bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of resistance mutations of Pro197, Asp376 and Trp574 on the characteristics of acetohydroxyacid synthase (AHAS) isozymes
Authors: Yang Qian , Deng Wei , Wang Shipeng , Liu Hongjie , Li Xuefeng , Zheng Mingqi
Published: February 2018

BACKGROUND

Descurainia sophia L., a problematic weed in winter wheat fields in China, has developed high resistance to tribenuron‐methyl. Amino acid substitutions at sites Pro197, Asp376 and Trp574 in the target acetohydroxyacid synthase (AHAS) were primarily responsible for D. sophia resistance to tribenuron‐methyl. In this study, purified subpopulations of D. sophia plants individually homozygous for a specific resistance mutation (Pro197Leu, Pro197His, Pro197Ser, Pro197Thr, Asp376Glu or Trp574Leu) in AHAS were generated, and the effects of resistance mutations on D. sophia resistance and AHAS characteristics were investigated.

RESULTS

All resistance mutations in this study not only caused D. sophia to evolve 152‐ to 811‐fold resistance to tribenuron‐methyl but also greatly reduced AHAS sensitivity to tribenuron‐methyl and increased AHAS binding affinity for the substrate pyruvate, which was primarily responsible for D. sophia resistance. The molecular docking results indicated that these resistance mutations altered AHAS binding affinity for tribenuron‐methyl by reducing the hydrogen bonds and changing hydrophobic interactions. Compared with the wild‐type AHAS, these resistance mutations exhibited no significant effects on AHAS feedback inhibition by branched‐chain amino acids (BCAAs) at concentrations <0.08 mm. The altered AHAS sensitivity to feedback inhibition by BCAAs did not necessarily increase or decrease the free BCAAs in resistant D. sophia plants.

CONCLUSION

The AHAS resistance mutations conferred D. sophia resistance to tribenuron‐methyl by decreasing the binding affinity for tribenuron‐methyl and/or increasing the binding affinity for pyruvate, but the mutations did not necessarily affect the biosynthesis of BCAAs in plants. © 2018 Society of Chemical Industry
An evaluation of the convection‐permitting ensemble COSMO‐E for three contrasting precipitation events in Switzerland
Authors: Klasa Christina , Arpagaus Marco , Walser André , Wernli Heini
Published: February 2018

Specific aspects of the performance of COSMO‐E, a newly operational convection‐permitting ensemble prediction system run by the Swiss national weather service, are evaluated for three contrasting precipitation events and compared with its driving model, the ECMWF ensemble (EC ENS). The events include locally triggered air‐mass convection on four consecutive days (CONV), a complex flood‐producing rainfall episode (LSF1), and a summertime cold‐frontal precipitation event (LSF2). Investigating the precipitation forecasts reveals that COSMO‐E outperforms EC ENS in all cases in terms of precipitation pattern, whereas both ensembles fail in predicting the correct domain‐averaged precipitation for LSF1 and struggle with the correct timing of the daily precipitation onset for CONV. For LSF2, EC ENS produces an almost perfect time series of domain‐averaged precipitation, but this seemingly excellent forecast fails in predicting the spatial distribution. Spread–error relationships also yield a rather complex picture. The higher resolution of COSMO‐E leads to increased spread and reduced underdispersion for near‐surface variables. However, in the free troposphere the two ensembles perform similarly, and the agreement of spread and error varies between cases, variables and levels. For both events with large‐scale advection, underdispersion occurs for mid‐tropospheric relative humidity near fronts, whose propagation is overconfident in EC ENS, while for the convective event COSMO‐E clearly shows larger spread than EC ENS. Because frontal propagation is largely determined by lateral boundary conditions, this underdispersion also occurs for COSMO‐E. In summary, this study confirms the benefit of a convection‐permitting model for many aspects of ensemble forecasting, and illustrates the challenge of robustly assessing the quality of an ensemble forecast for hydrometeorologically relevant events.
Simple solutions for the summer shallow atmospheric circulation over North Africa
Authors: Dalu G. A. , Gaetani M. , Lavaysse C. , Flamant C. , Evan A. T. , Baldi M.
Published: February 2018

The spring‐to‐summer shallow atmospheric circulation over North Africa is driven by two desert heat lows (DHLs), one over the Sahara (SHL) and one over Arabia (AHL), with cyclones embedded in the convective layer, capped by mid‐tropospheric anticyclones. The aim of this work is to produce a minimal theoretical framework for these dynamical features in terms of Kelvin, mixed and planetary mode solutions to a two‐layer Matsuno–Gill model with a lower Rayleigh frictional layer dynamically coupled to an almost frictionless upper layer. Results show that a DHL drives a Walker‐like cell with rising air over the low and subsiding air to its west, with the lower‐level cyclone to the east of the mid‐tropospheric anticyclone, the latter being bounded to the southwest by an unstable easterly jet. These features, related to frictional differences between the two layers, are enhanced by ambient easterly winds. In spring, the stronger SHL drives a cell with rising air over West Africa and subsiding air over the Atlantic. The weaker AHL drives a cell with rising air over Arabia and subsiding air over East Africa. In summer, the stronger AHL drives a cell with rising air over Arabia and subsiding air over Libya, and the weaker SHL drives a cell with rising air over West Sahara and subsiding air over the Atlantic. The concurrent contributions of easterly winds, monsoonal low‐level convergence, and seasonal airborne dust warming strengthen the SHL, making its winds stronger than those of the AHL. In addition, a third‐order expansion of the Coriolis parameter strengthens the zonal winds and weakens the meridional winds. These contributors strengthen anticyclones over the eastern Mediterranean and to the west of Gibraltar. The ability of the model to represent the main features of the North African atmospheric circulations suggests a potential for better understanding of climate dynamics in connected regions (Mediterranean, Tropical Atlantic).
The precipitation response to variable terrain forcing over low mountain ranges in different weather regimes
Authors: Schneider Linda , Barthlott Christian , Barrett Andrew I. , Hoose Corinna
Published: February 2018

The impact of terrain forcing on cloud formation and precipitation over low mountain ranges is investigated by numerical experiments with the COnsortium for Small‐scale MOdeling (COSMO) model. The investigation comprises six case studies divided into strong and weak large‐scale synoptic forcing. To understand how the terrain affects the occurrence and intensity of precipitation, sensitivity runs with flattened mountains and incrementally smoothed terrain were performed at 500‐m horizontal grid spacing. On days with weak forcing (i.e. air‐mass convection), results show that low‐level wind convergence is crucial for the initiation of deep convection. Its strength varies between the simulations, depending e.g. on the formation of boundary‐layer rolls, and determines whether there is an increase or decrease of total precipitation in the simulations with flattened individual mountains compared with the reference run. For cases with strong synoptic forcing (i.e. passage of frontal zones), the large‐scale advection of precipitation interacts with local effects, as advected cells are not intensified by orographic uplift in the absence of mountains. As a consequence, the runs with flattened mountains show higher moisture contents over flat terrain, which can lead to more precipitation downstream. The model runs with smoothed external parameters (i.e. terrain height, land use, roughness length) show small changes on days with strong forcing and slightly larger effects under weak forcing. However, changing the resolution of the external parameters has only a relatively small effect on precipitation in high‐resolution simulations. The results from this study demonstrate the complexity of multiple processes, like lifting or flow deviation by mountains and wind changes due to thermal instabilities, on different spatial scales for the initiation of deep convection over complex terrain.
A flexible additive inflation scheme for treating model error in ensemble Kalman filters
Authors: Sommer Matthias , Janjić Tijana
Published: February 2018

Data assimilation algorithms require an accurate estimate of the uncertainty of the prior (background) field that cannot be adequately represented by the ensemble of numerical model simulations. Partially, this is due to the sampling error that arises from the use of a small number of ensemble members to represent the background‐error covariance. It is also partially a consequence of the fact that the geophysical model does not represent its own error. Several mechanisms have been introduced so far to alleviate the detrimental effects of misrepresented ensemble covariances, allowing for the successful implementation of ensemble data assimilation techniques for atmospheric dynamics. One of the established approaches is additive inflation, which consists of perturbing each ensemble member with a sample from a given distribution. This results in a fixed rank of the effective model‐error covariance matrix. In this article, a more flexible approach is introduced, where the model error samples are treated as additional synthetic ensemble members, which are used in the update step of data assimilation but are not forecast. This way, the rank of the model‐error covariance matrix can be chosen independently of the ensemble. The effect of this altered additive inflation method on the performance of the filter is analyzed here in an idealized experiment. It is shown that the additional synthetic ensemble members can make it feasible to achieve convergence in an otherwise divergent parameter setting of data assimilation. The use of this method also allows for a less stringent localization radius.
Skilful multiweek tropical cyclone prediction in ACCESS‐S1 and the role of the MJO
Authors: Camp Joanne , Wheeler Matthew C. , Hendon Harry H. , Gregory Paul A. , Marshall Andrew G. , Tory Kevin J. , Watkins Andrew B. , MacLachlan Craig , Kuleshov Yuriy
Published: February 2018

The skill of predicting the weekly occurrence of tropical cyclone (TC) activity in the Southern Hemisphere is investigated in the Australian Bureau of Meteorology seasonal forecasting system (ACCESS‐S1). On multiweek time‐scales, the Madden–Julian Oscillation (MJO) has previously been shown to be a major driver of TC variability. ACCESS‐S1 shows high skill for predictions of the MJO out to a lead time of ∼30 days and is able to reproduce the observed modulation of TC activity by the MJO in the Southern Hemisphere. In particular, ACCESS‐S1 shows a clear eastward propagation of increased TC activity with the enhanced convective phase of the MJO. MJO modulated changes in the large‐scale environment associated with TC genesis, such as 850‐hPa absolute vorticity, 600‐hPa relative humidity and 850–200 hPa vertical wind shear, are well captured by ACCESS‐S1 except for off the northwest coast of Australia. There, the change in the large‐scale environment and associated TC activity is too weak in the model. Probabilistic forecast verification shows that ACCESS‐S1 is able to provide skilful forecasts of TC occurrence into week 5 if forecasts are calibrated to take into account model biases in TC frequency. Two different calibration strategies are tested: the first is a simple constant scaling factor applied across the Southern Hemisphere for all forecast leads; the second applies a different scaling factor for different regions and lead times. Results of this study suggest that ACCESS‐S1 can provide skilful multiweek forecasts of TC occurrence for the Southern Hemisphere, greatly extending the current TC forecast availability beyond the 1–5 day time‐scale.
Information‐entropic measures in free and confined hydrogen atom
Authors: Mukherjee Neetik , Roy Amlan K.
Published: February 2018

Shannon entropy (S), Rényi entropy (R), Tsallis entropy (T), Fisher information (I), and Onicescu energy (E) have been explored extensively in both free H atom (FHA) and confined H atom (CHA). For a given quantum state, accurate results are presented by employing respective exact analytical wave functions in r space. The p‐space wave functions are generated from respective Fourier transforms—for FHA these can be expressed analytically in terms of Gegenbauer polynomials, whereas in CHA these are computed numerically. Exact mathematical expressions of
,
are derived for circular states of a FHA. Pilot calculations are done taking order of entropic moments (α, β) as
in r and p spaces. A detailed, systematic analysis is performed for both FHA and CHA with respect to state indices n, l, and with confinement radius (rc) for the latter. In a CHA, at small rc, kinetic energy increases, whereas
decrease with growth of n, signifying greater localization in high‐lying states. At moderate rc, there exists an interplay between two mutually opposing factors: (i) radial confinement (localization) and (ii) accumulation of radial nodes with growth of n (delocalization). Most of these results are reported here for the first time, revealing many new interesting features. Comparison with literature results, wherever possible, offers excellent agreement.
Phosphate uptake behavior and mechanism analysis of facilely synthesized nanocrystalline Zn‐Fe layered double hydroxide with chloride intercalation
Authors: Yang Bokai , Liu Dongfang , Lu Jianbo , Meng Xianrong , Sun Yu
Published: February 2018

Zn‐Fe layered double hydroxide with chloride intercalation (ZFCL) was synthesized by a coprecipitation method at room temperature. ZFCL was characterized by N2 adsorption‐desorption isotherms, X‐ray diffraction, scanning electron microscope, Zeta‐sizer analyzer, X‐ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The results showed that ZFCL had large surface area and layered structure. The maximum adsorption capacity of ZFCL was 150.6 mg/g at 25°C. That was higher than most other adsorbent which were reported. The kinetic data were described better by the pseudo‐second‐order adsorption kinetic rate model. The adsorption isotherm on the adsorbent was described by Langmuir, Freundlich, and Sips models at pH 6 and followed the fitting order: Sips >Freundlich>Langmuir. Thermodynamic analyses indicated that the phosphate adsorption on ZFCL was endothermic and spontaneous in nature. The sequence of coexisting cations and anions competing with phosphate was Ca2+ > Mg2+ > Na+ and SO42− > NO3− > Cl−. ZFCL can be regenerated by the sequential use of NaOH and ZnCl2. The adsorption capacity remained high as 108.6 mg/g after regeneration of 3 times. The results of zeta potential, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy analyses indicated that the phosphate adsorption mechanisms involved ion exchange, Zn3(PO4)2 precipitation, and the formation of inner‐sphere complex via replacement of surface hydroxyl groups by phosphate.
A threshold‐free summary index of prediction accuracy for censored time to event data
Authors: Yuan Yan , Zhou Qian M. , Li Bingying , Cai Hengrui , Chow Eric J. , Armstrong Gregory T.
Published: February 2018

Prediction performance of a risk scoring system needs to be carefully assessed before its adoption in clinical practice. Clinical preventive care often uses risk scores toscreenasymptomatic population. The primary clinical interest is to predict the risk of having an event by a prespecifiedfuturetimet0. Accuracy measures such as positive predictive values have been recommended for evaluating the predictive performance. However, for commonly used continuous or ordinal risk score systems, these measures require a subjective cutoff threshold value that dichotomizes the risk scores. The need for a cutoff value created barriers for practitioners and researchers. In this paper, we propose a threshold‐free summary index of positive predictive values that accommodates time‐dependent event status and competing risks. We develop a nonparametric estimator and provide an inference procedure for comparing this summary measure between 2 risk scores for censored time to event data. We conduct a simulation study to examine the finite‐sample performance of the proposed estimation and inference procedures. Lastly, we illustrate the use of this measure on a real data example, comparing 2 risk score systems for predicting heart failure in childhood cancer survivors.
Inherent Flexibility vis‐à‐vis Structural Rigidity in Chemically Stable Antimalarial Dispiro N‐Sulfonylpiperidine Tetraoxanes
Authors: Sharma Chiranjeev , Sharma Kumkum , Kumar Yadav Jitendra , Agarwal Alka , Kumar Awasthi Satish
Published: February 2018

Structurally diverse and chemically stable tetraoxanes were formed by peroxidation of N‐sulfonylpiperidones. X‐ray analysis revealed that the crystal structures possess central spiro‐2,5‐disubstituted tetraoxane rings trans fused to 6‐membered piperidine and cyclohexylidene substituents in classical chair conformations. The more flexible cycloheptane ring exhibited pseudorotation between chair and twist chair conformation. The two sulfonyl oxygen atoms act as hydrogen‐bonding acceptors and participate in hydrogen bonding. Docking calculations showed that the tetraoxanes are aligned parallel to the plane of the porphyrin ring of heme so that the iron can attack the O−O bond to initiate redox‐mediated reaction to render nanomolar antimalarial potency to these compounds against P. falciparum 3D7.
Iodination and O‐Arylation of 2‐Arylquinolin‐4(1H)‐one with PhI(OAc)2 Under Metal‐free Conditions
Authors: Xie Ying , Zhong Junbo , Li Yulong , Xiao Xinsheng , Zou Like , Liu Yingle , Zhang Kaiming , He Jiao
Published: February 2018

Iodination and O‐arylation of 2‐arylquinolin‐4(1H)‐one with PIDA under mild conditions have been developed, in which PIDA play a dual role as an iodine source and an aryl source. This protocol provides a facile access to 3‐iodo‐4‐phenoxy‐2‐arylquinolines with tolerance of a broad range of functional groups. Furthermore, This method is employed for concise synthesis of topoisomerases catalytic inhibitor analogue.
Pathologies of the canal of Nuck
Authors: Holley Allison
Published: February 2018

Pathologies involving the canal of Nuck are a little known developmental disorder with this embryological entity barely mentioned in most embryology and anatomy textbooks. This article will review the embryology and anatomy of the canal of Nuck and discuss the different pathologies that may be diagnosed. Ultrasound has the ability to accurately diagnose canal of Nuck pathologies and to differentiate between the types of hydroceles and the contents of congenital inguinal hernias. Ultrasound also provides valuable information on the contents perfusion and reducibility, thus helping to facilitate clinical management and timing of any surgical intervention. Pathologies of the canal of Nuck, while rare, should be considered as a differential diagnosis when investigating groin, labia or inguinal masses in female children.
Institutional dimensions and conflict resolution strategy in international joint ventures: An empirical examination
Authors: Kwarteng Amoako , Dadzie Samuel Ato , Famiyeh Samuel , Aklamanu Alphones Mawusi Kwasi
Published: February 2018

This study examines the impact of the host‐country institutional structures on the choice of conflict resolution strategy in the international joint venture (IJV). Using the survey method and relying on multiple regression, we demonstrate that there is a statistically significant relationship between institutional pillars and the choice of conflict resolution strategy in the international joint venture in the context of Ghana. In particular, we demonstrate that legalistic and forcing conflict resolution strategies are influenced by the regulative institutional pillar, while compromising and problem‐solving conflict resolution strategies are impacted by normative and cognitive institutional pillars. The multigrouping analysis results show that the views and the choice of foreign partners on conflict resolution strategy differ from that of the local partners to the IJV. This study fills the gap by empirically testing the conflict resolution strategies of firms in relation to the role of regulative, normative, and cognitive institutional pillars of the host country.
Proteomic analysis of ametryn toxicity in zebrafish embryos
Authors: Lin Heng‐Dao , Hsu Li‐Sung , Chien Chih‐Ching , Chen Ssu‐Ching
Published: February 2018

Ametrym (AMT) is the most widely used herbicide and frequently detected in the aquatic environment. AMT also represent a potential health risk to aquatic organisms and animals, including humans. However, little data are available on their toxicity to zebrafish (Danio rerio). The aim of the present study was to evaluate the toxicological effects of AMT exposure on zebrafish embryos. In the acute toxicity test, 6 hpf embryos were exposed to various concentrations of AMT for 24 or 48 h. The results indicated that AMT induced malformation in larvae. To investigate the toxicological mechanism on the protein expression level. A proteomic approach was employed to investigate the proteome alterations of zebra fish embryos exposed to 20 mg/L AMT for 48 h. Among 2925 unique proteins identified, 298 differential proteins (> or <1.3‐fold, P < 0.05) were detected in the treated embryos as compared to the corresponding proteins in the untreated embryos. Gene ontology analysis showed that these up‐regulated proteins were most involved in glycolysis, lipid transport, protein polymerization, and nucleotide binding, and the down‐regulated proteins were related to microtubule‐based process, protein polymerization, oxygen transport. Moreover, KEGG pathway analysis indicated that tight junction, ribosome, and oxidative phosphorylation were inhibited in the treated embryos. These findings provide new insight into the mechanisms of toxicity induced by AMT.
Shifting demographic and attitudinal changes of TWS members (1991–2014)
Authors: Urbanek Rachael E. , Carrozzino‐Lyon Amy L. , Potts Gary E.
Published: February 2018

The Wildlife Society's (TWS) strategic plan for 2014–2019 intends to improve member services, organizational integration, and sustainability of the Society. To inform these efforts, we invited 12,681 TWS members to participate in an online survey covering demographics and perceptions of member services and benefits in 2014. Compared with a previous TWS member survey completed in 1991, member demographics have shifted: females comprise a greater proportion of the membership (32% in 2014; 19% in 1991), a smaller proportion of members are actively involved at any level of TWS (41%; 52%), and the median age of members has increased slightly from 39 to 44. A smaller proportion of current members supported expansion of the certification program (28%) as compared with member responses in 1991 (51%). Support for TWS becoming an accrediting agency for university wildlife programs declined from 79% to 50%. A greater proportion of current members (54%) opposed using TWS certification requirements as hiring guidelines for wildlife biologists, compared with 38% of members in 1991. In 2014, most TWS members viewed access to TWS publications and networking opportunities with other professionals as valuable membership benefits; however, lack of time or resources for involvement and lack of encouragement from employers were perceived as the main barriers to TWS participation. Although often an integral part of a member's professional career, our results suggest that members are less active in the Society and hold weaker positive attitudes toward the role of TWS in their career as it relates to certification, formal education, and employment compared with 1991. © 2018 The Wildlife Society.
Dimension Vectors of Indecomposable Objects for Nilpotent Operators of Degree 6 with One Invariant Subspace
Authors: Dowbor Piotr , Meltzer Hagen
Published: February 2018

Formulas for the dimension vectors of all objects M in the category

$\mathcal {S}(\tilde {6})$

S
(

6

~

)

of nilpotent operators with nilpotency degree bounded by 6, acting on finite dimensional vector spaces with invariant subspaces in a graded sense, are given (Theorem 2.3). For this purpose we realize a tubular algebra Λ, controlling the category

$\mathcal {S}(\tilde {6})$

S
(

6

~

)

, as an endomorphism algebra of a suitable tilting bundle over a weighted projective line of type (2,3,6) (Theorem 3.6). Using this description and a concept of mono-epi type, the interval multiplicity vector of an object in

$\mathcal {S}(\tilde {6})$

S
(

6

~

)

is introduced and determined (Theorem 2.8). This is a much finer invariant than the usual dimension vector.
Screening anal cancer in women living with HIV/AIDS
Authors: Diefenthäler Vanessa Laís , Zanella Janice de Fátima Pavan , Coser Janaina
Published: February 2018

Aim Addressing the main methodologies published in the scientific literature and used to screen anal cancer in women living with HIV/AIDS.

Methodology The current study is an integrative literature review applied to articles published between 2013 and 2017 in databases such as PUBMED, EBSCO and LILACS.

Results Eight studies were selected to compose the current review after the inclusion and exclusion criteria were applied. All the articles had evidence level IV. Anal cytology and the DNA-HPV test were the methodologies prevailing in the studies. The number of participants in the studies ranged from 35 to 863, and all the studies involved women living with HIV/AIDS. The aim of most of the herein reviewed studies was to assess the prevalence of anal cytologic changes or HPV infection in women living with HIV/AIDS (WLHA).

Conclusion Studies have pointed out that there is concern about high anal cancer and anal HPV infection rates. They also highlighted the importance of the screening procedure for anal cancer prevention through cytology associated, or not, with molecular HPV detection methods.
Bilateral Charcot hip Arthropathy Due to Tabes Dorsalis: A Case Report
Authors: Yeung Ip Hoi , Kan Yeung Yip , Shik Luk Kristine , Wy Lam Polly , Ho Wong Kwok
Published: February 2018

This article illustrates the clinical course of a patient diagnosed to have bilateral Charcot hip arthropathy secondary to tabes dorsalis from delayed untreated syphilitic infection. This differential diagnosis of rapid bilateral hip destruction was a near-extinct entity, and a high index of suspicion is needed to prevent untoward sequelae.
The science and application of IPS e.Max dental ceramic
Authors: Willard Alec , Gabriel Chu Tien‐Min
Published: February 2018

The aim of this paper is to report the state of current literature and recommendations for the lithium disilicate glass‐ceramic IPS e.Max. The materials science, mechanical and optical properties were reviewed. Additionally an assessment was conducted of current implementation recommendations and clinical outcomes. This paper provides a brief historical overview, summary of the findings the findings of current literature, and clinical recommendation for the use of IPS e.Max CAD in dental applications.
Polarity Reversals in the Earth's Magnetic Field
Authors: Florindo Fabio
Published: February 2018

Studies of geomagnetic polarity reversals have generated some of the biggest and most interesting debates in the paleomagnetic and wider solid Earth geophysics communities over the last 25 years.
Space Weather Research and Forecasting Act Introduced to Senate
Authors: Knipp Delores
Published: February 2018

This bill is a welcome and proactive effort to align all federal agencies to act in the nation's best interest when it comes to forecasting and responding to extreme space weather events.
Even the Magnetosphere Has Problems
Authors: Liemohn Mike
Published: February 2018

In a new conference and collection of papers, international space physicists narrow down the enigmas that puzzle magnetospheric science.
Here Comes the Anthropocene
Authors: van der Pluijm Ben
Published: February 2018

Two recent papers in Earth's Future discuss the addition of a new epoch to the geological timescale.
Exploring Formal Recognition of the Anthropocene
Authors: Hanson Brooks
Published: February 2018

Colin Waters of the Anthropocene Working Group, which has been exploring formal recognition of the Anthropocene as a unit in the geological time scale, discussed the group's recommendations at the IGC.
Volcanic Java and Climate Change
Authors: Wysession Michael
Published: February 2018

An account of a geophysicist's recent trip to Indonesia wouldn't be complete without intrigue and elucidations about what Java, climate change, and Butch Cassidy all have in common.
Anthropogenic Drought: How Humans Affect the Global Ecosystem
Authors: AghaKouchak Amir
Published: February 2018

Amir AghaKouchak discusses how human activity affects water supply and the environment.
Measurements and Models of Reactive Transport in Geological Media
Authors: Berkowitz Brian
Published: February 2018

Author Brian Berkowitz answers questions about his recently published article and the scientific and societal implications of his findings.
Frontiers in Cryoseismology
Authors: Florindo Fabio , Podolskiy Evgeny
Published: February 2018

Recent review provides timely and comprehensive resource for emerging field.
Growing Our Publication Partnership
Authors: Hanson Brooks , van der Hilst Rob
Published: February 2018

Renewed partnership aims to continue expanding the reach of scholarly Earth and space science.
Whither Heterogeneity and Stochastic Subsurface Hydrology?
Authors: Rajaram Harihar
Published: February 2018

A debate series in Water Resources Research examines the gap between research and practice in the application of stochastic concepts for describing subsurface heterogeneity.
Benefiting from Good Reviews: Part 1
Authors: Clark Martyn
Published: February 2018

Martyn Clark describes how thoughtful reviews can substantially enhance the quality and impact of published papers.
Benefiting from Good Reviews: Part 2
Authors: Clark Martyn
Published: February 2018

Martyn Clark reflects on how his experiences of going through the peer review process as an author have influenced him as an editor.
Competing Models of Mountain Formation Reconciled
Authors: Parsons Andy
Published: February 2018

The author of a prize-winning paper published in Geochemistry, Geophysics, Geosystems describes new insights into crustal mechanics and the formation of the Himalaya.
More Earthquakes May Be the Result of Fracking Than We Thought
Authors: Witman Sarah
Published: February 2018

Scientists show small earthquakes caused by fracking near Guy-Greenbrier, Ark., in 2010 that could have been early indicators of high stress levels on larger faults deeper underground.
Acoustic Imaging of Oceanic Mixing in the Gulf of Mexico
Authors: Stanley Sarah
Published: February 2018

Detailed analysis of acoustic reflections suggests that vertical mixing of oceanic water is enhanced at greater depths, thanks to weak stratification and the roughness of the seabed.
Cycles of Mountain Building Formed 2018 Winter Olympics Terrain
Authors: Sidder Aaron
Published: February 2018

The Korean Peninsula’s rich geologic history can be traced on the slopes of the alpine ski course.
Single-cell analyses of human islet cells reveal de-differentiation signatures
Authors: Teo Adrian Keong Kee , Lim Chang Siang , Cheow Lih Feng , Kin Tatsuya , Shapiro James A. , Kang Nam-Young , Burkholder William , Lau Hwee Hui
Published: February 2018

Human pancreatic islets containing insulin-secreting β-cells are notoriously heterogeneous in cell composition. Since β-cell failure is the root cause of diabetes, understanding this heterogeneity is of paramount importance. Recent reports have cataloged human islet transcriptome but not compared single β-cells in detail. Here, we scrutinized ex vivo human islet cells from healthy donors and show that they exhibit de-differentiation signatures. Using single-cell gene expression and immunostaining analyses, we found healthy islet cells to contain polyhormonal transcripts, and INS+ cells to express decreased levels of β-cell genes but high levels of progenitor markers. Rare cells that are doubly positive for progenitor markers/exocrine signatures, and endocrine/exocrine hormones were also present. We conclude that ex vivo human islet cells are plastic and can possibly de-/trans-differentiate across pancreatic cell fates, partly accounting for β-cell functional decline once isolated. Therefore, stabilizing β-cell identity upon isolation may improve its functionality.
Mapping molecular assemblies with fluorescence microscopy and object-based spatial statistics
Authors: Lagache Thibault , Grassart Alexandre , Dallongeville Stéphane , Faklaris Orestis , Sauvonnet Nathalie , Dufour Alexandre , Danglot Lydia , Olivo-Marin Jean-Christophe
Published: February 2018

Elucidating protein functions and molecular organisation requires to localise precisely single or aggregated molecules and analyse their spatial distributions. We develop a statistical method SODA (Statistical Object Distance Analysis) that uses either micro- or nanoscopy to significantly improve on standard co-localisation techniques. Our method considers cellular geometry and densities of molecules to provide statistical maps of isolated and associated (coupled) molecules. We use SODA with three-colour structured-illumination microscopy (SIM) images of hippocampal neurons, and statistically characterise spatial organisation of thousands of synapses. We show that presynaptic synapsin is arranged in asymmetric triangle with the 2 postsynaptic markers homer and PSD95, indicating a deeper localisation of homer. We then determine stoichiometry and distance between localisations of two synaptic vesicle proteins with 3D-STORM. These findings give insights into the protein organisation at the synapse, and prove the efficiency of SODA to quantitatively assess the geometry of molecular assemblies.
Clinical testing of BRCA1 and BRCA2: a worldwide snapshot of technological practices
Authors: Toland Amanda Ewart , Forman Andrea , Couch Fergus J. , Culver Julie O. , Eccles Diana M. , Foulkes William D. , Hogervorst Frans B. L. , Houdayer Claude , Levy-Lahad Ephrat , Monteiro Alvaro N. , Neuhausen Susan L. , Plon Sharon E. , Sharan Shyam K. , Spurdle Amanda B. , Szabo Csilla , Brody Lawrence C. ,   on behalf of the BIC Steering Committee
Published: February 2018

Clinical testing of BRCA1 and BRCA2 began over 20 years ago. With the expiration and overturning of the BRCA patents, limitations on which laboratories could offer commercial testing were lifted. These legal changes occurred approximately the same time as the widespread adoption of massively parallel sequencing (MPS) technologies. Little is known about how these changes impacted laboratory practices for detecting genetic alterations in hereditary breast and ovarian cancer genes. Therefore, we sought to examine current laboratory genetic testing practices for BRCA1/BRCA2. We employed an online survey of 65 questions covering four areas: laboratory characteristics, details on technological methods, variant classification, and client-support information. Eight United States (US) laboratories and 78 non-US laboratories completed the survey. Most laboratories (93%; 80/86) used MPS platforms to identify variants. Laboratories differed widely on: (1) technologies used for large rearrangement detection; (2) criteria for minimum read depths; (3) non-coding regions sequenced; (4) variant classification criteria and approaches; (5) testing volume ranging from 2 to 2.5 × 105 tests annually; and (6) deposition of variants into public databases. These data may be useful for national and international agencies to set recommendations for quality standards for BRCA1/BRCA2 clinical testing. These standards could also be applied to testing of other disease genes.
Excitations in the field-induced quantum spin liquid state of α-RuCl3
Authors: Banerjee Arnab , Lampen-Kelley Paula , Knolle Johannes , Balz Christian , Aczel Adam Anthony , Winn Barry , Liu Yaohua , Pajerowski Daniel , Yan Jiaqiang , Bridges Craig A. , Savici Andrei T. , Chakoumakos Bryan C. , Lumsden Mark D. , Tennant David Alan , Moessner Roderich , Mandrus David G. , Nagler Stephen E.
Published: February 2018

The celebrated Kitaev quantum spin liquid (QSL) is the paradigmatic example of a topological magnet with emergent excitations in the form of Majorana Fermions and gauge fluxes. Upon breaking of time-reversal symmetry, for example in an external magnetic field, these fractionalized quasiparticles acquire non-Abelian exchange statistics, an important ingredient for topologically protected quantum computing. Consequently, there has been enormous interest in exploring possible material realizations of Kitaev physics and several candidate materials have been put forward, recently including α-RuCl3. In the absence of a magnetic field this material orders at a finite temperature and exhibits low-energy spin wave excitations. However, at moderate energies, the spectrum is unconventional and the response shows evidence for fractional excitations. Here we use time-of-flight inelastic neutron scattering to show that the application of a sufficiently large magnetic field in the honeycomb plane suppresses the magnetic order and the spin waves, leaving a gapped continuum spectrum of magnetic excitations. Our comparisons of the scattering to the available calculations for a Kitaev QSL show that they are consistent with the magnetic field induced QSL phase.
Oscillatory spin-orbit torque switching induced by field-like torques
Authors: Lee Jong Min , Kwon Jae Hyun , Ramaswamy Rajagopalan , Yoon Jungbum , Son Jaesung , Qiu Xuepeng , Mishra Rahul , Srivastava Shalabh , Cai Kaiming , Yang Hyunsoo
Published: February 2018

Deterministic magnetization switching using spin-orbit torque (SOT) has recently emerged as an efficient means to electrically control the magnetic state of ultrathin magnets. The SOT switching still lacks in oscillatory switching characteristics over time, therefore, it is limited to bipolar operation where a change in polarity of the applied current or field is required for bistable switching. The coherent rotation based oscillatory switching schemes cannot be applied to SOT, because the SOT switching occurs through expansion of magnetic domains. Here we experimentally achieve oscillatory switching in incoherent SOT process by controlling domain wall dynamics. We find that a large field-like component can dynamically influence the domain wall chirality which determines the direction of SOT switching. Consequently, under nanosecond current pulses, the magnetization switches alternatively between the two stable states. By utilizing this oscillatory switching behavior, we demonstrate a unipolar deterministic SOT switching scheme by controlling the current pulse duration.
Confining excitation energy of Er3+-sensitized upconversion nanoparticles through introducing various energy trapping centers
Authors: Shang Yunfei , Hao Shuwei , Lv Weiqiang , Chen Tong , Tian Li , Lei Zuotao , Yang Chunhui
Published: February 2018

Various energy trapping centers are employed to simultaneously suppress concentration quenching and tune luminescence output through efficiently confining the excitation energy in Er3+-sensitized upconversion nanoparticles.
Organocatalytic asymmetric Michael/hemiacetalization/acyl transfer reaction of α-nitroketones with o-hydroxycinnamaldehydes: synthesis of 2,4-disubstituted chromans
Authors: Maity Rajendra , Pan Subhas Chandra
Published: February 2018

An organocatalytic asymmetric synthesis of 2,4-disubstituted chroman compounds has been developed via a Michael/hemiketalization/acyl transfer reaction between o-hydroxycinnamaldehydes and α-nitroketones.
Stabilisation of continuous‐time switched 2D systems with all unstable modes
Authors: Guan Chaoxu , Fei Zhongyang , Wang Zhenhuan , Wu Ligang
Published: February 2018

This study investigates the stabilisation of a class of continuous‐time two‐dimensional (2D) switched non‐linear Roesser model with all modes unstable. Other than design controllers for the system, the authors would like to schedule the switching signal to achieve the asymptotical stability of the system. The main idea in this study is to utilise the alternative running of different subsystems to compensate the divergence of each subsystem, which thus achieves the stabilisation goal. By taking advantage of mode‐dependent average dwell time property and a piecewise continuous Lyapunov function method, a general criterion is developed to guarantee the stability of the continuous‐time switched 2D non‐linear system with a designed switching law. The obtained result is further used to deal with switched 2D linear system. Finally, the effectiveness and superiority of the proposed methods are illustrated by two numerical examples.
Research on the modulation and control of multilevel matrix converter
Authors: Jianglei Qu , Lie Xu , Lina Wang , Yannian Hui
Published: February 2018

This paper discusses the effects of different space vector modulation (SVM) hexagon partition on common mode voltage suppression at high modulation index and presents an improved capacitor voltage balance strategy for multilevel matrix converter. Matrix converter is a compact designed converter which allows direct AC–AC power transfer without an intermediate DC link. Multilevel matrix converters, which utilises a multilevel structure on a traditional matrix converter, expand these characters to high‐voltage and high‐power situations. This paper is concerned with SVM of three‐level matrix converter and concentrates on the comparison between different hexagon partitions; the improved balancing strategy is employed to improve the performance of flying capacitor voltage control. Simulation from Matlab/Simulink and results from a small‐scale experimental prototype are presented to validate the theoretical results.
Emerging Concepts in Evidence-Based Asthma Management
Authors: Reddel Helen
Published: February 2018

Asthma management is in an intriguing phase, with acceptance of asthma as a heterogeneous condition with different phenotypes and underlying mechanisms and the potential for personalized asthma care, in parallel with increasing evidence about the population-level impact of basic strategies to increase access to medicines and improve inhaler technique and adherence. These changes have been facilitated by a more comprehensive view of evidence, including both randomized controlled trials with high internal validity and pragmatic and observational studies with high generalizability to patients in clinical practice. Evolving concepts of asthma control have led to new approaches to asthma assessment, recognizing the potential for discordance between symptom control and risk of exacerbations. A re-evaluation of evidence has also led to substantial changes in initial treatment of asthma, with the focus moving away from bronchodilator-only treatment, toward early use of inhaled corticosteroids and novel strategies for mild asthma. Sputum-guided treatment, where available, is successful in patients with moderate–severe asthma, but exhaled nitric oxide has not yet satisfied initial assumptions about its utility for biomarker-guided treatment. New interventions are emerging to improve adherence with asthma controller medications. A re-evaluation of evidence about written asthma action plans has led to encouragement of a rapid increase in controller dose, rather than relying on bronchodilator treatment and oral corticosteroids. Finally, new models of asthma care are emerging, utilizing the skills of allied health professionals and recognizing the potential role of telehealth.
Controlling the Risk Domain in Pediatric Asthma through Personalized Care
Authors: Szefler Stanley , Anderson William
Published: February 2018

Strategies to control the risk domain of NHLBI EPR-3 (National Heart, Lung, and Blood Institute Expert Panel Report-3) asthma guidelines, which includes exacerbations requiring systemic corticosteroids, reduction in lung growth, and progressive loss of lung function, and treatment-related adverse effects, are evolving in children and adolescents. Increasing evidence demonstrates that children and adolescents with asthma are at risk of a reduction in lung growth, leading to lower lung function and potentially chronic obstructive pulmonary disease as adults. Readily available clinical biomarkers for atopy, including aeroallergen testing, total serum IgE, blood eosinophilia, and spirometry, are being utilized to phenotype difficult-to-treat pediatric patients, to assess risk for seasonal exacerbations, and to predict response to controller therapies. The Composite Asthma Severity Index is a novel, freely available scoring system to define asthma control, incorporating NHLBI EPR-3 risk and impairment domains. As new asthma controller therapies, such as tiotropium, are introduced for pediatric use, the safety of established controller therapies including inhaled corticosteroid and long-acting beta-agonist are being reexamined. Macrolide antibiotics may be an oral corticosteroid sparing alternative for the treatment of severe respiratory tract infection in preschool-aged children. Seasonally directed courses of omalizumab may provide an alternative approach to prevent fall asthma exacerbations in children. Combining these pharmaceuticals and biomarker-directed therapies provide potential new options and personalized approaches to gain asthma control in pediatric patients failing current management.
Pediatric Neurotoxicity of Anesthetic Agents: Are We too Worried or too Little?
Authors: Bhatt Rashmi , Khanna Puneet
Published: February 2018

The debate on possible neurocognitive adverse effects of anesthetic agents refuses to cease. As evidence builds up, both for and against the debate, a conclusion evades us. More human studies on the subject have now been carried out, and yet we do not have a consensus. In this review, we attempt to relook at the existing evidence, as well as examine some new information as we pursue a greater understanding of this complex matter.
Das reversible zerebrale Vasokonstriktionssyndrom
Authors: Kamm K. , Ruscheweyh R. , Straube A.
Published: February 2018

Das reversible zerebrale Vasokonstriktionssyndrom (RCVS) ist eine häufige, wahrscheinlich unterdiagnostizierte Ursache des Donnerschlagkopfschmerzes. Typischerweise präsentiert sich das RCVS mit einem stärksten, innerhalb von weniger als 1 Minute sein Maximum erreichenden Kopfschmerz. Dieser kann innerhalb von wenigen Wochen, oft getriggert durch körperliche Anstrengung, emotionale Belastung oder Valsalva-Manöver, immer wieder auftreten. Die Erkrankung verläuft meist monosymptomatisch, selbstlimitierend und benigne, allerdings können intrazerebrale Blutungen, Ischämien oder ein PRES komplizierend auftreten. Im folgenden Artikel sollen die typische Präsentation des RCVS, Komplikationen, Verlauf, Therapie und Pathophysiologie vorgestellt werden.
Symptomatischer Clusterkopfschmerz
Authors: Holle-Lee D. , Gaul C.
Published: February 2018

Die Erstdiagnose eines Clusterkopfschmerzes macht immer eine weitere Diagnostik zum Ausschluss einer sekundären Ursache notwendig. Eine ungewöhnliche Anamnese oder ein auffälliger neurologischer Untersuchungsbefund können auf eine symptomatische Kopfschmerzursache hinweisen, eine typische Anamnese und ein unauffälliger Untersuchungsbefund schließen jedoch einen sekundären Clusterkopfschmerz keinesfalls aus. Eine Zusatzuntersuchung mittels cMRT sollte bei Erstdiagnose immer durchgeführt werden. Hypophysäre Raumforderungen und Dissektionen der Hirnversorgenden Gefäße sind häufige Grunderkrankungen, die phänomenologisch als Clusterkopfschmerz erscheinen können. Die Therapie richtet sich nach der Ursache der Clusterkopfschmerzen.