bluuebunny/crossref_metadata_2025 huggingface dataset:
Variational ansatz for p-wave fermions confined in a one-dimensional harmonic trap
Authors: Kościk Przemysław , Sowiński Tomasz
Published: August 2020

We propose a very accurate and efficient variational scheme for the ground state of the system of p-wave attractively interacting fermions confined in a one-dimensional harmonic trap. By the construction, the method takes the non-analytical part of interactions exactly into account and thus it approximates the true ground-state wave function in a whole range of interactions very accurately. Within the method, we determine different properties of the system for a different number of particles and different interactions. In this way, we explore how the system and its features transit from the ideal non-interacting Fermi gas to the system of infinitely strong attractions. Additionally, we demonstrate that the ansatz may also be used on a repulsive branch of interactions where other numerical methods break down. The presented method of including zero-range interactions is very universal and may be easily generalized to other one-dimensional confinements.
Invariant-mass distribution of top-quark pairs and top-quark mass determination *
Authors: Ju Wan-Li , Wang Guoxing , Wang Xing , Xu Xiaofeng , Xu Yongqi , Yang Li Lin
Published: August 2020

In this study, we investigate the invariant-mass distribution of top-quark pairs near the 2mt
threshold, which strongly influences the determination of the top-quark mass mt
. Higher-order non-relativistic corrections lead to large contributions, which are not included in the state-of-the-art theoretical predictions. A factorization formula is derived to resum such corrections to all orders in the strong-coupling, and necessary ingredients are calculated to perform the resummation at next-to-leading power. We combine the resummation with fixed-order results and present phenomenologically relevant numerical results. The resummation effect significantly increases the differential cross-section in the threshold region and makes the theoretical prediction more compatible with experimental data. We estimate that using our prediction in the determination of mt
will lead to a value closer to the direct measurement result.
Heavy Higgs bosons at the LHC upgrade *
Authors: Li Tong
Published: August 2020

We evaluate the discovery potential for the heavy Higgs bosons at the LHC energy upgrade with

TeV. We assume the degenerate mass spectrum and an approximate alignment limit in the Type-II Two Higgs Doublet Model for illustration. We explore the observability of the heavy neutral Higgs bosons by examining the clean signals from

via gluon-gluon fusion production. The associated production of a top quark and a charged Higgs boson via

is adopted to predict the discovery potential of heavy charged Higgses. We also emphasize the potential importance of the electroweak production of Higgs boson pairs, i.e.

and

. These are only governed by pure electroweak gauge couplings and can provide complementary information to the conventional signals in the determination of the nature of the Higgs sector.
Systematic study of the α decay preformation factors of the nuclei around the Z = 82, N = 126 shell closures within the generalized liquid drop model *
Authors: Liu Hong-Ming , Zou You-Tian , Pan Xiao , Bao Xiao-Jun , Li Xiao-Hua
Published: August 2020

In this study, we systematically investigate the

decay preformation factors,

, and the

decay half-lives of 152 nuclei around Z = 82, N = 126 closed shells based on the generalized liquid drop model (GLDM) with

being extracted from the ratio of the calculated

decay half-life to the experimental one. The results show that there is a remarkable linear relationship between

and the product of valance protons (holes)

and valance neutrons (holes)

. At the same time, we extract the

decay preformation factor values of the even–even nuclei around the Z = 82, N = 126 closed shells from the study of Sun

[J. Phys. G: Nucl. Part. Phys., 45: 075106 (2018)], in which the

decay was calculated by two different microscopic formulas. We find that the

decay preformation factors are also related to

. Combining with our previous studies [Sun

, Phys. Rev. C, 94: 024338 (2016); Deng

, ibid. 96: 024318 (2017); Deng

, ibid. 97: 044322 (2018)] and that of Seif

[Phys. Rev. C, 84: 064608 (2011)], we suspect that this phenomenon of linear relationship for the nuclei around the above closed shells is model-independent. This may be caused by the effect of the valence protons (holes) and valence neutrons (holes) around the shell closures. Finally, using the formula obtained by fitting the

decay preformation factor data calculated by the GLDM, we calculate the

decay half-lives of these nuclei. The calculated results agree with the experimental data well.
Abnormal odd-even staggering behavior around 132Sn studied by density functional theory *
Authors: Shi Haoqiang , Wang Xiao-Bao , Dong Guo-Xiang , Wang Hualei
Published: August 2020

In this work, we have performed Skyrme density functional theory (DFT) calculations of nuclei around 132Sn to study whether the abnormal odd-even staggering (OES) behavior of binding energies around N = 82 can be reproduced. With the Skyrme forces SLy4 and SkM*, we tested the volume- and surface-type pairing forces and also the intermediate between these two pairing forces, in the Hartree-Fock-Bogoliubov (HFB) approximation with or without the Lipkin-Nogami (LN) approximation or particle number projection after the convergence of HFBLN (PLN). The Universal Nuclear Energy Density Function (UNEDF) parameter sets are also used. The trend of the neutron OES against the neutron number or proton number does not change significantly by tuning the density dependence of the pairing force. Moreover, for the pairing force that is favored more at the nuclear surface, a larger mass OES is obtained, and vice versa. It appears that the combination of volume and surface pairing can give better agreement with the data. In the studies of the OES, a larger ratio of surface to volume pairing might be favored. Additionally, in most cases, the OES given by the HFBLN approximation agrees more closely with the experimental data. We found that both the Skyrme and pairing forces can influence the OES behavior. The mass OES calculated by the UNEDF DFT is explicitly smaller than the experimental one. The UNEDF1 and UNEDF2 forces can reproduce the experimental trend of the abnormal OES around 132Sn. The neutron OES of the tin isotopes given by the SkM* force agrees more closely with the experimental one than that given by the SLy4 force in most cases. Both SLy4 and SkM* DFT have difficulties in reproducing the abnormal OES around 132Sn. Using the PLN method, the systematics of OES are improved for several combinations of Skyrme and pairing forces.
Constraints on the generalized natural inflation after Planck 2018 *
Authors: Zhang Nan , Wu Ya-Bo , Lu Jun-Wang , Sun Chu-Wen , Shou Li-Jie , Xu Hai-Zhou
Published: August 2020

Based on the dynamics of single scalar field slow-roll inflation and the theory of reheating, we investigate the generalized natural inflationary (GNI) model. We introduce constraints on the scalar spectral index ns
and the tensor-to scalar ratio r for the

CDM

model, according to the latest data from Planck 2018 TT, TE, EE+low E+lensing (P18) and BICEP2/Keck 2015 season (BK15), i.e., with

at 68% confidence level (CL), and

at 95% CL. We find that the GNI model is favored by P18 and BK15 in the ranges

and

at 68% CL. In addition, the corresponding predictions of generalized and two-phase reheating are discussed. It follows that the parameter m has significant effect on the model behavior.
Conduction current density profile transformation near the earth’s surface, in connection with atmospheric stratification change
Authors: Panchishkina I N , Petrova G G , Petrov A I , Chkhetiani O G
Published: August 2020

The paper considers physical conditions that influence the formation of vertical profiles of the conduction current density in the surface atmosphere. The proximity of the earth’s surface, which is a source of radioactive emanations and aerosols, determines the significant variability of atmospheric-electrical characteristics in height. The results obtained made it possible to identify the features of the conduction current density vertical profiles transformation with regard to the atmosphere stratification. The study of the weather conditions dynamics at the observation point, as well as the study of the conduction current density profile variability makes it possible to determine the nature of the influence of meteorological parameters on the process of charge transfer and accumulation in the studied layer.
Interlink between lightning activity of hailstorms and their radar characteristics
Authors: Abshaev M T , Abshaev A M , Gekkieva J M , Kh Adzhiev A
Published: August 2020

The time course and the relationship of radar and lightning characteristics of the powerful hail clouds of the North Caucasus are considered. The studies were conducted in 2016-2018 at the automated meteorological radar complex ASU-MRL, which provided simultaneous acquisition and processing of radar data from the MRL-5 and 4-point network of LS-8000 lightning detection sensors, visualization of thunderstorm discharges on the background of the radar reflectivity map, as well as measurement complex of radar and thunderstorm cloud characteristics, including their maximum radar reflectivity Zmax, heights, volumes and water content of clouds at different reflectivity values, frequency of intracloud lightning discharges (VHF), “cloud-to-ground” discharges with positive (LF+) and negative polarity (LF-), current and duration of discharges. An analysis of the results showed that lightning discharges begin in the developing hail clouds of the North Caucasus when their maximum radar reflectivity reaches Zmax ≥ 40 dBZ, the frequency of discharges increases with increasing reflectivity, integral water content and enhancing the process of precipitation formation. The highest thunderstorm activity is noted at Zmax≈ 70-75 dBZ. Most low-frequency discharges of LF- and LF+ types are observed on the windward flank in the zone of intensive precipitation formation, and the majority of high-frequency VHF discharges are on their leeward side. Seeding of hail clouds with glaciogenic reagents with anti-hail rockets also leads to an increase in the frequency of discharges of all types.
Validation of the output of the global atmospheric model on days with the development of dangerous convective phenomena according to aerological sounding with a two-day lead time
Authors: Kh Kagermazov A , Sozaeva L T
Published: August 2020

Data from aerological sounding of weather stations in the North Caucasus (Mineralnye Vody, Divnoye), in days with the development of dangerous convective phenomena, were used to validate predictive data (with two-day advance) of the global atmosphere model GFS NCEP. A high degree of overlap between predicted and actual data is shown based on correlation analysis.
Features of the electric field of the atmosphere in various weather conditions
Authors: Adzhieva A A , Shapovalov V A , Kh Mashukov I , Tumgoeva H A
Published: August 2020

The article presents data on the measured series of electric field strength in the atmospheric surface layer for the period from 2010 to 2019 using the EFM550 electric field strength meter. The comparability of the influence of local (fogs, precipitation, thunderstorms, etc.) and global (cyclonic processes, solar-terrestrial communications, etc.) factors on atmospheric electric field variations is discussed. Global and local variations in the nature and dynamics of field strength for the conditions of the North Caucasus are confirmed. An analysis is made of the frequencies of the occurrence of a range of surface atmospheric electric field values. The obtained method of processing information about the repeating values of the polar atmosphere and the Earth’s atmosphere. For this purpose, a branch has been compared with a number of actual weather observations in the central part of hydrometeorology and environmental monitoring. Federal State Budgetary Institution “North Caucasus Office for Hydrometeorology and Environmental Monitoring” Roshydromet. The features of the influence of various meteorological phenomena on the state of the electric field strength were statistically described and a study was conducted to assess the influence of local phenomena -precipitation, clouds and thunderstorm activity on the change in the value of the electric field of the atmosphere in the area of the city of Nalchik.
Anharmonic effects on phase-space quantum profiles: an exact approach
Authors: Bernardini Alex E , Silva Caio Fernando e
Published: August 2020

Given its well known spectral decomposition profile, the 1-dim harmonic oscillator potential modified by an inverse square (1-dim angular momentum-like) contribution works as an efficient platform for probing classical and quantum information quantifiers in the context of the phase-space Weyl-Wigner formalism. In particular, the phase-space informational content related to the canonical ensemble driven by such a singular oscillator can be quantified in terms of well established analytical structures. Considering that, on one hand, the singular oscillator produce a spectral decomposition profile equivalent to that one of the unmodified harmonic system – in the sense that they result into identical thermodynamic statistics, even for different statistical mixtures – on the other hand, a more complete scrutinization of their phase-space information content can capture some different aspects of the encoded information for the related quantum ensembles. Besides the identification of decoherence effects, the Wigner flow analysis is presumedly useful in identifying stable quantum configurations, according to finite temperature and interaction parameter values. Unexpectedly, our results show that the equivalence between the statistical (quantum) mechanics of the anharmonic singular oscillator and an ordinary harmonic oscillator can also be extended to the phase-space quantum purity quantifier, which is analytically computed and reproduces exactly the same quantum ensemble statistical mixture profile, which does not depend on interaction parameter values.
Dynamics of quantum entanglement in matter field models
Authors: Castaños O. , del Río Lima A.
Published: August 2020

A review of the linear canonical transformations and its unitary representation is presented and its importance in the mathematical generation of a special two photon coherent state of light is demonstrated. The dynamical behaviour of the entanglement of the matter and field sectors of an initial composite system under the action of two effective model Hamiltonians is shown. The quantumness and delocalization properties of the corresponding electromagnetic field sectors are established. Finally for the two-photon process interacting with a two-level system, the violation of the Cauchy-Schwarz inequality is exhibited.
New correlation relations in classical and quantum systems with different numbers of subsystems1
Authors: Doskoch Igor Ya. , Man’ko Margarita A.
Published: August 2020

We present a review of the general approach to the problem of correlations in classical statistics and quantum statistics of systems with different numbers of subsystems and demonstrate the information-entropic relations for systems without subsystems recently obtained for Shannon entropies. We present the example of a single-qudit state corresponding to the N-level atom, consider explicitly the qutrit state, and show that qutrit can be interpreted as a set of several qubits. For each of these qubits, there exist corresponding von Neumann entropies, and constraints for these entropies determine the hidden correlations between the qubits in spite of the fact that the qutrit does not contain any subsystem. These constraints are expressed in terms of nonnegativity of the mutual information introduced, which usually exists only for the states of systems with subsystems. The value of information parameterizes the hidden correlations of artificial qubits in the system. We discuss examples of some qudits.
The Lee model: a tool to study decays
Authors: Giacosa Francesco
Published: August 2020

We describe- in a didactical and detailed way- the so-called Lee model (which shares similarities with the Jaynes-Cummings and Friedrichs models) as a tool to study unstable quantum states/particles. This Lee model is based on Quantum Mechanics (QM) but possesses some of the features of Quantum Field Theory (QFT). The decay process can be studied in great detail and typical QFT quantities such as propagator, one-loop resummation, and Feynman rules can be introduced. Deviations from the exponential decay law as well as the Quantum Zeno effects can be studied within this framework. The survival probability amplitude as a Fourier transform of the energy distribution, the normalization of the latter, and the Breit-Wigner limit can be obtained in a rigorous mathematical approach.
Comments on the Kramer Kramer Man’ko 2 × 2 matrix multiplication
Authors: Horn Martin Erik
Published: August 2020

This article is a complement to a paper by Kramer et al. that proposes a new matrix product, which is like a mixture of the usual and the Hadamard (or Schur) product. This new product is then related to the transformation group in the hyperbolic plane. Actually variations in the definition of internal operations lead to an infinity of products that can be associated with any of the Euclidean, hyperbolic or elliptic geometries in quite different manners. By the way: This article is not a review. The review can be found at the end of the paper.
Multimode Bogoliubov transformation and Husimi’s Q-function
Authors: Huh Joonsuk
Published: August 2020

In this paper, we present numerical schemes for evaluating the matrix elements of Gaussian/non-Gaussian operators in the Fock state basis, which are identified as multivariate Hermite polynomials (MHPs). Using the integral transformation operator to perform the multimode Bogoliubov transformation, Husimi’s Q-functions of Gaussian/non-Gaussian operators are easily derived as the generating functions of MHPs.
A dissertation on General Covariance and its application in particle physics
Authors: Petruzziello Luciano
Published: August 2020

In this paper, we provide a concise overview on the principle of General Covariance, one of the fundamental cornerstones of Einstein’s General Relativity. We retrace all the steps that led to the final settlement of a generally covariant theory of gravitation, dwelling specifically on the significance of the well-known “hole argument”. In addition, we discuss about the importance of General Covariance in connection with some recent claims in literature revolving around particle physics. In particular, we summarize the results associated with the decay of accelerated protons.
Trajectory-based conservation laws for massive spin-zero relativistic quantum particles in 1 + 1 spacetime
Authors: Poirier Bill , Tsai Hung-Ming
Published: August 2020

We present novel aspects of a trajectory-based theory of massive spin-zero relativistic quantum particles. In this approach, the quantum trajectory ensemble is the fundamental entity. It satisfies its own action principle, leading to a dynamical partial differential equation (via the Euler-Lagrange procedure), as well as to conservation laws (via Noether’s theorem). In this paper, we focus on the derivation of the latter. In addition to the usual expected energy and momentum conservation laws, there is also a third law that emerges, associated with the conditions needed to maintain global simultaneity. We also show that the nonrelativistic limits of these conservation laws match those of the earlier, nonrelativistic quantum trajectory theory [J. Chem. Phys. 136, 031102 (2012)].
Parity-time symmetry and asymmetric diffraction of light in four-level triple quantum wells
Authors: Mukherjee Rohit , Konar S
Published: August 2020

In this paper, we investigate two-dimensional parity-time (PT) symmetry and electromagnetically induced grating (EIG) in four-level asymmetric triple quantum wells (QWs). Here, PT-symmetry and EIG are realized by appropriately varying the detuning value of the probe, and the modulation amplitudes of a coupling field and standing wave (SW) pump. By virtue of its PT symmetry, the EIG asymmetrically diffracts the probe beam. The angular switching of the diffracted beam can be achieved either by varying the probe or the coupling and SW pump fields. The intensity distribution of the diffracted beam over higher-order diffraction peaks depends on the interaction length in the QW. For small interaction lengths, most of the energy is distributed close to the central diffraction peak. With an increase in the interaction length, energy is gradually transferred to higher order diffraction peaks.
SICaRiO: short indel call filtering with boosting
Authors: Bhuyan Md Shariful Islam , Pe’er Itsik , Rahman M Sohel
Published: August 2020

Despite impressive improvement in the next-generation sequencing technology, reliable detection of indels is still a difficult endeavour. Recognition of true indels is of prime importance in many applications, such as personalized health care, disease genomics and population genetics. Recently, advanced machine learning techniques have been successfully applied to classification problems with large-scale data. In this paper, we present SICaRiO, a gradient boosting classifier for the reliable detection of true indels, trained with the gold-standard dataset from ‘Genome in a Bottle’ (GIAB) consortium. Our filtering scheme significantly improves the performance of each variant calling pipeline used in GIAB and beyond. SICaRiO uses genomic features that can be computed from publicly available resources, i.e. it does not require sequencing pipeline-specific information (e.g. read depth). This study also sheds lights on prior genomic contexts responsible for the erroneous calling of indels made by sequencing pipelines. We have compared prediction difficulty for three categories of indels over different sequencing pipelines. We have also ranked genomic features according to their predictivity in determining false positives.
PanGPCR: predictions for multiple targets, repurposing and side effects
Authors: Liu Lu-Chi , Ho Ming-Yang , Su Bo-Han , Wang San-Yuan , Hsu Ming-Tsung , Tseng Yufeng J
Published: August 2020

Drug discovery targeting G protein-coupled receptors (GPCRs), the largest known class of therapeutic targets, is challenging. To facilitate the rapid discovery and development of GPCR drugs, we built a system, PanGPCR, to predict multiple potential GPCR targets and their expression locations in the tissues, side effects and possible repurposing of GPCR drugs. With PanGPCR, the compound of interest is docked to a library of 36 experimentally determined crystal structures comprising of 46 docking sites for human GPCRs, and a ranked list is generated from the docking studies to assess all GPCRs and their binding affinities. Users can determine a given compound’s GPCR targets and its repurposing potential accordingly. Moreover, potential side effects collected from the SIDER (Side-Effect Resource) database and mapped to 45 tissues and organs are provided by linking predicted off-targets and their expressed sequence tag profiles. With PanGPCR, multiple targets, repurposing potential and side effects can be determined by simply uploading a small ligand.

Availability and implementation

PanGPCR is freely accessible at https://gpcrpanel.cmdm.tw/index.html.

Supplementary information

Supplementary data are available at Bioinformatics online.
Inference for treatment effect parameters in potentially misspecified high-dimensional models
Authors: Dukes Oliver , Vansteelandt Stijn
Published: August 2020

Eliminating the effect of confounding in observational studies typically involves fitting a model for an outcome adjusted for covariates. When, as often, these covariates are high-dimensional, this necessitates the use of sparse estimators, such as the lasso, or other regularization approaches. Naïve use of such estimators yields confidence intervals for the conditional treatment effect parameter that are not uniformly valid. Moreover, as the number of covariates grows with the sample size, correctly specifying a model for the outcome is nontrivial. In this article we deal with both of these concerns simultaneously, obtaining confidence intervals for conditional treatment effects that are uniformly valid, regardless of whether the outcome model is correct. This is done by incorporating an additional model for the treatment selection mechanism. When both models are correctly specified, we can weaken the standard conditions on model sparsity. Our procedure extends to multivariate treatment effect parameters and complex longitudinal settings.
The expanding genetic landscape of hereditary motor neuropathies
Authors: Beijer Danique , Baets Jonathan
Published: August 2020

Hereditary motor neuropathies are clinically and genetically diverse disorders characterized by length-dependent axonal degeneration of lower motor neurons. Although currently as many as 26 causal genes are known, there is considerable missing heritability compared to other inherited neuropathies such as Charcot-Marie-Tooth disease. Intriguingly, this genetic landscape spans a discrete number of key biological processes within the peripheral nerve. Also, in terms of underlying pathophysiology, hereditary motor neuropathies show striking overlap with several other neuromuscular and neurological disorders. In this review, we provide a current overview of the genetic spectrum of hereditary motor neuropathies highlighting recent reports of novel genes and mutations or recent discoveries in the underlying disease mechanisms. In addition, we link hereditary motor neuropathies with various related disorders by addressing the main affected pathways of disease divided into five major processes: axonal transport, tRNA aminoacylation, RNA metabolism and DNA integrity, ion channels and transporters and endoplasmic reticulum.
Disentangling vulnerability, state and trait features of neurocognitive impairments in depression
Authors: Ang Yuen-Siang , Frontero Nicole , Belleau Emily , Pizzagalli Diego A
Published: August 2020

Depression is a debilitating disorder that often starts manifesting in early childhood and peaks in onset during adolescence. Neurocognitive impairments have emerged as clinically important characteristics of depression, but it remains controversial which domains specifically index pre-existing vulnerability, state-related or trait-related markers. Here, we disentangled these effects by analysing the Adolescent Brain Cognitive Development dataset (n = 4626). Using information of participants’ current and past mental disorders, as well as family mental health history, we identified low-risk healthy (n = 2100), high-risk healthy (n = 2023), remitted depressed (n = 401) and currently depressed children (n = 102). Factor analysis of 11 cognitive variables was performed to elucidate latent structure and canonical correlation analyses conducted to probe regional brain volumes reliably associated with the cognitive factors. Bayesian model comparison of various a priori hypotheses differing in how low-risk healthy, high-risk healthy, remitted depressed and currently depressed children performed in various cognitive domains was performed. Factor analysis revealed three domains: language and reasoning, cognitive flexibility and memory recall. Deficits in language and reasoning ability, as well as in volumes of associated regions such as the middle temporal and superior frontal gyrus, represented state- and trait-related markers of depression but not pre-existing vulnerability. In contrast, there was no compelling evidence of impairments in other domains. These findings—although cross-sectional and specific to 9–10-year-old children—might have important clinical implications, suggesting that cognitive dysfunction may not be useful targets of preventive interventions. Depressed patients, even after remission, might also benefit from less commonly used treatments such as cognitive remediation therapy.
“The Food Babe Blogger Is Full of Sh*t”: Gender, Class and Branding the “Expert” Self
Authors: Zimmerman Heidi
Published: August 2020

This article examines the ongoing effort to “take down” Vani Hari’s activism-cum-lifestyle brand, the Food Babe, with particular attention to the viral success of Yvette “SciBabe” d’Entremont’s 2015 Gawker post, “The Food Babe Blogger Is Full of Sh*t.” Popular discourse pits the two babes against each other. However, by examining both babes’ multiplatform branded personas as technologies of self-governance under postfeminist, neoliberal brand culture, I show that the Food Babe/SciBabe case is more than a struggle over “science versus pseudoscience.” This case study illuminates a gendered double bind that is intensifying in the so-called “post-truth” era as obligations to maximize oneself and one’s family come into conflict with longstanding and deeply classed anxieties about feminized media culture.
Fine Spike Timing in Hippocampal–Prefrontal Ensembles Predicts Poor Encoding and Underlies Behavioral Performance in Healthy and Malformed Brains
Authors: Hernan Amanda E , Mahoney J Matthew , Curry Willie , Mawe Seamus , Scott Rod C
Published: August 2020

Spatial working memory (SWM) is a central cognitive process during which the hippocampus and prefrontal cortex (PFC) encode and maintain spatial information for subsequent decision-making. This occurs in the context of ongoing computations relating to spatial position, recall of long-term memory, attention, among many others. To establish how intermittently presented information is integrated with ongoing computations we recorded single units, simultaneously in hippocampus and PFC, in control rats and those with a brain malformation during performance of an SWM task. Neurons that encode intermittent task parameters are also well modulated in time and incorporated into a functional network across regions. Neurons from animals with cortical malformation are poorly modulated in time, less likely to encode task parameters, and less likely to be integrated into a functional network. Our results implicate a model in which ongoing oscillatory coordination among neurons in the hippocampal–PFC network describes a functional network that is poised to receive sensory inputs that are then integrated and multiplexed as working memory. The background temporal modulation is systematically altered in disease, but the relationship between these dynamics and behaviorally relevant firing is maintained, thereby providing potential targets for stimulation-based therapies.
Microstructure of Human Corpus Callosum across the Lifespan: Regional Variations in Axon Caliber, Density, and Myelin Content
Authors: Lynn Jonathan D , Anand Chaitali , Arshad Muzamil , Homayouni Roya , Rosenberg David R , Ofen Noa , Raz Naftali , Stanley Jeffrey A
Published: August 2020

The myeloarchitecture of the corpus callosum (CC) is characterized as a mosaic of distinct differences in fiber density of small- and large-diameter axons along the anterior–posterior axis; however, regional and age differences across the lifespan are not fully understood. Using multiecho T2 magnetic resonance imaging combined with multi-T2 fitting, the myelin water fraction (MWF) and geometric-mean of the intra-/extracellular water T2 (geomT2IEW) in 395 individuals (7–85 years; 41% males) were examined. The approach was validated where regional patterns along the CC closely resembled the histology; MWF matched mean axon diameter and geomT2IEW mirrored the density of large-caliber axons. Across the lifespan, MWF exhibited a quadratic association with age in all 10 CC regions with evidence of a positive linear MWF-age relationship among younger participants and minimal age differences in the remainder of the lifespan. Regarding geomT2IEW, a significant linear age × region interaction reflected positive linear age dependence mostly prominent in the regions with the highest density of small-caliber fibers—genu and splenium. In all, these two indicators characterize distinct attributes that are consistent with histology, which is a first. In addition, these results conform to rapid developmental progression of CC myelination leveling in middle age as well as age-related degradation of axon sheaths in older adults.
Picocyanobacteria aggregation as a response to predation pressure: direct contact is not necessary
Authors: Ospina-Serna Juliana , Huber Paula , Odriozola Mariana , Fermani Paulina , Unrein Fernando
Published: August 2020

Picocyanobacteria (cells <2 µm) can be found either as single-cells (Pcy) or embedded in a mucilaginous sheath as microcolonies or colonies (CPcy). It has been demonstrated that phenotypic plasticity in picocyanobacteria (i.e. the capability of single-cells to aggregate into colonies) can be induced as a response to grazing pressure. The effect of the presence of different predators (cladocerans and rotifers) on the morphological composition of picocyanobacteria was studied in a natural community, and it was observed that the abundance of CPcy significantly increased in all treatments with zooplankton compared with the control without zooplankton. The aggregation capability was also evaluated in a single-cell strain by adding a conditioned medium of flagellates, rotifers and cladocerans. The proportion of cells forming colonies was significantly higher in all treatments with conditioned medium regardless of the predator. These results suggest that the aggregation of Pcy can be induced as a response to the predation pressure exerted by protists and different zooplankters, and also that Pcy has the capability to aggregate into CPcy even without direct contact with any predator, most probably due to the presence of an infochemical dissolved in the water that does not come from disrupted Pcy cells.
Spatial Distribution of Frankliniella schultzei (Thysanoptera: Thripidae) in Open-Field Yellow Melon, With Emphasis on the Role of Surrounding Vegetation as a Source of Initial Infestation
Authors: Carvalho Sindoval C , Junior Paulo A S , Pereira Poliana S , Sarmento Renato A , Farias Elizeu S , Lima Carlos H O , Santos Gil R , Picanço Marcelo C
Published: August 2020

Frankliniella schultzei (Trybom) is a serious pest of melon crops and is commonly found in the main producing areas of melon in Brazil (North and Northeast regions). This pest causes significant losses, damaging plants through feeding and tospovirus vectoring. Thus, the proper management of F. schultzei is crucial to prevent economic losses, and knowledge of the within-field distribution patterns of F. schultzei can be used to improve this pest management. This study aimed to determine the within-field distribution (through semivariogram modeling and kriging interpolation) and the factors associated with F. schultzei abundance in open-field yellow melon crops. We surveyed four yellow melon fields located in Formoso do Araguaia (Tocantins state, North Brazil) for thrips abundance in various crop stages (vegetative, flowering, and fruiting) in 2015 and 2016. Twelve models were fitted and it was determined that F. schultzei counts were strongly aggregated. The median spatial dependence was 4.79 m (range 3.55 to 8.02 m). The surface maps generated by kriging depicted an edge effect in fields 3 and 4. In addition, correlation analyses indicated that air temperature and presence of surrounding cucurbits are positively associated with F. schultzei abundance in yellow melon fields. Altogether, these insights can be combined for spatially based pest management, especially when the conditions (cucurbits in the surroundings and warmer periods) are favorable to F. schultzei.
Management, Organizational Performance, and Task Clarity: Evidence from Ghana’s Civil Service
Authors: Rasul Imran , Rogger Daniel , Williams Martin J
Published: August 2020

We study the relationship between management practices, organizational performance, and task clarity, using observational data analysis on an original survey of the universe of Ghanaian civil servants across 45 organizations and novel administrative data on over 3,600 tasks they undertake. We first demonstrate that there is a large range of variation across government organizations, both in management quality and in task completion, and show that management quality is positively related to task completion. We then provide evidence that this association varies across dimensions of management practice. In particular, task completion exhibits a positive partial correlation with management practices related to giving staff autonomy and discretion, but a negative partial correlation with practices related to incentives and monitoring. Consistent with theories of task clarity and goal ambiguity, the partial relationship between incentives/monitoring and task completion is less negative when tasks are clearer ex ante and the partial relationship between autonomy/discretion and task completion is more positive when task completion is clearer ex post. Our findings suggest that organizations could benefit from providing their staff with greater autonomy and discretion, especially for types of tasks that are ill-suited to predefined monitoring and incentive regimes.
Reiseangst: travel anxiety and psychological resilience during and beyond the COVID-19 pandemic
Authors: Flaherty Gerard T , Nasir Nizrull
Published: August 2020

The COVID-19 pandemic and its associated lockdown have had a negative impact on global mental health. Considerable fear and stigma surround the prospects of a return to non-essential international travel. The mental health aspects of travel have been historically neglected in the literature. The current pandemic has prompted a renewed focus on building psychological resilience in travellers by engaging innovative technological tools such as virtual reality.
Ejective and preventative: the IllustrisTNG black hole feedback and its effects on the thermodynamics of the gas within and around galaxies
Authors: Zinger Elad , Pillepich Annalisa , Nelson Dylan , Weinberger Rainer , Pakmor Rüdiger , Springel Volker , Hernquist Lars , Marinacci Federico , Vogelsberger Mark
Published: August 2020

Supermassive black holes (SMBHs) that reside at the centres of galaxies can inject vast amounts of energy into the surrounding gas and are thought to be a viable mechanism to quench star formation in massive galaxies. Here, we study the $10^{9-12.5}\, \mathrm{M_\odot }$ stellar mass central galaxy population of the IllustrisTNG simulation, specifically the TNG100 and TNG300 volumes at z = 0, and show how the three components – SMBH, galaxy, and circumgalactic medium (CGM) – are interconnected in their evolution. We find that gas entropy is a sensitive diagnostic of feedback injection. In particular, we demonstrate how the onset of the low-accretion black hole (BH) feedback mode, realized in the IllustrisTNG model as a kinetic, BH-driven wind, leads not only to star formation quenching at stellar masses $\gtrsim 10^{10.5}\, \mathrm{M_\odot }$ but also to a change in thermodynamic properties of the (non-star-forming) gas, both within the galaxy and beyond. The IllustrisTNG kinetic feedback from SMBHs increases the average gas entropy, within the galaxy and in the CGM, lengthening typical gas cooling times from $10\!-\!100\, \mathrm{Myr}$ to $1\!-\!10\, \mathrm{Gyr}$, effectively ceasing ongoing star formation and inhibiting radiative cooling and future gas accretion. In practice, the same active galactic nucleus (AGN) feedback channel is simultaneously ‘ejective’ and ‘preventative’ and leaves an imprint on the temperature, density, entropy, and cooling times also in the outer reaches of the gas halo, up to distances of several hundred kiloparsecs. In the IllustrisTNG model, a long-lasting quenching state can occur for a heterogeneous CGM, whereby the hot and dilute CGM gas of quiescent galaxies contains regions of low-entropy gas with short cooling times.
Rapid compact jet quenching in the Galactic black hole candidate X-ray binary MAXI J1535−571
Authors: Russell T D , Lucchini M , Tetarenko A J , Miller-Jones J C A , Sivakoff G R , Krauß F , Mulaudzi W , Baglio M C , Russell D M , Altamirano D , Ceccobello C , Corbel S , Degenaar N , van den Eijnden J , Fender R , Heinz S , Koljonen K I I , Maitra D , Markoff S , Migliari S , Parikh A S , Plotkin R M , Rupen M , Sarazin C , Soria R , Wijnands R
Published: August 2020

We present results from six epochs of quasi-simultaneous radio, (sub-)millimetre, infrared, optical, and X-ray observations of the black hole X-ray binary MAXI J1535−571. These observations show that as the source transitioned through the hard–intermediate X-ray state towards the soft–intermediate X-ray state, the jet underwent dramatic and rapid changes. We observed the frequency of the jet spectral break, which corresponds to the most compact region in the jet where particle acceleration begins (higher frequencies indicate closer to the black hole), evolves from the infrared band into the radio band (decreasing by ≈3 orders of magnitude) in less than a day. During one observational epoch, we found evidence of the jet spectral break evolving in frequency through the radio band. Estimating the magnetic field and size of the particle acceleration region shows that the rapid fading of the high-energy jet emission was not consistent with radiative cooling; instead, the particle acceleration region seems to be moving away from the black hole on approximately dynamical time-scales. This result suggests that the compact jet quenching is not caused by local changes to the particle acceleration, rather we are observing the acceleration region of the jet travelling away from the black hole with the jet flow. Spectral analysis of the X-ray emission shows a gradual softening in the few days before the dramatic jet changes, followed by a more rapid softening ∼1–2 d after the onset of the jet quenching.
Proper motion, spectra, and timing of PSR J1813–1749 using Chandra and NICER
Authors: Ho Wynn C G , Guillot Sebastien , Saz Parkinson P M , Limyansky B , Ng C-Y , Bejger Michał , Espinoza Cristóbal M , Haskell B , Jaisawal Gaurava K , Malacaria C
Published: August 2020

PSR J1813–1749 is one of the most energetic rotation-powered pulsars known, producing a pulsar wind nebula (PWN) and gamma-ray and TeV emission, but whose spin period is only measurable in X-ray. We present analysis of two Chandra data sets that are separated by more than 10 yr and recent NICER data. The long baseline of the Chandra data allows us to derive a pulsar proper motion $\mu _{\rm RA}=(-0.067\pm 0.010)\, \mathrm{ arcsec}\,\mathrm{yr^{-1}}$ and $\mu _{\rm Dec.}=(-0.014\pm 0.007)\, \mathrm{ arcsec}\,\mathrm{yr^{-1}}$ and velocity $v_\perp \approx 900\!-\!1600\, \mathrm{km\, s^{-1}}$ (assuming a distance d = 3–5 kpc), although we cannot exclude a contribution to the change in measured pulsar position due to a change in brightness structure of the PWN very near the pulsar. We model the PWN and pulsar spectra using an absorbed power law and obtain best-fitting absorption $N_{\rm H}=(13.1\pm 0.9)\times 10^{22}\, \mathrm{cm^{-2}}$, photon index Γ = 1.5 ± 0.1, and 0.3–10 keV luminosity $L_{\rm X}\approx 5.4\times 10^{34}\, \mathrm{erg\, s^{-1}}(d/\mbox{ 5 kpc})^2$ for the PWN and Γ = 1.2 ± 0.1 and $L_{\rm X}\approx 9.3\times 10^{33}\, \mathrm{erg\, s^{-1}}(d/\mbox{ 5 kpc})^2$ for PSR J1813–1749. These values do not change between the 2006 and 2016 observations. We use NICER observations from 2019 to obtain a timing model of PSR J1813–1749, with spin frequency ν = 22.35 Hz and spin frequency time derivative $\dot{\nu }=(-6.428\pm 0.003)\times 10^{-11}\, \mathrm{Hz\, s^{-1}}$. We also fit ν measurements from 2009 to 2012 and our 2019 value and find a long-term spin-down rate $\dot{\nu }=(-6.3445\pm 0.0004)\times 10^{-11}\, \mathrm{Hz\, s^{-1}}$. We speculate that the difference in spin-down rates is due to glitch activity or emission mode switching.
A super-sensitive auxin-inducible degron system with an engineered auxin-TIR1 pair
Authors: Nishimura Kohei , Yamada Ryotaro , Hagihara Shinya , Iwasaki Rie , Uchida Naoyuki , Kamura Takumi , Takahashi Koji , Torii Keiko U , Fukagawa Tatsuo
Published: August 2020

The auxin-inducible degron (AID) system enables rapid depletion of target proteins within the cell by applying the natural auxin IAA. The AID system is useful for investigating the physiological functions of essential proteins; however, this system generally requires high dose of auxin to achieve effective depletion in vertebrate cells. Here, we describe a super-sensitive AID system that incorporates the synthetic auxin derivative 5-Ad-IAA and its high-affinity-binding partner OsTIR1F74A. The super-sensitive AID system enabled more than a 1000-fold reduction of the AID inducer concentrations in chicken DT40 cells. To apply this system to various mammalian cell lines including cancer cells containing multiple sets of chromosomes, we utilized a single-step method where CRISPR/Cas9-based gene knockout is combined with insertion of a pAID plasmid. The single-step method coupled with the super-sensitive AID system enables us to easily and rapidly generate AID-based conditional knockout cells in a wide range of vertebrate cell lines. Our improved method that incorporates the super-sensitive AID system and the single-step method provides a powerful tool for elucidating the roles of essential genes.
European Consensus Statement on the diagnosis and management of osteoporosis in chronic kidney disease stages G4–G5D
Authors: Evenepoel Pieter , Cunningham John , Ferrari Serge , Haarhaus Mathias , Javaid Muhammad Kassim , Lafage-Proust Marie-Hélène , Prieto-Alhambra Daniel , Torres Pablo Ureña , Cannata-Andia Jorge ,   European Renal Osteodystrophy (EUROD) workgroup, an initiative of the CKD-MBD working group of the ERA-EDTA, and the committee of Scientific Advisors and National Societies of the IOF, Vervloet Marc , Mazzaferro Sandro , D’Haese Patrick , Bacchetta Justine , Ferreira Annibal , Salam Syazrah , Spasovski Goce
Published: August 2020

Controlling the excessive fracture burden in patients with chronic kidney disease (CKD) Stages G4–G5D remains an impressive challenge. The reasons are 2-fold. First, the pathophysiology of bone fragility in patients with CKD G4–G5D is complex and multifaceted, comprising a mixture of age-related (primary male/postmenopausal), drug-induced and CKD-related bone abnormalities. Second, our current armamentarium of osteoporosis medications has not been developed for, or adequately studied in patients with CKD G4–G5D, partly related to difficulties in diagnosing osteoporosis in this specific setting and fear of complications. Doubts about the optimal diagnostic and therapeutic approach fuel inertia in daily clinical practice. The scope of the present consensus paper is to review and update the assessment and diagnosis of osteoporosis in patients with CKD G4-G5D and to discuss the therapeutic interventions available and the manner in which these can be used to develop management strategies for the prevention of fragility fracture. As such, it aims to stimulate a cohesive approach to the management of osteoporosis in patients with CKD G4–G5D to replace current variations in care and treatment nihilism.