Note: This page contains sample records for the topic extra terrestrial bodies from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Extra Terrestrial Lava Flows  

NASA Technical Reports Server (NTRS)

Volcanism has been one of the major processes shaping the surfaces of the terrestrial planets. Lava flows have been identified on the Moon, Mars, Venus, and on Juptier's moon Io. The study of extra-terrestrial lavas has largely relied on the interpretation of remotely acquired imaging, topographic and spectroscopic data. Models relating the final flow morpohology to eruption characteristics and magma chemistry have been important tools in the interpretation of these data.

Lopes-Gautier, R.

1993-01-01

2

ExtraTerrestrial Radio Transmissions  

Microsoft Academic Search

WE are witness again to a surge of interest in, and speculation about, extra-terrestrial radio transmissions which had an earlier flare in the late twenties1. The favourable change in climate for the expression of such ideas since the turn of the century has been of particular interest to me. In 1899, Nikola Tesla established an experimental station at Colorado Springs,

Leland I. Anderson

1961-01-01

3

Core Drilling For Extra-Terrestrial Mining  

NASA Astrophysics Data System (ADS)

Space Resource Utilization involves the active identification and mining of planetary bodies for commodities ranging from platinum group metals to water, such as might be realized from a dormant comet or carbonaceous chondrite like 1998 KY26, estimated to contain over 1 million gallons of water. Some proposed ET mining processes require access to sub-surface "mining zones" ranging from 10 to 200 metres and beyond. The technology used must support the identification, mining and extraction processes and must operate in milli-gravity, airless and extreme environments. This paper proposes the use of the diamond core drilling apparatus as a multi-purpose enabling technology for any extra-terrestrial sub-surface resource utilization. It specifically examines the mechanics of Diamond Drill Coring and addresses the issues required to adapt the technology to space based operations.

Boucher, D. S.; Dupuis, E.

2000-01-01

4

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

5

The search for extra-terrestrial intelligence.  

PubMed

Modern history of the search for extra-terrestrial intelligence is reviewed. The history of radio searches is discussed, as well as the major advances that have occurred in radio searches and prospects for new instruments and search strategies. Recent recognition that searches for optical and infrared signals make sense, and the reasons for this are described, as well as the equipment and special detection methods used in optical searches. The long-range future of the search for extra-terrestrial intelligence (SETI) is discussed in the context of the history of rapid change, on the cosmic and even the human time scale, of the paradigms guiding SETI searches. This suggests that SETI searches be conducted with a very open mind. PMID:21220287

Drake, Frank

2011-02-13

6

Radio communications with extra-terrestrial civilizations  

NASA Technical Reports Server (NTRS)

Communications between civilizations within our galaxy at the present level of radio engineering is possible, although civilizations must begin to search for each other to achieve this. If an extra-terrestrial civilization possessing a technology at our level wishes to make itself known and will transmit special radio signals to do this, then it can be picked up by us at a distance of several hundreds of light years using already existing radio telescopes and specially built radio receivers. If it wishes, this civilization can also send us information without awaiting our answer.

Kotelnikov, V. A.

1974-01-01

7

Quarantine provisions for unmanned extra-terrestrial missions  

NASA Technical Reports Server (NTRS)

This document sets forth requirements applicable to unmanned planetary flight programs which are necessary to enable the Associate Administrator for Space Science to fulfill those responsibilities pertaining to planetary quarantine as stated in NPD 8020.7 and NPD 8020.10A. This document is specifically directed to the control of terrestrial microbial contamination associated with unmanned space vehicles intended to encounter, orbit, flyby, or otherwise be in the vicinity of extra-terrestrial solar system bodies. The requirements of this document apply to all unmanned planetary flight programs. This includes solar system exploratory missions to the major planets as well as missions to planet satellites, or to other solar system objects that may be of scientific interest. This document is not applicable to terrestrial (including lunar) missions and manned missions. NASA officials having cognizance of applicable flight programs will invoke these requirements in such directives or contractual instruments as may be necessary to assure their implementation.

1976-01-01

8

The Opportunities and Challenges in the Use of Extra-Terrestrial Acoustics in the Exploration of the Oceans of Icy Planetary Bodies  

NASA Astrophysics Data System (ADS)

Acoustic radiation is the signal of choice for exploring Earth's oceans. Its potential application for the oceans of icy moons requires investigation. However acoustic technology needs to be treated with care for extra-terrestrial purposes. Instruments, calibrations, and predictive codes that have served well on Earth may require fundamental redesign for use on other worlds. However when such an assessment is achieved, acoustic signals open up the possibility of exploring volumes exceeding one million cubic kilometres in a few minutes. This paper begins at tutorial level for novice acousticians, illustrating the principles by which acoustics can be used to monitor the environment at great distances from the source, both by projecting out signals and by using natural signals of opportunity. It then progresses to calculations for a generic icy moon (which resembles, but does not model Europa), proceeding from tutorial calculations of `flat world' models to calculate the propagation times for pulses to circumpropagate around the entire moon. Given that a single emitted pulse can produce multiple arrivals from different propagation paths, the paper discusses how the structure of the received time history can be used to monitor changes in the temperature profile in the ocean, position of the water/ice layer and the asphericity of the moon during orbit.

Leighton, T. G.; White, P. R.; Finfer, D. C.

2012-12-01

9

The extra-terrestrial vacuum-ultraviolet wavelength range  

Microsoft Academic Search

Electromagnetic radiation in the vacuum-ultraviolet (VUV) and extra-terrestrial range at wavelengths from 10 nm to 300 nm is absorbed in the upper atmosphere by ozone, molecular and atomic oxygen, and molecular nitrogen. Observations at wavelengths down to ≈ 200 nm can be carried out from stratospheric balloons, and observations below 200 nm require space platforms operating at altitudes above 250

J. Gethyn Timothy; Klaus Wilhelm; Lidong Xia

2010-01-01

10

An energy-efficient architecture for multi-hop communication between rovers and satellites in extra-terrestrial surfaces  

Microsoft Academic Search

Over the past three decades, several man-made vehicles have being sent into space to explore the extra-terrestrial bodies. As the search for water and other useful substances in the extra-terrestrial surfaces increases, this exploration activity is set to dramatically increase over the next decade (2020); with NASA planning to explore the surface of Mars, Moon and other planets and satellites.

Daniel Irwin; Hrishikesh Venkataraman; Gabriel-Miro Muntean

2012-01-01

11

Energy use, entropy and extra-terrestrial civilizations  

Microsoft Academic Search

The possible number of extra-terrestrial civilizations is estimated by the Drake-equation. Many articles pointed out that there are missing factors and over-estimations in the original equation. In this article we will point out that assuming some axioms there might be several limits for a technical civilization. The key role of the energy use and the problem of the centres and

Zsolt Hetesi

2010-01-01

12

Migration & Extra-solar Terrestrial Planets: Watering the Planets  

NASA Astrophysics Data System (ADS)

A diverse range of terrestrial planet compositions is believed to exist within known extrasolar planetary systems, ranging from those that are relatively Earth-like to those that are highly unusual, dominated by species such as refractory elements (Al and Ca) or C (as pure C, TiC and SiC)(Bond et al. 2010b). However, all prior simulations have ignored the impact that giant planet migration during planetary accretion may have on the final terrestrial planetary composition. Here, we combined chemical equilibrium models of the disk around five known planetary host stars (Solar, HD4203, HD19994, HD213240 and Gl777) with dynamical models of terrestrial planet formation incorporating various degrees of giant planet migration. Giant planet migration is found to drastically impact terrestrial planet composition by 1) increasing the amount of Mg-silicate species present in the final body; and 2) dramatically increasing the efficiency and amount of water delivered to the terrestrial bodies during their formation process.

Carter-Bond, Jade C.; O'Brien, David P.; Raymond, Sean N.

2014-04-01

13

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

14

Applying Biomimetic Algorithms for Extra-Terrestrial Habitat Generation  

NASA Technical Reports Server (NTRS)

The objective is to simulate and optimize distributed cooperation among a network of robots tasked with cooperative excavation on an extra-terrestrial surface. Additionally to examine the concept of directed Emergence among a group of limited artificially intelligent agents. Emergence is the concept of achieving complex results from very simple rules or interactions. For example, in a termite mound each individual termite does not carry a blueprint of how to make their home in a global sense, but their interactions based strictly on local desires create a complex superstructure. Leveraging this Emergence concept applied to a simulation of cooperative agents (robots) will allow an examination of the success of non-directed group strategy achieving specific results. Specifically the simulation will be a testbed to evaluate population based robotic exploration and cooperative strategies while leveraging the evolutionary teamwork approach in the face of uncertainty about the environment and partial loss of sensors. Checking against a cost function and 'social' constraints will optimize cooperation when excavating a simulated tunnel. Agents will act locally with non-local results. The rules by which the simulated robots interact will be optimized to the simplest possible for the desired result, leveraging Emergence. Sensor malfunction and line of sight issues will be incorporated into the simulation. This approach falls under Swarm Robotics, a subset of robot control concerned with finding ways to control large groups of robots. Swarm Robotics often contains biologically inspired approaches, research comes from social insect observation but also data from among groups of herding, schooling, and flocking animals. Biomimetic algorithms applied to manned space exploration is the method under consideration for further study.

Birge, Brian

2012-01-01

15

The weak force and SETH: The search for ExtraTerrestrial Homochirality  

Microsoft Academic Search

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality-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 Z0 boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how

Alexandra J. MacDermott

1996-01-01

16

The weak force and SETH: The search for ExtraTerrestrial Homochirality  

Microsoft Academic Search

We propose that a search for extra-terrestrial life can be approached as a Search for Extra-Terrestrial Homochirality—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 Z0 boson gives rise to a small parity-violating energy difference (PVED) between enantiomers, and discuss how

Alexandra J. MacDermott

1996-01-01

17

The child alone: Children's stories reminiscent of E. T.: The ExtraTerrestrial  

Microsoft Academic Search

In the summer of 1982, a new fairy-tale creature appeared in a motion picture which completely captured the popular imagination: E.T.: The Extra-Terrestrial. The film tells the story of an errant extra-terrestrial, physically repulsive by human standards, who is mistakenly abandoned by his people on a flora-gathering expedition on earth and who faces uncertainty, danger, and eventual death in an

Argiro L. Morgan

1985-01-01

18

Flat mirror optics to study extra-solar terrestrial planets from space  

Microsoft Academic Search

The Terrestrial Planet Finder (TPF) is currently envisioned as a 75-1,000 m, interferometer with four free-flying elements to detect and obtain spectra of extra-solar Earth-like planets. Because of the ambitious nature of the mission, a low-cost, precursor interferometer capable of detecting the nearest extra-solar planets would be very beneficial. It has been argued (P. Bely et al, N. Woolf et

R. Angel; J. Burge; N. Woolf

1999-01-01

19

Time-Bounded Kolmogorov Complexity May Help in Search for Extra Terrestrial Intelligence (SETI)  

Microsoft Academic Search

One of the main strategies in Search for Extra Terrestrial Intelligence (SETI) is trying to overhearcommunications between advanced civilizations. However, there is a (seeming) problem with this approach:advanced civilizations, most probably, save communication expenses by maximally compressingtheir messages, and the notion of a maximally compressed message is naturally formalized as a messagex for which Kolmogorov complexity C(x) is close to

M. Schmidt

1999-01-01

20

Searching for extra-terrestrial intelligence and the discovering of extrasolar planets  

Microsoft Academic Search

In this paper, the significance, instrumentality, and the status in the search for extra-terrestrial intelligence, and, in addition, the SETI program and its development, are introduced. Especial emphasis is on the discovery of extrasolar planets, its purpose, ways and means, achievement, and future.Finding extrasolar planets is one of the most popular issues at present. It will be one of the

Guang-Jie Wu; Dao-Han Chen

2002-01-01

21

On the relationship between extra-terrestrial radiation and surface pressure  

Microsoft Academic Search

The surface pressure of an Antarctic station displays two minima, one in spring, the other in autumn. It is believed that these minima are caused by radiative forcing, as the gradient of the extra-terrestrial radiation is largest during the two equinoxes. The best correlation (r = 0.85) was obtained when the pressure lagged the radiation gradient by ten days.

Gerd Wendler; Michael Pook

1996-01-01

22

The implications of the discovery of extra-terrestrial life for religion.  

PubMed

This paper asks about the future of religion: (i) Will confirmation of extra-terrestrial intelligence (ETI) cause terrestrial religion to collapse? 'No' is the answer based upon a summary of the 'Peters ETI Religious Crisis Survey'. Then the paper examines four specific challenges to traditional doctrinal belief likely to be raised at the detection of ETI: (ii) What is the scope of God's creation? (iii) What can we expect regarding the moral character of ETI? (iv) Is one earthly incarnation in Jesus Christ enough for the entire cosmos, or should we expect multiple incarnations on multiple planets? (v) Will contact with more advanced ETI diminish human dignity? More than probable contact with extra-terrestrial intelligence will expand the Bible's vision so that all of creation--including the 13.7 billion year history of the universe replete with all of God's creatures--will be seen as the gift of a loving and gracious God. PMID:21220288

Peters, Ted

2011-02-13

23

Discovery of extra-terrestrial life: assessment by scales of its importance and associated risks.  

PubMed

The Rio Scale accepted by the SETI Committee of the International Academy of Astronautics in 2002 is intended for use in evaluating the impact on society of any announcement regarding the discovery of evidence of extra-terrestrial (ET) intelligence. The Rio Scale is mathematically defined using three parameters (class of phenomenon, type of discovery and distance) and a ? factor, the assumed credibility of a claim. This paper proposes a new scale applicable to announcements alleging evidence of ET life within or outside our Solar System. The London Scale for astrobiology has mathematical structure and logic similar to the Rio Scale, and uses four parameters (life form, nature of phenomenon, type of discovery and distance) as well as a credibility factor ? to calculate a London Scale index (LSI) with values ranging from 0 to 10. The level of risk or biohazard associated with a purported discovery is evaluated independently of the LSI value and may be ranked in four categories. The combined information is intended to provide a scalar assessment of the scientific importance, validity and potential risks associated with putative evidence of ET life discovered on Earth, on nearby bodies in the Solar System or in our Galaxy. PMID:21220291

Almár, Iván; Race, Margaret S

2011-02-13

24

Techniques for the measurement of extra-terrestrial soft x-radiation  

Microsoft Academic Search

The electromagnetic spectrum has no clearly defined boundaries separating one part from another. Rather has each region become associated with a name which has arisen historically. It is therefore necessary to make some fairly arbitrary decision on the region to be included in the term soft X-radiation. The study of extra-terrestrial X-radiation grew historically from photometer type measurements using metal

R. L. F. Boyd; R. L. F

1965-01-01

25

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

Microsoft Academic Search

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

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

2008-01-01

26

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

27

Tidal Heating of Terrestrial ExtraSolar Planets and Implications for their Habitability  

Microsoft Academic Search

The tidal heating of hypothetical rocky (or terrestrial) extra-solar planets\\u000aspans a wide range of values depending on stellar masses and initial orbits.\\u000aTidal heating may be sufficiently large (in many cases, in excess of radiogenic\\u000aheating) and long-lived to drive plate tectonics, similar to the Earth's, which\\u000amay enhance the planet's habitability. In other cases, excessive tidal heating\\u000amay

Brian Jackson; Rory Barnes; Richard Greenberg

2008-01-01

28

Fear, pandemonium, equanimity and delight: human responses to extra-terrestrial life.  

PubMed

How will people respond to the discovery of extra-terrestrial life? Potentially useful resources for addressing this question include historical prototypes, disaster studies and survey research. Reactions will depend on the interplay of the characteristics of the newly found life, the unfolding of the discovery, the context and content of the message and human information processing as shaped by biology, culture and psychology. Pre-existing images of extra-terrestrials as god-like, demonic, or artificial will influence first impressions that may prove highly resistant to change. Most probably people will develop comprehensive images based on minimal information and assess extra-terrestrials in the same ways that they assess one another. Although it is easy to develop frightening scenarios, finding microbial life in our Solar System or intercepting a microwave transmission from many light years away are less likely to be met with adverse reactions such as fear and pandemonium than with positive reactions such as equanimity and delight. PMID:21220289

Harrison, Albert A

2011-02-13

29

Predicting what extra-terrestrials will be like: and preparing for the worst.  

PubMed

It is difficult to imagine evolution in alien biospheres operating in any manner other than Darwinian. Yet, it is also widely assumed that alien life-forms will be just that: strange, un-nerving and probably repulsive. There are two reasons for this view. First, it is assumed that the range of habitable environments available to extra-terrestrial life is far wider than on Earth. I suggest, however, that terrestrial life is close to the physical and chemical limits of life anywhere. Second, it is a neo-Darwinian orthodoxy that evolution lacks predictability; imagining what extra-terrestrial life would look like in any detail is a futile exercise. To the contrary, I suggest that the outcomes of evolution are remarkably predictable. This, however, leads us to consider two opposites, both of which should make our blood run cold. The first, and actually extremely unlikely, is that alien biospheres will be strikingly similar to our terrestrial equivalent and that in such biospheres intelligence will inevitably emerge. The reasons for this revolve around the ubiquity of evolutionary convergence, the determinate structure of the Tree of Life and molecular inherency. But if something like a human is an inevitability, why do I also claim that the first possibility is 'extremely unlikely'? Simply because the other possibility is actually the correct answer. Paradoxically, we and our biosphere are completely alone. So which is worse? Meeting ourselves or meeting nobody? PMID:21220280

Morris, Simon Conway

2011-02-13

30

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

31

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

32

Chemical methods for searching for evidence of extra-terrestrial life.  

PubMed

This paper describes the chemical concepts used for the purpose of detecting life in extra-terrestrial situations. These methods, developed initially within the oil industry, have been used to determine when life began on Earth and for investigating the Moon and Mars via space missions. In the case of Mars, the Viking missions led to the realization that we had meteorites from Mars on Earth. The study of Martian meteorites in the laboratory provides tantalizing clues for life on Mars in both the ancient and recent past. Meteorite analyses led to the launch of the Beagle 2 spacecraft, which was designed to prove that life-detection results obtained on Earth were authentic and not confused by terrestrial contamination. Some suggestions are made for future work. PMID:21220284

Pillinger, Colin

2011-02-13

33

The detection of extra-terrestrial life and the consequences for science and society.  

PubMed

Astronomers are now able to detect planets orbiting stars other than the Sun where life may exist, and living generations could see the signatures of extra-terrestrial life being detected. Should it turn out that we are not alone in the Universe, it will fundamentally affect how humanity understands itself--and we need to be prepared for the consequences. A Discussion Meeting held at the Royal Society in London, 6-9 Carlton House Terrace, on 25-26 January 2010, addressed not only the scientific but also the societal agenda, with presentations covering a large diversity of topics. PMID:21220276

Dominik, Martin; Zarnecki, John C

2011-02-13

34

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

PubMed

The existence of extra-terrestrial oceans offers the opportunities to set examination questions for which students in underwater acoustics do not already know the answers. The limited set of scenarios in Earth's oceans that can be presented to students as tractable examination questions means that, rather than properly assessing the individual scenario, students can rely on knowledge from previous examples in assessing, for example, which terms in equations are large and small, and what numerical values the answers are likely to take. The habit of adapting previous solutions with which the student is comfortable, to new scenarios, is not a safe approach to learn, as it ill equips the future scientist or engineer to identify and tackle problems which contain serious departures from their experience. PMID:22423807

Leighton, T G

2012-03-01

35

Origins of Non-mass-dependent Fractionation of Extra-terrestrial Oxygen  

NASA Astrophysics Data System (ADS)

The distribution of oxygen isotopes in meteorites and within the earliest solids that formed in the solar system hints that the precursors of these materials must have undergone a mass-independent process. The mass-independent process is specifically one that fractionates 16O from 17O and 18O. This chemical signature is indicative of non-equilibrium processing, which bear resemblance to some unusual terrestrial phenomenon such as fractionation of ozone in the upper Earth atmosphere. That the mass-independent fractionation of oxygen isotopes is preserved within petrological records presents planetary scientists interesting clues to the events that may have occurred during the formation of the solar system. Currently, there are several hypotheses on the origins of the oxygen isotope distribution within primitive planetary materials, which include both thermal and photochemical models. We present a new model based on a physico-chemical hypothesis for the origin of non-mass-dependent O-isotope distribution in oxygen-bearing extra-terrestrial materials, which originated from the disproportionation of CO in dark molecular clouds to create CO2 reservoirs. The disproportionation created a reservoir of heavy oxygen isotopes and could have occurred throughout the evolution of the disk. The CO2 was a carrier of the isotope anomaly in the solar nebula and we propose that non-steady-state mixing of these reservoirs with the early rock-forming materials during their formation corresponds with the birth and evolution of the solar system.

Barcena, Homar; Connolly, Harold C.

2012-08-01

36

The New Worlds Observer: a mission for high-resolution spectroscopy of extra-solar terrestrial planets  

Microsoft Academic Search

The New Worlds Observer (NWO) is a proposed space mission to provide high resolution spectroscopy from the far UV to the near IR of extra-solar terrestrial sized planets. The design of NWO is based on the concept of a large, space-based, pinhole camera made up of two spacecraft flying in formation. The first spacecraft is a large, thin occulting shield

Willard L. Simmons; Webster C. Cash; Sara Seager; Erik Wilkinson; N. Jeremy Kasdin; Robert J. Vanderbei; Naomi Chow; Erica Gralla; Johanna Kleingeld

2004-01-01

37

Likelihood deconvolution of diffuse prompt and extra-terrestrial neutrino fluxes in the AMANDA-II detector  

Microsoft Academic Search

The unknown flux of prompt atmospheric neutrinos presents a challenging background to searches for extra-terrestrial neutrinos in high-energy detectors. Uncertainties in this flux will weaken the power of the detector to place constraints on other expected signals. A new likelihood analysis, using the full information present in event arrival directions and energy will be presented, which allows simultaneous constraints on

Gary C. Hill

2008-01-01

38

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.

39

Searches for a diffuse flux of extra-terrestrial muon neutrinos with AMANDA-II and IceCube  

Microsoft Academic Search

The AMANDA-II data collected during the period 2000-03 have been analysed in a search for a diffuse flux of high-energy extra-terrestrial neutrinos from the sum of all sources in the universe. With no excess of events seen, an upper limit on an E-2 flux of E2 Phi < 8.8 x 10-8 GeV cm-2 s-1 sr-1 was obtained. The astrophysical implications

Kotoyo Hoshina; Jessica Hodges; Gary C. Hill

2008-01-01

40

The New Worlds Observer: a mission for high-resolution spectroscopy of extra-solar terrestrial planets  

NASA Astrophysics Data System (ADS)

The New Worlds Observer (NWO) is a proposed space mission to provide high resolution spectroscopy from the far UV to the near IR of extra-solar terrestrial sized planets. The design of NWO is based on the concept of a large, space-based, pinhole camera made up of two spacecraft flying in formation. The first spacecraft is a large, thin occulting shield (perhaps hundreds of meters in diameter) with a shaped "pinhole" aperture about 10m in diameter. The second spacecraft is a conventional-quality space telescope (possibly with a 10m primary mirror) which "flies" through the pinhole image of the planetary system to observe the extra-solar planets free from stellar background. In this paper we describe the design of the two spacecraft system. In particular, the shaped-pinhole design utilizes the shaped-pupil coronagraph pioneered for the Terrestrial Planet Finder. In this paper we describe some of the NWO's technology challenges and science opportunities. Additionally, we describe an extension of the design to provide 100km resolution images of extra-solar planets.

Simmons, Willard L.; Cash, Webster C.; Seager, Sara; Wilkinson, Erik; Kasdin, N. Jeremy; Vanderbei, Robert J.; Chow, Naomi; Gralla, Erica; Kleingeld, Johanna

2004-10-01

41

Exoskeletal chitin scales isometrically with body size in terrestrial insects.  

PubMed

The skeletal system of animals provides the support for a variety of activities and functions. For animals such as mammals, which have endoskeletons, research has shown that skeletal investment (mass) scales with body mass to the 1.1 power. In this study, we ask how exoskeletal investment in insects scales with body mass. We measured the body mass and mass of exoskeletal chitin of 551 adult terrestrial insects of 245 species, with dry masses ranging from 0.0001 to 2.41 g (0.0002-6.13 g wet mass) to assess the allometry of exoskeletal investment. Our results showed that exoskeletal chitin mass scales isometrically with dry body mass across the Insecta as M(chitin) = a M(dry) (b), where b = 1.03 +/- 0.04, indicating that both large and small terrestrial insects allocate a similar fraction of their body mass to chitin. This isometric chitin-scaling relationship was also evident at the taxonomic level of order, for all insect orders except Coleoptera. We additionally found that the relative exoskeletal chitin investment, indexed by the coefficient, a, varies with insect life history and phylogeny. Exoskeletal chitin mass tends to be proportionally less and to increase at a lower rate with mass in flying than in nonflying insects (M(flying insect chitin) = -0.56 x M(dry) (0.97); M(nonflying insect chitin) = -0.55 x M(dry) (1.03)), and to vary with insect order. Isometric scaling (b = 1) of insect exoskeletal chitin suggests that the exoskeleton in insects scales differently than support structures of most other organisms, which have a positive allometry (b > 1) (e.g., vertebrate endoskeleton, tree secondary tissue). The isometric pattern that we document here additionally suggests that exoskeletal investment may not be the primary limit on insect body size. PMID:20235123

Lease, Hilary M; Wolf, Blair O

2010-06-01

42

The evolution of maximum body size of terrestrial mammals.  

PubMed

The extinction of dinosaurs at the Cretaceous/Paleogene (K/Pg) boundary was the seminal event that opened the door for the subsequent diversification of terrestrial mammals. Our compilation of maximum body size at the ordinal level by sub-epoch shows a near-exponential increase after the K/Pg. On each continent, the maximum size of mammals leveled off after 40 million years ago and thereafter remained approximately constant. There was remarkable congruence in the rate, trajectory, and upper limit across continents, orders, and trophic guilds, despite differences in geological and climatic history, turnover of lineages, and ecological variation. Our analysis suggests that although the primary driver for the evolution of giant mammals was diversification to fill ecological niches, environmental temperature and land area may have ultimately constrained the maximum size achieved. PMID:21109666

Smith, Felisa A; Boyer, Alison G; Brown, James H; Costa, Daniel P; Dayan, Tamar; Ernest, S K Morgan; Evans, Alistair R; Fortelius, Mikael; Gittleman, John L; Hamilton, Marcus J; Harding, Larisa E; Lintulaakso, Kari; Lyons, S Kathleen; McCain, Christy; Okie, Jordan G; Saarinen, Juha J; Sibly, Richard M; Stephens, Patrick R; Theodor, Jessica; Uhen, Mark D

2010-11-26

43

Earthsickness: circumnavigation and the terrestrial human body, 1520-1800.  

PubMed

From their distinctive experience of going around the world, maritime circumnavigators concluded that their characteristic disease, sea scurvy, must result from their being away from land too long, much longer than any other sailors. They offered their scorbutic bodies as proof that humans were terrestrial creatures, physically suited to the earthly parts of a terraqueous globe. That arresting claim is at odds with the current literature on the cultural implications of European expansion, which has emphasized early modern colonists' and travelers' fear of alien places, and has concluded that they had a small and restricted geographic imagination that fell short of the planetary consciousness associated with the nineteenth and twentieth centuries. But circumnavigators did conceive of themselves as actors on a planetary scale, as creatures adapted to all of the land on Earth, not just their places of origin. PMID:23263345

Chaplin, Joyce E

2012-01-01

44

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

Microsoft Academic Search

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

John Elliott

2011-01-01

45

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

46

An observational signature of evolved oceans on extra-solar terrestrial planets  

Microsoft Academic Search

The increase in luminosity with time of a main sequence star eventually can\\u000alead to substantial evaporation of the oceans on an orbiting terrestrial\\u000aplanet. Subsequently, the gas phase water in the planet's upper atmosphere can\\u000abe photodissociated by stellar ultraviolet and the resulting atomic hydrogen\\u000athen may be lost in a wind. This gaseous envelope may pass in front

M. Jura

2004-01-01

47

Extra terrestrial abiogenic organization of organic matter: The hollow spheres of the Orgueil meteorite  

Microsoft Academic Search

Fragments of the Orgueil meteorite were macerated in mineral acids (HNO3-HF-HNO3) to dissolve the mineral matrix and separate the acid-resistant organic residues; a routine procedure in the extraction of pollen and spores from terrestrial sediments. Numerous spherical hollow objects were found, optically resembling the brown amorphous residual organic matrix of the meteorite. Their morphology, size-distribution, and chemical composition, revealed by

Martine Rossignol-Strick; Elso S. Barghoorn

1971-01-01

48

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

49

Production of pre-biotic molecules from extra-terrestrial ices  

NASA Astrophysics Data System (ADS)

Impacts of interstellar ices on early Earth could have been partially responsible for the creation of amino acids on the planet. We present ab initio molecular dynamics simulations of shock compressed aqueous mixtures representative of astrochemical ices found on dust grains and within other celestial bodies. We discover that high shock velocities drive the synthesis of a number of transient, exotic C--N bonded species at significantly higher pressures and temperatures than previously studied. Upon quenching to lower pressure conditions we observe a simple mechanism for the formation of the alpha amino acid glycine, an important component of protein synthesis. We find that shock compression of astrophysical ices followed by rapid expansion is a viable pathway for amino acid formation on the primitive planet.

Goldman, N.

2009-12-01

50

Planning An Efficient Search For ExtraSolar Terrestrial Planets: How To Find Exo-Earths With NWO  

Microsoft Academic Search

The search for exoplanets is an important goal for the Astronomy community in the next decade. We discuss the feasibility of finding terrestrial planets around nearby stars using direct-detection methods. The probability of finding a planet in the habitable zone around a given star depends on its brightness and distance from Earth, the fraction of stellar systems that contain terrestrial

Tiffany M. Glassman; L. Newhart; G. Barber; M. Turnbull

2009-01-01

51

Warming-induced reductions in body size are greater in aquatic than terrestrial species.  

PubMed

Most ectothermic organisms mature at smaller body sizes when reared in warmer conditions. This phenotypically plastic response, known as the "temperature-size rule" (TSR), is one of the most taxonomically widespread patterns in biology. However, the TSR remains a longstanding life-history puzzle for which no dominant driver has been found. We propose that oxygen supply plays a central role in explaining the magnitude of ectothermic temperature-size responses. Given the much lower oxygen availability and greater effort required to increase uptake in water vs. air, we predict that the TSR in aquatic organisms, especially larger species with lower surface area-body mass ratios, will be stronger than in terrestrial organisms. We performed a meta-analysis of 1,890 body mass responses to temperature in controlled experiments on 169 terrestrial, freshwater, and marine species. This reveals that the strength of the temperature-size response is greater in aquatic than terrestrial species. In animal species of ?100 mg dry mass, the temperature-size response of aquatic organisms is 10 times greater than in terrestrial organisms (-5.0% °C(-1) vs. -0.5% °C(-1)). Moreover, although the size response of small (<0.1 mg dry mass) aquatic and terrestrial species is similar, increases in species size cause the response to become increasingly negative in aquatic species, as predicted, but on average less negative in terrestrial species. These results support oxygen as a major driver of temperature-size responses in aquatic organisms. Further, the environment-dependent differences parallel latitudinal body size clines, and will influence predicted impacts of climate warming on food production, community structure, and food-web dynamics. PMID:23129645

Forster, Jack; Hirst, Andrew G; Atkinson, David

2012-11-20

52

Wet tropospheric delay spatial variability over terrestrial water bodies  

NASA Astrophysics Data System (ADS)

Among the sources of uncertainty in radar altimetry measurements of inland water bodies is the signal delay associated with space-time variations in water vapor in the atmosphere. Over the ocean, zenith wet tropospheric path delays (PD) can be measured by satellite microwave radiometry; however, the high brightness temperature of land prevents the use of these techniques over inland waters. SAR-based Atmospheric Phase Screens can be estimated over land, but not over water bodies. Radiosonde- and GPS-based estimates of PD over land are available, yet these measurements occur at specific, sparse locations. Atmospheric models are therefore the best source of information about space-time variations in PD, where observations (e.g., from radiosonde and GPS) are incorporated via data assimilation. The upcoming Surface Water and Ocean Topography mission (SWOT) will use Interferometric Synthetic Aperture Radar (InSAR) in Ka-band, at a high incidence angle, to measure temporal variations in water elevation, slope, and extent in rivers, lakes, and reservoirs. Images will be collected over a 120-km wide swath with <100 m spatial resolution and ~1 cm height precision when averaged over a 1 km2 area, with a 21-day repeat cycle. At present, the spatial and temporal variability of PD at spatial scales relevant to the mission's inland water objectives (e.g., measurement of variations in the storage of reservoirs and lakes with spatial extent order 1 sq. km and larger) is an open question. We report the results of simulations of PD based on simulations from the Weather Research and Forecasting (WRF) numerical weather prediction model. We consider two domains within the continental U.S.: 1) the Pacific Northwest (at 4-km and 4/3-km spatial resolutions, via WRF results provided by the Northwest Modeling Consortium), and 2) sections of New Mexico, Oklahoma, and Texas (at 2.33-km spatial resolution, via simulations performed for this study). We then investigate the spatial and temporal variability of these PD values over inland water bodies, with a focus on manmade reservoirs in the Western U.S., including Anderson Ranch, Ray Hubbard, Elephant Butte, Lake Mead, and Sam Rayburn. We also assess the degree of temporal correlation between PD and water level variations and spatial correlations between PD and water extent variations.

Clark, E.; Moller, D.; Andreadis, K.; Lettenmaier, D. P.

2013-12-01

53

Planning An Efficient Search For Extra-Solar Terrestrial Planets: How To Find Exo-Earths With NWO  

NASA Astrophysics Data System (ADS)

The search for exoplanets is an important goal for the Astronomy community in the next decade. We discuss the feasibility of finding terrestrial planets around nearby stars using direct-detection methods. The probability of finding a planet in the habitable zone around a given star depends on its brightness and distance from Earth, the fraction of stellar systems that contain terrestrial planets (?Earth), and the characteristics of the observatory. We discuss the available target stars and the completeness of a search for terrestrial exoplanets given different mission constraints. New Worlds Observer (NWO) is a two-spacecraft mission that consists of an external starshade and an UV-optical space telescope, flying in tandem. In this paper, we focus on NWO's ability to complete a feasible observing schedule designed to find and characterize 30 Exo-Earths around nearby stars (if ?Earth = 1). NWO offers the ability to create flexible, adaptable observing schedules to meet a variety of observing goals.

Glassman, Tiffany M.; Newhart, L.; Barber, G.; Turnbull, M.; NWO Study Team

2009-01-01

54

The search for extra-solar terrestrial planets: techniques and technology. Proceedings. Conference, Boulder, CO (USA), 14 - 17 May 1995  

Microsoft Academic Search

The following topics were dealt with: search for extrasolar terrestrial planets, techniques, technology, planetary atmosphere evolution, solar system evolution, photometric search, radial velocity searches, photon-noise limit, astrometric searches, OSI mission, GAIA mission, ground-based interferometry, FRESIP mission, DARWIN project, and public involvement in extrasolar planet detection.

J. M. Shull; H. A. Thronson Jr.; S. A. Stern

1996-01-01

55

Elucidating differences in metal absorption efficiencies between terrestrial soft-bodied and aquatic species.  

PubMed

It is unknown whether metal absorption efficiencies in terrestrial soft-bodied species can be predicted with the same metal properties as for aquatic species. Here, we developed models for metal absorption efficiency from the dissolved phase for terrestrial worms and several aquatic species, based on 23 metal physicochemical properties. For the worms, the absorption efficiency was successfully related to 7 properties, and is best predicted with the ionic potential. Different properties (8 in total) were found to be statistically significant in regressions predicting metal absorption in aquatic species, with the covalent index being the best predictor. It is hypothesized that metal absorption by soft-bodied species in soil systems is influenced by the rate of metal supply to the membrane, while in aquatic systems accumulation is solely determined by metal affinity to membrane bound transport proteins. Our results imply that developing predictive terrestrial bioaccumulation and toxicity models for metals must consider metal interactions with soil solids. This may include desorption of a cation bound to soil solids through ion exchange, or metal release from soil surfaces involving breaking of metal-oxygen bonds. PMID:25048944

Owsianiak, Miko?aj; Veltman, Karin; Hauschild, Michael Z; Hendriks, A Jan; Steinmann, Zoran J N; Huijbregts, Mark A J

2014-10-01

56

The Galactic Exoplanet Survey Telescope (GEST): A Search for Terrestrial Extra-solar Planets via Gravitational Microlensing  

NASA Astrophysics Data System (ADS)

GEST is a comprehensive extra-solar planet search mission sensitive to planets with masses as low as that of Mars. GEST will monitor the Galactic bulge for 8 months per year for three years to detect planets via gravitational microlensing and transits. GEST's microlensing survey will detect low-mass planets at separations of > 0.6 AU via high signal-to-noise variations of gravitational microlensing light curves. These planetary signals do not require follow-up observations to confirm the planetary interpretation, and they yield direct measurements of the star:planet mass ratio. GEST will be able to detect 100 Earth-mass planets at 1 AU (assuming 1 such planet per star) and will detect its first Earth-mass planets within a few months of launch. The GEST microlensing survey is the only proposed planet search program sensitive to old, free-floating planets. GEST's transit survey will search ~ 108 Galactic bulge stars for giant planets at separations of < 30 AU, and it is anticipated that more than 50,000 new giant planets will be discovered. When the Galactic bulge is not visible, GEST will survey ~ 1200 square degrees for Kuiper Belt Objects (KBOs) and operate a Participating Scienctist Program (PSP) with observational programs selected via competitive proposals. The KBO survey should discover 100,000 new KBOs.

Bennett, D. P.; Clampin, M.; Cook, K. H.; Drake, A.; Gould, A.; Horne, K.; Horner, S.; Jewitt, D.; Langston, G.; Lauer, T.; Lumsdaine, A.; Minniti, D.; Peale, S.; Rhie, S. H.; Shao, M.; Stevenson, R.; Tenerelli, D.; Tytler, D.; Woolf, N.

2000-12-01

57

Niche Habitats for Extra-Terrestrial Life: The Potential for Astrobiology on the Moons of Saturn and Jupiter  

NASA Astrophysics Data System (ADS)

Astrobiology today has a strong anticipatory focus, and efforts are concentrated on determining the factors behind the potential presence, type, and distribution of life in our solar system and beyond. The critical requirements for life: a liquid solvent, and electron acceptors and donors for metabolism, guide the search, and is a central concept to the location and extent of circumstellar habitable zones. For our own solar system, however, the search can be widened beyond this narrow band of 'earth-like' conditions, and our increasing knowledge of the capabilities of life, as well as higher resolution imaging and analysis of solar system bodies, warrants the application of a more expansive habitable niche approach. The Saturnian and Jovian satellite systems are ideal for the application of this concept, and are here used to demonstrate how a collection of system characteristics may be used to assess the potential for individual bodies to harbour life. Europa, Callisto, and Ganymede in the Jovian system, and Enceladus, Titan, Hyperion, Iapetus, and Hyperion in the Saturnian system all possess characters that could make them conducive to the origin or maintenance of life upon or within them. The possibility of some of these bodies containing extraterrestrial life is reflected in future explorative missions.

Battison, Leila

2011-03-01

58

Body size and extinction risk in terrestrial mammals above the species level.  

PubMed

Mammalian body mass strongly correlates with life history and population properties at the scale of mouse to elephant. Large body size is thus often associated with elevated extinction risk. I examined the North American fossil record (28-1 million years ago) of 276 terrestrial genera to uncover the relationship between body size and extinction probability above the species level. Phylogenetic comparative analysis revealed no correlation between sampling-adjusted durations and body masses ranging 7 orders of magnitude, an observation that was corroborated by survival analysis. Most of the ecological and temporal groups within the data set showed the same lack of relationship. Size-biased generic extinctions do not constitute a general feature of the Holarctic mammalian faunas in the Neogene. Rather, accelerated loss of large mammals occurred during intervals that experienced combinations of regional aridification and increased biomic heterogeneity within continents. The latter phenomenon is consistent with the macroecological prediction that large geographic ranges are critical to the survival of large mammals in evolutionary time. The frequent lack of size selectivity in generic extinctions can be reconciled with size-biased species loss if extinctions of large and small mammals at the species level are often driven by ecological perturbations of different spatial and temporal scales, while those at the genus level are more synchronized in time as a result of fundamental, multiscale environmental shifts. PMID:24231545

Tomiya, Susumu

2013-12-01

59

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

60

Body mass explains characteristic scales of habitat selection in terrestrial mammals.  

PubMed

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

2011-12-01

61

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.

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

2011-01-01

62

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

63

N-body Simulations of Terrestrial Planet Formation under the Influence of a Hot Jupiter  

NASA Astrophysics Data System (ADS)

We investigate the formation of multiple-planet systems in the presence of a hot Jupiter (HJ) using extended N-body simulations that are performed simultaneously with semianalytic calculations. Our primary aims are to describe the planet formation process starting from planetesimals using high-resolution simulations, and to examine the dependences of the architecture of planetary systems on input parameters (e.g., disk mass, disk viscosity). We observe that protoplanets that arise from oligarchic growth and undergo type I migration stop migrating when they join a chain of resonant planets outside the orbit of an HJ. The formation of a resonant chain is almost independent of our model parameters, and is thus a robust process. At the end of our simulations, several terrestrial planets remain at around 0.1 AU. The formed planets are not equal mass; the largest planet constitutes more than 50% of the total mass in the close-in region, which is also less dependent on parameters. In the previous work of this paper, we have found a new physical mechanism of induced migration of the HJ, which is called a crowding-out. If the HJ opens up a wide gap in the disk (e.g., owing to low disk viscosity), crowding-out becomes less efficient and the HJ remains. We also discuss angular momentum transfer between the planets and disk.

Ogihara, Masahiro; Kobayashi, Hiroshi; Inutsuka, Shu-ichiro

2014-06-01

64

Recent spatial and temporal changes in body size of terrestrial vertebrates: probable causes and pitfalls.  

PubMed

Geographical and temporal variations in body size are common phenomena among organisms and may evolve within a few years. We argue that body size acts much like a barometer, fluctuating in parallel with changes in the relevant key predictor(s), and that geographical and temporal changes in body size are actually manifestations of the same drivers. Frequently, the principal predictors of body size are food availability during the period of growth and ambient temperature, which often affects food availability. Food availability depends on net primary productivity that, in turn, is determined by climate and weather (mainly temperature and precipitation), and these depend mainly on solar radiation and other solar activities. When the above predictors are related to latitude the changes have often been interpreted as conforming to Bergmann's rule, but in many cases such interpretations should be viewed with caution due to the interrelationships among various environmental predictors. Recent temporal changes in body size have often been related to global warming. However, in many cases the above key predictors are not related to either latitude and/or year, and it is the task of the researcher to determine which particular environmental predictor is the one that determines food availability and, in turn, body size. The chance of discerning a significant change in body size depends to a large extent on sample size (specimens/year). The most recent changes in body size are probably phenotypic, but there are some cases in which they are partly genetic. PMID:21070587

Yom-Tov, Yoram; Geffen, Eli

2011-05-01

65

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

66

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

PubMed Central

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.

2011-01-01

67

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

68

The microbiome: the forgotten organ of the astronaut's body--probiotics beyond terrestrial limits.  

PubMed

Space medicine research has drawn immense attention toward provision of efficient life support systems during long-term missions into space. However, in extended missions, a wide range of diseases may affect astronauts. In space medicine research, the gastrointestinal microbiome and its role in maintaining astronauts' health has received little attention. We would like to draw researchers' attention to the significant role of microbiota. Because of the high number of microorganisms in the human body, man has been called a 'supra-organism' and gastrointestinal flora has been referred to as 'a virtual organ of the human body'. In space, the lifestyle, sterility of spaceship and environmental stresses can result in alterations in intestinal microbiota, which can lead to an impaired immunity and predispose astronauts to illness. This concern is heightened by increase in virulence of pathogens in microgravity. Thus, design of a personal probiotic kit is recommended to improve the health status of astronauts. PMID:22953705

Saei, Amir Ata; Barzegari, Abolfazl

2012-09-01

69

Diet Effect Study On Terrestrial Snail Body Tissues and Shell Carbonates In Experimental Conditions: Applications To Paleoenvironments  

NASA Astrophysics Data System (ADS)

The isotopic analysis of different materials yielded original elements to understanding the ecosystems and the paleoenvironments. Although most of the studies on fossil material was interpreted through the modern conditions at the vicinity of the fossil record, no precise analysis of the impact of the diet and precipitation was carried out in order to justify such assumptions. Here we present the results of the influence of diet and water on the carbone and oxygen isotope compositions of the body tissues and shell aragonite of terrestrial mollusk shells, a particularly accurate climate indicator. Our experiment consists of individuals from hatched eggs of Helix aspersa raised in our laboratory. Three groups of snails were fed on lettuce (C3 plant), corn (C4 plant) and mixed diet (C3+C4). They were sprayed at the same time with 3 different water in order to estimate the influence of continental effect. To estimate the paleotemperature changes, the hatched snails groups were placed in three rooms adjusted automatically to different temperatures. The experimental results indicate that the d13C of the shells is a good record of the isotopic composition of the snail body tissue, and therefore a good record of diet, and the d18O a good record of precipitations in relation with temperature change.

Metref, S.; Rousseau, D.-D.; Bentaleb, I.; Labonne, M.; Vianey-Liaud, M.; Moussa, I.

70

Extra Deimensions  

SciTech Connect

We describe recent ideas involving latticizing or "deconstructing" extra space time dimensions. Particles and geometry meld into the same thing. Intriguing topological beasts arise. Above all, new organizing principles for physics beyond the Standard Model come into view.

Chris Hill

2009-10-03

71

Branched chain amino acids improve body composition and nitrogen balance in a rat model of extra hepatic biliary atresia.  

PubMed

Malnutrition and growth retardation remain a major complication in infants with extrahepatic biliary atresia associated cholestasis. The purpose of this study was to investigate whether oral supplementation with branched chain amino acids (BCAA) can correct malnutrition in a rat model of biliary atresia. Four groups of 15 rats, 30 d old, were used. Group A were shamoperated animals, given a normal laboratory diet (17.5% of caloric intake as proteins). Group B were cholestatic rats (biliary atresia) fed a diet enriched in BCAA (supplement of 8.5%, valine/leucine/isoleucine ratio 1:1:1). Group C were cholestatic mice fed a diet enriched in casein (supplement of 8.5%). Group D were cholestatic mice fed a normal diet. Thirty-two days after surgery, groups were compared for body weight, serum amino acid content, nitrogen balance, muscle mass, and carcass composition. The results showed that the weight of group B, C, and D animals was 85, 81, and 64% of group A (controls). Serum BCAA levels were markedly increased in group B animals. Nitrogen retention was similar in groups B and A, but reduced to 63 and 44% in groups C and D, respectively. Dry weights were similar in group A (39.1% of body weight) and B (37.7%), but reduced to 28.1 and 28.6% of body weight in groups C and D. Body proteins were higher in groups A (13.9%) and B (14.2%) than in group D (9.7%) rats. Mineral content of group B animals was 84% of those of group A, 50% in group C, and 23% in group D rats. It was concluded that an oral supplement of BCAA can correct growth, nitrogen retention, and body composition in experimental biliary atresia. Administration of BCAA supplements to cholestatic infants should be considered. PMID:8798248

Sokal, E M; Baudoux, M C; Collette, E; Hausleithner, V; Lambotte, L; Buts, J P

1996-07-01

72

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

73

Main requirements for extra terrestrial sample preservation  

NASA Astrophysics Data System (ADS)

Returning extraterrestrial samples on Earth for scientific investigations imposes to comply with two major requirements: - At first, COSPAR Planetary Protection recommendations ask for the protectionof Earth biosphere and consequently to be sure, before the release of samples tothe scientific community, that no risk exis t, particularly biohazard. - Secondly, the sample properties must be preserved in order to ensure thevalidity of scientific results. The preservation of such samples is not limited tothe curation facility design and working conditions, and is also not limited tocleanliness, but begins with the design of spacecrafts and probes and has to betaken into account at every level of the project development and during thewhole mission. The paper will describe the main requirements for planetary protection and sample preservation in order particularly to point out that project teams need clear scientific specifications very early in the development and the design of a sample return mission.

Debus, A.

74

Directly interacting extra-terrestrial technological communities  

Microsoft Academic Search

The nature and distribution of intelligence in the galaxy is considered both in terms of the very great amounts of time that may have been available to the oldest civilisations which may exist and the capabilities of advanced, but not esoteric, technology. The effect of a 'multiplying' factor-colonisation-leads to a galactic scenario in which, by the present time, such older

D. Viewing

1975-01-01

75

Review of Extra-Terrestrial Mining Concepts.  

National Technical Information Service (NTIS)

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, i...

P. J. Van Susante R. P. Mueller

2012-01-01

76

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.

77

Quantifying The Impact of Extra-Nasal Testing Body Sites for MRSA Colonization at the Time of Hospital or Intensive Care Unit Admission  

PubMed Central

Objective Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of healthcare-associated infections. Recent legislative mandates require nares screening for MRSA at hospital and ICU admission in many states. However, MRSA colonization at extra-nasal sites is increasingly recognized. We conducted a systematic review of the literature to identify the yield of extra-nasal testing for MRSA. Design We searched MEDLINE from January 1966 through January 2012 for articles comparing nasal and extra-nasal screening for MRSA colonization. Studies were categorized by population tested, specifically those admitted to ICUs, and those admitted to hospitals with a high prevalence (?6%) or low prevalence (<6%) of MRSA carriers. Data were extracted using a standardized instrument. Results We reviewed 4,381 abstracts and 735 manuscripts. Twenty-three manuscripts met criteria for analysis (n=39,479 patients). Extra-nasal MRSA screening increased yield by approximately one-third over nares alone. The yield was similar upon ICU admission (weighted average 33%, range 9%–69%), and hospital admission in high (weighted average 37%, range 9–86%) and low prevalence (weighted average 50%, range 0–150%) populations. Comparing individual extra nasal sites, testing the oropharynx increased MRSA detection by 21% over nares alone; rectum by 20%; wounds by 17%; and axilla by 7%. Conclusions Extra-nasal MRSA screening at hospital or ICU admission in adults will increase MRSA detection by one-third compared to nares screening alone. Findings were consistent among subpopulations examined. Extra-nasal testing may be a valuable strategy for outbreak control or in settings of persistent disease, particularly when combined with decolonization or enhanced infection prevention protocols.

McKinnell, James A.; Huang, Susan S.; Eells, Samantha J.; Cui, Eric; Miller, Loren G.

2013-01-01

78

Enrichment of Non-Terrestrial L-Proteinogenic Amino Acids by Aqueous Alteration on the Tagish Lake Meteorite Parent Body  

NASA Technical Reports Server (NTRS)

The distribution and isotopic and enantiomeric compositions of amino acids found in three distinct fragments of the Tagish Lake C2-type carbonaceous chondrite were investigated via liquid chromatography fluorescence detection time-of-flight mass spectrometry and gas chromatography isotope ratio mass spectrometry. Large L-enantiomeric excesses (L(sub ee) approx. 43 to 59%) of the a-hydrogen aspartic and glutamic amino acids were measured in Tagish Lake, whereas alanine, another alpha-hydrogen protein amino acid, was found to be nearly racemic (D approx. L) using both techniques. Carbon isotope measurements of D- and L-aspartic acid and D- and L-alanine in Tagish Lake fall well outside of the terrestrial range and indicate that the measured aspartic acid enantioenrichment is indigenous to the meteorite. Alternate explanations for the Lexcesses of aspartic acid such as interference from other compounds present in the sample, analytical biases, or terrestrial amino acid contamination were investigated and rejected. These results can be explained by differences in the solid-solution phase behavior of aspartic acid, which can form conglomerate enantiopure solids during crystallization, and alanine, which can only form racemic crystals.

Glavin, Daniel P.; Elsila, Jamie E.; Burton, Aaron S.; Callahan, Michael P.; Dworkin, Jason P.; Herd, Christopher D. K.

2012-01-01

79

Super-long Anabiosis of Ancient Microorganisms in Ice and Terrestrial Models for Development of Methods to Search for Life on Mars, Europa and other Planetary Bodies  

NASA Technical Reports Server (NTRS)

Successful missions to Mars, Europe and other bodies of the Solar system have created a prerequisite to search for extraterrestrial life. The first attempts of microbial life detection on the Martian surface by the Viking landed missions gave no biological results. Microbiological investigations of the Martian subsurface ground ice layers seem to be more promising. It is well substantiated to consider the Antarctic ice sheet and the Antarctic and Arctic permafrost as terrestrial analogues of Martian habitats. The results of our long-standing microbiological studies of the Antarctic ice would provide the basis for detection of viable microbial cells on Mars. Our microbiological investigations of the deepest and thus most ancient strata of the Antarctic ice sheet for the first time gave evidence for the natural phenomenon of long-term anabiosis (preservation of viability and vitality for millennia years). A combination of classical microbiological methods, epifluorescence microscopy, SEM, TEM, molecular diagnostics, radioisotope labeling and other techniques made it possible for us to obtain convincing proof of the presence of pro- and eukaryotes in the Antarctic ice sheet. In this communication, we will review and discuss some critical issues related to the detection of viable microorganisms in cold terrestrial environments with regard to future searches for microbial life and/or its biological signatures on extraterrestrial objects.

Abyzov, S. S.; Duxbury, N. S.; Bobin, N. E.; Fukuchi, M.; Hoover, R. B.; Kanda, H.; Mitskevich, I. N.; Mulyukin, A. L.; Naganuma, T.; Poglazova, M. N.; Ivanov, M. V.

2007-01-01

80

Siderophile-element Anomalies in CK Carbonaceous Chondrites: Implications for Parent-body Aqueous Alteration and Terrestrial Weathering of Sulfides  

NASA Technical Reports Server (NTRS)

CK chondrites constitute the most oxidized anhydrous carbonaceous chondrite group; most of the Fe occurs in magnetite and in FeO-rich mafic silicates. The two observed CK falls (Karoonda and Kobe), along with thirteen relatively unweathered CK finds, have unfractionated siderophile-element abundance patterns. In contrast, a sizable fraction of CK finds (9 of 24 investigated) shows fractionated siderophile abundance patterns including low abundances of Ni, Co, Se and Au; the most extreme depletions are in Ni (0.24 of normal CK) and Au (0.14 of normal CK). This depletion pattern has not been found in other chondrite groups. Out of the 74 CK chondrites listed in the Meteoritical Bulletin Database (2006; excluded considerably paired specimens; see http://tin.er.usgs.gov/meteor/ metbull.php) we analyzed 24 and subclassified the CK chondrites in terms of their chemical composition and sulfide mineralogy: sL (siderophiles low; six samples) for large depletions in Ni, Co, Se and Au (>50% of sulfides lost); sM (siderophiles medium; two CKs) for moderately low Ni and Co abundances (sulfides are highly altered or partly lost); sH (siderophiles high; one specimen) for enrichments in Ni, Co, Se and Au; 'normal' for unfractionated samples (13 samples). The sole sH sample may have obtained additional sulfide from impact redistribution in the parent asteroid. We infer that these elements became incorporated into sulfides after asteroidal aqueous processes oxidized nebular metal; thermal metamorphism probably also played a role in their mineral siting. The siderophile losses in the SL and sM samples are mainly the result of oxidation of pentlandite, pyrite and violarite by terrestrial alteration followed by leaching of the resulting phases. Some Antarctic CK chondrites have lost most of their sulfides but retained Ni, Co, Se and Au, presumably as insoluble weathering products.

Huber, Heinz; Rubin, Alan E.; Kallemeyn, Gregory W.; Wasson, John T.

2006-01-01

81

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.

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

2014-01-01

82

The effect of 5 weeks Tribulus terrestris supplementation on muscle strength and body compostition during pre-season training in elite league players  

Microsoft Academic Search

Tribulus terrestris is an herbal nutritional supplement that is promoted to produce large gains in strength and lean muscle mass in 5–28 days (15, 18). Although some manufacturers claim T. terrestris will not lead to a positive drug test, others have suggested that T. terrestris may increase the urinary testosterone\\/epitestosterone (T\\/E) ratio, which may place athletes at risk of a

Shane Rogerson; Christopher J Riches; Carl Jennings; Robert P Weatherby; Rudi A Meir; Sonya M Marshall-Gradisnik

2007-01-01

83

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

84

Debris disks as signposts of terrestrial planet formation  

NASA Astrophysics Data System (ADS)

There exists strong circumstantial evidence from their eccentric orbits that most of the known extra-solar planetary systems are the survivors of violent dynamical instabilities. Here we explore the effect of giant planet instabilities on the formation and survival of terrestrial planets. We numerically simulate the evolution of planetary systems around Sun-like stars that include three components: (i) an inner disk of planetesimals and planetary embryos; (ii) three giant planets at Jupiter-Saturn distances; and (iii) an outer disk of planetesimals comparable to estimates of the primitive Kuiper belt. We calculate the dust production and spectral energy distribution of each system by assuming that each planetesimal particle represents an ensemble of smaller bodies in collisional equilibrium. Our main result is a strong correlation between the evolution of the inner and outer parts of planetary systems, i.e. between the presence of terrestrial planets and debris disks. Strong giant planet instabilities - that produce very eccentric surviving planets - destroy all rocky material in the system, including fully-formed terrestrial planets if the instabilities occur late, and also destroy the icy planetesimal population. Stable or weakly unstable systems allow terrestrial planets to accrete in their inner regions and significant dust to be produced in their outer regions, detectable at mid-infrared wavelengths as debris disks. Stars older than ~100 Myr with bright cold dust emission (in particular at ? ~ 70 ?m) signpost dynamically calm environments that were conducive to efficient terrestrial accretion. Such emission is present around ~16% of billion-year old Solar-type stars. Our simulations yield numerous secondary results: 1) the typical eccentricities of as-yet undetected terrestrial planets are ~0.1 but there exists a novel class of terrestrial planet system whose single planet undergoes large amplitude oscillations in orbital eccentricity and inclination; 2) by scaling our systems to match the observed semimajor axis distribution of giant exoplanets, we predict that terrestrial exoplanets in the same systems should be a few times more abundant at ~0.5 AU than giant or terrestrial exoplanets at 1 AU; 3) the Solar System appears to be unusual in terms of its combination of a rich terrestrial planet system and a low dust content. This may be explained by the weak, outward-directed instability that is thought to have caused the late heavy bombardment. The movie associated to Fig. 2 is available in electronic form at http://www.aanda.org

Raymond, S. N.; Armitage, P. J.; Moro-Martín, A.; Booth, M.; Wyatt, M. C.; Armstrong, J. C.; Mandell, A. M.; Selsis, F.; West, A. A.

2011-06-01

85

Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana).  

PubMed

Repeatability of physiological response variables, such as the stress hormone corticosterone, across numerous sampling occasions is an important assumption for their use as predictors of behaviour, reproduction and fitness in animals. Very few studies have actually tested this assumption in free-living animals under uncontrolled natural conditions. Non-invasive urine sampling and standard capture handling protocol have enabled the rapid quantification of baseline corticosterone and short-term corticosterone stress responses in anuran amphibians. In this study, established non-invasive methods were used to monitor physiological stress and urinary testosterone levels in male individuals of the terrestrial breeding Fijian ground frog (Platymantis vitiana). Adult male frogs (n = 20) were sampled at nighttime on three repeated occasions at intervals of 14 days during their annual breeding season on Viwa Island, Fiji. All frogs expressed urinary corticosterone metabolite responses to the capture and handling stressor, with some frogs showing consistently higher urinary corticosterone responses than others. Ranks of corticosterone values at 0, 4 and 8 h, and the corrected rank were highly significant (r = 0.75-0.99) between the three repeated sampling occasions. Statistical repeatabilities were high for baseline corticosterone (r = 0.973) and for corticosterone values at 2 h (r = 0.862), 4 h (r = 0.861), 6 h (r = 0.820) and 8 h (r = 0.926), and also for the total (inclusive of baseline corticosterone values) and the corrected integrated responses (index of the acute response) [r = 0.867 and r = 0.870]. Urinary testosterone levels also showed high statistical repeatability (r = 0.78). Furthermore, variation in baseline and short-term corticosterone stress responses was greater between individuals than within individuals. Baseline urinary corticosterone was significantly negatively correlated with the corrected integrated corticosterone response (r = -0.3, p < 0.001) but non-significantly with body-condition (r = -0.04) and baseline urinary testosterone (r = -0.07). In contrast, the corrected integrated corticosterone response was positively correlated (non-significantly) with baseline urinary testosterone (r = +0.04) and body-condition (r = +0.08). Urinary testosterone levels and body-condition were significantly negatively correlated (r = -0.23, p < 0.001). The results suggest that male frogs with higher levels of testosterone could have depleted energy reserve during the breeding period. The acute corticosterone responses help in replenishing energy that is needed for breeding and survival. The results also provide some support to the 'cort-fitness' hypothesis as highlighted by the negative correlation between baseline corticosterone and body-condition. It is most likely that the acute corticosterone response is adaptive and linked positively with reproductive fitness and survival in male anurans. PMID:23562802

Narayan, Edward J; Cockrem, John F; Hero, Jean-Marc

2013-06-01

86

Phenomenology of Extra Dimensions  

NASA Astrophysics Data System (ADS)

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

Kribs, Graham D.

2006-07-01

87

Phenomenology of Extra Dimensions.  

National Technical Information Service (NTIS)

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 i...

J. L. Hewett

2006-01-01

88

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...

89

Influence of Water Availability during Incubation on Hatchling Size, Body Composition, Desiccation Tolerance, and Terrestrial Locomotor Performance in the Snapping Turtle [ITAL]Chelydra serpentina[\\/ITAL  

Microsoft Academic Search

The effects of water availability during incubation on the water contents of neonatal snapping turtles at hatching were exam- ined, 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

Michael S. Finkler

1999-01-01

90

Terrestrial Weathering Effects on Meteoritic Organics  

NASA Astrophysics Data System (ADS)

It is now well established for meteorites which fall in hot deserts that weathering brings about a readjustment of extra-terrestrial minerals. Assemblages which had achieved a level of equilibrium on the meteorite parent body now become unstable when exposed to new chemical and physical conditions[1] with FeO and Fe2+ minerals converting to Fe3+ species. Ash and Pillinger[2] have suggested that meteoritic organic matter may also become degraded in desert environments but this is less well substantiated and the processes involved far from clear. To investigate the effects of weathering on meteorite organics, five Saharan carbon-rich chondrites were studied by Mossbauer spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py-GCMS). Experimental conditions are given elsewhere. The samples chosen were El Djouf (CR), Acfer 186 and 187 (both CR, undoubtably related to one another and probably El Djouf, even though the latter was found some 500km away), Acfer 182 an anomalous chondrite (possibly in the CR clan) and Acfer 202 (a C03) . Table 1 shows the relative amounts (%) of iron containing assemblages in four of the meteorites analysed as determined by Mossbauer spectroscopy. El Djouf is substantially weathered with Acfer 187 and Acfer 182 perhaps less so but more weathered than Acfer 202. Fig 1 shows the pyrograms of four of the meteorites analyzed. El Djouf, Acfer 182 and Acfer 186 (=Acfer 187) yield very few discrete organic compounds. However Py-GCMS of unweathered CRs frequently detects a variety of organic fragments. Therefore it seems reasonable to suggest that, in the two CRs at least, macromolecular material has been present but has been degraded by weathering. Such a conclusion agrees well with the results from Mossbauer spectroscopy which indicate extensive oxidation in the CR meteorites. Acfer 202 clearly contains a number of organic components almost exclusively without oxygen, indicating that the macromolecule in Acfer 202 has escaped significant terrestrial oxidation. Again this is consistent with our Mossbauer results which show that Acfer 202 contains predominantly ferrous iron indicative of low levels of terrestrial oxidation. At face value we would argue that Acfer 202 is a relatively fresh carbonaceous chondrite worthy of detailed organic study. Clearly the above samples represent almost end-member cases where terrestrial weathering has either destroyed or has yet to affect the organic material present. Perhaps the most valuable information would come from a sample where oxidation of the macromolecule is at an intermediate stage. References: [1] Bland P. A. et al. (1995) LPS XXVI, 39. [2] Ash R. D. and Pillinger C. T. (1995) Meteoritics, 30, 85-92.

Sephton, M. A.; Bland, P. A.; Gilmour, I.; Pillinger, C. T.

1995-09-01

91

Terrestrial Planets: Volatiles Loss & Speed of Rotation  

Microsoft Academic Search

There is a close relation between orbiting frequencies of terrestrial planets and intensities of their outgassing [1]. ``Sweeping'' out volatiles of their bodies is provoked and facilitated by body shaking (wave oscillations) caused by movement of celestial bodies in elliptical orbits. Non-round orbits cause inertia-gravity warpings in all spheres of the bodies producing their tectonic granulation. The higher orbiting frequency

G. G. Kochemasov

2004-01-01

92

Raman spectroscopic studies of carbon in extra-terrestrial materials  

NASA Technical Reports Server (NTRS)

The measurements obtained here indicate ways in which micro-Raman spectroscopy can be used to elucidate structural characteristics and distribution of carbon in meteorites and interplanetary dust particles (IDPs). Existing information about structurally significant aspects of Raman measurements of graphite is combined with structurally relevant findings from the present micro-Raman studies of carbons prepared by carbonization of polyvinylidine chloride (PVDC) at various temperatures and natural material, as well as several acid residues from the Allende and Murchison meteorites in order to establish new spectra-structure relationships. Structural features of many of the materials in this study have been measured by x ray analysis and electron microscopy: thus, their structural differences can be directly correlated with differences in the Raman spectra. The spectral parameters consequently affirmed as indicators of structure are used as a measure of structure in materials that have unknown carbon structure, especially IDPs. The unique applicability of micro-Raman spectroscopy is realized not only in the ability to conveniently measure spectra of micron-size IDPs, but also micro-sized parts of an inhomogeneous material. Microcrystalline graphite is known to give Raman spectra that differ dependent on crystallite size (see e.g., Lespade, et. al., 1984, or Nemanich and Solin, 1979). The spectral changes that accompany decreasing particle size include increase in the ratio (R) of the intensity of the band near 1350 cm(-1) (D band) to that of the band near 1600 cm(-1) (G band) increase in the half width of the D band (wD) increase in the frequency maximum of the G band and increase in the half-width (wG) of the 2nd order band near 2700 cm(-1) (G) band.

Macklin, John; Brownlee, Donald; Chang, Sherwood; Bunch, Ted

1990-01-01

93

The measurement of extra-terrestrial radio wave emission  

Microsoft Academic Search

Not Available Printing Options Send high resolution image to Level 2 Postscript Printer Send low resolution image to Level 2 Postscript Printer Send low resolution image to Level 1 Postscript Printer Get high resolution PDF image Get low resolution PDF Send 300 dpi image to PCL Printer Send 150 dpi image to PCL Printer More Article Retrieval Options HELP for

John P. Hagen

1949-01-01

94

Diffuse, global and extra-terrestrial solar radiation for Singapore  

Microsoft Academic Search

In this paper, equations have been developed to estimate diffuse fraction of the hourly, daily and monthly global insolation on a horizontal surface. These correlations are expressed in terms of Kd, the ratio of diffuse-to-total radiation, and KT, the clearness index. The hourly correlation equations, show a fairly similar trend to that of Orgill and Hollands (1) and Spencer (5)

M. N. A. Hawlader

1984-01-01

95

Raman spectroscopic studies of carbon in extra-terrestrial materials  

Microsoft Academic Search

The measurements obtained here indicate ways in which micro-Raman spectroscopy can be used to elucidate structural characteristics and distribution of carbon in meteorites and interplanetary dust particles (IDPs). Existing information about structurally significant aspects of Raman measurements of graphite is combined with structurally relevant findings from the present micro-Raman studies of carbons prepared by carbonization of polyvinylidine chloride (PVDC) at

John Macklin; Donald Brownlee; Sherwood Chang; Ted Bunch

1990-01-01

96

Cosmic ray produced nitrogen in extra terrestrial matter  

Microsoft Academic Search

Production rates of15N by both solar cosmic rays (SCR) and galactic cosmic rays (GCR) have been calculated for moon, as well as meteorites of various\\u000a sizes. Our production rates of15N which considered both the reaction channels16O(p, pn)15O and16O(p, 2p)15N separately are about 30% higher than those by Reedy (1981) who considered only the channel16O(p, pn)15O and used an empirical scaling

K. J. Mathew; S. V. S. Murty

1993-01-01

97

The "Ethical Paradox of Communication with Extra-Terrestrial Intelligences"  

NASA Astrophysics Data System (ADS)

Technological conditions required by the boundaries of our human intelligence to communicate with E.T. intelligence could put us within a situation in which one could abdicate a fundamental part of what it means to be human.

Lestel, D.

2010-04-01

98

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

99

Reducing Extra-Terrestrial Excavation Forces with Percussion.  

National Technical Information Service (NTIS)

High launch costs and mission requirements drive the need for low mass excavators with mobility platforms, which in turn have little traction and excavation reaction capacity in low gravity environments. This presents the need for precursor and long term ...

A. J. Nick J. D. Smith J. M. Schuler R. Mueller T. Lippitt

2012-01-01

100

Reducing extra-terrestrial excavation forces with percussion  

NASA Astrophysics Data System (ADS)

High launch costs and mission requirements drive the need for low mass excavators with mobility platforms, which in turn have little traction and excavation reaction capacity in low gravity environments. This presents the need for precursor and long term future missions with low mass robotic mining technology to perform In-Situ Resource Utilization (ISRU) tasks. This paper discusses a series of experiments that investigate the effectiveness of a percussive digging device to reduce excavation loads and thereby the mass of the excavator itself. A percussive mechanism and 30" wide pivoting bucket were attached to a test stand simulating a basic backhoe with a percussion direction tangent to the direction of movement. Impact energies from 13.6J to 30.5J and frequencies from 0 to 700 beats per minute (BPM) were investigated. A reduction in excavation force of as much as 50% was achieved in this experimental investigation.

Mueller, R.; Smith, J. D.; Lippitt, T.; Schuler, J.; Nick, A.

101

Problem of searching for extra-terrestrial civilizations  

NASA Technical Reports Server (NTRS)

Possible criteria characterizing extraterrestrial civilizations and their detection are: (1) deduction of their existence by evaluating astronomical prerequisites for the development of life in remote planetary systems; (2) detection and communication with extraterrestrial civilizations; and (3) the problem of language and content of information in transmitted signals.

Ambartsumyan, V. A.

1974-01-01

102

Sexual maturation of daughters depends on the mother’s body condition during pregnancy: An example of the water vole Arvicola terrestris L  

Microsoft Academic Search

The body condition of an animal directly depends on the amount, quality, and assimilation efficiency of available food and on the energy expenditures and may serve as a reliable criterion of both internal and external conditions favorable for the onset of reproduction. The body condition is known to determine the probability of participation in reproduction and its effectiveness [8, 11].

G. G. Nazarova; V. I. Evsikov

2007-01-01

103

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

104

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.

Brownlee, Sarah

105

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.

Selverstone, Jane

106

The terrestrial impact cratering record.  

NASA Astrophysics Data System (ADS)

Approximately 130 terrestrial hypervelocity impact craters are currently known. The rate of discovery of new craters is 3 - 5 craters per year. Although modified by erosion, terrestrial impact craters exhibit the range of morphologies observed for craters on other terrestrial planetary bodies. Due to erosion and its effects on form, terrestrial craters are recognized primarily by the occurrence of shock metamorphic effects. Terrestrial craters have a set of geophysical characteristics which are largely the result of the passage of a shock wave and impact-induced fracturing. Much current work is focused on the effects of impact on Earth evolution. Previous work on shock metamorphism and the contamination of impact melt rocks by meteoritic siderophile elements provides a basis for the interpretation of the physical and chemical evidence from Cretaceous-Tertiary boundary sites as resulting from a major impact. By analogy with the lunar record and modelling of the effects of very large impacts, it has been proposed that biological and atmospheric evolution of the Earth could not stabilize before the end of the late heavy bombardment ?3.8 Ga ago. The present terrestrial cratering rate is 5.4±2.7×10-15 km-2a-1 for a diameter ?20 km. On a gobal scale, a major impact sufficient to cripple human civilization severely will occur on time scales of ?106a.

Grieve, R. A. F.; Pesonen, L. J.

1992-12-01

107

Nonminimal universal extra dimensions  

SciTech Connect

In this paper, we investigate the phenomenological implications of boundary localized terms (BLTs) in the model of universal extra dimensions (UED). In particular, we study the electroweak Kaluza-Klein mass spectrum resulting from BLTs and their effect on electroweak symmetry breaking via the five-dimensional Higgs mechanism. We find that the addition of BLTs to massive five-dimensional fields induces a nontrivial extra-dimensional profile for the zero and nonzero Kaluza-Klein (KK) modes. Hence BLTs generically lead to a modification of standard model parameters and are therefore experimentally constrained, even at tree level. We study standard model constraints on three representative nonminimal UED models in detail and find that the constraints on BLTs are weak. On the contrary, nonzero BLTs have a major impact on the spectrum and couplings of nonzero KK modes. For example, there are regions of parameter space where the lightest Kaluza-Klein particle is either the Kaluza-Klein Higgs boson or the first KK mode of the W{sup 3}.

Flacke, Thomas; Menon, A.; Phalen, Daniel J. [Michigan Center for Theoretical Physics (MCTP), Randall Laboratory, Physics Department, University of Michigan, Ann Arbor, Michigan 48109 (United States)

2009-03-01

108

Super-long anabiosis of ancient microorganisms in ice and terrestrial models for development of methods to search for life on Mars, Europa and other planetary bodies  

Microsoft Academic Search

Successful missions to Mars, Europe and other bodies of the Solar system have created a prerequisite to search for extraterrestrial life. The first attempts of microbial life detection on the Martian surface by the Viking landed missions gave no biological results. Microbiological investigations of the Martian subsurface ground ice layers seem to be more promising. It is well substantiated to

S. S. Abyzov; N. S. Duxbury; N. E. Bobin; M. Fukuchi; R. B. Hoover; H. Kanda; I. N. Mitskevich; A. L. Mulyukin; T. Naganuma; M. N. Poglazova; M. V. Ivanov

2006-01-01

109

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

110

Qubits from extra dimensions  

NASA Astrophysics Data System (ADS)

We link the recently discovered black hole-qubit correspondence to the structure of extra dimensions. In particular we show that for toroidal compactifications of type IIB string theory simple qubit systems arise naturally from the geometrical data of the tori parametrized by the moduli. We also generalize the recently suggested idea of the attractor mechanism as a distillation procedure of GHZ-like entangled states on the event horizon, to moduli stabilization for flux attractors in F-theory compactifications on elliptically fibered Calabi-Yau four-folds. Finally using a simple example we show that the natural arena for qubits to show up is an embedded one within the realm of fermionic entanglement of quantum systems with indistinguishable constituents.

Lévay, Péter

2011-12-01

111

X-ray biosignature of bacteria in terrestrial and extra-terrestrial rocks  

Microsoft Academic Search

X-ray imaging techniques at the best spatial resolution and using synchrotron facilities are put forth as powerful techniques for the search of small life forms in extraterrestrial rocks under quarantine conditions (Lemelle et al. 2003). Samples, which may be collected in situ on the martian surface or on a cometary surface, will be brought back and finally stored in a

L. Lemelle; A. Simionovici; J. Susini; P. Oger; M. Chukalina; Ch. Rau; B. Golosio; P. Gillet

2003-01-01

112

Measurements of H2O in the Terrestrial Mesosphere and Implications for Extra-Terrestrial Sources.  

National Technical Information Service (NTIS)

Recent measurements of mesospheric water vapor and their implications for the existence of extraterrestrial sources of water are discussed. This study was prompted by the work of L. Frank and others who, based on their interpretation of transient dark spo...

J. J. Olivero

1988-01-01

113

A Theoretical Investigation of Isotopic Anomalies of Xenon in Terrestrial and Extra-Terrestrial Samples.  

National Technical Information Service (NTIS)

The abundance and isotopic composition of noble gases in meteorites is discussed in relation to the composition of the early solar system. Carbonaceous chondrites contain a unique Xenon-X, which is rich in heavy and light isotopes. Variations in the occur...

D. D. Sabu

1977-01-01

114

Measurements of H2O in the terrestrial mesosphere and implications for extra-terrestrial sources  

NASA Technical Reports Server (NTRS)

Recent measurements of mesospheric water vapor and their implications for the existence of extraterrestrial sources of water are discussed. This study was prompted by the work of L. Frank and others who, based on their interpretation of transient dark spots visible in ultraviolet images of the Earth's dayglow emission, have proposed that a large flux of small comets enters the Earth's upper atmosphere each day. To date, however, analysis does not conclusively refute or support the idea of an external source.

Olivero, John J.

1988-01-01

115

Magnetic fields of the terrestrial planets  

Microsoft Academic Search

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

C. T. Russell

1993-01-01

116

Inflation from extra dimensions  

SciTech Connect

The radial mode of n extra compact dimensions (the radion, b) can cause inflation in theories where the fundamental gravity scale, M, is smaller than the Planck scale M{sub P}. For radion potentials V(b) with a simple polynomial form, to get the observed density perturbations, the energy scale of V(b) must greatly exceed M{approx}1 TeV: V(b){sup 1/4}{identical_to}M{sub V}{approx}10{sup -4}M{sub P}. This gives a large radion mass and reheat temperature {approx}10{sup 9} GeV, thus avoiding the moduli problem. Such a value of M{sub V} can be consistent with the classical treatment if the new dimensions started sufficiently small. A new possibility is that b approaches its stable value from above during inflation. The same conclusions about M{sub V} may hold even if inflation is driven by matter fields rather than by the radion.

Cline, James M. [Physics Department, McGill University, 3600 University Street, Montreal, Quebec, H3A 2T8 (Canada)

1999-10-04

117

One universal extra dimension in PYTHIA  

NASA Astrophysics Data System (ADS)

The Universal Extra Dimensions model has been implemented in the PYTHIA generator from version 6.4.18 onwards, in its minimal formulation with one TeV -1-sized extra dimension. The additional possibility of gravity-mediated decays, through a variable number of eV -1-sized extra dimensions into which only gravity extends, is also available. The implementation covers the lowest lying Kaluza-Klein (KK) excitations of Standard Model particles, except for the excitations of the Higgs fields, with the mass spectrum calculated at one loop. 2?2 tree-level production cross sections and unpolarized KK number conserving 2-body decays are included. Mixing between iso-doublet and -singlet KK excitations is neglected thus far, and is expected to be negligible for all but the top sector. New version summaryProgram title: PYTHIA Version number: 6.420 Catalogue identifier: ACTU_v2_1 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ACTU_v2_1.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 79 362 No. of bytes in distributed program, including test data, etc.: 590 900 Distribution format: tar.gz Programming language: Fortran 77 Computer: CERN lxplus and any other machine with a Fortran 77 compiler Operating system: Linux Red Hat RAM: about 800 K words Word size: 32 bits Classification: 11.2 Catalogue identifier of previous version: ACTU_v2_0 Journal reference of previous version: Comput. Phys. Comm. 135 (2001) 238 Does the new version supersede the previous version?: Yes Nature of problem: At high energy collisions between elementary particles, physics beyond the Standard Model is searched for. Many models are being investigated, namely extra-dimensional models. Solution method: The Universal Extra Dimension model is implemented in the PYTHIA event generator. Reasons for new version: The Universal Extra Dimensions model has been implemented in the PYTHIA generator from version 6.4.18 onwards, in its minimal formulation with one TeV -1-sized extra dimension. The additional possibility of gravity-mediated decays, through a variable number of eV -1-sized extra dimensions into which only gravity extends, is also available. The implementation covers the lowest lying Kaluza-Klein (KK) excitations of Standard Model particles, except for the excitations of the Higgs fields, with the mass spectrum calculated at one loop. 2?2 tree-level production cross sections and unpolarized KK number conserving 2-body decays are included. Mixing between iso-doublet and -singlet KK excitations is neglected thus far, and is expected to be negligible for all but the top sector. Running time: 10-1000 events per second, depending on the process studied.

ElKacimi, M.; Goujdami, D.; Przysiezniak, H.; Skands, P.

2010-01-01

118

EXTRA-OSSEOUS EWING SARCOMA  

Microsoft Academic Search

Background: Clinical data and data on outcome of extra-osseous Ewing tumors are scarce. Procedure: After a search for Ewing tumors in the database of a single institution over a period of 20 years, 16 out of 192 cases were found to have extra-osseous primary tumors. Results: Ages at initial diagnosis ranged from 2.5 to 17 years. Follow-up period ranged from

Hendrik van den Berg; Richard C. Heinen; Pal van der H. J; Johannes H. M. Merks

2009-01-01

119

Tidally Heated Terrestrial Exoplanets  

NASA Astrophysics Data System (ADS)

This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity excursions. Viscoelastic solutions for GJ 876d are typical of extreme short period high eccentricity objects with tidal-convectiveequilibrium heat rates between ˜10,000 to 500,000 terawatts.

Henning, Wade Garrett

120

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

121

Perirenal extra-adrenal myelolipoma  

PubMed Central

Myelolipomas are rare tumors consisting of both adipose and hematopoietic tissue and are typically found within the adrenal gland. Extra-adrenal involvement is rare, especially those tumors involving the perirenal space and collecting system. We report a case of a patient with an incidentally discovered perirenal mass that was initially concerning for a retroperitoneal liposarcoma. Following surgical resection and pathological analysis, the lesion was found to be an extra-adrenal myelolipoma. This case report and review of the literature demonstrates the importance of the proper work-up and management of perirenal lipoma variants while addressing the issues of tissue biopsy, surgical intervention, and pre- and post-operative surveillance.

Hajiran, Ali; Morley, Chad; Jansen, Robert; Kandzari, Stanley; Bacaj, Patrick; Zaslau, Stanley; Cardinal, Jon

2014-01-01

122

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

123

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

124

Specific Extra-Corporeal Absorbents.  

National Technical Information Service (NTIS)

A number of new absorbent polymers for use in extra-corporeal loops (and also for possible use via ingestion) were prepared and studied. Attention was concentrated upon means for the removal of urea. Negative results were obtained in attempts to employ al...

H. P. Gregor J. S. Stamberg K. R. Brennen F. C. Chlanda C. Gryte

1970-01-01

125

TERRESTRIAL ECOSYSTEM SIMULATOR  

EPA Science Inventory

The Terrestrial Habitats Project at the Western Ecology Division (Corvallis, OR) is developing tools and databases to meet the needs of Program Office clients for assessing risks to wildlife and terrestrial ecosystems. Because habitat is a dynamic condition in real-world environm...

126

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

127

Collider Phenomenology of Extra Dimensions  

SciTech Connect

In recent years there has been much interest in the possibility that there exist more spacetime dimensions than the usual four. Models of particle physics beyond the Standard Model that incorporate these extra dimensions can solve the gauge hierarchy problem and explain why the fermion masses a spread over many orders of magnitude. In this thesis we explore several possibilities for models with extra dimensions. First we examine constraints on the proposal of Arkani-Hamed and Schmaltz that the Standard Model fermions are localized to different positions in an extra dimension, thereby generating the hierarchy in fermion masses. We find strong constraints on the compactification scale of such models arising from flavor-changing neutral currents. Next we investigate the phenomenology of the Randall-Sundrum model, where the hierarchy between the electroweak and Planck scales is generated by the warping in a five-dimensional anti-de Sitter space. In particular, we investigate the ''Higgsless'' model of electroweak symmetry breaking due to Csaki et. al., where the Higgs has been decoupled from the spectrum by taking its vacuum expectation value to infinity. We find that this model produces many distinctive features at the LHC. However, we also find that it is strongly constrained by precision electroweak observables and the requirement that gauge-boson scattering be perturbative. We then examine the model with a finite vacuum expectation value, and find that there are observable shifts to the Higgs scalar properties. Finally, in the original large extra dimension scenario of Arkani-Hamed, Dimopoulos, and Dvali, the hierarchy problem is solved by allowing gravity to propagate in a large extra dimensional volume, while the Standard Model fields are confined to 4 dimensions. We consider the case where there are a large number of extra dimensions (n {approx} 20). This model can solve the hierarchy problem without introducing a exponentially large radii for the extra dimensions, and represents a scenario that is difficult to obtain in string theory. We show that, if this scenario holds, the number of dimensions can be constrained to be larger than the number predicted by critical string theory. Searching for signals of many dimensions is then an important test of whether string theory is a good description of quantum gravity.

Lillie, Benjamin Huntington; /Stanford U., Phys. Dept. /SLAC

2006-03-10

128

Allometric Scaling of Decompression Sickness Risk in Terrestrial Mammals.  

National Technical Information Service (NTIS)

The objective with this study is to determine if there is an allometric relationship between body mass and decompression sickness (DCS) risk over a large range of terrestrial mammals. We have modified a previously published probabilistic model to assess D...

A. Fahlman P. L. Tyack R. Mahon

2011-01-01

129

Collider phenomenology of extra dimensions  

NASA Astrophysics Data System (ADS)

In recent years there has been much interest in the possibility that there exist more spacetime dimensions than the usual four. Models of particle physics beyond the Standard Model that incorporate these extra dimensions can solve the gauge hierarchy problem and explain why the fermion masses a spread over many orders of magnitude. In this thesis we explore several possibilities for models with extra dimensions. First we examine constraints on the proposal of Arkani-Hamed and Schmaltz that the Standard Model fermions are localized to different positions in an extra dimension, thereby generating the hierarchy in fermion masses. We find strong constraints on the compactification scale of such models arising from flavor-changing neutral currents. Next we investigate the phenomenology of the Randall-Sundrum model, where the hierarchy between the electroweak and Planck scales is generated by the warping in a five-dimensional anti-de Sitter space. In particular, we investigate the "Higgsless" model of electroweak symmetry breaking due to Csaki et al., where the Higgs has been decoupled from the spectrum by taking its vacuum expectation value to infinity. We find that this model produces many distinctive features at the LHC. However, we also find that it is strongly constrained by precision electroweak observables and the requirement that gauge-boson scattering be perturbative. We then examine the model with a finite vacuum expectation value, and find that there are observable shifts to the Higgs scalar properties. Finally, in the original large extra dimension scenario of Arkani-Hamed, Dimopoulos, and Dvali, the hierarchy problem is solved by allowing gravity to propagate in a large extra dimensional volume, while the Standard Model fields are confined to 4 dimensions. We consider the case where there are a large number of extra dimensions (n ˜ 20). We show that, if this scenario holds, the number of dimensions can be constrained to be larger than the number predicted by critical string theory. Searching for signals of many dimensions is then an important test of string theory.

Lillie, Benjamin Huntington

130

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.

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

2012-01-01

131

Extra-articular Snapping Hip  

PubMed Central

Context: Snapping hip, or coxa saltans, is a vague term used to describe palpable or auditory snapping with hip movements. As increasing attention is paid to intra-articular hip pathologies such as acetabular labral tears, it is important to be able to identify and understand the extra-articular causes of snapping hip. Evidence Acquisition: The search terms snapping hip and coxa sultans were used in PubMed to locate suitable studies of any publication date (ending date, November 2008). Results: Extra-articular snapping may be caused laterally by the iliotibial band or anteriorly by the iliopsoas tendon. Snapping of the iliopsoas tendon usually requires contraction of the hip flexors and may be difficult to differentiate from intra-articular causes of snapping. Dynamic ultrasound can help detect abrupt tendon translation during movement, noninvasively supporting the diagnosis of extra-articular snapping hip. The majority of cases of snapping hip resolve with conservative treatment, which includes avoidance of aggravating activities, stretching, and anti-inflammatory medication. In recalcitrant cases, surgery to lengthen the iliotibial band or the iliopsoas tendon has produced symptom relief but may result in prolonged weakness. Conclusions: In treating active patients with snapping soft tissues around the hip, clinicians should recognize that the majority of cases resolve without surgical intervention, while being mindful of the potential for concomitant intra-articular and internal snapping hips.

2010-01-01

132

New Worlds Observer: system architecture for terrestrial planet finding  

NASA Astrophysics Data System (ADS)

The New Worlds Observer (NWO) is a mission concept for the detection and characterization of extra-solar planets. It employs an external starshade and a space telescope. The starshade suppressed the parent star's light making detection of the extrasolar planet possible. This paper reviews the proposed requirements for the Terrestrial Planet Finding (TPF) mission. Using current understanding of the performance and trades inherent in the NWO architecture it is shown how to construct the allowed design space for a NWO mission.

Arenberg, Jonathan W.; Polidan, Ronald S.; Glassman, Tiffany; Lo, Amy S.; Lillie, Charles F.

2007-09-01

133

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

134

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

135

Comparative Climatology of Terrestrial Planets  

NASA Astrophysics Data System (ADS)

Public awareness of climate change on Earth is currently very high, promoting significant interest in atmospheric processes. We are fortunate to live in an era where it is possible to study the climates of many planets, including our own, using spacecraft and groundbased observations as well as advanced computational power that allows detailed modeling. Planetary atmospheric dynamics and structure are all governed by the same basic physics. Thus differences in the input variables (such as composition, internal structure, and solar radiation) among the known planets provide a broad suite of natural laboratory settings for gaining new understanding of these physical processes and their outcomes. Diverse planetary settings provide insightful comparisons to atmospheric processes and feedbacks on Earth, allowing a greater understanding of the driving forces and external influences on our own planetary climate. They also inform us in our search for habitable environments on planets orbiting distant stars, a topic that was a focus of Exoplanets, the preceding book in the University of Arizona Press Space Sciences Series. Quite naturally, and perhaps inevitably, our fascination with climate is largely driven toward investigating the interplay between the early development of life and the presence of a suitable planetary climate. Our understanding of how habitable planets come to be begins with the worlds closest to home. Venus, Earth, and Mars differ only modestly in their mass and distance from the Sun, yet their current climates could scarcely be more divergent. Our purpose for this book is to set forth the foundations for this emerging science and to bring to the forefront our current understanding of atmospheric formation and climate evolution. Although there is significant comparison to be made to atmospheric processes on nonterrestrial planets in our solar system — the gas and ice giants — here we focus on the terrestrial planets, leaving even broader comparisons to a future volume. Our authors have taken on the task to look at climate on the terrestrial planets in the broadest sense possible — by comparing the atmospheric processes at work on the four terrestrial bodies, Earth, Venus, Mars, and Titan (Titan is included because it hosts many of the common processes), and on terrestrial planets around other stars. These processes include the interactions of shortwave and thermal radiation with the atmosphere, condensation and vaporization of volatiles, atmospheric dynamics, chemistry and aerosol formation, and the role of the surface and interior in the long-term evolution of climate. Chapters herein compare the scientific questions, analysis methods, numerical models, and spacecraft remote sensing experiments of Earth and the other terrestrial planets, emphasizing the underlying commonality of physical processes. We look to the future by identifying objectives for ongoing research and new missions. Through these pages we challenge practicing planetary scientists, and most importantly new students of any age, to find pathways and synergies for advancing the field. In Part I, Foundations, we introduce the fundamental physics of climate on terrestrial planets. Starting with the best studied planet by far, Earth, the first chapters discuss what is known and what is not known about the atmospheres and climates of the terrestrial planets of the solar system and beyond. In Part II, Greenhouse Effect and Atmospheric Dynamics, we focus on the processes that govern atmospheric motion and the role that general circulation models play in our current understanding. In Part III, Clouds and Hazes, we provide an in-depth look at the many effects of clouds and aerosols on planetary climate. Although this is a vigorous area of research in the Earth sciences, and very strongly influences climate modeling, the important role that aerosols and clouds play in the climate of all planets is not yet well constrained. This section is intended to stimulate further research on this critical subject. The study of climate involves much more than

Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.

136

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

137

Traumatic insemination in terrestrial arthropods.  

PubMed

Traumatic insemination is a bizarre form of mating practiced by some invertebrates in which males use hypodermic genitalia to penetrate their partner's body wall during copulation, frequently bypassing the female genital tract and ejaculating into their blood system. The requirements for traumatic insemination to evolve are stringent, yet surprisingly it has arisen multiple times within invertebrates. In terrestrial arthropods traumatic insemination is most prevalent in the true bug infraorder Cimicomorpha, where it has evolved independently at least three times. Traumatic insemination is thought to occur in the Strepsiptera and has recently been recorded in fruit fly and spider lineages. We review the putative selective pressures that may have led to the evolution of traumatic insemination across these lineages, as well as the pressures that continue to drive divergence in male and female reproductive morphology and behavior. Traumatic insemination mechanisms and attributes are compared across independent lineages. PMID:24160423

Tatarnic, Nikolai J; Cassis, Gerasimos; Siva-Jothy, Michael T

2014-01-01

138

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.

Caro, Tim

2008-01-01

139

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

140

The debris disk - terrestrial planet connection  

NASA Astrophysics Data System (ADS)

The eccentric orbits of the known extrasolar giant planets provide evidence that most planet-forming environments undergo violent dynamical instabilities. Here, we numerically simulate the impact of giant planet instabilities on planetary systems as a whole. We find that populations of inner rocky and outer icy bodies are both shaped by the giant planet dynamics and are naturally correlated. Strong instabilities - those with very eccentric surviving giant planets - completely clear out their inner and outer regions. In contrast, systems with stable or low-mass giant planets form terrestrial planets in their inner regions and outer icy bodies produce dust that is observable as debris disks at mid-infrared wavelengths. Fifteen to twenty percent of old stars are observed to have bright debris disks (at ? ~ 70?m) and we predict that these signpost dynamically calm environments that should contain terrestrial planets.

Raymond, Sean N.; Armitage, Philip J.; Moro-Martín, Amaya; Booth, Mark; Wyatt, Mark C.; Armstrong, John C.; Mandell, Avi M.; Selsis, Franck

2011-11-01

141

Relationships between cerebral indices for 'extra' cortical parts and ecological categories in anthropoids.  

PubMed

The relationships between cerebral indices for 'extra' cortical parts associated with advanced functions [Jerison's 'extra' neurons (Nc), Hofman's 'extra' cortical volume (Ve)] and ecology and social structure were examined for a total of 86 species of anthropoids (28 species of New World monkeys, 48 species of Old World monkeys and 10 species of apes). The species were divided into a total of 39 'congeneric groups' of species which share common ecology and social structure (in most cases, congeneric groups are synonymous with genera). Both Nc and Ve were significantly larger for polygynous congeneric groups than for monogynous congeneric groups in the case of New World monkeys. In the case of Old World monkeys, both Nc and Ve were significantly larger for terrestrial congeneric groups than for arboreal congeneric groups. In the case of apes, although complete analyses could not be performed because of the limited size of the sample for which data were available, both Nc and Ve appeared to be larger for polygynous/terrestrial apes than for monogynous/arboreal apes. These results suggest that the expansion of the cerebral cortex in anthropoids may be associated with terrestriality and polygyny. PMID:2514960

Sawaguchi, T

1989-01-01

142

Arctic terrestrial ecosystem contamination.  

PubMed

Limited data have been collected on the presence of contaminants in the Arctic terrestrial ecosystem, with the exception of radioactive fallout from atmospheric weapons testing. Although southern and temperate biological systems have largely cleansed themselves of radioactive fallout deposited during the 1950s and 1960s, Arctic environments have not. Lichens accumulate radioactivity more than many other plants because of their large surface area and long life span; the presence and persistence of radioisotopes in the Arctic is of concern because of the lichen----reindeer----human ecosystem. Effective biological half-life of cesium 137 is reckoned to be substantially less than its physical half-life. The database on organochlorines in Canadian Arctic terrestrial mammals and birds is very limited, but indications are that the air/plant/animal contaminant pathway is the major route of these compounds into the terrestrial food chain. For terrestrial herbivores, the most abundant organochlorine is usually hexachlorobenzene followed by hexachlorocyclohexane isomers. PCB accumulation favours the hexachlorobiphenyl, pentachlorobiphenyl and heptachlorobiphenyl homologous series. The concentrations of the various classes of organochlorine compounds are substantially lower in terrestrial herbivore tissues than in marine mammal tissues. PCBs and DDT are the most abundant residues in peregrine falcons (a terrestrial carnivore) reaching average levels of 9.2 and 10.4 micrograms.g-1, respectively, more than 10 times higher than other organochlorines and higher than in marine mammals, including the polar bear. Contaminants from local sources include metals from mining activities, hydrocarbons and waste drilling fluids from oil and gas exploration and production, wastes from DEW line sites, naturally occurring radionuclides associated with uranium mineralization, and smoke containing SO2 and H2SO4 aerosol from the Smoking Hills at Cape Bathurst, N.W.T. PMID:1355310

Thomas, D J; Tracey, B; Marshall, H; Norstrom, R J

1992-07-15

143

Paleo-aridity index for terrestrial deposits  

Microsoft Academic Search

We present a paleo-aridity index for terrestrial deposits based on comparing 18-O in tooth enamel. Oxygen-18 is enriched in the residual fluid during evaporation, for example in lakes or in leaves. We characterize taxa that are sensitive to evaporation (ES) and compare them to others that are not sensitive to evaporation (EI). The 18-O concentration in body water is preserved

T. E. Cerling; N. E. Levin; B. H. Passey; J. M. Harris; J. R. Ehleringer

2005-01-01

144

Experimental Tribulus terrestris poisoning in goats  

Microsoft Academic Search

Seven, 1–2-year-old native goats were fed dried Tribulus terrestris from Sabzevar district of Khorasan province for 8 weeks. Two goats showed clinical signs of toxicity including weight loss, depression, ruminal stasis, icterus and elevation of body temperature. Haematological and biochemical trails revealed a declining of packed cell volume (PCV) and plasma total protein and elevation of total and direct bilirubin,

M. R. Aslani; A. R. Movassaghi; M. Mohri; V. Ebrahim-pour; A. N. Mohebi

2004-01-01

145

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

146

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

Hénault, François

2009-04-01

147

Can Extra Updates Delay Mixing?  

NASA Astrophysics Data System (ADS)

We consider Glauber dynamics (starting from an extremal configuration) in a monotone spin system, and show that interjecting extra updates cannot increase the expected Hamming distance or the total variation distance to the stationary distribution. We deduce that for monotone Markov random fields, when block dynamics contracts a Hamming metric, single-site dynamics mixes in O( n log n) steps on an n-vertex graph. In particular, our result completes work of Kenyon, Mossel and Peres concerning Glauber dynamics for the Ising model on trees. Our approach also shows that on bipartite graphs, alternating updates systematically between odd and even vertices cannot improve the mixing time by more than a factor of log n compared to updates at uniform random locations on an n-vertex graph. Our result is especially effective in comparing block and single-site dynamics; it has already been used in works of Martinelli, Toninelli, Sinclair, Mossel, Sly, Ding, Lubetzky, and Peres in various combinations.

Peres, Yuval; Winkler, Peter

2013-11-01

148

Terrestrial planet formation.  

PubMed

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

Righter, K; O'Brien, D P

2011-11-29

149

INTRODUCED TERRESTRIAL SPECIES (FUTURE)  

EPA Science Inventory

These data represent predicted future potential distributions of terrestrial plants, animals, and pathogens non-native to the Middle-Atlantic region. These data are available for 8-digit HUCs. The data are a weighted proportion of appropriate habitat overlapped by the potential...

150

Terrestrial photovoltaic measurement procedures  

NASA Technical Reports Server (NTRS)

Procedures for obtaining cell and array current-voltage measurements both outdoors in natural sunlight and indoors in simulated sunlight are presented. A description of the necessary apparatus and equipment is given for the calibration and use of reference solar cells. Some comments relating to concentration cell measurements, and a revised terrestrial solar spectrum for use in theoretical calculations, are included.

1977-01-01

151

Terrestrial planet formation  

PubMed Central

Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (?106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally embryos to planets (107–108 y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

Righter, K.; O'Brien, D. P.

2011-01-01

152

GLOBAL TERRESTRIAL CARBON CYCLE  

EPA Science Inventory

There is great uncertainty with regard to the future role of the terrestrial biosphere in the global carbon cycle, arising from both an inadequate understanding of current pools and fluxes as well as the potential effects of rising atmospheric concentrations of CO, on natural eco...

153

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

154

Smear positive extra pulmonary tuberculosis disease at University of Gondar Hospital, Northwest Ethiopia  

PubMed Central

Background While pulmonary tuberculosis is the most common presentation, extra pulmonary tuberculosis is also an important clinical problem. However, no adequate information had been made available on the prevalence of smear positive extra pulmonary tuberculosis in Gondar. The aim of this study was to assess the prevalence and possible risk factors of smear positive extra pulmonary tuberculosis among suspected patients at University of Gondar Hospital. Methods A cross-sectional study on extra pulmonary tuberculosis suspected patients was conducted at University of Gondar Hospital from January 2012 to April, 2012. Specimens of patients suspected of extra pulmonary tuberculosis were obtained from fine needle aspiration and body fluid samples collected by pathologist. Demographic characteristics and other variables were collected using a pretested semi-structured questionnaire. Smears were prepared from each sample and stained by Ziehel Neelson and Wright stain. The result of the study was analyzed with bivariate and multivariate logistic regression. Result A total of 344 extra pulmonary tuberculosis suspected clients were included in the study and specimens were taken from lymph node aspirates and body fluids. The overall prevalence of smear positive extra pulmonary tuberculosis was 34 (9.9%). Of these cases of extra pulmonary tuberculosis, lymph node tuberculosis constituted the largest proportion (82.4%). Among the 34 extra pulmonary tuberculosis patients, over half of them (52.9%) were positive for human immunodeficiency virus. The largest proportion of tuberculosis and human immunodeficiency virus cases occurred among persons with in the age group of 31–40 years. Previous history of tuberculosis (OR?=?4.77, 95% CI 1.86-12.24), contact to a known tuberculosis cases (OR?=?6.67 95% CI 2.78-16.90), history of underlying diseases (OR?=?2.79 95% CI 1.15-6.78) and income (OR?=?12.9 95% CI 2.25-68.02) were significantly associated with extra pulmonary tuberculosis infection. Conclusion The prevalence of smear positive extra pulmonary tuberculosis infection in Gondar is high. Screening of lymph node and other body fluid specimens for extra pulmonary tuberculosis could help for treatment, control and prevention of the disease.

2013-01-01

155

The Effect of a Planet in the Asteroid Belt on the Orbital Stability of the Terrestrial Planets  

Microsoft Academic Search

If a planetary-mass body were present in the asteroid belt, the orbits of the terrestrial planets and those of the giant planets would be more closely coupled. A greater exchange of angular momentum could affect the stability of the terrestrial planets. Moreover, the planet in the asteroid belt could itself excite terrestrial planet eccentricities. To study these effects, we have

Jack J. Lissauer; Elisa V. Quintana; Eugenio J. Rivera; Martin J. Duncan

2001-01-01

156

Non-mass-dependent Isotopic Fractionation Processes: Mechanisms and Recent Observations in Terrestrial and Extra-terrestrial Environments  

NASA Astrophysics Data System (ADS)

There were several key observations, which were made almost around the same time, that led to studies in the fields of stable isotope geochemistry and cosmochemistry. First, it was the physicochemical formalism for isotope effects, particularly the determination of the position of equilibrium in isotopic exchange reactions. Urey (1947) and Bigeleisen and Mayer (1947) demonstrated that the position of isotope exchange in a chemical reaction may be calculated with high precision. The difference in chemical behavior for isotopically substituted molecules in this specific instance arises from quantum mechanical effects. The vibrating molecule is energetically represented as a harmonic oscillator. Thus, in the case of isotopic substituted molecules, the quantized energy levels vary with the heavier species possessing lower vibrational frequencies. As a result, the isotopically substituted molecules possess slightly stronger bond strengths, which can be calculated with high precision. These can also be measured spectroscopically. Furthermore, since vibrational frequencies are temperature dependent, the partitioning of isotopes between two molecules is temperature dependent and the observed isotopic differences may be used as a temperature index for the equilibrium process of interest.This phenomenon forms the basis for the formulations of Urey (1947) and Bigeleisen and Mayer (1947) for the temperature dependence of isotopic exchange between two molecules. With the nearly simultaneous development of the isotope-ratio mass spectrometer by Nier et al. (1947), the potential for application of stable isotopes was created. Other isotopic fractionation processes are observed in kinetics, diffusion, evaporation-condensation, crystallization, and biology (e.g., photosynthesis, respiration, nitrogen fixation, sulfate reduction, and transpiration). The concomitant isotopic fractionations can also be used to provide details of the relevant process.Although, the conventional isotope effects vary widely in the physicochemical basis for their origin, they all are dependent upon relative isotopic mass differences. The first quantitative discussion of the mass dependence of isotope effects was given by Hulston andThode (1965), who showed that conventional isotope effects alter the isotope ratios in a manner strictly dependent upon relative mass differences. Specifically, the changes in ?33S and ?34S are shown to be highly correlated such that the change in ?33S is half that of ?34S. The mass range in the ?33S is 1 amu (33-32 amu) and for ?34S is 2 amu (34-32 amu). Thus,?33S?0.5?34Sis observed and arises due to the magnitude of the relative isotopic mass differences. The focus of the paper of Hulston and Thode was to utilize meteoritic stable-isotope-ratio measurements as a mechanism to resolve nuclear (nucleosynthetic or spallogenic) processes from non-nuclear processes. The fundamental assumption in this work was, based upon the assumption that all conventional physicochemical processes produce correlated mass-dependent arrays, that any deviation from this relation must reflect a nuclear process. The core assumption for this assertion was that any physical or chemical process may not lead to a variance in stable isotope ratio that does not depend upon mass differences.Clayton et al. (1973) observed that the high-temperature calcium-aluminum inclusions (CAIs) present in the carbonaceous chondrite Allende possess an oxygen isotope composition of ?17O??18O, rather than the expected mass-dependent ?17O?0.5?18O. It was suggested that this anomalous isotopic composition must derive from a nuclear, rather than chemical process. In general, an equality ?17O=?18O may arise in two ways, either by alteration of 17O and 18O by equal amounts or, by addition/subtraction of pure 16O. Models for supernova processes had shown that for certain conditions, essentially pure 16O is produced. Clayton et al. argued that it is unlikely that 17O and 18O would be equally altered, thus the supernova event was deemed the most plausible mechanism to a

Thiemens, M. H.

2003-12-01

157

Theoretical investigation of isotopic anomalies of xenon in terrestrial and extra-terrestrial samples. Final technical report, 1972--1977  

Microsoft Academic Search

The abundance and isotopic composition of noble gases in meteorites is discussed in relation to the composition of the early solar system. Carbonaceous chondrites contain a unique Xenon-X, which is rich in heavy and light isotopes. Variations in the occurrence of type-X and type-Y (the normal component) noble gases are of such magnitude that neither the injection of material from

Sabu

1977-01-01

158

Effects of geophysical extra-terrestrial and terrestrial physical stimuli on living organisms - Effects of gravity fields on living organisms  

NASA Technical Reports Server (NTRS)

The biologic effects of greatly reduced gravity resulting from space flight are examined. Aspects of U.S. space biology during the period from 1960 to 1972 are discussed, giving attention to the Discoverer satellites, the Gemini series, the OV1-4 satellite, the biosatellite project, the orbiting frog otolith experiment, and the Apollo program. Other studies considered are related to the effects of galactic particles on nonproliferating cells, a recoverable tissue culture experiment, cell cycle maintenance in human lung cells, and effects of space flight on circadian rhythms. Viking will land on the planet Mars in 1975 in search for life forms.

Saunders, R. J. F.

1972-01-01

159

Theoretical Investigation of Isotopic Anomaly of Xenon in Carbonaceous Chondrites and Other Terrestrial and Extra-Terrestrial Samples.  

National Technical Information Service (NTIS)

The composition of Xe released from carbonaceous chondrites between 600 and 1000 C, particularly its isotopic trapped forms, is analyzed. Data show trapped Xe to have the following forms: Xe-124, 126, 130, 131, 132, 134, and 136. Attempts were also made t...

D. D. Sabu

1974-01-01

160

Theoretical investigation of isotopic anomaly of xenon in carbonaceous chondrites and other terrestrial and extra-terrestrial samples  

NASA Technical Reports Server (NTRS)

The composition of Xe released from carbonaceous chondrites between 600 and 1000 C, particularly its isotopic trapped forms, is analyzed. Data show trapped Xe to have the following forms: Xe-124, 126, 130, 131, 132, 134, and 136. Attempts were also made to explain the Xe anomaly by mass fractionation as well as determine the relationship between metoritic trapped Xe and solar Xe.

Sabu, D. D.

1974-01-01

161

Ergogenic effects of Tribulus terrestris supplementation in men  

Microsoft Academic Search

The main objective of this research project was to evaluate the effects of Tribulus terrestris supplementation on body composition, muscular strength and serum hormone profile in men. The research material in- cluded 24 competitive basketball players (age- 26.2±3.4 years, body height 191.2±6.7 cm, body mass- 91.5±9.8 kg) divided into 3 groups of 8 subjects each. One group received a supplement

Stanislaw Poprzecki; Aleksandra Zebrowska; Jaroslaw Cholewa; Adam Zajac; Zbigniew Waskiewicz

162

The Terrestrial Planet Finder and Darwin Missions  

NASA Technical Reports Server (NTRS)

Both in the United States and in Europe, teams of scientists and engineers are exploring the feasibility of the Terrestrial Planet Finder (TPF) and Darwin missions, which are designed to search for Earth-like planets in the habitable zone of nearby stars. In the US, the TPF Science Working Group is studying four options - small (4m by 6 m primary mirror) and large (4m by 10 m primary mirror) coronagraphs for planet detection at visible wavelengths, and structurally connected and free-flyer interferometers at thermal infrared wavelengths. The US TPF-SWG is charged with selecting an option for NASA by the end of 2006. In Europe the Darwin Terrestrial Exo-planet Advisory Team (TE- SAT) is exploring the free-flyer interferometer option only at this time. I will discuss the vurtures and difficulties of detecting and characterizing extra-solar planets in both wavelength regions as well as some of the technical challenges and progress in the past year.

Danchi, William C.

2004-01-01

163

Satellite-Terrestrial Network Interoperability  

NASA Technical Reports Server (NTRS)

The developing national and global information infrastructures (NII/GII) are being built upon the asynchronous transfer mode (ATM) telecommunications protocol and associated protocol standards. These protocols are themselves under development through the telecommunications standards process defined by the International Telecommunications Union (ITU), which as a body is sanctioned by the United Nations. All telecommunications manufacturers use these standards to create products that can interoperate. The ITU has recognized the ATM Forum as the instrument for the development of ATM protocols. This forum is a consortium of industry, academia, and government entities formed to quickly develop standards for the ATM infrastructure. However, because the participants represent a predominately terrestrial network viewpoint, the use of satellites in the national and global information infrastructures could be severely compromised. Consequently, through an ongoing task order, the NASA Lewis Research Center asked Sterling Software, Inc., to communicate with the ATM Forum in support of the interoperability of satellite-terrestrial networks. This year, Dr. Raj Jain of the Ohio State University, under contract to Sterling, authored or coauthored 32 explanatory documents delivered to the ATM Forum in the areas of Guaranteed Frame Rate for Transmission Control Protocol/Internet Protocol (TCP/IP), Available Bit Rate, performance testing, Variable Bit Rate voice over ATM, TCP over Unspecified Bit Rate+, Virtual Source/Virtual Destination, and network management. These contributions have had a significant impact on the content of the standards that the ATM Forum is developing. Some of the more significant accomplishments have been: (1) The adoption by the ATM Forum of a new definition for Message-In, Message-Out latency; and (2) Improved text (clearer wording and newly defined terms) for measurement procedures, foreground and background traffic, and scalable configuration in the latency and throughput sections of the Performance Testing Baseline Text.

vonDeak, Thomas C.

1998-01-01

164

Extra-ocular chlamydial infection*  

PubMed Central

Chlamydia trachomatis, the causative agent of trachoma, affecting hundreds of millions of people, is now recognized as a major cause of sexually transmitted disease. In many countries chlamydial infection now outstrips gonorrhoea as the major cause of genital tract infection. Chlamydial urethritis and cervicitis are frequently complicated by ascending infection involving the endometrium, the fallopian tubes and epididymis. This often results in serious reproductive sequelae, e.g., infertility in the female and ectopic pregnancy. Extra-genital manifestations of chlamydial infection may occur involving the eyes (follicular conjunctivitis), joints (arthritis), and distal intestinal tract. Infection of the newborn child during birth may result in ocular or lung disease. There is need for further research on chlamydial infection, with the involvement of a number of different fields including medicine, epidemiology, microbiology, immunology, molecular genetics and operational research. The role of chlamydia has also to be defined in a variety of clinical syndromes for the development of improved diagnostic reagents and vaccine and the production of improved control and intervention strategies.

1986-01-01

165

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.

M?ller, A. P.

1997-01-01

166

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

167

Metabolic assessments during extra-vehicular activity.  

PubMed

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 CO2 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. PMID:11541598

Osipov YuYu; Spichkov, A N; Filipenkov, S N

1998-01-01

168

On transformation between international celestial and terrestrial reference systems  

NASA Astrophysics Data System (ADS)

Based on the current IAU hierarchy of the relativistic reference systems, practical formulae for the transformation between barycentric (BCRS) and geocentric (GCRS) celestial reference systems are derived. BCRS is used to refer to ICRS, International Celestial Reference System. This transformation is given in four versions, dependent on the time arguments used for BCRS (TCB or TDB) and for GCRS (TCG or TT). All quantities involved in these formulae have been tabulated with the use of the VSOP theories (IMCCE theories of motion of the major planets). In particular, these formulae may be applied to account for the indirect relativistic third-body perturbations in motion of Earth's satellites and Earth's rotation problem. We propose to use the SMART theory (IMCCE theory of Earth's rotation) in constructing the Newtonian three-dimensional spatial rotation transformation between GCRS and ITRS, the International Terrestrial Reference System. This transformation is compared with two other versions involving extra angular variables currently used by IERS, the International Earth Rotation Service. It is shown that the comparison of these three forms of the same transformation may be greatly simplified by using the proposed composite rotation formula. Tables 1-20 of Appendix B containing the initial terms of the VSOP-based series for the BCRS<->GCRS transformation are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/408/387. The work on ICRS<->GCRS transformation with the use of VSOP theories was done in February-March 2002 during the stay of the second author in IMCCE. The authors hoped to complete the second part concerning GCRS<->ITRS transformation with the use of SMART theory in September 2002 during the visit of the first author to IAA. The grave disease of Pierre Bretagnon which tragically resulted in his death on November 17, 2002, did not permit us to complete this work. The aim to improve SMART theory by taking into account the indirect relativistic third-body perturbations as indicated in the paper also remains unachieved. The second author is publishing this paper in memoriam of

Bretagnon, P.; Brumberg, V. A.

2003-09-01

169

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

170

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

171

Progress in Extra-Solar Planet Detection.  

National Technical Information Service (NTIS)

Progress in extra-solar planet detection is reviewed. The following subject areas are covered: (1) the definition of a planet; (2) the weakness of planet signals; (3) direct techniques - imaging and spectral detection; and (4) indirect techniques - reflex...

R. A. Brown

1991-01-01

172

Food Tampering: An Extra Ounce of Caution  

MedlinePLUS

... Health Educators Resources for You Health Educators Education Campaigns for the Hispanic Community Food Tampering, An Extra ... Facebook View FDA videos on YouTube View FDA photos on Flickr FDA Archive Combination Products Advisory Committees ...

173

Primary extra nodal Hodgkin disease: Bone presentation  

PubMed Central

Summary Background Extra nodal and extra lymphatic propagation of Hodgkin’s 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 Hodgkin’s 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 Hodgkin’s nodular sclerosing histological subtype disease has been established. The patient starts to receive chemotherapy. Conclusions Primary extra nodal Hodgkin’s 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.

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

2014-01-01

174

Extra Exercise Could Help Depressed Smokers Quit  

MedlinePLUS

... features on this page, please enable JavaScript. Extra Exercise Could Help Depressed Smokers Quit: Study Withdrawal symptoms, ... Tuesday, July 29, 2014 Related MedlinePlus Pages Depression Exercise and Physical Fitness Quitting Smoking TUESDAY, July 29, ...

175

Radiative isotropic cosmologies with extra dimensions  

SciTech Connect

We solve Einstein's equations in an n-italic-dimensional vacuum with the simplest ansatz leading to a Friedmann-Robertson-Walker (FRW) four-dimensional space time. We show that the FRW model must be of radiation. For the open models the extra dimensions contract as a result of cosmological evolution. For flat and closed models they contract only when there is one extra dimension.

Iba-acute-accentez, J.; Verdaguer, E.

1986-08-15

176

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.

177

Solar structure and terrestrial weather  

NASA Technical Reports Server (NTRS)

The possibility that solar activity has discernible effects on terrestrial weather is considered. Research involving correlation of weather conditions with solar and geomagnetic activity is discussed.

Wilcox, J. M.

1976-01-01

178

Modified dispersion relations in extra dimensions  

NASA Astrophysics Data System (ADS)

It has recently been shown that the thermodynamics of a FRW universe can be fully derived using the generalized uncertainty principle (GUP) in extra dimensions as a primary input. There is a phenomenologically close relation between the GUP and Modified Dispersion Relations (MDR). However, the form of the MDR in theories with extra dimensions is as yet not known. The purpose of this Letter is to derive the MDR in extra dimensional scenarios. To achieve this goal, we focus our attention on the thermodynamics of a FRW universe within a proposed MDR in an extra dimensional model universe. We then compare our results with the well-known results for the thermodynamics of a FRW universe in an extra dimensional GUP setup. The result shows that the entropy functionals calculated in these two approaches are the same, pointing to a possible conclusion that these approaches are equivalent. In this way, we derive the MDR form in a model universe with extra dimensions that would have interesting implications on the construction of the ultimate quantum gravity scenario.

Sefiedgar, A. S.; Nozari, K.; Sepangi, H. R.

2011-01-01

179

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

180

The Stability of the Terrestrial Planets in Systems with a Planet in the Asteroid Belt  

Microsoft Academic Search

If a massive planetary-sized body was present in the asteroid belt, the orbits of the terrestrial planets and those of the giant planets would be more closely coupled. A greater exchange in angular momentum could affect the stability of the terrestrial planets. To study this effect, we have simulated several systems consisting of the solar system planets and a planetary-sized

E. V. Quintana; E. J. Rivera; J. J. Lissauer; M. J. Duncan

2000-01-01

181

Search for Extra-Terrestrial planets: The DARWIN mission - Target Stars and Array Architectures  

NASA Astrophysics Data System (ADS)

The DARWIN mission is an Infrared free flying interferometer mission based on the new technique of nulling interferometry. Its main objective is to detect and characterize other Earth-like planets, analyze the composition of their atmospheres and their capability to sustain life, as we know it. DARWIN is currently in definition phase. This PhD work that has been undertaken within the DARWIN team at the European Space Agency (ESA) addresses two crucial aspects of the mission. Firstly, a DARWIN target star list has been established that includes characteristics of the target star sample that will be critical for final mission design, such as, luminosity, distance, spectral classification, stellar variability, multiplicity, location and radius of the star. Constrains were applied as set by planet evolution theory and mission architecture. Secondly, a number of alternative mission architectures have been evaluated on the basis of interferometer response as a function of wavelength, achievable modulation efficiency, number of telescopes and starlight rejection capabilities. The study has shown that the core mission goals should be achievable with a lower level of complexity as compared to the current baseline configuration.

Kaltenegger, Lisa

2005-04-01

182

Theoretical Studies of the Extra-terrestrial Chemistry of Biogenic Elements and Compounds  

NASA Technical Reports Server (NTRS)

Results are presented on the following:(A) Ab initio quantum chemical studies of reactions in astrophysical ices.Theoretical electronic structure calculations were used to investigate reactions between formaldehyde (H2CO) and both hydrogen cyanide (HCN) and isocyanide (HNC) in search of other favorable reactions such as ammonia-formaldehyde addition, which was found in a recent theoretical study to be strongly enhanced when it occurs within cold ices.The present study examines further reactions between this product and H2CO in ices.(B) Heterogeneous hydrogenation of CO and H2CO on icy grain mantles.Formaldehyde (H2CO) and methanol (CH30H) are thought to be produced in the interstellar medium by the successive hydrogenation of carbon monoxide (CO) on grain surfaces. In the gas phase, the steps in which H adds to CO and H2CO possess modest barriers and are too inefficient to account for the observed abundances. Recent laboratory work has confirmed that formaldehyde and methanol are formed when H atoms are deposited on CO ice at 12 K. The present study employed ab initio quantum chemical calculations to investigate the impact of water ice on the sequential hydrogenation of CO.(C) Ice-bound condensed-phase reactions involving formic acid (HCOOH), methylenimine (CH2NH), hydrogen cyanide (HCN), hydrogen isocyanide (HNC), and ammonia ( 3) were investigated in order to characterize possible pathways to larger organic species that are efficient at the cold temperatures prevalent in cometary nuclei and the interstellar medium. (D) Pathways to glycine and other amino acids in ultraviolet-irradiated ices determined via quantum chemical modeling.(E) Photoionization in ultraviolet processing of astrophysical ice analogs at cryogenic temperatures.

Woon, David E.

2003-01-01

183

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

184

The search for extra-terrestrial sources of high energy neutrinos  

Microsoft Academic Search

The field of high-energy neutrino astronomy has seen rapid progress over the\\u000alast 15 years, with the development and operation of the first large-volume\\u000adetectors. Here, we review the motivation for construction of these large\\u000ainstruments and discuss what construction and physics progress has been made.

Gary C. Hill

2009-01-01

185

The search for extra-terrestrial sources of high energy neutrinos  

Microsoft Academic Search

The field of high-energy neutrino astronomy has seen rapid progress over the last 15 years, with the development and operation of the first large-volume detectors. Here, we review the motivation for construction of these large instruments and discuss what construction and physics progress has been made.

Gary C. Hill

2009-01-01

186

Meteorological and extra-terrestrial causes of the daily variation of cosmic ray intensity  

Microsoft Academic Search

Summary  The daily variations of total cosmic ray intensity and the intensities of meson and electron components have been studied\\u000a at Alimedabad with vertical geiger counter telescopes. The influence of meteorological factors on these variations has been\\u000a examined, and it has been found that appropriate barometric coefficients for correcting the cosmic ray intensities can be\\u000a obtained from a consideration of the

V. Sarabhai; U. D. Desai; R. P. Kane

1953-01-01

187

A summary of extremes of isotopic variations in extra-terrestrial materials  

Microsoft Academic Search

In this comprehensive review of current research on isotopic variations of elements in extraterrestrial materials, the variations were classified in terms of the major process involved in the modification of the iostopic composition of the element concerned. Maximum isotopic variations of each element were retrieved from publications which were available in Tokyo up to December 1985, and are presented in

M. Shima

1986-01-01

188

An instrument for elemental and isotopic abundance characterization of extra-terrestrial materials  

Microsoft Academic Search

Samples returned from the Genesis and Stardust missions of NASA's Discovery Program require quantitative analysis at sensitivities unobtainable with present instruments. This has driven development of a new generation of instruments for laser-post-ionization secondary neutral mass spectrometry (laser-SNMS). Construction of a prototype time-of-flight (TOF) SNMS instrument has been completed recently at Argonne National Laboratory (ANL) and testing began in August

I. V. Veryovkin; W. F. Calaway; J. F. Moore; M. J. Pellin; M. R. Savina; B. V. King; M. Petravic; D. S. Burnett

2002-01-01

189

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

190

Earth's Ionosphere as a Gigantic Detector of Extra-terrestrial Energetic Phenomena: A Review  

NASA Astrophysics Data System (ADS)

The paper presents the ionospheric effects due to radiation from the transient extraterrestrial sources like Gamma Ray Bursts, Soft Gamma Ray Repeaters, Anomalous X-ray Pulsars, X-ray novae and X-ray transient sources. Gamma rays could penetrate deep in the atmosphere due to their high energy in comparison with other types of radiation. If the transient radiation from the above sources is strong enough to enhance the ionospheric ionization, VLF radio propagation could be affected. In the paper, we discuss the evidences of detection of such phenomena in VLF data and explain some of the observations using theoretical considerations.

Mondal, S. K.; Chakrabarti, S. K.

2010-10-01

191

A summary of extremes of isotopic variations in extra-terrestrial materials  

NASA Astrophysics Data System (ADS)

In this comprehensive review of current research on isotopic variations of elements in extraterrestrial materials, the variations were classified in terms of the major process involved in the modification of the iostopic composition of the element concerned. Maximum isotopic variations of each element were retrieved from publications which were available in Tokyo up to December 1985, and are presented in tabular form.

Shima, M.

1986-04-01

192

Mass-Independent Fractionation of Extra-Terrestrial Materials: The Role of CO2  

NASA Astrophysics Data System (ADS)

Mass-independent fractionation of oxygen in meteorites is hypothesized to have originated from CO disproportionation to give heavy CO2. This process could have initiated in dark molecular clouds and continued in the formation of the solar system.

Barcena, H. S.; Connolly, H. C.

2012-09-01

193

Energy Systems - Present, Future: Extra Terrestrials, Grades 7, 8, 9,/Science.  

ERIC Educational Resources Information Center

The 12 lessons presented in this guide are structured so that they may be integrated into science lessons in 7th-, 8th-, or 9th-grades. Suggestions are made for extension of study. Lessons are approached through classroom role-playing of outer space visitors who seek to understand energy conversion principles used on Earth. Major emphasis is…

National Science Teachers Association, Washington, DC.

194

Two systems analyses of SETI. [microwave Search for Extra-Terrestrial Intelligence  

NASA Technical Reports Server (NTRS)

The problem of receiving and identifying a single microwave signal transmitted by extraterrestrial intelligent beings is analyzed in the cases where the signal is designed to catch our attention and the signal is designed for internal purposes of another civilization. Six variables which yield uncertainty as to the exact signal which should be searched for are described: polarization, modulation, flux level, direction, frequency (including bandwidth and drift rate), and time. It is shown that if all reasonable variations of these parameters are to be examined sequentially for 1000 seconds, the search would take over a million times longer than the age of the Universe. Ways to simplify the search are considered, including widening the frequency bin, selecting specific targets, cutting the observation time, using a Fourier transform device for data processing, and building larger antennas as well as better low-noise receivers.

Machol, R. E.

1976-01-01

195

Oxygen Isotope Evidence for the Extra-Terrestrial Origin of the First Natural Quasicrystal  

NASA Astrophysics Data System (ADS)

SIMS oxygen-isotopic data indicate that the first naturally occurring quasicrystal is associated with a diverse assemblage of high-temperature refractory chondritic minerals (silicates and oxides) formed in the early solar system.

Guan, Y.; Bindi, L.; Eiler, J. M.; Hollister, L.; MacPherson, G. J.; Steinhardt, P. J.; Yao, N.

2011-03-01

196

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

197

Numerical simulation of the final stages of terrestrial planet formation  

NASA Technical Reports Server (NTRS)

Three representative numerical simulations of the growth of the terrestrial planets by accretion of large protoplanets are considered. The mass and relative-velocity distributions of the bodies are free to evolve simultaneously in response to close gravitational encounters and occasional collisions between bodies. The collisions between bodies arise therefore in a natural way and the assumption of expressions for the relative-velocity distribution and the gravitational collision cross section is unnecessary. These simulations indicate that the growth of bodies with final masses approaching those of Venus and earth is possible, at least for the case of a two-dimensional system

Cox, L. P.; Lewis, J. S.

1980-01-01

198

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 ...

199

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

200

How giant planets sculpt terrestrial exoplanets and debris disks  

NASA Astrophysics Data System (ADS)

There exists strong circumstantial evidence from their eccentric orbits that most of the known giant exoplanet systems are the survivors of violent dynamical instabilities. We numerically simulate the evolution of planetary systems around Sun-like stars with three components: (i) an inner disk of planetesimals and planetary embryos, (ii) three giant planets at Jupiter- Saturn distances, and (iii) an outer disk of planetesimals comparable to the primitive Kuiper belt. We calculate the dust production and spectral energy distribution of each system by assuming that each planetesimal particle represents an ensemble of smaller bodies in collisional equilibrium. Our main result is a strong correlation between the presence of terrestrial planets and debris disks. Strong giant planet instabilities that produce very eccentric surviving planets destroy all rocky material in the system, including fully-formed terrestrial planets if the instabilities occur late, and also destroy the icy planetesimal population. Stable or weakly unstable systems allow terrestrial planets to accrete in their inner regions and significant dust to be produced in their outer regions, detectable at midinfrared wavelengths as debris disks. Stars older than ˜ 100 Myr with bright cold dust emission (in particular at ? ˜ 70?m) signpost dynamically calm environments that were conducive to efficient terrestrial accretion. Such emission is present around ˜16% of billion-year old Solar-type stars. We make two predictions. First, eccentric giant planets should be anticorrelated with both debris disks and terrestrial exoplanets. Second, the presence of debris disks and terrestrial exoplanets should be correlated.

Raymond, S. N.; Armitage, P. J.; Moro-Martin, A.; Booth, M.; Wyatt, M. C.; Armstrong, J. C.; Mandell, A.; Selsis, F.; West, A. A.

2011-10-01

201

Universal extra dimensions : life with BLKTs  

NASA Astrophysics Data System (ADS)

In universal extra dimension (UED) models with one compactified extra dimension, a Z2 symmetry, termed KK-parity, ensures the stability of the lightest Kaluza-Klein particle (LKP) which could be a viable dark matter candidate. This symmetry leads to two fixed points in the extra space like direction. In non-minimal versions of UED boundary-localized kinetic terms (BLKT) of same strength at both fixed points induce a new Z2 symmetry which ensures the stability of LKP. The precision of the dark matter measurements severely correlates and restricts the BLKT parameters of gauge bosons and fermions. Furthermore, BLKT parameters of different strengths at the fixed would induce a non-consevation of KK-parity. We examine, in the presence of such terms, single production and decay of Kaluza-Klein excitations of the neutral electroweak gauge bosons in the context of LHC.

Datta, Anindya; Dey, Ujjal Kumar; Raychaudhuri, Amitava; Shaw, Avirup

2014-03-01

202

Statistical analysis for extra galactic exoplanets  

NASA Astrophysics Data System (ADS)

We present the first statistical analysis on extra galactic stars that could host an exoplanet. We analyze the photometric data of the Ursa Minor Dwarf Spheroidal galaxy, taken by the Isaac Newton Group of Telescopes (INT) and we calculate the probability to detect a planetary transit , based on the stellar characteristics of the statistical sample and the transit detection probability distribution. Our goal is to determine how many possible planets could be detected in the galaxy and therefore create the first catalogue of extra galactic exoplanet host star candidates for future space missions.

Karpouzas, K.

2013-09-01

203

Solar-terrestrial influence  

NASA Astrophysics Data System (ADS)

Solar phenomena are examined to assess the extent of knowledge of the effect of the sun on the earth. The earth is gravitationally coupled to the sun, imbedded in the solar corona and thereby subject to particle bombardment and the influence of the solar magnetic field, and is directly illuminated by the sun at a rate of 1.367 kW/sq m. The coronal density is 10 particles/cu cm at the earth's distance from the sun, and the solar magnetic field is 1/10,000 what it is at the solar surface. Particle bombardment from the sun causes auroral displays, while other particles are diverted by the terrestrial magnetosphere and form a bow shock. Incoming solar protons dissociate NO in the upper atmosphere and form ozone. The ability of the earth's atmosphere at any time to absorb the total incoming solar radiation is a determining factor in the heating of the atmosphere. The heated atmosphere expands and may slow down satellites in LEO, while no precise modelling has yet been accomplished for the relationship between heating and climatic variations.

Bonnet, R. M.

204

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

205

Probing large extra dimensions with neutrinos.  

National Technical Information Service (NTIS)

We study implications of theories with sub-millimeter extra dimensions and M(sub f)(approx)(1-10) TeV scale quantum gravity for neutrino physics. In these theories, the left-handed neutrinos as well as other standard model (SM) particles, are localized on...

G. Dvali A. Smirnov

1999-01-01

206

Kinks, extra dimensions, and gravitational waves  

Microsoft Academic Search

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

Eimear O'Callaghan; Ruth Gregory

2011-01-01

207

Precision Constraints on Extra Fermion Generations  

SciTech Connect

There has been recent renewed interest in the possibility of additional fermion generations. At the same time there have been significant changes in the relevant electroweak precision constraints, in particular, in the interpretation of several of the low energy experiments. We summarize the various motivations for extra families and analyze them in view of the latest electroweak precision data.

Erler, Jens; Langacker, Paul [Departamento de Fisica Teorica, Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510 Mexico D.F. (Mexico); School of Natural Sciences, Institute for Advanced Study, Einstein Drive, Princeton, New Jersey 08540 (United States)

2010-07-16

208

Progress in extra-solar planet detection  

NASA Technical Reports Server (NTRS)

Progress in extra-solar planet detection is reviewed. The following subject areas are covered: (1) the definition of a planet; (2) the weakness of planet signals; (3) direct techniques - imaging and spectral detection; and (4) indirect techniques - reflex motion and occultations.

Brown, Robert A.

1991-01-01

209

Extra-corporeal shock wave lithotripsy.  

PubMed

Extra-corporeal shock wave lithotripsy (ESWL) has proved to be a revolutionary advance in the treatment of renal stone disease. It, itself, is non-invasive but may necessitate or be used as an adjunct to more invasive auxiliary procedures. The basic principles of lithotripsy, the clinical experience thus far and probable future applications are discussed. PMID:3330235

Pemberton, J

1987-12-01

210

Adapting the GISS Climate GCM to Model Extra-Solar Climate Regimes  

NASA Astrophysics Data System (ADS)

Hundreds of extra-solar planets have been discovered by NASA's Kepler mission, some potentially habitable, most exhibiting extremes in climate beyond current modeling experience. Zero-order assessment of the stellar type and the planet's distance from the star serves to identify the ballpark of whether silicon dioxide is likely to be in gaseous or liquid phase in the planet's atmosphere, or a part of the solid planetary ground surface. A lot of first-order modeling would involve assessing the chemical limitations to establish the likely chemical composition of the planetary atmosphere. For a more detailed analysis of the prevailing climate on an extra-solar planet a 3-D global climate model would be required. We begin the Extra-Solar Climate Model development by starting the with GISS Climate GCM by having key model parameters be expressed in physics based terms rather than Earth specific parameters. Examples of such key parameters are: the Planet's mass and radius, mass and composition of the atmosphere, Star-Planet distance, rotation rate and orbital parameters, stellar spectral distribution, land topography, and land-ocean distribution. These are parameters that are more or less straight forward to redefine for extra-solar conditions that are not greatly different for what may be considered as the ';habitable' zone. We present extreme climate simulations ranging from snowball Earth conditions to near-runaway greenhouse conditions. The objective of this modeling study is the development of a more physically based climate model that will be adaptable for assessing habitable climate regimes on newly discovered extra-solar planets, and will also facilitate the study terrestrial climate system analysis in paleoclimate applications.

Lacis, A. A.

2013-12-01

211

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 ...

212

Evolution of the Terrestrial Atmospheres  

NSDL National Science Digital Library

This lecture compares terrestrial atmospheres and discusses atmospheric processes, atmospheric equilibrium, and the atmospheric development of Mars, Venus, and Earth. It ends with a discussion of natural and unnatural climate changes.

O'Connell, Robert

2005-06-28

213

The rise and fall of extra dimensions  

NASA Astrophysics Data System (ADS)

The Standard Model, as an effective theory, provides an extremely good description of particle physics. It is however plagued with various naturalness problems. The most serious one is the extreme sensitivity of the Higgs mass to high energy physics. This is seen as a very strong indication that new physics is needed at TeV energies to stabilize the weak scale. For a long time, the options for this new physics have been limited to supersymmetry and technicolor. In the last few years, extra dimensions and branes, previously used mainly by string theorists, became a common tool in beyond the Standard Model model building. In the second chapter of this dissertation, we present a formalism for writing supersymmetric extra-dimensional theories in term of 4D superfields. This helps in the construction of supersymmetric brane world models. More recently, it has been discovered that extra dimensions can be "deconstructed", and extra-dimensional models can be turned into four dimensional ones using locality in "theory space", an abstract space of gauge group factors. This was used to provide UV completions of extra dimensional theories and led to the discovery of new four dimensional model building possibilities. In particular, it led to the development of little Higgs theories, a new approach to the hierarchy problem where the Higgs is a pseudo-Goldstone boson. These models are the only fully realistic and natural alternative to supersymmetry that stabilizes the weak scale using weakly coupled physics. In the third chapter of the dissertation, we study little Higgs models based on the deconstruction of a torus. In the fourth chapter, we generalize and present the rules for building little Higgs theories using topological properties of general theory spaces. Finally in the fifth chapter, we discuss the UV completion of six dimensional gauge theories using a strongly coupled deconstructed torus.

Gregoire, Thomas

214

Fish out of water: terrestrial jumping by fully aquatic fishes.  

PubMed

Many teleosts that live at the water's edge will voluntarily strand themselves to evade predators or escape poor conditions-this behavior has been repeatedly observed in the field for killifishes (Cyprinodontiformes). Although most killifishes are considered fully aquatic and possess no obvious morphological specializations to facilitate terrestrial locomotion, individuals from several different species have been observed moving across land via a "tail flip" behavior that generates a terrestrial jump. Like aquatic fast starts, terrestrial jumps are produced by high-curvature lateral flexion of the body (stage one), followed by contralateral flexion of the posterior body (stage two). Here, terrestrial jumps and aquatic fast starts are quantified for two littoral teleosts: Gambusia affinis (a killifish, Cyprinodontiformes) and Danio rerio (a small carp, Cypriniformes) to determine if the tail flip is produced by other (non-killifish) teleosts and to test the null hypothesis that the tail flip is a fast start behavior, performed on land. Both Danio and Gambusia produce tail flip-driven terrestrial jumps, which are kinematically distinct from aquatic escapes and characterized by (1) a prolonged stage one, during which the fish bends, lifting and rolling the center of mass over the caudal peduncle, and (2) a relatively brief stage two, wherein the caudal peduncle pushes against the substrate to launch the fish into the aerial phase. The ability of these fully aquatic fishes to employ the same structure to produce distinct kinematic patterns in disparate environments suggests that a new behavior has evolved to facilitate movement on land and that anatomical novelty is not a prerequisite for effective terrestrial locomotion. PMID:21972177

Gibb, Alice C; Ashley-Ross, Miriam A; Pace, Cinnamon M; Long, John H

2011-12-01

215

Workshop on Oxygen in the Terrestrial Planets  

NASA Technical Reports Server (NTRS)

This volume contains abstracts that have been accepted for presentation at the Workshop on Oxygen in the Terrestrial Planets, July 20-23,2004, Santa Fe, New Mexico. The contents include: 1) Experimental Constraints on Oxygen and Other Light Element Partitioning During Planetary Core Formation; 2) In Situ Determination of Fe(3+)/SigmaFe of Spinels by Electron Microprobe: An Evaluation of the Flank Method; 3) The Effect of Oxygen Fugacity on Large-Strain Deformation and Recrystallization of Olivine; 4) Plagioclase-Liquid Trace Element Oxygen Barometry and Oxygen Behaviour in Closed and Open System Magmatic Processes; 5) Core Formation in the Earth: Constraints from Ni and Co; 6) Oxygen Isotopic Compositions of the Terrestrial Planets; 7) The Effect of Oxygen Fugacity on Electrical Conduction of Olivine and Implications for Earth s Mantle; 8) Redox Chemical Diffusion in Silicate Melts: The Impact of the Semiconductor Condition; 9) Ultra-High Temperature Effects in Earth s Magma Ocean: Pt and W Partitioning; 10) Terrestrial Oxygen and Hydrogen Isotope Variations: Primordial Values, Systematics, Subsolidus Effects, Planetary Comparisons, and the Role of Water; 11) Redox State of the Moon s Interior; 12) How did the Terrestrial Planets Acquire Their Water?; 13) Molecular Oxygen Mixing Ratio and Its Seasonal Variability in the Martian Atmosphere; 14) Exchange Between the Atmosphere and the Regolith of Mars: Discussion of Oxygen and Sulfur Isotope Evidence; 15) Oxygen and Hydrogen Isotope Systematics of Atmospheric Water Vapor and Meteoric Waters: Evidence from North Texas; 16) Implications of Isotopic and Redox Heterogeneities in Silicate Reservoirs on Mars; 17) Oxygen Isotopic Variation of the Terrestrial Planets; 18) Redox Exchanges in Hydrous Magma; 19) Hydrothermal Systems on Terrestrial Planets: Lessons from Earth; 20) Oxygen in Martian Meteorites: A Review of Results from Mineral Equilibria Oxybarometers; 21) Non-Linear Fractionation of Oxygen Isotopes Implanted in Lunar Metal Grains: Solar, Lunar or Terrestrial Origin? 22) Isotopic Zoning in the Inner Solar System; 23) Redox Conditions on Small Bodies; 24) Determining the Oxygen Fugacity of Lunar Pyroclastic Glasses Using Vanadium Valence - An Update; 25) Mantle Redox Evolution and the Rise of Atmospheric O2; 26) Variation of Kd for Fe-Mg Exchange Between Olivine and Melt for Compositions Ranging from Alkaline Basalt to Rhyolite; 27) Determining the Partial Pressure of Oxygen (PO,) in Solutions on Mars; 28) The Influence of Oxygen Environment on Kinetic Properties of Silicate Rocks and Minerals; 29) Redox Evolution of Magmatic Systems; 30) The Constancy of Upper Mantlefo, Through Time Inferred from V/Sc Ratios in Basalts: Implications for the Rise in Atmospheric 0 2; 31) Nitrogen Solubility in Basaltic Melt. Effects of Oxygen Fugacity, Melt Composition and Gas Speciation; 32) Oxygen Isotope Anomalies in the Atmospheres of Earth and Mars; 33) The Effect of Oxygen Fugacity on Interdiffusion of Iron and Magnesium in Magnesiowiistite 34) The Calibration of the Pyroxene Eu-Oxybarometer for the Martian Meteorites; 35) The Europium Oxybarometer: Power and Pitfalls; 36) Oxygen Fugacity of the Martian Mantle from PigeoniteMelt Partitioning of Samarium, Europium and Gadolinium; 37) Oxidation-Reduction Processes on the Moon: Experimental Verification of Graphite Oxidation in the Apollo 17 Orange Glasses; 38) Oxygen and Core Formation in the Earth; 39) Geologic Record of the Atmospheric Sulfur Chemistry Before the Oxygenation of the Early Earth s Atmosphere; 40) Comparative Planetary Mineralogy: V/(CrCAl) Systematics in Chromite as an Indicator of Relative Oxygen Fugacity; 41) How Well do Sulfur Isotopes Constrain Oxygen Abundance in the Ancient Atmospheres? 42) Experimental Constraints on the Oxygen Isotope (O-18/ O-16) Fractionation in the Ice vapor and Adsorbant vapor Systems of CO2 at Conditions Relevant to the Surface of Mars; 43) Micro-XANES Measurements on Experimental Spinels andhe Oxidation State of Vanadium in Spinel-Melt Pairs; 44) Testing the Magma Ocean Hypothesis Using

2004-01-01

216

CT and MR imaging of unusual locations of extra-adrenal paragangliomas (pheochromocytomas).  

PubMed

Our review was undertaken to describe CT and MRI features of unusual extra-adrenal paragangliomas (pheochromocytomas). We retrospectively reviewed CT and MRI findings in 29 patients with 39 extra-adrenal paragangliomas. For each tumour, site, size, MRI characteristics, CT appearances and enhancement after gadolinium and iohexol were recorded. There were 17 carotid body tumours, 1 mediastinal, 1 intra-cardiac, 15 retroperitoneal extra-adrenal paragangliomas, 2 bladder, 1 pelvic sidewall and 2 intra-spinal paragangliomas within the lumbo-sacral spine. All 39 paragangliomas were shown on MRI. Of the 32 lesions studied by MRI and CT, CT detected 30. Of the two lesions missed on CT, one was an intra-cardiac paraganglioma and the second a bladder wall paraganglioma. At detection, 25 tumours were larger than 4 cm, of which 20 were heterogeneous lesions on CT and MRI with variable contrast enhancement. The 14 smaller paragangliomas were smooth in contour and demonstrated avid, homogeneous contrast enhancement. Our review of extra-adrenal paragangliomas highlights their unusual sites and appearances. MRI demonstrated the greatest variability in the appearances of larger tumours, provided additional information compared to CT for surgical planning and is a useful screening tool for patients at high risk of extra-adrenal paragangliomas. PMID:15290072

Sahdev, Anju; Sohaib, A; Monson, John P; Grossman, Ashley B; Chew, Shern L; Reznek, Rodney H

2005-01-01

217

Universal extra dimensions on real projective plane  

NASA Astrophysics Data System (ADS)

We propose a six-dimensional Universal Extra Dimensions (UED) model compactified on a real projective plane RP2, a two-sphere with its antipodal points being identified. We utilize the Randjbar-Daemi-Salam-Strathdee spontaneous sphere compactification with a monopole configuration of an extra U(1 gauge field that leads to a spontaneous radius stabilization. Unlike the sphere and the S2/Z orbifold compactifications, the massless U(1 gauge boson is safely projected out. We show how a compactification on a non-orientable manifold results in a chiral four-dimensional gauge theory by utilizing 6D chiral gauge and Yukawa interactions. The resultant Kaluza-Klein mass spectra are distinct from the ordinary UED models compactified on torus. We briefly comment on the anomaly cancellation and also on a possible dark matter candidate in our model.

Dohi, Hideto; Oda, Kin-Ya

2010-08-01

218

Supernovae as Probes of Extra Dimensions  

SciTech Connect

Since the dawn of the new millennium, there has been a revived interest in the concept of extra dimensions. In this scenario all the standard model matter and gauge fields are confined to the 4 dimensions and only gravity can escape to higher dimensions of the universe. This idea can be tested using table-top experiments, collider experiments, astrophysical or cosmological observations. The main astrophysical constraints come from the cooling rate of supernovae, neutron stars, red giants and the sun. In this article, we consider the energy loss mechanism of SN1987A and study the constraints it places on the number and size of extra dimensions and the higher dimensional Planck scale.

Satheesh Kumar, V. H. [School of Physics, University of Hyderabad, Hyderabad 500 046 (India); Department of Physics, Jain International Residential School, Bangalore 562 112 (India); Suresh, P. K. [School of Physics, University of Hyderabad, Hyderabad 500 046 (India); Das, P. K. [The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600 113 (India)

2007-10-03

219

Formation of the terrestrial planets  

NASA Astrophysics Data System (ADS)

The early phases of formation in the inner solar system were dominated by collisions and short-range dynamical interactions among planetesimals. But the later phases, which account for most of the differences among planets, are unsure because the dynamics are more subtle. Jupiter's influence became more important, leading to drastic clearing out of the asteroid belt and the stunting of Mars's growth. Further in, the effect of Jupiter-- both directly and indirectly, through ejection of mass in the outer solar system-- was probably to speed up the process without greatly affecting the outcome. The great variety in bulk properties of the terrestrial bodies indicate a terminal phase of great collisions, so that the outcome is the result of small-N statistics. Mercury, 65 percent iron, appears to be a residual core from a high-velocity collision. All planets appear to require a late phase of high energy impacts to erode their atmospheres: including the Earth, to remove CO2 so that its ocean could form by condensation of water. Consistent with this model is that the largest collision, about 0.2 Earth masses, was into the proto-Earth, although the only property that appears to require it is the great lack of iron in the Moon. The other large differences between the Earth and Venus, angular momentum (spin plus satellite) and inert gas abundances, must arise from origin circumstances, but neither require nor forbid the giant impact. Venus's higher ratio of light to heavy inert gases argues for it receiving a large icy impactor, about 10-6 Earth masses from far out, requiring some improbable dynamics to get a low enough approach velocity. Core formation in both planets probably started rather early during accretion. Some geochemical evidences argue for the Moon coming from the Earth's mantle, but are inconclusive. Large scale melting of the mantle by the giant impact would plausibly have led to stratification. But the "lock-up" at the end of turbulent mantle convection is a trade-off between rates: crystallization of constituents of small density difference versus overall freezing. Also, factors such as differences in melting temperatures and densities, melt compressibilities, and phase transitions may have had homogenizing effects in the subsequent mantle convection.

Kaula, William M.

1994-01-01

220

Dimensional reduction without continuous extra dimensions  

SciTech Connect

We describe a novel approach to dimensional reduction in classical field theory. Inspired by ideas from noncommutative geometry, we introduce extended algebras of differential forms over space-time, generalized exterior derivatives, and generalized connections associated with the 'geometry' of space-times with discrete extra dimensions. We apply our formalism to theories of gauge- and gravitational fields and find natural geometrical origins for an axion- and a dilaton field, as well as a Higgs field.

Chamseddine, Ali H. [American University of Beirut, Physics Department, Beirut, Lebanon and I.H.E.S. F-91440 Bures-sur-Yvette (France)] [American University of Beirut, Physics Department, Beirut, Lebanon and I.H.E.S. F-91440 Bures-sur-Yvette (France); Froehlich, J.; Schubnel, B. [ETHZ, Mathematics and Physics Departments, Zuerich (Switzerland)] [ETHZ, Mathematics and Physics Departments, Zuerich (Switzerland); Wyler, D. [Institute of Theoretical Physics, University of Zuerich (Switzerland)] [Institute of Theoretical Physics, University of Zuerich (Switzerland)

2013-01-15

221

Extra-corporeal shock wave lithotripsy.  

PubMed Central

Extra-corporeal shock wave lithotripsy (ESWL) has proved to be a revolutionary advance in the treatment of renal stone disease. It, itself, is non-invasive but may necessitate or be used as an adjunct to more invasive auxiliary procedures. The basic principles of lithotripsy, the clinical experience thus far and probable future applications are discussed. Images Figure 2 Figure 4 Figure 5 Figure 7 Figure 8

Pemberton, J.

1987-01-01

222

Signals for Extra Dimensions at CLIC  

SciTech Connect

A brief overview is presented of the signatures for several different models with extra dimensions at CLIC, an e{sup +}e{sup -} linear collider with a center of mass energy of 3-5 TeV and an integrated luminosity of order 1 ab{sup -1}. In all cases the search reach for the resulting new physic signatures is found to be in the range of {approx} 15-80 TeV.

Rizzo, Thomas G.

2001-08-28

223

Extra gauge symmetries in BHT gravity  

NASA Astrophysics Data System (ADS)

We study the canonical structure of the Bergshoeff-Hohm-Townsend massive gravity, linearized around a maximally symmetric background. At the critical point in the space of parameters, defined by ? 0/ m 2 = -1, we discover an extra gauge symmetry, which reflects the existence of the partially massless mode. The number of the Lagrangian degrees of freedom is found to be 1. We show that the canonical structure of the theory at the critical point is unstable under linearization.

Blagojevi?, M.; Cvetkovi?, B.

2011-03-01

224

Solar System Bodies and “Primitiveness”  

Microsoft Academic Search

Planets and small bodies. Besides the Sun, which represents about 99.85% of its mass, the present day solar system include large bodies, i.e., the\\u000a four terrestrial planets, the four giant planets, and Pluto, which is probably not a planet, but rather an object from the\\u000a Edgeworth–Kuiper belt of comets captured by Neptune; more than 130 satellites of the planets. Jupiter,

Michel Maurette

2006-01-01

225

Planetary beat and solar-terrestrial responses  

NASA Astrophysics Data System (ADS)

Solar activity changes with time in a cyclic pattern. The origin of those changes may be caused by planetary motion around the Sun, affecting the position of the Sun's motion with respect to the centre of mass and subjecting the Sun to changes in angular momentum and gravitational tidal forces. With modern achievements, this multi-body problem can now be addressed in a constructive way. Indeed, there are multiple criteria suggesting that the solar variability is driven by a planetary beat also affecting a number of terrestrial variables: 14C and 10Be production, Earth's rotation, ocean circulation, paleoclimate, geomagnetism, etc. The centennial changes between grand solar maxima and minima imply that we will soon be in a new solar minimum and, in analogy with past events, probably also in Little Ice Age climatic conditions.

Mörner, N.-A.

2013-11-01

226

Primary Education in Vietnam: Extra Classes and Outcomes  

ERIC Educational Resources Information Center

Extra classes are increasingly observed in both developed and developing countries. In Vietnam, a country where education reforms are at their height, extra classes are proliferating and have become a concern to society and the government. Although the government has banned extra classes that are independent of school administration, teachers…

Ha, Tran Thu; Harpham, Trudy

2005-01-01

227

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

228

The storage of extra water by various tissues of Varanus griseus daud  

Microsoft Academic Search

1.Under conditions of water excess, Varanus can retain extra water amounting to 15% of its body weight in its tissues.2.Tissues of high metabolic activity as brain, heart and spinal cord and tissues of low metabolic activity as skin, bone and cartilage show no increase in their water content under conditions of water excess.3.The remaining tissues show an increase in their

Fouad Khalil; Guirguis Abdel-Messeih

1959-01-01

229

Furostanol saponins from Tribulus terrestris.  

PubMed

An HPLC-ELSD-ESI-MS method has been developed for the analysis of the steroidal saponins in the aerial parts of Tribulus terrestris. Protodioscin, a new saponin (5,6-dihydroprotodioscin, neoprotodioscin) and their respective sulfates were detected. The structure of the new compound was elucidated on the basis of NMR and ESI-MS spectral analysis. PMID:12946722

De Combarieu, E; Fuzzati, N; Lovati, M; Mercalli, E

2003-09-01

230

Atmospheric Circulation of Terrestrial Exoplanets  

NASA Astrophysics Data System (ADS)

The investigation of planets around other stars began with the study of gas giants, but is now extending to the discovery and characterization of super-Earths and terrestrial planets. Motivated by this observational tide, we survey the basic dynamical principles governing the atmospheric circulation of terrestrial exoplanets, and discuss the interaction of their circulation with the hydrological cycle and global-scale climate feedbacks. Terrestrial exoplanets occupy a wide range of physical and dynamical conditions, only a small fraction of which have yet been explored in detail. Our approach is to lay out the fundamental dynamical principles governing the atmospheric circulation on terrestrial planets — broadly defined — and show how they can provide a foundation for understanding the atmospheric behavior of these worlds. We first survey basic atmospheric dynamics, including the role of geostrophy, baroclinic instabilities, and jets in the strongly rotating regime (the "extratropics") and the role of the Hadley circulation, wave adjustment of the thermal structure, and the tendency toward equatorial superrotation in the slowly rotating regime (the "tropics"). We then survey key elements of the hydrological cycle, including the factors that control precipitation, humidity, and cloudiness. Next, we summarize key mechanisms by which the circulation affects the global-mean climate, and hence planetary habitability. In particular, we discuss the runaway greenhouse, transitions to snowball states, atmospheric collapse, and the links between atmospheric circulation and CO2 weathering rates. We finish by summarizing the key questions and challenges for this emerging field in the future.

Showman, A. P.; Wordsworth, R. D.; Merlis, T. M.; Kaspi, Y.

231

Furostanol saponins from Tribulus terrestris  

Microsoft Academic Search

An HPLC-ELSD-ESI-MS method has been developed for the analysis of the steroidal saponins in the aerial parts of Tribulus terrestris. Protodioscin, a new saponin (5,6-dihydroprotodioscin, neoprotodioscin) and their respective sulfates were detected. The structure of the new compound was elucidated on the basis of NMR and ESI-MS spectral analysis.

E De Combarieu; N Fuzzati; M Lovati; E Mercalli

2003-01-01

232

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

233

Topological solitons from deconstructed extra dimensions.  

PubMed

A topological monopolelike field configuration exists for Yang-Mills gauge fields in 4+1 dimensions. When the extra dimension is compactified to 3+1 dimensions with periodic lattice boundary conditions, these objects reappear in the low-energy effective theory as a novel solution, a gauged-bosonic Skyrmion. When the low-energy theory spontaneously breaks, the Nambu-Goldstone mode develops a vacuum expectation value, and the gauged-bosonic Skyrmion morphs into a 't Hooft-Polyakov monopole. PMID:11801102

Hill, Christopher T

2002-01-28

234

Amino acid compositional shifts during streptophyte transitions to terrestrial habitats.  

PubMed

Across the streptophyte lineage, which includes charophycean algae and embryophytic plants, there have been at least four independent transitions to the terrestrial habitat. One of these involved the evolution of embryophytes (bryophytes and tracheophytes) from a charophycean ancestor, while others involved the earliest branching lineages, containing the monotypic genera Mesostigma and Chlorokybus, and within the Klebsormidiales and Zygnematales lineages. To overcome heat, water stress, and increased exposure to ultraviolet radiation, which must have accompanied these transitions, adaptive mechanisms would have been required. During periods of dehydration and/or desiccation, proteomes struggle to maintain adequate cytoplasmic solute concentrations. The increased usage of charged amino acids (DEHKR) may be one way of maintaining protein hydration, while increased use of aromatic residues (FHWY) protects proteins and nucleic acids by absorbing damaging UV, with both groups of residues thought to be important for the stabilization of protein structures. To test these hypotheses we examined amino acid sequences of orthologous proteins representing both mitochondrion- and plastid-encoded proteomes across streptophytic lineages. We compared relative differences within categories of amino acid residues and found consistent patterns of amino acid compositional fluxuation in extra-membranous regions that correspond with episodes of terrestrialization: positive change in usage frequency for residues with charged side-chains, and aromatic residues of the light-capturing chloroplast proteomes. We also found a general decrease in the usage frequency of hydrophobic, aliphatic, and small residues. These results suggest that amino acid compositional shifts in extra-membrane regions of plastid and mitochondrial proteins may represent biochemical adaptations that allowed green plants to colonize the land. PMID:21153633

Jobson, Richard W; Qiu, Yin-Long

2011-02-01

235

Formation of the terrestrial planets from planetesimals  

NASA Technical Reports Server (NTRS)

Formation of the terrestrial planets from planetesimals is discussed. The following subject areas are covered: (1) formation of the original planetesimals; (2) growth of planetesimals into planetary embryos; and (3) growth of runaway planetary embryos into terrestrial planets.

Wetherill, George W.

1991-01-01

236

CARBON DIOXIDE SEQUESTRATION IN TERRESTRIAL ECOSYSTEMS  

EPA Science Inventory

The terrestrial biosphere plays a prominent role in the global carbon (C) cycle. errestrial ecosystems are currently accumulating C and it appears feasible to manage existing terrestrial (forest, agronomic, desert) ecosystems to maintain or increase C storage. orest ecosystems ca...

237

Transfer of radionuclides in the terrestrial environment.  

National Technical Information Service (NTIS)

The transfer of radionuclides in the terrestrial environment have been investigated. The thesis is divided into two parts. Part I; Dynamic model for the transfer of radionuclides in the terrestrial environment. The study comprises the development of a com...

M. Oehlenschlaeger

1991-01-01

238

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

239

The Extra-Zodiacal Explorer (EZE)  

NASA Astrophysics Data System (ADS)

We describe a mission architecture study designed to substantially increase the potential science performance of the NASA SMD Astrophysics Explorer Program for all AO offerors working within the near-UV to far-infrared spectrum. We have demonstrated that augmentation of Falcon 9 Explorer launch services with a Solar Electric Propulsion (SEP) stage can deliver a 700 kg science observatory payload to an extra-Zodiacal orbit. This new capability enables up to 10X increased photometric sensitivity and 150X increased observing speed relative to a Sun-Earth L2 or Earth-trailing orbit with no increase in telescope aperture. All enabling SEP stage technologies for this launch service augmentation have reached sufficient readiness (TRL-6) for Explorer Program application in conjunction with the Falcon 9. We demonstrate that enabling Astrophysics Explorers to reach extra-zodiacal orbit will allow this small payload program to rival the science performance of much larger long development time systems; thus, providing a means to realize major science objectives while increasing the SMD Astrophysics portfolio diversity and resiliency to external budget pressure. The SEP technology employed in this study has applicability to SMD Planetary competed missions and aligns with NASA in-space propulsion technology road map objectives and associated flight demonstration planning.

Greenhouse, Matthew A.; Benson, S. W.; Fixsen, D. J.; Gardner, J. P.; Kruk, J. W.; Thronson, H. A.

2012-01-01

240

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.

Reisz, Robert R.; Frobisch, Jorg

2014-01-01

241

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; Fröbisch, Jörg

2014-01-01

242

Gigantism, temperature and metabolic rate in terrestrial poikilotherms  

PubMed Central

The mechanisms dictating upper limits to animal body size are not well understood. We have analysed body length data for the largest representatives of 24 taxa of terrestrial poikilotherms from tropical, temperate and polar environments. We find that poikilothermic giants on land become two–three times shorter per each 10 degrees of decrease in ambient temperature. We quantify that this diminution of maximum body size accurately compensates the drop of metabolic rate dictated by lower temperature. This supports the idea that the upper limit to body size within each taxon can be set by a temperature-independent critical minimum value of mass-specific metabolic rate, a fall below which is not compatible with successful biological performance.

Makarieva, Anastassia M; Gorshkov, Victor G; Li, Bai-Lian

2005-01-01

243

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

244

Comparison of Titan's north polar lakes with terrestrial analogs  

NASA Astrophysics Data System (ADS)

The discovery of hydrocarbon lakes in the polar regions of Titan offers a unique opportunity to compare terrestrial lakes with those in an extraterrestrial setting. We selected 114 terrestrial lakes formed by different processes as analogs for comparison with the 190 Titanian lakes that we had mapped 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 mapping techniques, and found the automated techniques to produce as good representations of the lake shorelines as the manual mapping in the terrestrial dataset. We then calculated and compared terrestrial and Titanian shoreline statistical parameters including fractal dimension, shoreline development index and an elongation index. We found different lake generation mechanisms on Earth produce “statistically different” shorelines. However, we cannot identify any one mechanism or set of mechanisms to be responsible for forming the depressions enclosing the lakes on Titan, on the basis of our statistical analyses.

Sharma, Priyanka; Byrne, Shane

2011-12-01

245

Terrestrial photovoltaic collector technology trends  

NASA Technical Reports Server (NTRS)

Following the path of space PV collector development in its early stages, terrestrial PV technologies based upon single-crystal silicon have matured rapidly. Currently, terrestrial PV cells with efficiencies approaching space cell efficiencies are being fabricated into modules at a fraction of the space PV module cost. New materials, including CuInSe2 and amorphous silicon, are being developed for lowering the cost, and multijunction materials for achieving higher efficiency. Large grid-interactive, tracking flat-plate power systems and concentrator PV systems totaling about 10 MW, are already in operation. Collector technology development both flat-plate and concentrator, will continue under an extensive government and private industry partnership.

Shimada, K.; Costogue, E.

1984-01-01

246

Terrestrial based inflatable dish antennas  

Microsoft Academic Search

A terrestrial based 4.8-meter dish is presented. The dish is constructed using lightweight, thin film technologies used in spaced-based platforms. Seaming two parabolic dish films together forms a lenticular. One film is coated with a silver flake conductive paint, and the other is RF transparent. The lenticular is inflated to hold the parabolic shape of the dish. The lenticular is

Lany T. Lowe; Ronald D. Hackett

2003-01-01

247

Two sapogenins from tribulus terrestris  

Microsoft Academic Search

Studies on the constituents of Tribulus terrestris L. led to the isolation of two new steroidal sapogenins, (5?, 25R)-spirostan-3,6,12-trione and 25R-spirostan-4-ene-3,6,12-trione, together with five known steroidal sapogenins, tigogenin, hecogenin, gitogenin, hecogenone, and 25R-spirostan-4-ene-3,12-dione. The structures of the new sapogenins were established on the basis of chemical and spectroscopic evidence, especially 2D NMR spectroscopic techniques.

Yi-Xin Xu; Hai-Sheng Chen; Wen-Yong Liu; Zheng-Bing Gu; Hua-Qing Liang

1998-01-01

248

A comparative analysis of dispersal syndromes in terrestrial and semi-terrestrial animals.  

PubMed

Dispersal, the behaviour ensuring gene flow, tends to covary with a number of morphological, ecological and behavioural traits. While species-specific dispersal behaviours are the product of each species' unique evolutionary history, there may be distinct interspecific patterns of covariation between dispersal and other traits ('dispersal syndromes') due to their shared evolutionary history or shared environments. Using dispersal, phylogeny and trait data for 15 terrestrial and semi-terrestrial animal Orders (> 700 species), we tested for the existence and consistency of dispersal syndromes across species. At this taxonomic scale, dispersal increased linearly with body size in omnivores, but decreased above a critical length in herbivores and carnivores. Species life history and ecology significantly influenced patterns of covariation, with higher phylogenetic signal of dispersal in aerial dispersers compared with ground dwellers and stronger evidence for dispersal syndromes in aerial dispersers and ectotherms, compared with ground dwellers and endotherms. Our results highlight the complex role of dispersal in the evolution of species life-history strategies: good dispersal ability was consistently associated with high fecundity and survival, and in aerial dispersers it was associated with early maturation. We discuss the consequences of these findings for species evolution and range shifts in response to future climate change. PMID:24915998

Stevens, Virginie M; Whitmee, Sarah; Le Galliard, Jean-François; Clobert, Jean; Böhning-Gaese, Katrin; Bonte, Dries; Brändle, Martin; Matthias Dehling, D; Hof, Christian; Trochet, Audrey; Baguette, Michel

2014-08-01

249

Compact extra dimensions in cosmologies with f(T) structure  

NASA Astrophysics Data System (ADS)

The presence of compact extra dimensions in cosmological scenarios in the context of f(T)-like gravities is discussed. For the case of toroidal compactifications, the analysis is performed in an arbitrary number of extra dimensions. Spherical topologies for the extra dimensions are then carefully studied in six and seven spacetime dimensions, where the proper vielbein fields responsible for the parallelization process are found.

Fiorini, Franco; González, P. A.; Vásquez, Yerko

2014-01-01

250

Multistate dark matter from spherical extra dimensions  

NASA Astrophysics Data System (ADS)

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.; Sigurdson, Kris; Ng, John N.

2010-07-01

251

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

252

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

253

Extra-axial soft tissue chordoma of wrist.  

PubMed

Extra-axial soft tissue chordoma is rare. We report a case of extra-axial soft tissue chordoma of the right wrist in an 87-year-old man. The tumor was large, and the cut surface showed multinodular and myxoid appearance. Microscopically, nests of epithelioid and spindle cells were observed in the myxoid matrix. Vacuolated cells were also observed. The tumor cells were diffusely positive for brachyury and cytokeratin 19 on immunohistochemistry, suggesting that the tumor was extra-axial soft tissue chordoma. Extra-axial chordoma is the same entity as chordoma periphericum (parachordoma), as proposed by Laskowski and Dabska. PMID:21397407

Suzuki, Hiroaki; Yamashiro, Katsushige; Takeda, Hiroko; Nojima, Takayuki; Usui, Masamichi

2011-05-15

254

FORMATION OF THE TERRESTRIAL PLANETS FROM A NARROW ANNULUS  

SciTech Connect

We show that the assembly of the solar system terrestrial planets can be successfully modeled with all of the mass initially confined to a narrow annulus between 0.7 and 1.0 AU. With this configuration, analogs of Mercury and Mars often form from the collisional evolution of material diffusing out of the annulus under the scattering of the forming Earth and Venus analogs. The final systems also possess eccentricities and inclinations that match the observations, without recourse to dynamical friction from remnant small body populations. Finally, the characteristic assembly timescale for Earth analogs is rapid in this model and consistent with cosmochemical models based on the {sup 182}Hf-{sup 182}W isotopes. The agreement between this model and the observations suggests that terrestrial planet systems may also be formed in 'planet traps', as has been proposed recently for the cores of giant planets in our solar system and others.

Hansen, Brad M. S., E-mail: hansen@astro.ucla.ed [Department of Physics and Astronomy, and Institute of Geophysics and Planetary Physics, University of California Los Angeles, Los Angeles, CA 90095 (United States)

2009-09-20

255

Elliptical instability in terrestrial planets and moons  

NASA Astrophysics Data System (ADS)

Context. The presence of celestial companions means that any planet may be subject to three kinds of harmonic mechanical forcing: tides, precession/nutation, and libration. These forcings can generate flows in internal fluid layers, such as fluid cores and subsurface oceans, whose dynamics then significantly differ from solid body rotation. In particular, tides in non-synchronized bodies and libration in synchronized ones are known to be capable of exciting the so-called elliptical instability, i.e. a generic instability corresponding to the destabilization of two-dimensional flows with elliptical streamlines, leading to three-dimensional turbulence. Aims: We aim here at confirming the relevance of such an elliptical instability in terrestrial bodies by determining its growth rate, as well as its consequences on energy dissipation, on magnetic field induction, and on heat flux fluctuations on planetary scales. Methods: Previous studies and theoretical results for the elliptical instability are re-evaluated and extended to cope with an astrophysical context. In particular, generic analytical expressions of the elliptical instability growth rate are obtained using a local WKB approach, simultaneously considering for the first time (i) a local temperature gradient due to an imposed temperature contrast across the considered layer or to the presence of a volumic heat source and (ii) an imposed magnetic field along the rotation axis, coming from an external source. Results: The theoretical results are applied to the telluric planets and moons of the solar system as well as to three Super-Earths: 55 CnC e, CoRoT-7b, and GJ 1214b. For the tide-driven elliptical instability in non-synchronized bodies, only the early Earth core is shown to be clearly unstable. For the libration-driven elliptical instability in synchronized bodies, the core of Io is shown to be stable, contrary to previously thoughts, whereas Europa, 55 CnC e, CoRoT-7b, and GJ 1214b cores can be unstable. The subsurface ocean of Europa is slightly unstable. However, these present states do not preclude more unstable situations in the past.

Cebron, D.; Le Bars, M.; Moutou, C.; Le Gal, P.

2012-03-01

256

Catastrophic Collisions in the Terrestrial Planet Zone and the Epoch of Terrestrial Planet Formation around Intermediate Mass Stars  

NASA Astrophysics Data System (ADS)

We have completed an extensive search for stars hosting terrestrial planet zone dust by cross-correlating the Tycho-2 and IRAS catalogs. Near-infrared to far-infrared excess emission has been discovered towards a 10-20 Myr old, A-type member of the Upper-Centaurus-Lupus association. The hot dust component ( 750 K) in combination with the high fractional infrared luminosity (0.4%) suggest a recent catastrophic collision between rocky bodies in this intermediate mass star's inner planetary system. Synthesis of all published incidences of intermediate mass stars with evidence for terrestrial planet zone dust suggests that catastrophic collisions analogous to the Moon-forming event in our Solar System occur around intermediate mass stars when the star is 10-30 Myr old. Funding for this research came from NASA grants and an LLNL-Minigrant to UCLA and from the Spitzer Visiting Graduate Student Program.

Melis, Carl; Zuckerman, B.; Song, I.; Rhee, J. H.; Bessell, M. S.; Murphy, S. J.

2010-01-01

257

Body Piercing  

MedlinePLUS

MENU Return to Web version Body Piercing Body Piercing What is body piercing? Body piercing is when a hole is made in your skin or through a part of ... pierce? The earlobe is the most common body piercing. Other common places to pierce include the eyebrow, ...

258

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

259

Extra-osseous involvement of Langerhans’ cell histiocytosis in children  

Microsoft Academic Search

The predominant clinical and radiological features of Langerhans’ cell histiocytosis (LCH) in children are due to osseous involvement. Extra-osseous disease is far less common, occurring in association with bone disease or in isolation; nearly all anatomical sites may be affected and in very various combinations. The following article is based on a multicentre review of 31 children with extra-osseous LCH.

Sabine Schmidt; Georg Eich; Sylviane Hanquinet; Heinz Tschäppeler; Peter Waibel; François Gudinchet

2004-01-01

260

Extra quark-lepton generations and precision measurements  

Microsoft Academic Search

The existence of extra chiral generations with all fermions heavier than MZ is strongly disfavoured by the precision electroweak data. However the data are fitted nicely even by a few extra generations, if one allows neutral leptons to have masses close to 50 GeV. The data allow inclusion of one additional generation of heavy fermions in SUSY extension of Standard

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

2000-01-01

261

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

262

The Impact of Daily Extra Credit Quizzes on Exam Performance  

ERIC Educational Resources Information Center

This study examined whether offering daily extra credit quizzes predicted exam performance in an advanced psychology course (n = 36). Results revealed that extra credit performance was a strong predictor of exam performance, above and beyond gender, college grade point average, and ACT scores. In addition, results suggested that nearly half of the…

Padilla-Walker, Laura M.

2006-01-01

263

Continuity Equations for Many-Body Systems.  

National Technical Information Service (NTIS)

The four-divergence of a generalized current is related to the Green's function formulation of the many-body problem. The relations obtained take the form of continuity equations, with an extra source term corresponding to the creation or annihilation of ...

D. G. Pelka N. Rivier

1971-01-01

264

Syncyclons or Solitonic Signals from Extra Dimensions  

NASA Astrophysics Data System (ADS)

In theories where space-time is a direct product of Minkowski space (M4) and a d-dimensional compact space (Kd), there can exist topological solitons that simultaneously wind around ?3 (or ?2 or ?1) in M4 and the compact dimensions. A paradigmatic non-gravitational example of such "co-winding" solitons is furnished by Yang-Mills theory defined on M4 × S1. Point-like, string-like and sheet-like solitons can be identified by transcribing and generalizing the procedure used to construct the periodic instanton (caloron) solutions. Asymptotically the classical point-like objects have non-Abelian magnetic dipole fields together with a non-Abelian scalar potential while the "color" electric charge is zero. However quantization of collective coordinates associated with zero modes and coupling to fermions can radically change these quantum numbers due to fermion number fractionalization and its non-Abelian generalization. Interpreting the YM group as color (or the electroweak SU(2) group) and assuming that an extra circular dimension exists thus implies the existence of topologically stable solitonic objects which carry baryon(lepton) number and a mass O(1/g2R), where R is the radius of the compact dimension.

Aulakh, C. S.

265

Liver transplantation for extra hepatic biliary atresia.  

PubMed

Kasai portoenterostomy has transformed the prognosis for children with Extra Hepatic Biliary Atresia (EHBA). However, for children developing end stage liver disease following portoenterostomy, liver transplantation (OLT) is the treatment of choice. Between February 1989 and March 1996, 64 children with EHBA underwent 79 transplants (26 males, 38 females; median age 2.2 years, range 5 months-17 years; median weight 11.4 kg, range 5-65 kg). Of these, 58 (85%) had undergone previous portoenterostomy. Nineteen patients (30%) had gastrointestinal bleeding prior to OLT assessment. Mean serum bilirubin was 229 mumol/liter (range 11-801 muml/liter). Four children had associated polysplenia syndrome. Of the 79 transplants, 30 received whole and 41 reduced-size cadaveric grafts and 9 living related grafts. Eleven patients (17%) died, nine within one month of surgery. Thirteen patients were retransplanted once and one twice. There were 16 vascular complications (10 hepatic artery thrombosis, 3 portal vein thrombosis, 3 venous outflow obstruction) and 10 biliary complications (4 anastomotic leaks, 6 strictures). Ten patients (16%) had bowel perforation following the transplant. The 5 year actuarial patient and graft survival for this group is 84% and 69% respectively with normal physical and mental development in the majority. OLT provides satisfactory treatment for children with EHBA with end stage liver disease with long term survival in the majority. PMID:9149346

Nagral, S; Muiesan, P; Vilca-Melendez, H; Mieli-Vergani, G; Baker, A; Karani, J; Howard, E; Rela, M; Heaton, N

1997-01-01

266

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

267

Extra Solar Planetary Imaging Coronagraph and Science Requirements for the James Webb Telescope Observatory  

NASA Technical Reports Server (NTRS)

1) Extra solar planetary imaging coronagraph. Direct detection and characterization of Jovian planets, and other gas giants, in orbit around nearby stars is a necessary precursor to Terrestrial Planet Finder 0 in order to estimate the probability of Terrestrial planets in our stellar neighborhood. Ground based indirect methods are biased towards large close in Jovian planets in solar systems unlikely io harbor Earthlike planets. Thus to estimate the relative abundances of terrestrial planets and to determine optimal observing strategies for TPF a pathfinder mission would be desired. The Extra-Solar Planetary Imaging Coronagraph (EPIC) is such a pathfinder mission. Upto 83 stellar systems are accessible with a 1.5 meter unobscured telescope and coronagraph combination located at the Earth-Sun L2 point. Incorporating radiometric and angular resolution considerations show that Jovians could be directly detected (5 sigma) in the 0.5 - 1.0 micron band outside of an inner working distance of 5/D with integration times of -10 - 100 hours per observation. The primary considerations for a planet imager are optical wavefront quality due to manufacturing, alignment, structural and thermal considerations. pointing stability and control, and manufacturability of coronagraphic masks and stops to increase the planetary-to- stellar contrast and mitigate against straylight. Previously proposed coronagraphic concepts are driven to extreme tolerances. however. we have developed and studied a mission, telescope and coronagraphic detection concept, which is achievable in the time frame of a Discovery class NASA mission. 2) Science requirements for the James Webb Space Telescope observatory. The James Webb Space Observatory (JWST) is an infrared observatory, which will be launched in 201 1 to an orbit at L2. JWST is a segmented, 18 mirror segment telescope with a diameter of 6.5 meters, and a clear aperture of 25 mA2. The telescope is designed to conduct imaging and spectroscopic observations from 0.6-27 microns. The primary mirror find and understand predicted first light objects, observe galaxies back to their earliest precursors so that we can understand their growth and evolution, unravel the birth and early evolution of stars and planetary systems, and study planetary systems and the origins of life. In this paper we discuss the science goals for JWST in the context of the performance requirements they levy on the observatory.

Clampin, Mark

2004-01-01

268

Making Terrestrial Planets in the ? Centauri System  

NASA Astrophysics Data System (ADS)

Planetary formation in close binary systems is still an open problem. While accretion disks have already been observed around each individual component (Rodriguez et al., 1998), it is still uncertain that the process of planetesimal accretion can continue till the completion of a planet. The gravitational perturbations from the companion star can inhibit the planet formation process even in the last stage when planetary embryos collide together to form a planet. It is also of interest to determine the eventual dynamical properties of the planets that possibly form in these systems. Starting from the work of Marzari and Scholl (2000) we simulate the late stages of terrestrial-planet formation within 2 AU of the primary star in the ? Centauri system. This system has been longly suspected to harbour a planetary system and it is also a typical close binary system (the possible third component is far away, at more than 104 AU). Using N-body integrations based on the Mercury package (Chambers, 1999) we simulate the evolution of a 3-dimensional disk populated with up to 216 initially isolated and nearly coplanar planetary embryos. The secondary star is set at 17.6 AU from primary on an eccentric orbit (e=0.52). Our simulations tipically produce two large planets similar to Earth and Venus within 1.5 AU from the star.

Barbieri, M.; Marzari, F.

269

The Laboratory for Terrestrial Physics  

NASA Technical Reports Server (NTRS)

The Laboratory for Terrestrial Physics is dedicated to the advancement of knowledge in Earth and planetary science, by conducting innovative research using space technology. The Laboratory's mission and activities support the work and new initiatives at NASA's Goddard Space Flight Center (GSFC). The Laboratory's success contributes to the Earth Science Directorate as a national resource for studies of Earth from Space. The Laboratory is part of the Earth Science Directorate based at the GSFC in Greenbelt, MD. The Directorate itself is comprised of the Global Change Data Center (GCDC), the Space Data and Computing Division (SDCD), and four science Laboratories, including Laboratory for Terrestrial Physics, Laboratory for Atmospheres, and Laboratory for Hydrospheric Processes all in Greenbelt, MD. The fourth research organization, Goddard Institute for Space Studies (GISS), is in New York, NY. Relevant to NASA's Strategic Plan, the Laboratory ensures that all work undertaken and completed is within the vision of GSFC. The philosophy of the Laboratory is to balance the completion of near term goals, while building on the Laboratory's achievements as a foundation for the scientific challenges in the future.

2003-01-01

270

Dietary characterization of terrestrial mammals.  

PubMed

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

2014-08-22

271

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

Microsoft Academic Search

The maximum height reached by a turbulent plume rising in a stratified environment is a key tool to estimate the flux released at its source, particularly for large-scale flows because flux can often be very hard to measure directly. This height is known to be mainly controlled by the stratification of the ambient fluid, source buoyancy flux, and the efficiency

G. Carazzo; E. Kaminski; S. Tait

2008-01-01

272

Terrestrial isopods -- a good choice for toxicity testing of pollutants in the terrestrial environment  

Microsoft Academic Search

Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the

Damjana Drobne

1997-01-01

273

Effects of reference objects and extra-retinal information about pursuit eye movements on curvilinear path perception from retinal flow.  

PubMed

We have previously shown that when traveling on a circular path, observers use the rotation in the retinal velocity field for path curvature estimation and recover their path of forward travel relative to their perceived instantaneous heading (L. Li, & J. C. K. Cheng, 2011). Here, we examined the contribution of reference objects and extra-retinal information about pursuit eye movements to curvilinear path perception. In Experiment 1, the display simulated an observer traveling on a circular path over a textured ground with and without tall posts while looking at a fixed target on the future path, along heading, or along a fixed axis in the world. We found that reference objects did not help path perception. In Experiment 2, extra-retinal signals about pursuit eye movements were introduced in two viewing conditions: one that corresponded to the natural case of traveling on a circular path when the body orientation is aligned with the instantaneous heading and one that corresponded to the unnatural case of traveling when the body orientation is fixed relative to the world. We found that extra-retinal signals support accurate path perception only for the natural case of self-motion when the body orientation is aligned with heading such that pursuit compensation helps stabilize the heading in the body-centric coordinate system. PMID:22410585

Cheng, Joseph C K; Li, Li

2012-01-01

274

Body Composition.  

ERIC Educational Resources Information Center

Body composition refers to the types and amounts of tissues which make up the body. The most acceptable method for assessing body composition is underwater weighing. A subcutaneous skinfold provides a quantitative measurement of fat below the skin. The skinfold technique permits a valid estimate of the body's total fat content. (JN)

Mayhew, Jerry L.

1981-01-01

275

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

276

Lorentz Violation in Warped Extra Dimensions  

SciTech Connect

Higher dimensional theories which address some of the problematic issues of the Standard Model(SM) naturally involve some form of D = 4 + n-dimensional Lorentz invariance violation (LIV). In such models the fundamental physics which leads to, e.g., field localization, orbifolding, the existence of brane terms and the compactification process all can introduce LIV in the higher dimensional theory while still preserving 4-d Lorentz invariance. In this paper, attempting to capture some of this physics, we extend our previous analysis of LIV in 5-d UED-type models to those with 5- d warped extra dimensions. To be specific, we employ the 5-d analog of the SM Extension of Kostelecky et al. which incorporates a complete set of operators arising from spontaneous LIV. We show that while the response of the bulk scalar, fermion and gauge fields to the addition of LIV operators in warped models is qualitatively similar to what happens in the flat 5-d UED case, the gravity sector of these models reacts very differently than in flat space. Specifically, we show that LIV in this warped case leads to a non-zero bulk mass for the 5-d graviton and so the would-be zero mode, which we identify as the usual 4-d graviton, must necessarily become massive. The origin of this mass term is the simultaneous existence of the constant non-zero AdS{sub 5} curvature and the loss of general co-ordinate invariance via LIV in the 5-d theory. Thus warped 5-d models with LIV in the gravity sector are not phenomenologically viable.

Rizzo, Thomas G.; /SLAC

2011-08-11

277

Terrestrial Planet Formation in Extrasolar Planetary Systems  

NASA Astrophysics Data System (ADS)

The 47 UMa and Epsilon Eridani extrasolar planetary systems are among those that resemble the most our own solar system, with moderately massive planets (2.4 Mjup and 0.86 minimum mass) on relatively distant orbits (at 2.09 and 3.3 A.U.). It is thus natural to ask whether these systems can harbour terrestrial planets in their inner regions. We numerically investigate how the accretion process of such inner planets might have been affected by the presence of the detected massive external bodies. The crucial point is the timing of the giant planets's formation. We have investigated 2 different scenarios: 1) the perturbing planet was fully formed in the early phases of planetesimal accretion in the inner disk and 2) the giant planet reaches its final mass only later on when lunar-sized embryos already formed in the inner disk. For case 1) we focus on one crucial parameter driving the accretion process: the distribution of encounter velocities in the early inner disk, which is estimated using a deterministic code that takes into account the gravitational pull of external perturbers and the possible effect of gas drag. For case 2) a classical symplectic algorithm is used taking into account the mutual pull of protoplanetary embryos. The Epsilon Eridani system turns out to be very hostile to planetary accretion in the inner disk in the scenario 1) where the planet affects the initial phases of planetesimal accretion. The planet's high eccentricity (0.608) induces too large encounter velocities everywhere in the disk. Accretion of already formed large embryos is nevertheless possible in the a<0.8AU region. Planetesimal accretion is also strongly affected by an early formed giant planet in the 47 UMa system, with only a small inner region (a<0.3AU) being protected from too high impact velocities. The presence of gas drag could open a small chance for accretion, in particular for relatively large initial planetesimals. Nevertheless, as for Eps. Eridani, a later growth of the giant planet cannot prevent the accretion of lunar-sized embryos in the a<0.8AU area. Additional simulations are also in progress in order to investigate the perturbing effect of the second planet that has been recently discovered around 47 UMa orbiting at 3.73 AU from the central star. References: Thebault, P., Marzari, F., Scholl, H., ``Terrestrial planet formation in exoplanetary systems with a giant planet on an external orbit", submitted to A&A.

Thebault, P.; Marzari, F.; Scholl, H.

2001-11-01

278

Extra-osseous tenosynovial chondromatosis of the middle finger: a case report.  

PubMed

Extra-osseous tenosynovial chondromatosis is rare and has a high rate of local recurrence. We report a 23-year-old man who presented with a 6-month history of pain and swelling of the right middle finger and painful limitation of the ring finger flexion secondary to this condition. Surgical exploration revealed multiple loose bodies of varying size arising from the flexor tendon sheath. Histopathological examination revealed mature chondroid tissue and focal calcification. After 2 years of follow-up, the patient had achieved an excellent functional recovery and showed no evidence of recurrence. PMID:23255658

Khadilakar, Madhav S; Patil, Atul A; Shah, Nakul S; Deshmukh, Sanjay D; Anand, Mani

2012-12-01

279

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

280

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

281

Maximal activities of enzymes of intermediary metabolism in the estivating terrestrial snail Cepaea nemoralis  

Microsoft Academic Search

The effects of estivation on maximal activities of key enzymes of aerobic, carbohydrate, lipid, ketone body and amino acid metabolism were studied in tissues of the terrestrial snail Cepaea nemoralis. With the exception of a 40% decrease in citrate synthase activity in hepatopancreas, enzyme activities were unaltered in all tissues following 6 weeks of estivation. Activities of enzymes of lipid,

J. A Stuart; E.-L Ooi; J. S Ballantyne

1998-01-01

282

Integrated estimates of global terrestrial carbon sequestration  

Microsoft Academic Search

Assessing the contribution of terrestrial carbon sequestration to climate change mitigation requires integration across scientific and disciplinary boundaries. A comprehensive analysis incorporating ecologic, geographic and economic data was used to develop terrestrial carbon sequestration estimates for agricultural soil carbon, reforestation and pasture management. These estimates were applied in the MiniCAM integrated assessment model to evaluate mitigation strategies within policy and

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

2008-01-01

283

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

284

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

285

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

Hackstein, J H; Stumm, C K

1994-01-01

286

Lunar and terrestrial crust formation  

NASA Astrophysics Data System (ADS)

Planetary crusts may be accreted, produced in primordial differentiation, or built up piecemeal by serial magmatism. The existence of old, polygenetic, laterally heterogeneous, partial melt rocks in the lunar highlands suggests that the moon produced its early crust by serial magmatism. This view can be reconciled with lunar Eu anomalies, previously thought to support the magma ocean model of crust formation, if complications in the fractionation of mare basalts are recognized. Phase equilibrium and magmatic density information for mare basalts suggest a model in which plagioclase fractionation can occur even though plagioclase is not a near-liquidus phase. The cryptic fractionation of clinopyroxene in MORB provides a precedent for this model. The necessity for a lunar magma ocean is questioned, but a role for a terrestrial magma ocean of sorts at depths is suggested.

Walker, D.

1983-11-01

287

Solar-Terrestrial Ontology Development  

NASA Astrophysics Data System (ADS)

The development of an interdisciplinary virtual observatory (the Virtual Solar-Terrestrial Observatory; VSTO) as a scalable environment for searching, integrating, and analyzing databases distributed over the Internet requires a higher level of semantic interoperability than here-to-fore required by most (if not all) distributed data systems or discipline specific virtual observatories. The formalization of semantics using ontologies and their encodings for the internet (e.g. OWL - the Web Ontology Language), as well as the use of accompanying tools, such as reasoning, inference and explanation, open up both a substantial leap in options for interoperability and in the need for formal development principles to guide ontology development and use within modern, multi-tiered network data environments. In this presentation, we outline the formal methodologies we utilize in the VSTO project, the currently developed use-cases, ontologies and their relation to existing ontologies (such as SWEET).

McGuinness, D.; Fox, P.; Middleton, D.; Garcia, J.; Cinquni, L.; West, P.; Darnell, J. A.; Benedict, J.

2005-12-01

288

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

289

Line following terrestrial insect biobots.  

PubMed

The present day technology falls short in offering centimeter scale mobile robots that can function effectively under unknown and dynamic environmental conditions. Insects, on the other hand, exhibit an unmatched ability to navigate through a wide variety of environments and overcome perturbations by successfully maintaining control and stability. In this study, we use neural stimulation systems to wirelessly navigate cockroaches to follow lines to enable terrestrial insect biobots. We also propose a system-on-chip based ZigBee enabled wireless neurostimulation backpack system with on-board tissue-electrode bioelectrical coupling verification. Such a capability ensures an electrochemically safe stimulation and avoids irreversible damage to the interface which is often misinterpreted as habituation of the insect to the applied stimulation. PMID:23366056

Latif, Tahmid; Bozkurt, Alper

2012-01-01

290

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

291

Four Lectures on TeV Scale Extra Dimensions  

NASA Astrophysics Data System (ADS)

Compact spatial dimension at the TeV scale remain an intriguing possibility that is currently being tested at the LHC. We give an introductory review of extra-dimensional models and ideas, from a phenomenological perspective, but emphasizing the appropriate theoretical tools. We emphasize the power and limitations of such constructions, and give a self-contained account of the methods necessary to understand the associated physics. We also review a number of examples that illustrate how extra-dimensional ideas can shed light on open questions in the Standard Model. An introduction to holography is provided. These are the notes of my TASI 2011 Lectures on Extra Dimensions.

Pontón, Eduardo

2013-12-01

292

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.

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

293

The influence of load carrying on the energetics and kinematics of terrestrial locomotion in a diving bird  

PubMed Central

Summary The application of artificial loads to mammals and birds has been used to provide insight into the mechanics and energetic cost of terrestrial locomotion. However, only two species of bird have previously been used in loading experiments, the cursorial guinea fowl (Numida meleagris) and the locomotor-generalist barnacle goose (Branta leucopsis). Here, using respirometry and treadmill locomotion, we investigate the energetic cost of carrying trunk loads in a diving bird, the tufted duck (Aythya fuligula). Attachment of back loads equivalent to 10% and 20% of body mass increased the metabolic rate during locomotion (7.94% and 15.92%, respectively) while sternal loads of 5% and 10% had a greater proportional effect than the back loads (metabolic rate increased by 7.19% and 13.99%, respectively). No effect on locomotor kinematics was detected during any load carrying experiments. These results concur with previous reports of load carrying economy in birds, in that there is a less than proportional relationship between increasing load and metabolic rate (found previously in guinea fowl), while application of sternal loads causes an approximate doubling of metabolic rate compared to back loads (reported in an earlier study of barnacle geese). The increase in cost when carrying sternal loads may result from having to move this extra mass dorso-ventrally during respiration. Disparity in load carrying economy between species may arise from anatomical and physiological adaptations to different forms of locomotion, such as the varying uncinate process morphology and hindlimb tendon development in goose, guinea fowl and duck.

Tickle, Peter G.; Lean, Samantha C.; Rose, Kayleigh A. R.; Wadugodapitiya, Avanti P.; Codd, Jonathan R.

2013-01-01

294

The influence of load carrying on the energetics and kinematics of terrestrial locomotion in a diving bird.  

PubMed

The application of artificial loads to mammals and birds has been used to provide insight into the mechanics and energetic cost of terrestrial locomotion. However, only two species of bird have previously been used in loading experiments, the cursorial guinea fowl (Numida meleagris) and the locomotor-generalist barnacle goose (Branta leucopsis). Here, using respirometry and treadmill locomotion, we investigate the energetic cost of carrying trunk loads in a diving bird, the tufted duck (Aythya fuligula). Attachment of back loads equivalent to 10% and 20% of body mass increased the metabolic rate during locomotion (7.94% and 15.92%, respectively) while sternal loads of 5% and 10% had a greater proportional effect than the back loads (metabolic rate increased by 7.19% and 13.99%, respectively). No effect on locomotor kinematics was detected during any load carrying experiments. These results concur with previous reports of load carrying economy in birds, in that there is a less than proportional relationship between increasing load and metabolic rate (found previously in guinea fowl), while application of sternal loads causes an approximate doubling of metabolic rate compared to back loads (reported in an earlier study of barnacle geese). The increase in cost when carrying sternal loads may result from having to move this extra mass dorso-ventrally during respiration. Disparity in load carrying economy between species may arise from anatomical and physiological adaptations to different forms of locomotion, such as the varying uncinate process morphology and hindlimb tendon development in goose, guinea fowl and duck. PMID:24244861

Tickle, Peter G; Lean, Samantha C; Rose, Kayleigh A R; Wadugodapitiya, Avanti P; Codd, Jonathan R

2013-01-01

295

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

296

Body Piercing  

PubMed Central

OBJECTIVE To review the current information on medical complications, psychological implications, and legislative issues related to body piercing, a largely unregulated industry in the United States. METHODS We conducted a MEDLINE search of English language articles from 1966 until May 1998 using the search terms “body piercing” and “ear piercing.” Bibliographies of these references were reviewed for additional citations. We also conducted an Internet search for “body piercing” on the World Wide Web. MAIN RESULTS: In this manuscript, we review the available body piercing literature. We conclude that body piercing is an increasingly common practice in the United States, that this practice carries substantial risk of morbidity, and that most body piercing in the United States is being performed by unlicensed, unregulated individuals. Primary care physicians are seeing growing numbers of patients with body pierces. Practitioners must be able to recognize, treat, and counsel patients on body piercing complications and be alert to associated psychological conditions in patients who undergo body piercing.

Koenig, Laura M; Carnes, Molly

1999-01-01

297

Pulmonary compliance and lung volume are related to terrestriality in anuran amphibians.  

PubMed

Abstract Dehydration tolerance of anuran amphibians is directly related to their ability to mobilize lymphatic reserves, with more terrestrial species having more effective lymph mobilization dependent on specialized skeletal muscles acting directly on the lymph sacs and via pulmonary ventilation. Consequently, we tested the hypothesis that pulmonary compliance, lung volume, and femoral lymphatic sac volume were related to terrestriality-and, hence, lymph mobilization-for 18 species of aquatic, semiaquatic, or terrestrial anuran amphibians. Lung compliance and volume were significantly related to body mass, but there was no significant phylogenetic pattern. There were significant habitat-related patterns for mass-corrected and phylogenetically corrected residuals for these pulmonary variables. Femoral lymph volume was significantly related to body mass, with no significant phylogenetic pattern, and there was only a weak correlation for habitat with mass-corrected and phylogenetically corrected residuals. These results suggest that pulmonary volume and compliance are strongly related to terrestriality in anuran amphibians and are under significant selection pressure to enhance lymph mobilization, but lymph sac volume does not appear to have a major role in adaptation to terrestriality. PMID:24769702

Withers, Philip C; Hedrick, Michael S; Drewes, Robert C; Hillman, Stanley S

2014-01-01

298

Cosmological constraints on theories with large extra dimensions  

SciTech Connect

In theories with large extra dimensions, constraints from cosmology lead to non-trivial lower bounds on the gravitational scale M, corresponding to upper bounds on the radii of the compact extra dimensions. These constraints are especially relevant to the case of two extra dimensions, since only if M is 10 TeV or less do deviations from the standard gravitational force law become evident at distances accessible to planned sub-mm gravity experiments. By examining the graviton decay contribution to the cosmic diffuse gamma radiation, we derive, for the case of two extra dimensions, a conservative bound M > 110TeV, corresponding to r{sub 2} < 5.1 x 10{sup -5} mm, well beyond the reach of these experiments. We also consider the constraint coming from graviton overclosure of the universe and derive an independent bound M > 6.5/{radical}h TeV, or r{sub 2} < .015hmm.

Hall, Lawrence J.; Smith, David

1999-04-23

299

Extra Dimensions and New Vector Bosons Searches in CMS  

SciTech Connect

This paper addresses a series of searches for signals from extra dimensions and new vector bosons in the CMS experiment. A brief review of the CMS discovery potential of these signatures in different luminosity scenarios is presented.

Emam, W. [LLR, CNRS/IN2P3, Ecole Polytechnique, Palaiseau (France)

2008-04-21

300

Extra focal convective suppressing solar collector. Final technical progress report.  

National Technical Information Service (NTIS)

This progress report describes work done on the Extra Focal Convective Suppressing Solar Collector. The topics of the report include sensor refinement for the tracking electronics, tracking controller refinement, system optics evaluation, absorber system ...

1996-01-01

301

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.

Hakim, Arsany; Rozeik, Christoph

2014-01-01

302

Physical Mechanisms of Extra Area Effects from Weather Modification.  

National Technical Information Service (NTIS)

The physical mechanisms which could have produced extra area effects downwind of the Climax I and II wintertime orographic cloud seeding experiments were investigated. The two most probable mechanisms identified, namely, artificial nuclei transport and ic...

G. J. Mulvey

1977-01-01

303

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

304

Trace Element and Isotope Geochemistry of Cretaceous-Tertiary Boundary Sediments: Identification of Extra-Terrestrial and Volcanic Components.  

National Technical Information Service (NTIS)

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...

S. V. Margolis E. F. Doehne

1988-01-01

305

Dark matter and collider phenomenology of universal extra dimensions  

Microsoft Academic Search

We review the phenomenology of models with flat, compactified extra dimensions where all of the Standard Model fields are allowed to propagate in the bulk, known as Universal Extra Dimensions (UED). UED make for an interesting TeV-scale physics scenario, featuring a tower of Kaluza–Klein (KK) states approximately degenerate in mass at the scale set by the inverse size of the

Dan Hooper; Stefano Profumo

2007-01-01

306

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

307

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.

Eliassen, Sigrunn; J?rgensen, Christian

2014-01-01

308

Body Measurement.  

ERIC Educational Resources Information Center

Described are activities for measuring the human body. The activities include measurements and calculations, calculating volume and density, problems related to body measurement, and using a nomogram. Several charts, illustrations, and a nomogram are provided. (YP)

Neufeld, K. Allen

1989-01-01

309

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

310

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

311

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

312

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

313

Terrestrial Planet Finder: science overview  

NASA Technical Reports Server (NTRS)

The Terrestrial Planet Finder (TPF) seeks to revolutionize our understanding of humanity's place in the universe - by searching for Earth-like planets using reflected light, or thermal emission in the mid-infrared. Direct detection implies that TPF must separate planet light from glare of the nearby star, a technical challenge which has only in recent years been recognized as surmountable. TPF will obtain a low-resolution spectra of each planets it detects, providing some of its basic physical characteristics and its main atmospheric constituents, thereby allowing us to assess the likelihood that habitable conditions exist there. NASA has decided the scientific importance of this research is so high that TPF will be pursued as two complementary space observatories: a visible-light coronagraph and a mid-infrared formation flying interferometer. The combination of spectra from both wavebands is much more valuable than either taken separately, and it will allow a much fuller understanding of the wide diversity of planetary atmospheres that may be expected to exist. Measurements across a broad wavelength range will yield not only physical properties such as size and albedo, but will also serve as the foundations of a reliable and robust assessment of habitability and the presence of life.

Unwin, Stephen C.; Beichman, C. A.

2004-01-01

314

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

315

Steroidal saponins from Tribulus terrestris.  

PubMed

Five new steroidal saponins were isolated from the fruits of Tribulus terrestris. Their structures were fully established by spectroscopic and chemical analysis as (23S,25S)-5alpha-spirostane-24-one-3beta,23-diol-3-O-{alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-glucopyranosyl-(1-->4)]-beta-d-galactopyranoside} (1), (24S,25S)-5alpha-spirostane-3beta,24-diol-3-O-{alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-glucopyranosyl-(1-->4)]-beta-d-galactopyranoside} (2), 26-O-beta-d-glucopyranosyl-(25R)-5alpha-furostan-2alpha,3beta,22alpha,26-tetraol-3-O-{beta-d-glucopyranosyl-(1-->2)-O-beta-d-glucopyranosyl-(1-->4)-beta-d-galactopyranoside} (3), 26-O-beta-d-glucopyranosyl-(25R)-5alpha-furostan-20(22)-en-2alpha,3beta,26-triol-3-O-{beta-d-glucopyranosyl-(1-->2)-O-beta-d-glucopyranosyl-(1-->4)-beta-d-galactopyranoside} (4), and 26-O-beta-d-glucopyranosyl-(25S)-5alpha-furostan-12-one-22-methoxy-3beta,26-diol-3-O-{alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-glucopyranosyl-(1-->4)]-beta-d-galactopyranoside} (5). The isolated compounds were evaluated for cytostatic activity against HL-60 cells. PMID:19152803

Su, Lan; Chen, Gang; Feng, Sheng-Guang; Wang, Wei; Li, Zhi-Feng; Chen, Huan; Liu, Ying-Xue; Pei, Yue-Hu

2009-01-01

316

Isotopic identification of nitrogen hotspots across natural terrestrial ecosystems  

NASA Astrophysics Data System (ADS)

Nitrogen (N) influences local biological processes, ecosystem productivity, the composition of the atmospheric-climate system, and the human endeavour as a whole. Here we use natural variations in N isotopes, coupled with two models, to trace global pathways of N loss from the land to the water and atmosphere. We show that denitrification accounts for approximately 35 % of total N losses from the natural soil, with NO, N2O, and N2 fluxes equal to 15.7 ± 4.7 Tg N yr-1, 10.2 ± 3.0 Tg N yr-1, and 21.0 ± 6.1 Tg N yr-1, respectively. Our analysis points to tropical regions as the major "hotspot" of nitrogen export from the terrestrial biosphere, accounting for 71 % of global N losses from the natural land surface. The poorly studied Congo Basin is further identified as one of the major natural sources of atmospheric N2O. Extra-tropical areas, by contrast, lose a greater fraction of N via leaching pathways (~77 % of total N losses) than do tropical biomes, likely contributing to N limitations of CO2 uptake at higher latitudes. Our results provide an independent constraint on global models of the N cycle among different regions of the unfertilized biosphere.

Bai, E.; Houlton, B. Z.; Wang, Y. P.

2012-08-01

317

Transfer of terrestrial technology for lunar mining  

NASA Technical Reports Server (NTRS)

The functions, operational procedures, and major items of equipment that comprise the terrestrial mining process are characterized. These data are used to synthesize a similar activity on the lunar surface. Functions, operations, and types of equipment that can be suitably transferred to lunar operation are identified. Shortfalls, enhancements, and technology development needs are described. The lunar mining process and what is required to adapt terrestrial equipment are highlighted. It is concluded that translation of terrestrial mining equipment and operational processes to perform similar functions on the lunar surface is practical. Adequate attention must be given to the harsh environment and logistical constraints of the lunar setting. By using earth-based equipment as a forcing function, near- and long-term benefits are derived (i.e., improved terrestrial mining in the near term vis-a-vis commercial production of helium-3 in the long term.

Hall, Robert A.; Green, Patricia A.

1992-01-01

318

New Pest Response Guidelines: Temperate Terrestrial Gastropods.  

National Technical Information Service (NTIS)

Use New Pest Response Guidelines: Temperate Terrestrial Gastropods as a guide when designing a program to detect, monitor, control, contain, or eradicate an infestation of temperate climate pest snails and slugs in the United States and collaborating terr...

2008-01-01

319

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

320

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

321

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...

322

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

323

DEVELOPMENT OF SCALING CRITERIA FOR TERRESTRIAL MICROCOSMS  

EPA Science Inventory

Theoretical developments based on heat and moisture transfer in soil lead to dimensionless numbers that describe important processes taking place in a terrestrial microcosm. These numbers provide preliminary scientific criteria for scaling the results from microcosms both as a me...

324

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

325

Update on terrestrial ages of Antarctic meteorites  

SciTech Connect

Terrestrial ages of Antarctic meteorites are one of the few parameters that will help us to understand the meteorite concentration mechanism on blue-ice fields. Traditionally, terrestrial ages were determined on the basis of {sup 36}Cl in the metal phase, which has an uncertainty of about 70 ky. For young meteorites (< 40 ky), the terrestrial age is usually and most accurately determined using {sup 14}C in the stone phase. In recent years two methods have been developed which are independent of shielding effects, the {sup 10}Be-{sup 36}Cl/{sup 10}Be method and the {sup 41}Ca/{sup 36}Cl method. These methods have reduced the typical uncertainties in terrestrial ages by a factor of 2, to about 30 ky. The {sup 10}Be-{sup 36}Cl/{sup 10}Be method is quite dependent on the exposure age, which is unknown for most Antarctic meteorites. The authors therefore also attempt to use the relation between {sup 26}Al and {sup 36}Cl/{sup 26}Al to derive a terrestrial age less dependent on the exposure age. The authors have measured the concentrations of cosmogenic {sup 10}Be, {sup 26}Al and {sup 36}Cl in the metal phase of {approximately} 70 Antarctic meteorites, from more than 10 different ice-fields, including many new ones. They then discuss the trends in terrestrial ages of meteorites from different ice-fields.

Welten, K C; Nishiizumi, K; Caffee, M W

2000-01-14

326

[Arthroscopic extra-articular Bankart procedure].  

PubMed

The arthroscopic extraarticular Bankart procedure tries to imitate the open Bankart procedure. An anterior-inferior transmuscular approach through the subscapular muscle permits to implant self-locking tacks into the anterior inferior third of the glenoid rim. The extraarticular location of the implants makes a superomedial capsular shift possible, if required. A total of 257 arthroscopic repairs following traumatic recurrent anterior shoulder dislocation have been carried out between 1992 and 1996. 177 patients were treated only with bioabsorbable Suretac device. Clinical and radiological follow up was possible in 165 patients. According to the Rowe score 69.7% were classified as excellent, 10.9% as good, 9.7% fair and 9.7% poor. Postoperative complications: the recurrence rate was 9.7%, allergic reactions representing a foreign body reaction to the synthetic material were seen in 5 cases (3%) and a frozen shoulder in 6 cases 3.6%). 61% of the patients involved in overhead or contact sports returned to their preoperative sport activities. PMID:9779429

Golser, K; Wambacher, M; Hausberger, K; Krallinger, F; Wischatta, R; Kinigadner, M; Sperner, G

1998-08-01

327

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.

Lourenço, Diogo; Tackley, Paul

2013-04-01

328

Characterization of monoclonal antibody size variants containing extra light chains  

PubMed Central

Size exclusion chromatography (SEC) is the most commonly used method to separate and quantify monoclonal antibody (mAb) size variants. MAb-A is an IgG1 subtype humanized monoclonal antibody recombinantly produced in Chinese hamster ovary (CHO) cells. SEC analysis of MAb-A resolved a peak, named Peak 1, which elutes between monomer and dimer peaks. MAb-A lots produced from different clones and production scales all have 0.2–0.3% of SEC Peak 1. Electron spray ionization—time of flight mass spectrometry (ESI-TOF MS), microfluidics capillary electrophoresis and sodium dodecyl sulfate-PAGE (SDS PAGE) results demonstrated that SEC Peak 1 contains two structural variants: MAb-A with one extra light chain (2H3L) and MAb-A with two extra light chains (2H4L). The C-terminal Cys of the extra light chain in Peak 1 variants is either a free thiol, capped by glutathione, cysteine, or another light chain. Both electrophoresis and LC/MS analyses of non-reduced and reduced samples suggested that the extra light chains are linked to the MAb-A light chain through disulfide bonds. Isolated SEC Peak 1 fraction had a potency of 50% relative to MAb-A reference material. The 50% potency loss may result from the reduced accessibility to the antigen-binding site caused by the extra light chain(s)’ steric hindrance.

Lu, Connie; Liu, Dandan; Liu, Hongbin; Motchnik, Paul

2013-01-01

329

Extra-tropical cyclone and climate (Alfred Wegener Medal lecture)  

NASA Astrophysics Data System (ADS)

Extra-tropical cyclones play a key role in the climate system in effectively transporting heat, water vapour and momentum towards higher latitudes. The main energy source of extra-tropical cyclones is the available potential energy of the atmosphere first recognized by Max Margules in the beginning of the last century but clarified much later in a series of papers by Edward Lorenz. With the assumption that the initial state is well determined present weather prediction models are able to predict the development of extra-tropical systems several days in advance and this is one of the reasons to the large improvement in weather forecasting in recent years. Whilst our knowledge of extra-tropical cyclones has continued to improve several questions requires a better scientific understanding. One of these is the mutual interaction between transient cyclones and the large-scale quasi-stationary pattern of the atmospheric circulation such as blocking. Another important issue is the possible change in extra-tropical cyclones in a warmer climate. This might come about through changes in the storm tracks or in changes in extreme cyclones. In my presentation I will present some recent results based on the assessment of storm tracks and the evolution of cyclones in high-resolution global models in the present and future climate using a Lagrangean approach.

Bengtsson, L.

2009-04-01

330

Extra-abdominal periosteal desmoid tumor of the third toe.  

PubMed

Extra-abdominal periosteal desmoid tumors are uncommon nonmetastatic tumors of the extremities with a propensity for local recurrence. Lesions in the distal extremities are rare; a majority of extra-abdominal lesions occur in more proximal portions of the upper and lower extremities. This article reports a patient with an extra-abdominal periosteal desmoid tumor in the toe. A 37-year-old woman had a mass in her left third distal phalanx that was originally noted 3 years prior to presenting to the authors' institution. She reported the mass expanded during pregnancy. The toe was red and elongated and had expanded to approximately the same size as her great toe. The plantar aspect of the toe was thick and callused, and the toenail was slightly elevated. Marginal excision with retention of the nail was performed without complication. The mass was determined to be an extra-abdominal periosteal desmoid tumor and was successfully removed without recurrence. To date, the patient remains asymptomatic, with no pain and complete sensation in her third toe. Although extra-abdominal periosteal desmoid tumors have been identified in the extremities, to the authors' knowledge none have been reported as far distal as the toe. Identifying this lesion in the distal extremity will allow a hasty diagnosis and treatment in future cases of similar presentation. Knowledge of the existence of this type of tumor in the distal extremity may also assist in narrowing differential diagnoses. PMID:24025015

Saleem, Omar; Sayres, Stephanie; O'Malley, Martin

2013-09-01

331

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

332

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

333

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

334

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 I.

2012-06-26

335

Dark energy from Casimir energy on noncommutative extra dimensions  

SciTech Connect

We study the possibility that dark energy is a manifestation of the Casimir energy on extra dimensions with the topology of S{sup 2}. We consider our universe to be M{sup 4}xS{sup 2} and modify the geometry by introducing noncommutativity on the extra dimensions only, i.e. replacing S{sup 2} with the fuzzy version S{sub F}{sup 2}. We find the energy density as a function of the size of the representation M+1 of the algebra of S{sub F}{sup 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.

Fabi, S.; Harms, B.; Karatheodoris, G. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, Alabama 35487-0324 (United States)

2006-10-15

336

AMS-02 and next-to-minimal universal extra dimensions  

NASA Astrophysics Data System (ADS)

The anomaly detected by AMS-02 and PAMELA in the cosmic-ray positron flux when interpreted as arising from dark matter annihilation suggests that dark matter may interact differently with hadrons and leptons so as to remain compatible with cosmic-ray antiproton data. Such a scenario is readily accommodated in models with extra spatial dimensions. We study indirect detection of Kaluza–Klein (KK) dark matter in universal extra dimensions with brane-localized terms and fermion bulk masses: next-to-minimal universal extra dimensions. So that an excess of antiprotons is not produced in explaining the positron anomaly, it is necessary that the KK bulk masses in the lepton and hadron sectors be distinct. Even so, we find that cosmic-ray data disfavor a heavy KK photon dark matter scenario. Also, we find these scenarios with flavor-universal bulk masses to be in conflict with dijet and dilepton searches at the LHC.

Gao, Yu; Kong, Kyoungchul; Marfatia, Danny

2014-05-01

337

Extra ocular sebaceous carcinoma of the thigh: A case report  

PubMed Central

Context: Sebaceous cell carcinoma is a malignant neoplasm, rarely recognized in extra ocular sites. His prognosis depends of the precocity of the diagnosis. This neoplasm is aggressive in 29%; lymph node and visceral metastasis aren’t rare. Case Report An 80-year-old male had an ulcerated and infected nodule located on the left thigh. The lesion appeared after five months ago. It suspected a squamous cell carcinoma. The histologic findings revealed an extra ocular sebaceous carcinoma. The patient died one month later due to heart insufficiency. Conclusion: extra ocular sebaceous carcinoma is a rare neoplasm. It has more difficulties of diagnosis because it has diverse clinical presentations as well as a variety of histologic patterns. We will discuss the incidence, clinical, histological and the prognosis of this aggressive neoplasm.

Hammedi, Faten; Trabelsi, Amel; Belajouza, Colanda; Beizig, Nadia; Gannouchi, Nadia; Sriha, Badreddine; Mokni, Moncef

2010-01-01

338

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.

James, Samuel W.; Porco, David; Decaens, Thibaud; Richard, Benoit; Rougerie, Rodolphe; Erseus, Christer

2010-01-01

339

Extra Forces Evoked during Electrical Stimulation of the Muscle or Its Nerve Are Generated and Modulated by a Length-Dependent Intrinsic Property of Muscle in Humans and Cats  

PubMed Central

Extra forces or torques are defined as forces or torques that are larger than would be expected from the input or stimuli, which can be mediated by properties intrinsic to motoneurons and/or to the muscle. The purpose of this study was to determine whether extra forces/torques evoked during electrical stimulation of the muscle or its nerve with variable frequency stimulation are modulated by muscle length/joint angle. A secondary aim was to determine whether extra forces/torques are generated by an intrinsic neuronal or muscle property. Experiments were conducted in 14 able-bodied human subjects and in eight adult decerebrate cats. Torque and force were measured in human and cat experiments, respectively. Extra forces/torques were evoked by stimulating muscles with surface electrodes (human experiments) or by stimulating the nerve with cuff electrodes (cat experiments). In humans and cats, extra forces/torques were larger at short muscle lengths, indicating that a similar regulatory mechanism is involved. In decerebrate cats, extra forces and length-dependent modulation were unaffected by intrathecal methoxamine injections, despite evidence of increased spinal excitability, and by transecting the sciatic nerve proximal to the nerve stimulations. Anesthetic nerve block experiments in two human subjects also failed to abolish extra torques and the length-dependent modulation. Therefore, these data indicate that extra forces/torques evoked during electrical stimulation of the muscle or nerve are muscle length-dependent and primarily mediated by an intrinsic muscle property.

Frigon, Alain; Thompson, Christopher K.; Johnson, Michael D.; Manuel, Marin; Hornby, T. George; Heckman, C. J.

2014-01-01

340

Constraining extra fermion(s) from the Higgs boson data  

NASA Astrophysics Data System (ADS)

First, we study the fit of the Higgs boson rates, based on all the latest collider data, in the effective framework for any extra fermion(s) (EF). The best-fit results are presented in a generic formalism allowing us to apply those for the test of any EF scenario under the assumption that the corrections to the Higgs couplings are coming exclusively from EF effects. The variations of the fit with each one of the five fundamental parameters are described, and the obtained fits can be better than in the Standard Model (SM). We show how the determination of the EF loop contributions to the Higgs couplings with photons and gluons is relying on the knowledge of the top and bottom Yukawa couplings (affected by EF mixings); for determining the latter coupling, the relevance of the investigation of the Higgs production in association with bottom quarks is emphasized. In the instructive approximation of a single EF, we find that the constraints from the fit already turn out to be quite predictive in both cases of an EF mixed or not with SM fermions, and especially when combined with the extra-quark (-lepton) mass bounds from direct EF searches at the LHC (LEP) collider. In the case of an unmixed extra quark (in the same color representation as SM quarks), nontrivial fit constraints are pointed out on the Yukawa couplings for masses up to ˜200TeV. In particular, we define the extra dysfermiophilia, which is predicted at 68.27% C.L. for any single extra quark (independently of its electric charge). Another result is that, among any components of SM multiplet extensions, the extra quark with a -7/3 electric charge is the one preferred by the present Higgs fit.

Moreau, G.

2013-01-01

341

Reproductive synchrony and extra-pair mating strategy in a socially monogamous bird, Dendroica petechia  

Microsoft Academic Search

Depending on the circumstances under which extra-pair mating occurs, theory makes opposing predictions about how reproductive synchrony should influence extra-pair paternity. This study investigated which sex initiated extra-pair mating in the yellow warbler, whether extra-pair behaviour and extra-pair paternity were related to reproductive synchrony, and whether synchrony affected the mating success of all males equally. Observations and captures of individuals

STEPHEN M. YEZERINAC; PATRICK J. WEATHERHEAD

1997-01-01

342

Core formation in deforming terrestrial planets and planetesimals  

NASA Astrophysics Data System (ADS)

Our understanding of the processes by which metallic cores formed in the terrestrial planets is constrained by knowledge of the mechanisms of metal-silicate segregation. It is widely held that significant melting of the silicate portion of the early Earth, i.e. the formation of a silicate magma ocean, is required for differentiation of a metallic core to have occurred. This view is partly based on the results of a wealth of experiments conducted to determine the permeability of Fe-rich liquids in solid silicate matrices. These experiments, typically conducted in static systems over a range of conditions, generally preclude that metallic cores could have segregated efficiently from a crystalline silicate mantle by grain boundary percolation alone. By contrast, only a handful of experiments have been conducted in ‘dynamic systems' to investigate whether plastic deformation can aid segregation of metallic melts from solid silicate matrices. This is in spite of the seeming importance that deformation might have in young, hot terrestrial bodies undergoing rapid accretion. To date, such studies have been performed at relatively low pressures, largely due to constraints in conducting deformation experiments at higher pressures. Here we present the results of experiments performed to determine whether deformation could have provided a mechanism for segregating Fe-rich melts during formation of the terrestrial planets. Experiments in the system olivine-Fe3S have been conducted using the recently developed rotational Paris-Edinburgh Cell (roPEC) in a series of in-situ experiments conducted at the ID27 High-Pressure beamline at the European Synchrotron Radiation Source (ESRF), Grenoble, France. The roPEC uses rotation of opposed carbide anvils to impart controlled, variable torque on samples held at simultaneously high pressures and temperatures (currently up to 6 GPa, 2000 K). Design of the apparatus allows samples to be imaged in-situ, with sample volumes of sufficient size to permit additional detailed and statistically meaningful textural analysis of recovered samples using high resolution X-ray tomography and electron microscopy. Results from experiments performed at 2.5 GPa demonstrate that plastic deformation provides a highly effective mechanism for segregating Fe-melts over a wide range of temperatures, through the development of melt channels. This has previously been observed in deformation studies performed at lower pressures. However, as well as demonstrating that this mechanism operates at the higher pressure conditions of planetary differentiation, we also demonstrate that this mechanism also operates at much lower temperatures than previously suggested. Plastic deformation can, in fact, aid segregation of Fe-rich melts at temperatures below the Fe-S liquidus. This may be relevant to core-segregation on bodies much smaller than the Earth, for which the presence of a silicate magma ocean has been hypothesised but is less well supported. Plastic deformation during the early stages of planetary accretion may have led to the formation of Fe-rich (S-poor) cores before heating (due to ongoing accretion and breakdown of short-lived isotopes) had risen the temperature of early terrestrial bodies above the Fe-S solidus. This may be of relevance to core-formation in the early Earth, as it greatly increases the likelihood that larger bodies accreting to the Earth were already differentiated, and suggests that core composition may have been variable and dependent on size of the body.

Bromiley, Geoffrey D.; Redfern, Simon A. T.; Berg, Madeleine; Le Godec, Yann; Chien, Su Ying

2010-05-01

343

Core Shadow Zones of Terrestrial Planets and Icy Moons  

NASA Astrophysics Data System (ADS)

The internal dynamics of a planetary core is strongly dependent on its total radius. The volume/surface ratio of a planetary core is linked directly to the outgoing heat flux, which is also an indicator for the element partition between the surrounding mantle and the core. The determination of the core radius is thus an elementary step to better understand the origin and evolution of a planetary body. An observable that has been shown to serve as indicator for core size is the extent of the seismological (P-wave-) core shadow. It appears that the variation of seismic velocities with depth is dominated by quadratic terms, if not an essentially depth independent velocity can be assumed. The observed and predicted core shadow extents of many terrestrial planet models, computed as function of the relative core radius, thus align closely to the analytically derived function for objects with constant velocity profiles. The heavier solar system terrestrial planets, especially Venus and Earth, show the largest deviation from the relation between core radius and shadow width that holds for small bodies. For terrestrial planets more massive than Earth, as found for several exoplanets, the increasing internal pressure would cause increased curvature of tentative seismic rays and thus a more pronounced excursion from the relation for bodies with depth-independent elastic parameters. For Titan, a geophysical network has been suggested as a follow up to the highly successful Cassini-Huygens mission that is currently orbiting Saturn. Titan belongs to the class of weakly differentiated icy moons, which consist of an icy crust, underlain by a deep internal ocean and a central ice-rock body. Unlike any other moon in the solar system, Titan has a thick atmosphere that gives rise to surface processes resembling those on Earth. The goal of the proposed network is an improved understanding of the interactions between atmosphere, surficial ice and a putative subsurface water ocean. Key parameters for these processes are the thickness of the ice shell and the depth of the subsurface ocean. Due to the proximity of its massive parent body, Saturn, Titan is subject to significant tidal stresses that most likely cause tidally driven seismicity. Moreover, cryovolcanic activity may also be accompanied by seismic stress release. Technically, a subsurface water ocean has the same shadowing effect for elastic waves as a liquid iron core. It is thus possible to infer the ice shell thickness from the extent of this shadow zone. Also, the shadowing effect should be considered as a limiting factor for the planning of seismic network geometry. With a radius of 2575 km and the observed incomplete differentiation, the interior of Titan is likely not dominated by pressure effects and can be modeled adequately using layers of constant seismic properties. Thus the relation between outer ice shell thickness and the extent of the resulting P wave shadow fits nicely into the pattern that emerged for the terrestrial planet models.

Sohl, F.; Knapmeyer, M.; Gassner, L.; Lange, C.; Wagner, F. W.

2011-12-01

344

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

345

Influence of Tribulus terrestris on testicular enzyme in fresh water ornamental fish Poecilia latipinna.  

PubMed

The influence of Tribulus terrestris on the activities of testicular enzyme in Poecilia latipinna was assessed in lieu of reproductive manipulation. Different concentrations of (100, 150, 200, 250, and 300 mg) Tribulus terrestris extract and of a control were tested for testicular activity of enzymes in Poecilia latipinna for 2 months. The testis and liver were homogenized separately in 0.1 mol/l potassium phosphate buffer (0.1 mol/l, pH 7.2). The crude homogenate was centrifuged, and supernatant obtained was used as an enzyme extract for determination of activities. The activities of testicular functional enzyme ALP, ACP, SDH, LDH, and G6PDH levels were changed to different extent in treated groups compared with that of the control. The total body weight and testis weight were increased with the Tribulus terrestris-treated fish (Poecilia latipinna). These results suggest that Tribulus terrestris induced the testicular enzyme activity that may aid in the male reproductive functions. It is discernible from the present study that Tribulus terrestris has the inducing effect on reproductive system of Poecilia latipinna. PMID:21424528

Kavitha, P; Subramanian, P

2011-12-01

346

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

347

Estimating the masses of extra-solar planets  

NASA Astrophysics Data System (ADS)

All extra-solar planet masses that have been derived spectroscopically are lower limits since the inclination of the orbit to our line-of-sight is unknown except for transiting systems. In theory, however, it is possible to determine the inclination angle, i, between the rotation axis of a star and an observer's line-of-sight from measurements of the projected equatorial velocity (vsini), the stellar rotation period (Prot) and the stellar radius (R*). For stars which host planetary systems this allows the removal of the sini dependency of extra-solar planet masses derived from spectroscopic observations under the assumption that the planetary orbits lie perpendicular to the stellar rotation axis. We have carried out an extensive literature search and present a catalogue of vsini,Prot and R* estimates for stars hosting extra-solar planets. In addition, we have used Hipparcos parallaxes and the Barnes-Evans relationship to further supplement the R* estimates obtained from the literature. Using this catalogue, we have obtained sini estimates using a Markov-chain Monte Carlo analysis. This technique allows proper 1? two-tailed confidence limits to be placed on the derived sini's along with the transit probability for each planet to be determined. While we find that a small proportion of systems yield sini's significantly greater than 1, most likely due to poor Prot estimations, the large majority are acceptable. We are further encouraged by the cases where we have data on transiting systems, as the technique indicates inclinations of ~90° and high transit probabilities. In total, we are able to estimate the true masses of 133 extra-solar planets. Of these 133 extra-solar planets, only six have revised masses that place them above the 13MJ deuterium burning limit; four of those six extra-solar planet candidates were already suspected to lie above the deuterium burning limit before correcting their masses for the sini dependency. Our work reveals a population of high-mass extra-solar planets with low eccentricities, and we speculate that these extra-solar planets may represent the signature of different planetary formation mechanisms at work. Finally, we discuss future observations that should improve the robustness of this technique.

Watson, C. A.; Littlefair, S. P.; Collier Cameron, A.; Dhillon, V. S.; Simpson, E. K.

2010-11-01

348

Bulk scalar field in warped extra dimensional models  

NASA Astrophysics Data System (ADS)

This work presents a general formalism to analyze a generic bulk scalar field in a multiple warped extra-dimensional model with arbitrary number of extra dimensions. The Kaluza-Klein mass modes along with the self-interaction couplings are determined and the possibility of having lowest lying KK mode masses near TeV scale are discussed. Also some numerical values for low-lying KK modes has been presented showing explicit localization around TeV scale. It is argued that the appearance of large number of closely spaced KK modes with enhanced coupling may prompt possible new signatures in collider physics.

Chakraborty, Sumanta; SenGupta, Soumitra

2014-06-01

349

Hip arthroscopy for extra-articular hip disease.  

PubMed

The increasing popularity and success of hip arthroscopy has led to the development of related techniques for treating hip pathologies external to the joint proper. These minimally invasive endoscopic procedures serve in a diagnostic role to complement clinical evaluations and offer a therapeutic alternative to traditional open techniques. The indications for extra-articular hip endoscopy continue to expand. Recent literature describes applications for treating greater trochanteric pain syndrome, internal snapping hip, deep gluteal syndrome, and subspine impingement and for diagnosing and treating extra-articular sources of hip pain in patients who have undergone hip arthroplasty. PMID:23881610

Reich, Michael S; Shannon, Claire; Tsai, Eugene; Salata, Michael J

2013-09-01

350

Gravitational waves from mesoscopic dynamics of the extra dimensions  

PubMed

Recent models which describe our world as a brane embedded in a higher dimensional space introduce new geometrical degrees of freedom, associated with spatial variations in the position of the brane and the size of the extra dimensions, that can be coherently excited by symmetry breaking in the early universe even on "mesoscopic" scales as large as 1 mm. The characteristic frequency and intensity of resulting gravitational radiation backgrounds are estimated. Extra dimensions with scale between 10(-14) and 1 mm can produce detectable backgrounds at frequencies f approximately 10(3) to 10(-4) Hz. PMID:10970459

Hogan

2000-09-01

351

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

352

Extra-Solar Planetary Imager (ESPI) for Space Based Jovian Planetary Detection  

NASA Technical Reports Server (NTRS)

We report on out Extra-Solar Planetary Imager (ESPI) study for a recent Midex (NASA Medium Class Explorer Mission) proposal. Proposed for ESPI was a 1.5 x 1.5 square meter Jacquinot apodized square aperture telescope. The combination of apodization and a square aperture telescope significantly reduces the diffracted light from a bright central source over much of the telescope focal plane. As a result, observations of very faint astronomical objects next to bright sources with angular separations as small as 0.32 arcseconds become possible. This permits a sensitive search for exo-planets in reflected light. The system is capable of detecting a Jupiter-like planet in a relatively long-period orbit around as many as 160 to 175 stars with a signal-to-noise ratio greater than 5 in observations lasting maximally 100 hours per star. We discuss the effects of wavefront error, mirror speckle, pointing error and signal-to-noise issues, as well as the scalability of our ESPI study with respect to NASA's Terrestrial Planet Finder mission.

Lyon, Rick G.; Melnick, Gary J.; Nisenson, Peter; Papaliolios, Costa; Ridgeway, Steve; Friedman, Edward; Gezari, Dan Y.; Harwit, Martin; Graf, Paul

2002-01-01

353

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.

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

2012-01-01

354

Supporting tools of solar-terrestrial science  

NASA Technical Reports Server (NTRS)

Solar-terrestrial science is pursued by individuals and teams of workers situated in academia, research institutes, industry, and government laboratories. Progress in the field is made in various ways, but publication of results in scientific journals is the principal means of assuring that the knowledge gained from research is available to the public, now and in the future. In general, much of the research in the field is made via careful evaluation of data viewed in the context of fundamental physical principles as set forth in theoretical and analytical models, and computer simulations of physical processes. In addition, there is accumulation of knowledge expressed in the development of empirical or phenomenological models. Experience gained over the past three decades of solar-terrestrial research indicated that advances in the field require a diversity of resources and that the health of the entire discipline depends upon a balance among these. To maintain the health of the discipline, NASA and other federal funding agencies concerned with solar-terrestrial research must work together to insure that the following resources are available in reasonable measure to support solar-terrestrial research endeavors: ground-based facilities; balloons and rockets; spaceborne experiments; information networks; computational resources; models of solar terrestrial processes; data bases and archives; and research students.

1989-01-01

355

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

356

Orbital Evolution of ExtraSolar Giant Planets  

Microsoft Academic Search

The recent discoveries (Mayor and Queloz, 1995; Marcy and Butler, 1996; Butler and Marcy, 1996) of extra-solar giant planets (EGPs) at small heliocentric distances have prompted questions about the formation, evolution, and migration of these EGPs. The location of several EGPs at much less than 1 AU from their primaries has proved to be particularly problematic. Since it is thought

D. E. Trilling; W. Benz; T. Guillot; J. I. Lunine

1996-01-01

357

Chemical changes in extra virgin argan oil after thermal treatment.  

PubMed

Physicochemical parameters, measured every 6 hours, of extra virgin argan oil heated for 24 h at 180 degrees C were investigated and compared with those of five other edible oils treated in the same thermoxidative condition. Argan oil was found to be particularly stable at high temperature, its level of polar compounds remaining low even after 24 h of heating. PMID:23472453

Gharby, Saïd; Harhar, Hicham; Kartah, Badr Eddine; Guillaume, Dom; Charrouf, Zoubida

2013-01-01

358

ISLES: Probing Extra Dimensions Using a Superconducting Accelerometer.  

National Technical Information Service (NTIS)

In string theories, extra dimensions must be compactified. The possibility that gravity can have large radii of compactification leads to a violation of the inverse square law at submillimeter distances. The objective of ISLES is to perform a null test of...

H. J. Paik M. V. Moody V. A. Prieto-Gortcheva

2003-01-01

359

Supersymmetric large extra dimensions and the cosmological constant problem  

NASA Astrophysics Data System (ADS)

This article briefly summarizes and reviews the motivations for - and the present status of - the proposal that the small size of the observed Dark Energy density can be understood in terms of the dynamical relaxation of two large extra dimensions within a supersymmetric higher dimensional theory.

Burgess, C. P.

2006-06-01

360

Searches for large extra dimensions and technicolor at the Tevatron  

SciTech Connect

The authors presents the status of searches for large extra spacetime dimensions and technicolor at the Fermilab Tevatron. The author emphasizes recent D0 limits on graviton-mediated exchange processes, and CDF searches for new b{anti b} resonances and third-generation leptoquarks.

David Gerdes

2000-08-01

361

Baryogenesis in theories with large extra spatial dimensions  

Microsoft Academic Search

We describe a simple and predictive scenario for baryogenesis in theories with large extra dimensions which resembles Affleck–Dine baryogenesis. The Affleck–Dine field is a complex scalar field carrying a U(1)? charge which is dynamically broken after the end of inflation. This generates an excess of ? over ??, which then decays into Standard Model fermions to produce an excess of

Rouzbeh Allahverdi; Kari Enqvist; Anupam Mazumdar; Abdel Pérez-Lorenzana

2001-01-01

362

Baryon number violation, baryogenesis, and defects with extra dimensions  

Microsoft Academic Search

In generic models for grand unified theories (GUT), various types of baryon-number-violating processes are expected when quarks and leptons propagate in the background of GUT strings. On the other hand, in models with large extra dimensions, the baryon number violation in the background of a string is not trivial because it must depend on the mechanism of the proton stabilization.

Tomohiro Matsuda

2002-01-01

363

Lesson of the Heart: An Extra-Credit Assignment  

ERIC Educational Resources Information Center

Teacher candidates need to have a passion for teaching and a drive to do whatever is necessary even when it is uncomfortable, uncommon, or hard. Such efforts should not be considered extra, but essential. A purposeful, focused enthusiasm for one's students, a belief in their potential, along with heartfelt compassion and the perseverance to work…

Lehman, Linda L.

2012-01-01

364

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.

365

Sellar and parasellar extra-axial cavernous hemangiomas  

Microsoft Academic Search

Summary Cavernous hemangiomas can grow extra-axially within dural sinuses, particularly the cavernous sinus and present like tumours. Five cases of cavernous hemangiomas arising within or from the wall of the cavernous sinus are reported. Three of them had an “endophytic” growth within the cavernous sinus with a lateral extension into the middle cranial fossa, a medial extension into the sella

D. Lombardi; M. Giovanelli; N. de Tribolet

1994-01-01

366

Extra-articular Mimickers of Lateral Meniscal Tears  

PubMed Central

Context: Lateral meniscus tears are a common entity seen in sports medicine. Although lateral-side knee pain is often the result of a meniscus injury, several extra-articular pathologies share signs and symptoms with a meniscus tear. It is critical for the clinician to be able to identify and understand extra-articular pathologies that can present similar to a lateral meniscus tear. Evidence Acquisition: Data were collected through a thorough review of the literature conducted through a MEDLINE search for all relevant articles between 1980 and February 2010. Study Type: Clinical review. Results: Common extra-articular pathologies that can mimic lateral meniscal tears include iliotibial band syndrome, proximal tibiofibular joint instability, snapping biceps femoris or popliteus tendons, and peroneal nerve compression syndrome or neuritis. The patient history, physical examination features, and radiographic findings can be used to separate these entities from the more common intra-articular knee pathologies. Conclusions: In treating patients who present with lateral-sided knee pain, clinicians should be able to recognize and treat extra-articular pathologies that can present in a similar fashion as lateral meniscus tears.

Barker, Joseph U.; Strauss, Eric J.; Lodha, Sameer; Bach, Bernard R.

2011-01-01

367

CANAL EMERGES FROM EAST SIDE OF MTR BUILDING. "EXTRA" LENGTH ...  

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

CANAL EMERGES FROM EAST SIDE OF MTR BUILDING. "EXTRA" LENGTH WAS TO STORE SPENT FUEL THAT WOULD ACCUMULATE BEFORE THE CHEMICAL PROCESSING PLANT WAS READY TO PROCESS IT. INL NEGATIVE NO. 1659. Unknown Photographer, 3/9/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

368

Are Extra Classes the Success behind High Performance and Marks?  

ERIC Educational Resources Information Center

Extra classes have been a fixture in the educational system in India. They pre-date all existing educational programmes and examinations. Yet more recently the justification and reasons for the maintenance of these classes have been called into question. There have been unsubstantiated claims that in some cases the classes have been "organized" in…

Santhi, N.

2011-01-01

369

Health-Promoting Physical Activity and Extra-Curricular Sport  

ERIC Educational Resources Information Center

The primary purpose of this exploratory study was to determine the percentage of time in which school pupils coached by teachers were engaged in moderate to vigorous physical activity (MVPA) during extra-curricular sport practices. Three secondary purposes of the study were to determine (a) the percentage of time allocated by teachers for pupils…

Curtner-Smith, Matthew; Sofo, Seidu; Chouinard, Jeremy; Wallace, Sheila

2007-01-01

370

Surgical treatment of extra-abdominal desmoid tumours (aggressive fibromatoses)  

Microsoft Academic Search

Extra-abdominal desmoid tumours (EADT) are benign lesions but difficult to cure because of their infiltrative nature and tendency to recur. Among many treatments recommended in the past, wide excision has been successful, even in difficult cases. We have analyzed retrospectively 41 cases of histologically confirmed EADTs. A total of 98 operations were performed on these patients: 29 wide excisions on

S. Higaki; A. Tateishil; T. Ohnol; S. Abe; K. Ogawa; T. Iijima; T. Kojima

1995-01-01

371

An extra Z? gauge boson as a source of Higgs particles  

NASA Astrophysics Data System (ADS)

Models with extra gauge bosons are well motivated extensions of the standard model (SM) because of their connection with several unification schemes. These models include an extended Higgs sector in order to break the gauge symmetry and generate the required masses. The resulting spectrum of Higgs bosons could be searched for at current and future colliders using SM-like production mechanisms. However, the existence of the new gauge bosons could provide new production mechanisms, which could be used to probe the non-standard properties of Higgs particles. In this paper, we study the 3-body decays of the Z? associated with a model with an extra U(1)?, which could be used as a source of Higgs bosons. We find that the decays of a Z? into a Higgs boson and a top-anti-top pair, namely Z^{\\prime }\\rightarrow t\\bar{t} h, can reach branching ratios (Br?s) as high as 10-3, which could be detected at future colliders. We also study the production of Higgs bosons in association with the Z vector boson at a linear collider, through the reaction e+e- ? Z, Z? ? Z + h, including both the resonant and non-resonant effects.

Díaz-Cruz, J. Lorenzo; Hernández-López, Javier M.; Orduz-Ducuara, Javier A.

2013-12-01

372

Extra-articular manifestations of seronegative and seropositive rheumatoid arthritis.  

PubMed

Although considered a "joint disease," rheumatoid arthritis is associated with the involvement of extra-articular manifestations. The aim of the study is the investigation and comparison of frequency and type of extra-articular manifestations in a well defined community based cohort of patients with seropositive and seronegative rheumatoid arthritis. Using the ACR (1987) criteria for rheumatoid arthritis, patients have been classified into the 2nd and 3rd functional class (ARA). The studied group consisted of 125 seronegative patients with titters lower than 1:64 as defined by Rose-Waaler test, whereas the control group consisted of 125 seropositive patients with titters of 1:64 or higher. All patients were between 25-60 years of age (Xb=49,96), with disease duration between 1-27 years (Xb=6,41). In order to present the findings of the study, the structure, prevalence, arithmetic mean (Xb), standard deviation (SB), variation quotient (QV%) and variation interval (Rmax-Rmin) have been used. Probability level has been expressed by p<0,01 and p<0,05. Correlation between the number of extra-articular manifestations and duration of the disease has been calculated by means of Pearson linear correlation. Higher presence of diffuse lung fibrosis, central and peripheral nervous system damages have been confirmed in the seropositive group, and osteoporosis in the seronegative; however, no statistical difference has been found. In extra-articular manifestations, "rheumatoid core" in the seropositive subset (chi2=4,80, p<0,05) presented significant statistical difference. Rheumatoid nodules were more frequent in seropositive subset (12%:16%), in both sexes; however, they were not of significant statistical difference. Neuropathy and lung diseases were also frequently present in seropositive group, but no statistical difference has been found regarding the statistical difference. Longer duration of the disease resulted in an increase of the number of extra-articular manifestations. Calculated linear correlation by Pearson, resulted as positive and high correlation in total (r=0,36, p<0,01), and for groups [(r=0,52, p<0,01) seronegative, (r=0,25, p<0,01) seropositive], nevertheless no significant statistical difference was found regarding the sero-status. In conclusion, extra-articular manifestations are more frequent in the seropositive patients. The longer the duration of the disease the larger the number of extra-articular manifestations. Differences with regard to sero-status and sex, with some exceptions, are not observed. PMID:20192927

Sahatciu-Meka, Vjollca; Rexhepi, Sylejman; Manxhuka-Kerliu, Suzana; Rexhepi, Mjellma

2010-02-01

373

Realization of the BIH terrestrial system  

NASA Astrophysics Data System (ADS)

From 1968 through 1983, the BIH has maintained the orientation of the axes of a conventional terrestrial system on the basis of the stability of time series of the earth rotation parameters (ERP) that are implicitly referred to it. The principles of the definition and maintenance of this system are recalled, and its precision and long term stability are evaluated. It is now possible to realize the terrestrial reference system of the BIH, including the origin and orientation of the axes and the scale unit, on the basis of the permanent stations used in the monitoring of the earth's rotation by space geodesy. The transition to the proposed new realization is described. The principles of the future maintenance and dissemination of the BIH terrestrial system are also outlined.

Boucher, C.; Feissel, M.

374

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

375

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

376

Body lice  

MedlinePLUS

... be checked for head and public lice if you have body lice. ... live in clothing. To get rid of lice, destroy infected clothing ... also prescribe a cream that you put on your skin or a wash that ...

377

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

378

Body Image  

MedlinePLUS

... surgery Breast surgery Botox Liposuction Varicose or spider veins Body dysmorphic disorder (BDD) Eating disorders Anorexia nervosa ... policy | Disclaimers | FOIA | Link to us | USA.gov | Viewers and players A federal government website managed by ...

379

Body Systems  

NSDL National Science Digital Library

What are the parts and functions of the different systems in the body? Circulatory System Watch the Circulatory System and the Heart video. Complete one of the Circulatory System quizzes. Excretory System Label the parts of the excretory system. Respiratory System Quiz Complete respiratory system quiz to review parts. Skeletal System Label each part of the skeletal system. Vocabulary Review Change the settings to only include body system terms and play Hangman to review new vocabulary. ...

2011-11-02

380

Magnetic reconnection in the terrestrial magnetosphere  

SciTech Connect

An overview is given of quantitative comparisons between measured phenomena in the terrestrial magnetosphere thought to be associated with magnetic reconnection, and related theoretical predictions based on Petschek's simple model. Although such a comparison cannot be comprehensive because of the extended nature of the process and the relatively few in situ multipoint measurements made to date, the agreement is impressive where comparisons have been possible. This result leaves little doubt that magnetic reconnection does indeed occur in the terrestrial magnetosphere. The maximum reconnection rate, expressed in terms of the inflow Mach number, M/sub A/, is measured to be M/sub A/ = 0.2 +- 0.1.

Feldman, W.C.

1984-01-01

381

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

382

Problems of solar-terrestrial relationships  

NASA Astrophysics Data System (ADS)

Topics considered include studies on solar-terrestrial physics at the Academy of Sciences of the Turkmen SSR, the physical nature of solar flares, the energetics of solar-terrestrial relationships, and the energetics of the interplanetary medium at the earth's orbit. Attention is also given to the interaction of cosmic rays with the magnetosphere and ionosphere, the transport of solar wind energy to the earth's magnetosphere, and the precipitation of high-energy electrons from the inner magnetosphere to the lower ionosphere at subauroral latitudes.

Pushkov, N. V.; Ovezgeldyev, O. G.; Khanberdyev, A.; Miroshnichenko, M. I.

383

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

384

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

385

Elevated Trace Element Concentrations in Southern Toads, Bufo terrestris, Exposed to Coal Combustion Waste  

Microsoft Academic Search

.   A number of recent studies have linked developmental, physiological, and behavioral abnormalities in amphibians to coal\\u000a combustion wastes (coal ash). Few studies, however, have determined trace element concentrations in amphibians exposed to\\u000a coal ash. In the current study we compare total body concentrations of 20 trace elements in adult southern toads, Bufo terrestris, inhabiting coal ash settling basins with

W. A. Hopkins; M. T. Mendonça; C. L. Rowe; J. D. Congdon

1998-01-01

386

Physics Classroom: Drawing Free-Body Diagrams  

NSDL National Science Digital Library

This tutorial explains how free body diagrams are used in solving problems involving Newton's Second Law. This tutorials demonstrates how to draw free body diagrams, what the diagram means to Physics, and includes practice problems for the student. This tutorial also includes other tutorials, animations, and student activities in other concepts of Physics. The Physics Classroom is a set of resources created for learners and teachers of high school physics. It includes comprehensive tutorials, problem sets with solutions, extra help for struggling students, Shockwave animations, multimedia learning modules, labs, and photo gallery.

Henderson, Tom

2011-10-03

387

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 80°N 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

388

Proposal for periodic verifications of electromedical devices integrated to terrestrial Technical Ambulance Inspection (TAI)  

NASA Astrophysics Data System (ADS)

In Argentina, electromedical devices may only be commercialized if they meet safety and performance requirements established by current regulations, ensuring their safety and intended performance when leaving the Factory. However, during usage, natural wearing and overloading may change this condition, especially if used in extra hospital services performed by ambulances, which are likely to be subjected to rough handling conditions and hitting. This proposal explains the chosen methodology to address the periodic verification activities of electro medical devices within the process of terrestrial Technical Ambulance Inspection (TAI). Among the results stand out the set of methods for verification and the lists used to record the outcome of this evaluation. Outstanding conclusions include that the operations meet the conditions of an analogous mechanism to that of a Technical Vehicle Inspection (existing for other vehicles), and that the same working structure can be used as a basis for making a manual of procedures for a TAI.

Del Aguila Heidenreich, R.; Vanella, O.; Bruni, R.; Taborda, R.

2011-12-01

389

Bodie, CA  

NSDL National Science Digital Library

Held in a state of arrested decay, the ghost town of Bodie, California is one of the best known ghost towns in the United States. As with many a small town in the western part of the country, the town was part of the boom and bust cycle that was emblematic of the raucous world of mineral extraction, and as the gold in the region came and went, so did most of the residents of Bodie. This whole cycle began for Bodie in 1859, when a substantial quartz ledge was located in the region, along with significant deposits of gold. In 1962, the state of California took over what remained of the town in order to create a state historic park, and today approximately 200 structures remain on the site. At the website, visitors can take a photographic tour throughout many of these buildings (with some lovely interior photos as well), peruse a timeline of the townâÂÂs fortunes, and take a virtual tour of the Bodie cemetery. For persons interested in visiting Bodie, there is some helpful tips on nearby amenities and services.

390

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

391

DISSIPATION AND EXTRA LIGHT IN GALACTIC NUCLEI. II. 'CUSP' ELLIPTICALS  

SciTech Connect

We study the origin and properties of 'extra' or 'excess' central light in the surface brightness profiles of cusp or power-law elliptical galaxies. Dissipational mergers give rise to two-component profiles: an outer profile established by violent relaxation acting on stars already present in the progenitor galaxies prior to the final stages of the merger, and an inner stellar population comprising the extra light, formed in a compact central starburst. By combining a large set of hydrodynamical simulations with data that span a broad range of profiles at various masses, we show that observed cusp ellipticals appear consistent with the predicted 'extra light' structure, and we use our simulations to motivate a two-component description of the observations that allows us to examine how the properties and mass of this component scale with, e.g., the mass, gas content, and other properties of the galaxies. We show how to robustly separate the physically meaningful extra light and outer, violently relaxed profile, and demonstrate that the observed cusps and 'extra light' are reliable tracers of the degree of dissipation in the spheroid-forming merger. We show that the typical degree of dissipation is a strong function of stellar mass, roughly tracing the observed gas fractions of disks of the same mass over the redshift range z {approx} 0-2. We demonstrate a correlation between the strength of this component and effective radius at fixed mass, in the sense that systems with more dissipation are more compact, sufficient to explain the discrepancy in the maximum phase-space and mass densities of ellipticals and their progenitor spirals. We show that the outer shape of the light profile in simulated and observed systems (when fit to properly account for the central light) does not depend on mass, with a mean outer Sersic index {approx}2.5. We also explore how this relates to, e.g., the shapes, kinematic properties, and stellar population gradients of ellipticals. Extra light contributes to making remnants rounder and diskier, and imprints stellar population gradients. Simulations with the gas content needed to match observed surface brightness profiles reproduce the observed age, metallicity, and color gradients of cusp ellipticals, and we make predictions for how these can be used as tracers of the degree of dissipation in spheroid formation.

Hopkins, Philip F.; Cox, Thomas J.; Dutta, Suvendra N.; Hernquist, Lars [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kormendy, John [Department of Astronomy, University of Texas, 1 University Station, Austin, TX 78712 (United States); Lauer, Tod R. [National Optical Astronomy Observatory, Tucson, AZ 85726 (United States)

2009-03-15

392

Snow surface albedo estimation using terrestrial photography  

Microsoft Academic Search

A flexible and inexpensive remote sensing tool for albedo estimation using conventional terrestrial photography and its validation on an Alpine glacier are described. The proposed technique involves georeferencing oblique photographs to a digital elevation model (DEM), defining a mapping function between the information contained on a given pixel of the image and the corresponding cell of the DEM. This is

J. G. Corripio

2004-01-01

393

Validation of a terrestrial food chain model  

Microsoft Academic Search

An increasingly important topic in risk assessment is the estimation of human exposure to environmental pollutants through pathways other than inhalation. The Environmental Protection Agency (EPA) has recently developed a computerized methodology (EPA, 1990) to estimate indirect exposure to toxic pollutants from Municipal Waste Combuster emissions. This methodology estimates health risks from exposure to toxic pollutants from the terrestrial food

C. C. Travis; B. P. Blaylock

1992-01-01

394

CONSIDERATIONS FOR PLANNING TERRESTRIAL FIELD STUDIES  

EPA Science Inventory

In planning a terrestrial field study each component of the study should be considered in the context of all other components. here are close connections between the statement of the research question, the study design, the execution of the study and the final conclusions. hese c...

395

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

396

Orbiting mirrors for terrestrial energy supply  

NASA Technical Reports Server (NTRS)

A system of orbiting reflectors termed 'SOLARES' is proposed as a means of reducing the diurnal variation and increasing the average intensity of sunlight for terrestrial solar power systems. The paper discusses orbital considerations for the placement of the reflectors, insolation profiles, ground conversion options, costs, and environmental and social effects.

Billman, K. W.; Gilbreath, W. P.; Bowen, S. W.

1978-01-01

397

Monogenetic volcanoes of the terrestrial planets  

Microsoft Academic Search

Monogenetic volcanic activity has produced cinder cones and small shield volcanoes on the earth, moon, and Mars. Extraterrestrial cinder cones have median volumes only 25% as large as average terrestrial cinder cones, implying that their magma chambers are smaller and shallower (1 km depth vs 3 km). Ejection velocities for lunar and Martian cinder cones range from 20 to 70

C. A. Wood

1979-01-01

398

Alkaloids and other constituents from Tribulus terrestris  

Microsoft Academic Search

Three new compounds, terrestribisamide, 25R-spirost-4-en-3,12-dione and tribulusterine, together with 10 known compounds, N-p-coumaroyltyramine, terrestriamide, hecogenin, aurantiamide acetate, xanthosine, fatty acid ester, ferulic acid, vanillin, p-hydroxybenzoic acid and ?-sitosterol, were isolated and characterized from dried fruits of Tribulus terrestris. Structures of these compounds were determined by spectral analysis.

Tian-Shung Wu; Li-Shian Shi; Shang-Chu Kuo

1999-01-01

399

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

400

Steroid saponins II. Glycosides of Tribulus terrestris  

Microsoft Academic Search

Summary  1. It has been established that the epigeal part ofTribulus terrestris L. contains five steroid saponins. Diosgenin was identified as the aglycone of all these compounds.\\u000a \\u000a 2. The carbohydrate compositions of the saponins have been determined.

P. K. Kintya; É. D. Perepelitsa; V. Ya. Chirva; L. G. Kretsu

1972-01-01

401

UV-B EFFECTS ON TERRESTRIAL ECOSYSTEMS  

EPA Science Inventory

Dpeletion of stratospheric O3 layer should result in enhanced levels of ultraviolet-B (UV-B) radiation at the earth's surface compared to present, with potentially damaging effects on biological systems. his paper briefly summarizes some key findings for UV-B effects on terrestri...

402

Object Extraction from Terrestrial Laser Scanning Data  

Microsoft Academic Search

SUMMARY Terrestrial laser scanning emerges as a leading technology for direct 3D documentation of natural scenes irrespective of their complexity. The detailed level of description comes however at the cost of huge volume of data in form of unorganized, unevenly spaced, three- dimensional points. The cloud of points provides a geometric description of the scanned scene but carries no semantic

Sagi FILIN

2009-01-01

403

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

404

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

405

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

406

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

407

Large extra dimensions, sterile neutrinos and solar neutrino data.  

PubMed

Solar, atmospheric, and LSND neutrino oscillation results require a light sterile neutrino, nu(B), which can exist in the bulk of extra dimensions. Solar nu(e), confined to the brane, can oscillate in the vacuum to the zero mode of nu(B) and via successive Mikheyev-Smirnov-Wolfenstein transitions to Kaluza-Klein states of nu(B). This new way to fit solar data is provided by both low and intermediate string scale models. From average rates seen in the three types of solar experiments, the Super-Kamiokande spectrum is predicted with 73% probability, but dips characteristic of the 0.06 mm extra dimension should be seen in the SNO spectrum. PMID:11461607

Caldwell, D O; Mohapatra, R N; Yellin, S J

2001-07-23

408

Homografts and extra-anatomical reconstructions for infected vascular grafts.  

PubMed

Managing graft infections is a challenge in vascular surgery. The incidence of vascular graft infections varies between 2% and 6%. The number of patients treated by means of implantation of artificial prostheses is constantly growing. The treatment of vascular graft infections remains controversial. This article discusses in-situ repair and the role of extra-anatomic routes. Homografts present the lowest rate of reinfection with acceptable rates of degradation and aneurysm formation. Silvergrafts and synthetic grafts coated with antimicrobials show similar early and late mortality rates, but higher reinfection rates. The outcome extra-anatomic bypass surgery seems to be improved in actual series compared with historical results but their disadvantages (limited patency, higher rate of amputations as well as high rates of reintervention combined with higher early mortality) are obvious. PMID:24796916

Diener, H; Hellwinklel, O; Carpenter, S; Larena-Avellaneda, A; Debus, E S

2014-04-01

409

Student Response to Extra Credit Opportunities in a General Biology Course  

ERIC Educational Resources Information Center

Describes a course, and a research study, designed to evaluate student utilization of extra credit opportunities. Outlines factors that should be considered by an instructor in the use of extra credit units. (GS)

Canary, Pat; And Others

1976-01-01

410

Extensive Natural Intraspecific Variation in Stoichiometric (C:N:P) Composition in Two Terrestrial Insect Species  

PubMed Central

Heterotrophic organisms must obtain essential elements in sufficient quantities from their food. Because plants naturally exhibit extensive variation in their elemental content, it is important to quantify the within-species stoichiometric variation of consumers. If extensive stoichiometric variation exists, it may help explain consumer variation in life-history strategy and fitness. To date, however, research on stoichiometric variation has focused on interspecific differences and assumed minimal intraspecific differences. Here this assumption is tested. Natural variation is quantified in body stoichiometry of two terrestrial insects: the generalist field cricket, Gryllus texensis Cade and Otte (Orthoptera: Gryllidae) and a specialist curculionid weevil, Sabinia setosa (Le Conte) (Coleoptera: Curculionidae). Both species exhibited extensive intraspecific stoichiometric variation. Cricket body nitrogen content ranged from 8–12% and there was a four-fold difference in body phosphorus content, ranging from 0.32–1.27%. Body size explained half this stoichiometric variation, with larger individuals containing less nitrogen and phosphorus. Weevils exhibited an almost three-fold difference in body phosphorus content, ranging from 0.38–0.97%. Overall, the variation observed within each of these species is comparable to the variation previously observed across almost all terrestrial insect species.

Bertram, S. M.; Bowen, M.; Kyle, M.; Schade, J. D.

2008-01-01

411

One common structural peculiarity of the Solar system bodies including the star, planets, satellites and resulting from their globes rotation  

NASA Astrophysics Data System (ADS)

Often observed a sensible difference in appearance and structure between tropical and extra-tropical zones of various heavenly bodies including rocky and gas planets, satellites and Sun compels to look for a common reason of such phenomenon. All bodies rotate and their spherical shape makes zones at different latitudes to have differing angular momenta as a distance to the rotation axis diminishes gradually from the equator to the poles (this is felt particularly when one launches rockets into space -preferable more cheap launches are from the equatorial regions - Kourou is better than Baikonur). One of remarkable changes occurs at tropics. As a single rotating planetary body tends to have angular momenta of its tectonic blocks equilibrated it starts mechanisms leveling this basic physical property. At tropical zones (bulged also due to the rotation ellipsoid) the outer shell - crust as a consequence tends to be destroyed, sunk, subsided and shrunk; a density of crust material changes; the atmosphere reacts changing chemistry and structure; in terrestrial anthroposphere man looses its mass and stature. But according to the Le Chatelier rule mechanisms with an opposing tendency also begin to act. At Earth the wide planetary long tropical zone is marked by destruction of the crust. It is demonstrated by development of numerous islands of the Malay Archipelago (the Sunda Isls., Maluku Isls, Philippines) between the Southeastern Asia and Australia. In Africa and South America huge depressions of the Congo and Amazon Rivers develops where the Archean crust is subsided to depths of more than 2 km. In the Pacific along the equator numerous islands of Micronesia occur. Subsidence of the basaltic oceanic crust is followed by an intensive folding and faulting of basalt and sedimentary layers (Fig. 1) as a larger mass must be held by a smaller space (a planetary radius is diminished). The central Atlantic is very demonstrative in this sense suffering huge transform fault zones changing to more quite tectonics to the north and south where basaltic effusions form large provinces. This addition of dense basalts to the crust plays to increasing angular momentum of the extra-tropical blocks. At Mars the widespread enigmatic chaotic and fretted terrains at the highland-lowland boundary could be considered as traces of the crust destruction along the wide tropical belt. A system of hillocks and their relics and separating them depressions is controlled by a crosscutting tectonics. Prevailing subsidence here is characteristic. At Saturn a wide tropical zone usually has higher albedo than extra-tropical ones. Relatively heavier methane clouds in the H-He atmosphere are absent around the equator and concentrated on the higher latitudes (Fig. 2). In the tropical zone of Titan the darker methane lowlands (Fig. 3) are normally rippled in at least two directions with spacing a few km to 20 km (such forms erroneously are taken as dunes) (Fig. 4). This subsidence rippling gradually is replaced by smooth surfaces of dark basins (possibly liquid methane) at the higher northern and at lesser degree southern latitudes. This planetary pattern (Fig. 3, 4) is comparable with a behavior of the basalt floor of terrestrial oceans. On Iapetus the wide equatorial zone of the bright trailing hemisphere is distinguished by relatively numerous craters with darkened floors (Fig. 5). This terrain connects both flanks of the dark leading hemisphere and is a continuation of its equatorial bulge (a squeezed out feature as a result of the dark hemisphere subsidence). Thus looks tending subside and disintegrate tropical terrain on the uplifted bright hemisphere. Around the Tethys' equator there is a band of slightly darker surface material (Fig. 6). It may be an area of less contaminated ice and ice with a different structure than ice at higher latitudes as think Cassini scientists. If it is coarser-grained (more loosely packed) and purer then the equatorial region tends to be less dense diminishing its angular momentum. A crosscutting wave rippling producing chains of

Kochemasov, , G. G.

2008-09-01

412

Extra-articular hip endoscopy: A review of the literature.  

PubMed

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

2012-12-01

413

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

414

Dark matter and collider phenomenology of universal extra dimensions  

NASA Astrophysics Data System (ADS)

We review the phenomenology of models with flat, compactified extra dimensions where all of the Standard Model fields are allowed to propagate in the bulk, known as Universal Extra Dimensions (UED). UED make for an interesting TeV-scale physics scenario, featuring a tower of Kaluza Klein (KK) states approximately degenerate in mass at the scale set by the inverse size of the compactification radius. KK parity, the four-dimensional remnant of momentum conservation in the extra dimensions, implies two basic consequences: (1) contributions to Standard Model observables arise only at loop level, and KK states can only be pair-produced at colliders, and (2) the lightest KK particle (LKP) is stable, providing a suitable particle dark matter candidate. After a theoretical overview on extra dimensional models, and on UED in particular, we introduce the model particle spectrum and the constraints from precision electroweak tests and current colliders data. We then give a detailed overview of the LKP dark matter phenomenology, including the LKP relic abundance, and direct and indirect searches. We then discuss the physics of UED at colliders, with particular emphasis on the signatures predicted for the Large Hadron Collider and at a future Linear Collider, as well as on the problem of discriminating between UED and other TeV-scale new physics scenarios, particularly supersymmetry. We propose a set of reference benchmark models, representative of different viable UED realizations. Finally, we collect in the Appendix all the relevant UED Feynman rules, the scattering cross sections for annihilation and coannihilation processes in the early universe and the production cross section for strongly interacting KK states at hadron colliders.

Hooper, Dan; Profumo, Stefano

2007-12-01

415

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

416

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

417

Affleck-Dine baryogenesis in large extra dimensions  

Microsoft Academic Search

Baryogenesis in models in which the fundamental scale is as low as 1 TeV in the context of large extra dimensions is a challenging problem. The requirement for the departure from thermal equilibrium necessarily ties any low-scale baryogenesis with that of a successful inflationary model, which automatically provides the out-of-equilibrium condition after the end of inflation. However, it is also

Anupam Mazumdar; A. Pérez-Lorenzana

2002-01-01

418

Effects of large extra dimensions on cosmogenic neutrino fluxes  

NASA Astrophysics Data System (ADS)

We study the consequences of theories with extra dimensions and a gravity scale of a few TeVs on the cosmogenic flux of neutrinos. Taking into account the most recent upper limits for the onset of the gravity effects given by the LHC, and the updated predictions for the cosmogenic neutrino flux consistent with Fermi-LAT data, we compute the expected number of shower events to be detected with new generation acoustic detectors such as ARA.

Reynoso, M. M.; Sampayo, O. A.

2013-05-01

419

Differential transmission of extra genome chromosomes in pentaploid blueberry  

Microsoft Academic Search

Transmission of extra genome chromosomes by three Vaccinium ashei (2n=6x=72)\\/V. corymbosum (2n=4x=48) pentaploid hybrids backcrossed to the hexaploid species V. ashei was examined. Chromosome numbers were determined for 36 and 31 progeny representing 5x × 6x and 6x × 5x type crosses, respectively. Chromosome numbers ranged from hypopentaploid (2n=4x+11=59) to hexaploid with means of 2n=66.2 for 5x × 6x progeny

N. Vorsa

1988-01-01

420

Zero point energy on extra dimensions: Noncommutative torus  

Microsoft Academic Search

In this paper we calculate the zero point energy density experienced by observers on M due to a massless scalar field defined throughout MxT{sub F}², where T{sub F}² are fuzzy extra dimensions. Using the Green's function approach we calculate the energy density for the commutative torus and the fuzzy torus. We also calculate the energy density for the fuzzy torus

S. Fabi; B. Harms; G. Karatheodoris

2007-01-01

421

Zero point energy on extra dimensions: Noncommutative torus  

Microsoft Academic Search

In this paper we calculate the zero point energy density experienced by observers on M4 due to a massless scalar field defined throughout M4×TF2, where TF2 are fuzzy extra dimensions. Using the Green's function approach we calculate the energy density for the commutative torus and the fuzzy torus. We also calculate the energy density for the fuzzy torus using the

S. Fabi; B. Harms; G. Karatheodoris

2007-01-01

422

Extra-anatomical complications of antegrade double-J insertion  

PubMed Central

Introduction: Insertion of a double-J (JJ) stent is a common procedure often carried out in the retrograde route by the urologists and the antegrade route by the radiologists. Reported complications include stent migration, encrustation, and fracture. Extra-anatomic placement of an antegrade JJ stent is a rare but infrequently recognized complication. Materials and Methods: We performed a retrospective audit of 165 antegrade JJ stent insertions performed over three consecutive years by a single interventional radiologist. All renal units were hydronephrotic at the time of nephrostomy. All procedures were performed under local anaesthetic with antibiotic prophylaxis. Results: Antegrade stent insertion was carried out simultaneously at the time of nephrostomy in 55 of the 165 cases (33%). The remainder were inserted at a mean of 2 weeks following decompression. In five (3%) patients, who had delayed antegrade stenting following nephrostomy, the procedure was complicated by silent ureteric perforation and an extra-anatomic placement of the stent. These complications had delayed manifestations, which included two retroperitoneal abscesses, a pelvic urinoma, a case each of ureterorectal fistula, and ureterovaginal fistula. Risk factors for ureteric perforation include previous pelvic malignancy, pelvic surgery, pelvic radiation, and a history of ureteric manipulation. Conclusion: Antegrade ureteric JJ stenting is a procedure not without complications. Extra-anatomic placement of the antegrade stent is a hitherto the infrequently reported complication but needs a high index of suspicion to be diagnosed. Risk factors for ureteric perforation at the time of stent insertion have to be considered to prevent this potential complication.

Rao, A. R.; Alleemudder, A.; Mukerji, G.; Mishra, V.; Motiwala, H.; Charig, M.; Karim, O. M. A.

2011-01-01

423

Spinless photon dark matter from two universal extra dimensions  

SciTech Connect

We explore the properties of dark matter in theories with two universal extra dimensions, where the lightest Kaluza-Klein state is a spin-0 neutral particle, representing a six-dimensional photon polarized along the extra dimensions. Annihilation of this 'spinless photon' proceeds predominantly through Higgs boson exchange, and is largely independent of other Kaluza-Klein particles. The measured relic abundance sets an upper limit on the spinless photon mass of 500 GeV, which decreases to almost 200 GeV if the Higgs boson is light. The phenomenology of this dark matter candidate is strikingly different from Kaluza-Klein dark matter in theories with one universal extra dimension. Elastic scattering of the spinless photon with quarks is helicity suppressed, making its direct detection challenging, although possible at upcoming experiments. The prospects for indirect detection with gamma rays and antimatter are similar to those of neutralinos. The rates predicted at neutrino telescopes are below the sensitivity of next-generation experiments.

Dobrescu, Bogdan A.; Hooper, Dan; Kong, Kyoungchul; Mahbubani, Rakhi; /Fermilab

2007-06-01

424

Survival of scalar zero modes in warped extra dimensions  

SciTech Connect

Models with an extra dimension generally contain background scalar fields in a nontrivial configuration, whose stability must be ensured. With gravity present, the extra dimension is warped by the scalars, and the spin-0 degrees of freedom in the metric mix with the scalar perturbations. Where possible, we formally solve the coupled Schroedinger equations for the zero modes of these spin-0 perturbations. When specializing to the case of two scalars with a potential generated by a superpotential, we are able to fully solve the system. We show how these zero modes can be used to construct a solution matrix, whose eigenvalues tell whether a normalizable zero mode exists, and how many negative mass modes exist. These facts are crucial in determining stability of the corresponding background configuration. We provide examples of the general analysis for domain-wall models of an infinite extra dimension and domain-wall soft-wall models. For five-dimensional models with two scalars constructed using a superpotential, we show that a normalizable zero mode survives, even in the presence of warped gravity. Such models, which are widely used in the literature, are therefore phenomenologically unacceptable.

George, Damien P. [Nikhef Theory Group, Science Park 105, 1098 XG Amsterdam (Netherlands)

2011-05-15

425

Extra-team connections for knowledge transfer between staff teams.  

PubMed

As organizations implement novel health promotion programs across multiple sites, they face great challenges related to knowledge management. Staff social networks may be a useful medium for transferring program-related knowledge in multi-site implementation efforts. To study this potential, we focused on the role of extra-team connections (ties between staff members based in different site teams) as potential channels for knowledge sharing. Data come from a cross-sectional study of after-school child-care staff implementing a health promotion program at 20 urban sites of the Young Men's Christian Association of Greater Boston. We conducted a sociometric social network analysis and attempted a census of 91 program staff members. We surveyed 80 individuals, and included 73 coordinators and general staff, who lead and support implementation, respectively, in this study. A multiple linear regression model demonstrated a positive relationship between extra-team connections (beta = 3.41, P < 0.0001) and skill receipt, a measure of knowledge transfer. We also found that intra-team connections (within-team ties between staff members) were also positively related to skill receipt. Connections between teams appear to support knowledge transfer in this network, but likely require greater active facilitation, perhaps via organizational changes. Further research on extra-team connections and knowledge transfer in low-resource, high turnover environments is needed. PMID:19528313

Ramanadhan, Shoba; Wiecha, Jean L; Emmons, Karen M; Gortmaker, Steven L; Viswanath, Kasisomayajula

2009-12-01

426

Body Levers.  

ERIC Educational Resources Information Center

Explains how the muscle and bone arrangement of the human body can be used in teaching the principles of simple machines. Presents an activity that investigates the lever system of the forearm. Includes background information on levers and suggests questions for classroom discussion. (ML)

Chiappetta, Eugene L.

1987-01-01

427

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

428

The Degree of Extra-Pair Paternity Increases with Genetic Variability  

Microsoft Academic Search

The amount of extra-pair paternity in socially monogamous bird species varies from 0% to 76% extra-pair offspring. The causes of this remarkable interspecific variation are largely unknown, although intraspecific analyses suggest that females seek extra-pair matings to improve the genetic quality of their offspring. If this is a general explanation for the occurrence of extra-pair matings, then proportionally more females

Marion Petrie; Claudie Doums; Anders Pape Moller

1998-01-01

429

7 CFR 51.2750 - U.S. Extra Large Virginia.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false U.S. Extra Large Virginia. 51.2750 Section 51.2750 Agriculture... United States Standards for Shelled Virginia Type Peanuts Grades § 51.2750 U.S. Extra Large Virginia. âU.S. Extra Large...

2009-01-01

430

41 CFR 301-10.163 - What is an extra-fare train?  

Code of Federal Regulations, 2013 CFR

... 2012-07-01 true What is an extra-fare train? 301-10.163 Section 301-10...Train § 301-10.163 What is an extra-fare train? A train that operates at an increased fare due to the extra performance of the...

2013-07-01

431

41 CFR 301-10.164 - When may I use extra-fare train service?  

Code of Federal Regulations, 2013 CFR

...2012-07-01 true When may I use extra-fare train service? 301-10.164 Section 301-10...Train § 301-10.164 When may I use extra-fare train service? You may use extra-fare train service whenever your agency...

2013-07-01

432

Why is it necessary to establish a classification of extra-solar planets?  

NASA Astrophysics Data System (ADS)

While working with extra-solar planet databases, it is very useful to have a taxonomy scale (classification), for example, like the Harvard classification for stars. This new taxonomy has to be comprehensible and present the most relevant information about extra-solar planets. We propose an extra-solar planet taxonomy scale with five parameters. %

Plávalová, E.

2014-03-01

433

Is Extra Mixing Really Needed in Asymptotic Giant Branch Stars?  

NASA Astrophysics Data System (ADS)

We demonstrate that the amount of extra mixing required to fit the observed low C/N and 12C/13C ratios in first giant branch (FGB) stars is also sufficient to explain the carbon and nitrogen abundances of Galactic asymptotic/second giant branch (AGB) stars. We simulate the effect of extra mixing on the FGB by setting the composition of the envelope to that observed in low-mass (M <= 2 M sun) FGB stars, and then evolve the models to the tip of the AGB. The inclusion of FGB extra mixing compositional changes has a strong effect on the C and N abundance in our AGB models, leading to compositions consistent with those measured in Galactic carbon-rich stars. The composition of the models is also consistent with C and N abundances measured in mainstream silicon carbide grains. While our models cover the range of C abundances measured in carbon stars in the LMC cluster NGC 1846, we cannot simultaneously match the composition of the O- and C-rich stars at the same time. A second important result is that our models only match the oxygen isotopic composition of K and some M, MS giants, and are not able to match the oxygen composition of carbon-rich AGB stars. By increasing the abundance of 16O in the intershell (based on observational evidence) it is possible to reproduce the observed trend of increasing 16O/18O and 16O/17O ratios with evolutionary phase. We also find that some Li production takes place during the AGB and that Li-rich carbon stars (log epsilon(Li) >~ 1) can be produced. These models show a correlation between increasing Li abundances and C. The models cannot explain the composition of the most Li-enriched carbon stars, nor can we produce a Li-rich carbon star if we assume extra mixing occurs during the FGB owing to 3He destruction. We tentatively conclude that (1) if extra mixing occurs during the AGB it likely only occurs efficiently in low metallicity objects, or when the stars are heavily obscured making spectroscopic observations difficult and (2) the intershell compositions of AGB stars need further investigation.

Karakas, Amanda I.; Campbell, Simon W.; Stancliffe, Richard J.

2010-04-01

434

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

435

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

436

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

437

Nitrogen inputs accelerate phosphorus cycling rates across a wide variety of terrestrial ecosystems.  

PubMed

• Biologically essential elements--especially nitrogen (N) and phosphorus (P)--constrain plant growth and microbial functioning; however, human activities are drastically altering the magnitude and pattern of such nutrient limitations on land. Here we examine interactions between N and P cycles of P mineralizing enzyme activities (phosphatase enzymes) across a wide variety of terrestrial biomes. • We synthesized results from 34 separate studies and used meta-analysis to evaluate phosphatase activity with N, P, or N×P fertilization. • Our results show that N fertilization enhances phosphatase activity, from the tropics to the extra-tropics, both on plant roots and in bulk soils. By contrast, P fertilization strongly suppresses rates of phosphatase activity. • These results imply that phosphatase enzymes are strongly responsive to changes in local nutrient cycle conditions. We also show that plant phosphatases respond more strongly to fertilization than soil phosphatases. The tight coupling between N and P provides a mechanism for recent observations of N and P co-limitation on land. Moreover, our results suggest that terrestrial plants and microbes can allocate excess N to phosphatase enzymes, thus delaying the onset of single P limitation to plant productivity as can occur via human modifications to the global N cycle. PMID:22122515

Marklein, Alison R; Houlton, Benjamin Z

2012-02-01

438

The Geochronology of Terrestrial Meteorite and Cometary Impacts  

NASA Astrophysics Data System (ADS)

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 hypotheses of clustering and periodicity in the impact record, and compare ages with those for mass extinctions in the fossil record. Over 170 craters have been identified on the Earth's surface, but the ages of less than half are known to better than 10 million years. The crucial question of peak eruption ages for large igneous provinces (LIPs) formed during the Palaeozoic, such as Deccan and the Siberian Traps, has been resolved using radiometric dating techniques such as Ar-Ar and U-Pb dating. The precision of measured ages for LIPs is better than 1% in most cases, but the precision and accuracy of ages determined for impact events is very variable. The ages of the largest 5 known terrestrial impact craters (>100 km diameter) have been established using radiometric dating techniques such as Ar-Ar and U-Pb and are known to precisions of better than 1%. However, the ages of many smaller craters, even some over 50 km in diameter, are less well constrained. It is the record of these smaller impacts which is littered with low precision ages, inaccurate ages and impacts whose age is constrained only by the age of the target rock and the youngest overlying sediments. Why is the record of smaller impacts so poorly constrained? The main reason is the scarcity of samples and post impact alteration. The largest impacts form significant quantities of melt and which remain liquid for sufficiently long to coalesce and form conventional igneous bodies. It is these bodies which have been dated using radiometric dating techniques, often U-Pb dating of zircon crystallized from the melt. Smaller impacts form little or no melt and where present, they are heterogeneous mixtures of melt and host rock clasts of all sizes. The task of dating such samples is often made more difficult by alteration as a result of post impact hydrothermal activity. In addition, unlike LIPs, samples of impact melt are often rare even within the crater. Ar-Ar dating has become the technique of choice for these samples since both furnace heating and laser heating extraction techniques lend themselves to analysis of small heterogeneous samples. Ar-Ar analysis has been used to separate and identify components such as host rock clasts and the effects of later alteration, to reveal precise ages for the impacts. The Ar-Ar technique can also be used to determine argon loss in the host rock as a result of heating during the impact, and measure the remnants of host rock Ar dissolved in melt which can also indicate the rapidity of melt formation and freezing. In fact the geochronology of impacts is fast improving area and although more work is required before we can determine whether impacts fall randomly, with a periodicity, or in clusters, there are some strong indications of future directions. Some apparent clusters of impacts appear to warrant further study, whereas others may disappear as new geochronological data is acquired. In particular the long known 450-500 Ma asteriod break-up event seems to have a terrestrial corollary in a mid-Ordovician cluster of impacts.

Kelley, S. P.

2003-12-01

439

A prospective comparison between Kapandji and percutaneous extra-focal fixation in extra articular distal radius fractures  

PubMed Central

Introduction: there are multiple methods of distal radius fractures treatments. Of these percutaneous wire insertion has yielded popular acceptance. These percutaneous wire insertions can be done through many different ways with their own advantages and disadvantages. One of these methods is Kapandji method and because of its inherent stability in biomechanical examinations we suppose that we can begin the range of motion sooner than other methods with the hope of better outcome. Patients and methods: From 2010 to 2012 we studied 45 patients, of these 23 went under extra-focal technique and 22 went under Kapandji technique. After Kapandji we immobilized the limb in splint for 4 weeks and started partial motion thereafter and in the extra-focal group we immobilized them in for 6 weeks in long arm casts. Results: After 3 months and 6 months we assess the Gartland and Warley score and find 39% and 73% excellent and good result in extra-focal and 45% and 86% excellent and good result in Kapandji group after 3 and 6 months, respectively. Although there were about 0.22 mm collapse in both groups, here were no statistically significant differences in functional score or radiologic and anatomic parameters between groups. Conclusion: we have find Kapandji technique a suitable method of distal radius fracture fixation in cases with no articular involvement and we think it is better to immobilize the limb for at least 6 weeks after Kapandji fixation, in order to better control the pain.

Mirhamidi, Seyed Mehdi; Bayat, Farzad Merrikh

2013-01-01

440

Prospects for Detecting Young Terrestrial Planets During Their Collisional Formation  

NASA Astrophysics Data System (ADS)

We explore the appearance of terrestrial planets in formation by studying the emergent spectra of hot molten protoplanets during their collisional formation. While such collisions are rare, the surfaces of these bodies may remain hot at temperatures of 1000-3000 K for up to millions of years during the epoch of their formation (of duration 10-100 Myr). These object are luminous enough in the thermal infrared to be observable with current and next generation optical/IR telescopes, provided that the atmosphere of the forming planet permits astronomers to observe brightness temperatures approaching that of the molten surface. Detectability of a collisional afterglow depends on properties of the planet's atmosphere -- primarily on the mass of the atmosphere. A planet with a thin atmosphere is more readily detected, because there is little atmosphere to obscure the hot surface. Paradoxically, a more massive atmosphere prevents one from easily seeing the hot surface, but also keeps the planet hot for a longer time. In terms of planetary mass, more massive planets are also easier to detect than smaller ones because of their larger emitting surface areas -- up to a factor of 10 in brightness between 1 and 10 M_Earth planets. We present preliminary calculations assuming a range of protoplanet masses (1-10 M_Earth), surface pressures (1-1000 bar), and atmospheric compositions, for molten planets with surface temperatures ranging from 1000 to 1800 K, in order to explore the diversity of emergent spectra that are detectable. While current 8- to 10-m class ground-based telescopes may detect hot protoplanets at wide orbital separations beyond 30 AU (if they exist), we will likely have to wait for next-generation extremely large telescopes or improved diffraction suppression techniques to find terrestrial planets in formation within several AU of their host stars.

Miller-Ricci, Eliza

2009-09-01

441

Building Blocks of the Terrestrial Planets: Mineralogy of Hungaria Asteroids  

NASA Astrophysics Data System (ADS)

Deciphering the mineralogy of the Hungaria asteroids has the potential to place constraints on the material from which the terrestrial planets accreted. Among asteroids with semi-major axes interior to the main-belt (e.g., Hungarias, Mars-crossers, and near-Earth asteroids), only the Hungarias are located in relatively stable orbital space. Hungaria asteroids have likely resided in this orbital space since the planets completed their migration to their current orbits. The accretion and igneous differentiation of primitive asteroids appears to be a function of chronology and heliocentric distance. However, differentiated bodies that originated in the terrestrial planet region were either accreted or scattered out of this region early in solar system history. Thus, the Hungaria asteroids represent the closest reservoir of in situ material to the terrestrial planet region from early in solar system history. We present VISNIR 0.45-2.45 µm) and NIR spectra 0.65-2.45 µm) spectra of 24 Hungaria group (objects in similar orbital space) asteroids. Our NIR data (17 objects) were acquired using the InfraRed Telescope Facility and was supplemented with available visible data. Spectra of seven objects were obtained from the MIT-UH-IRTF survey. We distinguish our sample between Hungaria family (presumed fragments of parent 434 Hungaria; 2 objects) and Hungaria background (group minus family 22 objects) asteroids using proper orbital elements. The classification of each asteroid is determined using the taxonomy of Bus-DeMeo. We find that S- and S-subtypes are prevalent among the Hungaria background population (17/22). Spectral band parameters measurements (i.e., Band I and Band II centers and depths, and Band Area Ratio) indicate that eight of these S-types are analogous with undifferentiated ordinary chondrites (SIV “boot”