bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychometric evaluation and cultural adaptation of the Spanish version of the “Scale for End-of Life Caregiving Appraisal”
Authors: Hernández-Padilla José Manuel , Correa-Casado Matías , Granero-Molina José , Cortés-Rodríguez Alda Elena , Matarín-Jiménez Tamara María , Fernández-Sola Cayetano
Published: August 2018

Objective

To translate, culturally adapt, and psychometrically evaluate the Spanish version of the “Scale for End-of Life Caregiving Appraisal” (SEOLCAS).

Method

Observational cross-sectional study. Convenience sample of 201 informal end-of-life caregivers recruited in a southern Spanish hospital. The reliability of the questionnaire was assessed through its internal consistency (Cronbach's α) and temporal stability (Pearson's correlation coefficient [r] between test-retest). The content validity index of the items and the scale was calculated. Criterion validity was explored through performing a linear regression analysis to evaluate the SEOLCAS’ predictive validity. Exploratory factor analysis was used to examine its construct validity.

Results

The SEOLCAS’ reliability was very high (Cronbach's α = 0.92). Its content validity was excellent (all items’ content validity index = 0.8–1; scale's validity index = 0.88). Evidence of the SEOLCAS’ criterion validity showed that the participants’ scores on the SEOLCAS explained approximately 79.3% of the between-subject variation of their results on the Zarit Burden Interview. Exploratory factor analysis provided evidence of the SEOLCAS’ construct validity. This analysis revealed that two factors (“internal contingencies” and “external contingencies”) explained 53.77% of the total variance found and reflected the stoic Hispanic attitude toward adversity.

Significance of results

The Spanish version of the SEOLCAS has shown to be an easily applicable, valid, reliable, and culturally appropriate tool to measure the impact of end-of-life care provision on Hispanic informal caregivers. This tool offers healthcare professionals the opportunity to easily explore Hispanic informal end-of-life caregivers’ experiences and discover the type of support they may need (instrumental or emotional) even when there are communicational and organizational constraints.
Identification of major insect pests of Amaranthus spp. and germplasm screening for insect resistance in Tanzania
Authors: Smith Jason D. , Dinssa Fekadu F. , Anderson Robert S. , Su Fu-cheng , Srinivasan Ramasamy
Published: August 2018

Vegetable and grain amaranths represent a vital source of micronutrients and protein in Asia and Africa. However, various foliar lepidopteran pests and stem-mining weevils hinder amaranth production. Insect-resistant cultivars can enhance the productivity of this crop. Here, we report on the performances of amaranth varieties screened for their resistance to insect pests under the field conditions at The World Vegetable Center stations in Asia and sub-Saharan Africa. We conducted two preliminary screening trials with a total of 263 entries from around the world in Taiwan and a third preliminary screening trial with 49 African-indigenous entries in Tanzania. Promising entries from these preliminary trials were collectively evaluated in an advanced screening trial in Tanzania, to identify lines resistant to foliar and stem-boring pests in East Africa. Four entries exhibited moderate resistance to foliar pests: TZ51 and TZ53 (Amaranthus cruentus), TZ34 (A. dubius) and TZ39 (Amaranthus sp.). Five entries showed moderate resistance to stem weevils: TZ06 and TZ27 (A. cruentus), TZ52 (A. graecizans), TZ59 (A. palmeri) and TZ07 (Amaranthus sp.). Lepidopteran pests affecting leaves were reared to adulthood and identified as Spoladea recurvalis (Crambidae), Spodoptera exigua (Noctuidae) and Spodoptera littoralis (Noctuidae). Stem weevil larvae were also reared and identified as: Neocleonus sannio Herbst, Gasteroclisus pr. rhomboidalis Boheman, Hypolixus pr. haerens Boheman and Baradine sp. (Curculionidae). These results highlight key amaranth pests in East Africa and identify insect-resistant entries that will be useful in breeding programmes and resistance studies.
Distribution functions for resonantly trapped orbits in our Galaxy
Authors: Monari G. , Famaey B. , Fouvry J.-B. , Binney J.
Published: August 2018

We show how to capture the behaviour of the phase-space distribution function (DF) of a Galactic disc stellar population at a resonance. This is done by averaging the Hamiltonian over fast angle variables and re-expressing the DF in terms of a new set of canonical actions and angles variables valid in the resonant region. We then assign to the resonant DF the time average along the orbits of the axisymmetric DF expressed in the new set of actions and angles. This boils down to phase-mixing the DF in terms of the new angles, such that the DF for trapped orbits only depends on the new set of actions. This opens the way to quantitatively fitting the effects of the bar and spirals to Gaia data in terms of distribution functions in action space.
New insights on the origin of multiple stellar populations in globular clusters
Authors: Kim Jaeyeon , Lee Young-Wook
Published: August 2018

In order to investigate the origin of multiple stellar populations in the halo and bulge of the Milky Way, we have constructed chemical evolution models for the low-mass proto-Galactic subsystems such as globular clusters (GCs). Unlike previous studies, we assume that supernova blast waves undergo blowout without expelling the pre-enriched gas, while relatively slow winds of massive stars (WMS), together with the winds and ejecta from low and intermediate mass asymptotic-giant-branch stars (AGBs), are all locally retained in these less massive systems. We find that the observed Na-O anti-correlations in metal-poor GCs can be reproduced, when multiple episodes of starbursts are allowed to continue in these subsystems. A specific form of star formation history (SFH) with decreasing time intervals between the stellar generations, however, is required to obtain this result, which is in good agreement with the parameters obtained from our stellar evolution models for the horizontal-branch. The “mass budget problem” is also much alleviated by our models without ad-hoc assumptions on star formation efficiency (SFE) and initial mass function (IMF). We also applied these models to investigate the origin of super-helium-rich red clump stars in the metal-rich bulge as recently suggested by Lee et al. (2015). We find that chemical enrichments by the WMS can naturally reproduce the required helium enhancement (ΔY/ΔZ = 6) for the second generation stars. Disruption of proto-GCs in a hierarchical merging paradigm would have provided helium enhanced stars to the bulge field.
Impact of NLTE on determinations of atmospheric parameters and chemical abundances of very metal-poor stars
Authors: Mashonkina Lyudmila , Sitnova Tatyana , Pakhomov Yuri , Ryabchikova Tatyana
Published: August 2018

Based on high-resolution spectral observations for a sample of very metal-poor stars, we investigate how well stellar chemical abundances can be derived with available theoretical methods and computational tools.
Can we really use chemical properties of red-giant stars as age indicators?
Authors: Lagarde Nadège , Robin A. C. , Reylé C.
Published: August 2018

The cornerstone mission of the European Space Agency, Gaia, together with forthcoming complementary surveys (CoRoT, Kepler, K2, APOGEE and Gaia-ESO), will revolutionize our understanding of the formation and history of our Galaxy, providing accurate stellar masses, radii, ages, distances, as well as chemical properties for a very large sample of stars across different Galactic stellar populations. Using improved population synthesis approach and new stellar evolution models we attempt to evaluate the possibility to derive ages of clump stars from their chemical properties. A new version of the Besançon Galaxy models (BGM) is used in which new stellar evolutionary tracks are computed from the stellar evolution code STAREVOL. The effects of mixing on chemical composition of the stellar photosphere has a significant impact on the determined stellar age from the observed [C/N] ratio. We clearly show that transport processes occurring in red-giant stars should be taken into account in the determination of ages for future Galactic archaeology studies.
Carbon-enhanced metal-poor 3D model atmospheres
Authors: Steffen M. , Gallagher A. J. , Caffau E. , Bonifacio P. , Ludwig H.-G.
Published: August 2018

We present our latest 3D model atmospheres for carbon-enhanced metal-poor (CEMP) stars computed with the CO5BOLD code. The stellar parameters are representative of hot turn-off objects (Teff ~ 6250 K, log g = 4.0, [Fe/H]=−3). The main purpose of these models is to investigate the role of 3D effects on synthetic spectra of the CH G-band (4140-4400 Å), the CN BX-band (3870-3890 Å), and several UV OH transitions (3122-3128 Å). By comparison with the synthetic spectra from standard 1D model atmospheres (assuming local thermodynamic equilibrium, LTE), we derive 3D abundance corrections for carbon and oxygen of up to −0.5 and −0.7 dex, respectively.
What do RR Lyrae tell us about the formation of the Milky Way and M31 haloes?
Authors: Gallart C. , Fiorentino G. , Monelli M. , Martínez-Vázquez C. , Bernard E. J. , Bono G. , Stetson P. B.
Published: August 2018

RR Lyrae variables are old (>10 Gyr) stars and, as such, they are useful probes of the earliest events of star formation in galaxies (Bernard et al. 2008, Martínez-Vázquez et al. 2016) as well as of the galaxy assembly process predicted by ΛCDM simulations of structure formation. In fact, the nature of the building-blocks of galaxies such as the Milky Way, and in particular, those of their stellar haloes, has been a matter of a substantial debate (Venn et al. 2004). Unlike other stellar tracers, RR Lyrae offer a snapshot of the stellar content present at the epoch when most of the merging action is predicted to have taken place, and thus they are ideal witnesses of this process.
Ages for large samples of stars - caveats and uncertainties
Authors: Noels-Grötsch Arlette
Published: August 2018

Although a stellar age accuracy of about 10 % seems to be a reasonable requirement to draw a time line in the evolution of our Galaxy as well as in the formation and evolution of exo-planetary systems, theoretical stellar models are at present still too imperfect to really achieve this goal. Asteroseismic observations are definitely of invaluable assistance, especially if individual pulsation frequencies are available, which is still far from common. Large stellar samples are now in the spotlight with two different lines of attack, spectroscopic and photometric surveys as well as asteroseismic missions. I shall review the problems arising from stellar physics in the context of large stellar samples of main sequence and red giant stars, and I shall raise some alarm bells but also highlight some positive news for a drastic improvement in stellar age determinations below the limit of 10 % in a foreseeable future.
Abundance Analysis for Extremely Metal-Poor Stars from SDSS/SEGUE
Authors: Matsuno T. , Aoki W. , Beers T. C. , Lee Y. S. , Honda S.
Published: August 2018

We report the results of abundance analysis for high-resolution spectra of eight extremely metal-poor turn-off stars selected from SDSS/SEGUE. Based on differential analysis adopting stellar parameters from Balmer line profiles, we obtain the following results: i) Statistically significant scatter is found in [X/Fe] (X=Na, Mg, Cr, Ti, Sr and Ba), among which [Na/Fe] shows an apparent bimodal distribution, ii) Li abundances are ~0.3 dex lower in [Fe/H]<−3.5 than the Spite plateau value without significant scatter.
Metallicity Structure across the Galactic Disk: Radio Observations of H ii Regions
Authors: Balser Dana S. , Wenger Trey V. , Bania T. M. , Anderson L. D.
Published: August 2018

Hii regions are the sites of massive star formation and are the archetypal tracers of spiral arms. Because of their short lifetimes (<10 Myr) their abundances provide a measure of the nuclear processing of many stellar generations. Here we review our ongoing efforts to explore the metallicity structure of the Galactic disk by observing radio recombination line (RRL) and thermal radio continuum emission toward Hii regions. The RRL-to-continuum ratio provides an accurate measure of the electron temperature which is used as a proxy for metallicity. Since collisionally excited lines from metals (e.g., O, C) are the main coolant in Hii regions, the thermal electron temperature is well correlated with metallicity (e.g., [O/H]). We determine Hii region distances from maser parallax measurements when possible; otherwise we use kinematic distances. Such radio diagnostics of Hii regions yield an extinction free tracer to map the metallicity distribution across the entire Galactic disk.
Lifting the Veil on Ultra Metal-Poor Stars in the Outermost Halo
Authors: Yoon Jinmi , Whitten Devin D. , Beers Timothy C. , Placco Vinicius M. , Lee Young Sun , Dietz Sarah , Gudin Dmitrii , Rasmussen Kaitlin C.
Published: August 2018

The study of extremely metal-poor (EMP; [Fe/H] <−3.0) and ultra metal-poor (UMP; [Fe/H] <−4.0) stars is crucial for better understanding first-star nucleosynthesis and constraining the initial mass function in the early Universe. However, UMP stars discovered in the past 25 years only number ~25. A few recent theoretical studies have pointed out that there is likely to exist large numbers of EMP and UMP stars in the periphery of the Galactic halo, at distances exceeding 30-50 kpc. We present identifications of several new EMP/UMP stars and introduce a survey to expedite discovering hundreds to thousands of EMP/UMP stars in the outermost halo (as well as in the local volume) over the next few years, which could revolutionize chemical-evolution studies of the Galaxy.
Vertical velocity patterns in the Milky Way disc: RAVE-Gaia streaming motions
Authors: Carrillo I. , Minchev I. , Kordopatis G. , Steinmetz M. ,   RAVE
Published: August 2018

Using data from the Radial Velocity Experiment (RAVE) and the Tycho- Gaia astrometric solution catalogue (TGAS), we study the vertical velocity (Vz) patterns in the Milky Way disc. We search in particular for variation in velocity with distance above and below the disc midplane. In contrast to previous suggestions of a breathing mode seen in RAVE data, our results support a combination of bending and breathing modes, likely generated by a combination of external or internal and external mechanisms.
LAMOST-Subaru exploration of chemical relics of first stars
Authors: Li Haining , Aoki Wako , Zhao Gang , Suda Takuma , Honda Satoshi , Christlieb Norbert , Matsuno Tadafumi
Published: August 2018

Very metal-poor (VMP) stars preserve chemical signatures of early generations of stars, and are crutial to understand the early nucleosynthesis and first stars. Millions of stellar spectra obtained by LAMOST provide an unprecedented chance to enlarge the currently limited VMP star sample. Since 2014, a joint project on searching for VMP stars has been conducted based on the LAMOST survey and Subaru follow-up observations. So far, the project has obtained chemical abundances for about 250 VMP stars and a number of chemically interesting objects, e.g., three ultra metal-poor stars with [Fe/H] ~ − 4.0, a dozen Li-rich VMP stars distributed in a wide range of evolutionary stages. Statistics of the large homogeneous sample of VMP stars will be of great interest and importance to probe the chemical enrichment in the early Galaxy and low-mass star evolution.
Elemental high-precision abundances as function of stellar ages: Constrains on the Galactic chemical evolution
Authors: Maia Marcelo Tucci
Published: August 2018

Solar twins are a special group of stars that have spectra and stellar parameters very close to the Sun. Also having mass around 1 solar mass and roughly solar chemical composition, these stars follow a similar evolutionary path to the Sun, from the zero age main sequence to the end of their lives. Additional to that, the similarity between themselves permit us to obtain high-precision differential abundance and thus, very precise atmospheric parameters that allows a reliable estimation of their ages using the traditional isochronal method. Taking advantage of this very restrict group of stars we can better understand the effects of nucleosynthesis of chemical elements throughout the Galaxy and with this, finding constrains for its evolution.
Gaia first data release and beyond
Authors: Vallenari Antonella
Published: August 2018

The first Gaia data release took place in 2016, delivering astrometry and photometry for more than 1 billion sources in our Galaxy. After almost one year, Gaia data have already become the reference for astrometry, with applications in a wide range of topics. In this paper we summarize the impressive quality and the known limitations of the data; and we present the extensive validation work that was done by the Gaia Consortium before publication. We review a few results based on Gaia first data release, while looking ahead at the upcoming second data release
Using N-body simulations to understand the chemo-dynamical evolution of the inner Milky Way
Authors: Athanassoula E.
Published: August 2018

I present examples of how chemo-dynamical N-body simulations can help understanding the structure and evolution of the inner Galaxy. Such simulations reproduce the observed links between kinematics, morphology and chemistry in the bar/bulge region and explain them by the self-consistent cohabitation of a number of components. Galactic archaeology, applied to simulation snapshots, explains the sequence in which the stars of the various components were formed. The thick disc stars form earlier than those of the thin disc and in a much shorter time scale. The bar in the thick disc is horizontally thicker than that of the thin disc and has a different vertical morphology. The Galaxy’s inner disc scalelength is much smaller than what is expected from nearby galaxies of similar stellar mass.
Using low-mass stars as a tool: efforts towards precise models
Authors: Weiss Achim , Aguirre Victor Silva , Christensen-Dalsgaard Jørgen
Published: August 2018

We present results of an on-going effort to identify the minimum level of systematic, purely numerical differences in low-mass stellar models on the Red Giant Branch, by comparing models in selected phases for pre-defined physical input assumptions.
Getting off the ground: the case of bitcoin
Authors: LUTHER WILLIAM J.
Published: August 2018

By declaring an item legal tender or making it publicly receivable, governments might generate sufficient demand to determine the medium of exchange. How do private actors launch a new money? There are two views in the literature. The first requires offering an item with a use value to some agents that is distinct from its role as a medium of exchange. The second suggests that agents might coordinate on an intrinsically useless item. With these views in mind, I survey the logs from the original bitcoin forum, bitcoin-list. I find that early participants in the bitcoin community understood the importance of coordination and took steps to coordinate users.
Longitudinal Relationships Between Foster Children’s Mental Health Problems and Parental Stress in Foster Mothers and Fathers
Authors: Lohaus Arnold , Kerkhoff Denise , Chodura Sabrina , Möller Christine , Symanzik Tabea , Rueth Jana E. , Ehrenberg Daniela , Job Ann-Katrin , Reindl Vanessa , Konrad Kerstin , Heinrichs Nina
Published: August 2018

Abstract. This paper focuses on the longitudinal relationships between foster children’s mental health problems and parental stress across a 1-year interval with three measurements. A sample of 94 foster children and a comparison group of 157 biological children and their families participated in this study. The age of the children was between 2 and 7 years. At the initial assessment, the foster children had been in their foster families since 2–24 months. Based on Child Behavior Checklist (CBCL) scores, the results indicated increased internalizing and externalizing mental health problems in the foster children group. Both mental health scores remained rather stable across the longitudinal assessments in foster as well as in biological children. Internalizing as well as externalizing scores were substantially correlated with parental stress in both samples. Moreover, changes in mental health scores were associated with changes in parental stress. However, cross-lagged panel analyses showed no clear pattern of temporal relationships between children’s mental health scores and parental stress. Implications as well as strengths and limitations of the current study are addressed in the Discussion section.
Lithospheric Structure and Tectonic Processes Constrained by Microearthquake Activity at the Central Ultraslow‐Spreading Southwest Indian Ridge (49.2° to 50.8°E)
Authors: Yu Zhiteng , Li Jiabiao , Niu Xiongwei , Rawlinson Nicholas , Ruan Aiguo , Wang Wei , Hu Hao , Wei Xiaodong , Zhang Jie , Liang Yuyang
Published: August 2018

Beneath ultraslow‐spreading ridges, the oceanic lithosphere remains poorly understood. Using recordings from a temporary array of ocean bottom seismometers, we here report an ~17‐days‐long microearthquake study on two segments (27 and 28) of the ultraslow‐spreading Southwest Indian Ridge (49.2° to 50.8°E). A total of 214 locatable microearthquakes are recorded; seismic activity appears to be concentrated within the west median valley at Segment 28 and adjacent nontransform discontinuities. Earthquakes reach a maximum depth of ~20 km beneath the seafloor, and they mainly occur in the mantle, implying a cold and thick brittle lithosphere. The relatively uniform brittle/ductile boundary beneath Segment 28 suggests that there is no focused melting in this region. The majority of earthquakes is located below the Moho interface, and a 5‐km‐thick aseismic zone is present beneath Segment 28 and adjacent nontransform discontinuities. At the Dragon Flag hydrothermal vent field along Segment 28, the presence of a detachment fault has been inferred from geomorphic features and seismic tomography. Our seismicity data show that this detachment fault deeply penetrates into the mantle with a steeply dipping (~65°) interface, and it appears to rotate to a lower angle in the upper crust, with ~55° of rollover. There is a virtual seismic gap beneath magmatic Segment 27, which may be connected to the presence of an axial magma chamber beneath the spreading center and focused melting; in this scenario, the increased magma supply produces a broad, elevated temperature environment, which suppresses earthquake generation.
The Development of Late‐Stage Continental Breakup: Seismic Reflection and Borehole Evidence from the Danakil Depression, Ethiopia
Authors: Bastow Ian D. , Booth Adam D. , Corti Giacomo , Keir Derek , Magee Craig , Jackson Christopher A.‐L. , Warren John , Wilkinson Jason , Lascialfari Matteo
Published: August 2018

During continental breakup, the locus of strain shifts from a broad region of border faulting and ductile plate stretching to a narrow zone of magma intrusion in a young ocean basin. Recent studies of volcanic rifts and margins worldwide suggest this shift occurs subaerially, before the onset of seafloor spreading. We test this hypothesis using recently acquired seismic reflection and borehole data from the Danakil Depression, Ethiopia, a unique region of transition between continental rifting and seafloor spreading. Our data, located near Dallol, ~30 km northwest of the Erta'Ale Volcanic Segment, reveal a remarkably thick (>1‐km) sequence of young (~100‐ka) evaporites in a basin bound by a major (≤400‐m‐throw), east‐dipping normal fault. To generate such a large amount of subsidence in such a relatively short time, we propose that upper‐crustal extension in Danakil is currently dominated by faulting, not magmatic intrusion. Given the region's markedly thinned crust (~15‐km‐thick), relative to elsewhere in Afar where magma‐assisted rifting dominates and maintains crustal thickness at ~25 km, mechanical extension in Danakil is likely coupled with ductile extension of the lower‐crust and mantle lithosphere. Despite proximity to the voluminous lavas of the active Erta'Ale Volcanic Segment, evidence for igneous material in the upper ~2 km of the 6‐ to 10‐km‐wide basin is limited. Late‐stage stretching was likely aided by thermal/strain‐induced lithospheric weakening following protracted magma‐assisted rifting. Basin formation immediately prior to the onset of seafloor spreading may also explain the accumulation of thick marine‐seepage‐fed evaporite sequences akin to those observed, for example, along the South Atlantic rifted margins.
Discrimination in Tree Stems O2 Uptake and the Dole Effect
Authors: Hilman Boaz , Angert Alon
Published: August 2018

The difference in δ18O between the atmospheric O2 and seawater is named the Dole effect (DE). Interpretation of past DE variations, a proxy for monsoonal intensity, is based on current understanding of global O2 fluxes. One such O2 flux that was poorly studied is the discrimination in O2 uptake by tree stems (Dstem). Stems differ from leaves in their lower gas permeability, which reduces the internal [O2] and poses diffusion limitations to local respiration. Diffusion limitations are expected to lower the effective discrimination below enzymatic values (17–30‰). Given fixed permeability, the lowest internal [O2] and thus the greatest diffusional effect are expected in high O2 influx. Dstem and O2 influx values were obtained by measurements of stem‐chamber air and a numerical model that resolves the gas exchange in the chamber. According to 101 results of temperate, Mediterranean, and tropical trees, the global Dstem is 19.2‰. Assuming basal O2 diffusion limitation in the stems, the results indicate involvement of the alternative oxidase respiration, with enzymatic discrimination factor of above 20‰. Small seasonal variations in Dstem were uncoupled from the O2 influx rates that tracked the temperature changes. This indicates a possible adjustment between the aeration capability of the stems and O2 uptake rate, which helps to maintain sufficient O2 supply. The mean Dstem value agrees with the assumed discrimination for leaf respiration, thus supporting current DE understanding. The small Dstem seasonal variations give an indication that climate variations on millennial and interglacial scales did not have a strong effect on Dstem values.
The Effect of Air‐Sea Flux Products, Shortwave Radiation Depth Penetration, and Albedo on the Upper Ocean Overturning Circulation
Authors: Groeskamp Sjoerd , Iudicone Daniele
Published: August 2018

Water mass transformation quantifies transport of matter between different density classes of the World Ocean. We present the first observationally based quantification of transformation rates due to air‐sea buoyancy fluxes, which considers different parameterizations of shortwave radiation depth penetration, including the influence of albedo and the Chlorophyll a concentration. The results provide a range of solutions that can be used to compare model‐based transformation rates against. We compared two air‐sea flux products with limited representation of ice dynamics at high latitudes. We find that variations in the air‐sea heat fluxes due to Chlorophyll a and its horizontal distribution are as important for water mass transformation rates than differences between the freshwater flux products. An accurate representation of the effects and spatial distribution of Chlorophyll a is required to obtain realistic transformation rates.
Toward Low‐Level Turbulence Forecasting at Eddy‐Resolving Scales
Authors: Muñoz‐Esparza Domingo , Sharman Robert , Sauer Jeremy , Kosović Branko
Published: August 2018

Microscale turbulence in the atmospheric boundary layer (ABL) is characterized by significant spatiotemporal variability. Consequently, a change in the turbulence forecasting paradigm needs to occur, moving beyond average turbulence estimates at mesoscale grid resolutions (several kilometers) to eddy‐resolving forecasts. To that end, the viability of dynamic downscaling to large‐eddy simulation scales is evaluated. We present for the first time, multiday dynamic downscaling from currently available numerical weather prediction forecasts to a high‐resolution grid spacing of 25 m. It is found that these eddy‐resolving forecasts can realistically reproduce turbulence levels and peak events in the bulk of the daytime ABL, adequately capturing turbulence variability at subminute intervals. Moreover, probability distributions of turbulence quantities are in very good agreement when compared to in situ sonic‐anemometer observations. These results demonstrate the feasibility of eddy‐resolving forecasts to derive accurate probabilistic estimates of turbulence in the ABL and provide a path toward real‐time large‐eddy simulation scale prediction.
Sand Grain Sizes and Shapes in Eolian Bedforms at Gale Crater, Mars
Authors: Weitz Catherine M. , Sullivan Robert J. , Lapotre Mathieu G. A. , Rowland Scott K. , Grant John A. , Baker Mariah , Yingst R. Aileen
Published: August 2018

We measured sand sizes and shapes on diverse eolian bedforms in Gale crater to help constrain models of eolian sediment transport on Mars. All grains are subangular to rounded with circularities of ~0.93–0.97, indicating an extensive abrasion history. There are two types of active bedforms based on grain size: (1) ripples composed of 50‐ to 150‐μm grains and (2) ripples that also include 250‐ to 500‐μm grains along their crests, in some cases with small amounts of even coarser grains (up to 1.4 mm). The smallest grain sizes (50–150 μm) are volumetrically the most abundant at all active bedforms. Inactive bedforms have surfaces of 350‐ to 2,000‐μm grains with finer‐grained interiors, consistent with observations made by rovers at other landing sites. Grains coarser than ~300 μm are less prone to mobilization driven by smaller saltating grains, making bedforms with concentrations of coarser grains more susceptible to surface stabilization and inactivity.
Effect of Flood Hydrograph Duration, Magnitude, and Shape on Bed Load Transport Dynamics
Authors: Phillips C. B. , Hill K. M. , Paola C. , Singer M. B. , Jerolmack D. J.
Published: August 2018

Bed load sediment transport is an inherently challenging process to measure within a river, which is further complicated by the typically transient nature of the hydrograph. Here we use laboratory experiments to explore how sediment flux under transient—unsteady and intermittent—flow differ from those under steady flow. For a narrow unimodal sediment distribution, we calculated fluid stress and measured sediment flux for a range of hydrograph durations, magnitudes, shapes, and sequences. Within a hydrograph, we find considerable variability in sediment flux for a given stress above the threshold for motion. However, cumulative bed load flux resulting from a flood scales linearly with the integrated excess transport capacity (flow impulse). This scaling indicates that, to first order, flow magnitude, duration, shape, and sequence are only relevant to bed load flux in terms of their contribution to the total flow impulse, in agreement with prior field results. The flood impulse represents a quantitative parameter through which the effects of transient flow on coarse sediment transport may be parsed.
Enlarging Rainfall Area of Tropical Cyclones by Atmospheric Aerosols
Authors: Zhao Chuanfeng , Lin Yanluan , Wu Fang , Wang Yang , Li Zhanqing , Rosenfeld Daniel , Wang Yuan
Published: August 2018

The size of a tropical cyclone (TC), measured by the area of either rainfall or wind, is an important indicator for the potential damage by TC. Modeling studies suggested that aerosols tend to enhance rainfall in the outer rainbands, which enlarges the eyewall radius and expands the extent of rainfall area. However, no observational evidence has yet been reported. Using TC rainfall area and aerosol optical depth (AOD) data, we find that aerosols have a distinguishable footprint in the TC size. Other dynamical factors for TC size, such as relative SST and Coriolis parameter, are also quantified and discussed. We show that, on average, TC rainfall size increases 9–20 km for each 0.1 increase of AOD in the western North Pacific. This finding implies that anthropogenic aerosol pollution can increase not only TC rainfall rate, but also TC rainfall area, resulting in potentially more destructive flooding affecting larger areas.
On the Role of Thermospheric Winds and Sporadic E Layers in the Formation and Evolution of Electrified MSTIDs in Geomagnetic Conjugate Regions
Authors: Narayanan V. L. , Shiokawa K. , Otsuka Y. , Neudegg D.
Published: August 2018

The electrified medium‐scale traveling ionospheric disturbances (EMSTIDs) occurring as geomagnetically conjugate features in the middle latitude F region ionosphere are studied using multi‐instrument observations. Airglow imaging of OI 630 nm emission over Sata, Japan, and Darwin, Australia, are used to identify the occurrence of EMSTIDs. Thermospheric wind measurements made with the Fabry‐Perot interferometer observations of OI 630 nm from Shigaraki, Japan, and Darwin, Australia, are used along with ionosonde observations over Yamagawa, Japan, and Darwin, Australia, to study the thermospheric and ionospheric characteristics. These are the first results from such multi‐instrument observations simultaneously made from geomagnetic conjugate locations. Our results show that the amplitudes of the EMSTIDs are often different between the hemispheres. Thermospheric meridional winds appear to control the EMSTID amplitudes in the respective hemisphere. However, EMSTIDs are generated only when there is significant sporadic E activity with foEs often reaching greater than 6 MHz and (foEs − fbEs) reaching above 5 MHz at least for a short duration occurred. Existence of strong sporadic E activity on one of the hemispheres is found to be sufficient enough for generation of EMSTIDs in the conjugate F regions. These results conclusively indicate the importance of sporadic E layers in the generation of EMSTIDs. Further, it shows the significance of interhemispheric coupling between the E and F region ionospheres in the formation of EMSTIDs while their amplitudes in the respective hemispheres appear to have control of thermospheric neutral winds in the same hemisphere.
Wind‐Driven Coastal Upwelling and Downwelling in the Shelfbreak East Greenland Current
Authors: Håvik Lisbeth , Våge Kjetil
Published: August 2018

The East Greenland Current is a major pathway for freshwater export from the Arctic Ocean and for the transport of dense overflow waters toward the North Atlantic. We use moored measurements from the East Greenland Current north of Denmark Strait from October 2011 to April 2012 to analyze the wind‐driven variability of the shelfbreak branch of this current system. By combining the moored data with atmospheric reanalysis data we found that coastal upwelling and downwelling take place in the shelfbreak East Greenland Current throughout winter. In total, upwelling and downwelling events occur around five times per month, and these events modulate the volume transport and redistribute water masses. Specifically, we find that upwelling may lead to a deposition of dense water masses on the shelf and to an offshore transport of freshwater, while downwelling events are associated with a considerable increase in along‐stream freshwater transport. Based on wind patterns and wind‐driven ocean variability along the east Greenland coast, the integrated effect of these episodes is expected to be substantial.
Improving Multitarget Tracking in Synthetic Aperture Radar Within a High‐Density Clutter, Using a Technique Based on the Promoted PHD Filtering and MTI Filter
Authors: Daryasafar N. , Sadeghzadeh R. A. , Naser‐Moghadasi M.
Published: August 2018

A method is presented in this paper for simultaneous multitarget tracking in the presence of high‐density clutter through the received data by synthetic aperture radar (SAR) by the use of the promoted Gaussian mixture probability hypothesis density filtering. Simultaneous tracking of several moving targets in an environment with high density of clutters is a special feature of probability hypothesis density (PHD) filtering that has turned it into a powerful system for tracking moving targets in SAR. Moving targets are desirably tracked by applying range cell migration compensation on the raw data received by SAR. As simulation results revealed, applying moving target indicator (MTI) filter before tracking process could improve performance of the promoted PHD filtering in multitarget tracking in SAR radar. In other words, application of MTI filter to decrease the clutter would significantly reduce the computational loads of the processor in tracking moving targets through the reduction of observations that enter the processor. The main parameters for assessing the performance of the proposed algorithm in this paper, the extracted state of moving targets over time in the presence of noise for different values of clutter's density, are considered in received observations. By increasing clutter density, the tracking process will be carried out with poorer performance using the promoted Gaussian mixture probability hypothesis density and Sequential Monte Carlo‐PHD filterings.
Systematic identification of non-coding pharmacogenomic landscape in cancer
Authors: Wang Yue , Wang Zehua , Xu Jieni , Li Jiang , Li Song , Zhang Min , Yang Da
Published: August 2018

Emerging evidence has shown long non-coding RNAs (lncRNAs) play important roles in cancer drug response. Here we report a lncRNA pharmacogenomic landscape by integrating multi-dimensional genomic data of 1005 cancer cell lines and drug response data of 265 anti-cancer compounds. Using Elastic Net (EN) regression, our analysis identifies 27,341 lncRNA-drug predictive pairs. We validate the robustness of the lncRNA EN-models using two independent cancer pharmacogenomic datasets. By applying lncRNA EN-models of 49 FDA approved drugs to the 5605 tumor samples from 21 cancer types, we show that cancer cell line based lncRNA EN-models can predict therapeutic outcome in cancer patients. Further lncRNA-pathway co-expression analysis suggests lncRNAs may regulate drug response through drug-metabolism or drug-target pathways. Finally, we experimentally validate that EPIC1, the top predictive lncRNA for the Bromodomain and Extra-Terminal motif (BET) inhibitors, strongly promotes iBET762 and JQ-1 resistance through activating MYC transcriptional activity.
Deubiquitinase Usp12 functions noncatalytically to induce autophagy and confer neuroprotection in models of Huntington’s disease
Authors: Aron Rebecca , Pellegrini Pasquale , Green Edward W. , Maddison Daniel C. , Opoku-Nsiah Kwadwo , Oliveira Ana Osório , Wong Jinny S. , Daub Aaron C. , Giorgini Flaviano , Muchowski Paul , Finkbeiner Steven
Published: August 2018

Huntington’s disease is a progressive neurodegenerative disorder caused by polyglutamine-expanded mutant huntingtin (mHTT). Here, we show that the deubiquitinase Usp12 rescues mHTT-mediated neurodegeneration in Huntington’s disease rodent and patient-derived human neurons, and in Drosophila. The neuroprotective role of Usp12 may be specific amongst related deubiquitinases, as the closely related homolog Usp46 does not suppress mHTT-mediated toxicity. Mechanistically, we identify Usp12 as a potent inducer of neuronal autophagy. Usp12 overexpression accelerates autophagic flux and induces an approximately sixfold increase in autophagic structures as determined by ultrastructural analyses, while suppression of endogenous Usp12 slows autophagy. Surprisingly, the catalytic activity of Usp12 is not required to protect against neurodegeneration or induce autophagy. These findings identify the deubiquitinase Usp12 as a regulator of neuronal proteostasis and mHTT-mediated neurodegeneration.
Thick Film Ni0.5Mn0.5−xSnx Heusler Alloys by Multi-layer Electrochemical Deposition
Authors: Zhang Yijia , Shamberger Patrick J.
Published: August 2018

The design of multifunctional alloys with multiple chemical components requires controllable synthesis approaches. Physical vapor deposition techniques, which result in thin films (<1 μm), have previously been demonstrated for micromechanical devices and metallic combinatorial libraries. However, this approach deviates from bulk-like properties due to the residual stress derived in thin films and is limited by total film thickness. Here, we report a route to obtain ternary Ni-Mn-Sn alloy thick films with controllable compositions and thicknesses by annealing electrochemically deposited multi-layer monatomic (Ni, Mn, Sn) films, deposited sequentially from separate aqueous deposition baths. We demonstrate (1) controllable compositions, with high degree of uniformity, (2) smooth films, and (3) high reproducibility between film transformation behavior. Our results demonstrate a positive correlation between alloy film thicknesses and grain sizes, as well as consistent bulk-like transformation behavior.
Fenbendazole acts as a moderate microtubule destabilizing agent and causes cancer cell death by modulating multiple cellular pathways
Authors: Dogra Nilambra , Kumar Ashok , Mukhopadhyay Tapas
Published: August 2018

Drugs that are already clinically approved or experimentally tested for conditions other than cancer, but are found to possess previously unrecognized cytotoxicity towards malignant cells, may serve as fitting anti-cancer candidates. Methyl N-(6-phenylsulfanyl-1H benzimidazol-2-yl) carbamate [Fenbendazole, FZ], a benzimidazole compound, is a safe and inexpensive anthelmintic drug possessing an efficient anti-proliferative activity. In our earlier work, we reported a potent growth-inhibitory activity of FZ caused partially by impairment of proteasomal function. Here, we show that FZ demonstrates moderate affinity for mammalian tubulin and exerts cytotoxicity to human cancer cells at micromolar concentrations. Simultaneously, it caused mitochondrial translocation of p53 and effectively inhibited glucose uptake, expression of GLUT transporters as well as hexokinase (HK II) - a key glycolytic enzyme that most cancer cells thrive on. It blocked the growth of human xenografts in nu/nu mice model when mice were fed with the drug orally. The results, in conjunction with our earlier data, suggest that FZ is a new microtubule interfering agent that displays anti-neoplastic activity and may be evaluated as a potential therapeutic agent because of its effect on multiple cellular pathways leading to effective elimination of cancer cells.
Bifidobacterium adolescentis is intrinsically resistant to antitubercular drugs
Authors: Lokesh Dhanashree , Parkesh Raman , kammara Rajagopal
Published: August 2018

Multiple mutations in the β subunit of the RNA polymerase (rpoβ) of Mycobacterium tuberculosis (Mtb) are the primary cause of resistance to rifamycin (RIF). In the present study, bifidobacterial rpoβ sequences were analyzed to characterize the mutations that contribute to the development of intrinsic resistance to RIF, isoniazid, streptomycin and pyrazinamide. Sequence variations, which mapped to cassettes 1 and 2 of the rpoβ pocket, are also found in multidrug-resistant Mtb (MDR Mtb). Growth curves in the presence of osmolytes and different concentrations of RIF showed that the bacteria adapted rapidly by shortening the growth curve lag time. Insight into the adapted rpoβ DNA sequences revealed that B. adolescentis harbored mutations both in the RIF pocket and in regions outside the pocket. The minimum inhibitory concentrations (MICs) and mutant prevention concentrations (MPCs) indicated that B. longum, B. adolescentis and B. animalis are resistant to antitubercular drugs. 3D-homology modeling and binding interaction studies using computational docking suggested that mutants had reduced binding affinity towards RIF. RIF-exposed/resistant bacteria exhibited variant protein profiles along with morphological differences, such as elongated and branched cells, surface conversion from rough to smooth, and formation of a concentrating ring.
Mechanisms of wheat (Triticum aestivum) grain storage proteins in response to nitrogen application and its impacts on processing quality
Authors: Zheng Ting , Qi Peng-Fei , Cao Yong-Li , Han Ya-Nan , Ma Hong-Liang , Guo Zhen-Ru , Wang Yan , Qiao Yuan-Yuan , Hua Shi-Yu , Yu Hai-Yue , Wang Jiang-Ping , Zhu Jing , Zhou Cai-Yi , Zhang Ya-Zhou , Chen Qing , Kong Li , Wang Ji-Rui , Jiang Qian-Tao , Yan Ze-Hong , Lan Xiu-Jin , Fan Gao-Qiong , Wei Yu-Ming , Zheng You-Liang
Published: August 2018

Basis for the effects of nitrogen (N) on wheat grain storage proteins (GSPs) and on the establishment of processing quality are far from clear. The response of GSPs and processing quality parameters to four N levels of four common wheat cultivars were investigated at two sites over two growing seasons. Except gluten index (GI), processing quality parameters as well as GSPs quantities were remarkably improved by increasing N level. N level explained 4.2~59.2% and 10.4~80.0% variability in GSPs fractions and processing quality parameters, respectively. The amount of N remobilized from vegetative organs except spike was significantly increased when enhancing N application. GSPs fractions and processing quality parameters except GI were only highly and positively correlated with the amount of N remobilized from stem with sheath. N reassimilation in grain was remarkably strengthened by the elevated activity and expression level of glutamine synthetase. Transcriptome analysis showed the molecular mechanism of seeds in response to N levels during 10~35 days post anthesis. Collectively, we provided comprehensive understanding of N-responding mechanisms with respect to wheat processing quality from N source to GSPs biosynthesis at the agronomic, physiological and molecular levels, and screened candidate genes for quality breeding.
Bundles of Brain Microtubules Generate Electrical Oscillations
Authors: Cantero María del Rocío , Villa Etchegoyen Cecilia , Perez Paula L. , Scarinci Noelia , Cantiello Horacio F.
Published: August 2018

Microtubules (MTs) are long cylindrical structures of the cytoskeleton that control cell division, intracellular transport, and the shape of cells. MTs also form bundles, which are particularly prominent in neurons, where they help define axons and dendrites. MTs are bio-electrochemical transistors that form nonlinear electrical transmission lines. However, the electrical properties of most MT structures remain largely unknown. Here we show that bundles of brain MTs spontaneously generate electrical oscillations and bursts of electrical activity similar to action potentials. Under intracellular-like conditions, voltage-clamped MT bundles displayed electrical oscillations with a prominent fundamental frequency at 39 Hz that progressed through various periodic regimes. The electrical oscillations represented, in average, a 258% change in the ionic conductance of the MT structures. Interestingly, voltage-clamped membrane-permeabilized neurites of cultured mouse hippocampal neurons were also capable of both, generating electrical oscillations, and conducting the electrical signals along the length of the structure. Our findings indicate that electrical oscillations are an intrinsic property of brain MT bundles, which may have important implications in the control of various neuronal functions, including the gating and regulation of cytoskeleton-regulated excitable ion channels and electrical activity that may aid and extend to higher brain functions such as memory and consciousness.
Dynamic Nuclear Polarization
Authors: Corzilius Björn
Published: August 2018

In this chapter, dynamic nuclear polarization (DNP) is introduced as an effective tool to enhance the sensitivity of NMR, in particular in the solid-state under MAS. The relevant DNP mechanisms (i.e., solid effect, cross effect, and Overhauser effect) and the propagation of enhanced nuclear polarization via spin-diffusion is explained. Several polarizing agent (PA) classes are discussed in the context of DNP mechanism and their field or frequency profiles. In the final section practical aspects as well as contemporary DNP applications are presented, which highlight the tremendous potential DNP-enhanced MAS NMR bears towards challenging problems in structural biology.