bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamo theories
Authors: Rincon François
Published: August 2019

These lecture notes are based on a tutorial given in 2017 at a plasma physics winter school in Les Houches. Their aim is to provide a self-contained graduate-student level introduction to the theory and modelling of the dynamo effect in turbulent fluids and plasmas, blended with a review of current research in the field. The primary focus is on the physical and mathematical concepts underlying different (turbulent) branches of dynamo theory, with some astrophysical, geophysical and experimental contexts disseminated throughout the document. The text begins with an introduction to the rationale, observational and historical roots of the subject, and to the basic concepts of magnetohydrodynamics relevant to dynamo theory. The next two sections discuss the fundamental phenomenological and mathematical aspects of (linear and nonlinear) small- and large-scale magnetohydrodynamic (MHD) dynamos. These sections are complemented by an overview of a selection of current active research topics in the field, including the numerical modelling of the geo- and solar dynamos, shear dynamos driven by turbulence with zero net helicity and MHD-instability-driven dynamos such as the magnetorotational dynamo. The difficult problem of a unified, self-consistent statistical treatment of small- and large-scale dynamos at large magnetic Reynolds numbers is also discussed throughout the text. Finally, an excursion is made into the relatively new but increasingly popular realm of magnetic-field generation in weakly collisional plasmas. A short discussion of the outlook and challenges for the future of the field concludes the presentation.
To name those lost: assessing extinction likelihood in the Australian vascular flora
Authors: Silcock J.L. , Field A.R. , Walsh N.G. , Fensham R.J.
Published: August 2019

Extinction is a profound biological event, yet despite its finality it can be difficult to verify and many frameworks have been proposed to define formally that extinction has occurred. For most taxonomic groups and regions there is no reliable list of species considered to be probably or possibly extinct. The record of plant extinctions in Australia is no exception, characterized by high turn-over within lists, low transparency of attribution and lack of consistency between jurisdictions. This makes it impossible to evaluate how many plant taxa have become extinct in Australia. We present an ecological framework for assessing the likelihood of plant extinctions, based on taxonomic soundness, degree of habitat modification, detectability and search effort, underpinned by the best available expert knowledge. We show that, in sharp contrast to both the fate of the Australian fauna and prevailing assumptions, only 12 of 71 plant taxa currently listed as or assumed to be extinct are considered probably extinct, and a further 21 possibly extinct. Twenty taxa listed as or assumed to be extinct have dubious taxonomy or occurrence in Australia, and the remaining 18 taxa are considered possibly extant and further surveys are required to ascertain their status. The list of probably and possibly extinct plants is dwarfed by the number thought extinct but rediscovered since 1980. Our method can be used for vascular floras in other regions characterized by well-documented and curated floras and high levels of expert knowledge, and provides a transparent platform for assessing changes in the status of biodiversity.
Use of illicit substances and violent behaviour in psychotic disorders: two nationwide case-control studies and meta-analyses
Authors: Lamsma Jelle , Cahn Wiepke , Fazel Seena ,   GROUP and NEDEN investigators
Published: August 2019

Background

Substance use disorder explains much of the excess risk of violent behaviour in psychotic disorders. However, it is unclear to what extent the pharmacological properties and subthreshold use of illicit substances are associated with violence.

Methods

Individuals with psychotic disorders were recruited for two nationwide projects: GROUP (N= 871) in the Netherlands and NEDEN (N= 921) in the United Kingdom. Substance use and violent behaviour were assessed with standardized instruments and multiple sources of information. First, we used logistic regression models to estimate the associations of daily and nondaily use with violence for cannabis, stimulants, depressants and hallucinogens in the GROUP and NEDEN samples separately. Adjustments were made for age, sex and educational level. We then combined the results in random-effects meta-analyses.

Results

Daily use, compared with nondaily or no use, and nondaily use, compared with no use, increased the pooled odds of violence in people with psychotic disorders for all substance categories. The increases were significant for daily use of cannabis [pooled odds ratio (pOR) 1.6, 95% confidence interval (CI) 1.2–2.0), stimulants (pOR 2.8, 95% CI 1.7–4.5) and depressants (pOR 2.2, 95% CI 1.1–4.5), and nondaily use of stimulants (pOR 1.6, 95% CI 1.2–2.0) and hallucinogens (pOR 1.5, 95% CI 1.1–2.1). Daily use of hallucinogens, which could only be analysed in the NEDEN sample, significantly increased the risk of violence (adjusted odds ratio 3.3, 95% CI 1.2–9.3).

Conclusions

Strategies to prevent violent behaviour in psychotic disorders should target any substance use.
Profiles of psychosocial and clinical functioning in adolescence and risk for later depression and other outcomes
Authors: Olino Thomas M. , Klein Daniel N. , Seeley John R.
Published: August 2019

Background

Most studies examining predictors of the onset of depression focus on variable centered regression methods that focus on the effects of multiple predictors. In contrast, person-centered approaches develop profiles of factors and these profiles can be examined as predictors of onset. Here, we developed profiles of adolescent psychosocial and clinical functioning among adolescents without a history of major depression.

Methods

Data come from a subsample of participants from the Oregon Adolescent Depression Project who completed self-report measures of functioning in adolescence and completed diagnostic and self-report measures at follow-up assessments up to approximately 15 years after baseline.

Results

We identified four profiles of psychosocial and clinical functioning: Thriving; Average Functioning; Externalizing Vulnerability and Family Stress and Internalizing Vulnerability at the baseline assessment of participants without a history of depression at the initial assessment in mid-adolescence. Classes differed in the likelihood of onset and course of depressive disorders, experience of later anxiety and substance use disorders, and psychosocial functioning in adulthood. Moreover, the predictive utility of these classes was maintained when controlling for multiple other established risk factors for depressive disorders.

Conclusions

This work highlights the utility of examining multiple factors simultaneously to understand risk for depression.
Home First: Exploring the Impact of Community-based Home Care for Older Adults and Their Family Caregivers
Authors: Compton Roslyn M. , Olirus Owilli Alex , Caine Vera , Berendonk Charlotte , Jouan-Tapp Donna , Sommerfeldt Susan , McPhee D. Jane , Walz Darla
Published: August 2019

Given the rapidly expanding older adult population, finding health care approaches that support older adults to age in their choice of place, with an accompanying philosophical re-orientation of health services, is becoming more urgent. We studied the Home Care Home First – Quick Response Project to understand how clients over age 75 and their family caregivers perceived the enhanced community-based services delivered through Home First. Using interpretive description as the methodological design, we explored the experiences of eight older adults and 11 family caregivers; all older adults were enrolled in Home First due to a significant change in their health status. We identified four themes: growing older in chosen places with support, philosophy of care, processes of Home First, and the significance of Home First for clients. Overall, clients and family caregivers responded positively to the Home First services. Clients valued their independence and growing older in places they had specifically chosen.
Gender Gaps in Perceptions of Political Science Journals
Authors: Brown Nadia E. , Horiuchi Yusaku , Htun Mala , Samuels David
Published: August 2019

The gender publication gap puts women at a disadvantage for tenure and promotion, which contributes to the discipline’s leaky pipeline. Several studies published in PS find no evidence of gender bias in the review process and instead suggest that submission pools are distorted by gender. To make a contribution to this important debate, we fielded an original survey to a sample of American Political Science Association members to measure participants’ perceptions of political science journals. Results reveal that the gender submission gap is accompanied by a gender perception gap at some but not all political science journals we study. Women report that they are more likely to submit to and get published in some journals, whereas men report as such with regard to other journals. Importantly, these gaps are observed even among scholars with the same methodological (i.e., quantitative or qualitative) approach.
Does message framing matter for promoting the use of nutritional warnings in decision making?
Authors: Vidal Gabriela , Machín Leandro , Aschemann-Witzel Jessica , Ares Gastón
Published: August 2019

Objective:

To evaluate the impact of message framing on attitudes towards messages aimed at promoting the use of nutritional warnings, behavioural intention and actual behaviour, evaluated through visual attention to nutritional warnings and the choice of a snack product during a real choice task.

Design:

Following a between-subjects design, participants were exposed to loss-framed nutrition messages, gain-framed nutrition messages or non-nutrition-related messages (control group). After evaluating the messages, participants were asked to select a snack product as a compensation for their participation. The experiment was conducted using an eye tracker.

Setting:

Montevideo (Uruguay).

Participants:

Convenience sample of 201 people (18–51 years old, 58 % female).

Results:

The average percentage of participants who fixated their gaze on the nutritional warnings during the choice task was slightly but significantly higher for participants who attended to nutrition messages (regardless of their framing) compared with the control group. Participants who attended to loss-framed messages fixated their gaze on the warnings for the longest period of time. In addition, the healthfulness of the snack choices was higher for participants exposed to nutrition-related messages compared with the control group.

Conclusions:

Results from the present work suggest that nutrition messages aimed at increasing awareness of nutritional warnings may increase consumers’ visual attention and encourage more heathful choices. The framing of the messages only had a minor effect on their efficacy.
Celebrity, Democracy, and Epistemic Power
Authors: Archer Alfred , Cawston Amanda , Matheson Benjamin , Geuskens Machteld
Published: August 2019

What, if anything, is problematic about the involvement of celebrities in democratic politics? While a number of theorists have criticized celebrity involvement in politics, none so far have examined this issue using the tools of social epistemology, the study of the effects of social interactions, practices, and institutions on knowledge and belief acquisition. We will draw on these resources to investigate the issue of celebrity involvement in politics, specifically as this involvement relates to democratic theory and its implications for democratic practice. We will argue that an important and underexplored form of power, which we will callepistemic power,can explain one important way in which celebrity involvement in politics is problematic. This is because unchecked uses and unwarranted allocations of epistemic power, which celebrities tend to enjoy, threaten the legitimacy of existing democracies and raise important questions regarding core commitments of deliberative, epistemic, and plebiscitary models of democratic theory. We will finish by suggesting directions that democratic theorists could pursue when attempting to address some of these problems.
Understanding the Galaxy
Authors: Eyer L.
Published: August 2019

This general overview of our understanding of the Galaxy followed the lines of its main structures (halo, disc, bulge/bar) and emphasized some time-domain astronomy contributions. On the one hand the distance and tangential motions of the stars are essential to that understanding, and are obtained through multi-epoch surveys. On the other hand the chemistry of the stars and their radial velocities are also key elements for mapping the Galactic (sub-)structures, and unravelling their history and evolution. Contemporary surveys are revolutionizing our view of the Milky Way and of galaxies in general. Among those, the Gaia mission excels through its precise astrometry of 1.3 billion stars that populate the Milky Way and beyond, providing the first 3-D view of a major part of the Milky Way.
Exploring Data Sonification to Enable, Enhance, and Accelerate the Analysis of Big, Noisy, and Multi-Dimensional Data
Authors: Cooke J. , Díaz-Merced W. , Foran G. , Hannam J. , Garcia B.
Published: August 2019

We explore the properties of sound and human sound recognition as a means to enhance and accelerate visual-only data analysis methods. The aim of this work is to enable and improve the analysis of large data sets, data requiring rapid analysis, multi-dimensional data, and signal detection in data with low signal-to-noise ratio. We present a prototype tool, StarSound, to sonify data such as astronomical transient light curves, spectra, and power spectra. Stereophonic sound is used to ‘visualise’ and localise the data under examination, and 3-D sound is discussed in conjunction with virtual reality technology, as a means to enhance analysis efficiency and efficacy, including rapid data assessment and training machine learning software. In addition, we explore the use of higher-order harmonics as a means to examine simultaneously multi-dimensional data sets. Such an approach can allow the data to be interpreted in a holistic manner and facilitates the discovery of previously unseen connections and relationships. Furthermore, we exploit the capability of the human brain for selective or focused hearing that enables the identification of desired signals in noisy data, or amidst similar or more significant signals. Finally, we provide research examples that benefit directly from data sonification. The work presented here aims to help tackle the challenges of the upcoming era of Big Data and help optimise, speed up and expand aspects of data analysis requiring human interaction.
Multiwavelength Light-Curve Analysis of Cepheid Variables
Authors: Bhardwaj A. , Kanbur S. M. , Marconi M. , Singh H. P. , Rejkuba M. , Ngeow C-C.
Published: August 2019

This poster presented results from a detailed analysis of observed and theoretical light-curves of classical Cepheid variables in the Galaxy and the Magellanic Clouds. The theoretical light-curves were based on non-linear convective hydrodynamical pulsation models; the observational data were taken from ongoing wide-field variability surveys. The variation which we found in theoretical and observed light-curve parameters as a function of period, wavelength and metallicity was used to constrain the input physics to the pulsation models, such as the mass–luminosity relations obeyed by Cepheid variables. We also accounted for the variation in the convective efficiency as entered into the stellar pulsation models and its impact on the theoretical amplitudes and Period-Luminosity relations for Cepheid variables.
Detection of Sectoral Modes in the Eclipsing Binary KIC 4851217
Authors: Fedurco M. , Parimucha Š. , Gajdoš P.
Published: August 2019

KIC 4851217 is a short period eclipsing binary (P = 2.47 days) in the field of the Kepler K1 mission. As well as variability caused by the eclipses, low-amplitude pulsations are also present in the data. A frequency analysis of the residual light-curve revealed δ Sct pulsations in the frequency range from 15–21 d−1 with amplitudes up to 3.5 mmag. Strong linear coupling (fi = fp + kforb) to orbital frequency was found, indicating tidally locked modes. From an analysis of 5 selected groups of frequencies we identified a radial mode on the secondary component, 3 dipole modes (l = |m| = 1), one of them present on the secondary component, and a quadrupole mode (l = |m| = 2), also located on the secondary component.
Phase-resolved Spectroscopy and Photometry of the Eclipsing Polar UZ Fornacis
Authors: Khangale Z. N. , Potter S. B. , Woudt P. A.
Published: August 2019

The blue continuum of the eclipsing polar UZ For is dominated by single- or double-peaked emission from He ii, He i and the Balmer lines. The red spectrum shows weak emission from the Na i doublet at λ 8183 and 8194 Å and strong emission from the Ca ii lines at λ 8498 and 8542 Å. Doppler tomography of the strongest emission features reveals the presence of emission from the irradiated face of the secondary star, the threading region, and the ballistic and magnetically confined accretion stream. We have obtained 28 new eclipse times of UZ For during 2011–2016 as part of our eclipse timing follow-up programme to test the two-planet model proposed to explain variations in the eclipse times of UZ For.
The All-Sky Automated Search for Supernovæ Going Global
Authors: Stritzinger M. ,   the ASAS-SN Team
Published: August 2019

The All-Sky Automated-Survey for SuperNovæ (ASAS-SN) is a fully automated transient search programme that is currently observing the entire night sky every second night to a depth of about 18th magnitude. Since becoming on-line in mid-2014, ASAS-SN has discovered over half of all bright supernovæ, and along the way has also discovered numerous tidal disruption events, cataclysmic variables, stellar flares and even a comet! ASAS-SN currently has two units deployed between Chile and Hawaii, and an additional three units were slated to come on-line by the end of 2017 at observatories in South Africa, Chile and Texas. The poster provided a brief summary of ASAS-SNs accomplishments, and discussed future prospects based on its global expansion.
Design, Build and Test of the VOEvent Network for the SVOM Chinese Ground Segment
Authors: Zhang M. , Huang M. , Wu C.
Published: August 2019

The Space-based, multi-band, astronomical Variable Object Monitor (SVOM) is a collaborative project between China and France dedicated to the detection, localisation and study of about 60 Gamma Ray Bursts per year, and other high-energy transient phenomena. SVOM is planned to be launched in 2021, with a lifetime of 3–5 years. The poster described our construction and testing of a prototype to set up an interface between our data reduction sub-system, the global VOEvent network, and the French science centre.
Optimal Sample Sizes for Testing the Equivalence of Two	Means
Authors: Guo Jiin-Huarng , Chen Hubert J. , Luh Wei-Ming
Published: August 2019

Abstract. Equivalence tests (also known as similarity or parity tests) have become more and more popular in addition to equality tests. However, in testing the equivalence of two population means, approximate sample sizes developed using conventional techniques found in the literature on this topic have usually been under-valued as having less statistical power than is required. In this paper, the authors first address the reason for this problem and then provide a solution using an exhaustive local search algorithm to find the optimal sample size. The proposed method is not only accurate but is also flexible so that unequal variances or sampling unit costs for different groups can be considered using different sample size allocations. Figures and a numerical example are presented to demonstrate various configurations. An R Shiny App is also available for easy use ( https://optimal-sample-size.shinyapps.io/equivalence-of-means/ ).
Geodetic Observations of Time‐Variable Glacial Isostatic Adjustment in Southeast Alaska and Its Implications for Earth Rheology
Authors: Hu Yan , Freymueller Jeffrey T.
Published: August 2019

Global Positioning System observations in Southeast Alaska show evidence for interannual variations in uplift rates, which are consistent with an acceleration of mass loss rates across the region from the 1990s to 2012. We constructed an updated regional loading model based on updated twentieth century average deglaciation estimates. This model features a larger mass loss rate overall than the model used in previous studies. We adopted a viscosity model with an upper and lower mantle viscosity from VM5a but with a low viscosity asthenosphere as in previous regional studies. We varied the asthenospheric thickness, asthenospheric viscosity, and lithospheric thickness to find the Earth model that best fits the data, which has a lithospheric thickness of 55 km and an asthenosphere with thickness 230 km and viscosity 3 × 1019 Pa s. There is a strong tradeoff between the asthenosphere thickness and viscosity, and different estimates or assumptions about the asthenospheric thickness is one of the main causes of the varying viscosity estimates of previous studies. We find a higher viscosity than previous studies in part because we find that a thicker asthenosphere fits the data better than a thinner one and also because the higher twentieth century mass loss rate compared to earlier studies requires a higher viscosity to predict the same uplift rates. Vertical velocities predicted by the model drop rapidly with distance from the ice masses, while horizontal velocities are smaller but extend for a longer distance.
Influence of CO2 on the Electrical Conductivity and Streaming Potential of Carbonate Rocks
Authors: Cherubini A. , Garcia B. , Cerepi A. , Revil A.
Published: August 2019

Minimally intrusive geophysical methods are required to monitor CO2 leakages from underground storage reservoirs. We investigate the impact of gaseous CO2 on both electrical conductivity and electrokinetic properties of two limestones during their drainage. These data are contrasted with measurements performed on one clay‐free sandstone. The initial NaCl brine concentrations before drainage (from 8.5 to 17.1 mMol/L) correspond to the limit between freshwater and slightly brackish water. These values are representative to saturated brine formations inside which CO2 can be stored. Using these water salinities, the surface conductivity of the samples represents less than 5% of the overall electrical conductivity. A CO2 release leads to an increase of the electrical conductivity of the rock during drainage in limestones and no change in sandstone. This increase in the electrical conductivity is due to the dissolution of calcite with the concomitant release of Ca2+ and HCO3− in the pore water. It is not due to the CO2 dissociation in the pore water in the pore pressure range 0–0.5 MPa and at a temperature of T = 20 °C. The measurements of the streaming potential show a substantial decrease of the streaming potential coupling coefficient and zeta potential magnitudes after a CO2 release in carbonates. This observation is explained by the increase of the ionic strength of the pore water in the course of the experiment. This change can be used, in turn, to determine calcite dissolution rates from the measurement of the electrokinetic properties.
Tracking the Growth of the Himalayan Fold‐and‐Thrust Belt From Lower Miocene Foreland Basin Strata: Dumri Formation, Western Nepal
Authors: Stickroth S. F. , Carrapa B. , DeCelles P. G. , Gehrels G. E. , Thomson S. N.
Published: August 2019

New data from the lower Miocene Dumri Formation of western Nepal document exhumation of the Himalayan fold‐thrust belt and provenance of the Neogene foreland basin system. We employ U‐Pb zircon, Th‐Pb monazite, 40Ar/39Ar white mica, and zircon fission track chronometers to detrital minerals to constrain provenance, timing, and rate of exhumation of Himalayan source regions. Clusters of Proterozoic–early Paleozoic (900–400 Ma) Th‐Pb monazite and 40Ar/39Ar white mica detrital ages provide evidence for erosion of a Greater Himalayan sequence protolith unaffected by high‐grade Eohimalayan metamorphism. A small population of ~40 Ma cooling ages in detrital white mica grains shows exhumation of low‐grade metamorphic Tethyan Himalayan sequence through the ~350 °C closure temperature along the Tethyan Frontal thrust (proto‐South Tibetan detachment) during the late Eocene. Dumri Formation detritus shows a ~12 Myr time difference between cooling of its source rocks through the ~350 and ~240 °C closure temperatures as recorded by ~40–38 Ma youngest peak cooling ages in 40Ar/39Ar detrital white mica and ~28–24 Ma youngest populations in detrital zircon fission track. Exhumation between circa 40 and 28 Ma is consistent with slip and exhumation along the Main Central Thrust. Combined with similar data from northwestern India, our study suggests west‐to‐east spatially variable exhumation rates along strike of the Main Central Thrust. Our data also show an increase in exhumation during middle Miocene–Pliocene time, which is consistent with growth of the Lesser Himalaya duplex.
Impacts of Climate Change on Volcanic Stratospheric Injections: Comparison of 1‐D and 3‐D Plume Model Projections
Authors: Aubry T. J. , Cerminara M. , Jellinek A. M.
Published: August 2019

Explosive volcanic eruptions are one of the most important driver of climate variability. Yet, we still lack a fundamental understanding of how climate change may affect future eruptions. Here, we use an ensemble of simulations by 1‐D and 3‐D volcanic plume models spanning a large range of eruption source and atmospheric conditions to assess changes in the dynamics of future eruptive columns. Our results shed new light on differences between the predictions of 1‐D and 3‐D plume models. Furthermore, both models suggest that as a result of ongoing climate change, for tropical eruptions, (i) higher eruption intensities will be required for plumes to reach the upper troposphere/lower stratosphere and (ii) the height of plumes currently reaching the upper troposphere/lower stratosphere or above will increase. We discuss the implications of these results for the climatic impacts of future eruptions. Our simulations can directly inform climate model experiments on climate‐volcano feedback.
The Latest Spreading Periods of the South China Sea: New Constraints From Macrostructure Analysis of IODP Expedition 349 Cores and Geophysical Data
Authors: Sun Zhen , Ding Weiwei , Zhao Xixi , Qiu Ning , Lin Jian , Li Chun‐Feng
Published: August 2019

Macrostructures preserved in deformed rocks are essential for the understanding of their evolution, especially when the deformation is weak and hard to discriminate in regional scale or purely through geophysical data. In order to resolve the inconsistency between NS trending fracture zones and NE oriented spreading fabrics of the South China Sea during the latest spreading stage, we analyzed macrostructures identifiable from the basalt and consolidated sediment samples of the Integrated Ocean Drilling Program (IODP) Sites U1431 and U1433. These two sites are close to the East and Southwest relict spreading ridges and provide critical information on the latest spreading stages. The structures in the basalt of both sites suggest two dominant orientations of NS and NE. At U1431, sediments show mainly WNW trending slickensides, different from that of basalt. At U1433, no structures were found in postspreading sediment. Thus, NE and NS trending structures in basalt are most possibly formed by seafloor spreading. Crosscutting relationship suggests that NE trending structures formed first, followed by NS and finally WNW trending structures. These observations are consistent with geophysical features. Magnetic anomalies and ocean bottom seismometer velocity suggest that the latest relict ridge of the East Subbasin coincides with the EW trending seamount chain. Located between the relict ridges of East and Southwest Subbasins, NS trending Zhongnan‐Liyue Fracture Zone had acted as the latest transform fault. Based on the above evidences, we proposed that the South China Sea may have experienced a short period of NS oriented spreading after earlier SE spreading. These results resolve the previous inconsistencies.
Modification of the Seismic Properties of Subducting Continental Crust by Eclogitization and Deformation Processes
Authors: Zertani Sascha , John Timm , Tilmann Frederik , Motra Hem B. , Keppler Ruth , Andersen Torgeir B. , Labrousse Loic
Published: August 2019

Subduction zone processes and the resulting geometries at depth are widely studied by large‐scale geophysical imaging techniques. The subsequent interpretations are dependent on information from surface exposures of fossil subduction and collision zones, which help to discern probable lithologies and their structural relationships at depth. For this purpose, we collected samples from Holsnøy in the Bergen Arcs of western Norway, which constitutes a well‐preserved slice of continental crust, deeply buried and partially eclogitized during Caledonian collision. We derived seismic properties of both the lower crustal granulite‐facies protolith and the eclogite‐facies shear zones by performing laboratory measurements on cube‐shaped samples. P and S wave velocities were measured in three perpendicular directions, along the principal fabric directions of the rock. Resulting velocities agree with seismic velocities calculated using thermodynamic modeling and confirm that eclogitization causes a significant increase of the seismic velocity. Further, eclogitization results in decreased VP/VS ratios and, when associated with deformation, an increase of the seismic anisotropy due to the crystallographic preferred orientation of omphacite that were obtained from neutron diffraction measurements. The structural framework of this exposed complex combined with the characteristic variations of seismic properties from the lower crustal protolith to the high‐pressure assemblage provides the possibility to detect comparable structures at depth in currently active settings using seismological methods such as the receiver function method.
Stabilizing Effect of High Pore Fluid Pressure on Slip Behaviors of Gouge‐bearing Faults
Authors: Xing Tiange , Zhu Wenlu , French Melodie , Belzer Ben
Published: August 2019

We conducted experiments to investigate the influence of pore fluid pressure on the frictional strength and slip behavior of gouge bearing faults. Saw cut porous sandstone samples with a layer of gouge powders placed between the precut surfaces were deformed in the conventional triaxial loading configuration. A series of velocity‐step tests were performed to measure the response of the friction coefficient to variations in sliding velocity. Pore volume changes were monitored during shearing of the gouge. Our results demonstrate that under constant effective pressure, increasing pore pressure stabilizes the frictional slip of faults with all four gouge materials including antigorite, olivine, quartz, and chrysotile. The stabilizing effect is the strongest in antigorite gouge, which shows an evolution of friction parameters from velocity‐weakening toward velocity‐strengthening behavior with increasing pore pressure. Experiments with controlled pore volume show that the pore volume reduction diminishes under high pore fluid pressures, implying an increasing dilation component at these conditions. The dilatant hardening mechanism can explain the observed strengthening. These results provide a possible explanation to the observed spatial correlation between slow slip events and high pore pressure in many subduction zones.
Three Years of Near‐Coastal Antarctic Iceberg Distribution From a Machine Learning Approach Applied to SAR Imagery
Authors: Barbat Mauro M. , Rackow Thomas , Hellmer Hartmut H. , Wesche Christine , Mata Mauricio M.
Published: August 2019

Mass loss around the Antarctic Ice Sheet is driven by basal melting and iceberg calving, which constitute the two dominant paths of freshwater flux into the Southern Ocean. Although of similar magnitude, icebergs play an important and still not fully understood role in the balance of heat and freshwater around Antarctica. This lack of understanding is partly due to operational difficulties in large‐scale monitoring in polar regions, despite observational and remote sensing efforts. In this study, a novel machine learning approach, augmented by visual inspection, was applied to three Synthetic Aperture Radar (SAR) mosaics of the whole Antarctic continent and its adjacent coastal zone. Although originally intended for a mapping of the Antarctic continent, the SAR mosaics allow us to document the evolution and distribution of the size (and mass) of icebergs in the pan‐Antarctic near‐coastal zone for the years 1997, 2000, and 2008. Our novel algorithm identified 7,649 icebergs in 1997, 13,712 icebergs in 2000, and 7,246 icebergs in 2008 with surface areas between 0.1 and 4,567.82 km2 and total masses of 4,641.53, 6,862.81, and 5,263.69 Gt, respectively. Large regional variability was observed, although a zonal pattern distribution is present. This has implications for future climate modeling studies that try to estimate the freshwater flux from melting icebergs, which demands a realistic representation of the interannually varying near‐coastal iceberg pattern to initialize the simulations.
Study of Lateral Flow in a Stratified Tidal Channel‐Shoal System: The Importance of Intratidal Salinity Variation
Authors: Zhou Zaiyang , Ge Jianzhong , Wang Zheng Bing , van Maren D. S. , Ma Jianfei , Ding Pingxing
Published: August 2019

Lateral flow significantly contributes to the near‐bottom mass transport of salinity in a channel‐shoal system. In this study, an integrated tripod system was deployed in the transition zone of a channel‐shoal system of the Changjiang Estuary (CE), China, to observe the near‐bottom physics with high temporal/spatial resolution, particularly focusing on the lateral‐flow‐induced mass transport. These in situ observations revealed a small‐scale salinity fluctuation around low water slack during moderate and spring tidal conditions. A simultaneous strong lateral current was also observed, which was responsible for this small‐scale fluctuation. A high‐resolution unstructured‐grid Finite‐Volume Community Ocean Model has been applied for the CE to better understand the mechanism of this lateral flow and its impact on salinity transport. The model results indicate that a significant southward near‐bed shoal‐to‐channel current is generated by the salinity‐driven baroclinic pressure gradient. This lateral current affects the salinity transport pattern and the residual current in the cross‐channel direction. Cross‐channel residual current shows a two‐layer structure in the vertical, especially in the intermediate tide when the lateral flow notably occurred. Both observation and model results indicate that near‐bottom residual transport of water moved consistently southward (shoal to channel). Mechanisms for this intratidal salinity variation and its implications can be extended to other estuaries with similar channel‐shoal features.
Impacts of Ocean Warming, Sea Level Rise, and Coastline Management on Storm Surge in a Semienclosed Bay
Authors: Zhang Fan , Li Ming
Published: August 2019

Regional atmosphere and ocean models are used to investigate how sea level rise, ocean warming, and coastline management affect storm surge in the semienclosed Chesapeake Bay. Using Hurricane Isabel (2003) as a case study, the storm is placed under the climatic conditions projected for 2050 and 2100. Higher sea surface temperature increases the latent heat release from the ocean, resulting in large increases in storm intensity and maximum sustained wind speeds. The storm surge height, defined as the difference between storm tide and astronomical tide, is amplified in the future climate and amounts to ~30% of the relative sea level rise. Hardening shorelines further increases the storm surge height in the middle and upper parts of the Bay by up to 0.5 m. Sea level rise has a modest impact on the storm surge height: decreasing it by 0.1–0.2 m if the low‐lying areas are allowed to be flooded but increases it by 0.1–0.3 m if hypothetic walls are placed at the current coastline. Ocean warming is the main driver of storm surge amplification in the future climate. Energy budget analysis shows that allowing flooding over low‐lying areas leads to a significant energy loss and reduces the storm surge height in the estuary.
Searching for Lunar Horizon Glow With the Lunar Orbiter Laser Altimeter
Authors: Barker M. K. , Mazarico E. , McClanahan T. P. , Sun X. , Neumann G. A. , Smith D. E. , Zuber M. T. , Head J. W.
Published: August 2019

We present the results of a 2‐year‐long systematic campaign to monitor the lunar dust exosphere for enhancements in dust concentration at altitudes <20 km both during and outside of major meteor stream periods. We utilize the radiometric capabilities of the Lunar Orbiter Laser Altimeter Laser Ranging telescope onboard the Lunar Reconnaissance Orbiter to search for forward‐scattered sunlight from exospheric dust grains, called lunar horizon glow (LHG). Specifically, we test the hypothesis that major meteor streams can produce LHG similar to what was measured in Apollo 15 coronal photography. Assuming a one‐dimensional exponential vertical dust profile and a dust grain radius r∼0.1μm, we derive an upper limit of ∼10−11 g/cm2 on the overlying column dust mass density near the terminator during stream periods, a limit roughly 10 times lower than inferred from Apollo 15. Recent studies at altitudes ∼1–20 km outside of major meteor streams and at higher altitudes during streams placed limits on the density of similarly sized grains ∼100–1,000 times lower than Apollo 15. Our results show that Apollo 15‐like LHG, if real, is also a rare occurrence at altitudes <20 km during major meteor stream periods. This study is the first to quantitatively constrain the role of meteor streams in producing Apollo 15‐like LHG at altitudes <20 km and small forward‐scattering angles and further narrows the properties of any similar high‐altitude LHG and the conditions under which it can occur.
Smart polymer-based calcium-ion self-regulated nanochannels by mimicking the biological Ca2+-induced Ca2+ release process
Authors: Li Yunlong , Xiong Yuting , Wang Dongdong , Li Xiuling , Chen Zhixiang , Wang Cunli , Qin Haijuan , Liu Jinxuan , Chang Baisong , Qing Guangyan
Published: August 2019

In nature, ion channels play key roles in controlling ion transport between cells and their surroundings. Calcium ion (Ca2+)-induced Ca2+ release (CICR), a critical control mechanism for Ca2+ channels, occurs due to a Ca2+ concentration gradient working in synergy with ryanodine receptors, which are famously known as “calcium sparks”. Inspired by this self-regulated biological process, a smart Ca2+ concentration-modulated nanochannel system was developed by integrating a poly{N-isopropylacrylamide-co-acrylamide-[4-(trifluoromethyl) phenyl]-2-thiourea0.2-co-acrylamide-DDDEEKC0.2} (denoted as PNI-co-CF3-PT0.2-co-DDDEEKC0.2) three-component copolymer onto the nanochannels of a porous anodic alumina (PAA) membrane. In this smart polymer design, the DDDEEKC hepta-peptide unit has an extraordinary binding affinity with Ca2+ through coordination bonds, while CF3-PT functions as a hydrogen bond mediation unit, facilitating the remarkable conformational transition of the PNI main chain in response to Ca2+-specific adsorption. Due to these futures, the dynamic gating behaviors of the modified nanochannels could be precisely manipulated by the Ca2+ concentration. In addition, the sensitive Ca2+ response, as low as 10 pM with a high specificity toward Ca2+ capable of discriminating Ca2+ from other potential interference metal ions (e.g., K+, Cu2+, Mg2+, Zn2+, Fe3+, and Al3+), remarkable morphological change in the nanochannel and satisfactory reversibility indicate the great potential of Ca2+-responsive polymers for the fabrication of biodevices and artificial nanochannels.
Maximizing binary interactome mapping with a minimal number of assays
Authors: Choi Soon Gang , Olivet Julien , Cassonnet Patricia , Vidalain Pierre-Olivier , Luck Katja , Lambourne Luke , Spirohn Kerstin , Lemmens Irma , Dos Santos Mélanie , Demeret Caroline , Jones Louis , Rangarajan Sudharshan , Bian Wenting , Coutant Eloi P. , Janin Yves L. , van der Werf Sylvie , Trepte Philipp , Wanker Erich E. , De Las Rivas Javier , Tavernier Jan , Twizere Jean-Claude , Hao Tong , Hill David E. , Vidal Marc , Calderwood Michael A. , Jacob Yves
Published: August 2019

Complementary assays are required to comprehensively map complex biological entities such as genomes, proteomes and interactome networks. However, how various assays can be optimally combined to approach completeness while maintaining high precision often remains unclear. Here, we propose a framework for binary protein-protein interaction (PPI) mapping based on optimally combining assays and/or assay versions to maximize detection of true positive interactions, while avoiding detection of random protein pairs. We have engineered a novel NanoLuc two-hybrid (N2H) system that integrates 12 different versions, differing by protein expression systems and tagging configurations. The resulting union of N2H versions recovers as many PPIs as 10 distinct assays combined. Thus, to further improve PPI mapping, developing alternative versions of existing assays might be as productive as designing completely new assays. Our findings should be applicable to systematic mapping of other biological landscapes.
The value of understanding feedbacks from ecosystem functions to species for managing ecosystems
Authors: Xiao Hui , McDonald-Madden Eve , Sabbadin Régis , Peyrard Nathalie , Dee Laura E. , Chadès Iadine
Published: August 2019

Ecological systems are made up of complex and often unknown interactions and feedbacks. Uncovering these interactions and feedbacks among species, ecosystem functions, and ecosystem services is challenging, costly, and time-consuming. Here, we ask: for which ecosystem features does resolving the uncertainty about the feedbacks from ecosystem function to species improve management outcomes? We develop a dynamic value of information analysis for risk-neutral and risk-prone managers on motif ecosystems and explore the influence of five ecological features. We find that learning the feedbacks from ecosystem function to species does not improve management outcomes for maximising biodiversity, yet learning which species benefit from an ecosystem function improves management outcomes for ecosystem services by up to 25% for risk-neutral managers and 231% for risk-prone managers. Our general approach provides useful guidance for managers and researchers on when learning feedbacks from ecosystem function to species can improve management outcomes for multiple conservation objectives.
Are all cyclin-dependent kinases 4/6 inhibitors created equal?
Authors: Marra Antonio , Curigliano Giuseppe
Published: August 2019

The harnessing in clinical practice of cyclin-dependent kinases 4/6 inhibitors, namely palbociclib, ribociclib, and abemaciclib, has substantially changed the therapeutic approach for hormone receptor-positive metastatic breast cancer (BC). Phase II–III clinical trials evaluating the addition of these agents to standard endocrine therapy reported consistent improvements in response rates and progression-free survival as well as manageable toxicity profiles and excellent impact on patients’ quality of life. Hence, pivotal trials provided comparable results among different cyclin-dependent kinases 4/6 inhibitors, there is an increasing interest in finding substantial differences in order to implement their use in clinical practice. The aim of this paper is to summarize the current evidences raised from preclinical and clinical studies on cyclin-dependent kinases 4/6 inhibitors in BC, focusing on differences in terms of pharmacological properties, toxicity profile, and patients’ quality of life.
Sixteen years of bathymetry and waves at San Diego beaches
Authors: Ludka B. C. , Guza R. T. , O’Reilly W. C. , Merrifield M. A. , Flick R. E. , Bak A. S. , Hesser T. , Bucciarelli R. , Olfe C. , Woodward B. , Boyd W. , Smith K. , Okihiro M. , Grenzeback R. , Parry L. , Boyd G.
Published: August 2019

Sustained, quantitative observations of nearshore waves and sand levels are essential for testing beach evolution models, but comprehensive datasets are relatively rare. We document beach profiles and concurrent waves monitored at three southern California beaches during 2001–2016. The beaches include offshore reefs, lagoon mouths, hard substrates, and cobble and sandy (medium-grained) sediments. The data span two energetic El Niño winters and four beach nourishments. Quarterly surveys of 165 total cross-shore transects (all sites) at 100 m alongshore spacing were made from the backbeach to 8 m depth. Monthly surveys of the subaerial beach were obtained at alongshore-oriented transects. The resulting dataset consists of (1) raw sand elevation data, (2) gridded elevations, (3) interpolated elevation maps with error estimates, (4) beach widths, subaerial and total sand volumes, (5) locations of hard substrate and beach nourishments, (6) water levels from a NOAA tide gauge (7) wave conditions from a buoy-driven regional wave model, and (8) time periods and reaches with alongshore uniform bathymetry, suitable for testing 1-dimensional beach profile change models.
Tidal control of the flow through long, narrow straits: a modeling study for the Seto Inland Sea
Authors: Kurogi Masao , Hasumi Hiroyasu
Published: August 2019

Even in coastal oceans where tidal currents are predominant, long-term mean currents are of great interest since they are responsible for the transport of materials over long timescales. Tides could significantly affect mean currents in long, narrow straits due to tide-topography interaction, but it is yet unclear how and to what extent tides control throughflows. Here, we focus on the throughflow in the Seto Inland Sea, Japan, which has enormous impacts on the marine environment while its long-term mean characteristics, even the flow direction, are not well described by observations. By using a state-of-the-art ocean model, we show that the simulated throughflow is eastward on annual average and its volume transport is considerably suppressed by tides. It is found that tides enhance mixing and induce time-mean eddies, and both work to reduce the throughflow. A westward throughflow was previously estimated based on an acoustic measurement. The discrepancy between this estimate and our result would be due to whether or not such eddies are taken into account. These findings imply that tides may also suppress the throughflow of the other straits around the world. Revealing such tidal effects may contribute to a better performance of oceanic and climate simulations.