bluuebunny/crossref_metadata_2025 huggingface dataset:
$$ \mathcal{N} $$-extended Chern-Simons Carrollian supergravities in 2 + 1 spacetime dimensions
Authors: Ali Farhad , Ravera Lucrezia
Published: February 2020

Abstract

In this work we present the ultra-relativistic $$ \mathcal{N} $$
N
-extended AdS Chern-Simons supergravity theories in three spacetime dimensions invariant under $$ \mathcal{N} $$
N
-extended AdS Carroll superalgebras. We first consider the (2, 0) and (1, 1) cases; subsequently, we generalize our analysis to $$ \mathcal{N} $$
N
= ($$ \mathcal{N} $$
N
, 0), with $$ \mathcal{N} $$
N
even, and to $$ \mathcal{N} $$
N
= (p, q), with p, q > 0. The $$ \mathcal{N} $$
N
-extended AdS Carroll superalgebras are obtained through the Carrollian (i.e., ultra-relativistic) contraction applied to an so(2) extension of $$ \mathfrak{osp} $$
osp
(2|2) ⊗ $$ \mathfrak{sp} $$
sp
(2), to $$ \mathfrak{osp} $$
osp
(2|1) ⊗ $$ \mathfrak{osp} $$
osp
(2, 1), to an $$ \mathfrak{so}\left(\mathcal{N}\right) $$
so

N

extension of $$ \mathfrak{osp} $$
osp
(2|$$ \mathcal{N} $$
N
) ⊗ $$ \mathfrak{sp} $$
sp
(2), and to the direct sum of an $$ \mathfrak{so} $$
so
(p) ⊕ $$ \mathfrak{so} $$
so
(q) algebra and $$ \mathfrak{osp} $$
osp
(2|p) ⊗ $$ \mathfrak{osp} $$
osp
(2, q), respectively. We also analyze the flat limit (ℓ → ∞, being ℓ the length parameter) of the aforementioned $$ \mathcal{N} $$
N
-extended Chern-Simons AdS Carroll supergravities, in which we recover the ultra-relativistic $$ \mathcal{N} $$
N
-extended (flat) Chern-Simons supergravity theories invariant under $$ \mathcal{N} $$
N
-extended super-Carroll algebras. The flat limit is applied at the level of the superalgebras, Chern-Simons actions, supersymmetry transformation laws, and field equations.
O new physics, where art thou? A global search in the top sector
Authors: Brivio Ilaria , Bruggisser Sebastian , Maltoni Fabio , Moutafis Rhea , Plehn Tilman , Vryonidou Eleni , Westhoff Susanne , Zhang Cen
Published: February 2020

Abstract

We provide a comprehensive global analysis of Run II top measurements at the LHC in terms of dimension-6 operators. A distinctive feature of the top sector as compared to the Higgs-electroweak sector is the large number of four-quark operators. We discuss in detail how they can be tested and how quadratic terms lead to a stable limit on each individual Wilson coefficient. Predictions for all observables are computed at NLO in QCD. Our SFitter analysis framework features a detailed error treatment, including correlations between uncertainties.
Absorption of fermionic dark matter by nuclear targets
Authors: Dror Jeff A. , Elor Gilly , McGehee Robert
Published: February 2020

Abstract

Absorption of fermionic dark matter leads to a range of distinct and novel signatures at dark matter direct detection and neutrino experiments. We study the possible signals from fermionic absorption by nuclear targets, which we divide into two classes of four Fermi operators: neutral and charged current. In the neutral current signal, dark matter is absorbed by a target nucleus and a neutrino is emitted. This results in a characteristically different nuclear recoil energy spectrum from that of elastic scattering. The charged current channel leads to induced β decays in isotopes which are stable in vacuum as well as shifts of the kinematic endpoint of β spectra in unstable isotopes. To confirm the possibility of observing these signals in light of other constraints, we introduce UV completions of example higher dimensional operators that lead to fermionic absorption signals and study their phenomenology. Most prominently, dark matter which exhibits fermionic absorption signals is necessarily unstable leading to stringent bounds from indirect detection searches. Nevertheless, we find a large viable parameter space in which dark matter is sufficiently long lived and detectable in current and future experiments.
Deriving the AdS3/CFT2 correspondence
Authors: Eberhardt Lorenz , Gaberdiel Matthias R. , Gopakumar Rajesh
Published: February 2020

Abstract

It was recently argued that string theory on AdS3× S3× 𝕋4 with one unit (k = 1) of NS-NS flux is exactly dual to the symmetric orbifold CFT SymN (𝕋4). In this paper we show how to directly relate the n-point correlators of the two sides to one another. In particular, we argue that the correlators of the world-sheet theory are delta-function- localised in string moduli space to those configurations that allow for a holomorphic covering map of the S2-boundary of AdS3 by the world-sheet. This striking feature can be seen both from a careful Ward identity analysis, as well as from semi-classically exact AdS3 solutions that are pinned to the boundary. The world-sheet correlators therefore have exactly the same structure as in the Lunin-Mathur construction of symmetric orbifold CFT correlators in terms of a covering surface — which now gets identified with the world-sheet. Together with the results of [1, 2] this essentially demonstrates how the k = 1 AdS3 string theory becomes equivalent to the spacetime orbifold CFT in the genus expansion.
Field theories on null manifolds
Authors: Bagchi Arjun , Basu Rudranil , Mehra Aditya , Nandi Poulami
Published: February 2020

Abstract

We argue that generic field theories defined on null manifolds should have an emergent BMS or conformal Carrollian structure. We then focus on a simple interacting conformal Carrollian theory, viz. Carrollian scalar electrodynamics. We look at weak (on-shell) and strong invariance (off-shell) of its equations of motion under conformal Carrollian symmetries. Helmholtz conditions are necessary and sufficient conditions for a set of equations to arise from a Lagrangian. We investigate whether the equations of motion of Carrollian scalar electrodynamics satisfy these conditions. Then we proposed an action for the electric sector of the theory. This action is the first example for an interacting conformal Carrollian Field Theory. The proposed action respects the finite and infinite conformal Carrollian symmetries in d = 4. We calculate conserved charges corresponding to these finite and infinite symmetries and then rewrite the conserved charges in terms of the canonical variables. We finally compute the Poisson brackets for these charges and confirm that infinite Carrollian conformal algebra is satisfied at the level of charges.
Tensor hierarchy algebras and extended geometry. Part I. Construction of the algebra
Authors: Cederwall Martin , Palmkvist Jakob
Published: February 2020

Abstract

Tensor hierarchy algebras constitute a class of non-contragredient Lie superalgebras, whose finite-dimensional members are the “Cartan-type” Lie superalgebras in Kac’s classification. They have applications in mathematical physics, especially in extended geometry and gauged supergravity. We further develop the recently proposed definition of tensor hierarchy algebras in terms of generators and relations encoded in a Dynkin diagram (which coincides with the diagram for a related Borcherds superalgebra). We apply it to cases where a grey node is added to the Dynkin diagram of a rank r + 1 Kac-Moody algebra $$ \mathfrak{g} $$
g
+, which in turn is an extension of a rank r finite-dimensional semisimple simply laced Lie algebra $$ \mathfrak{g} $$
g
. The algebras are specified by $$ \mathfrak{g} $$
g
together with a dominant integral weight λ. As a by-product, a remarkable identity involving representation matrices for arbitrary integral highest weight representations of $$ \mathfrak{g} $$
g
is proven. An accompanying paper [1] describes the application of tensor hierarchy algebras to the gauge structure and dynamics in models of extended geometry.
Excitation Features of Speech for Emotion Recognition Using Neutral Speech as Reference
Authors: Kadiri Sudarsana Reddy , Gangamohan P. , Gangashetty Suryakanth V. , Alku Paavo , Yegnanarayana B.
Published: February 2020

In generation of emotional speech, there are deviations in the speech production features when compared to neutral (non-emotional) speech. The objective of this study is to capture the deviations in features related to the excitation component of speech and to develop a system for automatic recognition of emotions based on these deviations. The emotions considered in this study are anger, happiness, sadness and neutral state. The study shows that there are useful features in the deviations of the excitation features, which can be exploited to develop an emotion recognition system. The excitation features used in this study are the instantaneous fundamental frequency ($$F_0$$F0), the strength of excitation, the energy of excitation and the ratio of the high-frequency to low-frequency band energy ($$\beta $$β). A hierarchical binary decision tree approach is used to develop an emotion recognition system with neutral speech as reference. The recognition experiments showed that the excitation features are comparable or better than the existing prosody features and spectral features, such as mel-frequency cepstral coefficients, perceptual linear predictive coefficients and modulation spectral features.
Integrability Analysis of the Stretch–Twist–Fold Flow
Authors: Maciejewski Andrzej J. , Przybylska Maria
Published: February 2020

We study the integrability of an eight-parameter family of three-dimensional spherically confined steady Stokes flows introduced by Bajer and Moffatt. This volume-preserving flow was constructed to model the stretch–twist–fold mechanism of the fast dynamo magnetohydrodynamical model. In particular we obtain a complete classification of cases when the system admits an additional Darboux polynomial of degree one. All but one such case are integrable, and first integrals are presented in the paper. The case when the system admits an additional Darboux polynomial of degree one but is not evidently integrable is investigated by methods of differential Galois theory. It is proved that the four-parameter family contained in this case is not integrable in the Jacobi sense, i.e. it does not admit a meromorphic first integral. Moreover, we investigate the integrability of other four-parameter $${\textit{STF}}$$STF systems using the same methods. We distinguish all the cases when the system satisfies necessary conditions for integrability obtained from an analysis of the differential Galois group of variational equations.
Microstructure Investigations of Powders and Additive Manufactured Parts
Authors: Albu M. , Mitsche S. , Nachtnebel M. , Krisper R. , Dienstleder M. , Schröttner H. , Kothleitner G.
Published: February 2020

This paper presents an advanced microstructural analysis of the AlSiMg, Ti64, and N700 powders used for additive manufacturing. The internal microstructure of the regular and irregular powder grains were characterized down to atomic resolution by using scanning electron microscopy and high resolution scanning transmission electron microscopy.

The accretionary forms on top of the irregular AlSiMg powder grains exhibit a slightly coarse microstructure with a network of eutectic Si consisting of nano-crystallites, suggesting a slower cooling than the grain itself that contain a predominately amorphous Si network.

A nm thin amorphous C layer on the surface of some Ti64 plasma atomized powder grains promoted the attachment of satellites and growth of envelopes. In case of gas atomized N700 powder grains, we identified thin oxide and carbon amorphous layers as well as metal segregations at the interface between the grain body and the accretionary forms.
Improving access to services for psychotic patients: does implementing a waiting time target make a difference
Authors: Kreutzberg Anika , Jacobs Rowena
Published: February 2020

Objective

In April 2015, the English National Health Service started implementing the first waiting time targets in mental health care. This study aims to investigate the effect of the 14-day waiting time target for early intervention in psychosis (EIP) services after the first six months of its implementation.

Study design

We analyse a cohort of first-episode psychosis patients from the English administrative Mental Health and Learning Disabilities Dataset 2011 to 2015. We compare patients being treated by EIP services (treatment) with those receiving care from standard community mental health services (control). We combine non-parametric matching with a difference-in-difference approach to account for observed and unobserved group differences. We analyse the probability of waiting below target and look at different percentiles of the waiting time distribution.

Results

EIP patients had an 11.6–18.4 percentage point higher chance of waiting below target post-policy compared to standard care patients. However, post-policy trends at different percentiles of the waiting time distribution were not different between groups.

Conclusions

Mental health providers seem to respond to waiting time targets in a similar way as physical health providers. The increased proportion waiting below target did not, however, result in an overall improvement across the waiting time distribution.
Testing bat abundance and diversity predictions by PREBAT, a connectivity-based habitat suitability model for insectivorous bats
Authors: von Hirschheydt Gesa , Kindvall Oskar , de Jong Johnny
Published: February 2020

Where large landscape modifications are planned, e.g. for infrastructure or exploitation, ecological impact assessments are required because of their potential effects on environment and species. Methods that make such assessments more standardized, efficient, and reliable are highly desirable. This paper proposes a new connectivity-based habitat model for bats (PREBAT), which could be used as a tool for impact assessments. Using data that was specifically collected for this purpose, the performance of PREBAT is critically analyzed and discussed. For this study, 50 sites within an area of 850 km2in eastern Sweden were inventoried for four nights each using automatic ultrasound recorders to get an empiric measure of bat occurrence that could be compared with PREBAT predictions. The correlation between the predicted values from PREBAT and the observed bat activity (number of recordings) or species richness was tested using generalized linear mixed models. Predicted values of PREBAT are significantly correlated to the number of species that regularly (more than one night) occur at a given site, but not to the total number of species. PREBAT performed also much better at predicting the activity of forest-living species than overall bat activity, which makes PREBAT particularly suitable for predicting conflicts for those species. This study proposes a new habitat model for bats that takes spatial connectivity between habitat patches into account. PREBAT is shown to perform satisfyingly and has the potential to become a useful tool in assessing the ecological impact of large-scale landscape modifications.
Altruism, fast and slow? Evidence from a meta-analysis and a new experiment
Authors: Fromell Hanna , Nosenzo Daniele , Owens Trudy
Published: February 2020

Can we use the lens of dual-system theories to explain altruistic behavior? In recent years this question has attracted the interest of both economists and psychologists. We contribute to this emerging literature by reporting the results of a meta-study of the literature and a new experiment. Our meta-study is based on 22 experimental studies conducted with more than 12,000 subjects. We show that the overall effect of manipulating cognitive resources to promote the “intuitive” system at the expense of the “deliberative” system is very close to zero. One reason for this null result could be that promoting intuition has heterogeneous effects on altruism across different subgroups of subjects or contexts. Another reason could be that there simply is no real effect and that previously reported single results are false positives. We explore the role of heterogeneity both by performing a mediator analysis of the meta-analytic effect and by conducting a new experiment designed to circumvent the issue of potential heterogeneity in the direction of the effect of promoting intuition. In both cases, we find little evidence that heterogeneity explains the absence of an overall effect of intuition on altruism. Taken together, our results offer little support for dual-system theories of altruistic behavior.
A simple method for quantifying iodate and iodide fractions in solution using Ag+-impregnated activated carbon
Authors: Suorsa Valtteri , Otaki Miho , Zhang Wenzhong , Virkanen Juhani , Koivula Risto
Published: February 2020

The speciation of iodine in environment must be known in order to properly assess its geological fate and to study potential remediation materials for the decontamination of water containing radioactive iodine. In this study, the utilization of silver-impregnated granular activated carbon for separation between two iodine species, iodate and iodide, from each other was studied in different solution matrices with batch and column experiments. A high separation of the iodine species was achieved in the high concentrations of interfering ions, e.g. chloride, and in both μM and trace iodine concentrations. The method is suitable for both radioactive and non-radioactive iodine.
Perpendicular Transport of Energetic Particles in Magnetic Turbulence
Authors: Shalchi Andreas
Published: February 2020

Scientists have explored how energetic particles such as solar energetic particles and cosmic rays move through a magnetized plasma such as the interplanetary and interstellar medium since more than five decades. From a theoretical point of view, this topic is difficult because the particles experience complicated interactions with turbulent magnetic fields. Besides turbulent fields, there are also large scale or mean magnetic fields breaking the symmetry in such systems and one has to distinguish between transport of particles parallel and perpendicular with respect to such mean fields. In standard descriptions of transport phenomena, one often assumes that the transport in both directions is normal diffusive but non-diffusive transport was found in more recent work. This is in particular true for early and intermediate times where the diffusive regime is not yet reached. In recent years researchers employed advanced numerical tools in order to simulate the motion of those particles through the aforementioned systems. Nevertheless, the analytical description of the problem discussed here is of utmost importance since analytical forms of particle transport parameters need to be known in several applications such as solar modulation studies or investigations of shock acceleration. The latter process is directly linked to the question of what the sources of high energy cosmic rays are, a problem which is considered to be one of the most important problems of the sciences of the 21st century. The present review article discusses analytical theories developed for describing particle transport across a large scale magnetic field as well as field line random walk. A heuristic approach explaining the basic physics of perpendicular transport is also presented. Simple analytical forms for the perpendicular diffusion coefficient are proposed which can easily be incorporated in numerical codes for solar modulation or shock acceleration studies. Test-particle simulations are also discussed together with a comparison with analytical results. Several applications such as cosmic ray propagation and diffusive shock acceleration are also part of this review.
History of Spinal Fusion: Where we Came from and Where we are Going
Authors: Virk Sohrab , Qureshi Sheeraz , Sandhu Harvinder
Published: February 2020

Spinal fusion surgery is performed all over the world to help patients with cervical and thoracolumbar pathology. As outcomes continue to improve in patients with spine-related pathology, it is important to understand how we got to modern day spinal fusion surgery. Scientific innovations have ranged from the first spinal fusions performed with basic instrumentation in the late nineteenth century to contemporary tools such as pedicle screws, bone grafts, and interbody devices. This article tracks this technological growth so that surgeons may better serve their patients in treating spine-related pain and disability.
Design of an end-effector for robot-assisted ultrasound-guided breast biopsies
Authors: Welleweerd Marcel K. , Siepel Françoise J. , Groenhuis Vincent , Veltman Jeroen , Stramigioli Stefano
Published: February 2020

Purpose

The biopsy procedure is an important phase in breast cancer diagnosis. Accurate breast imaging and precise needle placement are crucial in lesion targeting. This paper presents an end-effector (EE) for robotic 3D ultrasound (US) breast acquisitions and US-guided breast biopsies. The EE mechanically guides the needle to a specified target within the US plane. The needle is controlled in all degrees of freedom (DOFs) except for the direction of insertion, which is controlled by the radiologist. It determines the correct needle depth and stops the needle accordingly.

Method

In the envisioned procedure, a robotic arm performs localization of the breast, 3D US volume acquisition and reconstruction, target identification and needle guidance. Therefore, the EE is equipped with a stereo camera setup, a picobeamer, US probe holder, a three-DOF needle guide and a needle stop. The design was realized by prototyping techniques. Experiments were performed to determine needle placement accuracy in-air. The EE was placed on a seven-DOF robotic manipulator to determine the biopsy accuracy on a cuboid phantom.

Results

Needle placement accuracy was 0.3 ± 1.5 mm in and 0.1 ± 0.36 mm out of the US plane. Needle depth was regulated with an accuracy of 100 µm (maximum error 0.89 mm). The maximum holding force of the stop was approximately 6 N. The system reached a Euclidean distance error of 3.21 mm between the needle tip and the target and a normal distance of 3.03 mm between the needle trajectory and the target.

Conclusion

An all in one solution was presented which, attached to a robotic arm, assists the radiologist in breast cancer imaging and biopsy. It has a high needle placement accuracy, yet the radiologist is in control like in the conventional procedure.
2D multi-parameter waveform inversion of land reflection seismic data obtained from the particle-motion response from the vertical geophone
Authors: Li Qingyang , Wu Guochen
Published: February 2020

Onshore seismic exploration analyzes seismic wave propagation in elastic media, which includes the conversion between P- and S-waves. The development of multi-wave and multi-component seismic exploration methods provides data that enable onshore elastic wave full-waveform inversion. However, most data sets of onshore exploration are single component obtained from the particle-motion response from the vertical geophone. When the aiming area has a low-velocity zone, the ray path of reflected wave that propagates to the detector is nearly perpendicular to the ground surface, so that we call it P-wave data. In this paper, we focus on multi-parameter waveform inversion using P-wave reflection seismic data. Although only P-wave data are received, it still contains the converted P-wave information, and the converted P-wave energy gradually increases as the offset increases. As seismic acquisition technology, observation systems and science develop, the folds and acquisition offset increase significantly, and the seismic data contain important converted P-wave information. In this paper, the first-order elastic velocity–stress equation is decomposed to obtain the scalar-P-wave equation from which the S-wave velocity is included firstly. Then we present the theoretical framework for onshore multi-parameter full-waveform inversion using P-wave data. In order to explore the inversion potential of the P-wave data (extracting the S-wave velocity from the converted P-wave information) and accuracy and stability of the P- and S-wave velocity inverted by our method, we carry out numerical tests via different inversion strategies, by using the P-wave data regarded as containing converted P-wave information, and get successful results.
Magnesium Alloys for Open-Pored Bioresorbable Implants
Authors: Maier Hans Jürgen , Julmi Stefan , Behrens Sabine , Klose Christian , Gartzke Ann-Kathrin , Wriggers Peter , Waselau Anja-Christina , Meyer-Lindenberg Andrea
Published: February 2020

If bone defects occur, the body’s own healing mechanism can close them below a critical size; for larger defects, bone autografts are used. These are typically cut from the same person’s hip in a second surgery. Consequently, the risk of complications, such as inflammations, rises. To avoid the risks resulting from the second surgery, absorbable, open-pored implants can be used. In the present study, the suitability of different magnesium alloys as absorbable porous bone substitute material has been investigated. Using the investment casting process with its design flexibility, the implant’s structure can be adapted to the ideal pore geometry with respect to bone ingrowth behavior. Different magnesium alloys (Mg-La2, LAE442, and ZX61) were studied and rated in terms of their degradation rate, bone ingrowth behavior, biocompatibility, and resorbability of the individual alloying elements.
American myths of linguistic assimilation: A sociolinguistic rebuttal
Authors: Erker Daniel , Otheguy Ricardo
Published: February 2020

This study examines the behavior of 331 Spanish speakers, 269 immigrants to the United States and sixty-two native-born individuals, through questionnaires and sociolinguistic interviews. Results show that increased US life experience correlates with expanded use of English in both private and public domains of life. Additionally, greater use of English co-exists with maintenance of fine-grained patterns of structured linguistic variation in Spanish, such that US-born speakers demonstrate remarkable similarity to the immigrant generation in their usage of three variables: (i) subject pronoun presence vs. absence, (ii) grammatical subject position, and (iii) syllable-final /s/. The co-occurence of increased use of English, on one hand, and intergenerational structural continuity in variable linguistic behavior in Spanish, on the other, challenges two misconceptions about Spanish in the United States: that (a) Spanish-speaking immigrants and their US-born children are unwilling or unable to learn English, and (b) regular use of English entails attrition and/or failed acquisition of Spanish. Neither of these views finds empirical support in our data. (Spanish in the United States, comparative variationist linguistics, subject personal pronouns, grammatical subject position, syllable final /s/, bilingualism)
Monoidal-closed categories of tree automata
Authors: Riba Colin
Published: February 2020

This paper surveys a new perspective on tree automata and Monadic second-order logic (MSO) on infinite trees. We show that the operations on tree automata used in the translations of MSO-formulae to automata underlying Rabin’s Tree Theorem (the decidability of MSO) correspond to the connectives of Intuitionistic Multiplicative Exponential Linear Logic (IMELL). Namely, we equip a variant of usual alternating tree automata (that we call uniform tree automata) with a fibered monoidal-closed structure which in particular handles a linear complementation of alternating automata. Moreover, this monoidal structure is actually Cartesian on non-deterministic automata, and an adaptation of a usual construction for the simulation of alternating automata by non-deterministic ones satisfies the deduction rules of the !(–) exponential modality of IMELL. (But this operation is unfortunately not a functor because it does not preserve composition.) Our model of IMLL consists in categories of games which are based on usual categories of two-player linear sequential games called simple games, and which generalize usual acceptance games of tree automata. This model provides a realizability semantics, along the lines of Curry–Howard proofs-as-programs correspondence, of a linear constructive deduction system for tree automata. This realizability semantics, which can be summarized with the slogan “automata as objects, strategies as morphisms,” satisfies an expected property of witness extraction from proofs of existential statements. Moreover, it makes it possible to combine realizers produced as interpretations of proofs with strategies witnessing (non-)emptiness of tree automata.
Nocturnal and Seasonal Variation of Na and K Layers Simultaneously Observed in the MLT Region at 23°S
Authors: Andrioli V. F. , Xu J. , Batista P. P. , Pimenta A. A. , Resende L. C. A. , Savio S. , Fagundes P. R. , Yang G. , Jiao J. , Cheng X. , Wang C. , Liu Z.
Published: February 2020

The present work shows for the first time the study of morphology of the mesopause sodium (Na) and potassium (K) layers simultaneously observed by a dual‐beam LIDAR in the Southern Hemisphere. We analyze these two alkali metal layers from November 2016 to February 2019 measured at São José dos Campos (23.1°S, 45.9°W) and present their nocturnal and seasonal behavior. The night of 25 April 2017 was investigated as a representative of the vertical descending structure frequently observed in the metal density data at this location. We discuss here the chemical and dynamical contribution in the formation of these distinct layers, using simultaneous meteor radar wind and ionosonde data. These downward structures are seen in 66% of Na/K LIDAR data and seem to occur preferentially around April. The good agreement with diurnal tide and the presence of Es layer, suggest a combining mechanism in the formation of these structures. Moreover, semiannual variations are observed in both layers; however, they present different maxima location. The Na density presents its maxima around May and September; whereas, K density shows a strong maximum around July and a weaker one around December. Likewise, semiannual variation with maxima at the equinoxes is observed in the centroid height for both layers. However, the column abundances of these two metals show distinct seasonal variation: Annual variation peaking from one equinox to the other is observed in Na and semiannual with maxima in the solstices in K. The same behavior of centroid height for both layers indicates the same mechanism acting in the seasonal variation, which is not yet completely understood.
Heatwave and Blocking in the Northeastern Asia: Occurrence, Variability, and Association
Authors: Fang Beijing , Lu Mengqian
Published: February 2020

The spatiotemporal variation and characteristics of heatwave in Northeastern Asia are investigated on both a grid basis and an event basis. We find that persistent, extensive, and intense heatwave has become more frequent during the last four decades. Such trend is found significantly correlated with the increase of temperature. The association between heatwave and blocking is also analyzed using two leading blocking indices, examining 500‐hPa geopotential height (TM index) and vertically averaged potential vorticity anomaly (PV index), respectively. A discrepancy between blocking climatology of TM index and PV index is exhibited, with the former displaying two high‐frequency zonal bands at the north and south regions, while the latter only showing one high frequency band in the north. However, grid‐based concurrence analysis using the two blocking indices agreeably suggests that blocking favors the occurrence of heatwave, especially in the north region where blocking often occurs. We further explicitly investigate their temporal association with time lags, which has not been done before in the literatures. It reveals that heatwave mostly occurs after or on the onset day of blocking and ends after or at the end of blocking. It indicates that blocking is more of a favorable environmental condition to trigger heatwave than maintain it. Lastly, the impact of blocking on the characteristics of heatwave events is explored on an event basis using a 3‐D spatiotemporal object model. Blocking‐related heatwave events are more likely to be more persistent, extensive, and intense than unrelated events.
Correlation Effects? A Major but Often Neglected Component in Sensitivity and Uncertainty Analysis
Authors: Do Nhu Cuong , Razavi Saman
Published: February 2020

Global sensitivity analysis (GSA) provides essential insights into the behavior of Earth and environmental systems models and identifies dominant controls of output uncertainty. Previous work on GSA, however, has typically been under the assumption that the controlling factors such as model inputs and parameters are independent, whereas, in many cases, they are correlated and their joint distribution follows a variety of forms. Although this assumption can limit the credibility of GSA and its results, very few studies in the field of water and environmental modeling address this issue. In this paper, we first discuss the significance of correlation effects in GSA and then propose a new GSA framework for properly accounting for correlations in input/parameter spaces. To this end, we extend the “variogram‐based” theory of GSA, called variogram analysis of response surfaces (VARS), and develop a new generalized star sampling technique (called gSTAR) to accommodate correlated multivariate distributions. We test the new gSTAR‐VARS method on two test functions, against a state‐of‐the‐art GSA method that handles correlation effects. We then apply gSTAR‐VARS to the HBV‐SASK model, calibrated via a Bayesian, Markov chain Monte Carlo approach, for design flood estimation in the Oldman River Basin in Canada. Results demonstrate that accounting for correlation effects can be critically important in GSA, especially in the presence of nonlinearity and interaction effects in the underlying response surfaces. The proposed method can efficiently handle correlations and different distribution types and simultaneously generate a range of sensitivity indices, such as total‐variogram effects, variance‐based total‐order effects, and derivative‐based elementary effects.
Reply to “Comment on ‘Two Papers About the Generalized Complementary Evaporation Relationships by Crago et al.’”
Authors: Crago R. , Szilagyi J. , Qualls R.
Published: February 2020

Liu et al. (2020, https://doi.org/10.1029/2019WR026292) provide comments on two papers introducing the rescaled Complementary Relationship (CR) of evaporation. Four concerns regarding the rescaled CR were raised and are addressed herein. Specifically, it is shown here that (1) the rescaled CR is not simply an asymmetric advection‐aridity model; (2) a discontinuity in the slope of the rescaled CR at the point where evaporation is zero is not problematic because that point represents a true minimum value; (3) a particular formulation of the rescaled CR presented in an earlier paper was not recommended by the present authors, but was simply intended to illustrate that a range of boundary conditions can be accommodated; and (4) while behavior of the model advocated by Liu et al. 2020) can be modified to match the lower limit introduced by the rescaled CR, there is little theoretical justification or practical utility for doing so. Inherent in several of the concerns seems to be a misconception held by the authors of the Comment regarding the nature of the lower limit in the rescaled CR. Once this misconception is addressed, none of the concerns represent a weakness in the rescaled CR concept.
Leigh Royden Receives 2019 Walter H. Bucher Medal
Authors:   AGU
Published: February 2020

Leigh Royden was awarded the 2019 Walter H. Bucher Medal at AGU’s Fall Meeting 2019 Honors Ceremony, held on 11 December 2019 in San Francisco, Calif. The medal is for “original contributions to the basic knowledge of the crust and lithosphere.”
S. Majid Hassanizadeh Receives 2019 Robert E. Horton Medal
Authors:   AGU
Published: February 2020

S. Majid Hassanizadeh was awarded the 2019 Robert E. Horton Medal at AGU’s Fall Meeting 2019 Honors Ceremony, held on 11 December 2019 in San Francisco, Calif. The medal is for “outstanding contributions to hydrology.”
Ulrich Christensen Receives 2019 Inge Lehmann Medal
Authors:   AGU
Published: February 2020

Ulrich Christensen was awarded the 2019 Inge Lehmann Medal at the AGU Fall Meeting Honors Ceremony, held on 11 December 2019 in San Francisco, Calif. The medal is for “contributions to the understanding of the structure, composition, and dynamics of the Earth’s mantle and core.”
Dust Older Than the Sun Sheds Light on Galactic History
Authors: Cartier Kimberly
Published: February 2020

A small pile of dust grains older than the Sun brings new evidence about the rate at which stars are born in the Milky Way.
Minireservoirs Could Save Farmers with Sandy Soils
Authors: Wheeling Kate
Published: February 2020

A recently revived subsurface water retention technology could conserve water and drastically increase crop yields in arid landscapes with sandy soils like sub-Saharan Africa.
Editorial Handover at Tectonics
Authors: Schildgen Taylor , Geissman John
Published: February 2020

The outgoing and incoming Editors in Chief of Tectonics reflect on recent years of growth and expansion in the journal while they ponder and plan for the challenges ahead.
How the Cold Climate Shaped Scotland’s Political Climate
Authors: Sima Richard
Published: February 2020

Tree rings reveal how severe cold and political isolation brought disaster to Scotland, inspired a colonization effort in Panama, and helped drive union with England.
Seeing the Greenland Ice Sheet Through Students' Eyes
Authors: Snide Chelsea , Gilbert Lydia , Meyer Abigail , Samson Perry , Flanner Mark , Bassis Jeremy
Published: February 2020

A team of students and faculty advisers revisited the site of pioneering geosciences expeditions from the 1920s, looking to introduce young researchers to polar science.
China Challenges U.S. Science Dominance
Authors: Showstack Randy
Published: February 2020

A recent Congressional hearing and National Science Board report show that U.S. leadership faces growing global competition.
The Give and Take of Mercury in Glacial Landscapes
Authors: Derouin Sarah
Published: February 2020

As glacial ice melts, toxic mercury is released into the environment. But a new study shows vegetation may be an effective cleanup crew.
From the Arctic to the Austral, and All the News Between
Authors:   AGU
Published: February 2020

What Earth and space science stories are we recommending this week?
Does This Fossil Reveal a Jurassic Tropical Freeze?
Authors: Leifert Harvey
Published: February 2020

On view for over a century, a fossil slab may display evidence of tropical freezing during the Jurassic, but scientists never noticed it—until one finally did. Some colleagues are not convinced.
Edmond Dewan, Citizen Science, and the Mystery of Ball Lightning
Authors: Fritts Rachel
Published: February 2020

In the early 1960s, a physicist enlisted the help of the public to study a rare atmospheric phenomenon.
Stress, inflammation and hippocampal subfields in depression: A 7 Tesla MRI Study
Authors: Tannous Jonika , Godlewska Beata R. , Tirumalaraju Vaishali , Soares Jair C. , Cowen Phil J. , Selvaraj Sudhakar
Published: February 2020

Experiencing stressful events throughout one’s life, particularly childhood trauma, increases the likelihood of being diagnosed with Major Depressive Disorder (MDD). Raised levels of cortisol, and markers of inflammation such as Interleukin (IL-6) and C-reactive protein (CRP), have been linked to both early life stress and MDD. We aimed to explore the biological stress signatures of early stress and MDD on hippocampal sub regional volumes using 7 Tesla MRI imaging. A cohort of 71 MDD patients was compared against 46 age and sex-matched healthy volunteers. MDD subjects had higher averages of IL-6 and CRP levels. These differences were significant for IL-6 levels and trended for CRP. There were no significant group differences in any of the hippocampal subfields or global hippocampal volumes; further, there were no hippocampal subfield differences between MDD subjects with high levels of our biological stress measures and MDDs with normal levels.
Correction: A multicentre, prospective study of plasma circulating tumour DNA test for detecting RAS mutation in patients with metastatic colorectal cancer
Authors: Bando Hideaki , Kagawa Yoshinori , Kato Takeshi , Akagi Kiwamu , Denda Tadamichi , Nishina Tomohiro , Komatsu Yoshito , Oki Eiji , Kudo Toshihiro , Kumamoto Hiroshi , Yamanaka Takeharu , Yoshino Takayuki
Published: February 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Mechanical properties measured by atomic force microscopy define health biomarkers in ageing C. elegans
Authors: Essmann Clara L. , Martinez-Martinez Daniel , Pryor Rosina , Leung Kit-Yi , Krishnan Kalaivani Bala , Lui Prudence Pokway , Greene Nicholas D. E. , Brown André E. X. , Pawar Vijay M. , Srinivasan Mandayam A. , Cabreiro Filipe
Published: February 2020

Genetic and environmental factors are key drivers regulating organismal lifespan but how these impact healthspan is less well understood. Techniques capturing biomechanical properties of tissues on a nano-scale level are providing new insights into disease mechanisms. Here, we apply Atomic Force Microscopy (AFM) to quantitatively measure the change in biomechanical properties associated with ageingCaenorhabditis elegansin addition to capturing high-resolution topographical images of cuticle senescence. We show that distinct dietary restriction regimes and genetic pathways that increase lifespan lead to radically different healthspan outcomes. Hence, our data support the view that prolonged lifespan does not always coincide with extended healthspan. Importantly, we identify the insulin signalling pathway inC.elegansand interventions altering bacterial physiology as increasing both lifespan and healthspan. Overall, AFM provides a highly sensitive technique to measure organismal biomechanical fitness and delivers an approach to screen for health-improving conditions, an essential step towards healthy ageing.
Structural basis for two-way communication between dynein and microtubules
Authors: Nishida Noritaka , Komori Yuta , Takarada Osamu , Watanabe Atsushi , Tamura Satoko , Kubo Satoshi , Shimada Ichio , Kikkawa Masahide
Published: February 2020

The movements of cytoplasmic dynein on microtubule (MT) tracks is achieved by two-way communication between the microtubule-binding domain (MTBD) and the ATPase domain via a coiled-coil stalk, but the structural basis of this communication remains elusive. Here, we regulate MTBD either in high-affinity or low-affinity states by introducing a disulfide bond to the stalk and analyze the resulting structures by NMR and cryo-EM. In the MT-unbound state, the affinity changes of MTBD are achieved by sliding of the stalk α-helix by a half-turn, which suggests that structural changes propagate from the ATPase-domain to MTBD. In addition, MT binding induces further sliding of the stalk α-helix even without the disulfide bond, suggesting how the MT-induced conformational changes propagate toward the ATPase domain. Based on differences in the MT-binding surface between the high- and low-affinity states, we propose a potential mechanism for the directional bias of dynein movement on MT tracks.
Author Correction: Increasing neurogenesis refines hippocampal activity rejuvenating navigational learning strategies and contextual memory throughout life
Authors: Berdugo-Vega Gabriel , Arias-Gil Gonzalo , López-Fernández Adrian , Artegiani Benedetta , Wasielewska Joanna M. , Lee Chi-Chieh , Lippert Michael T. , Kempermann Gerd , Takagaki Kentaroh , Calegari Federico
Published: February 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Publisher Correction: Cellular adaptation to oxygen deficiency beyond the Nobel award
Authors: López-Barneo José , Simon M. Celeste
Published: February 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Evaluating the promise of inclusion of African ancestry populations in genomics
Authors: Bentley Amy R. , Callier Shawneequa L. , Rotimi Charles N.
Published: February 2020

The lack of representation of diverse ancestral backgrounds in genomic research is well-known, and the resultant scientific and ethical limitations are becoming increasingly appreciated. The paucity of data on individuals with African ancestry is especially noteworthy as Africa is the birthplace of modern humans and harbors the greatest genetic diversity. It is expected that greater representation of those with African ancestry in genomic research will bring novel insights into human biology, and lead to improvements in clinical care and improved understanding of health disparities. Now that major efforts have been undertaken to address this failing, is there evidence of these anticipated advances? Here, we evaluate the promise of including diverse individuals in genomic research in the context of recent literature on individuals of African ancestry. In addition, we discuss progress and achievements on related technological challenges and diversity among scientists conducting genomic research.
The environment and species affect gut bacteria composition in laboratory co-cultured Anopheles gambiae and Aedes albopictus mosquitoes
Authors: Saab Sally A. , Dohna Heinrich zu , Nilsson Louise K. J. , Onorati Piero , Nakhleh Johnny , Terenius Olle , Osta Mike A.
Published: February 2020

The midgut microbiota of disease vectors plays a critical role in the successful transmission of human pathogens. The environment influences the microbiota composition; however, the relative mosquito-species contribution has not been rigorously disentangled from the environmental contribution to the microbiota structure. Also, the extent to which the microbiota of the adult sugar food source and larval water can predict that of the adult midgut andvice versais not fully understood. To address these relationships, larvae and adults ofAnopheles gambiaeandAedes albopictuswere either reared separately or in a co-rearing system, whereby aquatic and adult stages of both species shared the larval water and sugar food source, respectively. Despite being reared under identical conditions, clear intra- and interspecies differences in midgut microbiota-composition were observed across seven cohorts, collected at different time points over a period of eight months. Fitting a linear model separately for each OTU in the mosquito midgut showed that two OTUs significantly differed between the midguts of the two mosquito species. We also show an effect for the sugar food source and larval water on the adult midgut microbiota. Our findings suggest that the mosquito midgut microbiota is highly dynamic and controlled by multiple factors.
Deep Flexible Sequential (DFS) Model for Air Pollution Forecasting
Authors: Kaya Kıymet , Gündüz Öğüdücü Şule
Published: February 2020

Growing metropolitan areas bring rapid urbanization and air pollution problems. As diseases and mortality rates increase because of the air pollution problem, it becomes a necessity to estimate the air pollution density and inform the public to protect the health. Air pollution problem displays contextual characteristics such as meteorological conditions, industrial and technological developments, traffic problem etc. that change from country to country and also from city to city. In this study, we determined PM$${}_{10}$$10 as the target pollutant and designed a new deep learning based air quality forecasting model, namely DFS (Deep Flexible Sequential). Our study uses real world hourly data from Istanbul, Turkey between 2014 and 2018 to forecast the air pollution 4, 12, and 24 hours before. DFS model is a hybrid & flexible deep model including Long Short Term Memory (LSTM) and Convolutional Neural Network (CNN). The proposed model also is capable of generalization with standard and flexible Dropout layers. Through flexible Dropout layer, the model also obtains flexibility to adapt changing window sizes in sequential modelling. Moreover, this model can be applied to other air pollution time series data problems with small modifications on parameters by taking into account the nature of the data set.