Industrial structural geology : principles, techniques and integration : an introduction

The authors wish to acknowledge the generous financial support provided in association with this volume to the Geological Society and the Petroleum Group by Badley Geoscience Ltd, BP, CGG Robertson, Dana Petroleum Ltd, Getech Group plc, Maersk Oil North Sea UK Ltd, Midland Valley Exploration Ltd, Rock Deformation Research (Schlumberger) and Borehole Image & Core Specialists (Wildcat Geoscience, Walker Geoscience and Prolog Geoscience). We would like to thank the fine team at the Geological Society’s Publishing House for the excellent support and encouragement that they have provided to the editors and authors of this Special Publication.Peer reviewedPublisher PD

High Resolution STIS/HST and HIRES/Keck Spectra of Three Weak MgII Absorbers Toward PG 1634+706

High resolution optical (HIRES/Keck) and UV (STIS/HST) spectra, covering a large range of chemical transitions, are analyzed for three single-cloud weak MgII absorption systems along the line of sight toward the quasar PG 1634+706. Weak MgII absorption lines in quasar spectra trace metal-enriched environments that are rarely closely associated with the most luminous galaxies (>0.05L^*). The two weak MgII systems at z=0.81 and z=0.90 are constrained to have >=solar metallicity, while the metallicity of the z=0.65 system is not as well-constrained, but is consistent with >1/10th solar. These weak MgII clouds are likely to be local pockets of high metallicity in a lower metallicity environment. All three systems have two phases of gas, a higher density region that produces narrower absorption lines for low ionization transitions, such as MgII, and a lower density region that produces broader absorption lines for high ionization transitions, such as CIV. The CIV profile for one system (at z=0.81) can be fit with a single broad component (b~10 km/s), but those for the other two systems require one or two additional offset high ionization clouds. Two possible physical pictures for the phase structure are discussed: one with a low-ionization, denser phase embedded in a lower density surrounding medium, and the other with the denser clumps surrounding more highly ionized gas.Comment: 32 pages, 4 figures; to appear in ApJ on May 20, 200

Effects of Traveling Wave Ion Mobility Separation on Data Independent Acquisition in Proteomics Studies

qTOF mass spectrometry and traveling wave ion mobility separation (TWIMS) hybrid instruments (q- TWIMS-TOF) have recently become commercially available. Ion mobility separation allows an additional dimension of precursor separation inside the instrument, without incurring an increase in instrument time. We comprehensively investigated the effects of TWIMS on data-independent acquisition on a Synapt G2 instrument. We observed that if fragmentation is performed post TWIMS, more accurate assignment of fragment ions to precursors is possible in data independent acquisition. This allows up to 60% higher proteome coverage and higher confidence of protein and peptide identifications. Moreover, the majority of peptides and proteins identified upon application of TWIMS span the lower intensity range of the proteome. It has also been demonstrated in several studies that employing IMS results in higher peak capacity of separation and consequently more accurate and precise quantitation of lower intensity precursor ions. We observe that employing TWIMS results in an attenuation of the detected ion current. We postulate that this effect is binary; sensitivity is reduced due to ion scattering during transfer into a high pressure “IMS zone”, sensitivity is reduced due to the saturation of detector digitizer as a result of the IMS concentration effect. This latter effect limits the useful linear range of quantitation, compromising quantitation accuracy of high intensity peptides. We demonstrate that the signal loss from detector saturation and transmission loss can be deconvoluted by investigation of the peptide isotopic envelope. We discuss the origin and extent of signal loss and suggest methods to minimize these effects on q-TWIMS-TOF instrument in the light of different experimental designs and other IMS/MS platforms described previously

Spreading in Social Systems: Reflections

In this final chapter, we consider the state-of-the-art for spreading in social systems and discuss the future of the field. As part of this reflection, we identify a set of key challenges ahead. The challenges include the following questions: how can we improve the quality, quantity, extent, and accessibility of datasets? How can we extract more information from limited datasets? How can we take individual cognition and decision making processes into account? How can we incorporate other complexity of the real contagion processes? Finally, how can we translate research into positive real-world impact? In the following, we provide more context for each of these open questions.Comment: 7 pages, chapter to appear in "Spreading Dynamics in Social Systems"; Eds. Sune Lehmann and Yong-Yeol Ahn, Springer Natur

Multivariate data analysis enabling improved clone selection

Selecting a single cell from a heterogeneous transfection pool that will scale-up appropriately from a micro-scale system to a commercial facility is a challenging and hugely important task. This clonal cell line needs to demonstrate the desired product quality attributes and ensure manufacturability throughout the entire drug manufacturing lifecycle. This process typically requires 6 to 12 months and is a time, capital and labour intensive process. High throughput (HT) methodologies are increasingly being adopted to speed up this cell line selection protocol. However, often the large quantities of data generated in combination with the increase in availability of analytics results in a daunting multivariate data analysis problem. Typically, the cell line selection strategy focuses on quality attributes recorded at point of harvest such as final concentrations of process parameters including titre and viable cell density, level of aggregates or addition product quality attributes. Time-series data such as dissolved oxygen, pH or gas flow rates are often overlooked due to challenges with visualization and interpretation of the large number of process variables recorded. This work describes a novel method that implements advanced multivariate tools including principal component analysis (PCA) to better leverage the available data to help guide this challenging decision making process. The inclusion of additional process variables was demonstrated to enhance the selection of a high-yielding mammalian cell line through inclusion of scale-up dependent process parameters related to high oxygen demands and varying nutrient uptake rates. Furthermore, this technique was demonstrated to highlight problematic product heterogeneities of parent clones that were not identified through univariate analysis of the multiple cell lines. The inclusion of this MVDA methodology demonstrated a more efficient and better decision-making protocol compared to conventional cell line selection processes

A Quadruple-Phase Strong Mg II Absorber at z~0.9902 Toward PG 1634+706

The z=0.9902 system along the quasar PG 1634+706 line of sight is a strong MgII absorber (W(2796)>0.3A) with only weak CIV absorption (it is ``CIV-deficient''). To study this system, we used high-resolution spectra from both HST/STIS (R=30,000) and Keck/HIRES (R=45,000). These spectra cover key transitions, such as MgI, MgII, FeII, SiII, CII, SiIII, CIII, SiIV, and CIV. Assuming a Haardt and Madau extragalactic background spectrum, we modeled the system with a combination of photoionization and collisional ionization. Based on a comparison of synthetic spectra to the data profiles, we infer the existence of the following four phases of gas: i) Seven MgII clouds have sizes of 1-1000pc and densities of 0.002-0.1/cm^3, with a gradual decrease in density from blue to red. The MgII phase gives rise to most of the CIV absorption and resembles the warm, ionized inter-cloud medium of the Milky Way; ii) Instead of arising in the same phase as MgII, MgI is produced in separate, narrow components with b~0.75km/s. These small MgI pockets (~100AU) could represent a denser phase (~200/cm^3) of the interstellar medium (ISM), analogous to the small-scale structure observed in the Milky Way ISM; iii) A ``broad phase'' with a Doppler parameter, b~60km/s, is required to consistently fit Ly-alpha, Ly-beta, and the higher-order Lyman-series lines. A low metallicity (log Z <= -2) for this phase could explain why the system is ``CIV-deficient'', and also why NV and OVI are not detected. This phase may be a galactic halo or it could represent a diffuse medium in an early-type galaxy; iv) The strong absorption in SiIV relative to CIV could be produced in an extra, collisionally ionized phase with a temperature of T~60,000K. The collisional phase could exist in cooling layers that are shock-heated by supernovae-related processes.Comment: 25 pages, 4 figures; to appear in ApJ, April 20, 200

Microlensing Results Challenge the Core Accretion Runaway Growth Scenario for Gas Giants

We compare the planet-to-star mass-ratio distribution measured by gravitational microlensing to core accretion theory predictions from population synthesis models. The core accretion theory's runaway gas accretion process predicts a dearth of intermediate-mass giant planets that is not seen in the microlensing results. In particular, the models predict $\sim10\,\times$ fewer planets at mass ratios of $10^{-4} \leq q \leq 4 \times 10^{-4}$ than inferred from microlensing observations. This tension implies that gas giant formation may involve processes that have hitherto been overlooked by existing core accretion models or that the planet-forming environment varies considerably as a function of host-star mass. Variation from the usual assumptions for the protoplanetary disk viscosity and thickness could reduce this discrepancy, but such changes might conflict with microlensing results at larger or smaller mass ratios, or with other observations. The resolution of this discrepancy may have important implications for planetary habitability because it has been suggested that the runaway gas accretion process may have triggered the delivery of water to our inner solar system. So, an understanding of giant planet formation may help us to determine the occurrence rate of habitable planets.Comment: 12 pages, 2 figures, 1 table, accepted for publication in ApJ

The development and validation of a fast and robust dried blood spot based lipid profiling method to study infant metabolism.

Early life exposures and metabolic programming are associated with later disease risk. In particular lipid metabolism is thought to play a key role in the development of the metabolic syndrome and insulin resistance in later life. Investigative studies of metabolic programming are limited by the ethics and practicalities of sample collection in small infants. Dried blood spots on filter paper, derived from heel pricks are considered as the most suitable option for this age group. We validated a novel lipid profiling method, based on high resolution mass spectrometry to successfully determine the lipid composition of infants using dried blood spots. The spotting and air drying of blood on paper has noticeable effects on many of the lipids, leading to lipid oxidation and hydrolysis, which demand careful interpretation of the obtained data. We compared the lipid profiles from plasma or whole blood samples and the results from dried blood spots to determine if these revealed the same inter-subject differences. The results from dried blood spots were no less reproducible than other lipid profiling methods which required comparatively larger sample volumes. Therefore, lipid profiles obtained from dried blood spots can be successfully used to monitor infancy lipid metabolism and we show significant differences in the lipid metabolism of infants at age 3 versus 12 months