bluuebunny/crossref_metadata_2025 huggingface dataset:
Discrete-type approximations for non-Markovian optimal stopping problems: Part I
Authors: Leão Dorival , Ohashi Alberto , Russo Francesco
Published: December 2019

We present a discrete-type approximation scheme to solve continuous-time optimal stopping problems based on fully non-Markovian continuous processes adapted to the Brownian motion filtration. The approximations satisfy suitable variational inequalities which allow us to construct

$\varepsilon$

-optimal stopping times and optimal values in full generality. Explicit rates of convergence are presented for optimal values based on reward functionals of path-dependent stochastic differential equations driven by fractional Brownian motion. In particular, the methodology allows us to design concrete Monte Carlo schemes for non-Markovian optimal stopping time problems as demonstrated in the companion paper by Bezerra et al.
Skeletal stochastic differential equations for continuous-state branching processes
Authors: Fekete D. , Fontbona J. , Kyprianou A. E.
Published: December 2019

It is well understood that a supercritical continuous-state branching process (CSBP) is equal in law to a discrete continuous-time Galton–Watson process (the skeleton of prolific individuals) whose edges are dressed in a Poissonian way with immigration which initiates subcritical CSBPs (non-prolific mass). Equally well understood in the setting of CSBPs and superprocesses is the notion of a spine or immortal particle dressed in a Poissonian way with immigration which initiates copies of the original CSBP, which emerges when conditioning the process to survive eternally. In this article we revisit these notions for CSBPs and put them in a common framework using the well-established language of (coupled) stochastic differential equations (SDEs). In this way we are able to deal simultaneously with all types of CSBPs (supercritical, critical, and subcritical) as well as understanding how the skeletal representation becomes, in the sense of weak convergence, a spinal decomposition when conditioning on survival. We have two principal motivations. The first is to prepare the way to expand the SDE approach to the spatial setting of superprocesses, where recent results have increasingly sought the use of skeletal decompositions to transfer results from the branching particle setting to the setting of measure valued processes. The second is to provide a pathwise decomposition of CSBPs in the spirit of genealogical coding of CSBPs via Lévy excursions, albeit precisely where the aforesaid coding fails to work because the underlying CSBP is supercritical.
Industry and gender in recent representations of Sino-Italian relations
Authors: Chu Mark
Published: December 2019

As Italian society struggles to come to terms with the presence of Chinese immigrants and with changing global patterns of industrialisation and shifts in the dynamics of industrial power, the question of Sino-Italian relations is increasingly present in Italian cultural representations across media and genre. Among the themes which recur within Italian discourse on Chinese industry are Made in Italy vs Made in China, tradition vs modernity, and environmental responsibility. In this paper, I offer a reading of the complex and, at times, ambivalent treatment of these themes in Gianni Amelio's 2006 film,La stella che non c’è(The Missing Star), and Alessandro Perissinotto's 2014 novel,Coordinate d'Oriente(Oriental Coordinates). Central to my analysis of the two works is an examination of the trope of contacts between the economies and societies of the two countries being sublimated in the fictional narratives into relationships between Western men and Chinese women. Against this backdrop, I propose an interpretation of the power dynamics which underpin the narratives.
Italianerie: transculturality, co-creation and transforming identities between Italy and Asia
Authors: Marinelli Maurizio , Ling Wessie
Published: December 2019

Questo numero speciale di Modern Italy contiene sette saggi di studiosi internazionali sui rapporti tra l'Italia e l'Asia. L'attenzione primaria è sulla transculturalità, la co-creazione, il fascino e la reinvenzione dell'Italia in Asia (o dell'Asia in Italia) in settori e campi nodali quali l'architettura, il cinema, la letteratura, la moda, la comunicazione digitale, la storia e la geografia.
“Have You Not Heard of Florida?” Jean Ribault, Thomas Stukeley, and the Dream of England's First Overseas Colony
Authors: DeCoster Jonathan
Published: December 2019

English overseas colonialism is generally traced to the anti-Catholic and anti-Spanish ideologies of Richard Hakluyt, Humphrey Gilbert, and other exponents in the 1570s and 1580s. This article puts Florida at the forefront of English colonialism by taking seriously Thomas Stukeley's proposed colonisation expedition in 1563. The focus on the 1560s reveals how a dynastic rivalry with France, rather than a religious rivalry with Spain, gave birth to England's first colonial impulse. Jean Ribault, well known as the founder of French Florida, serves as the connecting link between Florida and England. His previously unappreciated role in European diplomacy unwittingly turned his fledgling colony into a pawn to be traded among France, Spain, and England. Furthermore, Queen Elizabeth's interest in joining the race for colonies may have been fuelled more by her desire to regain Calais from the French than to plant settlers in America. But while her motives may well have been cynical, the English public for the first time began to see itself as a colonising people. The end result was that Florida not only emerged as part of the fountainhead of English colonialism, but also came to play an important role in European politics.
Does the Pagan King Reply? Malayalam Documents on the Portuguese Arrival in India
Authors: Kooria Mahmood
Published: December 2019

This article is a response to Sebastian Prange's essay in Itinerario 41, no. 1 (2017): 151–173 wherein he presented a ‘virtually unknown manuscript’ on the Portuguese arrival in India as an Indian voice, unheard in the existing historiography. Prange had consulted the English translation of a Malayalam text by John Wye, that the former had assumed to be lost. However its original palm-leaf manuscript (ōla) is kept at the British Library. This ōla, entitled Kēraḷa Varttamānam, brings to light some remarkable omissions and a few discrepancies in Wye's translation. Closely reading different manuscripts in Malayalam, Arabic, and English I argue that this ōla is in fact a translation of a sixteenth-century Arabic text, Tuḥfat al-mujāhidīn, well known among scholars of its place and period. Taking it a step ahead, I argue that the very existence of this text points towards the cross-cultural and cross-linguistic interactions between the Arabic and Malayalam spheres of premodern Malabar. The ōla demonstrates one of the first instances of Malayalam literature's engagement with a secular and historical theme as the arrival of the Portuguese. In addition, Malayalam works such as Kēraḷōlpatti and Kēraḷa-paḻama are clear voices from Malabar on the Portuguese arrival and consequent episodes.
Bodies in High Places: Exploration, Altitude Sickness, and the Problem of Bodily Comparison in the Himalaya, 1800–1850
Authors: Fleetwood Lachlan
Published: December 2019

Motivated by both science and empire, European explorers increasingly ventured into the high Himalaya after 1800, where they encountered the insidious yet little understood effects of altitude sickness. They did not, however, do so alone. Tensions arising from the highly unpredictable distribution of symptoms were exacerbated by explorers’ dependence on pre-existing networks of labour and expertise, which forced them to measure their bodies against those of their Asian companions. This article examines altitude physiology in the early nineteenth century, largely overlooked by scholars in favour of the more systematic scientific studies of the later period. I consider engagement with indigenous explanations (resulting from poisonous miasmas from plants), the tropes travellers used in their accounts to avoid inverting hierarchies around bodily performance, and attempts to quantify symptoms and instrumentalise bodies by measuring pulses. I argue that high mountains became spaces of comparison, intensified by uncertainty over the scientific status of altitude sickness, and use this to bring into focus the practical, everyday aspects of relationships between explorers, guides, and porters. By considering comparisons at multiple scales, this article also historicises the formulation of high mountain medical topographies in the context of upland frontiers and imperial expansion.
Sex Differences in Cognitive Changes in De Novo Parkinson’s Disease
Authors: Bayram Ece , Banks Sarah J. , Shan Guogen , Kaplan Nikki , Caldwell Jessica Z.K.
Published: December 2019

Objective:

To evaluate the sex differences in cognitive course over 4 years in Parkinson’s disease (PD) patients with and without mild cognitive impairment (MCI) compared to controls.

Methods:

Four-year longitudinal cognitive scores of 257 cognitively intact PD, 167 PD-MCI, and 140 controls from the Parkinson’s Progression Markers Initiative were included. Longitudinal scores of men and women, and PD with and without MCI were compared.

Results:

Women had better verbal memory, men had better visuospatial function. There was no interaction between sex, diagnostic group, and/or time (4-year follow-up period).

Conclusions:

Sex differences in cognitive course in de novo PD are similar to healthy aging. Cognitive decline rates in PD with and without MCI are similar for the first 4 years of PD.
Operationalizing Impaired Performance in Neuropsychological Assessment: A Comparison of the Use of Published Versus Sample-Based Normative Data for the Prediction of Dementia
Authors: Callahan Brandy L. ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: December 2019

Objectives:

To compare the sensitivity, specificity, and predictive value of published versus sample-based norms to detect early dementia in the Uniform Data Set (UDS).

Methods:

The UDS was administered to 526 nondemented participants from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Baseline scores were standardized using published norms and healthy control data from ADNI corrected for age, education, and sex. Subjects obtaining two scores < −1 SD (determined separately using published and sample norms) were labeled “at risk for dementia.” Both methods were compared on sensitivity, specificity, and positive/negative predictive value (PPV/NPV) for dementia at follow-up.

Results:

Risk scores derived from published data had 86.1% sensitivity, 62.0% specificity, 68.6% accuracy, 46.1% PPV, and 92.2% NPV. Those from sample norms were more sensitive (91.0%), less specific (52.9%), and less accurate (63.3%), with worse PPV (42.1%) and similar NPV (94.0%). Sample norms were better at identifying incident dementia cases with relatively lower education than those with higher education. Discrepancies between both methods were more common in women.

Conclusions:

Sample norms are marginally more sensitive than published norms for predicting dementia, while published norms are slightly more accurate. Accuracy of risk estimates for women and those with lower education may be increased using locally generated norms.
Discrepancy-Based Evidence for Loss of Thinking Abilities (DELTA): Development and Validation of a Novel Approach to Identifying Cognitive Changes
Authors: Asken Breton M. , Thomas Kelsey R. , Lee Athene , Davis Jennifer D. , Malloy Paul F. , Salloway Stephen P. ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: December 2019

Objective:

To develop and validate the Discrepancy-based Evidence for Loss of Thinking Abilities (DELTA) score. The DELTA score characterizes the strength of evidence for cognitive decline on a continuous spectrum using well-established psychometric principles for improving detection of cognitive changes.

Methods:

DELTA score development used neuropsychological test scores from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort (two tests each from Memory, Executive Function, and Language domains). We derived regression-based normative reference scores using age, gender, years of education, and word-reading ability from robust cognitively normal ADNI participants. Discrepancies between predicted and observed scores were used for calculating the DELTA score (range 0–15). We validated DELTA scores primarily against longitudinal Clinical Dementia Rating-Sum of Boxes (CDR-SOB) and Functional Activities Questionnaire (FAQ) scores (baseline assessment through Year 3) using linear mixed models and secondarily against cross-sectional Alzheimer’s biomarkers.

Results:

There were 1359 ADNI participants with calculable baseline DELTA scores (age 73.7 ± 7.1 years, 55.4% female, 100% white/Caucasian). Higher baseline DELTA scores (stronger evidence of cognitive decline) predicted higher baseline CDR-SOB (ΔR2 = .318) and faster rates of CDR-SOB increase over time (ΔR2 = .209). Longitudinal changes in DELTA scores tracked closely and in the same direction as CDR-SOB scores (fixed and random effects of mean + mean-centered DELTA, ΔR2 > .7). Results were similar for FAQ scores. High DELTA scores predicted higher PET-Aβ SUVr (ρ = 324), higher CSF-pTau/CSF-Aβ ratio (ρ = .460), and demonstrated PPV > .9 for positive Alzheimer’s disease biomarker classification.

Conclusions:

Data support initial development and validation of the DELTA score through its associations with longitudinal functional changes and Alzheimer’s biomarkers. We provide several considerations for future research and include an automated scoring program for clinical use.
TRUTH, KNOWLEDGE, AND RELIGIOUS BELIEF
Authors: Hendry John
Published: December 2019

Religious beliefs are often criticized as lacking the rational justification we expect of factual knowledge claims. In this article I suggest that while religious believers do often claim ‘knowledge’ of the ‘truth’ they typically use these words in traditional, and indeed still current, senses that are quite different from the senses assumed both by their atheist critics and by standard theories of knowledge. The claims are not primarily claims of factual accuracy, subject to the norms of what philosophers call theoretical reasoning, but claims of acquaintance with what can be trusted in the making of practical judgements, and subject to the rather different norms of practical reasoning. This does not exempt them from rational critique, but it does call for a different kind of critique from that usually offered.
IN DEFENCE OF SPANKING
Authors: Hsiao Timothy
Published: December 2019

Opponents of spanking rest their arguments on the implicit assumption that punishment can only be justified by its corrective or deterrent effects. But this is a questionable assumption. Punishment is fundamentally about retribution: it seeks to give a wrongdoer what he deserves. It is for this reason that corporal punishment is morally permissible, irrespective of whether it corrects or deters future misbehaviour.
Entzündliche Vulvaerkrankungen aus dermatologischer Sicht
Authors: Kolm Isabel
Published: December 2019

Zusammenfassung. Entzündliche Vulvadermatosen umfassen eine Vielzahl von Erkrankungen – viele von ihnen haben einen chronischen Verlauf mit signifikanter Morbidität. Die Diagnose und vor allem die Behandlung kann eine Herausforderung für den Kliniker darstellen und erfordert oftmals eine interdisziplinäre Zusammenarbeit. Diese Übersicht umfasst die häufigsten nicht-infektiösen und nicht-malignen Vulvaerkrankungen – aus dermatologischer Sicht. In diesem Review werden die typischen klinischen Symptome, das klinische Erscheinungsbild sowie die Behandlungsmodalitäten der wichtigsten nicht-infektiösen Vulvadermatosen behandelt; eine Erwähnung finden zudem wichtige dermatologische Differenzialdiagnosen, die nicht vergessen werden sollten.
Ein süsser Drink mit Folgen
Authors: Noronha Beatriz , Kuster Marc , Forster Christian , Studhalter Michael
Published: December 2019

Zusammenfassung. Vergiftungen mit Ethylenglykol sind selten, jedoch führt bereits eine geringe eingenommene Menge der Substanz zu Toxizität. Die Schlüsselrolle in der Behandlung liegt im raschen Erkennen einer Intoxikation sowie der sofortigen und gezielten Therapie. Differenzialdiagnostisch sollte man bei Patienten mit einer schweren metabolischen Azidose eine Vergiftung mit Ethylenglykol oder Methanol immer ausschliessen. Dies gelingt nicht zuletzt dank der Berechnung der osmolaren Lücke.
Changes in Anthropogenic PM and the Resulting Global Climate Effects Under the RCP4.5 and RCP8.5 Scenarios by 2050
Authors: Yang Dongdong , Zhang Hua , Li Jiangnan
Published: December 2019

Using an aerosolclimate model, we studied the temporal and spatial variations of anthropogenic PM(aerodynamic diameter2.5 m) and coarse particulate matter (CPM; aerodynamic diameter2.5m) under Representative Concentration Pathway (RCP) 4.5 and RCP8.5 scenarios from 2014 to 2050. The corresponding radiative forcing and climate responses were also explored. The PMburden decreases over most continents, especially East Asia. The CPM particles increase over northern Asia, North America, and central Africa, in contrast to decrease over most regions of East Asia and North Africa. Relative to 2014, the global annual mean effective radiative forcing due to changes in PMand CPM burden are 1.17 (1.10) and0.06 (0.07) W munder RCP4.5 (RCP8.5), respectively. The reduction in PMburden leads to apparent warming, especially over high latitudes of the Northern Hemisphere, with global annual mean surface air temperature increasing by 1.25 K under RCP4.5, and 1.22 K under RCP8.5. In contrast, changes in CPM result in apparent cooling over North America and northern Asia, with global annual mean changes in surface air temperature of 0.10 K for both scenarios. The Northern Hemisphere Hadley cell weakens and moves northward due to changes in PMafter 2014, whereas the corresponding circulation in the Southern Hemisphere is strengthened, with the Intertropical Convergence Zone shifting to 10°N. Global annual mean precipitation increases by 0.10 mm dayunder both scenarios. Generally, anthropogenic PMcontributes significantly to future changes in radiative forcing and climate.
Meridional Heat Transport During Atmospheric Rivers in High‐Resolution CESM Climate Projections
Authors: Shields Christine A. , Rosenbloom Nan , Bates Susan , Hannay Cecile , Hu Aixue , Payne Ashley E. , Rutz Jonathan J. , Truesdale John
Published: December 2019

Meridional sensible and latent heat transport is evaluated for regions with landfalling atmospheric rivers using both MERRA‐2 reanalysis and fully coupled CESM1.3 high‐resolution climate projections. Western North America, the United Kingdom, and the Iberian Peninsula are chosen to represent the regions significantly impacted by atmospheric rivers (ARs). CESM1.3 historical simulations can accurately represent both sensible and latent regional meridional heat transports compared to MERRA‐2 both for the total period analyzed (1980–2016) and for days with atmospheric rivers only. Uncertainty in these calculations due to AR identification is assessed by applying available Tier 1 AR‐catalogs from Atmospheric Tracking Method Intercomparison Project (ARTMIP) to the MERRA‐2 analysis. CESM1.3 climate projections suggest that under global warming, latent heat transport increases across all regions in the mid‐latitudes where sensible heat decreases (increases) for western North America (Europe). Generally, changes to the meridional heat transport are forced by the upper‐level meridional wind component.
Future Reductions in Polar Cold Air Mass and Cold Air Outbreaks Revealed From Isentropic Analysis
Authors: Kanno Yuki , Iwasaki Toshiki
Published: December 2019

This study quantifies future changes in the polar cold air mass (PCAM) below a threshold potential temperature of 280 K and its horizontal fluxes, which are an indicator for the intensity of cold air outbreaks, by analyzing the outputs from five climate models from the Fifth Coupled Model Intercomparison Project. Under the business‐as‐usual scenario, the multimodel means of the wintertime total hemispheric PCAM decrease by 37% in the Northern Hemisphere and by 34% in the Southern Hemisphere by the end of the 21st century. The midlatitude equatorward PCAM fluxes are projected to decrease significantly by around 2050. This is primarily due to the reduction of the PCAM and to a lesser extent due to the weakening of the extratropical meridional circulation. Finally, intermodel differences in the total hemispheric PCAM reduction are shown to be linearly related to the climate sensitivity to the global mean surface air temperature.
Incidence of Alfvenic SC Pulse Onto the Conjugate Ionospheres
Authors: Pilipenko Vyacheslav A. , Fedorov Evgeniy N. , Xu Zhonghua , Hartinger Michael D. , Engebretson Mark J. , Edwards Thom R.
Published: December 2019

A circuit analogy for magnetosphere‐ionosphere current systems has two extremes: the voltage generator (when the ground magnetic response is proportional to the ionospheric conductance) and the current generator (when the ground magnetic response practically does not depend on the ionospheric conductance). Nonsteady field‐aligned currents interact with the ionosphere in a different way depending on the ratio between the driver time scale
and the Alfven field line eigenperiod
. Sudden Commencement (SC) impulses at high latitudes correspond to the situation when
. This case of Alfven pulses propagating independently away from the equatorial plane is analytically examined with the magnetospheric plasma box model with thin asymmetric conjugate ionospheres. At high latitudes the amplitude ratio in conjugate ionospheres in general does not correspond directly to either the current or voltage regimes. Theoretical predictions are supported by examples of typical SC event observations at conjugate magnetometer sites in Greenland and Antarctica during summer and winter periods.
Analysis of the Beaufort Gyre Freshwater Content in 2003–2018
Authors: Proshutinsky A. , Krishfield R. , Toole J. M. , Timmermans M.‐L. , Williams W. , Zimmermann S. , Yamamoto‐Kawai M. , Armitage T. W. K. , Dukhovskoy D. , Golubeva E. , Manucharyan G. E. , Platov G. , Watanabe E. , Kikuchi T. , Nishino S. , Itoh M. , Kang S.‐H. , Cho K.‐H. , Tateyama K. , Zhao J.
Published: December 2019

Hydrographic data collected from research cruises, bottom‐anchored moorings, drifting Ice‐Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of the Arctic Ocean document an increase of more than 6,400 km3 of liquid freshwater content from 2003 to 2018: a 40% growth relative to the climatology of the 1970s. This fresh water accumulation is shown to result from persistent anticyclonic atmospheric wind forcing (1997–2018) accompanied by sea ice melt, a wind‐forced redirection of Mackenzie River discharge from predominantly eastward to westward flow, and a contribution of low salinity waters of Pacific Ocean origin via Bering Strait. Despite significant uncertainties in the different observations, this study has demonstrated the synergistic value of having multiple diverse datasets to obtain a more comprehensive understanding of Beaufort Gyre freshwater content variability. For example, Beaufort Gyre Observational System (BGOS) surveys clearly show the interannual increase in freshwater content, but without satellite or Ice‐Tethered Profiler measurements, it is not possible to resolve the seasonal cycle of freshwater content, which in fact is larger than the year‐to‐year variability, or the more subtle interannual variations.
Experimental Assessments on Impacts of Salinity Anomalies on the Positive Indian Ocean Dipole
Authors: Kido Shoichiro , Tozuka Tomoki , Han Weiqing
Published: December 2019

Impacts of salinity anomalies associated with the positive Indian Ocean Dipole (pIOD) are assessed through novel sensitivity experiments using a regional ocean model (Regional Ocean Model System) and detailed diagnostics of heat and momentum budget. During the pIOD, density stratification in the eastern equatorial Indian Ocean is enhanced due to anomalous surface freshening and subsurface saltening. This causes momentum inputs from the wind forcing to be more strongly trapped in the surface layer, and zonal and vertical current anomalies to be more confined to the upper layer. As a result, upward transports of cold water from below the thermocline to the surface layer are significantly suppressed, and the cooling in the eastern equatorial Indian Ocean is suppressed by as much as 1.0 °C. The above arguments are further corroborated by a set of sensitivity experiments using a linear continuously stratified ocean model, which can isolate the effect of stratification change caused by salinity anomalies associated with the pIOD in the Regional Ocean Model System simulation. Our results suggest that salinity does play an active role in the evolution of the pIOD, rather than being passively affected by large‐scale anomalous atmospheric and oceanic conditions.
The Subsurface Coherent Rock Content of the Moon as Revealed by Cold‐Spot Craters
Authors: Elder C. M. , Douglass B. , Ghent R. R. , Hayne P. O. , Williams J.‐P. , Bandfield J. L. , Costello E.
Published: December 2019

A recently identified class of young lunar craters, cold‐spot craters, provides an optimal data set for probing the subsurface rock content on the Moon. Rocks, or lack of rocks, in crater ejecta have long been used as indicators of regolith thickness. However, the rockiness of crater ejecta depends on the subsurface rock content, crater excavation depth, and crater age. Cold‐spot craters are surrounded by a low thermal inertia signature that fades within 1 Myr, so any rocks in the proximal ejecta blanket have not yet been broken down or buried. Thus, the rock abundance in the proximal ejecta blankets of cold‐spot craters is affected only by the subsurface rock content of the target and the crater excavation depth, not the age of the crater. We show that an abrupt transition between fine‐grained regolith and underlying coherent rock cannot explain the observed rock abundance. Instead, we assume that the volume fraction of coherent rock (in contrast to fine‐grained regolith) increases exponentially in the lunar subsurface and use the observed Diviner rock abundance in cold‐spot crater ejecta to solve for the “e‐folding” depth over which the volume fraction of rock increases. In general, the subsurface rock content is higher in the maria than in the highlands consistent with more recent resurfacing of the maria. However, the highlands show a wider range of subsurface rock content values overall including some overlapping those of the maria. Some of this variability appears to be associated with the Orientale basin and possibly with several cryptomare deposits.
Phobos Surface Sputtering as Inferred From MAVEN Ion Observations
Authors: Nénon Q. , Poppe A. R. , Rahmati A. , Lee C. O. , McFadden J. P. , Fowler C. M.
Published: December 2019

Phobos is bombarded by both protons and alpha particles from the solar wind and by Martian atomic and molecular oxygen ions. A numerical model of the distribution of planetary ions has previously proposed that these ions may dominate solar wind ions in sputtering the surface of Phobos when the moon is located downstream of Mars. This conclusion suggests a unique link between planetary atmospheric escape at Mars and the surface processing of its moon yet, remains to be confirmed with in situ ion measurements. In this article, a 4‐year‐long average of the ion environment that Phobos is exposed to is constructed from in situ ion observations conducted by the Mars Atmosphere and Volatile Evolution (MAVEN) mission. In turn, the flux of material sputtered from the surface of Phobos by this environment is computed. We confirm that planetary atomic oxygen ions dominate over solar wind ions in sputtering the surface of Phobos downstream of Mars during 20% of the moon's orbit. We also reveal that molecular oxygen ions sputter the surface of Phobos as much as or more than atomic oxygen ions in the Martian magnetotail. In addition to the long‐term average picture, the time variation of Phobos surface sputtered fluxes is investigated during the series of solar wind events that hit the Martian system in March 2015. We find that the flux of material liberated from Phobos' surface increased by a factor of 50 during this period.
Linear Inverse Modeling for Coupled Atmosphere‐Ocean Ensemble Climate Prediction
Authors: Perkins W. Andre , Hakim Greg
Published: December 2019

Paleoclimate data assimilation (PDA) experiments reconstruct climate fields by objectively blending information from climate models and proxy observations. Due to high computational cost and relatively low forecast skill, most reconstruction experiments omit the prediction step, where a forecast is made from the previously reconstructed state to the next time proxy data is available. In order to enable this critical aspect of PDA, we propose an efficient method of generating forecast ensembles of coupled climate fields using a linear inverse model (LIM). We describe the general calibration of a LIM on multiple fields using a two‐step empirical orthogonal function field compression to efficiently represent the state. We find that a LIM calibrated on global climate model (GCM) data yields skillful forecasts, including for out‐of‐sample tests on data from a different GCM. The deterministic forecast skill tests for scalar indices show that the LIM outperforms damped persistence at leads up to 3 years and has skill up to 10 years for global average sea surface temperature. Analysis of 1‐year forecasts reveals that the LIM captures dynamic climate features with local and remote predictability related to teleconnections. The forecast ensemble characteristics of the LIM, which in part determine the weighting of information for PDA experiments, show that the LIM generally produces ensemble forecast errors that are 10% to 70% larger than ensemble variance for 1‐year forecasts on data representative of the last millennium. These results show that the LIM produces ensembles with reasonable calibration but also that LIMs for PDA may require some variance tuning to work optimally for data assimilation experiments.
Evaluation of the CABLEv2.3.4 Land Surface Model Coupled to NU‐WRFv3.9.1.1 in Simulating Temperature and Precipitation Means and Extremes Over CORDEX AustralAsia Within a WRF Physics Ensemble
Authors: Hirsch Annette L. , Kala Jatin , Carouge Claire C. , De Kauwe Martin G. , Di Virgilio Giovanni , Ukkola Anna M. , Evans Jason P. , Abramowitz Gab
Published: December 2019

The Community Atmosphere Biosphere Land Exchange (CABLE) model is a third‐generation land surface model (LSM). CABLE is commonly used as a stand‐alone LSM, coupled to the Australian Community Climate and Earth Systems Simulator global climate model and coupled to the Weather Research and Forecasting (WRF) model for regional applications. Here, we evaluate an updated version of CABLE within a WRF physics ensemble over the COordinated Regional Downscaling EXperiment (CORDEX) AustralAsia domain. The ensemble consists of different cumulus, radiation and planetary boundary layer (PBL) schemes. Simulations are carried out within the NASA Unified WRF modeling framework, NU‐WRF. Our analysis did not identify one configuration that consistently performed the best for all diagnostics and regions. Of the cumulus parameterizations the Grell‐Freitas cumulus scheme consistently overpredicted precipitation, while the new Tiedtke scheme was the best in simulating the timing of precipitation events. For the radiation schemes, the RRTMG radiation scheme had a general warm bias. For the PBL schemes, the YSU scheme had a warm bias, and the MYJ PBL scheme a cool bias. Results are strongly dependent on the region of interest, with the northern tropics and southwest Western Australia being more sensitive to the choice of physics options compared to southeastern Australia which showed less overall variation and overall better performance across the ensemble. Comparisons with simulations using the Unified Noah LSM showed that CABLE in NU‐WRF has a more realistic simulation of evapotranspiration when compared to GLEAM estimates.
Using a Down‐Looking Multifrequency ABS for Measuring Suspended Sediments in Rivers
Authors: Vergne Adrien , Le Coz Jérôme , Berni Céline , Pierrefeu Gilles
Published: December 2019

In the last decade, much progress has been made in continuously measuring suspended sediment concentration (SSC) in rivers using horizontal side‐looking Acoustic Doppler Current Profilers. However, these techniques do not provide information on the spatial variability of the suspension. In this study, we explore some new possibilities offered by the down‐looking deployment of a multifrequency acoustic backscatter system (ABS) in order to obtain information on the suspension throughout an entire river cross section. Two sites, with low and high levels of SSC, were investigated. The acoustic signal was processed using multifrequency inversion methods. Both water sample calibration data and modeling were used for retrieving the acoustic properties of the suspended particles. At the low SSC site (
30 mg/L), we successfully inverted the acoustic signal, except in some areas of high acoustic backscatter close to the surface that were probably generated by air microbubbles. At the high SSC site (
10 g/L), estimates of both fine and sand SSCs throughout the river cross section were successfully obtained, except in some areas close to the bottom where the acoustic signal was totally attenuated due to distance and high concentration of fine sediments. This work confirms the capacity of hydroacoustic technology for providing spatial information on river suspensions.
Predicting Shallow Groundwater Tables for Sloping Highland Aquifers
Authors: Alemie Tilashwork C. , Tilahun Seifu A. , Ochoa‐Tocachi Boris F. , Schmitter Petra , Buytaert Wouter , Parlange J‐Yves , Steenhuis Tammo S.
Published: December 2019

While hydrological science has made great strides forward during the last 50 years with the advance of computing power and availability of satellite images, much is unknown about the sustainable development of water for irrigation, domestic use, and livestock consumption for millions of households in the developing world. Specifically, quantification of shallow underground water resources for irrigation in highland regions remains challenging. The objective is to better understand the hydrology of highland watersheds with sloping hillside aquifers. Therefore, we present a subsurface flow model for hillside aquifers with recharge that varied from day to day. Recharge to the aquifer was estimated by the Thornthwaite Mather procedure. A characteristic time was identified for travel time of water flowing from the upper part of the hillside to the river or well. Using the method of characteristics, we found that the height of shallow groundwater level can be predicted by determining the total recharge over the characteristic time divided by drainable porosity. We apply the model to farmer‐dug wells in the Ethiopian highlands using observed rainfall, potential evaporation, and a fitted travel time. We find that the model performs well with maximum water table heights being determined by the soil surface and minimum heights by the presence or absence of volcanic dikes downhill. Our application shows that unless the water is ponded behind a natural or artificial barrier, hillslope aquifers are unable to provide a continuous source of water during the long, dry season. This clearly limits any irrigation development in the highlands from shallow sloping groundwater.
The Dynamics of Suspended Sediment in a Typical Alpine Alluvial River Reach: Insight From a Seasonal Survey
Authors: Misset C. , Recking A. , Legout C. , Valsangkar N. , Bodereau N. , Zanker S. , Poirel A. , Borgniet L.
Published: December 2019

The transport of suspended sediment is associated with important social, economic, and environmental issues. It is still unclear, however, how suspended sediments eroded on hillslopes are transferred downstream through the river system. In this study, we aimed to investigate this process by applying a sediment budget approach to a typical 3.5‐km‐long Alpine braided reach. Using high‐frequency suspended load measurements combined with Monte Carlo simulations for uncertainty propagation, we observed a significant buffering behavior of the reach studied. Thirty‐two of the 48 events observed during the 2‐month campaign showed significant differences between upstream and downstream mass transported as suspension, despite the reach studied was short compared to the upstream drainage area (130 km2). These differences at the event scale varied widely within an envelope comprised between a net erosion equivalent to 74% of upstream suspended mass and a net deposition equivalent to 71%. Budgets were found to be controlled at a nearly instantaneous time scale by the liquid discharges and the suspended sediment concentrations in an opposite way: for low upstream concentrations, net erosion increased when the discharges increased, while above a certain concentration, net deposition increased when the concentrations increased. Moreover, coarse particles mobility in the reach (characterized via bedload transport measurements) appeared to have a strong influence on the availability of suspended particles as both quantities evolved concomitantly through time. These observations have important implications for our understanding and modeling of the transfer of suspended particles in gravel bedded streams.
Evaluation of SNODAS Snow Water Equivalent in Western Canada and Assimilation Into a Cold Region Hydrological Model
Authors: Lv Zhibang , Pomeroy John W. , Fang Xing
Published: December 2019

Snow water equivalent (SWE) is one of the most hydrologically important physical properties of a snowpack. The U.S. National Weather Service's Snow Data Assimilation System (SNODAS) provides snow products at high spatial (~1 km2) and temporal (daily) resolution for the contiguous United States and southern Canada. This study evaluated the SNODAS SWE product in the boreal forest, prairie, and Canadian Rockies of western Canada against extensive snow survey measurements. SNODAS was found to work well in sheltered environments, to overestimate SWE under needle‐leaf forests, and to be unable to capture the spatial variation of SWE in windswept prairie and alpine environments. Results indicate that SNODAS SWE accuracy is strongly influenced by the missing blowing snow redistribution and canopy energetics and snow interception and sublimation processes in the mass balance calculations of the SNODAS model and by erroneous precipitation data forcing the model. To demonstrate how errors caused by missing processes can be corrected in areas with low assimilation frequency, SNODAS data were assimilated into a physically based hydrological model created using the modular Cold Region Hydrological Modelling (CRHM) platform that includes blowing and intercepted snow redistribution and subcanopy melt energetic processes. This approach decreased the overestimation of SWE compared to SNODAS from 135 to 79% in the study area and suggests that snow assimilation modeled SWE quality can be improved if snow redistribution, sublimation, and subcanopy melt processes are incorporated.
Integrating Bayesian Groundwater Mixing Modeling With On‐Site Helium Analysis to Identify Unknown Water Sources
Authors: Popp Andrea L. , Scheidegger Andreas , Moeck Christian , Brennwald Matthias S. , Kipfer Rolf
Published: December 2019

Analyzing groundwater mixing ratios is crucial for many groundwater management tasks such as assessing sources of groundwater recharge and flow paths. However, estimating groundwater mixing ratios is affected by various uncertainties, which are related to analytical and measurement errors of tracers, the selection of end‐members, and finding the most suitable set of tracers. Although these uncertainties are well recognized, it is still not common practice to account for them. We address this issue by using a new set of tracers in combination with a Bayesian modeling approach, which explicitly considers the possibility of unknown end‐members while fully accounting for tracer uncertainties. We apply the Bayesian model we developed to a tracer set, which includes helium (4He) analyzed on site to determine mixing ratios in groundwater. Thereby, we identify an unknown end‐member that contributes up to 84 ± 9% to the water mixture observed at our study site. For the 4He analysis, we use a newly developed Gas Equilibrium Membrane Inlet Mass Spectrometer (GE‐MIMS), operated in the field. To test the reliability of on‐site 4He analysis, we compare results obtained with the GE‐MIMS to the conventional lab‐based method, which is comparatively expensive and labor intensive. Our work demonstrates that (i) tracer‐aided Bayesian mixing modeling can detect unknown water sources, thereby revealing valuable insights into the conceptual understanding of the groundwater system studied, and (ii) on‐site 4He analysis with the GE‐MIMS system is an accurate and reliable alternative to the lab‐based analysis.
STING signaling and host defense against microbial infection
Authors: Ahn Jeonghyun , Barber Glen N.
Published: December 2019

The first line of host defense against infectious agents involves activation of innate immune signaling pathways that recognize specific pathogen-associated molecular patterns (PAMPs). Key triggers of innate immune signaling are now known to include microbial-specific nucleic acid, which is rapidly detected in the cytosol of the cell. For example, RIG-I-like receptors (RLRs) have evolved to detect viral RNA species and to activate the production of host defense molecules and cytokines that stimulate adaptive immune responses. In addition, host defense countermeasures, including the production of type I interferons (IFNs), can also be triggered by microbial DNA from bacteria, viruses and perhaps parasites and are regulated by the cytosolic sensor, stimulator of interferon genes (STING). STING-dependent signaling is initiated by cyclic dinucleotides (CDNs) generated by intracellular bacteria following infection. CDNs can also be synthesized by a cellular synthase, cGAS, following interaction with invasive cytosolic self-DNA or microbial DNA species. The importance of STING signaling in host defense is evident since numerous pathogens have developed strategies to prevent STING function. Here, we review the relevance of STING-controlled innate immune signaling in host defense against pathogen invasion, including microbial endeavors to subvert this critical process.
Quantum expander for gravitational-wave observatories
Authors: Korobko Mikhail , Ma Yiqiu , Chen Yanbei , Schnabel Roman
Published: December 2019

The quantum uncertainty of laser light limits the sensitivity of gravitational-wave observatories. Over the past 30 years, techniques for squeezing the quantum uncertainty, as well as for enhancing gravitational-wave signals with optical resonators have been invented. Resonators, however, have finite linewidths, and the high signal frequencies that are produced during the highly scientifically interesting ring-down of astrophysical compact-binary mergers still cannot be resolved. Here, we propose a purely optical approach for expanding the detection bandwidth. It uses quantum uncertainty squeezing inside one of the optical resonators, compensating for the finite resonators’ linewidths while keeping the low-frequency sensitivity unchanged. This quantum expander is intended to enhance the sensitivity of future gravitational-wave detectors, and we suggest the use of this new tool in other cavity-enhanced metrological experiments.
CLDN6 promotes tumor progression through the YAP1-snail1 axis in gastric cancer
Authors: Yu Site , Zhang Yeqian , Li Qing , Zhang Zizhen , Zhao Gang , Xu Jia
Published: December 2019

Claudin6 (CLDN6), a member of the tight junction family, is a molecule involved in intercellular adhesion, acting as a physical barrier that prevents solutes and water from freely passing through the extracellular space. CLDN6 has important biological functions, and its abnormal expression is associated with Hepatitis C infection. However, there is limited research regarding its role in gastric cancer. In this study, we found that the expression of CLDN6 mRNA and protein was upregulated in gastric cancer cell lines and tissues, which indicated poor prognosis. Both in vitro and in vivo experiments showed that abnormal CLDN6 expression was associated with enhanced proliferation and invasion abilities of gastric cancer. CLDN6 reduced the phosphorylation of LATS1/2 and YAP1 by interacting with LATS1/2 in the Hippo signaling pathway. Thus, CLDN6 affected the entry of YAP1 into the nucleus, causing changes in downstream target genes. Moreover, YAP1 interacted with snail1 to affect the process of EMT and enhanced the invasive ability of GC cells. Collectively, CLDN6 promoted the proliferation and invasive ability of gastric cancer by affecting YAP1 and YAP1-snail1 axis.
A large size-selective DNA nanopore with sensing applications
Authors: Thomsen Rasmus P. , Malle Mette Galsgaard , Okholm Anders Hauge , Krishnan Swati , Bohr Søren S.-R. , Sørensen Rasmus Schøler , Ries Oliver , Vogel Stefan , Simmel Friedrich C. , Hatzakis Nikos S. , Kjems Jørgen
Published: December 2019

Transmembrane nanostructures like ion channels and transporters perform key biological functions by controlling flow of molecules across lipid bilayers. Much work has gone into engineering artificial nanopores and applications in selective gating of molecules, label-free detection/sensing of biomolecules and DNA sequencing have shown promise. Here, we use DNA origami to create a synthetic 9 nm wide DNA nanopore, controlled by programmable, lipidated flaps and equipped with a size-selective gating system for the translocation of macromolecules. Successful assembly and insertion of the nanopore into lipid bilayers are validated by transmission electron microscopy (TEM), while selective translocation of cargo and the pore mechanosensitivity are studied using optical methods, including single-molecule, total internal reflection fluorescence (TIRF) microscopy. Size-specific cargo translocation and oligonucleotide-triggered opening of the pore are demonstrated showing that the DNA nanopore can function as a real-time detection system for external signals, offering potential for a variety of highly parallelized sensing applications.
Detection of the 5p – 4f orbital crossing and its optical clock transition in Pr9+
Authors: Bekker H. , Borschevsky A. , Harman Z. , Keitel C. H. , Pfeifer T. , Schmidt P. O. , Crespo López-Urrutia J. R. , Berengut J. C.
Published: December 2019

Recent theoretical works have proposed atomic clocks based on narrow optical transitions in highly charged ions. The most interesting candidates for searches of physics beyond the Standard Model are those which occur at rare orbital crossings where the shell structure of the periodic table is reordered. There are only three such crossings expected to be accessible in highly charged ions, and hitherto none have been observed as both experiment and theory have proven difficult. In this work we observe an orbital crossing in a system chosen to be tractable from both sides: Pr$${}^{9+}$$

9
+

. We present electron beam ion trap measurements of its spectra, including the inter-configuration lines that reveal the sought-after crossing. With state-of-the-art calculations we show that the proposed nHz-wide clock line has a very high sensitivity to variation of the fine-structure constant, $$\alpha$$
α
, and violation of local Lorentz invariance; and has extremely low sensitivity to external perturbations.