bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrathin interfacial layer with suppressed room temperature magnetization in magnesium aluminum ferrite thin films
Authors: Wisser Jacob J. , Emori Satoru , Riddiford Lauren , Altman Aaron , Li Peng , Mahalingam Krishnamurthy , Urwin Brittany T. , Howe Brandon M. , Page Michael R. , Grutter Alexander J. , Kirby Brian J. , Suzuki Yuri
Published: September 2019

Low-damping magnetic oxide thin films with small thicknesses are essential for efficient insulator spintronic devices, particularly those driven by spin torque effects. Here, we investigate the depth-resolved compositional and magnetic properties of epitaxial spinel MgAl0.5Fe1.5O4 (MAFO), which has recently been reported as a promising low-damping insulator. We find that ≈11 nm films exhibit optimal Gilbert damping, with a typical damping parameter of 0.001. While defects due to strain relaxation in the bulk of the film contribute to increased damping for large film thickness, the damping increase in thinner films is attributed to the presence of a chemically disordered magnetic dead layer at the film/substrate interface. This interfacial dead layer arises from an Fe-deficient MAFO layer. Notably, this layer is only about one-sixth the thickness of that found at the interface between yttrium iron garnet films and gadolinium gallium garnet substrates, making MAFO an ideal thin-film insulator for spin-torque applications.
Room-temperature stability of excitons and transverse-electric polarized deep-ultraviolet luminescence in atomically thin GaN quantum wells
Authors: Bayerl Dylan , Kioupakis Emmanouil
Published: September 2019

We apply first-principles calculations to study the effects of extreme quantum confinement on the electronic, excitonic, and radiative properties of atomically thin (1–4 atomic monolayers) GaN quantum wells embedded in AlN. We determine the quasiparticle bandgaps, exciton energies and wave functions, radiative lifetimes, and Mott critical densities as a function of well and barrier thickness. Our results show that quantum confinement in GaN monolayers increases the bandgap up to 5.44 eV and the exciton binding energy up to 215 meV, indicating the thermal stability of excitons at room temperature. Exciton radiative lifetimes range from 1 to 3 ns at room temperature, while the Mott critical density for exciton dissociation is approximately 1013 cm−2. The luminescence is transverse-electric polarized, which facilitates light extraction from c-plane heterostructures. We also introduce a simple approximate model for calculating the exciton radiative lifetime based on the free-carrier bimolecular radiative recombination coefficient and the exciton radius, which agrees well with our results obtained with the Bethe–Salpeter equation predictions. Our results demonstrate that atomically thin GaN quantum wells exhibit stable excitons at room temperature for potential applications in efficient light emitters in the deep ultraviolet as well as room-temperature excitonic devices.
Identifying mechanistically distinct pathways in kinetic transition networks
Authors: Sharpe Daniel J. , Wales David J.
Published: September 2019

We present an implementation of a scalable path deviation algorithm to find the k most kinetically relevant paths in a transition network, where each path is distinguished on the basis of having a distinct rate-limiting edge. The potential of the algorithm to identify distinct pathways that exist in separate regions of the configuration space is demonstrated for two benchmark systems with double-funnel energy landscapes, namely a model “three-hole” network embedded on a 2D potential energy surface and the cluster of 38 Lennard-Jones atoms (LJ38). The path cost profiles for the interbasin transitions of the two systems reflect the contrasting nature of the landscapes. There are multiple well-defined pathway ensembles for the three-hole system, whereas the transition in LJ38 effectively involves a single ensemble of pathways via disordered structures. A by-product of the algorithm is a set of edges that constitute a cut of the network, which is related to the discrete analog of a transition dividing surface. The algorithm ought to be useful for determining the existence, or otherwise, of competing mechanisms in large stochastic network models of dynamical processes and for assessing the kinetic relevance of distinguishable ensembles of pathways. This capability will provide insight into conformational transitions in biomolecules and other complex slow processes.
Diffusion dynamics of valley excitons by transient grating spectroscopy in monolayer WSe2
Authors: Wang Jing , Guo Yang , Huang Yuan , Luo Hailan , Zhou Xingjiang , Gu Changzhi , Liu Baoli
Published: September 2019

The transient grating spectroscopy is widely used to determine the diffusion coefficients of valley excitons or spins in low-dimensional semiconductor materials. Here, we present the investigation on the diffusion dynamics of the valley excitons in a high-quality large-scale mechanically exfoliated tungsten diselenide (WSe2) monolayer by this technique at room temperature. Collinearly polarized laser excitation (at a photon energy of 1.66 eV resonant to the energy of valley A-excitons) was used to introduce a spatially periodic density of valley excitons. Through probing the spatial and temporal evolution of the initial density of valley excitons, we find that the signals of transient grating exhibit an nonexponential decay, and its decay rate is independent of the period of optical grating Λ. Combined with the transient reflection measurements, we show that the exciton-exciton annihilation plays a key role in decay processes of the transient grating spectroscopy, which results in the distortion of sinusoidal gratings. Based on Einstein relationship, we estimate the diffusion coefficient of valley exciton DX = 0.7 cm2/s.
Magnetic field direction dependent magnetization reversal in synthetic antiferromagnets
Authors: Chen R. Y. , Zhang R. Q. , Liao L. Y. , Chen X. Z. , Zhou Y. J. , Gu Y. D. , Saleem M. S. , Zhou X. F. , Pan F. , Song C.
Published: September 2019

A perpendicularly magnetized synthetic antiferromagnetic structure is a promising alternative to a single ferromagnetic layer in spintronic applications because of its low net magnetization and high thermal stability. In general, the reversal sequences of the two ferromagnetic layers in the structure are fixed for a specific sample since they have different magnetic anisotropy. Here, we investigate the anomalous Hall effect of the [Pd/Co]/Ru/[Co/Pd] synthetic antiferromagnetic structure. By rotating the external field from out-of-plane to in-plane, three different types of anomalous Hall effect curves can be observed, which shows obvious magnetic field direction dependent magnetization reversal behavior. The mechanism can be explained with the help of the Stoner-Wohlfarth model calculation, and the result indicates that the competition among Zeeman, anisotropy, and exchange coupling energies in the system is sensitive to the magnetic field direction, which changes the switching sequences. Besides the fundamental significance, our finding provides a different dimension to manipulate the performance of spintronics.
Fibulin-4 exerts a dual role in LTBP-4L–mediated matrix assembly and function
Authors: Kumra Heena , Nelea Valentin , Hakami Hana , Pagliuzza Amelie , Djokic Jelena , Xu Jiongci , Yanagisawa Hiromi , Reinhardt Dieter P.
Published: September 2019

Significance

Soft tissues such as blood vessels, lung, and skin require various extracellular proteins, including tropoelastin, fibrillins, fibulin-4, and latent TGF-β binding protein-4 (LTBP-4) to synthesize functional elastic fibers in a highly hierarchical fashion. Mutations in these proteins cause heritable diseases, resulting in deficient elastic fibers and function. We provide evidence for a dual role of fibulin-4 in this context. Our results demonstrate how physical interactions between these elastogenic proteins play key roles in inducing conformational and functional changes, which then impacts self-assembly and elastic fiber formation. This fundamental finding is essential to understand the pathogenesis of diseases associated with mutations in elastogenic proteins.
Cell models of lipid-rich α-synuclein aggregation validate known modifiers of α-synuclein biology and identify stearoyl-CoA desaturase
Authors: Imberdis Thibaut , Negri Joseph , Ramalingam Nagendran , Terry-Kantor Elizabeth , Ho Gary P. H. , Fanning Saranna , Stirtz Georgia , Kim Tae-Eun , Levy Oren A. , Young-Pearse Tracy L. , Selkoe Dennis , Dettmer Ulf
Published: September 2019

Significance

Misfolding and accumulation of the protein α-synuclein (αS) inside nerve cells characterize Parkinson’s disease (PD) and related brain diseases, for which no disease-modifying therapies exist. Robust cell models are needed that recapitulate abnormal αS folding/accumulation in real time, especially for compound screening. We took advantage of the engineered αS “3K” (E35K+E46K+E61K) mutation, which amplifies the familial PD-causing E46K and readily forms round inclusions. We rescued the inclusions with known αS modulators and then screened a ∼2,000-compound library. We identified the potential therapeutic target stearoyl-CoA desaturase; its inhibition cleared αS inclusions, in accord with the effects of conditioning in saturated fatty acids. We propose a model for how fatty acids serve as key modulators of cellular αS homeostasis.
Variable impacts of contemporary versus legacy agricultural phosphorus on US river water quality
Authors: Stackpoole Sarah M. , Stets Edward G. , Sprague Lori A.
Published: September 2019

Phosphorus (P) fertilizer has contributed to the eutrophication of freshwater ecosystems. Watershed-based conservation programs aiming to reduce external P loading to surface waters have not resulted in significant water-quality improvements. One factor that can help explain the lack of water-quality response is remobilization of accumulated legacy (historical) P within the terrestrial-aquatic continuum, which can obscure the beneficial impacts of current conservation efforts. We examined how contemporary river P trends (between 1992 and 2012) responded to estimated changes in contemporary agricultural P balances [(fertilizer + manure inputs)—crop uptake and harvest removal] for 143 watersheds in the conterminous United States, while also developing a proxy estimate of legacy P contribution, which refers to anthropogenic P inputs before 1992. We concluded that legacy sources contributed to river export in 49 watersheds because mean contemporary river P export exceeded mean contemporary agricultural P balances. For the other 94 watersheds, agricultural P balances exceeded river P export, and our proxy estimate of legacy P was inconclusive. If legacy contributions occurred in these locations, they were likely small and dwarfed by contemporary P sources. Our continental-scale P mass balance results indicated that improved incentives and strategies are needed to promote the adoption of nutrient-conserving practices and reduce widespread contemporary P surpluses. However, a P surplus reduction is only 1 component of an effective nutrient plan as we found agricultural balances decreased in 91 watersheds with no consistent water-quality improvements, and balances increased in 52 watersheds with no consistent water-quality degradation.
Epsilon iron as a spin-smectic state
Authors: Lebert Blair W. , Gorni Tommaso , Casula Michele , Klotz Stefan , Baudelet François , Ablett James M. , Hansen Thomas C. , Juhin Amélie , Polian Alain , Munsch Pascal , Le Marchand Gilles , Zhang Zailan , Rueff Jean-Pascal , d’Astuto Matteo
Published: September 2019

Using X-ray emission spectroscopy, we find appreciable local magnetic moments until 30 GPa to 40 GPa in the high-pressure phase of iron; however, no magnetic order is detected with neutron powder diffraction down to 1.8 K, contrary to previous predictions. Our first-principles calculations reveal a “spin-smectic” state lower in energy than previous results. This state forms antiferromagnetic bilayers separated by null spin bilayers, which allows a complete relaxation of the inherent frustration of antiferromagnetism on a hexagonal close-packed lattice. The magnetic bilayers are likely orientationally disordered, owing to the soft interlayer excitations and the near-degeneracy with other smectic phases. This possible lack of long-range correlation agrees with the null results from neutron powder diffraction. An orientationally disordered, spin-smectic state resolves previously perceived contradictions in high-pressure iron and could be integral to explaining its puzzling superconductivity.
A marine plasmid hitchhiking vast phylogenetic and geographic distances
Authors: Petersen Jörn , Vollmers John , Ringel Victoria , Brinkmann Henner , Ellebrandt-Sperling Claire , Spröer Cathrin , Howat Alexandra M. , Murrell J. Colin , Kaster Anne-Kristin
Published: September 2019

Significance

Horizontal gene transfer (HGT) is the movement of genetic material between organisms other than by reproduction, which plays an important role in bacterial evolution. Often, mobile genetic elements such as plasmids are involved in HGT. In this study, we present phylogenetic, biogeographic, and functional analyses of a previously unrecognized plasmid that is found with 100% sequence identity in multiple distinct bacterial genera obtained from geographically separated locations. This is the only known instance where actual nucleotide identity and not only high synteny has been described for plasmids in environmental organisms. Furthermore, we provide experimental evidence for the potential of this plasmid to be transmitted across bacterial orders, thereby increasing our understanding of evolution and microbial niche adaptation in the environment.
Unusual dynamics of the divergent malaria parasite
Pf
Act1 actin filament
Authors: Lu Hailong , Fagnant Patricia M. , Trybus Kathleen M.
Published: September 2019

Significance

The unicellular apicomplexan parasite,
Plasmodium falciparum
, causes malaria in humans that results in >400,000 deaths per year. The parasite must produce force and motion to progress through its lifecycle and cause disease. The core of the macromolecular complex that powers invasion and motile stages consists of a unique single-headed myosin and a divergent actin (
Pf
Act1). We used total internal reflection fluorescence microscopy to visualize polymerization of individual
Pf
Act1 filaments in real time in the absence of stabilizing agents. The unique dynamic properties of both ends of the polar filament, and the high actin concentration needed for it to polymerize, provide a molecular explanation for why these filaments have been notoriously hard to visualize both in vitro and in the parasite.
Generation and detection of spin-orbit coupled neutron beams
Authors: Sarenac Dusan , Kapahi Connor , Chen Wangchun , Clark Charles W. , Cory David G. , Huber Michael G. , Taminiau Ivar , Zhernenkov Kirill , Pushin Dmitry A.
Published: September 2019

Significance

Extensive interest has been placed on the techniques to prepare and characterize optical and matter wave orbital angular momentum (OAM) beams and spin correlated OAM beams. They have been shown to be useful in a wide range of applications such as microscopy, quantum information processing, material characterization, and communication protocols. Here we demonstrate an observation of spin-orbit beams and lattices of spin-orbit beams with neutrons. Neutrons, which do not possess a charge and have significant mass, are probes of nature that are complementary to photons and electrons. The techniques shown here enable neutron OAM applications in material characterization and fundamental physics.
Generation of the configurational ensemble of an intrinsically disordered protein from unbiased molecular dynamics simulation
Authors: Shrestha Utsab R. , Juneja Puneet , Zhang Qiu , Gurumoorthy Viswanathan , Borreguero Jose M. , Urban Volker , Cheng Xiaolin , Pingali Sai Venkatesh , Smith Jeremy C. , O’Neill Hugh M. , Petridis Loukas
Published: September 2019

Significance

A major challenge in biology is characterizing the structural flexibility of intrinsically disordered proteins (IDPs). Ensemble-averaged experimental data do not provide the underlying protein structures. Here, we performed independently small-angle neutron and X-ray scattering experiments and unbiased molecular dynamics simulations to probe the solution structure of an IDP. We report that enhancing the sampling of the simulations can generate an ensemble of IDP structures in quantitative agreement with scattering and NMR, without the need for biasing the simulation or reweighting the results. The demonstration of established simulation technology that produces accurate physical models of flexible biosystems may pave the way to relating conformational flexibility to biological function.
A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators
Authors: Needham David M. , Yoshizawa Susumu , Hosaka Toshiaki , Poirier Camille , Choi Chang Jae , Hehenberger Elisabeth , Irwin Nicholas A. T. , Wilken Susanne , Yung Cheuk-Man , Bachy Charles , Kurihara Rika , Nakajima Yu , Kojima Keiichi , Kimura-Someya Tomomi , Leonard Guy , Malmstrom Rex R. , Mende Daniel R. , Olson Daniel K. , Sudo Yuki , Sudek Sebastian , Richards Thomas A. , DeLong Edward F. , Keeling Patrick J. , Santoro Alyson E. , Shirouzu Mikako , Iwasaki Wataru , Worden Alexandra Z.
Published: September 2019

Giant viruses are remarkable for their large genomes, often rivaling those of small bacteria, and for having genes thought exclusive to cellular life. Most isolated to date infect nonmarine protists, leaving their strategies and prevalence in marine environments largely unknown. Using eukaryotic single-cell metagenomics in the Pacific, we discovered a
Mimiviridae
lineage of giant viruses, which infects choanoflagellates, widespread protistan predators related to metazoans. The ChoanoVirus genomes are the largest yet from pelagic ecosystems, with 442 of 862 predicted proteins lacking known homologs. They are enriched in enzymes for modifying organic compounds, including degradation of chitin, an abundant polysaccharide in oceans, and they encode 3 divergent type-1 rhodopsins (VirR) with distinct evolutionary histories from those that capture sunlight in cellular organisms. One (VirR
DTS
) is similar to the only other putative rhodopsin from a virus (PgV) with a known host (a marine alga). Unlike the algal virus, ChoanoViruses encode the entire pigment biosynthesis pathway and cleavage enzyme for producing the required chromophore, retinal. We demonstrate that the rhodopsin shared by ChoanoViruses and PgV binds retinal and pumps protons. Moreover, our 1.65-Å resolved VirR
DTS
crystal structure and mutational analyses exposed differences from previously characterized type-1 rhodopsins, all of which come from cellular organisms. Multiple VirR types are present in metagenomes from across surface oceans, where they are correlated with and nearly as abundant as a canonical marker gene from
Mimiviridae
. Our findings indicate that light-dependent energy transfer systems are likely common components of giant viruses of photosynthetic and phagotrophic unicellular marine eukaryotes.
Early detection and monitoring of cerebral ischemia using calcium-responsive MRI probes
Authors: Savić Tanja , Gambino Giuseppe , Bokharaie Vahid S. , Noori Hamid R. , Logothetis Nikos K. , Angelovski Goran
Published: September 2019

Significance

The duration of cerebral ischemia is a key factor in determining the severity of brain damage and the course of action. Thus, an accurate and timely observation of the ischemic process is highly critical. Here we present a molecular neuroimaging approach that enables direct detection and real-time visualization of transient cerebral ischemia. The method relies on high-resolution observation of extracellular calcium alterations associated with the spatiotemporal dynamics of cerebral ischemia, using a selective molecular MRI probe. The rapid detection of calcium fluctuations in healthy and disease states will not only lead to essential insights for successful treatment and recovery of ischemic brain tissue but will also improve our understanding of the underlying neurobiology of neurological and psychiatric disorders.
Raman interrogation of the ferroelectric phase transition in polar metal LiOsO
3
Authors: Jin Feng , Wang Le , Zhang Anmin , Ji Jianting , Shi Youguo , Wang Xiaoqun , Yu Rong , Zhang Jiandi , Plummer E. W. , Zhang Qingming
Published: September 2019

Significance

Electric polarization due to polar structural distortion is a central characteristic of an ferroelectric (FE) material, which is normally unattainable in a metallic system because itinerant electrons screen the internal electric field. A possible exception for a polar metal is if the itinerant electrons are decoupled with FE distortion, as proposed by Anderson and Blount. Here, we reveal an unusual FE phase transition in recently discovered polar metal LiOsO
3
, different from the typical transition in insulating FEs, with dramatic temperature-dependent electron−phonon coupling. Our results provide a look at models for FE transitions with the interplay between FE dipoles and itinerant electrons, suggesting that an improvement of the Anderson and Blount model is needed.
Future epidemiological and economic impacts of universal influenza vaccines
Authors: Sah Pratha , Alfaro-Murillo Jorge A. , Fitzpatrick Meagan C. , Neuzil Kathleen M. , Meyers Lauren A. , Singer Burton H. , Galvani Alison P.
Published: September 2019

Significance

Diminished efficacy of influenza vaccines has fueled research and funding for a broadly protective vaccine. NIAID recently proposed at least 75% efficacy against symptomatic influenza as a key criterion for a universal vaccine. Our analyses demonstrate that universal vaccines with 75% efficacy would be highly impactful in reducing the epidemiological impacts of seasonal influenza at both the national and state levels. Reduced incidence and hospitalizations due to universal vaccine distribution would save $3.5 billion influenza-related direct medical costs per year. This economic benefit surpasses the current and proposed funding of $330 million combined toward the development of a universal influenza vaccine. Our results highlight that benefits of universal vaccine rollout justify the significant investment required for development.
NanoSIMS imaging reveals metabolic stratification within current-producing biofilms
Authors: Chadwick Grayson L. , Jiménez Otero Fernanda , Gralnick Jeffrey A. , Bond Daniel R. , Orphan Victoria J.
Published: September 2019

Significance

Electricity-producing bacteria are potential power sources, fermentation platforms, and desalination systems, if current densities could be increased. These organisms form conductive biofilms on electrodes, allowing new cell layers to contribute to current production until a limit is reached, but the biological underpinning of this limit is not well-understood. We investigated the limitation behind this phenomenon using stable isotope probing and nanoscale secondary ion mass spectrometry, showing active cells are restricted to layers closest to the electrode. This metabolic observation fundamentally changes our understanding of electron flow and cell growth within current-producing biofilms and provides constraints on the physical structure of natural communities reliant on this process for growth. We predict improvements in biofilm conductivity will yield higher current-producing systems.
Hepatitis C Virus RNA Is Commonly Detectable in Rectal and Nasal Fluids of Patients With High Viremia
Authors: Chromy David , Schmidt Ralf , Mandorfer Mattias , Lang Gerold Felician , Bauer David , Schwabl Philipp , Popow-Kraupp Theresia , Reiberger Thomas , Mayer Florian
Published: September 2019

Background

Increasing numbers of hepatitis C virus (HCV) infections among men who have sex with men (MSM) are being observed in the Western world. The actual routes of HCV transmission during high-risk sex practices and associated drug use remain poorly understood.

Methods

Forty-seven patients with HCV were prospectively enrolled. Rectal and nasal swabs were collected to quantify HCV-RNA levels within rectal and nasal fluids. Contamination by occult rectal bleeding was excluded by guaiac paper test. Risk behavior was assessed by standardized questionnaires.

Results

Median age was 41.9 years, 89% were HIV positive (+) (42/47) and 85% (40/47) were male, 58% (23/40) of whom were MSM. Acute HCV infection was diagnosed in 32% (15/47) ,with all patients being HIV+MSM and 93% (14/15) having a documented history of sexually transmitted disease. Thirty-three (70%) patients had ≥1 HCV+ swab sample (HCV+SS; 48%, 22/46 rectal; 62%, 29/47 nasal), and contamination with blood was excluded in all patients. Individuals with HCV+SS had significantly higher serum HCV-RNA levels than patients with HCV-negative SS (6.28 [IQR, 0.85] log IU/mL vs 4.08 [2.45] log IU/mL; P < .001). Using ROC-curve analysis, serum HCV-RNA cutoffs for ruling in/out any HCV+SS were established at 6.02 log IU/mL and 4.02 log IU/mL, respectively.

Conclusions

HCV-RNA is commonly detectable in rectal and nasal fluids of both HIV+ and HIV-negative HCV patients with high serum HCV-RNA, independently of the suspected route of HCV transmission. Accordingly, high-risk sex practices and sharing of nasal drug-sniffing “tools” might be important HCV transmission routes, especially in patients with high serum HCV-RNA.
A concise python implementation of the lattice Boltzmann method on HPC for geo-fluid flow
Authors: Mora Peter , Morra Gabriele , Yuen David A
Published: September 2019

The lattice Boltzmann method (LBM) is a method to simulate fluid dynamics based on modelling distributions of particles moving and colliding on a lattice. The Python scripting language provides a clean programming paradigm to develop codes based on the LBM, however in order to reach performance comparable to compiled languages, it needs to be carefully implemented, maximizing its vectorized tools, mostly integrated in the NumPy module. We present here the details of a Python implementation of a concise LBM code, with the purpose of offering a pedagogical tool for students and professionals in the geosciences who are approaching this technique for the first time. The first half of the paper focuses on how to vectorize a 2-D LBM code and show how if carefully done, this allows performance close to a compiled code. In the second part of the paper, we use the vectorization described earlier to naturally write a parallel implementation using MPI and test both weak and hard scaling up to 1280 cores. One benchmark, Poiseuille flow and two applications, one on sound wave propagation and another on fluid-flow through a simplified model of a rock matrix are finally shown.
Minnowbrook at 50: A Prelude
Authors: Carboni Julia L , Nabatchi Tina
Published: September 2019

This essay introduces the special issue on Minnowbrook at 50, a conference hosted in August 2018 by the Syracuse University Maxwell School of Citizenship and Public Affairs to celebrate the 50th anniversary of Minnowbrook I and honor the legacy of all the Minnowbrook conferences. After a brief discussion about the Minnowbrook conferences and the set-up of Minnowbrook 50, the essay offers short synopses of the seven articles included in this issue.
Margin Trading and Comovement During Crises*
Authors: Kahraman Bige , Tookes Heather
Published: September 2019

We exploit threshold rules governing margin trading eligibility in India to identify a causal link between margin trading and increased comovement during crises. Margin trading explains more than one-quarter of the increase return comovement that we observe during crises. To understand the mechanisms driving this result, we evaluate the relative importance of stock connections through common brokers (who provide margin financing) versus common margin traders. We find that common brokers are most important. Margin-eligible stocks that are more connected through common brokers experience larger crisis-period increases in pairwise return comovement, especially when those brokers’ clients have experienced recent portfolio losses, when their clients have outstanding margin loans in more volatile stocks, and when the brokers are large. These findings are consistent with Brunnermeier and Pedersen (2009), in which initial shocks propagate due to the tightening of margin constraints imposed by financial intermediaries.
Validation of Early Warning Scores at Two Long-Term Acute Care Hospitals
Authors: Churpek Matthew M. , Carey Kyle A. , Dela Merced Nino , Prister James , Brofman John , Edelson Dana P.
Published: September 2019

Objectives:

Early warning scores were developed to identify high-risk patients on the hospital wards. Research on early warning scores has focused on patients in short-term acute care hospitals, but there are other settings, such as long-term acute care hospitals, where these tools could be useful. However, the accuracy of early warning scores in long-term acute care hospitals is unknown.

Design:

Observational cohort study.

Setting:

Two long-term acute care hospitals in Illinois from January 2002 to September 2017.

Patients:

Admitted adult long-term acute care hospital patients.

Interventions:

None.

Measurements and Main Results:

Demographic characteristics, vital signs, laboratory values, nursing flowsheet data, and outcomes data were collected from the electronic health record. The accuracy of individual variables, the Modified Early Warning Score, the National Early Warning Score version 2, and our previously developed electronic Cardiac Arrest Risk Triage score were compared for predicting the need for acute hospital transfer or death using the area under the receiver operating characteristic curve. A total of 12,497 patient admissions were included, with 3,550 experiencing the composite outcome. The median age was 65 (interquartile range, 54–74), 46% were female, and the median length of stay in the long-term acute care hospital was 27 days (interquartile range, 17–40 d), with an 8% in-hospital mortality. Laboratory values were the best predictors, with blood urea nitrogen being the most accurate (area under the receiver operating characteristic curve, 0.63) followed by albumin, bilirubin, and WBC count (area under the receiver operating characteristic curve, 0.61). Systolic blood pressure was the most accurate vital sign (area under the receiver operating characteristic curve, 0.60). Electronic Cardiac Arrest Risk Triage (area under the receiver operating characteristic curve, 0.72) was significantly more accurate than National Early Warning Score version 2 (area under the receiver operating characteristic curve, 0.66) and Modified Early Warning Score (area under the receiver operating characteristic curve, 0.65; p < 0.01 for all pairwise comparisons).

Conclusions:

In this retrospective cohort study, we found that the electronic Cardiac Arrest Risk Triage score was significantly more accurate than Modified Early Warning Score and National Early Warning Score version 2 for predicting acute hospital transfer and mortality. Because laboratory values were more predictive than vital signs and the average length of stay in an long-term acute care hospital is much longer than short-term acute hospitals, developing a score specific to the long-term acute care hospital population would likely further improve accuracy, thus allowing earlier identification of high-risk patients for potentially life-saving interventions.
CASE REPORT OF THE ROLE OF OPTICAL COHERENCE TOMOGRAPHY IN RECOMBINANT GROWTH HORMONE THERAPY
Authors: Kohen Maryo C. , Orge Faruk H.
Published: September 2019

Purpose:

To report the correlation between recombinant growth hormone (rhGH) dosage and retinal nerve fiber layer (RNFL) thickness values measured by optical coherence tomography in a case of pseudotumor cerebri syndrome (PTCS) after rhGH.

Methods:

An 11-year-old girl was receiving rhGH for panhypopituitarism. The patient developed PTCS, and her rhGH dose was adjusted using optical coherence tomography RNFL thickness measurements. The linear correlation coefficient (r) and coefficient of determination (r2) were calculated to assess the relationship between RNFL thickness and rhGH dose.

Results:

As the rhGH dosage was increased, the RNFL thickness values also increased, especially when acetazolamide was excluded because of its confounding effect. (r = 0.64) In separate subgroup analysis, a higher acetazolamide dosage strongly correlated with reduced RNFL thickness (r = 0.77).

Conclusion:

Although PTCS is a rare complication after rhGH therapy, its detrimental effects cannot be ignored. In our case report, we used optical coherence tomography RNFL values in addition to clinical findings to carefully titrate the rhGH dosage to prevent a flare-up of PTCS. Despite the obvious need for larger studies, our case report shows the value of RNFL thickness measured by optical coherence tomography and the valuable additional data it provides to refine rhGH therapy as an adjunct noninvasive method in PTCS.
The association of early life stressors with pain sensitivity and pain experience at 22 years
Authors: Waller Robert , Smith Anne J. , O'Sullivan Peter B. , Slater Helen , Sterling Michele , Straker Leon M.
Published: September 2019

Early life stress (ELS) can significantly influence biological pathways associated with nociception, increasing vulnerability to future heightened pain sensitivity and subsequent risk of pain events. However, very little human research has investigated the association of ELS, measured across multiple domains, with future pain sensitivity. Data from Gen1 and Gen2 of the Raine Study were used to assess the association between a wide range of early life stressors, including antenatally, and pressure and cold pain sensitivity at young adulthood. Participants were classified into 2 groups according to their cold pain sensitivity. In addition, the interaction between ELS, pain sensitivity, and pain experience (based on Örebro Musculoskeletal Pain Questionnaire) at age 22 years was examined. Analysis was performed using both a complete case and multiple imputation approach, adjusting for contemporaneous 22-year correlates, with comparable results in each model. More problematic behaviour at age 2 years was associated with less pressure pain sensitivity at 22 years (13.7 kPa, 95% CI: 1.0-27.0, P = 0.037), with no interaction between problematic behaviour and pain experience at 22 years. For those reporting a moderate/high pain experience at 22 years, poor family functioning increased the odds ratio for high cold pain sensitivity (3.0, 95% CI: 1.6-5.6), but for those reporting no/low pain experience, it did not (OR:1.2, 95% CI: 0.8-1.8). This study provides the most comprehensive investigation of the relationship between ELS and pressure and cold pain sensitivity in young adults supporting early life as a critical period of development influencing future nociceptive processing.
Pulmonary Myoepithelial Tumors With Exuberant Reactive Pneumocytes
Authors: Yuan Lisi , Katabi Nora , Antonescu Cristina R. , Golden Andrew , Travis William D. , Rekhtman Natasha
Published: September 2019

Pneumocytic adenomyoepithelioma (PAM) was first described in 2007 and was included in the 2015 World Health Organization Classification of lung tumors as a variant of epithelial-myoepithelial tumor. This rare pulmonary neoplasm was reported to show both myoepithelial and duct-like components, with the latter exhibiting pneumocytic differentiation with TTF-1 expression. We present an index case and 6 additional retrospectively identified cases of pulmonary tumors with prototypical features of PAM. However, with additional clinicoradiologic, histologic, immunohistochemical and cytogenetic data, we were able to reclassify them as myoepithelial neoplasms—both primary and metastatic—with entrapped exuberantly hyperplastic alveolar structures lined by TTF-1+ pneumocytes. We reviewed the available literature related to PAM and myoepithelial tumors. Our cases suggest that the entity referred to as PAM represents interstitial growth of myoepithelial neoplasms enticing marked proliferation of entrapped pneumocytes rather than a distinct biphasic neoplasm with pneumocytic differentiation.
Using a Second Stakeholder-Driven Variance Reporting System Improves Pediatric Perioperative Safety
Authors: Kawaguchi Akemi L. , Jain Ranu , Hebballi Nutan B. , Pham Dean H. , Putnam Luke R. , Kao Lillian S. , Lally Kevin P. , Tsao Kuojen
Published: September 2019

Introduction:

Despite recognizing the occurrence of variances, we noted a low rate of reporting with the established computer variance program. Therefore, we developed and introduced a simple, handwritten variance reporting system. The goal of this study was to compare our pediatric perioperative handwritten variance cards to our established computerized variance reporting system.

Methods:

We developed a handwritten variance card program through a stakeholder-driven quality-improvement initiative. We collected variances from handwritten cards in 4 perioperative locations and also from the established computerized variance system. We analyzed the variances and categorized them into 6 safety domains and 5 variance categories.

Results:

Over 6 consecutive years, 3,434 variances were reported (687 computerized and 2,747 handwritten). For safety domains, the computerized system was more likely to capture adverse events and near-misses (8.7% vs. 1.1%, P < 0.001; 23.5% vs. 8.6%, P < 0.001, respectively) while the handwritten system was more likely to identify the safety process and other non-safety issues (20.1% vs. 38.3%, P < 0.001). Both systems addressed policy/process issues most often, with 37.9% of the handwritten cards and 66.6% of the computerized variance reports. Of the handwritten cards with a patient identifier (n = 1,407), only 5.1% (n = 72) also had a computerized variance filed about the same event. Thus, staff reported >1,300 additional variances that were not identified with the computerized variance system alone.

Conclusion:

The handwritten, stakeholder-driven variance reporting system was essential to identify local and system issues that would not have been identified by the computerized variance reporting system alone.
High-profile sexual misconduct media triggers sex harassment recall and reinterpretation
Authors: Amber Brittney , Dinh Tuyen K. , Lewis Arielle N. , Trujillo Leidy D. , Stockdale Margaret S.
Published: September 2019

Purpose

The purpose of this paper is to explore a possible effect of #MeToo media on individuals’ personal recall and reinterpretation of sex harassment (SH) experiences. The authors experimentally examine how exposure to high-profile stories of sexual misconduct triggers memories and reinterpretation of one’s own past SH experiences.

Design/methodology/approach

Using a sample of 393 US adults, participants were randomly assigned to read one of four media passages, two of which were news stories or transcripts of high-profile cases of sexual harassment or misconduct (e.g., the Trump Access Hollywood transcript), then completed the Sexual Experiences Questionnaire (SEQ) and follow-up questions about how the media impacted their memory of their prior SH experiences.

Findings

Sexual misconduct media stories, compared to control conditions, indirectly predicted self-report of past SH (SEQ) through both remembering and reinterpreting one’s past experiences. Gender and political ideology moderated the indirect effects such that the effects of the media stories were stronger for women and for those higher on progressive political ideology.

Practical implications

This study experimentally demonstrated what has publicly been assumed to be a driving force behind the upswing of SH reports and the seriousness by which they have been regarded during the #MeToo era: publicized stories of high-profile sexual misconduct triggers personal recall of having been sexually harassed in the past and reinterpretation of SH experiences. The #MeToo movement may be acting as a driver of social change, facilitating changes in social norms. As these social norms change, organizations should be prepared to effectively respond to a possible increase in reporting SH experiences due changes in norms around reporting SH.

Originality/value

This study uses an experimental design to investigate the role of high-profile media stories about SH as a driving force behind the #MeToo movement.
Thematic mapping of cloud computing based on a systematic review: a tertiary study
Authors: Delavari Vahid , Shaban Elahi , Janssen Marijn , Hassanzadeh Alireza
Published: September 2019

Purpose

A large number of systematic reviews (SRs) studies have been performed in the cloud computing field, demonstrating miscellaneous outcomes and utilizing different approaches. Accordingly, a meta-review of cloud SRs is needed to appraise the results of such studies and create an integrated understanding. The paper aims to discuss these issues.

Design/methodology/approach

A tertiary study was conducted using a systematic method to analyze SRs including two stages: searching and screening the SRs and thematic synthesis of results. As a qualitative data management tool, Nvivo software was used to support the research process, for data coding and synthesis.

Findings

First, by searching electronic sources between the year of 2011–2016, out of a total of 142 identified articles, 94 articles were included according to pre-determined criteria, of which 76 articles were approved after qualitative evaluation. In the second stage, identifying the research themes, a map of the concepts and issues related to each theme was drawn up. The analysis shows that the quality of articles has improved but can be further enhanced using methodological guidelines as well as supporting tools. The research has focused more on the technical aspect, although there is an equal demand for synthesizing of cloud governance concepts.

Originality/value

This is the first tertiary study which presents the main research themes and concepts of cloud SRs in form of thematic maps by using the thematic synthesis and SR methods. This paper also provides some recommendations to improve reviews after evaluating the quality of papers. This study can support reviewers for future SRs in the field and also helps practitioners and managers to have a better understanding of different aspects of cloud computing.
Including rewiring in the estimation of the robustness of mutualistic networks
Authors: Vizentin‐Bugoni Jeferson , Debastiani Vanderlei J. , Bastazini Vinicius A. G. , Maruyama Pietro K. , Sperry Jinelle H.
Published: September 2019

Species are entangled within communities by their interactions in such a manner that their local extinction may unchain coextinction cascades and impact community dynamics and stability. Despite increasing attention, simulation models to estimate the robustness of interaction networks largely neglect the important role of interaction rewiring, that is, the ability of species to switch partners.

Here we propose a new method to incorporate the potential of species to replace lost partners into a widely used coextinction model to estimate network robustness. In this model, species are allowed to rewire their interactions after initial loss of partners according to probabilities derived from well‐known mechanisms that determine mutualistic interactions, for example, trait matching, phenological overlap and abundances. To illustrate the use of this method, we analyzed a well‐sampled dataset of mutualistic plant–hummingbird interactions.

We found that (a) in general, rewiring increases the estimated robustness, (b) networks are similarly robust to the loss of pollinators or plants, (c) morphological matching and phenological overlap leads to higher robustness, (d) when multiple rewiring mechanisms are combined, however, robustness increases little, and (e) rewiring tends to increase robustness more in scenarios when the loss of generalist species occurs first.

Our results suggest that the same mechanisms known to drive plant–hummingbird network structure are relevant in buffering the effects of species loss via rewiring. The method proposed here can be applied to a wide range of interaction networks and is flexible to the inclusion of other variables important in determining interactions for specific systems. It also allows changes on the assumptions regarding the importance of distinct mechanisms, for instance including a hierarchical relationship, which facilitates insights into the relative importance of multiple variables influencing network disassembling. The analytical framework we offer here represents a step towards a more realistic estimation on how species loss may affect the integrity of interaction networks.
Understanding political−economic development in the American South
Authors: Krause George A. , Zarit Matthew
Published: September 2019

We propose an empirical strategy to adjudicate between competing explanations of political–economic development in the American South. This strategy evaluates the dynamic relationship between partisan control of representative institutions and economic performance, both before and after major partisan realignment forces and economic conditions had structurally transformed the American South. The political–economic development of low‐capacity Southern states since the early 1980s reflects a “virtuous cycle” of rising income growth and partisan balance of state legislatures mutually reinforcing one another. These findings reconcile conflicting claims regarding the catalytic nature of political–economic development coevolution in the American South and have broader implications for the study of comparative political–economic development.
Rationality as the rule of reason
Authors: Kauppinen Antti
Published: September 2019

This paper explores the prospects of a non‐structuralist account of rationality that doesn't postulate primitive structural requirements (whether of wide or narrow scope) for combinations of attitudes. Instead, it takes competent perceptions of reasons for attitudes to be basic. While broadly similar proposals have been offered before by Thomas Scanlon and Niko Kolodny, this paper adds two important elements to the picture. First, it argues that perceptions of reasons are implicit in intentions and at least certain beliefs (Normative Constitutivism). This allows for addressing challenges raised by John Broome, and makes it possible to derive norms for structural rationality in a natural way. Second, to avoid bootstrapping issues and to capture the authority of rationality, the paper argues that only competent perceptions of reasons give rise to rational requirements and permissions. The relevant kind of competence is a fallible sensitivity to at least basic favoring relations, including the weights of reasons and patterns among them. If we use Reason as the label for such competence, to be rational is to be ruled by one's Reason. If this proposal is successful, there is a common source for the diverse manifestations of rationality and irrationality.