If You Meet the Buddha on the Road with a Rosetta Stone: A Dialogue on Strategies of Inquiry and the New Rhetoric.

ERIC Educational Resources Information Center

Murphy, Christina

1985-01-01

Presents a dialogue between two adherents of the process centered paradigm of rhetoric: one a "classicist" who sees art as the knowledge necessary for producing preconceived results by conscious, directed actions, and the other a "romantic," who sees art as "magical" inspiration. (HTH)

New Coke, Rosetta Stones, and Functional Data Analysis: Recommendations for Developing and Validating New Measures of Depression

ERIC Educational Resources Information Center

Santor, Darcy A.

2006-01-01

In this article, the author outlines six recommendations that may guide the continued development and validation of measures of depression. These are (a) articulate and revise a formal theory of signs and symptoms; (b) differentiate complex theoretical goals from pragmatic evaluation needs; (c) invest heavily in new methods and analytic models;…

Forgetting of Foreign-Language Skills: A Corpus-Based Analysis of Online Tutoring Software

ERIC Educational Resources Information Center

Ridgeway, Karl; Mozer, Michael C.; Bowles, Anita R.

2017-01-01

We explore the nature of forgetting in a corpus of 125,000 students learning Spanish using the Rosetta Stone® foreign-language instruction software across 48 lessons. Students are tested on a lesson after its initial study and are then retested after a variable time lag. We observe forgetting consistent with power function decay at a rate that…

A Multiple Case Study Analysis of Digital Preservation Techniques Across Government, Private, and Public Service Organizations

DTIC Science & Technology

2008-03-01

capture archived encoded data. A black basalt slab with strange inscriptions on it, the Rosetta Stone was unearthed in July 1799 by Napoleon’s army...the bitstream. When you start thinking about 1s and 0s and when you start thinking about fiber optics, its just either on or off. So there is a

Polarization Observations of the Total Solar Eclipse of August 21, 2017

NASA Astrophysics Data System (ADS)

Burkepile, J.; Boll, A.; Casini, R.; de Toma, G.; Elmore, D. F.; Gibson, K. L.; Judge, P. G.; Mitchell, A. M.; Penn, M.; Sewell, S. D.; Tomczyk, S.; Yanamandra-Fisher, P. A.

2017-12-01

A total solar eclipse offers ideal sky conditions for viewing the solar corona. Light from the corona is composed of three components: the E-corona, made up of spectral emission lines produced by ionized elements in the corona; the K-corona, produced by photospheric light that is Thomson scattered by coronal electrons; and the F-corona, produced by sunlight scattered from dust particles in the near Sun environment and in interplanetary space. Polarized white light observations of the corona provide a way of isolating the K-corona to determine its structure, brightness, and density. This work focuses on broadband white light polarization observations of the corona during the upcoming solar eclipse from three different instruments. We compare coronal polarization brightness observations of the August 21, 2017 total solar eclipse from the NCAR/High Altitude Observatory (HAO) Rosetta Stone experiment using the 4-D Technology PolarCam camera with the two Citizen PACA_CATE17Pol telescopes that will acquire linear polarization observations of the eclipse and the NCAR/HAO K-Cor white light coronagraph observations from the Mauna Loa Solar Observatory in Hawaii. This comparison includes a discussion of the cross-calibration of the different instruments and reports the results of the coronal polarization brightness and electron density of the corona. These observations will be compared with results from previous coronal measurements taken at different phases of the solar cycle. In addition, we report on the performance of the three different polarimeters. The 4-D PolarCam uses a linear polarizer array, PACA_CATE17Pol uses a nematic liquid crystal retarder in a single beam configuration and K-Cor uses a pair of ferroelectric liquid crystal retarders in a dual-beam configuration. The use of the 4-D PolarCam camera in the Rosetta Stone experiment is to demonstrate the technology for acquiring high cadence polarization measurements. The Rosetta Stone experiment is funded through the NASA award NNH16ZDA001N-ISE. The Citizen Science approach to measuring the polarized solar corona during the eclipse is funded through NASA award NNX17AH76G. The NCAR Mauna Loa Solar Observatory is funded by the National Science Foundation.

Statistical analysis of dust signals observed by ROSINA/COPS onboard of the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Tzou, Chia-Yu; altwegg, kathrin; Bieler, Andre; Calmonte, Ursina; Gasc, Sébastien; Le Roy, Léna; Rubin, Martin

2016-10-01

ROSINA is the in situ Rosetta Orbiter Spectrometer for Ion and Neutral Analysis on board of Rosetta, one of the corner stone missions of the European Space Agency (ESA) to land and orbit the Jupiter family comet 67P/Churyumov-Gerasimenko (67P). ROSINA consists of two mass spectrometers and a pressure sensor. The Reflectron Time of Flight Spectrometer (RTOF) and the Double Focusing Mass Spectrometer (DFMS) complement each other in mass and time resolution.The Comet Pressure Sensor (COPS) provides density measurements of the neutral molecules in the cometary coma of 67P. COPS has two gauges, a nude gauge that measures the total neutral density and a ram gauge that measures the dynamic pressure from the comet. Combining the two COPS is also capable of providing gas dynamic information such as gas velocity and gas temperature of the coma.While Rosetta started orbiting around 67P in August 2014, COPS observed diurnal and seasonal variations of the neutral gas density in the coma. Surprisingly, additional to these major density variation patterns, COPS occasionally observed small spikes in the density that are associated with dust. These dust signals can be interpreted as a result of cometary dust releasing volatiles while heated up near COPS. A statistical analysis of dust signals detected by COPS will be presented.

A Rosetta Stone Relating Conventions In Photo-Meson Partial Wave Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

A.M. Sandorfi, B. Dey, A. Sarantsev, L. Tiator, R. Workman

2012-04-01

A new generation of complete experiments in pseudoscalar meson photo-production is being pursued at several laboratories. While new data are emerging, there is some confusion regarding definitions of asymmetries and the conventions used in partial wave analyses (PWA). We present expressions for constructing asymmetries as coordinate-system independent ratios of cross sections, along with the names used for these ratios by different PWA groups.

Ube2V2 Is a Rosetta Stone Bridging Redox and Ubiquitin Codes, Coordinating DNA Damage Responses.

PubMed

Zhao, Yi; Long, Marcus J C; Wang, Yiran; Zhang, Sheng; Aye, Yimon

2018-02-28

Posttranslational modifications (PTMs) are the lingua franca of cellular communication. Most PTMs are enzyme-orchestrated. However, the reemergence of electrophilic drugs has ushered mining of unconventional/non-enzyme-catalyzed electrophile-signaling pathways. Despite the latest impetus toward harnessing kinetically and functionally privileged cysteines for electrophilic drug design, identifying these sensors remains challenging. Herein, we designed "G-REX"-a technique that allows controlled release of reactive electrophiles in vivo. Mitigating toxicity/off-target effects associated with uncontrolled bolus exposure, G-REX tagged first-responding innate cysteines that bind electrophiles under true k cat / K m conditions. G-REX identified two allosteric ubiquitin-conjugating proteins-Ube2V1/Ube2V2-sharing a novel privileged-sensor-cysteine. This non-enzyme-catalyzed-PTM triggered responses specific to each protein. Thus, G-REX is an unbiased method to identify novel functional cysteines. Contrasting conventional active-site/off-active-site cysteine-modifications that regulate target activity, modification of Ube2V2 allosterically hyperactivated its enzymatically active binding-partner Ube2N, promoting K63-linked client ubiquitination and stimulating H2AX-dependent DNA damage response. This work establishes Ube2V2 as a Rosetta-stone bridging redox and ubiquitin codes to guard genome integrity.

Novel microclimate monitoring and microbial colonisation in sandstones of historic buildings, Glasgow, Scotland

NASA Astrophysics Data System (ADS)

Duthie, L.; Hyslop, E.; Lee, M.; Phoenix, V.; Kennedy, C.

2009-04-01

The impact of our changing climate on the historic built environment of Scotland has received surprisingly little attention. Current projections indicate that Scotland will become notably wetter and warmer over the coming decades. Winter temperatures are predicted to increase by 30C with 15% more precipitation, one result should be more aggressive microbial weathering of the sandstone buildings. In order to understand better and to quantify the damage potentially caused, it is necessary to analyse existing microbial populations but also to characterize conditions within building stones, how they change over diurnal and seasonal cycles, and how they differ from external conditions. In this study, temperature, humidity and moisture sensors were inserted at different depths into representative Scottish sandstones to record parameters key to microbial colonisation and organic weathering. Penetration of photosynthetically active radiation has also been measured. The within-stone data were compared to meteorological conditions recorded by an adjacent weather station. These data have then been compared with analysis of the microbial populations at different depths within the stone, using osmium stained polished blocks. Notably, microbes occur up to 7 mm beneath the outer sandstone surface, with community structure differing with depth. Clearly, different communities experience very different conditions within the stone, reflecting trophic structure, light penetration and microclimate. The sensor data confirm that temperature and water availability all vary within the stone and differ considerably with the external environment. We conclude that the warm and humid microclimate within Scottish building stones promotes microbial colonisation and stone decay and both will increase significantly with the changing climate of Scotland and north-west Europe.

Consolidation of degraded ornamental porous limestone stone by calcium carbonate precipitation induced by the microbiota inhabiting the stone.

PubMed

Jimenez-Lopez, C; Rodriguez-Navarro, C; Piñar, G; Carrillo-Rosúa, F J; Rodriguez-Gallego, M; Gonzalez-Muñoz, M T

2007-08-01

Although it has already been shown that calcareous stone can be consolidated by using a bacterially inoculated culture medium, a more user-friendly method is the in situ application of a sterile culture medium that is able to activate, among the microbial community of the stone, those bacteria with a potential for calcium carbonate precipitation. In order to test this new method for stone consolidation, non-sterilized decayed porous limestone was immersed in sterile nutritional media. Results were compared to those of the runs in which stone sterilized prior to the treatment was used. The effects of the microbial community on stone consolidation were determined by recording the evolution of the culture media chemistry. The treated stone was tested for mechanical resistance and porosity. Results demonstrate that the tested media were able to activate bacteria from the microbial community of the stone. As a consequence of the growth of these bacteria, an alkalinization occurred that resulted in calcium carbonate precipitation. The new precipitate was compatible with the substrate and consolidated the stone without pore plugging. Therefore, a good candidate to in situ consolidate decayed porous limestone is the application of a sterile culture medium with the characteristics specified in the present study.

Stone-isolated carbonatogenic bacteria as inoculants in bioconsolidation treatments for historical limestone.

PubMed

Jroundi, Fadwa; Gómez-Suaga, Patricia; Jimenez-Lopez, Concepción; González-Muñoz, Maria Teresa; Fernandez-Vivas, Maria Antonia

2012-05-15

Stone consolidation treatments that use bacterial biomineralization are mainly based on two strategies: (1) the inoculation of a bacterial culture with proven carbonatogenic ability and/or (2) the application of a culture medium capable of activating those bacteria able to induce the formation of calcium carbonate, from amongst the bacterial community of the stone. While the second strategy has been demonstrated to be effective and, unlike first strategy, it does not introduce any exogenous microorganism into the stone, problems may arise when the bacterial community of the stone is altered, for instance by the use of biocides in the cleaning process. In this study we isolate bacteria that belong to the natural microbial community of the stone and which have proven biomineralization capabilities, with the aim of preparing an inoculum that may be used in stone consolidation treatments wherein the natural community of those stones is altered. With this aim, outdoor experiments were undertaken to activate and isolate bacteria that display high biomineralization capacity from altered calcarenite stone. Most of the bacteria precipitated calcium carbonate in the form of calcite. The selected bacteria were phylogenetically affiliated with members of Actinobacteria, Gamma-proteobacteria and Firmicutes. Furthermore, the capability of these selected carbonatogenic bacteria to consolidate altered calcarenite stone slabs was studied in in vitro experiments, both in the presence and the absence of Myxococcus xanthus, as a potential reinforcement for the bacterial biomineralization. Herein, Acinetobacter species, belonging to the microbial community of the stone, are proposed as powerful carbonatogenic bacteria that, inoculated under appropriate conditions, may be used as inoculum for calcareous stone conservation/consolidation in restoration interventions where the microbial community of the stone is altered. Copyright © 2012 Elsevier B.V. All rights reserved.

ESA Unveils Its New Comet Chaser.

NASA Astrophysics Data System (ADS)

1999-07-01

The objective is to study one of these primordial objects at close quarters by placing a lander on its surface and chasing, with an orbiter, the comet for millions of kilometres through space. Comets - among the oldest (4.6 billion years!) and last altered objects in the solar system - are regarded as the building blocks from which the planets formed. Thus the Rosetta's discoveries will allow the scientists to learn more about birth and evolution of the planets and about the origin of life on the Earth. The final design of the Rosetta orbiter will be revealed for the first time at the Royal Society in London on 1 July when a 1:4 scale model will be unveiled by ESA's Director of Science, Prof.. Roger Bonnet. (The full size version of the spacecraft is 32 metres across, so large that it would stretch the entire width of a football pitch. Almost 90 of this is accounted for by the giant solar panels which are needed to provide electrical power in the dark depths of the Solar System). "Rosetta is a mission of major scientific importance," said Prof. Bonnet. "It will build on the discoveries made by Giotto and confirm ESA's leading role in the exploration of the Solar System and the Universe as a whole." The timing of this event has been chosen to coincide with the London meeting of the Rosetta Science Working Team and the second Earth flyby of the now non-operational Giotto spacecraft. In addition, the opening of the British Museum's 'Cracking Codes' Exhibition, for which the Rosetta Stone is the centrepiece, is set to take place on 10 July. The Rosetta mission. Rosetta is the third Cornerstone in ESA's 'Horizon 2000' long-term scientific programme. It will be launched by Ariane 5 rocket from Kourou spaceport in French Guiana in January 2003. In order to gain sufficient speed to reach the distant comet, Rosetta will require gravity assists from the Earth (twice) and Mars. After swinging around Mars in May 2005, Rosetta will return to Earth's vicinity in October 2005 and October 2007 before heading away from the Sun towards Comet Wirtanen. As it bounces around the Solar System, Rosetta will also make two excursions into the main asteroid belt, where it will obtain the first close-up images and information on two contrasting objects, 4979 Otawara and 140 Siwa. Scientists believe Otawara is less than 20 km across, whereas Siwa is probably 110 km in diameter, much larger than any asteroid which has so far been visited by spacecraft. Rosetta will fly to within 1,000 km of Otawara in July 2006, followed by a similar rendezvous with Siwa two years later. However, the most difficult phase of the mission will be the final rendezvous with the fast-moving comet (the foreseen date for the rendezvous manoeuvre is 27 November 2011, close approach is set for 20 May 2012 and orbit insertion around the nucleus is set for 28 May 2012). Thus, after a 5.3 billion km space odyssey, Rosetta will make first contact with Wirtanen about 675 million km from the Sun. At this distance, sunlight is 20 times weaker than on Earth, and the comet's nucleus will still be frozen and inactive. Once the navigation team are able to determine the comet's exact location from images returned by the spacecraft camera, a series of braking manoeuvres will allow Rosetta to match speed and direction with its target. After about seven months of edging closer, Rosetta will eventually close to within 2 km of Wirtanen's frozen nucleus. From its close orbit above the tiny nucleus, Rosetta will be able to send back the most detailed images and information ever obtained of a comet. When a suitable landing site has been chosen, about a month after global mapping starts, the orbiter will release a 100 kg lander onto the comet's solid surface. Touchdown must be quite slow - less than one metre per second - to allow for the almost negligible gravitational pull of the tiny nucleus. In order to ensure that the lander does not bounce and disappear into space, an anchoring harpoon will be fired into the surface immediately on impact. By this time, the warmth of the Sun will probably have begun to vapourise parts of the nucleus, initiating some form of surface outgassing. For a period of about a month, data from the lander's eight experiments will be relayed to Earth via the orbiter. They will send back unique information on the nature and composition of the nucleus. Samples for chemical analysis will be taken of the organic crust and ices to a depth of at least 20 cm. Other instruments will measure characteristics such as near-surface strength, density, texture, porosity and thermal properties. Meanwhile, as Comet Wirtanen approaches the Sun, the Rosetta orbiter will fly alongside it, mapping its surface and studying changes in its activity. As its icy nucleus evaporates, 12 experiments on the orbiter will map its surface and study the dust and gas particles it ejects. For the first time, scientists will be able to monitor at close quarters the dramatic changes which take place as a comet plunges sunwards at a speed of 46,000 kph. The stream of data will include a mass of new information about the comet's changes in behaviour as it approaches the Sun, including: * variations in the temperature of the nucleus, * changing intensity and location of gas and dust jets on the nucleus, * the amount of gas and dust emitted from the nucleus, * the size, composition and impact velocity of dust particles, * the nature of the comet's interaction with the charged particles of the solar wind. By mission's end in July 2013, Rosetta will have spent almost two years chasing the comet for millions of kilometres through space. It will also have returned a treasure trove of data, which will enable us to learn more about how the planets formed and where we came from. Why Rosetta? Space exploration is all about discovering the unknown. Just as, 200 years ago, the discovery of the Rosetta Stone eventually enabled Champollion to unravel the mysteries of ancient Egyptian hieroglyphics, so Rosetta will help scientists to unravel the mysteries of comets. Hieroglyphics were the building blocks of the Egyptian language. Comets are the most primitive objects in the Solar System, the building blocks from which the planets formed. Virtually unchanged after 4.6 billion years in the deep freeze of the outer Solar System, they still contain ices and dust from the original solar nebula. They also contain complex organic compounds which some scientists believe may have been the first building blocks for life on Earth. 200 years ago, the discovery of a slab of volcanic basalt near the Egyptian town of Rashid (Rosetta) led to a revolution in our understanding of the past. By comparing the inscriptions on the 'Rosetta Stone', historians were able to decipher Egyptian hieroglyphics for the first time. Just as the Rosetta Stone provided the key to an ancient civilisation, so the European Space Agency's Rosetta spacecraft will allow scientists to unlock the mysteries of the oldest building blocks of our Solar System - the comets. The legacy of Giotto. For centuries, comets have inspired awe and wonder. Many ancient civilisations saw them as portents of death and disaster, omens of great social and political upheavals. Shrouded in thin, luminous veils with tails streaming behind them, these 'long-haired stars' were given the name 'comets' by the ancient Greeks (the Greek word kome meant 'hair'). When ESA's Giotto spacecraft arrived at Halley's Comet in 1986, no one knew what a comet nucleus was really like. The problem was that it is impossible to see the solid heart of a comet from the Earth. As soon as the nucleus moves close enough to us for detailed observation, it is obscured from view by a shroud of gas and dust. The most popular theory about the nature of comets was put forward by American astronomer Fred Whipple, who believed they were like dirty snowballs - large chunks of water ice and dust mixed with ammonia, methane and carbon dioxide. As they approach the Sun, their outer ices begin to vapourise, releasing large amounts of dust and gas to form the surrounding coma and wispy tails. Today, largely thanks to data from Giotto and the Russian Vega spacecraft, we now know that Whipple's model was fairly accurate. A comet nucleus resembles a fluffy snowball, usually only a few kilometres across, coated with a crust of black (probably organic) material and spouting jets of vapourised ice. However, despite these advances, scientists want to learn more about these occasional visitors to the inner Solar System. Why is it important to study comets? Comets formed about 4.5 billion years ago, and so they are among the oldest, most primitive objects in our Solar System. Billions of these giant chunks of ice still linger in the depths of space, the remnants of a vast swarm of objects which once surrounded our Sun and eventually came together to form planets. During the early history of our planet, the Solar System was like a gigantic shooting gallery with comets and asteroids continually crashing into the Earth. Some of the water which makes up the oceans may have originated in these ancient comet collisions. Previous studies have shown that comets carry complex organic molecules, compounds which are rich in carbon, hydrogen, oxygen and nitrogen. Intriguingly, these are the elements, which make up nucleic acids and amino acids, essential ingredients for life as we know it. Did life on Earth begin with the help of cometary seeding? If so, it almost certainly began in a similar way somewhere else. Fortunately, comets rarely strike the Earth today. One of the most recent episodes which has been linked to a small comet occurred at Tunguska in Siberia in 1908. When the incoming object exploded in mid-air, trees were flattened for hundreds of kilometres around. Rosetta's target is the periodic Comet Wirtanen, a chunk of dirty ice less than 1 km across which orbits the Sun once every 5 and a half years. Wirtanen was chosen for the mission because it is much easier to reach than most comets and its path is predictable. Since its discovery in 1948, it has been well observed by ground-based instruments, so its orbit is well known. In recent years the comet's orbit has been altered by the gravitational pull of Jupiter so that it passes close to the Earth's orbit and never strays too far from the Sun. After multiple approaches to the Sun, Wirtanen has lost most of its volatile ices, so outgassing activity remains quite low. This will make it easier for the instruments on board the Rosetta orbiter and lander to image and study the comet's surface.

Concluding Remarks II

NASA Astrophysics Data System (ADS)

Ziółkowski, Janusz

2003-12-01

The program of the conference was prepared so well (thanks to the organizers) that we got complete and competent reviews in all important fields of high energy cosmic sources. It is not easy to select just a few topics and any choice will be, necessarily, arbitrary. I decided to make brief comments on cosmology, on gamma ray bursts and on X-ray flashes. My personal nomination for the hit of the conference goes this year to the ``Rosetta stone" of gamma ray bursts (term used by Elena Pian): GRB030329 = SN 2003dh.

Orbital period determination in an eclipsing dwarf nova HT Cas

NASA Astrophysics Data System (ADS)

Bąkowska, Karolina; Olech, Arkadiusz

2014-09-01

HT Cassiopeiae was discovered over seventy years ago (Hoffmeister 1943). Unfortunately, for 35 years this object did not receive any attention, until the eclipses of HT Cas were observed by Bond. After a first analysis, Patterson (1981) called HT Cas "a Rosetta stone among dwarf novae". Since then, the literature on this star is still growing, reaching several dozens of publications. We present an orbital period determination of HT Cas during the November 2010 super-outburst, but also during a longer time span, to check its stability.

Reproducing stone monument photosynthetic-based colonization under laboratory conditions.

PubMed

Miller, Ana Zélia; Laiz, Leonila; Gonzalez, Juan Miguel; Dionísio, Amélia; Macedo, Maria Filomena; Saiz-Jimenez, Cesareo

2008-11-01

In order to understand the biodeterioration process occurring on stone monuments, we analyzed the microbial communities involved in these processes and studied their ability to colonize stones under controlled laboratory experiments. In this study, a natural green biofilm from a limestone monument was cultivated, inoculated on stone probes of the same lithotype and incubated in a laboratory chamber. This incubation system, which exposes stone samples to intermittently sprinkling water, allowed the development of photosynthetic biofilms similar to those occurring on stone monuments. Denaturing gradient gel electrophoresis (DGGE) analysis was used to evaluate the major microbial components of the laboratory biofilms. Cyanobacteria, green microalgae, bacteria and fungi were identified by DNA-based molecular analysis targeting the 16S and 18S ribosomal RNA genes. The natural green biofilm was mainly composed by the Chlorophyta Chlorella, Stichococcus, and Trebouxia, and by Cyanobacteria belonging to the genera Leptolyngbya and Pleurocapsa. A number of bacteria belonging to Alphaproteobacteria, Bacteroidetes and Verrucomicrobia were identified, as well as fungi from the Ascomycota. The laboratory colonization experiment on stone probes showed a colonization pattern similar to that occurring on stone monuments. The methodology described in this paper allowed to reproduce a colonization equivalent to the natural biodeteriorating process.

Feasibility of removing surface deposits on stone using biological and chemical remediation methods.

PubMed

Polo, A; Cappitelli, F; Brusetti, L; Principi, P; Villa, F; Giacomucci, L; Ranalli, G; Sorlini, C

2010-07-01

The study was conducted on alterations found on stone artwork and integrates microbial control and a biotechnological method for the removal of undesirable chemical substances. The Demetra and Cronos sculptures are two of 12 stone statues decorating the courtyard of the Buonconsiglio Castle in Trento (Italy). An initial inspection of the statues revealed putative black crusts and highlighted the microbial contamination causing discoloration. In 2006, the Cultural Heritage Superintendence of Trento commissioned us to study and remove these chemical and biological stains. Stereomicroscopy characterised the stone of the sculptures as oolitic limestone, and infrared analyses confirmed the presence of black crusts. To remove the black crusts, we applied a remediation treatment of sulphate-reducing bacteria, which removes the chemical alteration but preserves the original stone and the patina noble. Using traditional and biomolecular methods, we studied the putative microbial contamination and confirmed the presence of biodeteriogens and chose biocide Biotin N for the removal of the agents causing the discolouration. Denaturing gradient gel electrophoresis fluorescent in situ hybridisation established that Cyanobacteria and green algae genera were responsible for the green staining whereas the black microbial contamination was due to dematiaceous fungi. After the biocide Biotin N treatment, we applied molecular methods and demonstrated that the Cyanobacteria, and most of the green algae and dematiaceous fungi, had been efficiently removed. The reported case study reveals that conservators can benefit from an integrated biotechnological approach aimed at the biocleaning of chemical alterations and the abatement of biodeteriogens.

The State and Future of Mars Polar Science and Exploration

NASA Technical Reports Server (NTRS)

Clifford, Stephen M.; Crisp, David; Fisher, David A.; Herkenhoff, Ken E.; Smrekar, Suzanne E.; Thomas, Peter C.; Wynn-Williams, David D.; Zurek, Richard W.; Barnes, Jeffrey R.; Bills, Bruce G.

2000-01-01

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of approx. 10(exp 6)sq km and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to he comparatively young-preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past approx. 10(exp 5)-10(exp 8) years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet-documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason-providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.

The State and Future of Mars Polar Science and Exploration

USGS Publications Warehouse

Clifford, S.M.; Crisp, D.; Fisher, D.A.; Herkenhoff, K. E.; Smrekar, S.E.; Thomas, P.C.; Wynn-Williams, D. D.; Zurek, R.W.; Barnes, J.R.; Bills, B.G.; Blake, E.W.; Calvin, W.M.; Cameron, J.M.; Carr, M.H.; Christensen, P.R.; Clark, B. C.; Clow, G.D.; Cutts, J.A.; Dahl-Jensen, D.; Durham, W.B.; Fanale, F.P.; Farmer, J.D.; Forget, F.; Gotto-Azuma, K.; Grard, R.; Haberle, R.M.; Harrison, W.; Harvey, R.; Howard, A.D.; Ingersoll, A.P.; James, P.B.; Kargel, J.S.; Kieffer, H.H.; Larsen, J.; Lepper, K.; Malin, M.C.; McCleese, D.J.; Murray, B.; Nye, J.F.; Paige, D.A.; Platt, S.R.; Plaut, J.J.; Reeh, N.; Rice, J.W.; Smith, D.E.; Stoker, C.R.; Tanaka, K.L.; Mosley-Thompson, E.; Thorsteinsson, T.; Wood, S.E.; Zent, A.; Zuber, M.T.; Zwally, H.J.

2000-01-01

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of ???106 km2 and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young - preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past ???105-108 years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet - documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason - providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding. ?? 2000 Academic Press.

The state and future of Mars polar science and exploration.

PubMed

Clifford, S M; Crisp, D; Fisher, D A; Herkenhoff, K E; Smrekar, S E; Thomas, P C; Wynn-Williams, D D; Zurek, R W; Barnes, J R; Bills, B G; Blake, E W; Calvin, W M; Cameron, J M; Carr, M H; Christensen, P R; Clark, B C; Clow, G D; Cutts, J A; Dahl-Jensen, D; Durham, W B; Fanale, F P; Farmer, J D; Forget, F; Gotto-Azuma, K; Zwally, H J

2000-04-01

As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of approximately 10(6) km2 and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young--preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past approximately 10(5)-10(8) years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet--documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason--providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.

Endolithic diversity of microorganisms on sandstone and implications for biogenic weathering

NASA Astrophysics Data System (ADS)

Hallmann, C.; Friedenberger, H.; Hoppert, M.

2012-04-01

Molecular methods allow a comprehensive view on uncultured microbial communities in dimension stone. In the presented study, we focus on depth profiles of microbial colonization in sandstones with different porosity and overall durability. All sandstones were taken from quarries where they were exposed to the environment for several years. Approximately 0.1 g of material from the stone surface, from 5 mm and from 30 mm depths was taken under sterile conditions and subjected to analysis of microbial DNA and culturing experiments. In particular, DNA was extracted from the material, the phylogenetic marker gene of eukaryotic organisms (18S rDNA) was amplified and used for generation of clone libraries, which were then analysed by sequencing. "Roter Wesersandstein" was just colonized at the material surface, predominantly with algal and fungal microorganisms. No environmental DNA could be isolated from depth profiles. From "Nebraer Sandstein" with high pore size (shown by thin sections), environmental DNA from depths down to 3 cm could be retrieved. Though the uppermost layer is dominated by microalgae (as concluded from the retrieved clones), the percentage of algal clones from 5 mm and 30 mm depths drop to 10 % of all clones. There, apart from filamentous fungi, moss clones clearly dominate the microbial community. At a depth of 30 mm, 70-80 % of the retrieved clones match to various mosses (Bryophyta). Though mosses do not form layers on the stone surfaces, moss rhizoids or protonemata must be abundant as endoliths inside the stone material. It is reasonable to assume that the rhizoids may contribute to an increase in pore size by active penetration of the clastic material, even though colonization of the surface by mosses is not obvious. This feature may imply stronger impact of stone decay induced by endolithic growth of bryophytes than hitherto observed.

Tiny Hiccups To Titanic Explosions: Tackling Transients in Anomalous X-ray Pulsars

NASA Astrophysics Data System (ADS)

Kaspi, Victoria

2006-09-01

Recently discovered transient events in Anomalous X-ray Pulsars (AXPs) may be a Rosetta Stone for understanding the persistent emission from magnetars. They also may hold the key to quantifying the number of magnetars in the Galaxy. Here we request Chandra TOO time to observe any AXP following a rare transient event, including a major outburst or a long-duration flare. Specifically, the requested observations will determine the pulsed fraction and spectral evolution of a transient AXP event as the source relaxes back to quiescence, in order to quantitatively test the "twisted magnetosphere" model for magnetars, and establish the basic phenomenology of transient AXP events.

TINY HICCUPS TO TITANIC EXPLOSIONS: Tackling Transients in Anomalous X-ray Pulsars

NASA Astrophysics Data System (ADS)

Kaspi, Victoria

2007-09-01

Recently discovered transient events in Anomalous X-ray Pulsars (AXPs) may be a Rosetta Stone for understanding the persistent emission from magnetars. They also may hold the key to quantifying the number of magnetars in the Galaxy. Here we request Chandra TOO time to observe any AXP following a rare transient event, including a major outburst or a long-duration flare. Specifically, the requested observations will determine the pulsed fraction and spectral evolution of a transient AXP event as the source relaxes back to quiescence, in order to quantitatively test the "twisted magnetosphere" model for magnetars, and establish the basic phenomenology of transient AXP events.

Hi-tech in space - Rosetta - a space sophisticate

NASA Astrophysics Data System (ADS)

2004-02-01

The European Space Agency’s Rosetta mission will be getting under way in February 2004. The Rosetta spacecraft will be pairing up with Comet 67P/Churyumov-Gerasimenko and accompanying it on its journey, investigating the comet’s composition and the dynamic processes at work as it flies sunwards. The spacecraft will even deposit a lander on the comet. “This will be our first direct contact with the surface of a comet,” said Dr Manfred Warhaut, Operations Manager for the Rosetta mission at ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany. The trip is certainly not short: Rosetta will need ten years just to reach the comet. This places extreme demands on its hardware; when the probe meets up with the comet, all instruments must be fully operational, especially since it will have been in “hibernation” for 2 and a half years of its journey. During this ‘big sleep’, all systems, scientific instruments included, are turned off. Only the on-board computer remains active. Twelve cubic metres of technical wizardry Rosetta’s hardware fits into a sort of aluminium box measuring just 12 cubic metres. The scientific payload is mounted in the upper part, while the subsystems - on-board computer, transmitter and propulsion system - are housed below. The lander is fixed to the opposite side of the probe from the steerable antenna. As the spacecraft orbits the comet, the scientific instruments will at all times be pointed towards its surface; the antenna and solar panels will point towards the Earth and Sun respectively. For trajectory and attitude control and for the major braking manœuvres, Rosetta is equipped with 24 thrusters each delivering 10 N. That corresponds to the force needed here on Earth to hold a bag containing 10 apples. Rosetta sets off with 1650 kg of propellant on board, accounting for more than half its mass at lift-off. Just 20% of total mass is available for scientific purposes. So when developing the research instruments the same rule applied as for supermodels: make every gram count. The calculation seems to have worked out right: the main probe will be carrying 11 scientific instruments and the Rosetta lander a further ten. They will analyse the composition and structure of the comet’s nucleus and study its interaction with the solar wind and the interplanetary plasma. Rosetta - unplugged “To provide the probe with the power it needs in space, we have given it the biggest solar panels ever carried by a European satellite,” Manfred Warhaut explained. “ These cells are its only source of electricity.” They span 32 metres tip to tip while, at 64 m2 the surface area is comparable to that of a two-bedroom flat. The panels may be rotated through 180° to catch the maximum amount of sunlight. These dimensions are also essential because when Rosetta meets Churyumov-Gerasimenko it will be 675 million kilometres away from the Sun. At that distance solar radiation is very weak and the solar collectors will supply only 440 W of power - compared with 8000 W towards the end of the mission when the two companions come closest to the Sun (at some 150 million kilometres from our star distance). “The probe is also equipped with a set of four 10-amp-hour batteries to maintain power supply while Rosetta flies in the shadow of the comet.” Rosetta lander - standing on its own three legs The Rosetta lander is another of the mission’s technical highlights. Using its scientific instruments, its job will be to investigate the comet’s surface on location. Thanks to a mechanical arm, the lander will operate in a two-metre radius. The soft landing is a particular problem given the extremely weak gravitational force exerted by the very small comet nucleus; the lander, weighing in at 100 kg on Earth, will on the comet be as light as a sheet of paper . If there were the slightest recoil, it would bounce back uncontrollably like a rubber ball. To make sure this doesn’t happen, the lander’s three legs are equipped with special shock-absorbers which take up most of the kinetic energy. The legs are also fitted with ice pitons; these bore into the ground immediately on touchdown. At the same moment, the lander fires a harpoon to anchor it to the ground - an opportunity also to investigate the mechanical properties of the surface. “If everything goes according to plan, the mission results could well fundamentally expand our knowledge of comets, just as the Rosetta Stone, after which the probe is named, helped unravel the mystery of Egyptian hieroglyphics,” said Manfred Warhaut. For further information on Rosetta and ESA projects, please consult our portal at: http://www.esa.int/science or directly at http://www.esa.int/rosetta

STEM Summer Academy on the Navajo Reservation

NASA Astrophysics Data System (ADS)

Alexander, C. J.

2012-12-01

The US Rosetta Project is the NASA contribution to the International Rosetta Mission, an ESA cornerstone mission to comet Churyumov-Gerasimenko. While the project's outreach efforts span multi-media, and a variety of age and ethnic groups, a special emphasis has been made to find a way to provide meaningful outreach to the reservation communities. Because language preservation is an issue of urgent concern to the reservation communities, and because Rosetta, uniquely among NASA missions, has been named after the notion that keys to missing understanding of elements of the ancient past were found in the language on the original Rosetta stone, the US Rosetta Project has embarked upon outreach with a focus on STEM vocabulary in ancient US languages of the Navajo, Hopi, Ojibwe, and other tribal communities as the project expands. NASA image and science are used and described in the native language, alongside lay English and scientific English curriculum elements. Additionally, science (geology/chemistry/botany/physics) elements drawn from the reservation environment, including geomorphology, geochemistry, soil physics, are included and discussed in the native language as much as possible — with their analogs in other planetary environments (such as Mars). In this paper we will report on the most recent Summer Science Academy [2012], a four week summer course for middle school children, created in collaboration with teachers and administrators in the Chinle Unified School District. The concept of the Academy was initiated in 2011, and the first Academy was conducted shortly thereafter, in June 2011 with 14 children, 3 instructors, and a NASA teacher workshop. The community requested three topics: geology, astronomy, and botany. The 2012 Academy built on the curriculum already developed with more robust field trips, addressed to specific science topics, additional quantitative measurements and activities, with more written material for the cultural components from Navajo contributors. In 2012, the Academy was conducted with 45 children and 4 instructors. Following up on lessons learned in previous reports, it is clear that community involvement and buy-in is critical to the success of the program. This means that the US Rosetta Project modified its goals and curriculum to accommodate the teaching desires of teachers in the district, and the capabilities of the medicine men that agreed to participate. The use of NASA material and imagery can be shown to have a positive impact on the accessibility of the overall STEM material. Metrics used in the program will be discussed. Future work to extract STEM language elements to enhance the program will include organized Elder's Round Tables for discussion, and recording, of language with first speakers. Work on this project was supported by NASA at California Institute of Technology/Jet Propulsion Laboratory.

Evidence for the timing of sea-level events during MIS 3

NASA Astrophysics Data System (ADS)

Siddall, M.

2005-12-01

Four large sea-level peaks of millennial-scale duration occur during MIS 3. In addition smaller peaks may exist close to the sensitivity of existing methods to derive sea level during these periods. Millennial-scale changes in temperature during MIS 3 are well documented across much of the planet and are linked in some unknown, yet fundamental way to changes in ice volume / sea level. It is therefore highly likely that the timing of the sea level events during MIS 3 will prove to be a `Rosetta Stone' for understanding millennial scale climate variability. I will review observational and mechanistic arguments for the variation of sea level on Antarctic, Greenland and absolute time scales.

The Martian valley networks: Origin by niveo-fluvial processes

NASA Technical Reports Server (NTRS)

Rice, J. W., Jr.

1993-01-01

The valley networks may hold the key to unlocking the paleoclimatic history of Mars. These enigmatic landforms may be regarded as the Martian equivalent of the Rosetta Stone. Therefore, a more thorough understanding of their origin and evolution is required. However, there is still no consensus among investigators regarding the formation (runoff vs. sapping) of these features. Recent climatic modeling precludes warm (0 degrees C) globally averaged surface temperatures prior to 2 b.y. when solar luminosity was 25-30 percent less than present levels. This paper advocates snowmelt as the dominant process responsible for the formation of the dendritic valley networks. Evidence for Martian snowfall and subsequent melt has been discussed in previous studies.

The analysis of microbial spectrum and antibiotic resistance of uropathogens isolated from patients with urinary stones.

PubMed

Chen, Dong; Zhang, Yuyan; Huang, Jian; Liang, Xiongfa; Zeng, Tao; Lan, Chuangxin; Duan, Xiaolu; Zhao, Zhijian; Zeng, Guohua; Tiselius, Hans-Göran; Lu, Xiaogang; Wu, Wenqi

2018-06-01

The characteristics and resistance patterns of urine bacteriology in patients with urinary tract stones have not been extensively studied. This study aims to investigate the microbial spectrum and antibiotic resistance of uropathogens isolated from urinary tract infections in patients with urinary stones and provide a basis for appropriate antimicrobial treatments. The results of positive bladder midstream urine cultures and their antimicrobial susceptibility were retrospectively analysed from hospitalised patients with diagnosis of urinary calculi and urinary tract infections between January 2010 and December 2015. A total of 3892 samples were analysed during the study period: 2201 were female patients (56.6%) and 1691 were male patients (43.4%). The 4 most common uropathogens were Escherichia coli (48.7%), Klebsiella pneumoniae (10.4%), Enterococcus faecalis (8.7%) and Proteus mirabilis (5.2%). Both E. coli (60.8%) and Proteus mirabilis (7.5%) were higher in female patients than in male patients (32.8%; 2.3%; P < .05). ESBL-positive E. coli accounted for 59.5% of total number of E. coli, while ESBL-positive K. pneumoniae comprised 42.0% of total K. pneumoniae. The majority of uropathogens in patients with stones had high resistance to fluoroquinolones, ceftriaxone, ceftazidime, cefepime, penicillins, sulfonamides and monobactams (resistance >20%). The microbial spectrum in patients with urinary stones had a complex pattern. The uropathogens showed marked multidrug resistance and a large proportion of the uropathogens were able to produce β-lactamase. © 2018 John Wiley & Sons Ltd.

Distribution and Diversity of Bacteria and Fungi Colonization in Stone Monuments Analyzed by High-Throughput Sequencing.

PubMed

Li, Qiang; Zhang, Bingjian; He, Zhang; Yang, Xiaoru

The historical and cultural heritage of Qingxing palace and Lingyin and Kaihua temple, located in Hangzhou of China, include a large number of exquisite Buddhist statues and ancient stone sculptures which date back to the Northern Song (960-1219 A.D.) and Qing dynasties (1636-1912 A.D.) and are considered to be some of the best examples of ancient stone sculpting techniques. They were added to the World Heritage List in 2011 because of their unique craftsmanship and importance to the study of ancient Chinese Buddhist culture. However, biodeterioration of the surface of the ancient Buddhist statues and white marble pillars not only severely impairs their aesthetic value but also alters their material structure and thermo-hygric properties. In this study, high-throughput sequencing was utilized to identify the microbial communities colonizing the stone monuments. The diversity and distribution of the microbial communities in six samples collected from three different environmental conditions with signs of deterioration were analyzed by means of bioinformatics software and diversity indices. In addition, the impact of environmental factors, including temperature, light intensity, air humidity, and the concentration of NO2 and SO2, on the microbial communities' diversity and distribution was evaluated. The results indicate that the presence of predominantly phototrophic microorganisms was correlated with light and humidity, while nitrifying bacteria and Thiobacillus were associated with NO2 and SO2 from air pollution.

Contributions of in situ microscopy to the current understanding of stone biodeterioration.

PubMed

de Los Ríos, Asunción; Ascaso, Carmen

2005-09-01

In situ microscopy consists of simultaneously applying several microscopy techniques without separating the biological component from its habitat. Over the past few years, this strategy has allowed characterization of the biofilms involved in biodeterioration processes affecting stone monuments and has revealed the biogeophysical and biogeochemical impact of the microbiota present. In addition, through in situ microscopy diagnosis, appropriate treatments can be designed to resolve the problems related to microbial colonization of stone monuments.

InteractiveROSETTA: a graphical user interface for the PyRosetta protein modeling suite.

PubMed

Schenkelberg, Christian D; Bystroff, Christopher

2015-12-15

Modern biotechnical research is becoming increasingly reliant on computational structural modeling programs to develop novel solutions to scientific questions. Rosetta is one such protein modeling suite that has already demonstrated wide applicability to a number of diverse research projects. Unfortunately, Rosetta is largely a command-line-driven software package which restricts its use among non-computational researchers. Some graphical interfaces for Rosetta exist, but typically are not as sophisticated as commercial software. Here, we present InteractiveROSETTA, a graphical interface for the PyRosetta framework that presents easy-to-use controls for several of the most widely used Rosetta protocols alongside a sophisticated selection system utilizing PyMOL as a visualizer. InteractiveROSETTA is also capable of interacting with remote Rosetta servers, facilitating sophisticated protocols that are not accessible in PyRosetta or which require greater computational resources. InteractiveROSETTA is freely available at https://github.com/schenc3/InteractiveROSETTA/releases and relies upon a separate download of PyRosetta which is available at http://www.pyrosetta.org after obtaining a license (free for academic use). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The PyRosetta Toolkit: a graphical user interface for the Rosetta software suite.

PubMed

Adolf-Bryfogle, Jared; Dunbrack, Roland L

2013-01-01

The Rosetta Molecular Modeling suite is a command-line-only collection of applications that enable high-resolution modeling and design of proteins and other molecules. Although extremely useful, Rosetta can be difficult to learn for scientists with little computational or programming experience. To that end, we have created a Graphical User Interface (GUI) for Rosetta, called the PyRosetta Toolkit, for creating and running protocols in Rosetta for common molecular modeling and protein design tasks and for analyzing the results of Rosetta calculations. The program is highly extensible so that developers can add new protocols and analysis tools to the PyRosetta Toolkit GUI.

A first insight on the biodegradation of limestone: the case of the World Heritage Convent of Christ

NASA Astrophysics Data System (ADS)

Rosado, Tânia; Silva, Mara; Galvão, Andreia; Mirão, José; Candeias, António; Caldeira, Ana Teresa

2016-12-01

The present study is a multidisciplinary approach applied to architectural stone materials of the Convent of Christ in Tomar (Portugal) in order to understand and mitigate the active decay processes. The structure and appearance of the stonework from the Convent of Christ are strongly affected by stains, biofilms and structural degradation. To investigate these phenomena, a multianalytical approach comprising X-ray microdiffraction, scanning electron microscopy, microRaman and microinfrared spectroscopy was applied to the examination of altered outdoor stone areas being detected calcium oxalates, carotenoids and microbial proliferation. The presence of these alteration products seems to be correlated with the microbial activity of bacteria, microalgae, cyanobacteria and filamentous fungi. This work showed that the application of complementary methodologies is an efficient strategy to characterise the stone decay, and constitute a starting point for successful conservation intervention plans that are urgent to ensure the preservation and safeguard of this emblematic monument.

PyRosetta: a script-based interface for implementing molecular modeling algorithms using Rosetta.

PubMed

Chaudhury, Sidhartha; Lyskov, Sergey; Gray, Jeffrey J

2010-03-01

PyRosetta is a stand-alone Python-based implementation of the Rosetta molecular modeling package that allows users to write custom structure prediction and design algorithms using the major Rosetta sampling and scoring functions. PyRosetta contains Python bindings to libraries that define Rosetta functions including those for accessing and manipulating protein structure, calculating energies and running Monte Carlo-based simulations. PyRosetta can be used in two ways: (i) interactively, using iPython and (ii) script-based, using Python scripting. Interactive mode contains a number of help features and is ideal for beginners while script-mode is best suited for algorithm development. PyRosetta has similar computational performance to Rosetta, can be easily scaled up for cluster applications and has been implemented for algorithms demonstrating protein docking, protein folding, loop modeling and design. PyRosetta is a stand-alone package available at http://www.pyrosetta.org under the Rosetta license which is free for academic and non-profit users. A tutorial, user's manual and sample scripts demonstrating usage are also available on the web site.

PyRosetta: a script-based interface for implementing molecular modeling algorithms using Rosetta

PubMed Central

Chaudhury, Sidhartha; Lyskov, Sergey; Gray, Jeffrey J.

2010-01-01

Summary: PyRosetta is a stand-alone Python-based implementation of the Rosetta molecular modeling package that allows users to write custom structure prediction and design algorithms using the major Rosetta sampling and scoring functions. PyRosetta contains Python bindings to libraries that define Rosetta functions including those for accessing and manipulating protein structure, calculating energies and running Monte Carlo-based simulations. PyRosetta can be used in two ways: (i) interactively, using iPython and (ii) script-based, using Python scripting. Interactive mode contains a number of help features and is ideal for beginners while script-mode is best suited for algorithm development. PyRosetta has similar computational performance to Rosetta, can be easily scaled up for cluster applications and has been implemented for algorithms demonstrating protein docking, protein folding, loop modeling and design. Availability: PyRosetta is a stand-alone package available at http://www.pyrosetta.org under the Rosetta license which is free for academic and non-profit users. A tutorial, user's manual and sample scripts demonstrating usage are also available on the web site. Contact: pyrosetta@graylab.jhu.edu PMID:20061306

Determining protein function and interaction from genome analysis

DOEpatents

Eisenberg, David; Marcotte, Edward M.; Thompson, Michael J.; Pellegrini, Matteo; Yeates, Todd O.

2004-08-03

A computational method system, and computer program are provided for inferring functional links from genome sequences. One method is based on the observation that some pairs of proteins A' and B' have homologs in another organism fused into a single protein chain AB. A trans-genome comparison of sequences can reveal these AB sequences, which are Rosetta Stone sequences because they decipher an interaction between A' and B. Another method compares the genomic sequence of two or more organisms to create a phylogenetic profile for each protein indicating its presence or absence across all the genomes. The profile provides information regarding functional links between different families of proteins. In yet another method a combination of the above two methods is used to predict functional links.

Assigning protein functions by comparative genome analysis protein phylogenetic profiles

DOEpatents

Pellegrini, Matteo; Marcotte, Edward M.; Thompson, Michael J.; Eisenberg, David; Grothe, Robert; Yeates, Todd O.

2003-05-13

A computational method system, and computer program are provided for inferring functional links from genome sequences. One method is based on the observation that some pairs of proteins A' and B' have homologs in another organism fused into a single protein chain AB. A trans-genome comparison of sequences can reveal these AB sequences, which are Rosetta Stone sequences because they decipher an interaction between A' and B. Another method compares the genomic sequence of two or more organisms to create a phylogenetic profile for each protein indicating its presence or absence across all the genomes. The profile provides information regarding functional links between different families of proteins. In yet another method a combination of the above two methods is used to predict functional links.

Serendipity: Accidental Discoveries in Science

NASA Astrophysics Data System (ADS)

Roberts, Royston M.

1989-06-01

Many of the things discovered by accident are important in our everyday lives: Teflon, Velcro, nylon, x-rays, penicillin, safety glass, sugar substitutes, and polyethylene and other plastics. And we owe a debt to accident for some of our deepest scientific knowledge, including Newton's theory of gravitation, the Big Bang theory of Creation, and the discovery of DNA. Even the Rosetta Stone, the Dead Sea Scrolls, and the ruins of Pompeii came to light through chance. This book tells the fascinating stories of these and other discoveries and reveals how the inquisitive human mind turns accident into discovery. Written for the layman, yet scientifically accurate, this illuminating collection of anecdotes portrays invention and discovery as quintessentially human acts, due in part to curiosity, perserverance, and luck.

PHYSICOCHEMICAL PROPERTIES AS PREDICTORS OF ORGANIC CHEMICAL EFFECTS ON SOIL MICROBIAL RESPIRATION

EPA Science Inventory

Structure-activity analysis was used to evaluate the effects of 19 hazardous organic chemicals on microbial respiration in two slightly acidic soils (a Captina silt loam from Roane County Tennessee, and a McLaurin sandy loam from Stone County, Mississippi), both low in organic ca...

Epilithic and endolithic bacterial communities in limestone from a Maya archaeological site.

PubMed

McNamara, Christopher J; Perry, Thomas D; Bearce, Kristen A; Hernandez-Duque, Guillermo; Mitchell, Ralph

2006-01-01

Biodeterioration of archaeological sites and historic buildings is a major concern for conservators, archaeologists, and scientists involved in preservation of the world's cultural heritage. The Maya archaeological sites in southern Mexico, some of the most important cultural artifacts in the Western Hemisphere, are constructed of limestone. High temperature and humidity have resulted in substantial microbial growth on stone surfaces at many of the sites. Despite the porous nature of limestone and the common occurrence of endolithic microorganisms in many habitats, little is known about the microbial flora living inside the stone. We found a large endolithic bacterial community in limestone from the interior of the Maya archaeological site Ek' Balam. Analysis of 16S rDNA clones demonstrated disparate communities (endolithic: >80% Actinobacteria, Acidobacteria, and Low GC Firmicutes; epilithic: >50% Proteobacteria). The presence of differing epilithic and endolithic bacterial communities may be a significant factor for conservation of stone cultural heritage materials and quantitative prediction of carbonate weathering.

Cyanobacteria cause black staining of the National Museum of the American Indian Building, Washington, DC, USA.

PubMed

Cappitelli, Francesca; Salvadori, Ornella; Albanese, Domenico; Villa, Federica; Sorlini, Claudia

2012-01-01

Microbial deterioration of stone is a widely recognised problem affecting monuments and buildings all over the world. In this paper, dark-coloured staining, putatively attributed to microorganisms, on areas of the National Museum of the American Indian Building, Washington, DC, USA, were studied. Observations by optical and electron microscopy of surfaces and cross sections of limestone indicated that biofilms, which penetrated up to a maximum depth of about 1 mm, were mainly composed of cyanobacteria, with the predominance of Gloeocapsa and Lyngbya. Denaturing gradient gel electrophoresis analysis revealed that the microbial community also included eukaryotic algae (Trebouxiophyceae) and fungi (Ascomycota), along with a consortium of bacteria. Energy-dispersive X-ray spectroscopy analysis showed the same elemental composition in stained and unstained areas of the samples, indicating that the discolouration was not due to abiotic chemical changes within the stone. The dark pigmentation of the stone was correlated with the high content of scytonemin, which was found in all samples.

RNA-protein interactions in an unstructured context.

PubMed

Zagrovic, Bojan; Bartonek, Lukas; Polyansky, Anton A

2018-05-31

Despite their importance, our understanding of noncovalent RNA-protein interactions is incomplete. This especially concerns the binding between RNA and unstructured protein regions, a widespread class of such interactions. Here, we review the recent experimental and computational work on RNA-protein interactions in an unstructured context with a particular focus on how such interactions may be shaped by the intrinsic interaction affinities between individual nucleobases and protein side chains. Specifically, we articulate the claim that the universal genetic code reflects the binding specificity between nucleobases and protein side chains and that, in turn, the code may be seen as the Rosetta stone for understanding RNA-protein interactions in general. © 2018 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Molecular monitoring of the microbial dynamics occurring on historical limestone buildings during and after the in situ application of different bio-consolidation treatments

PubMed Central

Ettenauer, Jörg; Piñar, Guadalupe; Sterflinger, Katja; Gonzalez-Muñoz, Maria Teresa; Jroundi, Fadwa

2011-01-01

Microbially Induced Carbonate Precipitation is proposed as an environmentally friendly method to protect decayed ornamental stone and introduced in the field of preservation of Cultural Heritage. Recent conservation studies performed under laboratory conditions on non-sterile calcarenite stones have successfully reported on the application of a suitable nutritional solution, inoculated and non-inoculated with Myxococcus xanthus, as a bioconsolidation treatment. Furthermore, this procedure has been applied in situ, very recently, to selected historical buildings in Granada, Spain. For the first time, we evaluate the efficiency and risks of the in situ application of the above mentioned treatments onto two historical buildings in Granada. The evaluation consists of a detailed investigation of the micro-biota actively growing during the seven days of the treatments – short-term monitoring and of that remaining on the stones after six and twelve months of the application – long-term monitoring. A molecular strategy, including DNA extraction, PCR amplification of 16S rRNA sequences, construction of clone libraries and fingerprinting by DGGE (Denaturing Gradient Gel Electrophoresis) analysis followed by sequencing was used to gain insight into the microbial diversity present on the differentially treated stones. The monitoring of M. xanthus was performed by PCR using species-specific primers. Similar dynamics were triggered on both buildings by the application of the nutritional solution (inoculated or non-inoculated). 16S rDNA sequencing revealed the dominant occurrence of members belonging to the Firmicutes and Proteobacteria during the seven days of the treatment, whereas after one year the order Bacillales of the phylum Firmicutes was the predominantly detected microorganisms. M. xanthus could be detected only during the seven days of the treatment. The treatments seem to activate no dangerous microorganisms and furthermore, to select the remainder of a homogeneous group of carbonatogenic bacteria on the stones after a long period of time. PMID:21944202

Serverification of Molecular Modeling Applications: The Rosetta Online Server That Includes Everyone (ROSIE)

PubMed Central

Conchúir, Shane Ó.; Der, Bryan S.; Drew, Kevin; Kuroda, Daisuke; Xu, Jianqing; Weitzner, Brian D.; Renfrew, P. Douglas; Sripakdeevong, Parin; Borgo, Benjamin; Havranek, James J.; Kuhlman, Brian; Kortemme, Tanja; Bonneau, Richard; Gray, Jeffrey J.; Das, Rhiju

2013-01-01

The Rosetta molecular modeling software package provides experimentally tested and rapidly evolving tools for the 3D structure prediction and high-resolution design of proteins, nucleic acids, and a growing number of non-natural polymers. Despite its free availability to academic users and improving documentation, use of Rosetta has largely remained confined to developers and their immediate collaborators due to the code’s difficulty of use, the requirement for large computational resources, and the unavailability of servers for most of the Rosetta applications. Here, we present a unified web framework for Rosetta applications called ROSIE (Rosetta Online Server that Includes Everyone). ROSIE provides (a) a common user interface for Rosetta protocols, (b) a stable application programming interface for developers to add additional protocols, (c) a flexible back-end to allow leveraging of computer cluster resources shared by RosettaCommons member institutions, and (d) centralized administration by the RosettaCommons to ensure continuous maintenance. This paper describes the ROSIE server infrastructure, a step-by-step ‘serverification’ protocol for use by Rosetta developers, and the deployment of the first nine ROSIE applications by six separate developer teams: Docking, RNA de novo, ERRASER, Antibody, Sequence Tolerance, Supercharge, Beta peptide design, NCBB design, and VIP redesign. As illustrated by the number and diversity of these applications, ROSIE offers a general and speedy paradigm for serverification of Rosetta applications that incurs negligible cost to developers and lowers barriers to Rosetta use for the broader biological community. ROSIE is available at http://rosie.rosettacommons.org. PMID:23717507

Rosetta begins its 10-year journey to the origins of the Solar System

NASA Astrophysics Data System (ADS)

2004-03-01

Rosetta’s mission began at 08h17 CET (07h17 GMT) on 2 March when a European Ariane 5 launch vehicle liftered off from the Guiana Space Centre, Europe’s spaceport in Kourou, French Guiana. The launcher successfully placed its upper stage and payload into an eccentric coast orbit (200 x 4000 km). About two hours later, at 10h14 CET (09h14 GMT) the upper stage ignited its own engine to reach an escape velocity in order to leave the Earth’s gravity field and enter heliocentric orbit. The Rosetta probe was released about 18 minutes later. “After the recent success of Mars Express, Europe is now heading to deep space with another fantastic mission. We will have to be patient, as the rendezvous with the comet will not take place until ten years from now, but I think it’s worth the wait” said ESA’s Director General Jean-Jacques Dordain witnessing the launch from Kourou. ESA’s Operations Centre (ESOC) in Darmstadt, Germany, has established contact with the probe as it flies away from Earth at a relative speed of about 3.4 km/s. ESOC will be in charge of Rosetta operations and orbit determination throughout the mission. During the next eight months, the spacecraft’s onboard systems will be checked and its science payload will be commissioned. A 10-year odyssey Rosetta will be reactivated for planetary flybys, which will be used to modify its trajectory through gravity assist manoeuvres. During the trip, the probe could also observe one or more asteroids, observation of asteroids being one of the mission's secondary objectives. The first planetary encounter will be in March 2005, as Rosetta flies by the Earth for the first time. The gravity assist will boost Rosetta into an orbit that will take it to Mars two years later. During its close encounter with Mars in February 2007, Rosetta will approach to a distance of about 200 km and conduct science observations. This Martian flyby will be followed by another Earth flyby in November the same year. Both planetary encounters will increase the probe’s orbital energy and boost it well into the asteroid belt. A third and last flyby of the Earth in November 2009 will send Rosetta toward the orbit of comet Churyumov-Gerasimenko. Then, by mid-2011, when it is about 800 million km from the Sun, Rosetta will ignite its main engine for a major deep-space manoeuvre that will place it onto an interception trajectory with the comet, which will take nearly three years to be reached. Rosetta will be reactivated for good in January 2014, as it enters a six-month approach phase, closing in slowly on the nucleus of comet Churyumov-Gerasimenko. The comet will then still be far from the Sun and should not be active. Rendezvous with a comet Like comet 46P/Wirtanen, which was the planned target for Rosetta until its launch was postponed in early 2003, comet 67P/Churyumov-Gerasimenko is one of the periodic comets that were “trapped” in the inner Solar System after they came too close to Jupiter. This comet was discovered in September 1969 at the Almaty Astrophysical Institute in Kazakhstan. It was detected by astronomer Klim Churyumov, from the University of Kiev, Ukraine, on pictures taken by his colleague Svetlana Gerasimenko, from the Institute of Astrophysics of Dushanbe, Tajikistan. Rosetta will start accompanying the comet's nucleus in August 2014. It will then conduct detailed mapping of its surface and a landing site will be selected for Philae, its 100 kg lander. Philae will be dropped from an altitude of about 1 km and, due to the tiny gravity of the nucleus, it will touch down at walking speed. The lander will even have to anchor itself to the surface with two harpoons to avoid bouncing back. Philae is expected to operate from the surface for several weeks, sending back very high resolution pictures and as information about the upper crust of the nucleus. These data will be relayed to Earth by the orbiter. Rosetta will continue its observations of the comet’s nucleus for over a year, at least until December 2015, and will have a ringside seat to monitor the « awakening » of the comet’s activity as it comes closer to the Sun and reached its perihelion, in October 2015. Probing the comet The Rosetta probe was built for ESA by an industrial team of over 50 European companies led by EADS Astrium. It is a 3 tonne spacecraft with solar arrays spanning an impressive 32 metres. This is the first probe designed to travel beyond the orbit of Mars to rely on solar cells for its power supply. In addition to the Philae lander, Rosetta incorporates a 165 kg science payload consisting of 11 instruments developed in partnership by ESA member countries and by the the United States. Four of these instruments are dedicated to observation of the nucleus: the ALICE ultraviolet spectrometer, the OSIRIS high-resolution camera, the VIRTIS imaging spectrometer and the MIRO microwave radiometer/spectrometer. Three more instruments will study the composition of the nucleus and its emanations; the COSIMA and ROSINA spectrometers and the MIDAS microscope. The GIADA collector will analyse dusts in the vicinity of the nucleus while the RPC group of sensors will characterise the internal structure of the comet’s coma and its interaction with the solar wind. The last two instruments, CONSERT and RSI, will use radio waves, one to probe the internal structure of the nucleus and the other to determine the distribution of masses inside the nucleus and the structure of the coma. The Philae lander, developed under the leadership of Germany’s DLR aerospace research agency, carries 9 instruments provided by ESA member countries in partnership with the United States, Hungary and Russia. Among these, the ÇIVA/ROLIS set of cameras will provide panoramic and stereoscopic high-resolution views. The APXS, COSAC and Ptolemy instruments will analyse soil compounds. The SESAME seismometer will probe the surface to a depth of 2 m, while its characteristics will be studied by the MUPUS instrument with sensors on the anchoring harpoon. The ROMAP magnetometer and a second model of the CONSERT experiment will study the magnetic field and its interactions with the solar wind. The Rosetta Stone -unearthed in Egypt more than 200 years ago- gave XIXth-century Egyptologists the keys to decipher hieroglyphic writing and to rediscover three millennia of forgotten Egyptian history and culture. The in-depth study of a comet’s nucleus and asteroids by the Rosetta probe is expected to enable today’s science community to decipher the mystery of the origins of our Solar System and to better understand the mechanisms ruling the formation of planetary systems around other stars.

The U.S. Rosetta Project: Preparations for Prime Mission, 2014

NASA Technical Reports Server (NTRS)

Alexander, C.; Chmielewski, A.; Aguinaldo, A. M.; Ko, A.; Accomazzo, A.; Taylor, M. G. G.

2014-01-01

In 2014, the International Rosetta mission will place a spacecraft in orbit around comet 67P/Churyumov-Gerasimenko and deliver a lander to the comet's surface. The National Aeronautics and Space Administration's (NASA) contribution to the International Rosetta mission, designated the U.S. Rosetta Project, includes several instruments, tracking support, and science support for some non-US payloads. In July 2011 the spacecraft was placed in a long-duration hibernation mode planned to last approximately 37 months to conserve electrical power. Rosetta will rendezvous with 67P/Churyumov-Gerasimenko in 2014. On the eve of the mission's arrival at its target, this paper highlights three issues related to Rosetta's looming prime mission: (A) measures taken in 2009 to prepare the US Rosetta Project for the long-duration hibernation mode; (B) risk reviews conducted in 2013 to prepare the US Rosetta Project for exit from hibernation; (C) ESA and NASA preparations for use of NASA Deep Space Network (DSN) assets related to keyword files.

Engineering, Life Sciences, and Health/Medicine Synergy in Aerospace Human Systems Integration: The Rosetta Stone Project

NASA Technical Reports Server (NTRS)

Williams, Richard S. (Editor); Doarn, Charles R. (Editor); Shepanek, Marc A.

2017-01-01

In the realm of aerospace engineering and the physical sciences, we have developed laws of physics based on empirical and research evidence that reliably guide design, research, and development efforts. For instance, an engineer designs a system based on data and experience that can be consistently and repeatedly verified. This reproducibility depends on the consistency and dependability of the materials on which the engineer works and is subject to physics, geometry and convention. In life sciences and medicine, these apply as well, but individuality introduces a host of variables into the mix, resulting in characteristics and outcomes that can be quite broad within a population of individuals. This individuality ranges from differences at the genetic and cellular level to differences in an individuals personality and abilities due to sex and gender, environment, education, etc.

RosettaRemodel: A Generalized Framework for Flexible Backbone Protein Design

PubMed Central

Huang, Po-Ssu; Ban, Yih-En Andrew; Richter, Florian; Andre, Ingemar; Vernon, Robert; Schief, William R.; Baker, David

2011-01-01

We describe RosettaRemodel, a generalized framework for flexible protein design that provides a versatile and convenient interface to the Rosetta modeling suite. RosettaRemodel employs a unified interface, called a blueprint, which allows detailed control over many aspects of flexible backbone protein design calculations. RosettaRemodel allows the construction and elaboration of customized protocols for a wide range of design problems ranging from loop insertion and deletion, disulfide engineering, domain assembly, loop remodeling, motif grafting, symmetrical units, to de novo structure modeling. PMID:21909381

Foldit Standalone: a video game-derived protein structure manipulation interface using Rosetta

PubMed Central

Kleffner, Robert; Flatten, Jeff; Leaver-Fay, Andrew; Baker, David; Siegel, Justin B.; Khatib, Firas; Cooper, Seth

2017-01-01

Abstract Summary: Foldit Standalone is an interactive graphical interface to the Rosetta molecular modeling package. In contrast to most command-line or batch interactions with Rosetta, Foldit Standalone is designed to allow easy, real-time, direct manipulation of protein structures, while also giving access to the extensive power of Rosetta computations. Derived from the user interface of the scientific discovery game Foldit (itself based on Rosetta), Foldit Standalone has added more advanced features and removed the competitive game elements. Foldit Standalone was built from the ground up with a custom rendering and event engine, configurable visualizations and interactions driven by Rosetta. Foldit Standalone contains, among other features: electron density and contact map visualizations, multiple sequence alignment tools for template-based modeling, rigid body transformation controls, RosettaScripts support and an embedded Lua interpreter. Availability and Implementation: Foldit Standalone is available for download at https://fold.it/standalone, under the Rosetta license, which is free for academic and non-profit users. It is implemented in cross-platform C ++ and binary executables are available for Windows, macOS and Linux. Contact: scooper@ccs.neu.edu PMID:28481970

ROSETTA: How to archive more than 10 years of mission

NASA Astrophysics Data System (ADS)

Barthelemy, Maud; Heather, D.; Grotheer, E.; Besse, S.; Andres, R.; Vallejo, F.; Barnes, T.; Kolokolova, L.; O'Rourke, L.; Fraga, D.; A'Hearn, M. F.; Martin, P.; Taylor, M. G. G. T.

2018-01-01

The Rosetta spacecraft was launched in 2004 and, after several planetary and two asteroid fly-bys, arrived at comet 67P/Churyumov-Gerasimenko in August 2014. After escorting the comet for two years and executing its scientific observations, the mission ended on 30 September 2016 through a touch down on the comet surface. This paper describes how the Planetary Science Archive (PSA) and the Planetary Data System - Small Bodies Node (PDS-SBN) worked with the Rosetta instrument teams to prepare the science data collected over the course of the Rosetta mission for inclusion in the science archive. As Rosetta is an international mission in collaboration between ESA and NASA, all science data from the mission are fully archived within both the PSA and the PDS. The Rosetta archiving process, supporting tools, archiving systems, and their evolution throughout the mission are described, along with a discussion of a number of the challenges faced during the Rosetta implementation. The paper then presents the current status of the archive for each of the science instruments, before looking to the improvements planned both for the archive itself and for the Rosetta data content. The lessons learned from the first 13 years of archiving on Rosetta are finally discussed with an aim to help future missions plan and implement their science archives.

ESA's Rosetta mission and the puzzles that Hale-Bopp left behind

NASA Astrophysics Data System (ADS)

1997-04-01

The scientific payload was confirmed by ESA's Science Programme Committee in February. Now the scientists must perfect the full range of ultra-sensitive yet spaceworthy instruments in good time for Rosetta's despatch by an Ariane 5 launcher in January 2003. And even as most of the world was admiring Comet Hale-Bopp at its brightest, dedicated astronomers were examining the comet that will be Rosetta's target. Although too faint to be seen with the naked eye, Comet Wirtanen made its closest approach to the Sun on 14 March and a fairly close approach to the Earth on 24 March. This comet comes back every 5.5 years. Rosetta will dance attendance on Comet Wirtanen, not at the next return in 2002, nor even in 2008, but in 2013. The project is an ambitious and patient effort to achieve the most thorough investigation of a comet ever attempted. As the successor to ESA's highly successful Giotto mission to Halley's Comet and Comet Grigg-Skjellerup (which took seven years) Rosetta will spend eight years positioning itself. It will manoeuvre around the planets until it is shadowing Comet Wirtanen far beyond Mars, on nearly the same path around the Sun. In 2011 it will rendezvous with the comet and fly near it. In April 2012 Rosetta will go into a near orbit around Comet Wirtanen, and escort it for 17 busy months, as it flies in to make its closest approach to the Sun in September 2013, at the climax of the mission. "The Giotto mission placed us at the forefront of cometary exploration," comments Roger Bonnet, ESA's director of science. "The motivation came from European scientists with a sharp sense of the special importance of comets for understanding the Solar System. The same enthusiasm drives us onward to Rosetta, which will ensure our continued leadership in this important branch of space science." Scientific tasks During its prolonged operations in very close company with the comet's nucleus, Rosetta will map and examine its entire surface from distances of 10 to 50 kilometres with a set of remote-sensing instruments. As the spacecraft moves around the nucleus at a very leisurely walking pace, other onboard instruments will analyse the dust and vapours, which will emanate from Comet Wirtanen with ever-increasing vigour as the Sun's rays warm it. Rosetta will drop a lander on to the comet's surface, for close inspection of its physical condition and chemical composition. The lander is a venture led by Germany, France and Italy, with participation from Austria, Finland, Hungary, Poland and the UK. As a box packed with scientific instruments and standing on three legs, the lander will be capable of anchoring itself to one spot and drilling into the surface. It may also be able to hop like a flea to visit another part of the nucleus. A combination of solar energy and electric batteries will enable operations to last for several months. "The combination of Rosetta in orbit around the comet and the lander on its surface is very powerful from a scientific point of view," says Gerhard Schwehm, ESA's project scientist for Rosetta. "We shall watch Comet Wirtanen brewing up like a volcano as it feels the heat of the Sun. In place of hazy impressions of the nucleus of a comet half hidden by its dust clouds, we shall see all the details with unprecedented clarity." Unanswered questions During and after the 1986 appearance of Halley's Comet, comet science made great progress. More recent comets have revealed important secrets to ESA's Infrared Space Observatory and to other space telescopes examining them at wavelengths unobservable from the Earth. Yet basic questions about comets remain unanswered. Just as the Rosetta Stone was the key that unlocked the meaning of Egyptian hieroglyphs, so the Rosetta spacecraft is intended to decipher the meaning of comets and their role in the origin and history of the Solar System. Here are a few of the main puzzles. * What does a comet weigh? Guesses about the density of cometary material vary widely, and only an orbiting spacecraft can give exact measurements of the comet's volume and mass. * Is a comet a dirty snowball or an icy dirtball? In other words, is it made of ices contaminated with mineral and tarry dust, or is it a consolidation of dust coated with ices? * Why is the nucleus of a comet so dark? Giotto established that Halley's nucleus is like brownish-black velvet, absorbing 96 per cent of the sunlight falling on it. Is the colour due to a surface deposit of tarry dust, or is the interior dark too? * Why are small regions of a comet highly active when most of its surface is not? Multiple jets of dust seen emanating from Halley's Comet, and spectacularly from Comet Hale-Bopp, imply that certain hot-spots differ physically or chemically from the rest of the comet's surface. * Is a comet made as single piece, or does it consist of loosely joined blocks, as suggested by the Giotto images? This relates to the questions of how comets are built, and why they break up into smaller fragments, as seen spectacularly with Comet Shoemaker-Levy 9 which hit Jupiter in 1994. * Does a dying comet evaporate and disappear, or does it simply exhaust the stocks of ice that drive the emissions of gas and dust from an active comet? If the latter answer is correct, dead comets persist long afterwards as dark, inactive masses of minerals and tar, and pose a lasting threat of collisions with the Earth. * What is a comet's exact composition? Many ingredients are known, and the approximate abundances of the main constituents. Details coming from Rosetta will pin down (1) how comets were fashioned from similar constituents of interstellar dust and (2) how comets contributed to building the planets, including the Earth, and stocking their atmospheres. * Is the tarry, carbon-rich material in comets a jumble of every kind of chemical that inorganic processes can make from carbon, nitrogen, oxygen and hydrogen, or does it contain special compounds? This is relevant to assessing the role of comets in the origin of life on the Earth. The comet specialist Uwe Keller of the Max-Planck Institut fur Aeronomie, Germany, is one of the Giotto veterans who has helped with the planning of Rosetta. He was in charge of Giotto's camera. "Rosetta is the mission we are all waiting for," Dr Keller comments. "After I spent six years analysing our images of the Halley nucleus, I say that basic scientific assumptions about the nature of comets are still contradictory. We shall settle the arguments only by the close, prolonged inspection that Rosetta will make possible." Engineering the Rosetta mission To build up the speed needed to adopt the same orbit around the Sun as Comet Wirtanen, Rosetta must steal energy of motion from the planets, in a swingby of Mars and two swingbys of the Earth. During its far-flung manoeuvres in pursuit of the comet, Rosetta will inspect the asteroids Mimistrobell and Rodari at close quarters. When Rosetta is far from the Earth, or on the wrong side of the Sun, communication will be difficult. The spacecraft will therefore have a high degree of robotic self-reliance. It will also be capable of hibernating for more than two years without attention -- a technique devised by ESA for the later stages of the Giotto mission. Rosetta will rely on solar power, even when more than five times further than the Earth from the Sun. Special low-intensity solar cells are under development for Rosetta. Conditions in this farthest phase of Rosetta's voyage will be very chilly, but ESA's engineers are satisfied that the temperatures inside the spacecraft can be kept within limits by black paint, multilayer insulation and electric heaters. Despite its originality and sophistication, Rosetta will be just a flying box with solar arrays like wings, looking rather like a telecommunications satellite. "Keep it simple," is the motto of John Credland, ESA's project manager for Rosetta. "Simplicity brings reliability," he explains, "and that is my overriding concern for the engineering of a spacecraft that has to survive and operate far from the Earth for nearly eleven years." To command Rosetta, and to receive its signals carrying new of the comet, ESA will use a new 32-metre deep-space tracking antenna at Perth in Australia, and a 15-metre antenna in Spain. The spacecraft operations, especially in the near-comet phase of the mission, will be a novel experience for the controllers at the European Space Operations Centre in Darmstadt, Germany. The gravity of the comet will be weak, and Rosetta's manoeuvres around it will be like a ballet in slow motion. At around 10 kilometres distance, the spacecraft will travel at only 1-2 kilometres per hour in relation to the comet and take about a week to circle once around the nucleus. Sometimes Rosetta will swoop even closer to the comet's surface, to inspect possible landing sights and to drop the lander. The spacecraft's thrusters will adjust the orbit. To keep manoeuvres to a minimum, and so conserve fuel and avoid polluting the comet's environment, computer simulations will help the spacecraft navigators to predict the consequences of any manoeuvre for weeks in advance. The target comet Present-day space propulsion systems allow a rendezvous only with a comet with a predictable and relatively small orbit around the Sun. All comets of this kind are "old", in the sense that they have visited the Sun's vicinity many times and are no longer vigorous in the dust and gas formation that makes their visible comas and tails. The second comet visited by Giotto, Comet Grigg-Skjellerup, was of this elderly kind. From among several short-period candidates, the mission team chose Comet Wirtanen as Rosetta's target comet because it offered the quickest timetable between the launch of the spacecraft and the completion of the mission. The comet was discovered by chance by Carl Wirtanen in 1948 on photographic plates at the Lick Observatory in California. In 1972 and 1984 encounters with the planet Jupiter reduced the size of Comet Wirtanen's orbit, and shortened the interval between its visits to the Sun from 6.65 to 5.5 years. Despite many observations no one really knows the comet's mass, size and shape. The uncertainties are reflected in the computer simulations of manoeuvres near the comet. These cover a wide range of possibilities from a lightweight comet to a massive one, and from a small comet 1 kilometre in diameter to a large one 20 kilometres wide. The best estimate may be 1.5 kilometres. But it is in the nature of a voyage of exploration like Rosetta's that you don't know what you will find!

Foldit Standalone: a video game-derived protein structure manipulation interface using Rosetta.

PubMed

Kleffner, Robert; Flatten, Jeff; Leaver-Fay, Andrew; Baker, David; Siegel, Justin B; Khatib, Firas; Cooper, Seth

2017-09-01

Foldit Standalone is an interactive graphical interface to the Rosetta molecular modeling package. In contrast to most command-line or batch interactions with Rosetta, Foldit Standalone is designed to allow easy, real-time, direct manipulation of protein structures, while also giving access to the extensive power of Rosetta computations. Derived from the user interface of the scientific discovery game Foldit (itself based on Rosetta), Foldit Standalone has added more advanced features and removed the competitive game elements. Foldit Standalone was built from the ground up with a custom rendering and event engine, configurable visualizations and interactions driven by Rosetta. Foldit Standalone contains, among other features: electron density and contact map visualizations, multiple sequence alignment tools for template-based modeling, rigid body transformation controls, RosettaScripts support and an embedded Lua interpreter. Foldit Standalone is available for download at https://fold.it/standalone , under the Rosetta license, which is free for academic and non-profit users. It is implemented in cross-platform C ++ and binary executables are available for Windows, macOS and Linux. scooper@ccs.neu.edu. © The Author(s) 2017. Published by Oxford University Press.

Web-accessible molecular modeling with Rosetta: The Rosetta Online Server that Includes Everyone (ROSIE).

PubMed

Moretti, Rocco; Lyskov, Sergey; Das, Rhiju; Meiler, Jens; Gray, Jeffrey J

2018-01-01

The Rosetta molecular modeling software package provides a large number of experimentally validated tools for modeling and designing proteins, nucleic acids, and other biopolymers, with new protocols being added continually. While freely available to academic users, external usage is limited by the need for expertise in the Unix command line environment. To make Rosetta protocols available to a wider audience, we previously created a web server called Rosetta Online Server that Includes Everyone (ROSIE), which provides a common environment for hosting web-accessible Rosetta protocols. Here we describe a simplification of the ROSIE protocol specification format, one that permits easier implementation of Rosetta protocols. Whereas the previous format required creating multiple separate files in different locations, the new format allows specification of the protocol in a single file. This new, simplified protocol specification has more than doubled the number of Rosetta protocols available under ROSIE. These new applications include pK a determination, lipid accessibility calculation, ribonucleic acid redesign, protein-protein docking, protein-small molecule docking, symmetric docking, antibody docking, cyclic toxin docking, critical binding peptide determination, and mapping small molecule binding sites. ROSIE is freely available to academic users at http://rosie.rosettacommons.org. © 2017 The Protein Society.

Application of calcifying bacteria for remediation of stones and cultural heritages

PubMed Central

Dhami, Navdeep Kaur; Reddy, M. Sudhakara; Mukherjee, Abhijit

2014-01-01

Since ages, architects and artists worldwide have focused on usage of durable stones as marble and limestone for construction of beautiful and magnificent historic monuments as European Cathedrals, Roman, and Greek temples, Taj Mahal etc. But survival of these irreplaceable cultural and historical assets is in question these days due to their degradation and deterioration caused by number of biotic and abiotic factors. These causative agents have affected not only the esthetic appearance of these structures, but also lead to deterioration of their strength and durability. The present review emphasizes about different causative agents leading to deterioration and application of microbially induced calcium carbonate precipitation as a novel and potential technology for dealing with these problems. The study also sheds light on benefits of microbial carbonate binders over the traditional agents and future directions. PMID:25018751

Application of calcifying bacteria for remediation of stones and cultural heritages.

PubMed

Dhami, Navdeep Kaur; Reddy, M Sudhakara; Mukherjee, Abhijit

2014-01-01

Since ages, architects and artists worldwide have focused on usage of durable stones as marble and limestone for construction of beautiful and magnificent historic monuments as European Cathedrals, Roman, and Greek temples, Taj Mahal etc. But survival of these irreplaceable cultural and historical assets is in question these days due to their degradation and deterioration caused by number of biotic and abiotic factors. These causative agents have affected not only the esthetic appearance of these structures, but also lead to deterioration of their strength and durability. The present review emphasizes about different causative agents leading to deterioration and application of microbially induced calcium carbonate precipitation as a novel and potential technology for dealing with these problems. The study also sheds light on benefits of microbial carbonate binders over the traditional agents and future directions.

Long-range transport of airborne microbes over the global tropical and subtropical ocean.

PubMed

Mayol, Eva; Arrieta, Jesús M; Jiménez, Maria A; Martínez-Asensio, Adrián; Garcias-Bonet, Neus; Dachs, Jordi; González-Gaya, Belén; Royer, Sarah-J; Benítez-Barrios, Verónica M; Fraile-Nuez, Eugenio; Duarte, Carlos M

2017-08-04

The atmosphere plays a fundamental role in the transport of microbes across the planet but it is often neglected as a microbial habitat. Although the ocean represents two thirds of the Earth's surface, there is little information on the atmospheric microbial load over the open ocean. Here we provide a global estimate of microbial loads and air-sea exchanges over the tropical and subtropical oceans based on the data collected along the Malaspina 2010 Circumnavigation Expedition. Total loads of airborne prokaryotes and eukaryotes were estimated at 2.2 × 10 21 and 2.1 × 10 21 cells, respectively. Overall 33-68% of these microorganisms could be traced to a marine origin, being transported thousands of kilometres before re-entering the ocean. Moreover, our results show a substantial load of terrestrial microbes transported over the oceans, with abundances declining exponentially with distance from land and indicate that islands may act as stepping stones facilitating the transoceanic transport of terrestrial microbes.The extent to which the ocean acts as a sink and source of airborne particles to the atmosphere is unresolved. Here, the authors report high microbial loads over the tropical Atlantic, Pacific and Indian oceans and propose islands as stepping stones for the transoceanic transport of terrestrial microbes..

U.S. Instruments Aboard Rosetta

NASA Image and Video Library

2014-01-24

Three of NASA contributions to the ESA Rosetta mission are pictured here: an ultraviolet spectrometer called Alice top, the Ion and Electron Sensor IES bottom left, and the Microwave Instrument for Rosetta Orbiter MIRO bottom right.

RosettaScripts: a scripting language interface to the Rosetta macromolecular modeling suite.

PubMed

Fleishman, Sarel J; Leaver-Fay, Andrew; Corn, Jacob E; Strauch, Eva-Maria; Khare, Sagar D; Koga, Nobuyasu; Ashworth, Justin; Murphy, Paul; Richter, Florian; Lemmon, Gordon; Meiler, Jens; Baker, David

2011-01-01

Macromolecular modeling and design are increasingly useful in basic research, biotechnology, and teaching. However, the absence of a user-friendly modeling framework that provides access to a wide range of modeling capabilities is hampering the wider adoption of computational methods by non-experts. RosettaScripts is an XML-like language for specifying modeling tasks in the Rosetta framework. RosettaScripts provides access to protocol-level functionalities, such as rigid-body docking and sequence redesign, and allows fast testing and deployment of complex protocols without need for modifying or recompiling the underlying C++ code. We illustrate these capabilities with RosettaScripts protocols for the stabilization of proteins, the generation of computationally constrained libraries for experimental selection of higher-affinity binding proteins, loop remodeling, small-molecule ligand docking, design of ligand-binding proteins, and specificity redesign in DNA-binding proteins.

Arenaviruses. Genes, proteins, and expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oldstone, M.B.A.

1987-01-01

This book provides a discussion of current knowledge on Arenaviruses. These viruses are the cause of major health problems, such as Lassa fever and Junin virus disease, and have been the Rosetta stone on which many of the major concepts in viral pathogenesis and immunobiology have been built. For example, study of lymphocytic choriomeningitis naturally and experimentally induced infection in the normal mouse host presented the scientific community with the first and definitive work on the following topics: virus induced immune response disease, immunologic tolerance, virus induced immune complex disease, presence and generation of cytotoxic T cells in vitro andmore » in vivo, H-2 restriction and dual recognition phenomena, and viral disease induced by altering physiologic or differential functions of a cell without causing alterations of house keeping or vital functions, i.e. pathology in the absence of cell or tissue lysis.« less

Biodiversity of cyanobacteria and green algae on monuments in the Mediterranean Basin: an overview.

PubMed

Macedo, Maria Filomena; Miller, Ana Zélia; Dionísio, Amélia; Saiz-Jimenez, Cesareo

2009-11-01

The presence and deteriorating action of micro-organisms on monuments and stone works of art have received considerable attention in the last few years. Knowledge of the microbial populations living on stone materials is the starting point for successful conservation treatment and control. This paper reviews the literature on cyanobacteria and chlorophyta that cause deterioration of stone cultural heritage (outdoor monuments and stone works of art) in European countries of the Mediterranean Basin. Some 45 case studies from 32 scientific papers published between 1976 and 2009 were analysed. Six lithotypes were considered: marble, limestone, travertine, dolomite, sandstone and granite. A wide range of stone monuments in the Mediterranean Basin support considerable colonization of cyanobacteria and chlorophyta, showing notable biodiversity. About 172 taxa have been described by different authors, including 37 genera of cyanobacteria and 48 genera of chlorophyta. The most widespread and commonly reported taxa on the stone cultural heritage in the Mediterranean Basin are, among cyanobacteria, Gloeocapsa, Phormidium and Chroococcus and, among chlorophyta, Chlorella, Stichococcus and Chlorococcum. The results suggest that cyanobacteria and chlorophyta colonize a wide variety of substrata and that this is related primarily to the physical characteristics of the stone surface, microclimate and environmental conditions and secondarily to the lithotype.

From Catheter to Kidney Stone: The Uropathogenic Lifestyle of Proteus mirabilis

PubMed Central

Norsworthy, Allison N.; Pearson, Melanie M.

2017-01-01

Proteus mirabilis is a model organism for urease-producing uropathogens. These diverse bacteria cause infection stones in the urinary tract and form crystalline biofilms on indwelling urinary catheters, frequently leading to poly-microbial infection. Recent work has elucidated how P. mirabilis causes all of these disease states. Particularly exciting is the discovery that this bacterium forms large clusters in the bladder lumen that are sites for stone formation. These clusters, and other steps of infection, require two virulence factors in particular: urease and MR/P fimbriae. Highlighting the importance of MR/P fimbriae is the cotranscribed regulator, MrpJ, which globally controls virulence. Overall, P. mirabilis exhibits an extraordinary lifestyle, and further probing will answer exciting basic microbiological and clinically relevant questions. PMID:28017513

Rosetta Planetary Science Archive (PSA) Status

NASA Astrophysics Data System (ADS)

Wirth, Kristin R.; Cardesin, A.; Barthelemy, M.; Diaz del Rio, J.; Zender, J.; Arviset, C.

2006-09-01

The Planetary Science Archive (PSA) is an online database (accessible via http://www.rssd.esa.int/PSA) implemented by ESA/RSSD. Currently the PSA contains the science data from the Giotto (Halley), Mars Express and SMART-1 (Moon) missions, and the Rosetta Supplementary Archive (Wirtanen). The PSA user is offered a broad range of search possibilities. Search queries can be combined without restrictions and are executed across the whole database. The PSA utilizes the Planetary Data System (PDS) standard. In spring 2007 the PSA will provide the first science and engineering data collected by Rosetta. In preparation for the initial Peer Review to be performed before publication of these data, an Internal Review was held in March 2006, executed by staff internal to the organizations responsible for the Rosetta archiving (ESA, PDS, CNES). The Internal Reviewers identified shortcomings in documentation, data structures, and completeness of the data delivery. They recommended the usage of unified conventions and formats across different instruments. Work is ongoing to include standardized geometry information in the datasets. Rosetta was launched in March 2004 to rendezvous with comet 67P/Churyumov-Gerasimenko (C-G) in May 2014. After having placed a lander on the comet's surface, the Rosetta orbiter will continue to orbit C-G and accompany the comet through perihelion. Rosetta makes use of three Earth swingbys and one Mars swingby in order to reach C-G. Rosetta will also perform close flybys at two asteroids, namely 2867 Steins in September 2008 and 21 Lutetia in July 2010. In addition, Rosetta makes scientific observations of targets of opportunity, e.g. lightcurves of the flyby asteroids to study the rotation, and plasma measurements when passing through cometary ion tails or meteoroid streams. Rosetta continuously monitored the encounter of the Deep Impact probe with comet 9P/Tempel 1 over an extended period of 16 days around the impact on 4 July 2005.

Microbiota Diversification and Crash Induced by Dietary Oxalate in the Mammalian Herbivore Neotoma albigula

PubMed Central

Dale, Colin; Dearing, M. Denise

2017-01-01

ABSTRACT Oxalate, broadly found in both dietary and endogenous sources, is a primary constituent in 80% of kidney stones, an affliction that has tripled in prevalence over the last 40 years. Oxalate-degrading bacteria within the gut microbiota can mitigate the effects of oxalate and are negatively correlated with kidney stone formation, but bacteriotherapies involving oxalate-degrading bacteria have met with mixed results. To inform the development of more effective and consistent bacteriotherapies, we sought to quantify the interactions and limits between oxalate and an oxalate-adapted microbiota from the wild mammalian herbivore Neotoma albigula (woodrat), which consumes a high-oxalate diet in the wild. We tracked the microbiota over a variable-oxalate diet ranging from 0.2% to 12%, with the upper limit approximating 10× the level of human consumption. The N. albigula microbiota was capable of degrading ~100% of dietary oxalate regardless of the amount consumed. However, the microbiota exhibited significant changes in diversity dynamically at the operational taxonomic unit (OTU), family, and community levels in accordance with oxalate input. Furthermore, a cohesive microbial network was stimulated by the consumption of oxalate and exhibited some resistance to the effects of prolonged exposure. This study demonstrates that the oxalate-adapted microbiota of N. albigula exhibits a very high level of degradation and tolerance for oxalate. IMPORTANCE The bacteria associated with mammalian hosts exhibit extensive interactions with overall host physiology and contribute significantly to the health of the host. Bacteria are vital to the mitigation of the toxic effects of oxalate specifically as mammals do not possess the enzymes to degrade this compound, which is present in the majority of kidney stones. Contrary to the body of literature on a few oxalate-degrading specialists, our work illustrates that oxalate stimulates a broad but cohesive microbial network in a dose-dependent manner. The unique characteristics of the N. albigula microbiota make it an excellent source for the development of bacteriotherapies to inhibit kidney stone formation. Furthermore, this work successfully demonstrates methods to identify microbial networks responsive to specific toxins, their limits, and important elements such as microbial network cohesivity and architecture. These are necessary steps in the development of targeted bacteriotherapies. PMID:29062900

Protocols for Molecular Modeling with Rosetta3 and RosettaScripts

PubMed Central

2016-01-01

Previously, we published an article providing an overview of the Rosetta suite of biomacromolecular modeling software and a series of step-by-step tutorials [Kaufmann, K. W., et al. (2010) Biochemistry 49, 2987–2998]. The overwhelming positive response to this publication we received motivates us to here share the next iteration of these tutorials that feature de novo folding, comparative modeling, loop construction, protein docking, small molecule docking, and protein design. This updated and expanded set of tutorials is needed, as since 2010 Rosetta has been fully redesigned into an object-oriented protein modeling program Rosetta3. Notable improvements include a substantially improved energy function, an XML-like language termed “RosettaScripts” for flexibly specifying modeling task, new analysis tools, the addition of the TopologyBroker to control conformational sampling, and support for multiple templates in comparative modeling. Rosetta’s ability to model systems with symmetric proteins, membrane proteins, noncanonical amino acids, and RNA has also been greatly expanded and improved. PMID:27490953

Rosetta science operations in support of the Philae mission

NASA Astrophysics Data System (ADS)

Ashman, Mike; Barthélémy, Maud; O`Rourke, Laurence; Almeida, Miguel; Altobelli, Nicolas; Costa Sitjà, Marc; García Beteta, Juan José; Geiger, Bernhard; Grieger, Björn; Heather, David; Hoofs, Raymond; Küppers, Michael; Martin, Patrick; Moissl, Richard; Múñoz Crego, Claudio; Pérez-Ayúcar, Miguel; Sanchez Suarez, Eduardo; Taylor, Matt; Vallat, Claire

2016-08-01

The international Rosetta mission was launched on 2nd March 2004 and after its ten year journey, arrived at its target destination of comet 67P/Churyumov-Gerasimenko, during 2014. Following the January 2014 exit from a two and half year hibernation period, Rosetta approached and arrived at the comet in August 2014. In November 2014, the Philae lander was deployed from Rosetta onto the comet's surface after which the orbiter continued its approximately one and a half year comet escort phase. The Rosetta Science Ground Segment's primary roles within the project are to support the Project Scientist and the Science Working Team, in order to ensure the coordination, development, validation and delivery of the desired science operations plans and their associated operational products throughout the mission., whilst also providing support to the Principle Investigator teams (including the Philae lander team) in order to ensure the provision of adequate data to the Planetary Science Archive. The lead up to, and execution of, the November 2014 Philae landing, and the subsequent Philae activities through 2015, have presented numerous unique challenges to the project teams. This paper discusses these challenges, and more specifically, their impact on the overall mission science planning activities. It details how the Rosetta Science Ground Segment has addressed these issues in collaboration with the other project teams in order to accommodate Philae operations within the continually evolving Rosetta science planning process.

Biofouling of marbles by oxygenic photosynthetic microorganisms.

PubMed

Karaca, Zeki; Öztürk, Ayten; Çolak, Emel

2015-08-01

Phototrophic microorganisms disfigure the surfaces of different types of stone. Stone structure is damaged by the activity of photoautotrophic and other microorganisms. However, to date few, investigations have been undertaken into the relationship between microorganisms and the properties of different types of marble. In this study, biological activity of photoautotrophic microorganisms on three types of marble (Yatagan White, Giallo Anticato and Afyon White) was investigated under laboratory conditions over a short period of time. The three types of marble supported the growth of phototrophic microbial communities on their outer and inner layers, turning their original colour from white to a yellowish green colour. The porosity of the marble types facilitated filamentous microbial growth in the presence of water. Scanning electron microscope analysis revealed the accumulation of aggregates such as small spherical, fibrillar, calcified globular bodies on the inner surfaces of the marbles. This suggests that the microscopic characteristics of particular marble types may stimulate the growth of certain types of microorganisms.

Correlating the magic numbers of inorganic nanomolecular assemblies with a {Pd84} molecular-ring Rosetta Stone

PubMed Central

Xu, Feng; Miras, Haralampos N.; Scullion, Rachel A.; Long, De-Liang; Thiel, Johannes; Cronin, Leroy

2012-01-01

Molecular self-assembly has often been suggested as the ultimate route for the bottom-up construction of building blocks atom-by-atom for functional nanotechnology, yet structural design or prediction of nanomolecular assemblies is still far from reach. Whereas nature uses complex machinery such as the ribosome, chemists use painstakingly engineered step-by-step approaches to build complex molecules but the size and complexity of such molecules, not to mention the accessible yields, can be limited. Herein we present the discovery of a palladium oxometalate {Pd84}-ring cluster 3.3 nm in diameter; [Pd84O42(OAc)28(PO4)42]70- ({Pd84} ≡ {Pd12}7) that is formed in water just by mixing two reagents at room temperature, giving crystals of the compound in just a few days. The structure of the {Pd84}-ring has sevenfold symmetry, comprises 196 building blocks, and we also show, using mass spectrometry, that a large library of other related nanostructures is present in solution. Finally, by analysis of the symmetry and the building block library that construct the {Pd84} we show that the correlation of the symmetry, subunit number, and overall cluster nuclearity can be used as a “Rosetta Stone” to rationalize the “magic numbers” defining a number of other systems. This is because the discovery of {Pd84} allows the relationship between seemingly unrelated families of molecular inorganic nanosystems to be decoded from the overall cluster magic-number nuclearity, to the symmetry and building blocks that define such structures allowing the prediction of other members of these nanocluster families. PMID:22753516

The Rosetta Science Archive: Status and Plans for Completing and Enhancing the Archive Content

NASA Astrophysics Data System (ADS)

Heather, D.; Barthelemy, M.; Fraga, D.; Grotheer, E.; O'Rourke, L.; Taylor, M.

2017-09-01

On 30 September 2016, Rosetta's signal flat-lined, confirming that the spacecraft had completed its incredible mission by landing on the surface of Comet 67P/Churyumov-Gerasimenko. Although this marked an end to the spacecraft's active operations, intensive work is still on-going with instrument teams preparing their final science data increments for delivery and ingestion into ESA's Planetary Science Archive (PSA). In addition to this, ESA is establishing contracts with a number of instrument teams to enhance and improve their data and documentation in an effort to provide the best long- term archive possible for the Rosetta mission. This presentation will outline the current status of the Rosetta archive, as well as highlighting some of the 'enhanced archiving' activities planned and underway with the various instrument teams on Rosetta to ensure the scientific legacy of the mission.

Characterizing the microbial colonization of a dolostone quarry: implications for stone biodeterioration and response to biocide treatments.

PubMed

Cámara, Beatriz; De los Ríos, Asuncion; Urizal, Marta; de Buergo, Mónica Alvarez; Varas, Maria Jose; Fort, Rafael; Ascaso, Carmen

2011-08-01

This study examines the microbial colonization of three fronts of an abandoned dolostone quarry (Redueña, Madrid, Spain) exposed to atmospheric conditions for different time periods since Roman times to the present. Through scanning electron microscopy in backscattered electron mode (SEM-BSE), endolithic colonization was predominantly detected in the most recently exposed front, while in the longer exposed quarry fronts, epilithic forms of growth were most often observed. These observations were confirmed by denaturing gradient gel electrophoresis (DGGE) analysis. Based on the distribution pattern of microbial colonization in the different quarry fronts, we then established a sequence of colonization events that took place over this long time frame. Bioalteration processes related to this sequential colonization were also identified. Characterizing these sequential processes can be useful for interpreting biodeterioration processes in historic dolostone monuments, especially those affecting constructions in the area of the Redueña stone quarry. In a second experimental stage, different biocide treatments were tested on this quarry rock to find the best way to avoid the microbial colonization effects identified. Through combined SEM-BSE/DGGE analysis, the efficacy of several biocides against the microorganisms inhabiting the dolostones was assessed after 4 and 16 months treatment. In general, all treatments were effective at reducing around 80% of the lichen cover, although effects on endolithic lithobiontic communities were dependent on how well the rock surface had been mechanically cleaned prior to treatment and gradually disappeared over time.

The U.S. Rosetta Project: Mars Gravity Assist

NASA Technical Reports Server (NTRS)

Alexander, Claudia; Holmes, Dwight P.; Goldstein, R.; Parker, Joel

2008-01-01

Since launch on March 2, 2004, the International Rosetta Mission has flown by the Earth/Moon system one time and conducted several distant observations of comets, including support for the Deep Impact measurements of comet 9 P/Tempel 1. In 2007, Rosetta flew by Mars for a gravity assist, and conducted observations of the Martian upper atmosphere as well as extended observations, in support of the New Horizons Jupiter encounter, of the Jovian magnetotail and Io torus. In late 2007 Rosetta had its second encounter with the Earth/Moon system. NASA's contribution to the Rosetta mission consists of three hardware experiments, and the portion of the electronics package for a fourth, as well as the participation of an Interdisciplinary Scientist (IDS); backup tracking, telecommunications, and navigation assurance provided by the Deep Space Network (DSN); support for the scientific participation of U.S. investigators on non-U.S. PI-led experiments. Collectively these elements are known as the U.S. Rosetta Project. In this paper we will update the status of the instruments following the both the Mars and Earth/Moon gravity assists. In addition, we will present a summary of the science observations for both Mars and Jupiter. 12.

Forgetting of Foreign-Language Skills: A Corpus-Based Analysis of Online Tutoring Software.

PubMed

Ridgeway, Karl; Mozer, Michael C; Bowles, Anita R

2017-05-01

We explore the nature of forgetting in a corpus of 125,000 students learning Spanish using the Rosetta Stone ® foreign-language instruction software across 48 lessons. Students are tested on a lesson after its initial study and are then retested after a variable time lag. We observe forgetting consistent with power function decay at a rate that varies across lessons but not across students. We find that lessons which are better learned initially are forgotten more slowly, a correlation which likely reflects a latent cause such as the quality or difficulty of the lesson. We obtain improved predictive accuracy of the forgetting model by augmenting it with features that encode characteristics of a student's initial study of the lesson and the activities the student engaged in between the initial and delayed tests. The augmented model can predict 23.9% of the variance in an individual's score on the delayed test. We analyze which features best explain individual performance. Copyright © 2016 Cognitive Science Society, Inc.

Rare but active taxa contribute to community dynamics of benthic biofilms in glacier-fed streams.

PubMed

Wilhelm, Linda; Besemer, Katharina; Fasching, Christina; Urich, Tim; Singer, Gabriel A; Quince, Christopher; Battin, Tom J

2014-08-01

Glaciers harbour diverse microorganisms, which upon ice melt can be released downstream. In glacier-fed streams microorganisms can attach to stones or sediments to form benthic biofilms. We used 454-pyrosequencing to explore the bulk (16S rDNA) and putatively active (16S rRNA) microbial communities of stone and sediment biofilms across 26 glacier-fed streams. We found differences in community composition between bulk and active communities among streams and a stronger congruence between biofilm types. Relative abundances of rRNA and rDNA were positively correlated across different taxa and taxonomic levels, but at lower taxonomic levels, the higher abundance in either the active or the bulk communities became more apparent. Here, environmental variables played a minor role in structuring active communities. However, we found a large number of rare taxa with higher relative abundances in rRNA compared with rDNA. This suggests that rare taxa contribute disproportionately to microbial community dynamics in glacier-fed streams. Our findings propose that high community turnover, where taxa repeatedly enter and leave the 'seed bank', contributes to the maintenance of microbial biodiversity in harsh ecosystems with continuous environmental perturbations, such as glacier-fed streams. © 2014 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Rosetta CONSERT operations and data analysis preparation: simulation software tools.

NASA Astrophysics Data System (ADS)

Rogez, Yves; Hérique, Alain; Cardiet, Maël; Zine, Sonia; Westphal, Mathieu; Micallef, Mickael; Berquin, Yann; Kofman, Wlodek

2014-05-01

The CONSERT experiment onboard Rosetta and Philae will perform the tomography of the 67P/CG comet nucleus by measuring radio waves transmission from the Rosetta S/C to the Philae Lander. The accurate analysis of travel time measurements will deliver unique knowledge of the nucleus interior dielectric properties. The challenging complexity of CONSERT operations requirements, combining both Rosetta and Philae, allows only a few set of opportunities to acquire data. Thus, we need a fine analysis of the impact of Rosetta trajectory, Philae position and comet shape on CONSERT measurements, in order to take optimal decisions in a short time. The integration of simulation results and mission parameters provides synthetic information to evaluate performances and risks for each opportunity. The preparation of CONSERT measurements before space operations is a key to achieve the best science return of the experiment. In addition, during Rosetta space operations, these software tools will allow a "real-time" first analysis of the latest measurements to improve the next acquisition sequences. The software tools themselves are built around a 3D electromagnetic radio wave simulation, taking into account the signal polarization. It is based on ray-tracing algorithms specifically designed for quick orbit analysis and radar signal generation. This allows computation on big domains relatively to the wavelength. The extensive use of 3D visualization tools provides comprehensive and synthetic views of the results. The software suite is designed to be extended, after Rosetta operations, to the full 3D measurement data analysis using inversion methods.

[The role of urinary tract infection in the development of recurrent nephrolithiasis].

PubMed

Khamidullin, K R; Pushkarev, A M; Tarasenko, A I; Pavlov, V N

2017-10-01

This is a literature review on the role of microbial flora in the development of recurrent urolithiasis. The authors outline pathogenetic aspects of recurrent stone formation associated bacterial flora. A number of studies reported that standard urine culture has limited sensitivity in detecting urinary tract infection.

Model of Dust Thermal Emission of Comet 67p-Churyumov-Gerasimenko for the Rosetta-MIRO Instrument

NASA Technical Reports Server (NTRS)

Gicquel, Adeline; Bockelee-Morvan, Dominique; Leyrat, Cedric; Zakharov, Vladimir; Crovisier, Jacques; Biver, Nicolas; Gulkis, Samuel

2013-01-01

The ESA's Rosetta spacecraft will arrive at comet 67P/Churyumov-Gerasimenko in 2014. The study of gas and dust emission is primary objective of several instruments on the Rosetta spacecraft, including the Microwave Instrument for the Rosetta Orbiter (MIRO). We developed a model of dust thermal emission to estimate the detectability of dust in the vicinity of the nucleus with MIRO. Our model computes the power received by the MIRO antenna in limb viewing as a function of the geometry of the observations and the physical properties of the grains. We show that detection in the millimeter and submillimeter channels can be achieved near perihelion.

Challenges of archiving science data from long duration missions: the Rosetta case

NASA Astrophysics Data System (ADS)

Heather, David

2016-07-01

Rosetta is the first mission designed to orbit and land on a comet. It consists of an orbiter, carrying 11 science experiments, and a lander, called 'Philae', carrying 10 additional instruments. Rosetta was launched on 2 March 2004, and arrived at the comet 67P/Churyumov-Gerasimenko on 6 August 2014. During its long journey, Rosetta has completed flybys of the Earth and Mars, and made two excursions to the main asteroid belt to observe (2867) Steins and (21) Lutetia. On 12 November 2014, the Philae probe soft landed on comet 67P/Churyumov-Gerasimenko, the first time in history that such an extraordinary feat has been achieved. After the landing, the Rosetta orbiter followed the comet through its perihelion in August 2015, and will continue to accompany 67P/Churyumov-Gerasimenko as it recedes from the Sun until the end of the mission. There are significant challenges in managing the science archive of a mission such as Rosetta. The first data were returned from Rosetta more than 10 years ago, and there have been flybys of several planetary bodies, including two asteroids from which significant science data were returned by many of the instruments. The scientific applications for these flyby data can be very different to those taken during the main science phase at the comet, but there are severe limitations on the changes that can be applied to the data pipelines managed by the various science teams as resources are scarce. The priority is clearly on maximising the potential science from the comet phase, so data formats and pipelines have been designed with that in mind, and changes limited to managing issues found during official archiving authority and independent science reviews. In addition, in the time that Rosetta has been operating, the archiving standards themselves have evolved. All Rosetta data are archived following version 3 of NASA's Planetary Data System (PDS) Standards. Currently, new and upcoming planetary science missions are delivering data following the new 'PDS4' standards, which are using a very different format and require significant changes to the archive itself to manage. There are no plans at ESA to convert the data to PDS4 formats, but the community may need this to be completed in the long term if we are to realise the full scientific potential of the mission. There is a Memorandum of Understanding between ESA and NASA that commits to there being a full copy of the Rosetta science data holdings both within the Planetary Science Archive (PSA) at ESA and with NASA's Planetary Data System, at the Small Bodies Node (SBN) in Maryland. The requirements from each archiving authority place sometimes contradictory restrictions on the formatting and structure of the data content, and there has also been a significant evolution of the archives on both side of the Atlantic. The SBN have themselves expressed a desire to 'convert' the Rosetta data to PDS4 formats, so this will need to be carefully managed between the archiving authorities to ensure consistency in the Rosetta archive overall. Validation of the returned data to ensure full compliance with both the PSA and the PDS archives has required the development of a specific tool (DVal) that can be configured to manage the specificities of each instrument team's science data. Unlike the PDS, which comprises an affiliation of 'nodes', each specialising in a planetary science discipline, the PSA is a single archive designed to host data from all of ESA's planetary science missions. There have been significant challenges in evolving the archive to meet Rosetta's needs as a long-term project, without compromising the service provided to the other ongoing missions. Partly in response to this, the PSA is currently implementing a number of significant changes, both to its web-based interface to the scientific community, and to its database structure. The newly designed PSA will aim to provide easier and more direct access to the Rosetta data (and all of ESA's planetary science data holdings), and will help to soften the impact of some of the issues that have arisen with managing missions such as Rosetta in the existing framework. Conclusions: Development and management of the Rosetta science archive has been a significant challenge, due in part to the long duration of the mission and the corresponding need for development of the archive infrastructure and of the archiving process to manage these changes. The definition of a single set of conventions to manage the diverse suite of instruments, targets and indeed archiving authorities on Rosetta over this time has been a major issue, as has the need to evolve the validation processes that allow the data to be fully ingested and released to the community. This presentation will discuss the many issues faced by the PSA in the archiving of data from Rosetta, and the approach taken to resolve them. Lessons learned will be presented along with recommendations for other archiving authorities who will in future have the need to design and operate a science archive for long duration and international missions.

Radiative Transfer Simulations of Earth Spectra as Registered by ROSETTA/VIRTIS

NASA Astrophysics Data System (ADS)

Hurley, Jane; Irwin, P.; Adriani, A.; Moriconi, M.; Oliva, F.; Coradini, A.

2010-10-01

Rosetta, part of ESA's Horizon 2000 programme, will orbit and land on the comet 67P/Churyumov-Gerasimenko in May 2014. However, launched in March 2004, its trajectory has thus far muchly consisted of a series of planetary fly-bys and gravitational assists using Mars (2007) and Earth (March 2005, 2007 and 2009). During these close fly-bys Rosetta captured measurements of these planets - and of particular interest are those registed by the Visual Infrared Thermal Imaging Spectrometer VIRTIS of Earth, which were taken to help calibrate VIRTIS. Rosetta/VIRTIS measures at high spectral resolution from 0.25 - 5.0 microns, a spectral range which has been well studied by Earth observing instruments such as Meteosat Second Generation Spinning Enhanced Visible and Infrared Imager (MSG/SEVIRI) and the Advanced Along-Track Scanning Radiometer (AATSR). Earth observing instruments, whilst having superior spatio-temporal coverage to the data provided during the Rosetta/VIRTIS fly-bys, are typically constrained to measuring in only a few spectral channels. Hence, Rosetta/VIRTIS should yield more detailed spectral information than these instruments - and is a good candidate for intercomparison studies. To this end, the radiative transfer software NEMESIS (Irwin et al., 2009) is employed for the first time on Earth simulations, having been used extensively for other bodies such as Venus, Mars, Jupiter, Saturn, Neptune, Uranus and Titan. This work compares Rosetta/VIRTIS measurements with NEMESIS-simulated spectra, concentrating on quantifying the ability of NEMESIS to reproduce spectral features associated with different surface topographies (such as ocean, desert and vegetation) in combination with clear and cloudy atmospheric states. Preliminary estimations of temperature and trace-species concentrations and distributions are presented as sample products.

Live Blogging Science News: The Rosetta Mission

NASA Astrophysics Data System (ADS)

Clark, S.

2016-03-01

When one of the world's most popular online news websites decides to cover a space science event live, you know that something big is brewing. Stuart Clark reports on how live blogging can be used for science reporting and how an idea that was triggered by his observations during the Rosetta flyby of the asteroid Lutetia and the landing of the Curiosity rover on Mars led to him live blogging two of Rosetta's most memorable occasions for The Guardian newspaper.

A Parametric Rosetta Energy Function Analysis with LK Peptides on SAM Surfaces.

PubMed

Lubin, Joseph H; Pacella, Michael S; Gray, Jeffrey J

2018-05-08

Although structures have been determined for many soluble proteins and an increasing number of membrane proteins, experimental structure determination methods are limited for complexes of proteins and solid surfaces. An economical alternative or complement to experimental structure determination is molecular simulation. Rosetta is one software suite that models protein-surface interactions, but Rosetta is normally benchmarked on soluble proteins. For surface interactions, the validity of the energy function is uncertain because it is a combination of independent parameters from energy functions developed separately for solution proteins and mineral surfaces. Here, we assess the performance of the RosettaSurface algorithm and test the accuracy of its energy function by modeling the adsorption of leucine/lysine (LK)-repeat peptides on methyl- and carboxy-terminated self-assembled monolayers (SAMs). We investigated how RosettaSurface predictions for this system compare with the experimental results, which showed that on both surfaces, LK-α peptides folded into helices and LK-β peptides held extended structures. Utilizing this model system, we performed a parametric analysis of Rosetta's Talaris energy function and determined that adjusting solvation parameters offered improved predictive accuracy. Simultaneously increasing lysine carbon hydrophilicity and the hydrophobicity of the surface methyl head groups yielded computational predictions most closely matching the experimental results. De novo models still should be interpreted skeptically unless bolstered in an integrative approach with experimental data.

In Situ Space Gas Dynamic Measurements by the ROSINA Comet Pressure Sensor COPS Onboard Rosetta Spacecraft

NASA Astrophysics Data System (ADS)

Tzou, Chia-Yu; Altwegg, Kathrin; Fiethe, Björn; Gasc, Sébastien; Rubin, Martin

2015-04-01

Rosetta is part of the cornerstone missions executed by the European Space Agency. It is the first space mission to orbit and also land on a comet. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) is one of the core payloads on board of the Rosetta spacecraft [Balsiger et al, 2007]. ROSINA's main objective is to determine the major atmospheric and ionospheric composition in the coma and to investigate the gas dynamics around the comet. ROSINA consists of two mass spectrometers and a pressure sensor. The COmet Pressure Sensor (COPS) includes two gauges: the "nude gauge" measures total neutral density in the coma and the "ram gauge" measures the dynamic pressure of the cometary gas flux. The combination of these two gauges makes COPS capable to derive the gas dynamics (velocity and temperature) at the location of the spacecraft. Over several months Rosetta has been carrying out a close study of comet 67P/Churyumov-Gerasimenko. In early August 2014 COPS detected the faint and expanding atmosphere of the comet while it was still outside of 3.5 AU from the Sun. We will present ROSINA COPS observations of the evolution and gas dynamics of the cometary coma following these first observations until spring 2015. Reference: Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007.

Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR.

PubMed

van der Schot, Gijs; Bonvin, Alexandre M J J

2015-08-01

We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on unassigned NOE lists (Huang et al. in J Am Chem Soc 127:1665-1674, 2005b, doi: 10.1021/ja047109h). We compare the original submissions using a previous version of the server based on Rosetta version 2.6 with recalculated targets using the new R3FP fragment picker for fragment selection and implementing a new annotation of prediction reliability (van der Schot et al. in J Biomol NMR 57:27-35, 2013, doi: 10.1007/s10858-013-9762-6), both implemented in the CS-Rosetta3 WeNMR server. In this second round of CASD-NMR, the WeNMR CS-Rosetta server has demonstrated a much better performance than in the first round since only converged targets were submitted. Further, recalculation of all CASD-NMR targets using the new version of the server demonstrates that our new annotation of prediction quality is giving reliable results. Predictions annotated as weak are often found to provide useful models, but only for a fraction of the sequence, and should therefore only be used with caution.

The 67P/Churyumov-Gerasimenko observation campaign in support of the Rosetta mission.

PubMed

Snodgrass, C; A'Hearn, M F; Aceituno, F; Afanasiev, V; Bagnulo, S; Bauer, J; Bergond, G; Besse, S; Biver, N; Bodewits, D; Boehnhardt, H; Bonev, B P; Borisov, G; Carry, B; Casanova, V; Cochran, A; Conn, B C; Davidsson, B; Davies, J K; de León, J; de Mooij, E; de Val-Borro, M; Delacruz, M; DiSanti, M A; Drew, J E; Duffard, R; Edberg, N J T; Faggi, S; Feaga, L; Fitzsimmons, A; Fujiwara, H; Gibb, E L; Gillon, M; Green, S F; Guijarro, A; Guilbert-Lepoutre, A; Gutiérrez, P J; Hadamcik, E; Hainaut, O; Haque, S; Hedrosa, R; Hines, D; Hopp, U; Hoyo, F; Hutsemékers, D; Hyland, M; Ivanova, O; Jehin, E; Jones, G H; Keane, J V; Kelley, M S P; Kiselev, N; Kleyna, J; Kluge, M; Knight, M M; Kokotanekova, R; Koschny, D; Kramer, E A; López-Moreno, J J; Lacerda, P; Lara, L M; Lasue, J; Lehto, H J; Levasseur-Regourd, A C; Licandro, J; Lin, Z Y; Lister, T; Lowry, S C; Mainzer, A; Manfroid, J; Marchant, J; McKay, A J; McNeill, A; Meech, K J; Micheli, M; Mohammed, I; Monguió, M; Moreno, F; Muñoz, O; Mumma, M J; Nikolov, P; Opitom, C; Ortiz, J L; Paganini, L; Pajuelo, M; Pozuelos, F J; Protopapa, S; Pursimo, T; Rajkumar, B; Ramanjooloo, Y; Ramos, E; Ries, C; Riffeser, A; Rosenbush, V; Rousselot, P; Ryan, E L; Santos-Sanz, P; Schleicher, D G; Schmidt, M; Schulz, R; Sen, A K; Somero, A; Sota, A; Stinson, A; Sunshine, J M; Thompson, A; Tozzi, G P; Tubiana, C; Villanueva, G L; Wang, X; Wooden, D H; Yagi, M; Yang, B; Zaprudin, B; Zegmott, T J

2017-07-13

We present a summary of the campaign of remote observations that supported the European Space Agency's Rosetta mission. Telescopes across the globe (and in space) followed comet 67P/Churyumov-Gerasimenko from before Rosetta's arrival until nearly the end of the mission in September 2016. These provided essential data for mission planning, large-scale context information for the coma and tails beyond the spacecraft and a way to directly compare 67P with other comets. The observations revealed 67P to be a relatively 'well-behaved' comet, typical of Jupiter family comets and with activity patterns that repeat from orbit to orbit. Comparison between this large collection of telescopic observations and the in situ results from Rosetta will allow us to better understand comet coma chemistry and structure. This work is just beginning as the mission ends-in this paper, we present a summary of the ground-based observations and early results, and point to many questions that will be addressed in future studies.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

High-resolution comparative modeling with RosettaCM.

PubMed

Song, Yifan; DiMaio, Frank; Wang, Ray Yu-Ruei; Kim, David; Miles, Chris; Brunette, Tj; Thompson, James; Baker, David

2013-10-08

We describe an improved method for comparative modeling, RosettaCM, which optimizes a physically realistic all-atom energy function over the conformational space defined by homologous structures. Given a set of sequence alignments, RosettaCM assembles topologies by recombining aligned segments in Cartesian space and building unaligned regions de novo in torsion space. The junctions between segments are regularized using a loop closure method combining fragment superposition with gradient-based minimization. The energies of the resulting models are optimized by all-atom refinement, and the most representative low-energy model is selected. The CASP10 experiment suggests that RosettaCM yields models with more accurate side-chain and backbone conformations than other methods when the sequence identity to the templates is greater than ∼15%. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hello, world: Harnessing social media for the Rosetta mission

NASA Astrophysics Data System (ADS)

Baldwin, Emily; Mignone, Claudia; O'Flaherty, Karen; Homfeld, Anne-Mareike; Bauer, Markus; McCaughrean, Mark

2015-04-01

The European Space Agency's (ESA) comet-chasing Rosetta mission was launched in 2004, before social media became a popular tool for mainstream communication. By harnessing a range of platforms for communicating the key messages of this unprecedented mission as it reached its destination ten years later, new audiences were reached and a global impact was achieved. Rosetta-specific social media accounts - @ESA_Rosetta on Twitter, the Rosetta Mission Facebook page and the rosettamission Instagram account - were developed during 2013/14 and used alongside the traditional reporting line of the main ESA website and the Rosetta blog to build awareness about the mission. Coordinated with ESA's existing social media channels (Flickr, YouTube, G+, Twitter, Facebook and Livestream) and with the support of ESA's country desks and Rosetta partner agency accounts (including @philae2014), information could be shared in a number of European languages, ensuring a wide reach across Europe - and the world. We discuss the roles of the various social media accounts in supporting and promoting the competitions and social media campaigns that were built around the key mission milestones of 2014: waking up from deep space hibernation (January), arriving at Comet 67P/Churyumov-Gerasimenko (August) and naming the landing site for Philae ahead of the landing event in November. We discuss the different approach to each channel, such as the first person twitter accounts, the dialogue with and between blog users, and the discussions held live via G+ Hangouts with leading scientists and spacecraft operators. We compare and contrast the audiences, the interaction we had with them and how challenges were overcome. We also use the science-fiction-meets-science-fact Ambition short movie, and its "undercover" dissemination on social media, as an example of how the profile of the Rosetta mission was raised in a unique way. By using a variety of social media platforms to target different audiences with specific content in a coordinated way, we have been able to share the human aspect of the mission, allowing our audiences to feel part of every step of the adventure.

RosettaHoles: rapid assessment of protein core packing for structure prediction, refinement, design, and validation.

PubMed

Sheffler, Will; Baker, David

2009-01-01

We present a novel method called RosettaHoles for visual and quantitative assessment of underpacking in the protein core. RosettaHoles generates a set of spherical cavity balls that fill the empty volume between atoms in the protein interior. For visualization, the cavity balls are aggregated into contiguous overlapping clusters and small cavities are discarded, leaving an uncluttered representation of the unfilled regions of space in a structure. For quantitative analysis, the cavity ball data are used to estimate the probability of observing a given cavity in a high-resolution crystal structure. RosettaHoles provides excellent discrimination between real and computationally generated structures, is predictive of incorrect regions in models, identifies problematic structures in the Protein Data Bank, and promises to be a useful validation tool for newly solved experimental structures.

RosettaHoles: Rapid assessment of protein core packing for structure prediction, refinement, design, and validation

PubMed Central

Sheffler, Will; Baker, David

2009-01-01

We present a novel method called RosettaHoles for visual and quantitative assessment of underpacking in the protein core. RosettaHoles generates a set of spherical cavity balls that fill the empty volume between atoms in the protein interior. For visualization, the cavity balls are aggregated into contiguous overlapping clusters and small cavities are discarded, leaving an uncluttered representation of the unfilled regions of space in a structure. For quantitative analysis, the cavity ball data are used to estimate the probability of observing a given cavity in a high-resolution crystal structure. RosettaHoles provides excellent discrimination between real and computationally generated structures, is predictive of incorrect regions in models, identifies problematic structures in the Protein Data Bank, and promises to be a useful validation tool for newly solved experimental structures. PMID:19177366

The final year of the Rosetta mission

NASA Astrophysics Data System (ADS)

Accomazzo, Andrea; Ferri, Paolo; Lodiot, Sylvain; Pellon-Bailon, Jose-Luis; Hubault, Armelle; Urbanek, Jakub; Kay, Ritchie; Eiblmaier, Matthias; Francisco, Tiago

2017-07-01

The International Rosetta Mission was launched on 2nd March 2004 on its 10 year journey to rendezvous with comet 67P Churyumov-Gerasimenko. Rosetta performed comet orbit insertion on the 6th of August 2014, after which it characterised the nucleus and orbited it at altitudes as low as a few kilometres. In November 2014 Rosetta delivered the lander Philae to perform the first soft landing ever on the surface of a comet. After this critical operation, Rosetta began the escort phase of the comet in its journey in the Solar System heading to the perihelion, reached in August 2015. Originally foreseen till the end of 2015, the mission was extended for another nine months to follow the comet on its outbound arc of the orbit. In view of the acquired experience and of the approaching end of mission the spacecraft was flown at much closer distances from the nucleus so that the scientific instruments had the chance to perform unique measurements. Following this phase of very close orbits, on the 30th of September 2016 Rosetta was set on a collision course trajectory with the comet to terminate the mission with a controlled impact. This paper describes the details of the extended mission phase and the issues encountered during these months. It also includes the changes implemented on the spacecraft and in the operations concept to optimise the remaining mission time. The paper also includes the lessons learned from this unique and complex mission phase.

Morning glory resin glycosides as modulators of antibiotic activity in multidrug-resistant gram-negative bacteria.

PubMed

Corona-Castañeda, Berenice; Pereda-Miranda, Rogelio

2012-01-01

Twenty-six microbiologically inactive (MIC > 512 µg/mL) convolvulaceous resin glycosides ( 1- 26) were tested for resistance modulatory activity in vitro against Escherichia coli Rosetta-gami and two nosocomial pathogens, Salmonella typhi and Shigella flexneri. These compounds exerted a potentiation effect of the clinically useful antibiotics tetracycline, kanamycin, and chloramphenicol against the tested gram-negative bacteria by increasing antibiotic susceptibility up to 32-fold at concentrations of 25 µg/mL. Therefore, the oligosaccharides from the morning glory family (Convolvulaceae) represent metabolites that reverse microbial resistance mechanisms, favoring an increase in the strength and effectiveness of current antibiotics that are not effective in the treatment of refractive infections caused by multidrug-resistant strains. © Georg Thieme Verlag KG Stuttgart · New York.

Rosetta Mission Selfie at 10 Miles

NASA Image and Video Library

2014-11-12

The Philae lander of the European Space Agency Rosetta mission took this self-portrait of the spacecraft on Sept. 7, 2014, at a distance of about 10 miles 16 kilometers from comet 67P/Churyumov-Gerasimenko.

Rosetta Mission Selfie at 30 Miles

NASA Image and Video Library

2014-11-11

The Philae lander of the European Space Agency Rosetta mission took this self-portrait of the spacecraft on Sept. 7, 2014, at a distance of about 30 miles 50 kilometers from comet 67P/Churyumov-Gerasimenko.

Rosetta Comet Spreads its Jets

NASA Image and Video Library

2014-10-24

This image was taken by the Optical, Spectroscopic, and Infrared Remote Imaging System, Rosetta main onboard scientific imaging system, on Sept. 10, 2014. Jets of cometary activity can be seen along almost the entire body of the comet.

Comets and the origin of the solar system - Reading the Rosetta Stone

NASA Technical Reports Server (NTRS)

Mumma, Michael J.; Weissman, Paul R.; Stern, S. A.

1993-01-01

It is argued that, from the measured volatile abundances, comets formed at temperatures near or below about 60 K and possibly as low as about 25 K. Grains in Comet Halley were found to be of two types: silicates and organics. Isotopic evidence shows that Comet Halley formed from material with the same compositional mix as the rest of the solar system, and is consistent with comets having been a major contributor to the volatile reservoirs on the terrestrial planets. A variety of processes have been shown to modify and reprocess the outer layers of comets both during their long residence time in the Oort cloud and following their entry back into the planetary system. The most likely formation site for comets is in the Uranus-Neptune zone or just beyond, with dynamical ejection by the growing protoplanets to distant orbits to form the Oort cloud. A substantial flux of interstellar comets was likely created by the same process, and may be detectable if cometary formation is common in planetary systems around other stars.

Hormesis as a mechanistic approach to understanding herbal treatments in traditional Chinese medicine.

PubMed

Wang, Dali; Calabrese, Edward J; Lian, Baoling; Lin, Zhifen; Calabrese, Vittorio

2018-04-01

Traditional Chinese medicine (TCM) has been long practiced and is becoming ever more widely recognized as providing curative and/or healing treatments for a number of diseases and physiological conditions. This paper posits that herbal medicines used in TCM treatments may act through hormetic dose-response mechanisms. It is proposed that the stimulatory (i.e., low dose) and inhibitory (i.e., high dose) components of the hormetic dose response correspond to respective "regulating" and "curing" aspects of TCM herbal treatments. Specifically, the "regulating" functions promote adaptive or preventive responses, while "curing" treatments alleviate the clinical symptoms. Patterns of hormetic responses are described, and the applicability of these processes to herbal medicines of TCM are explicated. It is noted that a research agenda aimed at elucidating these mechanisms and patterns would be expansive and complex. However, we argue its value, in that hormesis may afford something akin to a Rosetta Stone with which to interpret, translate, and explain TCM herbology in ways that are aligned with biomedical perspectives that could enable a more integrative approach to medicine. Copyright © 2017 Elsevier Inc. All rights reserved.

First Rosetta Radio Science Bistatic Radar Observations of 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Andert, Thomas P.; Remus, Stefan; Simpson, Richard A.; Pätzold, Martin; Asmar, Sami W.; Kahan, Daniel S.; Bird, Mike K.; Häusler, Bernd; Tellmann, Silvia

2015-04-01

The Rosetta spacecraft was successfully inserted on 6th August 2014 into orbit around comet 67P/Churyumov-Gerasimenko. In September Rosetta was placed into bound orbits with an initial distance of 30 km and a decreasing distance until the end October. After lander delivery, bound orbits were maintained again at 20 km and 30 km. One of the objectives of the Rosetta Radio Science Investigations (RSI) is to address the dielectric properties, small-scale roughness, and rotational state of the nucleus of the comet, which can be determined by means of a surface scattering experiment, also known as Bistatic Radar. The radio subsystem transmitter located on board the Rosetta spacecraft beams right circularly polarized radio signals at two wavelengths -3.6 cm (X-Band) and 13 cm (S-Band) - toward the nucleus surface. Part of the impinging radiation is then scattered toward a receiver at a ground station on Earth and recorded. On September 29th, 2014 the first Bistatic Radar experiment ever at a comet was successfully conducted. The distance between 67P/Churyumov-Gerasimenko and Rosetta was 20 km and both right circularly polarized (RCP) and left circularly polarized (LCP) reflected signals from the comet's surface in X-Band were detected during the experiment at the Goldstone complex of the NASA Deep Space Network. The ultra-stable oscillator (USO) on board Rosetta served during the experiment as a very stable reference frequency source. The direct and reflected signal were separated during the experiment by only a fraction of 1 Hz. The extreme stability of the USO allowed a detection and separation of the weak signals even on the required long integration times. Five additional Bistatic Radar experiments were conducted successfully between mid-October and mid-December 2014 with the 70-m DSN ground stations in Goldstone and Canberra at different distances to the comet (10 km, 20 km and 30 km) and reflected signals were observed in each case.

Comet 67P as seen by Rosetta/OSIRIS

NASA Astrophysics Data System (ADS)

Guettler, Carsten; Sierks, Holger; Barbieri, Cesare; Lamy, Philippe L.; Rodrigo, Rafael; Koschny, Detlef; Rickman, Hans; OSIRIS Team

2016-10-01

In September 2016, the ESA Rosetta mission will come to its ending. Having escorted comet 67P for more than two years, the scientific camera system OSIRIS onboard Rosetta witnessed all important milestones of the mission: after the first characterization and the Philae landing we saw the comet's activity increasing while it was approaching the Sun. During the peak of activity around perihel in August 2015, the spacecraft had to retreat to a safe distance but we witnessed strong but predictable jet activity and, at the same time, short lived eruptions, some of these being big outbursts. When the activity declined post perihelion and allowed the spacecraft to go back closer, comparison with the early characterization revealed numerous morphologic changes on the surface, which can be attributed to the strong activity during perihelion passage.The paper will give an overview of latest OSIRIS science and discoveries including the morphology, activity, and surface changes mentioned above. Implications on the nature of the comet and its mechanisms will be drawn from these. The current plan for the mission is to go to very close distances in August and September 2016 and finally land the spacecraft on 67P.Acknowledgements: OSIRIS was built by a consortium led by the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofísica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Técnica Aeroespacial, Madrid, Spain, the Universidad Politéchnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut für Datentechnik und Kommunikationsnetze der Technischen Universität Braunschweig, Germany.We thank the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission.

De Novo Enzyme Design Using Rosetta3

PubMed Central

Richter, Florian; Leaver-Fay, Andrew; Khare, Sagar D.; Bjelic, Sinisa; Baker, David

2011-01-01

The Rosetta de novo enzyme design protocol has been used to design enzyme catalysts for a variety of chemical reactions, and in principle can be applied to any arbitrary chemical reaction of interest, The process has four stages: 1) choice of a catalytic mechanism and corresponding minimal model active site, 2) identification of sites in a set of scaffold proteins where this minimal active site can be realized, 3) optimization of the identities of the surrounding residues for stabilizing interactions with the transition state and primary catalytic residues, and 4) evaluation and ranking the resulting designed sequences. Stages two through four of this process can be carried out with the Rosetta package, while stage one needs to be done externally. Here, we demonstrate how to carry out the Rosetta enzyme design protocol from start to end in detail using for illustration the triosephosphate isomerase reaction. PMID:21603656

The structure of cometary dust - first results from the MIDAS Atomic Force Microscope onboard Rosetta

NASA Astrophysics Data System (ADS)

Bentley, M. S.; Torkar, K.; Romstedt, J.

2014-12-01

A decade after launch the European Space Agency's Rosetta spacecraft has finally arrived at comet 67P/Churyumov-Gerasimenko. Unlike previous cometary missions, Rosetta is not a flyby, limited to taking a snapshot of the comet at a single heliocentric distance. Instead, Rosetta intercepted the comet prior to the onset of major activity and will chart its evolution during its perihelion passage and beyond. Such a unique mission requires a unique payload; as well as the more typical remote sensing instruments, Rosetta also carries sensors to sample in situ the gas and dust environment. One of these instruments is MIDAS, an atomic force microscope designed to collect dust and image it in three dimensions with nanometre resolution. Equipped with an array of sharp tips, four of which are magnetised to allow magnetic force microscopy, MIDAS exposes targets to the incident flux after which they are moved to the microscope for analysis. As well as extending coverage of the dust size distribution down to the finest particles, MIDAS has the unique capability to determine the shape of pristine particles - to determine, for example, if they are compact or fluffy, and to look for features which may be diagnostic of their formation environment or evolution. The magnetic mode lets MIDAS probe samples for magnetic material and to map its location if present. Having been operating almost continuously after hibernation imaging empty targets before exposure, the first exposures were performed when Rosetta entered 30 km bound orbits. The first MIDAS images and analyses of collected dust grains are presented here.

Encounter of a different kind: Rosetta observes asteroid at close quarters

NASA Astrophysics Data System (ADS)

2008-09-01

ESA's comet chaser, Rosetta, last night flew by a small body in the main asteroid belt, asteroid Steins, collecting a wealth of information about this rare type of minor Solar System body. At 20:58 CEST (18:58 UT) last night, ESA's Rosetta probe approached asteroid 2867 Steins, coming to within a distance of only 800 km from it. Steins is Rosetta's first nominal scientific target in its 11½ year mission to ultimately explore the nucleus of Comet 67P/Churyumov-Gerasimenko. The success of this 'close' encounter was confirmed at 22:14 CEST, when ESA's ground control team at the European Space Operations Centre (ESOC) in Darmstadt, Germany, received initial telemetry from the spacecraft. During the flyby operations, Rosetta was out of reach as regards communication links because its antenna had to be turned away from Earth. At a distance of about 2.41 AU (360 million kilometres) from our planet, the radio signal from the probe took 20 minutes to reach the ground. Steins is a small asteroid of irregular shape with a diameter of only 4.6 km. It belongs to the rare class of E-type asteroids, which had not been directly observed by an interplanetary spacecraft before. Such asteroids are quite small in size and orbit and are mostly found in the inner part of the main asteroid belt located between Mars and Jupiter. They probably originate from the mantle of larger asteroids destroyed in the early history of the Solar System, and are thought to be composed mainly of silicate minerals with little or no iron content. The data collected by Rosetta last night and which will be analysed over the coming days and weeks will finally unveil the true nature of Steins. Through the study of minor bodies such as asteroids, Rosetta is opening up a new window onto the early history of our Solar System. It will give us a better understanding of the origins and evolution of the planets, and also a key to better interpreting asteroid data collected from the ground. Under Rosetta's scope This is not Rosetta's first look at Steins. Over two years ago, in March 2006, the Osiris camera onboard Rosetta observed the brightness variations of this rotating asteroid from a distance of 159 million kilometres (a little over the distance between Earth and the Sun), and was able to determine that the tiny asteroid spins around its axis in about six hours. Together with the two navigation cameras onboard, Osiris was again pointed towards Steins on 4 August and continued to observe the asteroid until 4 September, in order to assist Rosetta's navigation by optical means - a first in the history of ESA spacecraft operations. A few days before the flyby, most of the Rosetta orbiter instruments, as well as the Philae lander magnetometer, were switched on to collect science data on the asteroid, with ever-increasing accuracy as the spacecraft closed in on it. Rosetta's powerful instruments have initially been focusing on the asteroid's orbital motion, rotation, shape and density. As the distance has diminished, the investigation has broadened to take in the observation of surface properties and features, and the analysis of the chemical and mineralogical composition of the terrains, as well as their relative ages and the effects of the solar wind on the surface. At its closest approach, Rosetta flew by Steins at a relative speed of 8.6 km/s. To keep the small asteroid in the field of view of its instruments, the spacecraft had to perform a rapid and highly demanding rotation manoeuvre, which had been successfully rehearsed in March this year. A preliminary analysis of the first data from the flyby was presented to the press at ESOC at 12:00 CEST today. To Steins and beyond "Steins might be small, but we're making big science here", said Dr David Southwood, ESA's Director of Science and Robotic Exploration. "The better we learn to know the different kinds of asteroids, the better we will understand our origins in the past. Moreover, when such Solar System wanderers escape from the belt they could become a threat to Earth. The better we know them, the better we will be able to mitigate the risks some of them might present in the future." "Rosetta performed very well all along," Southwood continued. " This was a complex manoeuvre to keep such a small target in sight, but the spacecraft came through with flying colours. Now we are even more confident in its capacity to conduct the complex tasks that await it at comet Churyumov-Gerasimenko." Science observations of Steins will continue until 10 September. Since its launch by an Ariane 5 rocket on 2 March 2004, Rosetta has already travelled about 3.7 thousand million kilometres and swung by the Earth twice and Mars once for gravity-assist manoeuvres. On 17 December this year Rosetta will reach the maximum distance from the Sun in its current orbit, and will then head back towards Earth for the next and last gravitational kick from our planet on 13 November 2009. This will give the probe its final push toward its cometary target. On its way, Rosetta is scheduled to conduct another flyby, this time with the much larger (21) Lutetia asteroid, on 10 July 2010. Arrival at 67P/Churyumov-Gerasimenko is due by mid-2014. By that time the probe will have covered a distance of about 6.5 thousand million kilometres.

The ROSETTA PHILAE Lander damping mechanism as probe for the Comet soil strength.

NASA Astrophysics Data System (ADS)

Roll, R.

2015-10-01

The ROSETTA Lander is equipped with an one axis damping mechanism to dissipate kinetic energy during the touch down. This damping is necessary to avoid damages to the Lander by a hard landing shock and more important to avoid re-bouncing from ground with high velocity. The damping mechanism works best for perpendicular impact, which means the velocity vector is parallel to the damper axis and all three feet touch the ground at the same time. That is usually not the case. Part of the impact energy can be transferred into rotational energy at ground contact if the impact is not perpendicular. This energy will lift up the Lander from the ground if the harpoons and the hold down thruster fail, as happen in mission. The damping mechanism itself is an electrical generator, driven by a spindle inside a telescopic tube. This tube was extended in mission for landing by 200mm. A maximum damping length of 140mm would be usually required to compensate a landing velocity of 1m/s, if the impact happens perpendicular on hard ground. After landing the potentiometer of the telescopic tube reading shows a total damping length of only 42,5mm. The damping mechanism and the overall mechanical behavior of the Lander at touch down are well tested and characterized and transferred to a multi-body computer model. The incoming and outgoing flightpath of PHILAE allow via computer-simulation the reconstruction of the touch down. It turns out, that the outgoing flight direction is dominated by the local ground slope and that the damping length is strongly dependent on the soil strength. Damping of soft comet ground must be included to fit the damping length measured. Scenario variations of the various feet contact with different local surface features (stone or regolith) and of different soil models finally lead to a restricted range for the soil strength at the touch down area.

Weighted recalibration of the Rosetta pedotransfer model with improved estimates of hydraulic parameter distributions and summary statistics (Rosetta3)

NASA Astrophysics Data System (ADS)

Zhang, Yonggen; Schaap, Marcel G.

2017-04-01

Pedotransfer functions (PTFs) have been widely used to predict soil hydraulic parameters in favor of expensive laboratory or field measurements. Rosetta (Schaap et al., 2001, denoted as Rosetta1) is one of many PTFs and is based on artificial neural network (ANN) analysis coupled with the bootstrap re-sampling method which allows the estimation of van Genuchten water retention parameters (van Genuchten, 1980, abbreviated here as VG), saturated hydraulic conductivity (Ks), and their uncertainties. In this study, we present an improved set of hierarchical pedotransfer functions (Rosetta3) that unify the water retention and Ks submodels into one. Parameter uncertainty of the fit of the VG curve to the original retention data is used in the ANN calibration procedure to reduce bias of parameters predicted by the new PTF. One thousand bootstrap replicas were used to calibrate the new models compared to 60 or 100 in Rosetta1, thus allowing the uni-variate and bi-variate probability distributions of predicted parameters to be quantified in greater detail. We determined the optimal weights for VG parameters and Ks, the optimal number of hidden nodes in ANN, and the number of bootstrap replicas required for statistically stable estimates. Results show that matric potential-dependent bias was reduced significantly while root mean square error (RMSE) for water content were reduced modestly; RMSE for Ks was increased by 0.9% (H3w) to 3.3% (H5w) in the new models on log scale of Ks compared with the Rosetta1 model. It was found that estimated distributions of parameters were mildly non-Gaussian and could instead be described rather well with heavy-tailed α-stable distributions. On the other hand, arithmetic means had only a small estimation bias for most textures when compared with the mean-like "shift" parameter of the α-stable distributions. Arithmetic means and (co-)variances are therefore still recommended as summary statistics of the estimated distributions. However, it may be necessary to parameterize the distributions in different ways if the new estimates are used in stochastic analyses of vadose zone flow and transport. Rosetta1 and Posetta3 were implemented in the python programming language, and the source code as well as additional documentation is available at: http://www.cals.arizona.edu/research/rosettav3.html.

Cometary science after Rosetta

PubMed Central

Knight, Matthew M.; Fitzsimmons, Alan

2017-01-01

The European Space Agency’s Rosetta mission ended operations on 30 September 2016 having spent over 2 years in close proximity to its target comet, 67P/Churyumov–Gerasimenko. Shortly before this, in summer 2016, a discussion meeting was held to examine how the results of the mission could be framed in terms of cometary and solar system science in general. This paper provides a brief history of the Rosetta mission, and gives an overview of the meeting and the contents of this associated special issue. This article is part of the themed issue ‘Cometary science after Rosetta’. PMID:28554982

From the Vega mission to comet Halley to the Rosetta mission to comet 67/P Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Zelenyi, L. M.; Ksanfomality, L. V.

2016-12-01

The data acquired by the Vega and Giotto spacecraft, while investigating comet 1P/Halley in 1986, are compared to the results of the first phase of exploration of the nucleus of comet 67P/Churyumov-Gerasimenko performed with the Rosetta and Philae modules. The course of the Rosetta mission activity and the status of the modules after the Philae probe landing on the comet's nucleus are overviewed. Since some elements of the touchdown equipment failed, a number of in-situ experiments on the comet's nucleus were not carried out.

The Rosetta mission orbiter science overview: the comet phase

PubMed Central

Altobelli, N.; Buratti, B. J.; Choukroun, M.

2017-01-01

The international Rosetta mission was launched in 2004 and consists of the orbiter spacecraft Rosetta and the lander Philae. The aim of the mission is to map the comet 67P/Churyumov–Gerasimenko by remote sensing, and to examine its environment in situ and its evolution in the inner Solar System. Rosetta was the first spacecraft to rendezvous with and orbit a comet, accompanying it as it passes through the inner Solar System, and to deploy a lander, Philae, and perform in situ science on the comet's surface. The primary goals of the mission were to: characterize the comet's nucleus; examine the chemical, mineralogical and isotopic composition of volatiles and refractories; examine the physical properties and interrelation of volatiles and refractories in a cometary nucleus; study the development of cometary activity and the processes in the surface layer of the nucleus and in the coma; detail the origin of comets, the relationship between cometary and interstellar material and the implications for the origin of the Solar System; and characterize asteroids 2867 Steins and 21 Lutetia. This paper presents a summary of mission operations and science, focusing on the Rosetta orbiter component of the mission during its comet phase, from early 2014 up to September 2016. This article is part of the themed issue ‘Cometary science after Rosetta’. PMID:28554981

Reduced Fragment Diversity for Alpha and Alpha-Beta Protein Structure Prediction using Rosetta.

PubMed

Abbass, Jad; Nebel, Jean-Christophe

2017-01-01

Protein structure prediction is considered a main challenge in computational biology. The biannual international competition, Critical Assessment of protein Structure Prediction (CASP), has shown in its eleventh experiment that free modelling target predictions are still beyond reliable accuracy, therefore, much effort should be made to improve ab initio methods. Arguably, Rosetta is considered as the most competitive method when it comes to targets with no homologues. Relying on fragments of length 9 and 3 from known structures, Rosetta creates putative structures by assembling candidate fragments. Generally, the structure with the lowest energy score, also known as first model, is chosen to be the "predicted one". A thorough study has been conducted on the role and diversity of 3-mers involved in Rosetta's model "refinement" phase. Usage of the standard number of 3-mers - i.e. 200 - has been shown to degrade alpha and alpha-beta protein conformations initially achieved by assembling 9-mers. Therefore, a new prediction pipeline is proposed for Rosetta where the "refinement" phase is customised according to a target's structural class prediction. Over 8% improvement in terms of first model structure accuracy is reported for alpha and alpha-beta classes when decreasing the number of 3- mers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

The Rosetta Science Archive: Status and Plans for Enhancing the Archive Content

NASA Astrophysics Data System (ADS)

Heather, David; Barthelemy, Maud; Besse, Sebastien; Fraga, Diego; Grotheer, Emmanuel; O'Rourke, Laurence; Taylor, Matthew; Vallat, Claire

2017-04-01

On 30 September 2016, Rosetta completed its incredible mission by landing on the surface of Comet 67P/Churyumov-Gerasimenko. Although this marked an end to the spacecraft's active operations, intensive work is still ongoing with instrument teams preparing their final science data deliveries for ingestion into ESA's Planetary Science Archive (PSA). In addition, ESA is establishing contracts with some instrument teams to enhance their data and documentation in an effort to provide the best long-term archive possible for the Rosetta mission. Currently, the majority of teams have delivered all of their data from the nominal mission (end of 2015), and are working on their remaining increments from the 1-year mission extension. The aim is to complete the nominal archiving with data from the complete mission by the end of this year, when a full mission archive review will be held. This review will assess the complete data holdings from Rosetta and ensure that the archive is ready for the long-term. With the resources from the operational mission coming to an end, ESA has established a number of 'enhanced archiving' contracts to ensure that the best possible data are delivered to the archive before instrument teams disband. Updates are focused on key aspects of an instrument's calibration or the production of higher level data / information, and are therefore specific to each instrument's needs. These contracts are currently being kicked off, and will run for various lengths depending upon the activities to be undertaken. The full 'archive enhancement' process will run until September 2019, when the post operations activities for Rosetta will end. Within these contracts, most instrument teams will work on providing a Science User Guide for their data, as well as updating calibrations. Several teams will also be delivering higher level and derived products. For example, the VIRTIS team will be updating both their spectral and geometrical calibrations, and will aim to deliver mapping products to the final archive. Similarly, the OSIRIS team will be improving their calibrations and delivering data additionally in FITS format. The Rosetta Plasma Consortium (RPC) instruments will complete cross-calibrations and a number of activities individual to each instrument. The MIDAS team will also be working on cross-calibrations and will produce a dust particle catalog from the comet coma. GIADA will be producing dust environment maps, with products in 3D plus time. A contract also exists to produce and deliver data set(s) containing sup-porting ground-based observations from amateur astronomers. In addition to these contracts, the Rosetta ESA archiving team will produce calibrated data sets for the NAVCAM instrument, and will work to include the latest shape models from the comet into the final Rosetta archive. Work is also underway to provide a centralized solution to the problem of geometry on the comet. This presentation will outline the current status of the Rosetta archive, as well as highlighting some of the 'enhanced archiving' activities planned with the various instrument teams on Rosetta.

Rosetta Comet Spreads its Jets

NASA Image and Video Library

2014-10-24

This image was taken by the Optical, Spectroscopic, and Infrared Remote Imaging System, Rosetta main onboard scientific imaging system, on Sept. 10, 2014. Jets of cometary activity can be seen along almost the entire body of the comet. http://photojournal.jpl.nasa.gov/catalog/PIA18886

Extending RosettaDock with water, sugar, and pH for prediction of complex structures and affinities for CAPRI rounds 20-27.

PubMed

Kilambi, Krishna Praneeth; Pacella, Michael S; Xu, Jianqing; Labonte, Jason W; Porter, Justin R; Muthu, Pravin; Drew, Kevin; Kuroda, Daisuke; Schueler-Furman, Ora; Bonneau, Richard; Gray, Jeffrey J

2013-12-01

Rounds 20-27 of the Critical Assessment of PRotein Interactions (CAPRI) provided a testing platform for computational methods designed to address a wide range of challenges. The diverse targets drove the creation of and new combinations of computational tools. In this study, RosettaDock and other novel Rosetta protocols were used to successfully predict four of the 10 blind targets. For example, for DNase domain of Colicin E2-Im2 immunity protein, RosettaDock and RosettaLigand were used to predict the positions of water molecules at the interface, recovering 46% of the native water-mediated contacts. For α-repeat Rep4-Rep2 and g-type lysozyme-PliG inhibitor complexes, homology models were built and standard and pH-sensitive docking algorithms were used to generate structures with interface RMSD values of 3.3 Å and 2.0 Å, respectively. A novel flexible sugar-protein docking protocol was also developed and used for structure prediction of the BT4661-heparin-like saccharide complex, recovering 71% of the native contacts. Challenges remain in the generation of accurate homology models for protein mutants and sampling during global docking. On proteins designed to bind influenza hemagglutinin, only about half of the mutations were identified that affect binding (T55: 54%; T56: 48%). The prediction of the structure of the xylanase complex involving homology modeling and multidomain docking pushed the limits of global conformational sampling and did not result in any successful prediction. The diversity of problems at hand requires computational algorithms to be versatile; the recent additions to the Rosetta suite expand the capabilities to encompass more biologically realistic docking problems. Copyright © 2013 Wiley Periodicals, Inc.

Rosetta Orbiter and Lander: Our Evolving Understanding of Comet Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Alexander, Claudia

2015-08-01

Rosetta is the third cornerstone mission of the European Space Agency's (ESA) comprehensive Horizon 2000 Programme. It was designed to find, and examine, some of the original material of the solar system; to help us understand how the comet works as a machine to absorb and re-radiate energy from the sun; to characterize the thermophysical properties and structure of the body, and to complete an inventory of its dusty, organic, and isotopic composition. At the time of the conference, Rosetta will be at perihelion, portions of the surface that were initially in sunlight will be in complete darkness, and portions initially only partially exposed to the sun will be experiencing summer. At the time of the conference, a planned pass into a comet plume may have yielded important measurements. Up-to-date logistics of Rosetta exploration will be discussed.Rosetta has already provided a rich mother-lode of data on this intriguing object, from the early measurements of D/H ratio, to the first-time measurement of N2 in a small body, to the unique ‘dragon-egg’ morphology seen in selected places on the surface. In this talk, I'll review some of the principle results so far of the Rosetta mission, including what we know of comet activity, the showers of grains, and developing magnetic field induced cometospheric boundaries and coma environment. I'll review the landing and walk through the 60 hours of time the probe spent on the comet's surface. Finally I'll discuss some of the intriguing questions that might be answered with the perihelion pass, such as does the observed increase in this comet’s rotation period indicate a sign of comet inflation or disruption?

Microbial healing of cracks in concrete: a review.

PubMed

Joshi, Sumit; Goyal, Shweta; Mukherjee, Abhijit; Reddy, M Sudhakara

2017-11-01

Concrete is the most widely used construction material of the world and maintaining concrete structures from premature deterioration is proving to be a great challenge. Early age formation of micro-cracking in concrete structure severely affects the serviceability leading to high cost of maintenance. Apart from conventional methods of repairing cracks with sealants or treating the concrete with adhesive chemicals to prevent the cracks from widening, a microbial crack-healing approach has shown promising results. The unique feature of the microbial system is that it enables self-healing of concrete. The effectiveness of microbially induced calcium carbonate precipitation (MICCP) in improving durability of cementitious building materials, restoration of stone monuments and soil bioclogging is discussed. Main emphasis has been laid on the potential of bacteria-based crack repair in concrete structure and the applications of different bacterial treatments to self-healing cracks. Furthermore, recommendations to employ the MICCP technology at commercial scale and reduction in the cost of application are provided in this review.

Rosetta Langmuir Probe Photoelectron Emission and Solar Ultraviolet Flux at Comet 67P

NASA Astrophysics Data System (ADS)

Johansson, F. L.; Odelstad, E.; Paulsson, J. J.; Harang, S. S.; Eriksson, A. I.; Mannel, T.; Vigren, E.; Edberg, N. J. T.; Miloch, W. J.; Simon Wedlund, C.; Thiemann, E.; Epavier, F.; Andersson, L.

2017-12-01

The Langmuir Probe instrument on Rosetta monitored the photoelectron emission current of the probes during the Rosetta mission at comet 67P/Churyumov-Gerasimenko, in essence acting as a photodiode monitoring the solar ultraviolet radiation at wavelengths below 250 nm. We have used three methods of extracting the photoelectron saturation current from the Langmuir probe measurements. The resulting dataset can be used as an index of the solar far and extreme ultraviolet at the Rosetta spacecraft position, including flares, in wavelengths that are important for photoionisation of the cometary neutral gas. Comparing the photoemission current to data measurements by MAVEN/EUVM and TIMED/SEE, we find good correlation when 67P was at large heliocentric distances early and late in the mission, but up to 50 percent decrease of the expected photoelectron current at perihelion. We discuss possible reasons for the photoemission decrease, including scattering and absorption by nanograins created by disintegration of cometary dust far away from the nucleus.

Rosetta photoelectron emission and solar ultraviolet flux at comet 67P

NASA Astrophysics Data System (ADS)

Johansson, Fredrik L.; Odelstad, E.; Paulsson, J. J. P.; Harang, S. S.; Eriksson, A. I.; Mannel, T.; Vigren, E.; Edberg, N. J. T.; Miloch, W. J.; Simon Wedlund, C.; Thiemann, E.; Eparvier, F.; Andersson, L.

2017-07-01

The Langmuir Probe instrument on Rosetta monitored the photoelectron emission current of the probes during the Rosetta mission at comet 67P/Churyumov-Gerasimenko, in essence acting as a photodiode monitoring the solar ultraviolet radiation at wavelengths below 250 nm. We have used three methods of extracting the photoelectron saturation current from the Langmuir probe measurements. The resulting data set can be used as an index of the solar far and extreme ultraviolet at the Rosetta spacecraft position, including flares, in wavelengths which are important for photoionization of the cometary neutral gas. Comparing the photoemission current to data measurements by MAVEN/EUVM and TIMED/SEE, we find good correlation when 67P was at large heliocentric distances early and late in the mission, but up to 50 per cent decrease of the expected photoelectron current at perihelion. We discuss possible reasons for the photoemission decrease, including scattering and absorption by nanograins created by disintegration of cometary dust far away from the nucleus.

Laboratory Gas Dynamic Measurements of the Comet Pressure Sensor COPS on the Rosetta Spacecraft

NASA Astrophysics Data System (ADS)

Tzou, Chia-Yu; Altwegg, Kathrin; Gasc, Sébastien; Rubin, Martin

2014-05-01

Rosetta is part of the cornerstone missions executed by the European Space Agency (ESA). It is the first space mission to orbit and also land on a comet. By the end of July 2014 Rosetta will be able to carry out a close study of comet 67P/Churyumov-Gerasimenko. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) is one of the core payloads on board of the Rosetta spacecraft [Balsiger et al, 2007]. ROSINA's main objective is to determine the major atmospheric and ionospheric composition in the coma and to investigate the gas dynamics around the comet. ROSINA consists of two mass spectrometers and a pressure sensor. The Comet Pressure Sensor (COPS) is not only a pressure sensor but also plays the role of a safety instrument for Rosetta by providing high-density alerts to the other payload instruments. It includes two gauges: the "nude gauge" measures total neutral density in the coma and the "ram gauge" measures the dynamic pressure of the cometary gas flux to obtain the bulk velocity of the neutral gas. The combination of these two gauges makes COPS capable to derive the gas dynamics in the coma. We recently performed laboratory gas dynamic measurements with the identical flight-spare instrument of COPS. Using the Calibration System for The Mass Spectrometer Instrument ROSINA (CASYMIR) we produce neutral gas beams to model cometary gas jets with velocities from thermal to 2 km/s. For COPS calibration we measure gas beams with different incident angles to derive the velocity and the temperature of the gas using different mixtures expected at the comet. We demonstrate that COPS will be ready for the prime mission and it will be fascinating to compare COPS measurements with numerous observation results and computer models starting in summer 2014 to gain new insights into the gas dynamics around a comet. Reference: Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007.

Personifying space: how the public learned to care for Rosetta and Philae

NASA Astrophysics Data System (ADS)

Mignone, Claudia; Baldwin, Emily; O'Flaherty, Karen; Homfeld, Anne-Mareike; Bauer, Markus; McCaughrean, Mark

2015-04-01

One of the aspects in the communications campaign promoted by the European Space Agency (ESA) and its partner institutions throughout 2014 to raise awareness about the comet-chasing mission, Rosetta, was the development of two anthropomorphic characters depicting the Rosetta probe and the lander Philae. The two characters were featured in a series of short cartoons with a fairy-tale flair that were distributed on the internet with the aim of breaking into new audience groups. The cartoon series, named "Once upon a time", tells the adventures of Rosetta and Philae, depicted as two bold and friendly explorers on a pioneering journey across the Solar System. The episodes cover the mission milestones, from Rosetta's wake-up from deep-space hibernation to its rendezvous with the comet and Philae's landing. They were promoted through the mission's dedicated social media accounts (mainly Twitter and Facebook) and through ESA's existing social media channels as part of the broader Rosetta communications campaign. We discuss how visual storytelling was used to make the mission's scientific goals more accessible, allowing the audience to share both its excitement and risks. We describe the development of the cartoon series and the level of engagement it generated, using estimates based on the response received through our social media channels. Other tools were also used to help the public identify with the two space probes. In particular, the Twitter accounts @ESA_Rosetta (managed by ESA) and @philae2014 (managed by DLR) were run in first person, as to give the impression that the probes were writing the tweets themselves, and even interacting with one another - as is often done in the case of spacecraft Twitter accounts. All these elements added a personal feel to the comet landing, with members of the public empathising with the two space probes and caring for their well-being. This wave of interest culminated in the last few hours of Philae's operations on the comet, before it entered hibernation. We also discuss issues that we encountered using this approach, including pitfalls and lessons learnt, and how the choice of anthropomorphising spacecraft was received by different publics.

Evolution of Cometary Activity at 67P/Churyumov-Gerasimenko as seen by ROSINA/Rosetta

NASA Astrophysics Data System (ADS)

Jäckel, A.; Altwegg, K.; Balsiger, H.; Calmonte, U.; Gasc, S.; Le Roy, L.; Rubin, M.; Tzou, C. Y.; Wurz, P.; Bieler, A.; Berthelier, J.-J.; Fiethe, B.; Hässig, M.; deKeyser, J.; Mall, U.; Rème, H.

2015-10-01

Since nine months the European Space Agency's spacecraft Rosetta, with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) onboard, is in the comet escort phase. ROSINA is a suite of three instruments, consisting of the COmetary Pressure Sensor (COPS), the Double Focusing Mass Spectrometer (DFMS), and the Reflectron-type Time-Of-Flight (RTOF) mass spectrometer [1]. The two mass spectrometers measure in situ the neutral and ionized volatile material in the coma of comet 67P/Churyumov- Gerasimenko (67P/C-G). With COPS we are able to derive the total gas density, bulk velocities and temperatures of the coma.

The Wide Angle Camera of the ROSETTA Mission

NASA Astrophysics Data System (ADS)

Barbieri, C.; Fornasier, S.; Verani, S.; Bertini, I.; Lazzarin, M.; Rampazzi, F.; Cremonese, G.; Ragazzoni, R.; Marzari, F.; Angrilli, F.; Bianchini, G. A.; Debei, S.; Dececco, M.; Guizzo, G.; Parzianello, G.; Ramous, P.; Saggin, B.; Zaccariotto, M.; Da Deppo, V.; Naletto, G.; Nicolosi, G.; Pelizzo, M. G.; Tondello, G.; Brunello, P.; Peron, F.

This paper aims to give a brief description of the Wide Angle Camera (WAC), built by the Centro Servizi e AttivitàSpaziali (CISAS) of the University of Padova for the ESA ROSETTA Mission to comet 46P/Wirtanen and asteroids 4979 Otawara and 140 Siwa. The WAC is part of the OSIRIS imaging system, which comprises also a Narrow Angle Camera (NAC) built by the Laboratoire d'Astrophysique Spatiale (LAS) of Marseille. CISAS had also the responsibility to build the shutter and the front cover mechanism for the NAC. The flight model of the WAC was delivered in December 2001, and has been already integrated on ROSETTA.

"Hello, World!" Harnessing Social Media for the Rosetta Mission

NASA Astrophysics Data System (ADS)

Baldwin, E.; Mignone, C.; Scuka, D.; Homfeld, A. M.; Ranero, K.; Rolfe, E.; Bennett, M.; Schepers, A.; O'Flaherty, K. S.; Bauer, M.; McCaughrean, M.

2016-03-01

The European Space Agency's comet-chasing Rosetta mission was launched in 2004, before social media became a popular tool for mainstream communication. As it reached its destination ten years later, new audiences were reached and inspired by this once-in-a-lifetime event by harnessing a range of outlets for communicating the key messages. These included traditional online platforms, such as news websites, blogs, and Livestream, as well as Twitter, Facebook, Instagram, Flickr, YouTube, Google+ and SoundCloud. In this article, we outline the role social media channels played in making Rosetta one of the European Space Agency's biggest communication and public engagement successes.

First Results from The PACA_Rosetta67P Group in Support of ESA/Rosetta Mission

NASA Astrophysics Data System (ADS)

Yanamandra-Fisher, Padma A.

2016-10-01

The PACA_Rosetta67P Facebook group is the amateur observing program, complementary to the ground-based professional observations, in support of ESA/Rosetta mission to the comet 67P/Churyumovs-Gerasimenko (CG). The amateur campaign has followed the ESA/Rosetta's escort of 67P from August 2014 to present. Although 67P/CG is faint in its current apparition (it is a Jupiter Family comet, with a period of 6.45 years and is on its seventh passage of the inner solar system), the comet is known to brighten from about a month before perihelion and post perihelion. The comet behaved as expected. With the vast amount of data collected by the global amateur network, we are now able to (i) archive the data to allow it to be crowdsourced by the professionals; (ii) mine the data to determine various trends such as the variation of magnitude with respect to heliospheric distance; map the changes in Afrho (the dust activity parameter) and a long baseline of observations that show features similar to the features seen in the ground-based observations of the professionals. We will highlight the campaign and the results now possible to determine and compare with other observations taken at the same time. We will highlight the first results of the campaign, with the challenges and lessons learned to apply when developing other amateur observing programs.

Rosetta performs ESA's closest-ever Earth fly-by

NASA Astrophysics Data System (ADS)

2005-03-01

The passage through the Earth-Moon system allowed ground controllers to test Rosetta's 'asteroid fly-by mode' (AFM) using the Moon as a 'fake' asteroid, rehearsing the fly-bys of asteroids Steins and Lutetia due in 2008 and 2010 respectively. The AFM test started at 23:01 GMT and ran for nine minutes during which the two onboard navigation cameras successfully tracked the Moon, allowing Rosetta's attitude to be automatically adjusted. Before and after closest approach, the navigation cameras also acquired a series of images of the Moon and Earth; these data will be downloaded early today for ground processing and are expected to be available by 8 March. In addition, other onboard instruments were switched on, including ALICE (ultraviolet imaging spectrometer), VIRTIS (visible and infrared mapping spectrometer) and MIRO (microwave instrument for the Rosetta orbiter), for calibration and general testing using the Earth and Moon as targets. The fly-by manoeuvre swung the three-tonne spacecraft around our planet and out towards Mars, where it will make a fly-by on 26 February 2007. Rosetta will return to Earth again in a series of four planet fly-bys (three times with Earth, once with Mars) before reaching Comet 67P/Churyumov-Gerasimenko in 2014, when it will enter orbit and deliver a lander, Philae, onto the surface. The fly-bys are necessary to accelerate the spacecraft so as to eventually match the velocity of the target comet. They are a fuel-saving way to boost speed using planetary gravity. Yesterday's fly-by came one year and two days after launch and highlights the valuable opportunities for instrument calibration and data gathering available during the mission's multi-year voyage. In just three months, on 4 July, Rosetta will be in a good position to observe and gather data during NASA's spectacular Deep Impact event, when the Deep Impact probe will hurl a 380 kg projectile into Comet Tempel 1, revealing data on the comet's internal structure. Certain of Rosetta’s unique instruments, such as its ultraviolet light instrument ALICE, should be able to make critical contributions to the American mission. About Rosetta Rosetta is the first mission designed to both orbit and land on a comet, and consists of an orbiter and a lander. The spacecraft carries 11 scientific experiments and will be the first mission to undertake long-term exploration of a comet at close quarters. After entering orbit around Comet 67P/Churyumov-Gerasimenko in 2014, the spacecraft will release a small lander onto the icy nucleus. Rosetta will orbit the comet for about a year as it heads towards the Sun, remaining in orbit for another half-year past perihelion (closest approach to the Sun). Comets hold essential information about the origin of our Solar System because they are the most primitive objects in the Solar System and their chemical composition has changed little since their formation. By orbiting and landing on Comet 67P/Churyumov-Gerasimenko, Rosetta will help us reconstruct the history of our own neighbourhood in space. Note for broadcasters: The ESA TV Service will transmit a TV exchange with images of the fly-by, together with science results/images from observations as far as available on 11 March. For further details : http://television.esa.int

Determination of the microbial diversity of spacecraft assembly, testing and launch facilities: First results of the ESA project MiDiv

NASA Astrophysics Data System (ADS)

Rettberg, P.; Fritze, D.; Verbarg, S.; Nellen, J.; Horneck, G.; Stackebrandt, E.; Kminek, G.

2006-01-01

In the near future, an increasing number of in situ life detection and sample return missions to planets and other solar system bodies will be launched. The demand to control spacecraft-carried microbial contamination becomes obvious. COSPAR (Committee of Space Research) has defined guidelines and bioburden limits for different types of missions and target bodies. The first step in the implementation of these planetary protection guidelines encompasses a qualitative and quantitative inventory of the bioburden of spacecraft assembly facilities. With information about the composition of these microbial communities the development and/or optimization of adequate cleaning, disinfection, and sterilization procedures for spacecraft preparation before launch will be possible. In the ESA project MiDiv, we started to investigate the diversity of cultivable microorganisms found on spacecraft and spacecraft assembly halls using the satellites SMART-1 and ROSETTA as test objects. The analyses to date include cultivation of microorganisms by varying pH, temperature, oxygen, and pasteurization. A culture collection of bacterial isolates and a database of 16S RNA gene sequences have been established. The results of our preliminary work, including the numbers of colony forming units, differentiated as aerobes and facultative anaerobes as well as their phylogenetic classification, give a first overview of the breadth of physiological potential of the identified microorganisms and their capability to withstand various cleaning and sterilizing procedures currently used for the planetary protection.

Study of the coma of comet 67P/Churyumov-Gerasimenko based on the ROSINA/RTOF instrument onboard Rosetta

NASA Astrophysics Data System (ADS)

Hoang, M.; Garnier, P.; Rème, H.; Altwegg, K.; Balsiger, H.; Calmonte, U.; Fiethe, B.; Galli, A.; Gasc, S.; Jäckel, A.; Mall, U.; Le Roy, L.; Rubin, M.; Tzou, C.-Y.; Waite, J. H.; Wurz, P.

2015-10-01

The Rosetta ESA mission investigates the environment of the comet 67P / Churyumov- Gerasimenko since August 2014. Among the experiments onboard the satellite, the ROSINA experiment (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) includes two mass spectrometers (DFMS and RTOF) to analyze the composition of neutrals and ions, and an instrument (COPS) to monitor the density and velocity of neutrals in the coma [1]. We will here analyze and discuss the data of the ROSINA/RTOF instrument during the comet escort phase. A detailed description of the main volatiles (H2O, CO2, CO) dynamics and of the heterogeneities of the coma will be provided.

Rosetta mission status: challenges of flying near a comet

NASA Astrophysics Data System (ADS)

Martin, P.; Taylor, M.; Kueppers, M.; O'Rourke, L.; Lodiot, S.

2015-10-01

Recent operational events, most likely due to the increased presence of dust near the spacecraft during close flybys of C67P/Churyumov-Gerasimenko in the comet escort phase, have led to a redefinition of the Rosetta mission through the design of new trajectories allowing the spacecraft and its payload to continue flying safely around the comet while augmenting the wealth of scientific data and results that has characterized the beginning of the mission so far. A decision process is being put in place in view of finding the best ways forward operationally so as to recover some capabilities that will allow Rosetta to continue optimising its scientific mission, in both the nominal and expected extended mission intervals.

The dust environment of 67P/Churyumov-Gerasimenko as seen through Rosetta/OSIRIS

NASA Astrophysics Data System (ADS)

Tubiana, C.; Güttler, C.; Sierks, H.; Bertini, I.; Osiris Team

2017-09-01

The ESA's Rosetta spacecraft had the unique opportunity to be in the vicinity of comet 67P/Churyumov-Gerasimenko for 2.5 years, observing how the comet evolved while approaching the Sun, passing through perihelion and then moving back into the outer solar system. OSIRIS, the scientific camera system onboard Rosetta, imaged the nucleus and the comet dust environment during the entire mission. We studied the unresolved dust coma, investigating its diurnal and seasonal variations and providing insights into the dust composition. Hundreds of individual particles, identified in the thousands of images dedicated to dust studies, have been characterized in terms of color, size distribution, distance, light curves and orbits.

"Rosetta" Mission's "7 Hours of Terror" and "Philae's" Descent

ERIC Educational Resources Information Center

Blanco, Philip

2015-01-01

In November 2014 the "Rosetta" mission to Comet 67P/Churyumov-Gerasimenko made the headlines when its "Philae" lander completed a successful unpowered descent onto the surface of the comet nucleus after "7 hours of terror" for the mission scientists. 67P's irregular shape and rotation made this task even more…

Cometary Plasma Probed by Rosetta

NASA Astrophysics Data System (ADS)

Galand, Marina; Vigren, Erik; Raghuram, Susarla; Schwartz, Steve; Eriksson, Anders; Edberg, Niklas; Lebreton, Jean-Pierre; Henri, Pierre; Burch, Jim; Fuselier, Stephen; Haessig, Myrtha; Mandt, Kathy; Altwegg, Kathrin; Tzou, Chia-You

2015-04-01

In Fall 2014, comet 67P/Churyumov-Gerasimenko, the main target of the Rosetta mission, was at 3 AU from the Sun. Its outgassing rate was only of the order of 5×1025 s-1 based on Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) / Cometary Pressure Sensor (COPS). Despite such a thin coma, a plasma of cometary origin has been detected by Rosetta Plasma Consortium (RPC) sensors and ROSINA/ Double Focusing Mass Spectrometer (DFMS). Close to the comet they have revealed the presence of a cometary ionosphere, with a hot electron population, consistent with the deposition of Extreme UltraViolet (EUV) solar radiation. We will present a comparison between RPC sensors and an energy deposition model in terms of suprathermal electron intensities [RPC/ Ion and Electron Sensor (IES)] and electron temperature and density [RPC/ LAngmuir Probe (LAP) and RPC/ Mutual Impedance Probe (MIP)]. We will also compare ion composition among the main species, between our ionospheric model and ROSINA/DFMS. We will discuss effects of the space environment on the cometary plasma. Finally, we will highlight any evolution in the cometary plasma as the comet is getting closer to perihelion.

Modeling an in-register, parallel "iowa" aβ fibril structure using solid-state NMR data from labeled samples with rosetta.

PubMed

Sgourakis, Nikolaos G; Yau, Wai-Ming; Qiang, Wei

2015-01-06

Determining the structures of amyloid fibrils is an important first step toward understanding the molecular basis of neurodegenerative diseases. For β-amyloid (Aβ) fibrils, conventional solid-state NMR structure determination using uniform labeling is limited by extensive peak overlap. We describe the characterization of a distinct structural polymorph of Aβ using solid-state NMR, transmission electron microscopy (TEM), and Rosetta model building. First, the overall fibril arrangement is established using mass-per-length measurements from TEM. Then, the fibril backbone arrangement, stacking registry, and "steric zipper" core interactions are determined using a number of solid-state NMR techniques on sparsely (13)C-labeled samples. Finally, we perform Rosetta structure calculations with an explicitly symmetric representation of the system. We demonstrate the power of the hybrid Rosetta/NMR approach by modeling the in-register, parallel "Iowa" mutant (D23N) at high resolution (1.2Å backbone rmsd). The final models are validated using an independent set of NMR experiments that confirm key features. Copyright © 2015 Elsevier Ltd. All rights reserved.

Holistic Approach to Partial Covalent Interactions in Protein Structure Prediction and Design with Rosetta.

PubMed

Combs, Steven A; Mueller, Benjamin K; Meiler, Jens

2018-05-29

Partial covalent interactions (PCIs) in proteins, which include hydrogen bonds, salt bridges, cation-π, and π-π interactions, contribute to thermodynamic stability and facilitate interactions with other biomolecules. Several score functions have been developed within the Rosetta protein modeling framework that identify and evaluate these PCIs through analyzing the geometry between participating atoms. However, we hypothesize that PCIs can be unified through a simplified electron orbital representation. To test this hypothesis, we have introduced orbital based chemical descriptors for PCIs into Rosetta, called the PCI score function. Optimal geometries for the PCIs are derived from a statistical analysis of high-quality protein structures obtained from the Protein Data Bank (PDB), and the relative orientation of electron deficient hydrogen atoms and electron-rich lone pair or π orbitals are evaluated. We demonstrate that nativelike geometries of hydrogen bonds, salt bridges, cation-π, and π-π interactions are recapitulated during minimization of protein conformation. The packing density of tested protein structures increased from the standard score function from 0.62 to 0.64, closer to the native value of 0.70. Overall, rotamer recovery improved when using the PCI score function (75%) as compared to the standard Rosetta score function (74%). The PCI score function represents an improvement over the standard Rosetta score function for protein model scoring; in addition, it provides a platform for future directions in the analysis of small molecule to protein interactions, which depend on partial covalent interactions.

On the Evolution of the Pulmonary Alveolar Lipofibroblast

PubMed Central

Torday, John S.; Rehan, Virender K.

2015-01-01

The pulmonary alveolar lipofibroblast was first reported in 1970. Since then its development, structure, function and molecular characteristics have been determined. Its capacity to actively absorb, store and ‘traffic’ neutral lipid for protection of the alveolus against oxidant injury, and for the active supply of substrate for lung surfactant phospholipid production have offered the opportunity to identify a number of specialized functions of these strategically placed cells. Namely, Parathyroid Hormone-related Protein (PTHrP) signaling, expression of Adipocyte Differentiation Related Protein, leptin, peroxisome proliferator activator receptor gamma, and the prostaglandin E2 receptor EP2-which are all stretch-regulated, explaining how and why surfactant production is ‘on-demand’ in service to ventilation-perfusion matching. Because of the central role of the lipofibroblast in vertebrate lung physiologic evolution, it is a Rosetta Stone for understanding how and why the lung evolved in adaptation to terrestrial life, beginning with the duplication of the PTHrP Receptor some 300 mya. Moreover, such detailed knowledge of the workings of the lipofibroblast have provided insight to the etiology and effective treatment of Bronchopulmonary Dysplasia based on physiologic principles rather than on pharmacology. PMID:26706109

Spatial memory: a Rosetta stone for rat and human hippocampal discourse: Theoretical comment on Goodrich-Hunsaker and Hopkins (2010).

PubMed

Sutherland, Robert J

2010-06-01

The article by Goodrich-Hunsaker and Hopkins (2010, this issue) takes up an important place among in the recent contributions on the role of the hippocampus in memory. They evaluate the effect of bilateral damage to the hippocampus on performance by human participants in a virtual 8-arm radial maze. The hippocampal damage appears to be highly selective and nearly complete. Exactly as with selective hippocampal damage in rats, the human participants showed a deficit in accurately choosing rewarded versus never-rewarded arms and a deficit in avoiding reentering recently visited arms. The results are triply significant: (1) They provide good support for the idea that the wealth of neurobiological information, from network to synapse to gene, on spatial memory in the rat may apply as a whole to the human hippocampal memory system; (2) They affirm the utility of human virtual task models of rat spatial memory tasks; (3) They support one interpretation of the dampening of the hippocampal functional MRI (fMRI) blood oxygen level-dependent (BOLD) signal during performance of the virtual radial arm maze observed by Astur et al. (2005).

Watching AGN feedback at its birth: HST observations of nascent outflow host IC860

NASA Astrophysics Data System (ADS)

Alatalo, Katherine

2016-10-01

IC860 is a nearby IR-luminous early-type spiral with a unique set of properties: it is a shocked, poststarburst galaxy that hosts an AGN-driven neutral wind and a compact core of molecular gas. IC860 can serve as a rosetta stone for the early stages of triggering AGN feedback. We propose to use WFC3 on HST to obtain NUV, optical and near-IR imaging of IC860. We will create a spatially-resolved history of star formation quenching through SED-fitting of 7 requested broadband filters, and compare the spatially resolved star formation histories to in different positions within the underlying stellar features (such as spiral structure) that might define a narrative of how star formation is quenching in IC860. These observations will also resolve the super-star cluster sites to trace the most recent star formation. Finally, these observations will trace the mass of the outflow by building an absorption map of the dust. IC860 presents a unique opportunity to study a galaxy at an early stage of transitioning from blue spiral to red early-type galaxy, that also hosts an AGN-driven neutral wind and a compact, turbulent molecular gas core.

In Situ Space Gas Dynamic Measurements by the ROSINA Comet Pressure Sensor COPS on the Rosetta Spacecraft

NASA Astrophysics Data System (ADS)

Tzou, C. Y.; Altwegg, K.; Fiethe, B.; Gasc, S.; Rubin, M.

2014-12-01

Rosetta is part of the cornerstone missions executed by the European Space Agency. It is the first space mission to orbit and also land on a comet. Starting in August 2014 Rosetta will be able to carry out a close study of comet 67P/Churyumov-Gerasimenko. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) is one of the core payloads on board of the Rosetta spacecraft [Balsiger et al, 2007]. ROSINA's main objective is to determine the major atmospheric and ionospheric composition in the coma and to investigate the gas dynamics around the comet. ROSINA consists of two mass spectrometers and a pressure sensor. The Comet Pressure Sensor (COPS) includes two gauges: the "nude gauge" measures total neutral density in the coma and the "ram gauge" measures the dynamic pressure of the cometary gas flux to obtain the bulk velocity of the neutral gas. The combination of these two gauges makes COPS capable to derive the gas dynamics at the location of the spacecraft. We performed laboratory gas dynamic measurements with the identical flight-spare instrument of COPS. Using the Calibration System for The Mass Spectrometer Instrument ROSINA (CASYMIR) we produce neutral gas beams to model cometary gas jets with velocities from thermal up to 2 km/s. We expect that COPS will be able to detect the faint and expanding atmosphere of comet 67P/Churyumov-Gerasimenko as early as August 2014 when the comet is still farther than 3 AU from the Sun. We will present the first ROSINA COPS observations of the gas dynamics around the comet together with the corresponding laboratory measurements required for the interpretation of these data. Reference: Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007.

Microbial monitoring in treated stone at the Royal Chapel of Granada

NASA Astrophysics Data System (ADS)

Jroundi, Fadwa; Pinar, Guadalupe; González-Muñoz, Maria Theresa; Sterflinger, Katja

2014-05-01

Biomineralization processes have been applied in situ to protect and consolidate decayed ornamental stone of the Royal Chapel in Granada (Spain). In few years, this conservation treatment has gained worth attention as environmentally friendly methodology for protection and consolidation of limestone because of the compatibilities shown between the new calcium carbonate cement and the original stone substrate. Moreover, the success of this approach may be related to the diversity of the microbiota inhabiting the stone and activated upon the biotreatment application and throughout the time. González-Muñoz et al. (2008) proposed a nutritional solution that activate among the bacteria inhabiting the stone those with carbonatogenic activity. In this study, a long-term (one, two and three years) monitoring of the microbiota present on the treated and untreated stones was done using a molecular strategy, including total DNA extraction, PCR amplification of 16S rRNA sequences, construction of clone libraries and fingerprinting by DGGE (Denaturing Gradient Gel Electrophoresis) analysis. Sequencing of the 16S rDNA revealed the dominant occurrence of members of Actinobacteria (44.20%), Gamma-proteobacteria (30.24%) and Chloroflexi (25.56%) after one year of the biotreatment. Whereas after two years, members of Cyanobacteria (22.10%) appeared and three years after, the microbiota consisted of only Actinobacteria and Cyanobacteria with approximately the same percentage in comparison with the untreated stones, dominated exclusively by Actinobacteria (100%). Fungal diversity followed the same dynamic as bacterial diversity being Ascomicota the predominant order before treatment. After one year, members of Basidiomycota and Viridiplantae appeared on the stone while two years after, the Viridiplantae dominated with a percentage of 84.77%. Finally, three years after the treatment, fungi population started to stabilize again and Ascomicota predominated next to 16.67% of Viridiplantae. The molecular strategy used here is proposed as an effective monitoring system to evaluate the impact of the application of bacterially induced calcium carbonate mineralization as restoration/conservation procedure for decayed ornamental stone. Moreover, these results confirm that the biotreatment, proposed by González Muñoz et al (2008), is friendly for the microbiota inhabiting the stone, which reaches stability after relatively few years. References: González-Muñoz et al. (2008) Spanish Patent no. 2008/009771 Acknowledgements: Supported by the Junta de Andalucia (grants RNM-3493) and by "José Castillejo" program from the "Ministerio de Educación, Cultura y Deporte" (I-D+i 2008-2011).

Microbial Community Transplant Results in Increased and Long-Term Oxalate Degradation

PubMed Central

Miller, Aaron W.; Oakeson, Kelly F.; Dale, Colin; Dearing, M. Denise

2016-01-01

Gut microbes are essential for the degradation of dietary oxalate, and this function may play a role in decreasing the incidence of kidney stones. However, many oxalate-degrading bacteria are susceptible to antibiotics and the use of oxalate-degrading probiotics has only led to an ephemeral reduction in urinary oxalate. The objective of the current study was to determine the efficacy of using whole-community microbial transplants from a wild mammalian herbivore, Neotoma albigula, to increase oxalate degradation over the long term in the laboratory rat, Rattus norvegicus. We quantified the change in total oxalate degradation in lab rats immediately after microbial transplants and at 2- and 9-month intervals following microbial transplants. Additionally, we tracked the fecal microbiota of the lab rats, with and without microbial transplants, using high-throughput Illumina sequencing of a hyper-variable region of the 16S rRNA gene. Microbial transplants resulted in a significant increase in oxalate degradation, an effect that persisted 9 months after the initial transplants. Functional persistence was corroborated by the transfer, and persistence of a group of bacteria previously correlated with oxalate consumption in N. albigula, including an anaerobic bacterium from the genus Oxalobacter known for its ability to use oxalate as a sole carbon source. The results of this study indicate that whole-community microbial transplants are an effective means for the persistent colonization of oxalate-degrading bacteria in the mammalian gut. PMID:27312892

Rosetta/OSIRIS - Nucleus morphology and activity of comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Sierks, Holger; Barbieri, Cesare; Lamy, Philippe; Rickman, Hans; Rodrigo, Rafael; Koschny, Detlef

2015-04-01

ESA's Rosetta mission arrived on August 6, 2014, at target comet 67P/Churyumov-Gerasimenko after 10 years of cruise. OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) is the scientific imaging system onboard Rosetta. It comprises a Narrow Angle Camera (NAC) for nucleus surface and dust studies and a Wide Angle Camera (WAC) for the wide field coma investigations. OSIRIS imaged the nucleus and coma of the comet from the arrival throughout the mapping phase, PHILAE landing, early escort phase and close fly-by. The overview paper will discuss the surface morpholo-gy and activity of the nucleus as seen in gas, dust, and local jets as well as small scale structures in the local topography.

Rosetta - a new target to solve planetary mysteries

NASA Astrophysics Data System (ADS)

2004-01-01

This delay meant that the original mission's target, Comet Wirtanen, could no longer be reached. Instead, a new target has been selected, Comet 67P/Churyumov-Gerasimenko, which Rosetta will encounter in 2014 after a ‘billiard ball’ journey through the Solar System lasting more than ten years. Rosetta’s name comes from the famous ‘Rosetta Stone’, from which Egyptian hieroglyphics were deciphered almost 200 years ago. In a similar way, scientists hope that the Rosetta spacecraft will unlock the mysteries of the Solar System. Comets are very interesting objects for scientists, since their composition reflects how the Solar System was when it was very young and still 'unfinished', more than 4600 million years ago. Comets have not changed much since then. In orbiting Comet Churyumov-Gerasimenko and landing on it, Rosetta will collect information essential to an understanding of the origin and evolution of our Solar System. It will also help discover whether comets contributed to the beginnings of life on Earth. In fact comets are carriers of complex organic molecules that, delivered to Earth through impacts, perhaps played a role in the origin of living forms. Furthermore, ‘volatile’ light elements carried by comets might also have played an important role in forming the Earth’s oceans and atmosphere. “Rosetta is one of the most challenging missions undertaken so far,” says Professor David Southwood, ESA Director of Science. “No one has ever attempted such a mission, unique for its scientific implications as well as for its complex and spectacular interplanetary space manoeuvres.” Before reaching its target in 2014, Rosetta will circle the Sun four times on wide loops in the inner Solar System. During its long trek, the spacecraft will have to endure some extreme thermal conditions. Once it is close to Comet Churyumov-Gerasimenko, scientists will take it through a delicate braking manoeuvre; the spacecraft will then closely orbit the comet, and gently drop a lander on it. It will be landing on a small, fast-moving ‘cosmic bullet’ about whose 'geography' very little is known yet. An amazing 10-year interplanetary trek Rosetta is a three-tonne box-type spacecraft about three metres high, with two 14-metre solar panels. It consists of an orbiter and a lander. The lander is approximately one metre across and 80 centimetres high. It will be attached to the side of the orbiter during the journey to Comet Churyumov-Gerasimenko. Rosetta carries 21 experiments in total, 10 of them on the lander. They will be kept in hibernation during most of its 10-year trek towards the comet. Why does Rosetta's cruise need to take so long? To reach Comet Churyumov-Gerasimenko, the spacecraft needs to go out into deep space as far out from the Sun as Jupiter. No launcher could possibly get Rosetta there directly. ESA's spacecraft will gather speed from gravitational ‘kicks’ provided by four planetary fly-bys: one of Mars in 2007 and three of Earth in 2005, 2007 and 2009. During the trip, Rosetta will also twice pass through the asteroid belt, where a fly-by with one or more of these primitive objects is possible. A number of candidate targets have already been identified, but the final selection will be made after launch, once the amount of surplus fuel has been verified by mission engineers. During these encounters, scientists plan to switch on Rosetta's instruments for scientific studies of these largely unexplored Solar System bodies. Long trips in deep space include many hazards, such as extreme changes in temperature. Rosetta will leave the benign environment of near-Earth space to the dark, frigid regions beyond the asteroid belt. To manage these thermal loads, experts have done very tough pre-launch tests to study Rosetta's endurance. For example, they have heated its external surfaces to more than 150°C, then cooled it to -150°C in the next test. The spacecraft will be fully reactivated prior to the comet rendezvous manoeuvre in 2014. Then, Rosetta will orbit the comet - an object only about 4 kilometres in diameter - while it cruises through the inner Solar System at 135 000 kilometres per hour. At the time of the rendezvous - around 675 million kilometres from the Sun - Comet Churyumov-Gerasimenko will hardly show any surface activity. This means that the characteristic ‘coma’ (the comet’s ‘atmosphere’) and the tail will not be formed yet, because of the distance from the Sun. The comet's tail is in fact made of dust grains and frozen gases from the comet's surface that vaporise because of the Sun's heat. Over a period of six months, Rosetta will extensively map the comet's surface, prior to selecting a landing site. In November 2014, the lander will be ejected from the spacecraft from a height which could be as low as one kilometre. Touchdown will be at walking speed, about one metre per second. Immediately after touchdown, the lander will fire a harpoon into the ground to avoid bouncing off the surface back into space, since the comet’s extremely weak gravity alone would not hold onto the lander. Operations and scientific observations on the surface will last at least a week, but may continue for many months. Besides taking close-up pictures, the lander will drill into the dark organic crust and sample the primordial ices and gases. During and after the lander operations, Rosetta will continue orbiting and studying the comet: it will be the first spacecraft to witness at close quarters the changes taking place in a comet when the comet approaches the Sun and grows its coma and tail and then travels away from it. The trip will end in December 2015, after 12 years of adventure, when the comet has made its closest approach to the Sun and is on its way towards the outer Solar System. Studying a comet on the spot Rosetta's goal is to examine the comet in great detail. The instruments on the orbiter include several cameras and spectrometers that work at different wavelengths: infrared, ultraviolet, visible and microwave. In addition, there are various other instruments to make in situ analysis. Together, they will provide, amongst other things, very high-resolution images and information about the shape, density, temperature and chemical composition of the comet. Rosetta’s instruments will analyse the gases and dust grains in the coma that forms when the comet becomes active, as well as the interaction with the solar wind. The ten experiments on the lander will make an on-the-spot analysis of the composition and structure of the comet’s surface and subsurface material. A drilling system will take samples down to 30 centimetres below the surface and feed these to the ‘composition analysers’. Other instruments will measure properties such as near-surface strength, density, texture, porosity, ice phases and thermal properties. Microscopic studies of individual grains will tell us about the texture. Ground operations All scientific data including those relayed from the lander will be stored on the orbiter for downlink to Earth at the next ground station contact. ESA has installed a new deep-space antenna at New Norcia, near Perth in Western Australia, as the main communications link between the spacecraft and ESOC Mission Control in Darmstadt, Germany. This 35-metre diameter parabolic antenna allows the radio signal to reach distances of more than a million kilometres from Earth. The radio signals, travelling at the speed of light, will take up to 50 minutes to cover the distance between the spacecraft and Earth. Rosetta's Science Operations Centre, which will be responsible for collecting and distributing the scientific data, will share locations at ESOC and ESTEC in Noordwijk, The Netherlands. The Lander Control Centre is located at DLR in Cologne, Germany, and the Lander Science Centre at CNES in Toulouse, France. Building Rosetta Rosetta was selected as a mission in 1993. The spacecraft has been built by Astrium Germany as prime contractor. Major subcontractors are Astrium UK (spacecraft platform), Astrium France (spacecraft avionics), and Alenia Spazio (assembly, integration, and verification). Rosetta’s industrial team involves more than 50 contractors from 14 European countries, Canada and the United States. Scientific consortia from institutes across Europe and the United States have provided the instruments on the orbiter. A European consortium under the leadership of the German Aerospace Research Institute (DLR) has provided the lander. Rosetta has cost ESA EUR 770 million at 2000 economic conditions. This includes the launch and the entire period of development and mission operations from 1996 to 2015. The lander and the experiments, the so-called 'payload', are not included since they are funded by the member states through scientific institutes.

Rosetta - a comet ride to solve planetary mysteries

NASA Astrophysics Data System (ADS)

2003-01-01

Comets are very interesting objects for scientists, since their composition reflects how the Solar System was when it was very young and still 'unfinished', more than 4600 million years ago. Comets have not changed much since then. By orbiting Comet Wirtanen and landing on it, Rosetta will collect essential information to understand the origin and evolution of our Solar System. It will also help discover whether comets contributed to the beginnings of life on Earth. In fact comets are carriers of complex organic molecules, that - delivered to Earth through impacts - perhaps played a role in the origin of living forms. Furthermore, “volatile” light elements carried by comets may have also played an important role in forming the Earth’s oceans and atmopshere. “Rosetta is one of the most challenging missions ever undertaken so far”, says Prof. David Southwood, ESA Director of Science, “No one before attempted a similar mission, unique for its scientific implications as well as for its complex and spectacular interplanetary space manoeuvres”. Before reaching its target in 2011, Rosetta will circle the Sun almost four times on wide loops in the inner Solar System. During its long trek, the spacecraft will have to endure some extreme thermal conditions. Once it is close to Comet Wirtanen, scientists will take it through a delicate braking manoeuvre; then the spacecraft will closely orbit the comet, and gently drop a lander on it. It will be like landing on a small, fast-moving cosmic bullet that still has - at present - an almost unknown 'geography'. An amazing 8-year interplanetary trek Rosetta is a 3-tonne box-type spacecraft about 3 metres high, with two 14-metre long solar panels. It consists of an orbiter and a lander. The lander is approximately 1 metre across and 80 centimetres high. It will be attached to the side of the Rosetta orbiter during the journey to Comet Wirtanen. Rosetta carries 21 experiments in total, 10 of them on the lander. They will be kept in hibernation during most of its 8-year trek towards Wirtanen. What makes Rosetta's cruise so long? To reach Comet Wirtanen, the spacecraft needs to go out in deep space as far from the Sun as Jupiter is. No launcher could possibly get Rosetta there directly. ESA's spacecraft will gather speed from gravitational ‘kicks’ provided by three planetary fly-bys: one of Mars in 2005 and two of Earth in 2005 and 2007. During the trip, Rosetta will also visit two asteroids, Otawara (in 2006) and Siwa (in 2008). During these encounters, scientists will switch on Rosetta's instruments for calibration and scientific studies. Long trips in deep space include many hazards, such as extreme changes in temperature. Rosetta will leave the benign environment of near-Earth space to the dark, frigid regions beyond the asteroid belt. To manage these thermal loads, experts have done very tough pre-launch tests to study Rosetta's endurance. For example, they have heated its external surfaces to more than 150°C, then quickly cooled it to -180°C in the next test. The spacecraft will be fully reactivated prior to the comet rendezvous manoeuvre in 2011. Then, Rosetta will orbit the comet - an object only 1.2 km wide - while it cruises through the inner Solar System at 135 000 kilometres per hour. At that time of the rendezvous - around 675 million km from the Sun - Wirtanen will hardly show any surface activity. It means that the carachteristic coma (the comet’s ‘atmosphere’) and the tail will not be formed yet, because of the large distance from the Sun. The comet's tail is in fact made of dust grains and frozen gases from the comet's surface that vapourise because of the Sun's heat. During 6-month, Rosetta will extensively map the comet surface, prior to selecting a landing site. In July 2012, the lander will self-eject from the spacecraft from a height of just one kilometre. Touchdown will take place at walking speed - less than 1 metre per second. Immediately after touchdown, the lander will fire a harpoon into the ground to avoid bouncing off the surface back into space, since the extremely weak comet’s gravity alone would not hold onto the lander. Operations and scientific observations on the comet surface will last 65 hours as a minimum, but may continue for many months. During and after the lander operations, Rosetta will continue orbiting and studying the comet: Rosetta will be the first spacecraft to witness at close quarters the changes taking place in a comet when the comet approaches the Sun and grows its coma and tail. The trip will end in July 2013, after 10.5 years of adventure, when the comet is closest to the Sun. Studying a comet on the spot Rosetta's goal is to examine the comet in great detail. The instruments on Rosetta orbiter include several cameras, spectrometers, and experiments that work at different wavelengths --infrared, ultraviolet, microwave, radio and a number of sensors. They will provide, among other things, very high-resolution images and information about the shape, density, temperature, and chemical composition of the comet. Rosetta’s instruments will analyse the gases and dust grains in the so-called “coma” that forms when the comet becomes active, as well as the interaction with the solar wind. The 10 instruments on board the lander will do an on-the-spot analysis of the composition and structure of the comet’s surface and subsurface material. A drilling system will take samples down to 30 centimetres below the surface and will feed these to the ‘composition analysers’. Other instruments will measure properties such as near-surface strength, density, texture, porosity, ice phases, and thermal properties. Microscopic studies of individual grains will tell us about the texture. In addition, instruments on the lander will study how the comet changes during the day-night cycle, and while it approaches the Sun. Ground operations Data from the lander are relayed to the orbiter, which stores them for downlink to Earth at the next ground station contact. ESA has installed a new deep-space antenna at New Norcia, near Perth in Western Australia, as the main communications link between the spacecraft and the ESOC Mission Control in Darmstadt, Germany. This 35-metre diameter parabolic antenna allows the radio signal to reach distances of more than 1 million kilometres from Earth. The radio signals, travelling at the speed of light, will take up to 50 minutes to cover the distance between the spacecraft and Earth. Rosetta's Science Operations Centre, which is responsible for collecting and distributing the scientific data, will share a location at ESOC and ESTEC in Noordwijk, The Netherlands. The Lander Control Centre is located in DLR in Cologne, Germany, and the Lander Science Centre in CNES in Toulouse, France. Building Rosetta Rosetta was selected as a mission in 1993. The spacecraft has been built by Astrium Germany as prime contractor. Major subcontractors are Astrium UK (spacecraft platform), Astrium France (spacecraft avionics), and Alenia Spazio (assembly, integration, and verification). Rosetta’s industrial team involves more than 50 contractors from 14 European countries, Canada and the United States. Scientific consortia from institutes across Europe and the United States have provided the instruments on the orbiter. A European consortium under the leadership of the German Aerospace Research Institute (DLR) has provided the lander. Rosetta has cost ESA Euro 701 million at 2000 economic conditions. This amount includes the launch and the entire period of development and mission operations from 1996 to 2013. The lander and the experiments, the so-called 'payload', are not included since they are funded by the member states through the scientific institutes. Note to editors Europe is certainly a pioneer in comet exploration. In 1986, ESA’s spacecraft Giotto performed the closest comet fly-by ever achieved by any spacecraft (at a distance of 600 kilometres of Halley). It sent back wonderful pictures and data that showed that comets contain complex organic molecules. These kinds of compounds are rich in carbon, hydrogen, oxygen, and nitrogen. Intriguingly, these are the elements which make up nucleic acids and amino acids, which are essential ingredients for life as we know it. Giotto continued its successful journey and flew by Comet Grigg-Skjellerup in 1992 within about 200 km distance. Now scientists will be eagerly waiting to be able to answer some of the new intriguing questions that arose from analysing the exciting results from Giotto. Other past missions that have flown by a comet were: NASA’s ICE mission in 1985, the two Russian VEGA spacecraft and the two Japanese spacecraft Suisei and Sakigake that were part of the armada that visited comet Halley in 1986; NASA’s Deep Space 1 flew-by comet Borelly in 2001 and NASA’s Stardust will fly-by comet Wild 2 in early 2004 and will return samples of the comet’s coma in 2006. Unfortunately NASA’s Contour launched in Summer 2002 failed when it was inserted onto its interplanetary trajectory. In 2004 we will see the launch of Deep Impact, a spacecraft that will shoot a massive block of copper into a comet nucleus.

The Rosetta video approach: An overview and lessons learned so far

NASA Astrophysics Data System (ADS)

Zender, J.; Schwehm, G.; Wilke, M.

2008-01-01

After an interplanetary cruise of 10 years, the Rosetta spacecraft and Philae lander, will arrive in 2014 at comet Churyomov-Gerasimenkov. All involved parties are aware of the knowledge decrease during these years and the potential complications that might arise during problem resolution before or during cometary operations. The Rosetta Science Operations Center (RSOC) supports the Rosetta orbiter experimenters in the preservation of their knowledge. The author will present the overall efforts that are done within the RSOC team to ensure the preservation of the existing information—address databases, documentation, etc.—but will emphasis on the effort to preserve existing experience using a video approach. The video approach included the visit of all orbiter experimenter teams for several days, executing interviews with engineers, technicians and scientists. During the interviews a table of content with attached keywords was generated. The final video was transferred into a computer readable form and connected with the table of content. We will present the methodology that was used to prepare and execute the interviews, to prepare the final video material and the storage and structure of the table of content and keyword. The experimenter interviews at their home institutes and the follow-up work are finished. The feedback we received so far from experimenters and the lessons learned from the interview team will be presented. In the meantime, the approach is continued during the Rosetta commissioning and interviews are executed after each instrument commissioning slot. The author will give an outlook of potential further usage of this approach.

An improved Rosetta pedotransfer function and evaluation in earth system models

NASA Astrophysics Data System (ADS)

Zhang, Y.; Schaap, M. G.

2017-12-01

Soil hydraulic parameters are often difficult and expensive to measure, leading to the pedotransfer functions (PTFs) an alternative to predict those parameters. Rosetta (Schaap et al., 2001, denoted as Rosetta1) are widely used PTFs, which is based on artificial neural network (ANN) analysis coupled with the bootstrap re-sampling method, allowing the estimation of van Genuchten water retention parameters (van Genuchten, 1980, abbreviated here as VG), saturated hydraulic conductivity (Ks), as well as their uncertainties. We present an improved hierarchical pedotransfer functions (Rosetta3) that unify the VG water retention and Ks submodels into one, thus allowing the estimation of uni-variate and bi-variate probability distributions of estimated parameters. Results show that the estimation bias of moisture content was reduced significantly. Rosetta1 and Posetta3 were implemented in the python programming language, and the source code are available online. Based on different soil water retention equations, there are diverse PTFs used in different disciplines of earth system modelings. PTFs based on Campbell [1974] or Clapp and Hornberger [1978] are frequently used in land surface models and general circulation models, while van Genuchten [1980] based PTFs are more widely used in hydrology and soil sciences. We use an independent global scale soil database to evaluate the performance of diverse PTFs used in different disciplines of earth system modelings. PTFs are evaluated based on different soil characteristics and environmental characteristics, such as soil textural data, soil organic carbon, soil pH, as well as precipitation and soil temperature. This analysis provides more quantitative estimation error information for PTF predictions in different disciplines of earth system modelings.

Early evolution of comet 67P studied with the RPC-LAP onboard Rosetta

NASA Astrophysics Data System (ADS)

Miloch, Wojciech; Edberg, Niklas J. T.; Eriksson, Anders I.; Yang, Lei; Paulsson, Joakim J. P.; Wedlund, Cyril Simon; Odelstad, Elias

2016-07-01

The Rosetta mission provides the in-situ measurements of a comet that are closest to a comet's aphelion ever made. The Rosetta Plasma Consortium (RPC) is a set of five instruments on board the spacecraft that specialise in the measurements of the plasma environment of comet 67P. One of the instruments is RPC-LAP, which consists of two Langmuir Probes and can measure the density, temperature, and flow speed of the plasma in the vicinity of the comet. At the early stage of the Rosetta mission, when the spacecraft is far from the nucleus of comet 67P, the ion part of the current-voltage characteristics of RPC-LAP1 is dominated by the photoemission current which surpasses the currents from the dilute solar wind plasma. As Rosetta starts orbiting around the nucleus in September 2014, LAP1 picks up signatures of local plasma density enhancements corresponding to variations of water-group ions observed in the vicinity of the comet. With the help of current-voltage characteristics and the spacecraft potential, we identify and characterise in space and time the entering of this coma-dominated plasma. In particular we determine the transition for entering the ion dominated region characterised by the 6-hour variations in the local plasma density due to the comet rotation. This transition manifests as a steep gradient in the density with respect to the distance to the comet nucleus. We discuss these RPC-LAP results together with the corresponding measurements by other instruments to provide a comprehensive picture of the transition.

Behind the Scenes of the Discovery Channel's Rosetta Mission Documentary Special

NASA Astrophysics Data System (ADS)

Ayres, S.

2016-03-01

On the evening of 12 November 2014, the Discovery Channel documentary Landing on a Comet: Rosetta Mission was broadcast around the world. This was the culmination of months of preparation and behind-the-scenes lming. Shelley Ayres, the producer, director and writer of the one-hour special recounts how this came about and re ects on her experience.

Rosetta launch postponed

NASA Astrophysics Data System (ADS)

2003-01-01

The Review Board called for Arianespace and all its partners to make sure, in the framework of a programme for the resumption of Ariane 5 flights, that all Ariane 5 system qualification and review processes have been checked. Arianespace and the European Space Agency, together with all interested parties, are now going to consult each other in order to determine arrangements for the soonest possible launch of Rosetta.

Rosetta:MSF: a modular framework for multi-state computational protein design.

PubMed

Löffler, Patrick; Schmitz, Samuel; Hupfeld, Enrico; Sterner, Reinhard; Merkl, Rainer

2017-06-01

Computational protein design (CPD) is a powerful technique to engineer existing proteins or to design novel ones that display desired properties. Rosetta is a software suite including algorithms for computational modeling and analysis of protein structures and offers many elaborate protocols created to solve highly specific tasks of protein engineering. Most of Rosetta's protocols optimize sequences based on a single conformation (i. e. design state). However, challenging CPD objectives like multi-specificity design or the concurrent consideration of positive and negative design goals demand the simultaneous assessment of multiple states. This is why we have developed the multi-state framework MSF that facilitates the implementation of Rosetta's single-state protocols in a multi-state environment and made available two frequently used protocols. Utilizing MSF, we demonstrated for one of these protocols that multi-state design yields a 15% higher performance than single-state design on a ligand-binding benchmark consisting of structural conformations. With this protocol, we designed de novo nine retro-aldolases on a conformational ensemble deduced from a (βα)8-barrel protein. All variants displayed measurable catalytic activity, testifying to a high success rate for this concept of multi-state enzyme design.

Fully Flexible Docking of Medium Sized Ligand Libraries with RosettaLigand

PubMed Central

DeLuca, Samuel; Khar, Karen; Meiler, Jens

2015-01-01

RosettaLigand has been successfully used to predict binding poses in protein-small molecule complexes. However, the RosettaLigand docking protocol is comparatively slow in identifying an initial starting pose for the small molecule (ligand) making it unfeasible for use in virtual High Throughput Screening (vHTS). To overcome this limitation, we developed a new sampling approach for placing the ligand in the protein binding site during the initial ‘low-resolution’ docking step. It combines the translational and rotational adjustments to the ligand pose in a single transformation step. The new algorithm is both more accurate and more time-efficient. The docking success rate is improved by 10–15% in a benchmark set of 43 protein/ligand complexes, reducing the number of models that typically need to be generated from 1000 to 150. The average time to generate a model is reduced from 50 seconds to 10 seconds. As a result we observe an effective 30-fold speed increase, making RosettaLigand appropriate for docking medium sized ligand libraries. We demonstrate that this improved initial placement of the ligand is critical for successful prediction of an accurate binding position in the ‘high-resolution’ full atom refinement step. PMID:26207742

Balancing exploration and exploitation in population-based sampling improves fragment-based de novo protein structure prediction.

PubMed

Simoncini, David; Schiex, Thomas; Zhang, Kam Y J

2017-05-01

Conformational search space exploration remains a major bottleneck for protein structure prediction methods. Population-based meta-heuristics typically enable the possibility to control the search dynamics and to tune the balance between local energy minimization and search space exploration. EdaFold is a fragment-based approach that can guide search by periodically updating the probability distribution over the fragment libraries used during model assembly. We implement the EdaFold algorithm as a Rosetta protocol and provide two different probability update policies: a cluster-based variation (EdaRose c ) and an energy-based one (EdaRose en ). We analyze the search dynamics of our new Rosetta protocols and show that EdaRose c is able to provide predictions with lower C αRMSD to the native structure than EdaRose en and Rosetta AbInitio Relax protocol. Our software is freely available as a C++ patch for the Rosetta suite and can be downloaded from http://www.riken.jp/zhangiru/software/. Our protocols can easily be extended in order to create alternative probability update policies and generate new search dynamics. Proteins 2017; 85:852-858. © 2016 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Improved cryoEM-Guided Iterative Molecular Dynamics–Rosetta Protein Structure Refinement Protocol for High Precision Protein Structure Prediction

PubMed Central

2016-01-01

Many excellent methods exist that incorporate cryo-electron microscopy (cryoEM) data to constrain computational protein structure prediction and refinement. Previously, it was shown that iteration of two such orthogonal sampling and scoring methods – Rosetta and molecular dynamics (MD) simulations – facilitated exploration of conformational space in principle. Here, we go beyond a proof-of-concept study and address significant remaining limitations of the iterative MD–Rosetta protein structure refinement protocol. Specifically, all parts of the iterative refinement protocol are now guided by medium-resolution cryoEM density maps, and previous knowledge about the native structure of the protein is no longer necessary. Models are identified solely based on score or simulation time. All four benchmark proteins showed substantial improvement through three rounds of the iterative refinement protocol. The best-scoring final models of two proteins had sub-Ångstrom RMSD to the native structure over residues in secondary structure elements. Molecular dynamics was most efficient in refining secondary structure elements and was thus highly complementary to the Rosetta refinement which is most powerful in refining side chains and loop regions. PMID:25883538

The flyby of Rosetta at asteroid Šteins - mission and science operations

NASA Astrophysics Data System (ADS)

Accomazzo, Andrea; Wirth, Kristin R.; Lodiot, Sylvain; Küppers, Michael; Schwehm, Gerhard

2010-07-01

The international Rosetta mission, a cornerstone mission of the european space agency scientific Programme, was launched on 2nd March 2004 on its 10 years journey towards a rendezvous with comet Churyumov-Gerasimenko ( Gardini et al., 1999). During its interplanetary flight towards its target Rosetta crosses the asteroid belt twice with the opportunity to observe at close quarters two asteroids: (2867)-Šteins in 2008 and (21)-Lutetia in 2010. The spacecraft design was such that these opportunities could be fully exploited to deliver valuable data to the scientific community. The mission trajectory was controlled such that Rosetta would fly next to asteroid Šteins on the 5th of September 2008 with a relative speed of 8.6 km/s at a minimum distance of 800 km. Mission operations have been carefully planned to achieve the best possible flyby scenario and scientific outcome. The flyby scenario, the optical navigation campaign, and the planning of the scientific observations had to be adapted by the Mission and the Science Operations Centres to the demanding requirements expressed by the scientific community. The flyby was conducted as planned with a large number of successful observations.

A “Rosetta Stone” for metazoan zooplankton: DNA barcode analysis of species diversity of the Sargasso Sea (Northwest Atlantic Ocean)

NASA Astrophysics Data System (ADS)

Bucklin, Ann; Ortman, Brian D.; Jennings, Robert M.; Nigro, Lisa M.; Sweetman, Christopher J.; Copley, Nancy J.; Sutton, Tracey; Wiebe, Peter H.

2010-12-01

Species diversity of the metazoan holozooplankton assemblage of the Sargasso Sea, Northwest Atlantic Ocean, was examined through coordinated morphological taxonomic identification of species and DNA sequencing of a ˜650 base-pair region of mitochondrial cytochrome oxidase I (mtCOI) as a DNA barcode (i.e., short sequence for species recognition and discrimination). Zooplankton collections were made from the surface to 5,000 meters during April, 2006 on the R/V R.H. Brown. Samples were examined by a ship-board team of morphological taxonomists; DNA barcoding was carried out in both ship-board and land-based DNA sequencing laboratories. DNA barcodes were determined for a total of 297 individuals of 175 holozooplankton species in four phyla, including: Cnidaria (Hydromedusae, 4 species; Siphonophora, 47); Arthropoda (Amphipoda, 10; Copepoda, 34; Decapoda, 9; Euphausiacea, 10; Mysidacea, 1; Ostracoda, 27); and Mollusca (Cephalopoda, 8; Heteropoda, 6; Pteropoda, 15); and Chaetognatha (4). Thirty species of fish (Teleostei) were also barcoded. For all seven zooplankton groups for which sufficient data were available, Kimura-2-Parameter genetic distances were significantly lower between individuals of the same species (mean=0.0114; S.D. 0.0117) than between individuals of different species within the same group (mean=0.3166; S.D. 0.0378). This difference, known as the barcode gap, ensures that mtCOI sequences are reliable characters for species identification for the oceanic holozooplankton assemblage. In addition, DNA barcodes allow recognition of new or undescribed species, reveal cryptic species within known taxa, and inform phylogeographic and population genetic studies of geographic variation. The growing database of "gold standard" DNA barcodes serves as a Rosetta Stone for marine zooplankton, providing the key for decoding species diversity by linking species names, morphology, and DNA sequence variation. In light of the pivotal position of zooplankton in ocean food webs, their usefulness as rapid responders to environmental change, and the increasing scarcity of taxonomists, the use of DNA barcodes is an important and useful approach for rapid analysis of species diversity and distribution in the pelagic community.

Rosetta comet-chaser takes a close look at planet Mars

NASA Astrophysics Data System (ADS)

2007-09-01

Its final destination is comet Churyumov-Gerasimenko, which it will reach only in 2014, after travelling some 6000 million kilometres in 10 years (its epic voyage began on 2 March 2004 with a launch by an Ariane 5 rocket). Rosetta will next be heading for the Sun, and its journey will require two more swing-bys around the Earth, in November this year and November 2009. Once at its destination, Rosetta will first deposit, from a height of about one kilometre, a small but very complex lander on the comet’s nucleus. This lander, a sort of miniature chemical laboratory packed with sophisticated instruments, will analyse the surface and provide information on the nucleus. The Rosetta probe will then chase the comet for one year and observe its nucleus as it continues on its trip towards the inner solar system at a speed of 135,000 km per hour. There is still a long way to go, but so far everything seems to be going exactly according to plan. ESA's Director of Science, David Southwood, witnessing the Mars swing-by at ESOC with scientists involved in the mission and the operations teams, said: "Interplanetary expeditions rely on very complex communication links. ESA’s mission operations centre here in Darmstadt is doing a great job. I and all the scientists involved in the mission are grateful to the experts who are taking such good care of 'our baby'. And this is only the beginning. The true excitement of targeting and releasing the lander on the comet’s nucleus is yet to come. Today we have reached another milestone on the way to finding an answer to questions such as whether life on Earth began with the help of comets." “The successful Mars swingby of the ESA Rosetta spacecraft has been the most critical event in the mission since launch. Now we are heading back to Earth in order to gain, in November this year, further momentum for the subsequent visits of the asteroids and the comet. I would like to thank all those who have contributed to this achievement”, said Manfred Warhaut, Head of the Mission Operations Department. During the approach to Mars, instruments onboard Rosetta - as well as on its lander - were switched on at predefined times to observe the environment and take imagery of the Red Planet. In September 2008 and July 2010, when it is deep inside the asteroid belt between Mars and Jupiter, Rosetta will also observe the asteroids Stein and Lutetia close up.

Solar-insolation-induced changes in the coma morphology of comet 67P/Churyumov-Gerasimenko. Optical monitoring with the Nordic Optical Telescope

NASA Astrophysics Data System (ADS)

Zaprudin, B.; Lehto, H. J.; Nilsson, K.; Somero, A.; Pursimo, T.; Snodgrass, C.; Schulz, R.

2017-07-01

Context. 67P/Churyumov-Gerasimenko (67P/C-G) is a short-period Jupiter family comet with an orbital period of 6.55 yr. Being the target comet of ESA's Rosetta mission, 67P/C-G has become one of the most intensively studied minor bodies of the solar system. The Rosetta Orbiter and the Philae Lander have brought us unique information about the structure and activity of the comet nucleus, as well as its activity along the orbit, composition of gas, and dust particles emitted into the coma. However, as Rosetta stayed in very close proximity to the cometary nucleus (less than 500 km with a few short excursions reaching up to 1500 km), it could not see the global picture of a coma at the scales reachable by telescopic observations (103 - 105 km). Aims: In this work we aim to connect in-situ observations made by Rosetta with the morphological evolution of the coma structures monitored by the ground-based observations. In particular, we concentrate on causal relationships between the coma morphology and evolution observed with the Nordic Optical Telescope (NOT) in the Canary Islands, and the seasonal changes of the insolation and the activity of the comet observed by the Rosetta instruments. Methods: Comet 67P/C-G was monitored with the NOT in imaging mode in two colors. Imaging optical observations were performed roughly on a weekly basis, which provides good coverage of short- and long-term variability. With the three dimensional modeling of the coma produced by active regions on the southern hemisphere, we aim to qualify the observed morphology by connecting it to the activity observed by Rosetta. Results: During our monitoring program, we detected major changes in the coma morphology of comet 67P/C-G. These were long-term and long-lasting changes. They do not represent any sudden outburst or short transient event, but are connected to seasonal changes of the surface insolation and the emergence of new active regions on the irregular shaped comet nucleus. We have also found significant deviations in morphological changes from the prediction models based on previous apparitions of 67P/C-G, like the time delay of the morphology changes and the reduced activity in the northern hemisphere. According to our modeling of coma structures and geometry of observations, the changes are clearly connected with the activity in the southern hemisphere observed by the Rosetta spacecraft.

Hello World: Harnessing social media for the Rosetta mission

NASA Astrophysics Data System (ADS)

Baldwin, E.; Mignone, C.; O'Flaherty, K. S.; Homfeld, A.-M.; Bauer, M.; McCaughrean, M. J.

2015-10-01

The European Space Agency's (ESA) comet-chasing Rosetta mission was launched in 2004, before social media became a popular tool for mainstream communication. By harnessing a range of platforms for communicating the key messages of this unprecedented space adventure as the spacecraft reached its destination ten years later, a wide range of new audiences were reached and could follow this once-in-a-lifetime mission.

Estimation method for serial dilution experiments.

PubMed

Ben-David, Avishai; Davidson, Charles E

2014-12-01

Titration of microorganisms in infectious or environmental samples is a corner stone of quantitative microbiology. A simple method is presented to estimate the microbial counts obtained with the serial dilution technique for microorganisms that can grow on bacteriological media and develop into a colony. The number (concentration) of viable microbial organisms is estimated from a single dilution plate (assay) without a need for replicate plates. Our method selects the best agar plate with which to estimate the microbial counts, and takes into account the colony size and plate area that both contribute to the likelihood of miscounting the number of colonies on a plate. The estimate of the optimal count given by our method can be used to narrow the search for the best (optimal) dilution plate and saves time. The required inputs are the plate size, the microbial colony size, and the serial dilution factors. The proposed approach shows relative accuracy well within ±0.1log10 from data produced by computer simulations. The method maintains this accuracy even in the presence of dilution errors of up to 10% (for both the aliquot and diluent volumes), microbial counts between 10(4) and 10(12) colony-forming units, dilution ratios from 2 to 100, and plate size to colony size ratios between 6.25 to 200. Published by Elsevier B.V.

Rosetta following a living comet

NASA Astrophysics Data System (ADS)

Accomazzo, Andrea; Ferri, Paolo; Lodiot, Sylvain; Pellon-Bailon, Jose-Luis; Hubault, Armelle; Porta, Roberto; Urbanek, Jakub; Kay, Ritchie; Eiblmaier, Matthias; Francisco, Tiago

2016-09-01

The International Rosetta Mission was launched on 2nd March 2004 on its 10 year journey to rendezvous with comet 67P Churyumov-Gerasimenko. Rosetta performed comet orbit insertion on the 6th of August 2014, after which it characterised the nucleus and orbited it at altitudes as low as a few kilometres. In November 2014 Rosetta delivered the lander Philae to perform the first soft landing ever on the surface of a comet. The critical landing operations have been conducted with remarkable accuracy and will constitute one of the most important achievements in the history of spaceflight. After this critical operation, Rosetta began the escort phase of the comet in its journey in the Solar System heading to the perihelion, reached in August 2015. Throughout this period, the comet environment kept changing with increasing gas and dust emissions. A first phase of bound orbits was followed by a sequence of complex flyby segments which allowed the scientific instruments to perform in depth investigation of the comet environment and nucleus. The unpredictable nature of the comet activity forced the mission control team to implement unplanned changes to the flight plan prepared for this mission phase and to plan the whole mission in a more dynamic way than originally conceived. This paper describes the details of the landing operations and of the main comet escort phase. It also includes the mission status as achieved after perihelion and the findings about the evolution of the comet and its environment from a mission operations point of view. The lessons learned from this unique and complex operations phase and the plans for the next mission phases, which include a mission extension into 2016, are also described.

Preliminary Inventory in the Early Coma of Comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Calmonte, Ursina; Altwegg, Kathrin; Le Roy, Léna; Rubin, Martin; Berthelier, Jean-Jacques; De Keyser, Johan; Fiethe, Björn; Fuselier, Steve A; Combi, Mike

2014-11-01

After a 10-year journey, the European Space Agency’s Rosetta mission encountered its target comet Churyumov-Gerasimenko. Rosetta will accompany the comet to perihelion and beyond. On board the Rosetta spacecraft is the ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) experiment. ROSINA consists of a pressure sensor and two complementary mass spectrometers. One is the Double Focusing Mass Spectrometer, which has high dynamic range and a mass resolution m/Δm = 3000 at 1% peak height (m/Δm = 9000 at 50% peak height) at mass 28 amu/q. It is therefore well suited to detect minor species in the lower mass range up to mass 140 amu [1].ROSINA has been taking data since May 2014 and first signals of the comet were detected at the beginning of August. We will present a preliminary inventory of species seen by ROSINA in the early coma of comet Churyumov-Gerasimenko.References[1] Balsiger, H., Altwegg, K., Bochsler, P., Eberhardt, P., Fischer, J., Graf, S., Jäckel, A., Kopp, E., Langer, U., Mildner, M., Müller, J., Riesen, T., Rubin, M., Scherer, S., Wurz, P., Wüthrich, S., Arijs, E., Delanoye, S., de Keyser, J., Neefs, E., Nevejans, D., Rème, H., Aoustin, C., Mazelle, C., Médale, J.-L., Sauvaud, J.A., Berthelier, J.-J., Bertaux, J.-L., Duvet, L., Illiano, J.-M., Fuselier, S.A., Ghielmetti, A.G., Magoncelli, T., Shelley, E.G., Korth, A., Heerlein, K., Lauche, H., Livi, S., Loose, A., Mall, U., Wilken, B., Gliem, F., Fiethe, B., Gombosi, T.I., Block, B., Carignan, G.R., Fisk, L.A., Waite, J.H., Young, D.T. and Wollnik, H.,. Rosina Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews 128, pp745-801, 2007.

Evolution of the coma composition at 67P/Churyumov-Gerasimenko as seen by ROSINA/Rosetta from November 2014 to April 2015

NASA Astrophysics Data System (ADS)

Gasc, Sébastien; Altwegg, Kathrin; Balsiger, Hans; Calmonte, Ursina; Galli, André; Jäckel, Annette; Le Roy, Léna; Rubin, Martin; Tzou, Chia-Yu; Wurz, Peter; Berthelier, Jean-Jacques; Fiethe, Björn; Fuselier, Stephen; Gombosi, Tamas; De Keyser, Johan; Mall, Urs; Rème, Henri

2015-04-01

The European Space Agency's Rosetta spacecraft, with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) onboard [1], has been following and observing comet 67P/Churyumov-Gerasimenko (67P/C-G) since August 2014. ROSINA has provided new information on the molecular, elemental, and isotopic composition of 67P/C-G's coma [2,3]. ROSINA consists of a pressure sensor (COPS) and two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron Time Of Flight mass spectrometer (RTOF). DFMS has a high mass resolution (ca. 3'000 at 1%) and a high sensitivity, whereas RTOF has a wide mass range (from 1 amu/e to >300 amu/e) and a high temporal resolution. Both mass spectrometers are designed to measure cometary neutral gas as well as cometary ions. In this work, we present the first results and discuss the evolution of the composition of the coma measured by ROSINA from November 2014 until the end of March 2015. During this period, Rosetta delivered the lander, then stayed in bound orbits at distances of 20-30 km away from the comet center, and finally performed comet flybys from 10 km up to 250 km away from 67P/C-G. [1] Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007 [2] Altwegg, K. et al.: Comet 67P/Churyumov-Gerasimenko, a true Kuiper belt comet as judged from its D/H in water, Science Express, 2014 [3] Hässig, M. et al.: Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko, Science, in press, 2015

Early Evolution of Comet 67P Studied with the RPC-LAP onboard Rosetta

NASA Astrophysics Data System (ADS)

Miloch, W. J.; Yang, L.; Paulsson, J. J.; Wedlund, C. S.; Odelstad, E.; Edberg, N. J. T.; Koenders, C.; Eriksson, A.

2016-12-01

In-situ measurements within the Rosetta mission allow for studies of the cometary environment at different stages of cometary evolution. The Rosetta Plasma Consortium (RPC) is a set of five instruments on board the spacecraft that specialise in the measurements of plasma environment of comet 67P. One of the instruments is RPC-LAP, which consists of two Langmuir Probes and can measure the density, temperature, and flow speed of the plasma in the vicinity of the comet. At the early stage of the Rosetta mission, when the spacecraft is far from the nucleus of comet 67P, the ion part of the current-voltage characteristics of RPC-LAP1 is dominated by the photoemission current, which surpasses the currents from the dilute solar wind plasma. As Rosetta starts orbiting around the nucleus in September 2014, LAP1 picks up signatures of local plasma density enhancements corresponding to variations of water-group ions observed in the vicinity of the comet. With the help of current-voltage characteristics and the spacecraft potential, we identify and characterise in space and time the entering of this coma-dominated, high-density plasma region. This high-density region is observed at the northern hemisphere of the comet during early activity. The transition manifests as a steep gradient in the density with respect to the distance to the comet nucleus. We discuss these RPC-LAP results together with the corresponding measurements by other instruments to provide a comprehensive picture of the transition. We show that the early cometary plasma can be seen as composed of two distinct regions: an outer region characterised by solar wind plasma and small quantities of pickup ions, and an inner region with enhanced plasma densities.

Scientific Benchmarks for Guiding Macromolecular Energy Function Improvement

PubMed Central

Leaver-Fay, Andrew; O’Meara, Matthew J.; Tyka, Mike; Jacak, Ron; Song, Yifan; Kellogg, Elizabeth H.; Thompson, James; Davis, Ian W.; Pache, Roland A.; Lyskov, Sergey; Gray, Jeffrey J.; Kortemme, Tanja; Richardson, Jane S.; Havranek, James J.; Snoeyink, Jack; Baker, David; Kuhlman, Brian

2013-01-01

Accurate energy functions are critical to macromolecular modeling and design. We describe new tools for identifying inaccuracies in energy functions and guiding their improvement, and illustrate the application of these tools to improvement of the Rosetta energy function. The feature analysis tool identifies discrepancies between structures deposited in the PDB and low energy structures generated by Rosetta; these likely arise from inaccuracies in the energy function. The optE tool optimizes the weights on the different components of the energy function by maximizing the recapitulation of a wide range of experimental observations. We use the tools to examine three proposed modifications to the Rosetta energy function: improving the unfolded state energy model (reference energies), using bicubic spline interpolation to generate knowledge based torisonal potentials, and incorporating the recently developed Dunbrack 2010 rotamer library (Shapovalov and Dunbrack, 2011). PMID:23422428

Rosetta3: An Object-Oriented Software Suite for the Simulation and Design of Macromolecules

PubMed Central

Leaver-Fay, Andrew; Tyka, Michael; Lewis, Steven M.; Lange, Oliver F.; Thompson, James; Jacak, Ron; Kaufman, Kristian; Renfrew, P. Douglas; Smith, Colin A.; Sheffler, Will; Davis, Ian W.; Cooper, Seth; Treuille, Adrien; Mandell, Daniel J.; Richter, Florian; Ban, Yih-En Andrew; Fleishman, Sarel J.; Corn, Jacob E.; Kim, David E.; Lyskov, Sergey; Berrondo, Monica; Mentzer, Stuart; Popović, Zoran; Havranek, James J.; Karanicolas, John; Das, Rhiju; Meiler, Jens; Kortemme, Tanja; Gray, Jeffrey J.; Kuhlman, Brian; Baker, David; Bradley, Philip

2013-01-01

We have recently completed a full re-architecturing of the Rosetta molecular modeling program, generalizing and expanding its existing functionality. The new architecture enables the rapid prototyping of novel protocols by providing easy to use interfaces to powerful tools for molecular modeling. The source code of this rearchitecturing has been released as Rosetta3 and is freely available for academic use. At the time of its release, it contained 470,000 lines of code. Counting currently unpublished protocols at the time of this writing, the source includes 1,285,000 lines. Its rapid growth is a testament to its ease of use. This document describes the requirements for our new architecture, justifies the design decisions, sketches out central classes, and highlights a few of the common tasks that the new software can perform. PMID:21187238

The nature of (sub-)micrometre cometary dust particles detected with MIDAS

NASA Astrophysics Data System (ADS)

Mannel, T.; Bentley, M. S.; Torkar, K.; Jeszenszky, H.; Romstedt, J.; Schmied, R.

2015-10-01

The MIDAS Atomic Force Microscope (AFM) onboard Rosetta collects dust particles and produces three-dimensional images with nano- to micrometre resolution. To date, several tens of particles have been detected, allowing determination of their properties at the smallest scale. The key features will be presented, including the particle size, their fragile character, and their morphology. These findings will be compared with the results of other Rosetta dust experiments.

Preliminary results seen with Rosetta/ROSINA: early cometary activity of 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Gasc, Sebastien; Altwegg, Kathrin; Jäckel, Annette; Rubin, Martin; Tzou, Chia-Yu; Wurz, Peter; Fiethe, Björn; Korth, Axel; Rème, Henri

2014-11-01

On 1 August 2014, the ROSETTA spacecraft approached the comet 67P/Churyumov-Gerasimenko (67P/CG) close enough to start its detailed characterisation. In this phase, the distance between Rosetta and 67P/CG is below 1’000 km, at a heliocentric distance of less than 3.6 AU. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) [1] measures the composition of 67P/CG’s atmosphere and ionosphere, and additionally derives the bulk velocity of gas. ROSINA consists of the COmetary Pressure Sensor (COPS) and two mass spectrometers for the analysis of neutral gas and cometary ions in the coma of the comet: the Double Focusing Mass Spectrometer (DFMS) and the Reflectron Time Of Flight mass spectrometer (RTOF). Since beginning of August, the ROSINA sensors are continuously monitoring the density and chemical composition of the coma of 67P/CG. The goal of this work is not only to determine the abundance of major species like CO2, CO, and H2O, but also to analyse the development of the composition as a function of the heliocentric distance. We will present the first mass spectra of RTOF as well as the total density and the molecular composition measurements obtained at 67P/CG.

Rosetta at comet 67P/Churyumov-Gerasimenko: Spacecraft orbit modeling

NASA Astrophysics Data System (ADS)

Hahn, Matthias; Paetzold, Martin; Tellmann, Silvia; Haeusler, Bernd; Andert, Thomas

The Rosetta spacecraft has been successfully launched on 2nd March 2004 to its target comet 67P/Churyumov-Gerasimenko. The science objectives of the Rosetta Radio Science Investiga-tions (RSI) experiment addresses fundamental aspects of cometary science such as the deter-minations of the nucleus mass and bulk density, its size and shape, its gravity field and internal structure, and its perturbed interplanetary orbit. The radio carrier links at X-band (8.4 GHz) and S-band (2.3 GHz) between the Rosetta spacecraft and the Earth will be used for these investigations. The motion of the spacecraft will be perturbed near the comet nucleus. The Doppler frequency shifts of the transmitted radio signals can be used to reconstruct the flown orbit. In order to extract small changes of the Doppler frequency, a prediction of the orbit is needed which includes best known estimates for all forces acting on the spacecraft. These forces are the nucleus gravity field, third body perturbations, the solar radiation pressure, the solar wind pressure, the cometary outgassing, etc. It is then possible to determine iteratively low degree and order harmonic coefficients of the nucleus gravity field or the gas pressure force and the gas production rate from outgassing from the differences between the predicted and the observed frequency shifts.

Interaction of the solar wind with comets: a Rosetta perspective

NASA Astrophysics Data System (ADS)

Glassmeier, Karl-Heinz

2017-05-01

The Rosetta mission provides an unprecedented possibility to study the interaction of comets with the solar wind. As the spacecraft accompanies comet 67P/Churyumov-Gerasimenko from its very low-activity stage through its perihelion phase, the physics of mass loading is witnessed for various activity levels of the nucleus. While observations at other comets provided snapshots of the interaction region and its various plasma boundaries, Rosetta observations allow a detailed study of the temporal evolution of the innermost cometary magnetosphere. Owing to the short passage time of the solar wind through the interaction region, plasma instabilities such as ring-beam and non-gyrotropic instabilities are of less importance during the early life of the magnetosphere. Large-amplitude ultra-low-frequency (ULF) waves, the `singing' of the comet, is probably due to a modified ion Weibel instability. This instability drives a cross-field current of implanted cometary ions unstable. The initial pick-up of these ions causes a major deflection of the solar wind protons. Proton deflection, cross-field current and the instability induce a threefold structure of the innermost interaction region with the characteristic Mach cone and Whistler wings as stationary interaction signatures as well as the ULF waves representing the dynamic aspect of the interaction. This article is part of the themed issue 'Cometary science after Rosetta'.

An Integrated Framework Advancing Membrane Protein Modeling and Design

PubMed Central

Weitzner, Brian D.; Duran, Amanda M.; Tilley, Drew C.; Elazar, Assaf; Gray, Jeffrey J.

2015-01-01

Membrane proteins are critical functional molecules in the human body, constituting more than 30% of open reading frames in the human genome. Unfortunately, a myriad of difficulties in overexpression and reconstitution into membrane mimetics severely limit our ability to determine their structures. Computational tools are therefore instrumental to membrane protein structure prediction, consequently increasing our understanding of membrane protein function and their role in disease. Here, we describe a general framework facilitating membrane protein modeling and design that combines the scientific principles for membrane protein modeling with the flexible software architecture of Rosetta3. This new framework, called RosettaMP, provides a general membrane representation that interfaces with scoring, conformational sampling, and mutation routines that can be easily combined to create new protocols. To demonstrate the capabilities of this implementation, we developed four proof-of-concept applications for (1) prediction of free energy changes upon mutation; (2) high-resolution structural refinement; (3) protein-protein docking; and (4) assembly of symmetric protein complexes, all in the membrane environment. Preliminary data show that these algorithms can produce meaningful scores and structures. The data also suggest needed improvements to both sampling routines and score functions. Importantly, the applications collectively demonstrate the potential of combining the flexible nature of RosettaMP with the power of Rosetta algorithms to facilitate membrane protein modeling and design. PMID:26325167

The dual role of microbes in corrosion

PubMed Central

Kip, Nardy; van Veen, Johannes A

2015-01-01

Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion. PMID:25259571

The dual role of microbes in corrosion.

PubMed

Kip, Nardy; van Veen, Johannes A

2015-03-01

Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion.

A microelectronics approach for the ROSETTA surface science package

NASA Technical Reports Server (NTRS)

Sandau, Rainer (Editor); Alkalaj, Leon

1996-01-01

In relation to the Rosetta surface science package, the benefits of the application of advanced microelectronics packaging technologies and other output from the Mars environmental survey (MESUR) integrated microelectronics study are reported on. The surface science package will be designed to operate for tens of hours. Its limited mass and power consumption make necessary a highly integrated design with all the instruments and subunits operated from a centralized control and information management subsystem.

Outbursts and diamagnetic cavities in comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Voelzke, M. R.

2018-03-01

On 2014 August 06 the Rosetta spacecraft arrived at comet 67P/Churyumov-Gerasimenko. Since then, the spacecraft accompanied the comet on its journey around the Sun (Glassmeier et al. 2007), until the end of the mission on 2016 September 30. This work tries to understand the possible connections between the 665 reported diamagnetic regions (Goetz et al. 2016), detected from April 2015 to February 2016 around the comet 67P/Churyumov-Gerasimenko, with the fluxgate magnetometer of the Rosetta Plasma Consortium (RPC-MAG), when the heliocentric distance of the comet from the sun varied from 1.8 to 2.4 AU and the 34 reported outbursts (Vincent et al. 2016), detected from July to September 2015, with the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) cameras, when the ESA's Rosetta spacecraft changed the cometocentric distance from 155 to 817 km.

Four-fluid MHD Simulations of the Plasma and Neutral Gas Environment of Comet Churyumov-Gerasimenko Near Perihelio

NASA Astrophysics Data System (ADS)

Huang, Z.; Toth, G.; Gombosi, T. I.; Jia, X.; Rubin, M.; Hansen, K. C.; Fougere, N.; Bieler, A. M.; Shou, Y.; Altwegg, K.; Combi, M. R.; Tenishev, V.

2015-12-01

The neutral and plasma environment is critical in understanding the interaction of comet Churyumov-Gerasimenko (CG), the target of the Rosetta mission, and the solar wind. To serve this need and support the Rosetta mission, we develop a 3-D four fluid model, which is based on BATS-R-US within the SWMF (Space Weather Modeling Framework) that solves the governing multi-fluid MHD equations and the Euler equations for the neutral gas fluid. These equations describe the behavior and interactions of the cometary heavy ions, the solar wind protons, the electrons, and the neutrals. This model incorporates different mass loading processes, including photo and electron impact ionization, charge exchange, dissociative ion-electron recombination, and collisional interactions between different fluids. We simulate the near nucleus plasma and neutral gas environment near perihelion with a realistic shape model of CG and compare our simulation results with Rosetta observations.

E-type asteroid (2867) Steins as imaged by OSIRIS on board Rosetta.

PubMed

Keller, H U; Barbieri, C; Koschny, D; Lamy, P; Rickman, H; Rodrigo, R; Sierks, H; A'Hearn, M F; Angrilli, F; Barucci, M A; Bertaux, J-L; Cremonese, G; Da Deppo, V; Davidsson, B; De Cecco, M; Debei, S; Fornasier, S; Fulle, M; Groussin, O; Gutierrez, P J; Hviid, S F; Ip, W-H; Jorda, L; Knollenberg, J; Kramm, J R; Kührt, E; Küppers, M; Lara, L-M; Lazzarin, M; Lopez Moreno, J; Marzari, F; Michalik, H; Naletto, G; Sabau, L; Thomas, N; Wenzel, K-P; Bertini, I; Besse, S; Ferri, F; Kaasalainen, M; Lowry, S; Marchi, S; Mottola, S; Sabolo, W; Schröder, S E; Spjuth, S; Vernazza, P

2010-01-08

The European Space Agency's Rosetta mission encountered the main-belt asteroid (2867) Steins while on its way to rendezvous with comet 67P/Churyumov-Gerasimenko. Images taken with the OSIRIS (optical, spectroscopic, and infrared remote( )imaging system) cameras on board Rosetta show that Steins is an oblate body with an effective spherical diameter of 5.3 kilometers. Its surface does not show color variations. The morphology of Steins is dominated by linear faults and a large 2.1-kilometer-diameter crater near its south pole. Crater counts reveal a distinct lack of small craters. Steins is not solid rock but a rubble pile and has a conical appearance that is probably the result of reshaping due to Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) spin-up. The OSIRIS images constitute direct evidence for the YORP effect on a main-belt asteroid.

Different Operating Modes of the Rosetta's Ion Composition Analyzer and Its Virtual Counterpart

NASA Astrophysics Data System (ADS)

Pospieszyński, R.

2009-12-01

The Ion Composition Analyzer (ICA) is a part of the Rosetta Plasma Consortium (RPC) which is on board the Rosetta space probe heading for the comet 67/P Churyumov-Gerasimenko. It is scheduled to reach the comet in year 2014. In order to reduce telemetry the ICA instrument has a number of data reduction modes (sampling modes). The effects of these different modes are investigated and a plan on how to best operate the instrument when in orbit around the comet will be prepared. In order to investigate all of the cases a virtual instrument is being prepared. The virtual instrument can be operated in different modes just as the ``real'' one. The work with sampling will be to calculate what particles are coming from each direction we are looking in, based on the ISSI Comet Model, and then see how much information we loose by too sparse sampling and incomplete spatial coverage.

The Strategy and Implementation of the Rosetta Communication Campaign

NASA Astrophysics Data System (ADS)

Bauer, M.; McCaughrean, M.; Landeau-Constantin, J.

2016-03-01

The communication campaign for Rosetta has been the biggest success in the history of European Space Agency outreach, resulting in global awareness for the agency. The mission itself is an extraordinary operational and scientific success, but communicating only the operational and scientific firsts would likely not have brought the Rosetta orbiter and Philae lander to the attention of so many people, and would not have made the mission part of people's lives across the globe. The additional impact brought to the mission through the communication campaign was based on a strategic approach focusing on: real-time release of information with maximum transparency; direct real-time access for media and social media; adding a human dimension to the story; and communicating the risks openly in order to manage expectations. In this article we describe our overall strategy, illustrate its implementation, and provide the framework for subsequent articles in this journal highlighting specific aspects of the campaign in more detail.

E-Type Asteroid (2867) Steins as Imaged by OSIRIS on Board Rosetta

NASA Astrophysics Data System (ADS)

Keller, H. U.; Barbieri, C.; Koschny, D.; Lamy, P.; Rickman, H.; Rodrigo, R.; Sierks, H.; A'Hearn, M. F.; Angrilli, F.; Barucci, M. A.; Bertaux, J.-L.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; De Cecco, M.; Debei, S.; Fornasier, S.; Fulle, M.; Groussin, O.; Gutierrez, P. J.; Hviid, S. F.; Ip, W.-H.; Jorda, L.; Knollenberg, J.; Kramm, J. R.; Kührt, E.; Küppers, M.; Lara, L.-M.; Lazzarin, M.; Moreno, J. Lopez; Marzari, F.; Michalik, H.; Naletto, G.; Sabau, L.; Thomas, N.; Wenzel, K.-P.; Bertini, I.; Besse, S.; Ferri, F.; Kaasalainen, M.; Lowry, S.; Marchi, S.; Mottola, S.; Sabolo, W.; Schröder, S. E.; Spjuth, S.; Vernazza, P.

2010-01-01

The European Space Agency’s Rosetta mission encountered the main-belt asteroid (2867) Steins while on its way to rendezvous with comet 67P/Churyumov-Gerasimenko. Images taken with the OSIRIS (optical, spectroscopic, and infrared remote imaging system) cameras on board Rosetta show that Steins is an oblate body with an effective spherical diameter of 5.3 kilometers. Its surface does not show color variations. The morphology of Steins is dominated by linear faults and a large 2.1-kilometer-diameter crater near its south pole. Crater counts reveal a distinct lack of small craters. Steins is not solid rock but a rubble pile and has a conical appearance that is probably the result of reshaping due to Yarkovsky-O’Keefe-Radzievskii-Paddack (YORP) spin-up. The OSIRIS images constitute direct evidence for the YORP effect on a main-belt asteroid.

ESO's VLT Helps ESA's Rosetta Spacecraft Prepare to Ride on a Cosmic Bullet

NASA Astrophysics Data System (ADS)

2002-02-01

New Images of Comet Wirtanen's Nucleus [1] Summary New images of Comet Wirtanen's 1-km 'dirty snowball' nucleus have been obtained with the ESO Very Large Telescope at Paranal (Chile). They show this object at a distance of approx. 435 million km from the Sun, about the same as when the Rosetta spacecraft of the European Space Agency (ESA) arrives in 2011. The new observations indicate that the comet has a very low degree of activity at this point in its orbit - almost no material is seen around the nucleus. This means that there will not be so much dust near the nucleus as to make the planned landing dramatically difficult. PR Photo 06a/02 : The Nucleus of Comet Wirtanen (composite photo). PR Photo 06b/02 : Comet Wirtanen's motion in the sky (animated). A distant target ESO PR Photo 06a/02 ESO PR Photo 06a/02 [Preview - JPEG: 400 x 445 pix - 120k] [Normal - JPEG: 800 x 890 pix - 1.1M] ESO PR Photo 06b/02 ESO PR Photo 06b/02 [Animated GIF: 400 x 420 pix - 312k] Caption : PR Photo 06a/02 shows a (false-colour) composite image of the nucleus of Comet Wirtanen (the point of light at the centre), recorded on December 9, 2001, with the FORS2 multi-mode instrument at the 8.2-m VLT YEPUN Unit Telescope. It is based on four exposures and since the telescope was set to track the motion of the comet in the sky, the images of stars in the field are seen as four consecutive trails. The measured brightness and the fact that the image of the comet's 'dirty snowball' nucleus is almost star-like indicates that it is surrounded by a very small amount of gas or dust. The diameter of the nucleus is about 1 km and the distance to the comet from the Earth was approx. 534 million km. In PR Photo 06b/02 , the four exposures have been combined to show the motion of the comet during the four exposures. Technical information about the photos is available below. Chase a fast-moving comet, land on it and 'ride' it while it speeds up towards the Sun: not the script of a science-fiction movie, but the very real task of ESA's Rosetta spacecraft. New observations with the ESO Very Large Telescope (VLT) provide vital information about Comet Wirtanen - Rosetta's target - to help ESA reduce uncertainties in the mission, one of the most difficult ever to be performed. Every 5.5 years Comet Wirtanen completes an orbit around the Sun. Wirtanen has been seen during several apparitions since its discovery in 1948, but only recently have astronomers obtained detailed observations that have allowed them to estimate the comet's size and behaviour, cf. ESO PR Photos 27a-b/99. The most recent of these observations was performed in December 2001 with the ESO VLT at the Paranal Observatory in Northern Chile, cf. PR Photos 06a-b/02 , reproduced here. As a result of these observations ESA will be able to refine plans for its Rosetta mission. Good news for Rosetta Rosetta will be launched next year and it will reach Comet Wirtanen in 2011. By that time the comet will be nearly as far from the Sun as Jupiter, charging headlong towards the inner Solar System at speeds of up to 135,000 km/h. To get there and to be able to match the comet's orbit, Rosetta will need to be accelerated by several planetary swing-bys, after which the spacecraft - following a series of difficult manoeuvres - will get close to the comet, enter into orbit around it and release a lander from a height of about 1 km. The VLT observations were planned specifically to investigate the 'activity' of Wirtanen at about the same solar distance as at the time of the landing manoeuvres . Because of this timing requirement, they had to be carried out at a certain moment - unfortunately, when the comet was low in the twilight evening sky and descending rapidly towards the western horizon. However, even though the exposures therefore had to be quite short, the VLT with its superb light-gathering capability and opto-mechanical perfection was still able to produce excellent images of this rather faint, moving object (about 6 million times fainter than what can be perceived with the unaided eye). These observations have now confirmed that - at the same distance from the Sun at which the landing will take place (about 450 million km from the Sun) - the activity on Wirtanen is very low, cf. PR Photo 06a/02 . This is very good news for the mission, because it means that there will not be so much dust near the nucleus as to make the landing dramatically difficult . Landing on a 1-km snowball Cometary nuclei are small frozen bodies made of ice and dust ('dirty snowballs'). When they get close to the Sun the heat causes ices on the surface to 'evaporate'. Gas and dust grains are ejected into the surrounding space forming the comet's atmosphere (coma) and the tail. In addition to dropping a lander on Wirtanen's nucleus for detailed in-situ observations, Rosetta's task is to investigate the evolution of the comet on its way to the Sun: in fact, Rosetta will keep orbiting around Wirtanen up to the end of the mission in July 2013, at which time the comet is at its closest approach to the Sun, at about 160 million km from it. These and earlier VLT observations have also provided Rosetta mission planners with an accurate measurement of their target's size: Wirtanen's nucleus is only 1.2 km in diameter, a true cosmic bullet . "Rosetta is certainly a very challenging space mission. No one has ever tried to land on a comet before," says Gerhard Schwehm , Rosetta's Project Scientist. "We need to learn as much as possible about our target. The new VLT data will allow us to improve our models and make decisions once we get there." "It is a pleasure to help our colleagues at ESA", says ESO astronomer and comet specialist Hermann Boehnhardt . "We will continue to keep an eye on this comet, in particular when Rosetta is approaching its target. We can then provide the spacecraft controllers and the astronomers with very useful, regular updates, e.g., about the 'cometary weather' at the time of arrival." More about Rosetta Rosetta's prime scientific goal is to unravel the origin of the Solar System. The chemical composition of comets is known to reflect that of the primordial nebula that gave birth to the Solar System - in the planets, that primeval material has gone through complex processing, but not in the comets. Therefore, Rosetta will allow scientists to look back 4.6 billion years, to an epoch when the Solar System formed. Previous studies by ESA's Giotto spacecraft and by ground-based observatories have shown that comets contain complex organic molecules - compounds that are rich in carbon, hydrogen, oxygen and nitrogen. Intriguingly, these are the elements which make up nucleic acids and amino acids, essential ingredients for life as we know it. Did life on Earth begin with the help of comet seeding? Rosetta may help us to find the answer to this fundamental question. Rosetta carries 21 experiments in total. These are provided by scientific consortia from institutes across Europe and the United States. The Wirtanen observations by the VLT fall into a tradition of fruitful collaboration between the European Space Agency (ESA) and the European Southern Observatory (ESO). The two organizations, both members of the EIROFORUM collaboration ( ESO PR 12/01 ), are already combining their efforts in several strategic areas, in order to facilitate the synergy between space and ground facilities, where mutual sharing of technology and procedures can result in substantial gains and savings.

Microalgae on dimension stone of a medieval castle in Thuringia

NASA Astrophysics Data System (ADS)

Hallmann, C.; Stannek, L.; Fritzlar, D.; Hoppert, M.

2012-04-01

Phototrophic microorganisms are important primary producers on hard rock substrata as well as on building facades. These eukaryotic microalgae and cyanobacteria, along with lichens, have also been recognized as important factors for rock weathering and stone decay. The rock substratum itself mostly provides extreme environmental conditions. Composition and diversity of sub-aeric phototrophic microbial communities is up to now poorly understood. Here we present a comparative study addressing the composition of algal biofilms on sandstone substrata based on the analysis of rDNA clone libraries from environmental samples and enrichment cultures. From a W-exposed, shaded wall area of a medieval castle ruin (Burg Gleichen, Thuringia, Germany cf. Hallmann et al., 2011), green algae like Prasiococcus, Prasiola and Elliptochloris could be retrieved. A ESE, sun-exposed wall section was colonized mainly by Apatococcus, Phyllosiphon and the lichen alga Trebouxia and Myrmecia. Accordingly, cyanobacterial communities show clear differences between both wall areas: the sun exposed area was dominated by Synechococcus-like organisms while on the W-exposed area cyanobacteria were almost absent. Just a few species, in particular Stichococcus-related strains, are ubiquitous in both areas. It is obvious that, apart from few generalists, different species colonize the wall areas that are situated in close vicinity, but provide different microclimatic conditions. These differences are discussed in view of biogenic weathering phenomena: certain microalgal species colonize crusts and scales along fracture planes and may contribute to rapid detachment and turnover of dimension stone surfaces. Hallmann, C., Fritzlar, D., Stannek, L., Hoppert, M. (2011) Ascomycete fungi on dimension stone of the "Burg Gleichen", Thuringia. Env. Earth Sci. 63, 1713-1722.

GIADA onboard Rosetta characterising comet 67/PChuryumov-Gerasimenko dust environment inbound to and outbound from perihelion.

NASA Astrophysics Data System (ADS)

Della Corte, Vincenzo; Rotundi, Alessandra; Fulle, Marco

2016-07-01

GIADA (Grain Impact Analyzer and Dust Accumulator) is an in-situ instrument onboard Rosetta monitoring the dust environment of comet 67P/Churyumov-Gerasimenko. GIADA is composed of 3 sub-systems: 1) the Grain Detection System, based on particle detection through light scattering; 2) the Impact Sensor, measuring particle momentum; 3) the Micro-Balances System, constituted of 5 quartz crystal microbalances, providing cumulated dust from different directions. From the combination of the measurements performed by the three subsystems we retrieve: the number, the mass, the momentum, the speed of individual dust particles and the cumulative dust flux emitted from the comet nucleus. We will present the coma dust environment as observed by GIADA during the pre-landing and escort phases of the Rosetta space mission. GIADA was able to detect temporal and spatial variation of dust density distribution and to disentangle different types of impacting dust particles. Specific high dust spatial density sectors of the coma have been identified and their evolution with respect to the heliocentric distance was studied. From August 2014 to December 2015, i.e. inbound, at and outbound perihelion, Rosetta performed different trajectories around the nucleus and flybys with different close approach distances, different coordinates of the sub-spacecraft point and different observing geometry (phase angle), allowed GIADA to characterize the dust environment within the 67P/C-G coma and its temporal variation. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF- Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developed from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site.

[Expression in Escherichia coli of the gspd(l) gene of the type II secretion system in Leptospira borgpetersenii serovariety hardjo].

PubMed

Reyes, Ernesto Armando Rodríguez; Cullen, Paul; Bulach, Dieter; Adler, Ben; Haake, David; de la Peña-Moctezuma, Alejandro

2005-01-01

A fragment of 1.539 pb of the gene homologous to gspD of Hardjobovis was clonated in the pET28a vector and it was transformed into E. coli C43 and Rosetta strains. The sequence of GspD(L) showed 46 % of similitude with E. coli GspD secretin. The expression of recombinant GspD(L) was obtained in Rosetta strain.

Ion composition at comet 67P near perihelion: Rosetta/ROSINA measurements and modeling

NASA Astrophysics Data System (ADS)

Beth, Arnaud; Altwegg, Kathrin; Balsiger, Hans; Berthelier, Jean-Jacques; Calmonte, Ursina; Combi, Michael R.; De Keyser, Johan; Dhooghe, Frederik; Fiethe, Björn; Fuselier, Stephen; Galand, Marina; Gasc, Sébastien; Gombosi, T. I.; Hansen, Kenneth C.; Hässig, Myrtha; Héritier, Kévin; Kopp, Ernest; Le Roy, Léna; Peroy, Solène; Rubin, Martin; Sémon, Thierry; Tzou, Chia-Yu; Vigren, Erik

2016-10-01

On August 13th, 2015, comet 67P/Churyumov-Gerasimenko reached its perihelion at 1.24 AU, a milestone for its cometary activity observed by the European Space Agency's Rosetta spacecraft which arrived in August 2014. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Comet Pressure Sensor (COPS) instrument onboard Rosetta measured local outgassing rates over 1028 molecules.s-1 in summer 2015. In the meantime, the ROSINA/Double Focusing Mass Spectrometer (DFMS) instrument measured the ion composition in the coma which was expected to be more diversified than during the early phase of the mission. Indeed, the increase in the cometary activity is expected to trigger new chemical pathways, yielding the formation of new cometary ions, other than the major water ions observed at larger heliocentric distances. Such new ion species can be produced from minor neutral species, such as those with proton affinity higher than that of water. This includes NH4+ whose detection has been recently reported (Beth et al., 2016).In this study, we propose to investigate other ion species during the perihelion period by:- analysing DFMS data to find any signature of substantial ion species,- modeling the ionosphere of 67P by driving the model with the neutral densities measured by DFMS and COPS to support or constrain the absence or the presence of these ion species,- discussing any discrepancy between observations and simulations.

Touch the comet! Testing of the "Rosetta's Comet Touchdown" educational kit in the Széchenyi István High School, Sopron, Hungary.

NASA Astrophysics Data System (ADS)

Lang, A.; Wesely, N.; Soós, B.; Sléber, B.; Majnovics, Z.; Ettingshausen, M.; Bodnár, L.; Németh, A.; Roos, M.

2011-10-01

In our school works a course in robotics where students build and program robots from a LEGO MINDSTORMS kit. We took part in the Hunveyor- Husar project with a Mars rover based on a rover model kit, of which the operating arms are built out of LEGO and controlled by an MINDSTORMS NXT computer. We presented our rover on the EPSC in Rome last September 2010 We presented our rover on the EPSC in Rome in September 2010. At that same conference the "Rosetta's Comet Touchdown" educational kit was officially presented. We were very interested and in conversation with the people from the project, we agreed that our school in Sopron would also participate in testing the kit. . The kit comes with a set of Interdisciplinary Activity Sheets (IAS, downloadable from Vimeo channel1) and a great feature is that the proposed activities in the IAS cover three areas: science, art/history and engineering. The 31 students from our class divided up in groups and each group chose a different topic: History of comets in Hungarian culture; Designing a T-shirt; Research on comets; Hungary in the Rosetta mission; Animation of Rosetta's orbit in space; building a LEGO MINDSTORM model; a film was made of the activities . In this presentation we report in particular the activities of the LEGO building team.

67P/Churyumov-Gerasimenko: Activity between March and June 2014 as observed from Rosetta/OSIRIS

NASA Astrophysics Data System (ADS)

Tubiana, C.; Snodgrass, C.; Bertini, I.; Mottola, S.; Vincent, J.-B.; Lara, L.; Fornasier, S.; Knollenberg, J.; Thomas, N.; Fulle, M.; Agarwal, J.; Bodewits, D.; Ferri, F.; Güttler, C.; Gutierrez, P. J.; La Forgia, F.; Lowry, S.; Magrin, S.; Oklay, N.; Pajola, M.; Rodrigo, R.; Sierks, H.; A'Hearn, M. F.; Angrilli, F.; Barbieri, C.; Barucci, M. A.; Bertaux, J.-L.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; De Cecco, M.; Debei, S.; Groussin, O.; Hviid, S. F.; Ip, W.; Jorda, L.; Keller, H. U.; Koschny, D.; Kramm, R.; Kührt, E.; Küppers, M.; Lazzarin, M.; Lamy, P. L.; Lopez Moreno, J. J.; Marzari, F.; Michalik, H.; Naletto, G.; Rickman, H.; Sabau, L.; Wenzel, K.-P.

2015-01-01

Aims: 67P/Churyumov-Gerasimenko is the target comet of the ESA's Rosetta mission. After commissioning at the end of March 2014, the Optical, Spectroscopic, and Infrared Remote Imaging System (OSIRIS) onboard Rosetta, started imaging the comet and its dust environment to investigate how they change and evolve while approaching the Sun. Methods: We focused our work on Narrow Angle Camera (NAC) orange images and Wide Angle Camera (WAC) red and visible-610 images acquired between 2014 March 23 and June 24 when the nucleus of 67P was unresolved and moving from approximately 4.3 AU to 3.8 AU inbound. During this period the 67P - Rosetta distance decreased from 5 million to 120 thousand km. Results: Through aperture photometry, we investigated how the comet brightness varies with heliocentric distance. 67P was likely already weakly active at the end of March 2014, with excess flux above that expected for the nucleus. The comet's brightness was mostly constant during the three months of approach observations, apart from one outburst that occurred around April 30 and a second increase in flux after June 20. Coma was resolved in the profiles from mid-April. Analysis of the coma morphology suggests that most of the activity comes from a source towards the celestial north pole of the comet, but the outburst that occurred on April 30 released material in a different direction.

Microbial vanadium (V) reduction in groundwater with different soils from vanadium ore mining areas.

PubMed

Hao, Liting; Zhang, Baogang; Feng, Chuanping; Zhang, Zhenya; Lei, Zhongfang; Shimizu, Kazuya; Cao, Xuelong; Liu, Hui; Liu, Huipeng

2018-07-01

This work investigated the potential of vanadium (V) (V(V)) bioreduction by using soils sampled from four main kinds of vanadium ore mining areas, i.e. vanadium titanomagnetite, stone coal, petroleum associated minerals and uvanite as inocula. During a typical operation cycle of 60 h, the soils from vanadium titanomagnetite area and petroleum associated minerals area exhibited higher V(V) removal efficiencies, about 92.0 ± 2.0% and 91.0 ± 1.9% in comparison to 87.1 ± 1.9% and 69.0 ± 1.1% for the soils from uvanite and stone coal areas, respectively. Results from high-throughput 16 S rRNA gene pyrosequencing analysis reflect the accumulation of Bryobacter and Acidobacteriaceae with capabilities of V(V) reduction, accompanied with other functional species. This study is helpful to search new functional species for V(V) reduction and to develop in situ bioremediations of V(V) polluted groundwater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Structure and Formation of Comets: Updates from Post-Rosetta Solid Fraction Analyses

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, A. C.; Bentley, M. S.; Kofman, W. W.; Brouet, Y.; Ciarletti, V.; Hadamcik, E.; Herique, A.; Lasue, J.; Mannel, T.; Schmied, R.

2016-12-01

The combination of investigations of 67P/C-G by Rosetta, theoretical and experimental studies, and remote observations allowed unprecedented insight into the structure and formation of comets. Rosetta mission has provided ground-truth for the low-density and high porosity of the nucleus, without heterogeneities larger than a few meters in its small lobe [1,2]. Further studies related to CONSERT experiment now suggest that the porosity increases inside the nucleus [3,4]. Rosetta has also provided ground-truth for the aggregated structure of dust particles within a wide range of sizes in the inner coma [e.g. 5-7]. Such discoveries confirm previous interpretations of remote observations of solar light scattered by dust in cometary comae. Differences in structure between the two parts of the nucleus, strongly suspected from previous high-resolution images of the surface [8] and possibly suggested from some remote observations in fragmenting sub-nuclei [9], might be pointed out from data obtained shortly before Rosetta controlled descent in September 2016. Further analyses by MIDAS of dust particles morphology at submicron-sizes [7,10], as well as compilations of remote observations of solar light scattered by 67P/C-G [11], are presently taking place. We will discuss how such results could lead to a better understanding of dust growth processes during the formation, specifically of 67P/C-G, and more generally, thanks to the link now provided between structural properties of dust and remote polarimetric observations, of comet's nuclei in the early Solar System. References. 1 Kofman et al. Science 2015. 2 Pätzold et al. Nature 2016. 3 Ciarletti et al. A&A 2015. 4 Brouet et al. MNRAS 2016 (under revision). 5. Rotundi et al. Science 2015. 6 Langevin et al. Icarus 2016. 7 Bentley et al. Nature 2016. 8 Massironi et al. Nature 2016. 9 Hadamcik et al. A&A 2016. 10. Mannel et al. Leiden symposium 2016. 11 Hadamcik et al. Leiden symposium 2016.

Inventory of Volatiles in the Coma of Comet 67P/Churyumov-Gerasimenko from Rosetta ROSINA - An Overview of First Results

NASA Astrophysics Data System (ADS)

Altwegg, K.; Rubin, M.; Balsiger, H. R.; Jäckel, A.; Le Roy, L.; Wurz, P.; Gasc, S.; Calmonte, U.; Tzou, C. Y.; Mall, U. A.; Fiethe, B.; De Keyser, J. M.; Berthelier, J. J.; Reme, H.; Gombosi, T. I.; Fuselier, S.

2014-12-01

The European Space Agency's Rosetta spacecraft is now close in a bound orbit around comet 67P/Churyumov-Gerasimenko (67P/C-G). On board is the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument suite. ROSINA consists of two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron-type Time-Of-Flight (RTOF), as well as the COmet Pressure Sensor (COPS). ROSINA is designed to detect and monitor the neutral gas and thermal plasma environment in the comet's coma by in situ investigation. The two mass spectrometers have high dynamic ranges and complement each other with high mass resolution (DFMS) and high time resolution and large mass range (RTOF). Especially the unprecedented sensitivity and mass resolution of DFMS together with the large mass range of RTOF will allow determining precisely light species (e.g. isotopologues) as well as detecting heavy organics. The pressure sensor COPS is capable to derive total gas densities, velocities, and temperatures. To date only limited data for the composition of cometary comae at heliocentric distances of more than 2.5 AU are available. The set is dominated by CO and daughter species of water from bright comets originating in the Oort cloud. While some molecules can be detected from far by remote sensing (e.g. CO) other molecules are much more difficult to observe from ground (e.g. CO2). The Rosetta mission presents a unique opportunity to directly probe the parent species in the thin cometary atmosphere of a Kuiper-belt object at more than 2.5 AU from the Sun and relate it to ground-based observations. Distances that far from the Sun are of particular interest as the comet's activity transitions from being super volatiles dominated to being water dominated. We will report on the first measurements of the volatile inventory obtained from ROSINA observations as Rosetta is following comet 67P/C-G in close vicinity.

Mapping Ross Ice Shelf with ROSETTA-Ice airborne laser altimetry

NASA Astrophysics Data System (ADS)

Becker, M. K.; Fricker, H. A.; Padman, L.; Bell, R. E.; Siegfried, M. R.; Dieck, C. C. M.

2017-12-01

The Ross Ocean and ice Shelf Environment and Tectonic setting Through Aerogeophysical surveys and modeling (ROSETTA-Ice) project combines airborne glaciological, geological, and oceanographic observations to enhance our understanding of the history and dynamics of the large ( 500,000 square km) Ross Ice Shelf (RIS). Here, we focus on the Light Detection And Ranging (LiDAR) data collected in 2015 and 2016. This data set represents a significant advance in resolution: Whereas the last attempt to systematically map RIS (the surface-based RIGGS program in the 1970s) was at 55 km grid spacing, the ROSETTA-Ice grid has 10-20 km line spacing and much higher along-track resolution. We discuss two different strategies for processing the raw LiDAR data: one that requires proprietary software (Riegl's RiPROCESS package), and one that employs open-source programs and libraries. With the processed elevation data, we are able to resolve fine-scale ice-shelf features such as the "rampart-moat" ice-front morphology, which has previously been observed on and modeled for icebergs. This feature is also visible in the ROSETTA-Ice shallow-ice radar data; comparing the laser data with radargrams provides insight into the processes leading to their formation. Near-surface firn state and total firn air content can also be investigated through combined analysis of laser altimetry and radar data. By performing similar analyses with data from the radar altimeter aboard CryoSat-2, we demonstrate the utility of the ROSETTA-Ice LiDAR data set in satellite validation efforts. The incorporation of the LiDAR data from the third and final field season (December 2017) will allow us to construct a DEM and an ice thickness map of RIS for the austral summers of 2015-2017. These products will be used to validate and extend observations of height changes from satellite radar and laser altimetry, as well as to update regional models of ocean circulation and ice dynamics.

Calcium Oxalate Urolithiasis: A Case of Missing Microbes?

PubMed

Batagello, Carlos Alfredo; Monga, Manoj; Miller, Aaron W

2018-05-29

Urinary stone disease (USD) has known associations with the gut microbiota. Approximately 80% of kidney stones contain oxalate as a primary constituent and diverse oxalate-degrading bacteria exist within the human gut that may protect against USD. While bacteriotherapy represents a promising strategy to eliminate oxalate and reduce the risk of USD, oxalate-degrading probiotics have had limited success. To identify limitations of oxalate-degrading probiotics and refine development of bacteriotherapies to prevent USD, we review the literature associated with the gut microbiota and USD. A literature search was performed to identify publications that examine the role of oxalate-degrading bacteria or the whole gut microbiota in oxalate metabolism and the pathophysiology of USD. We conducted a meta-analysis of studies that examined the association of the whole gut microbiota with USD. In addition, we evaluated the gut microbiota of healthy individuals and those with co-morbidities related to USD using publically available data from the American Gut Project (AGP). Studies on O. formigenes reveal that colonization by this species is not a good predictor of USD risk nor urinary oxalate excretion. The species of oxalate-degrading bacteria used in probiotics and duration of administration does not impact efficacy or persistence. Studies focused on the whole gut microbiota reveal broad shifts in the gut microbiota associated with USD and a diverse microbial network is associated with oxalate metabolism. AGP data analysis demonstrated a strong overlap in microbial genera depleted in diseased individuals among USD and co-morbidities. The associations between the gut microbiota and USD extend beyond individual functional microbial species. Common shifts in the gut microbiota may facilitate the onset of USD and/or co-morbidities. The successful development of bacteriotherapies to inhibit USD will need to incorporate strategies that target a broad diversity of bacteria rather than focus on few specialist species.

Understanding the gut-kidney axis in nephrolithiasis: an analysis of the gut microbiota composition and functionality of stone formers.

PubMed

Ticinesi, Andrea; Milani, Christian; Guerra, Angela; Allegri, Franca; Lauretani, Fulvio; Nouvenne, Antonio; Mancabelli, Leonardo; Lugli, Gabriele Andrea; Turroni, Francesca; Duranti, Sabrina; Mangifesta, Marta; Viappiani, Alice; Ferrario, Chiara; Dodi, Rossella; Dall'Asta, Margherita; Del Rio, Daniele; Ventura, Marco; Meschi, Tiziana

2018-04-28

The involvement of the gut microbiota in the pathogenesis of calcium nephrolithiasis has been hypothesised since the discovery of the oxalate-degrading activity of Oxalobacter formigenes , but never comprehensively studied with metagenomics. The aim of this case-control study was to compare the faecal microbiota composition and functionality between recurrent idiopathic calcium stone formers (SFs) and controls. Faecal samples were collected from 52 SFs and 48 controls (mean age 48±11). The microbiota composition was analysed through 16S rRNA microbial profiling approach. Ten samples (five SFs, five controls) were also analysed with deep shotgun metagenomics sequencing, with focus on oxalate-degrading microbial metabolic pathways. Dietary habits, assessed through a food-frequency questionnaire, and 24-hour urinary excretion of prolithogenic and antilithogenic factors, including calcium and oxalate, were compared between SFs and controls, and considered as covariates in the comparison of microbiota profiles. SFs exhibited lower faecal microbial diversity than controls (Chao1 index 1460±363vs 1658±297, fully adjusted p=0.02 with stepwise backward regression analysis). At multivariate analyses, three taxa ( Faecalibacterium , Enterobacter , Dorea ) were significantly less represented in faecal samples of SFs. The Oxalobacter abundance was not different between groups. Faecal samples from SFs exhibited a significantly lower bacterial representation of genes involved in oxalate degradation, with inverse correlation with 24-hour oxalate excretion (r=-0.87, p=0.002). The oxalate-degrading genes were represented in several bacterial species, whose cumulative abundance was inversely correlated with oxaluria (r=-0.85, p=0.02). Idiopathic calcium SFs exhibited altered gut microbiota composition and functionality that could contribute to nephrolithiasis physiopathology. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Getting together in deep space - The Rosetta space probe's long trek to Comet 67/P Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

2004-02-01

The countdown to Rosetta’s rendezvous in space began on 1 March 1997. At the end of February 2004, seven years and not a few headaches later, the European Space Agency (ESA) probe will at last be setting off on its journey to meet Comet Churyumov-Gerasimenko. The long-planned get-together will not however take place until the middle of 2014. A few months after arriving at the comet, Rosetta will release a small lander onto its surface. Then, for almost two years it will investigate Churyumov-Gerasimenko from close up. Dr Gerhard Schwehm, lead scientist for the Rosetta project, explains that, “With this mission we will be breaking new ground - this will be the first protracted cometary encounter.” The trip to the meeting place in space will certainly be a long one, located as it is some 4.5 astronomical units from the Sun, which translates into something like 675 million kilometres. Rosetta will be on the road for ten years, during which time it will clock up in excess of five billion kilometres. Launch in February 2004 Rosetta will be waved off on 26 February when it lifts off from the space centre in Kourou, French Guiana, aboard an Ariane 5 launcher. Shortly after the spacecraft’s release, its solar panels will be deployed and turned towards the Sun to build up the necessary power reserves. Its various systems and experiments will be gradually brought into operation and tested. Just three months into the mission the first active phase will be over, followed by final testing of the experiments in October 2004. Rosetta will then spend the following years flying a lonely path to the comet, passing by the Earth, Mars, the Earth and the Earth again. There is no alternative to this detour, for even Ariane 5, the most powerful launcher on the market today, lacks the power to hurl the probe on a direct route to the comet. To get the required momentum, it will rely on swing-by manœuvres, using the gravitation pull of Mars (in 2007) and the Earth (three times, in 2005, 2007 and 2008) to pick up speed. Asteroids for company A change is as good as a rest, and a meeting with at least one asteroid should help break the monotony for Rosetta. The spacecraft will come close to an asteroid at the end of 2008. Asteroids are, it will be remembered, rocky bodies, some as large as mountains, some even larger, that orbit the Sun in much the same way as planets. “These ‘brief encounters’ are a scientific opportunity and also a chance to test Rosetta’s instrument payload,” says Gerhard Schwehm. But asteroid exploration also serves an entirely practical purpose: “The more we find out about them, the better the prospect of being able one day to avert a possible collision.” Following a period of low-activity cruising, the probe’s course will be adjusted one last time in May 2011. From July 2011, a further two-and-a-half years' radio silence will be observed, and Rosetta, left entirely to its own resources, will fly close to the Jupiter orbit. Link-up in 2014 Finally, in January 2014, the probe will be reactivated and will, by October 2014, be only a few kilometres distant from Churyumov-Gerasimenko. This is where the dream of so many scientists becomes reality. Having deposited its precious lander cargo on the comet’s surface, Rosetta will continue to orbit Churyumov-Gerasimenko and together they will spend the next seventeen months flying towards the Sun. Rosetta was built by an international consortium led by Astrium. The lander probe was developed in Cologne under the aegis of the DLR, Germany’s space agency, with contributions from ESA and research centres in Austria, Finland, France, Hungary, Ireland, Italy and Great Britain. The comet explorer carries ten scientific instruments. Their job is to draw out the secrets of the comet’s chemical and physical composition and reveal its magnetic and electrical properties. Using a specially designed camera, the lander will take pictures in the macro and micro ranges and send all the data thus acquired back to Earth, via Rosetta. “This will be our first ever chance to be there, at first hand, so to speak, as a comet comes to life,” Schwehm goes on to explain. When Churyumov-Gerasimenko gets to within about 500 million kilometres of the Sun, the frozen gases that envelop it will evaporate and a trail of dust will be blown back over hundreds of thousands of kilometres. When illuminated by the Sun, this characteristic comet tail then becomes visible from Earth. In the course of the mission, the processes at work within the cometary nucleus will be studied and measured more precisely than has ever before been possible, for earlier probes simply flew past their targets. “As we will be accompanying Churyumov-Gerasimenko for two years, until the comet reaches the point closest to the Sun and travels away from it, we can at long last hope to acquire new knowledge about comets. We are confident we will come a step nearer to understanding the origins and formation of our solar system and the emergence of life on Earth.” More information on the Rosetta launch can be found on : http://www.esa.int/rosetta. More on ESA Science Programme at : http://www.esa.int/science

Rosetta Navigation at its Mars Swing-By

NASA Technical Reports Server (NTRS)

Budnik, Frank; Morley, Trevor

2007-01-01

This paper reports on the navigation activities during Rosetta s Mars swing-by. It covers the Mars approach phase starting after a deterministic deep-space maneuver in September 2006, the swing-by proper on 25 February 2007, and ends with another deterministic deep-space maneuver in April 2007 which was also foreseen to compensate any navigation error. Emphasis is put on the orbit determination and prediction set-up and the evolution of the targeting estimates in the B-plane and their adjustments by trajectory correction maneuvers.

Plasma properties at 67P/Churyumov-Gerasimenko: a comparision between PP-SESAME/Philae/Rosetta and RPC/MIP/Rosetta

NASA Astrophysics Data System (ADS)

Schmidt, Walter; Henri, Pierre; Lebreton, Jean Pierre; Vallières, Xavier; Grard, Réjean; Hamelin, Michel; Le Gall, Alice; Lethuillier, Anthony; Ciarletti, Valerie; Caujolle-Bert, Sylvain; Seidensticker, Klaus; Fischer, Hans-Herbert

2016-04-01

On November 12, 2014, the Rosetta landing module Philae approached the nucleus of 67P/Churyumov-Gerasimenko and eventually settled on the surface in a location named Abydos, though its exact coordinates are still unknown. The Permittivity Probe (PP) as part of the SESAME (Surface Electric Sounding and Acoustic Monitoring Experiment) instrument package [1] was designed to not only measure the electrical properties of the comet's surface material by actively injecting an alternating current at different frequencies into the material underneath the Lander but also to monitor potential variations between its two receivers and the electrical conductivity of the plasma environment while still in space. By sampling the potential difference at 40 kHz between the soles of two of the feet attached to Philae's landing gear, plasma waves between 20 and 20 000 Hz should be detectable if their amplitudes are large enough. The injection of low frequency currents into the plasma environment during Philae's descent gives indications for changes of the plasma density when approaching the comet. In this paper we present observations from the cross-calibration campaign with the Rosetta plasma package instrument MIP (Mutual Impedance Probe) [2] during the Pre-Delivery Calibration and Science (PDCS) operations on October 17, 2014, during the descent towards the comet surface on November 12, 2014, and from the First Science Sequence at Abydos on November 13. During the PDCS campaign most PP observation slots coincided with plasma waves dominantly in the 100 to 150 kHz range according to MIP measurements. Accordingly PP did not register any signals. Only in the afternoon of the 17th low frequency waves were recorded by MIP. At the same time the measured PP wave power signal was above the background for frequencies below 500 Hz in several subsequent measurements. During the descent [3] the injected current at 758 Hz dropped suddenly by about 5 % possibly indicating a decrease in the plasma density at an altitude of about 18.5 km above the comet surface. During the First Science Sequence PP was monitoring low frequency wave-like activities starting two hours after local sunset. References: [1] K. J. Seidensticker, H-H. Fischer, D. Medlener, S. Schieke, K. Thiel, A. Peter, W. Schmidt and R. Trautner, 2004: The Rosetta lander experiment sesame and the new target comet 67P/Churyumov-Gerasimenko. The New ROSETTA Targets - Observations, Simulations and Instrument Performances, Astrophys. Space Sci. 311, 297-307 [2] J. G. Trotignon et al., RPC-MIP: the Mutual Impedance Probe of the Rosetta Plasma Consortium, Space Science Reviews, February 2007, Volume 128, Issue 1, pp 713-728 [3] H.Krüger et al., Dust Impact Monitor (SESAME-DIM) Measurements at Comet 67P/Churyumov-Gerasimenko, Astronomy&Astrophysics, Volume 583, November 2015, DOI http://dx.doi.org/10.1051/0004-6361/201526400

The U.S. Rosetta Project at Its First Science Target: Asteroid (2867) Steins, 2008

NASA Technical Reports Server (NTRS)

Alexander, C.; Sweetnam, D.; Gulkis, S.; Weissman, P.; Holmes, D.; Parker, J.; Burch, J.; Goldstein, R.; Mokashi, P.; Fuselier, S.;

Modeling and docking antibody structures with Rosetta

PubMed Central

Weitzner, Brian D.; Jeliazkov, Jeliazko R.; Lyskov, Sergey; Marze, Nicholas; Kuroda, Daisuke; Frick, Rahel; Adolf-Bryfogle, Jared; Biswas, Naireeta; Dunbrack, Roland L.; Gray, Jeffrey J.

2017-01-01

We describe Rosetta-based computational protocols for predicting the three-dimensional structure of an antibody from sequence (RosettaAntibody) and then docking the antibody to protein antigens (SnugDock). Antibody modeling leverages canonical loop conformations to graft large segments from experimentally-determined structures as well as (1) energetic calculations to minimize loops, (2) docking methodology to refine the VL–VH relative orientation, and (3) de novo prediction of the elusive complementarity determining region (CDR) H3 loop. To alleviate model uncertainty, antibody–antigen docking resamples CDR loop conformations and can use multiple models to represent an ensemble of conformations for the antibody, the antigen or both. These protocols can be run fully-automated via the ROSIE web server (http://rosie.rosettacommons.org/) or manually on a computer with user control of individual steps. For best results, the protocol requires roughly 1,000 CPU-hours for antibody modeling and 250 CPU-hours for antibody–antigen docking. Tasks can be completed in under a day by using public supercomputers. PMID:28125104

MOSES: a modular sensor electronics system for space science and commercial applications

NASA Astrophysics Data System (ADS)

Michaelis, Harald; Behnke, Thomas; Tschentscher, Matthias; Mottola, Stefano; Neukum, Gerhard

1999-10-01

The camera group of the DLR--Institute of Space Sensor Technology and Planetary Exploration is developing imaging instruments for scientific and space applications. One example is the ROLIS imaging system of the ESA scientific space mission `Rosetta', which consists of a descent/downlooking and a close-up imager. Both are parts of the Rosetta-Lander payload and will operate in the extreme environment of a cometary nucleus. The Rosetta Lander Imaging System (ROLIS) will introduce a new concept for the sensor electronics, which is referred to as MOSES (Modula Sensor Electronics System). MOSES is a 3D miniaturized CCD- sensor-electronics which is based on single modules. Each of the modules has some flexibility and enables a simple adaptation to specific application requirements. MOSES is mainly designed for space applications where high performance and high reliability are required. This concept, however, can also be used in other science or commercial applications. This paper describes the concept of MOSES, its characteristics, performance and applications.

Mating in the Closest Living Relatives of Animals Is Induced by a Bacterial Chondroitinase.

PubMed

Woznica, Arielle; Gerdt, Joseph P; Hulett, Ryan E; Clardy, Jon; King, Nicole

2017-09-07

We serendipitously discovered that the marine bacterium Vibrio fischeri induces sexual reproduction in one of the closest living relatives of animals, the choanoflagellate Salpingoeca rosetta. Although bacteria influence everything from nutrition and metabolism to cell biology and development in eukaryotes, bacterial regulation of eukaryotic mating was unexpected. Here, we show that a single V. fischeri protein, the previously uncharacterized EroS, fully recapitulates the aphrodisiac-like activity of live V. fischeri. EroS is a chondroitin lyase; although its substrate, chondroitin sulfate, was previously thought to be an animal synapomorphy, we demonstrate that S. rosetta produces chondroitin sulfate and thus extend the ancestry of this important glycosaminoglycan to the premetazoan era. Finally, we show that V. fischeri, purified EroS, and other bacterial chondroitin lyases induce S. rosetta mating at environmentally relevant concentrations, suggesting that bacteria likely regulate choanoflagellate mating in nature. Copyright © 2017 Elsevier Inc. All rights reserved.

Replica Exchange Improves Sampling in Low-Resolution Docking Stage of RosettaDock

PubMed Central

Zhang, Zhe; Lange, Oliver F.

2013-01-01

Many protein-protein docking protocols are based on a shotgun approach, in which thousands of independent random-start trajectories minimize the rigid-body degrees of freedom. Another strategy is enumerative sampling as used in ZDOCK. Here, we introduce an alternative strategy, ReplicaDock, using a small number of long trajectories of temperature replica exchange. We compare replica exchange sampling as low-resolution stage of RosettaDock with RosettaDock's original shotgun sampling as well as with ZDOCK. A benchmark of 30 complexes starting from structures of the unbound binding partners shows improved performance for ReplicaDock and ZDOCK when compared to shotgun sampling at equal or less computational expense. ReplicaDock and ZDOCK consistently reach lower energies and generate significantly more near-native conformations than shotgun sampling. Accordingly, they both improve typical metrics of prediction quality of complex structures after refinement. Additionally, the refined ReplicaDock ensembles reach significantly lower interface energies and many previously hidden features of the docking energy landscape become visible when ReplicaDock is applied. PMID:24009670

Diamagnetic region(s): structure of the unmagnetized plasma around Comet 67P/CG

NASA Astrophysics Data System (ADS)

Henri, P.; Vallières, X.; Hajra, R.; Goetz, C.; Richter, I.; Glassmeier, K.-H.; Galand, M.; Rubin, M.; Eriksson, A. I.; Nemeth, Z.; Vigren, E.; Beth, A.; Burch, J. L.; Carr, C.; Nilsson, H.; Tsurutani, B.; Wattieaux, G.

2017-07-01

The ESA's comet chaser Rosetta has monitored the evolution of the ionized atmosphere of comet 67P/Churyumov-Gerasimenko (67P/CG) and its interaction with the solar wind, during more than 2 yr. Around perihelion, while the cometary outgassing rate was highest, Rosetta crossed hundreds of unmagnetized regions, but did not seem to have crossed a large-scale diamagnetic cavity as anticipated. Using in situ Rosetta observations, we characterize the structure of the unmagnetized plasma found around comet 67P/CG. Plasma density measurements from RPC-MIP are analysed in the unmagnetized regions identified with RPC-MAG. The plasma observations are discussed in the context of the cometary escaping neutral atmosphere, observed by ROSINA/COPS. The plasma density in the different diamagnetic regions crossed by Rosetta ranges from ˜100 to ˜1500 cm-3. They exhibit a remarkably systematic behaviour that essentially depends on the comet activity and the cometary ionosphere expansion. An effective total ionization frequency is obtained from in situ observations during the high outgassing activity phase of comet 67P/CG. Although several diamagnetic regions have been crossed over a large range of distances to the comet nucleus (from 50 to 400 km) and to the Sun (1.25-2.4 au), in situ observations give strong evidence for a single diamagnetic region, located close to the electron exobase. Moreover, the observations are consistent with an unstable contact surface that can locally extend up to about 10 times the electron exobase.

In-situ investigations of the ionosphere of comet 67P

NASA Astrophysics Data System (ADS)

Eriksson, A. I.; Edberg, N. J. T.; Odelstad, E.; Vigren, E.; Engelhardt, I.; Henri, P.; Lebreton, J.-P.; Galand, M.; Carr, C. M.; Koenders, C.; Nilsson, H.; Broiles, T.; Rubin, M.

2015-10-01

Since arrival of Rosetta at its target comet 67P/Churyumov-Gerasimenko in August 2014, the plasma environment has been dominated by ionized gas emanating from the comet nucleus rather than by solar wind plasma. This was evident early on from the strong modulation seen with Rosetta's position in a reference frame fixed to the rotating nucleus, with higher plasma densities observed when the spacecraft is above the neck region and when the comet exposes maximum area to the sun. In this respect, Rosetta is inside the comet ionosphere, providing excellent in situ investigation opportunities for the instruments of the Rosetta Plasma Consortium (RPC). In contrast to the often modelled scenario for a very active comet, the Langmuir probe instrument (RPC-LAP) finds electron temperatures mainly in the range of tens of thousand kelvin around this less active comet. This can be attributed to the lower density of neutral gas, meaning little cooling of recently produced electrons. A side effect of this is that the spacecraft charges negatively when within about 100 km from the nucleus. Interesting in itself, this also may point to similar charging for dust grains in the coma, with implications for the detection of the smallest particles and possibly for processes like electrostatic fragmentation. The inner coma also proves to be very dynamic, with large variations not only with latitude and longitude in a comet frame, but also with the solar wind and various wave phenomena.

Rosetta enters hibernation

NASA Astrophysics Data System (ADS)

Ferri, Paolo; Accomazzo, Andrea; Hubault, Armelle; Lodiot, Sylvain; Pellon-Bailon, Jose-Luis; Porta, Roberto

2012-10-01

The International Rosetta Mission was launched on 2nd March 2004 on its 10 years journey to comet 67P/Churyumov-Gerasimenko. Rosetta will reach the comet in 2014, orbit it for about 1.5 years down to distances of a few kilometres and deliver the Lander Philae onto its surface. Following the fly-by of Asteroid (21-)Lutetia in 2010, Rosetta continued its travel towards the planned comet encounter in 2014. In this phase Rosetta became the solar-powered spacecraft that reached the largest Sun distances in history of spaceflight, up to an aphelion at 5.3 AU in October 2012. At distances above 4.5 AU the spacecraft's solar generator power is not sufficient to keep all spacecraft systems active. Therefore in June 2011 the spacecraft was spun up to provide gyroscopic stabilisation, and most of its on-board units, including those used for attitude control and communications, were switched off. Over this "hibernation" phase of about 2.5 years the spacecraft will keep a minimum of autonomy active to ensure maintenance of safe thermal conditions. After Lutetia fly-by, flight controllers had to tackle two anomalies that had significant impacts on the mission operations. A leak in the reaction control subsystem was confirmed and led to the re-definition of the operational strategy to perform the comet rendezvous manoeuvres planned for 2011 and 2014. Anomalous jumps detected in the estimated friction torque of two of the four reaction wheels used for attitude control forced the rapid adoption of measures to slow down the wheels degradation. This included in-flight re-lubrication activities and changes in the wheels operational speed regime. Once the troubleshooting of the two anomalies was completed, and the related operational scenarios were implemented, the first large (790 m/s) comet rendezvous manoeuvre was executed, split into several long burns in January and February 2011. The second burn was unexpectedly interrupted due to the anomalous behaviour of two thrusters, causing attitude off-pointing. Flight controllers modified the thrusters operation parameters in the on-board software and managed to re-start the sequence of burns and successfully complete the manoeuvre. After the manoeuvre, preparation for the critical spin-up and hibernation entry activities, planned for June 2011, began. This paper presents the activities carried out on Rosetta in the final year before hibernation entry. The major anomalies and the related troubleshooting and workaround solutions are detailed. Lessons learned from the operation of the first spacecraft operating with solar power at Jupiter-like distances from the Sun are presented and discussed.

The activity of C-G at 3.5 AU from the Sun

NASA Astrophysics Data System (ADS)

Rubin, M.; Altwegg, K.

2014-04-01

Starting in early August the ROSINA instrument on board the Rosetta spacecraft (1] saw clearly cometary molecules above the spacecraft background. The COPS sensor, which measures the total density with its nude gauge, registered large density variations in line with the rotation period of the comet. Mapping this to the comet showed that especially the neck of the comet is very active whenever it comes into sunlight. However, the outgassing pattern is more complex. In this talk we give an overview on the measured density profiles along the Rosetta trajectory.

Studies on Thorium Adsorption Characteristics upon Activated Titanium Hydroxide Prepared from Rosetta Ilmenite Concentrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gado, M, E-mail: parq28@yahoo.com; Zaki, S

2016-01-01

The titanium hydroxide prepared from Rosetta ilmenite concentrate has been applied for Th (IV) adsorption from its acid aqueous solutions. The prepared hydroxide is first characterized by both Fourier transform infrared (FT-IR) spectrum and thermogravimetric analysis. The relevant factors affecting the adsorption process have been studied. The obtained equilibrium data fits well with the Langmuir isotherm rather than Freundlich isotherm, while the adsorption kinetic data follow the pseudo-second order model. The different thermodynamic parameters have also been calculated and indicate that the adsorption process is spontaneous.

A Contingency in the Rosetta Reaction Control System: Alternative Cruise Trajectory Strategies to Cope with Degraded Delta-V Resources

NASA Technical Reports Server (NTRS)

Bauske, Rainer; Companys, Vincente

2007-01-01

Since August 2006 a pressure transducer of the Rosetta Reaction Control System (RCS) shows anomalous telemetries indicating a possible leak in a pressurant line. The future operation mode of the RCS may be affected by this problem, resulting in performance degradation. The current propellant budget and its future evolution are evaluated to show the possible states w.r.t. the required mission delta-V. Alternative cruise trajectory strategies are analyzed, providing delta-V savings, to compensate for the expected performance loss of the RCS.

Magnetic Field Investigations During ROSETTA's Steins Flyby

NASA Astrophysics Data System (ADS)

Glassmeier, K.; Auster, H.; Richter, I.; Motschmann, U.; RPC/ROMAP Teams

2009-05-01

During the recent Steins flyby of the ROSETTA spacecraft magnetic field measurements have been made with both, the RPC orbiter magnetometer and the ROMAP lander magnetometer. These combined magnetic field measurements allow a detailed examination of any magnetic signatures caused either directly by the asteroid or indirectly by Steins different modes of interaction with the solar wind. Comparing our measurements with simulation results show that Steins does not possess a significant remanent magnetization. The magnetization is estimated at less than 1 mAm2/kg. This is significantly different from results at Braille and Gaspra.

Cooperatively Generated Stresslet Flows Supply Fresh Fluid to Multicellular Choanoflagellate Colonies

NASA Astrophysics Data System (ADS)

Roper, Marcus; Dayel, Mark J.; Pepper, Rachel E.; Koehl, M. A. R.

2013-05-01

The flagellated protozoan Salpingoeca rosetta is one of the closest relatives of multicellular animals. Unicellular S. rosetta can be induced to form multicellular colonies, but colonies swim more slowly than individual cells so the advantages conferred by colony formation are uncertain. Here we use theoretical models to show that hydrodynamic cooperation between cells can increase the fluid supply to the colony, an important predictor of feeding rate. Our results suggest that hydrodynamic benefits may have been an important selective factor in the evolution of early multicellular animals.

Gene fusion analysis in the battle against the African endemic sleeping sickness.

PubMed

Trimpalis, Philip; Koumandou, Vassiliki Lila; Pliakou, Evangelia; Anagnou, Nicholas P; Kossida, Sophia

2013-01-01

The protozoan Trypanosoma brucei causes African Trypanosomiasis or sleeping sickness in humans, which can be lethal if untreated. Most available pharmacological treatments for the disease have severe side-effects. The purpose of this analysis was to detect novel protein-protein interactions (PPIs), vital for the parasite, which could lead to the development of drugs against this disease to block the specific interactions. In this work, the Domain Fusion Analysis (Rosetta Stone method) was used to identify novel PPIs, by comparing T. brucei to 19 organisms covering all major lineages of the tree of life. Overall, 49 possible protein-protein interactions were detected, and classified based on (a) statistical significance (BLAST e-value, domain length etc.), (b) their involvement in crucial metabolic pathways, and (c) their evolutionary history, particularly focusing on whether a protein pair is split in T. brucei and fused in the human host. We also evaluated fusion events including hypothetical proteins, and suggest a possible molecular function or involvement in a certain biological process. This work has produced valuable results which could be further studied through structural biology or other experimental approaches so as to validate the protein-protein interactions proposed here. The evolutionary analysis of the proteins involved showed that, gene fusion or gene fission events can happen in all organisms, while some protein domains are more prone to fusion and fission events and present complex evolutionary patterns.

Gas Flows in Dual Active Galactic Nuclei

NASA Astrophysics Data System (ADS)

Mueller Sanchez, Francisco; Comerford, Julia M.; Davies, Richard; Treister, Ezequiel; Privon, George C.; Nevin, Becky

2018-06-01

Dual Active Galactic Nuclei (AGN) are the Rosetta stone to understand the role of galaxy mergers in triggering nuclear activity and regulating black hole (BH) and galaxy growth. But very little is known about the physical processes required to effectively trigger AGN activity and regulate the growth of the two BHs. The work I will present here characterizes for the first time the properties of the stars, gas (molecular, ionized, and highly-ionized) and dust in all the confirmed dual AGN at z < 0.05, using Keck/OSIRIS, VLT/SINFONI, SOFIA/FORCAST, and HST data. I will focus on the interplay between the several complex processes observed in dual AGN, using as an example the prototypical merger system NGC 6240: vigorous star formation, two AGNs, outflowing winds of ionized gas, rippling dust and gas lanes, and tidal tails. In this galaxy, we observe for the first time a dual outflow of different species of gas: an AGN-driven outflow of highly-ionized gas to the northeast and a starburst-driven outflow of ionized hydrogen to the northwest. This shows that stellar feedback and supermassive black hole feedback can work in tandem to regulate the stellar growth of a galaxy after a merger event. These results open a new door to studies of dual AGN and AGN pairs in general, and enable dual AGN to be used, for the first time, for studies of galaxy evolution.

A post-Rosetta understanding of polarimetric observations of comets

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, A. Chantal; Ciarletti, Valérie; Hadamcik, Edith; Lasue, Jérémie; Mannel, Thurid

2017-04-01

Numerous polarimetric observations of solar light scattered by dust in cometary comae have been obtained by various teams, providing phase angle and wavelength dependences for many comets and revealing different classes of comets [e.g., 1]. Besides, numerical and experimental simulations have suggested interpretations for such observations. The Rosetta long duration rendezvous with comet 67P/Churyumov-Gerasimenko (thereafter 67P/C-G) now allows us to compare our understanding of the polarimetric properties of cometary dust with the ground-truth provided by the Rosetta mission, at least for two typical results. First, some comets present a highly-polarized positive branch, the most conspicuous case being that of new comet C/1995 O1 Hale-Bopp [2], while other comets suffering a partial fragmentation or a total disruption, such as C/1995 S4 LINEAR [3], present a significant increase in polarization. We will discuss these observations in the context of evidence for changes between the porosity (and possibly the dust/ice ratio) of the subsurface and of the interior of 67P/C-G, a periodic Jupiter Family Comet, as derived from analyses [4] of the CONSERT bi-static radar measurements on board Rosetta and Philae. Secondly, numerical simulations of the phase and wavelength dependence of polarimetric observations of some comets (extensively observed on a wide range of wavelengths and phase angles) have suggested the presence of fractal, likely-porous aggregates and of compact particles within their comae [e.g., 5]. We will review such results in the context of evidence for porous and compact aggregates of submicron-sized grains in the inner coma of 67P/C-G [6], as given by 3D images (with a resolution down to tens of nanometers) of the MIDAS atomic force microscope on board Rosetta. References: [1] Kiselev et al., 2015, In Polarization of stars and planetary systems, CUP 379-404. [2] Levasseur-Regourd & Hadamcik, 2003, JQSRT 79-80, 903-910. [3] Hadamcik & Levasseur-Regourd, 2003, Icarus 166, 188-194. [4] Ciarletti et al., 2015, Astron. Astrophys. 583, A40. [5] Lasue et al., 2009, Icarus 199, 129-144. [6] Mannel et al., 2016, MNRAS 462, S 304-S311.

Structure and dynamics of the umagnetized plasma around comet 67P/CG

NASA Astrophysics Data System (ADS)

Henri, P.; Vallières, X.; Gilet, N.; Hajra, R.; Moré, J.; Goetz, C.; Richter, I.; Glassmeier, K. H.; Galand, M. F.; Heritier, K. L.; Eriksson, A. I.; Nemeth, Z.; Tsurutani, B.; Rubin, M.; Altwegg, K.

2016-12-01

At distances close enough to the Sun, when comets are characterised by a significant outgassing, the cometary neutral density may become large enough for both the cometary plasma and the cometary gas to be coupled, through ion-neutral and electron-neutral collisions. This coupling enables the formation of an unmagnetised expanding cometary ionosphere around the comet nucleus, also called diamagnetic cavity, within which the solar wind magnetic field cannot penetrate. The instruments of the Rosetta Plasma Consortium (RPC), onboard the Rosetta Orbiter, enable us to better constrain the structure, dynamics and stability of the plasma around comet 67P/CG. Recently, magnetic field measurements (RPC-MAG) have shown the existence of such a diamagnetic region around comet 67P/CG [Götz et al., 2016]. Contrary to a single, large scale, diamagnetic cavity such as what was observed around comet Halley, Rosetta have crossed several diamagnetic structures along its trajectory around comet 67P/CG. Using electron density measurements from the Mutual Impedance Probe (RPC-MIP) during the different diamagnetic cavity crossings, identified by the flux gate magnetometer (RPC-MAG), we map the unmagnetised plasma density around comet 67P/CG. Our aims is to better constrain the structure, dynamics and stability of this inner cometary plasma layer characterised by cold electrons (as witnessed by the Langmuir Probes RPC-LAP). The ionisation ratio in these unmagnetised region(s) is computed from the measured electron (RPC-MIP) and neutral gas (ROSINA/COPS) densities. In order to assess the importance of solar EUV radiation as a source of ionisation, the observed electron density will be compared to a the density expected from an ionospheric model taking into account solar radiation absorption. The crossings of diamagnetic region(s) by Rosetta show that the unmagnetised cometary plasma is particularly homogeneous, compared to the highly dynamical magnetised plasma observed in adjacent magnetised regions. Moreover, during the crossings of multiple, successive diamagnetic region(s) over time scales of tens of minutes or hours, the plasma density is almost identical in the different unmagnetised regions, suggesting that these unmagnetised regions may be a single diamagnetic structure crossed several times by Rosetta.

Variegation of active regions on comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Oklay, Nilda; Vincent, Jean-Baptiste; Fornasier, Sonia; Pajola, Maurizio; Besse, Sebastien; Lara, Luisa M.; Barucci, Maria Antonietta; Mottola, Stefano; Sierks, Holger; Pommerol, Antoine; Masoumzadeh, Nafiseh; Lazzarin, Monica; Scholten, Frank; Preusker, Frank; Hall, Ian

2015-11-01

Since Rosetta spacecraft’s arrival to the comet 67P, the OSIRIS scientific imager (Optical, Spectroscopic, and Infrared Remote Imaging System, Keller et al. 2007) is successfully observing the nucleus with high spatial resolution in the 250-1000 nm range thanks to set of 26 dedicated filters.While 67P has a typical red spectral slope, the active areas tend to display bluer spectra (Sierks et al. 2015, Fornasier et al. 2015). We performed a spectral analysis of the active areas and derived spectral characteristics of them, possibly indicating the presence of material enriched in volatiles.The ‘activity thresholds’ spectral method (Oklay et al, 2015) is used for the identification of the active areas. In most cases, areas detected with this technique have been later on confirmed as active sources (Lara et al. 2015, Lin et al. 2015, Vincent et al. 2015) by direct detection of dust jets. This technique is therefore able to identify currently active areas, but also predicts which regions of the surface are likely to become activated once they receive enough insolation.Acknowledgements: OSIRIS was built by a consortium led by the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofi­sica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut für Datentechnik und Kommunikationsnetze der Technischen Universität Braunschweig, Germany. We thank the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission.Keller, et al. 2007, Space Sci. Rev., 128, 433Sierks et al. 2015, Science, 347,1Fornasier et al. 2015, A&A, published onlineLara et al. 2015, A&A, published onlineLin et al. 2015, A&A, published onlineVincent et al. 2015, A&A, submittedOklay et al. 2015, in preparation

Planetary data distribution by the French Plasma Physics Data Centre (CDPP): the example of Rosetta Plasma Consortium in the perspective of Solar Orbiter, Bepi-Colombo and JUICE

NASA Astrophysics Data System (ADS)

Génot, V.; Dufourg, N.; Bouchemit, M.; Budnik, E.; André, N.; Cecconi, B.; Gangloff, M.; Durand, J.; Pitout, F.; Jacquey, C.; Rouillard, A.; Jourdane, N.; Heulet, D.; Lavraud, B.; Modolo, R.; Garnier, P.; Louarn, P.; Henri, P.; Galand, M.; Beth, A.

2017-09-01

The French Plasma Physics Data Centre (CDPP, http://www.cdpp.eu/ ) has been addressing for almost the past 20 years all issues pertaining to natural plasma data distribution and valorization. Initially established by CNES and CNRS on the ground of a solid data archive, CDPP activities diversified with the advent of broader networks and interoperability standards, and through fruitful collaborations (e.g. with NASA/PDS). Providing access to remote data, designing and building science driven analysis tools then became at the forefront of CDPP developments. In the frame of data distribution, the CDPP has provided to the Rosetta Plasma Consortium (RPC), a suite of five different plasma sensors, with the possibility to visualize plasma data acquired by the Rosetta mission through its data analysis tool AMDA. AMDA was used during the operational phase of the Rosetta mission, facilitating data access between different Rosetta PI sensor teams, thus allowing 1/ a more efficient instruments operation planning and 2/ a better understanding of single instrument observations in the context of other sensor measurements and of more global observations. The data are now getting open to the public via the AMDA tool as they are released to the ESA/PSA. These in-situ data are complemented by model data, for instance, a solar wind propagation model (see http://heliopropa.irap.omp.eu ) or illumination maps of 67P (available through http://vespa.obspm.fr ). The CDPP also proposes 3D visualization tool for planetary / heliospheric environments which helps putting data in context (http://3dview.cdpp.eu ); for instance all comets and asteroids in a given volume and for a given time interval can be searched and displayed. From this fruitful experience the CDPP intends to play a similar role for the forthcoming data of the Solar Orbiter, Bepi-Colombo and JUICE missions as it is officially part of several instrument consortia. Beside highlighting the current database and products, the presentation will show how these future data could be presented and valorized through a combined use of the tools and models provided by the CDPP.

Rosetta/ROSINA observations of the volatiles in the coma of comet 67P/Churyumov-Gerasimenko during the nominal mission

NASA Astrophysics Data System (ADS)

Rubin, M.; Altwegg, K.; Balsiger, H. R.; Berthelier, J. J.; Calmonte, U.; De Keyser, J.; Fiethe, B.; Fuselier, S. A.; Gasc, S.; Gombosi, T. I.; Hässig, M.; Jäckel, A.; Le Roy, L.; Mall, U. A.; Rème, H.; Sémon, T.; Tzou, C. Y.; Wurz, P.

2015-12-01

The European Space Agency's Rosetta spacecraft is in close proximity of comet 67P/Churyumov-Gerasimenko for well over a year now. During this time Rosetta followed the comet from almost 3.5 AU through perihelion at 1.25 AU and away from the Sun again. Part of the scientific payload scrutinizing the comet is the ROSINA experiment, the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis. The suite of instruments consists of the Double Focusing Mass Spectrometer DFMS, the Reflectron Time-Of-Flight mass spectrometer RTOF, and the COmet Pressure Sensor COPS. From the combined measurements by ROSINA, the composition and dynamics of the volatiles in the coma of the comet are derived. On 13 August 2015, comet 67P/Churyumov-Gerasimenko reached perihelion, the point along its orbits that is closest to the Sun. Furthermore equinox occurred in May 2015 leading to a change in season - the previous summer hemisphere is now in winter and vice versa. One of the goals of ROSINA is to track the activity of the comet during its apparition and to investigate potential changes in the chemical composition as the spacecraft orbits around the nucleus. In this presentation we will summarize some key findings obtained during the first year and a half of the nominal mission and present first results comparing the pre- and post perihelion neutral gas coma. The goal of these observations is to gather information about the formation and the composition of the comet and ultimately our early Solar System.

Contingency Operations during Failure of Inertial Attitude Acquisition Due to Star Tracker Blinding for Three-Axes-Stabilized Interplanetary Spacecraft

NASA Technical Reports Server (NTRS)

Keil, Joachim; Herfort, Ulrich

2007-01-01

The three interplanetary ESA missions Mars-Express, Rosetta and Venus-Express (launched 2003, 2004 and 2005 resp.) are three-axes stabilized spacecraft (s/c) that estimate their inertial attitude (i.e. the attitude of the s/c w.r.t. the inertial frame) using measurements from a redundant set of star trackers (STR). Each s/c is equipped with four reaction wheels, a reaction control system based on thrusters and a redundant set of ring laser gyroscopes (gyros). The STR h/w layout of the three s/c is identical whereas there is a difference in the star pattern recognition algorithm of Rosetta which uses five neighbouring stars around a central star instead of star triads. The Rosetta algorithm has been implemented to cope with the presence of false stars which are expected to be seen during operations around the comet. The attitude acquisition capability from lost in space is different also in terms of AOCMS: The survival mode of Rosetta which is entered upon STR failure is presented. The AOCMS of Mars- and Venus-Express manages temporary STR outages during sky occultation by the planet not even by using redundancy. Though, a blinding of both STR during cruise lasting for the order of days confronts the ground operators with the limits of the AOCMS design. The operations and analyses that have been planned and partially been performed to compensate for the outage of the STR are demonstrated for Mars-Express. The caution measures taken before Venus orbit insertion of Venus-Express are detailed.

Comparative analysis of expert and machine-learning methods for classification of body cavity effusions in companion animals.

PubMed

Hotz, Christine S; Templeton, Steven J; Christopher, Mary M

2005-03-01

A rule-based expert system using CLIPS programming language was created to classify body cavity effusions as transudates, modified transudates, exudates, chylous, and hemorrhagic effusions. The diagnostic accuracy of the rule-based system was compared with that produced by 2 machine-learning methods: Rosetta, a rough sets algorithm and RIPPER, a rule-induction method. Results of 508 body cavity fluid analyses (canine, feline, equine) obtained from the University of California-Davis Veterinary Medical Teaching Hospital computerized patient database were used to test CLIPS and to test and train RIPPER and Rosetta. The CLIPS system, using 17 rules, achieved an accuracy of 93.5% compared with pathologist consensus diagnoses. Rosetta accurately classified 91% of effusions by using 5,479 rules. RIPPER achieved the greatest accuracy (95.5%) using only 10 rules. When the original rules of the CLIPS application were replaced with those of RIPPER, the accuracy rates were identical. These results suggest that both rule-based expert systems and machine-learning methods hold promise for the preliminary classification of body fluids in the clinical laboratory.

Hall effect in the coma of 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Huang, Z.; Tóth, G.; Gombosi, T. I.; Jia, X.; Combi, M. R.; Hansen, K. C.; Fougere, N.; Shou, Y.; Tenishev, V.; Altwegg, K.; Rubin, M.

2018-04-01

Magnetohydrodynamics simulations have been carried out in studying the solar wind and cometary plasma interactions for decades. Various plasma boundaries have been simulated and compared well with observations for comet 1P/Halley. The Rosetta mission, which studies comet 67P/Churyumov-Gerasimenko, challenges our understanding of the solar wind and comet interactions. The Rosetta Plasma Consortium observed regions of very weak magnetic field outside the predicted diamagnetic cavity. In this paper, we simulate the inner coma with the Hall magnetohydrodynamics equations and show that the Hall effect is important in the inner coma environment. The magnetic field topology becomes complex and magnetic reconnection occurs on the dayside when the Hall effect is taken into account. The magnetic reconnection on the dayside can generate weak magnetic field regions outside the global diamagnetic cavity, which may explain the Rosetta Plasma Consortium observations. We conclude that the substantial change in the inner coma environment is due to the fact that the ion inertial length (or gyro radius) is not much smaller than the size of the diamagnetic cavity.

A comparison between VEGA 1, 2 and Giotto flybys of comet 1P/Halley: implications for Rosetta

NASA Astrophysics Data System (ADS)

Volwerk, M.; Glassmeier, K.-H.; Delva, M.; Schmid, D.; Koenders, C.; Richter, I.; Szegö, K.

2014-11-01

Three flybys of comet 1P/Halley, by VEGA 1, 2 and Giotto, are investigated with respect to the occurrence of mirror mode waves in the cometosheath and field line draping in the magnetic pile-up region around the nucleus. The time interval covered by these flybys is approximately 8 days, which is also the approximate length of an orbit or flyby of Rosetta around comet 67P/Churyumov-Gerasimenko. Thus any significant changes observed around Halley are changes that might occur for Rosetta during one pass of 67P/CG. It is found that the occurrence of mirror mode waves in the cometosheath is strongly influenced by the dynamical pressure of the solar wind and the outgassing rate of the comet. Field line draping happens in the magnetic pile-up region. Changes in nested draping regions (i.e. regions with different Bx directions) can occur within a few days, possibly influenced by changes in the outgassing rate of the comet and thereby the conductivity of the cometary ionosphere.

A comparison between VEGA 1, 2 and Giotto flybys of comet 1P/Halley: Implications for Rosetta

NASA Astrophysics Data System (ADS)

Volwerk, Martin; Glassmeier, Karl-Heinz; Delva, Magda; Schmid, Daniel; Koenders, Christoph; Richter, Ingo; Szegö, Karoly

2015-04-01

Three flybys of comet 1P/Halley, by VEGA 1, 2 and Giotto, are investigated with respect to the occurrence of mirror mode waves in the cometosheath and field line draping in the magnetic pile-up region around the nucleus. The time interval covered by these flybys is approximately 8 days, which is also the approximate length of an orbit or flyby of Rosetta around comet 67P/Churyumov-Gerasimenko. Thus any significant changes observed around Halley are changes that might occur for Rosetta during one pass of 67P/CG. It is found that the occurrence of mirror mode waves in the cometosheath is strongly influenced by the dynamical pressure of the solar wind and the outgassing rate of the comet. Field line draping happens in the magnetic pile-up region. Changes in nested draping regions (i.e. regions with different Bx-directions) can occur within a few days, possibly in fluenced by changes in the outgassing rate of the comet and thereby the conductivity of the cometary ionosphere.

The Activity of Comet 67P/Churyumov-Gerasimenko as Seen by Rosetta/OSIRIS

NASA Astrophysics Data System (ADS)

Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Rickman, H.; Koschny, D.

2015-12-01

The Rosetta mission of the European Space Agency arrived on August 6, 2014, at the target comet 67P/Churyumov-Gerasimenko. OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) is the scientific imaging system onboard Rosetta. OSIRIS consists of a Narrow Angle Camera (NAC) for the nucleus surface and dust studies and a Wide Angle Camera (WAC) for the wide field gas and dust coma investigations. OSIRIS observed the coma and the nucleus of comet 67P/C-G during approach, arrival, and landing of PHILAE. OSIRIS continued comet monitoring and mapping of surface and activity in 2015 with close fly-bys with high resolution and remote, wide angle observations. The scientific results reveal a nucleus with two lobes and varied morphology. Active regions are located at steep cliffs and collapsed pits which form collimated gas jets. Dust is accelerated by the gas, forming bright jet filaments and the large scale, diffuse coma of the comet. We will present activity and surface changes observed in the Northern and Southern hemisphere and around perihelion passage.

Single-molecule FRET-Rosetta reveals RNA structural rearrangements during human telomerase catalysis

PubMed Central

Parks, Joseph W.; Kappel, Kalli; Das, Rhiju; Stone, Michael D.

2017-01-01

Maintenance of telomeres by telomerase permits continuous proliferation of rapidly dividing cells, including the majority of human cancers. Despite its direct biomedical significance, the architecture of the human telomerase complex remains unknown. Generating homogeneous telomerase samples has presented a significant barrier to developing improved structural models. Here we pair single-molecule Förster resonance energy transfer (smFRET) measurements with Rosetta modeling to map the conformations of the essential telomerase RNA core domain within the active ribonucleoprotein. FRET-guided modeling places the essential pseudoknot fold distal to the active site on a protein surface comprising the C-terminal element, a domain that shares structural homology with canonical polymerase thumb domains. An independently solved medium-resolution structure of Tetrahymena telomerase provides a blind test of our modeling methodology and sheds light on the structural homology of this domain across diverse organisms. Our smFRET-Rosetta models reveal nanometer-scale rearrangements within the RNA core domain during catalysis. Taken together, our FRET data and pseudoatomic molecular models permit us to propose a possible mechanism for how RNA core domain rearrangement is coupled to template hybrid elongation. PMID:28096444

Cometary dust at the smallest scale - latest results of the MIDAS Atomic Force Microscope onboard Rosetta

NASA Astrophysics Data System (ADS)

Bentley, Mark; Torkar, Klaus; Jeszenszky, Harald; Romstedt, Jens; Schmied, Roland; Mannel, Thurid

2015-04-01

The MIDAS instrument onboard the Rosetta orbit is a unique combination of a dust collection and handling system and a high resolution Atomic Force Microscope (AFM). By building three-dimensional images of the dust particle topography, MIDAS addresses a range of fundamental questions in Solar System and cometary science. The first few months of dust collection and scanning revealed a deficit of smaller (micron and below) particles but eventually several 10 µm-class grains were discovered. In fact these were unexpectedly large and close to the limit of what is observable with MIDAS. As a result the sharp tip used by the AFM struck the particles from the side, causing particle breakage and distortion. Analyses so far suggest that the collected particles are fluffy aggregates of smaller sub-units, although determination of the size of these sub-units and high resolution re-imaging remains to be done. The latest findings will be presented here, including a description of the particles collected and the implications of these observations for cometary science and the Rosetta mission at comet 67P.

Analysis of the Cometary Plasma Environment of 67P/Churyumov-Gerasimenko Near Perihelion

NASA Astrophysics Data System (ADS)

Ostaszewski, K.; Goetz, C.; Motschmann, U.; Glassmeier, K. H.

2017-09-01

Over the course of its two year escort phase the Rosetta spacecraft has provided various observations that furthered our understanding of the cometary plasma environment. The use of numerical simulations is essential for this understanding because they allow to place the in situ measurements in a global context, in turn, through observations the numerical models can be ex- tended and improved. We use the simulation code A.I.K.E.F (Müller [7]) to simulate the cometary plasma environment of 67P/Churyumov-Gerasimenko (67P/CG). Based on observations made by the Rosetta spacecraft we extend the numerical model by electron impact ionization and the anisotropic outgassing model by Hansen et al. (2016). Both extensions result in an increase in the cometary ion production rate on the dayside. Therefore, the size of the interaction region and the contained structures increases. This causes the position of the different boundaries, e.g. bow shock, to shift further away from the comet. Considering this we can explain why no bow shock crossings could be observed during the dayside excursion of Rosetta in September 2015.

Microbial Efflux Systems and Inhibitors: Approaches to Drug Discovery and the Challenge of Clinical Implementation

PubMed Central

Kourtesi, Christina; Ball, Anthony R; Huang, Ying-Ying; Jachak, Sanjay M; Vera, D Mariano A; Khondkar, Proma; Gibbons, Simon; Hamblin, Michael R; Tegos, George P

2013-01-01

Conventional antimicrobials are increasingly ineffective due to the emergence of multidrug-resistance among pathogenic microorganisms. The need to overcome these deficiencies has triggered exploration for novel and unconventional approaches to controlling microbial infections. Multidrug efflux systems (MES) have been a profound obstacle in the successful deployment of antimicrobials. The discovery of small molecule efflux system blockers has been an active and rapidly expanding research discipline. A major theme in this platform involves efflux pump inhibitors (EPIs) from natural sources. The discovery methodologies and the available number of natural EPI-chemotypes are increasing. Advances in our understanding of microbial physiology have shed light on a series of pathways and phenotypes where the role of efflux systems is pivotal. Complementing existing antimicrobial discovery platforms such as photodynamic therapy (PDT) with efflux inhibition is a subject under investigation. This core information is a stepping stone in the challenge of highlighting an effective drug development path for EPIs since the puzzle of clinical implementation remains unsolved. This review summarizes advances in the path of EPI discovery, discusses potential avenues of EPI implementation and development, and underlines the need for highly informative and comprehensive translational approaches. PMID:23569468

Advantages of using microbial technology over traditional chemical technology in removal of black crusts from stone surfaces of historical monuments.

PubMed

Cappitelli, Francesca; Toniolo, Lucia; Sansonetti, Antonio; Gulotta, Davide; Ranalli, Giancarlo; Zanardini, Elisabetta; Sorlini, Claudia

2007-09-01

This study compares two cleaning methods, one involving an ammonium carbonate-EDTA mixture and the other involving the sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, for the removal of black crust (containing gypsum) on marble of the Milan Cathedral (Italy). In contrast to the chemical cleaning method, the biological procedure resulted in more homogeneous removal of the surface deposits and preserved the patina noble under the black crust. Whereas both of the treatments converted gypsum to calcite, allowing consolidation, the chemical treatment also formed undesirable sodium sulfate.

Advantages of Using Microbial Technology over Traditional Chemical Technology in Removal of Black Crusts from Stone Surfaces of Historical Monuments▿

PubMed Central

Cappitelli, Francesca; Toniolo, Lucia; Sansonetti, Antonio; Gulotta, Davide; Ranalli, Giancarlo; Zanardini, Elisabetta; Sorlini, Claudia

2007-01-01

This study compares two cleaning methods, one involving an ammonium carbonate-EDTA mixture and the other involving the sulfate-reducing bacterium Desulfovibrio vulgaris subsp. vulgaris ATCC 29579, for the removal of black crust (containing gypsum) on marble of the Milan Cathedral (Italy). In contrast to the chemical cleaning method, the biological procedure resulted in more homogeneous removal of the surface deposits and preserved the patina noble under the black crust. Whereas both of the treatments converted gypsum to calcite, allowing consolidation, the chemical treatment also formed undesirable sodium sulfate. PMID:17601804

A Search for Rarely Seen Ultraviolet Coma Emissions and New Species Upper Limits at Comet 67P/Churyumov-Gerasimenko Using the Rosetta-Alice Ultraviolet Spectrograph

NASA Astrophysics Data System (ADS)

Noonan, J.; Stern, S. A.; Parker, J. W.; Keeney, B. A.; Weaver, H. A., Jr.; Feldman, P.; Steffl, A.; Feaga, L. M.; Bertaux, J. L.

2017-12-01

The Alice far/extreme-UV spectrograph aboard Rosetta is one of three US instruments provided by NASA; it is the first UV spectrograph to reach any comet. Numerous scientific results have been obtained regarding 67P/Churyumov-Gerasimenko by this instrument. Here we summarize two new sets of results from a search for rarely appearing atomic and molecular spectral emission features and a grand sum spectrum allowing us to place new atomic and molecular neutral and ionized species upper limits in the comet's coma.

Rosetta Mission's "7 Hours of Terror" and Philae's Descent

NASA Astrophysics Data System (ADS)

Blanco, Philip

2015-09-01

In November 2014 the Rosetta mission to Comet 67P/Churyumov-Gerasimenko made the headlines when its Philae lander completed a successful unpowered descent onto the surface of the comet nucleus after "7 hours of terror" for the mission scientists. 67P's irregular shape and rotation made this task even more challenging. Philae fell almost radially towards 67P, as shown in an animation produced by the European Space Agency (ESA) prior to the event. Below, we investigate whether it is possible to model the spacecraft's descent time and impact speed using concepts taught in an introductory physics course.

Analysis of Rosetta/VIRTIS spectra of earth using observations from ENVISAT/AATSR, TERRA/MODIS and ENVISAT/SCIAMACHY, and radiative-transfer simulations

NASA Astrophysics Data System (ADS)

Hurley, J.; Irwin, P. G. J.; Adriani, A.; Moriconi, M.; Oliva, F.; Capaccioni, F.; Smith, A.; Filacchione, G.; Tosi, F.; Thomas, G.

2014-01-01

Rosetta, the Solar System cornerstone mission of ESA's Horizon 2000 programme, consists of an orbiter and a lander, and is due to arrive at the comet 67P/Churyumov-Gerasimenko in May 2014. Following its 2004 launch, Rosetta carried out a series of planetary fly-bys and gravitational assists. On these close fly-bys of the Earth, measurements were taken by the Visible Infrared Thermal Imaging Spectrometer (VIRTIS). Analysis of these spectra and comparison with spectra acquired by Earth-observing satellites can support the verification of the inflight calibration of Rosetta/VIRTIS. In this paper, measurements taken by VIRTIS in November 2009 are compared with suitable coincident data from Earth-observing instruments (ESA-ENVISAT/AATSR and SCIAMACHY, and EOS-TERRA/MODIS). Radiative transfer simulations using NEMESIS (Irwin et al., 2008) are fit to the fly-by data taken by VIRTIS, using representative atmospheric and surface parameters. VIRTIS measurements correlate 90% with AATSR's, 85-94% with MODIS, and 82-88% with SCIAMACHYs. The VIRTIS spectra are reproducible in the 1-5 μm region, except in the 1.4 μm deep water vapour spectral absorption band in the near-infrared in cases in which the radiance is very low (cloud-free topographies), where VIRTIS consistently registers more radiance than do MODIS and SCIAMACHY. Over these cloud-free regions, VIRTIS registers radiances a factor of 3-10 larger than SCIAMACHY and of 3-8 greater than MODIS. It is speculated that this discrepancy could be due to a spectral light leak originating from reflections from the order-sorting filters above the detector around 1.4 μm.

Vertical structure of the near-surface expanding ionosphere of comet 67P probed by Rosetta

NASA Astrophysics Data System (ADS)

Heritier, K. L.; Henri, P.; Vallières, X.; Galand, M.; Odelstad, E.; Eriksson, A. I.; Johansson, F. L.; Altwegg, K.; Behar, E.; Beth, A.; Broiles, T. W.; Burch, J. L.; Carr, C. M.; Cupido, E.; Nilsson, H.; Rubin, M.; Vigren, E.

2017-07-01

The plasma environment has been measured for the first time near the surface of a comet. This unique data set has been acquired at 67P/Churyumov-Gerasimenko during ESA/Rosetta spacecraft's final descent on 2016 September 30. The heliocentric distance was 3.8 au and the comet was weakly outgassing. Electron density was continuously measured with Rosetta Plasma Consortium (RPC)-Mutual Impedance Probe (MIP) and RPC-LAngmuir Probe (LAP) during the descent from a cometocentric distance of 20 km down to the surface. Data set from both instruments have been cross-calibrated for redundancy and accuracy. To analyse this data set, we have developed a model driven by Rosetta Orbiter Spectrometer for Ion and Neutral Analysis-COmetary Pressure Sensor total neutral density. The two ionization sources considered are solar extreme ultraviolet radiation and energetic electrons. The latter are estimated from the RPC-Ion and Electron Sensor (IES) and corrected for the spacecraft potential probed by RPC-LAP. We have compared the results of the model to the electron densities measured by RPC-MIP and RPC-LAP at the location of the spacecraft. We find good agreement between observed and modelled electron densities. The energetic electrons have access to the surface of the nucleus and contribute as the main ionization source. As predicted, the measurements exhibit a peak in the ionospheric density close to the surface. The location and magnitude of the peak are estimated analytically. The measured ionospheric densities cannot be explained with a constant outflow velocity model. The use of a neutral model with an expanding outflow is critical to explain the plasma observations.

Rosetta: Ensuring the Preservation and Usability of ASCII-based Data into the Future

NASA Astrophysics Data System (ADS)

Ramamurthy, M. K.; Arms, S. C.

2015-12-01

Field data obtained from dataloggers often take the form of comma separated value (CSV) ASCII text files. While ASCII based data formats have positive aspects, such as the ease of accessing the data from disk and the wide variety of tools available for data analysis, there are some drawbacks, especially when viewing the situation through the lens of data interoperability and stewardship. The Unidata data translation tool, Rosetta, is a web-based service that provides an easy, wizard-based interface for data collectors to transform their datalogger generated ASCII output into Climate and Forecast (CF) compliant netCDF files following the CF-1.6 discrete sampling geometries. These files are complete with metadata describing what data are contained in the file, the instruments used to collect the data, and other critical information that otherwise may be lost in one of many README files. The choice of the machine readable netCDF data format and data model, coupled with the CF conventions, ensures long-term preservation and interoperability, and that future users will have enough information to responsibly use the data. However, with the understanding that the observational community appreciates the ease of use of ASCII files, methods for transforming the netCDF back into a CSV or spreadsheet format are also built-in. One benefit of translating ASCII data into a machine readable format that follows open community-driven standards is that they are instantly able to take advantage of data services provided by the many open-source data server tools, such as the THREDDS Data Server (TDS). While Rosetta is currently a stand-alone service, this talk will also highlight efforts to couple Rosetta with the TDS, thus allowing self-publishing of thoroughly documented datasets by the data producers themselves.

Assessing the Age of an Asteroid's Surface with Data from the International Rosetta Mission

NASA Technical Reports Server (NTRS)

Lopez, Juan Carlos

2011-01-01

Rosetta is an international mission led by the European Space Agency (ESA) with key support and instrumentation from the National Aeronautics and Space Administration (NASA). Rosetta is currently on a ten-year mission to catch comet 67P/Churyumov-Gerasimenko (C-G); throughout its voyage, the spacecraft has performed flybys of two main belt asteroids (MBA): Steins and Lutetia. Data on the physical, chemical, and geological properties of these asteroids are currently being processed and analyzed. Accurate interpretation of such data is fundamental in the success of Rosetta's mission and overall objectives. Post-flyby data analyses strive to correlate the size, shape, volume, and rotational rate of Lutetia, in addition to interpreting its multi-color imagining, albedo, and spectral mapping. Although advancements in science have contributed to the examination of celestial bodies, methods to analyze asteroids remain largely empirical, not semi-empirical, nor ab initio. This study aims to interpret and document the scientific methods currently utilized in the characterization of asteroid (21) Lutetia in order to render these processes and methods accessible to the public. Examples include a standardized technique for assessing the age of an asteroid surface, complete with clickable reference maps, methodology of grouping surface characteristics together, and a standardized power law equation for the age. Other examples include determining the density of an object. Context for what both density and age mean is a bi-product of this study. Results of the study will aid in the development of pedagogical material on asteroids for public use, and in creation of an academic database for selected targets that might be used as a reference.

Science operations planning and implementation for Rosetta

NASA Astrophysics Data System (ADS)

Koschny, Detlef; Sweeney, Mark; Montagon, Elsa; Hoofs, Raymond; van der Plas, Peter

2002-07-01

The Rosetta mission is a cornerstone mission of the Horizon 2000 programme of the European Space Agency. It will be launched to comet 46P/Wirtanen in January 2003. This mission is the first of a series of planetary missions, including Mars Express, Smart-I (to the Moon), and BepiColombo (to Mercury). All these missions have similar requirements for their scientific operations. The Experiments H/W and S/W are developed by Principal Investigators, working at scientific institutes. They are also responsible for the operation of their experiments and for the generation of related operational documentation. The Science Operations Centre (SOC) has the task to consolidate the inputs of the different experimenters and the Lander and ensure that the resulting science operations timeline is free of conflicts. It forwards this timeline to the Mission Operations Centre (MOC) which combines the science operations with the operations of the other spacecraft subsystems and the orbit and attitude of the spacecraft. The MOC is also responsible for uplinking the operational command sequences to the spacecraft and for returning the received telemetry to the user. In a collaboration between the team of the Rosetta Project Scientist at the Research and Science Support Department of ESA/ESTEC and the European Space Operations Centre (ESA/ESOC), a concept for the SOC/MOC and their interfaces was developed for the Rosetta mission. This concept is generic enough to allow its implementation also for the other planetary missions. The design phase is now complete, and implementation is on-going. This paper briefly presents the architecture of the complex ground segment, concentrating on the elements required for planning of scientific operations, and then details the software tools EPS (Experiment Planning System) and PTB (Project Test Bed) which are used in the planning process.

Comet 67P Seen by Kepler

NASA Image and Video Library

2016-10-07

The European Space Agency's Rosetta mission concluded its study of comet 67P/Churyumov-Gerasimenko on Sept. 30, 2016. NASA's planet-hunting Kepler spacecraft observed the comet during the final month of the Rosetta mission, while the comet was not visible from Earth. This animation is composed of images from Kepler of the comet. From Sept. 7 through Sept. 20, the Kepler spacecraft, operating in its K2 mission, fixed its gaze on comet 67P. From the distant vantage point of Kepler, the comet's nucleus and tail could be observed. The long-range view from Kepler complements the closeup view of the Rosetta spacecraft, providing context for the high-resolution investigation Rosetta performed as it descended closer and closer to the comet. During the two-week period of study, Kepler took a picture of the comet every 30 minutes. The animation shows a period of 29.5 hours of observation from Sept. 17 thru Sept. 18. The comet is seen passing through Kepler's field of view from top right to bottom left, as outlined by the diagonal strip. The white dots represent stars and other regions in space studied during K2's tenth observing campaign. As a comet travels through space it sheds a tail of gas and dust. The more material that is shed, the more surface area there is to reflect sunlight. A comet's activity level can be obtained by measuring the reflected sunlight. Analyzing the Kepler data, scientists will be able to determine the amount of mass lost each day as comet 67P travels through the solar system. An animation is available at http://photojournal.jpl.nasa.gov/catalog/PIA21072

The dust environment of 67P/Churyumov-Gerasimenko as seen through Rosetta/OSIRIS

NASA Astrophysics Data System (ADS)

Tubiana, Cecilia; Bertini, Ivano; Deller, Jakob; Drolshagen, Esther; Frattin, Elisa; Güttler, Carsten; Hofmann, Marc; Koschny, Detlef; Oklay, Nilda; Ott, Theresa; Shi, Xian; Sierks, Holger; Vincent, Jean-Baptiste; OSIRIS Team

2016-10-01

The ESA's Rosetta spacecraft had the unique opportunity to stay in the vicinity of the comet for two years, observing how the comet evolved while approaching the Sun, passing through perihelion and then moving outwards. OSIRIS, the Optical, Spectroscopic, and Infrared Remote Imaging System onboard Rosetta, imaged the nucleus and the dust environment of 67/Churyumov-Gerasimenko since the beginning of post-hibernation operations in March 2014. We focus here on dust studies carried on with OSIRIS.Images obtained in different filters in the visible wavelength range have been used to study the unresolved dust coma, investigating its diurnal and seasonal variations and providing insights into the dust composition. A correlation has been found between the level of diurnal activity and the region of the nucleus surface in sunlight, suggesting that the topography and/or composition of the surface play an important role. The overall activity increases while the comet is approaching the Sun, peaking about a month after perihelion. Comparison with ground-based observations will allow to understand if the dust coma behaves in similar ways at small scales - as observed by Rosetta/OSIRIS - and at large scales - as observed from ground. Several times during the mission, we acquired images spanning the phase angle range 0-165 degrees. They are used to determine the dust phase function in different wavelengths, its evolution with heliocentric distance and to investigate the intimate nature of cometary dust aggregates by solving the inverse scattering problem. A large amount of individual aggregates is present in the vicinity of 67P/Churyumov-Gerasimenko. We used OSIRIS NAC and WAC images to determine the aggregate properties: size and distance distributions, colors and rotation. Thanks to observations performed at different heliocentric distances, we address how those properties are changing with heliocentric distance.

Evolution of Icy Dust Grains in the Vicinity of a Cometary Nucleus

NASA Astrophysics Data System (ADS)

Hilchenbach, M.

2009-12-01

From late 2014 onwards, ESA's cornerstone mission ROSETTA will orbit the comet 67P/Churyumov-Gerasimenko. One instrument, COSIMA, will collect cometary dust grains and analyze the grains via secondary mass spectrometry. Models of the evolution of icy dust, accelerated by drag forces of subliming gas and exposed to solar radiation, should set constrains on the detection limits of the COSIMA instrument for volatile icy components. A straightforward modeling approach is applied as a baseline for the observational planing schedule of the instrument operations in the years 2014/2015 as ROSETTA escorts the comet nucleus up to perihelion and beyond.

Magnetic field investigations during ROSETTA's 2867 Šteins flyby

NASA Astrophysics Data System (ADS)

Auster, H. U.; Richter, I.; Glassmeier, K. H.; Berghofer, G.; Carr, C. M.; Motschmann, U.

2010-07-01

During the 2867 Šteins flyby of the ROSETTA spacecraft on September 5, 2008 magnetic field measurements have been made with both the RPC orbiter magnetometer and the ROMAP lander magnetometer. These combined magnetic field measurements allow a detailed examination of any magnetic signatures caused either directly by the asteroid or indirectly by Šteins' different modes of interaction with the solar wind. Comparing measurements with simulation results show that Šteins does not posses a significant remanent magnetization. The magnetization is estimated at less than 10 -3 A m 2/kg. This is significantly different from results at 9969 Braille and 951 Gaspra.

Modeling the Structure of Helical Assemblies with Experimental Constraints in Rosetta.

PubMed

André, Ingemar

2018-01-01

Determining high-resolution structures of proteins with helical symmetry can be challenging due to limitations in experimental data. In such instances, structure-based protein simulations driven by experimental data can provide a valuable approach for building models of helical assemblies. This chapter describes how the Rosetta macromolecular package can be used to model homomeric protein assemblies with helical symmetry in a range of modeling scenarios including energy refinement, symmetrical docking, comparative modeling, and de novo structure prediction. Data-guided structure modeling of helical assemblies with experimental information from electron density, X-ray fiber diffraction, solid-state NMR, and chemical cross-linking mass spectrometry is also described.

Model-Observation Comparisons of Electron Number Densities in the Coma of 67P/Churyumov-Gerasimenko during January 2015

NASA Astrophysics Data System (ADS)

Vigren, E.; Altwegg, K.; Edberg, N. J. T.; Eriksson, A. I.; Galand, M.; Henri, P.; Johansson, F.; Odelstad, E.; Tzou, C.-Y.; Valliéres, X.

2016-09-01

During 2015 January 9-11, at a heliocentric distance of ˜2.58-2.57 au, the ESA Rosetta spacecraft resided at a cometocentric distance of ˜28 km from the nucleus of comet 67P/Churyumov-Gerasimenko, sweeping the terminator at northern latitudes of 43°N-58°N. Measurements by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis/Comet Pressure Sensor (ROSINA/COPS) provided neutral number densities. We have computed modeled electron number densities using the neutral number densities as input into a Field Free Chemistry Free model, assuming H2O dominance and ion-electron pair formation by photoionization only. A good agreement (typically within 25%) is found between the modeled electron number densities and those observed from measurements by the Mutual Impedance Probe (RPC/MIP) and the Langmuir Probe (RPC/LAP), both being subsystems of the Rosetta Plasma Consortium. This indicates that ions along the nucleus-spacecraft line were strongly coupled to the neutrals, moving radially outward with about the same speed. Such a statement, we propose, can be further tested by observations of H3O+/H2O+ number density ratios and associated comparisons with model results.

Effective ion speeds at ˜200-250 km from comet 67P/Churyumov-Gerasimenko near perihelion

NASA Astrophysics Data System (ADS)

Vigren, E.; André, M.; Edberg, N. J. T.; Engelhardt, I. A. D.; Eriksson, A. I.; Galand, M.; Goetz, C.; Henri, P.; Heritier, K.; Johansson, F. L.; Nilsson, H.; Odelstad, E.; Rubin, M.; Stenberg-Wieser, G.; Tzou, C.-Y.; Vallières, X.

2017-07-01

In 2015 August, comet 67P/Churyumov-Gerasimenko, the target comet of the ESA Rosetta mission, reached its perihelion at ˜1.24 au. Here, we estimate for a three-day period near perihelion, effective ion speeds at distances ˜200-250 km from the nucleus. We utilize two different methods combining measurements from the Rosetta Plasma Consortium (RPC)/Mutual Impedance Probe with measurements either from the RPC/Langmuir Probe or from the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Comet Pressure Sensor (COPS) (the latter method can only be applied to estimate the effective ion drift speed). The obtained ion speeds, typically in the range 2-8 km s-1, are markedly higher than the expected neutral outflow velocity of ˜1 km s-1. This indicates that the ions were de-coupled from the neutrals before reaching the spacecraft location and that they had undergone acceleration along electric fields, not necessarily limited to acceleration along ambipolar electric fields in the radial direction. For the limited time period studied, we see indications that at increasing distances from the nucleus, the fraction of the ions' kinetic energy associated with radial drift motion is decreasing.

Cloning and expression of Clostridium perfringens type D vaccine strain epsilon toxin gene in E. coli as a recombinant vaccine candidate.

PubMed

Aziminia, Parastoo; Pilehchian-Langroudi, Reza; Esmaeilnia, Kasra

2016-08-01

Clostridium perfringens, a Gram-positive obligate anaerobic bacterium, is able to form resistant spores which are widely distributed in the environment. C. perfringens is subdivided into five types A to E based on its four major alpha, beta, epsilon and iota toxins. The aim of the present study was cloning and expression of C. perfringens type D vaccine strain epsilon toxin gene. Genomic DNA was extracted and the epsilon toxin gene was amplified using Pfu DNA polymerase. The PCR product was cloned into pJET1.2/blunt cloning vector. The recombinant vector (pJETε) was sequenced using universal primers. At the next step epsilon toxin gene was subcloned into pET22b(+) expression vector and transformed into E. coli Rosetta (DE3) host strain. The recombinant protein has been expressed in E. coli Rosetta (DE3) cells after subcloning of C. perfringens etx gene (1008 bp) into the expression vector. We concluded that E. coli Rosetta strain was suitable for the expression of recombinant C. perfringens epsilon toxin protein from pET22ε expression vector. This recombinant cell can be used for further research on recombinant vaccine development.

Archiving for Rosetta: Lessons for IPDA

NASA Astrophysics Data System (ADS)

Heather, David

The Rosetta Project is unusual, possibly unique, in that all data must be archived both in NASA's Planetary Data System (PDS), and in ESA's Planetary Science Archive (PSA), ac-cording to an inter-agency agreement that predates the existence of ESA's PSA. This requires that all data are formatted according to NASA's PDS3 Standards. Scientific peer reviews of the data content for Rosetta have been carried out both in the US and in Europe and there was a very large overlap of the issues raised, illustrating the general scientific agreement, independent of geography, in what an archive must contain to be useful to the broader community of planetary scientists. However, validation of the data against the PDS Standards using both PSA and PDS devel-oped software has led to the discovery that many of the items that are validated are unstated assumptions in the written PDS Standards and are related, at least in large part, to how the two archiving systems operate rather than to the actual content that a scientist needs to use the data. The talk will illustrate some of these discrepancies with examples and suggest how to avoid such issues in future, optimizing the scientific return on the investment in archiving while minimizing the costs.

Diurnal and seasonal variations of gas emissions in the inner coma of comet 67P/Churyumov-Gerasimenko observed with OSIRIS/Rosetta

NASA Astrophysics Data System (ADS)

La Forgia, F.; Lazzarin, M.; Bodewits, D.; A'Hearn, M. F.; Bertini, I.; Penasa, L.; Naletto, G.; Cremonese, G.; Massironi, M.; Ferri, F.; Frattin, E.; Lucchetti, A.; Ferrari, S.; Barbieri, C.

2017-09-01

The gas filters of OSIRIS/Wide Angle Camera (WAC) on board Rosetta spacecraft allowed to study the gaseous emissions of the inner coma of comet 67P/Churyumov-Gerasimenko. OH, NH, CN, NH2 and OI gas species have been monitored between January and September 2015, i.e. from 2.47 AU pre-perihelion, to 1.37 AU post-perihelion, allowing the study of seasonal variations. Each gas sequence covers slightly more than one comet rotation period allowing also the study of diurnal changes. We measured the gas column density between 1 and 3 km from the nucleus limb in the sunward direction. Results will be presented on the gas diurnal light curves and on the long-term variations such as the dependence and correlation with time, heliocentric distance, range, phase angle and sub-solar point. Gas ratios are studied searching for evidence of any compositional change with time and orbital evolution. We searched for connections between particular "active zones" on the nucleus surface. This study will be helpful in connecting ground based observations of 67P with Rosetta in situ observations.

Ion acoustic waves at comet 67P/Churyumov-Gerasimenko. Observations and computations

NASA Astrophysics Data System (ADS)

Gunell, H.; Nilsson, H.; Hamrin, M.; Eriksson, A.; Odelstad, E.; Maggiolo, R.; Henri, P.; Vallieres, X.; Altwegg, K.; Tzou, C.-Y.; Rubin, M.; Glassmeier, K.-H.; Stenberg Wieser, G.; Simon Wedlund, C.; De Keyser, J.; Dhooghe, F.; Cessateur, G.; Gibbons, A.

2017-04-01

Context. On 20 January 2015 the Rosetta spacecraft was at a heliocentric distance of 2.5 AU, accompanying comet 67P/Churyumov-Gerasimenko on its journey toward the Sun. The Ion Composition Analyser (RPC-ICA), other instruments of the Rosetta Plasma Consortium, and the ROSINA instrument made observations relevant to the generation of plasma waves in the cometary environment. Aims: Observations of plasma waves by the Rosetta Plasma Consortium Langmuir probe (RPC-LAP) can be explained by dispersion relations calculated based on measurements of ions by the Rosetta Plasma Consortium Ion Composition Analyser (RPC-ICA), and this gives insight into the relationship between plasma phenomena and the neutral coma, which is observed by the Comet Pressure Sensor of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument (ROSINA-COPS). Methods: We use the simple pole expansion technique to compute dispersion relations for waves on ion timescales based on the observed ion distribution functions. These dispersion relations are then compared to the waves that are observed. Data from the instruments RPC-LAP, RPC-ICA and the mutual impedance probe (RPC-MIP) are compared to find the best estimate of the plasma density. Results: We find that ion acoustic waves are present in the plasma at comet 67P/Churyumov-Gerasimenko, where the major ion species is H2O+. The bulk of the ion distribution is cold, kBTI = 0.01 eV when the ion acoustic waves are observed. At times when the neutral density is high, ions are heated through acceleration by the solar wind electric field and scattered in collisions with the neutrals. This process heats the ions to about 1 eV, which leads to significant damping of the ion acoustic waves. Conclusions: In conclusion, we show that ion acoustic waves appear in the H2O+ plasmas at comet 67P/Churyumov-Gerasimenko and how the interaction between the neutral and ion populations affects the wave properties. Computer code for the dispersion analysis is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/600/A3

GIADA On-Board Rosetta: Early Dust Grain Detections and Dust Coma Characterization of Comet 67P/C-G

NASA Astrophysics Data System (ADS)

Rotundi, A.; Della Corte, V.; Accolla, M.; Ferrari, M.; Ivanovski, S.; Lucarelli, F.; Mazzotta Epifani, E.; Sordini, R.; Palumbo, P.; Colangeli, L.; Lopez-Moreno, J. J.; Rodriguez, J.; Fulle, M.; Bussoletti, E.; Crifo, J. F.; Esposito, F.; Green, S.; Grün, E.; Lamy, P. L.; McDonnell, T.; Mennella, V.; Molina, A.; Moreno, F.; Ortiz, J. L.; Palomba, E.; Perrin, J. M.; Rodrigo, R.; Weissman, P. R.; Zakharov, V.; Zarnecki, J.

2014-12-01

GIADA (Grain Impact Analyzer and Dust Accumulator) flying on-board Rosetta is devoted to study the cometary dust environment of 67P/Churiumov-Gerasimenko. GIADA is composed of 3 sub-systems: the GDS (Grain Detection System), based on grain detection through light scattering; an IS (Impact Sensor), giving momentum measurement detecting the impact on a sensed plate connected with 5 piezoelectric sensors; the MBS (MicroBalances System), constituted of 5 Quartz Crystal Microbalances (QCMs), giving cumulative deposited dust mass by measuring the variations of the sensors' frequency. The combination of the measurements performed by these 3 subsystems provides: the number, the mass, the momentum and the velocity distribution of dust grains emitted from the cometary nucleus.No prior in situ dust dynamical measurements at these close distances from the nucleus and starting from such large heliocentric distances are available up to date. We present here the first results obtained from the beginning of the Rosetta scientific phase. We will report dust grains early detection at about 800 km from the nucleus in August 2014 and the following measurements that allowed us characterizing the 67P/C-G dust environment at distances less than 100 km from the nucleus and single grains dynamical properties. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF-Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developped from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site (www.rssd.esa.int/index.php?project=PSA&page=index). Thanks Angioletta.

Biodegradation of Methyl Tertiary Butyl Ether (MTBE) by a Microbial Consortium in a Continuous Up-Flow Packed-Bed Biofilm Reactor: Kinetic Study, Metabolite Identification and Toxicity Bioassays

PubMed Central

Alfonso-Gordillo, Guadalupe; Flores-Ortiz, César Mateo; Morales-Barrera, Liliana

2016-01-01

This study investigated the aerobic biodegradation of methyl tertiary-butyl ether (MTBE) by a microbial consortium in a continuous up-flow packed-bed biofilm reactor using tezontle stone particles as a supporting material for the biofilm. Although MTBE is toxic for microbial communities, the microbial consortium used here was able to resist MTBE loading rates up to 128.3 mg L-1 h-1, with removal efficiencies of MTBE and chemical oxygen demand (COD) higher than 90%. A linear relationship was observed between the MTBE loading rate and the MTBE removal rate, as well as between the COD loading rate and the COD removal rate, within the interval of MTBE loading rates from 11.98 to 183.71 mg L-1 h-1. The metabolic intermediate tertiary butyl alcohol (TBA) was not detected in the effluent during all reactor runs, and the intermediate 2-hydroxy butyric acid (2-HIBA) was only detected at MTBE loading rates higher than 128.3 mg L-1 h-1. The results of toxicity bioassays with organisms from two different trophic levels revealed that the toxicity of the influent was significantly reduced after treatment in the packed-bed reactor. The packed-bed reactor system used in this study was highly effective for the continuous biodegradation of MTBE and is therefore a promising alternative for detoxifying MTBE-laden wastewater and groundwater. PMID:27907122

Biodegradation of Methyl Tertiary Butyl Ether (MTBE) by a Microbial Consortium in a Continuous Up-Flow Packed-Bed Biofilm Reactor: Kinetic Study, Metabolite Identification and Toxicity Bioassays.

PubMed

Alfonso-Gordillo, Guadalupe; Flores-Ortiz, César Mateo; Morales-Barrera, Liliana; Cristiani-Urbina, Eliseo

2016-01-01

This study investigated the aerobic biodegradation of methyl tertiary-butyl ether (MTBE) by a microbial consortium in a continuous up-flow packed-bed biofilm reactor using tezontle stone particles as a supporting material for the biofilm. Although MTBE is toxic for microbial communities, the microbial consortium used here was able to resist MTBE loading rates up to 128.3 mg L-1 h-1, with removal efficiencies of MTBE and chemical oxygen demand (COD) higher than 90%. A linear relationship was observed between the MTBE loading rate and the MTBE removal rate, as well as between the COD loading rate and the COD removal rate, within the interval of MTBE loading rates from 11.98 to 183.71 mg L-1 h-1. The metabolic intermediate tertiary butyl alcohol (TBA) was not detected in the effluent during all reactor runs, and the intermediate 2-hydroxy butyric acid (2-HIBA) was only detected at MTBE loading rates higher than 128.3 mg L-1 h-1. The results of toxicity bioassays with organisms from two different trophic levels revealed that the toxicity of the influent was significantly reduced after treatment in the packed-bed reactor. The packed-bed reactor system used in this study was highly effective for the continuous biodegradation of MTBE and is therefore a promising alternative for detoxifying MTBE-laden wastewater and groundwater.

Revision of Eocene Antarctic carpet sharks (Elasmobranchii, Orectolobiformes) from Seymour Island, Antarctic Peninsula.

PubMed

Engelbrecht, Andrea; Mörs, Thomas; Reguero, Marcelo A; Kriwet, Jürgen

2017-01-01

Seymour Island, Antarctic Peninsula, was once called the 'Rosetta Stone' of Southern Hemisphere palaeobiology, because this small island provides the most complete and richly fossiliferous Palaeogene sequence in Antarctica. Among fossil marine vertebrate remains, chondrichthyans seemingly were dominant elements in the Eocene Antarctic fish fauna. The fossiliferous sediments on Seymour Island are from the La Meseta Formation, which was originally divided into seven stratigraphical levels, TELMs 1-7 (acronym for Tertiary Eocene La Meseta) ranging from the upper Ypresian (early Eocene) to the late Priabonian (late Eocene). Bulk sampling of unconsolidated sediments from TELMs 5 and 6, which are Ypresian (early Eocene) and Lutetian (middle Eocene) in age, respectively, yielded very rich and diverse chondrichthyan assemblages including over 40 teeth of carpet sharks representing two new taxa, Notoramphoscyllium woodwardi gen. et sp. nov. and Ceolometlaouia pannucae gen. et sp. nov. Two additional teeth from TELM 5 represent two different taxa that cannot be assigned to any specific taxon and thus are left in open nomenclature. The new material not only increases the diversity of Eocene Antarctic selachian faunas but also allows two previous orectolobiform records to be re-evaluated. Accordingly, Stegostoma cf. faciatum is synonymized with Notoramphoscyllium woodwardi gen. et sp. nov., whereas Pseudoginglymostoma cf. brevicaudatum represents a nomen dubium . The two new taxa, and probably the additional two unidentified taxa, are interpreted as permanent residents, which most likely were endemic to Antarctic waters during the Eocene and adapted to shallow and estuarine environments.

Feather regeneration as a model for organogenesis

PubMed Central

Lin, Sung-Jan; Wideliz, Randall B; Yue, Zhicao; Li, Ang; Wu, Xiaoshan; Jiang, Ting-Xin; Wu, Ping; Chuong, Cheng-Ming

2013-01-01

In the process of organogenesis, different cell types form organized tissues and tissues are integrated into an organ. Most organs form in the developmental stage, but new organs can also form in physiological states or following injuries during adulthood. Feathers are a good model to study post-natal organogenesis because they regenerate episodically under physiological conditions and in response to injuries such as plucking. Epidermal stem cells in the collar can respond to activation signals. Dermal papilla located at the follicle base controls the regenerative process. Adhesion molecules (e.g., NCAM, tenascin), morphogens (e.g., Wnt3a, sprouty, FGF10), and differentiation markers (e.g., keratins) are expressed dynamically in initiation, growth and resting phases of the feather cycle. Epidermal cells are shaped into different feather morphologies based on the molecular micro-environment at the moment of morphogenesis. Chicken feather variants provide a rich resource for us to identify genetic determinants involved in feather regeneration and morphogenesis. An example of using genome-wide SNP analysis to identify alpha keratin 75 as the mutation in frizzled chickens is demonstrated. Due to its accessibility to experimental manipulation and observation, results of regeneration can be analyzed in a comprehensive way. The layout of time dimension along the distal (formed earlier) - proximal (formed later) feather axis makes the morphological analyses easier. Therefore feather regeneration can be a unique model for understanding organogenesis: from activation of stems cell under various physiological conditions to serving as the Rosetta stone for deciphering the language of morphogenesis. PMID:23294361

Photoacoustic monitoring of water transport process in calcareous stone coated with biopolymers

NASA Astrophysics Data System (ADS)

May-Crespo, J.; Ortega-Morales, B. O.; Camacho-Chab, J. C.; Quintana, P.; Alvarado-Gil, J. J.; Gonzalez-García, G.; Reyes-Estebanez, M.; Chan-Bacab, M. J.

2016-12-01

Moisture is a critical control of chemical and physical processes leading to stone deterioration. These processes can be enhanced by microbial biofilms and associated exopolymers (EPS). There is limited current understanding of the water transport process across rocks covered by EPS. In the present work, we employed the photoacoustic technique to study the influence of three biopolymers (xanthan, microbactan and arabic gum) in the water transport process of two types of limestone rock of similar mineralogy but contrasting porosity. Both controls of RL (low porosity) and RP (high porosity) presented the higher values of water diffusion coefficient ( D) than biopolymer-coated samples, indicating that biopolymer layers slowed down the transport of water. This trend was steeper for RP samples as water was transported seven times faster than in the more porous rock. Important differences of D values were observed among samples coated by different biopolymers. Scanning electron microscopy and optical microscopy showed that surface topography was different between both types of rocks; adherence of coatings was seen predominantly in the less porous rocks samples. FTIR and NMR analysis showed the presence of pyruvate and acetate in microbactan and xanthan gum, suggesting their participation on adherence to the calcareous surfaces, sealing surface pores. These results indicate that water transport at rock interfaces is dependent on the chemistry of biopolymer and surface porosity. The implications for reduced water transport in stone conservation under the influence of biopolymers include both enhanced and lower deterioration rates along with altered efficiency of biocide treatment of epilithic biofilms.

Metabolomic and high-throughput sequencing analysis-modern approach for the assessment of biodeterioration of materials from historic buildings.

PubMed

Gutarowska, Beata; Celikkol-Aydin, Sukriye; Bonifay, Vincent; Otlewska, Anna; Aydin, Egemen; Oldham, Athenia L; Brauer, Jonathan I; Duncan, Kathleen E; Adamiak, Justyna; Sunner, Jan A; Beech, Iwona B

2015-01-01

Preservation of cultural heritage is of paramount importance worldwide. Microbial colonization of construction materials, such as wood, brick, mortar, and stone in historic buildings can lead to severe deterioration. The aim of the present study was to give modern insight into the phylogenetic diversity and activated metabolic pathways of microbial communities colonized historic objects located in the former Auschwitz II-Birkenau concentration and extermination camp in Oświecim, Poland. For this purpose we combined molecular, microscopic and chemical methods. Selected specimens were examined using Field Emission Scanning Electron Microscopy (FESEM), metabolomic analysis and high-throughput Illumina sequencing. FESEM imaging revealed the presence of complex microbial communities comprising diatoms, fungi and bacteria, mainly cyanobacteria and actinobacteria, on sample surfaces. Microbial diversity of brick specimens appeared higher than that of the wood and was dominated by algae and cyanobacteria, while wood was mainly colonized by fungi. DNA sequences documented the presence of 15 bacterial phyla representing 99 genera including Halomonas, Halorhodospira, Salinisphaera, Salinibacterium, Rubrobacter, Streptomyces, Arthrobacter and nine fungal classes represented by 113 genera including Cladosporium, Acremonium, Alternaria, Engyodontium, Penicillium, Rhizopus, and Aureobasidium. Most of the identified sequences were characteristic of organisms implicated in deterioration of wood and brick. Metabolomic data indicated the activation of numerous metabolic pathways, including those regulating the production of primary and secondary metabolites, for example, metabolites associated with the production of antibiotics, organic acids and deterioration of organic compounds. The study demonstrated that a combination of electron microscopy imaging with metabolomic and genomic techniques allows to link the phylogenetic information and metabolic profiles of microbial communities and to shed new light on biodeterioration processes.

Metabolomic and high-throughput sequencing analysis—modern approach for the assessment of biodeterioration of materials from historic buildings

PubMed Central

Gutarowska, Beata; Celikkol-Aydin, Sukriye; Bonifay, Vincent; Otlewska, Anna; Aydin, Egemen; Oldham, Athenia L.; Brauer, Jonathan I.; Duncan, Kathleen E.; Adamiak, Justyna; Sunner, Jan A.; Beech, Iwona B.

2015-01-01

Preservation of cultural heritage is of paramount importance worldwide. Microbial colonization of construction materials, such as wood, brick, mortar, and stone in historic buildings can lead to severe deterioration. The aim of the present study was to give modern insight into the phylogenetic diversity and activated metabolic pathways of microbial communities colonized historic objects located in the former Auschwitz II–Birkenau concentration and extermination camp in Oświecim, Poland. For this purpose we combined molecular, microscopic and chemical methods. Selected specimens were examined using Field Emission Scanning Electron Microscopy (FESEM), metabolomic analysis and high-throughput Illumina sequencing. FESEM imaging revealed the presence of complex microbial communities comprising diatoms, fungi and bacteria, mainly cyanobacteria and actinobacteria, on sample surfaces. Microbial diversity of brick specimens appeared higher than that of the wood and was dominated by algae and cyanobacteria, while wood was mainly colonized by fungi. DNA sequences documented the presence of 15 bacterial phyla representing 99 genera including Halomonas, Halorhodospira, Salinisphaera, Salinibacterium, Rubrobacter, Streptomyces, Arthrobacter and nine fungal classes represented by 113 genera including Cladosporium, Acremonium, Alternaria, Engyodontium, Penicillium, Rhizopus, and Aureobasidium. Most of the identified sequences were characteristic of organisms implicated in deterioration of wood and brick. Metabolomic data indicated the activation of numerous metabolic pathways, including those regulating the production of primary and secondary metabolites, for example, metabolites associated with the production of antibiotics, organic acids and deterioration of organic compounds. The study demonstrated that a combination of electron microscopy imaging with metabolomic and genomic techniques allows to link the phylogenetic information and metabolic profiles of microbial communities and to shed new light on biodeterioration processes. PMID:26483760

Using Plant Phylogenetic Relatedness as a Predictor for Plants' Control on Soil Microbial Communities and Nitrogen Cycling

NASA Astrophysics Data System (ADS)

Potter, T.; Bowman, W. D.

2016-12-01

Despite the known importance of soil microbes and their influence on soil processes, a mechanistic understanding is still needed to predict how plants and soil microbes interact at scales that are relevant to community and ecosystem-scale processes. Closely related plant species have similar traits aboveground, but we don't know whether this is also true for belowground traits that affect soil microbial community structure and function. Determining how tightly plant phylogeny and plant functional traits are linked to soil microbial communities is a useful approach for discovering plant-microbe associations that are generalizable across plant species (a limitation of studies that employ a single or few plant species). Using this approach, we conducted a greenhouse study with seven congeneric grasses (genus Poa) and their native soils to examine whether plants' influences on microbial community structure were consistent with plant phylogenetic relatedness and/or plant functional traits. Seeds of each Poa species were planted in native soil (from the seed source population) as well as a homogenized soil from all seven populations. Additionally, a nitrogen treatment was added to address how an environmental change (such as nitrogen deposition) alters plant-microbe associations. Rhizosphere community composition of bacteria and fungi was obtained via marker gene sequencing to compare community composition across plant species. Patterns in plant-microbe associations across plant species reveal plant control on nutrient cycling via plant species' influence on microbial community structure. These results determine if we are ready to generalize about plant-microbe interactions at the genus level, an important stepping-stone to applying knowledge of plant-microbe interactions to larger ecological scales.

How Deep-Sea Wood Falls Sustain Chemosynthetic Life

PubMed Central

Bienhold, Christina; Pop Ristova, Petra; Wenzhöfer, Frank; Dittmar, Thorsten; Boetius, Antje

2013-01-01

Large organic food falls to the deep sea – such as whale carcasses and wood logs – are known to serve as stepping stones for the dispersal of highly adapted chemosynthetic organisms inhabiting hot vents and cold seeps. Here we investigated the biogeochemical and microbiological processes leading to the development of sulfidic niches by deploying wood colonization experiments at a depth of 1690 m in the Eastern Mediterranean for one year. Wood-boring bivalves of the genus Xylophaga played a key role in the degradation of the wood logs, facilitating the development of anoxic zones and anaerobic microbial processes such as sulfate reduction. Fauna and bacteria associated with the wood included types reported from other deep-sea habitats including chemosynthetic ecosystems, confirming the potential role of large organic food falls as biodiversity hot spots and stepping stones for vent and seep communities. Specific bacterial communities developed on and around the wood falls within one year and were distinct from freshly submerged wood and background sediments. These included sulfate-reducing and cellulolytic bacterial taxa, which are likely to play an important role in the utilization of wood by chemosynthetic life and other deep-sea animals. PMID:23301092

Rosetta Structure Prediction as a Tool for Solving Difficult Molecular Replacement Problems.

PubMed

DiMaio, Frank

2017-01-01

Molecular replacement (MR), a method for solving the crystallographic phase problem using phases derived from a model of the target structure, has proven extremely valuable, accounting for the vast majority of structures solved by X-ray crystallography. However, when the resolution of data is low, or the starting model is very dissimilar to the target protein, solving structures via molecular replacement may be very challenging. In recent years, protein structure prediction methodology has emerged as a powerful tool in model building and model refinement for difficult molecular replacement problems. This chapter describes some of the tools available in Rosetta for model building and model refinement specifically geared toward difficult molecular replacement cases.

Small-molecule ligand docking into comparative models with Rosetta

PubMed Central

Combs, Steven A; DeLuca, Samuel L; DeLuca, Stephanie H; Lemmon, Gordon H; Nannemann, David P; Nguyen, Elizabeth D; Willis, Jordan R; Sheehan, Jonathan H; Meiler, Jens

2017-01-01

Structure-based drug design is frequently used to accelerate the development of small-molecule therapeutics. Although substantial progress has been made in X-ray crystallography and nuclear magnetic resonance (NMR) spectroscopy, the availability of high-resolution structures is limited owing to the frequent inability to crystallize or obtain sufficient NMR restraints for large or flexible proteins. Computational methods can be used to both predict unknown protein structures and model ligand interactions when experimental data are unavailable. This paper describes a comprehensive and detailed protocol using the Rosetta modeling suite to dock small-molecule ligands into comparative models. In the protocol presented here, we review the comparative modeling process, including sequence alignment, threading and loop building. Next, we cover docking a small-molecule ligand into the protein comparative model. In addition, we discuss criteria that can improve ligand docking into comparative models. Finally, and importantly, we present a strategy for assessing model quality. The entire protocol is presented on a single example selected solely for didactic purposes. The results are therefore not representative and do not replace benchmarks published elsewhere. We also provide an additional tutorial so that the user can gain hands-on experience in using Rosetta. The protocol should take 5–7 h, with additional time allocated for computer generation of models. PMID:23744289

MODEL-OBSERVATION COMPARISONS OF ELECTRON NUMBER DENSITIES IN THE COMA OF 67P/CHURYUMOV–GERASIMENKO DURING 2015 JANUARY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vigren, E.; Edberg, N. J. T.; Eriksson, A. I.

2016-09-01

During 2015 January 9–11, at a heliocentric distance of ∼2.58–2.57 au, the ESA Rosetta spacecraft resided at a cometocentric distance of ∼28 km from the nucleus of comet 67P/Churyumov–Gerasimenko, sweeping the terminator at northern latitudes of 43°N–58°N. Measurements by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis/Comet Pressure Sensor (ROSINA/COPS) provided neutral number densities. We have computed modeled electron number densities using the neutral number densities as input into a Field Free Chemistry Free model, assuming H{sub 2}O dominance and ion-electron pair formation by photoionization only. A good agreement (typically within 25%) is found between the modeled electron numbermore » densities and those observed from measurements by the Mutual Impedance Probe (RPC/MIP) and the Langmuir Probe (RPC/LAP), both being subsystems of the Rosetta Plasma Consortium. This indicates that ions along the nucleus-spacecraft line were strongly coupled to the neutrals, moving radially outward with about the same speed. Such a statement, we propose, can be further tested by observations of H{sub 3}O{sup +}/H{sub 2}O{sup +} number density ratios and associated comparisons with model results.« less

The phase function and density of the dust observed at comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Fulle, Marco; Bertini, I.; Della Corte, V.; Güttler, C.; Ivanovski, S.; La Forgia, F.; Lasue, J.; Levasseur-Regourd, A. C.; Marzari, F.; Moreno, F.; Mottola, S.; Naletto, G.; Palumbo, P.; Rinaldi, G.; Rotundi, A.; Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Barucci, M. A.; Bertaux, J.-L.; Bodewits, D.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Deller, J.; Fornasier, S.; Groussin, O.; Gutiérrez, P. J.; Hviid, H. S.; Ip, W. H.; Jorda, L.; Keller, H. U.; Knollenberg, J.; Kramm, J. R.; Kührt, E.; Küppers, M.; Lara, M. L.; Lazzarin, M.; López-Moreno, J. J.; Shi, X.; Thomas, N.; Tubiana, C.

2018-05-01

The OSIRIS camera onboard Rosetta measured the phase function of both the coma dust and the nucleus. The two functions have a very different slope versus the phase angle. Here, we show that the nucleus phase function should be adopted to convert the brightness to the size of dust particles larger than 2.5 mm only. This makes the dust bursts observed close to Rosetta by OSIRIS, occurring about every hour, consistent with the fragmentation on impact with Rosetta of parent particles, whose flux agrees with the dust flux observed by GIADA. OSIRIS also measured the antisunward acceleration of the fragments, thus providing the first direct measurement of the solar radiation force acting on the dust fragments and thus of their bulk density, excluding any measurable rocket effect by the ice sublimation from the dust. The obtained particle density distribution has a peak matching the bulk density of most COSIMA particles, and represents a subset of the density distribution measured by GIADA. This implies a bias in the elemental abundances measured by COSIMA, which thus are consistent with the 67P dust mass fractions inferred by GIADA, i.e. (38 ± 8) {per cent} of hydrocarbons versus the (62 ± 8) {per cent} of sulphides and silicates.

Combining Rosetta with molecular dynamics (MD): A benchmark of the MD-based ensemble protein design.

PubMed

Ludwiczak, Jan; Jarmula, Adam; Dunin-Horkawicz, Stanislaw

2018-07-01

Computational protein design is a set of procedures for computing amino acid sequences that will fold into a specified structure. Rosetta Design, a commonly used software for protein design, allows for the effective identification of sequences compatible with a given backbone structure, while molecular dynamics (MD) simulations can thoroughly sample near-native conformations. We benchmarked a procedure in which Rosetta design is started on MD-derived structural ensembles and showed that such a combined approach generates 20-30% more diverse sequences than currently available methods with only a slight increase in computation time. Importantly, the increase in diversity is achieved without a loss in the quality of the designed sequences assessed by their resemblance to natural sequences. We demonstrate that the MD-based procedure is also applicable to de novo design tasks started from backbone structures without any sequence information. In addition, we implemented a protocol that can be used to assess the stability of designed models and to select the best candidates for experimental validation. In sum our results demonstrate that the MD ensemble-based flexible backbone design can be a viable method for protein design, especially for tasks that require a large pool of diverse sequences. Copyright © 2018 Elsevier Inc. All rights reserved.

Spatial Variations of Spectral Properties of (21) Lutetia as Observed by OSIRIS/Rosetta

NASA Astrophysics Data System (ADS)

Leyrat, Cedric; Sierks, H.; Barbieri, C.; Barucci, A.; Da Deppo, V.; De Leon, J.; Fulchignoni, M.; Fornasier, S.; Groussin, O.; Hviid, S. F.; Jorda, L.; Keller, H. U.; La Forgia, F.; Lara, L.; Lazzarin, M.; Magrin, S.; Marchi, S.; Thomas, N.; Schroder, S. E.; OSIRIS Team

2010-10-01

On July 10, 2010, the Rosetta ESA/NASA spacecraft successfully flew by the asteroid (21) Lutetia, which becomes the largest asteroid observed by a space probe. The closest approach occurred at 15H45 UTC at a relative speed of 15km/s and a relative distance of 3160 km. The Narrow Angle Camera (NAC) and the Wide Angle Camera (WAC) of the OSIRIS instrument onboard Rosetta acquired images at different phase angles ranging from almost zero to more than 150 degrees. The best spatial resolution (60 m/pixel) allowed to reveal a very complex topography with several features and different crater's surface densities. Spectrophotometric analysis of the data could suggest spatial variations of the albedo and spectral properties at the surface of the asteroid, at least in the northern hemisphere. Numerous sets of data have been obtained at different wavelengths from 270nm to 980nm. We will first present a color-color analysis of data in order to locate landscapes where surface variegation is present. We will also present a more accurate study of spectral properties using the shape model and different statistical methods. Possible variations of the surface spectral properties with the slope of the ground and the gravity field orientation will be discussed as well.

The distribution of gas and ions in the inner coma of 67P/Churyumov-Gerasimenko between 3 AU before and after its perihelion

NASA Astrophysics Data System (ADS)

Bodewits, Dennis; Lara, Luisa; La Forgia, Fiorangela; A'Hearn, Michael F.; Knollenberg, Jörg; Lazzarin, Monica; Li, Zhong-Yi; Osiris Team

2016-10-01

Rosetta explored a regime not accessible before: the inner coma of a low-activity comet at a large range of heliocentric distances. The Wide Angle Camera (WAC) of the OSIRIS instrument on board the Rosetta spacecraft is equipped with several narrowband filters that are centered on the emission lines and bands of various molecules and ions. These filters center on fragment species that are relatively bright and that have been used for numerous comet studies from the ground (e.g. A'Hearn et al. 1995). Surprisingly, we found that outside 2 AU pre-perihelion, the emission in the filters was dominated by emission from dissociative electron impact excitation (Bodewits et al. 2016). Closer to perihelion, higher gas densities reduced electron temperatures in the inner coma and photo-processes drove much if not most of the emission from the comet. Our observations allowed us to study changes in the physical environment of the inner coma, and Rosetta's excursions as far as 1000 km from the surface allowed us to study different regions of the coma.In this contribution, we will summarize the results of our OSIRIS observations from approximately 3 AU before to 3 AU after perihelion.

The interior of 67P/C-G comet as seen by CONSERT bistatic radar on ROSETTA, key results and implications.

NASA Astrophysics Data System (ADS)

Kofman, W.; Herique, A.; Ciarletti, V.; Lasue, J.; Levasseur-Regourd, AC.; Zine, S.; Plettemeier, D.

2017-09-01

The structure of the nucleus is one of the major unknowns in cometary science. The scientific objectives of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) aboard ESA's spacecraft Rosetta are to perform an interior characterization of comet 67P/Churyumov-Gerasimenko nucleus. This is done by means of a bistatic sounding between the lander Philae laying on the comet's surface and the orbiter Rosetta. Current interpretation of the CONSERT signals is consistent with a highly porous carbon rich primitive body. Internal inhomogeneities are not detected at the wavelength scale and are either smaller, or present a low dielectric contrast. Given the high bulk porosity of 75% inside the sounded part of the nucleus, a likely interior model would be obtained by a mixture, at this 3-m size scale, of voids (vacuum) and blobs with material made of ices and dust with porosity larger than 60%. The absence of any pulse spreading due to scattering allows us to exclude heterogeneity with higher contrast (0.25) and larger size (3m) (but smaller than few wavelengths scale, since larger scales would be responsible for multipath propagation). CONSERT is the first successful radar probe to study the sub-surface of a small body.

FUV Spectral Signatures of Molecules and the Evolution of the Gaseous Coma of Comet 67P/Churyumov–Gerasimenko

NASA Astrophysics Data System (ADS)

Feldman, Paul D.; A’Hearn, Michael F.; Bertaux, Jean-Loup; Feaga, Lori M.; Keeney, Brian A.; Knight, Matthew M.; Noonan, John; Parker, Joel Wm.; Schindhelm, Eric; Steffl, Andrew J.; Stern, S. Alan; Vervack, Ronald J.; Weaver, Harold A.

2018-01-01

The Alice far-ultraviolet imaging spectrograph onboard Rosetta observed emissions from atomic and molecular species from within the coma of comet 67P/Churyumov–Gerasimenko during the entire escort phase of the mission from 2014 August to 2016 September. The initial observations showed that emissions of atomic hydrogen and oxygen close to the surface were produced by energetic electron impact dissociation of H2O. Following delivery of the lander, Philae, on 2014 November 12, the trajectory of Rosetta shifted to near-terminator orbits that allowed for these emissions to be observed against the shadowed nucleus that, together with the compositional heterogeneity, enabled us to identify unique spectral signatures of dissociative electron impact excitation of H2O, CO2, and O2. CO emissions were found to be due to both electron and photoexcitation processes. Thus, we are able, from far-ultraviolet spectroscopy, to qualitatively study the evolution of the primary molecular constituents of the gaseous coma from start to finish of the escort phase. Our results show asymmetric outgassing of H2O and CO2 about perihelion, H2O dominant before and CO2 dominant after, consistent with the results from both the in situ and other remote sensing instruments on Rosetta.

Urban Soil Hydrology: bridging the data gap with a nationwide field study

NASA Astrophysics Data System (ADS)

Schifman, L. A.; Shuster, W.

2016-12-01

Urban communities generally rely on hydrologic models or tools for assessing suitable sites for green infrastructure. These rainfall-runoff models, e.g. National Stormwater Calculator (NSWC), query soil hydrologic information from national databases, e.g. Soil Survey Geographic Database (SSURGO), or are estimated via pedotransfer-based algorithms like USDA Rosetta. As part of urban soil hydrologic assessments we have collected soil textural and hydrologic data in 12 cities throughout the United States and compared these measurements to NSWC and SSURGO queried infiltration rates (Kunsat) and Rosetta-estimated drainage rates (Ksat and Kunsat). We found that soil hydrologic parameters obtained through pedotransfer functions and queries to soil databases are not representative of field-measured values (RMSE range from 6.2 to 15.2 for infiltration and from 13.2 to 16.3 for drainage). Although the NSWC queries SSURGO, we found that SSURGO overestimates infiltration and NSWC underestimates with MEs of 4.9, and -1.4, respectively. In Rosetta, we found that pedotransfer functions overestimated drainage rates (MEs 1.8 to 3.8). In an attempt to improve drainage estimates using Rosetta the soil texture was adjusted in soils with an apparent portion of finer sands. Here, sand included: very coarse, coarse, and medium sand, whereas silt included fine, and very fine sand and silt, with the justification that fine sands behave similarly to silt. These adjusted estimates resulted in generally underestimating drainage and still not suitable for use in planning for stormwater detention (e.g., infiltrative green infrastructure). With this work we highlight the importance of obtaining field measured values when assessing sites for green infrastructure planning instead of relying on estimates, as the discrepancies in sensitive parameters such as Kunsat and Ksat, implications for parameter selection in error propagation through rainfall-runoff models, and consequences for over- or under-design of stormwater control measures for detention.

Study of the coma of comet 67P/Churyumov-Gerasimenko based on the ROSINA/RTOF instrument onboard Rosetta

NASA Astrophysics Data System (ADS)

Hoang, M.; Garnier, P.; Lasue, J.; Reme, H.; Altwegg, K.; Balsiger, H. R.; Bieler, A. M.; Calmonte, U.; Fiethe, B.; Galli, A.; Gasc, S.; Gombosi, T. I.; Jäckel, A.; Mall, U.; Le Roy, L.; Rubin, M.; Tzou, C. Y.; Waite, J. H., Jr.; Wurz, P.

2015-12-01

The ROSETTA spacecraft of ESA is in the environment of comet 67P/Churyumov-Gerasimenko since August 2014. Among the experiments onboard the spacecraft, the ROSINA experiment (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) includes two mass spectrometers (DFMS and RTOF) to analyze the composition of neutrals and ions, and a pressure sensor (COPS) to monitor the density and velocity of neutrals in the coma [1]. We will here analyze and discuss the data of the ROSINA/RTOF instrument during the comet escort phase. The Reflectron-type Time-Of-Flight (RTOF) mass spectrometer possesses a wide mass range and a high temporal resolution [1,2]. It was designed to measure cometary neutral gas as well as cometary ions. A detailed description of the main volatiles (H2O, CO2, CO) dynamics and of the heterogeneities of the coma will then be provided. The influence of various parameters on the coma measurements is investigated on a statistical basis, with the parameters being distance to the comet, heliocentric distance, longitude and latitude of nadir point. Our analysis of the northern hemisphere summer season shows the presence of water vapor mostly in the illuminated northern hemisphere near the neck region with cyclic diurnal variations whereas CO2 was confined to the cold southern hemisphere with a more spatially homogeneous composition, in agreement with previous observations of 67P [2] or Hartley 2 [3]. A comparison will also be provided with the COPS total density and DFMS abundance measurements. [1] Balsiger et al., "ROSINA - Rosetta Orbiter Spectrometer for Ion and Neutral Analysis", Space Sci. Rev., 2007. [2] Scherer et al., "A novel principle for an ion mirror design in time-of-flight mass spectrometry," Int. Jou. Mass Spectr., 2006. [3] Hässig et al., "Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko", Science, 2015. [4] A'Hearn et al., "EPOXI at comet Hartley 2", Science, 2011.

Rosetta mission operations for landing

NASA Astrophysics Data System (ADS)

Accomazzo, Andrea; Lodiot, Sylvain; Companys, Vicente

2016-08-01

The International Rosetta Mission of the European Space Agency (ESA) was launched on 2nd March 2004 on its 10 year journey to comet Churyumov-Gerasimenko and has reached it early August 2014. The main mission objectives were to perform close observations of the comet nucleus throughout its orbit around the Sun and deliver the lander Philae to its surface. This paper describers the activities at mission operations level that allowed the landing of Philae. The landing preparation phase was mainly characterised by the definition of the landing selection process, to which several parties contributed, and by the definition of the strategy for comet characterisation, the orbital strategy for lander delivery, and the definition and validation of the operations timeline. The definition of the landing site selection process involved almost all components of the mission team; Rosetta has been the first, and so far only mission, that could not rely on data collected by previous missions for the landing site selection. This forced the teams to include an intensive observation campaign as a mandatory part of the process; several science teams actively contributed to this campaign thus making results from science observations part of the mandatory operational products. The time allocated to the comet characterisation phase was in the order of a few weeks and all the processes, tools, and interfaces required an extensive planning an validation. Being the descent of Philae purely ballistic, the main driver for the orbital strategy was the capability to accurately control the position and velocity of Rosetta at Philae's separation. The resulting operations timeline had to merge this need of frequent orbit determination and control with the complexity of the ground segment and the inherent risk of problems when doing critical activities in short times. This paper describes the contribution of the Mission Control Centre (MOC) at the European Space Operations Centre (ESOC) to this mission phase and the lessons learned that can be derived from this experience.

Major achievements of the Rosetta mission in connection with the origin of the solar system

NASA Astrophysics Data System (ADS)

Barucci, M. A.; Fulchignoni, M.

2017-10-01

Comets have been studied from a long time and are believed to preserve pristine materials, so they are fundamental to understand the origin of the solar system and life. Starting in the early 1990s, ESA decided to have a more risky and fantastic mission to a comet. As Planetary Cornerstone mission of the ESA Horizon 2000 program, the Rosetta mission was selected with the aim of realizing two asteroid fly-bys, a rendezvous with a comet to deliver a surface science package and to hover around the comet from 4 AU inbound up to perihelion and outbound back to 3.7 AU. The mission was successfully launched on March 2, 2004 with Ariane V that started its 10-year journey toward comet 67P/Churyumov-Gerasimenko. After several planetary gravity assists, Rosetta flew by two asteroids—on September 5, 2008 (Steins) and on July 10, 2010 (Lutetia), respectively, and performed the comet orbit insertion maneuver on August 6, 2014. The onboard instruments characterized the nucleus orbiting the comet at altitudes down to few kilometers. On November 12, 2014, the lander Philae was delivered realizing the first landing ever on a comet surface. Although the exploration of the comet was planned up to the end of 2015, the mission duration was extended for nine more months than the nominal one, to follow the comet on its outbound orbit. To terminate the mission, following a series of very low orbits, a controlled impact of Rosetta spacecraft with the comet was realized on September 30, 2016. The scientific objectives of the mission have been largely achieved. The challenging mission provided the science community with an enormous quantity of data of extraordinary scientific value. In this paper, a detailed description of the mission and the highlights of the obtained scientific results on the exploration of an extraordinary world are presented. The paper also includes lessons learned and directions for the future.

How well do you know The Earth, Asteroids, Comets?

NASA Astrophysics Data System (ADS)

Alexander, C. J.; Lopez, J.; Barkus, R. C.; Angrum, A.

2011-12-01

The U.S. Rosetta Project is the NASA contribution to the International Rosetta Mission, an ESA cornerstone mission. The mission will arrive at its target, comet 67 P/Churyumov-Gerasimenko, in 2014, and escort the comet around the Sun for the ensuing 17 months. Along the way, the mission has encountered two asteroids: 21/Lutetia, and 2867/Steins, and enjoyed gravity assists at Mars and several at the Earth. The challenge for outreach coordinators is to convey the excitement of the mission, the manner in which its experiments gather and interpret data, provide context for those interpretations, all in an engaging fashion, without heavy use of camera images -- the camera not being among the NASA contributed instruments. In other words, because the US Rosetta Project expects to present the data and results from: an ultraviolet spectrometer, a plasma instrument, and a microwave spectrometer, outreach is presented with the special challenges of engaging the public in data which at least visually is less accessible than that of camera images. The project has turned to online games, interactive simulations, animated cartoons, and virtual labs to provide a visually stimulating way to explain: how scientists determine the age of asteroids; the context of a timeline of Earth geologic history with which to understand the relative position of the ages of any given asteroid to some event on Earth; a model of the solar system that goes from our Sun to the next Star to understand the spatial distances covered by comets in their journey around the Sun; and a model of early solar system evolution in which to understand the possible scenarios of solar system evolution that comets can help us sort out. In this paper we will present these simulations, even if some of them remain in the beta-development phase at the time of the meeting itself. Work at the Jet Propulsion Laboratory, California Institute of Technology, was supported by NASA. Rosetta is a joint collaboration between NASA and the European Space Agency.

Coma dust environment observed by GIADA during the Perihelion of 67P/Churyumov-Gerasimenko.

NASA Astrophysics Data System (ADS)

Rotundi, A.; Della Corte, V.; Fulle, M.; Ferrari, M.; Ivanovski, S. L.; Sordini, R.; Mazzotta Epifani, E.; Palumbo, P.; Colangeli, L.; Lopez-Moreno, J. J.; Rodriguez, J.; Zakharov, V.; Bussoletti, E.; Crifo, J. F.; Esposito, F.; Green, S.; Gruen, E.; Lamy, P. L.; McDonnell, T.; Mennella, V.; Molina, A.; Moreno, F.; Ortiz, J. L.; Palomba, E.; Perrin, J. M.; Rodrigo, R.; Weissman, P. R.; Zarnecki, J.; Cosi, M.; Giovane, F.; Gustafson, B.; Herranz, M.; Jeronimo, J. M.; Leese, M.; Lopez-Jimenez, A.; Morales, R.

2015-12-01

GIADA (Grain Impact Analyzer and Dust Accumulator) is an in-situ instrument mounted onboard Rosetta monitoring the dust environment of comet 67P/Churyumov-Gerasimenko. GIADA is composed of 3 sub-systems: 1) the Grain Detection System, based on particle detection through light scattering; 2) the Impact Sensor, giving momentum measurement; 3) the Micro-Balances System, constituted of 5 quartz crystal microbalances, giving cumulative deposited dust. The combination of the measurements performed by these 3 subsystems provides: the number, the mass, the momentum and the speed distribution of dust particles emitted from the comet nucleus. We will present the coma dust environment as observed by GIADA during the perihelion phase of the Rosetta space mission. Despite the large distance from the nucleus, more than 200 km, GIADA was able to detect temporal and spatial variation of dust density distribution. Specific high dust spatial density sectors of the coma have been identified and their evolution during the perihelion phase was studied. Acknowledgements. GIADA was built by a consortium led by the Univ. Napoli "Parthenope" & INAF- Oss. Astr. Capodimonte, IT, in collaboration with the Inst. de Astrofisica de Andalucia, ES, Selex-ES s.p.a. and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with a support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developped from a PI proposal supported by the University of Kent; sci. & tech. contribution given by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their outstanding work. Science support provided by NASA through the US Rosetta Project managed by JPL/California Institute of Technology. GIADA calibrated data will be available through the ESA's PSA web site.

Sensitivity and fragmentation calibration of the time-of-flight mass spectrometer RTOF on board ESA's Rosetta mission

NASA Astrophysics Data System (ADS)

Gasc, Sébastien; Altwegg, Kathrin; Jäckel, Annette; Le Roy, Léna; Rubin, Martin; Fiethe, Björn; Mall, Urs; Rème, Henri

2014-05-01

The European Space Agency's Rosetta mission will rendez-vous comet 67P/Churyumov-Gerasimenko (67P) in September 2014. The Rosetta spacecraft with the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) onboard will follow and survey 67P for more than a year until the comet reaches its perihelion and beyond. ROSINA will provide new information on the global molecular, elemental, and isotopic composition of the coma [1]. ROSINA consists of a pressure sensor (COPS) and two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron Time Of Flight mass spectrometer (RTOF). RTOF has a wide mass range, from 1 amu/e to >300 amu/e, and contains two ion sources, a reflectron and two detectors. The two ion sources, the orthogonal and the storage source, are capable to measure cometary ions while the latter also allows measuring cometary neutral gas. In neutral gas mode the ionization is performed through electron impact. A built-in Gas Calibration Unit (GCU) contains a known gas mixture composed of He, CO2, and Kr that can be used for in-flight calibration of the instrument. Among other ROSINA specific scientific goals, RTOF's task will be to determine molecular composition of volatiles via measuring and separating heavy hydrocarbons; it has been designed to study the development of the cometary activity as well as the coma chemistry between 3.5 AU and perihelion. From the spectroscopic studies and in-situ observations of other comets, we expect to find molecules such as H2O, CO, CO2, hydrocarbons, alcohols, formaldehyde, and other organic compounds in the coma of 67P/Churyumov-Gerasimenko [2]. To demonstrate and quantify the sensitivity and functionality of RTOF, calibration measurements have been realized with more than 20 species among the most abundant molecules quoted above, as well as other species such as PAHs. We will describe the applied methods used to realize this calibration and will discuss our preliminary results, i.e. RTOF capabilities in terms of sensitivity, isotopic ratios, and fragmentation patterns. We will demonstrate that RTOF is well capable to meet the requirements to address the scientific questions discussed above. [1] Balsiger, H. et al.: ROSINA-Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Space Science Reviews, Vol. 128, 745-801, 2007. [2] Bockelée-Morvan, D., Crovisier, J., Mumma, M. J., and Weaver, H. A.: The Composition of Cometary Volatiles, in Comets II (M. C. Festou et al., eds), Univ. Arizona Press, Tucson, 2004

Comet 67P Through the Lens of Art

NASA Astrophysics Data System (ADS)

Smirnova, Ekaterina

2017-04-01

My proposal is to share my artistic exploration of a comet through the bodily senses, while finding inspiration in scientific data. I will present my artwork as a slideshow, showcasing: large scale paintings, ceramic sculptures, music and interactive augmented reality. The Rosetta mission of the European Space Agency (ESA) to comet 67P/ Churyumov-Gerasimenko is remarkable. The scientific investigation of the comet's composition, atmosphere, dust, vapor, surface and internal structure are crucial to help researchers understand the origin of the solar system and our own planet. Sight: Paintings Rosetta mission discovered that the water on the comet is different from the water on Earth; as measured with the ROSINA-DFMS instrument on Rosetta, water on 67P contains approximately 3 times more hydrogen­deuterium oxide - HDO, than found in Earth's oceans. In the art studio I re-create water that is close in composition to the water on the comet, by concentrating the level of HDO. With this water I paint large scale watermedia paintings, based on the photographs by Rosetta (OSIRIS, Nav. Cam.). Touch: Sculptures While exploring the comet's three-dimensional form, I focus more deeply on the composition of the comet. Stoneware clay and my choice of a glaze both include iron oxide, a common constituent of meteorites and comets. Hearing: Music An audio piece "A Singing Comet", by Manuel Senfft, based on the Rosetta Plasma Consortium data, inspired me to make a musical piece. In collaboration with clarinetist Lee Mottram (Wales) and composer Takuto Fukuda (Japan) we created an electro­acoustic composition in which we tell the story of comets visiting our Solar System, repeating their cycle, curving around the sun and releasing water, carrying away dust to form their tails. Smell In collaboration with The Open University, UK, postcards with a smell of the comet were created, introducing the chemical components of the comet. The smell was recreated by combining several molecules that were found in the comet's coma with the ROSINA instrument: in particular, hydrogen cyanide, ammonia and hydrogen sulphide. Interactive: Augmented Reality (AR) Inspired by spectroscopic data from OSIRIS, I introduce AR to reveal a "hidden" layer. I am highlighting that some scientific information can only be viewed by using special instruments, in this case - instruments on board the Rosetta spacecraft. Viewers can see a virtual layer on top of my paintings using a readily available instrument - ones cellphone. RGB colors, of a particular wavelength, will be introduced to the generally monochromatic paintings. Through my art I study the relationship between humans and the Universe, understanding the connection, the influence and the effect they have on each other. ESA's example of human scientists ambitiously exploring a distant cosmic object empowers me to create and share my personal exploration. This is the way I would like to share comet 67P with the world. I invite you to look through an artist's eyes and see science with renewed beauty and wonder. To view the artwork: http://www.ekaterina-smirnova.com/67p/ http://www.ekaterina-smirnova.com/67p-sculptures/

Identification, purification and characterization of furfural transforming enzymes from Clostridium beijerinckii NCIMB 8052.

PubMed

Zhang, Yan; Ujor, Victor; Wick, Macdonald; Ezeji, Thaddeus Chukwuemeka

2015-06-01

Generation of microbial inhibitory compounds such as furfural and 5-hydroxymethylfurfural (HMF) is a formidable roadblock to fermentation of lignocellulose-derived sugars to butanol. Bioabatement offers a cost effective strategy to circumvent this challenge. Although Clostridium beijerinckii NCIMB 8052 can transform 2-3 g/L of furfural and HMF to their less toxic alcohols, higher concentrations present in biomass hydrolysates are intractable to microbial transformation. To delineate the mechanism by which C. beijerinckii detoxifies furfural and HMF, an aldo/keto reductase (AKR) and a short-chain dehydrogenase/reductase (SDR) found to be over-expressed in furfural-challenged cultures of C. beijerinckii were cloned and over-expressed in Escherichia coli Rosetta-gami™ B(DE3)pLysS, and purified by histidine tag-assisted immobilized metal affinity chromatography. Protein gel analysis showed that the molecular weights of purified AKR and SDR are close to the predicted values of 37 kDa and 27 kDa, respectively. While AKR has apparent Km and Vmax values of 32.4 mM and 254.2 mM s(-1) respectively, using furfural as substrate, SDR showed lower Km (26.4 mM) and Vmax (22.6 mM s(-1)) values on the same substrate. However, AKR showed 7.1-fold higher specific activity on furfural than SDR. Further, both AKR and SDR were found to be active on HMF, benzaldehyde, and butyraldehyde. Both enzymes require NADPH as a cofactor for aldehydes reduction. Based on these results, it is proposed that AKR and SDR are involved in the biotransformation of furfural and HMF by C. beijerinckii. Copyright © 2015 Elsevier Ltd. All rights reserved.

Investigation of microbial community isolated from indoor artworks and air environment: identification, biodegradative abilities, and DNA typing.

PubMed

Pangallo, Domenico; Chovanová, Katarina; Simonovicová, Alexandra; Ferianc, Peter

2009-03-01

This study deals with establishing the characteristics of a microbial community isolated from indoor artworks and the surrounding air environment. It is one of the few studies on microbial degradation of indoor artworks. It shows the potential biodegradative risk that can occur if artworks are not exhibited and conserved in an appropriate environment. The microbial community isolated from the indoor artworks and air environment was examined by cultural and molecular methods. Different plate assays were used to screen the biodegradative activity of the isolated microflora: Remazol Brilliant Blue R, phenol red, and Azure B for the ligninolytic properties; Ostazin brilliant red H-3B for cellulose degradation; CaCO3 glucose agar for solubilization activity; and B4 agar for biomineralization. To type the bacterial and fungal isolates, 2 PCR methods, repetitive extragenic palindromes (REP) and random amplified microsatellite polymorphisms (RAMP) were used. The art objects were principally colonized by fungi. The most commonly isolated strains were represented by hyphomycetes of the genera Penicillium, Aspergillus, Cladosporium, and Chaetomium. Members of these genera showed intensive biodegradation activity, both on wood and on stone. Bacteria were predominant in the air, exhibiting complex communities, both in the air and on the artworks. The most frequently isolated genera were Bacillus and Staphylococcus with extensive biodegradation abilities. REP-PCR revealed high variability within strains belonging to the same genus. RAMP is a new PCR-based method, used in this research for the first time to cluster the microfilamentous fungi and to characterize and select especially Penicillium and Aspergillus strains, which were isolated in a large number.

Effect of the chemical composition of filter media on the microbial community in wastewater biofilms at different temperatures† †Electronic supplementary information (ESI) available: Tables S1–S6 are available. See DOI: 10.1039/c6ra21040f Click here for additional data file.

PubMed Central

Naz, Iffat; Hodgson, Douglas; Smith, Ann; Marchesi, Julian; Ahmed, Safia; Avignone-Rossa, Claudio

2016-01-01

This study investigates the microbial community composition in the biofilms grown on two different support media in fixed biofilm reactors for aerobic wastewater treatment, using next generation sequencing (NGS) technology. The chemical composition of the new type of support medium (TDR) was found to be quite different from the conventionally used support medium (stone). The analysis of 16S rRNA gene fragments recovered from the laboratory scale biofilm system show that biofilm support media and temperature conditions influence bacterial community structure and composition. Greater bacterial diversity was observed under each condition, primarily due to the large number of sequences available and sustenance of rare species. There were 6 phyla found, with the highest relative abundance shown by the phylum Proteobacteria (52.71%) followed by Bacteroidetes (33.33%), Actinobacteria (4.65%), Firmicutes, Verrucomicrobia (3.1%) and Chloroflex (>1%). The dataset showed 17 genera of bacterial populations to be commonly shared under all conditions, suggesting the presence of a core microbial community in the biofilms for wastewater treatment. However, some genera in the biofilms on TDR were observed in high proportions, which may be attributed to its chemical composition, explaining the improved level of wastewater treatment. The findings show that the structure of microbial communities in biofilm systems for wastewater treatment is affected by the properties of support matrix. PMID:28018581

Back to the past: "find the guilty bug-microorganisms involved in the biodeterioration of archeological and historical artifacts".

PubMed

Mazzoli, Roberto; Giuffrida, Maria Gabriella; Pessione, Enrica

2018-06-04

Microbial deterioration accounts for a significant percentage of the degradation processes that occur on archeological/historical objects and artworks, and identifying the causative agents of such a phenomenon should therefore be a priority, in consideration of the need to conserve these important cultural heritage items. Diverse microbiological approaches, such as microscopic evaluations, cultural methods, metabolic- and DNA-based techniques, as well as a combination of the aforementioned methods, have been employed to characterize the bacterial, archaeal, and fungal communities that colonize art objects. The purpose of the present review article is to report the interactions occurring between the microorganisms and nutrients that are present in stones, bones, wood, paper, films, paintings, and modern art specimens (namely, collagen, cellulose, gelatin, albumin, lipids, and hydrocarbons). Some examples, which underline that a good knowledge of these interactions is essential to obtain an in depth understanding of the factors that favor colonization, are reported. These data can be exploited both to prevent damage and to obtain information on historical aspects that can be decrypted through the study of microbial population successions.

Regolith Properties of Asteroid 21 Lutetia Constrained by Combined Data Sets of the MIRO and VIRTIS Instruments During the Rosetta Spacecraft Flyby

NASA Technical Reports Server (NTRS)

Keihm, S.; Tosi, F.; Kamp, L.; Capaccioni, F.; Grassi, D.; Gulkis, S.; Coradini, A.

2011-01-01

During the July 10, 2010 flyby of Asteroid 21 Lutetia by the Rosetta spacecraft, maps of surface and subsurface temperatures were derived from the VIRTIS and MIRO instruments respectively. Both data sets indicated a porous surface layer with an extremely low, lunar-like thermal inertia. However, comparisons of the VIRTIS-measured and MIRO-modelled surface temperatures revealed offsets of 10- 30 K, indicative of self-heating or "beaming" effects that were not taken into account in the MIRO thermal modeling. Inclusion of a model of hemispherical craters at all scales 1 cm and larger, covering 50% of the surface, removes most of the offsets in the VIRTIS, MIRO surface temperature determinations.

Stunning Image of Rosetta above Mars taken by the Philae Lander Camera

NASA Image and Video Library

2007-02-05

Stunning image taken by the CIVA imaging instrument on Rosetta Philae lander just 4 minutes before closest approach at a distance of some 1000 km from Mars on Feb. 25, 2007. A portion of the spacecraft and one of its solar arrays are visible in nice detail. Beneath, the Mawrth Vallis region is visible on the planet's disk. Mawrth Vallis is particularly relevant as it is one of the areas on the Martian surface where the OMEGA instrument on board ESA's Mars Express detected the presence of hydrated clay minerals -- a sign that water may have flown abundantly on that region in the very early history of Mars. Id 217487 http://photojournal.jpl.nasa.gov/catalog/PIA18154

Using Competitions to Engage the Public: Lessons Learnt from Rosetta

NASA Astrophysics Data System (ADS)

O'Flaherty, K. S.; Baldwin, E.; Mignone, C.; Homfeld, A. M.; Scuka, D.; Schepers, A.; Braun, M.; Croci, F.; Giacomini, L.; Journo, N.; Bauer, M.; McCaughrean, M.

2016-03-01

The year 2014 was an historic and challenging time for the Rosetta mission. On 20 January the spacecraft awoke from a 957-day hibernation; by August, it had arrived at Comet 67P/Churyumov-Gerasimenko; and in November, the lander Philae was deployed to the comet's surface. These milestones were communicated by traditional outreach channels -- on websites and via press events -- as well as through the extensive use of social media. To provide an opportunity for the public to participate actively in these milestones, the European Space Agency and its partners ran three competitions. In this article we outline how these competitions provided a means for the public to engage with what was to become one of the most exciting space science missions in decades.

Building and testing of MIDAS instrument sub-assemblies

NASA Astrophysics Data System (ADS)

Lewis, S. D.

2001-09-01

The MIDAS instrument is an atomic force microscope developed by ESTEC to fly on Rosetta. The purpose of the instrument is to sample and characterise cometary dust, which impinges upon a facetted wheel contained within the instrument enclosure. Due to its relative complexity, the long cruise phase of the Rosetta mission and the relatively novel use of piezomotors for all drive requirements the instrument has a number of interesting mechanisms engineering challenges. This paper describes the lubricant selection, EM and FM subassembly build and test campaigns carried out by AEA Technology Space in close support of the instrumentlevel activities which ran in parallel at ESTEC. The paper also identifies some lessons learned, which can be generally applied in other mechanism programmes.

The Systematic Classification of Gallbladder Stones

PubMed Central

Qiao, Tie; Ma, Rui-hong; Luo, Xiao-bing; Yang, Liu-qing; Luo, Zhen-liang; Zheng, Pei-ming

2013-01-01

Background To develop a method for systematic classification of gallbladder stones, analyze the clinical characteristics of each type of stone and provide a theoretical basis for the study of the formation mechanism of different types of gallbladder stones. Methodology A total of 807 consecutive patients with gallbladder stones were enrolled and their gallstones were studied. The material composition of gallbladder stones was analyzed using Fourier Transform Infrared spectroscopy and the distribution and microstructure of material components was observed with Scanning Electron Microscopy. The composition and distribution of elements were analyzed by an X-ray energy spectrometer. Gallbladder stones were classified accordingly, and then, gender, age, medical history and BMI of patients with each type of stone were analyzed. Principal Findings Gallbladder stones were classified into 8 types and more than ten subtypes, including cholesterol stones (297), pigment stones (217), calcium carbonate stones (139), phosphate stones (12), calcium stearate stones (9), protein stones (3), cystine stones (1) and mixed stones (129). Mixed stones were those stones with two or more than two kinds of material components and the content of each component was similar. A total of 11 subtypes of mixed stones were found in this study. Patients with cholesterol stones were mainly female between the ages of 30 and 50, with higher BMI and shorter medical history than patients with pigment stones (P<0.05), however, patients with pigment, calcium carbonate, phosphate stones were mainly male between the ages of 40 and 60. Conclusion The systematic classification of gallbladder stones indicates that different types of stones have different characteristics in terms of the microstructure, elemental composition and distribution, providing an important basis for the mechanistic study of gallbladder stones. PMID:24124459

Clonorcis sinensis eggs are associated with calcium carbonate gallbladder stones.

PubMed

Qiao, Tie; Ma, Rui-hong; Luo, Zhen-liang; Yang, Liu-qing; Luo, Xiao-bing; Zheng, Pei-ming

2014-10-01

Calcium carbonate gallbladder stones were easily neglected because they were previously reported as a rare stone type in adults. The aim of this study was to investigate the relationship between calcium carbonate stones and Clonorchis sinensis infection. A total of 598 gallbladder stones were studied. The stone types were identified by FTIR spectroscopy. The C. sinensis eggs and DNA were detected by microscopic examination and real-time fluorescent PCR respectively. And then, some egg-positive stones were randomly selected for further SEM examination. Corresponding clinical characteristics of patients with different types of stones were also statistically analyzed. The detection rate of C. sinensis eggs in calcium carbonate stone, pigment stone, mixed stone and cholesterol stone types, as well as other stone types was 60%, 44%, 36%, 6% and 30%, respectively, which was highest in calcium carbonate stone yet lowest in cholesterol stone. A total of 182 stones were egg-positive, 67 (37%) of which were calcium carbonate stones. The C. sinensis eggs were found adherent to calcium carbonate crystals by both light microscopy and scanning electron microscopy. Patients with calcium carbonate stones were mainly male between the ages of 30 and 60, the CO2 combining power of patients with calcium carbonate stones were higher than those with cholesterol stones. Calcium carbonate gallbladder stones are not rare, the formation of which may be associated with C. sinensis infection. Copyright © 2014 Elsevier B.V. All rights reserved.

Interaction of the solar wind with comets: a Rosetta perspective

PubMed Central

2017-01-01

The Rosetta mission provides an unprecedented possibility to study the interaction of comets with the solar wind. As the spacecraft accompanies comet 67P/Churyumov–Gerasimenko from its very low-activity stage through its perihelion phase, the physics of mass loading is witnessed for various activity levels of the nucleus. While observations at other comets provided snapshots of the interaction region and its various plasma boundaries, Rosetta observations allow a detailed study of the temporal evolution of the innermost cometary magnetosphere. Owing to the short passage time of the solar wind through the interaction region, plasma instabilities such as ring--beam and non-gyrotropic instabilities are of less importance during the early life of the magnetosphere. Large-amplitude ultra-low-frequency (ULF) waves, the ‘singing’ of the comet, is probably due to a modified ion Weibel instability. This instability drives a cross-field current of implanted cometary ions unstable. The initial pick-up of these ions causes a major deflection of the solar wind protons. Proton deflection, cross-field current and the instability induce a threefold structure of the innermost interaction region with the characteristic Mach cone and Whistler wings as stationary interaction signatures as well as the ULF waves representing the dynamic aspect of the interaction. This article is part of the themed issue ‘Cometary science after Rosetta’. PMID:28554976

Early Activity of Cometary Species from ROSINA/DFMS at 67P/ Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Hässig, Myrtha; Fuselier, Stephen A.; Altwegg, Kathrin; Balsiger, Hans; Berthelier, Jean-Jacques; Bieler, André; Calmonte, Ursina; Dhooghe, Frederik; Fiethe, Björn; Gasc, Sébastien; Gombosi, Tamas I.; Jäckel, Annette; Korth, Axel; Le Roy, Léna; Rème, Henri; Rubin, Martin; Tzou, Chia-Yu; Wurz, Peter

2014-11-01

The European Space Agency’s Rosetta spacecraft arrived after a journey of more than 10 years at comet 67P/Churyumov-Gerasimenko. ROSINA is an instrument package on board Rosetta. It consists of two mass spectrometers and a COmetary Pressure Sensor (COPS). The two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron Time of Flight (RTOF) complement each other with high mass resolution (e.g to resolve 13C from CH), high dynamic range (to detect low abundant isotopes and species), high mass range (to detect organics), and high time resolution. ROSINA is designed to measure the neutral gas and plasma composition in the coma of 67P/Churyumov-Gerasimenko in addition to the physical properties of the neutral component of the coma. For the first time, a comet can be observed in situ from its early activity towards and after perihelion. Little is known about what drives initial cometary activity very far from the Sun. Remote sensing observations to date are highly constrained to a limited number of a few bright comets (e.g. Hale-Bopp) and a limited number of species. Rosetta provides the first measurements of the early activity of a comet in situ and detected the first cometary molecules early August. We will focus on early activity of cometary species from the high resolution mass spectrometer ROSINA/DFMS.

Rosetta/VIRTIS investigation of the chemistry and activity of comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Bockelee-Morvan, Dominique; Drossart, Pierre; Piccioni, Giuseppe; Migliorini, Alessandra; Erard, Stéphane; Capaccioni, Fabrizio; Filacchione, Gianrico; Fougere, Nicolas; Leyrat, Cedric; Crovisier, Jacques; Capaccioni, Fabrizio

2016-07-01

The composition of cometary ices inside cometary nuclei provides clues to the chemistry of the protoplanetary disk where they formed, 4.6 Gyr ago. These ices sublimate when the body approches the Sun, so that the coma molecular species give insights on the nucleus surface and sub-surface composition. So far, most investigations of the coma chemical composition were performed from telescopic observations from the ground or space plateforms. Since August 2014, the ESA/Rosetta spacecraft has been investigating the nucleus and inner coma of 67P/Churyumov-Gerasimenko. This talk will present an overview of the results obtained by the Visual and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument onboard Rosetta, focussing on observations of molecular species. VIRTIS is composed of two channels. The VIRTIS-M channel is a spectro-imager covering the 0.27-5.1 microns range, which allowed us to map the spatial distribution of H2O and CO2 (Migliorini et al. 2016, A&A in press). VIRTIS-H is a high-spectral resolution spectrometer covering the 2-5 microns range. Spectra obtained with VIRTIS-H show signatures of H2O, CO2 (both fundamental and hot bands), 13CO2, CH4 and other C-H bearing species (Bockelee-Morvan et al. A&A, 583, A6,2015). VIRTIS is a key instrument to investigate regional, diurnal and seasonal variations of the comet outgassing.

Rosetta/Alice Measurements of Atomic and Molecular Abundances in the Coma of 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Vervack, R. J., Jr.; Weaver, H. A., Jr.; Knight, M. M.; Feldman, P.; Stern, A.; Parker, J. W.; Feaga, L. M.; Steffl, A.; Bertaux, J. L.; A'Hearn, M. F.; Keeney, B. A.

2017-12-01

During the Rosetta orbital phase from August 2014 through September 2016, the Alice far-ultraviolet (FUV) imaging spectrograph routinely monitored the FUV emission from the coma of 67P/Churyumov-Gerasimenko (67P). These data, spanning 700-2050 Å, provide both spatial and temporal information on the evolution of the coma composition throughout the encounter. Emissions from hydrogen (Lyman beta at 1025 Å), oxygen (1304 Å triplet, 1356 Å), sulfur (1429 Å and 1479 Å multiplets, 1814 Å triplet), and carbon (1561 Å, 1657 Å) were regularly observed, as well as emission from the CO Fourth Positive and Cameron bands. We present a preliminary analysis of these emissions with a focus on the abundances in the coma and a mapping of the temporal and spatial variations. Both short-term (days) and long-term (months) variations will be discussed in the context of rotational and seasonal timeframes. We also present ratios among various species with the goal of identifying the dominant processes at work in the coma as a function of time. Rosetta is an ESA mission with contributions from its member states and NASA. The Alice team acknowledges continuing support from NASA's Jet Propulsion Laboratory through contract 1336850 to the Southwest Research Institute. RJV's work was supported by a subcontract from Southwest Research Institute to the Johns Hopkins University Applied Physics Laboratory.

Mechanical and electrostatic experiments with dust particles collected in the inner coma of comet 67P by COSIMA onboard Rosetta.

PubMed

Hilchenbach, Martin; Fischer, Henning; Langevin, Yves; Merouane, Sihane; Paquette, John; Rynö, Jouni; Stenzel, Oliver; Briois, Christelle; Kissel, Jochen; Koch, Andreas; Schulz, Rita; Silen, Johan; Altobelli, Nicolas; Baklouti, Donia; Bardyn, Anais; Cottin, Herve; Engrand, Cecile; Fray, Nicolas; Haerendel, Gerhard; Henkel, Hartmut; Höfner, Herwig; Hornung, Klaus; Lehto, Harry; Mellado, Eva Maria; Modica, Paola; Le Roy, Lena; Siljeström, Sandra; Steiger, Wolfgang; Thirkell, Laurent; Thomas, Roger; Torkar, Klaus; Varmuza, Kurt; Zaprudin, Boris

2017-07-13

The in situ cometary dust particle instrument COSIMA (COmetary Secondary Ion Mass Analyser) onboard ESA's Rosetta mission has collected about 31 000 dust particles in the inner coma of comet 67P/Churyumov-Gerasimenko since August 2014. The particles are identified by optical microscope imaging and analysed by time-of-flight secondary ion mass spectrometry. After dust particle collection by low speed impact on metal targets, the collected particle morphology points towards four families of cometary dust particles. COSIMA is an in situ laboratory that operates remotely controlled next to the comet nucleus. The particles can be further manipulated within the instrument by mechanical and electrostatic means after their collection by impact. The particles are stored above 0°C in the instrument and the experiments are carried out on the refractory, ice-free matter of the captured cometary dust particles. An interesting particle morphology class, the compact particles, is not fragmented on impact. One of these particles was mechanically pressed and thereby crushed into large fragments. The particles are good electrical insulators and transform into rubble pile agglomerates by the application of an energetic indium ion beam during the secondary ion mass spectrometry analysis.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

Ultraviolet Observations of Coronal Mass Ejection Impact on Comet 67P/Churyumov–Gerasimenko by Rosetta Alice

NASA Astrophysics Data System (ADS)

Noonan, John W.; Stern, S. Alan; Feldman, Paul D.; Broiles, Thomas; Wedlund, Cyril Simon; Edberg, Niklas J. T.; Schindhelm, Eric; Parker, Joel Wm.; Keeney, Brian A.; Vervack, Ronald J., Jr.; Steffl, Andrew J.; Knight, Matthew M.; Weaver, Harold A.; Feaga, Lori M.; A’Hearn, Michael; Bertaux, Jean-Loup

2018-07-01

The Alice ultraviolet spectrograph on the European Space Agency Rosetta spacecraft observed comet 67P/Churyumov–Gerasimenko in its orbit around the Sun for just over two years. Alice observations taken in 2015 October, two months after perihelion, show large increases in the comet’s Lyβ, O I 1304, O I 1356, and C I 1657 Å atomic emission that initially appeared to indicate gaseous outbursts. However, the Rosetta Plasma Consortium instruments showed a coronal mass ejection (CME) impact at the comet coincident with the emission increases, suggesting that the CME impact may have been the cause of the increased emission. The presence of the semi-forbidden O I 1356 Å emission multiplet is indicative of a substantial increase in dissociative electron impact emission from the coma, suggesting a change in the electron population during the CME impact. The increase in dissociative electron impact could be a result of the interaction between the CME and the coma of 67P or an outburst coincident with the arrival of the CME. The observed dissociative electron impact emission during this period is used to characterize the O2 content of the coma at two peaks during the CME arrival. The mechanism that could cause the relationship between the CME and UV emission brightness is not well constrained, but we present several hypotheses to explain the correlation.

Rosetta Lander - Philae: preparations for landing on comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Ulamec, S.; Biele, J.; Jurado, E.; Gaudon, P.; Geurts, K.

2013-12-01

Rosetta is a Cornerstone Mission of the ESA Horizon 2000 programme. It is going to rendezvous with comet 67P/Churyumov-Gerasimenko after a ten year cruise and will study both its nucleus and coma with an orbiting spacecraft as well as with a Lander, Philae, that has been designed to land softly on the comet nucleus. Aboard Philae, a payload consisting of ten scientific instruments will perform in-situ studies of the cometary material. Philae will be separated from the mother spacecraft from a dedicated delivery trajectory. It then descends, ballistically, to the surface of the comet, stabilized with an internal flywheel. At touch-down anchoring harpoons will be fired and a damping mechanism within the landing gear will provide the lander from re-bouncing. Currently the characteristics of the nucleus of the comet are hardly known. Mapping with the orbiter cameras (shape, slopes, surface roughness) and essential measurements like gravity field, state of rotation or outgassing parameters can only be performed after arrival of the main spacecraft, between May and October 2014. These data will be used for selecting a landing site and defining the detailed landing strategy. Landing is foreseen for November 2014 at a heliocentric distance of 3 AU. The paper describes the Rosetta Lander system and its payload, but emphasizes on the preparations for landing, the landing site selection process and the planned operational timeline.

Inventory of the volatiles on comet 67P/Churyumov-Gerasimenko from Rosetta/ROSINA

NASA Astrophysics Data System (ADS)

Le Roy, Léna; Altwegg, Kathrin; Balsiger, Hans; Berthelier, Jean-Jacques; Bieler, Andre; Briois, Christelle; Calmonte, Ursina; Combi, Michael R.; De Keyser, Johan; Dhooghe, Frederik; Fiethe, Björn; Fuselier, Stephen A.; Gasc, Sébastien; Gombosi, Tamas I.; Hässig, Myrtha; Jäckel, Annette; Rubin, Martin; Tzou, Chia-Yu

2015-11-01

Context. The ESA Rosetta spacecraft (S/C) is tracking comet 67P/Churyumov-Gerasimenko in close vicinity. This prolonged encounter enables studying the evolution of the volatile coma composition. Aims: Our work aims at comparing the diversity of the coma of 67P/Churyumov-Gerasimenko at large heliocentric distance to study the evolution of the comet during its passage around the Sun and at trying to classify it relative to other comets. Methods: We used the Double Focussing Mass Spectrometer (DFMS) of the ROSINA experiment on ESA's Rosetta mission to determine relative abundances of major and minor volatile species. This study is restricted to species that have previously been detected elsewhere. Results: We detect almost all species currently known to be present in cometary coma with ROSINA DFMS. As DFMS measured the composition locally, we cannot derive a global abundance, but we compare measurements from the summer and the winter hemisphere with known abundances from other comets. Differences between relative abundances between summer and winter hemispheres are large, which points to a possible evolution of the cometary surface. This comet appears to be very rich in CO2 and ethane. Heavy oxygenated compounds such as ethylene glycol are underabundant at 3 AU, probably due to their high sublimation temperatures, but nevertheless, their presence proves that Kuiper belt comets also contain complex organic molecules.

Study of Plasma Waves Observed onboard Rosetta in the 67P/ChuryumovGerasimenko Comet Environment Using High Time Resolution Density Data Inferred from RPC-MIP and RPC-LAP Cross-calibration

NASA Astrophysics Data System (ADS)

Breuillard, H.; Henri, P.; Vallières, X.; Eriksson, A. I.; Odelstad, E.; Johansson, F. L.; Richter, I.; Goetz, C.; Wattieaux, G.; Tsurutani, B.; Hajra, R.; Le Contel, O.

2017-12-01

During two years, the groundbreaking ESA/Rosetta mission was able to escort comet 67P where previous cometary missions were only limited to flybys. This enabled for the first time to make in-situ measurements of the evolution of a comet's plasma environment. The density and temperature measured by Rosetta are derived from RPC-Mutual Impedance Probe (MIP) and RPC-Langmuir Probe (LAP). On one hand, low time resolution electron density are calculated using the plasma frequency extracted from the MIP mutual impedance spectra. On the other hand, high time resolution density fluctuations are estimated from the spacecraft potential measured by LAP. In this study, using a simple spacecraft charging model, we perform a cross-calibration of MIP plasma density and LAP spacecraft potential variations to obtain high time resolution measurements of the electron density. These results are also used to constrain the electron temperature. Then we make use of these new dataset, together with RPC-MAG magnetic field measurements, to investigate for the first time the compressibility and the correlations between plasma and magnetic field variations, for both singing comet waves and steepened waves observed, respectively during low and high cometary outgassing activity, in the plasma environment of comet 67P.

Integrating linear optimization with structural modeling to increase HIV neutralization breadth.

PubMed

Sevy, Alexander M; Panda, Swetasudha; Crowe, James E; Meiler, Jens; Vorobeychik, Yevgeniy

2018-02-01

Computational protein design has been successful in modeling fixed backbone proteins in a single conformation. However, when modeling large ensembles of flexible proteins, current methods in protein design have been insufficient. Large barriers in the energy landscape are difficult to traverse while redesigning a protein sequence, and as a result current design methods only sample a fraction of available sequence space. We propose a new computational approach that combines traditional structure-based modeling using the Rosetta software suite with machine learning and integer linear programming to overcome limitations in the Rosetta sampling methods. We demonstrate the effectiveness of this method, which we call BROAD, by benchmarking the performance on increasing predicted breadth of anti-HIV antibodies. We use this novel method to increase predicted breadth of naturally-occurring antibody VRC23 against a panel of 180 divergent HIV viral strains and achieve 100% predicted binding against the panel. In addition, we compare the performance of this method to state-of-the-art multistate design in Rosetta and show that we can outperform the existing method significantly. We further demonstrate that sequences recovered by this method recover known binding motifs of broadly neutralizing anti-HIV antibodies. Finally, our approach is general and can be extended easily to other protein systems. Although our modeled antibodies were not tested in vitro, we predict that these variants would have greatly increased breadth compared to the wild-type antibody.

Ion composition variety and variability around perihelion

NASA Astrophysics Data System (ADS)

Beth, Arnaud; Altwegg, Kathrin; Behar, Étienne; Broiles, Tom; Burch, Jim; Carr, Christopher; Eriksson, Anders; Galand, Marina; Goetz, Charlotte; Henri, Pierre; Heritier, Kévin; Nilsson, Hans; Odelstad, Elias; Richter, Ingo; Rubin, Martin; Vallieres, Xavier

2017-04-01

For two years, the Double Focusing Mass Spectrometer (DFMS), one of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) onboard Rosetta probed the neutral gas and the plasma composition of the comet 67P/Churyumov-Gerasimenko's coma (67P). Major ion species detected include water ions (e.g, H2O+, H3O+, HO+) observed throughout the escorting phase. The analysis of DFMS data revealed a large zoo of ion species near perihelion (summer 2015). In particular, protonated versions of high proton affinity neutrals (e.g., NH4+) were detected, but also hydrocarbon and organic ion species. Near perihelion, ion composition was also highly variable and showed interesting variations in the complexity of the observed ion species. We will first present an overview of the rich variety of ion species observed during perihelion. This study will be supported by ionospheric modeling of ion composition below the ion exobase. We will then show an intercomparison between DFMS data and Rosetta Plasma Consortium (RPC) plasma and particle data to interpret the DFMS ion composition variability. Our primary goal is to highlight any correlation between observations from these different instruments (i.e. ion composition, ion and electron number density, energy distribution, magnetic field) and to find relevant signatures of physical processes which can affect the chemistry and dynamics (e.g., acceleration and deflection) of the involved neutral and ion species.

Ground truth of (sub-)micrometre cometary dust - Results of MIDAS onboard Rosetta

NASA Astrophysics Data System (ADS)

Mannel, Thurid; Bentley, Mark; Schmied, Roland; Torkar, Klaus; Jeszenszky, Harald; Romsted, Jens; Levasseur-Regourd, A.; Weber, Iris; Jessberger, Elmar K.; Ehrenfreund, Pascale; Köberl, Christian; Havnes, Ove

2016-10-01

The investigation of comet 67P by Rosetta has allowed the comprehensive characterisation of pristine cometary dust particles ejected from the nucleus. Flying alongside the comet at distances as small as a few kilometres, and with a relative velocity of only centimetres per second, the Rosetta payload sampled almost unaltered dust. A key instrument to study this dust was MIDAS (the Micro-Imaging Dust Analysis System), a dedicated atomic force microscope that scanned the surfaces of hundreds of (sub-)micrometre sized particles in 3D with resolutions down to nanometres. This offers the unique opportunity to explore the morphology of smallest cometary dust and expand our current knowledge about cometary material.Here we give an overview of dust collected and analysed by MIDAS and highlight its most important features. These include the ubiquitous agglomerate nature of the dust, which is found at all size scales from the largest (>10 µm) through to the smallest (<1 µm) dust particles. The sub-units show characteristic sizes and shapes that are compared with model predictions for interstellar dust.Our findings constrain key parameters of the evolution of the early Solar System. We will discuss which dust growth model is favoured by the observed morphology and how the results restrict cometary formation. Finally, dust particles detected by MIDAS resemble primitive interplanetary dust which is a strong argument for a common cometary origin.

Measuring stone volume - three-dimensional software reconstruction or an ellipsoid algebra formula?

PubMed

Finch, William; Johnston, Richard; Shaida, Nadeem; Winterbottom, Andrew; Wiseman, Oliver

2014-04-01

To determine the optimal method for assessing stone volume, and thus stone burden, by comparing the accuracy of scalene, oblate, and prolate ellipsoid volume equations with three-dimensional (3D)-reconstructed stone volume. Kidney stone volume may be helpful in predicting treatment outcome for renal stones. While the precise measurement of stone volume by 3D reconstruction can be accomplished using modern computer tomography (CT) scanning software, this technique is not available in all hospitals or with routine acute colic scanning protocols. Therefore, maximum diameters as measured by either X-ray or CT are used in the calculation of stone volume based on a scalene ellipsoid formula, as recommended by the European Association of Urology. In all, 100 stones with both X-ray and CT (1-2-mm slices) were reviewed. Complete and partial staghorn stones were excluded. Stone volume was calculated using software designed to measure tissue density of a certain range within a specified region of interest. Correlation coefficients among all measured outcomes were compared. Stone volumes were analysed to determine the average 'shape' of the stones. The maximum stone diameter on X-ray was 3-25 mm and on CT was 3-36 mm, with a reasonable correlation (r = 0.77). Smaller stones (<9 mm) trended towards prolate ellipsoids ('rugby-ball' shaped), stones of 9-15 mm towards oblate ellipsoids (disc shaped), and stones >15 mm towards scalene ellipsoids. There was no difference in stone shape by location within the kidney. As the average shape of renal stones changes with diameter, no single equation for estimating stone volume can be recommended. As the maximum diameter increases, calculated stone volume becomes less accurate, suggesting that larger stones have more asymmetric shapes. We recommend that research looking at stone clearance rates should use 3D-reconstructed stone volumes when available, followed by prolate, oblate, or scalene ellipsoid formulas depending on the maximum stone diameter. © 2013 The Authors. BJU International © 2013 BJU International.

Treatment of the Infected Stone.

PubMed

Marien, Tracy; Miller, Nicole L

2015-11-01

Infected kidney stones refer to stones that form because of urinary tract infections with urease-producing bacteria, secondarily infected stones of any composition, or stones obstructing the urinary tract leading to pyelonephritis. The mainstay of treatment of infection stones is complete stone removal. Kidney stones that obstruct the urinary tract and cause obstructive pyelonephritis are also frequently referred to as infected stones. Obstructive pyelonephritis is a urologic emergency as it can result in sepsis and even death. Infection stones and obstructive stones causing pyelonephritis are different disease processes, and their workup and management are described separately. Copyright © 2015 Elsevier Inc. All rights reserved.

New Probe of Early Phases of Jet Formation and Evolution using Stellar Tidal Disruption Flares

NASA Astrophysics Data System (ADS)

Ranga Reddy Pasham, Dheeraj; van Velzen, Sjoert

2018-01-01

The tidal disruption of a star by a supermassive black hole can result in transient radio emission. The electrons producing these synchrotron radio flares could either be accelerated inside a relativistic jet or externally by shocks resulting from an outflow interacting with the circumnuclear medium. Until now, evidence for the internal emission mechanism has been lacking; nearly all tidal disruption flare studies have adopted the external shock model to explain the observed properties of radio flares. I will talk about a result that presents a challenge to external emission models: we discovered a cross-correlation between the soft X-ray (0.3-1 keV) and 16 GHz radio flux of Rosetta Stone tidal disruption flare ASASSN-14li. Variability features in the X-ray light curve appear again in the radio light curve, but after a time lag of about 13 days. This demonstrates that soft X-ray emitting accretion disk regulates the radio emission. This coupling appears to be inconsistent with all previous external emission models for this source but is naturally explained if the radio emission originates from a freely expanding jet. I will show that emission internal to an adiabatically expanding jet can also reproduce the observed evolution of the radio spectral energy distribution. Furthermore, both the correlation between X-ray and radio luminosity as well as our radio spectral modeling imply an approximately linear coupling between the accretion rate and jet power. I will also discuss how future tidal disruption events can help us understand how jets form and evolve in general.

Are ship tracks useful analogs for studying the aerosol indirect effect?

NASA Astrophysics Data System (ADS)

Christensen, M.; Toll, V.; Stephens, G. L.

2017-12-01

Vessels transiting the ocean sometimes leave their mark on the clouds - leaving behind reflective cloud lines, known as ship tracks. Ship tracks have been looked upon by some as a possible Rosetta Stone connecting the effects of changing aerosol over the ocean and cloud albedo effects on climate (Porch et al. 1990, Atmos. Enviorn., 1051-1059). In this research, we establish whether ship tracks, and volcano tracks - a natural analog, can be used to relate these cloud-scale perturbations to the aerosol effects occurring at larger regional-scales. Two databases containing over 1,500 ship and 900 volcano tracks, all carefully hand-selected from satellite imagery, are utilized; showing that ship tracks exhibit very similar cloud albedo effect responses to that of volcano tracks. For comparison, our global dataset utilises over 7 million CloudSat profiles consisting of single-layer marine warm cloud in which the retrievals are co-located with the MODerate Imaging Spectroradiometer (MODIS) product so that statistical relationships between aerosol and cloud can be computed over 4x4 degree regions. All datasets show the same key physical processes that govern the cloud-aerosol indirect effect, namely, the strong negative responses in cloud droplet size and the bidirectional responses in liquid water path and cloud albedo depending on the meteorological conditions. Finally, this analysis is extended to a comparison against several general circulation models where it is suggested that key processes such as cloud-top entrainment and evaporation that regulates against strong liquid water path responses are likely underrepresented in most models.

OJ287: Deciphering the "Rosetta stone of blazars★"

NASA Astrophysics Data System (ADS)

Britzen, S.; Fendt, C.; Witzel, G.; Qian, S.-J.; Pashchenko, I. N.; Kurtanidze, O.; Zajacek, M.; Martinez, G.; Karas, V.; Aller, M.; Aller, H.; Eckart, A.; Nilsson, K.; Arévalo, P.; Cuadra, J.; Subroweit, M.; Witzel, A.

2018-04-01

OJ287 is the best candidate Active Galactic Nucleus (AGN) for hosting a supermassive binary black hole (SMBBH) at very close separation. We present 120 Very Long Baseline Array (VLBA) observations (at 15 GHz) covering the time between Apr. 1995 and Apr. 2017. We find that the OJ287 radio jet is precessing on a timescale of ˜ 22 yr. In addition, our data are consistent with a jet-axis rotation on a yearly timescale. We model the precession (24±2 yr) and combined motion of jet precession and jet-axis rotation. The jet motion explains the variability of the total radio flux-density via viewing angle changes and Doppler beaming. Half of the jet-precession timescale is of the order of the dominant optical periodicity timescale. We suggest that the optical emission is synchrotron emission and related to the jet radiation. The jet dynamics and flux-density light curves can be understood in terms of geometrical effects. Disturbances of an accretion disc caused by a plunging black hole do not seem necessary to explain the observed variability. Although the SMBBH model does not seem necessary to explain the observed variability, a SMBBH or Lense-Thirring precession (disc aSround single black hole) seem to be required to explain the timescale of the precessing motion. Besides jet rotation also nutation of the jet axis could explain the observed motion of the jet axis. We find a strikingly similar scaling for the timescales for precession and nutation as indicated for SS433 with a factor of roughly 50 times longer in OJ287.

Burke-Fahn-Marsden dystonia severity, Gross Motor, Manual Ability, and Communication Function Classification scales in childhood hyperkinetic movement disorders including cerebral palsy: a 'Rosetta Stone' study.

PubMed

Elze, Markus C; Gimeno, Hortensia; Tustin, Kylee; Baker, Lesley; Lumsden, Daniel E; Hutton, Jane L; Lin, Jean-Pierre S-M

2016-02-01

Hyperkinetic movement disorders (HMDs) can be assessed using impairment-based scales or functional classifications. The Burke-Fahn-Marsden Dystonia Rating Scale-movement (BFM-M) evaluates dystonia impairment, but may not reflect functional ability. The Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS), and Communication Function Classification System (CFCS) are widely used in the literature on cerebral palsy to classify functional ability, but not in childhood movement disorders. We explore the concordance of these three functional scales in a large sample of paediatric HMDs and the impact of dystonia severity on these scales. Children with HMDs (n=161; median age 10y 3mo, range 2y 6mo-21y) were assessed using the BFM-M, GMFCS, MACS, and CFCS from 2007 to 2013. This cross-sectional study contrasts the information provided by these scales. All four scales were strongly associated (all Spearman's rank correlation coefficient rs >0.72, p<0.001), with worse dystonia severity implying worse function. Secondary dystonias had worse dystonia and less function than primary dystonias (p<0.001). A longer proportion of life lived with dystonia is associated with more severe dystonia (rs =0.42, p<0.001). The BFM-M is strongly linked with the GMFCS, MACS, and CFCS, irrespective of aetiology. Each scale offers interrelated but complementary information and is applicable to all aetiologies. Movement disorders including cerebral palsy can be effectively evaluated using these scales. © 2015 Mac Keith Press.

Imaging-based assessment of the mineral composition of urinary stones: an in vitro study of the combination of hounsfield unit measurement in noncontrast helical computerized tomography and the twinkling artifact in color Doppler ultrasound.

PubMed

Hassani, Hakim; Raynal, Gauthier; Spie, Romain; Daudon, Michel; Vallée, Jean-Noël

2012-05-01

We evaluated the value of combining noncontrast helical computerized tomography (NCHCT) and color Doppler ultrasound in the assessment of the composition of urinary stones. In vitro, we studied 120 stones of known composition, that separate into the five main types: 18 calcium oxalate monohydrate (COM) stones, 41 calcium oxalate dihydrate (COD) stones, 24 uric acid stones, 25 calcium phosphate stones and 12 cystine calculi. Stones were characterized in terms of their Hounsfield density (HU) in NCHCT and the presence of a twinkling artifact (TA) in color Doppler ultrasound. There were statistically significant HU differences between calcium and non-calcium stones (p < 0.001), calcium oxalate stones and calcium phosphate stones (p < 0.001) and uric acid stones and cystine calculi (p < 0.001) but not between COM and COD stones (p = 0.786). Hence, the HU was a predictive factor of the composition of all types of stones, other than for COM and COD stones within the calcium oxalate class (p > 0.05). We found that the TA does not enable differentiation between calcium and non-calcium stones (p > 0.999), calcium oxalate stones and calcium phosphate stones (p = 0.15), or uric acid stones and cystine calculi (p = 0.079). However, it did reveal a significant difference between COM and COD stones (p = 0.002). The absence of a TA is a predictive factor for the presence of COM stones (p = 0.008). Hence, the association of NCHCT and Doppler enables the accurate classification of the five types of stones in vitro. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Stone size limits the use of Hounsfield units for prediction of calcium oxalate stone composition.

PubMed

Stewart, Gregory; Johnson, Lewis; Ganesh, Halemane; Davenport, Daniel; Smelser, Woodson; Crispen, Paul; Venkatesh, Ramakrishna

2015-02-01

To evaluate the role of stone size in predicting urinary calculus composition using Hounsfield units on noncontrasted computed tomography (CT) scan. A retrospective review was performed for all patients who underwent ureteroscopy or percutaneous nephrolithotomy during a 1-year period, had a stone analysis performed, and had CT imaging available for review. All CT scans were reviewed by a board-certified radiologist. Variables evaluated included age, sex, body mass index, stone size, stone location, Hounsfield units (HUs), and stone composition. We identified a total of 91 patients (41 men and 50 women) with CT imaging and stone analysis available for review. Stone analysis showed 41 calcium oxalate monohydrate (CaOxMH), 13 calcium oxalate dihydrate, 29 calcium phosphate, 5 uric acid, 2 struvite, and 1 cystine stone. Average age was 46 years, and average body mass index was 32 kg/m2. Measured HUs varied significantly with size for CaOxMH and calcium oxalate dihydrate stones (P values <.05), but not for calcium phosphate stones (P = .126). Using a CaOxMH identification value of 700-1000 HUs, 28 of 41 stone compositions (68%) would not have been correctly identified, including all 10 (100%) small (<5 mm) stones, 13 of 22 (59%) medium (5-10 mm) stones, and 5 of 9 large (>10 mm) stones (55%). For calcium stones, the ability of CT HUs to predict stone composition was limited, likely due to the mixed stone composition. Within a cohort of CaOxMH stone formers, measured HUs varied linearly with stone size. All stones <5 mm were below thresholds for CaOxMH composition. Copyright © 2015 Elsevier Inc. All rights reserved.

Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Hässig, M.; Altwegg, K.; Balsiger, H.; Bar-Nun, A.; Berthelier, J. J.; Bieler, A.; Bochsler, P.; Briois, C.; Calmonte, U.; Combi, M.; De Keyser, J.; Eberhardt, P.; Fiethe, B.; Fuselier, S. A.; Galand, M.; Gasc, S.; Gombosi, T. I.; Hansen, K. C.; Jäckel, A.; Keller, H. U.; Kopp, E.; Korth, A.; Kührt, E.; Le Roy, L.; Mall, U.; Marty, B.; Mousis, O.; Neefs, E.; Owen, T.; Rème, H.; Rubin, M.; Sémon, T.; Tornow, C.; Tzou, C.-Y.; Waite, J. H.; Wurz, P.

2015-01-01

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface.

Protein Scaffolding for Small Molecule Catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, David

We aim to design hybrid catalysts for energy production and storage that combine the high specificity, affinity, and tunability of proteins with the potent chemical reactivities of small organometallic molecules. The widely used Rosetta and RosettaDesign methodologies will be extended to model novel protein / small molecule catalysts in which one or many small molecule active centers are supported and coordinated by protein scaffolding. The promise of such hybrid molecular systems will be demonstrated with the nickel-phosphine hydrogenase of DuBois et. al.We will enhance the hydrogenase activity of the catalyst by designing protein scaffolds that incorporate proton relays and systematicallymore » modulate the local environment of the catalyticcenter. In collaboration with DuBois and Shaw, the designs will be experimentally synthesized and characterized.« less

Collecting cometary soil samples? Development of the ROSETTA sample acquisition system

NASA Technical Reports Server (NTRS)

Coste, P. A.; Fenzi, M.; Eiden, Michael

1993-01-01

In the reference scenario of the ROSETTA CNRS mission, the Sample Acquisition System is mounted on the Comet Lander. Its tasks are to acquire three kinds of cometary samples and to transfer them to the Earth Return Capsule. Operations are to be performed in vacuum and microgravity, on a probably rough and dusty surface, in a largely unknown material, at temperatures in the order of 100 K. The concept and operation of the Sample Acquisition System are presented. The design of the prototype corer and surface sampling tool, and of the equipment for testing them at cryogenic temperatures in ambient conditions and in vacuum in various materials representing cometary soil, are described. Results of recent preliminary tests performed in low temperature thermal vacuum in a cometary analog ice-dust mixture are provided.

Dust Impact Monitor (SESAME-DIM) on-board Rosetta/Philae: Aerogel as comet analog material

NASA Astrophysics Data System (ADS)

Flandes, Alberto; Albin, Thomas; Arnold, Walter; Fischer, Hans-Herbert; Hirn, Attila; Loose, Alexander; Mewes, Cornelia; Podolak, Morris; Seidensticker, Klaus J.; Volkert, Cynthia; Krüger, Harald

2018-03-01

On 12 November 2014, during the descent of the Rosetta lander Philae to the surface of comet 67P/Churyumov-Gerasimenko the Dust Impact Monitor (DIM) on board Philae recorded an impact of a cometary dust impact of a cometary dust particle at 2.4 km from the comet surface (5 km from the nucleus' barycentre). In this work, we report further experiments that support the identification of this particle. We use aerogel as a comet analog material to characterise the properties of this particle. Our experiments show that this particle has a radius of 0.9 mm, a low density of 0.25 g/cm3 and a high porosity close to 90%. The particle likely moved at near 4 m/s with respect to the comet.

Protein Structure Determination using Metagenome sequence data

PubMed Central

Ovchinnikov, Sergey; Park, Hahnbeom; Varghese, Neha; Huang, Po-Ssu; Pavlopoulos, Georgios A.; Kim, David E.; Kamisetty, Hetunandan; Kyrpides, Nikos C.; Baker, David

2017-01-01

Despite decades of work by structural biologists, there are still ~5200 protein families with unknown structure outside the range of comparative modeling. We show that Rosetta structure prediction guided by residue-residue contacts inferred from evolutionary information can accurately model proteins that belong to large families, and that metagenome sequence data more than triples the number of protein families with sufficient sequences for accurate modeling. We then integrate metagenome data, contact based structure matching and Rosetta structure calculations to generate models for 614 protein families with currently unknown structures; 206 are membrane proteins and 137 have folds not represented in the PDB. This approach provides the representative models for large protein families originally envisioned as the goal of the protein structure initiative at a fraction of the cost. PMID:28104891

Bladder stones after bladder augmentation are not what they seem.

PubMed

Szymanski, Konrad M; Misseri, Rosalia; Whittam, Benjamin; Lingeman, James E; Amstutz, Sable; Ring, Joshua D; Kaefer, Martin; Rink, Richard C; Cain, Mark P

2016-04-01

Bladder and renal calculi after bladder augmentation are thought to be primarily infectious, yet few studies have reported stone composition. The primary aim was to assess bladder stone composition after augmentation, and renal stone composition in those with subsequent nephrolithiasis. The exploratory secondary aim was to screen for possible risk factors for developing infectious stones. Patients treated for bladder stones after bladder augmentation at the present institution between 1981 and 2012 were retrospectively reviewed. Data were collected on demographics, surgeries and stone composition. Patients without stone analysis were excluded. Stones containing struvite, carbonate apatite or ammonium acid ureate were classified as infectious. The following variables were analyzed for a possible association with infectious bladder stone composition: gender, history of cloacal exstrophy, ambulatory status, nephrolithiasis, recurrent urea-splitting urinary tract infections, first vs recurrent stones, timing of presentation with a calculus, history of bladder neck procedures, catheterizable channel and vesicoureteral reflux. Fisher's exact test was used for analysis. Of the 107 patients with bladder stones after bladder augmentation, 85 met inclusion criteria. Median age at augmentation was 8.0 years (follow-up 10.8 years). Forty-four patients (51.8%) recurred (14 multiple recurrences, 143 bladder stones). Renal calculi developed in 19 (22.4%) patients with a bladder stone, and 10 (52.6%) recurred (30 renal stones). Overall, 30.8% of bladder stones were non-infectious (Table). Among patients recurring after an infectious bladder stone, 30.4% recurred with a non-infectious one. Among patients recurring after a non-infectious stone, 84.6% recurred with a non-infectious one (P = 0.005). Compared with bladder stones, renal stones were more likely to be non-infectious (60.0%, P = 0.003). Of patients with recurrent renal calculi after an infectious stone, 40.0% recurred with a non-infectious one. No clinical variables were significantly associated with infectious stone composition on univariate (≥0.28) or bivariate analysis (≥0.36). This study had several limitations: it was not possible to accurately assess adherence with bladder irrigations, and routine metabolic evaluations were not performed. The findings may not apply to patients in all clinical settings. While stone analysis was available for 3/4 of the stones, similar rates of incomplete stone analyses have been reported in other series. In patients with bladder augmentation, 1/3 of bladder stones and >1/2 of renal stones were non-infectious. Furthermore, an infectious stone does not imply an infectious recurrent stone and no known clinical variables appear to be associated with stone composition, suggesting that there is a possible metabolic component in stone formation after bladder augmentation. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Renal stone composition does not affect the outcome of percutaneous nephrolithotomy in children.

PubMed

Kaygısız, Onur; Türegün, Fethi Ahmet; Satar, Nihat; Özen, Ender; Toksöz, Serdar; Doğan, Hasan Serkan; Pişkin, Mehmet Mesut; İzol, Volkan; Sarıkaya, Şaban; Kılıçarslan, Hakan; Çiçek, Tufan; Öztürk, Ahmet; Tekgül, Serdar; Önal, Bülent

2018-05-14

We sought to investigate the association between renal stone composition and percutaneous nephrolithotomy outcomes in pediatric patients and define the characterization of the stone composition. The data of 1157 children who underwent percutaneous nephrolithotomy between 1991 and 2012 were retrieved from the multicenter database of the Turkish Pediatric Urology Society. The study population comprised 359 children (160 girls, 199 boys) with stone analyses. Patients were divided into five groups according to the stone composition [group 1: calcium oxalate; group 2: calcium phosphate; group 3: infection stones (magnesium ammonium phosphate, ammonium urate); group 4: cystine; group 5: uric acid, xanthine stones]. Patient characteristics, perioperative, postoperative, and stone characteristics were compared considering the stone composition. There were no significant differences between the groups concerning age, sex, side involved, preoperative hematocrit levels, and solitary renal unit. Patients with cystine stones were more likely to have a history of stone treatment. Groups 2 and 5 had mostly solitary stones. However, group 3 had staghorn stone more often, and group 4 frequently had multiple stones. Overall stone-free rate (79.4%) was similar among the groups. Although stone composition was related to blood transfusion and prolonged operative and fluoroscopy screening times on univariate analysis, it was not a significant predictor of them on multivariate analysis. Stone composition was not a predictor of outcomes of pediatric percutaneous nephrolithotomy. However, cystine and infection stones, which are larger and filled multiple calyxes due to the nature of stone forming, were more challenging cases that need multiple tracts.

Stone heterogeneity index on single-energy noncontrast computed tomography can be a positive predictor of urinary stone composition

PubMed Central

Lee, Jong Soo; Cho, Kang Su; Lee, Seung Hwan; Yoon, Young Eun; Kang, Dong Hyuk; Jeong, Won Sik; Jung, Hae Do; Kwon, Jong Kyou

2018-01-01

The aim of this study was to investigate the correlation between stone composition and single-energy noncontrast computed tomography (NCCT) parameters, including stone heterogeneity index (SHI) and mean stone density (MSD), in patients with urinary calculi. We retrospectively reviewed medical records of 255 patients who underwent operations or procedures for urinary stones or had spontaneous stone passage between December 2014 and October 2015. Among these, 214 patients with urinary calculi who underwent NCCT and stone composition analyses were included in the study. Maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) were determined on pretreatment NCCT. The mean MSD (454.68±177.80 HU) and SHI (115.82±96.31 HU) of uric acid stones were lower than those of all other types. Based on post hoc tests, MSD was lower for uric acid stones than for the other types (vs. CaOx: P<0.001; vs. infection stones: P<0.001). SHI was lower for uric acid stones than for the other types (vs. CaOx: P<0.001; vs. infection stones: P<0.001) Receiver operating characteristic curves of uric acid stones for MSD and SHI demonstrated that SHI (cut-off value: 140.4 HU) was superior to MSD (cut-off value: 572.3 HU) in predicting uric acid stones (P<0.001). PMID:29649219

MECHANISMS OF HUMAN KIDNEY STONE FORMATION

PubMed Central

Evan, Andrew P.; Worcester, Elaine M.; Coe, Fredric L.; Williams, James; Lingeman, James E.

2014-01-01

The precise mechanisms of kidney stone formation and growth are not completely known, even though human stone disease appears to be one of the oldest diseases known to medicine. With the advent of the new digital endoscope and detailed renal physiological studies performed on well phenotyped stone formers, substantial advances have been made in our knowledge of the pathogenesis of the most common type of stone former, the idiopathic calcium oxalate stone former (ICSF) as well as nine other stone forming groups. The observations from our group on human stone formers and those of others on model systems have suggested four entirely different pathways for kidney stone formation. Calcium oxalate stone growth over sites of Randall’s plaque appear to be the primary mode of stone formation for those patients with hypercalciuria. Overgrowths off the ends of Bellini duct plugs have been noted in most stone phenotypes, do they result in a clinical stone? Micro-lith formation does occur within the lumens of dilated inner medullary collecting ducts of cystinuric stone formers and appear to be confined to this space. Lastly, cystinuric stone formers also have numerous small, oval, smooth yellow appearing calyceal stones suggestive of formation in free solution. The scientific basis for each of these four modes of stone formation are reviewed and used to explore novel research opportunities. PMID:25108546

The Effect of Stone Composition on the Efficacy of Retrograde Intrarenal Surgery: Kidney Stones 1 - 3 cm in Diameter.

PubMed

Xue, Yuquan; Zhang, Peng; Yang, Xiaojie; Chong, Tie

2015-05-01

The goal of this study was to analyze the effect of stone composition on the efficacy of retrograde intrarenal surgery (RIRS) with kidney stones of 1-3 cm, 1-2 cm, and 2-3 cm in diameter. We undertook a retrospective analysis of 74 patients with kidney stones who underwent RIRS. The patients were divided into two groups based on stone composition: Group I (n=47) (calcium oxalate monohydrate and calcium phosphate) was the hard to fragment stone group and group II (n=27) (calcium oxalate dihydrate, magnesium ammonium phosphate, and uric acid) was the easy to fragment stone group. Forty-six patients with kidney stones 1 to 2 cm in diameter were divided into group A (n=30) (smaller than 20 mm, hard to fragment stones) and group B (n=16) (smaller than 20 mm, easy to fragment stones). Twenty-eight patients with stones 2 to 3 cm in diameter were divided into group C (n=17) (larger than 20 mm, hard to fragment stones) and group D (n=11) (larger than 20 mm, easy-to-crush stones). The stone clearance rates of group I and group II were 66.0% and 88.9%, respectively (P<0.05). The stone clearance rates of group A and group B were 73.3% and 100% (P<0.05). The stone clearance rates of group C and group D were 52.9% and 72.7%, respectively. Stone composition has a significant impact on the efficacy of RIRS in the management of 1 to 3 cm kidney stones. For 2-3 cm calcium oxalate dihydrate stones, uric acid stones, and magnesium ammonium phosphate stones, the outcome of RIRS treatment was relatively good, and RIRS is recommended.

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro.

PubMed

Zarse, Chad A; Hameed, Tariq A; Jackson, Molly E; Pishchalnikov, Yuri A; Lingeman, James E; McAteer, James A; Williams, James C

2007-08-01

Calcium oxalate monohydrate (COM) stones are often resistant to breakage using shock wave (SW) lithotripsy. It would be useful to identify by computed tomography (CT) those COM stones that are susceptible to SW's. For this study, 47 COM stones (4-10 mm in diameter) were scanned with micro CT to verify composition and also for assessment of heterogeneity (presence of pronounced lobulation, voids, or apatite inclusions) by blinded observers. Stones were then placed in water and scanned using 64-channel helical CT. As with micro CT, heterogeneity was assessed by blinded observers, using high-bone viewing windows. Then stones were broken in a lithotripter (Dornier Doli-50) over 2 mm mesh, and SW's counted. Results showed that classification of stones using micro CT was highly repeatable among observers (kappa = 0.81), and also predictive of stone fragility. Stones graded as homogeneous required 1,874 +/- 821 SW/g for comminution, while stones with visible structure required half as many SW/g, 912 +/- 678. Similarly, when stones were graded by appearance on helical CT, classification was repeatable (kappa = 0.40), and homogeneous stones required more SW's for comminution than did heterogeneous stones (1,702 +/- 993 SW/g, compared to 907 +/- 773). Stone fragility normalized to stone size did not correlate with Hounsfield units (P = 0.85). In conclusion, COM stones of homogeneous structure require almost twice as many SW's to comminute than stones of similar mineral composition that exhibit internal structural features that are visible by CT. This suggests that stone fragility in patients could be predicted using pre-treatment CT imaging. The findings also show that Hounsfield unit values of COM stones did not correlate with stone fragility. Thus, it is stone morphology, rather than X-ray attenuation, which correlates with fragility to SW's in this common stone type.

A comparative study of mud-like and coralliform calcium carbonate gallbladder stones.

PubMed

Ma, Rui-Hong; Luo, Xiao-Bing; Wang, Xiao-Feng; Qiao, Tie; Huang, Hai-Yi; Zhong, Hai-Qiang

2017-07-01

To gain insight to underlying mechanism of the formation of calcium carbonate (CaCO 3 ) gallbladder stones, we did comparative study of stones with mud appearance and those with coralliform appearance. A total of 93 gallbladder stones with mud appearance and 50 stones with coralliform appearance were analyzed. The appearance, color, texture, and the detection of Clonorchis sinensis eggs by microscopic examination were compared between the two groups. Then, the material compositions of stones were analyzed using Fourier Transform Infrared spectroscopy and the spectrogram characteristics were compared. Moreover, microstructure characteristics of the two kinds of stones were observed and compared with Scanning Electron Microscopy. Mud-like gallbladder stones were mainly earthy yellow or brown with brittle or soft texture, while coralliform stones were mainly black with extremely hard texture, the differences between the two groups was significant (p < .05). The analytic results of FTIR spectroscopy showed that 95.7% (89/93) of the mud-like gallbladder stones were CaCO 3 stones, and mainly aragonite; while all of the coralliform stones were CaCO 3 stones, and mainly calcite (p < .05). Meanwhile, microscopic examination indicated that the detection rate of Clonorchis sinensis eggs in mud-like CaCO 3 stones was lower than that in coralliform CaCO 3 stones (p < .05), and that in aragonite CaCO 3 stones was lower than that in calcite CaCO 3 stones(p < .05). Mud-like CaCO 3 stones mainly happened to patients with cystic duct obstruction. Clonorchis sinensis infection was mainly associated with coralliform (calcite) CaCO 3 stones. Cystic duct obstruction was mainly associated with mud-like (aragonite) CaCO 3 stones. © 2017 Wiley Periodicals, Inc.

Is There A Difference Between Presence of Single Stone And Multiple Stones in Flexible Ureterorenoscopy And Laser Lithotripsy For Renal Stone Burden < 300mm2 ?

PubMed

Ozgor, Faruk; Kucuktopcu, Onur; Ucpinar, Burak; Gurbuz, Zafer Gokhan; Sarilar, Omer; Berberoglu, Ahmet Yalcin; Baykal, Murat; Binbay, Murat

2016-01-01

In this study, we aim to evaluate and compare the effectiveness of flexible ureterorenoscopy (f-URS) for solitary and multiple renal stones with < 300 mm2 stone burden. Patients' charts who treated with f-URS for kidney stone between January 2010 and June 2015 were reviewed, retrospectively. Patients with solitary kidney stones (n:111) were enrolled in group 1. We selected 111 patients with multiple kidney stones to serve as the control group and the patients were matched at a 1:1 ratio with respect to the patient's age, gender, body mass index and stone burden. Additionally, patients with multiple stones were divided into two groups according to the presence or abscence of lower pole stones. Stone free status was accepted as complete stone clearence and presence of residual fragments < 2 mm. According to the study design; age, stone burden, body mass index were comparable between groups. The mean operation time was longer in group 2 (p= 0.229). However, the mean fluoroscopy screening time in group 1 and in group 2 was 2.1±1.7 and 2.6±1.5 min, respectively and significantly longer in patients with multiple renal stones (P=0.043). The stone-free status was significantly higher in patients with solitary renal stones after a single session procedure (p=0.02). After third month follow up, overall success rate was 92.7% in Group 1 and 86.4% in Group 2. Our study revealed that F-URS achieved better stone free status in solitary renal stones < 300 mm2. However, outcomes of F-URS were acceptable in patients with multiple stones. Copyright® by the International Brazilian Journal of Urology.

Bacteria entombed in the center of cholesterol gallstones induce fewer infectious manifestations than bacteria in the matrix of pigment stones.

PubMed

Stewart, Lygia; Griffiss, J McLeod; Jarvis, Gary A; Way, Lawrence W

2007-10-01

The clinical significance of bacteria in the pigment centers of cholesterol stones is unknown. We compared the infectious manifestations and characteristics of bacteria from pigment stones and predominantly cholesterol stones. Three hundred forty patients were studied. Bile was cultured. Gallstones were cultured and examined with scanning electron microscopy. Level of bacterial immunoglobulin G (bile, serum), complement killing, and tumor necrosis factor-alpha production were determined. Twenty-three percent of cholesterol stones and 68% of pigment stones contained bacteria (P < 0.0001). Stone culture correlated with scanning electron microscopy results. Pigment stone bacteria were more often present in bile and blood. Cholesterol stone bacteria caused more severe infections (19%) than sterile stones (0%), but less than pigment stone bacteria (57%) (P < 0.0001). Serum and bile from patients with cholesterol stone bacteria had less bacterial-specific immunoglobulin G. Cholesterol stone bacteria produced more slime. Pigment stone bacteria were more often killed by a patient's serum. Tumor necrosis factor-alpha production of the groups was similar. Bacteria are readily cultured from cholesterol stones with pigment centers, allowing for analysis of their virulence factors. Bacteria sequestered in cholesterol stones cause infectious manifestations, but less than bacteria in pigment stones. Possibly because of their isolation, cholesterol stone bacteria were less often present in bile and blood, induced less immunoglobulin G, were less often killed by a patient's serum, and demonstrated fewer infectious manifestations than pigment stone bacteria. This is the first study to analyze the clinical relevance of bacteria within cholesterol gallstones.

The Guy's stone score--grading the complexity of percutaneous nephrolithotomy procedures.

PubMed

Thomas, Kay; Smith, Naomi C; Hegarty, Nicholas; Glass, Jonathan M

2011-08-01

To report the development and validation of a scoring system, the Guy's stone score, to grade the complexity of percutaneous nephrolithotomy (PCNL). Currently, no standardized method is available to predict the stone-free rate after PCNL. The Guy's stone score was developed through a combination of expert opinion, published data review, and iterative testing. It comprises 4 grades: grade I, solitary stone in mid/lower pole or solitary stone in the pelvis with simple anatomy; grade II, solitary stone in upper pole or multiple stones in a patient with simple anatomy or a solitary stone in a patient with abnormal anatomy; grade III, multiple stones in a patient with abnormal anatomy or stones in a caliceal diverticulum or partial staghorn calculus; grade IV, staghorn calculus or any stone in a patient with spina bifida or spinal injury. It was assessed for reproducibility using the kappa coefficient and validated on a prospective database of 100 PCNL procedures performed in a tertiary stone center. The complications were graded using the modified Clavien score. The clinical outcomes were recorded prospectively and assessed with multivariate analysis. The Guy's stone score was the only factor that significantly and independently predicted the stone-free rate (P = .01). It was found to be reproducible, with good inter-rater agreement (P = .81). None of the other factors tested, including stone burden, operating surgeon, patient weight, age, and comorbidity, correlated with the stone-free rate. The Guy's stone score accurately predicted the stone-free rate after PCNL. It was easy to use and reproducible. Copyright © 2011 Elsevier Inc. All rights reserved.

Electronics for a Spectrometer

NASA Image and Video Library

2014-01-24

NASA has provided part of the electronics package for an instrument called the Double Focusing Mass Spectrometer, which is part of the Swiss-built Rosetta Orbiter Spectrometer for Ion and Neutral Analysis ROSINA instrument.

Characteristics of organic matter fractions separated by wet-sieving and differences in density from five soils of different pedogenesis under mature beech forest.

NASA Astrophysics Data System (ADS)

Vormstein, Svendja; Kaiser, Michael; Ludwig, Bernard

2017-04-01

Forest top- and subsoil account for approximately 70 % of the organic C (OC) globally stored in soil reasoning their large importance for terrestrial ecosystem services such as the mitigation of climate change. In contrast to forest topsoil, there is much less information about the decomposition and stabilization of organic matter (OM) in subsoil. Therefore, we sampled the pedogenetic horizons of five soils under mature beech forest developed on different parent material (i.e. Tertiary Sand, Loess, Basalt, Lime Stone, Red Sandstone) down to the bedrock. The bulk soil samples were characterized for texture, oxalate and dithionite soluble Fe and Al, pH, OC, microbial biomass C and basal respiration (cumulative CO2 emission after 7 and 14 days). Furthermore, we analyzed aggregate size fractions separated by wet-sieving (i.e. >1000 µm, 1000-250 µm, 250-53 µm, <53 µm) and density fractions separated using NaPT (i.e. light, occluded light, and heavy fraction) from the soil horizon specific samples. The OC of the topsoil (Ah horizon) on Lime Stone and Red Sandstone was predominately stored in the larger macro-aggregates (>1000 µm). In contrast, the major part of the topsoil OC on Basalt and Tertiary Sand was found in the smaller macro-aggregates (1000-250 µm). For the topsoil samples, we found that the basal respiration as well as the microbial biomass C were positively correlated (p ≤0.05) with the OC amounts associated with the free and occluded light fraction and with the macro-aggregates (1000-250 µm) and micro-aggregates (250-53 µm) suggesting these fractions to store the major part of the easily decomposable OM. The OC amount associated with the heavy fraction and the fraction <53 µm was correlated with the contents of oxalate and dithionite soluble Fe and Al suggesting interactions between organic compounds and Fe- and Al-oxides to be highly important for the OM stabilization in forest topsoil. In the subsoil (horizons below the Ah), the contribution of the OC associated with the aggregate size fractions <250 µm to the OC stored in the subsoil increased with depth. The OC contents associated with the free and occluded light as well as the heavy fraction and with the aggregate size fractions >53 µm were positively correlated with basal respiration and the microbial biomass C. This suggests, in contrast to the topsoil, the easily decomposable OM to be distributed more homogeneously among fractions. Only the OC content of the <53 µm fraction showed positive correlations to soil mineral characteristics such as the contents of clay oxalate and dithionite soluble Fe or Al and no relationship to the basal respiration and microbial biomass C. This indicates the OM associated with this fraction to be most diagnostic for the amount of OC stabilized against microbial decay in the subsoil and interactions between OM and oxides as well as layer silicates to be relevant stabilization mechanisms. The results point toward similar OM stabilization mechanisms in the analysed forest top- and subsoils but revealed differences in the distribution of easily decomposable OM within the soil matrix.

Incidence of kidney stones in kidney transplant recipients: A systematic review and meta-analysis

PubMed Central

Cheungpasitporn, Wisit; Thongprayoon, Charat; Mao, Michael A; Kittanamongkolchai, Wonngarm; Jaffer Sathick, Insara J; Dhondup, Tsering; Erickson, Stephen B

2016-01-01

AIM To evaluate the incidence and characteristics of kidney stones in kidney transplant recipients. METHODS A literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the inception of the databases through March 2016. Studies assessing the incidence of kidney stones in kidney transplant recipients were included. We applied a random-effects model to estimate the incidence of kidney stones. RESULTS Twenty one studies with 64416 kidney transplant patients were included in the analyses to assess the incidence of kidney stones after kidney transplantation. The estimated incidence of kidney stones was 1.0% (95%CI: 0.6%-1.4%). The mean duration to diagnosis of kidney stones after kidney transplantation was 28 ± 22 mo. The mean age of patients with kidney stones was 42 ± 7 years. Within reported studies, approximately 50% of kidney transplant recipients with kidney stones were males. 67% of kidney stones were calcium-based stones (30% mixed CaOx/CaP, 27%CaOx and 10%CaP), followed by struvite stones (20%) and uric acid stones (13%). CONCLUSION The estimated incidence of kidney stones in patients after kidney transplantation is 1.0%. Although calcium based stones are the most common kidney stones after transplantation, struvite stones (also known as “infection stones”) are not uncommon in kidney transplant recipients. These findings may impact the prevention and clinical management of kidney stones after kidney transplantation. PMID:28058231

Coma dust scattering concepts applied to the Rosetta mission

NASA Astrophysics Data System (ADS)

Fink, Uwe; Rinaldi, Giovanna

2015-09-01

This paper describes basic concepts, as well as providing a framework, for the interpretation of the light scattered by the dust in a cometary coma as observed by instruments on a spacecraft such as Rosetta. It is shown that the expected optical depths are small enough that single scattering can be applied. Each of the quantities that contribute to the scattered intensity is discussed in detail. Using optical constants of the likely coma dust constituents, olivine, pyroxene and carbon, the scattering properties of the dust are calculated. For the resulting observable scattering intensities several particle size distributions are considered, a simple power law, power laws with a small particle cut off and a log-normal distributions with various parameters. Within the context of a simple outflow model, the standard definition of Afρ for a circular observing aperture is expanded to an equivalent Afρ for an annulus and specific line-of-sight observation. The resulting equivalence between the observed intensity and Afρ is used to predict observable intensities for 67P/Churyumov-Gerasimenko at the spacecraft encounter near 3.3 AU and near perihelion at 1.3 AU. This is done by normalizing particle production rates of various size distributions to agree with observed ground based Afρ values. Various geometries for the column densities in a cometary coma are considered. The calculations for a simple outflow model are compared with more elaborate Direct Simulation Monte Carlo Calculation (DSMC) models to define the limits of applicability of the simpler analytical approach. Thus our analytical approach can be applied to the majority of the Rosetta coma observations, particularly beyond several nuclear radii where the dust is no longer in a collisional environment, without recourse to computer intensive DSMC calculations for specific cases. In addition to a spherically symmetric 1-dimensional approach we investigate column densities for the 2-dimensional DSMC model on the day and night side of the comet. Our calculations are also applied to estimates of the dust particle densities and flux which are useful for the in-situ experiments on Rosetta.

An empirical model of H2O, CO2 and CO coma distributions and production rates for comet 67P/Churyumov-Gerasimenko based on ROSINA/DFMS measurements and AMPS-DSMC simulations

NASA Astrophysics Data System (ADS)

Hansen, Kenneth C.; Altwegg, Kathrin; Bieler, Andre; Berthelier, Jean-Jacques; Calmonte, Ursina; Combi, Michael R.; De Keyser, Johan; Fiethe, Björn; Fougere, Nicolas; Fuselier, Stephen; Gombosi, T. I.; Hässig, Myrtha; Huang, Zhenguang; Le Roy, Léna; Rubin, Martin; Tenishev, Valeriy; Toth, Gabor; Tzou, Chia-Yu; ROSINA Team

2016-10-01

We have previously used results from the AMPS DSMC (Adaptive Mesh Particle Simulator Direct Simulation Monte Carlo) model to create an empirical model of the near comet water (H2O) coma of comet 67P/Churyumov-Gerasimenko. In this work we create additional empirical models for the coma distributions of CO2 and CO. The AMPS simulations are based on ROSINA DFMS (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis, Double Focusing Mass Spectrometer) data taken over the entire timespan of the Rosetta mission. The empirical model is created using AMPS DSMC results which are extracted from simulations at a range of radial distances, rotation phases and heliocentric distances. The simulation results are then averaged over a comet rotation and fitted to an empirical model distribution. Model coefficients are then fitted to piecewise-linear functions of heliocentric distance. The final product is an empirical model of the coma distribution which is a function of heliocentric distance, radial distance, and sun-fixed longitude and latitude angles. The model clearly mimics the behavior of water shifting production from North to South across the inbound equinox while the CO2 production is always in the South.The empirical model can be used to de-trend the spacecraft motion from the ROSINA COPS and DFMS data. The ROSINA instrument measures the neutral coma density at a single point and the measured value is influenced by the location of the spacecraft relative to the comet and the comet-sun line. Using the empirical coma model we can correct for the position of the spacecraft and compute a total production rate based on single point measurements. In this presentation we will present the coma production rates as a function of heliocentric distance for the entire Rosetta mission.This work was supported by contracts JPL#1266313 and JPL#1266314 from the US Rosetta Project and NASA grant NNX14AG84G from the Planetary Atmospheres Program.

The Noble Gas Abundances in the Coma of Comet 67P/Churyumov-Gerasimenko from Rosetta/ROSINA

NASA Astrophysics Data System (ADS)

Rubin, M.; Altwegg, K.; Balsiger, H. R.; Berthelier, J. J.; Briois, C.; Combi, M. R.; De Keyser, J.; Fiethe, B.; Fuselier, S. A.; Gasc, S.; Gombosi, T. I.; Hansen, K. C.; Jäckel, A.; Kopp, E.; Korth, A.; Mall, U.; Marty, B.; Mousis, O.; Owen, T.; Reme, H.; Schuhmann, M.; Schroeder, I. R. H. G.; Semon, T.; Tzou, C. Y.; Waite, J. H., Jr.; Wurz, P.

2017-12-01

The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), the mass spectrometer suite on board the European Space Agency's Rosetta mission, was dedicated to the measurement of the volatiles in the coma of comet 67P/Churyumov-Gerasimenko (67P) [1]. Among many other species, ROSINA DFMS, the Double Focusing Mass Spectrometer, detected and quantified the three noble gases argon, krypton, and xenon including their major isotopes [2,3]. Noble gases provide important clues to the physical and chemical conditions during and possibly even before and after the comet's formation in the early solar system. Furthermore, measurements of the isotope ratios provide constraints on the amount of cometary material brought to Earth and its early atmosphere. In this presentation, we will report on the measured coma densities and derived nucleus bulk abundances of these three noble gases and investigate correlations with other volatiles. Furthermore, we will discuss the measured isotope ratios and the implications of these results. AcknowledgementsUoB was funded by the State of Bern, the Swiss National Science Foundation and by the European Space Agency PRODEX Programme. Work at MPS was funded by the Max-Planck Gesellschaft and BMWI (contract 50QP1302), at Southwest Research institute by Jet Propulsion Laboratory (subcontract #1496541 and JPL subcontract to JWH NAS703001TONMO710889), at the University of Michigan by NASA (contract JPL-1266313). This work has been supported through the A*MIDEX project from the French National Research Agency (ANR) (n° ANR-11-IDEX- 0001-02) and by CNES grants at IRAP, LATMOS, LPC2E, LAM, CRPG, by the European Research Council (grant no. 267255 to B. Marty) and at BIRA-IASB by the Belgian Science Policy Office via PRODEX/ROSINA PEA C4000107705. References[1] Balsiger, H., et al., Rosina - Rosetta orbiter spectrometer for ion and neutral analysis. Space Science Reviews. 128, 745-801, 2007. [2] Balsiger, H., et al., Detection of argon in the coma of comet 67P/Churyumov-Gerasimenko. Sci Adv. 1, e1500377, 2015. [3] Marty B., et al., Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth's atmosphere, Science, 356, 1069 - 1072, 2017.

Nile Delta exhibited a spatial reversal in the rates of shoreline retreat on the Rosetta promontory comparing pre- and post-beach protection

NASA Astrophysics Data System (ADS)

Ghoneim, Eman; Mashaly, Jehan; Gamble, Douglas; Halls, Joanne; AbuBakr, Mostafa

2015-01-01

The coastline of the Nile Delta experienced accelerated erosion since the construction of the Aswan High Dam in 1964 and, consequently, the entrapment of a large amount of river sediments behind it. The coastline of the Rosetta promontory showed the highest erosion in the Delta with an average retreat rate of 137.4 m year- 1. In 1991, in an effort to mitigate sediment loss, a 4.85 km long seawall was built on the outer margin of the promontory. For additional beach protection, 15 groins were constructed along the eastern and western sides of the seawall in 2003 and 2005. To quantify erosion and accretion patterns along the Rosetta promontory, 11 Landsat images acquired at unequal intervals during a 40 year time span (1972 and 2012) were analyzed. The positions of shorelines were automatically extracted from satellite imagery and compared with three very high resolution QuickBird and WorldView2 images for data validation. Analysis of the rates of shoreline change revealed that the construction of the seawall was largely successful in halting the recession along the tip of the promontory, which lost 10.8 km2 prior to coastal protection. Conversely, the construction of the 15 groins has negatively affected the coastal morphology of the promontory and caused a reversal from accretion to fast erosion along the promontory leeside, where some segments of the shoreline have undergone as much as 30.8 m year- 1 of erosion. Without hard structures, the tip of the Rosetta promontory would have retreated 2.3 km by 2013 and lost 7.2 km2 of land. About 10% of this land is deltaic fertile cultivated farms. Moreover, without additional protection the sides of the promontory will lose about 1.3 km2 of land and the coastline would recede at an average rate of 200 m by 2020. Unless action is taken, coastal erosion, enhanced by rising sea level, will steadily eat away the Nile Delta at an alarming rate. The successful demonstration of the advocated procedures in this study could be adopted, with appropriate modifications, for other deltas worldwide.

Laboratory polarization and permittivity measurements to interpret dust polarimetric observations and in-situ radar studies. Significance for Rosetta mission at 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, Anny-Chantal; Brouet, Yann; Hadamcik, Edith; Heggy, Essam; Hines, Dean; Lasue, Jérémie; Renard, Jean-Baptiste

2015-08-01

Polarimetric astronomical observations on dust clouds and regolithic surfaces require laboratory simulations on samples to provide information on properties (size distribution, porosity, refractive index) of the scattering media. Similarly, in-situ radar investigations in the solar system require laboratory studies on samples to infer physical properties (e.g. porosity, ice/dust ratio) of sub-surfaces and interiors. Recent developments are illustrated with present studies related to the Rosetta mission, which begun its rendezvous with comet 67P/Churyumov-Gerasimeko (C-G) and landed the Philae module on its nucleus in 2014.We will summarize laboratory simulations with the PROGRA2 suite of instruments that study (in the visible to near IR domain) the polarimetric properties of dust samples in microgravity conditions or on surfaces [1], with emphasis on the interpretation of polarimetric observations of C-G, during its previous perihelion passages from Earth observatories, and currently from HST [2,3]. The presence of large dust particles in the pre-perihelion coma previously inferred from remote observations agrees with Rosetta ground truth [4]. We will also present measurements on the permittivity (in the millimeter to meter domain) of various dust samples, with emphasis on porous samples [5,6]. Results provide constraints on the properties of the subsurface and interior of C-G, as explored by MIRO on Rosetta and CONSERT on Philae.Such studies are relevant for the interpretation of polarimetric observations of other dust clouds (e.g. debris disks, interplanetary dust cloud, clouds in planetary atmospheres) and surfaces (e.g. planets, moons), as well as for those of other radar characterization studies (e.g. Mars, moons, asteroids).[1] Levasseur-Regourd et al. In Polarization of stars and planetary systems, Cambridge UP, in press 2015.[2] Hadamcik et al. A&A 517 2010.[3] Hines and Levasseur-Regourd, PSS submitted 2015.[4] Schulz et al. Nature 518 2015.[5] Heggy et al. 2012, Icarus 221 2012.[6] Brouet et al. A&A submitted 2015.

Archival of Amateur Observations in Support to ESA/Rosetta Mission

NASA Astrophysics Data System (ADS)

Shirinian, R.; Yanamandra-Fisher, P. A.; Buratti, B. J.

2016-12-01

The European Space Agency's Rosetta mission to comet 67P/Churyumov-Gerasimenko (CG) has included a global ground-based observing campaign consisting of both professional and amateur observers. While professional observers have access to world class observatories with multi-spectral instruments, amateur observers use smaller aperture telescopes that mainly cover the optical spectrum. Amateur observers however, have the advantage of being able to observe as needed since their time is not competed by other observers as it is in professional facilities. This allows amateurs to create a temporal baseline of observations throughout a mission to complement professional observations with context. The Rosetta mission has had an active amateur observer campaign for over 2 years, from January 2014 to August 2016 and has nearly 150 active observers from around the globe. As the Rosetta mission and its observer campaign come to an end in September 2016, an important goal of the project is the collection and archival of the amateur observational data. The ESA's Planetary Science Archive (PSA) has created a unique system that provides firewalled user-specific directories for amateur observers to upload and archive their data, allowing professionals and amateurs to crowdsource data for future science analyses. Possible future science products could include analysis of luminosity, dust cover, position angle, and tail length, all of which can be analyzed over time due to the consistent amateur data taken for over two years. A challenge for the project is that amateur observers have varying amounts of data, ranging from a few megabytes to several gigabytes. Our project addresses the retrieval of amateur observations, renaming, reformatting, and upload to the PSA. The final steps of the archival of amateur observations are the quality check of the data, some of the possible analyses, and identification of data that can be integrated with professional data analysis. The unique integration of amateur observations and professional observations will be crowdsourced for future scientific analysis. This research project was conducted at NASA/JPL/Caltech with funding from NASA and the NSF REU site Consortium for Undergraduate Research Experiences (CURE) ran through LACC.

Small is different: RPC observations of a small scale comet interacting with the solar wind

NASA Astrophysics Data System (ADS)

Nilsson, Hans; Burch, James L.; Carr, Christopher M.; Eriksson, Anders I.; Glassmeier, Karl-Heinz; Henri, Pierre; Rosetta Plasma Consortium Team

2016-10-01

Rosetta followed comet 67P from low activity at more than 3 AU heliocentric distance to peak activity at perihelion and then out again. We study the evolution of the dynamic plasma environment using data from the Rosetta Plasma Consortium (RPC). Observations of cometary plasma began in August 2014, at a distance of 100 km from the comet nucleus and at 3.6 AU from the Sun. As the comet approached the Sun, outgassing from the comet increased, as did the density of the cometary plasma. Measurements showed a highly heterogeneous cold ion environment, permeated by the solar wind. The solar wind was deflected due to the mass loading from newly added cometary plasma, with no discernible slowing down. The magnetic field magnitude increased significantly above the background level, and strong low frequency waves were observed in the magnetic field, a.k.a. the "singing comet". Electron temperatures were high, leading to a frequently strongly negative spacecraft potential. In mid to late April 2015 the solar wind started to disappear from the observation region. This was associated with a solar wind deflection reaching nearly 180°, indicating that mass loading became efficient enough to form a solar wind-free region. Accelerated water ions, moving mainly in the anti-sunward direction, kept being observed also after the solar wind disappearance. Plasma boundaries began to form and a collisionopause was tentatively identified in the ion and electron data. At the time around perihelion, a diamagnetic cavity was also observed, at a surprisingly large distance from the comet. In late 2016 the solar wind re-appeared at the location of Rosetta, allowing for studies of asymmetry of the comet ion environment with respect to perihelion. A nightside excursion allowed us to get a glimpse of the electrodynamics of the innermost part of the plasma tail. Most of these phenomena are dependent on the small-scale physics of comet 67P, since for most of the Rosetta mission the solar wind - comet atmosphere interaction region is smaller than the pickup ion gyroradius in the undisturbed solar wind.

Hydrogen halides at Comet 67P/Churyumov-Gerasimenko as detected by ROSINA-DFMS

NASA Astrophysics Data System (ADS)

Dhooghe, Frederik

2017-04-01

The Rosetta spacecraft has been studying the coma of comet 67P/Churyumov-Gerasimenko (67P/C-G) in-situ from the comet encounter in August 2014 up to end of mission in September 2016. The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) contains a double focussing mass spectrometer (DFMS) with a mass range 13-140 u/e. It is optimized for high mass resolution and large dynamic range for the chemical and isotopic characterization of the volatiles in the coma. Since comets retained information about the physical and chemical conditions of the protoplanetary disk from which they formed, they may provide insights into the halogen chemistry in the early Solar System. We have studied the halogen-bearing compounds in the coma with DFMS on 67P/C-G's inbound journey during four periods, as the gas production increased towards perihelion and as the comet's subsolar latitude moved from the northern to the southern hemisphere: (A) when Rosetta was close to the comet, during 1-31/10/2014, at 3.0-3.3 AU, (B) during the close flybys on 14/2/2015 and on 28/3/2015 at 2.3 AU and 2.0 AU, (C) post-equinox between 10/5/2015 and 1/6/2015, at 1.5-1.7 AU, and (D) around perihelion between 9/7/2015 and 31/8/2015, at 1.24-1.31 AU. The main halogen-bearing compounds in the comet atmosphere were found to be the hydrogen halides HF (hydrogen fluoride), HCl (hydrogen chloride) and HBr (hydrogen bromide). HF and HCl could be observed during all four periods, while hydrogen bromide could, due to its low abundance, only be detected during period A, when Rosetta was close to the comet. An increase in the halogen-to-oxygen ratio as a function of distance was observed which suggests a distributed source for HF and HCl, probably through progressive release of these compounds from grains. This contribution will address the abundance and variability of the hydrogen halides in the coma as well as the cometary isotopic ratios for 37Cl/35Cl and 81Br/79Br.

Monitoring Comet 67P/C-G Micrometer Dust Flux: GIADA onboard Rosetta.

NASA Astrophysics Data System (ADS)

Della Corte, Vincenzo; Rotundi, Alessandra; Ivanovski, Stavro; Accolla, Mario; Ferrari, Marco; Sordini, Roberto; Lucarelli, Francesca; Zakharov, Vladimir; Fulle, Marco; Mazzotta Epifani, Elena; López-Moreno, José J.; Rodríguez, Julio; Colangeli, Luigi; Palumbo, Pasquale; Bussoletti, Ezio; Crifo, Jean-Francois; Esposito, Francesca; Green, Simon F.; Grün, Eberhard; Lamy, Philippe L.

2015-04-01

(21)ESA-ESAC, Camino Bajo del Castillo, s/n., Urb. Villafranca del Castillo, 28692 Villanueva de la Cañada, Madrid, Spagna The MicroBalance System (MBS) is one of the three measurement subsystems of GIADA, the Grain Impact Analyzer and Dust Accumulator on board the Rosetta/ESA spacecraft (S/C). It consists of five Quartz Crystal Microbalances (QCMs) in roughly orthogonal directions providing the cumulative dust flux of grains smaller than 10 microns. The MBS is continuously monitoring comet 67P/CG since the beginning of May 2014. During the first 4 months of measurements, before the insertion of the S/C in the bound orbit phase, there were no evidences of dust accumulation on the QCMs. Starting from the beginning of October, three out of five QCMs measured an increase of the deposited dust. The measured fluxes show, as expected, a strong anisotropy. In particular, the dust flux appears to be much higher from the Sun direction with respect to the comet direction. Acknowledgment: GIADA was built by a consortum led by the Univ. Napoli "Parthenope" & INAF- Oss. Astr. Capodimonte, in collaboration with the Inst. de Astrofisica de Andalucia, Selex-ES, FI and SENER. GIADA is presently managed & operated by Ist. di Astrofisica e Planetologia Spaziali-INAF, IT. GIADA was funded and managed by the Agenzia Spaziale Italiana, IT, with the support of the Spanish Ministry of Education and Science MEC, ES. GIADA was developed from a PI proposal from the University of Kent; sci. & tech. contribution were provided by CISAS, IT, Lab. d'Astr. Spat., FR, and Institutions from UK, IT, FR, DE and USA. We thank the RSGS/ESAC, RMOC/ESOC & Rosetta Project/ESTEC for their out-standing work. Science support provided was by NASA through the US Rosetta Project managed by the Jet Propulsion Laboratory/ California Institute of Technology. GIADA calibrated data will be available through ESA's PSA web site (www.rssd.esa.int/index.php? project=PSA&page=in dex). We would like to thank Angioletta Coradini for her contribution as a GIADA Co-I.

Flexible Ureterorenoscopy for Treatment of Kidney Stones: Establishment as Primary Standard Therapy in a Tertiary Stone Center.

PubMed

Ising, Stephan; Labenski, Heike; Baltes, Stefan; Khaffaf, Aso; Thomas, Christian; Wiesner, Christoph

2015-01-01

To analyze the primary stone free rate (pSFR) of flexible ureterorenoscopy (fURS) in the treatment of renal stones and to identify clinical predictors for the primary freedom from renal stones. Two hundred and seventy five patients, who underwent fURS for kidney stones were analyzed. Index stone size was 6 mm. The stone was located in the lower calyx in 48%. Ureteral access sheath was used in 97%. Operation time was 35 min and primary stone clearance was 83%. pSFR increased from 74% in 2012 to 83% in 2013 and 90% in 2014 (p = 0.001). Preoperative stenting, index stone size, cumulative stone size, lithotripsy, ureteral access sheath and operation time were significantly correlated with the pSFR by univariate analysis. Multivariate regression analysis showed index stone size, cumulative stone size, ureteral access sheath and operation time as independent parameters for pSFR. fURS for kidney stones is safe with a high pSFR. Clinical parameters for pSFR are stone size, use of ureteral access sheath and operation time. In future, the effective use of fURS for the removal of kidney stones needs to be checked by prospective randomized trials. © 2015 S. Karger AG, Basel.

Pneumatic ureteroscopic lithotripsy: is it still a reasonable treatment option for multiple ureteric stones?

PubMed

Isen, Kenan

2012-01-01

To assess the efficacy and safety of ureteroscopic pneumatic lithotripsy for multiple ureteric stones. 36 patients with multiple ureteric stones were treated with ureteroscopic lithotripsy (URSL). A 8/9.8-Fr Wolf semirigid ureteroscope and pneumatic lithotripter were used for stone fragmentation. 87 stones were treated with URSL. Successful fragmentation was achieved in 77 (88.5%) of the stones. The retreatment rate was 11.5%. The stone-free rate (SFR) of lower ureteric stones (93.3%) and middle ureteric stones (87.5%) was significantly higher compared with upper (73.3%) ureteric stones (p < 0.05). For patients with stones less than 1 cm and greater than 1 cm, the SFR was 91.5 and 75.0%, respectively (p < 0.05). Perforation occurred in 1 patient, mucosal injury occurred in 5 and stone migration in 5. No long-term complication was observed in any patient. Ureteroscopic pneumatic lithotripsy is still a reasonable treatment option for multiple ureteric stones. The procedure has high success rates with minimal morbidity. However, success rate can be affected by stone size and ureteric location. Copyright © 2012 S. Karger AG, Basel.

The use of chemical treatments for improved comminution of artificial stones.

PubMed

Heimbach, D; Kourambas, J; Zhong, P; Jacobs, J; Hesse, A; Mueller, S C; Delvecchio, F C; Cocks, F H; Preminger, G M

2004-05-01

The acoustic and mechanical properties of various stone compositions are significantly different and thus result in varying degrees of fragility. Consequently, results to shock wave lithotripsy (SWL) are influenced accordingly. We report the results of a study of fragility of various stone compositions, and the influence on each stone's baseline physical properties and fragility when exposed to various chemolytic solutions. Before SWL artificial stones of differing compositions were irrigated with various chemolytic solutions. Calcium oxalate monohydrate (COM) stones were treated with ethylenediaminetetraacetic acid (EDTA), stones composed of magnesium ammonium phosphate hydrogen were treated with hemiacidrin, and stones made of uric acid (UA) were treated with tromethamine. Synthetic urine served as a control for all stone groups. Using an ultrasound transmission technique, longitudinal wave propagation speed was measured in all groups of artificial stones. Stone density was also measured by using a pycnometer (based on Archimedes' principle). Based on these measurements transverse (shear) wave speed (assuming a constant Poisson's ratio), wave impedance and dynamic mechanical properties of the artificial stones were calculated. Moreover, the microhardness of these artificial stones was measured, and fragility testing using SWL with and without pretreatment with the previously mentioned chemolytic solutions, was performed. Wave speed, wave impedance, dynamic mechanical properties and microhardness of EDTA treated COM stones and tromethamine treated UA stones were found to decrease compared to untreated (synthetic urine) control groups. The suggestion that chemolytic pretreatment increases stone fragility was verified by the finding of increased stone comminution after SWL testing. Combining this medical pretreatment and SWL, the findings demonstrate a significant impact of various solvents on stone comminution, in particular EDTA treated COM stones, tromethamine treated UA stones and hemiacidrin treated magnesium ammonium phosphate hydrogen stones. These data suggest that by altering the chemical environment of the fluid surrounding the stones it is possible to increase the fragility of renal calculi in vitro. These results indicate that appropriate chemical treatments may provide a useful adjunctive modality for improving the efficacy of stone comminution during shock wave lithotripsy.

Kidney stones during pregnancy: an investigation into stone composition.

PubMed

Ross, Ashley E; Handa, Shelly; Lingeman, James E; Matlaga, Brian R

2008-05-01

Kidney stones can be a source of considerable morbidity for pregnant women. Although there is a body of literature confirming that different stone compositions predominate for different age and sex cohorts, there have been no similar reports characterizing the nature of stone disease during pregnancy. We performed a multi-institutional study to define the composition of renal calculi diagnosed during pregnancy. We retrospectively reviewed the records from two stone referral centers of all patients diagnosed with a de novo kidney stone during pregnancy who underwent a procedure for the purpose of stone removal from June 2001 through September 2007. A total of 27 patients were identified, with a mean age of 26.8 years (range, 21-34). Twenty patients (74%) had no history of prior stone formation. Seven patients (26%) had previously formed stones, although none of these patients had a known kidney stone at the time they became pregnant. Stones were removed in the first, second, third trimester and immediately post-partum in 4, 52, 22, and 22% respectively. Stone removal was performed without complication in all cases. Analysis found that in 74% of all cases (20 patients) stones were composed predominantly of calcium phosphate (hydroxyapatite). In 26% of cases, (7 patients) the stones were composed predominantly of calcium oxalate. Of the seven patients with prior stone history, three patients had previously formed calcium phosphate stones and four patients had previously formed calcium oxalate stones. Calcium oxalate calculi are the most common stone in non-pregnant women of a comparable age as our subjects. However, our present data suggest that stones detected during pregnancy are most commonly composed of calcium phosphate (hydroxyapatite). Indeed, it is the minority of stones that are composed of calcium oxalate. Although the reason for this unusual preponderance of calcium phosphate calculi is unclear, physiologic alterations that occur during pregnancy may be influential.

Guaifenesin stone matrix proteomics: a protocol for identifying proteins critical to stone formation.

PubMed

Kolbach-Mandel, A M; Mandel, N S; Cohen, S R; Kleinman, J G; Ahmed, F; Mandel, I C; Wesson, J A

2017-04-01

Drug-related kidney stones are a diagnostic problem, since they contain a large matrix (protein) fraction and are frequently incorrectly identified as matrix stones. A urine proteomics study patient produced a guaifenesin stone during her participation, allowing us to both correctly diagnose her disease and identify proteins critical to this drug stone-forming process. The patient provided three random midday urine samples for proteomics studies; one of which contained stone-like sediment with two distinct fractions. These solids were characterized with optical microscopy and Fourier transform infrared spectroscopy. Immunoblotting and quantitative mass spectrometry were used to quantitatively identify the proteins in urine and stone matrix. Infrared spectroscopy showed that the sediment was 60 % protein and 40 % guaifenesin and its metabolite guaiacol. Of the 156 distinct proteins identified in the proteomic studies, 49 were identified in the two stone-components with approximately 50 % of those proteins also found in this patient's urine. Many proteins observed in this drug-related stone have also been reported in proteomic matrix studies of uric acid and calcium containing stones. More importantly, nine proteins were highly enriched and highly abundant in the stone matrix and 8 were reciprocally depleted in urine, suggesting a critical role for these proteins in guaifenesin stone formation. Accurate stone analysis is critical to proper diagnosis and treatment of kidney stones. Many matrix proteins were common to all stone types, but likely not related to disease mechanism. This protocol defined a small set of proteins that were likely critical to guaifenesin stone formation based on their high enrichment and high abundance in stone matrix, and it should be applied to all stone types.

Evaluation of stone volume distribution in renal collecting system as a predictor of stone-free rate after percutaneous nephrolithotomy: a retrospective single-center study.

PubMed

Atalay, Hasan Anıl; Canat, Lutfi; Bayraktarlı, Recep; Alkan, Ilter; Can, Osman; Altunrende, Fatih

2017-06-23

We analyzed our stone-free rates of PNL with regard to stone burden and its ratio to the renal collecting system volume. Data of 164 patients who underwent PNL were analyzed retrospectively. Volume segmentation of renal collecting system and stones were done using 3D segmentation software with the images obtained from CT data. Analyzed stone volume (ASV) and renal collecting system volume (RCSV) were measured and the ASV-to-RCSV ratio was calculated after the creation of a 3D surface volume rendering of renal stones and the collecting system. Univariate and multivariate statistical analyses were performed to determine factors affecting stone-free rates; also we assessed the predictive accuracy of the ASV-to-RCSV ratio using the receiving operating curve (ROC) and AUC. The stone-free rate of PNL monotherapy was 53% (164 procedures).The ASV-to-RCSV ratio and calyx number with stones were the most influential predictors of stone-free status (OR 4.15, 95% CI 2.24-7.24, <0.001, OR 2.62, 95% CI 1.38-4.97, p < 0.001, respectively). Other factors associated with the stone-free rate were maximum stone size (p < 0.029), stone surface area (p < 0.010), and stone burden volume (p < 0.001). Predictive accuracy of the ASV-to-RCSV ratio was AUC 0.76. Stone burden volume distribution in the renal collecting system, which is calculated using the 3D volume segmentation method, is a significant determinant of the stone-free rate before PCNL surgery. It could be used as a single guide variable by the clinician before renal stone surgery to predict extra requirements for stone clearance.

Cystine Stone Formers Have Impaired Health-Related Quality of Life Compared with Noncystine Stone Formers: A Case-Referent Study Piloting the Wisconsin Stone Quality of Life Questionnaire Among Patients with Cystine Stones.

PubMed

Streeper, Necole M; Wertheim, Margaret L; Nakada, Stephen Y; Penniston, Kristina L

2017-04-01

Cystinuria is a rare cause of urolithiasis. Affected patients have an earlier onset and more aggressive disease than patients with other stone etiologies. We assessed the health-related quality of life (HRQOL) of cystine stone-forming patients using the disease-specific Wisconsin Stone Quality of Life questionnaire (WISQOL). Cystine patients treated in our stone clinics (n = 12) completed the WISQOL; information about medical and stone histories was gathered. Patients were matched with noncystine stone formers (n = 12) for gender, age, and comorbidities. In addition, a second control group (n = 90), also from our institution and consisting of mixed calcium stone formers, was included. WISQOL responses were compared between groups. Cystine patients had significantly lower total WISQOL scores than noncystine patients. Compared with noncystine stone formers, cystine stone formers also had lower HRQOL scores for subscales (domains) related to social impact, emotional impact, disease impact, and vitality (p ≤ 0.04 for all). On specific items, cystine patients reported significantly more sleep problems (p = 0.02), more bother with nocturia (p = 0.03), and feeling tired or fatigued (p = 0.02). Among those with current stones, cystine patients scored lower than noncystine patients for total score and in two of four domains. Using a stone-specific questionnaire, patients with cystine stones have lower HRQOL compared with noncystine stone formers. Identifying and addressing specific areas of decrement in patients with cystine stones may improve disease management and patients' HRQOL.

Definition and Facts for Kidney Stones in Adults

MedlinePlus

... Eating, Diet, & Nutrition Clinical Trials Definition & Facts for Kidney Stones What are kidney stones? Kidney stones are hard, pebble-like pieces ... stone may get stuck along the way. Do kidney stones have another name? The scientific name for ...

Spontaneous passage of ureteral stones in patients with indwelling ureteral stents.

PubMed

Baumgarten, Lee; Desai, Anuj; Shipman, Scott; Eun, Daniel D; Pontari, Michel A; Mydlo, Jack H; Reese, Adam C

2017-10-01

To determine rates of spontaneous ureteral stone passage in patients with indwelling ureteral stents, and to identify factors associated with the spontaneous passage of stones while a ureteral stent is in place. From our institutional database, we identified patients who underwent ureteroscopic procedures for stone disease between January 1, 2013 and March 1, 2015. We compared the rates of spontaneous stone passage between patients who had previously undergone ureteral stent placement and those who had not. In patients with indwelling stents, multivariate logistic regression was performed to identify factors associated with spontaneous stone passage. A total of 194 patients met inclusion criteria. Spontaneous stone passage rates were similar in the stented (17/119, 14%) and non-stented (15/75, 20%) groups (p = 0.30). In bivariate analysis of stented patients, smaller stone size (p < 0.001) and distal stone location (p = 0.01) were significantly associated with spontaneous stone passage. Multivariate logistic regression analysis of stented patients showed that only small stone size was significantly associated with the likelihood of stone passage (p = 0.01), whereas stent duration, stone location, and stone laterality were not. A small, but clinically significant percentage of ureteral stones pass spontaneously with a ureteral stent in place. Small stone size is associated with an increased likelihood of spontaneous passage in patients with indwelling stents. These findings may help to identify patients who can potentially avoid additional surgical procedures for definitive stone removal after ureteral stent placement.

Extracorporeal shock wave lithotripsy of proximal and distal ureteral stones.

PubMed

Pettersson, B; Tiselius, H G

1988-01-01

Extracorporeal shock wave lithotripsy (ESWL) was used for treatment of 105 patients with ureteral stones. There were 77 stones in the upper part of the ureter, i.e. above the pelvic brim, and 28 in the lower part, i.e. below the sacroiliac joint. Successful fragmentation was attained in 101 (96%). In 93% of the patients with stones in the upper ureter and in 100% with stones in the lower ureter the fragments were eliminated completely. In 87% of the patients with stones in the upper ureter, a ureteral catheter was introduced under local anesthesia but without fluoroscopic control. It was thereby possible to remove 30% of the stones from the ureter to the kidney. For the remaining stones, saline was infused through the catheter during ESWL. For patients with stones in the lower part of the ureter, a ureteral catheter was passed in 79% and saline infused during treatment. Whereas some form of anesthesia was used for treatment of all upper ureteral stones, 89% of the treatments for lower ureteral stones were performed without anesthesia. Auxiliary procedures after ESWL were limited to four ureteral catheter manipulations for distal stones. Four proximal stones which remained unaffected by ESWL had to be treated by open surgery (3 stones) or percutaneous surgery (1 stone). Of 82 ureteric stones treated in situ the success fragmentation rate was 95%. The average number of ESWL sessions was 1.04 for both proximal and distal ureteral stones.

Metabolic Characteristics and Risks Associated with Stone Recurrence in Korean Young Adult Stone Patients.

PubMed

Kang, Ho Won; Seo, Sung Pil; Kim, Won Tae; Kim, Yong-June; Yun, Seok-Joong; Kim, Wun-Jae; Lee, Sang-Cheol

2017-08-01

The aim of this study was to assess the metabolic characteristics and risks of stone recurrence in young adult stone patients in Korea. The medical records of 1532 patients presenting with renal or ureteric stones at our stone clinic between 1994 and 2015 were retrospectively reviewed. Patients were grouped according to age (young adult, 18-29 years; intermediate onset, 30-59 years; old age, ≥60 years) at first presentation, and measurements of clinicometabolic characteristics and risks of stone recurrence were compared. Overall, excretion of urinary stone-forming substances was highest in the intermediate onset group, followed by the young adult and old age groups. Importantly, excretion of urinary citrate was lowest in the young adult group. Kaplan-Meier analyses identified a significant difference between the three age groups in terms of stone recurrence (log rank test, p < 0.001). Multivariate Cox regression analyses revealed that age at first stone presentation was an independent risk factor for stone recurrence. Urinary citrate excretion was an independent risk factor for stone recurrence in young adult stone patients. Younger age (18-29 years) at first stone presentation was a significant risk factor for stone recurrence, and urinary citrate excretion was an independent risk factor affecting recurrence in this group. Metabolic evaluation and potassium citrate therapy should be considered for young adult stone patients to prevent recurrence.

Appropriate kidney stone size for ureteroscopic lithotripsy: When to switch to a percutaneous approach

PubMed Central

Takazawa, Ryoji; Kitayama, Sachi; Tsujii, Toshihiko

2015-01-01

Flexible ureteroscopy (fURS) has become a more effective and safer treatment for whole upper urinary tract stones. Percutaneous nephrolithotomy (PNL) is currently the first-line recommended treatment for large kidney stones ≥ 20 mm and it has an excellent stone-free rate for large kidney stones. However, its invasiveness is not negligible considering its major complication rates. Staged fURS is a practical treatment for such large kidney stones because fURS has a minimal blood transfusion risk, short hospitalization and few restrictions on daily routines. However, as the stone size becomes larger, the stone-free rate decreases, and the number of operations required increases. Therefore, in our opinion, staged fURS is a practical option for kidney stones 20 to 40 mm. Miniaturized PNL combined with fURS should be considered to be a preferred option for stones larger than 40 mm. Moreover, URS is an effective treatment for multiple upper urinary tract stones. Especially for patients with a stone burden < 20 mm, URS is a favorable option that promises a high stone-free rate after a single session either unilaterally or bilaterally. However, for patients with a stone burden ≥ 20 mm, a staged operation should be considered to achieve stone-free status. PMID:25664253

Is scoring system of computed tomography based metric parameters can accurately predicts shock wave lithotripsy stone-free rates and aid in the development of treatment strategies?

PubMed Central

Badran, Yasser Ali; Abdelaziz, Alsayed Saad; Shehab, Mohamed Ahmed; Mohamed, Hazem Abdelsabour Dief; Emara, Absel-Aziz Ali; Elnabtity, Ali Mohamed Ali; Ghanem, Maged Mohammed; ELHelaly, Hesham Abdel Azim

2016-01-01

Objective: The objective was to determine the predicting success of shock wave lithotripsy (SWL) using a combination of computed tomography based metric parameters to improve the treatment plan. Patients and Methods: Consecutive 180 patients with symptomatic upper urinary tract calculi 20 mm or less were enrolled in our study underwent extracorporeal SWL were divided into two main groups, according to the stone size, Group A (92 patients with stone ≤10 mm) and Group B (88 patients with stone >10 mm). Both groups were evaluated, according to the skin to stone distance (SSD) and Hounsfield units (≤500, 500–1000 and >1000 HU). Results: Both groups were comparable in baseline data and stone characteristics. About 92.3% of Group A rendered stone-free, whereas 77.2% were stone-free in Group B (P = 0.001). Furthermore, in both group SWL success rates was a significantly higher for stones with lower attenuation <830 HU than with stones >830 HU (P < 0.034). SSD were statistically differences in SWL outcome (P < 0.02). Simultaneous consideration of three parameters stone size, stone attenuation value, and SSD; we found that stone-free rate (SFR) was 100% for stone attenuation value <830 HU for stone <10 mm or >10 mm but total number SWL sessions and shock waves required for the larger stone group were higher than in the smaller group (P < 0.01). Furthermore, SFR was 83.3% and 37.5% for stone <10 mm, mean HU >830, SSD 90 mm and SSD >120 mm, respectively. On the other hand, SFR was 52.6% and 28.57% for stone >10 mm, mean HU >830, SSD <90 mm and SSD >120 mm, respectively. Conclusion: Stone size, stone density (HU), and SSD is simple to calculate and can be reported by radiologists to applying combined score help to augment predictive power of SWL, reduce cost, and improving of treatment strategies. PMID:27141192

The mass of Lutetia from Rosetta RSI radio tracking

NASA Astrophysics Data System (ADS)

Pätzold, Martin; Andert, Thomas; Haeusler, Bernd; Tellmann, Silvia; Anderson, John D.; Asmar, Sami; Barriot, Jean-Pierre; Bird, Michael

The Rosetta spacecraft will flyby at its second target asteroid (21) Lutetia on 10 July 2010. Simulations based on the currently known size of Lutetia and assumptions on the bulk density show that the tracking of the two radio carrier frequencies at X-band (8.4 GHz) and S-band (2.3 GHz) during the flyby will yield a mass determination of less than a few percent accuracy, assuming noise conditions similar to those observed during several in-flight payload checkouts. The derivation of the asteroid volume by camera observation will be the driver for the un-certainty in the derivation of the bulk density. The mass determination alone, however, can already give clues for the currently unknown taxonomy of the asteroid type. If possible, first impressions and results from the flyby will be presented at the conference.

Plasma density structures at comet 67P/Churyumov-Gerasimenko

NASA Astrophysics Data System (ADS)

Engelhardt, I. A. D.; Eriksson, A. I.; Stenberg Wieser, G.; Goetz, C.; Rubin, M.; Henri, P.; Nilsson, H.; Odelstad, E.; Hajra, R.; Vallières, X.

2018-06-01

We present a Rosetta Plasma Consortium (RPC) case study based on four events in 2015 autumn at various radial distances, phase angles and local times, just after the perihelion of comet 67P/Churyumov-Gerasimenko. Pulse-like (high-amplitude, up to minutes in time) signatures are seen with several RPC instruments in the plasma density (with the LAngmuir Probe, LAP and Mutual Impedance Probe, MIP), ion energy and flux (with the Ion Composition Analyzer, ICA) and the magnetic field intensity (with the magnetometer, MAG). Furthermore, the cometocentric distance relative to the electron exobase is seen to be a good organizing parameter for the measured plasma variations. The closer Rosetta is to this boundary, the more pulses are measured. This is consistent with the pulses being filaments of plasma originating from the diamagnetic cavity boundary, as predicted by simulations.

MIRO Calibration Switch Mechanism

NASA Technical Reports Server (NTRS)

Suchman, Jason; Salinas, Yuki; Kubo, Holly

2001-01-01

The Jet Propulsion Laboratory has designed, analyzed, built, and tested a calibration switch mechanism for the MIRO instrument on the ROSETTA spacecraft. MIRO is the Microwave Instrument for the Rosetta Orbiter; this instrument hopes to investigate the origin of the solar system by studying the origin of comets. Specifically, the instrument will be the first to use submillimeter and millimeter wave heterodyne receivers to remotely examine the P-54 Wirtanen comet. In order to calibrate the instrument, it needs to view a hot and cold target. The purpose of the mechanism is to divert the instrument's field of view from the hot target, to the cold target, and then back into space. This cycle is to be repeated every 30 minutes for the duration of the 1.5 year mission. The paper describes the development of the mechanism, as well as analysis and testing techniques.

PconsFold: improved contact predictions improve protein models.

PubMed

Michel, Mirco; Hayat, Sikander; Skwark, Marcin J; Sander, Chris; Marks, Debora S; Elofsson, Arne

2014-09-01

Recently it has been shown that the quality of protein contact prediction from evolutionary information can be improved significantly if direct and indirect information is separated. Given sufficiently large protein families, the contact predictions contain sufficient information to predict the structure of many protein families. However, since the first studies contact prediction methods have improved. Here, we ask how much the final models are improved if improved contact predictions are used. In a small benchmark of 15 proteins, we show that the TM-scores of top-ranked models are improved by on average 33% using PconsFold compared with the original version of EVfold. In a larger benchmark, we find that the quality is improved with 15-30% when using PconsC in comparison with earlier contact prediction methods. Further, using Rosetta instead of CNS does not significantly improve global model accuracy, but the chemistry of models generated with Rosetta is improved. PconsFold is a fully automated pipeline for ab initio protein structure prediction based on evolutionary information. PconsFold is based on PconsC contact prediction and uses the Rosetta folding protocol. Due to its modularity, the contact prediction tool can be easily exchanged. The source code of PconsFold is available on GitHub at https://www.github.com/ElofssonLab/pcons-fold under the MIT license. PconsC is available from http://c.pcons.net/. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press.

Close-up multispectral images of the surface of comet 67P/Churyumov-Gerasimenko by the ROLIS camera onboard the Rosetta Philae lander

NASA Astrophysics Data System (ADS)

Schroeder, S.; Mottola, S.; Arnold, G.; Grothues, H. G.; Jaumann, R.; Michaelis, H.; Neukum, G.; Pelivan, I.; Bibring, J. P.

2014-12-01

In November 2014 the Philae lander onboard Rosetta is scheduled to land on the surface of comet 67P/Churyumov-Gerasimenko. The ROLIS camera will provide the ground truth for the Rosetta OSIRIS camera. ROLIS will acquire images both during the descent and after landing. In this paper we concentrate on the post-landing images. The close-up images will enable us to characterize the morphology and texture of the surface, and the shape, albedo, and size distribution of the particles on scales as small as 0.3 mm per pixel. We may see evidence for a dust mantle, a refractory crust, and exposed ice. In addition, we hope to identify features such as pores, cracks, or vents that allow volatiles to escape the surface. We will not only image the surface during the day but also the night, when LEDs will illuminate the surface in four different colors (blue, green, red, near-IR). This will characterize the spectral properties and heterogeneity of the surface, helping us to identify its composition. Although the ROLIS spectral range and resolution are too limited to allow an exact mineralogical characterization, a study of the spectral slope and albedo will allow a broad classification of the solid surface phases. We expect to be able to distinguish between organic material, silicates and ices. By repeated imaging over the course of the mission ROLIS may detect long term changes associated with cometary activity.

Rosetta Lander - Philae: activities after hibernation and landing preparations

NASA Astrophysics Data System (ADS)

Ulamec, Stephan; Biele, Jens; Sierks, Holger; Blazquez, Alejandro; Cozzoni, Barbara; Fantinati, Cinzia; Gaudon, Philippe; Geurts, Koen; Jurado, Eric; Paetz, Brigitte.; Maibaum, Michael

Rosetta is a Cornerstone Mission of the ESA Horizon 2000 programme. It is going to rendezvous with comet 67P/Churyumov-Gerasimenko after a ten year cruise and will study both its nucleus and coma with an orbiting spacecraft as well as with a Lander, Philae. Aboard Philae, a payload consisting of ten scientific instruments will perform in-situ studies of the cometary material. Rosetta and Philae have been in hibernation until January 20, 2014. After the successful wakeup they will undergo a post hibernation commissioning. The orbiter instruments (like e.g. the OSIRIS cameras) are to characterize the target comet to allow landing site selection and the definition of a separation, descent and landing (SDL) strategy for the Lander. By August 2014 our currently very poor knowledge of the characteristics of the nucleus of the comet will have increased dramatically. The paper will report on the latest updates in Separation-Descent-Landing (SDL) planning. Landing is foreseen for November 2014 at a heliocentric distance of 3 AU. Philae will be separated from the mother spacecraft from a dedicated delivery trajectory. It then descends ballistically to the surface of the comet, stabilized with an internal flywheel. At touch-down anchoring harpoons will be fired and a damping mechanism within the landing gear will provide the lander from re-bouncing. The paper will give an overview of the Philae system, the operational activities after hibernation and the latest status on the preparations for landing.

Fire effects on flaked stone, ground stone, and other stone artifacts [Chapter 4

Treesearch

Krista Deal

2012-01-01

Lithic artifacts can be divided into two broad classes, flaked stone and ground stone, that overlap depending on the defining criteria. For this discussion, flaked stone is used to describe objects that cut, scrape, pierce, saw, hack, etch, drill, or perforate, and the debris (debitage) created when these items are manufactured. Objects made of flaked stone include...

Novel ultrasound method to reposition kidney stones

PubMed Central

Shah, Anup; Owen, Neil R.; Lu, Wei; Cunitz, Bryan W.; Kaczkowski, Peter J.; Harper, Jonathan D.; Bailey, Michael R.; Crum, Lawrence A.

2011-01-01

The success of surgical management of lower pole stones is principally dependent on stone fragmentation and residual stone clearance. Choice of surgical method depends on stone size, yet all methods are subject to post-surgical complications resulting from residual stone fragments. Here we present a novel method and device to reposition kidney stones using ultrasound radiation force delivered by focused ultrasound and guided by ultrasound imaging. The device couples a commercial imaging array with a focused annular array transducer. Feasibility of repositioning stones was investigated by implanting artificial and human stones into a kidney-mimicking phantom that simulated a lower pole and collecting system. During experiment, stones were located by ultrasound imaging and repositioned by delivering short bursts of focused ultrasound. Stone motion was concurrently monitored by fluoroscopy, ultrasound imaging, and video photography, from which displacement and velocity were estimated. Stones were seen to move immediately after delivering focused ultrasound and successfully repositioned from the lower pole to the collecting system. Estimated velocities were on the order of 1 cm/s. This in vitro study demonstrates a promising modality to facilitate spontaneous clearance of kidney stones and increased clearance of residual stone fragments after surgical management. PMID:20967437

[Factors affecting residual stones after percutaneous nephrolithotomy in patients with renal calculus].

PubMed

Qiao, Mingzhou; Zhang, Haifang; Zhou, Chenlong

2015-11-24

To explore the factors affecting the residual stones after percutaneous nephrolithotomy (PCNL) in patients with renal calculus. A retrospective analysis was performed for 1 200 patients who were affected by renal calculus and treated with PCNL between Jan 2008 and May 2014 in People's Hospital of Anyang City. Among those patients, 16 were diagnosed as bilateral renal stone and had two successive operations. The size, location and number of stones, previous history of surgery, the degree of hydronephrosis, urinary infection were included in the univariate analysis. Significant factors in univariate analysis were included in the multivariate analysis to determine factors affecting stone residual. A total of 385 cases developed stone residual after surgery. The overall residual rate was 31.7%. In univariate analysis, renal pelvis combined with caliceal calculus (P=0.006), stone size larger than 4 cm (P=0.005), stone number more than 4 (P=0.002), the amount of bleeding more than 200 ml (P=0.025), operation time longer than 120 minutes (P=0.028) were associated with an increased rate of stone residual. When subjected to the Cox multivariate analysis, the independent risk factors for residual stones were renal pelvis combined with caliceal calculus (P=0.049), stone size larger than 4 cm (P=0.038) and stone number more than 4 (P=0.018). Factors affecting the incidence of residual stones after PCNL are the size, location and number of stones. Larger size stone and the presence of renal pelvis combined with caliceal calculus are significantly associated with residual stones. Nevertheless, stone number less than 4 indicates an increased stone clearance rate.

Significance of lower-pole pelvicaliceal anatomy on stone clearance after shockwave lithotripsy in nonobstructive isolated renal pelvic stones.

PubMed

Sozen, Sinan; Kupeli, Bora; Acar, Cenk; Gurocak, Serhat; Karaoglan, Ustunol; Bozkirli, Ibrahim

2008-05-01

To investigate the probable effect of lower-pole pelvicaliceal anatomy on stone clearance after shockwave lithotripsy (SWL) in patients with nonobstructive renal pelvic stones. The clinical records of patients with isolated renal pelvic stones who underwent SWL between 1996 and 2005 were reviewed. After excluding patients with obstruction leading to dilatation, major anatomic abnormalities, noncalcium stones, metabolic abnormalities, history of recurrent stone disease, multiple stones, and previous renal surgery, 153 patients were enrolled in the study. Lower pole infundibulopelvic angle (IPA) and infundibular length and width were measured from intravenous urography. Patients were classified into three groups according to stone burden (group 1, <100 mm(2); group 2, 101-200 mm(2); group 3, 201-400 mm(2)). The mean stone size was 142.08+/-86.3 mm(2). Overall stone-free rate was 53.6%. Localization of clinically significant or insignificant residual fragments was in the lower calix, renal pelvis, and both in 50 (32.6%), 29 (18.9%), and 8 (5.2%) patients, respectively. There was no statistically significant difference in pelvicaliceal anatomic features except narrower IPA (P=0.02) in group 1 patients with residual stones. The falling of stone fragments to the lower calix in spite of the ureter whether clinically significant or not after SWL of pelvic stones initially seems to be related to stone burden rather than lower caliceal anatomy. However, existence of a more narrow IPA in group 1 patients with residual fragments led us to believe that lower-pole IPA can play a role in stone clearance, especially for smaller stones, probably because of smaller residual fragment size or the more mobile nature of the primary stone.

In Idiopathic Calcium Oxalate Stone Formers, Unattached Stones Show Evidence of Having Originated as Attached Stones on Randall’s Plaque

PubMed Central

Miller, Nicole L.; Williams, James C.; Evan, Andrew P.; Bledsoe, Sharon B.; Coe, Fredric L.; Worcester, Elaine M.; Munch, Larry C.; Handa, Shelly E.; Lingeman, James E.

2009-01-01

Objective To analyze the structure and composition of unattached stones in idiopathic calcium oxalate stone formers (ICSF) and compare them to attached stones from the same cohort in order to investigate whether more than one pathogenic mechanism exists for stone formation in ICSF. Patients and methods ICSF undergoing percutaneous nephrolithotomy or ureteroscopy for treatment of nephrolithiasis were consented for this study. All accessible renal papillae were endoscopically imaged using a digital endoscope. All stones were removed and determined by the operating surgeon to be attached or unattached to the underlying papilla. Micro-computed tomography (micro-CT), which provides three-dimensional analysis of entire stones, was used to compare the structure and composition of attached versus unattached stones. Results Of 115 stones collected from 9 patients (12 renal units), only 25 stones were found not to be attached to renal papillae. Of these 25 stones, 4 were lost and 12 showed definite morphological evidence of having been attached to tissue, probably having been knocked off of papillae during access. For the remaining 9 stones, micro-CT analysis revealed at least one internal region of calcium phosphate within each of these unattached calcium oxalate (CaOx) stones. That is, the internal structure of the unattached stones is consistent with their having originated attached to RP, and then having become detached but retained in the kidney, with new layers of CaOx eventually covering the original attachment site. Conclusions Micro CT analysis supports the hypothesis that in ICSF, both attached and unattached stones occur as a result of a common pathogenic mechanism. That is, in this type of stone former, CaOx stones—even those not showing morphology that betrays attachment—all originate attached to interstitial plaque on the renal papilla. PMID:19549258

Combined Burst Wave Lithotripsy and Ultrasonic Propulsion for Improved Urinary Stone Fragmentation.

PubMed

Zwaschka, Theresa A; Ahn, Justin S; Cunitz, Bryan W; Bailey, Michael R; Dunmire, Barbrina; Sorensen, Mathew D; Harper, Jonathan D; Maxwell, Adam D

2018-04-01

Burst wave lithotripsy (BWL) is a new technology in development to fragment urinary stones. Ultrasonic propulsion (UP) is a separate technology under investigation for displacing stones. We measure the effect of propulsion pulses on stone fragmentation from BWL. Two artificial stone models (crystalline calcite, BegoStone plaster) and human calcium oxalate monohydrate (COM) stones measuring 5 to 8 mm were subjected to ultrasound exposures in a polyvinyl chloride tissue phantom within a water bath. Stones were exposed to BWL with and without propulsion pulses interleaved for set time intervals depending on stone type. Fragmentation was measured as a fraction of the initial stone mass fragmented to pieces smaller than 2 mm. BegoStone model comminution improved from 6% to 35% (p < 0.001) between BWL and BWL with interleaved propulsion in a 10-minute exposure. Propulsion alone did not fragment stones, whereas addition of propulsion after BWL slightly improved BegoStone model comminution from 6% to 11% (p < 0.001). BegoStone model fragmentation increased with rate of propulsion pulses. Calcite stone fragmentation improved from 24% to 39% in 5 minutes (p = 0.047) and COM stones improved from 17% to 36% (p = 0.01) with interleaved propulsion. BWL with UP improved stone fragmentation compared with BWL alone in vitro. The improvement was greatest when propulsion pulses are interleaved with BWL treatment and when propulsion pulses are applied at a higher rate. Thus, UP may be a useful adjunct to enhance fragmentation in lithotripsy in vivo.

Black and brown pigment gallstones differ in microstructure and microcomposition.

PubMed

Malet, P F; Takabayashi, A; Trotman, B W; Soloway, R D; Weston, N E

1984-01-01

The two subtypes of pigment gallstones, black and brown stones, differ in chemical composition and pathogenesis. We examined a black bilirubinate stone and a black phosphate stone (which represented opposite ends of the compositional spectrum of black noncarbonate stones), a black carbonate stone, and a brown pigment stone using scanning electron microscopy and microchemical techniques to determine if stone microstructure and microcomposition reflected different patterns of formation. The cross-sectional surfaces of the black bilirubinate and black phosphate stones were smooth and homogenous. Electron probe microanalysis demonstrated high concentrations of sulfur and copper in the center of the black bilirubinate stone; sulfur was in a low valence state consistent with disulfide linkages in proteins. The brown stone was rough-surfaced with lamellated bands on cross-section. The lighter-colored bands in this stone contained virtually all of the detected calcium palmitate, while the darker sections contained much more calcium bilirubinate. Plasma oxygen etching demonstrated a network of protein interdigitating with calcium bilirubinate salts in the black bilirubinate and black phosphate stones but not in the black carbonate or brown stones. Argon ion etching demonstrated that calcium bilirubinate was in a closely packed rod-shaped arrangement in all three black stones but not in the brown stone. We conclude that the marked differences in structure and composition between the black noncarbonate and brown pigment gallstones support the hypothesis that the two major pigment gallstone types form by different mechanisms. In addition, the layered structures of the black carbonate and brown stones suggest that stone growth is affected by cyclic changes in biliary composition.

Is retrograde intrarenal surgery the game changer in the management of upper tract calculi? A single-center single-surgeon experience of 131 cases.

PubMed

Parikh, Kandarp Priyakant; Jain, Ravi Jineshkumar; Kandarp, Aditya Parikh

2018-01-01

Success of any modality for stone disease needs to be evaluated in terms of Stone Free Rates (SFR), auxiliary procedures needed; complications and follow up. SFR in RIRS is subject to parameters like stone burden, location, number, hardness, composition; calyceal and ureter anatomy; use of ureteric access sheath (UAS); surgeon experience etc. The aim of this study is to evaluate the efficacy and safety of RIRS for managing upper tract stones. The objectives include evaluating SFR in RIRS in relation to stone burden, location and number. Other objectives include evaluating SFR after re RIRS in relation to stone burden, necessity of pre DJ stenting, use of UAS and post operative complication rate. 131 patients operated by single surgeon for single/multiple renal and/or upper ureteric stones were evaluated. Stone size > 3 mm on follow up CT KUB was considered as residual. Re RIRS was required for residual stones. The overall SFR was 76%. SFR were statistically lower with stone burden > 1.5 cm, lower calyceal stones and single stones with stone burden > 1.5 cm. SFR was 90% after 2 nd RIRS and 98.5% after 3 rd RIRS procedure. No significant difference in SFR was noted between single v/s multiple stones, single calyx v/s multiple calyx stones and renal v/s upper ureteric stones. No major complication was noted. Larger stone burden and lower calyceal location are important factors deciding SFR in RIRS. With auxiliary procedure, RIRS is safe and effective compared to PCNL.

Impact of stone density on outcomes in percutaneous nephrolithotomy (PCNL): an analysis of the clinical research office of the endourological society (CROES) pcnl global study database.

PubMed

Anastasiadis, Anastasios; Onal, Bulent; Modi, Pranjal; Turna, Burak; Duvdevani, Mordechai; Timoney, Anthony; Wolf, J Stuart; De La Rosette, Jean

2013-12-01

This study aimed to explore the relationship between stone density and outcomes of percutaneous nephrolithotomy (PCNL) using the Clinical Research Office of the Endourological Society (CROES) PCNL Global Study database. Patients undergoing PCNL treatment were assigned to a low stone density [LSD, ≤ 1000 Hounsfield units (HU)] or high stone density (HSD, > 1000 HU) group based on the radiological density of the primary renal stone. Preoperative characteristics and outcomes were compared in the two groups. Retreatment for residual stones was more frequent in the LSD group. The overall stone-free rate achieved was higher in the HSD group (79.3% vs 74.8%, p = 0.113). By univariate regression analysis, the probability of achieving a stone-free outcome peaked at approximately 1250 HU. Below or above this density resulted in lower treatment success, particularly at very low HU values. With increasing radiological stone density, operating time decreased to a minimum at approximately 1000 HU, then increased with further increase in stone density. Multivariate non-linear regression analysis showed a similar relationship between the probability of a stone-free outcome and stone density. Higher treatment success rates were found with low stone burden, pelvic stone location and use of pneumatic lithotripsy. Very low and high stone densities are associated with lower rates of treatment success and longer operating time in PCNL. Preoperative assessment of stone density may help in the selection of treatment modality for patients with renal stones.

Histopathology Predicts the Mechanism of Stone Formation

NASA Astrophysics Data System (ADS)

Evan, Andrew P.

2007-04-01

About 5% of American women and 12% of men will develop a kidney stone at some time in their life and these numbers appear to be on the rise. Despite years of scientific research into the mechanisms of stone formation and growth, limited advances have been made until recently. Randall's original observations and thoughts on the mechanisms for kidney stone formation have been validated for idiopathic calcium oxalate stone formers (ICSF) but not for most other stone forming groups. Our current studies on selected groups of human stone formers using intraoperative papillary biopsies has shown overwhelming evidence for the presence of Randall's plaque in ICSF and that stone formation and growth are exclusively linked to its availability to urinary ions and proteins. Intense investigation of the plaque-stone junction is needed if we are to understand the factors leading to the overgrowth process on exposed regions of plaque. Such information should allow the development of treatment strategies to block stone formation in ICSF patients. Patients who form brushite stones, or who form apatite stones because of distal renal tubular acidosis (dRTA), or patients with calcium oxalate stones due to obesity bypass procedures, or patients with cystinuria, get plugged inner medullary collecting ducts (IMCD) which leads to total destruction of the lining cells and focal sites of interstitial fibrosis. These stone formers have plaque but at levels equal to or below non-stone formers, which would suggest that they form stones by a different mechanism than do ICSF patients.

Open stone surgery: a still-in-use approach for complex stone burden.

PubMed

Çakici, Özer Ural; Ener, Kemal; Keske, Murat; Altinova, Serkan; Canda, Abdullah Erdem; Aldemir, Mustafa; Ardicoglu, Arslan

2017-06-30

Urinary stone disease is a major urological condition. Endourologic techniques have influenced the clinical approach and outcomes. Open surgery holds a historic importance in the management of most conditions. However, complex kidney stone burden may be amenable to successful results with open stone surgery. In this article, we report our eighteen cases of complex urinary stone disease who underwent open stone removal. A total of 1701 patients have undergone surgical treatment for urinary stone disease in our clinic between July 2012 and July 2016, comprising eighteen patients who underwent open stone surgery. Patients' demographic data, stone analysis results, postoperative clinical data, and stone status were evaluated retrospectively. The choice of surgical approach is mostly dependent on the surgeon's preference. In two patients, open surgery was undertaken because of perioperative complications. We did not observe any Clavien-Dindo grade 4 or 5 complications. Three patients were managed with a course of antibiotics due to postoperative fever. One patient had postoperative pleurisy, one patient had urinoma, and two patients had postoperative ileus. Mean operation time was 84 (57-124) minutes and mean hospitalization time was 5.5 (3-8) days. Stone-free status was achieved in 15 patients (83.3%). Endourologic approaches are the first options for treatment of urinary stone disease. However, open stone surgery holds its indispensable position in complicated cases and in complex stone burden. Open stone surgery is also a valid alternative to endourologic techniques in all situations.

[Infrared spectrophotometry for crystalline composition of staghorn calculi].

PubMed

Ma, Kai; Huang, Xiao-bo; Xu, Qing-quan; Li, Jian-xing; Xiong, Liu-lin; Yang, Bo; Ye, Xiong-jun; Chen, Liang; Wang, Xiao-feng; Na, Yan-qun

2010-11-30

To provide theoretic rationales for treatment and prevention of staghorn calculi by analyzing stone composition and studying the relationship between stone and urinary tract infections. The clinical data of 51 staghorn calculi patients were analyzed retrospectively. The stone compositions were studied by infrared spectrophotometry. Six types of stone compositions were obtained. There were calcium oxalate monohydrate, calcium oxalate dehydrate, carbonate apatite, magnesium ammonium phosphate hexahydrate, uric acid and L-cystine. The majority of stones were of mixed compositions, pure stones were found in 15 cases (29.4%). Among all stones, calcium oxalate stones were found in 41 cases (80.4%) and uric stones in 10 cases (19.6%). Infectious stones were found in 26 cases (51.0%). Urinary tract infections were found in 40 (78.4%) patients and positive urine/stone culture was detected in 33 (64.7%) patients. With multiple crystalline compositions and etiological factors, the staghorn calculi are closely correlated with urinary tract infections.

Salivary stones: symptoms, aetiology, biochemical composition and treatment.

PubMed

Kraaij, S; Karagozoglu, K H; Forouzanfar, T; Veerman, E C I; Brand, H S

2014-12-05

Salivary stones, also known as sialoliths, are calcified concrements in the salivary glands. Sialoliths are more frequently located in the submandibular gland (84%), than in the parotid gland (13%). The majority of the submandibular stones are located in Wharton's duct (90%), whereas parotid stones are more often located in the gland itself. Salivary stones consist of an amorphous mineralised nucleus, surrounded by concentric laminated layers of organic and inorganic substances. The organic components of salivary stones include collagen, glycoproteins, amino acids and carbohydrates. The major inorganic components are hydroxyapatite, carbonate apatite, whitlockite and brushite. The management of salivary stones is focused on removing the salivary stones and preservation of salivary gland function which depends on the size and location of the stone. Conservative management of salivary stones consists of salivary gland massage and the use of sialogogues. Other therapeutic options include removal of the stone or in some cases surgical removal of the whole salivary gland.

Single-session ureteroscopic pneumatic lithotripsy for the management of bilateral ureteric stones.

PubMed

Isen, Kenan

2012-01-01

In nowadays there is no consensus on single-session ureteroscopic lithotripsy (URSL) for the management of bilateral ureteric stones. The aim of this study was to evaluate efficacy and safety of single-session URSL in patients with bilateral ureteric stones. 41 patients who have undergone bilateral single-session URSL were evaluted in this study. A 8/9.8 Fr Wolf semi-rigid ureteroscope was used for the procedures, and the stones were fragmented with pneumatic lithotripter. A high stone-free rate was achieved (90.2%) after single endoscopic procedure with a retreatment rate of 9.8%. The procedure was most successful for distal ureteric stones with a 96.2% stone-free rate followed by middle ureteric stones with a 81.8% stone-free rate while the least success was achieved for proximal ureteric stones with a 77.7% stone-free rate (p < 0.05). A greater stone-free rate was obtained in those with stones less than 10 mm (93.7%) than in those with stones larger than 10 mm (77.7%) (p < 0.05). Ureteral perforation occurred in only one patient (2.4%). No long-term complication was observed in any patient. Bilateral single-session URSL can be performed effectively and safely with a low complication rate in patients with bilateral ureteric stones. It can reduce the need of anaesthetics and hospital stay.

Using Helical CT to Predict Stone Fragility in Shock Wave Lithotripsy (SWL)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, James C. Jr.; Zarse, Chad A.; Jackson, Molly E.

2007-04-05

Great variability exists in the response of urinary stones to SWL, and this is true even for stones composed of the same mineral. Efforts have been made to predict stone fragility to shock waves using computed tomography (CT) patient images, but most work to date has focused on the use of stone CT number (i.e., Hounsfield units). This is an easy number to measure on a patient stone, but its value depends on a number of factors, including the relationship of the size of the stone to me resolution (i.e., the slicewidth) of the CT scan. Studies that have shownmore » a relationship between stone CT number and failure in SWL are reviewed, and all are shown to suffer from error due to stone size, which was not accounted for in the use of Hounsfield unit values. Preliminary data are then presented for a study of calcium oxalate monohydrate (COM) stones, in which stone structure-rather than simple CT number values-is shown to correlate with fragility to shock waves. COM stones that were observed to have structure by micro CT (e.g., voids, apatite regions, unusual shapes) broke to completion in about half the number of shock waves required for COM stones that were observed to be homogeneous in structure by CT. This result suggests another direction for the use of CT in predicting success of SWL: the use of CT to view stone structure, rather than simply measuring stone CT number. Viewing stone structure by CT requires the use of different viewing windows than those typically used for examining patient scans, but much research to date indicates that stone structure can be observed in the clinical setting. Future clinical studies will need to be done to verify the relationship between stone structure observed by CT and stone fragility in SWL.« less

Characteristics of renal papillae in kidney stone formers.

PubMed

Marien, Tracy P; Miller, Nicole L

2016-12-01

The mechanism of kidney stone formation is not well understood. In order to better understand the pathophysiology for specific kidney stone compositions and systemic diseases associated with kidney stones, endoscopic papillary mapping studies with concurrent biopsies have been conducted. This review will summarize the findings of these studies and proposed mechanisms for thirteen disease processes associated with kidney stones. A review of the literature was performed identifying thirteen studies that endoscopically mapped and biopsied renal papillae of different stone formers. These studies characterized renal papillae based on amount of Randall's plaque, Bellini's duct pathology, papillary contour changes, presence of attached stones, pitting, and frequently papillary and cortical biopsies. The groups studied and reviewed here are kidney stone formers who have a history of idiopathic calcium oxalate stone formation, cystinuria, brushite stones, gastric bypass, ileostomy, small bowel resection, primary hyperparathyroidism, distal renal tubular acidosis (dRTA), primary hyperoxaluria, idiopathic calcium phosphate stone formation, medullary sponge kidney (MSK), uric acid stones, and struvite stones. A proposed standardized scoring system for papillary pathology was also reviewed. The series showed various degrees and types of changes to the renal papillae and corresponding histopathologic changes for each type of stone former reviewed. Those with predominantly alone Randall's plaque pathology had less tissue damage versus those with extensive Bellini's duct lesions who had more interstitial fibrosis and cortical pathology. Randall's plaques are associated with stone formers who have low urinary volume, high urinary calcium, and acidic urine and thus are frequently seen in those with brushite stones, primary hyperparathyroidism, small bowel resection, and idiopathic calcium phosphate stone formers. Bellini's duct plugging and pathology is theorized to occur via free solution crystallization, ductal obstruction, inflammation, cellular injury, fibrosis, and acidification defects. Ureteroscopic manifestations of stone disease can vary from normal appearing papillae to significantly diseased appearing papillae. Some diseases have very characteristic papillary changes. Further studies are necessary to fully elucidate the mechanisms of stone formation in patients with nephrolithiasis.

Advances in lithotripsy and stone disease treatment.

PubMed

Newman, J

1996-01-01

Stone disease can be traced back as far as the human record. This article traces the diagnosis and treatment of stone disease from primitive attempts at stone removal in ancient civilizations to the advent of extracorporeal shock wave lithotripsy (ESWL) in the 1970s. ESWL revolutionized the treatment of stone disease, offering patients a less painful alternative to the traditional surgical removal of stones. This article discusses recent advances in ESWL, describes the radiologic technologist's role in diagnosing and managing stone disease, and outlines future prospects in the treatment of stone disease.

Infection (urease) stones.

PubMed

Griffith, D P; Osborne, C A

1987-01-01

Infection-induced stones in man probably form solely as a consequence of urealysis which is catalyzed by the bacterial protein urease. Urease stones composed of struvite and carbonate-apatite may form primarily, or as secondary stones or pre-existent metabolic stones. Struvite stones form and grow rapidly owing to (a) supersaturation of urine with stone forming salts, (b) 'salting out' of poorly soluble organic substances normally dissolved in urine and (c) ammonia-induced destruction of the normally protective urothelial glycosaminoglycan layer. Immature (predominantly organic) matrix stones mature into densely mineralized stones. Curative treatment is possible only by eliminating all of the stone and by eradicating all urinary and parenchymal infection. A variety of operative and pharmaceutical approaches are available. Patient treatment must be individualized inasmuch as some patients are better candidates for one type of treatment than another.

Wedge filter imaging spectrometer

NASA Astrophysics Data System (ADS)

Bernardi, Pernelle; Bonafous, M.; Motisi, M.; Reess, J.-M.; Tanrin, J.; Laubier, D.

2017-11-01

LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris-Meudon) has an extensive experience in visible and infrared imaging spectrometry with several instruments onboard planetary space missions (MarsExpress/OMEGA, VenusExpress/VIRTIS, Rosetta/VIRTIS).

Risk factors for recurrent symptomatic pigmented biliary stones after percutaneous transhepatic biliary extraction.

PubMed

Kim, Dong Won; Lee, Sang Yun; Cho, Jin-Han; Kang, Myong Jin; Noh, Myung Hwan; Park, Byeong-Ho

2010-07-01

To evaluate risk factors for the recurrence of biliary stones after a percutaneous transhepatic biliary stone extraction. The procedures were performed on 339 patients between July 2004 and December 2008 (54 months). Medical records and images were retrospectively reviewed for 135 patients (mean age, 66.4 years; 83 men and 52 women) who had undergone follow-up for a mean of 13.2 months (range, 3-37 months). To evaluate risk factors for the recurrence of biliary stones, variables were evaluated with univariate and multivariate analyses. Variables included sex, age, stone location, number of stones, stone size, presence of a peripapillary diverticulum, application of antegrade sphincteroplasty, presence of a biliary stricture, largest biliary diameter before the procedure, and gallbladder status. Thirty-three of the 135 patients (24%) had recurrent symptomatic biliary stones and underwent an additional extraction. The mean time to recurrence was 17.2 months +/- 8.7. Univariate analysis of risk factors for recurrence of biliary stones demonstrated that location, number of stones, stone size, application of antegrade sphincteroplasty, presence of a biliary stricture, and biliary diameter were significant factors (P < .05). With use of multivariate analysis, the number of stones (> or =6; relative risk, 64.8; 95% confidence interval: 5.8, 717.6) and stone size (> or =14 mm; relative risk, 3.8; 95% confidence interval: 1.138, 13.231) were determined to be significant risk factors. The independent risk factors for recurrence of symptomatic biliary stones after percutaneous transhepatic biliary stone extraction were a stone size of at least 14 mm and the presence of at least six stones. Copyright 2010 SIR. Published by Elsevier Inc. All rights reserved.

Stone clearance after extracorporeal shockwave lithotripsy in patients with solitary pure calcium oxalate stones smaller than 1.0 cm in the proximal ureter, with special reference to monohydrate and dihydrate content.

PubMed

Ichiyanagi, Osamu; Nagaoka, Akira; Izumi, Takuji; Kawamura, Yuko; Tsukigi, Masaaki; Ishii, Tatsuya; Ohji, Hiroshi; Kato, Tomoyuki; Tomita, Yoshihiko

2013-04-01

The aim of this study was to assess stone-free rates following extracorporeal shockwave lithotripsy (ESWL) of pure calcium oxalate (CaOx) stones in the proximal ureter. The investigators retrospectively examined 53 patients with 5-10 mm pure CaOx stones in the proximal ureter from the medical archives of 593 consecutive patients treated with ESWL. The compositions of calcium oxalate monohydrate (COM) and dihydrate (COD) in a given stone were determined by infrared spectrometry. Stone size, attenuation number and stone-to-skin distance (SSD) were measured using plain radiography and computed tomography (CT). ESWL success was evaluated by stone-free status after the first single session. On average, calculi were 8.0 × 5.3 mm in size, with an SSD of 11.0 cm. The mean CT attenuation value was 740.1 HU. Attenuation numbers correlated significantly with stone diameter (r = 0.49), but had no correlation with the stone content of COM or COD. A negative correlation was observed between COM and COD content (r = -0.925). With regard to patients' physical characteristics and COM and COD content, no differences were found between study subgroups with stone-free and residual status (n = 38 and 15, respectively). There were also no differences in clinical features between patient subgroups with COM- or COD-predominant stones (n = 22 and 31, respectively). The findings indicated that the differences in COM and COD content of CaOx stones had no impact on stone clearance after ESWL and that a favorable stone-free rate of the stones treated with ESWL may be achieved independently of CaOx hydration.

Combined retrograde flexible ureteroscopic lithotripsy with holmium YAG laser for renal calculi associated with ipsilateral ureteral stones.

PubMed

Cocuzza, Marcello; Colombo, Jose R; Ganpule, Arvind; Turna, Burak; Cocuzza, Antonio; Dhawan, Divyar; Santos, Bruno; Mazzucchi, Eduardo; Srougi, Miguel; Desai, Mahesh; Desai, Mihir

2009-02-01

The purpose of this study was to evaluate the effectiveness of combined ureteroscopic holmium YAG lithotripsy for renal calculi associated with ipsilateral ureteral stones. Between August 2002 and March 2007, retrograde flexible ureteroscopic stone treatment was attempted in 351 cases. Indication for treatment was concurrent symptomatic ureteral stones in 63 patients (group I). Additional operative time and perioperative complication rates were compared to a group of 39 patients submitted to ureteroscopic treatment for ureteral calculi exclusively (group II). Mean ureteral stone size was 8.0 +/- 2.6 mm and 8.1 +/- 3.4 mm for groups I and II, respectively. Mean operative time for group I was 67.9 +/- 29.5 minutes and for group 2 was 49.3 +/- 13.2 minutes (p < 0.001). Flexible ureteroscopic therapy for renal calculi increased 18 minutes in the mean operative time. The overall complication rate was 3.1% and 2.5% for groups I and II, respectively (p = 0.87). Mean renal stone size was 10.7 +/- 6.4 mm, overall stone free rate in group I was 81%. However, considering only patients with renal stones smaller than 15 mm, the stone free rate was 88%. Successful treatment occurred in 81% of patients presenting lower pole stones, but only 76% of patients with multiple renal stones became stone free. As expected, stone free rate showed a significant negative correlation with renal stone size (p = 0.03; r = -0.36). Logistic regression model indicated an independent association of renal stones smaller than 15 mm and stone free rate (OR = 13.5; p = 0.01). Combined ureteroscopic treatment for ureteral and ipsilateral renal calculi is a safe and attractive option for patients presenting for symptomatic ureteral stone and ipsilateral renal calculi smaller than 15 mm.

Stone-Mode Ultrasound for Determining Renal Stone Size.

PubMed

May, Philip C; Haider, Yasser; Dunmire, Barbrina; Cunitz, Bryan W; Thiel, Jeff; Liu, Ziyue; Bruce, Matthew; Bailey, Michael R; Sorensen, Mathew D; Harper, Jonathan D

2016-09-01

The purpose of this study was to measure the accuracy of stone-specific algorithms (S-mode) and the posterior acoustic shadow for determining kidney stone size with ultrasound (US) in vivo. Thirty-four subjects with 115 renal stones were prospectively recruited and scanned with S-mode on a research US system. S-mode is gray-scale US adjusted to enhanced stone contrast and resolution by minimizing compression and averaging, and increasing line density and frequency. Stone and shadow width were compared with a recent CT scan and, in 5 subjects with 18 stones, S-mode was compared with a clinical US system. Overall, 84% of stones identified on CT were detected on S-mode and 66% of these shadowed. Seventy-three percent of the stone measurements and 85% of the shadow measurements were within 2 mm of the size on CT. A posterior acoustic shadow was present in 89% of stones over 5 mm versus 53% of stones under 5 mm. S-mode visualized 78% of stones, versus 61% for the clinical system. S-mode stone and shadow measurements differed from CT by 1.6 ± 1.0 mm and 0.8 ± 0.6 mm, respectively, compared with 2.0 ± 1.5 mm and 1.6 ± 1.0 mm for the clinical system. S-mode offers improved visualization and sizing of renal stones. With S-mode, sizing of the stone itself and the posterior acoustic shadow were similarly accurate. Stones that do not shadow are most likely <5 mm and small enough to pass spontaneously.

Natural history of asymptomatic renal stones and prediction of stone related events.

PubMed

Kang, Ho Won; Lee, Sang Keun; Kim, Won Tae; Kim, Yong-June; Yun, Seok-Joong; Lee, Sang-Cheol; Kim, Wun-Jae

2013-05-01

The appropriate management for asymptomatic renal stones remains unclear. We assessed the natural history and progression rate of such stones and identified clinical factors associated with an increased risk of stone related events. We retrospectively reviewed the medical records of 201 male and 146 female patients with asymptomatic renal stones. It was recommended that patients be followed every 6 months. Mean followup was 31 months (range 6 to 180). Patients were divided into 2 groups by stone related events, including spontaneous stone passage, flank pain, stone growth or the need for intervention during followup. Spontaneous passage occurred in 101 patients (29.1%). Of the patients 186 (53.6%) and 161 (46.4%) did and did not have stone related events, respectively. Of the whole cohort 85 patients (24.5%) required intervention but only 4.6% needed surgery. At 19 months after diagnosis 50% of the patients had a symptom. Those with stone related events were more likely to be younger (mean ± SD age 46.6 ± 12.7 vs 49.3 ± 12.6 years) and male, and have a stone history (p = 0.047, 0.017 and 0.014, respectively). Male gender significantly decreased the probability of freedom from stone related events (log rank test p = 0.0135) and it was an independent predictor of stone related events (HR 1.521, p = 0.009). Younger patients, and those with smaller stones and no stone growth were more likely to experience spontaneous passage and less likely to undergo intervention (each p <0.05). Asymptomatic renal stones can be followed safely but long-term followup is necessary. Periodic followup and early intervention should be recommended in patients with risk factors. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Shock wave lithotripsy outcomes for lower pole and non-lower pole stones from a university teaching hospital: Parallel group comparison during the same time period

PubMed Central

Geraghty, Robert; Burr, Jacob; Simmonds, Nick; Somani, Bhaskar K.

2015-01-01

Introduction: Shock wave lithotripsy (SWL) is a treatment option for all locations of renal and ureteric stones. We compared the results of SWL for lower pole renal stones with all other non-lower pole renal and ureteric stones during the same time period. Material and Methods: All SWL procedures were carried out as day case procedures by a mobile lithotripter from January 2012 to August 2013. The follow-up imaging was a combination of KUB X-ray or USS. Following SWL treatment, the stone free rate (SFR) was defined as ≤3 mm fragments. Results: A total of 148 patients with a mean age of 62 years underwent 201 procedures. Of the 201 procedures, 93 (46%) were for lower pole stones. The non-lower pole stones included upper pole (n = 36), mid pole (n = 40), renal pelvis (n = 10), PUJ (n = 8), mid ureter (n = 3), upper ureter (n = 5) and a combination of upper, middle and/or lower pole (n = 6). The mean stone size for lower pole stones (7.4 mm; range: 4-16 mm) was slightly smaller than non-lower pole stones (8 mm; range: 4-17 mm). The stone fragmentation was successful in 124 (62%) of patients. However, the SFR was statistically significantly better (P = 0.023) for non-lower pole stones 43 (40%) compared to lower pole stones 23 (25%). There were 9 (4%) minor complications and this was not significantly different in the two groups. Conclusions: Although SWL achieves a moderately high stone fragmentation rate with a low complication rate, the SFR is variable depending on the location of stone and the definition of SFR, with lower pole stones fairing significantly worse than stones in all other locations. PMID:25657543

Shock wave lithotripsy outcomes for lower pole and non-lower pole stones from a university teaching hospital: Parallel group comparison during the same time period.

PubMed

Geraghty, Robert; Burr, Jacob; Simmonds, Nick; Somani, Bhaskar K

2015-01-01

Shock wave lithotripsy (SWL) is a treatment option for all locations of renal and ureteric stones. We compared the results of SWL for lower pole renal stones with all other non-lower pole renal and ureteric stones during the same time period. All SWL procedures were carried out as day case procedures by a mobile lithotripter from January 2012 to August 2013. The follow-up imaging was a combination of KUB X-ray or USS. Following SWL treatment, the stone free rate (SFR) was defined as ≤3 mm fragments. A total of 148 patients with a mean age of 62 years underwent 201 procedures. Of the 201 procedures, 93 (46%) were for lower pole stones. The non-lower pole stones included upper pole (n = 36), mid pole (n = 40), renal pelvis (n = 10), PUJ (n = 8), mid ureter (n = 3), upper ureter (n = 5) and a combination of upper, middle and/or lower pole (n = 6). The mean stone size for lower pole stones (7.4 mm; range: 4-16 mm) was slightly smaller than non-lower pole stones (8 mm; range: 4-17 mm). The stone fragmentation was successful in 124 (62%) of patients. However, the SFR was statistically significantly better (P = 0.023) for non-lower pole stones 43 (40%) compared to lower pole stones 23 (25%). There were 9 (4%) minor complications and this was not significantly different in the two groups. Although SWL achieves a moderately high stone fragmentation rate with a low complication rate, the SFR is variable depending on the location of stone and the definition of SFR, with lower pole stones fairing significantly worse than stones in all other locations.

KIDNEY STONES: AN UPDATE ON CURRENT PHARMACOLOGICAL MANAGEMENT AND FUTURE DIRECTIONS

PubMed Central

Xu, Hongshi; Zisman, Anna L.; Coe, Fredric L.; Worcester, Elaine M.

2013-01-01

Introduction Kidney stones are a common problem worldwide with substantial morbidities and economic costs. Medical therapy reduces stone recurrence significantly. Much progress has been made in the last several decades in improving therapy of stone disease. Areas covered 1) effect of medical expulsive therapy on spontaneous stone passage, 2) pharmacotherapy in the prevention of stone recurrence, 3) future directions in the treatment of kidney stone disease. Expert Opinion fluid intake to promote urine volume of at least 2.5L each day is essential to prevent stone formation. Dietary recommendations should be adjusted based on individual metabolic abnormalities. Properly dosed thiazide treatment is the standard therapy for calcium stone formers with idiopathic hypercalciuria. Potassium alkali therapy is considered for hypocitraturia, but caution should be taken to prevent potential risk of calcium phosphate stone formation. For absorptive hyperoxaluria, low oxalate diet and increased dietary calcium intake are recommended. Pyridoxine has been shown effective in some cases of primary hyperoxaluria type I. Allopurinol is used in calcium oxalate stone formers with hyperuricosuria. Treatment of cystine stones remains challenging. Tiopronin can be used if urinary alkalinization and adequate fluid intake are insufficient. For struvite stones, complete surgical removal coupled with appropriate antibiotic therapy is necessary. PMID:23438422

Retrograde intrarenal surgery for the treatment of renal stones in children: factors influencing stone clearance and complications.

PubMed

Azili, Mujdem Nur; Ozcan, Fatma; Tiryaki, Tugrul

2014-07-01

Retrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood. We retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients' age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded. There were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients' ages ranged from 8 months to 14 years (mean age 4.7 ± 3.4 years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1-4 years age group, abdominal pain was seen mostly in children aged 5-14 years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n=26). After the repeated sessions, the stone clearance rate reached to 85.1%. Retrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status. Copyright © 2014 Elsevier Inc. All rights reserved.

What happens to asymptomatic lower pole kidney stones smaller than 10 mm in children during watchful waiting?

PubMed

Telli, Onur; Hamidi, Nurullah; Bagci, Uygar; Demirbas, Arif; Hascicek, Ahmet Metin; Soygur, Tarkan; Burgu, Berk

2017-05-01

The optimal management of lower pole kidney (LPK) stones in children is controversial. The aim of this study was to determine the outcomes of children with asymptomatic isolated LPK stones smaller than 10 mm during follow-up. A total of 242 patients with 284 stones presenting at our institution between June 2004 and December 2014 with an asymptomatic, single LPK stone with a diameter of <10 mm were enrolled in the study. All children were assigned to receive first-line therapy and then categorized according to the need for medical intervention. Age, gender, stone laterality, stone size and type, associated urinary tract problems, and uncontrolled metabolic status were assessed as predictive factors of medical treatment for small (<10 mm) asymptomatic LPK stones. Stone-free rates were compared between interventions. The mean age and mean stone size were 9.4 ± 1.9 years and 7.4 ± 0.6 mm at admission, respectively. Stone progression rate was 61.2%, and the mean time for intervention was 19.2 ± 4.6 months. Flexible ureterorenoscopy (n = 68) or micro-percutaneous nephrolithotomy (n = 4) were performed for 72 stones (25.4%; group 1), and extracorporeal shock wave lithotripsy was performed for 102 stones (35.9%; group 2). The stone-free rates were 81.8 and 79.3% in group 1 and 2, respectively (p > 0.05). The remaining asymptomatic stones (110, 38.8%; group 3) were managed by continued observation, and at the end of the observation time (mean 40.8 ± 20.8 months) the spontaneous passage rate was 9.1% in this group. In the multivariate analysis, stone size of >7 mm, concurrent renal anomalies, and stones composed of magnesium ammonium phosphate (struvite) and cystine were statistically significant predictors of the need for intervention. Children with stones larger than 7 mm, renal anomalies, or stones composed of metabolically active cystine or struvite are more likely to require intervention, and those with asymptomatic LPK stones smaller than 10 mm can be managed by continued observation.

Noncontrast computed tomography can predict the outcome of shockwave lithotripsy via accurate stone measurement and abdominal fat distribution determination.

PubMed

Geng, Jiun-Hung; Tu, Hung-Pin; Shih, Paul Ming-Chen; Shen, Jung-Tsung; Jang, Mei-Yu; Wu, Wen-Jen; Li, Ching-Chia; Chou, Yii-Her; Juan, Yung-Shun

2015-01-01

Urolithiasis is a common disease of the urinary system. Extracorporeal shockwave lithotripsy (SWL) has become one of the standard treatments for renal and ureteral stones; however, the success rates range widely and failure of stone disintegration may cause additional outlay, alternative procedures, and even complications. We used the data available from noncontrast abdominal computed tomography (NCCT) to evaluate the impact of stone parameters and abdominal fat distribution on calculus-free rates following SWL. We retrospectively reviewed 328 patients who had urinary stones and had undergone SWL from August 2012 to August 2013. All of them received pre-SWL NCCT; 1 month after SWL, radiography was arranged to evaluate the condition of the fragments. These patients were classified into stone-free group and residual stone group. Unenhanced computed tomography variables, including stone attenuation, abdominal fat area, and skin-to-stone distance (SSD) were analyzed. In all, 197 (60%) were classified as stone-free and 132 (40%) as having residual stone. The mean ages were 49.35 ± 13.22 years and 55.32 ± 13.52 years, respectively. On univariate analysis, age, stone size, stone surface area, stone attenuation, SSD, total fat area (TFA), abdominal circumference, serum creatinine, and the severity of hydronephrosis revealed statistical significance between these two groups. From multivariate logistic regression analysis, the independent parameters impacting SWL outcomes were stone size, stone attenuation, TFA, and serum creatinine. [Adjusted odds ratios and (95% confidence intervals): 9.49 (3.72-24.20), 2.25 (1.22-4.14), 2.20 (1.10-4.40), and 2.89 (1.35-6.21) respectively, all p < 0.05]. In the present study, stone size, stone attenuation, TFA and serum creatinine were four independent predictors for stone-free rates after SWL. These findings suggest that pretreatment NCCT may predict the outcomes after SWL. Consequently, we can use these predictors for selecting the optimal treatment for patients with urinary stones. Copyright © 2014. Published by Elsevier Taiwan.

Factors affecting stone-free rate and complications of percutaneous nephrolithotomy for treatment of staghorn stone.

PubMed

el-Nahas, Ahmed R; Eraky, Ibrahim; Shokeir, Ahmed A; Shoma, Ahmed M; el-Assmy, Ahmed M; el-Tabey, Nasr A; Soliman, Shady; Elshal, Ahmed M; el-Kappany, Hamdy A; el-Kenawy, Mahmoud R

2012-06-01

To determine factors affecting the stone-free rate and complications of percutaneous nephrolithotomy (PNL) for treatment of staghorn stones. The computerized database of patients who underwent PNL for treatment of staghorn stones between January 2003 and January 2011 was reviewed. All perioperative complications were recorded and classified according to modified Clavien classification system. The stone-free rate was evaluated with low-dose noncontrast computed tomography (CT). Univariate and multivariate statistical analyses were performed to determine factors affecting stone-free and complication rates. The study included 241 patients (125 male and 116 female) with a mean age of 48.7 ±14.3 years. All patients underwent 251 PNL (10 patients had bilateral stones). The stone-free rate of PNL monotherapy was 56% (142 procedures). At 3 months, the stone-free rate increased to 73% (183 kidneys) after shock wave lithotripsy. Independent risk factors for residual stones were complete staghorn stone and presence of secondary calyceal stones (relative risks were 2.2 and 3.1, respectively). The complication rate was 27% (68 PNL). Independent risk factors for development of complications were performance of the procedure by urologists other than experienced endourologist and positive preoperative urine culture (relative risks were 2.2 and 2.1, respectively). Factors affecting the incidence of residual stones after PNL are complete staghorn stones and the presence of secondary calyceal stones. Complications are significantly high if PNL is not performed by an experienced endourologist or if preoperative urine culture is positive. Copyright © 2012 Elsevier Inc. All rights reserved.

Cholecystolithiasis is associated with Clonorchis sinensis infection.

PubMed

Qiao, Tie; Ma, Rui-hong; Luo, Xiao-bing; Luo, Zhen-liang; Zheng, Pei-ming

2012-01-01

The objective of this study was to analyze gallbladder stones for direct evidence of a relationship between Clonorchis sinensis infection and gallbladder stones formation. We investigated one hundred eighty-three gallbladder stones for the presence of Clonorchis sinensis eggs using microscopy, and analyzed their composition using Fourier transform infrared spectroscopy. We confirmed the presence of Clonorchis sinensis eggs in the gallbladder stones using real-time fluorescent PCR and scanning electron microscopy. Clonorchis sinensis eggs were detected in 122 of 183 gallbladder stones based on morphologic characteristics and results from real-time fluorescent PCR. The proportion of pigment stones, cholesterol stones and mixed gallstones in the egg-positive stones was 79.5% (97/122), 3.3% (4/122) and 17.2% (21/122), respectively, while 29.5% (18/61), 31.1% (19/61) and 39.3% (24/61) in the egg-negative stones. The proportion of pigment stone in the Clonorchis sinensis egg-positive stones was higher than in egg-negative stones (P<0.0001). In the 30 egg-positive stones examined by scanning electron microscopy, dozens or even hundreds of Clonorchis sinensis eggs were visible (×400) showing a distinct morphology. Many eggs were wrapped with surrounding particles, and in some, muskmelon wrinkles was seen on the surface of the eggs. Also visible were pieces of texture shed from some of the eggs. Some eggs were depressed or without operculum while most eggs were adhered to or wrapped with amorphous particles or mucoid matter (×3000). Clonorchis sinensis eggs were detected in the gallbladder stones which suggests an association between Clonorchis sinensis infection and gallbladder stones formation, especially pigment stones.

[Composition of 359 kidney stones from the East region of Algeria].

PubMed

Bouslama, S; Boutefnouchet, A; Hannache, B; Djemil, T; Kadi, A; Dahdouh, A; Saka, S; Daudon, M

2016-01-01

Determine stones composition of the upper urinary tract in the eastern region of Algeria. Our study focuses on a set of 359 stones of the upper urinary tract collected between January 2007 and December 2012 at hospitals in the eastern region of Algeria and analyzed by Fourier transform infrared spectroscopy. The male/female ratio was only 1.32. Calcium oxalate prevailed in 68.5% of stones and 49.3% of nuclei, mainly as whewellite (51.8% of stones and 37.9% of nuclei vs 16.7% and 11.4% respectively for weddellite). Carbapatite prevailed in 15% of stones and 29.8% of nuclei. The struvite, identified in 11.1% of calculi, prevailed in 3.9% of stones and 3.1% of nuclei. Among purines, uric acid prevailed with frequencies quite close to 8.9% and 7% respectively in the stone and in the nucleus while the ammonium urate prevailed in only 0.3% of stones and 3.3% of nuclei. The cystine frequency was 3.6% in both stone and nucleus. The frequency of stone with umbilication was 26.2%. Whewellite was the main component of umbilicated stones with Randall's plaque. Our results suggest that stones of the urinary tract in the Algerian east region resemble those observed in industrialized countries. Some features such as stones location, the whewellite prevalence, the frequencies of main components in both the stone and the nucleus as well as the formation of stones on renal papilla confirm this trend. 4. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

12. FLOOR 2; STONE CRANE IN PLACE FOR ROCK STONES; ...

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

12. FLOOR 2; STONE CRANE IN PLACE FOR ROCK STONES; STONE CRANE HAS OAK SPAR, JIB AND BRACE, METAL SCREW, IRON YOKE AND DOGS; IRON PINS FIT THROUGH HOLES IN DOGS INTO HOLES DRILLED IN RUNNER STONE - Hook Windmill, North Main Street at Pantigo Road, East Hampton, Suffolk County, NY

Kidney Stones (For Parents)

MedlinePlus

... Staying Safe Videos for Educators Search English Español Kidney Stones KidsHealth / For Parents / Kidney Stones What's in ... other treatments to help remove the stones. How Kidney Stones Form It's the kidneys' job to remove ...

Pediatric ureteroscopic management of intrarenal calculi.

PubMed

Tanaka, Stacy T; Makari, John H; Pope, John C; Adams, Mark C; Brock, John W; Thomas, John C

2008-11-01

Data addressing ureteroscopic management of intrarenal calculi in prepubertal children are limited. We reviewed our experience from January 2002 through December 2007. We retrospectively reviewed ureteroscopic procedures for intrarenal calculi in children younger than 14 years. Stone-free status was determined with postoperative imaging. Multiple logistic regression analysis was used to assess the influence of preoperative factors on initial stone-free status and the need for additional procedures. Intrarenal calculi were managed ureteroscopically in 52 kidneys in 50 children with a mean age of 7.9 years (range 1.2 to 13.6). Mean stone size was 8 mm (range 1 to 16). Stone-free rate after a single ureteroscopic procedure was 50% (25 of 50 patients) on initial postoperative imaging and 58% (29 of 50) with extended followup. Initial stone-free status was dependent on preoperative stone size (p = 0.005) but not stone location. Additional stone procedures were required in 18 upper tracts. Younger patient age (p = 0.04) and larger preoperative stone size (p = 0.002) were associated with the need for additional procedures. Additional procedures were required in more than half of the stones 6 mm or larger but in no stone smaller than 6 mm. Ureteroscopy is a safe method for the treatment of intrarenal calculi in the prepubertal population. Our ureteroscopic stone-free rate for intrarenal stones is lower than that reported for ureteral stones. Parents should be informed that additional procedures will likely be required, especially in younger patients and those with stones larger than 6 mm.

Urinary stone composition in Oman: with high incidence of cystinuria.

PubMed

Al-Marhoon, Mohammed S; Bayoumi, Riad; Al-Farsi, Yahya; Al-Hinai, Abdullhakeem; Al-Maskary, Sultan; Venkiteswaran, Krishna; Al-Busaidi, Qassim; Mathew, Josephkunju; Rhman, Khalid; Sharif, Omar; Aquil, Shahid; Al-Hashmi, Intisar

2015-06-01

Urinary stones are a common problem in Oman and their composition is unknown. The aim of this study is to analyze the components of urinary stones of Omani patients and use the obtained data for future studies of etiology, treatment, and prevention. Urinary stones of 255 consecutive patients were collected at the Sultan Qaboos University Hospital. Stones were analyzed by Fourier transform infrared spectrophotometer. The biochemical, metabolic, and radiological data relating to the patients and stones were collected. The mean age was 41 years, with M:F ratio of 3.7:1. The common comorbidities associated with stone formation were hypertension; diabetes, benign prostate hyperplasia; urinary tract infection; obesity; and atrophic kidney. The common presentation was renal colic and flank pain (96%). Stones were surgically retrieved in 70% of patients. Mean stone size was 9 ± 0.5 mm (range 1.3-80). Stone formers had a BMI ≥ 25 in 56% (P = 0.006) and positive family history of stones in 3.8%. The most common stones in Oman were as follows: Calcium Oxalates 45% (114/255); Mixed calcium phosphates & calcium oxalates 22% (55/255); Uric Acid 16% (40/255); and Cystine 4% (10/255). The most common urinary stones in Oman are Calcium Oxalates. Overweight is an important risk factor associated with stone formation. The hereditary Cystine stones are three times more common in Oman than what is reported in the literature that needs further genetic studies.

Laser-induced breakdown spectroscopy is a reliable method for urinary stone analysis

PubMed Central

Mutlu, Nazım; Çiftçi, Seyfettin; Gülecen, Turgay; Öztoprak, Belgin Genç; Demir, Arif

2016-01-01

Objective We compared laser-induced breakdown spectroscopy (LIBS) with the traditionally used and recommended X-ray diffraction technique (XRD) for urinary stone analysis. Material and methods In total, 65 patients with urinary calculi were enrolled in this prospective study. Stones were obtained after surgical or extracorporeal shockwave lithotripsy procedures. All stones were divided into two equal pieces. One sample was analyzed by XRD and the other by LIBS. The results were compared by the kappa (κ) and Spearman’s correlation coefficient (rho) tests. Results Using LIBS, 95 components were identified from 65 stones, while XRD identified 88 components. LIBS identified 40 stones with a single pure component, 20 stones with two different components, and 5 stones with three components. XRD demonstrated 42 stones with a single component, 22 stones with two different components, and only 1 stone with three different components. There was a strong relationship in the detection of stone types between LIBS and XRD for stones components (Spearman rho, 0.866; p<0.001). There was excellent agreement between the two techniques among 38 patients with pure stones (κ index, 0.910; Spearman rho, 0.916; p<0.001). Conclusion Our study indicates that LIBS is a valid and reliable technique for determining urinary stone composition. Moreover, it is a simple, low-cost, and nondestructive technique. LIBS can be safely used in routine daily practice if our results are supported by studies with larger numbers of patients. PMID:27011877

Direct peroral cholangioscopy using an ultraslim upper endoscope for management of residual stones after mechanical lithotripsy for retained common bile duct stones.

PubMed

Lee, Y N; Moon, J H; Choi, H J; Min, S K; Kim, H I; Lee, T H; Cho, Y D; Park, S-H; Kim, S-J

2012-09-01

The incidence of residual stones after mechanical lithotripsy for retained common bile duct (CBD) stones is relatively high. Peroral cholangioscopy using a mother-baby system may be useful for confirming complete extraction of stones, but has several limitations regarding routine use. We evaluated the role of direct peroral cholangioscopy (DPOC) using an ultraslim upper endoscope for the evaluation and removal of residual CBD stones after mechanical lithotripsy. From August 2006 to November 2010, 48 patients who had undergone mechanical lithotripsy for retained CBD stones with no evidence of filling defects in balloon cholangiography were recruited. The bile duct was inspected by DPOC after balloon cholangiography. Detected residual CBD stones were directly retrieved with a basket or balloon catheter under DPOC. The incidence of residual stones detected by DPOC, and the success rate of residual stone retrieval under DPOC were investigated. DPOC was successfully performed in 46 of the 48 patients (95.8%). Of these, 13 patients (28.3%) had residual CBD stones (mean number 1.4, range 1-3; mean diameter 4.5 mm, range 2.3-9.6). The residual stones were removed directly under DPOC in 11 of these patients (84.6%). There were no complications associated with DPOC or stone removal. DPOC using an ultraslim upper endoscope is a useful endoscopic procedure for the evaluation and extraction of residual stones after mechanical lithotripsy for retained CBD stones. © Georg Thieme Verlag KG Stuttgart · New York.

Calcium carbonate gallstones in children.

PubMed

Stringer, Mark D; Soloway, Roger D; Taylor, Donald R; Riyad, Kallingal; Toogood, Giles

2007-10-01

In the United States, cholesterol stones account for 70% to 95% of adult gallstones and black pigment stones for most of the remainder. Calcium carbonate stones are exceptionally rare. A previous analysis of a small number of pediatric gallstones from the north of England showed a remarkably high prevalence of calcium carbonate stones. The aims of this study were to analyze a much larger series of pediatric gallstones from our region and to compare their chemical composition with a series of adult gallstones from the same geographic area. A consecutive series of gallbladder stones from 63 children and 50 adults from the north of England were analyzed in detail using Fourier transform infrared microspectroscopy. Demographic and clinical data were collected on all patients. The relative proportions of each major stone component were assessed: cholesterol, protein and calcium salts of bilirubin, fatty acids, calcium carbonate, and hydroxyapatite. Thirty-nine (78%) adults had typical cholesterol stones, 7 (14%) had black pigment bilirubinate stones, and only 2 (4%) had calcium carbonate stones. In contrast, 30 (48%) children had black pigment stones, 13 (21%) had cholesterol stones, 15 (24%) had calcium carbonate stones, 3 (5%) had protein dominant stones, and 2 (3%) had brown pigment stones. In children, cholesterol stones were more likely in overweight adolescent girls with a family history of gallstones, whereas black pigment stones were equally common in boys and girls and associated with hemolysis, parenteral nutrition, and neonatal abdominal surgery. Calcium carbonate stones were more common in boys, and almost half had undergone neonatal abdominal surgery and/or required neonatal intensive care. The composition of pediatric gallstones differs significantly from that found in adults. In particular, one quarter of the children in this series had calcium carbonate stones, previously considered rare. Geographic differences are not the major reason for the high prevalence of calcium carbonate gallstones in children.

Compositional analysis of various layers of upper urinary tract stones by infrared spectroscopy

PubMed Central

He, Zhang; Jing, Zhang; Jing-Cun, Zheng; Chuan-Yi, Hu; Fei, Gao

2017-01-01

The objective of the present study was to determine the composition of various layers of upper urinary stones and assess the mechanisms of stone nucleation and aggregation. A total of 40 integrated urinary tract stones with a diameter of >0.8 cm were removed from the patients. All of the stones were cut in half perpendicularly to the longitudinal axis. Samples were selected from nuclear, internal and external layers of each stone. Fourier transform infrared spectroscopy (FT-IR) was adopted for qualitative and quantitative analysis of all of the fragments and compositional differences among nuclear, internal and external layers of various types of stone were subsequently investigated. A total of 25 cases of calcium oxalate (CaOx) stones and 10 cases of calcium phosphate (CaP) stones were identified to be mixed stones, while 5 uric acid (UA) calculi were pure stones (purity, >95%). In addition, the contents of CaOx and carbapatite (CA.AP) crystals in various layers of the mixed stones were found to be variable. In CaOx stones, the content of CA.AP in nuclear layers was significantly higher than that of the outer layers (32.0 vs. 6.8%; P<0.05), while the content of CaOx was lower in the inner than in the outer layers (57.6 vs. 86.6%; P<0.05). In CaP stones, the content of CA.AP in the nuclear layers was higher than that in the outer layers (74.0 vs. 47.3%; P<0.05), while the content of CaOx was lower in the inner than in the outer layers (7.0 vs. 40.0%; P<0.05). The UA stones showed no significant differences in their composition among different layers. In conclusion, FT-IR analysis of various layers of human upper urinary tract stones revealed that CaOx and CaP stones showed differences in composition between their core and surface, while all of the UA calculi were pure stones. The composition showed a marked variation among different layers of the stones, indicating that metabolism has an important role in different phases of the evolution of stones. The present study provided novel insight into the pathogenesis of urinary tract stones and may contribute to their prevention and treatment. PMID:28912866

Surgical management of pediatric urolithiasis

PubMed Central

Mishra, Shashi K.; Ganpule, A.; Manohar, T.; Desai, Mahesh R.

2007-01-01

Pediatric urolithiasis poses a technical challenge to the urologist. A review of the recent literature on the subject was performed to highlight the various treatment modalities in the management of pediatric stones. A Medline search was used to identify manuscripts dealing with management options such as percutaneous nephrolithotomy, shock wave lithotripsy, ureteroscopy and cystolithotripsy in pediatric stone diseases. We also share our experience on the subject. Shock wave lithotripsy should be the treatment modality for renal stone less than 1cm or < 150 mm2 and proximal non-impacted ureteric stone less than 1 cm with normal renal function, no infection and favorable anatomy. Indications for PCNL in children are large burden stone more than 2cm or more than 150mm2 with or without hydronephrosis, urosepsis and renal insufficiency, more than 1cm impacted upper ureteric stone, failure of SWL and significant volume of residual stones after open surgery. Shock wave lithotripsy can be offered for more soft (< 900 HU on CT scan) renal stones between 1-2cm. Primary vesical stone more than 1cm can be tackled with percutaneous cystolithomy or open cystolithotomy. Open renal stone surgery can be done for renal stones with associated structural abnormalities, large burden infective and staghorn stones, large impacted proximal ureteric stone. The role of laparoscopic surgery for stone disease in children still needs to be explored. PMID:19718300

Analysis of the utility of stone gram stain in urolithiasis treated with percutaneous nephrolithotomy.

PubMed

Cockerill, Patrick A; Rivera, Marcelino E; Krambeck, Amy E

2014-06-01

To define the sensitivity and specificity of stone gram stain for infected urolithiasis treated with percutaneous nephrolithotomy (PCNL). PCNL procedures performed at our institution were analyzed between January 2009 and May 2013. Stone fragments were sent in a sterile fashion for aerobic and fungal cultures. A gram stain and fungal smear were performed on the stones and reported within 24 hours of collection. A total of 228 patients underwent 248 PCNLs. Of the 248 stones, 81 (33%) had a positive stone culture. Stone gram stain was positive in 31 cases and negative in 50. There were 167 negative stone cultures, and in these cases, gram stain was positive in 5 and negative in 162. The calculated sensitivity and specificity of stone gram stain were 38% and 97%. The positive and negative predictive values were 86% and 76%, respectively. In the subset of 16 patients with positive stone fungal cultures, fungal smear was performed in 12 and was positive in 4, giving fungal smear a sensitivity of 33%. The results of this study suggest that stone gram stain cannot be relied on to detect a positive stone culture and may fail to detect up to 62% of infected stones. However, when positive, gram stain accurately predicts a positive stone culture in 86% of cases. Copyright © 2014 Elsevier Inc. All rights reserved.

Treatment and prevention of kidney stones: an update.

PubMed

Frassetto, Lynda; Kohlstadt, Ingrid

2011-12-01

The incidence of nephrolithiasis (kidney stones) is rising worldwide, especially in women and with increasing age. Kidney stones are associated with chronic kidney disease. Preventing recurrence is largely specific to the type of stone (e.g., calcium oxalate, calcium phosphate, cystine, struvite [magnesium ammonium phosphate]), and uric acid stones); however, even when the stone cannot be retrieved, urine pH and 24-hour urine assessment provide information about stone-forming factors that can guide prevention. Medications, such as protease inhibitors, antibiotics, and some diuretics, increase the risk of some types of kidney stones, and patients should be counseled about the risks of using these medications. Managing diet, medication use, and nutrient intake can help prevent the formation of kidney stones. Obesity increases the risk of kidney stones. However, weight loss could undermine prevention of kidney stones if associated with a high animal protein intake, laxative abuse, rapid loss of lean tissue, or poor hydration. For prevention of calcium oxalate, cystine, and uric acid stones, urine should be alkalinized by eating a diet high in fruits and vegetables, taking supplemental or prescription citrate, or drinking alkaline mineral waters. For prevention of calcium phosphate and struvite stones, urine should be acidified; cranberry juice or betaine can lower urine pH. Antispasmodic medications, ureteroscopy, and metabolic testing are increasingly being used to augment fluid and pain medications in the acute management of kidney stones.

Development of upper tract stones in patients with congenital neurogenic bladder.

PubMed

Stephany, Heidi A; Clayton, Douglass B; Tanaka, Stacy T; Thomas, John C; Pope, John C; Brock, John W; Adams, Mark C

2014-02-01

Patients with neurogenic bladder are at increased risk of developing upper tract stones. We hypothesized that patients with lower urinary tract stone disease are at greater risk of developing upper tract stones. We performed a 10-year retrospective case-control study of patients with neurogenic bladder to determine the association between bladder and upper tract stones. Independent risk factors for upper tract stones were assessed. Cases and controls were matched 1:1. Univariable analysis was performed by Fisher's exact test and the Mann-Whitney U test. Multivariable logistic regression was performed. 52 cases and controls were identified. Cases were significantly more likely to be non-ambulatory, have bowel-urinary tract interposition, thoracic level dysraphism, and history of bladder stones. On multivariable analysis, independent predictors of stone formation were male sex (OR 2.82; p = 0.02), dysraphism involving the thoracic spine (OR 3.37; p = 0.014) bowel-urinary tract interposition (OR 2.611; p = 0.038), and a history of bladder stones (OR 3.57; p = 0.015). Patients with neurogenic bladder are at increased risk for upper tract stones. The presence of bladder stones may herald the development of upper tract stones. The predictors of stone disease identified should guide prospective studies to better understand the natural history of upper tract stone development in this population. Copyright © 2013 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Protein content of human apatite and brushite kidney stones: significant correlation with morphologic measures.

PubMed

Pramanik, Rocky; Asplin, John R; Jackson, Molly E; Williams, James C

2008-10-01

Apatite and brushite kidney stones share calcium and phosphate as their main inorganic components. We tested the hypothesis that these stone types differ in the amount of proteins present in the stones. Intact stones were intensively analyzed by microcomputed tomography (micro CT) for both morphology (including the volume of voids, i.e., space devoid of X-ray dense material) and mineral type. To extract all proteins present in kidney stones in soluble form we developed a three-step extraction procedure using the ground stone powder. Apatite stones had significantly higher levels of total protein content and void volume compared to brushite stones. The void volume was highly correlated with the total protein contents in all stones (r2 = 0.61, P < 0.0001), and brushite stones contained significantly fewer void regions and proteins than did apatite stones (3.2 +/- 4.5% voids for brushite vs. 10.8 +/- 11.2% for apatite, P < 0.005; 4.1 +/- 1.6% protein for brushite vs. 6.0 +/- 2.4% for apatite, P < 0.03). Morphological observations other than void volume did not correlate with protein content of stones, and neither did the presence or absence of minor mineral components. Our results show that protein content of brushite and apatite stones is higher than that was previously thought, and also suggest that micro CT-visible void regions are related to the presence of protein.

Epidemiological study of urinary tract stones in a northern Italian city.

PubMed

Borghi, L; Ferretti, P P; Elia, G F; Amato, F; Melloni, E; Trapassi, M R; Novarini, A

1990-03-01

An epidemiological study of stone disease in a Northern Italian city was carried out by means of a postal questionnaire mailed to 6000 individuals (2.5% of the entire population). It was found that the incidence of stone disease was comparable to that of industrialised Western Europe. There was a relationship between stone disease and gout and stone disease and a positive family history. The frequency of uric acid stones was high (26.5%). Stone-formers showed no alimentary differences from non-stone formers apart from the use of spices and herbs. Stone-formers used less water from public aqueducts and more uncarbonated mineral water, but only 19% of these drank at least 2 litres a day.

Production and characterization of alpha-amylase from mango kernel by Fusarium solani NAIMCC-F-02956 using submerged fermentation.

PubMed

Kumar, Devendra; Yadav, Kaushlesh K; Muthukumar, M; Garg, Neelima

2013-11-01

Microbial production of enzymes using low valued agro industrial wastes is gaining importance globally. Mango is one of the major fruit processed into a variety of products. During processing 40-50% of solid waste is generated in form of peel and stones. After decortications of mango stone, kernel is obtained which is a rich source of starch (upto 60%). It was utilized as a substrate for alpha-amylase production using Fusarium soloni. Maximum alpha-amylase production (0.889 U g(-1)) was recorded using a substrate concentration of 5% (w/v), pH-4 and temperature 30 degrees C on 9th day of incubation. Supplementation of production medium with micronutrients viz., Ca2+, Fe2+ or Mg2+ improved the enzyme production while, Zn2+, B3+ or Mn2+ ions exhibited inhibitory effect. The extracellular protein was precipitated by ammonium sulphate up to 70% saturation, dialyzed and purified (27.84 fold) by gel-exclusion (Sephadex G-75) chromatography. Protein profiling on 12% SDS-PAGE revealed three bands corresponding to 26, 27 and 30 kDa molecular sizes. The optimum amylase activity was achieved at pH 5.0 at 40 degrees C. The Michaelis constant (KM), Vmax and activation energy (-Ea) were found to be 3.7 mg ml(-1), 0.24 U mg(-1) and 42.39 kJ mole(-1), respectively.

Characterization of Streptomyces isolates causing colour changes of mural paintings in ancient Egyptian tombs.

PubMed

Abdel-Haliem, M E F; Sakr, A A; Ali, M F; Ghaly, M F; Sohlenkamp, C

2013-08-25

Paintings in ancient Egyptian tombs often suffer colour changes due to microbial growth and colonization. Streptomyces strains were isolated from mural paintings of Tell Basta and Tanis tombs (East of Nile Delta, Egypt) and were identified using biochemical and molecular methods. The16S rDNA sequences data indicated that isolated strains were closely related to S. coelicolor, S. albidofuscus, S. ambofaciens, S. canarius, S. parvullus, S. corchorusii, S. albidofuscus and S. nigrifaciens. It could be shown that Streptomyces strains are involved on a large scale in the colour changes of paintings and stone support by producing a wide range of metabolites such as acids (oxalic, citric and sulphuric acids), biopigments of melanin, carotenoids, and hydrogen sulphide. Copyright © 2013 Elsevier GmbH. All rights reserved.

Motion artifacts in kidney stone imaging using single-source and dual-source dual-energy CT scanners: a phantom study.

PubMed

Ibrahim, El-Sayed H; Cernigliaro, Joseph G; Pooley, Robert A; Williams, James C; Haley, William E

2015-10-01

Dual-energy computed tomography (DECT) has shown the capability of differentiating uric acid (UA) from non-UA stones with 90-100% accuracy. With the invention of dual-source (DS) scanners, both low- and high-energy images are acquired simultaneously. However, DECT can also be performed by sequential acquisition of both images on single-source (SS) scanners. The objective of this study is to investigate the effects of motion artifacts on stone classification using both SS-DECT and DS-DECT. 114 kidney stones of different types and sizes were imaged on both DS-DECT and SS-DECT scanners with tube voltages of 80 and 140 kVp with and without induced motion. Postprocessing was conducted to create material-specific images from corresponding low- and high-energy images. The dual-energy ratio (DER) and stone material were determined and compared among different scans. For the motionless scans, all stones were correctly classified with SS-DECT, while two cystine stones were misclassified with DS-DECT. When motion was induced, 94% of the stones were misclassified with SS-DECT versus 11% with DS-DECT (P < 0.0001). Stone size was not a factor in stone misclassification under motion. Stone type was not a factor in stone misclassification under motion with SS-DECT, although with DS-DECT, cystine showed higher number of stone misclassification. Motion artifacts could result in stone misclassification in DECT. This effect is more pronounced in SS-DECT versus DS-DECT, especially if stones of different types lie in close proximity to each other. Further, possible misinterpretation of the number of stones (i.e., missing one, or thinking that there are two) in DS-DECT could be a potentially significant problem.

After urgent drainage of an obstructed kidney by internal ureteric stenting; is ureteroscopic stone extraction always needed?

PubMed Central

Taha, Diaa-Eldin; Elshal, Ahmed M.; Zahran, Mohamed H.; Harraz, Ahmed M.; El-Nahas, Ahmed R.; Shokeir, Ahmed A.

2015-01-01

Objectives To assess the probability of spontaneous stone passage and its predictors after drainage of obstructed kidney by JJ stent, as insertion of an internal ureteric stent is often used for renal drainage in cases of calcular ureteric obstruction. Patients and methods Between January 2011 and June 2013, patients for whom emergent drainage by ureteric stents were identified. The patients’ demographics, presentation, and stone characteristics were reviewed. The primary endpoint for this study was stone-free status at the time of stent removal, where all patients underwent non-contrast spiral computed tomography (NCCT) before stent removal. Ureteroscopic stone extraction was performed for CT detectable ureteric stones at the time of stent removal. Potential factors affecting the need for ureteroscopic stone extraction at the time of stent removal were assessed using univariate and multivariate statistical analyses. Results Emergent ureteric stents were undertaken in 196 patients (112 males, 84 females) with a mean (SD) age of 53.7 (16.2) years, for renal obstruction drainage. At the time of stent removal, 83 patients (42.3%) were stone free; with the remaining 113 patients (57.7%) undergoing ureteroscopic stone extraction. On multivariate analysis, stone width [odds ratio (OR) 15.849, 95% confidence interval (CI) 2.83; P = 0.002) and radio-opaque stones (OR 12.035, 95% CI 4.65; P < 0.001) were independent predictors of the need for ureteroscopic stone extraction at the time of stent removal. Conclusion Spontaneous ureteric stone passage is possible after emergent drainage of an obstructed kidney by ureteric stenting. Stone opacity, larger stone width, and positive preoperative urine culture are associated with a greater probability of requiring ureteroscopic stone extraction after emergent drainage by ureteric stenting. PMID:26609444

Retrospective comparison of measured stone size and posterior acoustic shadow width in clinical ultrasound images.

PubMed

Dai, Jessica C; Dunmire, Barbrina; Sternberg, Kevan M; Liu, Ziyue; Larson, Troy; Thiel, Jeff; Chang, Helena C; Harper, Jonathan D; Bailey, Michael R; Sorensen, Mathew D

2018-05-01

Posterior acoustic shadow width has been proposed as a more accurate measure of kidney stone size compared to direct measurement of stone width on ultrasound (US). Published data in humans to date have been based on a research using US system. Herein, we compared these two measurements in clinical US images. Thirty patient image sets where computed tomography (CT) and US images were captured less than 1 day apart were retrospectively reviewed. Five blinded reviewers independently assessed the largest stone in each image set for shadow presence and size. Shadow size was compared to US and CT stone sizes. Eighty percent of included stones demonstrated an acoustic shadow; 83% of stones without a shadow were ≤ 5 mm on CT. Average stone size was 6.5 ± 4.0 mm on CT, 10.3 ± 4.1 mm on US, and 7.5 ± 4.2 mm by shadow width. On average, US overestimated stone size by 3.8 ± 2.4 mm based on stone width (p < 0.001) and 1.0 ± 1.4 mm based on shadow width (p < 0.0098). Shadow measurements decreased misclassification of stones by 25% among three clinically relevant size categories (≤ 5, 5.1-10, > 10 mm), and by 50% for stones ≤ 5 mm. US overestimates stone size compared to CT. Retrospective measurement of the acoustic shadow from the same clinical US images is a more accurate reflection of true stone size than direct stone measurement. Most stones without a posterior shadow are ≤ 5 mm.

Cholecystolithiasis Is Associated with Clonorchis sinensis Infection

PubMed Central

Qiao, Tie; Ma, Rui-hong; Luo, Xiao-bing; Luo, Zhen-liang; Zheng, Pei-ming

2012-01-01

Background The objective of this study was to analyze gallbladder stones for direct evidence of a relationship between Clonorchis sinensis infection and gallbladder stones formation. Methodology We investigated one hundred eighty-three gallbladder stones for the presence of Clonorchis sinensis eggs using microscopy, and analyzed their composition using Fourier transform infrared spectroscopy. We confirmed the presence of Clonorchis sinensis eggs in the gallbladder stones using real-time fluorescent PCR and scanning electron microscopy. Principal Findings Clonorchis sinensis eggs were detected in 122 of 183 gallbladder stones based on morphologic characteristics and results from real-time fluorescent PCR. The proportion of pigment stones, cholesterol stones and mixed gallstones in the egg-positive stones was 79.5% (97/122), 3.3% (4/122) and 17.2% (21/122), respectively, while 29.5% (18/61), 31.1% (19/61) and 39.3% (24/61) in the egg-negative stones. The proportion of pigment stone in the Clonorchis sinensis egg-positive stones was higher than in egg-negative stones (P<0.0001). In the 30 egg-positive stones examined by scanning electron microscopy, dozens or even hundreds of Clonorchis sinensis eggs were visible (×400) showing a distinct morphology. Many eggs were wrapped with surrounding particles, and in some, muskmelon wrinkles was seen on the surface of the eggs. Also visible were pieces of texture shed from some of the eggs. Some eggs were depressed or without operculum while most eggs were adhered to or wrapped with amorphous particles or mucoid matter (×3000). Conclusion Clonorchis sinensis eggs were detected in the gallbladder stones which suggests an association between Clonorchis sinensis infection and gallbladder stones formation, especially pigment stones. PMID:22905137

Incidence and characteristics of kidney stones in patients with horseshoe kidney: A systematic review and meta-analysis

PubMed Central

Pawar, Aditya S.; Thongprayoon, Charat; Cheungpasitporn, Wisit; Sakhuja, Ankit; Mao, Michael A.; Erickson, Stephen B.

2018-01-01

Introduction: The horseshoe kidney (HSK) is the most common type of renal fusion anomaly. The incidence and characteristics of kidney stones in patients with HSK are not well studied. The aim of this meta-analysis was to evaluate the incidence and types of kidney stones in patients with HSK. Methods: A systematic literature search was performed using MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews from the databases' inception through November 2016. Studies assessing the incidence and types of kidney stones in patients with HSK were included. We applied a random-effects model to estimate the incidence of kidney stones. The study protocol was registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42016052037). Results: A total of 14 observational studies with 943 patients (522 adults and 421 pediatric) with HSK were enrolled. The estimated pooled incidence of kidney stones was 36% (95% confidence interval [CI], 15%–59%) in adults with the HSK. Kidney stones were less common in pediatric patients with HSK with an estimated pooled incidence of 3% (95% CI, 2%–5%). The mean age of adult stone formers with HSK was 44.9 ± 6.2 years, and 75% were males. Within reported studies, 89.2% of kidney stones were calcium-based stones (64.2% calcium oxalate [CaOx], 18.8% calcium phosphate [CaP], and 6.2% mixed CaOx/CaP), followed by struvite stones (4.2%), uric acid stones (3.8%), and others (2.8%). Conclusions: Kidney stones are very common in adult patients with HSK with an estimated incidence of 36%. Calcium-based stones are the most prevalent kidney stones in adults with HSKs. These findings may impact the prevention and clinical management of kidney stones in patients with HSK. PMID:29416282

The natural history of nonobstructing asymptomatic renal stones managed with active surveillance.

PubMed

Dropkin, Benjamin M; Moses, Rachel A; Sharma, Devang; Pais, Vernon M

2015-04-01

We documented the natural history of asymptomatic nonobstructing renal calculi managed with active surveillance and explored factors predicting stone related events to better inform shared decision making. Patients with asymptomatic nonobstructing renal calculi electing active surveillance of their stone(s) were retrospectively reviewed. Stone characteristics, patient characteristics, and stone related events were collected. We evaluated the effects of stone size and location on development of symptoms, spontaneous passage, requirement for surgical intervention, and stone growth. We identified 160 stones with an average size of 7.0 ± 4.2 mm among 110 patients with average followup of 41 ± 19 months. Forty-five (28% of total) stones caused symptoms during followup. Notably 3 stones (3% of asymptomatic subgroup, 2% of total stones) caused painless silent obstruction necessitating intervention after an average of 37 ± 17 months. The only significant predictor of spontaneous passage or symptom development was location. Upper pole/mid renal stones were more likely than lower pole stones to become symptomatic (40.6% vs 24.3%, p = 0.047) and to pass spontaneously (14.5% vs 2.9%, p = 0.016). Among asymptomatic nonobstructing renal calculi managed with active surveillance, most remained asymptomatic through an average followup of more than 3 years. Less than 30% caused renal colic, less than 20% were operated on for pain and 7% spontaneously passed. Lower poles stones were significantly less likely to cause symptoms or pass spontaneously. Despite 3 stones causing silent hydronephrosis suggestive of obstruction, regular followup imaging facilitated interventions that prevented renal loss. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Accurately Diagnosing Uric Acid Stones from Conventional Computerized Tomography Imaging: Development and Preliminary Assessment of a Pixel Mapping Software.

PubMed

Ganesan, Vishnu; De, Shubha; Shkumat, Nicholas; Marchini, Giovanni; Monga, Manoj

2018-02-01

Preoperative determination of uric acid stones from computerized tomography imaging would be of tremendous clinical use. We sought to design a software algorithm that could apply data from noncontrast computerized tomography to predict the presence of uric acid stones. Patients with pure uric acid and calcium oxalate stones were identified from our stone registry. Only stones greater than 4 mm which were clearly traceable from initial computerized tomography to final composition were included in analysis. A semiautomated computer algorithm was used to process image data. Average and maximum HU, eccentricity (deviation from a circle) and kurtosis (peakedness vs flatness) were automatically generated. These parameters were examined in several mathematical models to predict the presence of uric acid stones. A total of 100 patients, of whom 52 had calcium oxalate and 48 had uric acid stones, were included in the final analysis. Uric acid stones were significantly larger (12.2 vs 9.0 mm, p = 0.03) but calcium oxalate stones had higher mean attenuation (457 vs 315 HU, p = 0.001) and maximum attenuation (918 vs 553 HU, p <0.001). Kurtosis was significantly higher in each axis for calcium oxalate stones (each p <0.001). A composite algorithm using attenuation distribution pattern, average attenuation and stone size had overall 89% sensitivity, 91% specificity, 91% positive predictive value and 89% negative predictive value to predict uric acid stones. A combination of stone size, attenuation intensity and attenuation pattern from conventional computerized tomography can distinguish uric acid stones from calcium oxalate stones with high sensitivity and specificity. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Risk Factors for Stone Recurrence after Percutaneous Nephrolithotomy

NASA Astrophysics Data System (ADS)

Krambeck, Amy E.; Rangel, Laureano J.; LeRoy, Andrew J.; Patterson, David E.; Gettman, Matthew T.

2008-09-01

Recent studies have demonstrated more than 30% of percutaneous nephrolithotomy (PCNL) patients will experience a stone recurrence over a 20 year period. The goal of our study was to identify risk factors for stone recurrence after PCNL. Chart review identified 754 patients treated with PCNL for urolithiasis from March of 1983 to July 1984 at our institution. Of this cohort, 87 patients continued to receive medical care at our clinic and had been evaluated within the last 5 years. Of the 87 patients, 80 had recent radiographic imaging. Average follow-up was 19.2 years and 32 (40.0%) experienced at least 1 stone recurrence. There was no difference in preoperative BMI (p = 0.453) or change in BMI (p = 0.964) between patients that did and did not have a stone recurrence. Renal stone location (p = 0.605) and stone size (p = 0.238) were not predictive of recurrence. Patients with calcium oxalate monohydrate stones were less likely to recur (38.7% vs. 41.6%, p = 0.004) and those with calcium oxalate dihydrate (COD) were more likely to recur (31.1% vs. 19.6%, p = 0.006) compared to other compositions. Diabetes mellitus was not associated with recurrent stones (p = 0.810). Those patients with residual stones or fragments <3 mm were more likely to recur and to recur earlier than patients rendered entirely stone free at time of PCNL (p = 0.015). Stone recurrences were associated with the late development of renal insufficiency (25% vs. 2.1%, p = 0.002). In conclusion, stone composition, as well as the presence of residual fragments was associated with recurrent symptomatic stone events after PCNL. Recurrent stone events were significantly associated with the risk of developing renal insufficiency, further stressing the need for complete stone clearance at time of PCNL.

A neural network - based algorithm for predicting stone -free status after ESWL therapy

PubMed Central

Seckiner, Ilker; Seckiner, Serap; Sen, Haluk; Bayrak, Omer; Dogan, Kazım; Erturhan, Sakip

2017-01-01

ABSTRACT Objective: The prototype artificial neural network (ANN) model was developed using data from patients with renal stone, in order to predict stone-free status and to help in planning treatment with Extracorporeal Shock Wave Lithotripsy (ESWL) for kidney stones. Materials and Methods: Data were collected from the 203 patients including gender, single or multiple nature of the stone, location of the stone, infundibulopelvic angle primary or secondary nature of the stone, status of hydronephrosis, stone size after ESWL, age, size, skin to stone distance, stone density and creatinine, for eleven variables. Regression analysis and the ANN method were applied to predict treatment success using the same series of data. Results: Subsequently, patients were divided into three groups by neural network software, in order to implement the ANN: training group (n=139), validation group (n=32), and the test group (n=32). ANN analysis demonstrated that the prediction accuracy of the stone-free rate was 99.25% in the training group, 85.48% in the validation group, and 88.70% in the test group. Conclusions: Successful results were obtained to predict the stone-free rate, with the help of the ANN model designed by using a series of data collected from real patients in whom ESWL was implemented to help in planning treatment for kidney stones. PMID:28727384

Chronic Kidney Disease in Kidney Stone Formers

PubMed Central

Krambeck, Amy E.; Lieske, John C.

2011-01-01

Summary Recent population studies have found symptomatic kidney stone formers to be at increased risk for chronic kidney disease (CKD). Although kidney stones are not commonly identified as the primary cause of ESRD, they still may be important contributing factors. Paradoxically, CKD can be protective against forming kidney stones because of the substantial reduction in urine calcium excretion. Among stone formers, those with rare hereditary diseases (cystinuria, primary hyperoxaluria, Dent disease, and 2,8 dihydroxyadenine stones), recurrent urinary tract infections, struvite stones, hypertension, and diabetes seem to be at highest risk for CKD. The primary mechanism for CKD from kidney stones is usually attributed to an obstructive uropathy or pyelonephritis, but crystal plugs at the ducts of Bellini and parenchymal injury from shockwave lithotripsy may also contribute. The historical shift to less invasive surgical management of kidney stones has likely had a beneficial impact on the risk for CKD. Among potential kidney donors, past symptomatic kidney stones but not radiographic stones found on computed tomography scans were associated with albuminuria. Kidney stones detected by ultrasound screening have also been associated with CKD in the general population. Further studies that better classify CKD, better characterize stone formers, more thoroughly address potential confounding by comorbidities, and have active instead of passive follow-up to avoid detection bias are needed. PMID:21784825

Regional differences in constituents of gall stones.

PubMed

Ashok, M; Nageshwar Reddy, D; Jayanthi, V; Kalkura, S N; Vijayan, V; Gokulakrishnan, S; Nair, K G M

2005-01-01

The pathogenesis of pigment and mixed gall stone formation remains elusive. The elemental constituents of gall stones from southern states of Tamil Nadu, Kerala and Karnataka have been characterized. Our aim was to determine the elemental concentration of representative samples of pigment, mixed and cholesterol gall stones from Andhra Pradesh using proton-induced X-ray emission (PIXE) using a 3 MV horizontal pelletron accelerator. Pigment gall stones had significantly high concentrations of copper, iron and lead; chromium was absent. Except for iron all these elements were significantly low in cholesterol gall stones and intermediate levels were seen in mixed gall stones. Highest concentrations of chromium was seen in cholesterol and titanium in mixed gall stones respectively; latter similar to other southern states. Arsenic was distinctly absent in cholesterol and mixed gall stones. The study has identified differences in elemental components of the gall stones from Andhra Pradesh.

Kometen und Asteroiden

NASA Astrophysics Data System (ADS)

Borgeest, Ulf; Staude, Jakob; Hahn, Gerhard; Harris, Alan W.; Jaumann, Ralf; Köhler, Ulrich; Kührt, Ekkehard; Schulz, Rita; Neukum, Gerhard; Arnold, Gabriele; Keller, Horst Uwe; Denk, Tilmann; Müller, Thomas; Wulff, André; Maruhn, Nicolaus; Fischer, Daniel; Trieloff, Mario; Althaus, Tilmann

Contents: Die Kleinkörper des Sonnensystems. Kern, Koma und Schweife. Ziele der Planetenforschung. ROSETTA: Naherkundung von Kometen. Asteroiden: Trümmer aus planetarer Urzeit. Kleinkörper im Infrarotweltall. Selbs beobachten! Apocalypse - not now! Meteoriten - Boten aus der Urzeit des Sonnensystems.

Rosetta's comet 67P/Churyumov-Gerasimenko sheds its dusty mantle to reveal its icy nature.

PubMed

Fornasier, S; Mottola, S; Keller, H U; Barucci, M A; Davidsson, B; Feller, C; Deshapriya, J D P; Sierks, H; Barbieri, C; Lamy, P L; Rodrigo, R; Koschny, D; Rickman, H; A'Hearn, M; Agarwal, J; Bertaux, J-L; Bertini, I; Besse, S; Cremonese, G; Da Deppo, V; Debei, S; De Cecco, M; Deller, J; El-Maarry, M R; Fulle, M; Groussin, O; Gutierrez, P J; Güttler, C; Hofmann, M; Hviid, S F; Ip, W-H; Jorda, L; Knollenberg, J; Kovacs, G; Kramm, R; Kührt, E; Küppers, M; Lara, M L; Lazzarin, M; Moreno, J J Lopez; Marzari, F; Massironi, M; Naletto, G; Oklay, N; Pajola, M; Pommerol, A; Preusker, F; Scholten, F; Shi, X; Thomas, N; Toth, I; Tubiana, C; Vincent, J-B

2016-12-23

The Rosetta spacecraft has investigated comet 67P/Churyumov-Gerasimenko from large heliocentric distances to its perihelion passage and beyond. We trace the seasonal and diurnal evolution of the colors of the 67P nucleus, finding changes driven by sublimation and recondensation of water ice. The whole nucleus became relatively bluer near perihelion, as increasing activity removed the surface dust, implying that water ice is widespread underneath the surface. We identified large (1500 square meters) ice-rich patches appearing and then vanishing in about 10 days, indicating small-scale heterogeneities on the nucleus. Thin frosts sublimating in a few minutes are observed close to receding shadows, and rapid variations in color are seen on extended areas close to the terminator. These cyclic processes are widespread and lead to continuously, slightly varying surface properties. Copyright © 2016, American Association for the Advancement of Science.

Cometary science. Time variability and heterogeneity in the coma of 67P/Churyumov-Gerasimenko.

PubMed

Hässig, M; Altwegg, K; Balsiger, H; Bar-Nun, A; Berthelier, J J; Bieler, A; Bochsler, P; Briois, C; Calmonte, U; Combi, M; De Keyser, J; Eberhardt, P; Fiethe, B; Fuselier, S A; Galand, M; Gasc, S; Gombosi, T I; Hansen, K C; Jäckel, A; Keller, H U; Kopp, E; Korth, A; Kührt, E; Le Roy, L; Mall, U; Marty, B; Mousis, O; Neefs, E; Owen, T; Rème, H; Rubin, M; Sémon, T; Tornow, C; Tzou, C-Y; Waite, J H; Wurz, P

2015-01-23

Comets contain the best-preserved material from the beginning of our planetary system. Their nuclei and comae composition reveal clues about physical and chemical conditions during the early solar system when comets formed. ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) onboard the Rosetta spacecraft has measured the coma composition of comet 67P/Churyumov-Gerasimenko with well-sampled time resolution per rotation. Measurements were made over many comet rotation periods and a wide range of latitudes. These measurements show large fluctuations in composition in a heterogeneous coma that has diurnal and possibly seasonal variations in the major outgassing species: water, carbon monoxide, and carbon dioxide. These results indicate a complex coma-nucleus relationship where seasonal variations may be driven by temperature differences just below the comet surface. Copyright © 2015, American Association for the Advancement of Science.

The Oxygen Isotopic Composition (18O/16O) in the Dust of Comet 67P/Churyumov-Gerasimenko Measured by COSIMA On-board Rosetta

NASA Astrophysics Data System (ADS)

Paquette, J. A.; Engrand, C.; Hilchenbach, M.; Fray, N.; Stenzel, O. J.; Silen, J.; Rynö, J.; Kissel, J.

2018-03-01

The oxygen isotopic ratio 18O/16O has been measured in cometary gas for a wide variety of comets, but the only measurements in cometary dust were performed by the Stardust cometary sample return mission. Most such measurements find a value of the ratio that is consistent with Vienna Standard Mean Ocean Water (VSMOW) within errors. In this work we present the result of a measurement, using the COSIMA instrument on the Rosetta orbiter, of the oxygen isotopic ratio in dust from Comet 67P/Churyumov-Gerasimenko. Measuring the 18O/16O ratio with COSIMA is challenging for a number of reasons, but it is possible with a reasonable degree of precision. We find a result of 2.00 × 10-3 ± 1.2 × 10-4 which is consistent within errors with VSMOW.

Computational design of a red fluorophore ligase for site-specific protein labeling in living cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Daniel S.; Nivon, Lucas G.; Richter, Florian

In this study, chemical fluorophores offer tremendous size and photophysical advantages over fluorescent proteins but are much more challenging to target to specific cellular proteins. Here, we used Rosetta-based computation to design a fluorophore ligase that accepts the red dye resorufin, starting from Escherichia coli lipoic acid ligase. X-ray crystallography showed that the design closely matched the experimental structure. Resorufin ligase catalyzed the site-specific and covalent attachment of resorufin to various cellular proteins genetically fused to a 13-aa recognition peptide in multiple mammalian cell lines and in primary cultured neurons. We used resorufin ligase to perform superresolution imaging of themore » intermediate filament protein vimentin by stimulated emission depletion and electron microscopies. This work illustrates the power of Rosetta for major redesign of enzyme specificity and introduces a tool for minimally invasive, highly specific imaging of cellular proteins by both conventional and superresolution microscopies.« less

Four-fluid MHD Simulations of the Plasma and Neutral Gas Environment of Comet Churyumov-Gerasimenko Near Perihelion

NASA Astrophysics Data System (ADS)

Huang, Z.; Toth, G.; Gombosi, T.; Jia, X.; Rubin, M.; Fougere, N.; Tenishev, V.; Combi, M.; Bieler, A.; Hansen, K.; Shou, Y.; Altwegg, K.

2015-10-01

We develop a 3-D four fluid model to study the plasma environment of comet Churyumov- Gerasimenko (CG), which is the target of the Rosetta mission. Our model is based on BATS-R-US within the SWMF (Space Weather Modeling Framework) that solves the governing multifluid MHD equations and and the Euler equations for the neutral gas fluid. These equations describe the behavior and interactions of the cometary heavy ions, the solar wind protons, the electrons, and the neutrals. This model incorporates mass loading processes, including photo and electron impact ionization, furthermore taken into account are charge exchange, dissociative ion-electron recombination, as well as collisional interactions between different fluids. We simulate the near nucleus plasma and neutral gas environment with a realistic shape model of CG near perihelion and compare our simulation results with Rosetta observations.

Computational design of a red fluorophore ligase for site-specific protein labeling in living cells

DOE PAGES

Liu, Daniel S.; Nivon, Lucas G.; Richter, Florian; ...

2014-10-13

In this study, chemical fluorophores offer tremendous size and photophysical advantages over fluorescent proteins but are much more challenging to target to specific cellular proteins. Here, we used Rosetta-based computation to design a fluorophore ligase that accepts the red dye resorufin, starting from Escherichia coli lipoic acid ligase. X-ray crystallography showed that the design closely matched the experimental structure. Resorufin ligase catalyzed the site-specific and covalent attachment of resorufin to various cellular proteins genetically fused to a 13-aa recognition peptide in multiple mammalian cell lines and in primary cultured neurons. We used resorufin ligase to perform superresolution imaging of themore » intermediate filament protein vimentin by stimulated emission depletion and electron microscopies. This work illustrates the power of Rosetta for major redesign of enzyme specificity and introduces a tool for minimally invasive, highly specific imaging of cellular proteins by both conventional and superresolution microscopies.« less

A model for the solution structure of the rod arrestin tetramer.

PubMed

Hanson, Susan M; Dawson, Eric S; Francis, Derek J; Van Eps, Ned; Klug, Candice S; Hubbell, Wayne L; Meiler, Jens; Gurevich, Vsevolod V

2008-06-01

Visual rod arrestin has the ability to self-associate at physiological concentrations. We previously demonstrated that only monomeric arrestin can bind the receptor and that the arrestin tetramer in solution differs from that in the crystal. We employed the Rosetta docking software to generate molecular models of the physiologically relevant solution tetramer based on the monomeric arrestin crystal structure. The resulting models were filtered using the Rosetta energy function, experimental intersubunit distances measured with DEER spectroscopy, and intersubunit contact sites identified by mutagenesis and site-directed spin labeling. This resulted in a unique model for subsequent evaluation. The validity of the model is strongly supported by model-directed crosslinking and targeted mutagenesis that yields arrestin variants deficient in self-association. The structure of the solution tetramer explains its inability to bind rhodopsin and paves the way for experimental studies of the physiological role of rod arrestin self-association.

Gaining Confidence in Navigating Rosetta at Mars Swing-By

NASA Technical Reports Server (NTRS)

Crammn, Ruediger; Budnik, Frank

2007-01-01

The Mars swing-by in the early morning of the 25th of February 2007 was one of the most critical events the Rosetta mission has experienced so far on its way to the comet Churyumov-Gerasimenko. The closest approach took place at a distance of only 250 km from the planet s surface. Missing the optimal target would have translated into considerable fuel cost. In order to achieve confidence in operating through this highly critical mission phase, a navigation analysis exercise was carried out beforehand. This paper describes the purpose and the chosen approach for this preparatory Flight Dynamics activity. It presents and discusses results of the analysis. Emphasis is put on the question of what is needed to simulate a valuable data set representative for operations. The results of the navigation analysis are compared with real data obtained during swing-by operations.

Probing 67P/Churyumov-Gerasimenko's Electron Environment Through Ultraviolet Emission by Rosetta Alice Observations

NASA Astrophysics Data System (ADS)

Schindhelm, Eric; Noonan, John; Keeney, Brian A.; Broiles, Thomas; Bieler, Andre; A'Hearn, Michael F.; Bertaux, Jean-Loup; Feaga, Lori M.; Feldman, Paul D.; Parker, Joel Wm.; Steffl, Andrew Joseph; Stern, S. Alan; Weaver, Harold A.

2016-10-01

The Alice Far-Ultraviolet (FUV) Spectrograph onboard ESA's Rosetta spacecraft has observed the coma of comet 67P/Churyumov-Gerasimenko from far approach in summer 2014 until the end of mission in September 2016. We present an overall perspective of the bright FUV emission lines (HI 1026 Å, OI 1302/1305/1306 Å multiplet, OI] 1356 Å, CO 1510 (1-0) Å, and CI 1657 Å) above the sunward hemisphere, detailing their spatial extent and brightness as a function of time and the heliocentric distance of the comet. We compare our observed gas column densities derived using electron temperatures and densities from the Ion Electron Sensor (IES) with those derived using the Inner Coma Environment Simulator (ICES) models in periods when electron-impact excited emission dominates over solar fluorescence emission. The electron population is characterized with 2 three-dimensional kappa functions, one dense and warm, one rarefied and hot.

The oxygen isotopic composition (18O/16O) in the dust of comet 67P/Churyumov-Gerasimenko measured by COSIMA on-board Rosetta

NASA Astrophysics Data System (ADS)

Paquette, J. A.; Engrand, C.; Hilchenbach, M.; Fray, N.; Stenzel, O. J.; Silen, J.; Rynö, J.; Kissel, J.

2018-07-01

The oxygen isotopic ratio 18O/16O has been measured in cometary gas for a wide variety of comets, but the only measurements in cometary dust were performed by the Stardust cometary sample return mission. Most such measurements find a value of the ratio that is consistent with Vienna Standard Mean Ocean Water (VSMOW) within errors. In this work we present the result of a measurement, using the COSIMA (the COmetary Secondary Ion Mass Analyser) instrument on the Rosetta orbiter, of the oxygen isotopic ratio in dust from Comet 67P/Churyumov-Gerasimenko. Measuring the 18O/16O ratio with COSIMA is challenging for a number of reasons, but it is possible with a reasonable degree of precision. We find a result of 2.00 × 10-3 ± 1.2 × 10-4, which is consistent within errors with VSMOW.

The Rosetta phone: a hand-held device for automatic translation of signs in natural images

NASA Astrophysics Data System (ADS)

Jafri, Syed Ali Raza; Mikkilineni, Aravind K.; Boutin, Mireille; Delp, Edward J.

2008-02-01

When traveling in a region where the local language is not written using the Roman alphabet, translating written text (e.g., documents, road signs, or placards) is a particularly difficult problem since the text cannot be easily entered into a translation device or searched using a dictionary. To address this problem, we are developing the "Rosetta Phone," a handheld device (e.g., PDA or mobile telephone) capable of acquiring a picture of the text, identifying the text within the image, and producing both an audible and a visual English interpretation of the text. We started with English, as a developement language, for which we achieved close to 100% accuracy in identifying and reading text. We then modified the system to be able to read and translate words written using the Arabic character set. We currently achieve approximately 95% accuracy in reading words from a small directory of town names.

Cholecystectomy for Prevention of Recurrence after Endoscopic Clearance of Bile Duct Stones in Korea.

PubMed

Song, Myung Eun; Chung, Moon Jae; Lee, Dong Jun; Oh, Tak Geun; Park, Jeong Youp; Bang, Seungmin; Park, Seung Woo; Song, Si Young; Chung, Jae Bock

2016-01-01

Cholecystectomy in patients with an intact gallbladder after endoscopic removal of stones from the common bile duct (CBD) remains controversial. We conducted a case-control study to determine the risk of recurrent CBD stones and the benefit of cholecystectomy for prevention of recurrence after endoscopic removal of stones from the CBD in Korean patients. A total of 317 patients who underwent endoscopic CBD stone extraction between 2006 and 2012 were included. Possible risk factors for the recurrence of CBD stones including previous cholecystectomy history, bile duct diameter, stone size, number of stones, stone composition, and the presence of a periampullary diverticulum were analyzed. The mean duration of follow-up after CBD stone extraction was 25.4±22.0 months. A CBD diameter of 15 mm or larger [odds ratio (OR), 1.930; 95% confidence interval (CI), 1.098 to 3.391; p=0.022] and the presence of a periampullary diverticulum (OR, 1.859; 95% CI, 1.014 to 3.408; p=0.045) were independent predictive factors for CBD stone recurrence. Seventeen patients (26.6%) in the recurrence group underwent elective cholecystectomy soon after endoscopic extraction of CBD stones, compared to 88 (34.8%) in the non-recurrence group; the difference was not statistically significant (p=0.212). A CBD diameter of 15 mm or larger and the presence of a periampullary diverticulum were found to be potential predictive factors for recurrence after endoscopic extraction of CBD stones. Elective cholecystectomy after clearance of CBD stones did not reduce the incidence of recurrent CBD stones in Korean patients.

[Correlation between urinary stones and urinary tract infections].

PubMed

Chen, Peilin; Zhang, Liguo; Meng, Bin

2014-05-01

To explore the correlation of urinary stones and urinary tract infections. 300 cases with urinary tract stones received in our hospital from Feb. 2010 to Oct. 2013 were chosen as study samples. Urine routine index, situation of urine positivity and urinary tract infection after surgery were analyzed while, intraoperative cotton swabs were tested after being dipped in liquid near stones. Main components of stones in non-infected and infected stone group were analyzed and compared. Data on urolithiasis was collected. 96 infected stones were found in 300 patients, accounting for 32%, which including 35 cases of E. coli (36.5%), 28 cases of Staphylococcus epidermidis (29.2%), and 15 cases of Proteus mirabilis (15.6%). Numbers of urine abnormalities, urine positivities, positive intraoperative cotton swabs and urinary tract infections in patients in the group with infected stones, were significantly higher than in the group without infected stones and the differences were statistically significant (χ² = 8.203, 73.99, 178.9, 24.26, P < 0.05). The incidence rates of hexahydrate magnesium ammonium phosphate, carbonate apatite and hydroxyapatite stones in the group with infected stones were significantly higher than those in the non-infected-rock group while the incidence rates of calcium oxalate and uric acid stones were found significantly lower than those in the non-infected-stone group, with differences statistically significant (χ² = 167.6, 21.00, 8.586, 73.17, 48.79, P < 0.05). Bacteria could cause urinary tract stones, and infected stones were always associated with urinary tract infections. Bacteria detection in patients with urinary calculi was particularly important to avoid the urinary tract infections.

Nutritional Management of Kidney Stones (Nephrolithiasis)

PubMed Central

Segal, Adam M.; Seifter, Julian L.; Dwyer, Johanna T.

2015-01-01

The incidence of kidney stones is common in the United States and treatments for them are very costly. This review article provides information about epidemiology, mechanism, diagnosis, and pathophysiology of kidney stone formation, and methods for the evaluation of stone risks for new and follow-up patients. Adequate evaluation and management can prevent recurrence of stones. Kidney stone prevention should be individualized in both its medical and dietary management, keeping in mind the specific risks involved for each type of stones. Recognition of these risk factors and development of long-term management strategies for dealing with them are the most effective ways to prevent recurrence of kidney stones. PMID:26251832

Villamayor stone (Golden Stone) as a Global Heritage Stone Resource from Salamanca (NW of Spain)

NASA Astrophysics Data System (ADS)

Garcia-Talegon, Jacinta; Iñigo, Adolfo; Vicente-Tavera, Santiago

2013-04-01

Villamayor stone is an arkosic stone of Middle Eocene age and belongs to the Cabrerizos Sandstone Formation that comprising braided fluvial systems and paleosoils at the top of each stratigraphic sequence. The sandstone is known by several names: i) the Villamayor Stone because the quarries are located in Villamayor de Armuña village that are situated at 7 km to the North from Salamanca city; ii) the Golden Stone due to its patina that produced a ochreous/golden color on the façades of monuments of Salamanca (World Heritage City,1988) built in this Natural stone (one of the silicated rocks utilised). We present in this work, the Villamayor Stone to be candidate as Global Heritage Stone Resource. The Villamayor Stone were quarrying for the construction and ornamentation of Romanesque religious monuments as the Old Cathedral and San Julian church; Gothic (Spanish plateresc style) as the New Cathedral, San Esteban church and the sculpted façade of the Salamanca University, one of the oldest University in Europe (it had established in 1250); and this stone was one of the type of one of the most sumptuous Baroque monuments is the Main Square of the its galleries and arcades (1729). Also, this stone was used in building palaces, walls and reconstruction of Roman bridge. Currently, Villamayor Stone is being quarried by small and family companies, without a modernized processing, for cladding of the façades of the new buildings until that the construction sector was burst (in 2008 the international economic crisis). However, Villamayor Stone is the main stone material used in the city of Salamanca for the restoration of monuments and, even in small quantities when compared with just before the economic crisis, it would be of great importance for future generations protect their quarries and the craft of masonry. Villamayor Stone has several varieties from channels facies to floodplains facies, in this work the selected varieties are: i) the fine-grained stone, microporous, is partially cemented by dolomite, 27% (bulk porosity), ii) the ochre and fine-grained stone, microporous, with smectite, 30% (bulk porosity), iii) the medium-grained stone, 38% (bulk porosity). Main components for all three varieties: Quartz (up to 60%), feldspars, 2:1 layered silicates (smectites), palygorskite-type fibrous silicates, and small amounts of micaceous minerals (illite/mica).

Extensive characterizations of bacteria isolated from catheterized urine and stone matrices in patients with nephrolithiasis.

PubMed

Tavichakorntrakool, Ratree; Prasongwattana, Vitoon; Sungkeeree, Seksit; Saisud, Phitsamai; Sribenjalux, Pipat; Pimratana, Chaowat; Bovornpadungkitti, Sombat; Sriboonlue, Pote; Thongboonkerd, Visith

2012-11-01

Urinary tract infections are generally known to be associated with nephrolithiasis, particularly struvite stone, in which the most common microbe found is urea-splitting bacterium, i.e. Proteus mirabilis. However, our observation indicated that it might not be the case of stone formers in Thailand. We therefore extensively characterized microorganisms associated with all types of kidney stones. A total of 100 kidney stone formers (59 males and 41 females) admitted for elective percutaneous nephrolithotomy were recruited and microorganisms isolated from catheterized urine and cortex and nidus of their stones were analyzed. From 100 stone formers recruited, 36 cases had a total of 45 bacterial isolates cultivated from their catheterized urine and/or stone matrices. Among these 36 cases, chemical analysis by Fourier-transformed infrared spectroscopy revealed that 8 had the previously classified 'infection-induced stones', whereas the other 28 cases had the previously classified 'metabolic stones'. Calcium oxalate (in either pure or mixed form) was the most common and found in 64 and 75% of the stone formers with and without bacterial isolates, respectively. Escherichia coli was the most common bacterium (approximately one-third of all bacterial isolates) found in urine and stone matrices (both nidus and periphery). Linear regression analysis showed significant correlation (r = 0.860, P < 0.001) between bacterial types in urine and stone matrices. Multidrug resistance was frequently found in these isolated bacteria. Moreover, urea test revealed that only 31% were urea-splitting bacteria, whereas the majority (69%) had negative urea test. Our data indicate that microorganisms are associated with almost all chemical types of kidney stones and urea-splitting bacteria are not the major causative microorganisms found in urine and stone matrices of the stone formers in Thailand. These data may lead to rethinking and a new roadmap for future research regarding the role of microorganisms in kidney stone formation.

Contribution of stone size to chronic kidney disease in kidney stone formers.

PubMed

Ahmadi, Farrokhlagha; Etemadi, Samira Motedayen; Lessan-Pezeshki, Mahbob; Mahdavi-Mazdeh, Mitra; Ayati, Mohsen; Mir, Alireza; Yazdi, Hadi Rokni

2015-01-01

To determine whether stone burden correlates with the degree of chronic kidney disease in kidney stone formers. A total of 97 extracorporeal shockwave lithotripsy candidates aged 18 years and older were included. Size, number and location of the kidney stones, along with cumulative stone size, defined as the sum of diameters of all stones) were determined. Estimated glomerular filtration rate was determined using the Chronic Kidney Disease Epidemiology Collaboration cystatin C/creatinine equation, and chronic kidney disease was defined as estimated glomerular filtration rate <60 mL/min/1.73 m(2). In individuals with cumulative stone size <20 mm, estimated glomerular filtration rate significantly decreased when moving from the first (estimated glomerular filtration rate 75.5 ± 17.8 mL/min/1.73 m(2)) to the fourth (estimated glomerular filtration rate 56.4 ± 20.44 mL/min/1.73 m(2) ) quartile (P = 0.004). When patients with a cumulative stone size ≥ 20 mm were included, the observed association was rendered non-significant. In individuals with a cumulative stone size < 20 mm, each 1-mm increase in cumulative stone size was associated with a 20% increased risk of having chronic kidney disease. The relationship persisted even after adjustment for age, sex, body mass index, C-reactive protein, fasting plasma glucose, thyroid stimulating hormone, presence of microalbuminuria, history of renal calculi, history of extracorporeal shockwave lithotripsy, number and location of the stones (odds ratio 1.24, 95% confidence interval 1.02-1.52). The same was not observed for individuals with a cumulative stone size ≥ 20 mm. In kidney stone formers with a cumulative stone size up to 20 mm, estimated glomerular filtration rate linearly declines with increasing cumulative stone size. Additionally, cumulative stone size is an independent predictor of chronic kidney disease in this group of patients. © 2014 The Japanese Urological Association.

Risk of Hypertension among First-Time Symptomatic Kidney Stone Formers

PubMed Central

Kittanamongkolchai, Wonngarm; Mara, Kristin C.; Mehta, Ramila A.; Vaughan, Lisa E.; Denic, Aleksandar; Knoedler, John J.; Enders, Felicity T.; Lieske, John C.

2017-01-01

Background and objectives Prior work has suggested a higher risk of hypertension in kidney stone formers but lacked disease validation and adjustment for potential confounders. Certain types of stone formers may also be at higher risk of hypertension. Design, setting, participants, & measurements In our study, incident symptomatic stone formers in Olmsted County from 2000 to 2011 were manually validated by chart review and age and sex matched to Olmsted County controls. We followed up patients through November 20, 2015. Hypertension was also validated by manual chart review, and the risk of hypertension in stone formers compared with controls was assessed both univariately and after adjusting for comorbidities. The risk of hypertension among different subtypes of stone formers was also evaluated. Results Among 3023 coded stone formers from 2000 to 2011, a total of 1515 were validated and matched to 1515 controls (mean age was 45 years old, and 56% were men). After excluding those with baseline hypertension (20% of stone formers and 18% of controls), 154 stone formers and 110 controls developed hypertension. Median follow-up time was 7.8 years in stone formers and 9.6 years in controls. Stone formers were found to have a higher risk of hypertension compared with controls (hazard ratio, 1.50; 95% confidence interval, 1.18 to 1.92), even after adjusting for age, sex, body mass index, serum creatinine, CKD, diabetes, gout, coronary artery disease, dyslipidemia, tobacco use, and alcohol abuse (hazard ratio, 1.58; 95% confidence interval, 1.12 to 2.21). Results were similar after excluding patients who were ever on a thiazide diuretic (hazard ratio, 1.65; 95% confidence interval, 1.16 to 2.38). Stone composition, radiographic stone burden, number of subsequent stone events, and stone removal surgeries were not associated with hypertension (P>0.05 for all). Conclusions The risk of hypertension was higher after the first symptomatic kidney stone event. However, kidney stone severity, type, and treatment did not associate with hypertension. PMID:28148559

Has the pelvic renal stone position inside the upper loop of JJ stent any influence on the extracorporeal shock wave lithotripsy results?

PubMed

Pricop, Catalin; Serban, Dragomir N; Serban, Ionela Lacramioara; Cumpanas, Alin-Adrian; Gingu, Constantin-Virgil

2016-01-01

JJ stents are often encountered in patients with pelvic renal stones referred for shock wave lithotripsy, most of them being placed either for obstructive renal pelvic stones or for ureteric stones mobilized retrograde during the JJ stent insertion. The aim of the study was to determine whether the relative stone position in the upper loop of the JJ stent during extracorporeal shock wave lithotripsy (SWL) influences the efficiency of the procedure. The study was designed as a prospective cohort study on 162 patients addressing the same urological department, with single renal pelvic stone (primary or mobilized to the renal pelvis during the insertion of JJ stent), smaller than 15 mm, with JJ stent, treated by SWL using a second generation spark gap lithotripter, 18 kV, 3000 waves/session. Patients were divided in three groups according to the relative position of the stone to the upper loop of the JJ stent as appears on plain X-ray: stone-inside-loop, loop-crossing-stone and stone-outside the loop. The SWL success rate was the primary outcome of the study. p Value, Chi square and Kruskal-Wallis tests were used for statistical analysis. For stone-inside-loop cases, SWL efficiency was 22.7 versus 42 % for all the other cases (p = 0.002). Other factors for decreased SWL success rate were: higher stone radio-opacity, larger JJ of stent and obese patients. Study limitation is represented by the relative small study group and by the evaluation of stone density using plain X-ray instead of computer tomography. For pelvic renal stones having the same density characteristics studied by plain X-ray, the SWL efficiency is lower in stone-inside-loop cases comparing with the other positions. The overall stone free rate for renal pelvic stones could be explained by the second generation lithotripter used for all procedures.

Wanted: suitable replacement stones for the Lede stone (Belgium)

NASA Astrophysics Data System (ADS)

De Kock, T.; Dewanckele, J.; Boone, M. A.; De Boever, W.; De Schutter, G.; Jacobs, P.; Cnudde, V.

2012-04-01

The Lede stone is an arenaceous limestone with a Lutetian age, occurring as discrete (most of the times three) stone banks in the marine sandy sediments of the Lede Formation (Belgium). It has a quartz content of approximate 40%. This increases abrasion strength and together with the cementation results in an average compressive strength of about 80-85 MPa. The cement is a microsparitic calcite cement. Other carbonate particles are both microfossils (mainly foraminifers) and macrofossils (bivalves, serpulids, echinoderms, …). This great diversity gives the stone a heterogeneous, animated appearance. The intra- and interparticle porosity is in total 5-10 % in average and the apparent density is 2400-2550 kg/m3. Another important constituent is glauconite, present in a few percent. In fresh state, the stone has a greenish-grey colour, but when it is exposed to atmospheric conditions for a couple of years, the stone acquires a yellowish to rust-coloured patina due to the weathering of glauconite. Sulphatation causes severe damage to the stone, and black gypsum crusts are common in urban environments on stones protected from runoff. This stone was excavated in both open air and underground quarries in the areas of Brussels and Ghent. The proximity of main rivers such as the Scheldt and Zenne provided transport routes for export towards the north (e.g. Antwerp and The Netherlands). Its first known use dates back to Roman times but the stone flourished in Gothic architecture due to its easy workability and its 'divine' light coloured patina. This results nowadays in a dominant occurrence in the cultural heritage of northwestern Belgium and the south of The Netherlands. Socio-economical reasons caused several declines and revivals of Lede stone in use. In the beginning of the 20th century, only a few excavation sites remained, with as main quarry the one located at Bambrugge (Belgium). By the end of the first half of the 20th century, however, no quarry sites remained. In the sixties, a sand quarry located in Balegem (Belgium) started with the extraction of Lede stone combined with its other activities. Until now, only this site supplies blocks of fresh Lede stones and it doesn't seem there will rise an opportunity of a new site in the near future. Therefore, during the huge amount of renovation works in the past century, the Lede stone was often replaced by imported (mostly French) limestones such as Massangis stone, Savonnières stone and Euville stone. The commercial value seems to have had a large impact and too little attention was paid on the optical appearance, ageing and technical compatibility of the stones. The use of especially Massangis stone was taken for granted. In the 21st century, there is a growing awareness of the impact of such consequent replacement for the historical value of our cultural heritage and several alternative stones are suggested and even used. These include stones from France, Spain and Portugal, but also from other regions in Belgium. For the moment, there is no consensus on the most appropriate replacement stone and further research should be done in order to evaluate compatibility of the different stone types with Lede stone. In this context, it is also very important to actively search for better alternatives, which resemble the Lede stone in both a mechanical and aesthetical point of view. Therefore, this abstract is an open question to its readers. Any commercial natural stone suggestions with affiliation to the aforementioned properties are welcome by e-mailing the corresponding author.

Supernova 1987A Interpreted through the SLIP Pulsar Model

NASA Astrophysics Data System (ADS)

Middleditch, John

2010-01-01

The model of pulsar emission through superluminally induced polarization currents (SLIP) predicts that pulsations produced by such currents, induced by a rotating, magnetized body at many light cylinder radii, as would be the case for a neutron star born within any star of >1.5 solar masses, will drive pulsations close to the axis of rotation. Such highly collimated pulsations (<= 1 in 10,000), and the similarly collimated jets of particles which it drove, including 1e-6 solar masses with velocities of up to 0.95 c, were responsible for the features of its very early light curve (days 3 - 20), the "Mystery Spot," observed slightly later (days 30 - 50 and >), and later, in less collimated form, the bipolarity of SN 1987A itself. The pulsations and jet interacted with circumstellar material (CM), to produce features observed in the very early light curve which correspond to: 1) the entry of the pulsed beam into the CM; 2) the entry of the 0.95 c particles into the CM; 3) the exit of the pulsed beam from the CM (with contributions in the B and I bands -- the same as later inferred/observed for its 2.14 ms pulsations); and 4) the exit of the fastest particles from the CM. Because of the energy requirements of the jet in these early stages, the spindown required of its pulsar could exceed 1e-5 Hz/s at a rotation rate of 500 Hz. There is no reason to suggest that this mechanism is not universally applicable to all SNe with gaseous remnants remaining, and thus SN 1987A is the Rosetta Stone for 99% of SNe, gamma-ray bursts, and millisecond pulsars. This work was supported in part by the Department of Energy through the Los Alamos Directed Research Grant DR20080085.

Predicting a double mutant in the twilight zone of low homology modeling for the skeletal muscle voltage-gated sodium channel subunit beta-1 (Nav1.4 β1).

PubMed

Scior, Thomas; Paiz-Candia, Bertin; Islas, Ángel A; Sánchez-Solano, Alfredo; Millan-Perez Peña, Lourdes; Mancilla-Simbro, Claudia; Salinas-Stefanon, Eduardo M

2015-01-01

The molecular structure modeling of the β1 subunit of the skeletal muscle voltage-gated sodium channel (Nav1.4) was carried out in the twilight zone of very low homology. Structural significance can per se be confounded with random sequence similarities. Hence, we combined (i) not automated computational modeling of weakly homologous 3D templates, some with interfaces to analogous structures to the pore-bearing Nav1.4 α subunit with (ii) site-directed mutagenesis (SDM), as well as (iii) electrophysiological experiments to study the structure and function of the β1 subunit. Despite the distant phylogenic relationships, we found a 3D-template to identify two adjacent amino acids leading to the long-awaited loss of function (inactivation) of Nav1.4 channels. This mutant type (T109A, N110A, herein called TANA) was expressed and tested on cells of hamster ovary (CHO). The present electrophysiological results showed that the double alanine substitution TANA disrupted channel inactivation as if the β1 subunit would not be in complex with the α subunit. Exhaustive and unbiased sampling of "all β proteins" (Ig-like, Ig) resulted in a plethora of 3D templates which were compared to the target secondary structure prediction. The location of TANA was made possible thanks to another "all β protein" structure in complex with an irreversible bound protein as well as a reversible protein-protein interface (our "Rosetta Stone" effect). This finding coincides with our electrophysiological data (disrupted β1-like voltage dependence) and it is safe to utter that the Nav1.4 α/β1 interface is likely to be of reversible nature.

Multi-wavelength observations of the solar atmosphere from the August 21, 2017 total solar eclipse

NASA Astrophysics Data System (ADS)

Tomczyk, S.; Boll, A.; Bryans, P.; Burkepile, J.; Casini, R.; DeLuca, E.; Gibson, K. L.; Judge, P. G.; McIntosh, S. W.; Samra, J.; Sewell, S. D.

2017-12-01

We will conduct three experiments at the August 21, 2017 total solar eclipse that we call the Rosetta Stone experiments. First, we will obtain narrow-bandpass images at infrared wavelengths of the magnetically sensitive coronal emission lines of Fe IX 2855 nm, Mg VIII 3028 nm and Si IX 3935 nm with a FLIR thermal imager. Information on the brightness of these lines is important for identifying the optimal lines for coronal magnetometry. These images will also serve as context images for the airborne AirSpec IR coronal spectroscopy experiment (Samra et al). Second, we will obtain linear polarization images of the visible emission lines of Fe X 637 nm and Fe XI 789 nm as well as the continuum polarization near 735 nm. These will be obtained with a novel detector with an integral array of linear micro-polarizers oriented at four different angles that enable polarization images without the need for liquid crystals or rotating elements. These measurements will provide information on the orientation of magnetic fields in the corona and serve to demonstrate the new detector technology. Lastly, we will obtain high cadence spectra as the moon covers and uncovers the chromosphere immediately after 2nd contact and before third contact. This so-called flash spectrum will be used to obtain information about chromospheric structure at a spatial resolution higher than is possible by other means. In this talk, we will describe the instrumentation used in these experiments and present initial results obtained with them. This work is supported by a grant from NASA, through NSF base funding of HAO/NCAR and by generous loans of equipment from our corporate partners, FLIR, 4D Technologies and Avantes.

Observational Evidence for Mixing and Dust Condensation in Core-Collapse Supernovae

NASA Technical Reports Server (NTRS)

Wooden, Diane; Young, Richard E. (Technical Monitor)

1997-01-01

Recent findings of isotopic anomalies of Ca-44 (the decay product of Ti-44) and the enhanced ratio of Si-28/Si-30 in SiC grains X, TiC subgrains, and graphite dust grains within primitive meteorites provides strong evidence that these presolar grains came from core-collapse supernovae. The chemical composition of the presolar grains requires macroscopic mixing of newly nucleo-synthesized elements from explosive silicon burning at the innermost zone of the ejects to higher velocities where C exists and where C/O > 1 in either the outer edge of the oxygen zone or in the He-C zone. To date, the only core-collapse supernova observed to form dust is the brightest supernova of the past four centuries, SN1987A in the Large Magellanic Cloud. Observations of SN1987A confirm large scale macroscopic mixing occurs in the explosions of massive stars. Rayleigh-Taylor instabilities macroscopically mix most of the ejects into regions which are still chemically homogeneous and which cool with different time scales. Only small clumps in the ejects are microscopically mixed. Observations show that dust condensed in the ejects of SN1987A after approx.500 days in the Fe-rich gas. Neither silicates nor SiC grains were seen in the dust emission spectrum of SN1987A. SN1987A, the Rosetta Stone of core-collapse supernovae, shows that while the mixing required to explain presolar grains occurs, the rapid cooling of the Fe zone and the sustained high temperatures of the O-Si, O-C, and He-C zones favor the formation of iron-rich rather than oxygen- or carbon-rich grains.

LabRS: A Rosetta stone for retrospective standardization of clinical laboratory test results.

PubMed

Hauser, Ronald George; Quine, Douglas B; Ryder, Alex

2018-02-01

Clinical laboratories in the United States do not have an explicit result standard to report the 7 billion laboratory tests results they produce each year. The absence of standardized test results creates inefficiencies and ambiguities for secondary data users. We developed and tested a tool to standardize the results of laboratory tests in a large, multicenter clinical data warehouse. Laboratory records, each of which consisted of a laboratory result and a test identifier, from 27 diverse facilities were captured from 2000 through 2015. Each record underwent a standardization process to convert the original result into a format amenable to secondary data analysis. The standardization process included the correction of typos, normalization of categorical results, separation of inequalities from numbers, and conversion of numbers represented by words (eg, "million") to numerals. Quality control included expert review. We obtained 1.266 × 109 laboratory records and standardized 1.252 × 109 records (98.9%). Of the unique unstandardized records (78.887 × 103), most appeared <5 times (96%, eg, typos), did not have a test identifier (47%), or belonged to an esoteric test with <100 results (2%). Overall, these 3 reasons accounted for nearly all unstandardized results (98%). Current results suggest that the tool is both scalable and generalizable among diverse clinical laboratories. Based on observed trends, the tool will require ongoing maintenance to stay current with new tests and result formats. Future work to develop and implement an explicit standard for test results would reduce the need to retrospectively standardize test results. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Comprehensive Phylogenetic Analysis Sheds Light on the Diversity and Origin of the MLO Family of Integral Membrane Proteins

PubMed Central

Kusch, Stefan; Pesch, Lina; Panstruga, Ralph

2016-01-01

Mildew resistance Locus O (MLO) proteins are polytopic integral membrane proteins that have long been considered as plant-specific and being primarily involved in plant–powdery mildew interactions. However, research in the past decade has revealed that MLO proteins diverged into a family with several clades whose members are associated with different physiological processes. We provide a largely increased dataset of MLO amino acid sequences, comprising nearly all major land plant lineages. Based on this comprehensive dataset, we defined seven phylogenetic clades and reconstructed the likely evolution of the MLO family in embryophytes. We further identified several MLO peptide motifs that are either conserved in all MLO proteins or confined to one or several clades, supporting the notion that clade-specific diversification of MLO functions is associated with particular sequence motifs. In baker’s yeast, some of these motifs are functionally linked to transmembrane (TM) transport of organic molecules and ions. In addition, we attempted to define the evolutionary origin of the MLO family and found that MLO-like proteins with highly diverse membrane topologies are present in green algae, but also in the distinctly related red algae (Rhodophyta), Amoebozoa, and Chromalveolata. Finally, we discovered several instances of putative fusion events between MLO proteins and different kinds of proteins. Such Rosetta stone-type hybrid proteins might be instructive for future analysis of potential MLO functions. Our findings suggest that MLO is an ancient protein that possibly evolved in unicellular photosynthetic eukaryotes, and consolidated in land plants with a conserved topology, comprising seven TM domains and an intrinsically unstructured C-terminus. PMID:26893454

The MMI Semantic Framework: Rosetta Stones for Earth Sciences

NASA Astrophysics Data System (ADS)

Rueda, C.; Bermudez, L. E.; Graybeal, J.; Alexander, P.

2009-12-01

Semantic interoperability—the exchange of meaning among computer systems—is needed to successfully share data in Ocean Science and across all Earth sciences. The best approach toward semantic interoperability requires a designed framework, and operationally tested tools and infrastructure within that framework. Currently available technologies make a scientific semantic framework feasible, but its development requires sustainable architectural vision and development processes. This presentation outlines the MMI Semantic Framework, including recent progress on it and its client applications. The MMI Semantic Framework consists of tools, infrastructure, and operational and community procedures and best practices, to meet short-term and long-term semantic interoperability goals. The design and prioritization of the semantic framework capabilities are based on real-world scenarios in Earth observation systems. We describe some key uses cases, as well as the associated requirements for building the overall infrastructure, which is realized through the MMI Ontology Registry and Repository. This system includes support for community creation and sharing of semantic content, ontology registration, version management, and seamless integration of user-friendly tools and application programming interfaces. The presentation describes the architectural components for semantic mediation, registry and repository for vocabularies, ontology, and term mappings. We show how the technologies and approaches in the framework can address community needs for managing and exchanging semantic information. We will demonstrate how different types of users and client applications exploit the tools and services for data aggregation, visualization, archiving, and integration. Specific examples from OOSTethys (http://www.oostethys.org) and the Ocean Observatories Initiative Cyberinfrastructure (http://www.oceanobservatories.org) will be cited. Finally, we show how semantic augmentation of web services standards could be performed using framework tools.

American Society of Functional Neuroradiology-Recommended fMRI Paradigm Algorithms for Presurgical Language Assessment.

PubMed

Black, D F; Vachha, B; Mian, A; Faro, S H; Maheshwari, M; Sair, H I; Petrella, J R; Pillai, J J; Welker, K

2017-10-01

Functional MR imaging is increasingly being used for presurgical language assessment in the treatment of patients with brain tumors, epilepsy, vascular malformations, and other conditions. The inherent complexity of fMRI, which includes numerous processing steps and selective analyses, is compounded by institution-unique approaches to patient training, paradigm choice, and an eclectic array of postprocessing options from various vendors. Consequently, institutions perform fMRI in such markedly different manners that data sharing, comparison, and generalization of results are difficult. The American Society of Functional Neuroradiology proposes widespread adoption of common fMRI language paradigms as the first step in countering this lost opportunity to advance our knowledge and improve patient care. A taskforce of American Society of Functional Neuroradiology members from multiple institutions used a broad literature review, member polls, and expert opinion to converge on 2 sets of standard language paradigms that strike a balance between ease of application and clinical usefulness. The taskforce generated an adult language paradigm algorithm for presurgical language assessment including the following tasks: Sentence Completion, Silent Word Generation, Rhyming, Object Naming, and/or Passive Story Listening. The pediatric algorithm includes the following tasks: Sentence Completion, Rhyming, Antonym Generation, or Passive Story Listening. Convergence of fMRI language paradigms across institutions offers the first step in providing a "Rosetta Stone" that provides a common reference point with which to compare and contrast the usefulness and reliability of fMRI data. From this common language task battery, future refinements and improvements are anticipated, particularly as objective measures of reliability become available. Some commonality of practice is a necessary first step to develop a foundation on which to improve the clinical utility of this field. © 2017 by American Journal of Neuroradiology.

Equating accelerometer estimates among youth: the Rosetta Stone 2

PubMed Central

Brazendale, Keith; Beets, Michael W.; Bornstein, Daniel B.; Moore, Justin B.; Pate, Russell R.; Weaver, Robert G.; Falck, Ryan S.; Chandler, Jessica L.; Andersen, Lars B.; Anderssen, Sigmund A.; Cardon, Greet; Cooper, Ashley; Davey, Rachel; Froberg, Karsten; Hallal, Pedro C.; Janz, Kathleen F.; Kordas, Katarzyna; Kriemler, Susi; Puder, Jardena J.; Reilly, John J.; Salmon, Jo; Sardinha, Luis B.; Timperio, Anna; van Sluijs, Esther MF

2017-01-01

Objectives Different accelerometer cutpoints used by different researchers often yields vastly different estimates of moderate-to-vigorous intensity physical activity (MVPA). This is recognized as cutpoint non-equivalence (CNE), which reduces the ability to accurately compare youth MVPA across studies. The objective of this research is to develop a cutpoint conversion system that standardizes minutes of MVPA for six different sets of published cutpoints. Design Secondary data analysis Methods Data from the International Children’s Accelerometer Database (ICAD; Spring 2014) consisting of 43,112 Actigraph accelerometer data files from 21 worldwide studies (children 3-18 years, 61.5% female) were used to develop prediction equations for six sets of published cutpoints. Linear and non-linear modeling, using a leave one out cross-validation technique, was employed to develop equations to convert MVPA from one set of cutpoints into another. Bland Altman plots illustrate the agreement between actual MVPA and predicted MVPA values. Results Across the total sample, mean MVPA ranged from 29.7 MVPA min.d-1 (Puyau) to 126.1 MVPA min.d-1 (Freedson 3 METs). Across conversion equations, median absolute percent error was 12.6% (range: 1.3 to 30.1) and the proportion of variance explained ranged from 66.7% to 99.8%. Mean difference for the best performing prediction equation (VC from EV) was -0.110 min.d-1 (limits of agreement (LOA), -2.623 to 2.402). The mean difference for the worst performing prediction equation (FR3 from PY) was 34.76 min.d-1 (LOA, -60.392 to 129.910). Conclusions For six different sets of published cutpoints, the use of this equating system can assist individuals attempting to synthesize the growing body of literature on Actigraph, accelerometry-derived MVPA. PMID:25747468

Urinary Tract Stones and Osteoporosis: Findings From the Women’s Health Initiative

PubMed Central

Carbone, Laura D; Hovey, Kathleen M; Andrews, Christopher A; Thomas, Fridtjof; Sorensen, Mathew D; Crandall, Carolyn J; Watts, Nelson B; Bethel, Monique; Johnson, Karen C

2017-01-01

Kidney and bladder stones (urinary tract stones) and osteoporosis are prevalent, serious conditions for postmenopausal women. Men with kidney stones are at increased risk of osteoporosis; however, the relationship of urinary tract stones to osteoporosis in postmenopausal women has not been established. The purpose of this study was to determine whether urinary tract stones are an independent risk factor for changes in bone mineral density (BMD) and incident fractures in women in the Women’s Health Initiative (WHI). Data were obtained from 150,689 women in the Observational Study and Clinical Trials of the WHI with information on urinary tract stones status: 9856 of these women reported urinary tract stones at baseline and/or incident urinary tract stones during follow-up. Cox regression models were used to determine the association of urinary tract stones with incident fractures and linear mixed models were used to investigate the relationship of urinary tract stones with changes in BMD that occurred during WHI. Follow-up was over an average of 8 years. Models were adjusted for demographic and clinical factors, medication use, and dietary histories. In unadjusted models there was a significant association of urinary tract stones with incident total fractures (HR 1.10; 95% CI, 1.04 to 1.17). However, in covariate adjusted analyses, urinary tract stones were not significantly related to changes in BMD at any skeletal site or to incident fractures. In conclusion, urinary tract stones in postmenopausal women are not an independent risk factor for osteoporosis. PMID:25990099

Should metabolic evaluation be performed in patients with struvite stones?

PubMed

Iqbal, Muhammad Waqas; Shin, Richard H; Youssef, Ramy F; Kaplan, Adam G; Cabrera, Fernando J; Hanna, Jonathan; Scales, Charles D; Ferrandino, Michael N; Preminger, Glenn M; Lipkin, Michael E

2017-04-01

Previous studies suggested that patients with pure struvite calculi rarely have underlying metabolic abnormalities. Therefore, most of these patients do not undergo metabolic studies. We report our experience with these patients and their response to directed medical therapy. Between 1/2005 and 9/2012, 75 patients treated with percutaneous nephrolithotomy for struvite stones were identified. Of these, 7 had pure struvite stones (Group 1), 32 had mixed struvite stones (Group 2), both with metabolic evaluation, and 17 had pure struvite stones without metabolic evaluation (Group 3). The frequency of metabolic abnormalities and stone activity (defined as stone growth or stone-related events) was compared between groups. The median age was 55 years and 64 % were female. No significant difference in race, infection history, family history, stone location or volume existed between groups. Metabolic abnormalities were found in 57 % of Group 1 and 81 % of Group 2 patients. A similar proportion of Group 1 and 2 patients received modification to or continuation of metabolic therapy, whereas no Group 3 patients received any directed therapy. In patients with >6 months follow-up, the stone activity rate between Groups 1 and 2 appeared similar whereas Group 3 trended towards higher stone activity rate. Metabolic abnormalities in pure struvite stone formers appear to be more common than previously reported. Directed medical therapy in these patients may reduce stone activity. The role of metabolic evaluation and directed medical therapy needs reconsideration in patients with pure struvite stones.

[Management of Intrahepatic Duct Stone].

PubMed

Cha, Sang Woo

2018-05-25

Intrahepatic duct (IHD) stone is the presence of calculi within the intrahepatic bile duct specifically located proximal to the confluence of the left and right hepatic ducts. This stone is characterized by its intractable nature and frequent recurrence, requiring multiple therapeutic interventions. Without proper treatment, biliary strictures and retained stones can lead to repeated episodes of cholangitis, liver abscesses, secondary biliary cirrhosis, portal hypertension, and death from sepsis or hepatic failure. The ultimate treatment goals for IHD stones are complete removal of the stone, the correction of the associated strictures, and the prevention of recurrent cholangitis. A surgical resection can satisfy the goal of treatment for hepatolithiasis, i.e., complete removal of the IHD stones, stricture, and the risk of cholangiocarcinogenesis. On the other hand, in some cases, such as bilateral IHD stones, surgery alone cannot achieve these goals. Therefore, the optimal treatments require a multidisciplinary approach, including endoscopic and radiologic interventional procedures before and/or after surgery. Percutaneous transhepatic cholangioscopic lithotomy (PTCS-L) is particularly suited for patients at poor surgical risk or who refuse surgery and those with previous biliary surgery or stones distributed in multiple segments. PTCS-L is relatively safe and effective for the treatment of IHD stones, and complete stone clearance is mandatory to reduce the sequelae of IHD stones. An IHD stricture is the main factor contributing to incomplete clearance and stone recurrence. Long-term follow-up is required because of the overall high recurrence rate of IHD stones and the association with cholangiocarcinoma.

Preventing stone retropulsion during intracorporeal lithotripsy.

PubMed

Elashry, Osama M; Tawfik, Ahmad M

2012-12-01

Several studies of ureteroscopic treatment for ureteral stones have reported that most stone clearance failures can be attributed to stone fragment retropulsion. Stone retropulsion can result in increased operative time and cost-resulting from the need to change from the semi-rigid ureteroscope to a flexible instrument to chase migrated calculi-and additional procedures to treat residual migrated fragments are often required. The degree of migration depends mainly on the energy source used for lithotripsy; pneumatic and electrohydraulic lithotripters are associated with a greater degree of retropulsion than lasers. Different stone-trapping strategies and devices have been developed to minimize stone migration. Novel devices include the Lithovac(®) suction device, the Passport(™) balloon, the Stone Cone(™), the PercSys Accordion(®), the NTrap(®), and stone baskets such as the LithoCatch(™), the Parachute(™), and the Escape(®). Some authors have also reported on the use of lubricating jelly and BackStop(®) gel (a reverse thermosensitive polymeric plug); these devices are instilled proximal to the stone prior to the application of kinetic energy in order to prevent retrograde stone migration.

Evaluation of biochemical urinary stone composition and its relationship to tap water hardness in Qom province, central Iran.

PubMed

Moslemi, Mohammad Kazem; Saghafi, Hossein; Joorabchin, Seyed Mohammad Amin

2011-01-01

The aim of this study was to evaluate the biochemical stone composition in general population of Qom province, central Iran, and its relationship with high tap water hardness. In a prospective study, from March 2008 to July 2011, biochemical analysis of urinary stones in patients living in Qom province for at least 5 years was performed. Stones were retrieved by spontaneous passage, endoscopic or open surgery, and after extracorporeal shockwave lithotripsy. Demographic findings and the drinking water supply of patients were evaluated and compared with biochemical stone analysis. Stone analysis was performed in 255 patients. The most dominant composition of urinary stones was calcium oxalate (73%), followed by uric acid (24%), ammonium urate (2%), and cystine (1%). The peak incidence of urinary stone was in patients in their forties. Overall male to female ratio was 4.93:1. The dominant stone composition in inhabitants of central Iran, where tap water hardness is high, was calcium oxalate stones. On the basis of this study, biochemical urinary stone composition of Qom does not differ from other regions of Iran with lower water hardness.

Pathophysiology of kidney, gallbladder and urinary stones treatment with herbal and allopathic medicine: A review

PubMed Central

Alok, Shashi; Jain, Sanjay Kumar; Verma, Amita; Kumar, Mayank; Sabharwal, Monika

2013-01-01

Medicinal plants have been known for millennia and are highly esteemed all over the world as a rich source of therapeutic agents for the prevention of various ailments. Today large number of population suffers from kidney stone, gall stone and urinary calculi. Stone disease has gained increasing significance due to changes in living conditions i.e. industrialization and malnutrition. Changes in prevalence and incidence, the occurrence of stone types and stone location, and the manner of stone removal are explained. Medicinal plants are used from centuries due to its safety, efficacy, cultural acceptability and lesser side effects as compared to synthetic drugs. The present article deals with measures to be adopted for the potential of medicinal plants in stone dissolving activity. The problem of urinary stones or calculi is a very ancient one and many remedies have been employed during the ages these stones are found in all parts of the urinary tract, the kidney, the ureters and the urinary bladder and may vary considerably in size. In the present article, an attempt has been made to emphasis on herbal option for urinary stone.

Prediction of calcium level in melamine-related urinary calculi with helical CT: diagnostic performance evaluation and clinical significance.

PubMed

Yuan, Li; Xiaorui, Ru; Gang, Huang; Xinsheng, Xi; Xiaogang, Huang; Li, Dong; Yirong, Chen

2012-06-01

The aim of the study was to investigate the relationship between CT-attenuation and stone calcium level in melamine-related urinary calculi (MRUC). A total of 25 MRUC with known composition and calcium level were included (11 uric acid stones, 2 calcium oxalate stones and 12 mixture stones of uric acid and calcium oxalate). Of all, 18 renal stones accepted alkalization therapy except for 5 lower urinary tract stones and 2 stones of unknown position. With well-matched composition, 61 adult urinary stones were included as controls. Every stone was scanned by helical CT (80 kV/120 kV, 300 mA, pitch 0.625 mm) and the highest CT-attenuation value measured. CT-attenuation values of MRUC increased gradually from uric acid stones, mixture stones to calcium oxalate stones, but were always lower than the values of controls. Furthermore, a strong positive correlation was found between stone CT-attenuation value and stone calcium level (n = 25, r (80kV) = 0.883, p = 0.000; r (120kV) = 0.855, p = 0.000). Compared with alkalization-therapy-alone group, stone CT-attenuation values and stone calcium level in the comprehensive-therapy group were significantly greater (CT(80kV) 1,057 ± 639 vs. 172 ± 61 HU, p = 0.001; CT(120kV) 783 ± 476 vs. 162 ± 60 HU, p = 0.001; Ca 19.83 ± 7.48% vs. 1.30 ± 1.51%, p = 0.000). Fisher's exact test suggested that the stones with higher CT-attenuation values tended to resist alkalization when 400 HU served as the cutoff value (P (80kV) = 0.002, P (120kV) = 0.000). In conclusion, the study was the first to illustrate that the CT-attenuation value could reflect calcium level in MRUC and found that stones with higher CT-attenuation value were not amenable to alkalization because they probably contained greater calcium. For those patients, we believe that comprehensive therapy will be the best choice.

Mineralogy and chemistry of urinary stones: patients from North Jordan.

PubMed

Abboud, Iyad Ahmed

2008-10-01

Urinary stone diseases are increasing in the Middle East. The majority of urinary stone cases are found in the northern part of the country. Stone samples taken from patients living in the Irbid area were collected from Princess Basma Hospital. The present study concentrates on the mineralogical and chemical composition of the urinary stones and on the effective environmental factors that assist in developing the different types of urinary stones. Using X-ray diffraction techniques, the mineralogical composition of the urinary stones was found to be as follows: oxalate, cholesten, and uric acid, with cystine stones occuring more frequently than the others. Cholesten and calcium oxalate stones are the most dominant types of stones. Calcium oxalate is the most common type of oxalate stone. Calcium oxalate is represented in: whewellite, wheddellite, and calcium carbonate oxalate hydrate minerals, in addition to other minerals such as brushite, ammonium phosphate, vaterite, valleriite, and bobierrite from other types of stones. Bobierrite (phosphate group) is a new mineral reported in urinary stones, and this has not been determined in any previous study worldwide. Apatite (calcium phosphate) is deduced using scanning electron microscope (SEM) images. The SEM technique determined crystal forms and systems, shapes, morphological features, and the names of the minerals forming urine stones, while optical properties are studied by polarizing microscope. X-ray fluorescence technique determined the concentrations of major and some trace elements. It revealed that Ca is the main constituent of the urinary stones, especially those composed of calcium oxalate and calcium phosphate. The concentration of trace elements was Ba = 1.57, P = 3.61, Fe = 1.78, S = 2.08, Zr = 4.63, Mo = 3.92, Cu = 1.89, Co = 1.56, and F = 4.2% and was higher in the urinary stones of Jordanian patients than in foreigners in the country. Questionnaires completed by patients suggest that the most significant factors directly effecting the formation of stones are water, climate conditions, food rich in protein and rich in different chemicals. Moreover, some drugs and diseases might also help in developing other stones.

Laboratory simulations of the Vis-NIR spectra of comet 67P using sub-μm sized cosmochemical analogues

NASA Astrophysics Data System (ADS)

Rousseau, B.; Érard, S.; Beck, P.; Quirico, É.; Schmitt, B.; Brissaud, O.; Montes-Hernandez, G.; Capaccioni, F.; Filacchione, G.; Bockelée-Morvan, D.; Leyrat, C.; Ciarniello, M.; Raponi, A.; Kappel, D.; Arnold, G.; Moroz, L. V.; Palomba, E.; Tosi, F.; Virtis Team

2018-05-01

Laboratory spectral measurements of relevant analogue materials were performed in the framework of the Rosetta mission in order to explain the surface spectral properties of comet 67P. Fine powders of coal, iron sulphides, silicates and their mixtures were prepared and their spectra measured in the Vis-IR range. These spectra are compared to a reference spectrum of 67P nucleus obtained with the VIRTIS/Rosetta instrument up to 2.7 μm, excluding the organics band centred at 3.2 μm. The species used are known to be chemical analogues for cometary materials which could be present at the surface of 67P. Grain sizes of the powders range from tens of nanometres to hundreds of micrometres. Some of the mixtures studied here actually reach the very low reflectance level observed by VIRTIS on 67P. The best match is provided by a mixture of sub-micron coal, pyrrhotite, and silicates. Grain sizes are in agreement with the sizes of the dust particles detected by the GIADA, MIDAS and COSIMA instruments on board Rosetta. The coal used in the experiment is responsible for the spectral slope in the visible and infrared ranges. Pyrrhotite, which is strongly absorbing, is responsible for the low albedo observed in the NIR. The darkest components dominate the spectra, especially within intimate mixtures. Depending on sample preparation, pyrrhotite can coat the coal and silicate aggregates. Such coating effects can affect the spectra as much as particle size. In contrast, silicates seem to play a minor role.

Ionising sources in the coma of 67P probed by Rosetta

NASA Astrophysics Data System (ADS)

Heritier, Kevin; Galand, Marina; Henri, Pierre; Eriksson, Anders; Odelstad, Elias; Altwegg, Kathrin; Beth, Arnaud; Broiles, Thomas; Burch, Jim; Carr, Christopher; Cupido, Emanuele; Glassmeier, Karl-Heinz; Nilsson, Hans; Richter, Ingo; Rubin, Martin; Vallieres, Xavier; Vigren, Erik

2017-04-01

An ionospheric model has been developed in order to quantify the ion number density in the coma of 67P/Churyumov-Gerasimenko. The model is driven by Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA)/Cometary Pressure Sensor (COPS) neutral density and assumes isentropic expansion for the neutral density profile. The two ionisation sources considered are photo-ionisation by solar extreme ultraviolet (EUV) radiation and electron-impact ionisation. The EUV radiation is estimated from fluxes measured by the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)/ Solar EUV Experiment (SEE), taking into account the phase shift and the heliocentric distance ratio; between Earth and comet 67P. The electron-impact ionisation production rates are derived from Rosetta Plasma Consortium (RPC)-Ion and Electron Sensor (IES) integrated electron fluxes and corrected for the S/C potential from RPC/LAngmuir Probe (LAP) measurements. Our results are compared with in situ measurements of the plasma density from RPC-Mutual Impedance Probe (MIP) and RPC-LAP. There is a good agreement between the modelled and RPC observed electron densities. The ionospheric model enables to distinguish the relative contributions of the different sources to the total cometary plasma. At high heliocentric distances, electron-impact ionisation becomes the dominant ionisation source and is enhanced over the winter hemisphere. As the solar activity has decreased since the beginning of the mission in 2014, the relative importance of photo-ionisation has decreased as well. However, at low heliocentric distances, photo-ionisation seems to be the most dominant ionising source, in particular through the perihelion period in summer 2015.

Early Activity of Churyumov-Gerasimenko: ROSINA/RTOF Results

NASA Astrophysics Data System (ADS)

Wurz, P.; Altwegg, K.; Balsiger, H. R.; Gasc, S.; Galli, A.; Rubin, M.; Jäckel, A.; Le Roy, L.; Calmonte, U.; Tzou, C. Y.; Mall, U. A.; Korth, A.; Fiethe, B.; De Keyser, J. M.; Berthelier, J. J.; Rème, H.; Gombosi, T. I.; Fuselier, S.

2014-12-01

The European Space Agency's Rosetta spacecraft is now close to the comet 67P/Churyumov-Gerasimenko (67P/C-G). On board is the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) instrument suite. ROSINA consists of two mass spectrometers, the Double Focusing Mass Spectrometer (DFMS) and the Reflectron-type Time-Of-Flight (RTOF), as well as the COmet Pressure Sensor (COPS). The first signal with ROSINA/RTOF of the gaseous environment of the comet was a significant increase in water density observed on DOY 218.1 of 2014 (at 3.5 AU) by RTOF above the gaseous envelope of the Rosetta spacecraft. A similar density increase is observed by COPS at the same time. A preliminary analysis shows that the water density is nH2O ≈ 1012 m-3 at 100 km distance from the comet (located at 3.5 AU from the Sun). This gives a density at the surface of nH2O ≈ 6.4·1015 m-3 and a vertical column density of water of NCH2O ≈ 6.5·1018 m-2. Assuming an active area of 4% we arrive at a production rate of QH2O ≈ 5.8·1024 mole s-1. These values are preliminary and will be refined by forthcoming observations. Other than water, no signal related to cometary activity could be observed above the molecular background from the spacecraft at present, e.g. cometary CO and CO2 are not observed in the RTOF data so far. This hints at a possible deficiency of carbon bearing compounds in the comet.

Alternative Computational Protocols for Supercharging Protein Surfaces for Reversible Unfolding and Retention of Stability

PubMed Central

Der, Bryan S.; Kluwe, Christien; Miklos, Aleksandr E.; Jacak, Ron; Lyskov, Sergey; Gray, Jeffrey J.; Georgiou, George; Ellington, Andrew D.; Kuhlman, Brian

2013-01-01

Reengineering protein surfaces to exhibit high net charge, referred to as “supercharging”, can improve reversibility of unfolding by preventing aggregation of partially unfolded states. Incorporation of charged side chains should be optimized while considering structural and energetic consequences, as numerous mutations and accumulation of like-charges can also destabilize the native state. A previously demonstrated approach deterministically mutates flexible polar residues (amino acids DERKNQ) with the fewest average neighboring atoms per side chain atom (AvNAPSA). Our approach uses Rosetta-based energy calculations to choose the surface mutations. Both protocols are available for use through the ROSIE web server. The automated Rosetta and AvNAPSA approaches for supercharging choose dissimilar mutations, raising an interesting division in surface charging strategy. Rosetta-supercharged variants of GFP (RscG) ranging from −11 to −61 and +7 to +58 were experimentally tested, and for comparison, we re-tested the previously developed AvNAPSA-supercharged variants of GFP (AscG) with +36 and −30 net charge. Mid-charge variants demonstrated ∼3-fold improvement in refolding with retention of stability. However, as we pushed to higher net charges, expression and soluble yield decreased, indicating that net charge or mutational load may be limiting factors. Interestingly, the two different approaches resulted in GFP variants with similar refolding properties. Our results show that there are multiple sets of residues that can be mutated to successfully supercharge a protein, and combining alternative supercharge protocols with experimental testing can be an effective approach for charge-based improvement to refolding. PMID:23741319

Algorithm for selection of optimized EPR distance restraints for de novo protein structure determination

PubMed Central

Kazmier, Kelli; Alexander, Nathan S.; Meiler, Jens; Mchaourab, Hassane S.

2010-01-01

A hybrid protein structure determination approach combining sparse Electron Paramagnetic Resonance (EPR) distance restraints and Rosetta de novo protein folding has been previously demonstrated to yield high quality models (Alexander et al., 2008). However, widespread application of this methodology to proteins of unknown structures is hindered by the lack of a general strategy to place spin label pairs in the primary sequence. In this work, we report the development of an algorithm that optimally selects spin labeling positions for the purpose of distance measurements by EPR. For the α-helical subdomain of T4 lysozyme (T4L), simulated restraints that maximize sequence separation between the two spin labels while simultaneously ensuring pairwise connectivity of secondary structure elements yielded vastly improved models by Rosetta folding. 50% of all these models have the correct fold compared to only 21% and 8% correctly folded models when randomly placed restraints or no restraints are used, respectively. Moreover, the improvements in model quality require a limited number of optimized restraints, the number of which is determined by the pairwise connectivities of T4L α-helices. The predicted improvement in Rosetta model quality was verified by experimental determination of distances between spin labels pairs selected by the algorithm. Overall, our results reinforce the rationale for the combined use of sparse EPR distance restraints and de novo folding. By alleviating the experimental bottleneck associated with restraint selection, this algorithm sets the stage for extending computational structure determination to larger, traditionally elusive protein topologies of critical structural and biochemical importance. PMID:21074624

Rosetta FlexPepDock ab-initio: simultaneous folding, docking and refinement of peptides onto their receptors.

PubMed

Raveh, Barak; London, Nir; Zimmerman, Lior; Schueler-Furman, Ora

2011-04-29

Flexible peptides that fold upon binding to another protein molecule mediate a large number of regulatory interactions in the living cell and may provide highly specific recognition modules. We present Rosetta FlexPepDock ab-initio, a protocol for simultaneous docking and de-novo folding of peptides, starting from an approximate specification of the peptide binding site. Using the Rosetta fragments library and a coarse-grained structural representation of the peptide and the receptor, FlexPepDock ab-initio samples efficiently and simultaneously the space of possible peptide backbone conformations and rigid-body orientations over the receptor surface of a given binding site. The subsequent all-atom refinement of the coarse-grained models includes full side-chain modeling of both the receptor and the peptide, resulting in high-resolution models in which key side-chain interactions are recapitulated. The protocol was applied to a benchmark in which peptides were modeled over receptors in either their bound backbone conformations or in their free, unbound form. Near-native peptide conformations were identified in 18/26 of the bound cases and 7/14 of the unbound cases. The protocol performs well on peptides from various classes of secondary structures, including coiled peptides with unusual turns and kinks. The results presented here significantly extend the scope of state-of-the-art methods for high-resolution peptide modeling, which can now be applied to a wide variety of peptide-protein interactions where no prior information about the peptide backbone conformation is available, enabling detailed structure-based studies and manipulation of those interactions. © 2011 Raveh et al.

Rosetta FlexPepDock ab-initio: Simultaneous Folding, Docking and Refinement of Peptides onto Their Receptors

PubMed Central

Raveh, Barak; London, Nir; Zimmerman, Lior; Schueler-Furman, Ora

2011-01-01

Flexible peptides that fold upon binding to another protein molecule mediate a large number of regulatory interactions in the living cell and may provide highly specific recognition modules. We present Rosetta FlexPepDock ab-initio, a protocol for simultaneous docking and de-novo folding of peptides, starting from an approximate specification of the peptide binding site. Using the Rosetta fragments library and a coarse-grained structural representation of the peptide and the receptor, FlexPepDock ab-initio samples efficiently and simultaneously the space of possible peptide backbone conformations and rigid-body orientations over the receptor surface of a given binding site. The subsequent all-atom refinement of the coarse-grained models includes full side-chain modeling of both the receptor and the peptide, resulting in high-resolution models in which key side-chain interactions are recapitulated. The protocol was applied to a benchmark in which peptides were modeled over receptors in either their bound backbone conformations or in their free, unbound form. Near-native peptide conformations were identified in 18/26 of the bound cases and 7/14 of the unbound cases. The protocol performs well on peptides from various classes of secondary structures, including coiled peptides with unusual turns and kinks. The results presented here significantly extend the scope of state-of-the-art methods for high-resolution peptide modeling, which can now be applied to a wide variety of peptide-protein interactions where no prior information about the peptide backbone conformation is available, enabling detailed structure-based studies and manipulation of those interactions. PMID:21572516

Characterizing Cometary Electrons with Kappa Distributions

NASA Technical Reports Server (NTRS)

Broiles, T. W.; Livadiotis, G.; Burch, J. L.; Chae, K.; Clark, G.; Cravens, T. E.; Davidson, R.; Eriksson, A.; Frahm, R. A.; Fuselier, S. A.;

Predicting available water of soil from particle-size distribution and bulk density in an oasis-desert transect in northwestern China

NASA Astrophysics Data System (ADS)

Li, Danfeng; Gao, Guangyao; Shao, Ming'an; Fu, Bojie

2016-07-01

A detailed understanding of soil hydraulic properties, particularly the available water content of soil, (AW, cm3 cm-3), is required for optimal water management. Direct measurement of soil hydraulic properties is impractical for large scale application, but routinely available soil particle-size distribution (PSD) and bulk density can be used as proxies to develop various prediction functions. In this study, we compared the performance of the Arya and Paris (AP) model, Mohammadi and Vanclooster (MV) model, Arya and Heitman (AH) model, and Rosetta program in predicting the soil water characteristic curve (SWCC) at 34 points with experimental SWCC data in an oasis-desert transect (20 × 5 km) in the middle reaches of the Heihe River basin, northwestern China. The idea of the three models emerges from the similarity of the shapes of the PSD and SWCC. The AP model, MV model, and Rosetta program performed better in predicting the SWCC than the AH model. The AW determined from the SWCCs predicted by the MV model agreed better with the experimental values than those derived from the AP model and Rosetta program. The fine-textured soils were characterized by higher AW values, while the sandy soils had lower AW values. The MV model has the advantages of having robust physical basis, being independent of database-related parameters, and involving subclasses of texture data. These features make it promising in predicting soil water retention at regional scales, serving for the application of hydrological models and the optimization of soil water management.

Calcium Tartrate Tetrahydrate, Case Report of a Novel Human Kidney Stone.

PubMed

Kleinguetl, Colin; Williams, James C; Ibrahim, Samar A; Daudon, Michel; Bird, Erin T; El Tayeb, Marawan M

2017-01-01

Background: Calcium tartrate tetrahydrate has been reported as the main mineral in urinary stones in rats that have significant tartrate in their diet, but in humans, there has been only one mention of calcium tartrate stones in the form of bladder stone, and that case was in Africa. Case Presentation: Patient is a 34-year-old Caucasian male who presented with typical symptoms of nephrolithiasis. CT abd/pelvis (renal stone protocol) revealed a 2 cm nonobstructing stone of the right renal pelvis. Patient underwent an uncomplicated right percutaneous nephrolithotomy and was noted to be stone free after surgery. Stone analysis was difficult with regard to determining composition, but was finally identified as calcium tartrate tetrahydrate. Conclusion: This was an unusual case, as this is the first recorded case of a calcium tartrate tetrahydrate outside of Africa. This type of stone had only been mainly described in rat models with dl- bitartrate in their diet. Our patient was an otherwise healthy, relatively muscular individual with no obvious source for this stone other than a vitamin and amino acid supplement that he takes regularly that contains l-carnitine (as tartrate) and choline (as bitartrate and citrate). The prevalence of this stone type is presently unknown, as stone analysis laboratories have not had the ability to recognize it. Although a connection between the supplement and stone formation is conjecture at this time, we believe this necessitates further investigation.

Quantification of the Range of Motion of Kidney and Ureteral Stones During Shockwave Lithotripsy in Conscious Patients.

PubMed

Harrogate, Suzanne R; Yick, L M Shirley; Williams, James C; Cleveland, Robin O; Turney, Benjamin W

2016-04-01

Effective shockwave lithotripsy requires accurate targeting of the stone throughout the course of treatment. Stone movement secondary to respiratory movement can make this more difficult. In vitro work has shown that stone motion outside the focal region reduces the efficacy of stone fragmentation; however, there are few clinical data on the degree of stone movement in patients during treatment. To investigate this, X-ray fluoroscopic images of the kidney and ureteral stones at the upper and lower limits of the normal respiratory cycle were acquired during shock wave lithotripsy of 58 conscious patients, and stone excursion was calculated from these images. In addition, the respiration rate and patient perceived pain were recorded during the course of the treatment. It was found that stone motion secondary to respiration was 7.7 ± 2.9 mm for kidney stones and 3.6 ± 2.1 mm for ureteral stones-less than has been reported in studies with anesthetized patients. There was no significant change of motion over the course of treatment although pain was found to increase. These data suggest that stone motion in conscious patients is less than in anesthetized patients. Furthermore, it suggests that lithotripters with focal regions of 8 mm or greater should not suffer from a marked drop in fragmentation efficiency due to stone motion.

Pathogenesis of pigment gallstones in Western societies: the central role of bacteria.

PubMed

Stewart, Lygia; Oesterle, Adair L; Erdan, Ihsan; Griffiss, J MacLeod; Way, Lawrence W

2002-01-01

Bacteria are traditionally accorded a greater role in pigment gallstone formation in Eastern populations. Stone color is thought to predict the presence of bacteria; that is, black stones (Western predominant) are supposedly sterile and brown stones (Eastern predominant) contain bacteria. We previously reported that, regardless of appearance, most pigment gallstones contain bacteria. This study examined, in a large Western population (370 patients), the incidence, appearance, and chemical composition of pigment stones, and the characteristics of gallstone bacteria. One hundred eighty-six pigment stones were obtained aseptically. Bacteria were detected by means of scanning electron microscopy and gallstone culture. Chemical composition was determined by infrared spectroscopy. Bacteria were tested for slime and beta-glucuronidase production. Seventy-three percent of pigment stones contained bacteria. Choledocholithiasis was associated with gallstone bacteria. Ca-bilirubinate was present in all pigment stones. Ca-palmitate was characteristic of infected stones, and more than 75% Ca-carbonate was characteristic of sterile stones. Neither chemical composition nor stone appearance predicted the presence of bacteria. Ninety-five percent and 67% of infected pigment stones contained bacteria that produced slime and beta-glucuronidase, respectively. Most pigment stones contained bacteria that produced beta-glucuronidase, slime, and phospholipase, factors that facilitate stone formation. Thus bacteria have a major role in Western pigment gallstone formation. Furthermore, gallstone color did not predict composition or bacterial presence.

Sedimentary rocks in our mouth: dental pulp stones made by nanobacteria

NASA Astrophysics Data System (ADS)

Ciftcioglu, Neva; Ciftcioglu, Vefa; Vali, Hojatollah; Turcott, Eduardo; Kajander, E. Olavi

1998-07-01

The mechanisms of dental pulp stone formation are still largely unknown. Pulp stones are mainly composed of carbonate apatite. Only few experimental reports have elucidated the potential of some selected bacteria to produce apatite under in vitro conditions using special calcification media. The tested stone forming bacteria were, in fact, often better known for their cariogenic potential. Our preliminary work with 18 dental pulp stones from Turkey, selected only by severity of the stone formation, indicated the presence of nanobacterial antigens in the demineralized stones. Furthermore, high incidence of kidney stones and gall stones in the patient group and in their parents was found. This raises the implication that nanobacteria may enter the body also via oral route, in addition to the parenteral and transplacental routes. The role of nanobacteria in dental pulp stone formation was further studied by following nanobacterial colonization and mineral formation on human tooth in vitro. Two molar teeth, one having pulp stone and one without, were vertically cut into two pieces, sterilized by autoclaving and incubated with or without nanobacteria in DMEM. Electron microscopic observations indicate that nanobacteria can cause apatite stone formation on tooth surface. The sever from of dental pulp stone formation might be associated with nanobacteria. This form of dental disease results in loss of teeth due to osteolytic processes. This addresses the necessity for a study on unconventional mineral-forming bacteria as a cause for human diseases.

Wild capuchin monkeys spontaneously adjust actions when using hammer stones of different mass to crack nuts of different resistance.

PubMed

Liu, Qing; Fragaszy, Dorothy M; Visalberghi, Elisabetta

2016-09-01

Expert tool users are known to adjust their actions skillfully depending on aspects of tool type and task. We examined if bearded capuchin monkeys cracking nuts with stones of different mass adjusted the downward velocity and the height of the stone when striking palm nuts. During a field experiment carried out in FBV (Piauí, Brazil), eight adult wild capuchin monkeys (five males) cracked Orbygnia nuts of varied resistance with hammer stones differing in mass. From recorded videos, we identified the highest strike per nut-cracking episode, and for this strike, we calculated the height to which the monkey lifted the stone, the maximum velocity of the stone during the downward phase, the work done on the stone, and the kinetic energy of the strike. We found that individual capuchins achieved average maximum kinetic energy of 8.7-16.1 J when using stones between 0.9 and 1.9 kg, and maximum kinetic energy correlated positively with mass of the stone. Monkeys lifted all the stones to an individually consistent maximum height but added more work to the stone when using lighter stones. One male and one female monkey lifted stones higher when they cracked more resistant nuts. The high resistance of the Orbygnia nut elicits production of maximum kinetic energy, which the monkeys modulate to some degree by adding work to lighter stones. Capuchin monkeys, like chimpanzees, modulate their actions in nut-cracking, indicating skilled action, although neither species regulates kinetic energy as precisely as skilled human stone knappers. Kinematic analyses promise to yield new insights into the ways and extent to which nonhuman tool users develop expertise. Am J Phys Anthropol 161:53-61, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Kidney Stones in Primary Hyperoxaluria: New Lessons Learnt

PubMed Central

Jacob, Dorrit E.; Grohe, Bernd; Geßner, Michaela; Beck, Bodo B.; Hoppe, Bernd

2013-01-01

To investigate potential differences in stone composition with regard to the type of Primary Hyperoxaluria (PH), and in relation to the patient’s medical therapy (treatment naïve patients versus those on preventive medication) we examined twelve kidney stones from ten PH I and six stones from four PH III patients. Unfortunately, no PH II stones were available for analysis. The study on this set of stones indicates a more diverse composition of PH stones than previously reported and a potential dynamic response of morphology and composition of calculi to treatment with crystallization inhibitors (citrate, magnesium) in PH I. Stones formed by PH I patients under treatment are more compact and consist predominantly of calcium-oxalate monohydrate (COM, whewellite), while calcium-oxalate dihydrate (COD, weddellite) is only rarely present. In contrast, the single stone available from a treatment naïve PH I patient as well as stones from PH III patients prior to and under treatment with alkali citrate contained a wide size range of aggregated COD crystals. No significant effects of the treatment were noted in PH III stones. In disagreement with findings from previous studies, stones from patients with primary hyperoxaluria did not exclusively consist of COM. Progressive replacement of COD by small COM crystals could be caused by prolonged stone growth and residence times in the urinary tract, eventually resulting in complete replacement of calcium-oxalate dihydrate by the monohydrate form. The noted difference to the naïve PH I stone may reflect a reduced growth rate in response to treatment. This pilot study highlights the importance of detailed stone diagnostics and could be of therapeutic relevance in calcium-oxalates urolithiasis, provided that the effects of treatment can be reproduced in subsequent larger studies. PMID:23940605

The impact of pelvicaliceal anatomy on the success of retrograde intrarenal surgery in patients with lower pole renal stones.

PubMed

Resorlu, Berkan; Oguz, Ural; Resorlu, Eylem Burcu; Oztuna, Derya; Unsal, Ali

2012-01-01

To evaluate the impact of pelvicaliceal anatomy on the success of retrograde intrarenal surgery (RIRS) for lower pole renal stones and determine which of these factors can be used to select patients who will benefit from RIRS. We evaluated 67 patients who underwent RIRS between 2009 and 2010 for isolated lower pole renal stones. The infundibular length (IL), infundibular width (IW), pelvicaliceal height (PCH), and infundibulopelvic angle (IPA) were measured by preoperative intravenous urogram. Success was defined as either complete clearance or clearance with insignificant residual fragments≤3 mm in size at 2-months follow-up. Mean IL was 26.7±7.9 and 28.2±5.3 mm, mean PCH was 20.7±6.6 and 23.2±4.9 mm in stone-free and non-stone-free patients, respectively. These were slightly larger in the non-stone-free group but not statistically significant (P=.140 and P=.072, respectively). Mean IW was 5.8±3.5 and 5.6±2.2 mm in stone-free and non-stone-free patients, respectively, which had no significant impact on the stone-free rate (P=.719). There were significant differences between the groups in terms of stone length (P=.001) and IPA (P=.003). The mean IPA was 49.37±11.83 and 37.61±13.22 mm in stone-free and non-stone-free patients, respectively. In addition to the influence of stone size, lower pole anatomy, especially IPA, has a significant impact on stone clearance for lower pole stones after RIRS. Copyright © 2012 Elsevier Inc. All rights reserved.

Nile Delta

Atmospheric Science Data Center

2013-04-15

... west are the Great Pyramids of Giza. North of here the Nile branches into two distributaries, the Rosetta to the west and the Damietta to ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

Renal geology (quantitative renal stone analysis) by 'Fourier transform infrared spectroscopy'.

PubMed

Singh, Iqbal

2008-01-01

To prospectively determine the precise stone composition (quantitative analysis) by using infrared spectroscopy in patients with urinary stone disease presenting to our clinic. To determine an ideal method for stone analysis suitable for use in a clinical setting. After routine and a detailed metabolic workup of all patients of urolithiasis, stone samples of 50 patients of urolithiasis satisfying the entry criteria were subjected to the Fourier transform infrared spectroscopic analysis after adequate sample homogenization at a single testing center. Calcium oxalate monohydrate and dihydrate stone mixture was most commonly encountered in 35 (71%) followed by calcium phosphate, carbonate apatite, magnesium ammonium hexahydrate and xanthine stones. Fourier transform infrared spectroscopy allows an accurate, reliable quantitative method of stone analysis. It also helps in maintaining a computerized large reference library. Knowledge of precise stone composition may allow the institution of appropriate prophylactic therapy despite the absence of any detectable metabolic abnormalities. This may prevent and or delay stone recurrence.

[Uroliths of cats in Switzerland from 2002 to 2009].

PubMed

Gerber, B; Brandenberger-Schenk, F; Rothenanger, E; Müller, C

2016-10-01

In this study data on composition of uroliths collected from cats and epidemiologic data of affected cats in Switzerland from 2002 to 2009 are summarised. Of 884 stones analysed 50% (n=441) were composed of calcium oxalate, 45% (n=398) of struvite, 3% (n=18) of ammonium urate, 1% (n=12) were mixed stones, 1% (n=9) were composed of silica, 3 stones were solidified blood, 2 consisted of cystine and 1of xanthine. 40% of the ureteral stones were composed of struvite. Domestic cats had significantly less calcium oxalate stones compared to British Shorthair or Persian cats. Cats with calcium oxalate stones were older and cats with struvite stones were younger than other affected cats. Female and male cats were equally affected with stones. Compared to studies from other countries, in Switzerland silica stones occurred more often and ureteral stones were more often composed of Struvite. The present study shows that occurrence and prevalence of urinary calculi of cats from Switzerland exhibited only slight differences to studies from other countries.

Wait-and-see policy versus cholecystectomy after endoscopic sphincterotomy for bile-duct stones in high-risk patients with co-existing gallbladder stones: a prospective randomised trial.

PubMed

Zargar, Showkat A; Mushtaq, Mosin; Beg, Mashkoor A; Javaid, Gul; Khan, Bashir A; Hassan, Rayhana; Kasana, Reyaz A; Tabassum, Sameena

2014-03-01

Endoscopic sphincterotomy (ES) is one of the most important advances in the treatment of common bile duct (CBD) stones. However, the use of ES to remove CBD stones in high-risk patients without cholecystectomy is still debatable. The aim of this study was to compare the efficacy of a wait-and-see policy versus cholecystectomy after ES for CBD stones in high-risk patients with co-existing cholelithiasis. A total of 162 patients after undergoing ES with the clearance of CBD stones were randomised after informed consent to cholecystectomy or conservative management of their gallbladder stones. The results indicated that cholecystectomy after ES for CBD stones significantly reduced the biliary complications in high-risk patients. Every patient who has both CBD stones and gallstones with significant co-morbid illnesses, after clearance of CBD stones by ES, should undergo early cholecystectomy. Copyright © 2014 Arab Journal of Gastroenterology. Published by Elsevier Ltd. All rights reserved.

Nucleus structure and dust morphology: Post-Rosetta understanding and implications

NASA Astrophysics Data System (ADS)

Levasseur-Regourd, A.; Bentley, Mark; Ciarletti, Valérie; Kofman, Woldek; Lasue, Jeremie; Mannel, Thurid; Herique, Alain

2017-10-01

The structure of cometary nuclei and the morphology of dust particles they eject have long been unknowns in cometary science. The combination of these two subjects, as revealed by the Rosetta mission at 67P/C-G, is currently providing an unprecedented insight about Solar System formation and early evolution.Rosetta has established that the bulk porosity of 67P/C-G nucleus is high, in the 70% to 85% range, both from the determination of its density and from permittivity measurements with CONSERT bistatic radar experiment [1-2]. CONSERT, through operations after Philae landing on 12-13 November 2014, has also allowed us to estimate that i) the porosity is likely to be higher inside the nucleus than on its subsurface, ii) a major component of the nucleus is refractory carbonaceous compounds, and iii) the small lobe is homogeneous at a scale of a few wavelengths (i.e., about 10 m), while heterogeneities in the 3-m range (similar to the rounded nodules noticed on walls of large pits) cannot be ruled out [2-4].Rosetta has also established, through its 26 months rendezvous with 67P/C-G, the aggregated structure of dust particles within a wide range of sizes in the inner cometary coma. The MIDAS atomic force microscope experiment has given us evidence (from 3D topographic images with nano- to micrometer resolution) for i) a hierarchical structure of aggregated dust particles, down to tens of nm-sized grains, ii) one extremely porous dust particle, with a fractal dimension of (1.7 ± 0.1) [5-6]. The accuracy of comparisons between cometary dust particles and interplanetary dust particles collected in the stratosphere (including CP-IDPs) could thus be improved.Such results should further refine the main processes (e.g., low velocity aggregation) that allowed the formation of comets in the early Solar System, and the implications of a possible late heavy bombardment on the interplanetary dust clouds and on telluric planets.References. 1. Pätzold et al. Nature 530 63 2016. 2. Kofman et al. Science 349 6247 2015. 3. Herique et al. MNRAS 462 S516 2016. 4. Ciarletti et al. A&A 583 A40 2015. 5. Bentley et al., Nature 537 73 2016. 6. Mannel et al., MNRAS 462 S304 2016.

Enantioselective Analysis in instruments onboard ROSETTA/PHILAE and ExoMars

NASA Astrophysics Data System (ADS)

Hendrik Bredehöft, Jan; Thiemann, Wolfram; Meierhenrich, Uwe; Goesmann, Fred

It has been suggested a number of times in the past, to look for chirality as a biomarker. So far, for lack of appropriate instrumentation, space missions have never included enantioselective analysis. The distinction between enantiomers is of crucial importance to the question of the origin of the very first (pre)biotic molecules. If molecules detected in situ on another celestial body were found to exhibit a chiral bias, this would mean that at least partial asymmetric synthesis could take place abiotically. If this chiral bias should be found to be near 100For the currently flying ESA mission ROSETTA an enantioselective instrument was built, to try for the first time to detect and separate chiral molecules in situ. This instrument is COSAC, the Cometary Sampling and Acquisition Experiment, an enantioselective GCMS device[1,2], which is included in the lander PHLIAE that will eventually in 2014 land on the nucleus of comet 67P/Churyumov-Gerasimenko. A similar but even more powerful type of enantioselective GC-MS is in preparation for ESA's ExoMars mission. This instrument is part of MOMA, the Mars Organic Molecules Analyser. It has the objective of identifying and quantifying chiral organic molecules in surface and subsurface samples of Mars. Currently ExoMars is scheduled for 2018. The newly developed enantioselective technique utilized by both COSAC and MOMA will be described, including sample acquisition, derivatization, and separation in space-resistant chiral stationary capillary columns with time-of-flight mass spectrometric detection. Results of enantioselective analyses of representative test samples with special emphasis on amino acids[3], the building blocks of protein polymers, will be presented and we will discuss potential results of space missions Rosetta and ExoMars. [1] Thiemann W.H.-P., Meierhenrich U.: ESA Mission ROSETTA Will Probe for Chirality of Cometary Amino Acids. Origins of Life and Evolution of Biospheres 31 (2001), 199-210. [2] Goesmann F., Rosenbauer H., Roll R., Szopa C., Raulin F., Sternberg R., Israel G., Meier-henrich U., Thiemann W., Muñoz Caro G.M.: COSAC, The cometary sampling and composi-n tion experiment on Philae. Space Science Reviews 128 (2007), 257-280. [3] Meierhenrich U.J.: Amino Acids and the Asymmetry of Life -Caught in the Act of Forma-tion. Springer, Heidelberg Berlin New York (2008).

Efficacy of combining flexible and rigid ureteroscopy for transurethral lithotripsy.

PubMed

Shigemura, Katsumi; Yasufuku, Tomihiko; Yamashita, Masuo; Arakawa, Soichi; Fujisawa, Masato

2010-08-23

Transurethral lithotripsy (TUL) is a common procedure in urology. However, controversy persists about how to deal with stones pushed up into kidney from the ureter during the procedure of TUL. This study investigated the efficacy of combining flexible ureteroscopy and rigid ureteroscopy for pushed-up stones into kidney during TUL. Fotry-one patients underwent TUL by a single surgeon from July 2007 to May 2009. Eight cases resulted in pushed-up stones during operation or involved existing kidney stones. We used a Zero-tip or Litho Catch Basket catheter and a flexible ureteroscope to carry these stones in kidney down into the ureter where the rigid ureteroscope could then reach and handle the stone for lithotripsy or being taken away. A Lithoclast system was used for lithotripsy. Five cases involved stones pushed up during surgery and 3 cases involved stones already in the kidney in detail. We pulled the stones down into the ureter in all cases and successfully completed lithotripsy or removed the stone, thus avoiding the performance of additional extracorporeal shock wave lithotripsy (ESWL). In conclusions, combined use of flexible ureteroscopy and rigid ureteroscopy for upper urinary tract stones pushed up into the kidney during TUL or renal stones could be useful for avoiding additional ESWL.

Nephrolithiasis: Molecular Mechanism of Renal Stone Formation and the Critical Role Played by Modulators

PubMed Central

Aggarwal, Kanu Priya; Narula, Shifa; Kakkar, Monica

2013-01-01

Urinary stone disease is an ailment that has afflicted human kind for many centuries. Nephrolithiasis is a significant clinical problem in everyday practice with a subsequent burden for the health system. Nephrolithiasis remains a chronic disease and our fundamental understanding of the pathogenesis of stones as well as their prevention and cure still remains rudimentary. Regardless of the fact that supersaturation of stone-forming salts in urine is essential, abundance of these salts by itself will not always result in stone formation. The pathogenesis of calcium oxalate stone formation is a multistep process and essentially includes nucleation, crystal growth, crystal aggregation, and crystal retention. Various substances in the body have an effect on one or more of the above stone-forming processes, thereby influencing a person's ability to promote or prevent stone formation. Promoters facilitate the stone formation while inhibitors prevent it. Besides low urine volume and low urine pH, high calcium, sodium, oxalate and urate are also known to promote calcium oxalate stone formation. Many inorganic (citrate, magnesium) and organic substances (nephrocalcin, urinary prothrombin fragment-1, osteopontin) are known to inhibit stone formation. This review presents a comprehensive account of the mechanism of renal stone formation and the role of inhibitors/promoters in calcium oxalate crystallisation. PMID:24151593

Diversity in Protein Profiles of Individual Calcium Oxalate Kidney Stones

PubMed Central

Okumura, Nobuaki; Tsujihata, Masao; Momohara, Chikahiro; Yoshioka, Iwao; Suto, Kouzou; Nonomura, Norio; Okuyama, Akihiko; Takao, Toshifumi

2013-01-01

Calcium oxalate kidney stones contain low amounts of proteins, some of which have been implicated in progression or prevention of kidney stone formation. To gain insights into the pathophysiology of urolithiasis, we have characterized protein components of calcium oxalate kidney stones by proteomic approaches. Proteins extracted from kidney stones showed highly heterogeneous migration patterns in gel electrophoresis as reported. This was likely to be mainly due to proteolytic degradation and protein-protein crosslinking of Tamm-Horsfall protein and prothrombin. Protein profiles of calcium oxalate kidney stones were obtained by in-solution protease digestion followed by nanoLC-MALDI-tandem mass spectrometry, which resulted in identification of a total of 92 proteins in stones from 9 urolithiasis patients. Further analysis showed that protein species and their relative amounts were highly variable among individual stones. Although proteins such as prothrombin, osteopontin, calgranulin A and calgranulin B were found in most stones tested, some samples had high contents of prothrombin and osteopontin, while others had high contents of calgranulins. In addition, calgranulin-rich stones had various neutrophil-enriched proteins such as myeloperoxidase and lactotransferrin. These proteomic profiles of individual kidney stones suggest that multiple systems composed of different groups of proteins including leucocyte-derived ones are differently involved in pathogenesis of individual kidney stones depending on situations. PMID:23874695

Metabolic syndrome: a multifaceted risk factor for kidney stones.

PubMed

Domingos, Fernando; Serra, Adelaide

2014-10-01

Kidney stones and metabolic syndrome (MetS) are common conditions in industrialized countries. There is growing evidence of associations between kidney stone disease and MetS or some of its components. The link between uric acid stones and MetS is well understood, but the link with calcium oxalate (CaOx) stones, the most common kidney stone composition, is more complex, and MetS is frequently overlooked as a risk factor for calcium nephrolithiasis. The physiopathological mechanisms of kidney stone disease in MetS are reviewed in this article. Uric acid stones are a consequence of the excessively acidic urine that results from insulin resistance. The pathophysiology of CaOx stones may include: increased excretion of lithogenesis promoters and decreased excretion of inhibitors; increased risk of Randall's plaque development; and inflammatory damage to renal epithelia by oxidative stress, as a consequence of the insulin-resistant milieu that characterizes MetS. The last mechanism contributes to the adhesion of CaOx crystals to subepithelial calcium deposits working as anchor sites where stones can grow. The predominant MetS features could determine the chemical composition of the stones in each patient. Kidney stones may be a renal manifestation of MetS and features of this syndrome should be looked for in patients with idiopathic nephrolithiasis.

Stone orientation affects the mechanism of failure in artificial kidney stones subject to shock waves

NASA Astrophysics Data System (ADS)

van Cauwelaert, Javier; Cleveland, Robin O.

2003-10-01

Micro computed tomography (CT) imaging was used to follow the progressive development of cracks in artificial kidney stones. The artificial stones were made from U30 cement with a cylindrical shape (6.5 mm diameter and 8.5 mm long). The stones were held within a polypropylene vial in one of three orientations: vertical, horizontal, and angled at 45 deg. The stones were treated with an electromagnetic lithotripter and the initiation and growth of cracks was observed using microCT. The images show that the orientation of the stones with respect to the shock changes the dominant mechanism for fragmentation. Vertical stones developed a spall-like crack near the distal surface, which propagated from the surface to the interior of the stone. Initiation of a secondary spall-like crack was observed proximal to the first crack. Little surface damage was observed. Horizontal stones presented pitting in the proximal surface and erosion in lateral faces, indicating the action of cavitation. Angled stones presented both spall-like fracture in either the leading or the distal corners and surface damage (pitting) in the proximal surface. Experiments are being performed to follow the development of cracks in human kidney stones. [Work supported by the Whitaker Foundation.

Changes in urinary stone composition in the Tunisian population: a retrospective study of 1,301 cases.

PubMed

Alaya, Akram; Nouri, Abdellatif; Belgith, Mohsen; Saad, Hammadi; Jouini, Riadh; Najjar, Mohamed Fadhel

2012-05-01

Studies that evaluate the effect of age on stone composition are scarce. The aim of this study was to highlight the changes in epidemiological characteristics (stone composition and location) of urolithiasis according to patients' age. We studied 1,301 urolithiasis patients with age ranging from 6 months to 92 yr (781 males and 520 females). Stone analysis was performed using a stereomicroscope and infrared spectroscopy to determine the morphological type and molecular composition of each stone. The annual average incidence of new stone formation was 31.7 per 100,000 persons. In 71.8% of cases, calculi were located in the upper urinary tract. Compared to other age groups, children and old men were more affected by bladder stones. Calcium oxalate monohydrate was the most frequent stone component, even though its frequency decreased with age (59.5% in young adults and 43.7% in the elderly, P<0.05) in favor of an increase in uric acid stones (11.5% in young adults and 36.4% in the elderly, P<0.05). Struvite stones were rare (3.8%) and more frequent in children than in adults. The analysis of these data showed that urinary stones in Tunisian patients are tending to evolve in the same direction as the stones in patients from industrialized countries.

Impaction and Prediction: Does Ureteral Wall Thickness Affect the Success of Medical Expulsive Therapy in Pediatric Ureteral Stones?

PubMed

Tuerxun, Aierken; Batuer, Abudukahaer; Erturhan, Sakip; Eryildirim, Bilal; Camur, Emre; Sarica, Kemal

2017-01-01

The study aimed to evaluate the predictive value of ureteral wall thickness (UWT) and stone-related parameters for medical expulsive therapy (MET) success with an alpha blocker in pediatric upper ureteral stones. A total of 35 children receiving MET ureteral stones (<10 mm) were evaluated. Patients were divided into 2 subgroups where MET was successful in 18 children (51.4%) and unsuccessful in 17 children (48.6%). Prior to management, stone size, stone density (in Hounsfield unit), degree of hydronephrosis, and UWT were evaluated with patient demographics and recorded. The possible predictive value of these parameters in success rates and time to stone expulsion were evaluated in a comparative manner between the 2 groups. The overall mean patient age and stone size values were 5.40 ± 0.51 years and 6.24 ± 0.28 mm, respectively. Regarding the predictive values of these parameters for the success of MET, while stone size and UWT were found to be highly predictive for MET success, patients age, body mass index, stone density, and degree of hydronephrosis had no predictive value on this aspect. Our findings indicated that some stone and anatomical factors may be used to predict the success of MET in pediatric ureteral stones in an effective manner. With this approach, unnecessary use of these drugs that may cause a delay in removing the stone will be avoided, and the possible adverse effects of obstruction as well as stone-related clinical symptoms could be minimized. © 2017 S. Karger AG, Basel.

First in Human Clinical Trial of Ultrasonic Propulsion of Kidney Stones.

PubMed

Harper, Jonathan D; Cunitz, Bryan W; Dunmire, Barbrina; Lee, Franklin C; Sorensen, Mathew D; Hsi, Ryan S; Thiel, Jeff; Wessells, Hunter; Lingeman, James E; Bailey, Michael R

2016-04-01

Ultrasonic propulsion is a new technology using focused ultrasound energy applied transcutaneously to reposition kidney stones. We report what are to our knowledge the findings from the first human investigational trial of ultrasonic propulsion toward the applications of expelling small stones and dislodging large obstructing stones. Subjects underwent ultrasonic propulsion while awake without sedation in clinic, or during ureteroscopy while anesthetized. Ultrasound and a pain questionnaire were completed before, during and after propulsion. The primary outcome was to reposition stones in the collecting system. Secondary outcomes included safety, controllable movement of stones and movement of stones less than 5 mm and 5 mm or greater. Adverse events were assessed weekly for 3 weeks. Kidney stones were repositioned in 14 of 15 subjects. Of the 43 targets 28 (65%) showed some level of movement while 13 (30%) were displaced greater than 3 mm to a new location. Discomfort during the procedure was rare, mild, brief and self-limited. Stones were moved in a controlled direction with more than 30 fragments passed by 4 of the 6 subjects who had previously undergone a lithotripsy procedure. The largest stone moved was 10 mm. One patient experienced pain relief during treatment of a large stone at the ureteropelvic junction. In 4 subjects a seemingly large stone was determined to be a cluster of small passable stones after they were moved. Ultrasonic propulsion was able to successfully reposition stones and facilitate the passage of fragments in humans. No adverse events were associated with the investigational procedure. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Inaccurate reporting of mineral composition by commercial stone analysis laboratories: implications for infection and metabolic stones.

PubMed

Krambeck, Amy E; Khan, Naseem F; Jackson, Molly E; Lingeman, James E; McAteer, James A; Williams, James C

2010-10-01

We determined the accuracy of stone composition analysis at commercial laboratories. A total of 25 human renal stones with infrared spectroscopy determined composition were fragmented into aliquots and studied with micro computerized tomography to ensure fragment similarity. Representative fragments of each stone were submitted to 5 commercial stone laboratories for blinded analysis. All laboratories agreed on the composition of 6 pure stones. Only 2 of 4 stones (50%) known to contain struvite were identified as struvite at all laboratories. Struvite was reported as a component by some laboratories for 4 stones previously determined not to contain struvite. Overall there was disagreement regarding struvite in 6 stones (24%). For 9 calcium oxalate stones all laboratories reported some mixture of calcium oxalate but the quantity of subtypes differed significantly among laboratories. In 6 apatite containing stones apatite was missed by the laboratories in 20% of samples. None of the laboratories identified atazanavir in a stone containing that antiviral drug. One laboratory reported protein in every sample while all others reported it in only 1. Nomenclature for apatite differed among laboratories with 1 reporting apatite as carbonate apatite and never hydroxyapatite, another never reporting carbonate apatite and always reporting hydroxyapatite, and a third reporting carbonate apatite as apatite with calcium carbonate. Commercial laboratories reliably recognize pure calculi. However, variability in the reporting of mixed calculi suggests a problem with the accuracy of stone analysis results. There is also a lack of standard nomenclature used by laboratories. Copyright © 2010 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

INACCURATE REPORTING OF MINERAL COMPOSITION BY COMMERCIAL STONE ANALYSIS LABORATORIES: IMPLICATIONS FOR INFECTION AND METABOLIC STONES

PubMed Central

Krambeck, Amy E.; Khan, Naseem F.; Jackson, Molly E.; Lingeman, James E.; McAteer, James A; Williams, James C.

2011-01-01

INTRODUCTION The goal of this study was to determine the accuracy of stone composition analysis by commercial laboratories. METHODS 25 human renal stones with infrared spectroscopy (IR) determined compositions were fragmented into aliquots and studied with micro-computed tomography (CT) to ensure fragment similarity. Representative fragments of each stone were submitted to 5 commercial stone laboratories for blinded analysis. RESULTS All laboratories agreed on composition for 6 pure stones. Of 4 stones known to contain struvite, only 2(50%) were identified as struvite by all laboratories. Struvite was reported as a component by some laboratories for 4 stones previously determined not to contain struvite. Overall, there was disagreement regarding struvite in 6(24%) stones. For 9 calcium oxalate (CaOx) stones, all laboratories reported some mixture of CaOx, but the quantities of subtypes differed significantly among laboratories. In 6 apatite containing stones, apatite was missed by the laboratories in 20% of the samples. None of the laboratories identified atazanavir in a stone containing that antiviral drug. One laboratory reported protein in every sample, while all others reported it in only 1 sample. Nomenclature for apatite differed among laboratories, with one reporting apatite as carbonate apatite (CA) and never hydroxyapatite (HA), another never reporting CA and always reporting HA, and a third reporting CA as apatite with calcium carbonate. CONCLUSIONS Commercial laboratories reliably recognize pure calculi; however, variability in reporting of mixed calculi suggests a problem with accuracy of stone analysis results. Furthermore, there is a lack of standard nomenclature used by laboratories. PMID:20728108

Lessons from a Stone Farm

NASA Astrophysics Data System (ADS)

Kavanagh, John P.; Rao, P. Nagaraj

2007-04-01

The stone farm is a system for measuring macroscopic stone growth of 12 calcium stones simultaneously. It is based on mixed suspension, mixed product removal continuous crystallization principles and the stones are grown continuously for about 500 hours or more. The growth of the stones follows a surface area dependent pattern and the growth rate constants are very similar irrespective of whether the stating materials are fragments of human stone or pieces of marble chip. Increasing citrate from 2mM to 6mM caused a significant growth inhibition which persisted in the presence of urinary macromolecules. Phytate was a very effective inhibitor (about 50% at sub-μM concentrations) but the effective concentration was increased by an order of magnitude in the presence of urinary macromolecules. The effective concentration for inhibition in a crystallization assay was a further two orders of magnitude higher. Urinary macromolecules or almost whole urine were also strongly inhibitory although neither human serum albumin nor bovine mucin had any great effect. The relationship between the size distribution of crystals in suspension and the stone enlargement rate suggests that the primary enlargement mechanism for these in vitro stones is through aggregation. The stone farm is a powerful tool with which to study crystallization inhibitors in a new light. Some differences between inhibition of crystallization and inhibition of stone growth have emerged and we have obtained quantitative evidence on the mechanism of stone enlargement in vitro. Our findings suggest that the interface between crystals in suspension and the stone surface is the key to controlling stone enlargement.

Urinary Tract Stones and Osteoporosis: Findings From the Women's Health Initiative.

PubMed

Carbone, Laura D; Hovey, Kathleen M; Andrews, Christopher A; Thomas, Fridtjof; Sorensen, Mathew D; Crandall, Carolyn J; Watts, Nelson B; Bethel, Monique; Johnson, Karen C

2015-11-01

Kidney and bladder stones (urinary tract stones) and osteoporosis are prevalent, serious conditions for postmenopausal women. Men with kidney stones are at increased risk of osteoporosis; however, the relationship of urinary tract stones to osteoporosis in postmenopausal women has not been established. The purpose of this study was to determine whether urinary tract stones are an independent risk factor for changes in bone mineral density (BMD) and incident fractures in women in the Women's Health Initiative (WHI). Data were obtained from 150,689 women in the Observational Study and Clinical Trials of the WHI with information on urinary tract stones status: 9856 of these women reported urinary tract stones at baseline and/or incident urinary tract stones during follow-up. Cox regression models were used to determine the association of urinary tract stones with incident fractures and linear mixed models were used to investigate the relationship of urinary tract stones with changes in BMD that occurred during WHI. Follow-up was over an average of 8 years. Models were adjusted for demographic and clinical factors, medication use, and dietary histories. In unadjusted models there was a significant association of urinary tract stones with incident total fractures (HR 1.10; 95% CI, 1.04 to 1.17). However, in covariate adjusted analyses, urinary tract stones were not significantly related to changes in BMD at any skeletal site or to incident fractures. In conclusion, urinary tract stones in postmenopausal women are not an independent risk factor for osteoporosis. © 2015 American Society for Bone and Mineral Research.

The clinical research office of the endourological society percutaneous nephrolithotomy global study: staghorn versus nonstaghorn stones.

PubMed

Desai, Mahesh; De Lisa, Antonello; Turna, Burak; Rioja, Jorge; Walfridsson, Helena; D'Addessi, Alessandro; Wong, Carson; Rosette On Behalf Of The Croes Pcnl Study Group, Jean

2011-08-01

The study compared characteristics and outcomes in patients with staghorn or nonstaghorn stones who were treated with percutaneous nephrolithotomy (PCNL) within the Clinical Research Office of the Endourological Society (CROES) PCNL Global Study. Data over a 1-year period from consecutively treated patients from 96 centers worldwide were collated. The following variables in patients with staghorn or nonstaghorn stones were compared: National prevalence, patient characteristics, access method, puncture frequency and outcomes, including bleeding rates, operative time, and duration of hospital stay. Data from 5335 eligible patients were collated; 1466 (27.5%) with staghorn and 3869 (72.5%) with nonstaghorn stones. Staghorn stone presentation varied between centers from 67% in Thailand to 13% in Argentina. The frequencies of previous procedures were similar between groups, but shockwave lithotripsy was less frequent in patients with staghorn stones compared with nonstaghorn (16.8% vs 22.6%) and positive preoperative urine cultures were more frequent in patients with staghorn than nonstaghorn stones (23.4% vs 13.1%). Patients with staghorn stones underwent multiple punctures more frequently than those with nonstaghorn stones (16.9% vs 5.0%). Postoperative fever, bleeding, and the need for blood transfusion were more frequent, the median operative time and duration of hospital stay were longer, while the proportion of patients remaining stone free was lower (56.9% vs 82.5%) in patients with staghorn than nonstaghorn stones. The proportion of patients with staghorn stones varies widely between centers. Stone-free rates were lower, complications more frequent, and operative time and hospital stay were longer in patients with staghorn stones.

Natural History of Conservatively Managed Ureteral Stones: Analysis of 6600 Patients.

PubMed

Yallappa, Sachin; Amer, Tarik; Jones, Patrick; Greco, Francesco; Tailly, Thomas; Somani, Bhaskar K; Umez-Eronini, Nkem; Aboumarzouk, Omar M

2018-05-01

Ureteral colic has a lifetime prevalence of 10%-15% and is one of the most common emergency urologic presentations. Current European Association of Urology recommends conservative management for "small" (<6 mm) ureteral stones if active removal is not indicated. It is important to understand the natural history of ureteral stone disease to help counsel patients with regard to their likelihood of stone passage and anticipated time frame with which they could be safely observed. We aimed to conduct a systematic review to better establish the natural history of stone expulsion. Literature search was performed using Cochrane and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines. Outcome measures were patient and stone demographics, expulsion rates, expulsion times, and side effect of the medication. A cumulative analysis, with subgroup analysis, was performed on stone location and size. The results were depicted as percentages and an intention-to-treat basis was used. The literature search identified 70 studies and a total of 6642 patients, with a median age of 46 and range of 18-74 years. Overall, 64% of patients successfully passed their stones spontaneously. About 49% of upper ureteral stones, 58% of midureteral stones, and 68% of distal ureteral stones passed spontaneously. Almost 75% of stones <5 mm and 62% of stones ≥5 mm passed spontaneously. The average time to stone expulsion was about 17 days (range 6-29 days). Nearly 5% of participants required rehospitalization due to a deterioration of their condition and only about 1% of patients experienced side effects from analgesia provided. We believe this current review is the largest study for the evaluation of natural history of ureteral stones. The evidence suggests that ureteral stones will pass without intervention in 64% of patients, however, this varies from nearly 50%-75% depending on the size and location, in the span of 1-4 weeks.

Protecting Space Travelers from Kidney Stones: Renal Stone Risk During Space Flight

NASA Technical Reports Server (NTRS)

Whitson, Peggy; Bloomberg, Jacob; Lee, Angie (Technical Monitor)

2002-01-01

Renal stones, popularly known as kidney or bladder stones, are small rock-like objects formed in the kidneys or urinary tract by deposits of calcium and other minerals. The problem arises when the stones block the drainage of the kidney, resulting in urinary obstruction and pain. Passing these stones can be one of the most painful experiences a person will endure so doctors often prescribe pain relievers to ease the experience. Drinking plenty of fluids, which help flush waste out of the body, and eating a well-balanced diet are the first steps to preventing stones. For individuals at risk, this may not be enough, and a doctor may recommend a special diet and medications. Unfortunately, approximately 60 percent of people who have had a renal stone will experience a recurrence. This is particularly true of men, who are four to five times more likely to develop stones than women. Renal stones do not discriminate based on age; even children are at risk. Astronauts are particularly at risk of developing renal stones because they lose bone and muscle mass; calcium, other minerals, and protein normally used for bone and muscle end up in the bloodstream and then in the kidneys. Without plenty of fluid to wash them away, crystals can form and then grow into stones. This factor compounds the risk for astronauts, since they also perceive that they are less thirsty in space and will drink less than normal during the mission. To minimize all of these factors, doctors must instead treat the stone-forming compounds with medication. This study will use potassium citrate to reduce the risk of stone formation. Renal stones are never convenient, but they are a particular concern for astronauts who have limited access to treatment during flight. Researchers are examining how earthbound preventions for renal stone formation work in flight, ensuring missions are not ended prematurely due to this medical condition. During STS-107, earthbound preventions and treatments become astronauts' gain.

A clinical nomogram to predict the successful shock wave lithotripsy of renal and ureteral calculi.

PubMed

Wiesenthal, Joshua D; Ghiculete, Daniela; Ray, A Andrew; Honey, R John D'A; Pace, Kenneth T

2011-08-01

Although shock wave lithotripsy is dependent on patient and stone related factors, there are few reliable algorithms predictive of its success. In this study we develop a comprehensive nomogram to predict renal and ureteral stone shock wave lithotripsy outcomes. During a 5-year period data from patients treated at our lithotripsy unit were reviewed. Analysis was restricted to patients with a solitary renal or ureteral calculus 20 mm or less. Demographic, stone, patient, treatment and 3-month followup data were collected from a prospective database. All patients were treated using the Philips Lithotron® lithotripter. A total of 422 patients (69.7% male) were analyzed. Mean stone size was 52.3±39.3 mm2 for ureteral stones and 78.9±77.3 mm2 for renal stones, with 95 (43.6%) of the renal stones located in the lower pole. The single treatment success rates for ureteral and renal stones were 60.3% and 70.2%, respectively. On univariate analysis predictors of shock wave lithotripsy success, regardless of stone location, were age (p=0.01), body mass index (p=0.01), stone size (p<0.01), mean stone density (p<0.01) and skin to stone distance (p<0.01). By multivariate logistic regression for renal calculi, age, stone area and skin to stone distance were significant predictors with an AUC of 0.75. For ureteral calculi predictive factors included body mass index and stone size (AUC 0.70). Patient and stone parameters have been identified to create a nomogram that predicts shock wave lithotripsy outcomes using the Lithotron lithotripter, which can facilitate optimal treatment based decisions and provide patients with more accurate single treatment success rates for shock wave lithotripsy tailored to patient specific situations. Copyright © 2011 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Study of stone composition changes in melamine-related urinary calculi and its clinical significance.

PubMed

Li, Yuan; Chen, YiRong; Zhang, Wei; Huang, XiaoGang; Li, WenHui; Ru, XiaoRui; Meng, Min; Xi, Xinsheng; Huang, Gang; Shi, BaoGuang; Liu, Gang; Li, WeiHua; Xu, Hui

2011-08-01

To investigate the composition changes in melamine-related urinary calculi and their clinical significance. A total of 49 melamine-related urinary calculi were included from 49 children (age 4-82 months, mean 22). The qualitative analysis of stone composition was determined using Fourier transform infrared. The quantitative analysis of the stone computed tomography (CT) attenuation value, stone uric acid level, and stone calcium level were measured using spiral CT, high-performance liquid chromatography, and flame atomic absorption spectrum, respectively. Fourier transform infrared showed that 41 (84%) of the 49 stones contained uric acid and 25 (51%) contained calcium compounds. The data from the qualitative and quantitative analysis were available for 15 stones because of sample consumption in the detection process (Fourier transform infrared, atomic absorption spectrum, and high-performance liquid chromatography). A negative correlation was observed between stone uric acid level and stone calcium level (n = 15, r = -0.629, P = .009). A positive correlation was observed between the stone calcium level and stone CT attenuation value (n = 25, r = 0.855, P = .000). Compared with the ≤1-year-age group and the 1-2-year-age group, the stone calcium level in the >2-year-age group was significantly greater (27.51% ± 12.65% vs 1.60% ± 1.68% or 10.12% ± 8.69%, P = .000 and P = .003, respectively). Compared with the alkalization-alone group, the stone calcium level in the nonalkalization-alone group was significant greater (19.83% ± 7.48% vs 1.25% ± 1.43%, n = 19, P = .000). The stones from children >2 years old were not amenable to medical treatment because they contained greater levels of calcium, which can be demonstrated by the radiologic "positive stone image" or stone CT attenuation value. We believe that surgical invention will be the best choice for such patients if extracorporeal shock wave lithotripsy has failed. Copyright © 2011 Elsevier Inc. All rights reserved.

Prevalence of kidney stones in the United States.

PubMed

Scales, Charles D; Smith, Alexandria C; Hanley, Janet M; Saigal, Christopher S

2012-07-01

The last nationally representative assessment of kidney stone prevalence in the United States occurred in 1994. After a 13-yr hiatus, the National Health and Nutrition Examination Survey (NHANES) reinitiated data collection regarding kidney stone history. Describe the current prevalence of stone disease in the United States, and identify factors associated with a history of kidney stones. A cross-sectional analysis of responses to the 2007-2010 NHANES (n=12 110). Self-reported history of kidney stones. Percent prevalence was calculated and multivariable models were used to identify factors associated with a history of kidney stones. The prevalence of kidney stones was 8.8% (95% confidence interval [CI], 8.1-9.5). Among men, the prevalence of stones was 10.6% (95% CI, 9.4-11.9), compared with 7.1% (95% CI, 6.4-7.8) among women. Kidney stones were more common among obese than normal-weight individuals (11.2% [95% CI, 10.0-12.3] compared with 6.1% [95% CI, 4.8-7.4], respectively; p<0.001). Black, non-Hispanic and Hispanic individuals were less likely to report a history of stone disease than were white, non-Hispanic individuals (black, non-Hispanic: odds ratio [OR]: 0.37 [95% CI, 0.28-0.49], p<0.001; Hispanic: OR: 0.60 [95% CI, 0.49-0.73], p<0.001). Obesity and diabetes were strongly associated with a history of kidney stones in multivariable models. The cross-sectional survey design limits causal inference regarding potential risk factors for kidney stones. Kidney stones affect approximately 1 in 11 people in the United States. These data represent a marked increase in stone disease compared with the NHANES III cohort, particularly in black, non-Hispanic and Hispanic individuals. Diet and lifestyle factors likely play an important role in the changing epidemiology of kidney stones. Published by Elsevier B.V.

Determining the composition of urinary tract calculi using stone-targeted dual-energy CT: evaluation of a low-dose scanning protocol in a clinical environment

PubMed Central

Chaytor, Richard J; Rajbabu, Krishnamoorthy; Jones, Paul A

2016-01-01

Objective: This study will evaluate the accuracy of dual-energy CT (DECT) in characterizing urinary tract stone composition on patients presenting to a UK hospital with renal colic. The study will also assess the additional radiation dose burden of DECT over standard protocol. Methods: Data from 106 DECTs between October 2011 and October 2015 were retrospectively analyzed. Patients were imaged using a Toshiba Aquilion ONE™ CT scanner (Toshiba Medical Systems, Otawara-shi, Japan). All patients received a low-dose non-contrast CT of the abdomen and pelvis prior to stone-targeted DECT at 80 and 135 kVp and 40-mm field of view. Radiation dose output was evaluated using dose–length product (DLP). 19 stones were recovered and their compositions were analyzed using Fourier transform infrared spectroscopy. Results: 137 stones were characterized. Mean stone diameter was 8.8 mm (range 3–48 mm). There was an 18.7% increase in mean DLP for DECT over standard CT protocol (319.4 vs 269.1 mGy cm; p < 0.001). Infrared spectroscopy analysis of 19 recovered stones identified 15 stones as calcium, 2 stones as cystine and 2 stones as mixed composition. Dual energy correctly predicted 11 (78.6%) of 14 calcium stones, 2 (100%) of 2 mixed composition stones and 0 (0%) of 2 cystine stones, resulting in a fair agreement (Cohen's κ = 0.374, p = 0.009). Conclusion: DECT is able to determine the composition of urinary tract stones with fair accuracy. Its utility is offset by a small but significant supplementary radiation exposure. Advances in knowledge: DECT can provide urological surgeons with useful diagnostic stone material information prior to planning optimal management of stone disease. PMID:27587309

Ureteroscopy

MedlinePlus

Ureteral stone surgery; Kidney stone - ureteroscopy; Ureteral stone removal - ureteroscopy; Calculi - ureteroscopy ... sent through the scope to grab and remove kidney stones or break them up using a laser. Place ...

Gender Distribution of Pediatric Stone Formers

NASA Astrophysics Data System (ADS)

Novak, Thomas E.; Trock, Bruce J.; Lakshmanan, Yegappan; Gearhart, John P.; Matlaga, Brian R.

2008-09-01

Recent epidemiologic evidence suggests that the gender prevalence among adult stone-formers is changing, with an increasing incidence of stone disease among women. No similar data have ever been reported for the pediatric stone-forming population. We performed a study to define the gender distribution among pediatric stone-formers using a large-scale national pediatric database. Our findings suggest that gender distribution among stone formers varies by age with male predominance in the first decade of life shifting to female predominance in the second decade. In contrast to adults, females in the pediatric population are more commonly affected by stones than are males. The incidence of pediatric stone disease appears to be increasing at a great rate in both sexes. Further studies should build on this hypothesis-generating work and define the effects of metabolic and environmental risk factors that may influence stone risk in the pediatric patient population

The sports science of curling: a practical review.

PubMed

Bradley, John L

2009-01-01

Curling is a sport played on ice in which two teams each deliver 8 granite stones towards a target, or 'house'. It is the only sport in which the trajectory of the projectile can be influenced after it has been released by the athlete. This is achieved by sweeping the ice in front of the stone to change the stone-ice friction and thereby enable to stone to travel further, curl more or stay straight. Hard sweeping is physically demanding. Different techniques of sweeping can also have different effects on the stone. This paper will review the current research behind sweeping a curling stone, outline the physiological demands of sweeping, the associated performance effects and suggest potential strategies of sweeping that can be used by both coaches and curling teams. Key pointsSweeping a curling stone can be highly physically demanding.Effective sweeping requires a combination of downward force and brush head speed, determined by the stone velocity.Sweeping on the left or right of a stone can help the stone to remain straight or curl more depending on the rotation of the stone.This can lead to the development of sweeping and playing tactics and contribute to team selection.