bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimicrobial activity of polypyrrole nanoparticles and aqueous extract ofMoringa oleiferaagainstStaphylococcusspp. carriers of multi-drug efflux system genes isolated from dairy farms
Authors: Silva José Givanildo da , Barros Mariana de , Santos Nataly Diniz de Lima , Paiva Patrícia Maria Guedes , Napoleão Thiago Henrique , Sena Maria José de , Costa Mateus Matiuzzi da , Oliveira Helinando Pequeno de , Moreira Maria Aparecida Scatamburlo , Mota Rinaldo Aparecido
Published: September 2020

Our objectives were to identify genes of the multi-drug efflux system and to evaluate the antimicrobial activities of polypyrrole nanoparticles (PPy-NPs) and aqueous extract ofMoringa oleiferaagainstStaphylococcusspp. isolated from dairy farms in Northeast Brazil. Initially, 162Staphylococcusspp. isolates were subjected toin vitroantimicrobial sensitivity tests. Of these, 35 presented antimicrobial multi-drug resistance phenotypes. These 35 isolates were then referred for the detection ofnorA, norB, norC, msrA, mgrA, tet-38,andlmrSgenes, all of which feature in multi-drug efflux systems. In the isolates carrying the genes, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PPy-NPs andMoringa oleiferaaqueous extract were determined. In the molecular analysis of the 35 isolatesnorA, norC, tet-38,andmsrAgenes were detected and for the other genesnorB, lmrSandmgrAthere was no amplification. Antimicrobial activity was verified of PPy-NPs and aqueous extract ofMoringa oleiferainStaphylococcusspp. carrying multi-drug efflux system genes. We concluded that there are multi-drug efflux system genes present in theStaphylococcusspp. from the agricultural environment in Northeast Brazil, and that aqueous extract ofMoringa oleiferaand PPy-NPs show bactericidal activity against these isolates.
Fluctuation dynamo in a weakly collisional plasma
Authors: St-Onge D. A. , Kunz M. W. , Squire J. , Schekochihin A. A.
Published: September 2020

The turbulent amplification of cosmic magnetic fields depends upon the material properties of the host plasma. In many hot, dilute astrophysical systems, such as the intracluster medium (ICM) of galaxy clusters, the rarity of particle–particle collisions allows departures from local thermodynamic equilibrium. These departures – pressure anisotropies – exert anisotropic viscous stresses on the plasma motions that inhibit their ability to stretch magnetic-field lines. We present an extensive numerical study of the fluctuation dynamo in a weakly collisional plasma using magnetohydrodynamic (MHD) equations endowed with a field-parallel viscous (Braginskii) stress. When the stress is limited to values consistent with a pressure anisotropy regulated by firehose and mirror instabilities, the Braginskii-MHD dynamo largely resembles its MHD counterpart, particularly when the magnetic field is dynamically weak. If instead the parallel viscous stress is left unabated – a situation relevant to recent kinetic simulations of the fluctuation dynamo and, we argue, to the early stages of the dynamo in a magnetized ICM – the dynamo changes its character, amplifying the magnetic field while exhibiting many characteristics reminiscent of the saturated state of the large-Prandtl-number (

${Pm}\gtrsim {1}$

) MHD dynamo. We construct an analytic model for the Braginskii-MHD dynamo in this regime, which successfully matches simulated dynamo growth rates and magnetic-energy spectra. A prediction of this model, confirmed by our numerical simulations, is that a Braginskii-MHD plasma without pressure-anisotropy limiters will not support a dynamo if the ratio of perpendicular and parallel viscosities is too small. This ratio reflects the relative allowed rates of field-line stretching and mixing, the latter of which promotes resistive dissipation of the magnetic field. In all cases that do exhibit a viable dynamo, the generated magnetic field is organized into folds that persist into the saturated state and bias the chaotic flow to acquire a scale-dependent spectral anisotropy.
Vitamin D increases killing of intracellularLeishmania amazonensis in vitroindependently of macrophage oxidative mechanisms
Authors: Machado Patrícia de Almeida , Escrivani Douglas Oliveira , Gomes Daniel Claudio Oliveira , Rossi-Bergmann Bartira , Chaves Suzana Passos , Coimbra Elaine Soares , de Matos Guedes Herbert Leonel
Published: September 2020

Vitamin D has been reported to activate macrophage microbicidal mechanisms by inducing the production of antimicrobial peptides and nitric oxide (NO), but conversely has been shown to contribute to a greater susceptibility toLeishmania amazonensisinfection in mice. Thus, this study aimed to evaluate the role of vitamin D during intracellular infection withL. amazonensisby examining its effect on macrophage oxidative mechanisms and parasite survivalin vitro. Vitamins D2and D3significantly inhibited promastigote and amastigote growthin vitro. Vitamin D3was not able to induce NO and reactive oxygen species (ROS) production in uninfected macrophages or macrophages infected withL. amazonensis. In addition, vitamin D3in combination with interferon (IFN)-γdid not enhance amastigote killing and in fact, significantly reduced NO and ROS production when compared with the effect of IFN-γalone. In this study, we demonstrated that vitamin D directly reduces parasite growth in infected macrophages (approximately 50–60% at 50μm) but this effect is independent of the activation of macrophage oxidative mechanisms. These findings will contribute to a better understanding of the role of vitamin D in cutaneous leishmaniasis.
It is marine: distinguishing a new species ofCatatropis(Digenea: Notocotylidae) from its freshwater twin
Authors: Gonchar Anna , Galaktionov Kirill V.
Published: September 2020

The morphology of sexual adults is the cornerstone of digenean systematics. In addition, life cycle data have always been significant. The integration of these approaches, supplemented with molecular data, has allowed us to detect a new species that many researchers may have previously seen, but not recognized. Sexual adults from common eiders that we found in northern European seas were extremely similar to other notocotylids, but the discovery of their intermediate host, a marine snail, revealed the true nature of this material. Here we describe sexual adults, rediae and cercariae ofCatatropis onobaesp. nov. We discuss how ‘Catatropis verrucosa’should be regarded, justify designation of the new speciesC. onobaefor our material and explain why it can be considered a cryptic species. The phylogenetic position ofC. onobaewithin Notocotylidae, along with other evidence, highlights the challenges for the taxonomy of the family, for which two major genera appear to be polyphyletic and life cycle data likely undervalued.
The Thucydidean Tragic View: The Moral Implications
Authors: Mittelstadt Michael C.
Published: September 2020

No Greek of any calibre, at least in the fifth century, could remain intellectually or spiritually altogether unconditioned by a conscious feeling for, or awareness of, the tragic in human affairs. His poetry and his art, indeed his history, were saturated with the idea of the tragic. Thucydides is certainly no exception, and the most uninformed reader of his History will come away from the work with a keen sense of the immediately perceptible tragic coloration with which it is permeated. Interpreted from any leading, unifying thematic idea the explanation of Thucydides' work must include as central and dominant the tragic deterioration of Athens from the Periclean ideals so well expressed in the Funeral Oration, through the nadir of cynicism and moral decline of the Melian Dialogue, to the utter demoralization expressed through the catastrophe of the Sicilian campaign and its aftermath.

One has merely to examine the obvious and purposefully wrought antitheses throughout the History to determine the dramatic nature of Thucydides' work. The drastic metamorphosis in Athenian character that occurs between Books One and Five, for instance, points up such a tragic contrast. The Athenians of the first assembly at Sparta claim that they more than any others were the saviors of Hellas (1.74.2), fearless and self-sacrificing in the common cause of all allies, that they acted with sagacity of judgement (1.75.1), that the empire had not been acquired by force (1.75.2) but by necessity of circumstances, that they had been more observant of justice than actually required, the overwhelming balance of power being in their favor (1.76.3), that in the courts in Athens suits of allies are judged under the same laws (1.77.1). If we compare these same Athenians with the Athenians of the Melian Dialogue it becomes abundantly clear that a deterioration of character and moral standards has taken place and that Thucydides has linked the moral with the tragic. The earlier Athenians, in spite of their desire for imperial expansion, were at least concerned with a minimum of justice and fair play in their international dealings. The Athenians of the Melian Dialogue do not even make a pretence of upholding the commonly accepted nomoi which had from time immemorial been established among men to protect the weaker. Thucydides' strong editorial statements on the effects of anomia (‘lawlessness’) during and following the plague (2.52-53), and during the stasis on Corcyra (3.81ff.) also make firm the link between the moral and the tragic.
Syllable effects in beginning and intermediate European-Portuguese readers: Evidence from a sandwich masked go/no-go lexical decision task
Authors: CAMPOS Ana Duarte , OLIVEIRA Helena Mendes , SOARES Ana Paula
Published: September 2020

Reading is one of the most important milestones a child achieves throughout development. Above the letter level, the syllable has been shown to play a relevant role at early stages of visual word recognition in adult skilled readers. However, studies aiming to examine when, during reading acquisition, the syllable emerges as a functional sublexical unit are scarce, and the studies conducted so far have led to inconsistent results. In this work, beginning and intermediate European-Portuguese (EP) developing readers performed a sandwich masked lexical decision task in which CV (e.g., RU.MOR[rumour]) and CVC (e.g., CIS.NE[swan]) first-syllable EP words were preceded either by syllable congruent (e.g., rum.ba-RU.MOR, cis.ra-CIS.NE), syllable incongruent (e.g., rum.ba-RU.MOR, ci.ser-CIS.NE), unrelated (e.g., va.cra-RU.MOR, zar.vo-CIS.NE) pseudowords primes, or identity (e.g., ru.mour-RU.MOUR, cis.ne-CIS.NE) primes. Results showed reliable syllable effects only for intermediate readers and for CV and CVC words alike. Findings are discussed attending to current models of visual word recognition.
Childhood polyvictimization and marijuana use trajectories
Authors: Plummer Lee ChienTi , Mersky Joshua , Marsee Ian , Fuemmeler Bernard
Published: September 2020

Despite public sentiment to the contrary, recreational marijuana use is deleterious to adolescent health and development. Prospective studies of marijuana use trajectories and their predictors are needed to differentiate risk profiles and inform intervention strategies. Using data on 15,960 participants in the National Longitudinal Study of Adolescent to Adult Health, variable-centered approaches were used to examine the impact of childhood polyvictimization on marijuana onset, marijuana use from age 15 to 24 years, and marijuana dependence symptoms. Zero-Inflated Poisson latent class growth analysis (ZIP-LCGA) was used to identify marijuana use subgroups, and their associations with childhood polyvictimization were tested via multinomial logit regression within ZIP-LCGA. Results showed that the overall probability and frequency of marijuana use increased throughout adolescence, peaked in early adulthood, and diminished gradually thereafter. Polyvictimization was associated with earlier onset and greater overall use, frequency of use, and dependence symptoms. ZIP-LCGA uncovered four subgroups, including non-users and three classes of users: adolescence-limited users, escalators, and chronic users. Polyvictimization distinguished non-users from all classes of marijuana users. The findings underscore the lasting developmental implications of significant childhood trauma. Children who experience polyvictimization represent a group that may benefit from selective interventions aimed at preventing early, frequent, chronic, and dependent marijuana use.
Implementation of a standardized oral screening tool by paediatric cardiologists
Authors: McCargar Shelley I. , Olsen Joanne , Steelman Robert J. , Huang Jennifer H. , Palmer Elizabeth A. , Burch Grant H. , Reed Richard , LaBarge Sara K.
Published: September 2020

Background:

An examination of invasive procedure cancellations found that the lack of pre-procedural oral screening was a preventable cause, for children with congenital heart disease. The purpose of this study was to implement an oral screening tool within the paediatric cardiology clinic, with referral to paediatric dental providers for positive screens. The target population were children aged ≥6 months to <18 years old, being referred for cardiac procedures.

Methods:

The quality implementation framework method was used for this study design. The multi-modal intervention included education, audit and feedback, screening guidelines, environmental support, and interdisciplinary collaboration. Baseline rates for oral screenings were determined by retrospective chart audit from January 2018 to January 2019 (n = 211). Provider adherence to the oral screening tool was the outcome measure. Positive oral screens, resulting in referral to the paediatric dental clinic, were measured as a secondary outcome. Provider adherence rates were used as a process measure.

Results:

Data collected over 14 weeks showed a 29% increase in documentation of oral screenings prior to referral, as compared to the retrospective chart audit. During the study period, 13% of completed screenings were positive (n = 5). Provider compliance for the period was averaged at 70% adherence.

Conclusion:

A substantial increase in pre-procedural oral screenings by paediatric cardiologists was achieved using the quality implementation framework and targeted interventions.
Neuroendocrine tumour with Tetralogy of Fallot: a case report
Authors: Balasubramanian Harapriya , Munisamy Ragavan , Coelho Robert
Published: September 2020

Paragangliomas occurring with cyanotic heart disease is a known association. We present a case of an active paraganglioma in a child with unoperated Tetralogy of Fallot, which posed a management challenge considering the pathophysiology of both these conditions.
Doctor Gachet, in the kitchen, with the foxglove
Authors: Mainwaring Richard D. , Mainwaring Stephanie
Published: September 2020

Vincent van Gogh (1853–1890) is one of the most famous artists in the world. During his 10-year career as an artist, he created more than 850 paintings. These works of art are now displayed in museums around the globe. It is therefore even more surprising that van Gogh sold just one painting during his lifetime. Van Gogh is also well-known for his mental illness. In 1888, at the age of 35, he famously sliced off his left ear. This was followed by multiple mental collapses in early 1889, leading to his admission to a mental hospital. Despite living in the asylum, van Gogh continued to paint and created some of his most beautiful works of art during the year at Saint-Rémy. Tragically, he committed suicide in 1890 at the age of 37. Over the 130 years since his death, there has been much speculation about the underlying illness of Vincent van Gogh. Many of his contemporary physicians felt that he had a form of epilepsy as the cause of his sudden “attacks”. By the last quarter of the 19th century, science and medicine were moving rapidly forward, and there were many medical conditions that had effective treatments. One example is the use of digoxin for the treatment of heart failure, and another is the discovery of potassium bromide for seizures. This paper provides an overview of van Gogh’s mental illness, the treatments that were offered by his contemporaneous physicians, and the role that these factors may have influenced his paintings.
The National Emergency Medical Service Role During the COVID-19 Pandemic in Sierra Leone
Authors: Caviglia Marta , Buson Riccardo , Pini Sara , Jambai Amara , Vandy Matthew Jusu , Venturini Francesco , Rosi Paolo , Barone-Adesi Francesco , Della Corte Francesco , Ragazzoni Luca , Putoto Giovanni
Published: September 2020

This report describes the main adaptive and transformative changes adopted by the brand-new National Emergency Medical Service (NEMS) to face the novel coronavirus disease 2019 (COVID-19) in Sierra Leone, including ambulance re-distribution, improvements in communication flow, implementation of ad-hoc procedures and trainings, and budget re-allocation. In a time-span of four months, 1,170 COVID-19 cases have been handled by the NEMS through a parallel referral system, while efforts have been made to manage the routine emergencies of the country, causing a substantial intensification of daily activities.
A Late COVID-19 Complication: Male Sexual Dysfunction
Authors: Shoar Saeed , Khavandi Siamak , Tabibzadeh Elsa , Vaez Aydin , Oskouei Ali Khabbazi , Hosseini Fatemeh , Naderan Mohammad , Shoar Nasrin
Published: September 2020

Since the beginning of the coronavirus infectious disease 2019 (COVID-19) pandemic, an exponentially large amount of data has been published to describe the pathology, clinical presentations, and outcomes in patients infected with the severe acute respiratory syndrome novel coronavirus 2 (SARS-CoV-2). Although COVID-19 has been shown to cause a systemic inflammation predisposing the involvement of multiple organs, its mechanism affecting the urogenital system has not been well-documented. This case report presents the clinical course of two male patients with COVID-19 who developed sexual dysfunction, as anorgasmia, following recovery from the infection. Although no evidence of viral replication or inflammatory involvement could be identified in these cases’ urogenital organs, a lack of other known risk factors for anorgasmia points to the role of COVID-19 as the contributing factor.
eclingo : A Solver for Epistemic Logic Programs
Authors: Cabalar Pedro , Fandinno Jorge , Garea Javier , Romero Javier , Schaub Torsten
Published: September 2020

We describe eclingo, a solver for epistemic logic programs under Gelfond 1991 semantics built upon the Answer Set Programming system clingo. The input language of eclingo uses the syntax extension capabilities of clingo to define subjective literals that, as usual in epistemic logic programs, allow for checking the truth of a regular literal in all or in some of the answer sets of a program. The eclingo solving process follows a guess and check strategy. It first generates potential truth values for subjective literals and, in a second step, it checks the obtained result with respect to the cautious and brave consequences of the program. This process is implemented using the multi-shot functionalities of clingo. We have also implemented some optimisations, aiming at reducing the search space and, therefore, increasing eclingo ’s efficiency in some scenarios. Finally, we compare the efficiency of eclingo with two state-of-the-art solvers for epistemic logic programs on a pair of benchmark scenarios and show that eclingo generally outperforms their obtained results.
Flexible coinductive logic programming
Authors: DAGNINO FRANCESCO , ANCONA DAVIDE , ZUCCA ELENA
Published: September 2020

Recursive definitions of predicates are usually interpreted either inductively or coinductively. Recently, a more powerful approach has been proposed, called flexible coinduction, to express a variety of intermediate interpretations, necessary in some cases to get the correct meaning. We provide a detailed formal account of an extension of logic programming supporting flexible coinduction. Syntactically, programs are enriched by coclauses, clauses with a special meaning used to tune the interpretation of predicates. As usual, the declarative semantics can be expressed as a fixed point which, however, is not necessarily the least, nor the greatest one, but is determined by the coclauses. Correspondingly, the operational semantics is a combination of standard SLD resolution and coSLD resolution. We prove that the operational semantics is sound and complete with respect to declarative semantics restricted to finite comodels.
Use of broken rice in broiler diet
Authors: Rezaei M , Fathi M K , Kor A K
Published: September 2020

Maize is the principal energy source in most poultry diet in developing countries. As the cultivating of maize is limited in Iran, annually a large amount of maize is imported. Broken rice (BR) is a major cereal by-product for animal feeding in rice-growing countries. The annual production of rice paddy in Iran is about 2 million tonnes. After milling of paddy, broken rice is available for utilization in animal diet. BR consists of 40 to 80 g/kg of rice paddy. It contains good sources of protein (100-110 g/kg), fat (60-110 g/kg), carbohydrate, fibre (20-50 g/kg). Due to mixing with bran and hull the chemical composition of BR varies in different samples. In some part of the country the price of this ingredient is lower than maize. The objective of the present experiment was to evaluate the effect diets containing different levels of BR on performance of broiler chicks from 1 to 8 weeks of age.
Atrazine residues in flooded and nonflooded soil and effects on soybean
Authors: Mueller Thomas C. , Kincer David R. , Steckel Lawrence E.
Published: September 2020

Atrazine applied at planting is commonly used for weed control in corn. With global climate change causing an increase in river flooding in the United States over the past decade, producers need information to determine the best course of action in flooded fields treated with atrazine into which they wish to immediately plant soybean. Studies were designed to understand the effect of flooding on atrazine residual activity including atrazine concentration, soybean injury, and soybean yield. In 2012, soybean yield in flooded treatments was reduced by prior atrazine application. In 2014, soybean injury was <10% in all plots, and nonflooded, atrazine-treated soils had yields equal to the nontreated. Findings from this research indicated that it is possible for producers to consider replanting soybean after atrazine application, with appropriate changes to product labeling.
Apatite Fission Track Signatures of the Ross Sea Ice Flows During the Last Glacial Maximum
Authors: Li X. , Zattin M. , Olivetti V.
Published: September 2020

The catchment for the Ross Sea ice includes both the East and the West Antarctic ice sheets, but the mass balance is a direct response to climate change. Our work is aimed to reconstruct the ice flows after the Last Glacial Maximum and is based on apatite fission track data from samples collected from 18 piston cores across the Ross Sea embayment. Fission track ages have been divided into meaningful populations and then compared with bedrock ages from West and East Antarctica. Furthermore, fission track lengths have been measured on each population and then compared through forward modeling with thermal histories derived from literature. The widespread presence of apatites with cooling ages of about 30–40 Ma reveals a main exhumation phase of the Transantarctic Mountains during the Oligocene associated to the last phases of the West Antarctic Rift System. Furthermore, the presence of key marker apatites (e.g., younger than 21 Ma or older than 230 Ma) allows to identify the Central High as a major ice flow divide.
The Complexity of the 2018 Kaktovik Earthquake Sequence in the Northeast of the Brooks Range, Alaska
Authors: Xu Guangyu , Xu Caijun , Wen Yangmao , Xiong Wei , Valkaniotis Sotiris
Published: September 2020

We use mainly geodetic observations to constrain the fault geometry and coseismic distribution of the 2018 Kaktovik earthquake sequence, Alaska. We find that at least three faults were activated. The earthquake sequence ruptured mainly an ESE‐striking, SSW‐dipping strike‐slip fault and a secondary rupture on an SE‐striking, SW‐dipping normal fault. Slip also occurred on a small SSW‐striking fault plane, which is found first in geodetic data and further verified with geological data and focal mechanism solutions. We also map 6 months of postseismic deformation and find obvious displacements in the center of the Sadlerochit Mountains. A geological model is proposed to interpret the relationship between this earthquake sequence and the regional structure. We suggest that the 2018 Kaktovik earthquake sequence may first have occurred on a fault unknown prior to the mainshock and triggered slip on both the pre‐existing ramp structure below the Sadlerochit Mountains and a secondary structure.
Abyssal Pathways and the Double Silica Maximum in the Northeast Pacific Basin
Authors: Hautala Susan L. , Hammond Douglas E.
Published: September 2020

This study examines causes of the double silica maximum in the deep interior Northeast Pacific Basin using a stochastic Lagrangian tracer model based on steady‐state advective fields and diapycnal diffusion established by a hydrographic inverse method that conserves potential vorticity and salinity. Lateral diffusion, unresolved by the inverse model, is adjusted for overall agreement with radiocarbon distribution. The double silica maximum in vertical profiles arises from an eastern‐intensified single maximum in the North Pacific Deep Water along the northern domain boundary (originating in the western Pacific), and a strong subarctic bottom source supplying silica to Upper Circumpolar Deep Water density surfaces that successively intersect the seafloor over a broad area east of 150°W, associated geostrophically with southward flow. The existence of the double silica maximum requires weak diapycnal transport in the deep interior, with broader implications for the conceptual picture of meridional overturning circulation in the North Pacific.
Cross‐Over Infrared Spectroscopy: A New Tool for the Remote Determination of Olivine Composition
Authors: Kremer C. H. , Mustard J. F. , Pieters C. M.
Published: September 2020

Olivine ([Mg,Fe]2SiO4) has been remotely detected on numerous solar system bodies, but its composition has been only partially constrained using visible‐near infrared (VNIR, 0.5–3 μm) and midinfrared (MIR, 8–15 μm) spectra. Meanwhile, the spectral character of olivine in the “cross‐over” region of the infrared (4–8 μm) remains generally unexplored. We examine the relationship between olivine Mg# (molar Mg/[Mg + Fe] × 100) and the wavelength positions of two strong, discrete overtone‐combination bands at ~5.6 and ~6.0 μm. In reflectance and thermal emission spectra measured for 47 synthetic and natural olivine samples that span the Mg‐Fe solid solution, we find that the 5.6 and 6.0 μm bands shift systematically to longer wavelengths by 0.11 and 0.10 μm, respectively, with increasing Fe content. Our results indicate that olivine Mg# may be determined within ±10 mol% forsterite using the positions of these two bands, making “cross‐over” region spectroscopy a potentially powerful remote sensing tool.
Unusual Changes in the Antarctic Middle Atmosphere During the 2019 Warming in the Southern Hemisphere
Authors: Eswaraiah S. , Kim Jeong‐Han , Lee Wonseok , Hwang Junyoung , Kumar Kondapalli Niranjan , Kim Yong Ha
Published: September 2020

A rare sudden stratosphere warming (SSW) occurred in the Southern Hemisphere polar region in 2019. The polar stratosphere temperature and planetary wave (PW) enhancements are found to be unusual from the history for 40 years; hence, it is an “Extremely‐Rare” SSW. The distinct features of the mesosphere winds were observed during the SSW, in association with the traveling PWs in the stratosphere. The mesosphere zonal winds reversed for about 20 days before the peak SSW. Meteor radar (MR) and Modern‐Era Retrospective Analysis for Research and Applications (MERRA)‐2 observations indicate that the zonal wind reversal was descended with time, and the reversal was larger over ~72°S than the MR site (62°S). The MR detected the PWs of 14–22 days before and 8–12 days following the SSW in the mesosphere. We further noticed the enhancement of wavenumber 1 signature in the mesosphere during the peak SSW over the polar region. Thus, the polar middle‐atmosphere is greatly affected by the SSW.
A New Technique for Investigating Dust Charging in the PMSE Source Region
Authors: Mahmoudian Alireza , Kosch Mike J. , Vierinen Juha , Rietveld Michael T.
Published: September 2020

A new technique for investigating dust charging in the PMSE (polar mesospheric summer echoes) source region is proposed and discussed in this paper. The first high‐frequency (HF) modulation of the PMSE with varying pump power was employed during a recent experimental campaign at EISCAT (European Incoherent Scatter Scientific Association). Two experiment setups including HF pump power stepping as well as quasi‐continuous power sweeping were used. The experiment was designed based on a computational model capable of simulation of PMSE evolution during HF pump modulation in order to develop a new approach for studying the dust charging process in the PMSE source region. The charge state of dust particles along with background dusty plasma parameters is estimated using the experimental and computational results. A detailed future experimental design based on background dusty‐plasma parameters is proposed.
Latitudinal Response of Storm Activity to Abrupt Climate Change During the Last 6,500 Years
Authors: Yang Yang , Maselli Vittorio , Normandeau Alexandre , Piper David J. W. , Li Michael Z. , Campbell D. Calvin , Gregory Taylor , Gao Shu
Published: September 2020

This study examines the influence of the strength of Atlantic Meridional Overturning Circulation (AMOC) on storminess at different latitudes in the North Atlantic, based on a new 6.5‐Kyr record of large storms from the Scotian Shelf (Eastern Canada) that provides the first >3.5‐ka record from middle latitudes. Comparison with a compilation of other paleostorm records shows that peaks in storminess are at times synchronous (4.5–2.5 and since 0.5 ka) between low and middle latitudes but in the intervening period (2.5–0.5 ka) were latitudinally asynchronous. Synchronous (asynchronous) behavior correlates with sustained increase (decrease) of AMOC. Regime shifts in storm activity between low and middle latitudes were more frequent since 2.5 ka, related to increased frequency of abrupt climate changes. These findings indicate a latitudinal response of storm activity due to abrupt climate change, which is critical to correctly assess future storm risks along the North Atlantic coastline.
The Global Distribution of Ultralow‐Frequency Waves in Jupiter's Magnetosphere
Authors: Manners H. , Masters A.
Published: September 2020

Jupiter's giant magnetosphere is a complex system seldom in a configuration approximating steady state, and a clear picture of its governing dynamics remains elusive. Crucial to understanding how the magnetosphere behaves on a large scale are disturbances to the system on length‐scales comparable to the cavity, which are communicated by magnetohydrodynamic waves in the ultralow‐frequency band (<1 mHz). In this study we used magnetometer data from multiple spacecraft to perform the first global heritage survey of these waves in the magnetosphere. To map the equatorial region, we relied on the large local‐time coverage provided by the Galileo spacecraft. Flyby encounters performed by Voyager 1 and 2, Pioneer 10 and 11, and Ulysses provided local‐time coverage of the dawn sector. We found several hundred events where significant wave power was present, with periods spanning ∼5–60 min. The majority of events consisted of multiple superposed discrete periods. Periods at ∼15, ∼30, and ∼40 min dominated the event‐averaged spectrum, consistent with the spectra of quasi‐periodic pulsations often reported in the literature. Most events were clustered in the outer magnetosphere close to the magnetopause at noon and dusk, suggesting that an external driving mechanism may dominate. The most energetic events occurred close to the planet, though more sporadically, indicating an accumulation of wave energy in the inner magnetosphere or infrequent impulsive drivers in the region. Our findings suggest that dynamics of the system at large scales is modulated by this diverse population of waves, which permeate the magnetosphere through several cavities and wave guides.
Benthic Respiration in Hypoxic Waters Enhances Bottom Water Acidification in the Northern Gulf of Mexico
Authors: Wang Hongjie , Lehrter John , Maiti Kanchan , Fennel Katja , Laurent Arnaud , Rabalais Nancy , Hussain Najid , Li Qian , Chen Baoshan , Scaboo K. Michael , Cai Wei‐Jun
Published: September 2020

It is known that surface water eutrophication enhances bottom water ocean acidification via respiration in coastal oceans. However, the role of benthic processes in influencing bottom water acidification has not been sufficiently explored. We examined this issue by analyzing a 10‐year summer carbonate chemistry dataset in bottom water together with recent benthic flux measurements and literature benthic flux data in the northern Gulf of Mexico. The difference between the observed and estimated pH (Ω) values calculated from anthropogenic CO2 increase and water column aerobic respiration were defined as ΔpH (ΔΩ). We found that ΔpH and ΔΩ values in hypoxic condition were −0.03 ± 0.04 (mean ± standard deviation) and −0.15 ± 0.39, respectively. Both ΔpH and ΔΩ values in hypoxic conditions were significantly lower than zero (p < 0.05). The net results of anaerobic respiration, oxidation of reduced chemcials, burial of iron sulfide minerals, and possible CaCO3 dissolution may have led to an alkalinity to DIC production ratio of less than 1 in porewater. This caused the ratio of alkalinity to dissolved inorganic carbon fluxes from sediment to bottom water to be less than 1, which led to additional bottom water acidification. Our analysis and model simulations demonstrate that severe hypoxic and anoxic conditions, which correspond to less water movement, favor the accumulation of benthic respiration products, leading to additional pH and Ω reductions. The findings on sediment processes contributing to acidification in bottom waters provide new insights into the sensitivity of coastal ocean acidification to low‐oxygen conditions under current and future climates and anthropogenic nutrient loading scenarios.
A Continental Shelf Pump for CO2 on the Adélie Land Coast, East Antarctica
Authors: Arroyo Mar C. , Shadwick Elizabeth H. , Tilbrook Bronte , Rintoul Stephen R. , Kusahara Kazuya
Published: September 2020

We quantify the transport of inorganic carbon from the continental shelf to the deep ocean in Dense Shelf Water (DSW) from the Mertz and Ninnis Polynyas along the Adélie Land coast in East Antarctica. For this purpose, observations of total dissolved inorganic carbon (TCO2) from two summer hydrographic surveys in 2015 and 2017 were paired with DSW volume transport estimates derived from a coupled ocean‐sea ice‐ice shelf model to examine the fate of inorganic carbon in DSW from Adélie Land. Transports indicate a net outflow of 227 ± 115 Tg C yr−1 with DSW in the postglacial calving configuration of the Mertz Polynya. The greatest outflow of inorganic carbon from the shelf region was delivered through the northern boundary across the Adélie and Mertz Sills, with an additional transport westward from the Mertz Polynya. Inorganic carbon in DSW is derived primarily from inflowing TCO2‐rich modified Circumpolar Deep Water; local processes (biological productivity, air‐sea exchange of CO2, and the addition of brine during sea ice formation) make much smaller contributions. This study proposes that DSW export serves as a continental shelf pump for CO2 and is a pathway to sequester inorganic carbon from the shallow Antarctic continental shelf to the abyssal ocean, removing CO2 from atmospheric exchange on the time scale of centuries.
Radio Interferometer Observations of an Energetic in‐Cloud Pulse Reveal Large Currents Generated by Relativistic Discharges
Authors: Tilles Julia N. , Krehbiel Paul R. , Stanley Mark A. , Rison William , Liu Ningyu , Lyu Fanchao , Cummer Steven A. , Dwyer Joseph R. , Senay Seda , Edens Harald , Fan Xiangpeng , Brown Robert G. , Wilson Jennifer
Published: September 2020

The production mechanism for terrestrial gamma ray flashes (TGFs) is not entirely understood, and details of the corresponding lightning activity and thunderstorm charge structure have yet to be fully characterized. Here we examine sub‐microsecond VHF (14–88 MHz) radio interferometer observations of a 247‐kA peak‐current EIP, or energetic in‐cloud pulse, a reliable radio signature of a subset of TGFs. The EIP consisted of three high‐amplitude sferic pulses lasting ≃60 μs in total, which peaked during the second (main) pulse. The EIP occurred during a normal‐polarity intracloud lightning flash that was highly unusual, in that the initial upward negative leader was particularly fast propagating and discharged a highly concentrated region of upper‐positive storm charge. The flash was initiated by a high‐power (46 kW) narrow bipolar event (NBE), and the EIP occurred about 3 ms later after ≃3 km upward flash development. The EIP was preceded ≃200 μs by a fast 6 × 106 m/s upward negative breakdown and immediately preceded and accompanied by repeated sequences of fast (107–108 m/s) downward then upward streamer events each lasting 10 to 20 μs, which repeatedly discharged a large volume of positive charge. Although the repeated streamer sequences appeared to be a characteristic feature of the EIP and were presumably involved in initiating it, the EIP sferic evolved independently of VHF‐producing activity, supporting the idea that the sferic was produced by relativistic discharge currents. Moreover, the relativistic currents during the main sferic pulse initiated a strong NBE‐like event comparable in VHF power (115 kW) to the highest‐power NBEs.
Ionospheric Irregularities Observed During the GLEAM Survey
Authors: Helmboldt J. F. , Hurley‐Walker N.
Published: September 2020

Nearly 200 hr of observing with the Murchison Widefield Array (MWA) radio telescope during the Galactic and Extragalactic All‐sky MWA (GLEAM) survey was used to assemble images of ionospheric structure. These images cover a nearly 50° wide area on the sky at a cadence of 10 min over many 5–7 hr long observing runs. They are generated by tracking the apparent motions of ∼200–800 cosmic radio sources caused by changes in the transverse gradient of the ionospheric total electron content. Spectral analysis of these images revealed that the data set was dominated by three distinct signatures. The first is consistent with field‐aligned structures within the topside ionosphere/lower plasmasphere previously imaged with the MWA. The second are structures that are relatively large and aligned nearly east/west. Regional weather data imply that these are preferentially detected when there is a noticeable shear within the subtropical jet stream, which passes near the MWA. This suggests that this signature may be related to gravity waves launched by jet stream shear. The final signature is consistent with the properties of so‐called electrobuoyancy waves that are known to occur at midlatitudes at night. Detections of these were more common when regional sporadic E (ES) was present, supporting a proposed connection between these waves and polarization electric fields that may arise within ES. We discuss the implications for future observations with the Square Kilometer Array.
Prediction of independence in bowel function after spinal cord injury: validation of a logistic regression model
Authors: Khan Omar , Badhiwala Jetan H. , Fehlings Michael G.
Published: September 2020

Study design

Retrospective analysis of prospectively collected data.

Objectives

Recently, logistic regression models were developed to predict independence in bowel function 1 year after spinal cord injury (SCI) on a multicenter European SCI (EMSCI) dataset. Here, we evaluated the external validity of these models against a prospectively accrued North American SCI dataset.

Setting

Twenty-five SCI centers in the United States and Canada.

Methods

Two logistic regression models developed by the EMSCI group were applied to data for 277 patients derived from three prospective multicenter SCI studies based in North America. External validation was evaluated for both models by assessing their discrimination, calibration, and clinical utility. Discrimination and calibration were assessed using ROC curves and calibration curves, respectively, while clinical utility was assessed using decision curve analysis.

Results

The simplified logistic regression model, which used baseline total motor score as the predictor, demonstrated the best performance, with an area under the ROC curve of 0.869 (95% confidence interval: 0.826–0.911), a sensitivity of 75.5%, and a specificity of 88.5%. Moreover, the model was well calibrated across the full range of observed probabilities and displayed superior clinical benefit on the decision curve.

Conclusions

A logistic regression model using baseline total motor score as a predictor of independent bowel function 1 year after SCI was successfully validated against an external dataset. These findings provide evidence supporting the use of this model to enhance the care for individuals with SCI.
Interaction between adverse childhood experiences and polygenic risk in patients with bipolar disorder
Authors: Park Young-Min , Shekhtman Tatyana , Kelsoe John R.
Published: September 2020

The interaction between genes and environment often occurs when they depend on one another. We hypothesized that adverse childhood experiences (ACEs) would interact with genetic predispositions to bipolar disorder (BD), demonstrating earlier age at onset (AAO) and worse clinical outcomes. We aimed to clarify the effects of the interaction between ACEs and genetic susceptibility using polygenic risk score (PRS) on AAO and clinical outcomes. Single nucleotide polymorphisms and clinical data, including ACEs, were obtained from the Bipolar Genomic Study, which contains a large sample of BD participants. A total of 1615 subjects with BD I were obtained and divided into two groups according to the presence or absence of ACEs and an additional four groups based on the number of ACEs (none versus one versus two versus ≥ three types). ACEs was evaluated using the childhood life events scale (CLES). BD–PRS was obtained from the Psychiatric Genomics Consortium, which compared BD patients and healthy controls. The BD–PRS was higher in the group with ACEs than without ACEs at most p-value thresholds. In multivariate linear regression analyses, both groups with more ACEs and higher BD–PRS were independently and interactively associated with an earlier AAO of BD; however, only greater ACEs were associated with worsened clinical outcome. These findings highlight the clinical importance of evaluating ACEs and polygenic risk in research of the etiology of BD.
miR-196b-5p-mediated downregulation of FAS promotes NSCLC progression by activating IL6-STAT3 signaling
Authors: Huang Xiangjie , Xiao Sisi , Zhu Xinping , Yu Yun , Cao Meng , Zhang Xiaodong , Li Shaotang , Zhu Wangyu , Wu Fengjiao , Zheng Xiaohui , Jin Libo , Xie Congying , Huang Xiaoying , Zou Peng , Li Xiaokun , Cui Ri
Published: September 2020

Our recent study demonstrated that the QKI-5 regulated miRNA, miR-196b-5p, and it functions as an onco-microRNA in non-small cell lung cancer (NSCLC) by directly targeting GATA6 and TSPAN12. However, the role of miR-196b-5p in NSCLC progression and metastasis still remains unclear. We found that miR-196b-5p promotes lung cancer cell proliferation and colony formation by directly targeting tumor suppressor, FAS. The expression of FAS was significantly downregulated in NSCLC tissue samples and was negatively correlated with the miR-196b-5p expression. Knocking down FAS activates NFkB signaling and subsequent IL6 secretion, resulting in phosphorylation of signal transducer and activator of transcription 3 (STAT3) to promote lung cancer cell growth. Our findings indicated that miR-196b-5p might exhibit novel oncogenic function by FAS-mediated STAT3 activation in NSCLC, and suggested that targeting the miR-196b-5p/FAS/NFkB/IL6/STAT3 pathway might be a promising therapeutic strategy in treating NSCLC.
IL-33-ST2 axis regulates myeloid cell differentiation and activation enabling effective club cell regeneration
Authors: Dagher Rania , Copenhaver Alan M. , Besnard Valerie , Berlin Aaron , Hamidi Fatima , Maret Marielle , Wang Jingya , Qu Xiaotao , Shrestha Yashaswi , Wu Jincheng , Gautier Gregory , Raja Rajiv , Aubier Michel , Kolbeck Roland , Humbles Alison A. , Pretolani Marina
Published: September 2020

Evidence points to an indispensable function of macrophages in tissue regeneration, yet the underlying molecular mechanisms remain elusive. Here we demonstrate a protective function for the IL-33-ST2 axis in bronchial epithelial repair, and implicate ST2 in myeloid cell differentiation. ST2 deficiency in mice leads to reduced lung myeloid cell infiltration, abnormal alternatively activated macrophage (AAM) function, and impaired epithelial repair post naphthalene-induced injury. Reconstitution of wild type (WT) AAMs to ST2-deficient mice completely restores bronchial re-epithelialization. Central to this mechanism is the direct effect of IL-33-ST2 signaling on monocyte/macrophage differentiation, self-renewal and repairing ability, as evidenced by the downregulation of key pathways regulating myeloid cell cycle, maturation and regenerative function of the epithelial niche in ST2−/−mice. Thus, the IL-33-ST2 axis controls epithelial niche regeneration by activating a large multi-cellular circuit, including monocyte differentiation into competent repairing AAMs, as well as group-2 innate lymphoid cell (ILC2)-mediated AAM activation.
Enteroendocrine cells couple nutrient sensing to nutrient absorption by regulating ion transport
Authors: McCauley Heather A. , Matthis Andrea L. , Enriquez Jacob R. , Nichol Jonah T. , Sanchez J. Guillermo , Stone William J. , Sundaram Nambirajan , Helmrath Michael A. , Montrose Marshall H. , Aihara Eitaro , Wells James M.
Published: September 2020

The ability to absorb ingested nutrients is an essential function of all metazoans and utilizes a wide array of nutrient transporters found on the absorptive enterocytes of the small intestine. A unique population of patients has previously been identified with severe congenital malabsorptive diarrhea upon ingestion of any enteral nutrition. The intestines of these patients are macroscopically normal, but lack enteroendocrine cells (EECs), suggesting an essential role for this rare population of nutrient-sensing cells in regulating macronutrient absorption. Here, we use human and mouse models of EEC deficiency to identify an unappreciated role for the EEC hormone peptide YY in regulating ion-coupled absorption of glucose and dipeptides. We find that peptide YY is required in the small intestine to maintain normal electrophysiology in the presence of vasoactive intestinal polypeptide, a potent stimulator of ion secretion classically produced by enteric neurons. Administration of peptide YY to EEC-deficient mice restores normal electrophysiology, improves glucose and peptide absorption, diminishes diarrhea and rescues postnatal survival. These data suggest that peptide YY is a key regulator of macronutrient absorption in the small intestine and may be a viable therapeutic option to treat patients with electrolyte imbalance and nutrient malabsorption.