bluuebunny/crossref_metadata_2025 huggingface dataset:
Caring for patients with congenital cardiac disease – Introduction
Authors: Jacobs Jeffrey P.
Published: September 2005

The sixth, and final, section of this Supplement is titled “Caring for Patients with Congenital Cardiac Disease”. In it, we have included reviews that address a variety of issues related to caring for patients with congenital cardiac disease, including analysis of data, training, organization of the cardiac intensive care unit, quality of life, intraoperative imaging, and databases relating to congenital cardiac malformations. The purpose of this section of the Supplement is to take time to ponder the future of our professions, and what will be required to improve this future. My own belief is that, to quote the American football coach Jon Gruden, “I think the future's so bright here I've got to wear shades (sunglasses)”.1 Still, we all must work, ideally together, to ensure this bright future. This final section of the Supplement reviews several ideas and concepts which are representative of areas that our professional collaboration and work will lead to a better future for both patients with congenital cardiac disease, and the professionals caring for these often challenging patients. Indeed, part of being a Professional is self-regulating the profession, and taking measures to improve the state of the art in this profession, and in the process, “raising the bar”.
Data, dogma, or latest fashion? How scientific meetings and peer-reviewed literature affect cardiac surgical practice
Authors: Spray Thomas L.
Published: September 2005

For many years, surgeons have been able to implement new techniques and treatments with minimal oversight. Although regulatory control over application of new strategies for treatment is far different today, surgeons have enjoyed a greater degree of freedom than other specialists. The laboratory of the surgeon, and particularly the congenital cardiac surgeon, is often the operating room, since appropriate animal models are not available. Thus, the congenital cardiac surgeon has often been stimulated to modify existing techniques, or create new surgical approaches, to improve the perceived limitations of previously known surgical strategies.1 The introduction of a new surgical technique has often taken the strong ego and persistence of a surgical innovator, and has subjected the surgeon to criticism from medical colleagues. Although innovation is a proud heritage of the development of congenital cardiac, it now seems appropriate, as we are more cognizant of the past accomplishments in the development of repairs for congenital cardiac malformations, to evaluate how surgical techniques become widely adopted, often with only minimal data to suggest improvement over previously accepted procedures.
I wasn't trained for this!
Authors: Elliott Martin J.
Published: September 2005

As once observed by Tom Spray, “When they invite you to give the history talk, you're finished!” Those words flashed through my mind when I was invited to deliver the version of the lecture celebrating George Daicoff, and forced me to think carefully about what I do, and what I believe about doing it. I have been doing cardiac surgery for 25 years, and paediatric cardiac surgery for 20 of those. Looking back, it would be tempting to think that I am here to follow in the illustrious footsteps of Kirklin, Debakey, Lillehei, Cooley, Ross, Yacoub or Daicoff. But I have to admit that would not be the truth. I was more influenced by Dr Kildare and M.A.S.H., driven by the drama of their lives and the beauty of their nurses. I have not been disappointed.
Common problems and their solutions in paediatric cardiac intensive care
Authors: Chang Anthony C.
Published: September 2005

There are many daunting challenges that need to be met by any seeking to achieve leadership in the area of cardiac intensive care. Paediatric cardiac intensive care has now emerged as a specialized clinical area, focusing on the unique needs of critically-ill neonates, children, and adults with congenital and acquired heart disease.1 Although an increasing number of centres dealing with paediatric cardiology have either started, or are considering starting, a dedicated cardiac intensive care unit and programme, there are no published primers regarding the logistical aspects of such a challenging endeavour. While there may be an ongoing debate about the preferred strategy in the clinical ownership of the patients treated in intensive care, most authorities agree that it is beneficial to have a dedicated team devoted to the needs of critically-ill children and adults with congenital and acquired cardiac disease.
The hows and whys of intraoperative imaging
Authors: Elliott Martin J. , Kanani Mazyar
Published: September 2005

The detail of cardiac morphology, with its subtle complexity and variation, is difficult to convey to colleagues and families, and even more time-consuming to learn. The terminology is occasionally unresolved, visual representations challenging, and there is often a mismatch between the presentation of the defect by the morphologist, the echocardiographic impression gained by the cardiologist, and the view obtained by the surgeon in the operating room. It can be said, therefore, that size, complexity and three-dimensional configuration, the three most important concepts to grasp when describing the congenitally malformed heart, are seldom touched upon with traditional illustrations or texts.
The current status and future directions of efforts to create a global database for the outcomes of therapy for congenital heart disease
Authors: Jacobs Jeffrey P. , Maruszewski Bohdan , Tchervenkov Christo I. , Lacour-Gayet Francois G. , Jacobs Marshall L. , Clarke David R. , Gaynor J. William , Spray Thomas L. , Stellin Giovanni , Elliott Martin J. , Ebels Tjark , Franklin Rodney C. G. , Béland Marie J. , Kurosawa Hiromi , Aiello Vera D. , Colan Steven D. , Krogmann Otto N. , Weinberg Paul , Tobota Zdzislaw , Dokholyan Rachel S. , Peterson Eric D. , Mavroudis Constantine
Published: September 2005

There are many reasons for seeking to create a global database with which to record the outcomes of therapy for congenital heart disease. Such a database can function as a tool to support a variety of purposes:
Introduction to the Supplement
Authors: Jacobs J. P.
Published: September 2005

Florida is the fourth largest state in the United States of America. “Heart Week in Florida” is a joint collaborative project sponsored by The Children's Hospital of Philadelphia and The Congenital Heart Institute of Florida. The cardiac programme of Children's Hospital of Philadelphia is one of the largest and most prestigious comprehensive cardiac programmes in the world. The Congenital Heart Institute of Florida is the largest programme providing services for patients with congenital cardiac disease in Florida. Both institutions are very grateful to Bob Anderson, and the team at Cardiology in the Young, for their support of “Heart Week in Florida”, and for the opportunity to publish this Supplement. Bob Anderson was a valued faculty member, and tremendous supporter, of both the fourth annual International Symposium on Congenital Heart Disease held at All Children's Hospital and University of South Florida, and the seventh annual Update on Pediatric Cardiovascular Disease organized by Children's Hospital of Philadelphia.
Spatial dynamics of homochiralization
Authors: Multamäki Tuomas , Brandenburg Axel
Published: September 2005

The emergence and spread of chirality on the early Earth is considered by studying a set of reaction-diffusion equations based on a polymerization model. It is found that effective mixing of the early oceans is necessary to reach the present homochiral state. The possibility of introducing mass extinctions and modifying the emergence rate of life are discussed.
Chirality in the RNA world and beyond
Authors: Sandars P.G.H.
Published: September 2005

Homochirality is an essential feature of biology, but how it developed in early life remains unclear. Our aim in this paper is to add to the discussion by taking a somewhat arbitrary but definite sequence of events and examining carefully the chirality at each stage. Our scenario for the development of life starts with the prebiotic, continues through a pre-RNA stage to the RNA world. This leads to the development of proteins and then to the incorporation of DNA in RNA–DNA–protein biochemistry.

We argue that homochirality probably did not develop prebiotically. We see the likely chiral bifurcation point to be during the development of RNA from an achiral pre-RNA. Surprisingly, we find the driving force for this to be enantiomeric cross-inhibition in which the addition of a ‘wrong-handed’ enantiomer to a growing polymer brings the polymerization to a halt. This, it is often argued, is a serious impediment to the development of chiral purity. We suggest that the sign of handedness at this stage was probably determined by chance. We then point out that homochiral RNA was unlikely by itself to lead to homochiral proteins. We identify the additional nonlinear feature required for bifurcation to be the rapid increase in enzymic power available when the amino acids in proteins approach single handedness and structural features such as α-helices and β-sheets become viable. If this is correct, then the handedness of the protein sector is indeed linked to that of RNA. However, the relative sign of the two handednesses will have depended on the precise stereo-sensitive interaction between the RNA and protein systems. We suggest that the most plausible scenario is via the recently discovered RNA binding sites for amino acids, which are both stereo-selective and have contact with the developing genetic code. The detailed steps that determine the handedness are not yet clear and may be specific to the precise development path.

It follows that if biochemistry similar to that on Earth developed extraterrestrially, we would surely have homochirality but at this stage we cannot be sure about the handedness of either the nucleic acid or the protein components.
Characterization of growth and photosynthesis of Synechocystis sp. PCC 6803 cultures under reduced atmospheric pressures and enhanced CO2 levels
Authors: Kanervo Eira , Lehto Kirsi , Ståhle Kurt , Lehto Harry , Mäenpää Pirkko
Published: September 2005

Efficient life support systems are needed to maintain adequate oxygen, water and food for humans in extraterrestrial conditions. On the near-Earth missions, these are supplied by transport from the Earth, and by physical and chemical cleaning and recycling, but on long-term missions to far-away destinations, such as Mars, on-site production of the consumables may be required. Molecular oxygen and organic biomass can be most efficiently produced biologically, i.e. by photosynthesis. The conditions on Mars are distinctly harsh, and they strictly limit the growth and survival of any photosynthetic organisms to artificially maintained containments. For obtaining most economical growth conditions, minimal parameters need to be determined which still allow efficient growth of photosynthetic organisms. In this work we are testing how reduced air pressures (hypobaria) and increased CO2 concentrations, i.e. features typical for Martian conditions, affect the durability, growth and photosynthesis of laboratory strains of cyanobacteria, a group of prokaryotic organisms capable of plant-like photosynthesis. Our preliminary results show that air pressures down to 0.1 atm or CO2 concentrations up to 20% have no harmful effect on the photosynthetic oxygen production or growth rate of the cyanobacterial model species, Synechocystis sp. PCC 6803.
Thermodynamics of life on the planetary scale
Authors: Rosing Minik T.
Published: September 2005

The generation of organic matter from CO2 and H2O is a highly endothermic reaction. Energy for biological carbon fixation can be derived from chemical potential gradients in the environment by chemoautotrophic organisms or it can be harvested from photon energy by photosynthesis. On Earth, the plate tectonically driven carbon flux through the surface environment is of such a magnitude that the chemical free energy production within the Earth is insufficient to support conversion of any significant fraction of the carbon to organic matter through chemoautotrophy. Therefore, the chemical and isotopic fingerprints we observe in the Earth's surface environments are based on the invention of photosynthesis by life. We cannot a priori assume that life on any planet will invent photosynthesis and remote life detection should thus not be based exclusively on the expectations from our own ecosystem.
Editorial
Authors: Anderson Anja C. , Brandenburg Axel
Published: September 2005

Astrobiology harbours a number of rather diverse disciplines combining expertise in astronomy and astrophysics, biophysics and biology, chemistry and biochemistry, geophysics and geology, as well as mathematics. The need to foster advances in astrobiology are two-fold. On the one hand, there are many scientific reasons: the discoveries of extra-solar planets which contribute to our understanding of the Solar System and the formation of Earth-like planets, the realization that life can thrive under rather extreme conditions making it more probable for life to exist elsewhere in the Solar System and beyond, and the fact that major resources are being spent in developing the technology to produce artificial life, which helps us to appreciate the range of possibilities that nature may have utilized on Earth or elsewhere. On the other hand, astrobiology touches upon some fundamental questions regarding our very existence, and it is perhaps this that attracts the broad interest of scientists and the public alike. As a result, astrobiology networks and astrobiology centres have been emerging all over the world.
Photochemical stability of biomolecules in the experiments modelling Martian surface conditions
Authors: Gontareva N.B.
Published: September 2005

Life has probably existed on Earth for about 3.5 billion years and ever since people could wonder, they have tried to understand its origins. It is thought that organisms as complex as bacteria emerged within 0.5–1 billion years. Organic molecules, such as amino acids, organic acids and sugars have been observed in material from extraterrestrial sources in the solar system. But, to confirm the possibility of nucleic acid bases also being synthesized under these conditions, we have replicated the synthesis of monophosphates as dry pellets (5′-monophosphates, the predominant reaction products) under simulated Martian conditions. Our research task was to find out whether the main organic substances were able to survive in the absence of water. This reaction must proceed under solvent-free conditions and incident short ultraviolet radiation (UVC) in a vacuum. After 5 months of reaction time monophosphates could be identified in detectable quantities. These experiments utilized basalt and limonite as protectors and successfully shielded the products from decomposition by UVC. Our team has obtained more results concerning prebiotic synthesis of polypeptides and nucleotides in the presence of meteorite dust; these are the same kind of experiment, but using different extraterrestrial material.
Big-Fish-Little-Pond Effect on Academic Self-Concept 1Dieser Beitrag und die darauf bezogenen Stellungnahmen wurden von D.H. Rost akzeptiert.
Authors: Marsh Herbert W.
Published: September 2005

Abstract: In its simplest form, the big-fish-little-pond effect (BFLPE) predicts that equally able students have lower academic self-concepts when attending schools where the average ability levels of classmates is high, and higher academic self-concepts when attending schools where the school-average ability is low. In this article, I summarize theoretical, empirical, and policy-related implications of the BFLPE.
Can the Academic Self-Concept be Positive and Realistic?
Authors: Kornmann Reimer
Published: September 2005

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.
The Benefit of Gifted Classes and Talent Schools for Developing Students' Competences and Enhancing Academic Self-Concept
Authors: Rindermann Heiner , Heller Kurt A.
Published: September 2005

Summary: In a vast amount of educational research, it has been documented that a negative causal relationship exists between class or school ability level and ability self-concept. However, the aim of educational institutions is not to improve self-concept, but rather to support cognitive ability development (acquisition of new knowledge, school performance, etc.). A recent 11-year-long study of six grammar schools in Baden-Württemberg (Germany) involving 22 classes and 544 pupils demonstrated over a 2-year interval that mean class ability lowers individual ability self-concept. Yet it also revealed that this negative effect was compensated for by a positive school effect on self-concept. In particular, it showed that the sum of the effects of class and school level on individual ability development was positive (teachers adapted teaching to the class ability level, and students were stimulated by classmates). Selective schools have a positive effect.
The Big-Fish-Little-Pond Effect
Authors: Trautwein Ulrich , Lüdtke Oliver
Published: September 2005

Summary: Reference group effects on self-concept have been examined in a multitude of empirical studies in various educational settings. Effects of this kind have been most rigorously demonstrated by Herbert W. Marsh, who introduced the term big-fish-little-pond effect (BFLPE) to describe the finding that students' self-concept is negatively affected by the achievement level of other students in the same class or school. The phenomenon of the BFLPE is supported by a large body of empirical research. In this contribution, we first discuss mechanisms underlying the BFLPE. Second, we address reference group effects on educational outcomes other than self-concept. Finally, we briefly discuss educational implications of the BFLPE.
Big-Fish-Little-Pond Effect on Academic Self-Concept: A Reply to Responses
Authors: Marsh Herbert W.
Published: September 2005

Summary: The purpose of this article is to reply - within the designated length limitation - to three invited responses to my ( Marsh, 2005 ) overview of the big-fish-little-pond effect (BFLPE). In its simplest form, the BFLPE predicts that equally able students have lower academic self-concepts when attending schools or classes where the school-average ability levels of classmates is high, and higher academic self-concepts when attending schools where the school-average ability is low. None of the three responses to Marsh (2005) argues against the basic theoretical and empirical research in support of the BFLPE - that school- or class-average ability has a negative effect on academic self-concept. However, each of the three responses - coming from very different perspectives - proposes new questions and addresses broader implications that provide a rich basis for further BFLPE research in Germany and throughout the world.
Prädiktoren der akademischen Laufbahnintention
Authors: Berweger Simone , Keller Carmen
Published: September 2005

Zusammenfassung: Auf dem Hintergrund der Social Cognitive Career Theory (SCCT) von Lent, Brown und Hackett (1994) wurde untersucht, welche Faktoren das Ausmaß der akademischen Laufbahnintention von Doktorierenden (N = 246) beeinflussen. Es wurde überprüft, ob (a) Einstellungen, Interessen, Selbstwirksamkeitserwartungen und Kontextfaktoren einen Einfluss auf die Laufbahnintention haben, ob (b) Doktorandinnen eine geringere Selbstwirksamkeitserwartung und Laufbahnintention bezüglich einer akademischen Laufbahn aufweisen und die Vereinbarkeit von Laufbahn und Familie sowie die privaten Kosten einer Laufbahn negativer beurteilen als Doktoranden und ob (c) für die Erklärung der Laufbahnintention der beiden Gruppen unterschiedliche Prädiktoren bedeutsam sind. Die Ergebnisse bestätigen die geringere Laufbahnintention und Selbstwirksamkeit der Doktorandinnen. Wie erwartet spielten die Kontextfaktoren im Modell der Doktoranden keine Rolle. Hingegen konnte die Varianzaufklärung in der Laufbahnintention der Doktorandinnen durch den Einbezug der Kontextfaktoren signifikant um rund 10 Prozent verbessert werden.
Lernen oder Freunde treffen?
Authors: Dietz Franziska , Schmid Sebastian , Fries Stefan
Published: September 2005

Zusammenfassung: Schulisches Lernen ist häufig anstrengend und kostet Zeit, die nicht mehr für andere Tätigkeiten zur Verfügung steht. Modelle der Lernmotivation versuchen, Lernaktivitäten aus positiven Tätigkeits- und Folgenanreizen sowie deren Passung zu relevanten Persönlichkeitsmerkmalen vorherzusagen. Mit dem Lernen verknüpfte Kosten werden dagegen meistens vernachlässigt. Wir postulieren demgegenüber, dass bei der Realisierung von Lernhandlungen auch zwei Kostenarten eine Rolle spielen: Direkte Kosten, die den negativen Anreizen der Lerntätigkeit entsprechen, und indirekte Kosten, die die entgangenen Anreize alternativer Handlungsmöglichkeiten widerspiegeln, welche aufgrund des Lernens verpasst werden. In einer Fragebogenstudie mit n = 184 Schüler/innen weiterführender Schulen wird mit Hilfe von Strukturgleichungsmodellen bestätigt, dass neben der positiven Valenz des Lernens dessen Ausführung mit negativen Valenzen (direkte Kosten) der Tätigkeit und mit dem entgangenen Nutzen ebenfalls verfügbarer Freizeitalternativen (indirekte Kosten) zusammenhängt. Erleben und subjektive Performanz beim Lernen, aber auch bei Freizeitaktivitäten, scheinen auch davon abzuhängen, ob alternative Handlungsangebote präsent sind.
The water‐column chemical signature after the 1998 Eruption of Axial Volcano
Authors: Resing Joseph A. , Feely Richard A. , Massoth Gary J. , Baker Edward T.
Published: September 2005

The eruption of Axial Volcano in January 1998 produced extensive plumes in the overlying water column with large anomalies in Fe, Mn, pH, light attenuation, and temperature. A strong correlation between total iron and light attenuation (dc) suggests a low abundance of particulate sulfur (PS) in the plumes. Because total carbon dioxide (ΣCO2) samples were not collected, high‐precision pH measurements were used to estimate maximum CO2 anomalies (ΔCO2) which, when compared to the other physical and chemical data, suggest that the fluids being vented 3 weeks after eruption were formed by the interaction between an intruded dike and a mixture of interstitial seawater and mature hydrothermal fluids.
High‐frequency Alfvén waves in multi‐ion coronal plasma: Observational implications
Authors: Ofman L. , Davila J. M. , Nakariakov V. M. , Viñas A.‐F.
Published: September 2005

We investigate the effects of high‐frequency (of order ion gyrofrequency) Alfvén and ion‐cyclotron waves on ion emission lines by studying the dispersion of these waves in a multi‐ion coronal plasma. For this purpose we solve the dispersion relation of the linearized multifluid and Vlasov equations in a magnetized multi‐ion plasma with coronal abundances of heavy ions. We also calculate the dispersion relation using nonlinear one‐dimensional hybrid kinetic simulations of the multi‐ion plasma. When heavy ions are present the dispersion relation of parallel propagating Alfvén cyclotron waves exhibits the following branches (in the positive Ω − k quadrant): right‐hand polarized nonresonant and left‐hand polarized resonant branch for protons and each ion. We calculate the ratio of ion to proton velocities perpendicular to the direction of the magnetic field for each wave modes for typical coronal parameters and find strong enhancement of the heavy ion perpendicular fluid velocity compared with proton perpendicular fluid velocity. The linear multifluid cold plasma results agree with linear warm plasma Vlasov results and with the nonlinear hybrid simulation model results. In view of our findings we discuss how the observed nonthermal line broadening of minor ions in coronal holes may relate to the high‐frequency wave motions.
Three‐dimensional seismic structure of the Mid‐Atlantic Ridge (35°N): Evidence for focused melt supply and lower crustal dike injection
Authors: Dunn Robert A. , Lekić Vedran , Detrick Robert S. , Toomey Douglas R.
Published: September 2005

We gathered seismic refraction and wide‐angle reflection data from several active source experiments that occurred along the Mid‐Atlantic Ridge near 35°N and constructed three‐dimensional anisotropic tomographic images of the crust and upper mantle velocity structure and crustal thickness. The tomographic images reveal anomalously thick crust (8–9 km) and a low‐velocity “bull's‐eye”, from 4 to 10 km depth, beneath the center of the ridge segment. The velocity anomaly is indicative of high temperatures and a small amount of melt (up to 5%) and likely represents the current magma plumbing system for melts ascending from the mantle. In addition, at the segment center, seismic anisotropy in the lower crust indicates that the crust is composed of partially molten dikes that are surrounded by regions of hot rock with little or no melt fraction. Our results indicate that mantle melts are focused at mantle depths to the segment center and that melt is delivered to the crust via dikes in the lower crust. Our results also indicate that the segment ends are colder, receive a reduced magma supply, and undergo significantly greater tectonic stretching than the segment center.
Distribution and variability of iron input to Oregon coastal waters during the upwelling season
Authors: Chase Zanna , Hales Burke , Cowles Timothy , Schwartz Roseanne , van Geen Alexander
Published: September 2005

We measured iron concentrations off the Oregon coast in spring (May–June) and summer (August) of 2001 as part of the Coastal Ocean Advances in Shelf Transport (COAST) program. Dissolvable and total dissolvable iron levels in surface waters were generally higher in spring (mean of 2.1 and 33.9 nmol L−1, respectively) than in summer (means of 1.4 and 15.4 nmol L−1). In spring and summer, high iron concentrations in surface waters were associated with both cold and saline, recently upwelled waters, and with fresh, relatively warm water influenced by the Columbia River. Comparison of total dissolvable iron in 0.45 μm filtered and in unfiltered samples indicated a substantial contribution from particulate iron. Iron concentrations in summer were generally lower than in spring throughout the water column, with the exception of the near‐bottom, where concentrations were generally higher in summer than spring. Optical backscatter data from moored sensors were used to infer the vertical and cross‐shelf transport of iron‐bearing particles during the upwelling season over a steep shelf. Cross‐correlation analysis showed downslope movement of particles from the deep inner shelf to the deep midshelf. There was also evidence for sinking of biogenic particles at the midshelf and inner shelf, but we found no evidence of upslope transport of benthic particles. Sufficient iron is available in this system to meet the demands of the phytoplankton, which are able to make full use of available nitrate.
Utility of deep sea CO2 release experiments in understanding the biology of a high‐CO2 ocean: Effects of hypercapnia on deep sea meiofauna
Authors: Barry James P. , Buck Kurt R. , Lovera Chris , Kuhnz Linda , Whaling Patrick J.
Published: September 2005

Oceanic CO2 levels are expected to rise during the next 2 centuries to levels not seen for 10–150 million years by the uptake of atmospheric CO2 in surface waters or potentially through the disposal of waste CO2 in the deep sea. Changes in ocean chemistry caused by CO2 influx may have broad impacts on ocean ecosystems. Physiological processes animals use to cope with CO2‐related stress are known, but the range of sensitivities and effects of changes in ocean chemistry on most ocean life remain unclear. We evaluate the effectiveness of various designs for in situ CO2 release experiments in producing stable perturbations in seawater chemistry over experimental seafloor plots, as is desirable for evaluating the CO2 sensitivities of deep sea animals. We also discuss results from a subset of these experiments on the impacts of hypercapnia on deep sea meiofauna, in the context of experimental designs. Five experiments off central California show that pH perturbations were greatest for experiments using “point source” CO2 pools surrounded by experimental plots. CO2 enclosure experiments with experimental plots positioned within a circular arrangement of CO2 pools had more moderate pH variation. The concentration of dissolution plumes from CO2 pools were related to the speed and turbulence of near‐bottom currents, which influence CO2 dissolution and advection. Survival of meiofauna (nematodes, amoebae, euglenoid flagellates) was low after episodic severe hypercapnia but lower and variable where pH changes ranged from 0 to 0.2 pH units below normal.
Sea level rise and the warming of the oceans in the Simple Ocean Data Assimilation (SODA) ocean reanalysis
Authors: Carton James A. , Giese Benjamin S. , Grodsky Semyon A.
Published: September 2005

A new reanalysis of the global ocean circulation is used to distinguish between the steric and eustatic components of sea level rise. Recent altimeter observations indicate an increase in the rate of sea level rise during the past decade to 3.2 mm/yr, well above the centennial estimate of 1.5–2 mm/yr. This apparent increase could have resulted from enhanced melting of continental ice or from decadal changes in thermosteric and halosteric effects. The contribution from steric effects is explored using the new eddy‐permitting Simple Ocean Data Assimilation version 1.2 (SODA1.2) reanalysis of global temperature, salinity, and sea level spanning the period 1958–2001. The applicability of this ocean reanalysis for sea level studies is evaluated by comparing subseasonal variability with a collection of 20 tide gauge station sea level records, comprising a total of 740 years of data. A positive relationship is found at all gauge stations, with an average correlation of r = 0.7 after correction for the inverted barometer effect. Dynamic height calculated relative to 1000m from the SODA1.2 reanalysis, used as a proxy for the steric component of sea level, is compared with satellite‐derived sea level for the years 1993–2001. During this 9‐year period dynamic height increases at a global rate of 2.3 ± 0.8 mm yr−1, a substantial acceleration beyond the multidecadal steric rate of 0.5 mm yr−1. The similarity of the rate of increase in the thermosteric contribution to sea level rise as well as the similarity of its spatial structure in comparison with satellite‐derived sea level rise suggests that the recent acceleration in sea level rise is explainable to within the error estimates by fluctuations in warming and thermal expansion of the oceans.
Evaluation of a hybrid satellite‐ and NWP‐based turbulent heat flux product using Tropical Atmosphere‐Ocean (TAO) buoys
Authors: Jiang ChuanLi , Cronin Meghan F. , Kelly Kathryn A. , Thompson LuAnne
Published: September 2005

Gridded hybrid turbulent heat flux fields were created by applying the state‐of‐the‐art Coupled Ocean‐Atmosphere Response Experiment (COARE) version 3.0 bulk algorithm to state variables (sea surface temperature, winds relative to currents, air temperature, and air specific humidity) derived from either numerical weather prediction (NWP) reanalysis (National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP‐NCAR) reanalysis (NCEP1), NCEP reanalysis‐2 (NCEP2), and 40‐year European Centre for Medium‐Range Weather Forecasts (ECMWF) reanalysis (ERA40)) or satellite sensors (QuikSCAT winds and Tropical Rainfall Measuring Mission (TRMM) Microwave Imager microwave sea surface temperature). The most accurate source for each state variable was determined by comparing variables to tropical Pacific Tropical Atmosphere‐Ocean (TAO) buoy observations for the years 2000–2001. The selected sources were as follows: QuikSCAT for winds relative to currents, ERA40 for air temperature and specific humidity, and TRMM Microwave Imager fusion product for sea surface temperature. Errors in latent and sensible heat fluxes to state variables were analyzed. Specific humidity errors contributed the most to errors in latent heat flux (LHF). Overall, the hybrid LHF product had a bias of −5.8 W m−2 and a standard deviation of difference of 16.2 W m−2, which is comparable to the accuracy of LHF derived from TAO measurements.
Influence of cumulative convergence on lithospheric thrust fault development and topography along the Australian‐Pacific plate boundary south of New Zealand
Authors: Meckel T. A. , Mann P. , Mosher Sharon , Coffin Millard F.
Published: September 2005

The development of faulting and topography resulting from initial convergence within oceanic lithosphere is largely unknown. We explore relationships among convergence, structural development, and topography along ∼1500 km of the submarine Australian‐Pacific plate boundary south of New Zealand, the Macquarie Ridge Complex (MRC). Due to the variable orientation of the boundary and close proximity of the Australian‐Pacific poles of rotation, individual segments of the plate boundary have experienced different convergence histories since ∼10.95 Ma (Chron 5o). Because interaction along the oceanic extent of the boundary involves oceanic lithosphere of broadly the same age and therefore thermal structure, structural and morphologic differences can be attributed primarily to variations in angles and rates of convergence with respect to the plate boundary orientation since 10.95 Ma. We relate plate boundary‐normal convergence determined from stage pole rotations to structural development, focusing on transitions from purely strike‐slip faulting to partitioned thrust and strike‐slip faulting between 47°S and 60°S since 10.95 Ma. Our results indicate that boundary‐normal convergence of ∼100 km marks the transition from strike‐slip dominated faulting to partitioned underthrusting and strike‐slip faulting (incipient subduction). Establishment of subduction at the Puysegur Trench and incipient subduction at the Hjort Trench corresponds to convergence at rates between ∼2 and 4 cm/yr, angles >30°, and with durations of at least 10 m.y., resulting in >100 km of boundary‐normal convergence. Anomalous topographic volumes resulting from tectonic deformation are quantified from swath bathymetry and compared to convergence history. Results from analysis of the central MRC suggest that prior to lithospheric‐scale thrust faulting, ∼100 km of boundary‐normal convergence can be accommodated by crustal deformation (6 km relief from ridge crest to adjacent trough) and strike‐slip faulting. Our research supports induced/forced intraoceanic initiation of subduction.
Deformation in the diffuse India‐Capricorn‐Somalia triple junction from a multibeam and magnetic survey of the northern Central Indian ridge, 3°S–10°S
Authors: Drolia R. K. , DeMets C.
Published: September 2005

We use new multibeam and magnetic observations from 3°S–10°S along the Central Indian ridge to describe morphotectonic features and spreading fabrics within the study area and quantify deformation across the diffuse India‐Capricorn‐Somalia triple junction. A megamullion adjacent to the Vityaz transform fault is the first reported for the northern Central Indian ridge. The principal transform displacement zone (PTDZ) of the Vema transform fault consists of several closely spaced faults that can be traced for more than 150 km. Serpentinite or volcanic intrusions that are offset by the Vema PDTZ have inferred ages of 30,000–45,000 years, testifying to the youth of active features on the valley floor. Abyssal hill orientations throughout the study area have remained constant since at least 4 Ma, implying little or no change in the opening direction during this period. Abyssal hills from opposite sides of the ridge have the same orientations within our 1°–3° errors, implying that slip along reactivated fracture zones in the diffuse triple junction neither significantly rotates nor shears the intervening seafloor. Transform fault azimuths in the survey area agree with the NUVEL‐1 Africa‐Australia slip direction but are 5°–9° clockwise from the Africa‐India direction. In contrast, seafloor spreading rates in the study area agree better with the NUVEL‐1 Africa‐India predictions. These seemingly conflicting observations are reconciled by a model in which seafloor within the diffuse triple junction rotates about the India‐Capricorn pole at angular rotation rates that increase monotonically from zero to the full rotation rate across the deforming zone.
Evolution of volcanism and faulting in a segment of the Mid‐Atlantic Ridge at 25°N
Authors: Cann Johnson R. , Smith Deborah K.
Published: September 2005

We reconstruct the volcanic and tectonic evolution over the last 250,000 years of the median valley floor in the spreading segment of the Mid‐Atlantic Ridge centered at 25°N. In the center of the segment, multibeam bathymetry and deep‐towed side‐scan images show a large area of smooth‐textured lava flows more like those of the East Pacific Rise than those of the Mid‐Atlantic Ridge. Hummocky flows more typical of the Mid‐Atlantic Ridge are found toward the southern end of the segment. The presence of the abundant smooth‐textured flows allows us to interpret the volcanic and tectonic relationships in the segment. We construct a geological map using (1) multibeam bathymetry to identify the key volcanic structures and fault scarps and (2) high‐resolution TOBI side‐scan sonar images to interpret age relationships between features on the basis of overall sediment cover as shown by backscatter brightness. Bottom photographs across key features on the median valley floor yield detailed information on stratigraphic relationships between volcanic features and faults and allow us to calibrate backscatter brightness in terms of sediment cover and hence of age. In this way we derive a history of volcanic activity and deformation in a detailed survey area at the segment center, with the most recent flows erupted about 5000 years ago, and the youngest smooth flows about 10,000 years ago, separated by an episode of faulting. Using bathymetry and side‐scan surveys, we extrapolate this to the whole of the median valley floor. The volcanic activity giving rise to the smooth flows has been continuous for about a quarter of a million years at the segment center. Over the same period, hummocky flows have been continuously erupted at the southern end of the segment. Electron probe analyses of dredged basalt glasses show that there is a systematic variation in composition with position in the segment. Basalts from the segment center are all more evolved than those at the southern end of the segment. There is, however, no relation of chemistry with lava type. The basalts from the segment center have very nearly the same composition whether they come from hummocky flows or smooth flows. The boundary between the smooth flows and hummocky flows has fluctuated with time and migrated rapidly northward over the last few thousand years, so that shortly the eruption of smooth flows will probably have ceased. The survey shows that flows that are smooth on side‐scan images are not necessarily sheet flows. In this study they uniformly show pillow morphology. We conclude that smooth flows were probably erupted at faster eruption rates than hummocky flows.
Water controls the fields of metastable olivine in cold subducting slabs
Authors: Hosoya Tomofumi , Kubo Tomoaki , Ohtani Eiji , Sano Asami , Funakoshi Ken‐ichi
Published: September 2005

We have measured the rate of the olivine‐wadsleyite transformation in Mg2SiO4 under hydrous condition by in‐situ X‐ray diffraction method. The concentration of hydroxyl of samples was estimated using infrared spectroscopy. Combined with previous kinetic data on this transformation, a total of 15 growth rate data obtained at 13.4–15.8 GPa, 1003–1373 K, and 660–5000 ppm weight H2O have been used to establish the pressure, temperature and OH content dependences. Results demonstrate that the growth rate in the olivine‐wadsleyite transformation is proportional to OH content to the power of about 3. The depth of the olivine transformation significantly changes with the water content in cold slabs, which must be considered to estimate fields of the metastable olivine.
Assessment of ICESat performance at the salar de Uyuni, Bolivia
Authors: Fricker H. A. , Borsa A. , Minster B. , Carabajal C. , Quinn K. , Bills B.
Published: September 2005

The primary goal of the Ice, Cloud and land Elevation Satellite (ICESat) mission is ice sheet elevation change detection. Confirmation that ICESat is achieving its stated scientific requirement of detecting spatially‐averaged changes as small as 1.5 cm/year requires continual assessment of ICESat‐derived elevations throughout the mission. We use a GPS‐derived digital elevation model (DEM) of the salar de Uyuni, Bolivia for this purpose. Using all twelve ICESat passes over the salar survey area acquired to date, we show that the accuracy of ICESat‐derived elevations is impacted by environmental effects (e.g., forward scattering and surface reflectance) and instrument effects (e.g., pointing biases, detector saturation, and variations in transmitted laser energy). We estimate that under optimal conditions at the salar de Uyuni, ICESat‐derived elevations have an absolute accuracy of <2 cm and precision of <3 cm.
A regional index of northeast Pacific variability based on satellite altimeter data
Authors: Cummins Patrick F. , Lagerloef Gary S. E. , Mitchum Gary
Published: September 2005

An index of climate variability to monitor the state of the upper ocean is proposed for the northeast (NE) Pacific Ocean based on sea surface height (SSH) data from satellite altimetry. While sea surface temperature (SST) is often used characterize ocean variability, SSH reflects the integrated influence of temperature and salinity anomalies through the water column. A canonical correlation analysis shows that SSH and SST anomalies vary coherently at large spatial scales and low frequencies over the region. SSH anomalies are less subject to short period variability and the temporal components for SSH resemble smoothed, low‐pass‐filtered versions of the SST components. Also examined is the relationship between the SST‐based Pacific Decadal Oscillation (PDO) index and the large‐scale, upper ocean variability reflected in the leading principal component of SSH anomalies. The comparison demonstrates that the SSH principal component provides a robust index of regional climate variability that is less noisy than the PDO. The results are used to examine the 1998–2002 climate event over the NE Pacific.
Predicting wave heights in the north Indian Ocean using genetic algorithm
Authors: Basu Sujit , Sarkar Abhijit , Satheesan K. , Kishtawal C. M.
Published: September 2005

The present work reports the development of a nonlinear technique based on genetic algorithm (GA) for the prediction of wave heights in the north Indian Ocean. Time series observations of surface wind speed and significant wave height at three locations in the Arabian Sea (AS) and the Bay of Bengal (BOB) have been used for developing and testing the technique. The predictions have been compared with persistence forecasts and it has been found that the prediction by GA is always superior to persistence forecast and thus represents a net information gain. The predicted wave heights have been found to be consistent with the results obtained with autocorrelation analysis applied on the respective time series of wave heights.
Observational evidence of the loading‐unloading substorm scheme
Authors: Shukhtina M. A. , Dmitrieva N. P. , Popova N. G. , Sergeev V. A. , Yahnin A. G. , Despirak I. V.
Published: September 2005

According to the loading‐unloading substorm scenario, the magnetic flux, stored in the magnetotail during the substorm growth phase,is dissipated in the course of the expansion phase. However so far only separate estimates of both accumulated and dissipated flux values were made due to the lack of methods to calculate those quantities, doing their direct comparison impossible. First, we analyzed the magnetotail magnetic flux at substorm onset as a function of solar wind parameters to show that the tail magnetic flux, stored during the growth phase (ΔFT), depends mainly (CC = 0.95) on the merging electric field Em = VSWBtsin3θ/2. It implies the lack of threshold magnetic flux at substorm onset. Also, the magnetic flux through the auroral bulge at substorm maximum (FB) was calculated from Polar UVI images. Comparison of ΔFT and FB shows their correlation and confirms their balance. These results quantitatively support the substorm model, based on reconnection mechanism.
Dispersive and reflected tsunami signals from the 2004 Indian Ocean tsunami observed on hydrophones and seismic stations
Authors: Hanson Jeffrey A. , Bowman J. Roger
Published: September 2005

The tsunami caused by the Great Sumatra Earthquake on 26 December 2004 generated dispersive signals recorded on hydrophones near Diego Garcia and Cape Leeuwin, Australia and on seismographs in coastal locations around the Indian Ocean. The onset of these signals was coincident with predicted tsunami arrival times, signal durations were from 12 to more than 36 hours, and signal frequencies ranged from less than 1 mHz at onset to 25 mHz. Signal onset times and dispersion are consistent with propagation from the earthquake rupture zone to the receivers as tsunami waves. Signal arrival azimuths were estimated from coherent processing of groups of sensors. The azimuth and dispersion of the signal are consistent with the direct tsunami wave, and secondary signals are consistent with reflections of the tsunami from the Mascarene Plateau and other bathymetric features in the Indian Ocean.
Multiple CMT source analysis of the 2004 Sumatra earthquake
Authors: Tsai Victor C. , Nettles Meredith , Ekström Göran , Dziewonski Adam M.
Published: September 2005

While it is agreed that the great Sumatra earthquake of December 26, 2004 was among the largest earthquakes of the past century, there has been disagreement on how large it was, which part of the fault ruptured, and how the rupture took place. We present a centroid‐moment‐tensor (CMT) analysis of the earthquake in which multiple point sources are used in the inversion to mimic a propagating slip pulse. The final model consists of five point sources, with the southernmost sources accounting for the majority of the moment release. The presumed fault planes of the southern sources strike northwest, while those in the north strike northeast, consistent with the geometry of the subduction trench. Slip on the fault is found to be more oblique in the north than in the south. The inversion with five sources leads to a moment magnitude for the Sumatra earthquake of MW = 9.3, consistent with estimates from long‐period normal‐mode amplitudes.