Building a data sharing model for global genomic research

Data sharing models designed to facilitate global business provide insights for improving transborder genomic data sharing. We argue that a flexible, externally endorsed, multilateral arrangement , combined with an objective third-party assurance mechanism, can effectively balance privacy with the need to share genomic data globally

Composition Systematics in the Exoskeleton of the American Lobster, Homarus americanus and Implications for Malacostraca

Studies of biominerals from the exoskeletons of lobsters and other crustaceans report chemical heterogeneities across disparate body parts that have prevented the development of composition-based environmental proxy models. Anecdotal evidence, however, suggests underlying composition systematics may exist in the mineral component of this biocomposite material. We test this idea by designing a protocol to separately extract the mineral [amorphous calcium carbonate (ACC) plus calcite] and organic (chitin plus protein) fractions of the exoskeleton. The fractions were analyzed by ICP-OES and other wet chemistry methods to quantify Mg, Ca, and P contents of the bulk, mineral, and organic matrix. Applying this approach to the exoskeleton for seven body parts of the American lobster, Homarus americanus, we characterize the chemical composition of each fraction. The measurements confirm that Mg, P, and Ca concentrations in lobster exoskeletons are highly variable. However, the ratios of Mg/Ca and P/Ca in the mineral fraction are constant for all parts, except the chelae (claws), which are offset to higher values. By normalizing concentrations to obtain P/Ca and Mg/Ca, we show that all body parts conserve P/Mg to 1.27 ± 0.30. The findings suggest lobsters hold promise as a novel class of animals that record composition systematics within their CaCO3 biominerals. Parallel structural analyses of the bulk samples confirm a large proportion of ACC relative to calcite in the mineral fractions for each body part using high-energy X-ray diffraction and PDF analysis. There is no evidence for a phosphate phase. Returning to compositions reported for other marine (crab, lobster, and marine shrimp) and terrestrial (pillbug) crustaceans, we find evidence for similar Mg/Ca and P/Ca patterns in these organisms. The relationships provide a basis for developing new proxies for environmental reconstructions using animals from the class Malacostraca and provide insights into how composition may be optimized to meet functional requirements of the mineral fraction in exoskeletons. Compositional variability, and hence differential solubility, suggests a thermodynamic basis for the taphonomic bias that is observed in the fossil record

Asimow, Jahren, and Randerson receive 2005 James B. Macelwane Medal

It is my great pleasure to present my friend and colleague, Paul Asimow, recipient of one of this year's three James B. Macelwane Medals. Paul is a petrologist interested in the origins and evolution of basaltic magmas, and he is being recognized for a series of profoundly insightful papers on the energetics of decompression melting and how it controls the compositions of the oceanic crust and upper mantle. The significance of what Paul has done comes from the simplicity of the question that first inspired him: How should we describe the way the mantle melts as it upwells during convection? The importance of the problem is obvious; this is how the Earth makes most of its crust, and so it is the starting point for most of geology But does it sound like something we already understand? Wasn't I taught this as an undergraduate? Paul's first and perhaps most important contribution was to recognize, as a second‐year graduate student working with Ed Stolper [California Institute of Technology (Caltech),Pasadena],that the explanation of mantle melting we were telling each other was a Rube Goldberg device masquerading as physical theory

Controls of sorbed aluminum of quartz reactivity : an integrated experimental investigation of dissolution rates and surface reaction processes

Issued as final repor

Biomineralization : systematics of organic-directed controls on carbonate growth morphologies and kinetics determined by in situ atomic force microscopy

Issued as final repor

Investigating the physical basis of biomineralization. Final report

During the three years of this project, Professor Dove's laboratory made tremendous progress in understanding fundamental controls on crystal growth in simple model systems for the complex phenomenon of biological mineralization. Our collaboration with J.J. DeYoreo was productive and we surpassed the goals set forth in the original proposal to establish a new quantitative understanding of carbonate mineral crystallization. The findings from this project have been widely recognized across the scientific community by the award of the Mineralogical Society of America best paper award in 1998 and the Best University Research Award of 1999 at the Basic Energy sciences, Division of Geosciences ''Interfacial Processes Symposium''. In addition, two students working on this project received six different awards for their research findings

Quantifying Silica Reactivity in Subsurface Environments: An Integrated Experimental Study of Quartz and Amorphous Silica to Establish a Baseline for Glass Durability

An immediate EM science need is a reliable kinetic model that predicts long-term waste glass performance. A framework for which the kinetics of mineral-solution reactions can be used to interpret complex silicate glass properties is required to accurately describe the current and future behavior of glasses as synthetic monoliths or natural analogs. Reaction rates and mechanisms are essential elements in deciphering mineral/material reactivity trends within a compositional series or across a matrix of complex solution compositions. An essential place to start, and the goal of this research, is to quantify the reactivity of crystalline and amorphous SiO2 phases in the complex fluids of natural systems

Quantifying Silica Reactivity in Subsurface Environments: Reaction Affinity and Solute Matrix Controls on Quartz and SiO2 Glass Dissolution Kinetics

During the three years of this project, Professor Dove's laboratory made tremendous progress in understanding controls on amorphous silica dissolution kinetics in aqueous solutions. Our findings have already received considerable attention. In hydrothermal and low temperature studies, the work focused on determining quantitative and mechanistic controls on the most abundant silica polymorphs in Earth environments--quartz and amorphous silica. Our studies achieved goals set forth in the original proposal to establish a new quantitative understanding of amorphous silica dissolution. This support has resulted in 10 journal, 12 abstracts and 2 thesis publications. The PI and students were also recognized with 6 awards during this period. The 1998 EMSP conference in Chicago was an important meeting for our project. The symposium, enabled P.I. Dove to establish valuable contacts with ''users'' having specific needs for the findings of our EMSP project related to the urgency of problems in the Tanks Focus Area (TFA). Since that time, our working relations developed as Dove interacted with TFA scientists and engineers on the problems of waste glass properties. These interactions refined our experimental objectives to better meet their needs. Dove presented the results of EMSP research findings to a TFA subgroup at a Product Acceptance Workshop held in Salt Lake City during December 1998. The travel costs to attend this unanticipated opportunity were paid from EMSP project funds. In January 2000, Dove also attended a similar meeting in Atlanta with PNNL, SRL and BNF scientists/engineers to discuss new issues and make another level of decisions on the Product Acceptance goals. Our EMSP-funded research interfaced very well with the ongoing studies of Dr. Pete McGrail and colleagues in the Applied Geochemistry Group at PNNL. The value of our work to ''users'' was further demonstrated when Dove's EMSP-funded Postdoc, Dr. Jonathan Icenhower was hired by the same PNNL group. With the Icenhower move from postdoc in the Dove lab to a senior scientist position at PNNL, we directly facilitated information transfer from the ''university to user'' environment. Icenhower brought experience in silica-water reactivity and the experimental expertise in high-quality methods of mineral-water reaction kinetics to the PNNL waste clean-up effort. In a further interaction, M.S. student Troy Lorier was hired at the Savannah River Laboratory for a staff position with the Bill Holtzcheiter glass group. His research meshed well with on-going efforts at SRL. In short, our EMSP project went well beyond the academic goals of producing high quality scientific knowledge to establish connections with on-site users to solve problems in TFA. This project also produced new talent for the waste immobilization effort. This EMSP project was highly successful and we thank our sponsors for the opportunity to advance scientific knowledge in this important area of research

Quantifying Silica Reactivity in Subsurface Environments: Reaction Affinity and Solute Matrix Controls on Quartz and SiO2 Glass Dissolution Kinetics

Our goal is to develop a quantitative and mechanistic understanding of amorphous silica, SiO2(am), dissolution kinetics in aqueous solutions. A knowledge of fundamental controls on the reactivity of simple Si-O bonded phases is the baseline of behavior for understanding highly complex silica phases. In the Earth, silicate minerals comprise >70% of the crust and dominate virtually every subsurface system. More importantly for the objectives of this EMSP project, the silicates are important because compositionally complex glasses will become the front line of defense in containing radioactive wastes in the nation's long term and interim storage strategies. To date, the behavior of SiO2(am) is largely inferred from studies of the better known crystalline polymorphs (e.g. alpha-quartz). In the first step towards constructing a general model for amorphous silica reactivity in the complex fluid compositions of natural waters, we are determining the dissolution behavior as a function of temperature, solution pH and cation concentration. With these data we are determining relationships between SiO2 glass structure and dissolution rates in aqueous solutions, as described below

Quantifying silica reactivity in subsurface environments: Controls of reaction affinity and solute matrix. 1998 annual progress report

'The authors goal is to develop a quantitative and mechanistic understanding of amorphous silica, SiO{sub 2} (am), dissolution kinetics in aqueous solutions. A knowledge of fundamental controls on the reactivity of simple SiO{sub 2} bonded phases is the compositional baseline for understanding highly complex silica phases. In the Earth, silicate minerals comprise >70% of the crust and dominate virtually every subsurface system. More importantly for the objectives of this EMSP project, silicate minerals and materials are significant because compositionally complex silicate glasses will become the front line of defense in containing radioactive wastes in the nation''s long term and interim storage strategies (Dove and Icenhower, 1997). To date, the behavior of SiO{sub 2} (am) is largely inferred from studies of the better known crystalline polymorphs (e.g. a-quartz). In the first step towards constructing a general model for amorphous silica reactivity in the complex fluid compositions of natural waters, the authors are determining the dissolution behavior as a function of temperature, solution pH and NaCl concentration. With these data they are determining relationships between SiO{sub 2} glass structure and dissolution rates in aqueous solutions, as described below. This report outlines the first year''s progress and the resulting publications to date. In this experimental investigation, the dissolution kinetics of SiO{sub 2} (am) (fused and flame pyrolysis silica) were measured in solutions over the pH range of 4 to 10 containing 0.0 (deionized water, DIW) to 0.15 M NaCl at 40 to 275 C. Dissolution rates were determined in low temperature (40 to 80 C) and hydrothermal (120 to 275 C) reactor systems, using flow-through reactors that are broadly similar in design. Rate data collected from these two reactor designs are consistent with each other and yield the first comprehensive model of amorphous silica reactivity in deionized water and electrolyte solutions (Icenhower and Dove, 1998). Measurements of rates show important similarities and differences between the corrosion behavior of SiO{sub 2} (am) and a-quartz. They find that the experimental energy of activation, E a,xp , for the dissolution of SiO{sub 2} (am) is 75 \261 5 kJ mol -1 in DIW. The introduction of up to 0.05 M NaCl yields similar E a,xp values of 80 \261 5 kJ mol -1 . These values are \30510 kJ mol -1 higher than previous estimates of E a,xp for SiO{sub 2} (am) but are consistent with reported values of E a,xp for a-quartz. Dissolution rates measured at 200 C in DIW show that SiO{sub 2} (am) dissolves \3053 to 30X faster than a-quartz. A possible explanation for this difference is that SiO 2 (am) has a fraction of Si-O-Si bonds (angles up to 180\260) that have a greater ionic character, and are therefore more reactive than a-quartz constituents (mean angle of 152\260 ) (Icenhower and Dove, in prep.). Measurements of SiO{sub 2} (am) dissolution rates versus NaCl concentrations at 200 C show that sodium enhances rates by a factor of \30510 to 30X compared to rates measured in DIW, which are less than rates for a-quartz under identical experimental conditions. In addition, they find that the dissolution rates of the two forms of SiO{sub 2} (am) (fused and flame pyrolysis silica) are similar within the experimental error of the early experiments. Results of this study suggest that the role of physical (structural) properties (e.g., Si-O-Si bonds) in governing reactivities of crystalline versus amorphous SiO{sub 2} polymorphs is significant.