bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic phase diagram of sigma-phase Fe55Re45 compound in the H-T coordinates
Authors: Dubiel Stanisław M. , Felner Israel , Tsindlekht Menahem I.
Published: October 2019

In-field DC and AC magnetization measurements were carried out on a sigma-phase Fe55Re45 intermetallic compound aimed at the determination of the magnetic phase diagram in the H-T plane. Field-cooled, MFC, and zero-field-cooled, MZFC, DC magnetization curves were measured in the magnetic field, H, of up to 1200 Oe. AC magnetic susceptibility measurements were carried out at a constant frequency of 1465 Hz under DC fields of up to H = 500 Oe. The obtained results provide evidence for re-entrant magnetism in the investigated sample. The magnetic phase diagrams in the H-T plane have been outlined based on characteristic temperatures determined from the DC and AC measurements. The phase diagrams are similar, yet not identical. The main difference is that, in the DC diagram constructed, there are two crossover transitions within the strong-irreversibility spin-glass state, whereas, in the AC susceptibility based diagram, only one transition is observed. The border lines (irreversibility, crossover) can be described in terms of the power laws.
Lamellae and parking garage structures in amphiphilic homopolymer brushes with different grafting densities
Authors: Lazutin Alexei A. , Kosmachev Alexei N. , Vasilevskaya Valentina V.
Published: October 2019

This article is devoted to the study of polymer layers of amphiphilic homopolymers tightly grafted to a flat surface at the nodes of a square lattice. It was shown that, due to the amphiphilicity of monomer units containing groups with different affinities, in a selective solvent, such layers form lamellae perpendicular to the grafting surface. The period of the lamellae depends on the grafting density and the quality of the solvent. The results are presented in the form of a state diagram in variables “the energy of attraction of the side groups” (effective solvent quality) and “the distance between the grafting points” (inversely proportional to the square root of the grafting density). The diagram contains the regions of stability of lamellae with significantly different periods, and a transitional area with a parking garage structure. The diagram is constructed by calculating the layer-by-layer structure factor and the angle of inclination of the lamellae in the slice. The calculations were performed for different sizes of the simulation box, and the most commensurate size was determined by a special procedure for each grafting density. The results may be interesting not only to specialists in polymer science but also to all those who investigate the processes of self-organization and rearrangement in dense systems.
The interplay of an external torque and E×B structure formation in tokamak plasmas
Authors: Seiferling F. , Peeters A. G. , Grosshauser S. R. , Rath F. , Weikl A.
Published: October 2019

The interplay between an external torque and spontaneously occurring mesoscale structures, known as staircases, is investigated. Gyrokinetic simulations show that the E × B shear connected with the external torque does not simply add to the shear of the mesoscale structures. A positive (negative) externally forced E × B shear leads to a broadening of the positive (negative) region of the staircase but does not significantly change the plateau value or the narrow zero shear layer. In consequence, while the space and time averaged shearing rate is enhanced by the external torque, there is little or no effect on the turbulent transport. This raises doubts about the importance of driven or intrinsic rotation as a means to improve plasma confinement close to the stability threshold.
Exploring local range separation: The role of spin scaling and one-electron self-interaction
Authors: Aschebrock Thilo , Kümmel Stephan
Published: October 2019

Range-separated hybrid functionals with a fitted or tuned global range-separation parameter are frequently used in density functional theory. We here explore the concept of local range separation, i.e., of turning the range-separation parameter into an explicit semilocal density functional. We impose three simple constraints on the local range-separation parameter that are frequently used in density functional construction: uniform density scaling, the homogeneous electron gas limit, and freedom from one-electron self-interaction. We further discuss different ways of how to model the spin dependence in combination with local range separation. We evaluate our local range-separation energy functionals exactly for closed-shell atoms using the previously suggested hypergeneralized gradient approximation for molecules and assess the quality of this approximation. We find a local range-separated hybrid functional that yields accurate binding energies for a set of small molecules.
Ion-induced n-p inversion of conductivity in TiNiSn compound for thermoelectric applications
Authors: Kirievsky K. , Donchev I. , Kiv A. , Fuks D. , Gelbstein Y.
Published: October 2019

Density functional theory calculations of the electronic properties of TiNiSn compound with point defects in the form of vacancies have shown that the formation of titanium vacancies may lead to n-p inversion of the type of conductivity in these materials. In this paper, the possibility of ion-induced formation of Sn clusters in TiNiSn is demonstrated. Furthermore, conditions of ionic irradiation of this compound that can lead to improvement in the thermoelectric parameters of this material are proposed.
Dipole-relaxation dynamics in a modified polythiourea with high dielectric constant for energy storage applications
Authors: Wu Chao , Li Zongze , Treich Gregory M. , Tefferi Mattewos , Casalini Riccardo , Ramprasad Rampi , Sotzing Gregory A. , Cao Yang
Published: October 2019

Enhancing dipole polarization has been demonstrated as an effective approach to increase the dielectric constant of polymer dielectrics and thus to improve their discharged energy density for energy storage applications in electrical power and electronic systems. However, further optimization to get a higher dielectric constant and lower polarization loss hinges upon a more insightful understanding of the dynamics of dipole relaxation. Here, we demonstrate an approach, based on the Dissado-Hill dielectric response model, to probe the dynamics of dipole polarization in an all organic polythiourea (PDTC-HK511) composed of p-phenylene diisothiocyanate (PDTC) as rigid segments and Jeffamine® HK511 as flexible segments. Our results reveal that PDTC-HK511 possesses strong subglass transition β and γ relaxation processes in conjunction with the quasi-DC diffusion process at relatively high temperature and a low frequency range. The γ relaxation enhances the dielectric constant by 20%–25% but causes no apparent loss at the operating temperature and frequency conditions due to the high flexibility and short relaxation time of the dipole orientation. In comparison to β relaxation, the weak interactions and much shorter relaxation time of dipoles in γ relaxation evidenced the large flexibility of dipole movement. This work provides deeper insight into the dipole movement and aids future rational designs of polymers for dielectric energy storage.
Coupling ferromagnets to materials with phase transitions allows thermal tuning of magnetism
Authors: Jaycen Amelia
Published: October 2019

Thin films of nickel are grown on top of alloys of iron rhodium at suitable temperatures, locking in different crystallographic textures that increase the coercivity of nickel by 500% at room temperature.
Universal behavior of cascading failures in interdependent networks
Authors: Duan Dongli , Lv Changchun , Si Shubin , Wang Zhen , Li Daqing , Gao Jianxi , Havlin Shlomo , Stanley H. Eugene , Boccaletti Stefano
Published: October 2019

Significance

Catastrophic events affecting technological or critical infrastructures are often originated by a cascading failure triggered by marginal perturbations, which are on their turn localized in one of the many interdependent graphs describing the systems. Understanding the robustness of these graphs is therefore of utmost importance for preventing crashes and/or for engineering more efficient and stalwart networked systems. Here we give a fresh framework by means of which cascading failures can be described in a very rich variety of dynamical models and/or topological network structures and which provides a series of quantitative answers able to predict the extent of the system’s failure.
Proteostasis collapse is a driver of cell aging and death
Authors: Santra Mantu , Dill Ken A. , de Graff Adam M. R.
Published: October 2019

Significance

Cells and organisms grow old and die. We develop a biophysical model of the mechanism. Young cells are kept healthy by the positive processes of protein synthesis, degradation, and chaperoning (the activity of keeping proteins properly folded). But, with age, negative processes increase: Oxidative damage accumulates randomly in the cell’s proteins, healthy synthesis and degradation slow down, and—like overfilled garbage cans—chaperone capacity is exceeded. The chaperones are distracted trying to fold irreversibly damaged proteins, leading to accumulating misfolded and aggregated proteins in the cell. The tipping point to death happens when the negative overwhelms the positive. The model makes several quantitative predictions of the life span of the worm
Caenorhabditis elegans
.
Uniformly accurate machine learning-based hydrodynamic models for kinetic equations
Authors: Han Jiequn , Ma Chao , Ma Zheng , E Weinan
Published: October 2019

Significance

This paper addresses 2 very important issues of current interest: multiscale modeling in the absence of scale separation and building interpretable and truly reliable physical models using machine learning. We demonstrate that machine learning can indeed help us to build reliable multiscale models for problems with which classical multiscale methods have had trouble. To this end, one has to develop the appropriate models or algorithms for each of the 3 major components in the machine-learning procedure: labeling the data, learning from the data, and exploring the state space. We use the kinetic equation as an example and demonstrate that uniformly accurate moment systems can be constructed this way.
Topological analysis of the gp41 MPER on lipid bilayers relevant to the metastable HIV-1 envelope prefusion state
Authors: Wang Yi , Kaur Pavanjeet , Sun Zhen-Yu J. , Elbahnasawy Mostafa A. , Hayati Zahra , Qiao Zhi-Song , Bui Nhat N. , Chile Camila , Nasr Mahmoud L. , Wagner Gerhard , Wang Jia-Huai , Song Likai , Reinherz Ellis L. , Kim Mikyung
Published: October 2019

The membrane proximal external region (MPER) of HIV-1 envelope glycoprotein (gp) 41 is an attractive vaccine target for elicitation of broadly neutralizing antibodies (bNAbs) by vaccination. However, current details regarding the quaternary structural organization of the MPER within the native prefusion trimer [(gp120/41)
3
] are elusive and even contradictory, hindering rational MPER immunogen design. To better understand the structural topology of the MPER on the lipid bilayer, the adjacent transmembrane domain (TMD) was appended (MPER-TMD) and studied. Membrane insertion of the MPER-TMD was sensitive both to the TMD sequence and cytoplasmic residues. Antigen binding of MPER-specific bNAbs, in particular 10E8 and DH511.2_K3, was significantly impacted by the presence of the TMD. Furthermore, MPER-TMD assembly into 10-nm diameter nanodiscs revealed a heterogeneous membrane array comprised largely of monomers and dimers, as enumerated by bNAb Fab binding using single-particle electron microscopy analysis, arguing against preferential trimeric association of native MPER and TMD protein segments. Moreover, introduction of isoleucine mutations in the C-terminal heptad repeat to induce an extended MPER α-helical bundle structure yielded an antigenicity profile of cell surface-arrayed Env variants inconsistent with that found in the native prefusion state. In line with these observations, electron paramagnetic resonance analysis suggested that 10E8 inhibits viral membrane fusion by lifting the MPER N-terminal region out of the viral membrane, mandating the exposure of residues that would be occluded by MPER trimerization. Collectively, our data suggest that the MPER is not a stable trimer, but rather a dynamic segment adapted for structural changes accompanying fusion.
Membrane association but not identity is required for LRRK2 activation and phosphorylation of Rab GTPases
Authors: Gomez Rachel C. , Wawro Paulina , Lis Pawel , Alessi Dario R. , Pfeffer Suzanne R.
Published: October 2019

LRRK2 kinase mutations cause familial Parkinson’s disease and increased phosphorylation of a subset of Rab GTPases. Rab29 recruits LRRK2 to the trans-Golgi and activates it there, yet some of LRRK2’s major Rab substrates are not on the Golgi. We sought to characterize the cell biology of LRRK2 activation. Unlike other Rab family members, we show that Rab29 binds nucleotide weakly, is poorly prenylated, and is not bound to GDI in the cytosol; nevertheless, Rab29 only activates LRRK2 when it is membrane bound and GTP bound. Mitochondrially anchored, GTP-bound Rab29 is both a LRRK2 substrate and activator, and it drives accumulation of active LRRK2 and phosphorylated Rab10 on mitochondria. Importantly, mitochondrially anchored LRRK2 is much less capable of phosphorylating plasma membrane–anchored Rab10 than soluble LRRK2. These data support a model in which LRRK2 associates with and dissociates from distinct membrane compartments to phosphorylate Rab substrates; if anchored, LRRK2 can modify misdelivered Rab substrates that then become trapped there because GDI cannot retrieve them.
Diamond power devices: state of the art, modelling, figures of merit and future perspective
Authors: Donato N , Rouger N , Pernot J , Longobardi G , Udrea F
Published: October 2019

With its remarkable electro-thermal properties such as the highest known thermal conductivity (~22 W cm−1∙K−1 at RT of any material, high hole mobility (>2000 cm2 V−1 s−1), high critical electric field (>10 MV cm−1), and large band gap (5.47 eV), diamond has overwhelming advantages over silicon and other wide bandgap semiconductors (WBGs) for ultra-high-voltage and high-temperature (HT) applications (>3 kV and  >450 K, respectively). However, despite their tremendous potential, fabricated devices based on this material have not yet delivered the expected high performance. The main reason behind this is the absence of shallow donor and acceptor species. The second reason is the lack of consistent physical models and design approaches specific to diamond-based devices that could significantly accelerate their development. The third reason is that the best performances of diamond devices are expected only when the highest electric field in reverse bias can be achieved, something that has not been widely obtained yet. In this context, HT operation and unique device structures based on the two-dimensional hole gas (2DHG) formation represent two alternatives that could alleviate the issue of the incomplete ionization of dopant species. Nevertheless, ultra-HT operations and device parallelization could result in severe thermal management issues and affect the overall stability and long-term reliability. In addition, problems connected to the reproducibility and long-term stability of 2DHG-based devices still need to be resolved.

This review paper aims at addressing these issues by providing the power device research community with a detailed set of physical models, device designs and challenges associated with all the aspects of the diamond power device value chain, from the definition of figures of merit, the material growth and processing conditions, to packaging solutions and targeted applications. Finally, the paper will conclude with suggestions on how to design power converters with diamond devices and will provide the roadmap of diamond device development for power electronics.
Anomalous Nernst effect in Co2MnSi thin films
Authors: Cox C D W , Caruana A J , Cropper M D , Morrison K
Published: October 2019

Separation of the anomalous Nernst and spin Seebeck voltages in bilayer devices is often problematic when both layers are metallic, and the anomalous Nernst effect (ANE) becomes non-negligible. Co2MnSi, a strong candidate for the spin generator in spin Seebeck devices, is a predicted half-metal with 100% spin polarisation at the Fermi energy, however, typically B2 or L21 order is needed to achieve this. We demonstrate the optimisation of thin film growth of Co2MnSi on glass, where choice of deposition and annealing temperature can promote various ordered states. The contribution from the ANE is then investigated to inform future measurements of the spin Seebeck. A maximum ANE coefficient of 0.662 µV K−1 is found for an A2 disordered polycrystalline Co2MnSi film. This value is comparable to ordered Heusler thin films deposited onto single crystal substrates but obtained at a far lower fabrication temperature and material cost.
The British Cameroons Mandate Regime: The Roots of the Twenty-First-Century Political Crisis in Cameroon
Authors: Njung George N.
Published: October 2019

A century after the victorious Allied powers distributed their spoils of victory in 1919, the world still lives with the geopolitical consequences of the mandates system established by the League of Nations. The Covenant article authorizing the new imperial dispensation came cloaked in the old civilizationist discourse, entrusting sovereignty over “peoples not yet able to stand by themselves under the strenuous conditions of the modern world” to the “advanced nations” of Belgium, England, France, Japan, and South Africa. In this series of “reflections” on the mandates, ten scholars of Europe, Africa, the Middle East, Asia, and the international order consider the consequences of the new geopolitical order birthed by World War I. How did the reshuffling of imperial power in the immediate postwar period configure long-term struggles over minority rights, decolonization, and the shape of nation-states when the colonial era finally came to a close? How did the alleged beneficiaries—more often the victims—of this “sacred trust” grasp their own fates in a world that simultaneously promised and denied them the possibility of self-determination? From Palestine, to Namibia, to Kurdistan, and beyond, the legacies of the mandatory moment remain pressing questions today.
Failure mode and effects analysis to reduce risk of heparin use
Authors: Pino Felicity A , Weidemann Darcy K , Schroeder Lisa L , Pabst Damon B , Kennedy Audrey R
Published: October 2019

Purpose

Failure mode and effects analysis (FMEA) was used to identify safety risks of unfractionated heparin (UFH) use and to develop and implement countermeasures to improve safety.

Methods

FMEA was used to analyze the transportation, preparation, dispensation, administration, therapeutic monitoring, and disposal of UFH in a tertiary care, freestanding pediatric hospital. The FMEA was conducted in a stepwise fashion. First, frontline staff mapped the different steps within the UFH use process. Next, key stakeholders identified potential failures of each process step. Finally, using calibrated scales, the stakeholders ranked the likelihood of occurrence, severity, and detectability for each potential failure’s cause. The rankings were used to prioritize high-risk areas on which to focus efforts for improvement countermeasures.

Results

The analysis revealed 233 potential failures and 737 unique potential causes. After ranking of all identified potential causes, 45 were deemed high scoring. Those 45 causes were further refined into 13 underlying contributing causes. To address the contributing causes, selected team members developed 22 countermeasures. The FMEA showed that implementation of the countermeasures reduced the level of mathematical risk.

Conclusion

FMEA was helpful in identifying, ranking, and prioritizing medication risks in the UFH use process. Twenty-two countermeasures were developed to reduce potential for error in the riskiest steps of the process.
Tracing the origin of the placental trophoblast cells in mouse embryo development†
Authors: Guo Shanshan , Cui Xiuhong , Jiang Xiangxiang , Duo Shuguang , Li Shiwen , Gao Fei , Wang Hongmei
Published: October 2019

The placenta, which originates from the trophectoderm (TE), is the first organ to form during mammalian embryogenesis. Recent studies based on bioinformatics analysis have revealed that heterogeneous gene expression initiates cell-fate decisions and directs two distinct cell fates by modulating the balance of pluripotency and differentiation as early as the four-cell stage. However, direct developmental evidence to support this is still lacking. To address at which stage the cell fate of the TE and inner cell mass (ICM) is determined, in this study, we administered a microinjection of Cre mRNA into a single blastomere of the mTmG mouse at different cleavage stages before implantation to examine the distributions of the descendants of the single-labeled cell in the mouse fetus and the placenta at E12.5. We found that the descendants of the labeled cells at the two-cell stage contributed to both the placenta and the fetus. Notably, the derivatives of the labeled cells at the four-cell stage fell into three categories: (1) distributed in both embryonic and extraembryonic lineages, (2) distributed only in mouse placental trophoblast layers, or (3) distributed only in the lineage derived from the ICM. In addition, these results fell in line with single-cell studies focusing on gene expression patterns that characterize particular lineages within the blastocyst. In conclusion, this study shows that the four-cell blastomeres differ in their individual developmental properties insofar as they contribute to either or both the ICM and trophoblast fate.
In Their Own Words: Kent Holsinger
Authors: Verdier James M
Published: October 2019

In Their Own Words chronicles the stories of scientists who have made great contributions to their fields, particularly within the biological sciences. These short oral histories provide our readers a way to learn from and share their experiences. Each month, we will publish in the pages of BioScience and in our podcast, BioScience Talks (http://bioscienceaibs.libsyn.com), the results of these conversations. This second oral history is with Dr. Kent Holsinger, board of trustees distinguished professor of biology in the Department of Ecology and Evolutionary Biology at the University of Connecticut. He previously served as president of the American Institute of Biological Sciences.
Adolescent Decision-Making Under Risk: Neural Correlates and Sex Differences
Authors: Korucuoglu Ozlem , Harms Michael P , Kennedy James T , Golosheykin Semyon , Astafiev Serguei V , Barch Deanna M , Anokhin Andrey P
Published: October 2019

An increased propensity for risk taking is a hallmark of adolescent behavior with significant health and social consequences. Here, we elucidated cortical and subcortical regions associated with risky and risk-averse decisions and outcome evaluation using the Balloon Analog Risk Task in a large sample of adolescents (n = 256, 56% female, age 14 ± 0.6), including the level of risk as a parametric modulator. We also identified sex differences in neural activity. Risky decisions engaged regions that are parts of the salience, dorsal attention, and frontoparietal networks, but only the insula was sensitive to increasing risks in parametric analyses. During risk-averse decisions, the same networks covaried with parametric levels of risk. The dorsal striatum was engaged by both risky and risk-averse decisions, but was not sensitive to escalating risk. Negative-outcome processing showed greater activations than positive-outcome processing. Insula, lateral orbitofrontal cortex, middle, rostral, and superior frontal areas, rostral and caudal anterior cingulate cortex were activated only by negative outcomes, with a subset of regions associated with negative outcomes showing greater activation in females. Taken together, these results suggest that safe decisions are predicted by more accurate neural representation of increasing risk levels, whereas reward-related processes play a relatively minor role.
Hospitalization Rates and Outcomes Among Persons Living With Human Immunodeficiency Virus in the Southeastern United States, 1996–2016
Authors: Davy-Mendez Thibaut , Napravnik Sonia , Wohl David A , Durr Amy L , Zakharova Oksana , Farel Claire E , Eron Joseph J
Published: October 2019

Background

Antiretroviral therapy (ART) advances, aging, and comorbidities impact hospitalizations in human immunodeficiency virus (HIV)–positive populations. We examined temporal trends and patient characteristics associated with hospitalization rates and outcomes.

Methods

Among patients in the University of North Carolina Center for AIDS Research HIV Clinical Cohort receiving care during 1996–2016, we estimated annual hospitalization rates, time to inpatient mortality or live discharge, and 30-day readmission risk using bivariable Poisson, Fine-Gray, and log-binomial regression models.

Results

The 4323 included patients (29% women, 60% African American) contributed 30 007 person-years. Overall, the hospitalization rate per 100 person-years was 34.3 (95% confidence interval [CI], 32.4–36.4) with a mean annual change of −3% (95% CI, −4% to −2%). Patients who were black (vs white), older, had HIV RNA >400 copies/mL, or had CD4 count <200 cells/μL had higher hospitalization rates (all P < .05). Thirty-day readmission risk was 18.9% (95% CI, 17.7%–20.2%), stable over time (P > .05 for both 2010–2016 and 2003–2009 vs 1996–2002), and higher among black patients, those with detectable HIV RNA, and those with lower CD4 cell counts (all P < .05). Higher inpatient mortality was associated with older age and lower CD4 cell count (both P < .05).

Conclusions

Hospitalization rates decreased from 1996 to 2016, but high readmissions persisted. Older patients, those of minority race/ethnicity, and those with uncontrolled HIV experienced higher rates and worse hospitalization outcomes. These findings underscore the importance of early ART and care engagement, particularly at hospital discharge.
Non-intubated spontaneous ventilation in video-assisted thoracoscopic surgery: a meta-analysis
Authors: Wen Yaokai , Liang Hengrui , Qiu Guanping , Liu Zhichao , Liu Jun , Ying Weiqiang , Liang Wenhua , He Jianxing
Published: October 2019

It remains unclear whether non-intubated video-assisted thoracoscopic surgery (VATS) is comparable or advantageous compared with conventional intubated VATS. Thus, we systematically assessed the feasibility and safety of non-intubated VATS compared with intubated VATS perioperatively for the treatment of different thoracic diseases. An extensive search of literature databases was conducted. Perioperative outcomes were compared between 2 types of operations. The time trend of the overall results was evaluated through a cumulative meta-analysis. Subgroup analyses of different thoracic diseases and study types were examined. Twenty-seven studies including 2537 patients were included in the analysis. A total of 1283 patients underwent non-intubated VATS; intubated VATS was performed on the other 1254 patients. Overall, the non-intubated VATS group had fewer postoperative overall complications [odds ratios (OR) 0.505; P < 0.001]; shorter postoperative fasting times [standardized mean difference (SMD) −2.653; P < 0.001]; shorter hospital stays (SMD −0.581; P < 0.001); shorter operative times (SMD −0.174; P = 0.041); shorter anaesthesia times (SMD −0.710; P < 0.001) and a lower mortality rate (OR 0.123; P = 0.020). Non-intubated VATS may be a safe and feasible alternative to intubated VATS and provide a more rapid postoperative rehabilitation time than conventional intubated VATS.
Cryoballoon vs. radiofrequency lesions as detected by late-enhancement cardiac magnetic resonance after ablation of paroxysmal atrial fibrillation: a case–control study
Authors: Alarcón Francisco , Cabanelas Nuno , Izquierdo Marc , Benito Eva , Figueras i Ventura Rosa , Guasch Eduard , Prat-Gonzalez Susana , Perea Rosario Jesus , Borràs Roger , Trotta Omar , Arbelo Elena , Tolosana José Maria , Sitges Marta , Berruezo Antonio , Brugada Josep , Mont Lluís
Published: October 2019

Aims

Cryoballoon (CB) ablation has emerged as a reliable modality to isolate pulmonary veins (PVs) in atrial fibrillation. Ablation lesions and the long-term effects of energy delivery can be assessed by delayed-enhancement cardiac magnetic resonance (DE-CMR). The aim of the study was to compare the number, extension, and localization of gaps in CB and radiofrequency (RF) techniques in pulmonary vein isolation (PVI).

Methods and results

Consecutive patients submitted to PVI with CB in whom DE-CMR images were available (n = 30) were matched (1:1) to patients who underwent PVI with RF (n = 30), considering age, sex, hypertension, and diabetes. Delayed-enhancement cardiac magnetic resonance was obtained at 3 months post-procedure, and images were processed to assess the mean number of gaps around PV ostia, their localization, and the normalized gap length (NGL), calculated as the difference between total gap length and total PV perimeter. Patients were followed up for 12 months. The CB and RF procedures did not differ in the mean number of gaps per patient (4.40 vs. 5.13 gaps, respectively; P = 0.21) nor NGL (0.35 vs. 0.32, P = 0.59). For both techniques, a higher mean number of gaps were detected in right vs. left PVs (3.18 vs. 1.58, respectively; P = 0.01). The incidence of recurrences did not differ between techniques (odds ratio 1.87, 95% confidence interval 0.66–4.97; P = 0.29).

Conclusion

Location and extension of ablation gaps in PVI did not differ between CB and RF groups in DE-CMR image analysis.
Geometric and level set tomography using ensemble Kalman inversion
Authors: Muir Jack B , Tsai Victor C
Published: October 2019

Tomography is one of the cornerstones of geophysics, enabling detailed spatial descriptions of otherwise invisible processes. However, due to the fundamental ill-posedness of tomography problems, the choice of parametrizations and regularizations for inversion significantly affect the result. Parametrizations for geophysical tomography typically reflect the mathematical structure of the inverse problem. We propose, instead, to parametrize the tomographic inverse problem using a geologically motivated approach. We build a model from explicit geological units that reflect the a priori knowledge of the problem. To solve the resulting large-scale nonlinear inverse problem, we employ the efficient Ensemble Kalman Inversion scheme, a highly parallelizable, iteratively regularizing optimizer that uses the ensemble Kalman filter to perform a derivative-free approximation of the general iteratively regularized Levenberg–Marquardt method. The combination of a model specification framework that explicitly encodes geological structure and a robust, derivative-free optimizer enables the solution of complex inverse problems involving non-differentiable forward solvers and significant a priori knowledge. We illustrate the model specification framework using synthetic and real data examples of near-surface seismic tomography using the factored eikonal fast marching method as a forward solver for first arrival traveltimes. The geometrical and level set framework allows us to describe geophysical hypotheses in concrete terms, and then optimize and test these hypotheses, helping us to answer targeted geophysical questions.
Deformation associated with sliver transport in Costa Rica: seismic and geodetic observations of the July 2016 Bijagua earthquake sequence
Authors: Araya Maria C , Biggs Juliet
Published: October 2019

Tectonic slivers form in the overriding plate in regions of oblique subduction. The inner boundaries of the sliver are often poorly defined and can consist of well-defined faults, rotating blocks or diffuse fault systems, which pass through or near the volcanic arc. The Guanacaste Volcanic Arc Sliver (GVAS) as defined by Montero et al., is a segment of the Central American Forearc Sliver, whose inner boundary is the ∼87-km-long Haciendas-Chiripa fault system (HCFS), which is located ∼10 km behind the volcanic arc and consists of strike slip faults and pull apart steps. We characterize the current ground motion on this boundary by combining earthquake locations and focal mechanisms of the 2016 Bijagua earthquake sequence, with the surface ground deformation obtained from Interferometric Synthetic Aperture Radar (InSAR) images from the ALOS-2 satellite. The coseismic stack of interferograms show ∼6 cm of displacement towards the line of sight of the satellite between the Caño Negro fault and the Upala fault, indicating uplift or SE horizontal surface displacement. The largest recorded earthquake of the sequence was Mw 5.4, and the observed deformation is one of the smallest earthquakes yet detected by InSAR in the Central American region. Forward and inverse models show the surface deformation can be partially explained by slip on a single fault, but it can be better explained by slip along two faults linked at depth. The best-fitting model consists of 0.33 m of right lateral slip on the Caño Negro fault and 0.35 m of reverse slip on the Upala fault, forming a positive flower structure. As no reverse seismicity was recorded, we infer the slip on the Upala fault occurred aseismically. Observations of the Bijagua earthquake sequence suggests the forearc sliver boundary is a complex and diffuse fault system. There are localized zones of transpression and transtension and areas where there is no surface expression suggesting the fault system is not yet mature. Although aseismic slip is common on subduction interfaces and mature strike-slip faults, this is the first study to document aseismic slip on a continental tectonic sliver boundary fault.
Interpersonal Gun Violence Research in the Social Work Literature
Authors: Aspholm Roberto R , St Vil Christopher , Carter Kimberly A E
Published: October 2019

Interpersonal gun violence remains a major public health issue in the United States and beyond. This article explores the research on interpersonal gun violence published in peer-reviewed social work journals since the mid-1990s. Findings from this review indicate that the existing scholarship offers some important insights into this topic, particularly related to risk factors for and the effects of exposure to gun violence. These findings, however, also point to some shortcomings in the literature, including problems with the measurement and analytic treatment of exposure to gun violence and a lack of research with direct victims and perpetrators of gun violence. Implications for future research are discussed.
The Wittenoom legacy
Authors: Musk Arthur W (Bill) , Reid Alison , Olsen Nola , Hobbs Michael , Armstrong Bruce , Franklin Peter , Hui Jennie , Layman Lenore , Merler Enzo , Brims Fraser , Alfonso Helman , Shilkin Keith , Sodhi-Berry Nita , de Klerk Nicholas
Published: October 2019

The Wittenoom crocidolite (blue asbestos) mine and mill ceased operating in 1966. The impact of this industry on asbestos-related disease in Western Australia has been immense. Use of the employment records of the Australian Blue Asbestos Company and records of the Wittenoom township residents has permitted two cohorts of people with virtually exclusive exposure to crocidolite to be assembled and studied. Follow-up of these two cohorts has been conducted through data linkage with available hospital, mortality and cancer records. The evolution of asbestos-related disease has been recorded and, with the establishment of exposure measurements, quantitative exposure–response relationships have been estimated. There has been an ongoing epidemic of mortality from lung cancer and malignant mesothelioma and, less so, from asbestosis. Wittenoom crocidolite was used extensively in asbestos-cement products in Western Australia. As a result, the state has recorded a higher malignant-mesothelioma mortality rate than in any other Australian state and in any defined general population in the world. Thus, the legacy of Wittenoom has extended beyond the mine and the town, and is still evident more than 50 years after the closure of the mine.
Occupational exposure to chronic ionizing radiation increases risk of Parkinson's disease incidence in Russian Mayak workers
Authors: Azizova Tamara V , Bannikova Maria V , Grigoryeva Evgeniya S , Rybkina Valentina L , Hamada Nobuyuki
Published: October 2019

Background

Patients receiving radiotherapy demonstrate cognitive deficits, impairment of neurogenesis and neurovascular damage developing as late side effects of radiation exposure to the head. In light of the increasing use of diagnostic radiological procedures, epidemiological data raise concerns about possible harmful effects of low-level radiation on the human brain. A series of studies of chronically exposed Russian nuclear workers have provided information on risks of cancer and non-cancer diseases.

Methods

This study aimed to assess the risk of Parkinson’s-disease (PD) incidence in a cohort of workers occupationally exposed to chronic radiation. The cohort comprised workers of a Russian nuclear production facility who were first employed in 1948–1982 and followed up until the end of 2013 (22 377 individuals; 25% female). Using the AMFIT module of EPICURE software, relative risk and excess relative risk per unit dose (ERR/Gy) were calculated based on maximum likelihood.

Results

A linear association was found between PD incidence and cumulative γ-dose after adjusting for sex and attained age [ERR/Gy = 1.02 (95% confidence interval, 0.59 to 1.63, p = 5.44 × 10–5)]. The ERR/Gy of external radiation for PD incidence was stable after adjusting for neutron dose (ERR/Gy = 1.03; 95% confidence interval: 0.59 to 1.67, p = 6.86 × 10–5). The risk increased with increasing lag period and decreased notably after adjusting for body mass index, smoking and alcohol consumption. Additional adjustments for hypertension, gout, gastric ulcer, head injuries with loss of awareness and diabetes mellitus did not affect the risk estimate.

Conclusions

This study is the first to suggest that PD is associated with prolonged occupational external γ-ray exposure.
Explaining Citizen Attitudes to Strategies of Democratic Defense in Europe: A Resource in Responses to Contemporary Challenges to Liberal Democracy?
Authors: de Leeuw Sjifra E , Bourne Angela K
Published: October 2019

It has long been speculated that banning parties from participation in elections may be counterproductive because it might provoke societal resistance. Using the European Social Survey (2002–2010; N = 195,405), our study suggests otherwise. We demonstrate that party bans enjoy the legitimacy of majority support. This holds true irrespective of countries’ resilience to extremist influences (or lack thereof) resulting from “institutional intolerance,” electoral entry barriers and authoritarian legacies. Individual orientations toward the democratic establishment do matter to a small extent: citizens with authoritarian tendencies and low system support are less supportive, while this is less so for citizens with extremist ideological orientations. Even though party bans entail significant democratic dilemmas, this study reveals societal resources supportive of repressive responses to extremist parties.
Log Picard Algebroids and Meromorphic Line Bundles
Authors: Gualtieri Marco , Luk Kevin
Published: October 2019

We introduce logarithmic Picard algebroids, a natural class of Lie algebroids adapted to a simple normal crossings divisor on a smooth projective variety. We show that such algebroids are classified by a subspace of the de Rham cohomology of the divisor complement determined by its mixed Hodge structure. We then solve the prequantization problem, showing that under the appropriate integrality condition, a log Picard algebroid is the Lie algebroid of symmetries of what is called a meromorphic line bundle, a generalization of the usual notion of line bundle in which the fibers degenerate along the divisor. We give a geometric description of such bundles and establish a classification theorem for them, showing that they correspond to a subgroup of the holomorphic line bundles on the divisor complement. Importantly, these holomorphic line bundles need not be algebraic. Finally, we provide concrete methods for explicitly constructing examples of meromorphic line bundles, such as for a smooth cubic divisor in the projective plane.
Choice of Study Populations for Vaccines
Authors: Griffiths Paul , Hughes Brenna
Published: October 2019

The natural history of cytomegalovirus (CMV) infection is complex. Individuals may experience primary infection, reactivation of latent infection, or reinfection with a new strain despite natural immunity. The ability of this virus to continue to replicate despite substantial immune responses is attributable to the many immune evasion genes encoded within its genome. Given this complex natural history and immunology, the design of clinical trials of CMV vaccines may require components not usually found in trials of vaccines designed to protect against viruses that cause only acute infections.

In this article, we focus on specific aspects of clinical trial design that could be adopted to address the complexities of CMV infections. We consider women of childbearing age, toddlers, recipients of solid organ transplantation, and stem cell transplant patients, emphasizing the parallels between women and solid organ transplantation that could allow vaccines to be developed in parallel in both these patient groups. We emphasize the potential for studies of passive immunity to inform the selection of immunogens as candidates for active immunization and vice versa. We also illustrate how application of whole-genomic sequencing could document whether vaccines protect against reactivation or reinfection of CMV or both.
Nicotinamide Limits Replication of Mycobacterium tuberculosis and Bacille Calmette-Guérin Within Macrophages
Authors: Simmons Jason D , Peterson Glenna J , Campo Monica , Lohmiller Jenny , Skerrett Shawn J , Tunaru Sorin , Offermanns Stefan , Sherman David R , Hawn Thomas R
Published: October 2019

Novel antimicrobials for treatment of Mycobacterium tuberculosis are needed. We hypothesized that nicotinamide (NAM) and nicotinic acid (NA) modulate macrophage function to restrict M. tuberculosis replication in addition to their direct antimicrobial properties. Both compounds had modest activity in 7H9 broth, but only NAM inhibited replication in macrophages. Surprisingly, in macrophages NAM and the related compound pyrazinamide restricted growth of bacille Calmette-Guérin but not wild-type Mycobacterium bovis, which both lack a functional nicotinamidase/pyrazinamidase (PncA) rendering each strain resistant to these drugs in broth culture. Interestingly, NAM was not active in macrophages infected with a virulent M. tuberculosis mutant encoding a deletion in pncA. We conclude that the differential activity of NAM and nicotinic acid on infected macrophages suggests host-specific NAM targets rather than PncA-dependent direct antimicrobial properties. These activities are sufficient to restrict attenuated BCG, but not virulent wild-type M. bovis or M. tuberculosis.
IMFT of the sigmoid colon: a case report
Authors: Pandit Narendra , Yadav Tek Narayan , Shrestha Deepa , Adhikari Purbesh , Awale Laligen
Published: October 2019

Inflammatory myofibroblastic tumor (IMFT) of the colon is a very rare entity, characterized by proliferation of myofibroblast cells admixed with inflammatory infiltrates. The entity was first described in the late 1990s, and since then less than 30 cases have been described. It frequently mimics other neoplasm of the colon, such as adenocarcinoma, lymphoma and stromal tumor, and is very difficult to clinch the diagnosis preoperatively based on the clinical and radiological findings. Here, we discuss an uncommon case of sigmoid IMFT in a 35-year old male, presenting with bleeding per rectum and managed successfully by colectomy.
The Community Balance and Mobility Scale: Detecting Impairments in Military Service Members With Mild Traumatic Brain Injury
Authors: Pape Marcy M , Kodosky Paula N , Hoover Peter
Published: October 2019

Introduction

The objective of this study was to determine the utility of the Community Balance and Mobility scale (CB&M) among service members presenting with mild traumatic brain injury (mTBI), to compare the results against well-established balance assessments, and to find a new military-specific CB&M cut score to help differentiate those with and without mTBI.

Materials and Methods

The setting was a 4-week, intensive-outpatient, interdisciplinary program for active duty service members with mTBI. This was a nonrandomized, cross-sectional design that compared multiple measures between two groups: active duty service members with (n = 45) and without (n = 45) mTBI. The assessments, including the Activities-Specific Balance Confidence Scale, gait speed (comfortable and fast), the Functional Gait Assessment, and the CB&M, were provided to both sample groups.

Results

The mTBI group performed significantly worse (P ≤ 0.01) across all measures. A higher cut score for the CB&M of 81.5 is suggested. The CB&M demonstrated the best sensitivity (78%) and specificity (91%) ratio, as well as the largest effect size and area under the curve(0.92).

Conclusion

All objective measures distinguish participants with mTBI from controls, ranging from fair to excellent. The recommended CB&M cut score of 81.5 allows for good variance, standard deviation, and reduced risk of ceiling or floor effects. Further examination of the recommended CB&M cut score is warranted for use in the mTBI civilian populations.
Social Identity Theory Guides Junior Leader to Excellence
Authors: Farmer Aaron , Magee Charlie
Published: October 2019

Junior Medical Corps officers are often thrust directly into leadership roles following training. Although their clinical skills may be finely tuned, they often face a steep learning curve related to leadership responsibilities. This scenario highlights a junior officer making a policy change and how Social Identity Theory relates to leadership.
LOFAR early-time search for coherent radio emission from GRB 180706A
Authors: Rowlinson A , Gourdji K , van der Meulen K , Meyers Z S , Shimwell T W , ter Veen S , Wijers R A M J , Kuiack M J , Shulevski A , Broderick J W , van der Horst A J , Tasse C , Hardcastle M J , Mechev A P , Williams W L
Published: October 2019

The nature of the central engines of gamma-ray bursts (GRBs) and the composition of their relativistic jets are still under debate. If the jets are Poynting flux dominated rather than baryon dominated, a coherent radio flare from magnetic reconnection events might be expected with the prompt gamma-ray emission. There are two competing models for the central engines of GRBs; a black hole or a newly formed millisecond magnetar. If the central engine is a magnetar it is predicted to produce coherent radio emission as persistent or flaring activity. In this paper, we present the deepest limits to date for this emission following LOFAR rapid response observations of GRB 180706A. No emission is detected to a 3σ limit of 1.7 mJy beam−1 at 144 MHz in a 2-h LOFAR observation starting 4.5 min after the gamma-ray trigger. A forced source extraction at the position of GRB 180706A provides a marginally positive (1σ) peak flux density of 1.1 ± 0.9 mJy. The data were time sliced into different sets of snapshot durations to search for FRB like emission. No short duration emission was detected at the location of the GRB. We compare these results to theoretical models and discuss the implications of a non-detection.