partially-polarized states as well as two specific non-magnetic states including a critical spin-liquid phase controlled by two Gaussinal conformal theories as well as a critical nematic-like phase characterized by dominant quadrupolar S-spin fluctuations. Most of the established effects are related to some specific features of the three-body interaction such as the promotion of local collinear spin configurations and the enhanced tendency towards nearest-neighbor clustering of the spins. It may be expected that most of the predicted effects of the isotropic three-body interaction persist in higher space dimensions.

Ivanov, Nedko B.; Ummethum, Jrg; Schnack, Jrgen

2014-10-01

37

Influence of Water Availability during Incubation on Hatchling Size, Body Composition, Desiccation Tolerance, and Terrestrial  

E-print Network

, Desiccation Tolerance, and Terrestrial Locomotor Performance in the Snapping Turtle Chelydra serpentina incubation has been examined extensively, es- pecially in the common snapping turtle, Chelydra serpentina

Finkler, Michael S.

38

Extra Terrestrial Environmental Chamber Design  

NASA Technical Reports Server (NTRS)

A vacuum chamber designed to simulate the dusty environment on the Moon or Mars has been built for Goddard Space Flight Center. The path from concept to delivery is reviewed, with lessons learned and pitfalls highlighted along the way.

Hughes, David W.

2008-01-01

39

ENERGETICS AND MECHANICS OF TERRESTRIAL LOCOMOTION I. METABOLIC ENERGY CONSUMPTION AS A FUNCTION OF SPEED AND BODY SIZE IN BIRDS AND MAMMALS  

Microsoft Academic Search

SUMMARY This series of four papers investigates the link between the energetics and the mechanics of terrestrial locomotion. Two experimental variables are used throughout the study: speed and body size. Mass-specific metabolic rates of running animals can be varied by about tenfold using either variable. This first paper considers metabolic energy consumed during terrestrial locomotion. New data relating rate of

C. R. TAYLOR; N. C. HEGLUND; G. M. O. MALOIY

40

Gravitational N-body problem on the accretion process of terrestrial planets  

NASA Technical Reports Server (NTRS)

Numerical integration of the gravitational N-body problem has been carried out for a variety of protoplanetary clusters in the range N = 100 to 200. Particles are assumed to coagulate at collisions irrespective of relative velocity and mass ratio of the particles. It is shown graphically how the dispersed N-bodies accumulate to a single planet through mutual collisions. The velocity distribution and size distribution of bodies are also investigated as functions of time in the accretion process. Accretion rates of planets are found to be dependent strongly on the initial number density distribution, the initial size distribution, and the initial velocity distribution of bodies. Formation of satellites of about 10% in the planet mass is common to most cases in the present study. A substantial mass of bodies also escapes from the cluster. Many satellites and escapers formed during the accretion process of planets may be source materials of heavy bombardment in the early history of planets.

Matsui, T.; Mizutani, H.

1978-01-01

41

An interesting journey of an ingested needle: a case report and review of the literature on extra-abdominal migration of ingested foreign bodies.  

PubMed

Swallowed foreign bodies encounter a major problem especially in children, but fortunately they mostly do not cause any related complication and are easily passed with the stool. In this paper, an interesting journey of a needle is presented. A 20-year old female admitted to our emergency service after she had swallowed a sewing machine needle, which is initially observed in the stomach in the plain abdominal radiography. During the follow-up period, the needle traveled through bowels, and surprisingly was observed in the left lung on 10th day of the follow-up. It was removed with a thoracotomy and pneumotomy under the fluoroscopic guidance. The postoperative period was uneventful and the patient was discharged from the hospital on the day 5. We also review the literature on interesting extra-abdominal migrations of swallowing foreign bodies. PMID:21615959

Ozkan, Zeynep; Kement, Metin; Karg?, Ahmet B; Censur, Zafer; Gezen, Fazli C; Vural, Selahattin; Oncel, Mustafa

2011-01-01

42

Body hydration and haemolymph osmolality affect feeding and its neural correlate in the terrestrial gastropod, Limax maximus.  

PubMed

When terrestrial slugs (Limax maximus) are dehydrated to 65-70% of their initial body weight (IBW) their feeding responsiveness is greatly decreased. There is a 90% decrease in feeding responsiveness when slugs are injected with hyperosmotic mannitol solution that raises the haemolymph osmolality to that of slugs dehydrated to 65-70% IBW (i.e. 200 mosmol kg-1 H2O). The duration of the Feeding Motor Programme (FMP) that can be recorded from an isolated CNS-lip preparation is reduced by increasing the osmolality of the saline bathing the preparation. The osmolality of the saline that can modify the FMP corresponds to that of the haemolymph of a slug dehydrated to 65-70% IBW. The pattern of the motor programme is not affected. A gradual increase in saline osmolality which temporally mimics the progressive increase in haemolymph osmolality of a dehydrating slug also causes a decrease in the duration of the FMP. The neural network underlying the FMP appears to adapt to hyperosmotic saline since the duration of FMP bouts gradually returns to normal levels after long-term exposure (6-8 h). PMID:3937884

Phifer, C B; Prior, D J

1985-09-01

43

A Postulated Planetary Collision, the Terrestrial Planets, the Moon and Smaller Solar-System Bodies  

NASA Astrophysics Data System (ADS)

In a scenario produced by the Capture Theory of planetary formation, a collision between erstwhile solar-system giant planets, of masses 798.75 and 598.37 M ?, is simulated using smoothed-particle hydrodynamics. Due to grain-surface chemistry that takes place in star-forming clouds, molecular species containing hydrogen, with a high D/H ratio taken as 0.01, form a layer around each planetary core. Temperatures generated by the collision initiate D-D reactions in these layers that, in their turn, trigger a reaction chain involving heavier elements. The nuclear explosion shatters and disperses both planets, leaving iron-plus-silicate stable residues identified as a proto-Venus and proto-Earth. A satellite of one of the colliding planets, captured or retained by the proto-Earth core, gave the Moon; two massive satellites released into heliocentric orbits became Mercury and Mars. For the Moon and Mars, abrasion of their surfaces exposed to collision debris results in hemispherical asymmetry. Mercury, having lost a large part of its mantle due to massive abrasion, reformed to give the present high-density body. Debris from the collision gave rise to asteroids and comets, much of the latter forming an inner reservoir stretching outwards from the inner Kuiper Belt that replenishes the Oort Cloud when it is depleted by a severe perturbation. Other features resulting from the outcome of the planetary collision are the relationship of Pluto and Triton to Neptune, the presence of dwarf planets and light-atom isotopic anomalies in meteorites.

Woolfson, M. M.

2013-11-01

44

High-temperature fractionation of stable iron isotopes in terrestrial and extra-terrestrial samples determined by ultra-precise measurements with a 57Fe-58Fe double spike and MC-ICPMS  

NASA Astrophysics Data System (ADS)

We have developed techniques for precise stable Fe isotope measurement utilising a 57Fe-58Fe double spike and pseudo-high-resolution MC-ICPMS. Instrumental mass bias is corrected using a 57Fe-58Fe double spike with a spike 58Fe/57Fe ratio of 1.012. Fe isotope analyses are carried out on a Nu Plasma MC-ICPMS with a DSN-100 desolvating nebuliser system. The MC-ICPMS is operated in pseudo-high-resolution mode with a mass resolution of ca. 3000 on all Fe isotopes permitting resolution of Fe isotope peaks from argide interferences. Residual interferences in the form of tails from these Ar-based interferences are corrected for by normalizing data to analyses of bracketing standards of the IRMM-014 standard. Repeated measurement of IRMM-014 yields an external reproducibility of 0.02 (2sd, n=26) on ?56Fe. Fe is separated from samples using conventional anion-exchange techniques. Replicate digestions of the JF-2 alkali feldspar standard yield an external reproducibility of 0.025 (2sd, n=5). Based on those results, error models predict that precisions of ? 0.01 (2sd) are attainable for standards and samples by combining multiple measurements of several sample digestions. We will present ultra-precise measurements of an array of international rock standards utilizing these techniques. We have obtained precise stable Fe isotope results on silicate minerals from a range of terrestrial magmatic rocks (basalt to rhyolite) and basaltic meteorites (angrites and eucrites). These results indicate that substantial stable Fe isotope fractionations (?56Fe = -1.0 to 0.85) exist in high-temperature magmatic systems on Earth, which appear to be redox-controlled. Fe2+-dominated minerals like olivine display marked enrichment in light isotopes of Fe (?56Fe = -0.35 to -0.30) compared to the host basaltic melt (?56Fe = 0.05 to 0.22). Conversely, clinopyroxene typically has a stable Fe isotope composition only slightly lower or similar to the host melt. Notably, plagioclase feldspar, which predominantly incorporates Fe3+ shows significantly heavy stable Fe isotope ratios (?56Fe = 0.25 to 0.42), particularly in rhyolitic and pegmatitic samples. Basaltic meteorites from planetesimals that differentiated in the early Solar System under reducing magmatic conditions, show muted stable Fe isotope fractionations between olivine, pyroxene and plagioclase, and a very limited range in stable Fe isotopes (?56Fe = 0.03 to 0.15). These results indicate that a significant stable Fe isotope fractionation between Fe2+ and Fe3+ exists at high temperatures in magmas, which is captured by minerals that crystallize with variable Fe3+/Fe2+ ratios. However, analyses of multiple individual olivine phenocrysts from a high-Mg basaltic andesite from a subduction setting on Earth show a wide range of ?56Fe (?56Fe = -1.0 to +0.19; n=9) implying that redox effects are not the sole influence on stable Fe isotope variations in magmas and their phenocryst assemblages at high temperatures.

Millet, M.; Baker, J.

2010-12-01

45

Terrestrial Planets  

NASA Astrophysics Data System (ADS)

The four terrestrial planets (Mercury, Venus, Earth, and Mars) and Earth's Moon display similar compositions, interior structures, and geologic histories. The terrestrial planets formed by accretion 4.5 Ga ago out of the solar nebula, whereas the Moon formed through accretion of material ejected off Earth during a giant impact event shortly after Earth formed. Geophysical investigations (gravity anomalies, seismic analysis, heat flow measurements, and magnetic field studies) reveal that all five bodies have differentiated into a low-density silicate crust, an intermediate density silicate mantle, and an iron-rich core. Seismic and heat flow measurements are only available for Earth and its Moon, and only Earth and Mercury currently exhibit actively produced magnetic fields (although Mars and the Moon retain remanent fields). Surface evolutions of all five bodies have been influenced by impact cratering, volcanism, tectonism, and mass wasting. Aeolian activity only occurs on bodies with a substantial atmosphere (Venus, Earth, and Mars) and only Earth and Mars display evidence of fluvial and glacial processes. Earth's volcanic and tectonic activity is largely driven by plate tectonics, whereas those processes on Venus result from vertical motions associated with hotspots and mantle upwellings. Mercury displays a unique tectonic regime of global contraction caused by gradual solidification of its large iron core. Early large impact events stripped away much of Mercury's crust and mantle, produced Venus' slow retrograde rotation, ejected material off Earth that became the Moon, and may have created the Martian hemispheric dichotomy. The similarities and differences between the interiors and surfaces of these five bodies provide scientists with a better understanding of terrestrial planet evolutionary paths.

Barlow, Nadine G.

46

Beyond Earth: Using Google Earth to Visualize Other Planetary Bodies  

Microsoft Academic Search

Virtual globes have revolutionized the way we visualize and understand the Earth, but there are other planetary bodies that can be visualized as well. We will demonstrate the use of Google Earth, KML, and other modern mapping tools for visualizing data that's literally out of this world. Extra-terrestrial virtual globes are poised to revolutionize planetary science, bring an exciting new

M. Hancher; R. Beyer; M. Broxton; N. Gorelick; E. Kolb; M. Weiss-Malik

2008-01-01

47

On the rise of turbulent plumes: Quantitative effects of variable entrainment for submarine hydrothermal vents, terrestrial  

E-print Network

hydrothermal vents, terrestrial and extra terrestrial explosive volcanism G. Carazzo,1 E. Kaminski,1 and S: Quantitative effects of variable entrainment for submarine hydrothermal vents, terrestrial and extra terrestrial, paleo-Martian, and Venusian conditions and by submarine hydrothermal activity at mid-ocean ridges

Kaminski, Edouard

48

Searching for extra-terrestrial civilizations  

NASA Technical Reports Server (NTRS)

The probability of radio interchange with extraterrestrial civilizations is discussed. Difficulties constitute absorption, scattering, and dispersion of signals by the rarified interstellar medium as well as the deciphering of received signals and convergence of semantic concept. A cybernetic approach considers searching for signals that develop from astroengineering activities of extraterrestrial civilizations.

Gindilis, L. M.

1974-01-01

49

The Search for ExtraTerrestrial Intelligence  

Microsoft Academic Search

Aliens abound on the movie screens, but in reality we are still trying to find out if we share our universe with other sentient creatures. Intelligence is very difficult to define, and impossible to directly detect over interstellar distances. Therefore, SETI, the search for extraterrestrial intelligence, is actually an attempt to detect evidence of another distant technology. If we find

J. Tarter

1998-01-01

50

Late-stage accretion and habitability of terrestrial planets  

NASA Astrophysics Data System (ADS)

The final stage in the formation of terrestrial planets consists of the accumulation of ~1000 km "planetary embryos" and ~1 km planetesimals via collisional accretion., under the mutual gravity of other solid bodies and the gas giant planets (if any). Water is delivered to planets via collisions with volatile-rich bodies that condensed past the snow line, beyond about 2.5 AU. We present results of a large number of relatively low-resolution simulations, designed to assess the predictability of systems of terrestrial planets as a function of "observables" such as the orbit of gas giant planets. These show that a variety of terrestrial planets can form, from small, dry, Mars-like worlds to planets with similar properties to Earth, to >3 Earth mass "water worlds" with >=30 times as much water as the Earth. The terrestrial planets are largely shaped by the influence of the giant planets and the surface density of material. We have uncovered trends between the terrestrial planets and (i) the mass, (ii) the orbital distance and (iii) the orbital eccentricity of a giant planet, (iv) the surface density of the disk, and (v) the disk's density profile. Five simulations with 1000-2000 particles reveal new aspects of the accretion process Water is delivered to the terrestrial planets as a few large planetesimals in a "hit or miss" process, and as billions of planetesimals in a robust way. The water delivery process is therefore more robust than previously thought, implying that the range of water contents of extra-solar Earths is less stochastic than indicated in previous studies; most planets accrete water- rich bodies. We simulate terrestrial accretion in the presence of close-in giant planets (e.g., "hot jupiters"), assuming these form and migrate quickly. Potentially habitable planets can form in these systems, but are likely to be iron-poor. Asteroid belts may exist between the terrestrial planets and hot jupiters in these systems. We have also tested the accretion process in four known extra- solar planetary systems. In 55 Cancri, terrestrial planets form relatively easily, and may have orbits in the habitable zone and significant water contents.

Raymond, Sean Neylon

51

ON THE EFFECT OF GIANT PLANETS ON THE SCATTERING OF PARENT BODIES OF IRON METEORITE FROM THE TERRESTRIAL PLANET REGION INTO THE ASTEROID BELT: A CONCEPT STUDY  

SciTech Connect

In their model for the origin of the parent bodies of iron meteorites, Bottke et al. proposed differentiated planetesimals, formed in 1-2 AU during the first 1.5 Myr, as the parent bodies, and suggested that these objects and their fragments were scattered into the asteroid belt as a result of interactions with planetary embryos. Although viable, this model does not include the effect of a giant planet that might have existed or been growing in the outer regions. We present the results of a concept study where we have examined the effect of a planetary body in the orbit of Jupiter on the early scattering of planetesimals from the terrestrial region into the asteroid belt. We integrated the orbits of a large battery of planetesimals in a disk of planetary embryos and studied their evolutions for different values of the mass of the planet. Results indicate that when the mass of the planet is smaller than 10 M{sub Circled-Plus }, its effects on the interactions among planetesimals and planetary embryos are negligible. However, when the planet mass is between 10 and 50 M{sub Circled-Plus }, simulations point to a transitional regime with {approx}50 M{sub Circled-Plus} being the value for which the perturbing effect of the planet can no longer be ignored. Simulations also show that further increase of the mass of the planet strongly reduces the efficiency of the scattering of planetesimals from the terrestrial planet region into the asteroid belt. We present the results of our simulations and discuss their possible implications for the time of giant planet formation.

Haghighipour, Nader [Institute for Astronomy and NASA Astrobiology Institute, University of Hawaii-Manoa, Honolulu, HI 96822 (United States); Scott, Edward R. D., E-mail: nader@ifa.hawaii.edu [Hawaii Institute for Geophysics and Planetology, University of Hawaii-Manoa, Honolulu, HI 96822 (United States)

2012-04-20

52

Limitations of terrestrial life.  

NASA Technical Reports Server (NTRS)

Questions of the suitability of other planets in the solar system for terrestrial organisms are discussed. It is found that life forms similar to terrestrial organisms but modified to fit the prevailing conditions could exist on Venus, Mars, and Jupiter. Of these, only in the case of Jupiter is there any evidence that life would have been able to evolve. Life on Jupiter would be restricted to the clouds. It is pointed out that life may have developed on other celestial bodies in forms which are quite dissimilar to terrestrial organisms with regard to their biochemistry.

Molton, P.

1973-01-01

53

Terrestrial sequestration  

SciTech Connect

Terrestrial sequestration is the enhancement of CO2 uptake by plants that grow on land and in freshwater and, importantly, the enhancement of carbon storage in soils where it may remain more permanently stored. Terrestrial sequestration provides an opportunity for low-cost CO2 emissions offsets.

Charlie Byrer

2008-03-10

54

Terrestrial sequestration  

ScienceCinema

Terrestrial sequestration is the enhancement of CO2 uptake by plants that grow on land and in freshwater and, importantly, the enhancement of carbon storage in soils where it may remain more permanently stored. Terrestrial sequestration provides an opportunity for low-cost CO2 emissions offsets.

Charlie Byrer

2010-01-08

55

ZO-1 and ZO-2 Are Required for Extra-Embryonic Endoderm Integrity, Primitive Ectoderm Survival and Normal Cavitation in Embryoid Bodies Derived from Mouse Embryonic Stem Cells  

PubMed Central

The Zonula Occludens proteins ZO-1 and ZO-2 are cell-cell junction-associated adaptor proteins that are essential for the structural and regulatory functions of tight junctions in epithelial cells and their absence leads to early embryonic lethality in mouse models. Here, we use the embryoid body, an in vitro peri-implantation mouse embryogenesis model, to elucidate and dissect the roles ZO-1 and ZO-2 play in epithelial morphogenesis and de novo tight junction assembly. Through the generation of individual or combined ZO-1 and ZO-2 null embryoid bodies, we show that their dual deletion prevents tight junction formation, resulting in the disorganization and compromised barrier function of embryoid body epithelial layers. The disorganization is associated with poor microvilli development, fragmented basement membrane deposition and impaired cavity formation, all of which are key epithelial tissue morphogenetic processes. Expression of Podocalyxin, which positively regulates the formation of microvilli and the apical membrane, is repressed in embryoid bodies lacking both ZO-1 and ZO-2 and this correlates with an aberrant submembranous localization of Ezrin. The null embryoid bodies thus give an insight into how the two ZO proteins influence early mouse embryogenesis and possible mechanisms underlying the embryonic lethal phenotype. PMID:24905925

Ali, Safiah Mohamed; Boey, Adrian; Gounko, Natalia V.; Hunziker, Walter

2014-01-01

56

Climate and Habitability of Terrestrial Planets around other Stars  

E-print Network

extraterrestrial intelligent life directly by looking for radio signals. The ``Search for Extra­Terrestrial@lmd.jussieu.fr). Abstract. The recent discovery of extra­solar giant planets, the quest for extraterrestrial radio Intelligence'' (SETI) programs involve sev­ eral major radio­telescopes around the world. The main SETI project

Forget, François

57

Terrestrial ecology  

Microsoft Academic Search

Terrestrial studies continue to contribute ideas and ecological data ; relevant to nuclear-power plant siting and the management of stored radioactive ; wastes in the semi-arid steppe region of Washington. These ideas and data are ; also largely applicable to steppe regions of Oregon, Idaho, and Nevada. Much of ; the available information concerning the ecology of steppe ecosystems has

1974-01-01

58

TERRESTRIAL ECOTOXICOLOGY  

EPA Science Inventory

Terrestrial ecotoxicology is the study of how environmental pollutants affect land-dependent organisms and their environment. It requires three elements: (1) a source, (2) a receptor, and (3) an exposure pathway. This article reviews the basic principles of each of each element...

59

15. PALEOLIMNOLOGY OF EXTREME COLD TERRESTRIAL AND EXTRATERRESTRIAL ENVIRONMENTS  

E-print Network

15. PALEOLIMNOLOGY OF EXTREME COLD TERRESTRIAL AND EXTRATERRESTRIAL ENVIRONMENTS 475 R. Pienitz, M understanding of life's origins on our planet and other extraterrestrial bodies. Liquid water is essential

Priscu, John C.

60

Influence of water availability during incubation on hatchling size, body composition, desiccation tolerance, and terrestrial locomotor performance in the snapping turtle Chelydra serpentina.  

PubMed

The effects of water availability during incubation on the water contents of neonatal snapping turtles at hatching were examined, along with the influence of hatchling water content on desiccation tolerance and terrestrial locomotor performance. The water contents of hatchlings from eggs incubated on wet substrates were both absolutely and proportionally greater than were those of hatchlings from eggs incubated on dry substrates. Hatchlings with greater water contents at hatching were able to survive longer and to lose more water before physiological performance was adversely affected by desiccation. Increased water contents in hatchlings with greater water availability during incubation may enhance survival by increasing the amount of water the animal can afford to lose before dehydration begins to adversely affect whole animal performance. PMID:10603335

Finkler, M S

1999-01-01

61

Terrestrial Planet Finder Coronagraph Observatory summary  

NASA Technical Reports Server (NTRS)

Creating an optical space telescope observatory capable of detecting and characterizing light from extra-solar terrestrial planets poses technical challenges related to extreme wavefront stability. The Terrestrial Planet Finder Coronagraph design team has been developing an observatory based on trade studies, modeling and analysis that has guided us towards design choices to enable this challenging mission. This paper will describe the current flight baseline design of the observatory and the trade studies that have been performed. The modeling and analysis of this design will be described including predicted performance and the tasks yet to be done.

Ford, Virginia; Levine-Westa, Marie; Kissila, Andy; Kwacka, Eug; Hoa, Tim; Dumonta, Phil; Lismana, Doug; Fehera, Peter; Cafferty, Terry

2005-01-01

62

Physics From Extra Dimensions  

Microsoft Academic Search

A brief review of the recent developments in the physics from extra dimensions is given with a focus on the effects of Kaluza-Klein excitations in the Standard Model sector. It is shown that the current accurate data on the Fermi constant and on other electro-weak parameters puts a lower bound on the scale of extra dimensions of $\\\\sim$ 3 TeV,

Pran Nath

2000-01-01

63

Introduction to Extra Dimensions  

SciTech Connect

Extra dimensions provide a very useful tool in addressing a number of the fundamental problems faced by the Standard Model. The following provides a very basic introduction to this very broad subject area as given at the VIII School of the Gravitational and Mathematical Physics Division of the Mexican Physical Society in December 2009. Some prospects for extra dimensional searches at the 7 TeV LHC with {approx}1 fb{sup -1} of integrated luminosity are provided.

Rizzo, Thomas G.; /SLAC

2010-04-29

64

Extra-terrestrial Life in the Milky Way Galaxy?  

NASA Astrophysics Data System (ADS)

Are we alone? Along with questions about black holes, this is one of the questions most commonly asked of astrophysicists. While the simple answer is that we don't know, logical and rational exploration of the question can be illuminating and a very good way to introduce non-scientists to the "scientific worldview." This short essay is based on a class for students not majoring in science, which I have taught for nearly forty years at the University of Texas at Austin.

Evans, Neal J.

2014-09-01

65

A SETI experiment. [Search for Extra Terrestrial Intelligence  

NASA Technical Reports Server (NTRS)

In order to increase the probability of contact in the search for extraterrestrial intelligence (SETI), it has been proposed to search more intensively in certain regions of the electromagnetic spectrum ('the water hole'). The present paper describes a similar narrowing of the search in the time domain. Application of this strategy results in the SETI experiments searching for signals from the Tau Ceti system late in 1986 and early in 1987, and from the Epsilon Eridani system in mid 1988.

Mclaughlin, W. I.

1986-01-01

66

Provenance of the terrestrial planets.  

PubMed

Earlier work on the simultaneous accumulation of the asteroid belt and the terrestrial planets is extended to investigate the relative contribution to the final planets made by material from different heliocentric distances. As before, stochastic variations intrinsic to the accumulation processes lead to a variety of final planetary configurations, but include systems having a number of features similar to our solar system. Fifty-nine new simulations are presented, from which thirteen are selected as more similar to our solar system than the others. It is found that the concept of "local feeding zones" for each final terrestrial planet has no validity for this model. Instead, the final terrestrial planets receive major contributions from bodies ranging from 0.5 to at least 2.5 AU, and often to greater distances. Nevertheless, there is a correlation between the final heliocentric distance of a planet and its average provenance. Together with the effect of stochastic fluctuations, this permits variation in the composition of the terrestrial planets, such as the difference in the decompressed density of Earth and Mars. Biologically important light elements, derived from the asteroidal region, are likely to have been significant constituents of the Earth during its formation. PMID:11539576

Wetherill, G W

1994-01-01

67

Extra Credit Problem Set  

NSDL National Science Digital Library

This problem set was assigned at the end of the year as a way for the students to get some extra credit and to help them study for the final exam. The problem set has 3 parts: 1) Strain: finding S1 and S3, measuring angular shear, and determining coaxial vs. noncoaxial deformation, 2) Calculating surface stresses on an inclined surface, and 3) Mohr stress circles.

Sarah Brownlee

68

Extra Credit Crossword Puzzles  

NSDL National Science Digital Library

These are two crossword puzzles that I hand out for extra credit, one for the igneous half of the course and the other for the metamorphic half. The puzzles reinforce concepts, vocabulary, and mineral formulae that we have gone over in class and labs. The students *love* them, and usually end up working on them in groups. Both puzzles were created using the Discovery Channel Puzzlemaker: http://puzzlemaker.school.discovery.com.

Jane Selverstone

69

Extra Housepayments Effect  

NSDL National Science Digital Library

How financial institutions use the monthly mortgage payment and mortgage amortization formulas can be a confusing concept to grasp. This lesson asks students to find a current interest mortgage rate for their city and state. This rate is then applied to an Internet based mortgage calculator to discover the effect that paying extra on a monthly house payment has on total interest paid and length of the loan. A student worksheet is included in the document.

2011-01-05

70

Magnetic fields of the terrestrial planets  

NASA Technical Reports Server (NTRS)

The four terrestrial planets, together with the Earth's Moon, provide a significant range of conditions under which dynamo action could occur. All five bodies have been visited by spacecraft, and from three of the five bodies (Earth, Moon and Mars) we have samples of planetary material upon which paleomagnetic studies have been undertaken. At the present time, only the Earth and Mercury appear to have a significant dipole magnetic field. However, the Moon, and possibly Mars, appear to have had ancient planetary dynamos. Venus does not now have a significant planetary magnetic field, and the high surface temperatures should have prevented the recording of evidence of any ancient magnetic field. Since the solidification of the solid inner core is thought to be the energy source for the terrestrial magnetic field, and since smaller bodies evolve thermally more rapidly than larger bodies, we conjecture that the terrestrial planets are today in three different phases of magnetic activity. Venus is in a predynamo phase, not having cooled to the point of core solidification. Mercury and the Earth are in the middle of their dynamo phase, with Mercury perhaps near the end of its activity. Mars and the Moon seem to be well past their dynamo phase. Much needs to be done in the study of the magnetism of the terrestrial planets. We need to characterize the multipole harmonic structure of the Mercury magnetic field plus its secular variation, and we need to analyze returned samples to attempt to unfold the long-term history of Mercury's dynamo. We need to more thoroughly map the magnetism of the lunar surface and to analyze samples obtained from a wider area of the lunar surface. We need a more complete survey of the present Martian magnetic field and samples from a range of different ages of Martian surface material. Finally, a better characterization of the secular variation of the terrestrial magnetic field is needed in order to unfold the workings of the terrestrial dynamo.

Russell, C. T.

1993-01-01

71

Impact erosion of terrestrial planetary atmospheres  

NASA Technical Reports Server (NTRS)

I review current ideas about the nature of the planetesimals - composition, size distribution, and the planetary encounter velocity. Previous papers on accretion and erosion of planetary atmospheres as a result of multiple impacts are reviewed. Finally, the effects of blowing off a substantial fraction of the atmosphere from a terrestrial planet due to a single giant body impact are discussed.

Ahrens, Thomas J.

1992-01-01

72

Impact erosion of terrestrial planetary atmospheres  

NASA Technical Reports Server (NTRS)

I review current ideas about the nature of the planetesimals - composition, size distribution, and the planetary encounter velocity. Previous papers on accretion and erosion of planetary atmospheres as a result of multiple impacts are reviewed. Finally, the effects of blowing off a substantial fraction of the atmosphere from a terrestrial planet due to a single giant body impact are discussed.

Ahrens, Thomas J.

1993-01-01

73

Phenomenology of Extra Dimensions  

SciTech Connect

If the structure of spacetime is different than that readily observed, gravitational physics, particle physics and cosmology are all immediately affected. The physics of extra dimensions offers new insights and solutions to fundamental questions arising in these fields. Novel ideas and frameworks are continuously born and evolved. They make use of string theoretical features and tools and they may reveal if and how the 11-dimensional string theory is relevant to our four-dimensional world. We have outlined some of the experimental observations in particle and gravitational physics as well as astrophysical and cosmological considerations that can constrain or confirm these scenarios. These developing ideas and the wide interdisciplinary experimental program that is charted out to investigate them mark a renewed effort to describe the dynamics behind spacetime. We look forward to the discovery of a higher dimensional spacetime.

Hewett, J.L.; /SLAC

2006-11-07

74

Terrestrial Planets: Comparative Planetology  

NASA Technical Reports Server (NTRS)

Papers were presented at the 47th Annual Meteoritical Society Meeting on the Comparative planetology of Terrestrial Planets. Subject matter explored concerning terrestrial planets includes: interrelationships among planets; plaentary evolution; planetary structure; planetary composition; planetary Atmospheres; noble gases in meteorites; and planetary magnetic fields.

1985-01-01

75

Terrestrial Planet Finder  

NASA Technical Reports Server (NTRS)

Integrating and testing the proposed Terrestrial Planet Finder imposes constraints on the design. Some of these will be discussed including the dimensions of existing test facilities, the effects of gravity, ambient vibrations and the size of GSE optics.

Smith, Andrew

2004-01-01

76

Terrestrial photovoltaic measurements, 2  

NASA Technical Reports Server (NTRS)

The following major topics are discussed; (1) Terrestrial solar irradiance; (2) Solar simulation and reference cell calibration; and (3) Cell and array measurement procedures. Numerous related subtopics are also discussed within each major topic area.

1976-01-01

77

Terrestrial and Extraterrestrial Fullerenes  

Microsoft Academic Search

This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous?Tertiary?Boundary and Permian?Triassic?Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated

D. Heymann; L. W. Jenneskens; J. Jehli?ka; Carola Koper; E. J. Vlietstra

2003-01-01

78

Extra-adrenal perirenal myelolipoma.  

PubMed

Extra-adrenal perirenal myelolipomas are rare benign tumors that consist of adipose and hematopoietic tissue. We report a case of perirenal myelolipoma in an otherwise healthy man and review the literature. PMID:8411435

Sneiders, A; Zhang, G; Gordon, B E

1993-11-01

79

Computer simulations of the accumulation of the terrestrial planets  

Microsoft Academic Search

The problem of the accumulation of the terrestrial planets from a protoplanetary disk is studied. The studies are based on the computer simulation results of plane disks consisting of gravitating bodies moving around the Sun and coagulating under collisions. The density of the bodies is similar to that of the present planets. The results of computer simulations of the evolution

S. I. Ipatov

1982-01-01

80

Contrasting coloration in terrestrial mammals  

PubMed Central

Here I survey, collate and synthesize contrasting coloration in 5000 species of terrestrial mammals focusing on black and white pelage. After briefly reviewing alternative functional hypotheses for coloration in mammals, I examine nine colour patterns and combinations on different areas of the body and for each mammalian taxon to try to identify the most likely evolutionary drivers of contrasting coloration. Aposematism and perhaps conspecific signalling are the most consistent explanations for black and white pelage in mammals; background matching may explain white pelage. Evidence for contrasting coloration is being involved in crypsis through pattern blending, disruptive coloration or serving other functions, such as signalling dominance, lures, reducing eye glare or in temperature regulation has barely moved beyond anecdotal stages of investigation. Sexual dichromatism is limited in this taxon and its basis is unclear. Astonishingly, the functional significance of pelage coloration in most large charismatic black and white mammals that were new to science 150 years ago still remains a mystery. PMID:18990666

Caro, Tim

2008-01-01

81

Consumer Control of Terrestrial Ecosystems  

NASA Astrophysics Data System (ADS)

More than half of the earth's terrestrial surface is grazed by large herbivores and their effects on plant and soil carbon and nitrogen processes are large and widespread. Yet the large effects of these animals on terrestrial processes have largely been ignored in global change models. This presentation will explore the many pathways that consumers affect short and long time-scale terrestrial nitrogen and carbon processes. Large herbivores influence the quality of soil organic matter and the size of the active (i.e., labile) pool of soil carbon and nitrogen in several ways. Herbivory leads to greater abundance of species producing low quality material in forest and dry grassland, via feeding preferentially on high quality forage, and high quality material in mesic grassland habitat, via the high quality of material that regrows after a plant is grazed. Defoliation stimulates the rate of root exudation that enhances rhizospheric processes and the availability of nitrogen in the plant rhizosphere. Herbivores also change the species composition of mycorrhizae fungal associates that influence plant growth and affect soil structure and the turnover rate of soil carbon. Recent radiocarbon measurements have revealed that herbivores also markedly affect the turnover dynamics of the large pool of old soil carbon. In Yellowstone Park, ungulates slow the mean turnover of the relatively old (i.e., slow and passive) 0 - 20 cm deep soil organic carbon by 350 years in upland, dry grassland and speed up that rate in slope-bottom, mesic grassland by 300 years. This represents a 650 year swing in the turnover period of old soil carbon across the Yellowstone landscape. By comparison, mean turnover time for the old pool of 0 - 10 cm deep soil organic carbon shifts by about 300 years across the steep climatic gradient that includes tropical, temperate, and northern hardwood forest, and tallgrass, shortgrass and desert grassland. This large body of evidence suggests consumers play a major role in global carbon cycling and likely are important regulators of the terrestrial response to climate change.

Frank, D.

2012-12-01

82

Global terrestrial carbon cycle  

SciTech Connect

There is great uncertainty with regard to the future role of the terrestrial biosphere in the global carbon cycle. The uncertainty arises from both an inadequate understanding of current pools and fluxes as well as the potential effects of rising atmospheric concentrations of CO2 on natural ecosystems. Despite these limitations, a number of studies have estimated current and future patterns of terrestrial carbon storage. Future estimates focus on the effects of a climate change associated with a doubled atmospheric concentration of CO2. Available models for examining the dynamics of terrestrial carbon storage and the potential role of forest management and landuse practices on carbon conservation and sequestration are discussed. (Copyright (c) 1993 Kluwer Academic Publishers.)

Smith, T.M.; Cramer, W.P.; Dixon, R.K.; Leemans, R.; Neilson, R.P.

1993-01-01

83

Scientific Visualization of Extra Dimensions  

NASA Astrophysics Data System (ADS)

In the 21st Century, many theoretical physicists claim that higher dimensions may indeed exist. Arkani-Hamed, Dimopoulos, & Dvali (ADD) and Randall-Sundrum (RS), in addition to Kaluza-Klein (KK) and M-string theorists, have introduced reasonable explanations for the existence of heretofore ``invisible'' higher dimensions. Whether or not these extra dimensions actually exist is irrelevant to their contributions to the visionary conceptualization associated with novel and improved mathematical and physical analysis. Envisioning extra dimensions beyond the three of common experience is a daunting challenge for three dimensional observers. Intuition relies on experience gained in a three dimensional environment. Gaining experience with virtual four dimensional objects and virtual three manifolds in four-space on a personal computer may provide the basis for an intuitive grasp of four dimensions. This presentation is a video ``outtake'' of the author's research into ``Visualizing Extra Spatial Dimensions'' at the University of California at Irvine.

Black, Don V.

2010-10-01

84

Collider searches for extra dimensions  

SciTech Connect

Searches for extra spatial dimensions remain among the most popular new directions in our quest for physics beyond the Standard Model. High-energy collider experiments of the current decade should be able to find an ultimate answer to the question of their existence in a variety of models. Until the start of the LHC in a few years, the Tevatron will remain the key player in this quest. In this paper, we review the most recent results from the Tevatron on searches for large, TeV{sup -1}-size, and Randall-Sundrum extra spatial dimensions, which have reached a new level of sensitivity and currently probe the parameter space beyond the existing constraints. While no evidence for the existence of extra dimensions has been found so far, an exciting discovery might be just steps away.

Landsberg, Greg; /Brown U.

2004-12-01

85

Large Extra Dimensions and Holography  

E-print Network

The holographic principle asserts that the entropy of a system cannot exceed its boundary area in Planck units. However, conventional quantum field theory fails to describe such systems. In this Letter, we assume the existence of large $n$ extra dimensions and propose a relationship between UV and IR cutoffs in this case. We find that if $n=2$, this effective field theory could be a good description of holographic systems. If these extra dimensions are detected in future experiments, it will help to prove the validity of the holographic principle. We also discuss implications for the cosmological constant problem.

Chao Cao; Yi-Xin Chen

2008-09-24

86

J. Field Ornithol. 84(1):112, 2013 DOI: 10.1111/jofo.12000 Microhabitat associations of terrestrial insectivorous  

E-print Network

of terrestrial insectivorous birds in Amazonian rainforest and second-growth forests Jeffrey A. Stratford1. Across the Neotropics, small-bodied terrestrial insectivores are sensitive to forest fragmentation characterized habitat at sites where nine species of terrestrial insectivores were observed foraging, as well

Stouffer, Phil

87

Overview of terrestrial thermionics  

Microsoft Academic Search

The application of the thermionic energy conversion systems first designed for spacecraft to terrestrial energy systems entails the development of a method for the protection of the high temperature refractory metals employed from the ambient air. A trilayer structure consisting of a tungsten emitter, a silicon carbide protective layer, and an intermediate graphite substrate, has been fabricated by means of

F. Huffman

1983-01-01

88

Solar-Terrestrial Predictions  

Microsoft Academic Search

Volume 1: The following subject areas are covered: the magnetosphere environment; forecasting magnetically quiet periods; radiation hazards to human in deep space (a summary with special reference to large solar particle events); solar proton events (review and status); problems of the physics of solar-terrestrial interactions; prediction of solar proton fluxes from x-ray signatures; rhythms in solar activity and the prediction

R. J. Thompson; D. G. Cole; P. J. Wilkinson; M. A. Shea; D. Smart

1990-01-01

89

The Terrestrial Silica Pump  

PubMed Central

Silicon (Si) cycling controls atmospheric CO2 concentrations and thus, the global climate, through three well-recognized means: chemical weathering of mineral silicates, occlusion of carbon (C) to soil phytoliths, and the oceanic biological Si pump. In the latter, oceanic diatoms directly sequester 25.8 Gton C yr?1, accounting for 43% of the total oceanic net primary production (NPP). However, another important link between C and Si cycling remains largely ignored, specifically the role of Si in terrestrial NPP. Here we show that 55% of terrestrial NPP (33 Gton C yr?1) is due to active Si-accumulating vegetation, on par with the amount of C sequestered annually via marine diatoms. Our results suggest that similar to oceanic diatoms, the biological Si cycle of land plants also controls atmospheric CO2 levels. In addition, we provide the first estimates of Si fixed in terrestrial vegetation by major global biome type, highlighting the ecosystems of most dynamic Si fixation. Projected global land use change will convert forests to agricultural lands, increasing the fixation of Si by land plants, and the magnitude of the terrestrial Si pump. PMID:23300825

Carey, Joanna C.; Fulweiler, Robinson W.

2012-01-01

90

Terrestrials Dwarf Planets  

E-print Network

Terrestrials Gas Giants Ice Giants Dwarf Planets The Solar System #12;Neptune Uranus Saturn Jupiter Density: 3900 ­ 5500 kg m-3 #12;Jupiter 318 ME 5.2 AU Uranus 15 ME 19.6 AUSaturn 95 ME 9.5 AU Neptune 17 3.88 RE Uranus Neptune Uranus and Neptune are Ice Giants made mostly of ices with thin Hydrogen

Gaudi, B. Scott

91

Terrestrial cosmic rays  

Microsoft Academic Search

This paper reviews the basic physics of those cosmic rays which can affect terrestrial electronics. Cosmic rays at sea level consist mostly of neutrons, protons, pions, muons, electrons, and photons. The particles which cause significant soft fails in electronics are those particles with the strong interaction: neutrons, protons, and pions. At sea level, about 95% of these particles are neutrons.

James F. Ziegler

1996-01-01

92

Terrestrial analogs to Mars  

NASA Technical Reports Server (NTRS)

It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing.

Farr, T. G.; Arcone, S.; Arvidson, R.; Baker, V.; Barlow, N.; Beaty, D.; Bell, M.; Blankenship, D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S.; Craddock, R.; Dickerson, P.; Duxbury, N.

2002-01-01

93

Volcanic ash - Terrestrial versus extraterrestrial  

NASA Technical Reports Server (NTRS)

A principal difference between terrestrial and extraterrestrial lavas may consist in the greater ability of terrestrial lavas to form thin films (like those of soap bubbles) and hence foams. It would follow that, in place of the pumice and spiny shards found in terrestrial volcanic ash, an extraterrestrial ash should contain minute spherules. This hypothesis may help to explain lunar microspherules.

Okeefe, J. A.

1976-01-01

94

Arsenic Speciation of Terrestrial Invertebrates  

Microsoft Academic Search

The distribution and chemical form (speciation) of arsenic in terrestrial food chains determines both the amount of arsenic available to higher organisms, and the toxicity of this metalloid in affected ecosystems. Invertebrates are part of complex terrestrial food webs. This paper provides arsenic concentrations and arsenic speciation profiles for eight orders of terrestrial invertebrates collected at three historical gold mine

Maeve M. Moriarty; Iris Koch; Robert A. Gordon; Kenneth J. Reimer

2009-01-01

95

Overview of terrestrial thermionics  

NASA Astrophysics Data System (ADS)

The application of the thermionic energy conversion systems first designed for spacecraft to terrestrial energy systems entails the development of a method for the protection of the high temperature refractory metals employed from the ambient air. A trilayer structure consisting of a tungsten emitter, a silicon carbide protective layer, and an intermediate graphite substrate, has been fabricated by means of chemical vapor deposition. Performance tests have demonstrated excellent results in combustion atmospheres.

Huffman, F.

96

The Terrestrial Planet Finder  

NASA Technical Reports Server (NTRS)

The Terrestrial Planet Finder (TPF) missions has as its goal the detection and characterization of earth-like planets around nearby stars. NASA is currently funding a number of small studies to look at the trade-offs in the design of TPF. The possible trade-offs include orbit location (1 to 5 AU), aperture size (6 to 1.5m), physically connected baselines or separated spacecraft flying in close formation.

Beichman, Charles

1997-01-01

97

Terrestrial Planet Formation in Binary Star Systems  

NASA Technical Reports Server (NTRS)

Most stars reside in binary/multiple star systems; however, previous models of planet formation have studied growth of bodies orbiting an isolated single star. Disk material has been observed around one or both components of various young close binary star systems. If planets form at the right places within such disks, they can remain dynamically stable for very long times. We have simulated the late stages of growth of terrestrial planets in both circumbinary disks around 'close' binary star systems with stellar separations ($a_B$) in the range 0.05 AU $\\le a_B \\le$ 0.4 AU and binary eccentricities in the range $0 \\le e \\le 0.8$ and circumstellar disks around individual stars with binary separations of tens of AU. The initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and around individual stars in the Alpha Centauri system (Quintana et al. 2002, A.J., 576, 982); giant planets analogous to Jupiter and Saturn are included if their orbits are stable. The planetary systems formed around close binaries with stellar apastron distances less than or equal to 0.2 AU with small stellar eccentricities are very similar to those formed in the Sun-Jupiter-Saturn, whereas planetary systems formed around binaries with larger maximum separations tend to be sparser, with fewer planets, especially interior to 1 AU. Likewise, when the binary periastron exceeds 10 AU, terrestrial planets can form over essentially the entire range of orbits allowed for single stars with Jupiter-like planets, although fewer terrestrial planets tend to form within high eccentricity binary systems. As the binary periastron decreases, the radial extent of the terrestrial planet systems is reduced accordingly. When the periastron is 5 AU, the formation of Earth-like planets near 1 AU is compromised.

Lissauer, J. J.; Quintana, E. V.; Adams, F. C.; Chambers, J. E.

2006-01-01

98

Extra-articular hip endoscopy  

PubMed Central

The aim of this review is to evaluate the current available literature evidencing on peri-articular hip endoscopy (the third compartment). A comprehensive approach has been set on reports dealing with endoscopic surgery for recalcitrant trochanteric bursitis, snapping hip (or coxa-saltans; external and internal), gluteus medius and minimus tears and endoscopy (or arthroscopy) after total hip arthroplasty. This information can be used to trigger further research, innovation and education in extra-articular hip endoscopy. PMID:23610664

Verhelst, L.; Guevara, V.; De Schepper, J.; Van Melkebeek, J.; Pattyn, C.; Audenaert, E. A.

2012-01-01

99

Anisotropic inflation from extra dimensions  

Microsoft Academic Search

Vacuum multidimensional cosmological models with internal spaces being compact n-dimensional Lie group manifolds are considered. Products of 3-spheres and SU(3) manifold (a novelty in cosmology) are studied. It turns out that the dynamical evolution of the internal space drives (power-law) inflation in the external world. This inflationary solution brings two extra bonuses: 1) it is an attractor in phase space

Marco Litterio; Leszek M. Soko?owski; Zdzis?aw A. Golda; Luca Amendola; Andrzej Dyrek

1996-01-01

100

Experimental constraints on extra dimensions  

NASA Astrophysics Data System (ADS)

We investigate the implications for experiment of the existence of compactified dimensions with a scale much larger than the Planck length. Such manifolds might occur in certain string models, for instance, if the compactification process is related to the mechanism generating electroweak or supersymmetry breaking. Model-independent upper bounds on the size of any extra dimensions are obtained by examining a wide range of experimental data.

Alan Kosteleck, V.; Samuel, Stuart

1991-11-01

101

Terrestrial adaptations in the hands of Equatorius africanus revisited.  

PubMed

Interpretations of the postcranial anatomy of East African early and middle Miocene large-bodied hominoids (e.g., Proconsul, Afropithecus, Turkanapithecus, Nacholapithecus) have suggested that these diverse primates utilized positional behaviors dominated by arboreal quadrupedalism. Preliminary descriptions of the Equatorius africanus partial skeleton (KNM-TH 28860) and other forelimb specimens, however, have argued that this animal relied more on terrestrial locomotion compared to its contemporaries, possibly similar to extant large papionin monkeys. In this paper, we reevaluate this interpretation by examining intrinsic hand proportions based on the lengths of the third proximal phalanx and fifth metacarpal in Equatorius in reference to a large sample of extant catarrhine primate taxa. We focused on the lengths of these hand bones because the ratio between phalanx and metacarpal lengths has been previously documented to discriminate terrestrial from arboreal mammalian taxa, including primates. The Equatorius hand displays semi-terrestrial hand proportions with a relatively shorter proximal phalanx compared to most arboreal monkeys. Its proximal phalanx, however, is relatively longer than those of habitually terrestrial monkeys (e.g., Theropithecus, Papio). Accordingly, although Equatorius retains some arboreal quadrupedal characteristics, these results corroborate the previous inference that it engaged in more terrestrial locomotion than earlier Miocene apes such as Proconsul. We suggest that the postcranial skeleton of Equatorius evinces the earliest signs of semi-terrestriality in the hominoid fossil record. It is likely that the terrestrial specialization utilized by living hominoids, e.g., knuckle-walking, evolved separately. PMID:19879632

Patel, Biren A; Susman, Randall L; Rossie, James B; Hill, Andrew

2009-12-01

102

Terrestrial planet formation from a truncated disk -- The 'Grand Tack'  

NASA Astrophysics Data System (ADS)

A new terrestrial planet formation model (Walsh et al., 2011) explores the effects of a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation (Masset & Snellgrove 2001, Morbidelli & Crida 2007, Pierens & Nelson 2008, Pierens & Raymond 2011). The inward migration of Jupiter truncates the disk of planetesimals and embryos in the terrestrial planet region. Subsequent accretion in that region then forms the terrestrial planets, in particular it produces the correct Earth/Mars mass ratio, which has been difficult to reproduce in simulations with a self-consistent set of initial conditions (see, eg. Raymond et al. 2009, Hansen 2009). Additionally, the outward migration of the giant planets populates the asteroid belt with distinct populations of bodies, with the inner belt filled by bodies originating inside of 3 AU, and the outer belt filled with bodies originating from beyond the giant planets. This differs from previous models of terrestrial planet formation due to the early radial mixing of material due to the giant planet's substantial migration. Specifically, the assumption that the current radial distribution of material in the inner Solar System is reflective of the primordial distribution of material in that region is no longer necessary. We will discuss the implications of this model in relation to previous models of terrestrial planet formation as well as available chemical and isotopic constraints.

Walsh, K. J.; Morbidelli, A.; Raymond, S.; O'Brien, D. P.; Mandell, A. M.

2012-12-01

103

Terrestrialization, miniaturization and rates of diversification in African frogs (Anura: Phrynobatrachidae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Terrestrialization, the evolution of non-aquatic oviposition, and miniaturization, the evolution of tiny adult body size, have been identified as a key features in the evolution of modern amphibians. This study examines anuran terrestrialization and miniaturization in a phylogenetic context to deter...

104

Bergmann's rule and the terrestrial caecilian Schistometopum thomense (Amphibia: Gymnophiona: Caeciliidae)  

Microsoft Academic Search

Question: Do caecilians follow Bergmann's rule? Hypothesis: Bergmann's rule explains the wide variation in body sizes found among populations of the terrestrial caecilian Schistometopum thomense. Field site: This is a range-wide study incorporating most terrestrial habitats throughout the island of So Tom in the Gulf of Guinea. Methods: We performed morphological measurements on 95 museum specimens and 187 field-collected individuals

G. John Measey; Stefan Van Dongen

2006-01-01

105

Olfactory recognition of terrestrial shelters in female Northern Spectacled Salamanders Salamandrina perspicillata (Caudata, Salamandridae)  

Microsoft Academic Search

Olfactory recognition of terrestrial shelters in female Northern Spectacled Salamanders Salamandrina perspicillata (Caudata, Salamandridae). Chemical cues are used as ubiquitous markers of individual, group, kinship, and species identity. Northern Spectacled Salamander (Salamandrina perspicillata) is a semi-terrestrial and elusive species. Females can be found in water bodies just in the spawning season but spend most of their life, as well as

Antonio Romano; Antonio Ruggiero

2008-01-01

106

Formation of Terrestrial Planets in a Dissipating Gas Disk with Jupiter and Saturn  

Microsoft Academic Search

We have performed N body simulation on formation of terrestrial planets, including the effect of dynamical friction of gas disk. Jupiter and Saturn are also included in the integrations to see the effect of gas giant planets. Terrestrial planets are formed through coagulation of protoplanets which are about the size of Mars. Their orbits are almost circular when they are

J. Kominami; S. Ida

2003-01-01

107

Solar terrestrial observatory  

NASA Technical Reports Server (NTRS)

Eight basic solar-terrestrial scientific objectives that benefit from the Shuttle/Platform approach and a program of measurements for each are discussed. The objectives are to understand: (1) solar variability, (2) wave-particle processes, (3) magnetosphere-ionosphere mass transport, (4) the global electric circuit, (5) upper atmospheric dynamics, (6) middle atmospheric chemistry and energetics, (7) lower atmospheric turbidity, and (8) planetary atmospheric waves. A two stage approach to a multidisciplinary payload is developed: an initial STO, that uses a single platform in a low-Earth orbit, and an advanced STO that uses two platforms in differing orbits.

1981-01-01

108

Overview of terrestrial thermionics  

SciTech Connect

Thermionic energy conversion addresses important national objectives such as fossil fuel conservation and space reactors. Historically, thermionics was first developed for space applications where the refractory materials required at emitter temperatures could operate indefinitely in the vacuum. Translation of this space technology to terrestrial applications required that a means of protecting the high temperature refractory metals from the air be found. A trilayer structure (tungsten emitter, silicon carbide protective layer and intermediate graphite substrate) made by chemical vapor deposition has given excellent results in combustion atmospheres.

Huffman, F.

1983-08-01

109

Antarctic terrestrial ecosystems  

SciTech Connect

The Maritime and Continental Antarctic terrestrial ecosystems are considered in the context of environmental impacts - habitat destruction, alien introductions, and pollution. Four types of pollution are considered: nutrients, radionuclides, inert materials, and noxious chemicals. Their ability to recover from perturbation is discussed in the light of present scientific knowledge, and the methods used to control impacts are reviewed. It is concluded that techniques of waste disposal are still inadequate, adequate training in environmental and conservation principles for Antarctic personnel in many countries is lacking, and scientific investigations may be a much more serious threat than tourism to the integrity of these ecosystems. Some priorities crucial to future management are suggested.

Walton, D.W.H.

1987-01-01

110

Terrestrial Planet Growth in Circumbinary Disks  

NASA Technical Reports Server (NTRS)

We examine the accuulation of terrestrial from circumbinary disks surrounding pairs of stars with masses of either 0.5 solar masses each or 0.8 and 0.2 solar masses and orbital separations of 0.05 AU to 0.4 AU by performing numerical simulations of the late stages of planetary growth. Initial disks contain about 2.6 Earth masses of lunar to Mars-sized bodies orbiting within 2 AU of the center of mass of the system, plus giant planets with masses and orbits analogous to those of Jupiter and Saturn. We also performed simulations using analogous disks orbiting single 1 solar mass stars. The dynamics of planetary growth is quite chaotic because the gravitational perturbations resulting from close approaches greatly amplify differences in orbits. Thus, several simulations of each configuration were run with very slightly different initial conditions to enable us to distinguish systematic effects resulting from differences in the binary orbit (or differences of the initial orbits of the bodies within the disk) from pseudo-random variability in outcomes resulting from chaos. Most runs simulated 200 million years of evolution. At least one terrestrial planet remained at the end of each run; one simulation produced 6 terrestrial planets in a configuration that appears to be quite stable. The systems that formed around stars with binary apastron separations of less than 0.2 AU contained on average slightly more planets than those that formed around single stars, with the outermost planet typically orbiting at a greater distance from the system barycenter. Greater stellar separations tended to result in fewer planets, with the inner planet orbiting farther from the stars. More eccentric binaries have a more pronounced effect for the same apastron distance. The statistical distribution of final systems is not sensitive to moderate differences in the initial eccentricities of the bodies in the disk.

Lissauer, J. J.; Quintana, E. V.

2006-01-01

111

Earth and Terrestrial Planet Formation  

E-print Network

The growth and composition of Earth is a direct consequence of planet formation throughout the Solar System. We discuss the known history of the Solar System, the proposed stages of growth and how the early stages of planet formation may be dominated by pebble growth processes. Pebbles are small bodies whose strong interactions with the nebula gas lead to remarkable new accretion mechanisms for the formation of planetesimals and the growth of planetary embryos. Many of the popular models for the later stages of planet formation are presented. The classical models with the giant planets on fixed orbits are not consistent with the known history of the Solar System, fail to create a high Earth/Mars mass ratio, and, in many cases, are also internally inconsistent. The successful Grand Tack model creates a small Mars, a wet Earth, a realistic asteroid belt and the mass-orbit structure of the terrestrial planets. In the Grand Tack scenario, growth curves for Earth most closely match a Weibull model. The feeding zon...

Jacobson, Seth A

2015-01-01

112

Fibered nulling telescope for extra-solar coronagraphy.  

PubMed

A family of fibered nulling telescopes is described, based on the joint use of several recent suggested or demonstrated techniques, namely, pupil densification, multiaxial recombination and single-mode fiber modal filtering, and the use of a fully symmetric beam splitter arrangement. The concept seems appropriate for the realization of a spaceborne nulling telescope, searching for Jupiter-like extra-solar planets and a precursor of future missions, such as Darwin or terrestrial planet finder interferometer (TPF-I). However, it is generally not possible to satisfy at the same time two major requirements, being the depth and size of the central nulling area, and the global throughput for the observed planet. PMID:19340231

Hnault, Franois

2009-04-01

113

Extra-solar Oort cloud encounters and planetary impact rates  

SciTech Connect

Upper limits are estimated to the number density of extra-solar Oort clouds (ESOC) through which the solar system might pass and to the probable number of attendant planetary impacts by comets. All stars are assumed to have Oort clouds. The model is based on the observed stellar spatial density and the ratio of the total number density to the observed number density. It is estimated that 486 close stellar passages and 12,160 ESOC encounters may have occurred. Each encounter would have produced a shower of hyperbolic comets, with the results of 1-3 ESOC impacts with the earth. It is concluded that the great majority of terrestrial cratering events by comets have and will come from solar Oort cloud comets. 19 references.

Stern, A.

1987-01-01

114

Terrestrial Planet Atmospheres and Biosignatures  

NASA Astrophysics Data System (ADS)

The search for terrestrial exoplanets - rocky worlds in orbit around stars other than the Sun - is one of humanity's most exciting science goals. The discovery of super Earths, terrestrial planets more massive than Earth, has opened a new era in exoplanet science, confirming the basic idea that our solar system is not the only planetary system to harbor terrestrial planets. Terrestrial exoplanets will expand planetary diversity, with masses and compositions likely very different from those found in our solar system. Most significantly, terrestrial exoplanets have the potential to host habitable environments on or below their solid surfaces, and are the most likely places beyond our solar system to search for signs of life. In the coming decades, instrumentation will be developed to expand our census of terrestrial exoplanets and directly characterize the atmospheres and biosignatures of these worlds. In the meantime, scientific progress in this field is made via extensive photochemical, climate, and radiative transfer modeling of terrestrial planetary environments together with remote sensing studies of solar system terrestrial planets, including Earth. This chapter provides an overview of terrestrial exoplanet atmosphere modeling techniques, a review of the scientific advances to date, and a discussion of outstanding questions and future directions.

Meadows, V.; Seager, S.

115

Physics with Large Extra Dimensions  

NASA Astrophysics Data System (ADS)

A theory with such a mathematical beauty cannot be wrong: this was one of the main arguments in favor of string theory, which unifies all known physical theories of fundamental interactions in a single coherent description of the universe. But no one has ever observed strings, not even indirectly, neither the space of extra dimensions where they live. However, there is a hope that the "hidden" dimensions of string theory are much larger than what we thought in the past and they become within experimental reach in the near future, together with the strings themselves.

Antoniadis, I.

2003-01-01

116

Physics with large extra dimensions  

NASA Astrophysics Data System (ADS)

A theory with such a mathematical beauty cannot be wrong: this was one of the main arguments in favor of string theory, which unifies all known physical theories of fundamental interactions in a single coherent description of the universe. But no one has ever observed strings, not even indirectly, neither the space of extra dimensions where they live. However, there is a hope that the "hidden"dimensions of string theory are much larger than what we thought in the past and they become within experimental reach in the near future, together with the strings themselves.

Antoniadis, I.

2004-02-01

117

PBS Newshour Extra: AIDS Today  

NSDL National Science Digital Library

AIDS Today, a lesson plan for grades 9-12 form PBS Newshour Extra, "engages students in learning about the AIDS epidemic and focuses them on the importance of HIV prevention, at home and abroad." The lesson plan requires two 90-minute periods to complete and calls for nothing fancier than Internet access for materials. Links to PBS Newshour story transcripts are provided for use with the lesson plan, which consists primarily of questions for class discussion as well as small group and individual learning activities.

2002-01-01

118

Does Terrestrial Carbon Subsidize Production of Estuarine Fish Larvae?  

EPA Science Inventory

The study shows important connections between terrestrial, riverine and marine energy sources in supporting larval fish production across an estuarine ecosystem in Chesapeake Bay, VA. It adds to a growing body of evidence that across ecosystem energy-exchanges play an important ...

119

SOLAR PHYSICS AND TERRESTRIAL EFFECTS Solar-Terrestrial Interactions  

E-print Network

SOLAR PHYSICS AND TERRESTRIAL EFFECTS Chapter 4 Chapter 4 Solar-Terrestrial Interactions from the charged particles that reach the planet steadily as part of the solar wind and the much it will be deflected into a circular or spiral path by the Lorentz Force. Most charged particles in the solar wind

Mojzsis, Stephen J.

120

Terrestrial Planet Formation in the ? Centauri System  

NASA Astrophysics Data System (ADS)

We examine the late stages of terrestrial planet formation around each star in the ? Centauri A and ? Centauri B binary system. Each integration begins with a ``bimodal'' mass distribution of 14 large embryos embedded in a disk of smaller planetesimals orbiting one of the stars. These initial conditions were chosen because when they are used in simulations about a single star with giant planets, they lead to systems most closely resembling our solar system. However, it is far from certain that such a planetesimal distribution actually occurs either in single or binary star systems. We follow the evolution of the accreting bodies at various values of the inclination of the midplane of the disk relative to the binary orbit for 200 Myr to 1 Gyr. In simulations in which the midplane of the disk was inclined <=30 relative to the binary orbital plane, three to five terrestrial planets were formed around ? Cen A. When the embryos in the disk were moving retrograde relative to the binary plane, four or five terrestrial planets formed. From two to five planets formed in a disk centered around ? Cen B, with ? Cen A perturbing the system in the same plane. The aforementioned resulting terrestrial planetary systems are quite similar to those produced by calculations of terrestrial planet growth in the Sun-Jupiter or Sun-Jupiter-Saturn systems. In contrast, terrestrial planet growth around a star lacking both stellar and giant planet companions is slower and extends to larger semimajor axis for the same initial disk of planetary embryos. In systems with the accreting disk initially inclined at 45 relative to the binary star orbit, two to five planets formed despite the fact that more than half of the disk mass was perturbed into the central star. When the disk was inclined at 60 to the binary plane, the stability of the planetary embryos decreased dramatically because of larger variations in eccentricity caused by the Kozai resonance, and almost all of the planetary embryos and planetesimals were lost from these systems.

Quintana, Elisa V.; Lissauer, Jack J.; Chambers, John E.; Duncan, Martin J.

2002-09-01

121

Terrestrial Coordinate Systems and Frames  

NASA Astrophysics Data System (ADS)

A terrestrial reference system (TRS) is a spatial reference system corotating with the Earth in its DIURNAL MOTION in space. In such a system, the positions of points anchored on the Earth's solid surface have coordinates which have only small variations with time, as a result of geophysical effects (tectonic or tidal deformations; see TECTONICS, EARTH'S INTERIOR, TIDES). A terrestrial reference ...

Boucher, C.; Murdin, P.

2000-11-01

122

Extra Harmonic Vowel in Chicahuaxtla Trique  

E-print Network

Extra Harmonic Vowel in Chicahuaxtla Trique1 Kosuke Matsukawa State University of New York at Albany 1. Introduction Chicahuaxtla Trique is spoken in Oaxaca, Mexico and belongs to the Trique language group of the Mixtecan family...). In Chicahuaxtla Trique, an extra harmonic vowel is added after a laryngealized vowel (either a glottalized vowel or an aspirated vowel) in a final syllable. The extra harmonic vowel does not exist in Copala Trique or Itunyoso Trique and is attached mostly...

Matsukawa, Kosuke

2008-01-01

123

Supersymmetry in gauge theories with extra dimensions  

SciTech Connect

We show that a quantum-mechanical N=2 supersymmetry is hidden in 4d mass spectrum of any gauge invariant theories with extra dimensions. The N=2 supercharges are explicitly constructed in terms of differential forms. The analysis can be extended to extra dimensions with boundaries, and for a single extra dimension we clarify a possible set of boundary conditions consistent with 5d gauge invariance, although some of the boundary conditions break 4d gauge symmetries.

Lim, C.S.; Sakamoto, Makoto; Sonoda, Hidenori [Department of Physics, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Nagasawa, Tomoaki [Graduate School of Science and Technology, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan)

2005-09-15

124

Extra Chance Generalized Hybrid Monte Carlo  

NASA Astrophysics Data System (ADS)

We study a method, Extra Chance Generalized Hybrid Monte Carlo, to avoid rejections in the Hybrid Monte Carlo method and related algorithms. In the spirit of delayed rejection, whenever a rejection would occur, extra work is done to find a fresh proposal that, hopefully, may be accepted. We present experiments that clearly indicate that the additional work per sample carried out in the extra chance approach clearly pays in terms of the quality of the samples generated.

Campos, Cdric M.; Sanz-Serna, J. M.

2015-01-01

125

Extra-Territorial Siting of Nuclear Installations  

SciTech Connect

Arrangements might be created for siting nuclear installations on land ceded by a host State for administration by an international or multinational organization. Such arrangements might prove useful in terms of resolving suspicions of proliferation in troubled areas of the world, or as a means to introduce nuclear activities into areas where political, financial or technical capabilities might otherwise make such activities unsound, or as a means to enable global solutions to be instituted for major nuclear concerns (e.g., spent fuel management). The paper examines practical matters associated with the legal and programmatic aspects of siting nuclear installations, including diplomatic/political frameworks, engaging competent industrial bodies, protection against seizure, regulation to ensure safety and security, waste management, and conditions related to the dissolution of the extra-territorial provisions as may be agreed as the host State(s) achieve the capabilities to own and operate the installations. The paper considers the potential for using such a mechanism across the spectrum of nuclear power activities, from mining to geological repositories for nuclear waste. The paper considers the non-proliferation dimensions associated with such arrangements, and the pros and cons affecting potential host States, technology vendor States, regional neighbors and the international community. It considers in brief potential applications in several locations today.

Shea, Thomas E.; Morris, Frederic A.

2009-10-07

126

Extra-solar planet detection  

NASA Technical Reports Server (NTRS)

Extra-solar planet detection has been a goal of astronomers for many decades. This paper describes current efforts in planet detection using interferometric techniques. At present, the Mark III long baseline interferometer has been operational for a number of years. The Mark III has achieved significant improvement in astrometric accuracy in two areas, wide angle astrometry and double star astrometry. Two new interferometers are being developed. The first is a direct combination IR interferometer, an upgrade of the UCB IR heterodyne interferometer. The second is the Keck Interferometer Array. This instrument, to be operational at the end of the decade will be a major interferometric facility, with the capability to combine coherently the light from the two 10-meter Keck telescopes as well as four 1.5-meter movable outrigger telescopes. The last project directed at planet detection is OSI, a space-based long-baseline interferometer with a planned astrometric accuracy of 1-10 microarcsec.

Shao, Michael

1991-01-01

127

(Extra)Ordinary Gauge Mediation  

E-print Network

We study models of "(extra)ordinary gauge mediation," which consist of taking ordinary gauge mediation and extending the messenger superpotential to include all renormalizable couplings consistent with SM gauge invariance and an R-symmetry. We classify all such models and find that their phenomenology can differ significantly from that of ordinary gauge mediation. Some highlights include: arbitrary modifications of the squark/slepton mass relations, small mu and Higgsino NLSP's, and the possibility of having fewer than one effective messenger. We also show how these models lead naturally to extremely simple examples of direct gauge mediation, where SUSY and R-symmetry breaking occur not in a hidden sector, but due to the dynamics of the messenger sector itself.

Clifford Cheung; A. Liam Fitzpatrick; David Shih

2007-11-29

128

Immune defence, extra-pair paternity, and sexual selection in birds  

PubMed Central

Secondary sexual characters have been suggested to reliably reflect the ability of individuals to resist debilitating parasites, and females may gain direct or indirect fitness benefits from preferring the most extravagantly ornamented males. Extra-pair paternity provides an estimate of an important component of sexual selection in birds. Species with a high frequency of extra-pair paternity have a variance in realized reproductive success that is greater than the variance in apparent reproductive success, and extra-pair copulations and hence extra-pair paternity by females are often directly associated with the expression of male secondary sexual characters. If sexually dichromatic species have experienced a long period of antagonistic coevolution with their parasites, such species should have evolved larger immune defence organs than sexually monochromatic species. Bird species with sexual dichromatism had larger spleens for their body size than monochromatic species in a comparative analysis. Furthermore, species with a high frequency of extra-pair paternity were sexually dichromatic and had large spleens for their body size. These results are consistent with the hypothesis that females of dichromatic bird species seek extra-pair copulations to obtain indirect fitness benefits in terms of superior resistance of their offspring to virulent parasites.

Mller, A. P.

1997-01-01

129

Sustained periodic terrestrial locomotion in air-breathing fishes.  

PubMed

While emergent behaviours have long been reported for air-breathing osteichthyians, only recently have researchers undertaken quantitative analyses of terrestrial locomotion. This review summarizes studies of sustained periodic terrestrial movements by air-breathing fishes and quantifies the contributions of the paired appendages and the axial body to forward propulsion. Elongate fishes with axial-based locomotion, e.g. the ropefish Erpetoichthys calabaricus, generate an anterior-to-posterior wave of undulation that travels down the axial musculoskeletal system and pushes the body against the substratum at multiple points. In contrast, appendage-based locomotors, e.g. the barred mudskipper Periophthalmus argentilineatus, produce no axial bending during sustained locomotion, but instead use repeated protraction-retraction cycles of the pectoral fins to elevate the centre of mass and propel the entire body anteriorly. Fishes that use an axial-appendage-based mechanism, e.g. walking catfishes Clarias spp., produce side-to-side, whole-body bending in co-ordination with protraction-retraction cycles of the pectoral fins. Once the body is maximally bent to one side, the tail is pressed against the substratum and drawn back through the mid-sagittal plane, which elevates the centre of mass and rotates it about a fulcrum formed by the pectoral fin and the ground. Although appendage-based terrestrial locomotion appears to be rare in osteichthyians, many different species appear to have converged upon functionally similar axial-based and axial-appendage-based movements. Based on common forms observed across divergent taxa, it appears that dorsoventral compression of the body, elongation of the axial skeleton or the presence of robust pectoral fins can facilitate effective terrestrial movement by air-breathing fishes. PMID:24502775

Pace, C M; Gibb, A C

2014-03-01

130

Origin of extra chromosome in Patau syndrome  

Microsoft Academic Search

Five live-born infants with Patau syndrome were studied for the nondisjunctional origin of the extra chromosome. Transmission modes of chromosomes 13 from parents to a child were determined using both QFQ- and RFA-heteromorphims as markers, and the origin was ascertained in all of the patients. The extra chromosome had originated in nondisjunction at the maternal first meiotic division in two

S. Ishikiriyama; N. Niikawa

1984-01-01

131

Utility terrestrial biodiversity issues  

SciTech Connect

Results from a survey of power utility biologists indicate that terrestrial biodiversity is considered a major issued by only a few utilities; however, a majority believe it may be a future issue. Over half of the respondents indicated that their company is involved in some management for biodiversity, and nearly all feel that it should be a goal for resource management. Only a few utilities are funding biodiversity research, but a majority felt more research was needed. Generally, larger utilities with extensive land holdings had greater opportunities and resources for biodiversity management. Biodiversity will most likely be a concern with transmission rights-of-way construction and maintenance, endangered species issues and general land resource management, including mining reclamation and hydro relicensing commitments. Over half of the companies surveyed have established voluntary partnerships with management groups, and biodiversity is a goal in nearly all the joint projects. Endangered species management and protection, prevention of forest fragmentation, wetland protection, and habitat creation and protection are the most common partnerships involving utility companies. Common management practices and unique approaches are presented, along with details of the survey. 4 refs.

Breece, G.A. [Southern Company, Atlanta, GA (United States); Ward, B.J. [Carolina Power and Light Company, Raleigh, NC (United States)

1996-11-01

132

Radiocarbon dating of terrestrial carbonates  

USGS Publications Warehouse

Terrestrial carbonates encompass a wide range of materials that potentially could be used for radiocarbon (14C) dating. Biogenic carbonates, including shells and tests of terrestrial and aquatic gastropods, bivalves, ostracodes, and foraminifera, are preserved in a variety of late Quaternary deposits and may be suitable for 14C dating. Primary calcareous deposits (marls, tufa, speleothems) and secondary carbonates (rhizoliths, fracture fill, soil carbonate) may also be targeted for dating when conditions are favorable. This chapter discusses issues that are commonly encountered in 14C dating of terrestrial carbonates, including isotopic disequilibrium and open-system behavior, as well as methods used to determine the reliability of ages derived from these materials. Recent methodological advancements that may improve the accuracy and precision of 14C ages of terrestrial carbonates are also highlighted.

Pigati, Jeffrey S.

2014-01-01

133

Contaminant Exposure in Terrestrial Vertebrates  

EPA Science Inventory

Manuscript is a critical review of the state of the science for quantifying exposures of terrestrial wildlife species to chemical contamination. It describes the unique aspects of birds, mammals, reptiles, amphibians and threatened and endangered species. Fate and transport of ...

134

Neutralino decay in the $?$-problem solvable extra U(1) models  

E-print Network

We study the neutralino decay in the supersymmetric extra U(1) models which can solve the $\\mu$-problem. In these models the neutralino sector is extended at least into six components by an extra U(1) gaugino and a superpartner of a singlet Higgs. Focussing on its two lower mass eigenstates $\\tilde\\chi_2^0$ and $\\tilde\\chi_1^0$, decay processes such as a tree level three body decay $\\tilde\\chi_2^0\\to \\tilde\\chi_1^0 f\\bar f$ and a one-loop radiative decay $\\tilde\\chi_2^0\\to \\tilde\\chi_1^0\\gamma$ are estimated. We investigate the condition under which the radiative decay becomes the dominant mode and also numerically search for such parameter regions. In this analysis we take account of the abelian gaugino kinetic term mixing. We suggest that the gaugino mass relation $M_W\\sim M_Y$ may not be necessary for the radiative decay dominance in the extra U(1) models.

Daijiro Suematsu

1997-11-15

135

Parallel Computing for Terrestrial Ecosystem Carbon Modeling  

Microsoft Academic Search

Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest,

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

2011-01-01

136

Metabolic assessments during extra-vehicular activity  

NASA Astrophysics Data System (ADS)

Extra-vehicular activity (EVA) has a significant role during extended space flights. It demonstrates that humans can survive and perform useful work outside the Orbital Space Stations (OSS) while wearing protective space suits (SS). When the International Space Station 'Alpha'(ISSA) is fully operational, EVA assembly, installation, maintenance and repair operations will become an everyday repetitive work activity in space. It needs new ergonomic evaluation of the work/rest schedule for an increasing of the labor amount per EVA hour. The metabolism assessment is a helpful method to control the productivity of the EVA astronaut and to optimize the work/rest regime. Three following methods were used in Russia to estimate real-time metabolic rates during EVA: 1. Oxygen consumption, computed from the pressure drop in a high pressure bottle per unit time (with actual thermodynamic oxygen properties under high pressure and oxygen leakage taken into account). 2. Carbon dioxide production, computed from CO 2 concentration at the contaminant control cartridge and gas flow rate in the life support subsystem closed loop (nominal mode) or gas leakage in the SS open loop (emergency mode). 3. Heat removal, computed from the difference between the temperatures of coolant water or gas and its flow rate in a unit of time (with assumed humidity and wet oxygen state taken into account). Comparison of heat removal values with metabolic rates enables us to determine the thermal balance during an operative medical control of EVA at "Salyut-6", "Salyut-7" and "Mir" OSS. Complex analysis of metabolism, body temperature and heat rate supports a differential diagnosis between emotional and thermal components of stress during EVA. It gives a prognosis of human homeostasis during EVA. Available information has been acquired into an EVA data base which is an effective tool for ergonomical optimization.

Osipov, Yu. Yu.; Spichkov, A. N.; Filipenkov, S. N.

137

Sliding GAIT Algorithm for the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE)  

NASA Technical Reports Server (NTRS)

The design of a surface robotic system typically involves a trade between the traverse speed of a wheeled rover and the terrain-negotiating capabilities of a multi-legged walker. The ATHLETE mobility system, with both articulated limbs and wheels, is uniquely capable of both driving and walking, and has the flexibility to employ additional hybrid mobility modes. This paper introduces the Sliding Gait, an intermediate mobility algorithm faster than walking with better terrain-handling capabilities than wheeled mobility.

Townsend, Julie; Biesiadecki, Jeffrey

2012-01-01

138

Making Friends with an Extra-Terrestrial: Conversation Skills and Friendship Formation in Young Children.  

ERIC Educational Resources Information Center

A novel paradigm was developed and two studies conducted to test the contribution of six conversational skills to children's friendship formation. In study 1, 4- and 5-year-olds individually played for 30 minutes with a 2-foot-tall talking doll. The doll contained a wireless hidden receiver/speaker enabling a concealed female assistant to converse

Parker, Jeffrey G.; Gottman, John M.

139

Symphony of Space OP.20 An extra-terrestrial symphony for large wind orchestra and chorus  

E-print Network

'effets (extrait audio de Neil Armstrong et son fameux « That's one small step for man... »)... Puis, notre système-bip » du Spoutnik, Neil Armstrong sur la Lune,... La création est prévue en Midi-Pyrénées à la Grotte de

Dintrans, Boris

140

TimeBounded Kolmogorov Complexity May Help in Search for Extra Terrestrial Intelligence (SETI)  

E-print Network

Intelligence (SETI) is trying to overhear communications between advanced civilizations. However, there is a (seeming) problem with this ap­ proach: advanced civilizations, most probably, save communication expenses random noise, and thus, trying to detect such a message does not seem to be a working SETI strategy. We

Ward, Karen

141

HYDROTHERMAL VENT COMPLEXES AND THE SEARCH FOR EXTRA-TERRESTRIAL WATER. H. Svensen1  

E-print Network

. They comprise up to 7 km deep pipe structures filled with brecciated sedimentary rocks (Fig. 1). Some also con is generally inferred from particular sedimentary structures using an Earth analogy. We present the ex- tra's) are identified in major sedimentary basins in Europe and Africa, directly linked to the presence of water

Mazzini, Adriano

142

ELF and VLF observations of ionospheric disturbances caused by extra-terrestrial origin  

NASA Astrophysics Data System (ADS)

Very Low Frequency (VLF) radio wave propagates within the Earth-ionosphere waveguide, and hence measurement of the VLF amplitude and phase can be utilized to study physics of phenomena taking place in the lower ionosphere below about 100 km. Observation of Extremely Low Frequency (ELF) radio wave is also a powerful tool to investigate ionospheric phenomena such as lightning. Here we present ELF and VLF observations of ionospheric disturbances caused by extraterrestrial phenomena. Cosmological Gamma-ray bursts has already been known as the origin of ionospheric disturbances. In addition to this, "magnetar" flares has also been recognized to affect the Earth's ionosphere. Ordinary neutron stars possess magnetic fields of about 10^12 Gauss, while magnetars are considered to have extremely strong magnetic fields of about 10^15 G. Some of the magnetars emit short-duration (~0.1 s) gamma-ray bursts repeatedly in active phases, thereby they are named as "Soft Gamma-ray Repeaters (SGRs)". As rare events, SGRs emit exceptionally bright gamma-ray flares "giant flares", whose peak fluxes exceed those of X-class large solar flares by several order of magnitudes. Recent sensitive measurement of ELF and VLF radio waves can observe ionospheric disturbances caused by these short-repeated and giant flares. Namely, we have found that transient ELF radio wave and Schumann resonance were caused by SGR giant flares in 2004. The emission mechanism is still unclear, but similarity of nuclear detonation in 1960's might give some hints to unveil the emission mechanism. Interesting application of VLF measurement of magnetar flare is that we can deduce the gamma-ray spectrum from VLF data. Intensive astronomical X-ray and gamma-ray observations have been performed by satellites in space using very sensitive detectors. Since SGR giant flare emits huge X-ray/gamma-ray flux, such sensitive detectors are affected by severe saturation problems and precise measurement is very difficult. In my presentation, we present how we deduce the photon spectrum from the VLF data. Using Monte Carlo method, we modeled ionization of lower ionosphere, and obtained altitude profile of electron number density. We then utilized Finite-Difference Time Domain (FDTD) method to simulate VLF propagation. The altitude profile and simulated amplitude change differs depending on the energy spectrum. Therefore, by comparing simulation results with the observation, we can infer the source spectrum as an inverse problem.

Tanaka, Y.; Hayakawa, M.; Hobara, Y.; Raulin, J.; Takahashi, Y.; Sato, M.; Terasawa, T.

2013-05-01

143

Combustion of Metals in Reduced-Gravity and Extra Terrestrial Environments  

NASA Technical Reports Server (NTRS)

The combustion of metals is a field with important practical applications in rocket propellants, high-temperature flames, and material synthesis. Also, the safe operation of metal containers in high-pressure oxygen systems and with cryogenic fuels and oxidizers remains an important concern in industry. The increasing use of metallic components in spacecraft and space structures has also raised concerns about their flammability properties and fire suppression mechanisms. In addition, recent efforts to embark on unmanned and manned planetary exploration, such as on Mars, have also renewed the interest in metal/carbon-dioxide combustion as an effective in situ resource utilization technology. In spite of these practical applications, the understanding of the combustion properties of metals remains far behind that of the most commonly used fuels such as hydrocarbons. The lack of understanding is due to the many problems unique to metal- oxidizer reactions such as: low-temperature surface oxidation prior to ignition, heterogeneous reactions, very high combustion temperatures, product condensation, high emissivity of products, and multi-phase interactions. Very few analytical models (all neglecting the influence of gravity) have been developed to predict the burning characteristics and the flame structure details. Several experimental studies attempting to validate these models have used small metal particles to recreate gravity-free conditions. The high emissivity of the flames, rapid reaction, and intermittent explosions experienced by these particles have made the gathering of any useful information on burning rates and flame structure very difficult. The use of a reduced gravity environment is needed to clarify some of the complex interactions among the phenomena described above. First, the elimination of the intrusive buoyant flows that plague all combustion phenomena is of paramount importance in metal reactions due to the much higher temperatures reached during combustion. Second, a low-gravity environment is absolutely essential to remove the destructive effect of gravity on the shape of a molten metal droplet in order to study a spherically symmetric condition with large bulk samples. The larger size of the spherical metal droplet and the longer burning times available in reduced gravity extend the spatial and temporal dimensions to permit careful probing of the flame structure and dynamics. Third, the influence of the radiative heat transfer from the solid oxides can be studied more carefully by generating a stagnant spherical shell of condensed products undisturbed by buoyancy.

Branch, M.C.; Abbud-Madrid, A.; Daily, J. W.

1999-01-01

144

A numerical study on collisions of icy bodies using SPH method combined with GRAPE  

NASA Astrophysics Data System (ADS)

We have worked on the collisions of icy bodies using Smoothed Particles Hydrodynamics (SPH) method combined with Gravity PipE (GRAPE) in order to understand the basic behavior of icy bodies during impacts. Collisions of Mars-size rocky bodies have been investigated well, because those collisions are related to the origin of the moon and the formation of the terrestrial planets. On the other hand, collisions of icy bodies have not been studied yet, although these collisions would frequently occur in the solar and extra-solar systems, such as the formation of icy exoplanets. Through our research, we figure out the effect of ice during impact in detail. Our SPH code has two special features. First, GRAvity PipE computer (GRAPE) is used, which calculates the gravitational force of each particle up to 100 times faster than usual computers. Second, SESAME equation of state database is used to build a realistic model, taking into account the effect of phase change. In this research, we focused on differences and similarities between collisions of icy bodies and those of rocky ones, such as a merging criterion. Agnor & Asphaug (2004) have shown that a collision of rocky Mars-size protoplanets leads to an inelastic collision when its relative velocities are smaller than 1.4-1.5v, 1.1-1.2v, 1.1-1.2v when its impact angles are 30, 45, and 60 degrees, respectively. Here, v means escape velocity. The same calculations for icy bodies are performed in our numerical code. They have shown that the merging criterion of icy bodies is the same as that of rocky bodies. In addition to the merging criterion, we also clarify the relationship between impact parameters and the change of solid, liquid/vapor mass ratio due to impacts.

Nakajima, M.; Genda, H.; Ida, S.

2009-12-01

145

Grazers: biocatalysts of terrestrial silica cycling  

PubMed Central

Silica is well known for its role as inducible defence mechanism countering herbivore attack, mainly through precipitation of opaline, biogenic silica (BSi) bodies (phytoliths) in plant epidermal tissues. Even though grazing strongly interacts with other element cycles, its impact on terrestrial silica cycling has never been thoroughly considered. Here, BSi content of ingested grass, hay and faeces of large herbivores was quantified by performing multiple chemical extraction procedures for BSi, allowing the assessment of chemical reactivity. Dissolution experiments with grass and faeces were carried out to measure direct availability of BSi for dissolution. Average BSi and readily soluble silica numbers were higher in faeces as compared with grass or hay, and differences between herbivores could be related to distinct digestive strategies. Reactivity and dissolvability of BSi increases after digestion, mainly due to degradation of organic matrices, resulting in higher silica turnover rates and mobilization potential from terrestrial to aquatic ecosystems in non-grazed versus grazed pasture systems (2 versus 20 kg Si ha?1 y?1). Our results suggest a crucial yet currently unexplored role of herbivores in determining silica export from land to ocean, where its availability is linked to eutrophication events and carbon sequestration through CSi diatom interactions. PMID:24107532

Vandevenne, Floor Ina; Baro, Ana Lcia; Schoelynck, Jonas; Smis, Adriaan; Ryken, Nick; Van Damme, Stefan; Meire, Patrick; Struyf, Eric

2013-01-01

146

Higgs boson decay constraints on a model with a universal extra dimension  

NASA Astrophysics Data System (ADS)

We investigate the impact of the latest data on Higgs boson branching ratios on the minimal model with a universal extra dimension. Combining constraints from vacuum stability requirements with these branching ratio measurements we are able to make realistic predictions for the signal strengths in this model. We use these to find a lower bound of 1.3 TeV on the size parameter R-1 of the model at 95% confidence level, which is far more stringent than any other terrestrial bound obtained till now and is compatible with the dark matter constraints from the Wilkinson Microwave Anisotropy Probe data.

Datta, Anindya; Patra, Ayon; Raychaudhuri, Sreerup

2014-05-01

147

Extra-adrenal paraganglioma of the prostate  

PubMed Central

Extra-adrenal pheochromocytomas, or paragangliomas, are rare tumours that may develop from extra-adrenal chromaffin cells, and most occur in the organ of Zuckerkandl. Extra-adrenal paraganglioma of the prostate is extremely rare. We report a 53-year-old man with hypertension and lower urinary tract symptoms, who was initially diagnosed with benign prostate hyperplasia. Computed tomography (CT) showed a large heterogenously enhancing mass in the prostate, imprinting the right distal ureter and urinary bladder. Before surgical intervention, CT-guided biopsy of the prostatic mass was performed and the result of histologic examination confirmed extra-adrenal paraganglioma. He underwent radical prostatectomy, partial cystectomy and right ureteroneocystostomy. The patient recovered and his blood pressure returned within normal range after surgical removal of the prostate tumour. In this article, we stress that the rarity of prostatic paraganglioma, preoperative localization and imaging-guided biopsy were useful in determining the surgical strategy. PMID:23766843

Wang, Hong-Hau; Chen, Yen-Lin; Kao, Hao-Lun; Lin, Shih-Chung; Lee, Chiao-Hua; Huang, Guo-Shu; Chang, Wei-Chou

2013-01-01

148

Primary extra nodal Hodgkin disease: Bone presentation  

PubMed Central

Summary Background Extra nodal and extra lymphatic propagation of Hodgkins disease is a characteristic of the fourth stage of disease when the organs are affected. Primary appearances of the disease outside the lymph node is a rare event. Therefore, it makes diagnostic problem. Skeletal system is possible localization of primary extra nodal Hodgkins disease. Case Report Women, 42-years-old, was admitted to hospital because of swelling and pain in the right shoulder. After imaging and histological examination diagnosed Hodgkins nodular sclerosing histological subtype disease has been established. The patient starts to receive chemotherapy. Conclusions Primary extra nodal Hodgkins disease of bone is manifested with painful swelling in geared area. Imaging method shows destruction of the affected bone, with swelling of the soft tissues. Propagation in soft tissue is not accompanied by their destruction, but rather manifested swelling of the surrounding soft tissue. PMID:24808935

Nikolica, Goran; Badnjar, Zorka; Cadjenovic, Tanja; Raceta-Masic, Dijana

2014-01-01

149

Terrestrial planet composition: simulation and observation  

NASA Astrophysics Data System (ADS)

As direct detection and examination of terrestrial exoplanets is not yet possible, we must persue alternative methods to constarin the types of planets likely to be found within extrasolar planetary systems and thus guide future missions. Such studies cannot be undertaken by transit surveys. Instead, secondary sources must be utilized. In addition to simultions of terrestrial planet formation, based on spectroscopic observations of known stars, observations of polluted white dwarfs (e.g. Jura, M., & Xu, S. (2012); Gaensicke et al., (2013)) and simulations of the pollution of migrating gas giants may be utilized to determine the composition of solid bodies withn extrasolar planetary systems. Observations of polluted white dwarfs (e.g. Jura, M., & Xu, S. (2012); Gaensicke et al., (2013)) will be compared to simulations of the bulk composition of terrestrial planets (Carter-Bond et al. (2012)). Combining dynamical simulations of Carter-Bond et al. (2012) and Raymond et al. (2006) with spectrally-derived abundances for 15 planet-forming elements (H, C, N, O, Na, Mg, Al, Si, P, S, Ca, Ti, Cr, Fe and Ni), bulk compositions for simulated terrestrial planets have been obtained. This is the first time that compositional simulations can be compared with observations (albeit of a proxy for solid composition) and will be crucial for placing constraints on both the true diversity of planetary compositions expected to exist in extrasolar planetary systems and the simulations currently utilized. Simulations of the change in composition resulting from pollution of a gas giant as it migrates through a planetary system will also be presented. These simulations represent an as-yet untested approach to determining the solid composition within a planetary system. By simulating the amount and composition of material accreted by the gas giant (following Carter-Bond et al. (2012)), we will be able to determine what effect, if any, the accretion of solid material during migration has on giant planet composition. This study represents the first attempt at untangling what fraction of the observed composition is primordial and what fraction has been accreted and may, ultimately, provide further limitation on the composition of solids within extrasolar planetary systems. Such a study is especially timely, given the rising number of spectral observations of transiting giant planets and their unusual implications (e.g. Madhusudhan et al. (2011)).

Carter-Bond, J.; Bolmont, E.; Raymond, S.

2014-03-01

150

Accretion of Terrestrial Planets from Oligarchs in a Turbulent Disk  

Microsoft Academic Search

We have investigated the final accretion stage of terrestrial planets from Mars-mass protoplanets that formed through oligarchic growth in a disk comparable to the minimum mass solar nebula (MMSN), through N-body simulation including random torques exerted by disk turbulence due to Magneto-Rotational-Instability. For the torques, we used the semi-analytical formula developed by Laughlin et al. (2004). The damping of orbital

Masahiro Ogihara; S. Ida; A. Morbidelli

2006-01-01

151

Accretion of terrestrial planets from oligarchs in a turbulent disk  

Microsoft Academic Search

We have investigated the final accretion stage of terrestrial planets from Mars-mass protoplanets that formed through oligarchic growth in a disk comparable to the minimum mass solar nebula (MMSN), through N-body simulation including random torques exerted by disk turbulence due to Magneto-Rotational Instability. For the torques, we used the semi-analytical formula developed by Laughlin et al. [Laughlin, G., Steinacker, A.,

Masahiro Ogihara; Shigeru Ida; Alessandro Morbidelli

2007-01-01

152

Investigation of the extra-extra-push by pre-scission neutron measurements with DEMON  

SciTech Connect

The objective of this talk is to present a simple method to calculate pre- and post-scission neutron multiplicities in the frame of the Bass model. This method is of particular interest for very heavy systems for which an extra-extra-push is supposed to hinder fusion. The multiplicities calculated by the model are compared to published data covering a broad range of projectile and target masses, and to more recent ones obtained with the help of the Demon detector and addressing specifically the existence of the extra-extra-push.

Rudolf, Gerard

1998-02-15

153

Space Physics and Terrestrial Effects  

NSDL National Science Digital Library

This curriculum guide is intended for high school teachers who are teaching solar physics, especially the effects of solar activity on terrestrial planets. The chapters discuss stellar evolution, the structure of the sun, studying the sun, and solar and terrestrial interactions. Lab activities provided include: building a spectroscope, energy transport within the sun, measuring the solar constant, luminosity of the sun and stars, seeing different wavelengths, the Earth-Sun orientation, the effect of the solar wind on the geomagnetic field, determining the rotation period of the sun, and radiation hazards in space.

2005-05-23

154

Groundwater and Terrestrial Water Storage  

NASA Technical Reports Server (NTRS)

Groundwater is a vital resource and also a dynamic component of the water cycle. Unconfined aquifer storage is less responsive to short term weather conditions than the near surface terrestrial water storage (TWS) components (soil moisture, surface water, and snow). However, save for the permanently frozen regions, it typically exhibits a larger range of variability over multi-annual periods than the other components. Groundwater is poorly monitored at the global scale, but terrestrial water storage (TWS) change data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission are a reasonable proxy for unconfined groundwater at climatic scales.

Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

2012-01-01

155

Observing terrestrial gamma ray flashes  

NASA Astrophysics Data System (ADS)

Terrestrial Gamma Ray Flash Workshop; Huntsville, Alabama, 13-14 July 2011 Terrestrial gamma ray flashes (TGFs) were the focus of a workshop held at the University of Alabama in Huntsville (UAH), with observation and theory well represented by the 38 attendees. Discovered in 1991 as brief (submillisecond), bright flashes of gamma rays detected over regions of thunderstorm activity by the spaceborne Burst And Transient Source Experiment, TGFs may be entering an observational golden era. Three space-based gamma ray telescopes currently make TGFs a scientific priority.

Connaughton, Valerie; Briggs, Michael S.

2011-12-01

156

The Oldest Caseid Synapsid from the Late Pennsylvanian of Kansas, and the Evolution of Herbivory in Terrestrial Vertebrates  

PubMed Central

The origin and early evolution of amniotes (fully terrestrial vertebrates) led to major changes in the structure and hierarchy of terrestrial ecosystems. The first appearance of herbivores played a pivotal role in this transformation. After an early bifurcation into Reptilia and Synapsida (including mammals) 315 Ma, synapsids dominated Paleozoic terrestrial vertebrate communities, with the herbivorous caseids representing the largest vertebrates on land. Eocasea martini gen. et sp. nov., a small carnivorous caseid from the Late Carboniferous, extends significantly the fossil record of Caseidae, and permits the first clade-based study of the origin and initial evolution of herbivory in terrestrial tetrapods. Our results demonstrate for the first time that large caseid herbivores evolved from small, non-herbivorous caseids. This pattern is mirrored by three other clades, documenting multiple, independent, but temporally staggered origins of herbivory and increase in body size among early terrestrial tetrapods, leading to patterns consistent with modern terrestrial ecosystem. PMID:24739998

Reisz, Robert R.; Frbisch, Jrg

2014-01-01

157

The oldest caseid synapsid from the Late Pennsylvanian of Kansas, and the evolution of herbivory in terrestrial vertebrates.  

PubMed

The origin and early evolution of amniotes (fully terrestrial vertebrates) led to major changes in the structure and hierarchy of terrestrial ecosystems. The first appearance of herbivores played a pivotal role in this transformation. After an early bifurcation into Reptilia and Synapsida (including mammals) 315 Ma, synapsids dominated Paleozoic terrestrial vertebrate communities, with the herbivorous caseids representing the largest vertebrates on land. Eocasea martini gen. et sp. nov., a small carnivorous caseid from the Late Carboniferous, extends significantly the fossil record of Caseidae, and permits the first clade-based study of the origin and initial evolution of herbivory in terrestrial tetrapods. Our results demonstrate for the first time that large caseid herbivores evolved from small, non-herbivorous caseids. This pattern is mirrored by three other clades, documenting multiple, independent, but temporally staggered origins of herbivory and increase in body size among early terrestrial tetrapods, leading to patterns consistent with modern terrestrial ecosystem. PMID:24739998

Reisz, Robert R; Frbisch, Jrg

2014-01-01

158

PROPULSION AND ENERGY Terrestrial energy  

E-print Network

PROPULSION AND ENERGY Terrestrial energy On the morning of Monday, August 29, Hurri- cane Katrina, hydro, and nuclear, have not come to the forefront, and what can be done to remedy this situation, nuclear, solar, and geothermal energy. New initiatives by the Dept. of Energy are focusing

Aggarwal, Suresh K.

159

Scientist Using Terrestrial Lidar Equipment  

USGS Multimedia Gallery

Chris Soulard using the Terrestrial Lidar to scan studyarea in the Grand Canyon-Parashant National Monument, AZ. Note the bag of ice on the equipment. High temperates can cause equipment to overheat, requiring scientists tobe creativein protecting equipment....

160

Measurement of Terrestrial Radio Noise  

Microsoft Academic Search

The terrestrial noise experiment on the Ariel III satellite is designed to measure the radio noise from lighting discharges, and to deduce the distribution of the sources. The measurements are made at high frequencies; at optimum frequencies the noise penetrates the ionosphere only at near vertical incidence and the sources can therefore be localized. The receivers operate in narrow bandwidths

F. Horner; R. B. Bent

1969-01-01

161

Terrestrial heat flow in Cuba  

NASA Astrophysics Data System (ADS)

The results of two joint expeditions to Cuba to measure terrestrial heat flow in 1983 and 1986 are summarized. Twenty-three new values are presented, which confirm the low heat flow in practically all of the island. The mean and standard deviation (44.7 13.4 mW m -2) agree well with previous observations.

?ermk, V.; Krel, M.; afanda, J.; Bodri, L.; Npoles-Pruna, M.; Tenreyro-Perez, R.

162

Alternatives to the Seesaw: Extra Z's and Constraints on Large Extra Dimensions  

E-print Network

Alternatives to the traditional grand unified theory seesaw for neutrino masses are briefly described. These include the possibility of large extra dimensions and various possibilities for models involving an extra U(1)' gauge symmetry. The difficulty of observing Majorana phases in neutrinoless double beta decay is also briefly commented on.

Paul Langacker

2003-04-10

163

In situ observations of the atmospheres of terrestrial planetary bodies  

NASA Astrophysics Data System (ADS)

Direct observations of planetary atmospheres are scarce and significantly more data are needed for the understanding of their behavior. The principal theme of this dissertation is the exploration of planetary atmospheres by means of in situ observations, focusing on investigations performed by payloads operating on the planetary surface. The contextual frame includes the whole palette of planetary exploration including definition of scientific objectives, observational strategies, scientific payload and data analysis, as well as development of technological solutions and simulation models for planetary missions. Thus approach also led to the initiation of the planetary missions MetNet and NetLander to Mars. This work contributes to both in situ atmospheric observations and atmospheric modeling, which are strongly intertwined. Modeling efforts require observations to give solid background and foundation for the simulations, and on the other hand, definition of observational strategies and instrumentation gets guidance from modeling efforts to optimize the use of mission resources, as is successfully demonstrated in this dissertation. The dissertation consists of Summary and nine original scientific publications. Publications 1 to 7 and Summary address the development of new atmospheric science payloads for exploration missions to Mars and Titan, a Saturnian moon. Actual and planned missions included are the Mars-96 Program and its Small Surface Stations and Penetrators during the years 1988-1996, PPI/HASI onboard the Cassini/Huygens spacecraft to Saturn and its moon Titan in 1989-2005, the MET-P payload onboard the Mars Polar Lander in 1997-1999, the BAROBIT instrument for the Beagle 2 lander in 2001-2003, the NetLander Mars Mission in 1997-2001 and the ongoing Mars MetNet Mission, started in 2000. Specifically, Publication 4 reviews the sensor qualification process that facilitated the use of new type of atmospheric sensors at Mars, while Publications 2 and 7, as well as Summary, address the highly successful determination of the Titan atmospheric pressure profile. Publication 8 combines in situ observations and simulations by analyzing Mars Pathfinder measurements with the help of a Martian mesoscale atmospheric model. Finally, in Publication 9 the effect of airborne dust and CO 2 on the radiative transfer in the Martian atmosphere is assessed and a new radiative transfer paramerization scheme for the mesoscale model is introduced.

Harri, Ari-Matti

2005-11-01

164

Long-term solar-terrestrial observations  

NASA Technical Reports Server (NTRS)

The results of an 18-month study of the requirements for long-term monitoring and archiving of solar-terrestrial data is presented. The value of long-term solar-terrestrial observations is discussed together with parameters, associated measurements, and observational problem areas in each of the solar-terrestrial links (the sun, the interplanetary medium, the magnetosphere, and the thermosphere-ionosphere). Some recommendations are offered for coordinated planning for long-term solar-terrestrial observations.

1988-01-01

165

Fragmentation of metal diapirs in terrestrial magma oceans  

NASA Astrophysics Data System (ADS)

Due to mechanisms such as impact heating, early atmospheric thermal blanketing or radioactive heating, the presence of at least one global magma ocean stage in the early histories of terrestrial planets seems unavoidable. In such a context, a key question is whether (and how much) iron diapirs provided by differentiated impactors have emulsified during their sinking towards the bottom of an early magma ocean. Addressing this problem allows one to put strong constraints on metal-silicate equilibration processes as well as heat distribution within a young terrestrial planet. Previous theoretical studies have focused on this question, however no dynamic studies have conducted a systematic exploration of the relevant parameter space corresponding to terrestrial magma oceans. We therefore perform a series of numerical experiments where we follow the sinking of iron diapirs until they fragment (or not) into smaller bodies. Metal-silicate thermal and chemical exchanges are also monitored during the sinking process. Our models include an accurate treatment of surface tension, inertial effects, as well as viscous heating and we investigate systematically the effect of rheological properties and diapir sizes on the conditions and on the consequences of metal diapir fragmentation in terrestrial magma oceans.

Samuel, H.; Rubie, D. C.; Melosh, H. J.

2010-12-01

166

Terrestrial biogeochemical feedbacks in the climate system  

Microsoft Academic Search

The terrestrial biosphere is a key regulator of atmospheric chemistry and climate. During past periods of climate change, vegetation cover and interactions between the terrestrial biosphere and atmosphere changed within decades. Modern observations show a similar responsiveness of terrestrial biogeochemistry to anthropogenically forced climate change and air pollution. Although interactions between the carbon cycle and climate have been a central

A. Arneth; S. P. Harrison; S. Zaehle; K. Tsigaridis; S. Menon; P. J. Bartlein; J. Feichter; A. Korhola; M. Kulmala; D. O'Donnell; G. Schurgers; S. Sorvari; T. Vesala

2010-01-01

167

The Economic Potential of Terrestrial Impact Craters  

Microsoft Academic Search

Like concentrations of economic resources, terrestrial impact structures are the result of relatively rare geologic events. Economic resources occur in a number of terrestrial impact structures. After providing a context by briefly summarizing the salient points of the terrestrial impact record and the characteristics of impact craters, the relationship between impact craters and economic resources is explored. Approximately 25% of

R. A. F. Grieve; V. L. Masaitis

1994-01-01

168

Tidal evolution of extra-solar planets  

NASA Astrophysics Data System (ADS)

In both our solar system and extra-solar planetary systems, tides may have a variety of effects, driving complex orbital evolution and geophysical processes. For extra-solar planets with orbits that pass very close to their host stars, tides have reduced orbital eccentricities and semi-major axes, and the rates of tidal evolution may change dramatically as orbits evolve. Understanding how the orbits have evolved and, ultimately, discerning the origins of close-in extra-solar planets require accounting for all the complexity of tidal evolution. The accompanying dissipation of tidal energy within the planets has probably also affected their internal structures. In some cases, tidal dissipation may account the apparent discrepancy between predictions and observations of the radii of extra-solar planets that transit their host stars. Evolutionary models for these planets that allow determinations of their internal structures and composition must include highly variable tidal heating rates. The same tidal evolution and heating probably also affects the orbital and geophysical properties of rocky extra-solar planets and may play a key role in determining whether such a planet can harbor life. As tides reduce a planet's semi-major axis, the planet may eventually pass so close to its host star that the star's gravity completely disrupts the planet, leading to the destruction of many planets. Tidal destruction has left a discernible signature on the distribution of extra-solar planetary orbits, and so interpretations of the distribution in terms of the origins of planets must include consideration of the effects of tidal destruction.

Jackson, Brian Kendall

169

Signatures of extra dimensional sterile neutrinos  

NASA Astrophysics Data System (ADS)

We study a large extra dimension model with active and sterile Dirac neutrinos. The sterile neutrino masses stem from compactification of an extra dimension with radius R and are chosen to have masses around eV or keV, in order to explain short-baseline anomalies or act as warm dark matter candidates. We study the effect of the sterile neutrino Kaluza-Klein tower in short-baseline oscillation experiments and in the beta spectrum as measurable by KATRIN-like experiments.

Rodejohann, Werner; Zhang, He

2014-10-01

170

Error analysis of penetrator impacts on bodies without atmospheres  

NASA Technical Reports Server (NTRS)

Penetrators are missile shaped objects designed to implant electronic instrumentation in various of surface materials with a nominal impact speed around 150 m/sec. An interest in the application of this concept to in situ subsurface studies of extra terrestrial bodies and planetary satellites exists. Since many of these objects do not have atmospheres, the feasibility of successfully guiding penetrators to the required near-zero angle-of-attack impact conditions in the absence of an atmosphere was analyzed. Two potential targets were included, i.e., the moon and Mercury and several different penetrator deployment modes were involved. Impact errors arising from open-loop and closed-loop deployment control systems were given particular attention. Successful penetrator implacement requires: (1) that the impact speed be controlled, nominally to 150 m/sec, (2) that the angle of attack be in range 0 deg - 11 deg at impact, and (3) that the impact flight path angle be with 15 deg of vertical.

Davis, D. R.

1975-01-01

171

Exploring Warped Compactifications of Extra Dimensions  

NASA Astrophysics Data System (ADS)

In 1920s, the concept of extra dimensions was considered for the first time to unify gravity and electromagnetism. Since then there have been many developments to understand the unification of fundamental forces using extra dimensions. In this thesis, we study this idea of extra dimensions in higher dimensional gravity theories such as String Theory or Supergravity to make connections with cosmology. We construct a family of non-singular time-dependent solutions of a six-dimensional gravity with a warped geometry. The warp factor is time-dependent and breaks the translation invariance along one of the extra directions. Our solutions have the desired property of homogeneity and isotropy along the non-compact space. These geometries are supported by matter that does not violate the null energy condition. These 6D solutions do not have a closed trapped surface and hence the Hawking-Penrose singularity theorems do not apply to these solutions. These solutions are constructed from 7D locally flat solution by performing Kaluza-Klein reduction. We also study warped compactifications of string/M theory with the help of effective potentials for the construction of de Sitter vacua. The dynamics of the conformal factor of the internal metric is explored to investigate instabilities. The results works the best mainly in the case of a slowly varying warp factor. We also present interesting ideas to find AdS vacua of N=1 flux compactifications using smooth, compact toric manifolds as internal space.

Dabholkar, Sujan

172

Particle physics probes of extra spacetime dimensions  

Microsoft Academic Search

The possibility that spacetime extends beyond the familiar 3 + 1 dimensions has intrigued physicists for a century. The consequences of a dimensionally richer spacetime would be profound. Recently, new theories with higher-dimensional spacetimes have been developed to resolve the hierarchy problem in particle physics. The distinct predictions of these scenarios allow experiment to probe the existence of extra dimensions

Joanne Hewett; Maria Spiropulu

2002-01-01

173

Arsenic Speciation of Terrestrial Invertebrates  

SciTech Connect

The distribution and chemical form (speciation) of arsenic in terrestrial food chains determines both the amount of arsenic available to higher organisms, and the toxicity of this metalloid in affected ecosystems. Invertebrates are part of complex terrestrial food webs. This paper provides arsenic concentrations and arsenic speciation profiles for eight orders of terrestrial invertebrates collected at three historical gold mine sites and one background site in Nova Scotia, Canada. Total arsenic concentrations, determined by inductively coupled plasma mass spectrometry (ICP-MS), were dependent upon the classification of invertebrate. Arsenic species were determined by high-performance liquid chromatography (HPLC) ICP-MS and X-ray absorption spectroscopy (XAS). Invertebrates were found by HPLC ICP-MS to contain predominantly arsenite and arsenate in methanol/water extracts, while XAS revealed that most arsenic is bound to sulfur in vivo. Examination of the spatial distribution of arsenic within an ant tissue highlighted the differences between exogenous and endogenous arsenic, as well as the extent to which arsenic is transformed upon ingestion. Similar arsenic speciation patterns for invertebrate groups were observed across sites. Trace amounts of arsenobetaine and arsenocholine were identified in slugs, ants, and spiders.

Moriarty, M.M.; Koch, I.; Gordon, R.A.; Reimer, K.J. ((Simon)); ((Royal))

2009-07-01

174

Practicality of Using Oxygen Atom Emissions to Evaluate the Habitability of Extra-Solar Planets  

NASA Astrophysics Data System (ADS)

It has previously been proposed [Akasofu, 1999] that observation of the O(1S - 1D) green line from the atmospheres of extra-solar planets might be a marker for habitability. Guidance on this question is available within our own solar system. The green line is a dominant feature in the visible terrestrial nightglow, and the ultimate origin of its mesospheric emission is the three-body recombination of oxygen atoms. Until recently, it was believed that the green line was not a feature of the nightglows of the CO2 planets, Venus and Mars. It is now known that Venus at times shows green line emission with an intensity equal to terrestrial values [Slanger et al., 2001]. Furthermore, the intensity is quite variable, as is true for the much stronger O2( a-X) 1.27 ? emission. Recent observations of the Mars nightglow [Bertaux et al., 2005] give ambiguous results in the region of the O(1S-3P) line at 297.2 nm, but the same line in the dayglow is very strong, as evidenced in earlier Mariner results [Barth et al., 1971], and from the recent Mars Express data [F. Leblanc, private communication]. The O(1D-3P) 630 nm red line is a feature associated with Io, where dissociation of SO2 is a presumed source [Scherb et al., 1998]. Thus, observation of the oxygen green/red lines in the atmospheres of extrasolar planets provides insufficient information to reach conclusions about a habitable environment. Such detection would only indicate that there are oxygen-containing molecules present. Determination of an O2 column depth, by Fraunhofer A-band absorption, would be much more conclusive. Akasofu, S.-I., EOS, Transactions of the American Geophysical Union, 80, 397, 1999. Barth, C.A., C.W. Hord, J.B. Pearce, K.K. Kelly, G.P. Anderson, and A.I. Stewart, Mariner 6 and 7 Ultraviolet Spectrometer Experiment: Upper Atmosphere Data, Journal of Geophysical Research, 76, 2213-2227, 1971. Bertaux, J.-L., F. Leblanc, S. Perrier, E. Quemerais, O. Korablev, E. Dimarellis, A. Reberac, F. Forget, P.C. Simon, S.A. Stern, and B. Sandel, Nightglow in the Upper Atmosphere of Mars and Implications for Atmospheric Transport, Science, 307, 566-569, 2005. Scherb, F., R.J. Oliversen, F.L. Roesler, J. R. C. Woodward, J. Corliss, M. Fred, and W.H. Smyth, Recent Ground-Based Observations of OI 6300 Emission from Io., EOS, Transactions of the American Geophysical Union, 79(17), S201, 1998. Slanger, T.G., P.C. Cosby, D.L. Huestis, and T.A. Bida, Discovery of the Atomic Oxygen Green Line in the Venus Night Airglow, Science, 291, 463-465, 2001.

Slanger, T. G.

2005-12-01

175

The distal forelimb musculature in aquatic and terrestrial turtles: phylogeny or environmental constraints?  

PubMed Central

We compared the muscular anatomy of the distal front limb in terrestrial and aquatic chelonians to test whether observed differences between the two groups are associated with their divergent lifestyles and locomotor modes. Given the different use of the forelimb in the two environments (body support and propulsion on land vs. mainly propulsion in water) we expected that: (1) aquatic and terrestrial turtles would show differences in their muscular anatomy, with aquatic species having more individualized muscle bundles to allow for the complex forearm movements observed during swimming, and (2) that terrestrial turtles would have more robust muscles to support their body weight against gravity. To address these questions, we examined the forelimb myology and associated tissues in six aquatic or semi-aquatic turtles (Phyrnops hilarii, Podocnemis unifilis, Trachemys scripta, Sacalia bealei, Cuora amboinensis and Mauremys caspica) and six terrestrial or semi-terrestrial turtles (Geochelone chilensis, Testudo graeca, Cuora galbinifrons, Glyptemys insculpta, Terrapene carolina and Rhinoclemmys pulcherrima). This paper describes the general structure of the forelimb musculature in all species, and quantifies muscle masses in those species with more than five specimens available (Ph. hilarii, Po. unifilis and Ge. chilensis). The general structure of the forelimb muscles in the strictly terrestrial species Ge. chilensis and Tes. graeca was found to be notably different from the pattern of the aquatic and semi-aquatic species examined, showing a distinct fusion of the different muscular bodies. Ter. carolina also show a distinctly terrestrial pattern, but a less extensive tendon development. R. pulcherrima and Gl. insculpta were found to be morphologically intermediate; in the geoemydids the strictly terrestrial bauplan never appears. Quantitative differences in the robustness or mass of the distal forelimb muscles were also observed for the species investigated, supporting our prediction that the extensor muscles are more robust in terrestrial turtles. However, in contrast to our expectations, not only the extensor muscles of the distal forelimb (which are crucial in providing both body support and propulsion), but all muscles acting around the wrist were found to be heavier in terrestrial turtles. PMID:19172731

Abdala, Virginia; Manzano, Adriana S; Herrel, Anthony

2008-01-01

176

The universal extra dimensional model with S 2 \\/ Z 2 extra-space  

Microsoft Academic Search

We propose a new universal extra dimensional model that is defined on a six-dimensional spacetime which has a two-sphere orbifold S2\\/Z2 as an extra-space. We specify our model by choosing the gauge symmetry as SU(3)SU(2)U(1)YU(1)X, introducing field contents in six dimensions as their zero modes correspond to the standard model particles, and determining a boundary condition of these fields on

Nobuhito Maru; Takaaki Nomura; Joe Sato; Masato Yamanaka

2010-01-01

177

Topological Interactions in Warped Extra Dimensions  

E-print Network

Topological interactions will be generated in theories with compact extra dimensions where fermionic chiral zero modes have different localizations. This is the case in many warped extra dimension models where the right-handed top quark is typically localized away from the left-handed one. Using deconstruction techniques, we study the topological interactions in these models. These interactions appear as trilinear and quadrilinear gauge boson couplings in low energy effective theories with three or more sites, as well as in the continuum limit. We derive the form of these interactions for various cases, including examples of Abelian, non-Abelian and product gauge groups of phenomenological interest. The topological interactions provide a window into the more fundamental aspects of these theories and could result in unique signatures at the Large Hadron Collider, some of which we explore. We also show that it is generally not possible to have stable KK-mode dark matter candidates in these scenarios owing to th...

Bai, Yang; Hill, Christopher T

2009-01-01

178

Resonances from Two Universal Extra Dimensions  

E-print Network

Standard model gauge bosons propagating in two universal extra dimensions give rise to heavy spin-1 and spin-0 particles. The lightest of these, carrying Kaluza-Klein numbers (1,0), may be produced only in pairs at colliders, whereas the (1,1) modes, which are heavier by a factor of \\sqrt{2}, may be singly produced. We show that the cascade decays of (1,1) particles generate a series of closely-spaced narrow resonances in the t\\bar{t} invariant mass distribution. At the Tevatron, s-channel production of (1,1) gluons and electroweak bosons will be sensitive to t\\bar{t} resonances up to masses in the 0.5 - 0.7 TeV range. Searches at the LHC for resonances originating from several higher-level modes will further test the existence of two universal extra dimensions.

Burdman, G; Ponton, E; Burdman, Gustavo; Dobrescu, Bogdan A.; Ponton, Eduardo

2006-01-01

179

Kinks, extra dimensions, and gravitational waves  

SciTech Connect

We investigate in detail the gravitational wave signal from kinks on cosmic (super)strings, including the kinematical effects from the internal extra dimensions. We find that the signal is suppressed, however, the effect is less significant that that for cusps. Combined with the greater incidence of kinks on (super)strings, it is likely that the kink signal offers the better chance for detection of cosmic (super)strings.

O'Callaghan, Eimear; Gregory, Ruth, E-mail: r.a.w.gregory@durham.ac.uk [Institute for Particle Physics Phenomenology and Centre for Particle Theory, Durham University, South Road, Durham, DH1 3LE (United Kingdom)

2011-03-01

180

Cystic lesions accompanying extra-axial tumours.  

PubMed

We examined the mechanism of cyst formation in extra-axial tumours in the central nervous system (CNS). Cyst fluid, cerebrospinal fluid (CSF) and blood plasma were analysed in eight patients with nine peritumoral cysts: four with meningiomas, two with intracranial and two spinal intradural schwannomas. Measuring concentrations of various proteins [albumin, immunoglobulin G (IgG), IgA, alpha 2-macroglobulin and IgM] in cyst fluid, CSF and blood plasma provides insight into the state of the semipermeability of the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier. Peritumoral cysts accompanying intra-axial brain tumours are the end result of disruption of the BBB and oedema formation. Unlike intra-axial tumours which lie embedded within nervous tissue, extra-axial tumours tend to be separated from nervous tissue by arachnoid and pia mater. High concentrations of proteins were measured in the cyst fluid, approaching blood plasma levels, suggesting a local barrier disruption, and passage across the arachnoid, pia mater and cortical/medullary layer into the CNS parenchyma, leaving the protein concentrations of CSF practically unchanged. We confirmed that very high concentrations of protein are to be found in tumour cysts, plasma proteins forming almost 90% of the total protein in the cyst. We review current hypotheses on the pathogenesis of cysts accompanying neoplasms, particularly meningiomas and schwannomas, and conclude that the majority of proteins in cyst fluid in extra-axial, intradural meningiomas and schwannomas are plasma proteins. This provides a strong argument for pathogenesis of extra-axial intradural tumour cysts in favour of leakage of plasma proteins out of the tumour vessels into the nervous tissue. PMID:9987761

Lohle, P N; Wurzer, H A; Seelen, P J; Kingma, L M; Go, K G

1999-01-01

181

MODIS-Derived Terrestrial Primary Production  

Microsoft Academic Search

\\u000a Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems\\u000a not only create environments suitable for human habitation, but also provide materials essential for survival, such as food,\\u000a fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of all the acronyms\\u000a is available in the

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

182

Irreversible evolution of the terrestrial planets (geological and petrological data)  

NASA Astrophysics Data System (ADS)

Abstract Comparative studying of tectonomagmatic evolution of the Earth and the Moon shows that cardinal irreversible change in character of tectonomagmatic processes occurred at middle stages of their evolution; very likely such changes took place on other terrestrial planets (Venus, Mars and Mercury). As a result, primordial crusts of the planets were in considerable degree replaced by secondary basaltic ones. The established succession of events on the Earth could be provided by a combination of two independent factors: (1) it was originally heterogeneous and 2) its downward heating was followed by the cooling of its outer shells. As a result the primary iron core material was long time remained untouched and was involved into global tectonomagmatic processes at ca. 2.4-2.3 Ga. We concluded about a similar scenario for the evolution of Moon and other terrestrial planets. Tectonomagmatic evolution of the terrestrial planets (Earth, Venus, Mars, Mercury and Moon) was studied. What did major stages of their irreversible evolution occur before they turned into "dead" stone balls? We discuss these problems on examples of the Earth and the Moon, which evolution studied the best. According to modern views, after accretion of these bodies, magma oceans of some hundreds km deep appeared on their surface. According to Jeffries [1], solidification of large molted bodies, because of the difference between adiabatic gradient in silicate melts (0.3oC/km) and gradient of their melting points (3oC/km), could be going only upwards, from the bottom to the surface. As a result a powerful crystallizing differentiation of the oceans' magmas occurred with accumulation of the most low-melting components to the surface. Due to different deep of the magma oceans on the Earth and the Moon, the primordial crusts on these bodies were rather different: sialic on the Earth and basic (anorthosite) on the Moon.

Sharkov, E.; Bogatikov, O.

2008-09-01

183

23 CFR 635.120 - Changes and extra work.  

Code of Federal Regulations, 2010 CFR

...and non-major extra work, formal approval is...should establish and document with the Division Administrator's...and non-major extra work. (c) Changes in...perform and adequately document a cost analysis of each...change or negotiated extra work order. The method...

2010-04-01

184

23 CFR 635.120 - Changes and extra work.  

Code of Federal Regulations, 2011 CFR

...and non-major extra work, formal approval is...should establish and document with the Division Administrator's...and non-major extra work. (c) Changes in...perform and adequately document a cost analysis of each...change or negotiated extra work order. The method...

2011-04-01

185

Standard Model scales from warped extra dimensions  

E-print Network

If in the Randall and Sundrum RS1 model the inverse of the compactification radius, the AdS curvature scale, and the five and four-dimensional Planck scales are equal in size, as is natural, then the warp factor at the location of the low energy brane is of value 1/pi. So that all scales derive from locations in the space, we identify the extra dimension with the infinite covering space of the S1/Z2 orbifold. The extra dimension is then essentially a series of connected line intervals, punctuated by branes. Scales on successive branes in the extra dimension descend from Planck scale in a geometric sequence of common ratio 1/pi. Evidence is provided for such a sequence within the spectrum of particle masses, and of a second geometric sequence, of common ratio 2/pi, which suggests that the AdS spacetime is six-dimensional and doubly warped. The scales of the Standard Model lie at coincident levels within the two sequences. A third sequence, of common ratio 1/e, provides a symmetrical framework for the Standard Model and points to a warped product spacetime.

Bernard Riley

2008-08-31

186

Extra Large Temporal Tunnel Cataract Extraction [ETCE  

PubMed Central

Purpose: To determine the outcomes of extra large temporal sclero-corneal tunnel incision Cataract Surgery. Materials and Methods: This consecutive case series of eyes undergoing temporal tunnel cataract extraction with tunnel length of 8 to 10 mm was identified retrospectively. Surgical procedure details, follow up, complications, visual and astigmatic outcomes at 6wks were recorded and analysed. Results: Ninety six eyes with extra large tunnel incision were identified for analysis from a dataset of 670 manual small incision cataract surgery cases. 58% eyes had NO5 or denser cataracts. Intraoperative complications included, tunnel related problems (1 eye, 1.04%), bleeding into Anterior Chamber (10 eyes, 10.4%), Posterior Capsular Rent (2 eyes, 2.1%). Early postoperative complications included striate keratopathy (7 eyes, 7.3%). The mean Best Corrected Visual Acuity was 6/7.5 (0.1 logMAR) and 98% cases had Best Corrected Visual Acuity of 6/12 (0.3 logMAR) or better at 6wk. The aggregate Surgically Induced Astigmatism was 0.32D at 850. Conclusion: Extra Large Tunnel of length 8 to 10 mm can be self sealing with low SIA. The complication rates and visual outcomes of ETCE are comparable to those of conventional MSICS. This method can be valuable in complicated cases and during learning period. PMID:25386505

U., Vivekanand

2014-01-01

187

About Tagish Lake as a Potential Parent Body for Polar Micrometeorites; Clues from their Hydrogen Isotopic Compositions  

NASA Technical Reports Server (NTRS)

The origin of the Antarctic micrometeorites (AMMs) is still a matter of debate. Their closest meteoritic counterparts are the C2 chondrites, but the match is not perfect, and the parent body(ies) of the AMMs is(are) still to be identified. Tagish Lake is a new meteorite fall which bears similarity with CI1 and CM2 chondrites, but is distinct from both. Based on the mineralogy of phyllosilicates, Noguchi et al. proposed that the phyllosilicate-rich AMMs and the Tagish Lake meteorites could derive from similar asteroids. The hydrogen isotopic compositions of extra-terrestrial samples can be used to get some insight on their origin. The D/H ratios of AMMs and of Tagish Lake have been measured, but using different analytical techniques. They are therefore not directly comparable. We performed additional hydrogen isotopic analyses of fragments of Tagish Lake using the same experimental setup previously used for the measurement of the hydrogen isotopic composition of AMMs. In this work, we could also analyze separately both lithologies of Tagish Lake (carbonate-poor and -rich). The distributions of delta D values measured in the two lithologies of Tagish Lake are very similar, indicating that fluids with similar hydrogen isotopic compositions altered the meteorite on the parent body for the two lithologies. Yet, the hydrogen isotopic composition of Tagish Lake is different from that of AMMs, suggesting that they do not derive from the same parent body.

Engrand, C.; Gounelle, M.; Zolensky, M. E.; Duprat, J.

2003-01-01

188

Toxic effects of acid rain on aquatic and terrestrial ecosystems.  

PubMed

The historical perspective as well as the nature and causes of acid precipitation are presented. The toxicological effects of acid precipitation on lakes, other water bodies, fish, and invertebrate fauna are reviewed. In addition, the effects of this phenomenon on soil productivity and forest growth are examined. It appears that grave toxic effects have been and are being experienced by aquatic systems, but there is little reliable evidence of economic damage to crops, natural vegetation, and soil and biological processes. There may be insidious long-term effects on terrestrial ecosystems, particularly in the more susceptible areas. PMID:6488090

Rutherford, G K

1984-08-01

189

Simple Non-Coriolis Treatments for Explaining Terrestrial East-West Deflections  

ERIC Educational Resources Information Center

Presents two simple methods of calculating the respective terrestrial westward and eastward displacements of a vertically projected and a perpendicularly dropped body which give due emphasis to physical principles, including Kepler's law, conservation of angular momentum, and nonrotating coordinate system with origin at the earth's center. (CC)

Wild, John F.

1973-01-01

190

Internal Representation and Memory Formation of Odor Preference Based on Oscillatory Activities in a Terrestrial Slug  

ERIC Educational Resources Information Center

The terrestrial slug "Limax" exhibits a highly developed ability to learn odors with a small nervous system. When a fluorescent dye, Lucifer Yellow (LY), is injected into the slug's body cavity after odor-taste associative conditioning, a group of neurons in the procerebral (PC) lobe, an olfactory center of the slug, is labeled by LY. We examined

Sekiguchi, Tatsuhiko; Furudate, Hiroyuki; Kimura, Tetsuya

2010-01-01

191

Comparison of Titan's north polar lakes with terrestrial analogs Priyanka Sharma1  

E-print Network

in our previous study. Using the Shuttle Radar Topography Mission (SRTM) C-band backscatter data and the SRTM Water Body Data (SWBD), we carried out an assessment of manual mapping versus existing automated features of the shoreline. We performed a similar fractal analysis on terrestrial lake shorelines

Byrne, Shane

192

Dietary characterization of terrestrial mammals  

PubMed Central

Understanding the feeding behaviour of the species that make up any ecosystem is essential for designing further research. Mammals have been studied intensively, but the criteria used for classifying their diets are far from being standardized. We built a database summarizing the dietary preferences of terrestrial mammals using published data regarding their stomach contents. We performed multivariate analyses in order to set up a standardized classification scheme.Ideally, food consumption percentages should be used instead of qualitative classifications. However, when highly detailed information is not available we propose classifying animals based on their main feeding resources. They should be classified as generalists when none of the feeding resources constitute over 50% of the diet. The term omnivore should be avoided because it does not communicate all the complexity inherent to food choice. Moreover, the so-called omnivore diets actually involve several distinctive adaptations. Our dataset shows that terrestrial mammals are generally highly specialized and that some degree of food mixing may even be required for most species. PMID:25009067

Pineda-Munoz, Silvia; Alroy, John

2014-01-01

193

Lunar and Terrestrial Planet Formation in the Grand Tack Scenario  

E-print Network

We present conclusions from a large number of N-body simulations of the giant impact phase of terrestrial planet formation. We focus on new results obtained from the recently proposed Grand Tack model, which couples the gas-driven migration of giant planets to the accretion of the terrestrial planets. The giant impact phase follows the oligarchic growth phase, which builds a bi-modal mass distribution within the disc of embryos and planetesimals. By varying the ratio of the total mass in the embryo population to the total mass in the planetesimal population and the mass of the individual embryos, we explore how different disc conditions control the final planets. The total mass ratio of embryos to planetesimals controls the timing of the last giant (Moon forming) impact and its violence. The initial embryo mass sets the size of the lunar impactor and the growth rate of Mars. After comparing our simulated outcomes with the actual orbits of the terrestrial planets (angular momentum deficit, mass concentration) ...

Jacobson, Seth A

2014-01-01

194

Accumulation of the terrestrial planets and implications concerning lunar origin  

NASA Technical Reports Server (NTRS)

In order to provide a context for understanding lunar formation, 28 new three-dimensional simulations of terrestrial planet formation from a gas-free planetesimal swarm have been carried out. The natural orbital and collisional evolution of 500 initial planetesimals ranging in mass from 5.7 x 10 to the 24th g to 1.1 x 10 to the 26th g is followed until only final planets in noncrossing orbits remain. The results are in general agreement with the number, size, and orbits of the observed terrestrial planets, but also show considerable variation of stochastic origin. These results are combined with 11 simulations using 500 bodies of equal initial mass presented earlier, as well as with some other numerical studies, to conclude that for a wide range of initial conditions, terrestrial planet accumulation was characterized by giant impacts, ranging in mass up to 3 times the mass of Mars, at typical impact velocities of about 9 km/sec. These large planetesimals and the impacts they produce are sufficient to explain the unexpectedly large angular momentum of the earth-moon system.

Wetherill, G. W.

1986-01-01

195

Effects of pentachlorophenol on survival of earthworms (Lumbricus terrestris) and phagocytosis by their immunoactive coelomocytes  

Microsoft Academic Search

Earthworms, Lumbricus terrestris, exposed for 96 h to filter paper saturated with five nominal concentrations of pentachlorophenol, exhibited a 50% lethal concentration (LC50) of 25.0 μg PCP\\/cm² and corresponding whole worm body burden-based 50% lethal dose (LD50) of 877.7 μg PCP\\/g dry mass. Linear regression modeling showed that worms increased body concentrations (BC = μg PCP\\/g dry tissue mass) with

Marina A. Giggleman; Lloyd C. Fitzpatrick; Arthur J. Goven; Barney J. Venables

1998-01-01

196

Body Hair  

MedlinePLUS

Home Body Puberty Body hair Body hair Even before you get your first period , you will likely see new hair growing in your pubic area , under your arms, and ... removing pubic hair Ways to get rid of hair top Removing body hair can cause skin irritation, ...

197

Robust frameless stereotactic localization in extra-cranial radiotherapy  

SciTech Connect

In the field of extra-cranial radiotherapy, several inaccuracies can make the application of frameless stereotactic localization techniques error-prone. When optical tracking systems based on surface fiducials are used, inter- and intra-fractional uncertainties in marker three-dimensional (3D) detection may lead to inexact tumor position estimation, resulting in erroneous patient setup. This is due to the fact that external fiducials misdetection results in deformation effects that are poorly handled in a rigid-body approach. In this work, the performance of two frameless stereotactic localization algorithms for 3D tumor position reconstruction in extra-cranial radiotherapy has been specifically tested. Two strategies, unweighted versus weighted, for stereotactic tumor localization were examined by exploiting data coming from 46 patients treated for extra-cranial lesions. Measured isocenter displacements and rotations were combined to define isocentric procedures, featuring 6 degrees of freedom, for correcting patient alignment (isocentric positioning correction). The sensitivity of the algorithms to uncertainties in the 3D localization of fiducials was investigated by means of 184 numerical simulations. The performance of the implemented isocentric positioning correction was compared to conventional point-based registration. The isocentric positioning correction algorithm was tested on a clinical dataset of inter-fractional and intra-fractional setup errors, which was collected by means of an optical tracker on the same group of patients. The weighted strategy exhibited a lower sensitivity to fiducial localization errors in simulated misalignments than those of the unweighted strategy. Isocenter 3D displacements provided by the weighted strategy were consistently smaller than those featured by the unweighted strategy. The peak decrease in median and quartile values of isocenter 3D displacements were 1.4 and 2.7 mm, respectively. Concerning clinical data, the weighted strategy isocentric positioning correction provided the reduction of fiducial registration errors, featuring up to 61.7% decrease in median values (versus 46.8% for the unweighted strategy) of initial displacements. The weighted strategy proved high performance in minimizing the effects of fiducial localization errors, showing a great potential in improving patient setup. The clinical data analysis revealed that the application of a robust reconstruction algorithm may provide high-quality results in patient setup verification, by properly managing external fiducials localization errors.

Riboldi, Marco; Baroni, Guido; Spadea, Maria Francesca; Bassanini, Fabio; Tagaste, Barbara; Garibaldi, Cristina; Orecchia, Roberto; Pedotti, Antonio [TBMLab, Department of Bioengineering, Politecnico di Milano University, P.za Leonardo da Vinci 32, Milan 20133 (Italy); Medical Physics, European Institute of Oncology, Via Ripamonti 435, Milan 20141 (Italy); Radiotherapy Division, European Institute of Oncology, Via Ripamonti 435, Milan 20141 (Italy) and Instituto di Scienze Radiologiche, Polo Universitario H S. Paolo, Via Rudini 8, Milan 20142 (Italy); TBMLab, Department of Bioengineering, Politecnico di Milano University, P.za Leonardo da Vinci 32, Milan 20133 (Italy)

2006-04-15

198

Confirmation and Distribution of Tetrodotoxin for the First Time in Terrestrial Invertebrates: Two Terrestrial Flatworm Species (Bipalium adventitium and Bipalium kewense)  

PubMed Central

The potent neurotoxin tetrodotoxin (TTX) is known from a diverse array of taxa, but is unknown in terrestrial invertebrates. Tetrodotoxin is a low molecular weight compound that acts by blocking voltage-gated sodium channels, inducing paralysis. However, the origins and ecological functions of TTX in most taxa remain mysterious. Here, we show that TTX is present in two species of terrestrial flatworm (Bipalium adventitium and Bipalium kewense) using a competitive inhibition enzymatic immunoassay to quantify the toxin and high phase liquid chromatography to confirm the presence. We also investigated the distribution of TTX throughout the bodies of the flatworms and provide evidence suggesting that TTX is used during predation to subdue large prey items. We also show that the egg capsules of B. adventitium have TTX, indicating a further role in defense. These data suggest a potential route for TTX bioaccumulation in terrestrial systems. PMID:24963791

Stokes, Amber N.; Ducey, Peter K.; Neuman-Lee, Lorin; Hanifin, Charles T.; French, Susannah S.; Pfrender, Michael E.; Brodie, Edmund D.; Brodie Jr, Edmund D.

2014-01-01

199

Confirmation and distribution of tetrodotoxin for the first time in terrestrial invertebrates: two terrestrial flatworm species (Bipalium adventitium and Bipalium kewense).  

PubMed

The potent neurotoxin tetrodotoxin (TTX) is known from a diverse array of taxa, but is unknown in terrestrial invertebrates. Tetrodotoxin is a low molecular weight compound that acts by blocking voltage-gated sodium channels, inducing paralysis. However, the origins and ecological functions of TTX in most taxa remain mysterious. Here, we show that TTX is present in two species of terrestrial flatworm (Bipalium adventitium and Bipalium kewense) using a competitive inhibition enzymatic immunoassay to quantify the toxin and high phase liquid chromatography to confirm the presence. We also investigated the distribution of TTX throughout the bodies of the flatworms and provide evidence suggesting that TTX is used during predation to subdue large prey items. We also show that the egg capsules of B. adventitium have TTX, indicating a further role in defense. These data suggest a potential route for TTX bioaccumulation in terrestrial systems. PMID:24963791

Stokes, Amber N; Ducey, Peter K; Neuman-Lee, Lorin; Hanifin, Charles T; French, Susannah S; Pfrender, Michael E; Brodie, Edmund D; Brodie, Edmund D

2014-01-01

200

Aerospace Power Technology for Potential Terrestrial Applications  

NASA Technical Reports Server (NTRS)

Aerospace technology that is being developed for space and aeronautical applications has great potential for providing technical advances for terrestrial power systems. Some recent accomplishments arising from activities being pursued at the National Aeronautics and Space Administration (NASA) Centers is described in this paper. Possible terrestrial applications of the new aerospace technology are also discussed.

Lyons, Valerie J.

2012-01-01

201

Love numbers of the terrestrial planets  

Microsoft Academic Search

The latest geodetic parameters of the terrestrial planets are used to construct parametric models of the internal structure of the terrestrial planets. These models are then used to compute the static Love numbers from order 2 to 30. The influence of the outer core rigidity on the second-order Love numbers is discussed. The obtained results indicate that the probable ranges

Cheng-Zhi Zhang

1991-01-01

202

Love numbers of the terrestrial planets  

Microsoft Academic Search

Using the latest geodetic parameters of the terrestrial planets, the author constructed the parametric models of the internal structure of the terrestrial planets. By means of these models he computed their static Love numbers from order 2 to 30 and listed the results. Then he discussed the influence of the outer core rigidity on the second-order Love numbers.

Zhangzhi Cheng

1991-01-01

203

Does terrestrial epidemiology apply to marine systems?  

Microsoft Academic Search

Most of epidemiological theory has been developed for terrestrial systems, but the significance of disease in the ocean is now being recognized. However, the extent to which terrestrial epidemiology can be directly trans- ferred to marine systems is uncertain. Many broad types of disease-causing organism occur both on land and in the sea, and it is clear that some emergent

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

2004-01-01

204

Terrestrial Mammals of the Riparian Corridor  

E-print Network

Terrestrial Mammals of the Riparian Corridor in Big Bend National Park1 William J. Boeer and David J. Schmidly2 Abstract.--Thirty species of terrestrial mammals inhabit riparian habitats in Big and Peromyscus leucopus). Compared to the other major plant communities in BBNP, the rodent fauna of the riparian

205

Terrestrial Ages of Antarctic Meteorites- Update 1999  

NASA Technical Reports Server (NTRS)

We are continuing our ongoing study of cosmogenic nuclides in Antarctic meteorites. In addition to the studies of exposure histories of meteorites, we study terrestrial ages and pairing of Antarctic meteorites and desert meteorites. Terrestrial ages of Antarctic meteorites provide information on meteorite accumulation mechanisms, mean weathering lifetimes, and influx rates. The determination of Cl-36(half-life=3.01 x 10(exp 5) y) terrestrial ages is one of our long-term on-going projects, however, in many instances neither Cl-36 or C-14 (5,730 y) yields an accurate terrestrial age. Using Ca-14 (1.04 x 10(exp 5) y) for terrestrial age determinations solves this problem by filling the c,ap in half-life between 14-C and Cl-36 ages. We are now applying the new Ca-41- Cl-36 terrestrial age method as well as the Cl-36-Be-10 method to Antarctic meteorites. Our measurements and C-14 terrestrial age determinations by the University of Arizona group are always complementary. We have measured Cl-36 in over 270 Antarctic meteorites since our previous compilation of terrestrial ages. Since a large number of meteorites have been recovered from many different icefields in Antarctica, we continue to survey the trends of terrestrial ages for different icefields. We have also measured detailed terrestrial ages vs. sample locations for Allan Hills, Elephant Moraine, and Lewis Cliff Icefields, where meteorites have been found with very long ages. The updated histograms of terrestrial ages of meteorites from the Allan Hills Main Icefield and Lewis Cliff Icefield are shown. These figures include C-14 ages obtained by the University of Arizona group. Pairs of meteorites are shown as one object for which the age is the average of all members of the same fall. The width of the bars represents 70,000 years, which was a typical uncertainty for Cl-36 ages. We reduced the uncertainty of terrestrial age determinations to approx. 40,000 years by using pairs of nuclides such as Ca-41-Cl-36 or Cl-36-Be-10. Meteorites found at the Allan Hills Icefields are much older than any other meteorites. The terrestrial ages cover a wide range and are as old as 2 My. Many of the Lewis Cliff meteorites are as old as the Allan Hills meteorites. So far, no clear correlation has been found between the terrestrial ages and the locations of the Lewis Cliff meteorites.

Nishiizumi, Kunihiko; Welten, K. C.; Caffee, Marc W.

1999-01-01

206

Energetic Strategies of Terrestrial Vertebrates  

NSDL National Science Digital Library

This laboratory exercise investigates the difference in metabolic response of representative endotherms (mice) and ectotherms (green anoles) to temperature changes and ecological consequences are studied through behavior and preferred body temperature in a temperature gradient.

Kathy Winnett-Murray (Hope College;); K. Greg Murray (Hope College;); Lori Hertel (Hope College;); Christopher C. Barney (Hope College;)

2000-01-01

207

Insignificant solar-terrestrial triggering of earthquakes  

USGS Publications Warehouse

We examine the claim that solar-terrestrial interaction, as measured by sunspots, solar wind velocity, and geomagnetic activity, might play a role in triggering earthquakes. We count the number of earthquakes having magnitudes that exceed chosen thresholds in calendar years, months, and days, and we order these counts by the corresponding rank of annual, monthly, and daily averages of the solar-terrestrial variables. We measure the statistical significance of the difference between the earthquake-number distributions below and above the median of the solar-terrestrial averages by ?2 and Student's t tests. Across a range of earthquake magnitude thresholds, we find no consistent and statistically significant distributional differences. We also introduce time lags between the solar-terrestrial variables and the number of earthquakes, but again no statistically significant distributional difference is found. We cannot reject the null hypothesis of no solar-terrestrial triggering of earthquakes.

Love, Jeffrey J.; Thomas, Jeremy N.

2013-01-01

208

Methane production in terrestrial arthropods  

SciTech Connect

The authors have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. The authors show that arthropod symbionts can contribute substantially to atmospheric methane.

Hackstein, J.H.P.; Stumm, C.K. (Catholic Univ. of Nijmegen (Netherlands))

1994-06-07

209

Methane production in terrestrial arthropods.  

PubMed Central

We have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. We show that arthropod symbionts can contribute substantially to atmospheric methane. Images PMID:8202505

Hackstein, J H; Stumm, C K

1994-01-01

210

Terrestrial gamma-ray flashes  

NASA Astrophysics Data System (ADS)

Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models.

Marisaldi, Martino; Fuschino, Fabio; Labanti, Claudio; Tavani, Marco; Argan, Andrea; Del Monte, Ettore; Longo, Francesco; Barbiellini, Guido; Giuliani, Andrea; Trois, Alessio; Bulgarelli, Andrea; Gianotti, Fulvio; Trifoglio, Massimo

2013-08-01

211

Phytopharmacological overview of Tribulus terrestris  

PubMed Central

Tribulus terrestris (family Zygophyllaceae), commonly known as Gokshur or Gokharu or puncture vine, has been used for a long time in both the Indian and Chinese systems of medicine for treatment of various kinds of diseases. Its various parts contain a variety of chemical constituents which are medicinally important, such as flavonoids, flavonol glycosides, steroidal saponins, and alkaloids. It has diuretic, aphrodisiac, antiurolithic, immunomodulatory, antidiabetic, absorption enhancing, hypolipidemic, cardiotonic, central nervous system, hepatoprotective, anti-inflammatory, analgesic, antispasmodic, anticancer, antibacterial, anthelmintic, larvicidal, and anticariogenic activities. For the last few decades or so, extensive research work has been done to prove its biological activities and the pharmacology of its extracts. The aim of this review is to create a database for further investigations of the discovered phytochemical and pharmacological properties of this plant to promote research. This will help in confirmation of its traditional use along with its value-added utility, eventually leading to higher revenues from the plant. PMID:24600195

Chhatre, Saurabh; Nesari, Tanuja; Somani, Gauresh; Kanchan, Divya; Sathaye, Sadhana

2014-01-01

212

Steroidal glycosides from Tribulus terrestris  

Microsoft Academic Search

In addition to hecogenin 3-O-?-d-glucopyranosyl(1 ? 4)-?-d-galactopyranoside, two new steroidal saponins were isolated from the aerial parts of Tribulus terrestris L. On the basis of chemical and spectroscopic evidence, especially 2D NMR spectroscopic techniques, the structures of the new saponins were established as 26-O-?-d-glucopyranosyl-3-O-[{?-d-xylopyranosyl(1 ? 3)}{?-d-galactopyranosyl(1 ? 2)}-?-d-glucopyranosyl (1 ? 4)-?-d-glucopyranosyl]-5?-furost-20(22)-en-12-one-3?,26-diol and 26-O-?-d-glucopyranosyl-3-O-[rm[{?-d-xylopyranosyl(1 ? 3){?-d-galactopyranosyl(1 ? 2)}-?-d-glucopyranosyl (1 ? 4)-?-d-glucopyranosyl]-5?-furostan-12-one-3?,22,26-triol.

Gong Wu; Shanhao Jiang; Fuxiang Jiang; Dayuan Zhu; Houming Wu; Shaokai Jiang

1996-01-01

213

Extra-Credit Problems in Space Science  

NSDL National Science Digital Library

These activities comprise a series of 20 practical math applications in space science. Students looking for additional challenges in math and physical science can use these as extra credit. The problems are authentic glimpses of modern engineering issues that arise in designing satellites to work in space. Each word problem has background information providing insight into the basic phenomena of the sun-Earth system, specifically space weather. The one-page assignments are accompanied by one-page teachers guides with answer keys.

2007-01-01

214

Large Extra Dimension and Dark Matter Detection  

SciTech Connect

If our space has the large extra dimensions as proposed by Arkani-Hamed, Dimopoulos and Dvali (ADD), then gravity would start to deviate from Newtonian gravity and be greatly enhanced in sub-millimeter scales. Here we show that in the ADD scenario, gravity could play an important role (compared to the weak interaction) in the interactions between dark matter particles and the electron. We find that for typical WIMP dark matter, such dark matter-electron 'gravitational' scattering cross section may be much larger than the dark matter-nucleon cross section constrained by current dark matter experiments.

Qin Bo [National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012 (China); Starkman, Glenn D. [Department of Physics, Case Western Reserve University, Cleveland, OH 44106-7079 (United States); Silk, Joseph [Astrophysics Department, University of Oxford, Oxford OX1 3RH (United Kingdom)

2008-01-03

215

A Spherical Aerial Terrestrial Robot  

NASA Astrophysics Data System (ADS)

This thesis focuses on the design of a novel, ultra-lightweight spherical aerial terrestrial robot (ATR). The ATR has the ability to fly through the air or roll on the ground, for applications that include search and rescue, mapping, surveillance, environmental sensing, and entertainment. The design centers around a micro-quadcopter encased in a lightweight spherical exoskeleton that can rotate about the quadcopter. The spherical exoskeleton offers agile ground locomotion while maintaining characteristics of a basic aerial robot in flying mode. A model of the system dynamics for both modes of locomotion is presented and utilized in simulations to generate potential trajectories for aerial and terrestrial locomotion. Details of the quadcopter and exoskeleton design and fabrication are discussed, including the robot's turning characteristic over ground and the spring-steel exoskeleton with carbon fiber axle. The capabilities of the ATR are experimentally tested and are in good agreement with model-simulated performance. An energy analysis is presented to validate the overall efficiency of the robot in both modes of locomotion. Experimentally-supported estimates show that the ATR can roll along the ground for over 12 minutes and cover the distance of 1.7 km, or it can fly for 4.82 minutes and travel 469 m, on a single 350 mAh battery. Compared to a traditional flying-only robot, the ATR traveling over the same distance in rolling mode is 2.63-times more efficient, and in flying mode the system is only 39 percent less efficient. Experimental results also demonstrate the ATR's transition from rolling to flying mode.

Dudley, Christopher J.

216

Scaling of the hydrostatic skeleton in the earthworm Lumbricus terrestris.  

PubMed

The structural and functional consequences of changes in size or scale have been well studied in animals with rigid skeletons, but relatively little is known about scale effects in animals with hydrostatic skeletons. We used glycol methacrylate histology and microscopy to examine the scaling of mechanically important morphological features of the earthworm Lumbricus terrestris over an ontogenetic size range from 0.03 to 12.89 g. We found that L. terrestris becomes disproportionately longer and thinner as it grows. This increase in the length to diameter ratio with size means that, when normalized for mass, adult worms gain ~117% mechanical advantage during radial expansion, compared with hatchling worms. We also found that the cross-sectional area of the longitudinal musculature scales as body mass to the ~0.6 power across segments, which is significantly lower than the 0.66 power predicted by isometry. The cross-sectional area of the circular musculature, however, scales as body mass to the ~0.8 power across segments, which is significantly higher than predicted by isometry. By modeling the interaction of muscle cross-sectional area and mechanical advantage, we calculate that the force output generated during both circular and longitudinal muscle contraction scales near isometry. We hypothesize that the allometric scaling of earthworms may reflect changes in soil properties and burrowing mechanics with size. PMID:24871920

Kurth, Jessica A; Kier, William M

2014-06-01

217

Background exposure rates of terrestrial wildlife in England and Wales.  

PubMed

It has been suggested that, when assessing radiation impacts on non-human biota, estimated dose rates due to anthropogenically released radionuclides should be put in context by comparison to dose rates from natural background radiation. In order to make these comparisons, we need data on the activity concentrations of naturally occurring radionuclides in environmental media and organisms of interest. This paper presents the results of a study to determine the exposure of terrestrial organisms in England and Wales to naturally occurring radionuclides, specifically (40)K, (238)U series and (232)Th series radionuclides. Whole-body activity concentrations for the reference animals and plants (RAPs) as proposed by the ICRP have been collated from literature review, data archives and a targeted sampling campaign. Data specifically for the proposed RAP are sparse. Soil activity concentrations have been derived from an extensive geochemical survey of the UK. Unweighted and weighted absorbed dose rates were estimated using the ERICA Tool. Mean total weighted whole-body absorbed dose rates estimated for the selected terrestrial organisms was in the range 6.9 x 10(-2) to 6.1 x 10(-1) microGy h(-1). PMID:18440107

Beresford, N A; Barnett, C L; Jones, D G; Wood, M D; Appleton, J D; Breward, N; Copplestone, D

2008-09-01

218

Introduction Multiple lineages of terrestrial vertebrates, including frogs,  

E-print Network

3358 Introduction Multiple lineages of terrestrial vertebrates, including frogs, snakes, lizards crossing a large gap between trees Among terrestrial vertebrate gliders, take-off presents a unique problem

Socha, Jake

219

Studying silicate-ice bodies in the Solar System  

Microsoft Academic Search

Evolution of Small Silicate-Ice Bodies in the Solar System; Winthrop, Washington, 6-8 August 2010; Interest is growing in a class of small bodies in the solar system, some of which are believed to be the building blocks of the terrestrial planets. These include Ceres, Vesta, Pallas, the icy satellites, and some solid objects farther out in the solar system. Many

Thomas B. McCord; Julie C. Castillo-Rogez

2011-01-01

220

Accelerating Universe from Extra Spatial Dimension  

NASA Astrophysics Data System (ADS)

We present a simple higher dimensional FRW-type of model where the acceleration is apparently caused by the presence of the extra dimensions. Assuming an ansatz in the form of the deceleration parameter, we get a class of solutions some of which shows the desirable feature of dimensional reduction as well as reasonably good physical properties of matter. Interestingly we do not have to invoke an extraneous scalar field or a cosmological constant to account for this acceleration. One argues that the terms containing the higher dimensional metric coefficients produces an extra negative pressure that apparently drives the inflation of the 4D space with an accelerating phase. It is further found that in line with the physical requirements our model admits of a decelerating phase in the early era along with an accelerating phase at present. Further the models asymptotically mimic a steady-state-type of universe although it starts from a big-bang-type of singularity. Correspondence to Wesson's induced matter theory is also briefly discussed and, in line with it, it is argued that the terms containing the higher dimensional metric coefficients apparently creates a negative pressure which drives the inflation of the 3-space with an accelerating phase.

Chatterjee, S.; Banerjee, A.; Zhang, Y. Z.

221

Unveiling long-term variability in XMM-Newton surveys: the EXTraS project  

NASA Astrophysics Data System (ADS)

The 3XMM-DR4 catalogue, the XMM-Newton Slew Survey (XSS) and the associated XMM-Newton EPIC data, are extensive resources for exploring high energy, time-domain astrophysics. Amongst these data are potential, hitherto unidentified variable sources, ranging from short duration (~seconds) transients through to objects varying on timescales of years. Variability signatures can be key to understanding the energetics and physical processes in a diverse range of astrophysical settings. The EU/FP7-Cooperation Space framework project, `Exploring the X-ray transient and variable sky' (EXTraS), aims to exploit these XMM-Newton resources to explore, as fully as possible, the range of X-ray variability present and provide the results to the community through a public database. Here we outline one of the project's core aims, i.e. identifying and characterising long-term (days to years) variability. The 3XMM-DR4 catalogue contains 67000 sources with multiple detections. 3XMM, in conjunction with the XSS, which has now covered almost 70% of the sky, often with multiple slews, offers excellent scope for identifying new variable objects by tracking their flux between XMM-Newton observations. We discuss the plans for the EXTraS long-term variability catalogue and highlight some examples of the detection of long-term variability in 3XMM-DR4/XSS data.

Rosen, S.; Read, A.; De Luca, A.; EXTraS Collaboration

2014-07-01

222

The EXTraS project: Exploring the X-ray Transient and variable Sky  

NASA Astrophysics Data System (ADS)

Modern X-ray observatories can yield unique insights into time domain astrophysics. Indeed, a huge amount of information is already stored - and largely unexploited - in data archives. The EXTraS project will harvest the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) instrument onboard the ESA XMM-Newton mission since its launch. This will include a search for fast transients, missed by standard image analysis, and a search and characterization of variability (both periodic and aperiodic) in hundreds of thousands of sources spanning more than nine orders of magnitude in time scale (from <1 s to >10 yr) and six orders of magnitude in flux (from 10^{-9} to 10^{-15} erg cm^{-2} s^{-1} in 0.2-12 keV). X-ray results will be complemented by multiwavelength characterization of new discoveries. Phenomenological classification of variable sources will also be performed. Our final catalogue and results will be made available to the community, together with new analysis tools, at the end of the project (late 2016). EXTraS is funded within the EU/FP7-Cooperation Space framework and is carried out by a collaboration including INAF (Italy), IUSS (Italy), CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany).

De Luca, A.; D'Agostino, D.; Haberl, F.; Tiengo, A.; Watson, M.; Wilms, J.

2014-07-01

223

FORMATION OF TERRESTRIAL PLANETS FROM PROTOPLANETS UNDER A REALISTIC ACCRETION CONDITION  

SciTech Connect

The final stage of terrestrial planet formation is known as the giant impact stage where protoplanets collide with one another to form planets. So far this stage has been mainly investigated by N-body simulations with an assumption of perfect accretion in which all collisions lead to accretion. However, this assumption breaks for collisions with high velocity and/or a large impact parameter. We derive an accretion condition for protoplanet collisions in terms of impact velocity and angle and masses of colliding bodies, from the results of numerical collision experiments. For the first time, we adopt this realistic accretion condition in N-body simulations of terrestrial planet formation from protoplanets. We compare the results with those with perfect accretion and show how the accretion condition affects terrestrial planet formation. We find that in the realistic accretion model about half of collisions do not lead to accretion. However, the final number, mass, orbital elements, and even growth timescale of planets are barely affected by the accretion condition. For the standard protoplanetary disk model, typically two Earth-sized planets form in the terrestrial planet region over about 10{sup 8} yr in both realistic and perfect accretion models. We also find that for the realistic accretion model, the spin angular velocity is about 30% smaller than that for the perfect accretion model, which is as large as the critical spin angular velocity for rotational instability. The spin angular velocity and obliquity obey Gaussian and isotropic distributions, respectively, independently of the accretion condition.

Kokubo, Eiichiro [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Genda, Hidenori [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Ookayama, Meguro, Tokyo 152-8551 (Japan)], E-mail: kokubo@th.nao.ac.jp, E-mail: genda@geo.titech.ac.jp

2010-05-01

224

Integrated Estimates of Global Terrestrial Carbon Sequestration  

SciTech Connect

Assessing the contribution of terrestrial carbon sequestration to international climate change mitigation requires integration across scientific and disciplinary boundaries. As part of a scenario analysis for the US Climate Change Technology Program, measurements and geographic data were used to develop terrestrial carbon sequestration estimates for agricultural soil carbon, reforestation and pasture management. These estimates were then applied in the MiniCAM integrated assessment model to evaluate mitigation strategies within policy and technology scenarios aimed at achieving atmospheric CO2 stabilization by 2100. Adoption of terrestrial sequestration practices is based on competition for land and economic markets for carbon. Terrestrial sequestration reach a peak combined rate of 0.5 to 0.7 Gt carbon yr-1 in mid-century with contributions from agricultural soil (0.21 Gt carbon yr-1), reforestation (0.31 Gt carbon yr-1) and pasture (0.15 Gt carbon yr-1). Sequestration rates vary over time period and with different technology and policy scenarios. The combined contribution of terrestrial sequestration over the next century ranges from 31 to 41 GtC. The contribution of terrestrial sequestration to mitigation is highest early in the century, reaching up to 20% of total carbon mitigation. This analysis provides insight into the behavior of terrestrial carbon mitigation options in the presence and absence of climate change mitigation policies.

Thomson, Allison M.; Izaurralde, R Cesar; Smith, Steven J.; Clarke, Leon E.

2008-02-01

225

Astronomers Report Discovery of New Extra-solar Planets: Four Reports  

NSDL National Science Digital Library

If you are feeling alone in the universe, this news from 2000 of the search for new planets might inspire you. This account is from the popular space science Website, Space.com. It chronicles the latest detection of at least nine possible planetary bodies orbiting stars outside of our solar system. The text includes a discussion of how detection of wobble behavior is used in the search for extra-solar planets and plans for future planet hunts. This site also features links to Websites of the observatories involved in extra-solar planet detection, related Space.com stories, a diagram of Doppler shift due to stellar wobble and a table of the nine planet candidates's size and distance from Earth.

Weinstock, Maia.

2000-01-01

226

Solar Terrestrial Physics: Present and Future  

NASA Technical Reports Server (NTRS)

The following topics relating to solar-terrestrial interactions are considered: (1) reconnection of magnetic fields; (2) particle acceleration; (3) solar magnetic flux; (4) magnetohydrodynamic waves and turbulence in the Sun and interplanetary medium; (5) coupling of the solar wind to the magnetosphere; (6) coronal transients; (7) the connection between the magnetosphere and ionosphere; (8) substorms in the magnetosphere; (9) solar flares and the solar terrestrial environment; (10) shock waves in the solar terrestrial environment; (11) plasma transport and convection at high latitudes; and (12) high latitude ionospheric structure.

Butler, D. M. (editor); Papadopoulos, K. (editor)

1984-01-01

227

The initial IERS Terrestrial Reference Frame.  

NASA Astrophysics Data System (ADS)

The IERS standards has adopted a description of the Convential Terrestrial Reference System (CTRS) to be used for all IERS activities. In order to facilitate the actual implementation of the IERS Terrestrial Reference System (ITRS) by the various analysis centers which participate to IERS, but also by potential users, this study presents several informations which could be useful for these purposes: 1. A critical description of the latest TRF established by BIH, namely BTS 87. 2. A currently improved combination of BTS 87 input data, following strictly the IERS standards, and to be used as Initial IERS Terrestrial Reference Frame (ITRF-0). 3. Some suggestions for implementation of the ITRS.

Boucher, C.; Altamimi, Z.

1989-06-01

228

Solar-terrestrial models and application software  

NASA Technical Reports Server (NTRS)

The empirical models related to solar-terrestrial sciences are listed and described which are available in the form of computer programs. Also included are programs that use one or more of these models for application specific purposes. The entries are grouped according to the region of the solar-terrestrial environment to which they belong and according to the parameter which they describe. Regions considered include the ionosphere, atmosphere, magnetosphere, planets, interplanetary space, and heliosphere. Also provided is the information on the accessibility for solar-terrestrial models to specify the magnetic and solar activity conditions.

Bilitza, Dieter

1990-01-01

229

Chemical impurity produces extra compound eyes and heads in crickets  

SciTech Connect

A chemical impurity isolated from commercially purchased acridine causes cricket embryos to develop extra compound eyes, branched antennae, extra antennae, and extra heads. Purified acridine does not produce similar duplications of cricket heads or head structures nor do the substituted acridines proflavine, acriflavine, or acridine orange. A dose-response relation exists such that the number and severity of abnormalities increase with increasing concentration of the teratogen.

Walton, B.T.

1981-04-03

230

MATE GUARDING AND EXTRA-PAIR PATERNITY IN NORTHERN CARDINALS  

Microsoft Academic Search

We studied patterns of mate guarding and paternity in 21 pairs of Northern Cardinals (Cardinalis cardinalis) nesting in~central_Kentucky. DbJA fingerprinting revealed that five of 37 nestlinas (13.5%) resulted from extra-pair fertilizations (EPFs). Of 19 broods sampled, three (16%)-bad at least one extra-pair young. Although our observations of male cardinals making extra-territorial movements suggest that some males in the population may

DAVID F. WESTNEAT

231

Economics and ethics of paediatric respiratory extra corporeal life support.  

PubMed

Extra corporeal membrane oxygenation (ECMO) is a form of life support, which facilitates gas exchange outside the body via an oxygenator and a centrifugal pumping system. A paediatric cardiac ECMO programme was established in 2005 at Our Lady's Children's Hospital, Crumlin (OLCHC) and to date 75 patients have received ECMO, the majority being post operative cardiac patients. The outcome data compares favourably with international figures. ECMO has been most successful in the treatment of newborn infants with life threatening respiratory failure from conditions such as meconium aspiration, respiratory distress syndrome and respiratory infections. There is no formal paediatric respiratory ECMO programme at OLCHC, or anywhere else in Ireland. Currently, neonates requiring respiratory ECMO are transferred to centres in Sweden or the UK at an average cost of 133,000 Euros/infant, funded by the Health Service Executive E112 treatment abroad scheme. There is considerable morbidity associated with the transfer of critically ill infants, as well as significant psycho-social impact on families. OLCHC is not funded to provide respiratory ECMO, although the equipment and expertise required are similar to cardiac ECMO and are currently in place. The average cost of an ECMO run at OLCHC is 65,000 Euros. There is now a strong argument for a fully funded single national cardiac and respiratory paediatric ECMO centre, similar to that for adult patients. PMID:24282901

Callaghan, M; Doyle, Y; O'Hare, B; Healy, M; Nlke, L

2013-09-01

232

Gamma ray lines from a universal extra dimension  

SciTech Connect

Indirect Dark Matter searches are based on the observation of secondary particles produced by the annihilation or decay of Dark Matter. Among them, gamma-rays are perhaps the most promising messengers, as they do not suffer deflection or absorption on Galactic scales, so their observation would directly reveal the position and the energy spectrum of the emitting source. Here, we study the detailed gamma-ray energy spectrum of Kaluza--Klein Dark Matter in a theory with 5 Universal Extra Dimensions. We focus in particular on the two body annihilation of Dark Matter particles into a photon and another particle, which produces monochromatic photons, resulting in a line in the energy spectrum of gamma rays. Previous calculations in the context of the five dimensional UED model have computed the line signal from annihilations into \\gamma \\gamma, but we extend these results to include \\gamma Z and \\gamma H final states. We find that these spectral lines are subdominant compared to the predicted \\gamma \\gamma signal, but they would be important as follow-up signals in the event of the observation of the \\gamma \\gamma line, in order to distinguish the 5d UED model from other theoretical scenarios.

Bertone, Gianfranco; Jackson, C.B.; Shaughnessy, Gabe; Tait, Tim M.P.; Vallinotto, Alberto

2012-03-01

233

Spatial patterns of extra-pair paternity: beyond paternity gains and losses.  

PubMed

Most studies on extra-pair paternity (EPP) focus either on a specific male's extra-pair gains or his extra-pair losses. For an individual bird however, mate choice or mate availability may underlie strong spatial restrictions. Disregarding this spatial aspect may underestimate or mask effects of parameters influencing observed EPP patterns. Here, we propose a spatially explicit model for investigating the probability of having extra-pair offspring (EPO) within local networks of breeding pairs. The data set includes all realized and unrealized potential extra-pair matings. This method is biologically meaningful because it allows (a) considering both members of an extra-pair mating and their social mates, and (b) direct modelling of the spatial context in which extra-pair behaviour occurs. The method has the advantage that it can provide inference about the relative contribution of spatial and non-spatial parameters, and about the relative importance of male and female neighbourhoods. We apply this method to parentage data from 1025 broods collected over 12 breeding seasons in two independent study populations of blue tits (Cyanistes caeruleus). We investigate a set of predictions based on the EPP literature, namely that EPP depends on male age and body size, breeding density and breeding synchrony. In all analyses, we control for breeding distance, a parameter that is expected to influence EPP even under random mating. The results show that older and larger males were more likely to sire EPO, but both effects decreased with increasing breeding distance. Local breeding density but not synchrony predicted whether a particular male-female combination had EPO, at least in one of the study areas. Apart from breeding distance, male age had the strongest effect on EPP, followed by a measure of breeding density. The method thus allows a comprehensive assessment of the relative importance of different types of spatial and non-spatial parameters to explain variation in the occurrence of EPP, while controlling for the fact that individuals that breed further apart are less likely to have EPO. The proposed approach is not limited to investigate EPP, but can be applied to other behavioural interactions between two individuals, such as dominance, competition and (social) mating. PMID:25266005

Schlicht, Lotte; Valcu, Mihai; Kempenaers, Bart

2014-09-29

234

Terrestrial Energy Storage SPS Systems  

NASA Technical Reports Server (NTRS)

Terrestrial energy storage systems for the SSP system were evaluated that could maintain the 1.2 GW power level during periods of brief outages from the solar powered satellite (SPS). Short-term outages of ten minutes and long-term outages up to four hours have been identified as "typical" cases where the ground-based energy storage system would be required to supply power to the grid. These brief interruptions in transmission could result from performing maintenance on the solar power satellite or from safety considerations necessitating the power beam be turned off. For example, one situation would be to allow for the safe passage of airplanes through the space occupied by the beam. Under these conditions, the energy storage system needs to be capable of storing 200 MW-hrs and 4.8 GW-hrs, respectively. The types of energy storage systems to be considered include compressed air energy storage, inertial energy storage, electrochemical energy storage, superconducting magnetic energy storage, and pumped hydro energy storage. For each of these technologies, the state-of-the-art in terms of energy and power densities were identified as well as the potential for scaling to the size systems required by the SSP system. Other issues addressed included the performance, life expectancy, cost, and necessary infrastructure and site locations for the various storage technologies.

Brandhorst, Henry W., Jr.

1998-01-01

235

Bibliography of terrestrial impact structures  

NASA Technical Reports Server (NTRS)

This bibliography lists 105 terrestrial impact structures, of which 12 are proven structures, that is, structures associated with meteorites, and 93 are probable. Of the 93 probable structures, 18 are known to contain rocks with meteoritic components or to be enriched in meteoritic signature-elements, both of which enhance their probability of having originated by impact. Many of the structures investigated in the USSR to date are subsurface features that are completely or partly buried by sedimentary rocks. At least 16 buried impact structures have already been identified in North America and Europe. No proven nor probable submarine impact structure rising above the ocean floor is presently known; none has been found in Antarctica or Greenland. An attempt has been made to cite for each impact structure all literature published prior to mid-1983. The structures are presented in alphabetical order by continent, and their geographic distribution is indicated on a sketch map of each continent in which they occur. They are also listed tables in: (1) alphabetical order, (2) order of increasing latitude, (3) order of decreasing diameter, and (4) order of increasing geologic age.

Grolier, M. J.

1985-01-01

236

Proton Radius Puzzle and Large Extra Dimensions  

NASA Astrophysics Data System (ADS)

We propose a theoretical scenario to solve the proton radius puzzle which recently arises from the muonic hydrogen experiment. In this framework, (4+n)-dimensional theory is incorporated with modified gravity. The extra gravitational interaction between the proton and muon at very short range provides an energy shift which accounts for the discrepancy between spectroscopic results from muonic and electronic hydrogen experiments. Assuming the modified gravity is a small perturbation to the existing electromagnetic interaction, we find the puzzle can be solved with stringent constraint on the range of the new force. Our result not only provides a possible solution to the proton radius puzzle but also suggests a direction to test new physics at very small length scale.

Wang, Li-Bang; Ni, Wei-Tou

2013-06-01

237

Multistate dark matter from spherical extra dimensions  

SciTech Connect

We demonstrate a new model which uses an Arkani-Hamed-Dimopoulos-Dvali type braneworld scenario to produce a multistate theory of dark matter. Compactification of the extra dimensions onto a sphere leads to the association of a single complex scalar in the bulk with multiple Kaluza-Klein towers in an effective four-dimensional theory. A mutually interacting multistate theory of dark matter arises naturally within which the dark matter states are identified with the lightest Kaluza-Klein particles of fixed magnetic quantum number. These states are protected from decay by a combination of a global U(1) symmetry and the continuous rotational symmetry about the polar axis of the spherical geometry. We briefly discuss the relic abundance calculation and investigate the spin-independent elastic scattering off nucleons of the lightest and next-to-lightest dark matter states.

Winslow, Peter T. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Theory Group, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada); Sigurdson, Kris [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1 (Canada); Ng, John N. [Theory Group, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada)

2010-07-15

238

The Network Packing Problem in Terrestrial Broadcasting  

E-print Network

In the context of terrestrial video broadcasting, digital technology most likely will re- ... and to the scarce penetration of cable and satellite networks, the Italian context ..... This requirement can be expressed by the following set of constraints: .

2005-03-03

239

The Geology of the Terrestrial Planets  

NASA Technical Reports Server (NTRS)

The geologic history of the terrestrial planets is outlined in light of recent exploration and the revolution in geologic thinking. Among the topics considered are planet formation; planetary craters, basins, and general surface characteristics; tectonics; planetary atmospheres; and volcanism.

Carr, M. H. (editor); Saunders, R. S.; Strom, R. G.; Wilhelms, D. E.

1984-01-01

240

AIR POLLUTION EFFECTS ON TERRESTRIAL ECOSYSTEMS  

EPA Science Inventory

This report presents information on the effects of ozone, nitrogen oxides, sulfur oxides, particulate matter, and acidic disposition on terrestrial ecosystems. A brief explanation of ecosystem dynamics is presented to provide a framework for discussion of air pollutant effects. D...

241

Data Base of Terrestrial Impact Structures  

NSDL National Science Digital Library

Database of Terrestrial Impact Structures leads to Natural Resources Canada's interactive global database of impact structures, complete with photographs and summary information. For those interested in learning more about Impact Craters, this is a fine starting point.

1997-01-01

242

Space Vehicle Terrestrial Environment Design Requirements Guidelines  

NASA Technical Reports Server (NTRS)

The terrestrial environment is an important driver of space vehicle structural, control, and thermal system design. NASA is currently in the process of producing an update to an earlier Terrestrial Environment Guidelines for Aerospace Vehicle Design and Development Handbook. This paper addresses the contents of this updated handbook, with special emphasis on new material being included in the areas of atmospheric thermodynamic models, wind dynamics, atmospheric composition, atmospheric electricity, cloud phenomena, atmospheric extremes, and sea state. In addition, the respective engineering design elements are discussed relative to terrestrial environment inputs that require consideration. Specific lessons learned that have contributed to the advancements made in the application and awareness of terrestrial environment inputs for aerospace engineering applications are presented.

Johnson, Dale L.; Keller, Vernon W.; Vaughan, William W.

2006-01-01

243

Global Change and the Terrestrial Biosphere  

SciTech Connect

Terrestrial ecosystems sustain life on Earth through the production of food, fuel, fiber, clean air, and naturally purified water. But how will agriculture and ecosystems be affected by global change? Rogers describes the impact of projected climate change on the terrestrial biosphere and explains why plants are not just passive respondents to global change, but play an important role in determining the rate of change.

Alistair Rogers

2009-04-22

244

The NASA-Lewis terrestrial photovoltaics program  

NASA Technical Reports Server (NTRS)

Those parts of the present NASA-Lewis research and technology effort on solar cells and arrays having relevance to terrestrial uses are outlined. These include raising cell efficiency, developing the FEP-covered module concept, and exploring low-cost cell concepts. Solar cell-battery power systems for remote weather stations have been built to demonstrate the capabilities of solar cells for terrestrial applications.

Bernatowicz, D. T.

1974-01-01

245

DNA Barcoding Reveals Cryptic Diversity in Lumbricus terrestris L., 1758 (Clitellata): Resurrection of L. herculeus (Savigny, 1826)  

PubMed Central

The widely studied and invasive earthworm, Lumbricus terrestris L., 1758 has been the subject of nomenclatural debate for many years. However these disputes were not based on suspicions of heterogeneity, but rather on the descriptions and nomenclatural acts associated with the species name. Large numbers of DNA barcode sequences of the cytochrome oxidase I obtained for nominal L. terrestris and six congeneric species reveal that there are two distinct lineages within nominal L. terrestris. One of those lineages contains the Swedish population from which the name-bearing specimen of L. terrestris was obtained. The other contains the population from which the syntype series of Enterion herculeum Savigny, 1826 was collected. In both cases modern and old representatives yielded barcode sequences allowing us to clearly establish that these are two distinct species, as different from one another as any other pair of congeners in our data set. The two are morphologically indistinguishable, except by overlapping size-related characters. We have designated a new neotype for L. terrestris. The newly designated neotype and a syntype of L. herculeus yielded DNA adequate for sequencing part of the cytochrome oxidase I gene (COI). The sequence data make possible the objective determination of the identities of earthworms morphologically identical to L. terrestris and L. herculeus, regardless of body size and segment number. Past work on nominal L. terrestris could have been on either or both species, although L. herculeus has yet to be found outside of Europe. PMID:21206917

James, Samuel W.; Porco, David; Decans, Thibaud; Richard, Benoit; Rougerie, Rodolphe; Ersus, Christer

2010-01-01

246

Extra Z-axis Coverage at CT Imaging Resulting in Excess Radiation Dose: Frequency, Degree and Contributory Factors  

PubMed Central

OBJECTIVE To assess the degree of extra scanning beyond the prescribed anatomic boundaries for thoracic and body CT scans and to identify associated factors. METHODS For 442 consecutive chest, abdomen and/or pelvis CT exams, the length of extra scanning beyond the prescribed anatomic boundaries was determined. Exams were grouped according to the locations/types of the prescribed boundaries and compared with regard to length of extra scanning. RESULTS 438 of 442 (99%) CT exams included extraneous imaging, showing a mean excess scanning length of 43.2 mm per exam (range 0180 mm). Significantly more extraneous imaging was performed when soft tissue or vascular structures defined anatomic boundaries compared to when osseous (p < 0.001) or air/soft tissue interfaces (p < 0.0001) defined the boundaries. Average percent of total scan dose attributable to extra imaging was 8.6410.38%. CONCLUSIONS CT scanning beyond the prescribed anatomic boundaries occurs commonly, resulting in moderate extra radiation dose. PMID:21245690

Liao, Eric A.; Quint, Leslie E.; Goodsitt, Mitchell M.; Francis, Isaac R.; Khalatbari, Shokoufeh; Myles, James D.

2012-01-01

247

Body Parts  

NSDL National Science Digital Library

In this online game, learners test their knowledge of human anatomy. Learners are presented a mystery image of a body part and use their mouse to select the proper body part from a full size anatomical model (known as "Jerome"). Learners try to match all 10 body parts correctly. Use this activity to review human anatomy and/or introduce learners to the use of anatomical models.

National Museum of American History, Smithsonian Institution

2012-06-26

248

Black Body  

Microsoft Academic Search

A black body was first defined by Gustav R. Kirchhoff (182487) in 1859 as an object that absorbs all radiation falling upon\\u000a it. Such a conception of an ideal black body was crucial for understanding heat radiation and its laws. Since a completely\\u000a black body does not exist in nature, it had to be constructed. Kirchhoff had already suggested that

Dieter Hoffmann

249

Derivation of transfer parameters for use within the ERICA Tool and the default concentration ratios for terrestrial biota.  

PubMed

An ability to predict radionuclide activity concentrations in biota is a requirement of any method assessing the exposure of biota to ionising radiation. Within the ERICA Tool fresh weight whole-body activity concentrations in organisms are estimated using concentration ratios (the ratio of the activity concentration in the organism to the activity concentration in an environmental media). This paper describes the methodology used to derive the default terrestrial ecosystem concentration ratio database available within the ERICA Tool and provides details of the provenance of each value for terrestrial reference organisms. As the ERICA Tool considers 13 terrestrial reference organisms and the radioisotopes of 31 elements, a total of 403 concentration ratios were required for terrestrial reference organisms. Of these, 129 could be derived from literature review. The approaches taken for selecting the remaining values are described. These included, for example, assuming values for similar reference organisms and/or biogeochemically similar elements, and various simple modelling approaches. PMID:18406022

Beresford, N A; Barnett, C L; Howard, B J; Scott, W A; Brown, J E; Copplestone, D

2008-09-01

250

The effect of melting and crustal production on plate tectonics on terrestrial planets  

NASA Astrophysics Data System (ADS)

In the Solar System, Earth is the only planet to be in a mobile-lid regime, whilst it is generally accepted that all the other terrestrial planets are currently in a stagnant-lid regime, showing little or no surface motion. A transitional regime between these two, showing episodic overturns of an unstable stagnant lid, is also possible and has been proposed for Venus (e.g. Armann and Tackley, JGR 2012). In recent years a number of studies have focused on the feasibility of plate tectonics on large (1-10 Earth masses) extra-solar terrestrial planets; so-called super-Earths, with some studies concluding that these bodies should be in a mobile-regime mode (Valencia et al., ApJ 2007; van Heck and Tackley, EPSL 2011), but others predicting that they should be in a stagnant-lid regime (O'Neill and Leonardic, GRL 2007; Stein et al., GRL 2011). Using plastic yielding to self-consistently generate plate tectonics on an Earth-like planet with strongly temperature-dependent viscosity is now well-established, but such models typically focus on purely thermal convection, whereas compositional variations in the lithosphere can alter the stress state and greatly influence the likelihood of plate tectonics. For example, Rolf and Tackley (GRL, 2011) showed that the addition of a continent can reduce the critical yield stress for mobile-lid behaviour by a factor of ~2, while Armann and Tackley (JGR, 2012) found that bursts of crustal production caused by partial melting my trigger lithospheric overturn events, suggesting that laterally-heterogeneous crustal production in earlier studies (e.g. papers by Nakagawa and Tackley) may also play an important role in facilitating plate tectonics. Complicating matters is the finding that the final state of the system (stagnant- or mobile-lid) can depend on initial condition (Tackley, G3 2000 - part 2); Weller and Lenardic (GRL, 2012) found that the parameter range in which two solutions are obtained increases with viscosity contrast, leading to Lenardic and Crowley (ApJ, 2012) proposing a bistability of the system, introducing bifurcation theory to predict the tectonic state of a planet. Here we thus test (i) whether melting-induced crustal production changes the critical yield stress needed to obtain mobile-lid behaviour as a function of governing parameters (particularly Rayleigh number and viscosity contrast (Moresi and Solomatov, GJI 1998) as well as internal heating rate), and (ii) whether, under these conditions, there is an initial-condition dependence (bimodality) to the state of the system Weller and Lenardic (GRL, 2012). We study these using StagYY (Tackley, PEPI 2008), which uses a finite-volume scheme for advection of temperature, a multigrid solver to obtain a velocity-pressure solution at each timestep, tracers to track composition, and a treatment of partial melting and crustal formation.

Loureno, Diogo; Tackley, Paul

2013-04-01

251

Possible climates on terrestrial exoplanets.  

PubMed

What kind of environment may exist on terrestrial planets around other stars? In spite of the lack of direct observations, it may not be premature to speculate on exoplanetary climates, for instance, to optimize future telescopic observations or to assess the probability of habitable worlds. To begin with, climate primarily depends on (i) the atmospheric composition and the volatile inventory; (ii) the incident stellar flux; and (iii) the tidal evolution of the planetary spin, which can notably lock a planet with a permanent night side. The atmospheric composition and mass depends on complex processes, which are difficult to model: origins of volatiles, atmospheric escape, geochemistry, photochemistry, etc. We discuss physical constraints, which can help us to speculate on the possible type of atmosphere, depending on the planet size, its final distance for its star and the star type. Assuming that the atmosphere is known, the possible climates can be explored using global climate models analogous to the ones developed to simulate the Earth as well as the other telluric atmospheres in the solar system. Our experience with Mars, Titan and Venus suggests that realistic climate simulators can be developed by combining components, such as a 'dynamical core', a radiative transfer solver, a parametrization of subgrid-scale turbulence and convection, a thermal ground model and a volatile phase change code. On this basis, we can aspire to build reliable climate predictors for exoplanets. However, whatever the accuracy of the models, predicting the actual climate regime on a specific planet will remain challenging because climate systems are affected by strong positive feedbacks. They can drive planets with very similar forcing and volatile inventory to completely different states. For instance, the coupling among temperature, volatile phase changes and radiative properties results in instabilities, such as runaway glaciations and runaway greenhouse effect. PMID:24664919

Forget, F; Leconte, J

2014-04-28

252

Lunar and terrestrial planet formation in the Grand Tack scenario  

NASA Astrophysics Data System (ADS)

We present conclusions from a large number of N-body simulations of the giant impact phase of terrestrial planet formation. We focus on new results obtained from the recently proposed Grand Tack model, which couples the gas-driven migration of giant planets to the accretion of the terrestrial planets. The giant impact phase follows the oligarchic growth phase, which builds a bi-modal mass distribution within the disc of embryos and planetesimals. By varying the ratio of the total mass in the embryo population to the total mass in the planetesimal population and the mass of the individual embryos, we explore how different disc conditions control the final planets. The total mass ratio of embryos to planetesimals controls the timing of the last giant (Moon forming) impact and its violence. The initial embryo mass sets the size of the lunar impactor and the growth rate of Mars. After comparing our simulated outcomes with the actual orbits of the terrestrial planets (angular momentum deficit, mass concentration) and taking into account independent geochemical constraints on the mass accreted by the Earth after the Moon forming event and on the timescale for the growth of Mars, we conclude that the protoplanetary disc at the beginning of the giant impact phase must have had most of its mass in Mars-sized embryos and only a small fraction of the total disc mass in the planetesimal population. From this, we infer that the Moon forming event occurred between 60 and 130 My after the formation of the first solids, and was caused most likely by an object with a mass similar to that of Mars.

Jacobson, S. A.; Morbidelli, A.

2014-09-01

253

Microbarom Sources from Tropical and Extra-tropical Cyclones  

E-print Network

Microbarom Sources from Tropical and Extra-tropical Cyclones Justin E. Stopa Co with similar frequencies most commonly generated in the lee of extra-tropical and tropical cyclones. The generation of microbaroms from within a tropical cyclone is demonstrated by the use of a parametric wind

Frandsen, Jannette B.

254

19 CFR 151.64 - Extra copy of entry summary.  

Code of Federal Regulations, 2014 CFR

...CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate per clean kilogram shall be filed in...

2014-04-01

255

19 CFR 151.64 - Extra copy of entry summary.  

Code of Federal Regulations, 2012 CFR

...CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate per clean kilogram shall be filed in...

2012-04-01

256

19 CFR 151.64 - Extra copy of entry summary.  

Code of Federal Regulations, 2013 CFR

...CONTINUED) EXAMINATION, SAMPLING, AND TESTING OF MERCHANDISE Wool and Hair 151.64 Extra copy of entry summary. One extra copy of the entry summary covering wool or hair subject to duty at a rate per clean kilogram shall be filed in...

2013-04-01

257

Quantifying inbreeding avoidance through extra-pair reproduction  

PubMed Central

Extra-pair reproduction is widely hypothesized to allow females to avoid inbreeding with related socially paired males. Consequently, numerous field studies have tested the key predictions that extra-pair offspring are less inbred than females alternative within-pair offspring, and that the probability of extra-pair reproduction increases with a female's relatedness to her socially paired male. However, such studies rarely measure inbreeding or relatedness sufficiently precisely to detect subtle effects, or consider biases stemming from failure to observe inbred offspring that die during early development. Analyses of multigenerational song sparrow (Melospiza melodia) pedigree data showed that most females had opportunity to increase or decrease the coefficient of inbreeding of their offspring through extra-pair reproduction with neighboring males. In practice, observed extra-pair offspring had lower inbreeding coefficients than females within-pair offspring on average, while the probability of extra-pair reproduction increased substantially with the coefficient of kinship between a female and her socially paired male. However, simulations showed that such effects could simply reflect bias stemming from inbreeding depression in early offspring survival. The null hypothesis that extra-pair reproduction is random with respect to kinship therefore cannot be definitively rejected in song sparrows, and existing general evidence that females avoid inbreeding through extra-pair reproduction requires reevaluation given such biases. PMID:25346331

Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin

2015-01-01

258

20 CFR 332.4 - Restrictions in extra service.  

Code of Federal Regulations, 2010 CFR

...be considered to exist in rotating extra board, pool, or chain gang service when there is in effect an arrangement between the...arrangement is such that an employee in extra board, pool, or chain gang service gets the equivalent of full-time work, his lack...

2010-04-01

259

20 CFR 332.4 - Restrictions in extra service.  

Code of Federal Regulations, 2011 CFR

...be considered to exist in rotating extra board, pool, or chain gang service when there is in effect an arrangement between the...arrangement is such that an employee in extra board, pool, or chain gang service gets the equivalent of full-time work, his lack...

2011-04-01

260

20 CFR 332.4 - Restrictions in extra service.  

Code of Federal Regulations, 2013 CFR

...be considered to exist in rotating extra board, pool, or chain gang service when there is in effect an arrangement between the...arrangement is such that an employee in extra board, pool, or chain gang service gets the equivalent of full-time work, his lack...

2013-04-01

261

20 CFR 332.4 - Restrictions in extra service.  

Code of Federal Regulations, 2012 CFR

...be considered to exist in rotating extra board, pool, or chain gang service when there is in effect an arrangement between the...arrangement is such that an employee in extra board, pool, or chain gang service gets the equivalent of full-time work, his lack...

2012-04-01

262

20 CFR 332.4 - Restrictions in extra service.  

Code of Federal Regulations, 2014 CFR

...be considered to exist in rotating extra board, pool, or chain gang service when there is in effect an arrangement between the...arrangement is such that an employee in extra board, pool, or chain gang service gets the equivalent of full-time work, his lack...

2014-04-01

263

The progress of exploring extra-solar planetary systems  

Microsoft Academic Search

With the advance of the space exploring, the study of the extra-solar planetary systems becomes an interesting topic since such system may exist the life or even the modern civilization. In this paper we give a brief introduction on the discovery of extra-solar planetary systems, and discuss the feasibility of detection techniques and methods developed in recent years. In particular,

Yu-Juan Liu; Gang Zhao

2005-01-01

264

Early Giant Planet Migration in the Solar System: Geochemical and Cosmochemical Implications for Terrestrial Planet Formation  

NASA Astrophysics Data System (ADS)

A new terrestrial planet formation model (Walsh et al., this meeting) explores the effects of a two-stage, inward-then-outward migration of Jupiter and Saturn, as found in numerous hydrodynamical simulations of giant planet formation (Masset & Snellgrove 2001, Morbidelli & Crida 2007, Pierens & Nelson 2008). Walsh et al. show that the inward migration of Jupiter truncates the disk of planetesimals and embryos in the terrestrial planet region. Subsequent accretion in that region then forms a realistic system of terrestrial planets, in particular giving a low-mass Mars, which has been difficult to reproduce in simulations with a self-consistent set of initial conditions (see, eg. Raymond et al. 2009). Additionally, the outward migration of the giant planets populates the asteroid belt with distinct populations of bodies, with the inner belt filled by bodies originating inside of 3 AU, and the outer belt filled with bodies originating from beyond the giant planets. From a geochemical and cosmochemical point of view, this scenario differs significantly from the "standard model" in which essentially all of the material in the inner Solar System initially formed there. Specifically, the assumption that the current radial distribution of material in the inner Solar System is reflective of the primordial distribution of material in that region is no longer necessary. This is important for understanding the chemical and isotopic diversity of the inner Solar System as inferred from studies of the terrestrial planets, asteroids, and meteorites, as well as for understanding the origin of Earth's water. We will discuss the geochemical and cosmochemical implications of this model in relation to available constraints, as well as to previous models of terrestrial planet formation. Masset & Snellgrove (2001), MNRAS 320, L55. Morbidelli & Crida (2007), Icarus 191, 158. Pierens & Nelson (2008), A&A 482, 333. Raymond et al. (2009), Icarus 203, 644.

O'Brien, David P.; Walsh, K. J.; Morbidelli, A.; Raymond, S. N.; Mandell, A. M.; Bond, J. C.

2010-10-01

265

Terrestrialization, Miniaturization and Rates of Diversification in African Puddle Frogs (Anura: Phrynobatrachidae)  

PubMed Central

Terrestrialization, the evolution of non-aquatic oviposition, and miniaturization, the evolution of tiny adult body size, are recurring trends in amphibian evolution, but the relationships among the traits that characterize these phenomena are not well understood. Furthermore, these traits have been identified as possible key innovations that are predicted to increase rates of speciation in those lineages in which they evolve. We examine terrestrialization and miniaturization in sub-Saharan puddle frogs (Phrynobatrachidae) in a phylogenetic context to investigate the relationship between adaptation and diversification through time. We use relative dating techniques to ascertain if character trait shifts are associated with increased diversification rates, and we evaluate the likelihood that a single temporal event can explain the evolution of those traits. Results indicate alternate reproductive modes evolved independently in Phrynobatrachus at least seven times, including terrestrial deposition of eggs and terrestrial, non-feeding larvae. These shifts towards alternate reproductive modes are not linked to a common temporal event. Contrary to the key innovations hypothesis, clades that exhibit alternate reproductive modes have lower diversification rates than those that deposit eggs aquatically. Adult habitat, pedal webbing and body size have no effect on diversification rates. Though these traits putatively identified as key innovations for Phrynobatrachus do not seem to be associated with increased speciation rates, they may still provide opportunities to extend into new niches, thus increasing overall diversity. PMID:22509392

Zimkus, Breda M.; Lawson, Lucinda; Loader, Simon P.; Hanken, James

2012-01-01

266

Evaluation of five different suture materials in the skin of the earthworm (Lumbricus terrestris).  

PubMed

The purpose of this study was to determine which suture material is the most appropriate for dermal closure of terrestrial annelids. This paper describes the tissue reactions of the earthworm, Lumbricus terrestris, to five different types of suture materials in order to determine which suture material is the most appropriate for dermal closure. Silk, monofilament nylon, polydiaxonone, polyglactin 910, and chromic gut were studied. There was mild to moderate tissue reaction to all five suture materials. In all of the biopsies wound-healing reaction consisted of aggregates of blastemal cells which appeared in various stages of dedifferentiation from the body wall. Inflammatory cells infiltrated the wound sites, reminiscent of the typical foreign body reaction in vertebrates. The results indicate polyglactin 910 would be the best suture material with regards to tissue security and reaction scores. Chromic gut occupies the next position but there were problems with suture security over time. This appears to be the first suture material performance study on a terrestrial invertebrate. The earthworm, Lumbricus terrestris, was chosen for its wide availability, size, and the extensive species knowledge base. The earthworm may prove to be a good surgical/suture model for economically important invertebrates such as mollusks, tunicates, and insect larval stages. PMID:25143875

Salgado, Melissa A; Lewbart, Gregory A; Christian, Larry S; Griffith, Emily H; Law, Jerry McHugh

2014-01-01

267

Repeatability of extra-pair mating in tree swallows.  

PubMed

Models of sexual selection assume that female mating preferences are heritable and, thus, repeatable for individual females across multiple mating episodes. Previous studies of the repeatability of female preference have examined individuals in captivity and focused presumably on social mate choice. However, extra-pair mating is widespread and can also influence sexual selection. We examined the repeatability of extra-pair mating in a wild population of tree swallows (Tachycineta bicolor) by experimentally inducing females to lay two clutches in rapid succession within the same season. We found that the proportion of extra-pair young and the number of extra-pair sires were highly repeatable for individual females. However, the repeatability of specific extra-pair sires was low. We suggest that this unusual pattern of mating may be due to females maximizing the heterozygosity of their offspring. PMID:16499706

Whittingham, Linda A; Dunn, Peter O; Stapleton, Mary K

2006-03-01

268

Body Piercing  

MedlinePLUS

... is not a professional. This will help prevent infection. Select the body site and jewelry carefully. Avoid jewelry made or nickel or brass, which can cause allergic reactions. Look for jewelry made of titanium, 14-carat gold or surgical-grade steel. Source Complications of Body Piercing by ...

269

Body Basics  

MedlinePLUS

... more about how the body works, what basic human anatomy is, and what happens when parts of the body don't function properly. Blood Bones, Muscles, and Joints Brain and Nervous System Digestive System Endocrine System Eyes Female Reproductive System ...

270

Pemberton et al: ALIEN TERRESTRIAL ORCHID, EULOPHIA GRAMINEA, INVADES MIAMI ALIEN TERRESTRIAL ORCHID, EULOPHIA GRAMINEA,  

E-print Network

Pemberton et al: ALIEN TERRESTRIAL ORCHID, EULOPHIA GRAMINEA, INVADES MIAMI 183 ALIEN TERRESTRIAL ORCHID, EULOPHIA GRAMINEA, INVADES MIAMI Bob Pemberton, PhD, Suzanne Koptur, PhD & Timothy Collins, PhD We first encountered an Asian orchid, Eulophia graminea, in South Miami during the autumn of 2007

Koptur, Suzanne

271

Groundwater and Terrestrial Water Storage  

NASA Technical Reports Server (NTRS)

Most people think of groundwater as a resource, but it is also a useful indicator of climate variability and human impacts on the environment. Groundwater storage varies slowly relative to other non-frozen components of the water cycle, encapsulating long period variations and trends in surface meteorology. On seasonal to interannual timescales, groundwater is as dynamic as soil moisture, and it has been shown that groundwater storage changes have contributed to sea level variations. Groundwater monitoring well measurements are too sporadic and poorly assembled outside of the United States and a few other nations to permit direct global assessment of groundwater variability. However, observational estimates of terrestrial water storage (TWS) variations from the GRACE satellites largely represent groundwater storage variations on an interannual basis, save for high latitude/altitude (dominated by snow and ice) and wet tropical (surface water) regions. A figure maps changes in mean annual TWS from 2009 to 2010, based on GRACE, reflecting hydroclimatic conditions in 2010. Severe droughts impacted Russia and the Amazon, and drier than normal weather also affected the Indochinese peninsula, parts of central and southern Africa, and western Australia. Groundwater depletion continued in northern India, while heavy rains in California helped to replenish aquifers that have been depleted by drought and withdrawals for irrigation, though they are still below normal levels. Droughts in northern Argentina and western China similarly abated. Wet weather raised aquifer levels broadly across western Europe. Rains in eastern Australia caused flooding to the north and helped to mitigate a decade long drought in the south. Significant reductions in TWS seen in the coast of Alaska and the Patagonian Andes represent ongoing glacier melt, not groundwater depletion. Figures plot time series of zonal mean and global GRACE derived non-seasonal TWS anomalies (deviation from the mean of each month of the year) excluding Greenland and Antarctica. The two figures show that 2010 was the driest year since 2003. The drought in the Amazon was largely responsible, but an excess of water in 2009 seems to have buffered that drought to some extent. The drying trend in the 25-55 deg S zone is a combination of Patagonian glacier melt and drought in parts of Australia.

Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

2011-01-01

272

Early Formation of Terrestrial Crust  

NASA Astrophysics Data System (ADS)

Early (?4.5 Ga) Formation of Terrestrial Crust T.M. Harrison1, A.K. Schmitt1, M.T. McCulloch2, and O.M. Lovera1 1Department of Earth and Space Sciences and IGPP, UCLA, Los Angeles, CA 90095, USA; 2Research School of Earth Sciences, Australian National University, Canberra, A.C.T. 2601 AUSTRALIA Large deviations in ?repsilonHf(T) from bulk silicate Earth seen in >4 Ga detrital zircons from Jack Hills, Western Australia, have been interpreted as reflecting a major differentiation of the silicate Earth at ca. 4.4 to 4.5 Ga. We have expanded the characterization of 176Hf/177Hf (Hf) in Hadean zircons by acquiring a further 116 laser ablation Lu-Hf measurements on 87 grains with ion microprobe 207Pb/206Pb ages up to 4.36 Ga. Most measurements employed concurrent Lu-Hf and 207Pb/206Pb analyses, permitting assessment of the use of ion microprobe data to characterize the age of the volumetrically larger domain sampled by laser drilling. Our new results confirm and extend the earlier observation of significant negative deviations in ?repsilonHf(T) throughout the Hadean, although no positive ?repsilonHf(T) values were documented in this study. These data yields an essentially uniform spectrum of single-stage model ages between 4.54 and 4.20 Ga for extraction of the zircons' protoliths from a chondritic reservoir. We derived the full error propagation expression for a parameter, ?repsilono, which measures the difference of a sample from solar system initial (Hf) (Hfo), and from this conclude that data plotting close to (Hfo), are statistically meaningful and consistent with silicate differentiation at 4.5400.006 Ga. ?18O and Ti thermometry for these Hadean zircons show little obvious correlation with initial (Hf), consistent with their derivation through fusion of a broad suite of crustal rock types under near water-saturated conditions. Together with the inclusion assemblage and other isotopic and trace element data obtained from these ancient zircons, our results indicate essentially continuous derivation of crust from the mantle from 4.5 to 4.2 Ga, concurrent with recycling into the mantle and internal crustal re-working. These results represent further evidence that by 4.35 Ga, portions of the crust had taken on continental characteristics.

Harrison, T. M.; Schmitt, A. K.; McCulloch, M. T.; Lovera, O. M.

2007-12-01

273

Terrestrial teleconnections link global rivers  

NASA Astrophysics Data System (ADS)

We present analyses of river discharge data from across the world, which we used to identify links between annual river flow regimes across different continents. Our hypothesis was that, as atmospheric processes are subject to large-scale teleconnection patterns, and because these atmospheric processes are inherently linked to precipitation regimes across the world, there should be identifiable links between river flow regimes driven by these atmospheric processes. We used discharge data from the Global Runoff Data Centre (GRDC) to identify cross-correlations (and accounted for serial dependence) between 23 of the world's largest river basins where overlapping data were available over a period of 12 years or more: two in South America; five in Africa; one in Australasia; five in North America and ten in Eurasia. The selected river basins drain approximately a third of the Earth's landmass at their furthest downstream gauging station. Where significant cross-correlations were found, we compared these to known patterns associated with the ENSO and NAO teleconnections. In total, 85 of the 253 possible correlations were deemed significant at p<0.05, this reduced to 36 at p<0.01 and 21 at p<0.001. Of the significant correlations (p<0.05), 22 were classified as strong (r ? 0.5), 45 as moderate (0.5< r ?0.25) and 18 as weak (0.25< r >0). We compared these significant cross-correlations with known atmospheric teleconnection patterns, and while these were consistent for the majority of cases, we found a number of significant correlations that are inconsistent with the anticipated effects of known atmospheric teleconnections. Our results provide new insight into the inter-continental links between global river systems and the way in which these are controlled by large-scale atmospheric processes. We suggest this may be useful for global industries, such as insurers or aid agencies, who seek to understand correlations between the magnitudes of extreme events across different regions of the world. For the former, this may enable more efficient management of global liabilities, for the latter it may enable better logistical planning of disaster relief requirements. Aside from these practical applications, the results also suggest teleconnections exist between terrestrial, as well as ocean and atmospheric water systems.

O'Loughlin, F.; Howden, N. J.; Woods, R. A.; Bates, P. D.

2013-12-01

274

Radiology and Children: Extra Care Required  

MedlinePLUS

... body of interest, reduce dose while maintaining diagnostic image quality, reduce the number of multiple scans with contrast material, and eliminate inappropriate patient referrals for CT. CT: Tips for Parents Meanwhile, the Image Gently campaign advises parents to Talk with your ...

275

LHC Signals from Warped Extra Dimensions  

E-print Network

We study production of Kaluza-Klein gluons (KKG) at the Large Hadron Collider (LHC) in the framework of a warped extra dimension with the Standard Model (SM) fields propagating in the bulk. We show that the detection of KK gluon is challenging since its production is suppressed by small couplings to the proton's constituents. Moreover, the KK gluon decays mostly to top pairs due to an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for m_{KKG} \\lesssim 4 TeV, 100 fb^{-1} of data at the LHC can provide discovery of the KK gluon. We utilize a sizeable left-right polarization asymmetry from the KK gluon resonance to maximize the signal significance, and we explore the novel feature of extremely highly energetic "top-jets". We briefly discuss how the detection of electroweak gauge KK states (Z/W) faces a similar challenge since their leptonic decays (``golden'' modes) are suppressed. Our analysis suggests that other frameworks, for example little Higgs, which rely on UV completion via strong dynamics might face similar challenges, namely (1) Suppressed production rates for the new particles (such as Z'), due to their ``light-fermion-phobic'' nature, and (2) Difficulties in detection since the new particles are broad and decay predominantly to third generation quarks and longitudinal gauge bosons.

Kaustubh Agashe; Alexander Belyaev; Tadas Krupovnickas; Gilad Perez; Joseph Virzi

2006-12-04

276

LHC Signals from Warped Extra Dimensions  

SciTech Connect

We study production of Kaluza-Klein gluons (KKG) at the Large Hadron Collider (LHC) in the framework of a warped extra dimension with the Standard Model (SM) fields propagating in the bulk. We show that the detection of KK gluon is challenging since its production is suppressed by small couplings to the proton's constituents. Moreover, the KK gluon decaysmostly to top pairs due to an enhanced coupling and hence is broad. Nevertheless, we demonstrate that for MKKG<~;; 4 TeV, 100 fb-1 of data at the LHC can provide discovery of the KK gluon. We utilize a sizeable left-right polarization asymmetry from the KK gluon resonance to maximize the signal significance, and we explore the novel feature of extremely highly energetic"top-jets." We briefly discuss how the detection of electroweak gauge KK states (Z/W) faces a similar challenge since their leptonic decays ("golden" modes) are suppressed. Our analysis suggests that other frameworks, for example little Higgs, which rely on UV completion via strong dynamics might face similar challenges, namely (1) Suppressed production rates for the new particles (such as Z'), due to their"lightfermion-phobic" nature, and (2) Difficulties in detection since the new particles are broad and decay predominantly to third generation quarks and longitudinal gauge bosons.

Agashe, K.; Belyaev, A.; Krupovnickas, T.; Perez, G.; Virzi, J.

2006-12-06

277

The decoding problem: do we need to search for extra terrestrial intelligence in order to search for extraterrestrial intelligence?  

Microsoft Academic Search

There is a widespread and perhaps uncritically accepted assumption on the part of SETI researchers and popularizers that we could tell what an ETI might be trying to tell us. We raise difficulties for this assumption. If the assumption is abandoned, a lot follows. We might even be able to argue, in a novel way, that SETI will be utterly

Neil W. Tennant

1993-01-01

278

Trace element and isotope geochemistry of Cretaceous-Tertiary boundary sediments: identification of extra-terrestrial and volcanic components  

NASA Technical Reports Server (NTRS)

Trace element and stable isotope analyses were performed on a series of sediment samples crossing the Cretaceous-Tertiary (K-T) boundary from critical sections at Aumaya and Sopelano, Spain. The aim is to possibly distinguish extraterrestrial vs. volcanic or authigenic concentration of platinum group and other elements in K-T boundary transitional sediments. These sediments also have been shown to contain evidence for step-wise extinction of several groups of marine invertebrates, associated with negative oxygen and carbon isotope excursions occurring during the last million years of the Cretaceous. These isotope excursions have been interpreted to indicate major changes in ocean thermal regime, circulation, and ecosystems that may be related to multiple events during latest Cretaceous time. Results to date on the petrographic and geochemical analyses of the Late Cretaceous and Early Paleocene sediments indicate that diagenesis has obviously affected the trace element geochemistry and stable isotope compositions at Zumaya. Mineralogical and geochemical analysis of K-T boundary sediments at Zumaya suggest that a substantial fraction of anomalous trace elements in the boundary marl are present in specific mineral phases. Platinum and nickel grains perhaps represent the first direct evidence of siderophile-rich minerals at the boundary. The presence of spinels and Ni-rich particles as inclusions in aluminosilicate spherules from Zumaya suggests an original, non-diagenetic origin for the spherules. Similar spherules from southern Spain (Caravaca), show a strong marine authigenic overprint. This research represents a new approach in trying to directly identify the sedimentary mineral components that are responsible for the trace element concentrations associated with the K-T boundary.

Margolis, S. V.; Doehne, E. F.

1988-01-01

279

Planetary Protection: Two Relevant Terrestrial Examples  

NASA Astrophysics Data System (ADS)

Concerns about potential pathogens in returned samples from Mars ("Mars Sample Return: Issues and Recommendations", National Research Council, 1997) or planetary satellites ("Evaluating the Biological Potential in Samples Returned from Planetary Satellites and Small Solar System Bodies", National Research Council, 1998) focus on two potential types of pathogenesis, toxic and infectious. The National Research Council reports cited above state that the chances of extraterrestrial organisms proving either toxic or infectious to humans are extremely low, but cannot be entirely ruled out. Here I discuss recently discovered terrestrial examples relevant to each possibility, in order to make these concerns concrete. The first example concerns the production of hepatotoxins (toxins affecting the liver) and neurotoxins by cyanobacteria in glacial lakes on alpine pastures in Switzerland. In this example, mat-forming benthic cyanobacteria are implicated in a hundred cattle poisonings that have been reported from alpine pasteurs in southeastern Switzerland over the past twenty-five years (e.g. K. Mez et al, Hydrobiologia 368, 1-15 (1998)). It is unlikely that these cyanobacteria evolved the toxins in response to dairy cows; rather the susceptibility of cattle to these toxins seems simply to be an unfortunate coincidence of a toxin working across a large evolutionary distance. The second example concerns the recent demonstration that the decimation of shallow-water Caribbean elkhorn coral is due to infection by a common fecal enterobacterium associated with the human gut (K. L. Patterson et al., PNAS 99, 8725-8730 (2002)). The bacterium, Serratia marcenscens, is also a free-living microbe in water and soil, as well as an opportunistic pathogen in a variety of animal species. The distance between humans and corals emphasizes the possibility that certain organisms may prove pathogenic across a wide evolutionary divide. Of course, in neither of these cases are the evolutionary distances crossed as large as those that would likely exist between any martian organisms and human beings. The possibility that life on the two worlds might share a common ancestor suggests that these distances may not be altogether incomparable, but this remains speculation pending further exploration. This work is supported in part by the NASA Exobiology Program and a Presidential Early Career Award for Scientists and Engineers.

Chyba, C.

2002-09-01

280

Terrestrial Planet Formation Around Close Binary Stars  

NASA Technical Reports Server (NTRS)

Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets around close binary stars, using a new, ultrafast, symplectic integrator that we have developed for this purpose. The sum of the masses of the two stars is one solar mass, and the initial disk of planetary embryos is the same as that used for simulating the late stages of terrestrial planet growth within our Solar System and in the Alpha Centauri wide binary star system. Giant planets &are included in the simulations, as they are in most simulations of the late stages of terrestrial planet accumulation in our Solar System. When the stars travel on a circular orbit with semimajor axis of up to 0.1 AU about their mutual center of mass, the planetary embryos grow into a system of terrestrial planets that is statistically identical to those formed about single stars, but a larger semimajor axis and/or a significantly eccentric binary orbit can lead to significantly more dynamically hot terrestrial planet systems.

Lissauer, Jack J.; Quintana, Elisa V.

2003-01-01

281

Visible Body  

NSDL National Science Digital Library

The human body is an intricate, and often mysterious, place. With today's technology, however, many websites and apps provide entry into this fascinating world. Visible Body is one of the more compelling avenues for exploration. While there are paid products on the site, some of the content is available at no charge. Visitors can look over the Human Anatomy Atlas, which contains a range of visualizations that allow users to explore body systems in exquisite detail. For a small fee, users may access the other specific areas of the site, which include Digestive Anatomy, Respiratory Anatomy, and Reproductive & Urinary Anatomy.

282

Genital and extra-genital warts increase the risk of asymptomatic genital human papillomavirus infection in men  

Microsoft Academic Search

ObjectivesTo evaluate the relationship of warts in different parts of the body and the risk of asymptomatic genital human papillomavirus (HPV) infection in men.MethodsWe examined the relationship of self-reported genital and extra-genital warts with the subsequent acquisition of asymptomatic genital HPV infection in a cohort of 331 adult men. Participants were followed at 2-month intervals for up to 4 years.

Brenda Y Hernandez; Yurii B Shvetsov; Marc T Goodman; Lynne R Wilkens; Pamela J Thompson; Xuemei Zhu; James Tom; Lily Ning

2011-01-01

283

Global calibration of terrestrial reference cells and errors involved in using different irradiance monitoring techniques  

NASA Technical Reports Server (NTRS)

The feasibility of global calibration of terrestrial reference cells is discussed. A simple, accurate 'secondary' calibration technique based on ratios of test to reference cell currents measured in natural sunlight is described. Different techniques for monitoring incident irradiance during solar cell performance measurements are also examined and assessed, including the techniques of black-body detectors, calibrated reference cells, and the convolution of spectral response with solar irradiance.

Curtis, H. B.

1980-01-01

284

Pathology of extra-nodal non Hodgkin lymphomas.  

PubMed

In the management of extra-nodal lymphomas it is important to determine whether the tumour has disseminated and whether lymph nodes are involved. Some extra-nodal lymphomas may be the result of random spread of nodal lymphoma. Specific homing, however, determines the site of many extra-nodal lymphomas, as exemplified by cutaneous T-cell lymphomas, which seem to be derived from skin-homing T-cells and mucosa-associated lymphoid tissue lymphomas that show features of the mucosal immune system. Enteropathy-associated T-cell lymphoma is derived from mucosal T-cells in patients with coeliac disease. Immunological sanctuary accounts for the localisation of primary brain, eye and testicular lymphoma. Mantle cell lymphoma frequently causes tumours in the gastrointestinal tract. Random biopsies have shown that a high proportion of patients with this lymphoma have extensive occult involvement of the gastrointestinal tract at the time of first diagnosis. Follicular lymphoma occurs at both nodal and extra-nodal sites, but uncommonly at both sites at the same time. Extra-nodal follicular lymphomas frequently lack t(14;18)(q32;q21) and do not express bcl-2, which are characteristics of the nodal disease. At extra-nodal sites, follicular lymphoma is more likely to be curable than nodal follicular lymphoma. The behaviour of extra-nodal lymphomas cannot be assumed to follow that of their nodal counterparts. PMID:22480571

Wright, D H

2012-06-01

285

Cytomorphologic spectrum in aspirates of extra-adrenal paraganglioma  

PubMed Central

Background: Paraganglioma is a rare tumor arising from clusters of neuroendocrine cells in association with sympathetic and parasympathetic nervous system. It poses a diagnostic challenge because of its widespread anatomic distribution, subtle clinical manifestations, and a variety of morphologic patterns. Aim: The aim of this study is to have an insight into the diverse morphologic spectrum of extra-adrenal paraganglioma (EAP). Materials and Methods: A retrospective analysis of seven cytologically diagnosed cases of EAP over a period of 10 years was performed. There were five superficial swellings and two deep seated retroperitoneal masses. The superficial swellings were aspirated directly, and the retroperitoneal masses were aspirated under ultrasound guidance using 22-gauge lumbar puncture needle fitted to a 10 mL syringe. Smears were reviewed for cellularity, pattern, cell shape, cytoplasm, nuclear features, and background. Results: The age of patients ranged from 25 to 75 years; four patients were males and three were females. Sites involved were carotid body region (four cases), para-pharyngeal space (one case) and para-aortic region (two cases). All the cases yielded hemorrhagic material on fine-needle aspiration. Smears showed scattered and clusters of cells and loosely cohesive acini of tumor cells. Cells were round to polygonal with pleomorphic nuclei, granular chromatin, inconspicuous nucleoli, and moderate to abundant cytoplasm containing fine pink granules and vacuolations. The cases were confirmed on radiology and histopathology. Conclusion: The cytologic features in EAP along with pertinent clinicoradiologic findings help in making an accurate preoperative diagnosis of an otherwise rare tumor. PMID:25210234

Handa, Uma; Kundu, Reetu; Mohan, Harsh

2014-01-01

286

Introduction - Solar and Extra-Solar Planetary Systems  

NASA Astrophysics Data System (ADS)

Over the last decade, there have been many exciting advances in all fields relating to our understanding of planetary systems. There has been a significant increase in our understanding of the general process of star formation, leading to an expectation that matter will be captured in a flattened envelope or nebula surrounding the young Sun. Theoretical models had predicted this for some time, but in the last decade, firm observational evidence of this has become fairly commonplace, with ? Pictoris in particular displaying all the characteristics that were expected in systems where planets formed. The discovery of extra-solar planets has also confirmed the view that planetary formation is a normal phenomenon so that our system is no longer regarded as a one off or special. Within the Solar System itself, both space exploration and improved facilities for ground-based observations have increased our knowedge of our own system dramatically. Pluto is now the only planet not to have been visited by a spacecraft, and spacecraft images also exist of asteroids and comets. In addition, it is now known that all the major planets have extensive satellite systems as well as complex ring structures. Finally, two new classes of objects have been discovered: the Centaurs orbiting between the major planets; and the Edgeworth-Kuiper objects beyond Neptune.This book is based on the lectures given at a Pre-Doctoral Summer School held in Ballyvaughn, County Clare, Ireland during 7 - 18 September 1998, supported by the European Astrophysical Doctoral Network (EADN). The aim of the School was to give an authoritative account of these new developments so that a thorough general background in the state of our knowledge would be obtained by all participants. The scientific contents of the School can be divided into a number of broad fields. The areas are: Formation of Planetary Systems; Planets and Satellites; and Small Bodies and Dust. The chapter on Dynamics by Murray spans all of these areas.

Williams, Iwan P.

287

Planetary geology and terrestrial analogs in Asia  

NASA Astrophysics Data System (ADS)

2011 PERC Planetary Geology Field Symposium;Kitakyushu City, Japan, 5-6 November 2011 In spite of the extremely diverse geological settings that exist in Asia, relatively little attention has previously been paid to this region in terms of terrestrial analog studies for planetary application. Asia is emerging as a major center of studies in planetary geology, but no attempt had been made in the past to organize a broadly based meeting that would allow planetary geologists in Asia to meet with ones from more advanced centers, such as the United States and Europe, and that would include the participation of many geologists working primarily on terrestrial research. The Planetary Exploration Research Center (PERC) of the Chiba Institute of Technology hosted the first planetary geology field symposium in Asia to present results from recent planetary geology studies and to exchange ideas regarding terrestrial analogs (http://www.perc.it-chiba.ac.jp/meetings/pgfs2011/index.html).

Komatsu, Goro; Namiki, Noriyuki

2012-04-01

288

Comparative planetology: Significance for terrestrial geology  

NASA Technical Reports Server (NTRS)

The crustal evolution of the terrestrial planets increase in complexity and duration with increasing size and mass of the planet. The lunar and mercurian surfaces are largely the result of intense, post-differentiation impact bombardment and subsequent volcanic filling of major impact basins. Mars, being larger, has evolved further: crustal uplifts, rifting, and shield volcanoes have begun to modify its largely Moon-like surface. The Earth is the large end-number of this sequence, where modern plate tectonic processes have erased the earlier lunar and martian type of surfaces. Fundamental problems of the origin of terrestrial continents, ocean basins, and plate tectonics are now addressed within the context of the evolutionary pattern of the terrestrial planets.

Frey, H. V.; Lowman, P. D., R.

1978-01-01

289

Body Signals.  

ERIC Educational Resources Information Center

Describes an activity in which students observe pairs of students engaged in conversation. Observations of "body language" are made, shifts in stance, and duration of stance. Discusses the application of this type of study to other species. (TW)

Gurley-Dilger, 'Laine

1986-01-01

290

Body Swatter  

NSDL National Science Digital Library

Students work in cooperative groups to research and write questions for an active game designed to review the major organs of the systems of the human body (digestive, respiratory, circulatory, and excretory system).

2013-02-15

291

Error bounds from extra precise iterative refinement  

SciTech Connect

We present the design and testing of an algorithm for iterative refinement of the solution of linear equations, where the residual is computed with extra precision. This algorithm was originally proposed in the 1960s [6, 22] as a means to compute very accurate solutions to all but the most ill-conditioned linear systems of equations. However two obstacles have until now prevented its adoption in standard subroutine libraries like LAPACK: (1) There was no standard way to access the higher precision arithmetic needed to compute residuals, and (2) it was unclear how to compute a reliable error bound for the computed solution. The completion of the new BLAS Technical Forum Standard [5] has recently removed the first obstacle. To overcome the second obstacle, we show how a single application of iterative refinement can be used to compute an error bound in any norm at small cost, and use this to compute both an error bound in the usual infinity norm, and a componentwise relative error bound. We report extensive test results on over 6.2 million matrices of dimension 5, 10, 100, and 1000. As long as a normwise (resp. componentwise) condition number computed by the algorithm is less than 1/max{l_brace}10,{radical}n{r_brace} {var_epsilon}{sub w}, the computed normwise (resp. componentwise) error bound is at most 2 max{l_brace}10,{radical}n{r_brace} {center_dot} {var_epsilon}{sub w}, and indeed bounds the true error. Here, n is the matrix dimension and w is single precision roundoff error. For worse conditioned problems, we get similarly small correct error bounds in over 89.4% of cases.

Demmel, James; Hida, Yozo; Kahan, William; Li, Xiaoye S.; Mukherjee, Soni; Riedy, E. Jason

2005-02-07

292

Terrestrial impact melt rocks and glasses  

NASA Astrophysics Data System (ADS)

The effects of meteorite and comet impact on Earth are rock brecciation, the formation of shock metamorphic features, rock melting, and the formation of impact structures, i.e. simple craters, complex craters, and multi-ring basins. Large events, such as the 65-Ma Chicxulub impact, are believed to have had catastrophic environmental effects that profoundly influenced the development of life on Earth. In this review, an attempt is made to summarize some of the voluminous literature on impact melting, one important aspect of planetary impact, provide some comments on this process, and to make suggestions for future research. The products of impact melting are glasses, impact melt rocks, and pseudotachylites. Our treatise deals mainly with the geological setting, petrography, and major-element chemistry of melt rocks and glasses. Impact glasses, in several petrographic aspects, are similar to volcanic glasses, but they are associated with shock metamorphosed mineral and rock fragments and, in places, with siderophile element anomalies suggestive of meteoritic contamination. They are found in allogenic breccia deposits within (fall-back 'suevite') and outside (fall-out 'suevite') impact craters and, as spherules, in distal ejecta. Large events, such as the K/T boundary Chicxulub impact, are responsible for the formation of worldwide ejecta horizons which are associated with siderophile element anomalies and shock metamorphosed mineral and rock debris. Impact glasses have a bulk chemical composition that is homogeneous but exemptions to this rule are common. On a microscopic scale, however, impact glasses are commonly strikingly heterogeneous. Tektites are glasses ejected from craters over large distances. They are characterized by very low water and volatile contents and element abundances and ratios that are evidence that tektites formed by melting of upper crustal, sedimentary rocks. Four tektite strewn-fields are known, three of which can be tied to specific impact craters. Impact melt rocks form sheets, lenses, and dike-like bodies within or beneath allogenic fallback breccia deposits in the impact crater and possibly on crater terraces and flanks. Dikes of impact melt rocks also intrude the rocks of the crater floor. They commonly contain shock metamorphosed target rock and mineral fragments in various stages of assimilation and are glassy or fine- to coarse-grained. Chemically, they are strikingly homogeneous, but as with impact glasses, exemptions to this rule do exist. Large and thick melt bodies, such as the Sudbury Igneous Complex (SIC), are differentiated or may represent a combination of impact melt rocks sensu-strictu and impact-triggered, deep-crustal melts. A concerted, multidisciplinary approach to future research on impact melting and on other aspects of meteorite and comet impact is advocated. Impact models are models only and uncritical reliance on their validity will not lead to a better understanding of impact processesespecially of melting, excavation, and deposition of allogenic breccias and the spatial position of breccias in relation to sheets and lenses of melt rocks within the crater. Impact-triggered pressure-release melting of target rocks beneath the excavation cavity may be responsible for the existence of melt rocks beneath the impact melt rocks sensu-strictu. This controversial idea needs to be tested by a re-evaluation of existing data and models, be they based on field or laboratory research. Only a relatively small number of terrestrial impact structures has been investigated in sufficient detail as it relates to geological and geophysical mapping. In this review, we summarize observations made on impact melt rocks and impact glasses in a number of North American (Brent, Haughton, Manicouagan, New Quebec, Sudbury, Wanapitei, all in Canada), Asian (Popigai, Russia; Zhamanshin, Kazakhstan), two South African structures (Morokweng and Vredefort), the Henbury crater field of Australia, and one European crater (Ries, Germany). Our tables listing major-element chemical compositions of impact

Dressler, B. O.; Reimold, W. U.

2001-12-01

293

Extra generations and discrepancies of electroweak precision data  

E-print Network

It is shown that additional chiral generations are not excluded by the latest electroweak precision data if one assumes that there is no mixing with the known three generations. In the case of ``heavy extra generations'', when all four new particles are heavier than $Z$ boson, quality of the fit for the one new generation is as good as for zero new generations (Standard Model). In the case of neutral leptons with masses around 50 GeV (``partially heavy extra generations'') the minimum of $\\chi^2$ is between one and two extra generations.

V. A. Novikov; L. B. Okun; A. N. Rozanov; M. I. Vysotsky

2002-01-27

294

Responses of terrestrial aridity to global warming  

NASA Astrophysics Data System (ADS)

dryness of terrestrial climate can be measured by the ratio of annual precipitation (P) to potential evapotranspiration (PET), where the latter represents the evaporative demand of the atmosphere, which depends on the surface air temperature, relative humidity, wind speed, and available energy. This study examines how the terrestrial mean aridity responds to global warming in terms of P/PET using the Coupled Model Intercomparison Project phase 5 transient CO2 increase to 2 CO2 simulations. We show that the (percentage) increase (rate) in P averaged over land is ~1.7%/C ocean mean surface air temperature increase, while the increase in PET is 5.3%/C, leading to a decrease in P/PET (i.e., a drier terrestrial climate) by ~3.4%/C. Noting a similar rate of percentage increase in P over land to that in evaporation (E) over ocean, we propose a framework for examining the change in P/PET, in which we compare the change in PET over land and E over ocean, both expressed using the Penman-Monteith formula. We show that a drier terrestrial climate is caused by (i) enhanced land warming relative to the ocean, (ii) a decrease in relative humidity over land but an increase over ocean, (iii) part of increase in net downward surface radiation going into the deep ocean, and (iv) different responses of PET over land and E over ocean for given changes in atmospheric conditions (largely associated with changes in temperatures). The relative contributions to the change in terrestrial mean aridity from these four factors are about 35%, 35%, 15%, and 15%, respectively. The slight slowdown of the surface wind over both land and ocean has little impact on the terrestrial mean aridity.

Fu, Qiang; Feng, Song

2014-07-01

295

Tectonic Evolution of the Terrestrial Planets  

NASA Technical Reports Server (NTRS)

The NASA Planetary Geology and Geophysics Program supported a wide range of work on the geophysical evolution of the terrestrial planets during the period 1 April 1997 - 30 September 2001. We here provide highlights of the research carried out under this grant over the final year of the award, and we include a full listing of publications and scientific meeting presentations supported by this project. Throughout the grant period, our group consisted of the Principal Investigator and several Postdoctoral Associates, all at the Department of Terrestrial Magnetism (DTM) of the Carnegie Institution of Washington.

Solomon, Sean C.; Senski, David G. (Technical Monitor)

2002-01-01

296

Solar-Terrestrial Science Strategy Workshop  

NASA Technical Reports Server (NTRS)

The conclusions and recommendations reached at the Solar Terrestrial Science Strategy Workshop are summarized. The charter given to this diverse group was: (1) to establish the level of scientific understanding to be accomplished with the completion of the current and near term worldwide programs; (2) identify the significant scientific questions to be answered by future solar terrestrial programs, and the programs required to answer these questions; and (3) map out a program strategy, taking into consideration currently perceived space capabilities and constraints, to accomplish the identified program.

Banks, Peter M. (editor); Roberts, William T. (editor); Kropp, Jack (editor)

1989-01-01

297

Female house wrens (Troglodytes aedon) increase the size, but not immunocompetence, of their offspring through extra-pair mating.  

PubMed

House wrens are typically socially monogamous, but frequently engage in extra-pair matings leading to multisired broods. Because females do not appear to acquire direct material benefits from their extra-pair mates, we tested the hypothesis that female house wrens derive indirect genetic benefits, such as enhanced immunocompetence (cutaneous immune activity, humoral immunity, and plasma bactericidal activity) and condition (size and haematoserological traits) for their offspring, by mating polyandrously. We predicted that extra-pair young (EPY) should show greater immune responsiveness and better body condition than their within-pair maternal half-siblings (WPY). Contrary to our prediction, WPY had higher cutaneous immune activity than their EPY brood-mates in two of three years, and EPY and WPY did not differ in measures of innate and humoral immunity. WPY also had higher albumin to gamma-globulin ratios than EPY; however, they were not in better condition based on other measures. EPY had consistently longer tarsi (a measure of long-bone size) than their WPY half-siblings, suggesting that females engage in extra-pair copulations with larger males. The benefits of large structural size in the study population is unknown, but based on evidence from other passerines, we suggest that structural size may be an important fitness-related trait in house wrens. We conclude that our results are not consistent with the hypothesis that females gain immune-related benefits for their offspring by engaging in extra-pair matings. Further study of the fitness consequences of differences in tarsus length is needed to determine whether females acquire size-related benefits for their offspring from extra-pair mates. PMID:18662223

Forsman, Anna M; Vogel, Laura A; Sakaluk, Scott K; Johnson, Bonnie G; Masters, Brian S; Johnson, L Scott; Thompson, Charles F

2008-08-01

298

Terrestrial ecosystem regulation of interannual variability in atmospheric CO2  

NASA Astrophysics Data System (ADS)

Linking interannual variability in the global carbon dioxide, CO2, growth rate to its ecological and physical drivers may provide a means to improve predictions of long-term carbon-climate feedbacks. Many studies have attributed variability in the global CO2 record to a single factor, such as temperature, drought, or fire, or have asserted a combination of controls using complex ecosystem models. The evolving temporal and spatial structure of atmospheric CO2 may enable a more effective attribution of these processes, but has not been used systematically for this purpose. Here we simulated the fingerprints that terrestrial fluxes of carbon originating from temperature and drought stress and biomass burning imprint on the latitudinal and temporal distribution atmospheric CO2 for the 1997-2009 period using the GEOS-Chem atmospheric model. In general, temperature, precipitation, and drought signatures were highly correlated across different latitude bands, indicating that no single factor was the dominant mechanism explaining most of the CO2 variability. Fires had a unique signature, particularly in the northern hemisphere as a consequence of large events in the boreal forest during 1998, 2004, and 2008. Statistical models that combined these factors were able to explain between 20% and 40% of the CO2 variability in the northern hemisphere and 40-50% in the southern hemisphere. Net ecosystem exchange fluxes from the tropics, temperature, precipitation, and drought time series explained a considerable amount of flux variability in the NH and SH extra-tropics. Fires accounted for 25% to 30% of the total modeled variability in the NH (north of 23N) with this amount decreasing to about 20% in the SH (south of 23S). We also examined results from CMIP5 coupled Earth System Models to quantify patterns of variability in atmospheric CO2 originating from terrestrial ecosystems. We compared the variations correlated with temperature and precipitation variability to estimate the apparent climate sensitivity over the historical period, and examined the implications for long term carbon storage as climate changes. The results from these generalized simulations show that accounting for the latitudinal variability in atmospheric CO2 as well as the time-lag from transport facilitates a better relationship between fluxes and observed variations.

Keppel-Aleks, G.; Randerson, J. T.; Mu, M.; Doney, S. C.; van der Werf, G.; Collatz, G. J.; Morton, D. C.

2013-12-01

299

BOOK REVIEW: Black Holes, Cosmology and Extra Dimensions Black Holes, Cosmology and Extra Dimensions  

NASA Astrophysics Data System (ADS)

The book Black holes, Cosmology and Extra Dimensions written by Kirill A Bronnikov and Sergey G Rubin has been published recently by World Scientific Publishing Company. The authors are well known experts in gravity and cosmology. The book is a monograph, a considerable part of which is based on the original work of the authors. Their original point of view on some of the problems makes the book quite interesting, covering a variety of important topics of the modern theory of gravity, astrophysics and cosmology. It consists of 11 chapters which are organized in three parts. The book starts with an introduction, where the authors briefly discuss the main ideas of General Relativity, giving some historical remarks on its development and application to cosmology, and mentioning some more recent subjects such as brane worlds, f(R)-theories and gravity in higher dimensions. Part I of the book is called 'Gravity'. Chapters two and three are devoted to the Einstein equations and their spherical symmetric black hole solutions. This material is quite standard and can be found in practically any book on General Relativity. A brief summary of the Kerr metric and black hole thermodynamics are given in chapter four. The main part of this chapter is devoted to spherically symmetric black holes in non-Einstein gravity (with scalar and phantom fields), black holes with regular interior, and black holes in brane worlds. Chapters five and six are mainly dedicated to wormholes and the problem of their stability. Part II (Cosmology) starts with discussion of the Friedmann-Robertson-Walker and de Sitter solutions of the Einstein equations and their properties. It follows by describing a `big picture' of the modern cosmology (inflation, post-inflationary reheating, the radiation-dominated and matter-dominated states, and modern stage of the (secondary) inflation). The authors explain how the inflation models allow one to solve many of the long-standing problems of cosmology, such as flatness of the Universe, the horizon problem and isotropy of cosmological microwave background. All this material is covered in chapter seven. Chapter eight contains brief discussion of several popular inflation models. Chapter nine is devoted to the problem of the large-scale structure formation from initial quantum vacuum fluctuation during the inflation and the spectrum of the density fluctuations. It also contains remarks on the baryonic asymmetry of the Universe, baryogenesis and primordial black holes. Part III covers the material on extra dimensions. It describes how Einstein gravity is modified in the presence of one or more additional spatial dimensions and how these extra dimensions are compactified in the Kaluza-Klein scheme. The authors also discuss how extra dimensions may affect low energy physics. They present examples of higher-dimensional generalizations of the gravity with higher-in-curvature corrections and discuss a possible mechanism of self-stabilization of an extra space. A considerable part of the chapter 10 is devoted to cosmological models with extra dimensions. In particular, the authors discuss how extra dimensions can modify 'standard' inflation models. At the end of this chapter they make several remarks on a possible relation of the value of fundamental constants in our universe with the existence of extra dimensions. Finally, in chapter 11 they demonstrate that several observable properties of the Universe are closely related with the special value of the fundamental physical constants and their fine tuning. They give interesting examples of such fine tuning and summarize many other cases. The book ends with discussion of a so-called 'cascade birth of universes in multidimensional spaces' model, proposed by one of the authors. As is evident from this brief summary of topics presented in the book, many interesting areas of modern gravity and cosmology are covered. However, since the subject is so wide, this inevitably implies that the selection of the topics and level of their presentation in many cases reflects the authors' own pre

Frolov, Valeri P.

2013-10-01

300

Evolution of the terrestrial planets (geological and petrological data)  

NASA Astrophysics Data System (ADS)

How the terrestrial solid planetary bodies were developed? What major stages of their irreversible evolution took place before they turned into "dead" stone balls? We discuss these problems on examples of the Earth and the Moon, which evolution studied the best. According to modern views, after accretion of these bodies, magma oceans of some hundreds km deep appeared on their surface. According to Jeffries (1929), solidification of large molted bodies, because of the difference between adiabatic gradient in silicate melts (0.3oC/km) and gradient of their melting points (3oC/km), could be going only upwards, from the bottom to the surface. As a result a powerful crystallizing differentiation of the oceans' magmas took place with accumulation of the most low-melting components to the surface. Due to different deep of the oceans on the Moon and the Earth, the primordial crusts on these bodies were rather different: mafic on the Moon and sialic on the Earth. Geological evolution of the Earth began 4 Ga ago from appearance of Archean granite-greenstone terranes (GGT) and divided them granulite belts. Mantle-derived magmatism of high-Mg komatiite-basaltic series was located in greenstone belts, which formed irregular network within GGTs and composed 10-15 The sharp change of the magmatic activity with appearance in global scale of geochemical-enriched Fe-Ti picrites and basalts occurred in interval 2.3-2.0 Ga ago. Such melts was typical for Phanerozoic within-plate magmatism and linked with thermochemical mantle plumes of the second generation, which ascended from the liquid core-mantle boundary (CMB). It was followed by plate tectonic appearance 2 Ga ago and from this particular time such tectonic regime has existed till now. From this particular time, ancient Earth's continental crust began to involved in subduction processes and interchange by secondary oceanic crust which forms about 70Where this geochemical-enriched material was conserved and how it was activated? We suggest that such situation could be possible only in case when (1) accretion of the Earth was heterogeneous, and (2) warming of the Earth occurred downwards, from surface to core. It was, probably, a result of moving inwards a wave of deformations, accompanied by emission of heat. At the first stage the wave went through depleted (in result of directed solidification of magma ocean) mantle and led to appearance of mantle superplumes of the first generation. At the second stage it reached iron core, melted it, which led to appearance of mantle supeplumes of the second generation (thermochemical), enriched in fluids, Fe, Ti, alcalies, incompatible elements, etc. Material of such superplumes could rich more shallow levels and led to active interactions of their extended heads with solid lithosphere, which caused changing of tectonic activity character. We suggest that terrestrial planets were developed at the same, but shortened scenario, and more quick. At the Moon the earliest magmatism of highlands were close to terrestrial early Paleoproterozoic SHMS and at the boundary 3.9-3.8 Ga ago was changed by maria magmatism, close in composition to MORB and OIB. By analogy with the Earth, we suggest that maria magmatism was linked with ascending of thermochemical superplumes, generated at the lunar CMB, when it's liquid iron core was yet existed. Ancient planums on Mars and tesseras at the Venus among vast planides, composed by basaltic flows can also evidence about two stages of their development. Judging on absence of magnetic field, their liquid cores ("energetic hearts") are of no consequence and they are dead bodies now. Work was supported by grant RFBR 07-05-00496

Sharkov, Evgenii

301

Probing large extra dimensions with IceCube  

NASA Astrophysics Data System (ADS)

In models with Large Extra Dimensions the smallness of neutrino masses can be naturally explained by introducing gauge singlet fermions which propagate in the bulk. The Kaluza-Klein modes of these fermions appear as towers of sterile neutrino states on the brane. We study the phenomenological consequences of this picture for the high energy atmospheric neutrinos. For this purpose we construct a detailed equivalence between a model with large extra dimensions and a (3+n) scenario consisting of three active and n extra sterile neutrino states, which provides a clear intuitive understanding of Kaluza-Klein modes. Finally, we analyze the collected data of high energy atmospheric neutrinos by IceCube experiment and obtain bounds on the radius of extra dimensions.

Esmaili, Arman; Peres, O. L. G.; Tabrizi, Zahra

2014-12-01

302

Adrenal and Extra-adrenal Myelolipomas - A Comparative Case Report  

PubMed Central

Myelolipoma is an uncommon benign tumour composed of mature fat tissue and haematopoietic elements and is most commonly found in the adrenal gland. We report a case, which was discovered incidentally on chest X-ray, of a rare occurrence of multifocal extra-adrenal myelolipoma in the thoracic paravertebral region. This was further investigated with multi-detector computed tomography and magnetic resonance imaging. The presumed diagnosis, of extra-adrenal myelolipoma, was histologically confirmed via tissue sample obtained by computed tomography guided biopsy. We compare the adrenal and extra-adrenal entities from the perspective of published literature and also review the cases, published in Pubmed, of extra-adrenal myelolipomas in order to summarize the different locations of this lesion. PMID:24967008

Hakim, Arsany; Rozeik, Christoph

2014-01-01

303

TASI 2004 Lectures on the Phenomenology of Extra Dimensions  

E-print Network

The phenomenology of large, warped, and universal extra dimensions is reviewed. Characteristic signals are emphasized rather than an extensive survey. This is the writeup of lectures given at the Theoretical Advanced Study Institute in 2004.

Graham D. Kribs

2006-05-30

304

Is dark matter an extra-dimensional effect?  

E-print Network

We investigate the possibility that the observed behavior of test particles outside galaxies, which is usually explained by assuming the presence of dark matter, is the result of the dynamical evolution of particles in higher dimensional space-times. Hence, dark matter may be a direct consequence of the presence of an extra force, generated by the presence of extra-dimensions, which modifies the dynamic law of motion, but does not change the intrinsic properties of the particles, like, for example, the mass (inertia). We discuss in some detail several possible particular forms for the extra force, and the acceleration law of the particles is derived. Therefore, the constancy of the galactic rotation curves may be considered as an empirical evidence for the existence of the extra dimensions.

M. E. Kahil; T. Harko

2009-03-26

305

29 CFR 541.604 - Minimum guarantee plus extras.  

Code of Federal Regulations, 2014 CFR

...DEPARTMENT OF LABOR REGULATIONS DEFINING AND DELIMITING THE EXEMPTIONS FOR EXECUTIVE, ADMINISTRATIVE, PROFESSIONAL, COMPUTER AND OUTSIDE SALES EMPLOYEES Salary Requirements 541.604 Minimum guarantee plus extras. (a) An...

2014-07-01

306

Body Image  

NSDL National Science Digital Library

Whether you feel flabby or fit depends on your brain as well as your waistline. This according to neurologist Henrik Ehrsson and his colleagues at University College, London. They stimulated the nerves in volunteers' bodies in a way that tricked them into feeling like their waistlines were shrinking. The illusion activated a part of the subjects' brains called the posterior parietal cortex, which integrates sensory signals from all over the body. The nerve stimulation for each person was the same, yet some experienced the shrinking sensation more strongly--and they had more activity in this part of the brain. That suggests that two people who have identical bodies might experience their body image differently. This may lead to a better understanding of anorexia and other body-image disorders. This Science Update also contains in text format details of the research, which leads to these findings presented in the Science Update podcast. It also offers links to the other podcasts topics and resources for further inquiry.

American Association for the Advancement of Science (;)

2006-01-02

307

Extra-Axial Chordoma Presenting as a Lung Mass  

Microsoft Academic Search

Chordomas are slow-growing, malignant tumors of bone that are thought to be derived from the primitive notochord and occur almost exclusively in the axial skeleton. The so-called extra-axial chordoma has been shown to demonstrate identical features to the classic chordoma, except that it is found outside the axial skeleton. Only six cases of extra-axial chordoma have been reported in the

Seung Yong Park; So Ri Kim; Yeong Hun Choe; Ka Young Lee; Seoung Ju Park; Heung Bum Lee; Gong Yong Jin; Kyu Yun Jang; Yong Chul Lee

2009-01-01

308

Radical loss of an extreme extra-pair mating system  

Microsoft Academic Search

BACKGROUND: Mating outside the pair-bond is surprisingly common in socially monogamous birds, but rates of extra-pair paternity (EPP) vary widely between species. Although differences in life-history and contemporary ecological factors may explain some interspecific variation, evolutionary forces driving extra-pair (EP) mating remain largely obscure. Also, since there is a large phylogenetic component to the frequency of EPP, evolutionary inertia may

Sjouke A Kingma; Michelle L Hall; Gernot Segelbacher; Anne Peters

2009-01-01

309

MICROBIAL ECOLOGY OF THE TERRESTRIAL SUBSURFACE  

EPA Science Inventory

A current view is presented of the microbial ecology of the terrestrial subsurface by considering primarily the ecology of shallow aquifer sediments. The properties of the aquifer sediments and groundwater determine their ability to support microbial life and control the abundanc...

310

Design considerations of terrestrial communications system  

Microsoft Academic Search

We study design considerations, measure of effectiveness (MOE) factors, for tactical communications system. Terrestrial communications system (TCS) architecture for army is described and the link delay performance as a grade of service (GOS) factor is analyzed. One can see that flood search routing algorithm in mesh networks is well suited for tactical communications network and survivability requirements.

Y. C. Park

2007-01-01

311

Trophic polymorphism in a terrestrial salamander  

Microsoft Academic Search

Question: Does habitat heterogeneity promote trophic polymorphism in a terrestrial salamander? Hypothesis: Eastern red-backed salamanders (Plethodon cinereus) in upland and lowland habitats differ morphologically because their prey's size differs between those habitats. Field site: Five mature hardwood forests in central New York and northern Pennsylvania, USA, with known differences in diet between upland and lowland habitats. Methods: We collected animals

John C. Maerz; Erin M. Myers

2006-01-01

312

Resonant Mechanism of Solar-Terrestrial Relationships  

Microsoft Academic Search

The present paper studies the resonant mechanism of solar-terrestrial relationships and their influence on the state of individual systems of the human organism. The level of statistical correlation between the characteristics of the human cardiovascular system and the brain activity and the fundamental modes of circumterrestrial resonators are numerically evaluated.

A. G. Kolesnik; A. S. Borodin; S. A. Kolesnik; S. V. Pobachenko

2003-01-01

313

Dinosaurs and the Cretaceous Terrestrial Revolution  

E-print Network

Dinosaurs and the Cretaceous Terrestrial Revolution Graeme T. Lloyd1,*, Katie E. Davis2 , Davide of dinosaurs reached its highest peak during the mid- and Late Cretaceous, the 50 Myr that preceded their extinction, and yet this explosion of dinosaur diversity may be explained largely by sampling bias. It has

Benton, Michael

314

Research in solar-terrestrial physics  

NASA Astrophysics Data System (ADS)

A report on research in solar-terrestrial physics includes the following: Ultra Low Frequency Waves; Magnetic Pulsations; Predicting Geomagnetic Activity Using Solar Wind Data; Auroral Electrojets; Partial Ring Current; The Symmetric Ring Current; The Role of Driven and Unloading Processes in Substorms; A Study of the Near-Earth Plasma Sheet; and Methods of Time Series Data Base Management.

1986-01-01

315

Saponins in Tribulus terrestris Chemistry and Bioactivity  

Microsoft Academic Search

Tribulus terrestris is a valuable herb known for its application in the folk medicine in many parts of the world. Furostanol and spirostanol saponins of tigogenin, neotigogenin, gitogenin, neogitogenin, hecogenin, neohecogenin, diosgenin, chlorogenin, ruscogenin and sarsasapogenin type are frequently found in this plant. Four sulphated saponins of tigogenin and diosgenin type are also isolated. Extracts and steroidal saponins have been

I. Kostova; D. Dinchev

2005-01-01

316

High efficiency, long life terrestrial solar panel  

NASA Technical Reports Server (NTRS)

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

1977-01-01

317

High efficiency, long life terrestrial solar panel  

Microsoft Academic Search

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was

T. Chao; S. Khemthong; R. Ling; S. Olah

1977-01-01

318

Widespread genetic exchange among terrestrial bacteriophages  

E-print Network

Widespread genetic exchange among terrestrial bacteriophages Olin K. Silander*§ , Daniel M October 27, 2005 (received for review April 15, 2005) Bacteriophages are the most numerous entities Microbes are the most numerous entities in the biosphere, and viruses that infect bacteria (bacteriophages

Hartl, Daniel L.

319

Two new terrestrial Enchytraeus species (Oligochaeta, Annelida)  

Microsoft Academic Search

Enchytraeus crypticus n.sp. and Enchytraeus doerjesi n.sp. were discovered in laboratory cultures of terrestrial enchytraeids in the course of a project evaluating various non-light-microscopical techniques for their taxonomic utility. Ultrastructural and molecular features of the two species are published elsewhere; the present paper describes their conventional morphological characters and their life cycle data under laboratory conditions.

W. Westheide; U. Graefe

1992-01-01

320

Terrestrial solar cells present and future  

Microsoft Academic Search

In this paper the principles of operation of various types of solar cell are described. Progress in photovoltaics is traced through the development of the monocrystalline silicon cell for space applications where the emphasis is upon reliability and power\\/weight ratio, to terrestrial cells where the emphasis is upon low-cost production. The role of other contenders such as polycrystalline silicon, amorphous

B. T. Debney; J. R. Knight

1978-01-01

321

The geophysical signature of terrestrial impact craters  

Microsoft Academic Search

Terrestrial impact craters are examined in terms of their geophysical characteristics which can be used to identify additional impact craters. The geophysical signatures examined include the circular gravity low which is modeled for the cases of bowl-shaped and complex craters. The size of the gravity anomaly for both types of craters is established and modeled with known morphometric parameters of

M. Pilkington; R. A. F. Grieve

1992-01-01

322

DISS. ETH NO. 17036 Calibration of a Terrestrial Laser Scanner  

E-print Network

DISS. ETH NO. 17036 Calibration of a Terrestrial Laser Scanner for Engineering Geodesy For several years now, terrestrial laser scanning has become an additional surveying technique in geodesy heritage, reverse engineering, and engineering geodesy. Due to the increased requirements regarding

Giger, Christine

323

Extra-Pair Mating and Evolution of Cooperative Neighbourhoods  

PubMed Central

A striking but unexplained pattern in biology is the promiscuous mating behaviour in socially monogamous species. Although females commonly solicit extra-pair copulations, the adaptive reason has remained elusive. We use evolutionary modelling of breeding ecology to show that females benefit because extra-pair paternity incentivizes males to shift focus from a single brood towards the entire neighbourhood, as they are likely to have offspring there. Male-male cooperation towards public goods and dear enemy effects of reduced territorial aggression evolve from selfish interests, and lead to safer and more productive neighbourhoods. The mechanism provides adaptive explanations for the common empirical observations that females engage in extra-pair copulations, that neighbours dominate as extra-pair sires, and that extra-pair mating correlates with predation mortality and breeding density. The models predict cooperative behaviours at breeding sites where males cooperate more towards public goods than females. Where maternity certainty makes females care for offspring at home, paternity uncertainty and a potential for offspring in several broods make males invest in communal benefits and public goods. The models further predict that benefits of extra-pair mating affect whole nests or neighbourhoods, and that cuckolding males are often cuckolded themselves. Derived from ecological mechanisms, these new perspectives point towards the evolution of sociality in birds, with relevance also for mammals and primates including humans. PMID:24987839

Eliassen, Sigrunn; Jrgensen, Christian

2014-01-01

324

Body Imaging  

NASA Technical Reports Server (NTRS)

The high-tech art of digital signal processing (DSP) was pioneered at NASA's Jet Propulsion Laboratory (JPL) in the mid-1960s for use in the Apollo Lunar Landing Program. Designed to computer enhance pictures of the Moon, this technology became the basis for the Landsat Earth resources satellites and subsequently has been incorporated into a broad range of Earthbound medical and diagnostic tools. DSP is employed in advanced body imaging techniques including Computer-Aided Tomography, also known as CT and CATScan, and Magnetic Resonance Imaging (MRI). CT images are collected by irradiating a thin slice of the body with a fan-shaped x-ray beam from a number of directions around the body's perimeter. A tomographic (slice-like) picture is reconstructed from these multiple views by a computer. MRI employs a magnetic field and radio waves, rather than x-rays, to create images.

2001-01-01

325

Body Imaging  

NASA Technical Reports Server (NTRS)

The high-tech art of digital signal processing (DSP) was pioneered at NASA's Jet Propulsion Laboratory (JPL) in the mid-1960s for use in the Apollo Lunar Landing Program. Designed to computer enhance pictures of the Moon, this technology became the basis for the Landsat Earth resources satellites and subsequently has been incorporated into a broad range of Earthbound medical and diagnostic tools. DSP is employed in advanced body imaging techniques including Computer-Aided Tomography, also known as CT and CATScan, and Magnetic Resonance Imaging (MRI). CT images are collected by irradiating a thin slice of the body with a fan-shaped x-ray beam from a number of directions around the body's perimeter. A tomographic (slice-like) picture is reconstructed from these multiple views by a computer. MRI employs a magnetic field and radio waves, rather than x-rays, to create images. In this photograph, a patient undergoes an open MRI.

2001-01-01

326

Evolution of the structure of iron meteorites under terrestrial climate  

NASA Astrophysics Data System (ADS)

Introduction: Meteoritic iron is affected by many factors in terrestrial conditions. First of all, abundance of water induces an oxidization process. Despite rather high nickel concentration in meteoritic iron, rust is forming on a surface of extraterrestrial matter. But also transformation processes occur inside meteorites at rather low climatic temperatures (0.15 of the melting temperature). Such reaction has been observed for the first time in the Bilibino meteorite [1]. Experiments: Structural changes in kamacite were investigated in ancient iron meteorite falls (Aliskerovo IIIAB, Bilibino IIAB). All of them demonstrate uncompleted recrystallization. Polished sections were analyzed using inverted optical microscope Axiovert 40 MAT and SEM SIGMA VP with EDS and EBSD units. Results: Different percentage of recrystallization was found in Aliskerovo and Bilibino meteorites. 4 % of the section surface in Aliskerovo is occupied by recrystallization products. This value for Bilibino is equal to 80 %. It was noticed that recrystallization started from the kamacite-rhabdite boundaries in the Bilibino meteorite and from the kamacite-schreibersite boundaries in the Aliskerovo meteorite. There are strongly-etched sites in the recrystallized zones. One can suggest that these sites are traces of former boundaries. It is possible to think that the boundaries were moving with jumps because of the position of these sites in the recrystallized zone. Also it was noticed that there is a net of cracks before the recrystallization reaction front. A possible reason for this phenomenon is a wedge of extra material which generates an elastic stress field in the vicinity of the grain boundary [2]. All these phenomena can be explained using the Kirkendall effect on the grain boundary: the boundary shift is the result of the different concentrations of vacancies between the boundary sides.

Yakovlev, G.; Grokhovsky, V.

2014-07-01

327

Body Imaging  

NASA Technical Reports Server (NTRS)

Magnetic Resonance Imaging (MRI) and Computer-aided Tomography (CT) images are often complementary. In most cases, MRI is good for viewing soft tissue but not bone, while CT images are good for bone but not always good for soft tissue discrimination. Physicians and engineers in the Department of Radiology at the University of Michigan Hospitals are developing a technique for combining the best features of MRI and CT scans to increase the accuracy of discriminating one type of body tissue from another. One of their research tools is a computer program called HICAP. The program can be used to distinguish between healthy and diseased tissue in body images.

1990-01-01

328

Terrestrial Sea Ice Morphology: Considerations for Europa  

NASA Astrophysics Data System (ADS)

The Galileo mission has returned the first high-resolution (21 m/pixel) images of the surface of Europa. These images reveal structures with morphologies reminiscent of those seen on terrestrial sea ice. Although it is premature to make one-to-one analogies between sea ice and Europa's surface, a review of the types of surface features commonly formed on Earth and of various sea-ice processes can provide insight into the complex geology of Europa. For example, deformation of terrestrial sea ice results from winds, tides, and currents and from thermally induced stresses; the resulting features include fractures ranging in width from millimeters to kilometers, pressure ridges, shear ridges, and rafted ice. Potential agents of deformation on Europa are more likely to be limited to tidal flexing and possibly convection, but could produce similar features and perhaps account for the ridges and fractures seen in many areas. Subtle differences in albedo and color in terrestrial sea ice result from differences in ice thickness and grain size, attributed to factors such as the rate of ice-crystal growth, water turbulence, age of the ice, and deformation. Similar factors could account for differences observed in the bright icy plains of Europa. Moreover, salts in both the solid form and as brine vary in concentration and composition as a function of space and time on Earth, leading to differences in density and the strength of ice sheets. Salts are also suspected in the europan ice and could lead to similar differences, enhancing the creation of topographic relief from density contrasts and the formation of fractures from brittle failure of the ice. Differences in the environments between Europa and terrestrial sea ice in terms of parameters such as temperature, gravity, time, and ice compositions suggest caution in drawing direct analogies. Future work by the planetary and sea-ice communities must include understanding the terrestrial processes sufficiently for extrapolation to Europa.

Greeley, Ronald; Sullivan, Robert; Coon, Max D.; Geissler, Paul E.; Tufts, B. Randall; Head, James W.; Pappalardo, Robert T.; Moore, Jeffrey M.

1998-09-01

329

In-line digital holographic microscopy for terrestrial and exobiological research  

NASA Astrophysics Data System (ADS)

We describe here a simple digital in-line holographic microscope (DIHM) that was used to investigate the microbial life forms that exist in perennial springs and glacial melt-water pools on Axel Heiberg Island at near 80N latitude in the Canadian High Arctic. The instrument determined an upper limit of the density of microbial organisms in the springs and also found an abundance of algae and bacteria in the pools formed from glacial run off. The discovery of life in extra-terrestrial regions of our solar system has been the aim of several space missions. DIHM can capture the dynamics of objects throughout an imaging volume with wavelength limited resolution. The simplicity of DIHM technology furthermore allows the construction of very light-weight and rugged instruments that we believe can be easily adapted for space missions and exobiological studies.

Jericho, S. K.; Klages, P.; Nadeau, J.; Dumas, E. M.; Jericho, M. H.; Kreuzer, H. J.

2010-03-01

330

A combined terrestrial reference frame based on space geodesy.  

NASA Astrophysics Data System (ADS)

A terrestrial reference frame of 64 sites has been compiled on the basis of several space geodesy analyses, leading to the last realisation of the Terrestrial System of the BIH, BTS 1987. This realisation provides the initial definition of the IERS Terrestrial System.

Boucher, C.; Altamimi, Z.; Feissel, M.

1989-06-01

331

Global response patterns of terrestrial plant species to nitrogen addition  

Microsoft Academic Search

Summary Better understanding of the responses of terrestrial plant species under global nitrogen (N) enrichment is critical for projection of changes in structure, functioning, and service of terrestrial ecosystems. Here, a meta-analysis of data from 304 studies was carried out to reveal the general response patterns of terrestrial plant species to the addition of N. Across 456

Jianyang Xia; Shiqiang Wan

2008-01-01

332

Linking Terrestrial and Marine Conservation Planning and Threats Analysis  

Microsoft Academic Search

The existence of the Gulf of Mexico dead zone makes it clear that marine ecosystems can be damaged by terrestrial inputs. Marine and terrestrial conservation planning need to be aligned in an explicit fashion to fully represent threats to marine systems. To integrate conservation planning for terrestrial and marine systems, we used a novel threats assessment that included 5 cross-system

HEATHER TALLIS; ZACH FERDAA; ELIZABETH GRAY

2008-01-01

333

Assessing New Materials, Technologies, and Implementing Strategies for Space Fusion Propulsion as Applied to an Extra-Solar-System Mission  

NASA Astrophysics Data System (ADS)

In this paper, we strive to achieve four goals: (1) to place into the open literature additional basic information relevant to the continuous-mode space fusion power (for example, fusion-fuel choice, the importance of plasma-ion fuel mix, plasma temperature, and four important radiations), (2) to give an example of the application of this information to adapt (using three design principles), and then optimize (using a new design tool) a terrestrial fusion reactor for space propulsion, (3) to describe a candidate deep-space mission called the Solar Gravity Lens (SGL) mission that demonstrates it is technically reasonable to propose, and intensify, studies for performing an extra-solar- system mission, and (4) to describe the application of new materials and technology (identified in the laboratory but not necessarily developed) that may dramatically improve performance of space-fusion-propulsion concepts.

Carpenter, Scott A.; Deveny, Marc E.; Vulpetti, Giovanni

1994-07-01

334

DC and transient characterization of a compact Schottky body contact technology for SOI transistors  

Microsoft Academic Search

A self-aligned Schottky diode method for body contacting partially depleted silicon-on-insulator (SOI) transistors applicable to technologies that incorporate silicide cladded junctions is presented. The Schottky body contacted transistor requires no extra manufacturing steps, uses the same or less area than a transistor using other body contacting schemes and allows bi-directional operation. Extensive dc and transient characterization of the Schottky body

Jeffrey W. Sleight; Kaizad R. Mistry

1999-01-01

335

Body Circulation  

NSDL National Science Digital Library

Students are introduced to the circulatory system, the heart, and blood flow in the human body. Through guided pre-reading, during-reading and post-reading activities, students learn about the circulatory system's parts, functions and disorders, as well as engineering medical solutions. By cultivating literacy practices as presented in this lesson, students can improve their scientific and technological literacy.

Integrated Teaching and Learning Program,

336

Formation and Internal Structure of Terrestrial Planets, and Atmospheric Escape  

NASA Astrophysics Data System (ADS)

As of 2014 April 21, over 1490 confirmed exoplanets and 3705 Kepler candidates have been detected. This implies that exoplanets may be ubiquitous in the universe. In this paper, we focus on the formation, evolution, and internal structure of terrestrial planets, and the atmospheric escape of close-in planets. In chapter 2, we investigate the dynamical evolution of planetary system after the protoplanetary disk has dissipated. We find that in the final assembly stage, the occurrence of terrestrial planets is quite common and in 40% of our simulations finally at least one planet is formed in the habitable zone. We also find that if there is a highly-inclined giant planet in the system, a great many bodies will be either driven out of the system, or collide with the giant planet or the central star. This will lead to the difficulty in planetary accretion. Moreover, our results show that planetary migration can lead to the formation of close-in planets. Besides migration, close-in terrestrial planets can also be formed by a collision-merger mechanism, which means that planetary embryos can kick terrestrial planets directly into orbits that are extremely close to their parent stars. In chapter 3, we construct numerically an internal structure model for terrestrial planets, and provide three kinds of possible internal structures of Europa (Jupiter's moon) based on this model. Then, we calculate the radii of low-mass exoplanets for various mass combinations of core and mantle, and find that some of them are inconsistent with the observed radius of rocky planets. This phenomenon can be explained only if there exists a large amount of water in the core, or they own gaseous envelopes. In chapter 4, we improve our planetary evolution codes using the semi-gray model of Guillot (2010), which includes the incident flux from the host star as a heating source in planetary atmosphere. The updated codes can solve the structure of the top radiative zone of intensely irradiated planets, and thus can simulate the atmospheric escape of close-in planets driven by strong stellar X-ray or EUV emissions. We find that low-mass planets are sensitive to the atmospheric escape, and they could lose all their initial H/He envelopes during the evolution. On the other hand, gas giant can only lose a small fraction of their initial envelopes. We then carry out a parameter study of atmospheric escape at the planetary core mass, envelope mass fraction, and semi-major axis space. We find that the most intense phase of evaporation occurs within the early 100 Myr. Afterwards, atmospheric escape only has a small impact on the planetary evolution. In chapter 5, we apply our new planetary evolution model to different synthetic planet populations that are directly produced by the core-accretion paradigm (Mordasini et al. 2012a,b). We show that although the mass distribution of the planet populations is hardly affected by evaporation, the radius distribution clearly shows a break around 2 R_{?}. This break leads to a bimodal distribution in planet sizes (Owen & Wu 2013). Furthermore, the bimodal distribution is related to the initial characteristics of the planetary populations. We find that in two extreme cases, namely without any evaporation or with a 100% heating efficiency in the evaporation model, the final radius distributions show significant differences compared to the radius distribution of Kepler candidates. In chapter 6, we introduce a radiative transfer model that can calculate the radiation spectrum of close-in exoplanets.

Jin, S.

2014-11-01

337

Planetary System Evolution in the Terrestrial Zone  

NASA Astrophysics Data System (ADS)

We propose to characterize the role of major collisional episodes in the terrestrial zones of other planetary systems, using data from WISE (and Spitzer). We will: 1.) identify old stars whose terrestrial zones have recently been shaken up dynamically (e.g., activity similar to the Late Heavy Bombardment); and 2.) look for young stars where major collisions are occurring, signaling a phase analogous to the one when our Moon was formed. These two phases represent critical periods in the evolution of the Solar System. The Late Heavy Bombardment resulted from a destabilization of the Solar System by a mean-motion resonance between Jupiter and Saturn, leading to ejection of most of the planetesimals and an intense period of impacts onto the terrestrial planets. The formation of the Moon occurred in a younger violent phase, extending roughly from 30 to 130 Myr, when dynamical models predict that giant impacts will still occur even though most of the terrestrial planet formation is complete. Both of these phases would have produced copious dust in the terrestrial zone. Similar activity around other stars is detectable through the mid-infrared excesses emitted by such dust when it is warmed by the star (creating warm debris disks). However, previous infrared surveys have lacked the sensitivity, accuracy, or sky coverage to study this process systematically. For the first time, the WISE all-sky survey at 22 microns combines: 1.) a sufficiently large number of stars that these rare events should be seen in reasonable numbers; and 2.) mid-infrared photometry with sufficient accuracy to detect the excesses, even to within < 10% of the stellar photospheres. After extracting candidates from the WISE data, we will weed out false positives due to chance superpositions of sources or stellar mass loss. This will require acquiring ancillary data through a combination of information from the literature and new targeted observations using groundbased facilities. We will determine ages for the stars that survive this screening, using indicators such as chromospheric activity, spectral type (giant vs. main sequence), and position on a metallicity-adjusted HR diagram. The result will be a listing of stars with well-estimated ages and accurately- measured excesses signaling likely violent collisional episodes, providing a broad perspective on the frequency and intensity of the violent phases of planetary system evolution. We will put this work into context by comparison with the results of our theoretical models of debris disk collisional cascades and evolution. Our proposed work will allow comparison of critical events in the evolution of the Solar System and the Earth with the evolution of other planetary systems in their terrestrial zones.

Rieke, George

338

Linkages between terrestrial ecosystems and the atmosphere  

NASA Technical Reports Server (NTRS)

The primary research issue in understanding the role of terrestrial ecosystems in global change is analyzing the coupling between processes with vastly differing rates of change, from photosynthesis to community change. Representing this coupling in models is the central challenge to modeling the terrestrial biosphere as part of the earth system. Terrestrial ecosystems participate in climate and in the biogeochemical cycles on several temporal scales. Some of the carbon fixed by photosynthesis is incorporated into plant tissue and is delayed from returning to the atmosphere until it is oxidized by decomposition or fire. This slower (i.e., days to months) carbon loop through the terrestrial component of the carbon cycle, which is matched by cycles of nutrients required by plants and decomposers, affects the increasing trend in atmospheric CO2 concentration and imposes a seasonal cycle on that trend. Moreover, this cycle includes key controls over biogenic trace gas production. The structure of terrestrial ecosystems, which responds on even longer time scales (annual to century), is the integrated response to the biogeochemical and environmental constraints that develop over the intermediate time scale. The loop is closed back to the climate system since it is the structure of ecosystems, including species composition, that sets the terrestrial boundary condition in the climate system through modification of surface roughness, albedo, and, to a great extent, latent heat exchange. These separate temporal scales contain explicit feedback loops which may modify ecosystem dynamics and linkages between ecosystems and the atmosphere. The long-term change in climate, resulting from increased atmospheric concentrations of greenhouse gases (e.g., CO2, CH4, and nitrous oxide (N2O)) will further modify the global environment and potentially induce further ecosystem change. Modeling these interactions requires coupling successional models to biogeochemical models to physiological models that describe the exchange of water, energy, and biogenic trace gases between the vegetation and the atmosphere at fine time scales. There does not appear to be any obvious way to allow direct reciprocal coupling of atmospheric general circulation models (GCM's), which inherently run with fine time steps, to ecosystem or successional models, which have coarse temporal resolution, without the interposition of physiological canopy models. This is equally true for biogeochemical models of the exchange of carbon dioxide and trace gases. This coupling across time scales is nontrivial and sets the focus for the modeling strategy.

Bretherton, Francis; Dickinson, Robert E.; Fung, Inez; Moore, Berrien, III; Prather, Michael; Running, Steven W.; Tiessen, Holm

1992-01-01

339

Space and Terrestrial Photovoltaics: Synergy and Diversity  

NASA Technical Reports Server (NTRS)

A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the '70s and '80s and the '90s and beyond. The synergy of both communities in the beginning and once again in the present and hopefully future are highlighted, with examples of the important features in each program. The space community which was impressed by the light-weight and reliability of photovoltaics drove much of the early development. Even up to today, nearly every satellites and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems were only a small fraction of the satellite and launch cost, the use of much of this technology for the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advancements, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost non-existent. Recent work by both communities have focused on the development thin film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and terrestrial solar cell communities shall once again share many common goals and, in fact, companies may manufacture both space and terrestrial solar cells in III-V materials and thin film materials. Basic photovoltaics research including these current trends in nanotechnology provides a valuable service for both worlds in that fundamental understanding of cell processes is still vitally important, particularly with new materials or new cell structures. It is entirely possible that one day we might have one solar array design that will meet the criteria for success in both space and on the Earth or perhaps the Moon or Mars.

Bailey, Sheila; Raffaelle, Ryne; Emery, Keith

2002-01-01

340

Space and Terrestrial Photovoltaics: Synergy and Diversity  

NASA Astrophysics Data System (ADS)

A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the '70s and '80s and the '90s and beyond. The synergy of both communities in the beginning and once again in the present and hopefully future are highlighted, with examples of the important features in each program. The space community which was impressed by the light-weight and reliability of photovoltaics drove much of the early development. Even up to today, nearly every satellites and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems were only a small fraction of the satellite and launch cost, the use of much of this technology for the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advancements, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost non-existent. Recent work by both communities have focused on the development thin film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and terrestrial solar cell communities shall once again share many common goals and, in fact, companies may manufacture both space and terrestrial solar cells in III-V materials and thin film materials. Basic photovoltaics research including these current trends in nanotechnology provides a valuable service for both worlds in that fundamental understanding of cell processes is still vitally important, particularly with new materials or new cell structures. It is entirely possible that one day we might have one solar array design that will meet the criteria for success in both space and on the Earth or perhaps the Moon or Mars.

Bailey, Sheila; Raffaelle, Ryne; Emery, Keith

2002-10-01

341

Blood, Sweat, and Trivia: Faculty Ratings of Extra-Credit Opportunities  

Microsoft Academic Search

Presents a study of psychology faculty who rated each of 39 extra-credit opportunities based on their of the item, educational value and the likelihood that all students would be able to complete the opportunity. Percentage of respondents using extra credit; Positive correlations between rated educational value an use of extra credit; Most commonly used extra-credit opportunities.

Hill G. William IV; Joseph J. Palladino; James A. Eison

1993-01-01

342

The Role of Extra-Credit Assignments in the Teaching of World Languages  

ERIC Educational Resources Information Center

The granting of extra credit is a hotly debated topic in all fields of education. Teachers are reluctant to offer extra credit for fear of inflating grades, but students are persistent in their demands for extra-credit points to which they have become accustomed. This article considers extra-credit assignments in the teaching of world languages.

Alley, David

2011-01-01

343

Body Code  

NSDL National Science Digital Library

This 9-minute animation -- the joint effort of a scientific animator, a time-lapse imaging expert, and a sound artist -- takes the viewer on a wordless journey through the molecular universe of the body's cells, tissues, and organs. One scene captures the signal for a cell to divide while another takes the viewer on a roller-coaster ride through a DNA strand as it is transcribed.

Drew Berry (The Walter and Eliza Hall Institute, Melbourne, Australia;); Jeremy Pickett-Heaps (University of Melbourne;); Fran§ois T©taz (The Walter and Eliza Hall Institute, Melbourne, Australia;)

2003-01-01

344

Extra area effects of cloud seeding - An updated assessment  

NASA Astrophysics Data System (ADS)

This paper examines the commonly-held hypothesis that cloud seeding reduces precipitation in regions adjacent to seeding target areas, sometimes referred to as downwind but more correctly referred to as extra area effects (the robbing Peter to pay Paul hypothesis). The overall concept in the potential creation of extra area effects from seeding is illustrated with respect to the hydrologic cycle, which includes both dynamical and microphysical processes. For the first time, results were synthesized from five operational and research weather modification experiments, including winter orographic snowpack enhancement and summer experiments to enhance rainfall. One of the most surprising aspects of these results is that extra area seeding effects on precipitation appear to be uniformly positive (5-15% increases, perhaps greater for some convective systems) for both winter and summer seeding projects examined in this paper. The spatial extent of the positive extra area seeding effects may extend to a couple hundred kilometers for winter orographic seeding projects and summer convective seeding projects (such as North Dakota, Texas, Thailand). Both microphysical and dynamical effects of seeding appear to be contributors to these extra area effects. Future work needs to incorporate larger data sets from some of the larger more sustained projects with advanced cloud models and tracer experiments.

DeFelice, T. P.; Golden, J.; Griffith, D.; Woodley, W.; Rosenfeld, D.; Breed, D.; Solak, M.; Boe, B.

2014-01-01

345

Particle creation in the presence of a warped extra dimension  

SciTech Connect

Particle creation in spacetimes with a warped extra dimension is studied. In particular, we investigate the dynamics of a conformally coupled, massless scalar field in a five-dimensional warped geometry where the induced metric on the 3-branes is that of a spatially flat cosmological model. We look at situations where the scale of the extra dimension is assumed (i) to be time independent or (ii) to have specific functional forms for time dependence. The warp factor is chosen to be that of the Randall-Sundrum model. With particular choices for the functional form of the scale factor (and also the function characterizing the time evolution of the extra dimension) we obtain the |{beta}{sub k}|{sup 2}, the particle number and energy densities after solving (wherever possible, analytically but, otherwise, numerically) the conformal scalar field equations. The behaviours of these quantities for the massless and massive Kaluza-Klein modes are examined. Our results show the effect of a warped extra dimension on particle creation and illustrate how the nature of particle production on the brane depends on the nature of warping, and the type of cosmological evolution as well as the temporal evolution of the extra dimension.

Ghosh, Suman; Kar, Sayan, E-mail: suman@cts.iitkgp.ernet.in, E-mail: sayan@cts.iitkgp.ernet.in [Department of Physics and Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur 721 302 (India)] [Department of Physics and Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur 721 302 (India)

2008-08-15

346

Detection of Terrestrial Planets Using Transit Photometry  

NASA Technical Reports Server (NTRS)

Transit photometry detection of planets offers many advantages: an ability to detect terrestrial size planets, direct determination of the planet's size, applicability to all main-sequence stars, and a differential brightness change of the periodic signature being independent of stellar distance or planetary orbital semi-major axis. Ground and space based photometry have already been successful in detecting transits of the giant planet HD209458b. However, photometry 100 times better is required to detect terrestrial planets. We present results of laboratory measurements of an end-to-end photometric system incorporating all of the important confounding noise features of both the sky and a space based photometer including spacecraft jitter. In addition to demonstrating an instrumental noise of less than 10 ppm (an Earth transit of a solar-like star is 80 ppm), the brightnesses of individual stars were dimmed to simulate Earth-size transit signals. These 'transits' were reliably detected as part of the tests.

Koch, David; Witteborn, Fred; Jenkins, Jon; Dunham, Edward; Boruci, William; DeVincenzi, Donald (Technical Monitor)

2001-01-01

347

Terrestrial Laser Scanner for Scour Visualizaton  

NASA Astrophysics Data System (ADS)

Examination of spatio-temporal variations of a terrestrial surface requires high-resolution measurements. Surface Examining Imager (SExI) developed by the University of Iowa Lidar Group is a terrestrial laser measurement system capable of spatially profiling a relatively small area (<20m^2) with mm-scale resolution. It was designed to be simple, affordable, and robust. Because the system employs line of sight principles, two SExIs can be deployed to scan the same area from different positions to see behind surface features and increase spatial resolution. Snell's law of refraction has been applied to underwater datasets to obtain a bathymetric survey for use in sediment scour visualization. This technique has been paired with Particle Image Velocimetry (PIV) to overlay surface velocity profiles on a raster image of the bathymetry.

Plenner, S.; Eichinger, W. E.

2011-12-01

348

The terrestrial bioluminescent animals of Japan.  

PubMed

Light production by organisms, or bioluminescence, has fascinated not only scientists but also ordinary people all over the world, and it has been especially so in Japan. Here we review the biological information available to date for all luminous terrestrial animals known from Japan, particularly focusing on their diversity and systematics, their biology and ecology in Japan, and putative function and biochemistry of their luminescence. In total 58 luminous terrestrial animals have been described from Japan, which consist of 50 fireflies (Coleoptera: Lampyridae), one glowworm beetle (Coleoptera: Phengodidae), two fungus gnats (Diptera: Keroplatidae), one springtail (Collembola), one millipede (Diplopoda), one centipede (Chilopoda) and two earthworms (Oligochaeta). For all except some firefly species, the DNA "barcode" sequences of a cytochrome oxidase subunit I region are provided. We also introduce how intricately the seasonal appearance and glimmering of luminous insects, in particular those of fireflies, have been interwoven into the culture, art, literature and mentality of Japanese people. PMID:22035300

Oba, Yuichi; Branham, Marc A; Fukatsu, Takema

2011-11-01

349

The precambrian evolution of terrestrial life.  

NASA Astrophysics Data System (ADS)

The early appearance of life on Earth suggests that under appropriate environmental conditions the probability of chemical evolution proceeding to the point of biogenesis may be reasonably high. Most of biological history has been the history of microorganisms, with tissue-grade plants and animals characterizing only the most recent 15% or so of the fossil record. Intelligent life has occupied only the latest instant in geological time. The time table of terrestrial evolution is governed more by the particulars of our planet's physical and biological history than by some universal tempo of evolutionary change. One aspect of terrestrial life that is likely to be universal is the organization of populations into efficient biogeochemical systems.

Knoll, A. H.

350

Global change and terrestrial hydrology - A review  

NASA Technical Reports Server (NTRS)

This paper reviews the role of terrestrial hydrology in determining the coupling between the surface and atmosphere. Present experience with interactive numerical simulation is discussed and approaches to the inclusion of land hydrology in global climate models ae considered. At present, a wide range of answers as to expected changes in surface hydrology is given by nominally similar models. Studies of the effects of tropical deforestation and global warming illustrate this point.

Dickinson, Robert E.

1991-01-01

351

A toy terrestrial carbon flow model  

NASA Technical Reports Server (NTRS)

A generalized carbon flow model for the major terrestrial ecosystems of the world is reported. The model is a simplification of the Century model and the Forest-Biogeochemical model. Topics covered include plant production, decomposition and nutrient cycling, biomes, the utility of the carbon flow model for predicting carbon dynamics under global change, and possible applications to state-and-transition models and environmentally driven global vegetation models.

Parton, William J.; Running, Steven W.; Walker, Brian

1992-01-01

352

Interferometer Designs for the Terrestrial Planet Finder  

NASA Technical Reports Server (NTRS)

The Terrestrial Planet Finder (TPF) is a space-based infrared interferometer that will combine high sensitivity and spatial resolution to detect and characterize planetary systems within 15 pc of our sun. TPF is a key element in NASA's Origins Program and is currently under study in its Pre-Project Phase. We review some of the interferometer designs that have been considered for starlight nulling, with particular attention to the architecture and subsystems of the central beam-combiner.

Lawson, P. R.; Dumont, P. J.; Colavita, M. M.

1999-01-01

353

Lunar and Planetary Science XXXV: Terrestrial Planets  

NASA Technical Reports Server (NTRS)

The session "Terrestrial Planets: included:Lunar Soils May Tell Us When the Geomagnetic Field First Appeared; Metal-Silicate Segregation in Deforming Dunitic Rocks: Applications to Core Formation in Europa and Ganymede; Diamond Formation in Core Segregation Experiments; The Effect of Pressure on Potassium Partitioning Between Metallic Liquid and Silicate Melt; Reduction of W, Mn, and Fe, During High-Temperature Vaporization; Micrometeoritic Neon in the Earth s Mantle ; and New Analyses of Diverse Hadean Zircon Inclusions from Jack Hills.

2004-01-01

354

Cosmogenic helium in a terrestrial igneous rock  

NASA Technical Reports Server (NTRS)

New helium isotopic measurements on samples from the Kula formation of Haleakala volcano of Hawaii are presented that are best explained by an in situ cosmogenic origin for a significant fraction of the He-3. Results from crushing and stepwise heating experiments, and consideration of the exposure age of the sample at the surface and the cosmic ray fluxes strongly support this hypothesis. Although crustal cosmogenic helium has been proposed previously, this represents its first unambiguous identification in a terrestrial sample.

Kurz, M. D.

1986-01-01

355

Comparison Charts of Geological Processes: Terrestrial Planets  

NSDL National Science Digital Library

This chart presents information on the geological processes (volcanism, impact cratering, tectonics, and gradation) that have affected the Earth, Moon, and the terrestrial planets. Students compare the effects these processes have had on the Moon and planets. There is also a blank chart and a sheet of notes on the geological processes that may be used in conjunction with this chart. This chart is one of the activities for the Exploring Planets in the Classroom's Introduction to the Solar System.

356

Long-period solar-terrestrial variability  

SciTech Connect

Studies aimed at extending the record of solar-terrestrial variability to longer periods are discussed in a critical review of US research from the period 1987--1990. Sections are devoted to the sunspot index, radioactive carbon studies, a potential climate connection between radiocarbon changes and the solar irradiance cycle, Be-10 studies, geological laminae, solar neutrino counts, and the construction of data sets. Also included is a selective bibliography. 66 refs.

Sonett, C.P. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

357

Comet and Asteroid Hazard to the Terrestrial Planets  

NASA Technical Reports Server (NTRS)

We made computer simulations of orbital evolution for intervals of at least 5-10 Myr of N=2000 Jupiter-crossing objects (JCOs) with initial orbits close to those of real comets with period P less than 10 yr, 500 objects with orbits close to that of Comet 10P, and the asteroids initially located at the 3:1 and 5:2 resonances with Jupiter at initial eccentricity e(sub 0)=0.15 and initial inclination i(sub 0)=10(sup 0). The gravitational influence of all planets, except for Mercury and Pluto, was taken into account (without dissipative factors). We calculated the probabilities of collisions of bodies with the terrestrial planets, using orbital elements obtained with a step equal to 500 yr, and then summarized the results for all bodies, obtaining, the total probability Psigma of collisions with a planet and the total time interval Tsigma during which perihelion distance q of bodies was less than a semimajor axis of the planet. The values of p(sub r) =10(exp 6)Psigma/N and T(sub r)=T/1000 yr (where T=Tsigma/N) are presented in a table together with the ratio r of the total time interval when orbits were of Apollo type (at a greater than 1 AU, q less than 1.017 AU, e less than 0.999) to that of Amor type (1.017 less than q less than 1.33 AU), r(sub 2) is the same as r but for Apollo objects with e less than 0.9. For asteroids we present only results obtained by direct integration, as a symplectic method can give large errors for these resonances.

Ipatov, S. I.; Mather, J. C.; Oegerle, William (Technical Monitor)

2002-01-01

358

Examining the prey mass of terrestrial and aquatic carnivorous mammals: minimum, maximum and range.  

PubMed

Predator-prey body mass relationships are a vital part of food webs across ecosystems and provide key information for predicting the susceptibility of carnivore populations to extinction. Despite this, there has been limited research on the minimum and maximum prey size of mammalian carnivores. Without information on large-scale patterns of prey mass, we limit our understanding of predation pressure, trophic cascades and susceptibility of carnivores to decreasing prey populations. The majority of studies that examine predator-prey body mass relationships focus on either a single or a subset of mammalian species, which limits the strength of our models as well as their broader application. We examine the relationship between predator body mass and the minimum, maximum and range of their prey's body mass across 108 mammalian carnivores, from weasels to baleen whales (Carnivora and Cetacea). We test whether mammals show a positive relationship between prey and predator body mass, as in reptiles and birds, as well as examine how environment (aquatic and terrestrial) and phylogenetic relatedness play a role in this relationship. We found that phylogenetic relatedness is a strong driver of predator-prey mass patterns in carnivorous mammals and accounts for a higher proportion of variance compared with the biological drivers of body mass and environment. We show a positive predator-prey body mass pattern for terrestrial mammals as found in reptiles and birds, but no relationship for aquatic mammals. Our results will benefit our understanding of trophic interactions, the susceptibility of carnivores to population declines and the role of carnivores within ecosystems. PMID:25162695

Tucker, Marlee A; Rogers, Tracey L

2014-01-01

359

Oxygen isotopic composition of opaline phytoliths: Potential for terrestrial climatic reconstruction  

SciTech Connect

Opaline mineralized bodies are produced by many terrestrial plants and accumulate in certain soils and archaeological sites. Analyses of the oxygen isotopic compositions of these so-called phytoliths from stems and leaves of wheat plants grown in a greenhouse showed a linear relationship with stem and leaf water isotopic compositions and hence, indirectly, rain water isotopic composition. Analyses of wheat plants grown in fields showed that stem phytoliths isotopic composition directly reflects the seasonal air temperature change, whereas leaf phytoliths isotopic composition reflects both temperature and relative humidity. Temperature and the oxygen isotopic composition of stem phytoliths were related by an equation similar to that proposed for marine opal. Oxygen isotopic compositions of fossil phytoliths, and in particular those from stems, could be valuable for reconstructing past terrestrial climate change.

Shahack-Gross, R.; Weiner, S.; Shemesh, A.; Yakir, D. [Weizmann Institute of Science, Rehovot (Israel)] [Weizmann Institute of Science, Rehovot (Israel)

1996-10-01

360

No evidence of genetic benefits from extra-pair fertilisations in female sand martins ( Riparia riparia )  

Microsoft Academic Search

Genetic parentage studies of socially monogamous birds reveal a widespread prevalence of extra-pair paternity. Variation in\\u000a extra-pair paternity among individuals may depend on how different individuals benefit from extra-pair fertilisations and\\u000a on the opportunity to pursue extra-pair copulations. A long-term study of sand martins (Riparia riparia) in Hungary allowed us to examine patterns of extra-pair fertilisations in a large colony

Jakob Augustin; Donald Blomqvist; Tibor Szp; Zoltn D. Szab; Richard H. Wagner

2007-01-01

361

Dark Energy from Casimir Energy on Noncommutative Extra Dimensions  

E-print Network

We study the possibility that dark energy is a manifestation of the Casimir energy on extra dimensions with the topology of $S^2$. We consider our universe to be $M^4 \\times S^2$ and modify the geometry by introducing noncommutativity on the extra dimensions only, i.e. replacing $S^2$ with the fuzzy version $S_{F}^2$. We find the energy density as a function of the size of the representation $M+1$ of the algebra of $S_{F}^2$, and we calculate its value for the $M+1=2$ case. The value of the energy density turns out to be positive, i.e. provides dark energy, and the size of the extra dimensions agrees with the experimental limit. We also recover the correct commutative limit as the noncommutative parameter goes to zero.

S. Fabi; B. Harms; G. Karatheodoris

2006-07-20

362

The generalized uncertainty principle in the presence of extra dimensions  

E-print Network

We argue that in the Generalized Uncertainty Principle (GUP) model, the parameter $\\beta_0$ whose square root, multiplied by Planck length $\\ell_p$, approximates the minimum measurable distance, varies with energy scales. Since minimal measurable length and extra dimensions are both suggested by quantum gravity theories, we investigate models based on GUP and one extra dimension, compactified with radius $\\rho$. We obtain an inspiring relation $\\sqrt{\\beta_0} \\ell_p/\\rho \\sim {\\cal O}(1)$. This relation is also consistent with predictions at Planck scale and usual quantum mechanics scale. We also make estimations on the application range of the GUP model. It turns out that the minimum measurable length is exactly the compactification radius of the extra dimension.

Benrong Mu; Houwen Wu; Haitang Yang

2009-09-24

363

Differentiating various extra $Z^{\\prime}$'s at Future Colliders  

E-print Network

We propose a way to differentiate between various extra $U(1)$ models using flavor tagging in the decay modes $Z^{\\prime}\\rightarrow q{\\bar{q}}$ once the extra $Z^{\\prime}$ is observed at future colliders in the lepton channel. A generalization of the R parameter, namely, one for charge $\\frac{1}{3}$ and one for charge $\\frac{2}{3}$ quark gives a two parameter test for the various models. Flavor tagging eliminates the uncertainty because of extra fermions and can reduce the QCD background at SSC/LHC dramatically. For $E_{6}$ and $SO(10)$ based models the former is always 3. This seems to be a very good way to eliminate certain models.

Mohapatra, P K

1993-01-01

364

CP violation from pure gauge in extra dimensions  

NASA Astrophysics Data System (ADS)

One of the Sakharov's condition for baryogenesis is the violation of both C and CP. In the Standard Model, gauge interactions break maximally C, but CP is only broken through the Yukawa couplings in the poorly understood scalar sector. In extra-dimensional models, extra components of gauge fields behave as scalars in 4D and can acquire effective vev's through (finite) quantum effects (Hosotani mechanism). This mechanism is used to build a toy model with 2 extra-dimensions compactified on a flat torus T 2, where a SU(2) gauge symmetry is broken to U(1) and CP violation (in 4D) is expected. This is verified by computing a non-vanishing electric dipole moment.

Frre, Jean-Marie; Libanov, Maxim; Mollet, Simon

2014-06-01

365

Stability of Mitochondrial Membrane Proteins in Terrestrial Vertebrates Predicts Aerobic Capacity and Longevity  

PubMed Central

The cellular energy produced by mitochondria is a fundamental currency of life. However, the extent to which mitochondrial (mt) performance (power and endurance) is adapted to habitats and life strategies of vertebrates is not well understood. A global analysis of mt genomes revealed that hydrophobicity (HYD) of mt membrane proteins (MMPs) is much lower in terrestrial vertebrates than in fishes and shows a strong negative correlation with serine/threonine composition (STC). Here, we present evidence that this systematic feature of MMPs was crucial for the evolution of large terrestrial vertebrates with high aerobic capacity. An Arrhenius-type equation gave positive correlations between STC and maximum life span (MLS) in terrestrial vertebrates (with a few exceptions relating to the lifestyle of small animals with a high resting metabolic rate [RMR]) and negative correlations in secondary marine vertebrates, such as cetaceans and alligators (which returned from land to water, utilizing buoyancy with increased body size). In particular, marked STC increases in primates (especially hominoids) among placentals were associated with very high MLS values. We connected these STC increases in MMPs with greater stability of respiratory complexes by estimating the degradation of the Arrhenius plot given by accelerating mtRMR up to mt maximum metabolic rate. Both mtRMR and HYD in terrestrial vertebrates decreased with increasing body mass. Decreases in mtRMR raise MMP stability when high mobility is not required, whereas decreased HYD may weaken this stability under the hydrophobic environment of lipid bilayer. High maximal metabolic rates (510 RMR), which we postulate require high MMP mobility, presumably render MMPs more unstable. A marked rise in STC may therefore be essential to stabilize MMPs, perhaps as dynamic supercomplexes, via hydrogen bonds associated with serine/threonine motifs. PMID:21824868

Kitazoe, Yasuhiro; Kishino, Hirohisa; Hasegawa, Masami; Matsui, Atsushi; Lane, Nick; Tanaka, Masashi

2011-01-01

366

Hydrolytic microbial communities in terrestrial ecosystems  

NASA Astrophysics Data System (ADS)

Hydrolytic microbial communities in terrestrial ecosystems Manucharova N.A., Chernov T.I., Kolcova E.M., Zelezova A.D., Lukacheva E.G. Lomonosov Moscow State University, Russia Vertical differentiation of terrestrial biogeocenoses is conditioned by the formation of vertical tiers that differ considerably in the composition and structure of microbial communities. All the three tiers, phylloplane, litter and soil, are united by a single flow of organic matter, and are spatially separated successional stages of decomposition of organic substances. Decomposition of organic matter is mainly due to the activity of microorganisms producing enzymes - hydrolase and lyase - which destroy complex organic compounds. Application of molecular biological techniques (FISH) in environmental studies provides a more complete information concerning the taxonomic diversity and potential hydrolytic activity of microbial complexes of terrestrial ecosystems that exist in a wide range of environmental factors (moisture, temperature, redox potential, organic matter). The combination of two molecular biological techniques (FISH and DGGE-analysis of fragments of gene 16S rRNA total amplificate) enables an informative assessment of the differences in the structure of dominant and minor components of hydrolytic complexes formed in different tiers of terrestrial ecosystems. The functional activity of hydrolytic microbial complexes of terrestrial ecosystems is determined by the activity of dominant and minor components, which also have a high gross enzymatic activity. Degradation of biopolymers in the phylloplane is mainly due to the representatives of the Proteobacteria phylogenetic group (classes alpha and beta). In mineral soil horizons, the role of hydrolytic representatives of Firmicutes and Actinobacteria increases. Among the key environmental parameters that determine the functional activity of the hydrolytic (chitinolytic) complex of soil layer (moisture, nutrient supply, successional time), the most significant one is moisture. Moisture levels providing maximum activity of a hydrolytic microbial complex depend on the soil type. Development of a hydrolytic microbial complex occurs in a very wide moisture range - from values close to field capacity to those close to the wilting moisture point. The functional role of mycelial actinobacteria in the metabolism of chitin consists, on the one hand, in active decomposition of this biopolymer, and on the other hand, in the regulation of microbial hydrolytic complex activity through the production of biologically active regulatory metabolites, which occurs in a wide range of environmental parameters (moisture, temperature, organic matter, successional time). Experimental design is applicable to identify in situ optimal values of environmental factors that considerably affect the functional parameters of hydrolytic microbial complexes.

Manucharova, Natalia; Chernov, Timofey; Kolcova, Ekaterina; Zelezova, Alena; Lukacheva, Euhenia; Zenova, Galina

2014-05-01

367

Is the Higgs boson a sign of extra dimensions?  

NASA Astrophysics Data System (ADS)

We introduce a four-dimensional cutoff in the scenario of gauge-Higgs unification to control the ultraviolet behavior. A one-loop effective potential for a Higgs field and the Higgs mass are obtained with the cutoff. We find an interrelation between the four-dimensional cutoff and the scale of extra dimensions, which is concretized through the Higgs mass. Combining this interrelation and the recently discovered Higgs boson at the LHC, we obtain an interesting constraint for the four-dimensional cutoff and the extra-dimensional scale.

So, Hiroto; Takenaga, Kazunori

2013-07-01

368

Minimum length, extra dimensions, modified gravity and black hole remnants  

SciTech Connect

We construct a Hilbert space representation of minimum-length deformed uncertainty relation in presence of extra dimensions. Following this construction, we study corrections to the gravitational potential (back reaction on gravity) with the use of correspondingly modified propagator in presence of two (spatial) extra dimensions. Interestingly enough, for r?0 the gravitational force approaches zero and the horizon for modified Schwarzschild-Tangherlini space-time disappears when the mass approaches quantum-gravity energy scale. This result points out to the existence of zero-temperature black hole remnants in ADD brane-world model.

Maziashvili, Michael, E-mail: maziashvili@gmail.com [Particle Physics and Cosmology Group, Ilia State University, 3/5 Cholokashvili Ave., Tbilisi 0162, Georgia (United States)

2013-03-01

369

Inheritance contradictions between functional and extra-functional requirements  

SciTech Connect

This paper discusses the tension which may arise between functional and extra-functional requirements during the process of object-oriented design. A sketch of some design conflicts in object-oriented development induced by concurrency and security requirements will serve as a basis for rather provocative prospects on an essential distinction between the core requirements for systems dealing with their proper purpose and functionality and the requirements which can be considered to be of extra-functional nature in constraining the systems solution space.

Hochmueller, E. [Universitaet Kiagenfurt (Austria)

1996-12-31

370

Two universal extra dimensions and spinless photons at the ILC  

E-print Network

We study the ILC phenomenology of (1,0) Kaluza-Klein (KK) modes along two universal extra dimensions compactified on the chiral square. We compute production cross sections of various (1,0) particles at the ILC with sqrt(s)=1 TeV, focusing on decays of KK-leptons and the KK partner of hypercharge gauge boson down to the "spinless photon" which is the lightest KK particle. We contrast this model to one universal extra dimension with KK-photon (spin-1) and supersymmetry with neutralino (spin-1/2) or gravitino (spin-3/2) dark matter.

Freitas, Ayres

2008-01-01

371

An intraorbital metallic foreign body  

PubMed Central

A 30-year-old male presented with diplopia for 20 days post occupational accident involving left side of his nose, while he was working with a nail gun. He was fully conscious and did not have any neurological deficits. Patient narrated the mechanism of injury and was sure that the nail fell down after hitting the left side of his nose. He had normal vision, but extra ocular movements were restricted and painful. Computed tomography (CT) scan revealed a curved metal object lodged in the posterior aspect of the left orbit extending diagonally from medial wall to the anterior-superior aspect of the orbital roof. The object was removed via a small surgical approach, inflicting least possible surgical trauma. Post surgery, the patient recovered with complete resolution of diplopia. The original aspects of this case are the lack of signs of a foreign body entry and its relative harmlessness in spite of its large size. PMID:25494256

Asif, Jawaad Ahmed; Pohchi, Abdullah; Alam, Mohammad Khursheed; Athar, Yousuf; Shiekh, Rayees Ahmad

2014-01-01

372

Attitude Strength: An Extra-Content Aspect of Attitude.  

ERIC Educational Resources Information Center

Attitude strength is considered as an extra-content aspect of attitude. A model of the relationship of attitude strength to attitude direction and behavior proposes that attitude strength is comprised of three dimensions that moderate the relationship between attitude direction and behavior. The dimensions are parallel to the tripartite dimensions

Alwitt, Linda F.

373

Extra-lobar Pulmonary Sequestration Requiring Intrauterine Thoracentesis  

PubMed Central

Congenital lung malformations can result in significant morbidity and mortality in children. Pulmonary sequestration is an uncommon congenital malformation of the lung that can cause complications even in fetal life. We herein present a newborn with extra-lobar sequestration (ELS) that lead to hydrops fetalis necessitating fetal intervention.

Kahvecioglu, Dilek; Alan, Serdar; Yildiz, Duran; Akduman, Hasan; Erdeve, Omer; Bahadir, Gulnur Gollu; Kologlu, Meltem; Atasay, Begum; Arsan, Saadet

2015-01-01

374

University Extra-Mural Studies and Extension Outreach: Incompatibilities  

ERIC Educational Resources Information Center

The argument of this paper is that--within a wide range of university responses to the challenge of outreach--there grew up in the extra-mural or adult education departments of many UK universities an alternative epistemological paradigm to the older and more traditional extension programmes. This paradigm threatened the extension approach and has

Rogers, Alan

2014-01-01

375

Extra-adrenal paraganglioma of the median nerve.  

PubMed

An extra-adrenal paraganglioma is an uncommon tumour that arises from the paraganglia associated with the autonomous nervous system. A paraganglioma arising in the sensory-somatic nervous system is extremely rare and clinically is easily confused with other neurogenic tumours. We describe a paraganglioma that arose in the median nerve of a 22-year-old woman. PMID:23750845

Chong, Yosep; Park, Minjong; Ko, Young-Hyeh

2014-12-01

376

The Extra Strand of the Maori Science Curriculum  

ERIC Educational Resources Information Center

This paper comments on the process of re-development of the Maori-medium Science (Putaiao) curriculum, as part of overall curriculum development in Aotearoa New Zealand. A significant difference from the English Science curriculum was the addition of an "extra strand" covering the history and philosophy of science. It is recommended that this

Stewart, Georgina

2011-01-01

377

Origin of the extra chromosome No. 21 in Down's syndrome  

Microsoft Academic Search

Eighteen of 38 examined families with children with Down's syndrome showed polymorphisms of chromosome 21 elucidating the origin of the extra chromosome 21. Maternal origin was found in 10 cases and paternal origin in 8 cases. In both sexes errors occurred both in the first and in the second meiotic division.

P. Wagenbichler; W. Killian; A. Rett; W. Schnedl

1976-01-01

378

Investigation of Possible Extra ~Recharge During Pumping in Nottinghant .Aquifer  

E-print Network

completely from aquifer storage. The value may approach zero if it is estimated based on the draw- downInvestigation of Possible Extra ~Recharge During Pumping in Nottinghant .Aquifer by Jiu J. Jiaoa by analyzing the pumping test data from the Nottingham aquifer, UK. The pumping lasted more than 200 days

Jiao, Jiu Jimmy

379

Comparative study of extra and intrafollicular hamster oocyte maturation  

E-print Network

of intra- and extra-follicular maturation of hamster oocytes checked by in vitro fertilization showed many possibilities for in vitro studies on fertilization and on their further development. However of gonadotropins. The ability of hamster sperm to be capacitated in vitro and to fertilize ovulated oocytes (Barros

Paris-Sud XI, Université de

380

EXTRA-HEPATIC CANCER SUPPRESSES NUCLEAR RECEPTOR REGULATED DRUG METABOLISM  

PubMed Central

Purpose To determine the mechanisms by which tumors situated in extra-hepatic sites can cause profound changes in hepatic drug clearance, contributing to altered drug response and chemotherapy resistance. Experimental Design We studied in wild type or transgenic CYP3A4 reporter mice implanted with the murine EngelbrethHolmSwarm sarcoma, changes in nuclear receptor and hepatic transcription factor expression and/or function, particularly related to CYP3A gene regulation. Results Repression of hepatic CYP3A induction was dramatic and associated with reduced levels of C/EBP? isoforms and impaired PXR and CAR function. Unexpectedly, extra-hepatic tumors strongly reduced nuclear accumulation of RXR? in hepatocytes, providing a potential explanation for impaired function of nuclear receptors that rely on RXR? dimerization. Profiling revealed 38 nuclear receptors were expressed in liver with 14 showing between 1.5 and 4 fold reduction in expression in livers of tumour-bearing animals, including Car, Tr?, Lxr?, Ppar?, Err?/?, Reverb?/? and Shp. Altered Ppar? and ? induction of target genes provided additional evidence of perturbed hepatic metabolic control elicited by extra-hepatic tumors. Conclusions Extra-hepatic malignancy can affect hepatic drug metabolism by nuclear receptor re-localization and decreased receptor expression and function. These findings could aid the design of intervention strategies to normalize drug clearance and metabolic pathways in cancer patients at risk of chemotherapy-induced toxicity or cancer cachexia. PMID:21498392

Kacevska, Marina; Downes, Michael R.; Sharma, Rohini; Evans, Ronald M.; Clarke, Stephen J.; Liddle, Christopher; Robertson, Graham R.

2011-01-01

381

46 CFR Sec. 8 - Extra work and changes.  

Code of Federal Regulations, 2010 CFR

...AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 8 Extra work and...Change Order as provided in Article 6 of the NSA-LUMPSUMREP Contract. (c) A supplemental...completion date as provided in Article 27 of the NSA-LUMPSUMREP...

2010-10-01

382

46 CFR Sec. 8 - Extra work and changes.  

Code of Federal Regulations, 2011 CFR

...AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 8 Extra work and...Change Order as provided in Article 6 of the NSA-LUMPSUMREP Contract. (c) A supplemental...completion date as provided in Article 27 of the NSA-LUMPSUMREP...

2011-10-01

383

46 CFR Sec. 8 - Extra work and changes.  

Code of Federal Regulations, 2012 CFR

...AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 8 Extra work and...Change Order as provided in Article 6 of the NSA-LUMPSUMREP Contract. (c) A supplemental...completion date as provided in Article 27 of the NSA-LUMPSUMREP...

2012-10-01

384

46 CFR Sec. 8 - Extra work and changes.  

Code of Federal Regulations, 2013 CFR

...AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 8 Extra work and...Change Order as provided in Article 6 of the NSA-LUMPSUMREP Contract. (c) A supplemental...completion date as provided in Article 27 of the NSA-LUMPSUMREP...

2013-10-01

385

46 CFR Sec. 8 - Extra work and changes.  

Code of Federal Regulations, 2014 CFR

...AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 8 Extra work and...Change Order as provided in Article 6 of the NSA-LUMPSUMREP Contract. (c) A supplemental...completion date as provided in Article 27 of the NSA-LUMPSUMREP...

2014-10-01

386

Estimating the extra cost of living with disability in Vietnam.  

PubMed

Disability is shown to be both a cause and a consequence of poverty. However, relatively little research has investigated the economic cost of living with a disability. This study reports the results of a study on the extra cost of living with disability in Vietnam in 2011. The study was carried out in eight cities/provinces in Vietnam, including Hanoi and Ho Chi Minh cities (two major metropolitan in Vietnam) and six provinces from each of the six socio-economic regions in Vietnam. Costs are estimated using the standard of living approach whereby the difference in incomes between people with disability and those without disability for a given standard of living serves as a proxy for the cost of living with disability. The extra cost of living with disability in Vietnam accounted for about 8.8-9.5% of annual household income, or valued about US$200-218. Communication difficulty was shown to result in highest additional cost of living with disability and self-care difficulty was shown to lead to the lowest levels of extra of living cost. The extra cost of living with disability increased as people had more severe impairment. Interventions to promote the economic security of livelihood for people with disabilities are needed. PMID:25353274

Minh, Hoang Van; Giang, Kim Bao; Liem, Nguyen Thanh; Palmer, Michael; Thao, Nguyen Phuong; Duong, Le Bach

2015-01-01

387

A Tiling Technology for Creating Extra-Large Scale Terrain  

Microsoft Academic Search

The paper proposes a real-time terrain tiling method for extra-large scale terrain rendering. The core idea is based on a loading-on-demand technique which dynamically loads visible parts of the terrain model, then tiling and rendering. The method solves the boundary match problem for adjacent terrain blocks in dynamic loading which avoids \\

Zhou Zheng-chun; Wan Wang-gen; Tang Jing-zhou; Miao Xiao-liang

2007-01-01

388

Jumping sans legs: does elastic energy storage by the vertebral column power terrestrial jumps in bony fishes?  

PubMed

Despite having no obvious anatomical modifications to facilitate movement over land, numerous small fishes from divergent teleost lineages make brief, voluntary terrestrial forays to escape poor aquatic conditions or to pursue terrestrial prey. Once stranded, these fishes produce a coordinated and effective "tail-flip" jumping behavior, wherein lateral flexion of the axial body into a C-shape, followed by contralateral flexion of the body axis, propels the fish into a ballistic flight-path that covers a distance of multiple body lengths. We ask: how do anatomical structures that evolved in one habitat generate effective movement in a novel habitat? Within this context, we hypothesized that the mechanical properties of the axial skeleton play a critical role in producing effective overland movement, and that tail-flip jumping species demonstrate enhanced elastic energy storage through increased body flexural stiffness or increased body curvature, relative to non-jumping species. To test this hypothesis, we derived a model to predict elastic recoil work from the morphology of the vertebral (neural and hemal) spines. From ground reaction force (GRF) measurements and high-speed video, we calculated elastic recoil work, flexural stiffness, and apparent material stiffness of the body for Micropterus salmoides (a non-jumper) and Kryptolebias marmoratus (adept tail-flip jumper). The model predicted no difference between the two species in work stored by the vertebral spines, and GRF data showed that they produce the same magnitude of mass-specific elastic recoil work. Surprisingly, non-jumper M. salmoides has a stiffer body than tail-flip jumper K. marmoratus. Many tail-flip jumping species possess enlarged, fused hypural bones that support the caudal peduncle, which suggests that the localized structures, rather than the entire axial skeleton, may explain differences in terrestrial performance. PMID:24388492

Ashley-Ross, Miriam A; Perlman, Benjamin M; Gibb, Alice C; Long, John H

2014-02-01

389

Teppeki, selective insecticide about Bombus terrestris.  

PubMed

At a time when a highly controversial debate about the causes of the widespread deaths of bees is taking place all over Europe, which accused the agriculture and its practices with particular reference to the harmful effects of some insecticides, it seems important to point out as another insecticide, the Teppeki, can be selective about bumble and have a good compatibility with the activity of the apiaries. This insecticide has the active ingredient flonicamid (500 g/kg) belonging to a new chemical class, called pyridinecarboxamides: the product works systemic and is known as having a long lasting efficacy against all important aphid species. Bioagritest test facility of Pignola (PZ, Italy) has conducted in two successive production cycles an experimental trial on a tomato hydroponic cultivation within the Agricola Bonsai farm in Sibari (CS, Italy), whose objective was to measure the selectivity of flonicamid on Bombus terrestris, insects playing an important role in the pollination of certain species grown in greenhouse such as Tomato, Eggplant, Pepper and Cucumber. On the pollinated flower B. terrestris leaves some trace of its visit, a typical dark trademark: on the detection of the marking of flowers was based the testing program conducted by Bioagritest. Two thesis were compared: A, standard) treatment with a foliar insecticide, the neonicotinoide acetamiprid, normally used for control of aphids and whiteflies (unlike other neonicotinoides--imidacloprid and thiametoxam--quite selective about B. terrestris) and B, Teppeki) foliar treatment with Teppeki, to the maximum dose indicated on the label. The experimental design included the use of randomized blocks with 4 repetitions (4 plots/thesis with 100 plants each). In every thesis six B. terrestris hives were placed 2 days before treatment: the respective holes remained closed during the treatment and the 12 following hours. In order to verify the pollination, by the detection of the flower marking, 2 flowers per plant were observed, for a total of 200 flowers per plot. The measurements were made on the 3rd (I relief) and 8th day (II relief) after treatment. Statistical analysis was performed by the use of XLSTAT data analysis and statistical software. The analysis of collected data shows that flonicamid has a minor effect of interference with the activity of pollination by B. terrestris, compared to the standard used. 14 days after treatment, 3 hives per thesis were inspected in order to verify the status of the colonies (adults, larvae, eggs, pollen). The colonies appeared generally homogeneous as concerning the number of alive adults--100 for each--all at the end of the development cycle. There was no dead adult. Two colonies, one for thesis, presented evidence of eggs. All colonies had low stocks of pollen. Ultimately, treatment with Teppeki has not given any acute effect on B. terrestris, nor any effect of interference in respect of its pollination activity. PMID:20222598

Fanigliulo, Angela; Fil, Vittorio; Pacella, Rosa; Comes, Soccorsa; Crescenzi, Aniello

2009-01-01

390

Lewy bodies  

PubMed Central

Lewy bodies (LB) in the substantia nigra are a cardinal pathological feature of Parkinson's disease, but they occur in a number of neurodegenerative diseases and can be widespread in the nervous system. The characteristics, locations, and composition of LB are reviewed, with particular attention to ?-synuclein (?-SYN), which appears to be the major component of LB. The propensity for ?-SYN, a presynaptic protein widely expressed in the brain, to aggregate is because of an amyloidogenic central region. The factors that favor the aggregation of ?-SYN and mechanisms of toxicity are examined, and a mechanism through which aggregates of ?-SYN could induce mitochondrial dysfunction and/or release of proapoptotic molecules is proposed. PMID:16449387

Shults, Clifford W.

2006-01-01

391

Terrestrial Effects of High Energy Cosmic Rays  

NASA Astrophysics Data System (ADS)

On geological timescales, the Earth is likely to be exposed to an increased flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. These high-energy particles strike the Earth's atmosphere initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles. Increased ionization could lead to changes in atmospheric chemistry, resulting in ozone depletion. This could increase the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit can could possibly enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of nuclear interactions are able to reach the ground, enhancing the biological radiation dose. The muon flux dominates radiation dose from cosmic rays causing DNA damage and increase in the mutation rates, which can have serious biological implications for terrestrial and sub-terrestrial life. This radiation dose is an important constraint on the habitability of a planet. Using CORSIKA, we perform massive computer simulations and construct lookup tables from 10 GeV - 1 PeV primaries (1 PeV - 0.1 ZeV in progress), which can be used to quantify these effects. These tables are freely available to the community and can be used for other studies, not necessarily relevant to Astrobiology. We use these tables to study the terrestrial implications of galactic shock generated by the infall of our galaxy toward the Virgo cluster. This could be a possible mechanism explaining the observed periodicity in biodiversity in paleobiology databases.

Atri, Dimitra

2011-01-01

392

Aquatic predation alters a terrestrial prey subsidy.  

PubMed

Organisms with complex life histories (CLH) often cross habitat or ecosystem boundaries as they develop from larvae to adults, coupling energy flow between ecosystems as both prey (bottom-up) and consumers (top-down). Predation effects on one stage of this life cycle can therefore cascade across ecosystems, magnifying the impact of local predation. The majority of predation studies have assessed effects only on a local level, within the habitat of the predator. I used large outdoor stream mesocosms to test the hypothesis that predation in an aquatic habitat alters the magnitude and trophic structure of a prey assemblage in a terrestrial habitat. I also tested how a consumer in the terrestrial habitat (web-weaving spiders) responded to these changes in prey export. Two fish species were the predators (red shiner, Cyprinella lutrensis and orangethroat darter, Etheostoma spectabile) in an experiment with three treatments: both fish species monocultures plus a fishless control. Fish predation reduced aquatic insect emergence biomass by 50% compared to the fishless control and altered the trophic structure of the emergent community, reducing emerging insect predator biomass by 50%, but had no effect on other insect trophic groups. Spiders captured only insects that were unaffected by fish predation (mostly chironomids) and therefore did not respond numerically to overall changes in insect abundance or biomass. Patterns of insect emergence were largely driven by a strong negative relationship between fish and a predatory dragonfly (Pantala flavescens). The results of this experiment show that predation in one habitat can have strong effects on the biomass and trophic structure of subsidies entering adjacent habitats, resulting in contrasting predictions for the role of these subsidies in recipient food webs. In the absence of fish, aquatic habitats produced terrestrial insect communities with higher biomass (bottom-up potential) and a higher proportion of predators (top-down potential) than when fish were present. PMID:20503875

Wesner, Jeff Scott

2010-05-01

393

Terrestrial and freshwater Tardigrada of the Americas.  

PubMed

This paper provides a comprehensive list of the freshwater and terrestrial tardigrade fauna reported from the Americas (North America, South America, Central America and the West Indies), their distribution in the Americas, and the substrates from which they have been reported. Data were obtained from 316 published references. Authors' identifications were accepted at face value unless subsequently amended. Taxa were assigned to sub-national units (states, provinces, etc.). Many areas, in particular large portions of Central America and the West Indies, have no reported tardigrade fauna. The presence of 54 genera and 380 species has been reported for the Americas; 245 species have been collected in the Nearctic ecozone and 251 in the Neotropical ecozone. Among the tardigrade species found in the Americas, 52 are currently considered cosmopolitan, while 153 species have known distributions restricted to the Americas. Based on recent taxonomic revision of the genus Milnesium, the vast majority of records of M. tardigradum in the Americas should now be reassigned to Milnesium tardigradum sensu lato, either because the provided description differs from M. tardigradum sensu stricto or because insufficient description is provided to make a determination; the remainder should be considered Milnesium cf. tardigradum. Most terrestrial tardigrade sampling in the Americas has focused on cryptogams (mosses, lichens and liverworts); 90% of the species have been collected in such substrates. The proportion of species collected in other habitats is lower: 14% in leaf litter, 20% in soil, and 24% in aquatic samples (in other terrestrial substrates the proportion never exceeds 5%). Most freshwater tardigrades have been collected from aquatic vegetation and sediment. For nine species in the Americas no substrates have been reported. PMID:25113595

Meyer, Harry A

2013-01-01

394

Ammonia transport by terrestrial and aquatic insects.  

PubMed

Ammonia, an end product from amino acid and nucleic acid metabolism, is highly toxic for most animals. This review will provide an update on nitrogen metabolism in terrestrial and aquatic insects with emphasis on ammonia generation and transport. Aspects that will be discussed include metabolic pathways of nitrogenous compounds, the origin of ammonia and other nitrogenous waste products, ammonia toxicity, putative ammonia transporters as well as ammonia transport processes known in insects. Ammonia transport mechanisms in the mosquito Aedes aegypti, the tobacco hornworm Manduca sexta and the locust Schistocerca gregaria will be discussed in detail while providing additional, novel data. PMID:22100291

Weihrauch, Dirk; Donini, Andrew; O'Donnell, Michael J

2012-04-01

395

International Solar Terrestrial Physics (ISTP) program  

NASA Technical Reports Server (NTRS)

The International Solar Terrestrial Physics (ISTP) Program is a large, multi-national program involving three space agencies and up to eight spacecraft. NASA, together with the Institute of Space and Astronomical Science (ISAS) and the European Space Agency (ESA), has agreed in principle to coordinate their efforts in investigating the Sun and the Earth. Each agency is planning to construct and operate different spacecraft as part of this cooperative venture: Geotail provided by ISAS, the Solar Heliospheric Observatory (SOHO) and Cluster (four spacecraft) contributed by ESA, and Wind and Polar by NASA. A general description of the program is presented.

Sanford, R.; Muhonen, D.; Sizemore, K. O.

1991-01-01

396

Fermi GBM Observations of Terrestrial Gamma Flashes  

NASA Technical Reports Server (NTRS)

In its first two years of operation, the Fermi Gamma Ray Burst Monitor (GBM) has observed 79 Terrestrial Gamma Flashes (TGFs). The thick Bismuth Germanate (BGO) detectors are excellent for TGF spectroscopy, having a high probability of recording the full energy of an incident photon, spanning a broad energy range from 150 keV to 40 MeV, and recording a large number of photons per TGF. Correlations between GBM TGF triggers and lightning sferics detected with the World-Wide Lightning Location Network indicate that TGFs and lightning are simultaneous to within tens of microseconds.

Wilson-Hodge, Colleen A.; Briggs, M. S.; Connaughton, V.; Fishman, G. J.; Bhat, P. N.; Paciesas, W. S.; Preece, R. D.; Kippen, R. M.; vonKienlin, A.; Dwyer, J. R.; Smith, D. M.; Holzworth, R.

2010-01-01

397

Identification of Terrestrial Reflectance From Remote Sensing  

NASA Technical Reports Server (NTRS)

Correcting for atmospheric effects is an essential part of surface-reflectance recovery from radiance measurements. Model-based atmospheric correction techniques enable an accurate identification and classification of terrestrial reflectances from multi-spectral imagery. Successful and efficient removal of atmospheric effects from remote-sensing data is a key factor in the success of Earth observation missions. This report assesses the performance, robustness and sensitivity of two atmospheric-correction and reflectance-recovery techniques as part of an end-to-end simulation of hyper-spectral acquisition, identification and classification.

Alter-Gartenberg, Rachel; Nolf, Scott R.; Stacy, Kathryn (Technical Monitor)

2000-01-01

398

Terrestrial Gamma-Ray Flashes (TGFs)  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the observation of Terrestrial Gamma Ray Flashes (TGFs) by Gamma-Ray Telescopes. These were: (1) BATSE /Compton Observatory, (2) Solar Spectroscopic Imager, (3) AGILE Gamma-ray Telescope, and (4) Gamma-ray Burst Monitor (GBM) on the Fermi Gamma-ray Space Telescope. It contains charts which display the counts over time, a map or the TGFs observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). and a map showing the latitude and longitude of 85 of the TGFs observed by the Fermi GBM.

Fishman, Gerald J.

2010-01-01

399

Terrestrial manganese-53 A new monitor of Earth surface processes  

Microsoft Academic Search

We report the first systematic study of the terrestrial cosmogenic radionuclide manganese-53 (T1\\/2=3.7Ma) measured in thirteen samples from nine dolerite surfaces in the Dry Valleys, Antarctica. The terrestrial manganese-53 concentrations correlate well with cosmic-ray-produced helium-3 and neon-21 concentrations in the same samples, implying that the manganese-53 is produced continuously in situ and retained quantitatively over millions of years. The terrestrial

Joerg M. Schaefer; Thomas Faestermann; Gregory F. Herzog; Klaus Knie; Gunther Korschinek; Jozef Masarik; Astrid Meier; Michail Poutivtsev; Georg Rugel; Christian Schlchter; Feride Serifiddin; Gisela Winckler

2006-01-01

400

Expression of ionotropic receptors in terrestrial hermit crab's olfactory sensory neurons  

PubMed Central

Coenobitidae are one out of at least five crustacean lineages which independently succeeded in the transition from water to land. This change in lifestyle required adaptation of the peripheral olfactory organs, the antennules, in order to sense chemical cues in the new terrestrial habitat. Hermit crab olfactory aesthetascs are arranged in a field on the distal segment of the antennular flagellum. Aesthetascs house approximately 300 dendrites with their cell bodies arranged in spindle-like complexes of ca. 150 cell bodies each. While the aesthetascs of aquatic crustaceans have been shown to be the place of odor uptake and previous studies identified ionotropic receptors (IRs) as the putative chemosensory receptors expressed in decapod antennules, the expression of IRs besides the IR co-receptors IR25a and IR93a in olfactory sensory neurons (OSNs) has not been documented yet. Our goal was to reveal the expression and distribution pattern of non-co-receptor IRs in OSNs of Coenobita clypeatus, a terrestrial hermit crab, with RNA in situ hybridization. We expanded our previously published RNAseq dataset, and revealed 22 novel IR candidates in the Coenobita antennules. We then used RNA probes directed against three different IRs to visualize their expression within the OSN cell body complexes. Furthermore we aimed to characterize ligand spectra of single aesthetascs by recording local field potentials and responses from individual dendrites. This also allowed comparison to functional data from insect OSNs expressing antennal IRs. We show that this orphan receptor subgroup with presumably non-olfactory function in insects is likely the basis of olfaction in terrestrial hermit crabs.

Groh-Lunow, Katrin C.; Getahun, Merid N.; Grosse-Wilde, Ewald; Hansson, Bill S.

2015-01-01

401

The evolution of the moon and the terrestrial planets  

NASA Technical Reports Server (NTRS)

The thermal evolutions of the Moon, Mars, Venus and Mercury are calculated theoretically starting from cosmochemical condensation models. An assortment of geological, geochemical and geophysical data are used to constrain both the present day temperatures and the thermal histories of the planets' interiors. Such data imply that the planets were heated during or shortly after formation and that all the terrestrial planets started their differentiations early in their history. The moon, smallest in size, is characterized as a differentiated body with a crust, a thick solid mantle and an interior region which may be partially molten. Mars, intermediate in size, is assumed to have differentiated an Fe-FeS core. Venus is characterized as a planet not unlike the earth in many respects. Core formation has occurred probably during the first billion years after the formation. Mercury, which probably has a large core, may have a 500 km thick solid lithosphere and a partially molten core if it is assumed that some heat sources exist in the core.

Toksoez, M. N.; Johnston, D. H.

1974-01-01

402

The Use of Resistivity Methods in Terrestrial Forensic Searches  

NASA Astrophysics Data System (ADS)

The increasing use of near-surface geophysical methods in forensic searches has demonstrated the need for further studies to identify the ideal physical, environmental and temporal settings for each geophysical method. Previous studies using resistivity methods have shown promising results, but additional work is required to more accurately interpret and analyze survey findings. The Ontario Provincial Police's UCRT (Urban Search and Rescue; Chemical, Biolgical, Radiological, Nuclear and Explosives; Response Team) is collaborating with the University of Toronto and two additional universities in a multi-year study investigating the applications of near-surface geophysical methods to terrestrial forensic searches. In the summer of 2012, on a test site near Bolton, Ontario, the OPP buried weapons, drums and pigs (naked, tarped, and clothed) to simulate clandestine graves and caches. Our study aims to conduct repeat surveys using an IRIS Syscal Junior with 48 electrode switching system resistivity-meter. These surveys will monitor changes in resistivity reflecting decomposition of the object since burial, and identify the strengths and weaknesses of resistivity when used in a rural, clandestine burial setting. Our initial findings indicate the usefulness of this method, as prominent resistivity changes have been observed. We anticipate our results will help to assist law enforcement agencies in determining the type of resistivity results to expect based on time since burial, depth of burial and state of dress of the body.

Wolf, R. C.; Raisuddin, I.; Bank, C.

2013-12-01

403

Accretion of Terrestrial Planets from Oligarchs in a Turbulent Disk  

E-print Network

We have investigated the final accretion stage of terrestrial planets from Mars-mass protoplanets that formed through oligarchic growth in a disk comparable to the minimum mass solar nebula (MMSN), through N-body simulation including random torques exerted by disk turbulence due to Magneto-Rotational-Instability. For the torques, we used the semi-analytical formula developed by Laughlin et al.(2004). The damping of orbital eccentricities (in all runs) and type-I migration (in some runs) due to the tidal interactions with disk gas are also included. We found that the orbital eccentricities pumped up by the turbulent torques and associated random walks in semimajor axes tend to delay isolation of planets, resulting in more coagulation of planets than in the case without turbulence. The eccentricities are still damped after planets become isolated. As a result, the number of final planets decreases with increase in strength of the turbulence, while Earth-mass planets with small eccentricities are still formed. In the case of relatively strong turbulence, the number of final planets are 4-5 at 0.5-2AU, which is consistent with Solar system, for relatively wide range of disk surface density (~10^{-4}-10^{-2} times MMSN).

Masahiro Ogihara; Shigeru Ida; Alessandro Morbidelli

2006-12-21

404

Extreme Environment Technologies for Space and Terrestrial Applications  

NASA Technical Reports Server (NTRS)

Over the next decades, NASA's planned solar system exploration missions are targeting planets, moons and small bodies, where spacecraft would be expected to encounter diverse extreme environmental (EE) conditions throughout their mission phases. These EE conditions are often coupled. For instance, near the surface of Venus and in the deep atmospheres of giant planets, probes would experience high temperatures and pressures. In the Jovian system low temperatures are coupled with high radiation. Other environments include thermal cycling, and corrosion. Mission operations could also introduce extreme conditions, due to atmospheric entry heat flux and deceleration. Some of these EE conditions are not unique to space missions; they can be encountered by terrestrial assets from the fields of defense,oil and gas, aerospace, and automotive industries. In this paper we outline the findings of NASA's Extreme Environments Study Team, including discussions on state of the art and emerging capabilities related to environmental protection, tolerance and operations in EEs. We will also highlight cross cutting EE mitigation technologies, for example, between high g-load tolerant impactors for Europa and instrumented projectiles on Earth; high temperature electronics sensors on Jupiter deep probes and sensors inside jet engines; and pressure vessel technologies for Venus probes and sea bottom monitors. We will argue that synergistic development programs between these fields could be highly beneficial and cost effective for the various agencies and industries. Some of these environments, however, are specific to space and thus the related technology developments should be spear headed by NASA with collaboration from industry and academia.

Balint, Tibor S.; Cutts, James A.; Kolawa, Elizabeth A.; Peterson, Craig E.

2008-01-01

405

Self-sterilization of bodies during outer planet entry  

NASA Technical Reports Server (NTRS)

A body encountering the atmosphere of an outer planet is subjected to heat loads which could result in high temperature conditions that render terrestrial organisms on or within the body nonviable. To determine whether an irregularly shaped entering body, consisting of several different materials, would be sterilized during inadvertent entry at high velocity, the thermal response of a typical outer planet spacecraft instrument was studied. The results indicate that the Teflon insulated cable and electronic circuit boards may not experience sterilizing temperatures during a Jupiter, Saturn, or Titan entry. Another conclusion of the study is that small plastic particles entering Saturn from outer space have wider survival corridors than do those at Jupiter.

Hoffman, A. R.; Jaworski, W.; Taylor, D. M.

1974-01-01

406

Keypoint based autonomous registration of terrestrial laser point-clouds  

NASA Astrophysics Data System (ADS)

Registration of terrestrial laser scanning point-clouds involves handling huge datasets, irregular point distribution, multiple views, and relatively low textured surfaces. Common approaches for the registration are based in large on the iterative closest point (ICP) model, which is non-linear and requires good initial values to secure convergence to the actual solution. Computation of the initial approximations to launch the ICP algorithm requires the extraction of distinct features, devising methods for matching them among the datasets, and then computing the transformation parameters. In this paper we present a computational approach for the registration problem. In essence we exploit 3D rigid-body transformation invariant features to reduce significantly the computational load involved in the matching between key features. Generally, with the partial overlap among datasets and among the extracted features the identification of corresponding key features can be viewed as a sub-graph matching problem. This problem is hard to solve, but as the actual matched entities are subjected to a six parameters transformation it becomes manageable. We show that distances, which are invariant to rigid body transformation, can be applied for solving this problem. We then show that by using selected keypoints, the matching process can be optimized. We also show how the information embedded within the range data is utilized to improve the quality of the selected points. Following the presentation of our algorithm, we demonstrate its application on a sequence of scans taken in areas featuring a clutter of objects. Results and the analysis show its efficiency and robustness.

Barnea, Shahar; Filin, Sagi

407

Bryophyte Influence on terrestrial and Epiphytic Fern Gametophytes.  

E-print Network

??The climate and structural complexity of tropical forests enable vertical habitat differentiation between epiphytic and terrestrial communities. Because fern spores are copiously released one might (more)

McCarthy, Mirabai Rachel

2007-01-01

408

Occurrence of giant impacts during the growth of the terrestrial planets  

NASA Technical Reports Server (NTRS)

Three dimensional Monte Carlo simulations of the accumulation of the terrestrial planets in the absence of gas drag produced results that are in general agreement with the number and distribution of the present planets. The accumulation process appears to be characterized by impact of bodies as large as three times the mass of Mars at velocities of about 9 kilometers per second. These giant impacts on earth may have supplied the material and angular momentum that formed the moon, should have heated earth to the melting point, and may have been responsible for the differences in the content of inert gases of the atmospheres of earth and Venus.

Wetherill, G. W.

1985-01-01

409

Hermit crabs perceive the extent of their virtual bodies.  

PubMed

A flexible body image is required by animals if they are to adapt to body changes and move effectively within a structurally complex environment. Here, we show that terrestrial hermit crabs, Coenobita rugosus, which frequently change shells, can modify walking behaviour, dependent on the shape of the shell. Hermit crabs walked along a corridor that had alternating left and right corners; if it was narrow at the corner, crabs rotated their bodies to avoid the wall, indicating an awareness of environmental obstacles. This rotation increased when a plastic plate was attached to the shell. We suggest that the shell, when extended by the plate, becomes assimilated to the hermit crab's own body. While there are cases of a tool being assimilated with the body, our result is the first example of the habitat where an animal lives and/or carries being part of a virtual body. PMID:22378741

Sonoda, Kohei; Asakura, Akira; Minoura, Mai; Elwood, Robert W; Gunji, Yukio-P

2012-08-23

410

Constraining uncertainties in terrestrial carbon cycle modeling  

NASA Astrophysics Data System (ADS)

Global climate models differ in their representation of uptake of CO2 in the biosphere. Our study focuses on constraining the uncertainty in terrestrial carbon cycle modeling by comparing climate model results to observed atmospheric CO2 concentrations. The goal is to improve the representations of the seasonal cycle of terrestrial carbon uptake in the land model. We use the NCAR Community Earth System Model (CESM) climate components CLM4CN and CAM4 to run a prognostic version of the coupled land-atmosphere model where the atmospheric CO2 concentration in CAM4 is interactively calculated. Atmospheric CO2 concentrations from the model are compared to observations provided by flux towers in the AMERIFLUX network through the FLUXNET database and from the WDCGG for year 2000. We compare model results from sensitivity studies using different Q10 and Vcmax parameterizations, which are important functions in calculating plant growth. The carbon uptake in the biosphere is also under anthropogenic influence through emission of nitrogen and ozone from air pollution. Whereas nitrogen limitations in the soil reduce land ecosystem response to increasing CO2 concentrations, nitrogen from anthropogenic emissions increases the nitrogen availability and hence stimulates plant growth. These two nitrogen effects as well as the damaging impact on plants due to tropospheric ozone fertilization have been included in this study.

Kvalevg, M.; Myhre, G.

2011-12-01

411

An Imaging Interferometer for Terrestrial Remote Sensing  

NASA Technical Reports Server (NTRS)

A prototype imaging interferometer called DASI (digital array scanned interferometer) is under development at our laboratories. Our objective is to design an instrument for remote sensing of Earth's atmosphere and surface. This paper describes the unusual characteristics of DASIs which make them promising candidates for ground and aircraft-based terrestrial measurements. These characteristics include superior signal-to-noise, design simplicity and compactness, relative to dispersion based imaging spectrometers. Perhaps one of the most notable features of DASIs is their ability to acquire an entire interferogram simultaneously without any moving optical elements. We also describe selected laboratory and ground based field measurements using the prototype DASI. A CCD detector array was placed at the DASI detector plane for wavelength coverage from 0.4 to 1.0 micron. A NICMOS MCT detector was used for coverage from 1.1 to 2.2 micron. The DASI was configured to have a spectral resolution of about 300 1/cm, a spatial field of view of 5 degrees, and a constant number of transverse spatial elements (detector dependent) for each exposure frame. Frame exposure rates were up to 0.6 Hz with the potential to achieve 5 Hz. Image cube measurements of laboratory targets and terrestrial scenes were obtained by multiple frame scanning over the field of view. These data sets reveal the potential science yields from obtaining simultaneous high resolution spatial and spectral information.

Hammer, Philip D.; Valero, Francisco P. J.; Peterson, David L.; Smith, William Hayden

1993-01-01

412

Lunar apatite with terrestrial volatile abundances.  

PubMed

The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO(2)-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained approximately 1,600 parts per million H(2)O and approximately 3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought. PMID:20651686

Boyce, Jeremy W; Liu, Yang; Rossman, George R; Guan, Yunbin; Eiler, John M; Stolper, Edward M; Taylor, Lawrence A

2010-07-22

413

Terrestrial applications of the heatpipe power system  

SciTech Connect

A terrestrial reactor that uses the same design approach as the Heatpipe Power System (HPS) may have applications both on earth and on other planetary surfaces. The baseline HPS is a potential, near-term, low-cost space fission power system. The system will be composed of independent modules, and all components operate within the existing database. The HPS has relatively few system integration issues; thus, the successful development of a module is a significant step toward verifying system feasibility and performance estimates. A prototypic, refractory-metal HPS module is being fabricated, and testing is scheduled to begin in November 1996. A successful test will provide high confidence that the HPS can achieve its predicted performance. An HPS incorporating superalloys will be better suited for some terrestrial or planetary applications. Fabrication and testing of a superalloy HPS module should be less challenging than that of the refractory metal module. A superalloy HPS core capable of delivering > 100 kWt to a power conversion subsystem could be fabricated for about $500k (unfueled). Tests of the core with electric heat (used to simulate heat from fission) could demonstrate normal and off-normal operation of the core, including the effects of heatpipe failure. A power conversion system also could be coupled to the core to demonstrate full system operation.

Houts, M.G.; Poston, D.I.

1997-02-01

414

Classification and generation of terrestrial rare gases  

NASA Technical Reports Server (NTRS)

A Kr-84/Xe-130 versus Ne-20/Ar-36 diagram is a very useful format with which to study the elemental ratios of rare gases from terrestrial materials. It can separate not only the three types of rare gases which Ozima and Alexander (1976) classified but also the 'planetary' type rare gases from the other three types of rare gases. When all the available terrestrial rare gas data are plotted in a Kr-84/Xe-130 versus Ne-20/Ar-36 diagram, several observations can be made. First, most of the analyses of rare gases from shales yield Kr-84/Xe-130 ratios between the 'planetary' and atmospheric values. If, however, the atmosphere's high Kr-84/Xe-130 ratio was produced by the selective adsorption of xenon onto shales from an initially 'planetary' atmosphere, as is widely accepted, then the Kr-84/Xe-130 ratio in shales should be even lower than the 'planetary' value. Second, the rare gas pattern in the quenched rims of submarine basalts may be explained as fractionated samples of the rare gases in sea water.

Saito, K.

1978-01-01

415

Solar-terrestrial coupling through atmospheric electricity  

NASA Technical Reports Server (NTRS)

There are a number of measurements of electrical variations that suggest a solar-terrestrial influence on the global atmospheric electrical circuit. The measurements show variations associated with solar flares, solar magnetic sector boundary crossings, geomagnetic activity, aurorae, differences between ground current and potential gradients at high and low latitudes, and solar cycle variations. The evidence for each variation is examined. Both the experimental evidence and the calculations made with a global model of atmospheric electricity indicate that there is solar-terrestrial coupling through atmospheric electricity which operates by altering the global electric current and field distribution. A global redistribution of currents and fields can be caused by large-scale changes in electrical conductivity, by alteration of the columnar resistance between thunderstorm cloud tops and the ionosphere, or by both. If the columnar resistance is altered above thunderstorms, more current will flow in the global circuit, changing the ionospheric potential and basic circuit variables such as current density and electric fields. The observed variations of currents and fields during solar-induced disturbances are generally less than 50% of mean values near the earth's surface.

Roble, R. G.; Hays, P. B.

1979-01-01

416

Advanced Stirling conversion systems for terrestrial applications  

NASA Technical Reports Server (NTRS)

Under the Department of Energy's (DOE) Solar Thermal Technology Program, Sandia National Laboratories (SNLA) is developing heat engines for terrestrial Solar Distributed Heat Receivers. SNLA has identified the Stirling to be one of the most promising candidates for the terrestrial applications. The free-piston Stirling engine (FPSE) has the potential to meet the DOE goals for both performance and cost. The National Aeronautics and Space Administration (NASA) Lewis Research Center (LeRC) is conducting free-piston Stirling activities which are directed toward a dynamic power source for space applications. Space power system requirements include high efficiency, very long life, high reliability and low vibration. The FPSE has the potential for future high power space conversion systems, either solar or nuclear. Generic free-piston technology is currently being developed by LeRC for DOE/ORNL for use with a residential heat pump under an Interagency Agreement. Since 1983, the SP-100 Program (DOD/NASA/DOE) is developing dynamic power sources for space. Although both applications (heat pump and space power) appear to be quite different, their requirements complement each other. A cooperative Interagency Agreement (IAA) was signed in 1985 with NASA Lewis to provide technical management for an Advanced Stirling Conversion System (ASCS) for SNLA. Conceptual design(s) using a free-piston Stirling (FPSE), and a heat pipe will be discussed. The ASCS will be designed using technology which can reasonably be expected to be available in the 1980's.

Shaltens, R. K.

1987-01-01

417

Terrestrial Planet Formation in Binary Star Systems  

NASA Technical Reports Server (NTRS)

Most stars reside in multiple star systems; however, virtually all models of planetary growth have assumed an isolated single star. Numerical simulations of the collapse of molecular cloud cores to form binary stars suggest that disks will form within such systems. Observations indirectly suggest disk material around one or both components within young binary star systems. If planets form at the right places within such circumstellar disks, they can remain in stable orbits within the binary star systems for eons. We are simulating the late stages of growth of terrestrial planets within binary star systems, using a new, ultrafast, symplectic integrator that we have developed for this purpose. We show that the late stages of terrestrial planet formation can indeed take place in a wide variety of binary systems and we have begun to delineate the range of parameter space for which this statement is true. Results of our initial simulations of planetary growth around each star in the alpha Centauri system and other 'wide' binary systems, as well as around both stars in very close binary systems, will be presented.

Lissauer, Jack J.; Quintana, Elisa V.; Chambers, John; Duncan, Martin J.; Adams, Fred

2003-01-01

418

Advanced Stirling conversion systems for terrestrial applications  

SciTech Connect

Sandia National Laboratories (SNLA) is developing heat engines for terrestrial Solar distributed Heat Receivers. SNLA has identified the Stirling to be one of the most promising candidates for the terrestrial applications. The free-piston Stirling engine (FPSE) has the potential to meet the DOE goals for both performance and cost. Free-piston Stirling activities which are directed toward a dynamic power source for the space application are being conducted. Space power system requirements include high efficiency, very long life, high reliability and low vibration. The FPSE has the potential for future high power space conversion systems, either solar or nuclear powered. Generic free-piston technology is currently being developed for use with a residential heat pump under an Interagency Agreement. Also, an overview is presented of proposed conceptual designs for the Advanced Stirling Conversion System (ASCS) using a free-piston Stirling engine and a liquid metal heat pipe receiver. Power extraction includes both a linear alternator and hydraulic output capable of delivering approximately 25 kW of electrical power to the electric utility grid. Target cost of the engine/alternator is 300 dollars per kilowatt at a manufacturing rate of 10,000 units per year. The design life of the ASCS is 60,000 h (30 y) with an engine overhaul at 40,000 h (20 y). Also discussed are the key features and characteristics of the ASCS conceptual designs.

Shaltens, R.K.

1987-01-01

419

Effects of pentachlorophenol on survival of earthworms (Lumbricus terrestris) and phagocytosis by their immunoactive coelomocytes  

SciTech Connect

Earthworms, Lumbricus terrestris, exposed for 96 h to filter paper saturated with five nominal concentrations of pentachlorophenol, exhibited a 50% lethal concentration (LC50) of 25.0 {micro}g PCP/cm{sup 2} and corresponding whole worm body burden-based 50% lethal dose (LD50) of 877.7 {micro}g PCP/g dry mass. Linear regression modeling showed that worms increased body concentrations (BC = {micro}g PCP/g dry tissue mass) with increasing exposure concentrations (EC) according to BC = 113.5 + 29.5EC. Phagocytosis of yeast cells by immunoactive coelomocytes was suppressed only at body concentrations (863.3 {micro}g PCP/g dry mass) that approximated the calculated LD50 and overlapped those demonstrating lethality, indicating a sharp transition between sublethal and lethal toxicity. An exposure concentration of 15 {micro}g PCP/cm{sup 2} produced significant suppression of phagocytosis of yeast cells by immunoactive coelomocytes. However, the average measured body burden from this group approximated the estimated LD50, indicating a sharp toxic response slope. Exposure to 10 {micro}g PCP/cm{sup 2} with a corresponding body concentration of 501.3 {micro}g PCP/g dry mass did not affect phagocytosis. The importance of body burden data is emphasized.

Giggleman, M.A.; Fitzpatrick, L.C.; Goven, A.J. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Denton, TX (United States)

1998-12-01

420

Extra-Oral Approach for Removal of Ectopic Impacted Lower Third Molar: A Case Report  

PubMed Central

Extra oral approach for removal of the lower third molar is uncommon. This case report illustrates an example of removal of lower third molar by extra-oral approach preserving the inferior dental nerve. PMID:25584338

Vishnu, Priya; Kannadasan, Kamal; Kengagsubbiah, Srivatsa; Kumar, Senthil

2014-01-01

421

46 CFR 9.1 - Extra compensation; Coast Guard civilian personnel.  

Code of Federal Regulations, 2011 CFR

...Section 9.1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC EXTRA COMPENSATION... Extra compensation; Coast Guard civilian personnel. Civilians assigned to the duties formerly...

2011-10-01

422

46 CFR 9.1 - Extra compensation; Coast Guard civilian personnel.  

Code of Federal Regulations, 2013 CFR

...Section 9.1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC EXTRA COMPENSATION... Extra compensation; Coast Guard civilian personnel. Civilians assigned to the duties formerly...

2013-10-01

423

46 CFR 9.1 - Extra compensation; Coast Guard civilian personnel.  

Code of Federal Regulations, 2012 CFR

...Section 9.1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC EXTRA COMPENSATION... Extra compensation; Coast Guard civilian personnel. Civilians assigned to the duties formerly...

2012-10-01

424

46 CFR 9.1 - Extra compensation; Coast Guard civilian personnel.  

Code of Federal Regulations, 2014 CFR

...Section 9.1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC EXTRA COMPENSATION... Extra compensation; Coast Guard civilian personnel. Civilians assigned to the duties formerly...

2014-10-01

425

46 CFR 9.1 - Extra compensation; Coast Guard civilian personnel.  

Code of Federal Regulations, 2010 CFR

...Section 9.1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC EXTRA COMPENSATION... Extra compensation; Coast Guard civilian personnel. Civilians assigned to the duties formerly...

2010-10-01

426

The European Space Agency's infastructure for observing the terrestrial biosphere  

NASA Astrophysics Data System (ADS)

Our understanding of many biogeochemical processes strongly depends on the availability of long-term, large scale observation systems. In recent years satellite remote sensing has proven invaluable tool for providing a wide range of observations on a global scale. This presentation will present the most recent status of the satellite infrastructure of the European Space Agency (ESA) and its future development. We will review ESA's Sentinel satellite system, a family of operational satellites, and the Earth Explorer system, dedicated research satellites. ESA currently develops five new Sentinel missions specifically for the operational needs of the Global Monitoring for Environment and Security programme. The Sentinels are based on a constellation of two satellites to fulfill revisit and coverage requirements, providing robust datasets for a wide range of applications. The Sentinels will be launched from 2013 onwards. These missions carry a range of technologies, such as radar and multi-spectral imaging instruments for land, ocean and atmospheric monitoring. Out of the five Sentinel missions Sentinel 1,2 and 3 carry instruments that will provide operational observation streams for terrestrial applications Sentinel-1 is a polar-orbiting, all-weather, day-and-night radar imaging mission. Among others it will provide information about land-cover, biomass, soil moisture and water bodies. The first Sentinel-1 satellite is planned for launch in 2013. Sentinel-2 is a polar-orbiting, multispectral high-resolution imaging mission for land monitoring providing, for example, imagery of vegetation, soil and water cover and coastal areas. The first Sentinel-2 satellite is planned for launch in 2014. Sentinel-3 is polar-orbiting, multi-instrument mission to measure variables such as land colour with high-end accuracy and reliability. The first Sentinel-3 satellite is planned for launch in 2014. Beside the operational Sentinel system ESA currently assesses the feasibility of novel instrument concepts within its Earth Explorer Programme. Two candidate missions are dedicated to provide novel information about the terrestrial Earth surface. Biomass is a polar-orbiting, all-weather, day-and-night radar imaging mission designed to measure biomass of the global forests and its change with time. Fluorescence Explorer (FLEX) is a polar-orbiting, spectral imaging mission. FLEX aims to provide global maps of vegetation fluorescence, which can be converted into an indicator of photosynthetic activity. This talk will inform the community about the observation capability and data policy of these missions. Further examples of data products will be presented and their characteristics will be discussed.

Scipal, Klaus

2013-04-01

427

Effects of oceanic salinity on body condition in sea snakes.  

PubMed

Since the transition from terrestrial to marine environments poses strong osmoregulatory and energetic challenges, temporal and spatial fluctuations in oceanic salinity might influence salt and water balance (and hence, body condition) in marine tetrapods. We assessed the effects of salinity on three species of sea snakes studied by mark-recapture in coral-reef habitats in the Neo-Caledonian Lagoon. These three species include one fully aquatic hydrophiine (Emydocephalus annulatus), one primarily aquatic laticaudine (Laticauda laticaudata), and one frequently terrestrial laticaudine (Laticauda saintgironsi). We explored how oceanic salinity affected the snakes' body condition across various temporal and spatial scales relevant to each species' ecology, using linear mixed models and multimodel inference. Mean annual salinity exerted a consistent and negative effect on the body condition of all three snake species. The most terrestrial taxon (L. saintgironsi) was sensitive to salinity over a short temporal scale, corresponding to the duration of a typical marine foraging trip for this species. In contrast, links between oceanic salinity and body condition in the fully aquatic E. annulatus and the highly aquatic L. laticaudata were strongest at a long-term (annual) scale. The sophisticated salt-excreting systems of sea snakes allow them to exploit marine environments, but do not completely overcome the osmoregulatory challenges posed by oceanic conditions. Future studies could usefully explore such effects in other secondarily marine taxa such as seabirds, turtles, and marine mammals. PMID:22710931

Brischoux, Franois; Rolland, Virginie; Bonnet, Xavier; Caillaud, Matthieu; Shine, Richard

2012-08-01

428

A Source of Terrestrial Organic Carbon to Investigate the Browning of Aquatic Ecosystems  

PubMed Central

There is growing evidence that terrestrial ecosystems are exporting more dissolved organic carbon (DOC) to aquatic ecosystems than they did just a few decades ago. This browning phenomenon will alter the chemistry, physics, and biology of inland water bodies in complex and difficult-to-predict ways. Experiments provide an opportunity to elucidate how browning will affect the stability and functioning of aquatic ecosystems. However, it is challenging to obtain sources of DOC that can be used for manipulations at ecologically relevant scales. In this study, we evaluated a commercially available source of humic substances (Super Hume) as an analog for natural sources of terrestrial DOC. Based on chemical characterizations, comparative surveys, and whole-ecosystem manipulations, we found that the physical and chemical properties of Super Hume are similar to those of natural DOC in aquatic and terrestrial ecosystems. For example, Super Hume attenuated solar radiation in ways that will not only influence the physiology of aquatic taxa but also the metabolism of entire ecosystems. Based on its chemical properties (high lignin content, high quinone content, and low C:N and C:P ratios), Super Hume is a fairly recalcitrant, low-quality resource for aquatic consumers. Nevertheless, we demonstrate that Super Hume can subsidize aquatic food webs through 1) the uptake of dissolved organic constituents by microorganisms, and 2) the consumption of particulate fractions by larger organisms (i.e., Daphnia). After discussing some of the caveats of Super Hume, we conclude that commercial sources of humic substances can be used to help address pressing ecological questions concerning the increased export of terrestrial DOC to aquatic ecosystems. PMID:24124511

Lennon, Jay T.; Hamilton, Stephen K.; Muscarella, Mario E.; Grandy, A. Stuart; Wickings, Kyle; Jones, Stuart E.

2013-01-01

429

Scaling of olfactory antennae of the terrestrial hermit crabs Coenobita rugosus and Coenobita perlatus during ontogeny.  

PubMed

Although many lineages of terrestrial crustaceans have poor olfactory capabilities, crabs in the family Coenobitidae, including the terrestrial hermit crabs in the genus Coenobita, are able to locate food and water using olfactory antennae (antennules) to capture odors from the surrounding air. Terrestrial hermit crabs begin their lives as small marine larvae and must find a suitable place to undergo metamorphosis into a juvenile form, which initiates their transition to land. Juveniles increase in size by more than an order of magnitude to reach adult size. Since odor capture is a process heavily dependent on the size and speed of the antennules and physical properties of the fluid, both the transition from water to air and the large increase in size during ontogeny could impact odor capture. In this study, we examine two species of terrestrial hermit crabs, Coenobita perlatus H. Milne-Edwards and Coenobita rugosus H. Milne-Edwards, to determine how the antennule morphometrics and kinematics of flicking change in comparison to body size during ontogeny, and how this scaling relationship could impact odor capture by using a simple model of mass transport in flow. Many features of the antennules, including the chemosensory sensilla, scaled allometrically with carapace width and increased slower than expected by isometry, resulting in relatively larger antennules on juvenile animals. Flicking speed scaled as expected with isometry. Our mass-transport model showed that allometric scaling of antennule morphometrics and kinematics leads to thinner boundary layers of attached fluid around the antennule during flicking and higher odorant capture rates as compared to antennules which scaled isometrically. There were no significant differences in morphometric or kinematic measurements between the two species. PMID:25177536

Waldrop, Lindsay D; Bantay, Roxanne M; Nguyen, Quang V

2014-01-01

430

Scaling of olfactory antennae of the terrestrial hermit crabs Coenobita rugosus and Coenobita perlatus during ontogeny  

PubMed Central

Although many lineages of terrestrial crustaceans have poor olfactory capabilities, crabs in the family Coenobitidae, including the terrestrial hermit crabs in the genus Coenobita, are able to locate food and water using olfactory antennae (antennules) to capture odors from the surrounding air. Terrestrial hermit crabs begin their lives as small marine larvae and must find a suitable place to undergo metamorphosis into a juvenile form, which initiates their transition to land. Juveniles increase in size by more than an order of magnitude to reach adult size. Since odor capture is a process heavily dependent on the size and speed of the antennules and physical properties of the fluid, both the transition from water to air and the large increase in size during ontogeny could impact odor capture. In this study, we examine two species of terrestrial hermit crabs, Coenobita perlatus H. Milne-Edwards and Coenobita rugosus H. Milne-Edwards, to determine how the antennule morphometrics and kinematics of flicking change in comparison to body size during ontogeny, and how this scaling relationship could impact odor capture by using a simple model of mass transport in flow. Many features of the antennules, including the chemosensory sensilla, scaled allometrically with carapace width and increased slower than expected by isometry, resulting in relatively larger antennules on juvenile animals. Flicking speed scaled as expected with isometry. Our mass-transport model showed that allometric scaling of antennule morphometrics and kinematics leads to thinner boundary layers of attached fluid around the antennule during flicking and higher odorant capture rates as compared to antennules which scaled isometrically. There were no significant differences in morphometric or kinematic measurements between the two species. PMID:25177536

Bantay, Roxanne M.; Nguyen, Quang V.

2014-01-01

431

Terrestrial distribution of pond-breeding salamanders around an isolated wetland.  

PubMed

Terrestrial habitats surrounding isolated wetlands are a critical resource for many pond-breeding amphibian species, yet few studies have examined the terrestrial distribution of post-metamorphic juveniles and adults. We used an encircling drift fence at a breeding pond in conjunction with partial fences at 90, 172, and 332 m from the wetland to estimate the terrestrial distribution of adult marbled salamanders (Ambystoma opacum; four breeding seasons) and mole salamanders (A. talpoideum; two seasons), as well as the dispersion of newly metamorphosed A. opacum (one summer). For newly metamorphosed A. opacum, 79% emigrated < 90 m from the wetland, and 8% moved beyond 172 m; movement distance was unrelated to body size. Distribution of adult A. opacum varied among years, with an average of 28% (range 23-31%) occurring beyond 172 m in all years. Averaged across two years, 51% of adult A. talpoideum occurred beyond 172 m. Lognormal models provided a good fit to both the juvenile and adult ambystomatid distributions, and parameters differed between age classes, sexes, species, and years within species. For adult A. opacum a buffer radius of 300 m or 340 m, depending on the year, is estimated to include 95% of adults; for A. talpoideum the estimate is 464 m or 501 m. A reanalysis of distribution data for seven ambystomatid species shows that a previous estimate of a 164-m radius to protect 95% of a population underestimates the needed buffer radius by 185 m. Because our study wetland requires a nearly 500 m wide radius to protect 95% of its ambystomatid adults, preservation of similar communities may require much more surrounding terrestrial habitat than previously thought. PMID:24400505

Scott, David E; Komoroski, Mark J; Croshaw, Dean A; Dixon, Philip M

2013-11-01

432

Nucleopolyhedrovirus detection and distribution in terrestrial, freshwater, and marine habitats of Appledore Island, Gulf of Maine.  

PubMed

Viruses in aquatic ecosystems comprise those produced by both autochthonous and allochthonous host taxa. However, there is little information on the diversity and abundance of viruses of allochthonous origin, particularly from non-anthropogenic sources, in freshwater and marine ecosystems. We investigated the presence of nucleopolyhedroviruses (NPV) (Baculovirus), which commonly infect terrestrial lepidopteran taxa, across the landscape of Appledore Island, Gulf of Maine. PCR and qPCR primers were developed around a 294-bp fragment of the polyhedrin (polH) gene, which is the major constituent protein of NPV multivirion polyhedral occlusion bodies. polH was successfully amplified from several aquatic habitats, and recovered polH sequences were most similar to known lepidopteran NPV. Using quantitative PCR designed around a cluster of detected sequences, we detected polH in Appledore Island soils, supratidal freshwater ponds, nearshore sediments, near- and offshore plankton, and in floatsam. This diverse set of locations suggests that NPVs are widely dispersed along the terrestrial--marine continuum and that free polyhedra may be washed into ponds and eventually to sea. The putative hosts of detected NPVs were webworms (Hyphantria sp.) which form dense nests in late summer on the dominant Appledore Island vegetation (Prunus virginiana). Our data indicate that viruses of terrestrial origin (i.e., allochthonous viruses) may be dispersed widely in coastal marine habitats. The dispersal of NPV polH and detection within offshore net plankton (>64 ?m) demonstrates that terrestrial viruses may interact with larger particles and plankton of coastal marine ecosystem, which further suggests that viral genomic information may be transported between biomes. PMID:21509607

Hewson, Ian; Brown, Julia M; Gitlin, Shari A; Doud, Devin F

2011-07-01

433

Transfer of metric fluctuations when extra dimensions bounce or stabilize  

SciTech Connect

In this report, we study within the context of general relativity with one extra dimension compactified either on a circle or an orbifold, how radion fluctuations interact with metric fluctuations in the three noncompact directions. The background is nonsingular and can either describe an extra dimension on its way to stabilization, or immediately before and after a series of nonsingular bounces. We find that the metric fluctuations transfer undisturbed through the bounces or through the transients of the stabilization epoch. Our background is obtained by considering the effects of a gas of massless string modes in the context of a consistent 'massless background' (or low energy effective theory) limit of string theory. We discuss applications to various approaches to early universe cosmology, including the ekpyrotic/cyclic universe scenario and string gas cosmology.

Battefeld, Thorsten J. [Dept. of Physics, Brown University, Providence R.I. 02912 (United States); Patil, Subodh P. [Dept. of Physics, Brown University, Providence R.I. 02912 (United States); Dept. of Physics, McGill University, Montreal QC, H3A 2T8 (Canada); Brandenberger, Robert H. [Dept. of Physics, McGill University, Montreal QC, H3A 2T8 (Canada)

2006-04-15

434

Gamma rays from the Galactic bulge and large extra dimensions.  

PubMed

An intriguing feature of extra dimensions is the possible production of Kaluza-Klein gravitons by nucleon-nucleon bremsstrahlung, in the course of core collapse of massive stars, with gravitons then being trapped around the newly born neutron stars and decaying into two gamma rays, making neutron stars gamma-ray sources. We strengthen the limits on the radius of compactification of extra dimensions for a small number n of them, or alternatively the fundamental scale of quantum gravity, considering the gamma-ray emission of the whole population of neutron stars sitting in the Galactic bulge, instead of the closest member of this category. For n=1 the constraint on the compactification radius is R<400 microm. PMID:15089121

Cass, Michel; Paul, Jacques; Bertone, Gianfranco; Sigl, Gnter

2004-03-19

435

Extra dimensions and neutrinoless double beta decay experiments  

NASA Astrophysics Data System (ADS)

The neutrinoless double beta decay is one of the few phenomena, belonging to the nonstandard physics, which is extensively being sought for in experiments. In the present paper the link between the half-life of the neutrinoless double beta decay and theories with large extra dimensions is explored. The use of the sensitivities of currently planned 0?2? experiments: DAMA, CANDLES, COBRA, DCBA, CAMEO, GENIUS, GEM, MAJORANA, MOON, CUORE, EXO, and XMASS, gives the possibility for a nondirect experimental verification of various extra dimensional scenarios. We discuss also the results of the Heidelberg-Moscow Collaboration. The calculations are based on the Majorana neutrino mass generation mechanism in the Arkani-Hamed-Dimopoulos-Dvali model.

G?d?, Marek; Kami?ski, Wies?aw A.; Faessler, Amand

2005-05-01

436

A Small Cosmological Constant from a Large Extra Dimension  

E-print Network

We propose a new approach to the Cosmological Constant Problem which makes essential use of an extra dimension. A model is presented in which the Standard Model vacuum energy ``warps'' the higher-dimensional spacetime while preserving 4D flatness. We argue that the strong curvature region of our solutions may effectively cut off the size of the extra dimension, thereby giving rise to macroscopic 4D gravity without a cosmological constant. In our model, the higher-dimensional gravity dynamics is treated classically with carefully chosen couplings. Our treatment of the Standard Model is however fully quantum field-theoretic, and the 4D flatness of our solutions is robust against Standard Model quantum loops and changes to Standard Model couplings.

Nima Arkani-Hamed; Savas Dimopoulos; Nemanja Kaloper; Raman Sundrum

2000-01-31

437

Extra-Renal Manifestations of Complement-Mediated Thrombotic Microangiopathies  

PubMed Central

Thrombotic microangiopathies (TMA) are rare but severe disorders, characterized by endothelial cell activation and thrombus formation leading to hemolytic anemia, thrombocytopenia, and organ failure. Complement over activation in combination with defects in its regulation is described in an increasing number of TMA and if primary for the disease denominated as atypical hemolytic-uremic syndrome. Although TMA predominantly affects the renal microvasculature, extra-renal manifestations are observed in 20% of patients including involvement of the central nerve system, cardiovascular system, lungs, skin, skeletal muscle, and gastrointestinal tract. Prompt diagnosis and treatment initiation are therefore crucial for the prognosis of disease acute phase and the long-term outcome. This review summarizes the available evidence on extra-renal TMA manifestations and discusses the role of acute and chronic complement activation by highlighting its complex interaction with inflammation, coagulation, and endothelial homeostasis. PMID:25250305

Hofer, Johannes; Rosales, Alejandra; Fischer, Caroline; Giner, Thomas

2014-01-01

438

Reasoning with Extra Frame Axioms and Qualification Axioms (Extended Abstract)  

E-print Network

This paper introduces an inference mechanism for reasoning with frame axioms and qualication axioms which are not included in the action description based on the extended propositional dynamic logic, introduced in a previous paper. Such a mechanism allows us to reason with an incomplete action description. Then we prove that for any particular query, the extra frame axioms and qualication axioms which are needed for answering the query could only involve the objects which are relevant to the query and action description. Therefore, the required extra axioms can be reduced by localization of description language, and we can postpone listing or generating other frame axioms and qualication axioms until needed by a query. In this sense, the frame problem is avoidable. Keywords: Representations of Action, Reasoning about Action, Frame problem 1 Introduction In knowledge representation and reasoning, the frame problem is a central issue in reasoning about actions. A common ...

unknown authors

439

Study on Extra Heavy Oil Gasification Reaction Process  

NASA Astrophysics Data System (ADS)

From the viewpoints of global environment and energy security, raising the thermal efficiency of a thermal power plant and the diversification of fuel are issues that must be resolved as soon as possible. As to resolving these two issues, it is very effective that extra heavy oil is used in a gas-steam combined cycle power generation system. Accordingly, in order to establish technology for supporting to rationally design and operate a gasifier using extra heavy oil, the Central Research Institute of Electric Power Industry (CRIEPI) targeted at clarifying significant phenomena in a gasifier, improving the accuracy of numerical analytical technique under development and verifying the technique. This report describes the major specifications of Research Gasifier for Liquid Fuel constructed in 1999 and the results of studies in respect to the reaction process in the gasifier based on OrimulsionTM (Trademark of BITOR) gasification tests in 2000.

Kidoguchi, Kazuhiro; Hara, Saburo; Ashizawa, Masami; Inumaru, Jun

440

Fermion families from two layer warped extra dimensions  

NASA Astrophysics Data System (ADS)

In extra dimensions, the quark and lepton mass hierarchy can be reproduced from the same order bulk mass parameters, and standard model fermion families can be generated from one generation in the high dimensional space. We try to explain the origin of the same order bulk mass parameters and address the family replication puzzle simultaneously. We show that they correlate with each other. We construct models that families are generated from extra dimensional space, and in the meantime the bulk mass parameters of same order emerge naturally. The interesting point is that the bulk mass parameters, which are in same order, correspond to the eigenvalues of a Schrdinger-like equation. We also discuss the problem existing in this approach.

Guo, Zhi-qiang; Ma, Bo-Qiang

2008-08-01

441

COLD CLIMATE OIL SPILLS: A TERRESTRIAL AND FRESHWATER RESEARCH REVIEW  

EPA Science Inventory

The first part of this study reviews world-wide research on cold climate oil spills on land to identify some of the terrestrial environmental factors in cold regions affected by oil spills and some of the techniques for measuring impacts and terrestrial systems, primarily soils. ...

442

The effects of forest management on terrestrial salamanders  

Microsoft Academic Search

Maintaining a balance of timber production and conservation in forest management requires an understanding of how timber harvest techniques affect wildlife species. Terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and their sensitivity to environmental change. The topic of timber harvests and their effect on terrestrial salamanders has received much attention

Jami E MacNeil

2011-01-01

443

Concordance of freshwater and terrestrial biodiversity Robin Abell1  

E-print Network

, & Jonathan Hoekstra2 1 World Wildlife Fund, 1250 24th St. NW, Washington, D.C., USA 2 The Nature Conservancy-setting; rarity-weighted richness; terrestrial. Correspondence Robin Abell, World Wildlife Fund, 1250 24th St. NW of equivalent terrestrial importance. A new global database of freshwater fish distributions enabled

Vermont, University of

444

Benchmark analysis of parameterization for terrestrial carbon cycle model (Invited)  

Microsoft Academic Search

Parameterization of terrestrial ecosystem models plays an important role in accurately predicting carbon-climate feedback. More and more studies have shown that a fixed set of parameters cannot adequately represent spatial and temporal variations of ecosystem functions over broad geographical locations and\\/or over long time. In this study, we conducted benchmark analysis of a terrestrial ecosystem (TECO) model against a highly

Y. Luo; X. Zhou; P. Verburg; J. Arnone

2010-01-01

445

DOES TERRESTRIAL CARBON SUBSIDIZE PRODUCTION OF ESTUARINE FISH LARVAE?  

EPA Science Inventory

The research presented demonstrates the important role that terrestrial ecosystems can play in coastal food webs. We show that terrestrial carbon subsidizes the tidal freshwater and oligohaline portions of an estuarine food web, but that this exogenous carbon source is not impor...

446

China-US Collaborative Research on Life in Terrestrial  

E-print Network

Symposium: China-US Collaborative Research on Life in Terrestrial Geothermal Springs Information, Agenda, and Abstracts June 26-28, 2013, Kunming, China #12;Symposium: China-US Collaborative Research on Life in Terrestrial Geothermal Springs Kunming, China June 26-28, 2013 Information, Agenda

Ahmad, Sajjad

447

Can Terrestrial Planets Form in Hot-Jupiter Systems?  

E-print Network

Models of terrestrial planet formation in the presence of a migrating giant planet have challenged the notion that hot-Jupiter systems lack terrestrial planets. We briefly review this issue and suggest that hot-Jupiter systems should be prime targets for future observational missions designed to detect Earth-sized and potentially habitable worlds.

Martyn J. Fogg; Richard P. Nelson

2007-10-19

448

LOCOMOTION (TERRESTRIAL AND AERIAL) AND COMMUNICATION OF AUTONOMOUS ROBOT NETWORKS  

E-print Network

1 LOCOMOTION (TERRESTRIAL AND AERIAL) AND COMMUNICATION OF AUTONOMOUS ROBOT NETWORKS Arvin Agah This report focuses on locomotion and communication aspects of mobile robot networks for harsh polar environments. The report is organized into seven sections: terrestrial locomotion, aerial locomotion, micro air

Kansas, University of

449

Zoogeographic distribution of terrestrial\\/freshwater tardigrades from current literature  

Microsoft Academic Search

The literature on terrestrial and freshwater Tardigrada is relatively limited, being concerned with 617 species world wide. Many of the references are in obscure publications. This paper attempts to bring this information together, tabulating the numbers of tardigrade species recorded from terrestrial and freshwater habitats in various countries and the number of countries from which tardigrades have been recorded. Each

S. J. McInnes

1994-01-01

450

SYMPOSIUM-IN-PRINT: ULTRAVIOLET RADIATION AND TERRESTRIAL ECOSYSTEMS  

Technology Transfer Automated Retrieval System (TEKTRAN)

This article provides an introduction to a Symposium-in-Print on Ultraviolet Radiation and Terrestrial Ecosystemsand summarizes the findings of ten papers that were presented at an invited Symposium on UV Effects on Terrestrial Ecosystems held at the annual meeting of the American Society for Ph...

451

Exploring the Sensitivity of Terrestrial Ecosystems and Atmospheric Exchange  

E-print Network

Exploring the Sensitivity of Terrestrial Ecosystems and Atmospheric Exchange of CO2 to Global, USA December 5-9, 2011 #12;ISAM Estimated Net Ecosystem Exchange (NEE) Winter (DJF) Summer (JJA) 1996- 1997 1999- 2000 1990s negative is net C gain by the terrestrial ecosystems #12;Environmental Factors

Jain, Atul K.

452

The Geochronology of Terrestrial Meteorite and Cometary Impacts  

Microsoft Academic Search

Geochronology has become a crucial part of the debate over the influx of extraterrestrial material and its long term importance to terrestrial life. Many of the known terrestrial craters have ages attached to them, but all too often the ages are imprecise and unfortunately some are inaccurate. Despite these problems the database of measured ages has been used to support

S. P. Kelley

2003-01-01

453

Terrestrial Models and Global Change: Challenges for the Future  

NASA Technical Reports Server (NTRS)

A wide variety of models have illustrated the potential importance of terrestrial biological feedbacks on climate and climate change, yet our ability to make precise predictions is severely limited, due to a high degree of uncertainty. In this paper, after briefly reviewing current models, we present challenges for new terrestrial models and introduce a simple mechanistic approach that may complement existing approaches.

Hurtt, George C.; Moorcroft, Paul R.; Pacala, Stephen W.; Levin, Simon A.

1998-01-01

454

Management opportunities for enhancing terrestrial CO2 sinks  

Technology Transfer Automated Retrieval System (TEKTRAN)

To address climate change and the implications of a global mean temperature increase of more than two degrees Celsius over current levels will require terrestrial carbon (C) management along with reductions in fossil fuel emissions. To achieve all or part of the global terrestrial C sequestration p...

455

Satellite and terrestrial integrated services digital networks in Japan  

Microsoft Academic Search

Satellite and terrestrial Integrated Services Digital Networks (ISDN) to provide cost effective ISDN services and to enhance installation of ISDN services all over the nation are proposed. The proposed networks are based on the traffic sharing between satellite and terrestrial networks for traffic transmission among telephone offices and provide satellite subscriber lines for ISDN customers in rural areas. The former

Heiichi Yamamoto; Shuzo Kato

1991-01-01

456

Earth station site engineering in a terrestrial interference environment  

Microsoft Academic Search

Reception of C-band satellite television signals is now widespread throughout Canada. One problem that many satellite users still face is signal degradation due to terrestrial interference. The desired satellite signal is deteriorated due to the simultaneous reception of an unwanted microwave signal originating from land based (terrestrial) common carrier transmission networks. Careful antenna site engineering can reduce interfering carrier levels

Ralph Voneppinghoven

1989-01-01

457

Energetic Metastable Oxygen and Nitrogen Atoms in the Terrestrial Atmosphere  

NASA Technical Reports Server (NTRS)

We have investigated the energy distributions of the metastable oxygen atoms in the terrestrial thermosphere. Nascent O(lD) atoms play a fundamental role in the energy balance and chemistry of the terrestrial atmosphere, because they are produced by photo-chemical reactions in the excited electronic states and carry significant translational energies.

Kharchenko, Vasili

2003-01-01

458

Auto-Concealment of Supersymmetry in Extra Dimensions  

E-print Network

In supersymmetric (SUSY) theories with extra dimensions the visible energy in sparticle decays can be significantly reduced and its energy distribution broadened, thus significantly weakening the present collider limits on SUSY. The mechanism applies when the lightest supersymmetric particle (LSP) is a bulk state-- e.g. a bulk modulino, axino, or gravitino-- the size of the extra dimensions larger than ~$10^{-14}$ cm, and for a broad variety of visible sparticle spectra. In such cases the lightest ordinary supersymmetric particle (LOSP), necessarily a brane-localised state, decays to the Kaluza-Klein (KK) discretuum of the LSP. This dynamically realises the compression mechanism for hiding SUSY as decays into the more numerous heavier KK LSP states are favored. We find LHC limits on right-handed slepton LOSPs evaporate, while LHC limits on stop LOSPs weaken to ~350-410 GeV compared to ~700 GeV for a stop decaying to a massless LSP. Similarly, for the searches we consider, present limits on direct production of degenerate first and second generation squarks drop to ~450 GeV compared to ~800 GeV for a squark decaying to a massless LSP. Auto-concealment typically works for a fundamental gravitational scale of $M_*$~10-100 TeV, a scale sufficiently high that traditional searches for signatures of extra dimensions are mostly avoided. If superpartners are discovered, their prompt, displaced, or stopped decays can also provide new search opportunities for extra dimensions with the potential to reach $M_*$~$10^9$ GeV. This mechanism applies more generally than just SUSY theories, pertaining to any theory where there is a discrete quantum number shared by both brane and bulk sectors.

Savas Dimopoulos; Kiel Howe; John March-Russell; James Scoville

2014-12-02

459

17. NBS TOOL ROOM. MISCELLANEOUS TOOLS USED DURING EXTRA VEHICULAR ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. NBS TOOL ROOM. MISCELLANEOUS TOOLS USED DURING EXTRA VEHICULAR ACTIVITY (EVA) MISSIONS AND NBS TRAINING. FROM LEFT TO RIGHT THE TOOLS ARE: SHUTTLE TRANSPORTATION SYSTEM (STS) PORTABLE FOOT RESTRAINT (PFR), ESSEX WRENCH, SOCKET WRENCH, SAFETY TETHER REEL (LEFT REAR), MINI WORKSTATION (CENTER REAR), TETHERS (FRONT CENTER), HUBBLE SPACE TELESCOPE (HST) POWER TOOL (FRONT RIGHT), HUBBLE SPACE TELESCOPE & PORTABLE FOOT RESTRAINT (REAR RIGHT). - Marshall Space Flight Center, Neutral Buoyancy Simulator Facility, Rideout Road, Huntsville, Madison County, AL

460

MRI diagnosis of intramedullary metastases from extra-CNS tumors  

Microsoft Academic Search

The purpose of this study was to evaluate the topography, morphology and contrast enhancement of the intramedullary metastases\\u000a (IM) from extra-CNS neoplasms. We report the results of a multicenter retrospective study on 18 patients with 26 IM examined\\u000a with a 0.5T MR imaging system; intravenous injection of Gd-DTPA was performed in all cases. We found that the lesions are\\u000a most

S. Crasto; S. Duca; O. Davini; L. Rizzo; I. Gomes Pavanello; T. Avataneo; S. Cirillo; D. Regge; R. Soffietti

1997-01-01

461

Universal extra dimensions and the Higgs boson mass  

Microsoft Academic Search

We study the combined constraints on the compactification scale 1\\/R and the Higgs boson mass mH in the standard model with one or two universal extra dimensions. Focusing on precision measurements and employing the Peskin-Takeuchi S and T parameters, we analyze the allowed region in the (mH,1\\/R) parameter space consistent with current experiments. For this purpose, we calculate complete one-loop

Thomas Appelquist; Ho-Ung Yee

2003-01-01

462

Effect of extra dimensions on gravitational waves from cosmic strings.  

PubMed

We show how the motion of cosmic superstrings in extra dimensions can modify the gravitational wave signal from cusps. Additional dimensions both round off cusps, as well as reducing the probability of their formation, and thus give a significant dimension dependent damping of the gravitational waves. We look at the implication of this effect for LIGO and LISA, as well as commenting on more general frequency bands. PMID:20868089

O'Callaghan, Eimear; Chadburn, Sarah; Geshnizjani, Ghazal; Gregory, Ruth; Zavala, Ivonne

2010-08-20

463

Effect of Extra Dimensions on Gravitational Waves from Cosmic Strings  

SciTech Connect

We show how the motion of cosmic superstrings in extra dimensions can modify the gravitational wave signal from cusps. Additional dimensions both round off cusps, as well as reducing the probability of their formation, and thus give a significant dimension dependent damping of the gravitational waves. We look at the implication of this effect for LIGO and LISA, as well as commenting on more general frequency bands.

O'Callaghan, Eimear [Institute for Particle Physics Phenomenology, Department of Physics, South Road, Durham, DH1 3LE (United Kingdom); Chadburn, Sarah [Centre for Particle Theory, Department of Mathematical Sciences, South Road, Durham, DH1 3LE (United Kingdom); Geshnizjani, Ghazal [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo Ontario, N2L 2Y (Canada); Gregory, Ruth [Institute for Particle Physics Phenomenology, Department of Physics, South Road, Durham, DH1 3LE (United Kingdom); Centre for Particle Theory, Department of Mathematical Sciences, South Road, Durham, DH1 3LE (United Kingdom); Zavala, Ivonne [Bethe Center for Theoretical Physics and Physikalisches Institut der Universitaet Bonn, Nussallee 12, D-53115 Bonn (Germany)

2010-08-20

464

The Merits of Giving an Extra Credit Quiz  

ERIC Educational Resources Information Center

In the past, Ryall Carroll struggled to get students to arrive on time, read the material in advance of the class, and to start class on topic. In an attempt to address these issues, he started implementing an extra-credit two-question quiz at the beginning of every class, hoping it would provide a small incentive for students to at least come on

Carroll, Ryall

2014-01-01

465