julilili42/papers huggingface dataset:
Large ice loss variability at Nioghalvfjerdsfjorden Glacier, Northeast-Greenland
2018-07-11

Abstract Nioghalvfjerdsfjorden is a major outlet glacier in Northeast-Greenland. Although earlier studies showed that the floating part near the grounding line thinned by 30% between 1999 and 2014, the temporal ice loss evolution, its relation to external forcing and the implications for the grounded ice sheet remain largely unclear. By combining observations of surface features, ice thickness and bedrock data, we find that the ice shelf mass balance has been out of equilibrium since 2001, with large variations of the thinning rates on annual/multiannual time scales. Changes in ice flux and surface ablation are too small to produce this variability. An increased ocean heat flux is the most plausible cause of the observed thinning. For sustained environmental conditions, the ice shelf will lose large parts of its area within a few decades and ice modeling shows a significant, but locally restricted thinning upstream of the grounding line in response.
Broad host range species in specialised pathogen groups should be treated with suspicion – a case study on Entyloma infecting Ranunculus
2018-07-11

Plant pathogenic smut fungi in the broader sense can be divided into the Ustilaginomycetes , which cause classical smut symptoms with masses of blackish spores being produced in a variety of angiosperms, and the Exobasidiomycetes , which are often less conspicuous, as many do not shed large amounts of blackish spores. The leaf-spot causing members of the genus Entyloma ( Entylomatales , Exobasidiomycetes ) belong to the latter group. Currently, 172 species that all infect eudicots are included in the genus. Vánky (2012) recognised five Entyloma species on species of Ranunculus s.lat. Two have been reported only from Ficaria verna s.lat . , while three, E. microsporum , E. ranunculi-repentis , E. verruculosum , have been reported to have a broad host range, encompassing 30, 26, and 5 species of Ranunculus , respectively. This broad host range is in contrast to the generally high host specificity assumed for species of Entyloma , indicating that they may represent complexes of specialised species. The aim of this study was to investigate Entyloma on Ranunculus s.lat. using multigene phylogenies and morphological comparisons. Phylogenetic analyses on the basis of up to four loci (ITS, atp 2, ssc 1, and map ) showed a clustering of Entyloma specimens according to host species. For some of these Entyloma lineages, names not currently in use were available and reinstated. In addition, Entyloma microsporum s.str. is neotypified. Six novel species are described in this study, namely, Entyloma jolantae on Ranunculus oreophilus , E. klenkei on R. marginatus , E. kochmanii on R. lanuginosus , E. piepenbringiae on R. polyanthemos subsp. nemorosus (type host) and R. repens , E. savchenkoi on R. paludosus , and E. thielii on R. montanus . For all species diagnostic bases and morphological characteristics are provided. The results in this study once more highlight the importance of detailed re-investigation of broad host-range pathogens of otherwise specialised plant pathogen groups.
relxill_nk: A Relativistic Reflection Model for Testing Einstein’s Gravity
2018-07-11

Einstein’s theory of general relativity was proposed over 100 years ago and has successfully passed a large number of observational tests in the weak field regime. However, the strong field regime is largely unexplored, and there are many modified and alternative theories that have the same predictions as Einstein’s gravity for weak fields and present deviations when gravity becomes strong. relxill_nk is the first relativistic reflection model for probing the spacetime metric in the vicinity of astrophysical black holes and testing Einstein’s gravity in the strong field regime. Here, we present our current constraints on possible deviations from Einstein’s gravity obtained from the black holes in 1H0707–495, Ark 564, GX 339–4, and GS 1354–645.
Influence of different wastewater treatment technologies on genotoxicity and dioxin-like toxicity in effluent-exposed fish
2018-07-11

Abstract Background In situ exposure of rainbow trout up- and downstream of differently equipped wastewater treatment plants (WWTPs) and subsequent analyses of micronuclei frequencies and hepatic EROD activities were used to evaluate the impact of the effluents on fish health. Two of the facilities (WWTPs A and B) were conventional treatment plants. WWTP C has been equipped with a powdered activated carbon stage. Here, analyses were conducted prior and subsequent to this upgrade. Results Differences did not only occur when comparing conventional (WWTPs A, B and C prior to the upgrade) and advanced treatment (WWTP C after the upgrade), but also between the conventionally equipped WWTPs. There was no indication for genotoxic effects or pollution-related EROD induction in fish exposed at WWTP A. In contrast, trout exposed at WWTP B expressed strong reactions. However, here, adverse reactions were also observed in fish kept upstream. Similar observations were made for EROD activities in fish exposed at WWTP C prior to the upgrade, whereas genotoxic effects could only be seen in trout kept downstream of this effluent. Upgrading of WWTP C resulted in a significant reduction of both genotoxic effects and EROD levels. Conclusions The results show financial investments in advanced wastewater treatment to be beneficial for aquatic ecosystems, especially when conventional technologies do not sufficiently remove pollutants. Yet, negative impacts of effluents on aquatic organisms can, under certain conditions, also be avoided by conventional treatment. Therefore, we recommend deciding on the necessity and the type of WWTP upgrading on a case-by-case basis.
Magnesium Stung by Nonclassical Scorpionate Ligands: Synthesis and Cone‐Angle Calculations
2018-07-11

Abstract A series of tris(pyrazolyl)alkane (RCTp) scorpionate ligands of the type RCTp 3‐R′ (R=Me, n Bu, SiMe 3 ; R′=H, Me, Ph, i Pr, t Bu) were synthesized and their ability to coordinate methylmagnesium moieties was examined. The reaction of Mg(AlMe 4 ) 2 with neutral proligands HCTp 3‐Ph or Me 3 SiCTp 3‐Me , containing a non‐innocent backbone methine moiety, led to deprotonation/rearrangement and SiMe 3 /AlMe 3 exchange to afford [(Me 3 AlCTp 3‐Ph ) 2 Mg] and [(Me 3 AlCTp 3‐Me )Mg(AlMe 4 )], respectively, with monoanionic tripodal ligands. Treatment of sterically less demanding RCTp 3‐R′ with Mg(AlMe 4 ) 2 produced isostructural dicationic “metal‐in‐a‐box” complexes of the type [(RCTp 3‐R′ ) 2 Mg][AlMe 4 ] 2 (R=Me, n Bu; R′=H, Me). Utilization of the superbulky ligands MeCTp 3‐Ph and MeCTp 3‐ t Bu gave monocationic complexes [(MeCTp 3‐Ph )MgMe][AlMe 4 ] and [(MeCTp 3‐ t Bu )MgMe][Al 2 Me 7 ] as separated ion pairs. The reaction of Mg(AlMe 4 ) 2 with n BuCTp 3‐Ph led to the formation of the dimagnesium complex [{( n BuCTp 3‐Ph )Mg(AlMe 4 )} 2 (μ‐CH 3 )], which features a bridging methyl moiety and terminal η 1 ‐coordinated tetramethylaluminato ligands. Isopropyl‐substituted ligand MeCTp 3‐ i Pr emerged from further fine‐tuning of the steric and electronic parameters and, upon reaction with Mg(AlMe 4 ) 2 , gave (MeCTp 3‐ i Pr )Mg(AlMe 4 ) 2 ; this represents the first example of a magnesium bis(alkyl) complex with an intact RCTp 3‐R′ ligand. The exact ligand cone angles Θ ° of all magnesium complexes were determined according to the mathematical analysis developed by Allen et al. [ J. Comput. Chem . 2013 , 34 , 1189–1197].
Feasibility of Functional MRI at Ultralow Magnetic Field via Changes in Cerebral Blood Volume
2018-07-11

Abstract We investigate the feasibility of performing functional MRI (fMRI) at ultralow field (ULF) with a Superconducting QUantum Interference Device (SQUID), as used for detecting magnetoencephalography (MEG) signals from the human head. While there is negligible magnetic susceptibility variation to produce blood oxygenation level-dependent (BOLD) contrast at ULF, changes in cerebral blood volume (CBV) may be a sensitive mechanism for fMRI given the five-fold spread in spin-lattice relaxation time ( T 1 ) values across the constituents of the human brain. We undertook simulations of functional signal strength for a simplified brain model involving activation of a primary cortical region in a manner consistent with a blocked task experiment. Our simulations involve measured values of T 1 at ULF and experimental parameters for the performance of an upgraded ULFMRI scanner. Under ideal experimental conditions we predict a functional signal-to-noise ratio of between 3.1 and 7.1 for an imaging time of 30 minutes, or between 1.5 and 3.5 for a blocked task experiment lasting 7.5 minutes. Our simulations suggest it may be feasible to perform fMRI using a ULFMRI system designed to perform MRI and MEG in situ.
Spatial modelling with Euclidean distance fields and machine learning
2018-07-12

Summary This study introduces a hybrid spatial modelling framework, which accounts for spatial non‐stationarity, spatial autocorrelation and environmental correlation. A set of geographic spatially autocorrelated Euclidean distance fields (EDF) was used to provide additional spatially relevant predictors to the environmental covariates commonly used for mapping. The approach was used in combination with machine‐learning methods, so we called the method Euclidean distance fields in machine‐learning (EDM). This method provides advantages over other prediction methods that integrate spatial dependence and state factor models, for example, regression kriging (RK) and geographically weighted regression (GWR). We used seven generic (EDFs) and several commonly used predictors with different regression algorithms in two digital soil mapping (DSM) case studies and compared the results to those achieved with ordinary kriging (OK), RK and GWR as well as the multiscale methods ConMap, ConStat and contextual spatial modelling (CSM). The algorithms tested in EDM were a linear model, bagged multivariate adaptive regression splines (MARS), radial basis function support vector machines (SVM), Cubist, random forest (RF) and a neural network (NN) ensemble. The study demonstrated that DSM with EDM provided results comparable to RK and to the contextual multiscale methods. Best results were obtained with Cubist, RF and bagged MARS. Because the tree‐based approaches produce discontinuous response surfaces, the resulting maps can show visible artefacts when only the EDFs are used as predictors (i.e. no additional environmental covariates). Artefacts were not obvious for SVM and NN and to a lesser extent bagged MARS. An advantage of EDM is that it accounts for spatial non‐stationarity and spatial autocorrelation when using a small set of additional predictors. The EDM is a new method that provides a practical alternative to more conventional spatial modelling and thus it enhances the DSM toolbox. Highlights We present a hybrid mapping approach that accounts for spatial dependence and environmental correlation. The approach is based on a set of generic Euclidean distance fields (EDF). Our Euclidean distance fields in machine learning (EDM) can model non‐stationarity and spatial autocorrelation. The EDM approach eliminates the need for kriging of residuals and produces accurate digital soil maps.
Inactivation of TCA cycle enhances Staphylococcus aureus persister cell formation in stationary phase
2018-07-12

Abstract Persister cells constitute a small subpopulation of bacteria that display remarkably high antibiotic tolerance and for pathogens such as Staphylococcus aureus are suspected as culprits of chronic and recurrent infections. Persisters formed during exponential growth are characterized by low ATP levels but less is known of cells in stationary phase. By enrichment from a transposon mutant library in S . aureus we identified mutants that in this growth phase displayed enhanced persister cell formation. We found that inactivation of either sucA or sucB , encoding the subunits of the α-ketoglutarate dehydrogenase of the tricarboxylic acid cycle (TCA cycle), increased survival to lethal concentrations of ciprofloxacin by 10–100 fold as did inactivation of other TCA cycle genes or atpA encoding a subunit of the F 1 F 0 ATPase. In S . aureus , TCA cycle activity and gene expression are de-repressed in stationary phase but single cells with low expression may be prone to form persisters. While ATP levels were not consistently affected in high persister mutants they commonly displayed reduced membrane potential, and persistence was enhanced by a protein motive force inhibitor. Our results show that persister cell formation in stationary phase does not correlate with ATP levels but is associated with low membrane potential.
DEGUM, ÖGUM, SGUM and FMF Germany Recommendations for the Implementation of First-Trimester Screening, Detailed Ultrasound, Cell-Free DNA Screening and Diagnostic Procedures
2018-07-12

Abstract First-trimester screening between 11 + 0 and 13 + 6 weeks with qualified prenatal counseling, detailed ultrasound, biochemical markers and maternal factors has become the basis for decisions about further examinations. It detects numerous structural and genetic anomalies. The inclusion of uterine artery Doppler and PlGF screens for preeclampsia and fetal growth restriction. Low-dose aspirin significantly reduces the prevalence of severe preterm eclampsia. Cut-off values define groups of high, intermediate and low probability. Prenatal counseling uses detection and false-positive rates to work out the individual need profile and the corresponding decision: no further diagnosis/screening – cell-free DNA screening – diagnostic procedure and genetic analysis. In pre-test counseling it must be recognized that the prevalence of trisomy 21, 18 or 13 is low in younger women, as in submicroscopic anomalies in every maternal age. Even with high specificities, the positive predictive values of screening tests for rare anomalies are low. In the general population trisomies and sex chromosome aneuploidies account for approximately 70 % of anomalies recognizable by conventional genetic analysis. Screen positive results of cfDNA tests have to be proven by diagnostic procedure and genetic diagnosis. In cases of inconclusive results a higher rate of genetic anomalies is detected. Procedure-related fetal loss rates after chorionic biopsy and amniocentesis performed by experts are lower than 1 to 2 in 1000. Counseling should include the possible detection of submicroscopic anomalies by comparative genomic hybridization (array-CGH). At present, existing studies about screening for microdeletions and duplications do not provide reliable data to calculate sensitivities, false-positive rates and positive predictive values.
Structural Optimization of a Pyridinylimidazole Scaffold: Shifting the Selectivity from p38α Mitogen-Activated Protein Kinase to c-Jun N-Terminal Kinase 3
2018-07-12

Starting from known p38α mitogen-activated protein kinase (MAPK) inhibitors, a series of inhibitors of the c-Jun N-terminal kinase (JNK) 3 was obtained. Altering the substitution pattern of the pyridinylimidazole scaffold proved to be effective in shifting the inhibitory activity from the original target p38α MAPK to the closely related JNK3. In particular, a significant improvement for JNK3 selectivity could be achieved by addressing the hydrophobic region I with a small methyl group. Furthermore, additional structural modifications permitted to explore structure-activity relationships. The most potent inhibitor 4-(4-methyl-2-(methylthio)-1<i>H</i>-imidazol-5-yl)-<i>N</i>-(4-morpholinophenyl)pyridin-2-amine showed an IC<sub>50</sub> value for the JNK3 in the low triple digit nanomolar range and its binding mode was confirmed by X-ray crystallography.
Genetic Adaptation of a Mevalonate Pathway Deficient Mutant in Staphylococcus aureus
2018-07-12

In this study we addressed the question how a mevalonate (MVA)-auxotrophic <i>Staphylococcus aureus</i>Δ<i>mvaS</i> mutant can revert to prototrophy. This mutant couldn't grow in the absence of MVA. However, after a long lag-phase of 4-6 days the mutant adapted from auxotrophic to prototrophic phenotype. During that time, it acquired two point mutations: One mutation in the coding region of the regulator gene <i>spx</i>, which resulted in an amino acid exchange that decreased Spx function. The other mutation in the upstream-element within the core-promoter of the mevalonolactone lactonase gene <i>drp35</i>. This mutation led to an increased expression of <i>drp35</i>. In repeated experiments the mutations always occurred in <i>spx</i> and <i>drp35</i> and in the same order. The first detectable mutation appeared in <i>spx</i> and allowed slight growth; the second mutation, in <i>drp35</i>, increased growth further. Phenotypical characterizations of the mutant showed that small amounts of the lipid-carrier undecaprenol are synthesized, despite the lack of <i>mvaS</i>. The growth of the adapted clone, Δ<i>mvaS</i><sup>ad</sup>, indicates that the mutations reawake a rescue bypass. We think that this bypass enters the MVA pathway at the stage of MVA, because blocking the pathway downstream of MVA led to growth arrest of the mutant. In addition, the lactonase Drp35 is able to convert mevalonolactone to MVA. Summarized, we describe here a mutation-based two-step adaptation process that allows resuscitation of growth of the Δ<i>mvaS</i> mutant.
Next-to-leading order QCD corrections to inclusive heavy-flavor production in polarized deep-inelastic scattering
2018-07-12

We provide a first calculation of the complete next-to-leading order QCD\\ncorrections for heavy flavor contributions to the inclusive structure function\\n in longitudinally polarized deep-inelastic scattering. The results are\\nderived with largely analytical methods and retain the full dependence on the\\nheavy quark's mass. We discuss all relevant technical details of the\\ncalculation and present numerical results for the heavy quark scaling\\nfunctions. We perform important crosschecks to verify our results in the known\\nlimit of photoproduction and for the unpolarized electroproduction of heavy\\nquarks. We also compare our calculations to the available, partial results in\\nthe polarized case, in particular, in the limit of asymptotically large photon\\nvirtualities, and analyze the behavior of the scaling functions near threshold.\\nFirst steps towards phenomenological applications are taken by providing some\\nestimates for inclusive charm production in polarized deep-inelastic scattering\\nat a future electron-ion collider and studying their sensitivity to the\\npolarized gluon distribution. The residual dependence of heavy quark\\nelectroproduction on unphysical factorization and renormalization scales and on\\nthe heavy quark mass is investigated.\\n
Simultaneous Acquisition of Words and Syntax: Effects of Exposure Condition and Declarative Memory
2018-07-12

This study examined the simultaneous acquisition of vocabulary and grammar by adult learners and the role of exposure condition and declarative memory. Most experimental studies investigating the acquisition of artificial or natural languages focus on either vocabulary or grammar, but not both. However, a systematic investigation of the simultaneous learning of multiple linguistic features is important given that it mirrors language learning outside the lab. Native English speakers were exposed to an artificial language under either incidental or intentional exposure conditions. Participants had to learn both novel pseudowords and word order patterns while also processing stimulus sentences for meaning. The results showed that adult learners are able to rapidly acquire basic syntactic information of a novel language while processing the input for meaning (plausibility judgments) and attempting to learn novel vocabulary at the same time. The results further indicated that exposure condition (incidental versus intentional) made no difference in terms of either vocabulary or grammar learning gains. Findings also revealed that learners developed explicit, not implicit, knowledge of lexis and syntax. Finally, the results indicated that individuals' declarative memory capacity was not related to vocabulary learning but only to grammar learning. Our study underscores the importance of studying the simultaneous acquisition of different language features and from different perspectives of comprehension versus production, incidental versus intentional learning conditions, implicit/explicit knowledge, and individual differences in cognitive abilities.
Weak gravitational lensing: A compact object with arbitrary quadrupole moment immersed in plasma
2018-07-12

We study weak gravitational lensing around a compact object with arbitrary\\nquadrupole moment in the presence of plasma. The studied compact objects are\\nconsidered to be spherically symmetric. The additional parameter \\nregulating the quadrupole moment in the metric alters the deflection angle of\\nlight rays along with the plasma parameters. In the vacuum, the number of\\nimages due to the presence of the parameter increases and causes the\\nincrease of the magnification of the image source. The effects of uniform and\\nnonuniform plasma on gravitational lensing around the compact object are also\\nstudied.\\n
Zwitterionic codeine‐derived methacrylate monoliths for enantioselective capillary electrochromatography of chiral acids and chiral bases
2018-07-12

Abstract Thiol‐ene click reaction of N ‐acetyl‐L‐cysteine methyl ester to codeine, followed by reaction with allyl isocyanate and hydrolysis to the corresponding zwitterionic chiral selector and its subsequent bonding to the surface of a methacrylate monolith provided a new chiral capillary column for enantiomer separation of chiral acids and chiral bases. First, the epoxy groups of a poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) monolith were converted into amine residues, followed by reaction with allylglycidyl ether. In this way, a spacer arm was bonded to the surface before coating and cross‐linking poly(3‐mercaptopropyl methylsiloxane) (PMPMS) via radical addition (thiol‐ene click reaction) to the surface. In order to improve the performance of the monolithic chiral stationary phase, thio ether and residual thiol groups were oxidized to sulfonyl and sulphonate groups, respectively. This novel chiral stationary phase (CSP) was evaluated by capillary electrochromatography (CEC) using two chiral model compounds, namely N ‐3,5‐dinitrobenzoyl‐R,S‐leucine (retained by anion‐exchange mechanism) and mefloquine (by cation‐exchange process). The ion‐exchange retention mechanism on the CSP was characterized for these two counterionic model solutes by varying the mobile phase composition, including the nature of solvents, the concentration of counter‐ions and co‐ions, and the acid‐to‐base ratio. A series of chiral β‐blockers and amino acid derivatives was used to further check the performance of the modified monolith under the optimal conditions. Several enantiomers were baseline resolved with reasonable peak efficiencies (up to 60,000 theoretical plates per meter for the second eluted enantiomer).