bluuebunny/crossref_metadata_2025 huggingface dataset:
New robust LMI synthesis conditions for mixed gain‐scheduled reduced‐order DOF control of discrete‐time LPV systems
Authors: Rosa Tábitha E. , Morais Cecília F. , Oliveira Ricardo C.L.F.
Published: October 2018

This paper investigates the problems of stabilization and mixed
 reduced‐order dynamic output‐feedback control of discrete‐time linear systems. The synthesis conditions are formulated in terms of parameterdependent linear matrix inequalities (LMIs) combined with scalar parameters, dealing with state‐space models where the matrices depend polynomially on time‐varying parameters and are affected by norm‐bounded uncertainties. The motivation to handle these models comes from the context of networked control systems, particularly when a continuous‐time plant is controlled by a digitally implemented controller. The main technical contribution is a distinct LMI‐based condition for the dynamic output‐feedback problem, allowing an arbitrary structure (polynomial of arbitrary degree) for the measured output matrix. Additionally, an innovative heuristic is proposed to reduce the conservativeness of the stabilization problem. Numerical examples are provided to illustrate the potentialities of the approach to cope with several classes of discrete‐time linear systems (time‐invariant and time‐varying) and the efficiency of the proposed design conditions when compared with other methods available in the literature.
Site‐sensitive X‐ray photoelectron spectroscopy of Fe3O4 by photoelectron diffraction
Authors: Hashimoto Yusuke , Taguchi Munetaka , Fukami Shun , Momono Hiroki , Matsushita Tomohiro , Matsuda Hiroyuki , Matsui Fumihiko , Daimon Hiroshi
Published: October 2018

Fe 2p core‐level photoelectron spectra of magnetite were measured using soft X‐ray and hard X‐ray, and its emission angle dependence was investigated. The photoelectron diffraction pattern from different atomic sites differs because the atomic arrangement surrounding each site is different. By selecting the forward‐focusing‐peak (FFP) directions characteristic to each atomic site and measuring the kinetic energy dependence of the FFP intensities at the Fe 2p core‐level range, we succeed in detecting the variation of the peak intensity of Fe 2p core‐level spectra at different emission directions. This result, consistent with recent results, suggests that the lower‐binding‐energy peak of the Fe 2p core‐level spectrum may be assigned as the B site component.
Development of sample preparation technique to characterize chemical structure of humin by synchrotron‐radiation–based X‐ray photoelectron spectroscopy
Authors: Pham Duyen Minh , Miyata Yasushi , Awata Takanori , Nakatake Masashi , Zhang Chung Fang , Kanda Keiji , Ogawa Satoshi , Ohta Shozo , Yagi Shinya , Katayama Arata
Published: October 2018

Carbon‐binding state of humin (HM, a non‐conductive insoluble organo‐mineral humic substance) was successfully characterized for the first time by synchrotron‐radiation–based X‐ray photoelectron spectroscopy (XPS). Four sample preparation techniques—HM on double‐sided carbon tape, indium sheet, copper mesh, and in pellet formed from the mixture of HM and copper powder (Cu) at different mixing ratios (1:1, 1:2, and 1:6 v/v)—were compared. The results show that HM samples prepared using the first three methods had significant charge buildup, which made the interpretation of the XPS spectra impossible because of the shifts in the binding energy of C 1s XPS spectra. Pellets of HM:Cu mixture enhanced the electrical conductivity and reduced charge buildup on the sample surface. Pellets prepared with HM:Cu ratio of 1:1 (v/v) provided the minimum charge buildup and high sensitivity with difference in C 1s spectra regardless of the observing position. The C 1s spectra, estimated by the subtraction of the carbon contamination in Cu, showed the resolution of CC (284.0 eV), CC/CH (285.1 eV), CO (286.3 eV), CO (287.3 eV), and OCO (288.3 eV) and three additional peaks of CF (289.3 eV), CF2 (290.2 eV), and CF3 (291.4 eV). Soft X‐ray absorption spectroscopic (XAS) analysis further proved the existence of fluoride (F 1s) in HM structure. The detection of fluorinated carbon in HM showed a great advancement of XPS compared with other conventional analyses. X‐ray with the incident angle of 0° provided the smallest (nearly negligible) energy shift in the C 1s spectra of HM and did not damage the surface of the sample.
Constrained empirical‐likelihood confidence regions in nonignorable covariate‐missing data problems
Authors: Xie Yanmei , Zhang Biao
Published: October 2018

Missing covariates in regression analysis are a pervasive problem in medical, social, and economic researches. We study empirical‐likelihood confidence regions for unconstrained and constrained regression parameters in a nonignorable covariate‐missing data problem. For an assumed conditional mean regression model, we assume that some covariates are fully observed but other covariates are missing for some subjects. By exploitation of a probability model of missingness and a working conditional score model from a semiparametric perspective, we build a system of unbiased estimating equations, where the number of equations exceeds the number of unknown parameters. Based on the proposed estimating equations, we introduce unconstrained and constrained empirical‐likelihood ratio statistics to construct empirical‐likelihood confidence regions for the underlying regression parameters without and with constraints. We establish the asymptotic distributions of the proposed empirical‐likelihood ratio statistics. Simulation results show that the proposed empirical‐likelihood methods have a better finite‐sample performance than other competitors in terms of coverage probability and interval length. Finally, we apply the proposed empirical‐likelihood methods to the analysis of a data set from the US National Health and Nutrition Examination Survey.
The performance of ultrasound in determining the cause of biliary dilation
Authors: Jones Matthew , Necas Martin
Published: October 2018

Introduction

Transabdominal ultrasound (US) is the modality of choice for the initial investigation of patients with suspected biliary disease. There are multiple factors that can affect the quality of an US examination including – operator experience, patient habitus and bowel gas. This study investigated the performance of US in determining the cause of biliary dilation and correlated US findings with definitive diagnoses from other modalities and procedures.

Methods

One hundred patients were retrospectively identified with an US‐reported common bile duct diameter of 8 mm or greater. Patient records were used to correlate US findings with ‘gold standard’ diagnostic tests – other imaging modalities with conclusive findings and/or endoscopic procedures or surgery with histology. The performance of US was calculated for the most common pathologies encountered.

Results

A definitive cause for dilation was identified in 38 patients (n = 38). The US diagnosis was correct in 19 of these patients (50% of cases where a cause was identified). Choledocholithiasis was the most common pathology, with 23 instances identified by US (61% of the cases where an aetiology was found). Malignancy formed the next largest group (four cases).

Conclusions

For most patients with a US‐reported common bile duct 8 mm or greater, a cause for biliary dilation was not established. Further study and methodological refinements are required to understand the clinical context of the cases with no recorded follow up. Performance of US is concordant with published literature. Distal choledocholithiasis remains a challenging area for US.
Material Design Concept of Lithium‐Excess Electrode Materials with Rocksalt‐Related Structures for Rechargeable Non‐Aqueous Batteries
Authors: Yabuuchi Naoaki
Published: October 2018

Dependence on lithium‐ion batteries for automobile applications is rapidly increasing, and further improvement, especially for positive electrode materials, is indispensable to increase energy density of lithium‐ion batteries. In the past several years, many new lithium‐excess high‐capacity electrode materials with rocksalt‐related structures have been reported. These materials deliver high reversible capacity with cationic/anionic redox and percolative lithium migration in the oxide/oxyfluoride framework structures, and recent research progresses on these electrode materials are reviewed. Material design strategies for these lithium‐excess electrode materials are also described. Future possibility of high‐energy non‐aqueous batteries with advanced positive electrode materials is discussed for more details.
Laminar responses in the auditory cortex using a multielectrode array substrate for simultaneous stimulation and recording
Authors: Takahashi Sota , Muramatsu Shuto , Nishikawa Jun , Satoh Kazuo , Murakami Shuichi , Tateno Takashi
Published: October 2018

Here, we report the design, fabrication, and characterization of a multielectrode array (MEA) substrate for the use of simultaneous stimulation and recording in vivo. The fabricated substrate has two sharp shanks in which we arranged multiple electrode arrays with surface areas of 50 × 50 µm2 in one shank for stimulation (interelectrode interval, 150 µm) and 15 × 15 µm2 in the other for recording (interelectrode interval, 100 µm). Our impedance measurements show that the electrode values are in good agreement with specified values for silicon‐based commercially available devices or slightly smaller‐sized electrode devices. After electrode characterization, the MEAs were evaluated for simultaneous stimulation and acute neural recording in the mouse auditory cortex in vivo. Using MEA substrates, we recorded spatiotemporal local field potential profiles driven by short local electrical stimulation, particularly to layer 4 of the mouse auditory cortex. Our results demonstrate successful simultaneous stimulation and recordings using the devices in vivo. Indeed, the device may contribute to understanding similarities and differences in local network activity driven by sound stimulation and electric microstimulation in near future work. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Lepton flavor violating dilepton dijet signatures from sterile neutrinos at proton colliders
Authors: Antusch Stefan , Cazzato Eros , Fischer Oliver , Hammad A. , Wang Kechen
Published: October 2018

Abstract

In this article we investigate the prospects of searching for sterile neutrinos in lowscale seesaw scenarios via the lepton flavour violating (but lepton number conserving) dilepton dijet signature. In our study, we focus on the final state e
±
μ
∓
jj at the HL-LHC and the FCC-hh (or the SppC). We perform a multivariate analysis at the detector level including the dominant SM backgrounds from di-top, di-boson, and tri-boson. Under the assumption of the active-sterile neutrino mixings |V

lN
|2 = |θ

e
|2 = |θ

μ
|2 and |V

τN
|2 = |θ
τ
|2 = 0, the sensitivities on the signal production cross section times branching ratio σ(pp → l
±
N) × BR(N → l
∓
jj) and on |V

lN
|2 for sterile neutrino mass M

N
between 200 and 1000 GeV are derived. For the benchmark M

N
= 500 GeV, when ignoring systematic uncertainties at the HL-LHC (FCC-hh/SppC) with 3 (20) ab−1 luminosity, the resulting 2-σ limits on |V

lN
|2 are 4.9 × 10−3 (7.0 × 10−5), while the 2-σ limit on σ × BR are 4.4 × 10−2 (1.6 × 10−2) fb, respectively. The effect of the systematic uncertainty is also studied and found to be important for sterile neutrinos with smaller masses. We also comment on searches with τ
±
μ
∓
jj and τ
±
e
∓
jj final states.
Measuring the triple Higgs self-couplings in two Higgs doublet model
Authors: Sonmez Nasuf
Published: October 2018

Abstract

The determination of the Higgs self-coupling in the Standard Model is one of the primary motivations among all the future lepton colliders. Extending the scalar sector of the Standard Model by a new Higgs doublet with a quadratic Higgs potential gives many new features to the model, and most importantly additional Higgs self-couplings emerge. Measuring these couplings is the only way to reconstruct the shape of the scalar potential. In this study, the numerical analysis of several scattering processes is carried out for the two-Higgs-doublet model to determine Higgs self-couplings. These processes are selected among various possible combinations of additional Higgs states. The computation is carried out in the exact alignment limit (s

βα
 = 1). The distribution of the cross sections is presented regarding the polarization of the incoming beams and up to

$$ \sqrt{s}=3 $$

s

=
3

TeV. A strategy for extracting the Higgs self-couplings is considered in 2HDM and at the future lepton colliders. Possible final states that could be used for each of the processes are investigated using the decays of the final state particles.
Carbon-Fiber-Reinforced Polymer Intramedullary Nails Perform Poorly in Long-Bone Surgery
Authors: Fragomen Austin T. , Teplensky Jason , Robert Rozbruch S.
Published: October 2018

Background

Carbon-fiber-reinforced (CFR) polymer has produced great excitement in the orthopedic community as a material that will reduce bone healing times and provide improved image quality. Osteotomy stabilized with an intramedullary (IM) nail has become a common technique to address post-traumatic malalignment of the lower extremity.

Purposes/Questions

The following questions were asked: (1) Did CFR polymer nails provide a rapid healing time after long bone osteotomy, shortening, or fracture? (2) Did the CFR polymer nails produce unexpected complications?

Methods

A retrospective review was conducted in patients who received CFR polymer IM nails for various indications, from April 2016 to January 2017 in a deformity and trauma practice, ﻿using patient charts and radiographs. The primary outcomes were time to union and incidence of complications including nonunion, hardware failure, neurovascular injury, venous thromboembolism, and infection.

Results

Twelve patients who received CFR polymer IM nails in 16 limbs for various indications were included in our analysis. Patients were followed for an average of 16.9 months. Eleven limbs underwent realignment and were corrected an average of 23° through a diaphyseal osteotomy. Three limbs underwent limb-shortening surgery, an average of 25 mm, through an open, excisional osteotomy of the femoral diaphysis. Two diaphyseal, closed tibia fractures underwent routine IM nailing. The average time to union was 107.6 days, which included all limbs that united (11/16, 69%). Nonunion occurred in 5/16 (31%) of limbs. Complications recorded included nonunion and hardware failure, most of which resulted in unplanned surgery.

Conclusions

The use of the CFR polymer IM nail was associated with loss of fixation and nonunion after surgeries that have traditionally healed uneventfully. The increased elasticity of the CFR polymer allows for more motion at the osteotomy/fracture interface than the stiffer titanium counterparts, exposing long-bone osteotomies to delayed union and nonunion, a finding seen with CFR polymer plates. The overwhelmingly poor early results of this device applied to a long-bone deformity practice have led these authors to abandon the use of this implant.
Lime Dissolution in Foaming BOF Slag
Authors: Martinsson Johan , Glaser Björn , Sichen Du
Published: October 2018

The paper describes the dissolution mechanisms of lime into liquid and foaming slags relevant to the BOF process. Two different master slags are employed, representing two different periods of the converter process: an early stage where the FeO content is fixed to 45 wt pct, and a later stage where the FeO content is fixed to 25 wt pct. For these master slags, the ratio between CaO/SiO2 is varied to examine the effect of basicity on lime dissolution. Calcium silicates are formed and peeled off, or partially peeled off, from the interface between the lime cube and the slag in all cases. The main difference for the dissolutions in pure liquid slag and foaming slag is the controlling step for dissolution. In liquid slag, the controlling mechanism is the removal of the calcium silicate layers, while in foaming slag, the controlling mechanism is the contact area between the lime and the liquid slag phase of the foam. The strong convection in the foam enhance the dissolution process, in some cases, the lime even dissociates into small pieces.
Group‐based trajectories of parent‐child communication and parental knowledge between sexual minority and heterosexual girls and their associations with substance use
Authors: Montano Gerald T. , Marshal Michael P. , McCauley Heather L. , Miller Elizabeth , Chung Tammy , Hipwell Alison E.
Published: October 2018

Introduction

Sexual minority girls (SMGs) may be at high risk for substance use partially due to anti‐gay discrimination. Low levels of parent‐child communication and parental knowledge may contribute to this risk. This study seeks to identify parent‐child communication and parental knowledge trajectories, determine the likelihood of SMGs following these trajectories, and describe the relationships between these trajectories, sexual orientation, and substance use.

Methods

This is a secondary data analysis of the Pittsburgh Girls Study (N = 2450), a longitudinal study on the changes in behaviors among girls throughout childhood. We generated group trajectory models of parentchild communication and parental knowledge starting from age 12 to age 17 years. We then tested the likelihood of SMGs belonging to these group trajectories and the association between group trajectory membership and substance use at age 18 years.

Results

SMGs were more likely than were heterosexual girls to follow the infrequent decreasing parent‐child communication trajectory and the slowly decreasing parental knowledge trajectory and were more likely than were heterosexual girls to engage in substance use at age 18 years. Parent‐child communication and parental knowledge trajectories were statistically significant mediators between sexual orientation and substance use.

Conclusion

Frequency of parent‐child communication and levels of parental knowledge may be determinants of substance use among SMGs. These results have implications for developing substance use prevention programs among sexual minority youth targeting parent‐child relationships.
Classification of Error in Abdominal Imaging: Pearls and Pitfalls for Radiologists
Authors: Egri Csilla , Darras Kathryn E. , Scali Elena P. , Harris Alison C.
Published: October 2018

Peer review for radiologists plays an important role in identifying contributing factors that can lead to diagnostic errors and patient harm. It is essential that all radiologists be aware of the multifactorial causes of diagnostic error in radiology and the methods available to reduce it. This pictorial review provides readers with an overview of common errors that occur in abdominal radiology and strategies to reduce them. This review aims to make readers more aware of pitfalls in abdominal imaging so that these errors can be avoided in the future. This essay also provides a systematic approach to classifying abdominal imaging errors that will be of value to all radiologists participating in peer review.
Training by Using an Adaptive Foot Switch and Video Games to Improve Balance and Mobility Following Stroke: A Randomised Controlled Trial
Authors: Hsieh Hsieh-Chun
Published: October 2018

In this study, an altered switch for rehabilitation was invented to make home training accessible for the stroke patients, by modifying a computer mouse into a foot switch. This study examined the effects of training with an adaptive foot switch and video games (VG) on walking performance and balance abilities (Centre of Pressure (CoP) sway) in people after stroke.

The intervention was evaluated through a randomised controlled trial. The intervention group received 10 weeks of VG rehabilitation, for approximately 3.5 hours/week, using a pressure-activated electronic foot switch, in addition to standard rehabilitation. The control group received regular rehabilitation only. The experiment included a force platform (measuring CoP sway kinematics) and a 10-Metre Test of Walking (10MWT) to measure the standing balance and walking performance of 56 stroke patients.

There were no differences between the two groups (intervention and control) at baseline in terms of the demographic or dependent variables. Multivariate tests indicated a significant interaction between the Patient Group and the Time-type variables. Subsequent analysis of the main effects revealed significant between-group differences over time in all dependent variables (10MWT, sway area, CoP sway in anterior–posterior direction (AP sway) and CoP sway in medial–lateral direction (ML sway)). Patients in the intervention group demonstrated better performance than those in the control group after the VG rehabilitation according to the post-test.

This study suggests that ankle muscle training using an adaptive foot switch and VG may improve exercise compliance and enhance recovery of balance and mobility following stroke.
Non-modal stability analysis of miscible viscous fingering with non-monotonic viscosity profiles
Authors: Hota Tapan Kumar , Mishra Manoranjan
Published: October 2018

A non-modal linear stability analysis (NMA) of the miscible viscous fingering in a porous medium is studied for a toy model of non-monotonic viscosity variation. The onset of instability and its physical mechanism are captured in terms of the singular values of the propagator matrix corresponding to the non-autonomous linear equations. We discuss two types of non-monotonic viscosity profiles, namely, with unfavourable (when a less viscous fluid displaces a high viscous fluid) and with favourable (when a more viscous fluid displaces a less viscous fluid) endpoint viscosities. A linear stability analysis yields instabilities for such viscosity variations. Using the optimal perturbation structure, we are able to show that an initially unconditional stable state becomes unstable corresponding to the most unstable initial disturbance. In addition, we also show that to understand the spatio-temporal evolution of the perturbations it is necessary to analyse the viscosity gradient with respect to the concentration and the location of the maximum concentration $c_{m}$. For the favourable endpoint viscosities, a weak transient instability is observed when the viscosity maximum moves close to the pure invading or defending fluid. This instability is attributed to an interplay between the sharp viscosity gradient and the favourable endpoint viscosity contrast. Further, the usefulness of the non-modal analysis demonstrating the physical mechanism of the quadruple structure of the perturbations from the optimal concentration disturbances is discussed. We demonstrate the dissimilarity between the quasi-steady-state approach and NMA in finding the correct perturbation structure and the onset, for both the favourable and unfavourable viscosity profiles. The correctness of the linear perturbation structure obtained from the non-modal stability analysis is validated through nonlinear simulations. We have found that the nonlinear simulations and NMA results are in good agreement. In summary, a non-monotonic variation of the viscosity of a miscible fluid pair is seen to have a larger influence on the onset of fingering instabilities than the corresponding Arrhenius type relationship.
Early-time jet formation in liquid–liquid impact problems: theory and simulations
Authors: Cimpeanu R. , Moore Madeleine Rose
Published: October 2018

We perform a thorough qualitative and quantitative comparison of theoretical predictions and direct numerical simulations for the two-dimensional, vertical impact of two droplets of the same fluid. In particular, we show that the theoretical predictions for the location and velocity of the jet root are excellent in the early stages of the impact, while the predicted jet velocity and thickness profiles are also in good agreement with the computations before the jet begins to bend. By neglecting the role of the surrounding gas both before and after impact, we are able to use Wagner theory to describe the early-time structure of the impact. We derive the model for general droplet velocities and radii, which encompasses a wide range of impact scenarios from the symmetric impact of identical drops to liquid drops impacting a deep pool. The leading-order solution is sufficient to predict the curve along which the root of the high-speed jet travels. After moving into a frame fixed in this curve, we are able to derive the zero-gravity shallow-water equations governing the leading-order thickness and velocity of the jet. Our numerical simulations are performed in the open-source software Gerris, which allows for the level of local grid refinement necessary for a problem with such a wide variety of length scales. The numerical simulations incorporate more of the physics of the problem, in particular the surrounding gas, the fluid viscosities, gravity and surface tension. We compare the computed and predicted solutions for a range of droplet radii and velocities, finding excellent agreement in the early stage. In light of these successful comparisons, we discuss the tangible benefits of using Wagner theory to confidently track properties such as the jet-root location, jet thickness and jet velocity in future studies of splash jet/ejecta evolution.
Artificial chemotaxis of phoretic swimmers: instantaneous and long-time behaviour
Authors: Tătulea-Codrean Maria , Lauga Eric
Published: October 2018

Phoretic swimmers are a class of artificial active particles that has received significant attention in recent years. By making use of self-generated gradients (e.g. in temperature, electric potential or some chemical product) phoretic swimmers are capable of self-propulsion without the complications of mobile body parts or a controlled external field. Focusing on diffusiophoresis, we quantify in this paper the mechanisms through which phoretic particles may achieve chemotaxis, both at the individual and the non-interacting population level. We first derive a fully analytical law for the instantaneous propulsion and orientation of a phoretic swimmer with general axisymmetric surface properties, in the limit of zero Péclet number and small Damköhler number. We then apply our results to the case of a Janus sphere, one of the most common designs of phoretic swimmers used in experimental studies. We next put forward a novel application of generalised Taylor dispersion theory in order to characterise the long-time behaviour of a population of non-interacting phoretic swimmers. We compare our theoretical results with numerical simulations for the mean drift and anisotropic diffusion of phoretic swimmers in chemical gradients. Our results will help inform the design of phoretic swimmers in future experimental applications.
Preferential orientation of spheroidal particles in wavy flow
Authors: DiBenedetto Michelle H. , Ouellette Nicholas T.
Published: October 2018

We report a theoretical study of the angular dynamics of small, non-inertial spheroidal particles in a linear wave field. We recover the observation recently reported by DiBenedetto et al. (J. Fluid Mech., vol. 837, 2018, pp. 320–340) that the orientation of these spheroids tends to a stable limit cycle consisting of a preferred value with a superimposed oscillation. We show that this behaviour is a consequence of finite wave amplitude and is the angular analogue of Stokes drift. We derive expressions for both the preferred orientation of the particles, which depends only on particle shape, and the amplitude of the oscillation about this preferred value, which additionally depends on the wave parameters and the depth of the particle in the water column.
Does Political Uncertainty Increase External Financing Costs? Measuring the Electoral Premium in Syndicated Lending
Authors: Kim Olivia S.
Published: October 2018

This article investigates the impact of political uncertainty on contractual lending terms using a large sample of syndicated loans and a within-firm estimation approach to achieve identification. Firms pay 7 basis points (bps) more on loans originated when their lenders are undergoing an election relative to when their lenders are not undergoing an election. Lenders from less financially developed countries are more likely to pass political uncertainty costs to borrowers. Consistent with electoral uncertainty driving this premium, the most contested elections have the largest impact (17 bps). Overall, political uncertainty leads to a tangible increase in firms’ financing costs.
Exponential density transition-based enhanced second harmonic generation in plasma
Authors: Thakur Vishal , Kant Niti
Published: October 2018

Enhanced harmonic generation of second order based on exponential density ramp in plasma has been noticed. It is well known that self-focusing of pump laser induces a transverse intensity gradient, which gives rise to the plasma wave at the pump frequency. Highly intense Gaussian laser with exponential density ramp profile generates a second harmonic pulse in plasma. It is noticed that the amplitude of second-harmonic pulse varies periodically with the distance and reaches its peak value in the focal region. Further, it is found that exponential plasma density ramp is useful for stronger self-focusing, which lead to rise second harmonic generation (SHG). Wiggler magnetic field provides the additional angular momentum required for second harmonic photon and aids in growing of resonant process. One may clearly see that exponential plasma density ramp imparts a major role in enhancing the SHG in plasma. Further, the combined effect of exponential density ramp and wiggler magnetic field boosts the SHG in plasma.
Rational discrete first degree cohomology for totally disconnected locally compact groups
Authors: CASTELLANO ILARIA
Published: October 2018

It is well known that the existence of more than two ends in the sense of J.R. Stallings for a finitely generated discrete group G can be detected on the cohomology group H1(G,R[G]), where R is either a finite field, the ring of integers or the field of rational numbers. It will be shown (cf. Theorem A*) that for a compactly generated totally disconnected locally compact group G the same information about the number of ends of G in the sense of H. Abels can be provided by dH1(G, Bi(G)), where Bi(G) is the rational discrete standard bimodule of G, and dH•(G, _) denotes rational discrete cohomology as introduced in [6].

As a consequence one has that the class of fundamental groups of a finite graph of profinite groups coincides with the class of compactly presented totally disconnected locally compact groups of rational discrete cohomological dimension at most 1 (cf. Theorem B).
Using the Past and Bridging the Gap: Premodern Islamic Legal Texts in New Media
Authors: Kooria Mahmood
Published: October 2018

This article analyses the internal dynamics of online Islamic legal discourses embedded in their offline and multimedia contexts that use of a rich repository of legal texts composed over a period of about a thousand years. Through their vigorous and spirited engagements with these historical texts, contemporary Islamic jurists simultaneously create new digital platforms in mass and social media to disseminate their ideas. In so doing, they perpetuate a long textual legal tradition through hypertext commentaries and super-commentaries. The premodern texts are thus reborn through new forms ofḥāshiyas such as audio commentaries, video commentaries, audio-video commentaries and hypertext commentaries. These new developments from the age of new media contribute to the textuallongue-duréeof Islamic law. Tracking the peregrinations of three Islamic legal texts in the mass media and cyber world, I argue that the dissemination of premodern Islamic legal texts via cyber space has resulted in the “democratization” of a knowledge-system that was previously dominated by trained fuqahā and affiliated institutional structures and has enlivened the traditional school affiliations.
Single-centre experience in stenting arterial shunts for adult CHD patients with single-ventricle physiology and pulmonary blood flow dependent on arterial shunts
Authors: Kasem Mohamed , Bentham James , Thomson John
Published: October 2018

Objectives

The objectives of this study were to describe the approach to stenting arterial shunts in adult congenital patients with single-ventricle physiology and to assess the medium-term clinical and haemodynamic outcomes following stent insertion.

Background

Adult patients with single-ventricle physiology and pulmonary blood flow dependent on a surgically placed arterial shunt who did not progress to venous palliation are extremely challenging to manage. Progressive cyanosis secondary to narrowing of the shunt has a marked impact on exercise tolerance and results in intolerable well-being for these patients. Stenting arterial shunts in adult patients is one method that can help improve pulmonary blood flow. There is very limited information in the literature about this patient.

Methods

This is a retrospective study for arterial shunts stenting conducted between 2008 and 2016. The peripheral oxygen saturations, the NYHA status, the haemoglobin, and the degree of atrio-ventricular valve regurgitation as assessed on transthoracic echo were compared before and 6–12 months after procedures.

Results

There was a short-term improvement in oxygen saturations; the pre-procedure mean was 75.8 (SD 2.55)% (range 70–85%) and post-procedure mean was 83 (SD 2.52)% (range 78–87%), with a p value of 0.04. Haemoglobin level decreased from a pre-procedure mean of 22.06–20.28 g/L 6 months post procedure (range 18.1–24.4 to 13–23.3 g/L), with a p value of 0.44. NYHA class decreased from a mean of 3.2–2.2 post procedure. Left atrial volume for four of the cases did not change (22.6–76.6 ml [mean 48.4 ml] to 29.6–72.9 ml [mean 52 ml], p value: 0.83).

Conclusions

Stenting stenotic arterial shunts is a useful method to gain a medium-term improvement on the oxygen saturation and clinical symptoms, and may act as a useful intermediate step for further management plans.
Safety of outpatient cardiac catheterisation in infants with single-ventricle or shunt-dependent biventricular congenital heart disease
Authors: Colombo Jamie N. , Spaeder Michael C. , Hainstock Michael R.
Published: October 2018

Objective

We aimed to investigate the incidence and causes of readmission of infants with single-ventricle and shunt-dependent biventricular CHD following routine, outpatient cardiac catheterisation.

Background

Cardiac catheterisation is commonly performed in patients with single-ventricle and shunt-dependent biventricular CHD for haemodynamic assessment and surgical planning. Best practices for post-procedural care in this population are unknown, and substantial variation exists between centres. Outpatient catheterisation reduces parental anxiety and decreases cost. Our institutional strategy is to discharge patients following a 4- to 6-hour post-procedure observation period.

Methods

Retrospective cohort study using the Society of Thoracic Surgeons Database identified patients <1 year of age with pre-stage II single-ventricle CHD or shunt-dependent biventricular CHD who underwent cardiac catheterisation between 2007 and 2015. Readmission was defined as admission to the hospital within 48 hours after discharge after catheterisation.

Results

A total of 92 patients were included in the analysis. Among them, 62 patients (67%) were discharged after a 4- to 6-hour observation period with only 3% readmission, 18 patients (20%) stayed for a 23-hour observation period, and 12 patients (13%) were admitted for >23 hours. There were no differences in baseline characteristics between discharged and admitted patients. Patients who underwent intervention were more likely to be admitted. Patients with hypoplastic left heart syndrome did not have major adverse events or readmissions. No intra- or peri-procedural deaths occurred.

Conclusions

Outpatient cardiac catheterisation may be a safe option for infants with single-ventricle and shunt-dependent biventricular CHD, with low readmission rates and minimal morbidity.
Kinder mit Fluchtbiografie an pädagogischen Orten
Authors: Weise Marion , Morys Regine , Lempp Marion , Oeltjendiers Laura
Published: October 2018

Zusammenfassung. Infolge des Zuzugs von Kindern mit Fluchtbiografie weisen Träger dieser Zielgruppe Plätze in Kindertageseinrichtungen zu oder richten andere Formen der Betreuung für sie ein. Das Forschungsprojekt TanGO1(Akronym für „Transitions- und Aneignungsprozesse geflüchteter Kinder an pädagogischen Orten“) untersucht die Wahrnehmungen und Alltagspraktiken von Kindern, Eltern und Fachkräften an drei differenten Betreuungssettings. In Anlehnung an Winkler (2009) werden diese als pädagogische Ort(e) bezeichnet. Der Beitrag fokussiert auf ein mittels der Dokumentarischen Methode ( Bohnsack, 2010 , Bohnsack, 2011 ) rekonstruiertes gemeinsames Orientierungsmuster von Kindern und Fachkräften. Das Gemeinsame wird anhand exemplarischer Passagen aus dem bisher vorliegenden Datenkorpus aufgezeigt. Das empirische Material zeigt in der Auseinandersetzung von Kindern und Fachkräften mit den Betreuungssettings, wie die Organisationslogik auf gelebte Alltagspraxis trifft.
Family, Health, and Poverty Factors Impacting Suicide Attempts in Cambodian Women
Authors: Seponski Desiree M. , Somo Charity M. , Kao Sovandara , Lahar Cindy J. , Khann Sareth , Schunert Tanja
Published: October 2018

Abstract. Background: Our recent report demonstrates that 5.5% of Cambodian women have previously attempted suicide. Despite these high rates and critical need for intervention, research on suicide attempts in Cambodia is lacking, and life-saving information on suicide prevention is therefore unknown. Aims: This study explores factors impacting Cambodian women suicide attempts. Method: A total of 1,801 women participated in the large national survey during which 100 of these women (5.5%) reported at least one suicide attempt. Of the 100 participants 76 provided qualitative reasons for the suicide attempts. Only the 76 who provided the reasons for suicide attempt were included for analysis in this study. Results: Four major themes emerged: (1) family conflict, (2) emotional distress, (3) poverty, and (4) illness. Family conflict, emotional distress, poverty, and illness were all interrelated with each other; for example, women without money were unable to pay for treatment of otherwise treatable illnesses. Limitations: Owing to the nature of the data collection, member checking could not be conducted. Conclusion: Cumulative and intertwined personal, interpersonal, and contextual-level factors impacting suicide attempts included emotional distress, illness, family conflict, and poverty. Findings highlight points of intervention at individual, familial, and contextual levels to prevent suicide.
Exploring the Unknown of the Ross Sea in Sea Ice–Free Conditions
Authors: De Santis Laura , Colleoni Florence , Bergamasco Andrea , Rebesco Michele , Accettella Daniela , Kovacevic Vedrana , Gales Jennifer , Sookwan Kim , Olivo Elisabetta
Published: October 2018

A team of polar scientists aboard the OGS Explora, cruising in rare ice-free conditions, discovered new evidence of ancient and modern-day ice sheet sensitivity to climatic fluctuations.
Analysts Forecast Midterm Election’s Impact on Climate Change
Authors: Showstack Randy
Published: October 2018

A Democratic wave could prompt more legislation on climate change but might dampen bipartisan efforts.
Soil Organic Matter Persistence as a Stochastic Process: Age and Transit Time Distributions of Carbon in Soils
Authors: Sierra Carlos A. , Hoyt Alison M. , He Yujie , Trumbore Susan E.
Published: October 2018

The question of why some types of organic matter are more persistent while others decompose quickly in soils has motivated a large amount of research in recent years. Persistence is commonly characterized as turnover or mean residence time of soil organic matter (SOM). However, turnover and residence times are ambiguous measures of persistence, because they could represent the concept of either age or transit time. To disambiguate these concepts and propose a metric to assess SOM persistence, we calculated age and transit time distributions for a wide range of soil organic carbon models. Furthermore, we show how age and transit time distributions can be obtained from a stochastic approach that takes a deterministic model of mass transfers among different pools and creates an equivalent stochastic model at the level of atoms. Using this approach we show the following: (1) Age distributions have relatively old mean values and long tails in relation to transit time distributions, suggesting that carbon stored in soils is on average much older than carbon in the release flux. (2) The difference between mean ages and mean transit times is large, with estimates of soil organic carbon persistence on the order of centuries or millennia when assessed using ages and on the order of decades when using transit or turnover times. (3) The age distribution is an appropriate metric to characterize persistence of SOM. An important implication of our analysis is that random chance is a factor that helps to explain why some organic matter persists for millennia in soil.
Predicted Chance That Global Warming Will Temporarily Exceed 1.5 °C
Authors: Smith D. M. , Scaife A. A. , Hawkins E. , Bilbao R. , Boer G. J. , Caian M. , Caron L.‐P. , Danabasoglu G. , Delworth T. , Doblas‐Reyes F. J. , Doescher R. , Dunstone N. J. , Eade R. , Hermanson L. , Ishii M. , Kharin V. , Kimoto M. , Koenigk T. , Kushnir Y. , Matei D. , Meehl G. A. , Menegoz M. , Merryfield W. J. , Mochizuki T. , Müller W. A. , Pohlmann H. , Power S. , Rixen M. , Sospedra‐Alfonso R. , Tuma M. , Wyser K. , Yang X. , Yeager S.
Published: October 2018

The Paris Agreement calls for efforts to limit anthropogenic global warming to less than 1.5 °C above preindustrial levels. However, natural internal variability may exacerbate anthropogenic warming to produce temporary excursions above 1.5 °C. Such excursions would not necessarily exceed the Paris Agreement, but would provide a warning that the threshold is being approached. Here we develop a new capability to predict the probability that global temperature will exceed 1.5 °C above preindustrial levels in the coming 5 years. For the period 2017 to 2021 we predict a 38% and 10% chance, respectively, of monthly or yearly temperatures exceeding 1.5 °C, with virtually no chance of the 5‐year mean being above the threshold. Our forecasts will be updated annually to provide policy makers with advanced warning of the evolving probability and duration of future warming events.
Solving Controversies on the Iron Phase Diagram Under High Pressure
Authors: Morard Guillaume , Boccato Silvia , Rosa Angelika D. , Anzellini Simone , Miozzi Francesca , Henry Laura , Garbarino Gaston , Mezouar Mohamed , Harmand Marion , Guyot François , Boulard Eglantine , Kantor Innokenty , Irifune Tetsuo , Torchio Raffaella
Published: October 2018

As the main constituent of planetary cores, pure iron phase diagram under high pressure and temperature is of fundamental importance in geophysics and planetary science. However, previously reported iron‐melting curves show large discrepancies (up to 1000 K at the Earth's core–mantle boundary, 136 GPa), resulting in persisting high uncertainties on the solid‐liquid phase boundary. Here we unambiguously show that the observed differences commonly attributed to the nature of the used melting diagnostic are due to a carbon contamination of the sample as well as pressure overestimation at high temperature. The high melting temperature of pure iron under core‐mantle boundary (4250 ± 250 K), here determined by X‐ray absorption experiments at the Fe K‐edge, indicates that volatile light elements such as sulfur, carbon, or hydrogen are required to lower the crystallization temperature of the Earth's liquid outer core in order to prevent extended melting of the surrounding silicate mantle.
Diagnosis of ULF Wave‐Particle Interactions With Megaelectron Volt Electrons: The Importance of Ultrahigh‐Resolution Energy Channels
Authors: Hartinger M. D. , Claudepierre S. G. , Turner D. L. , Reeves G. D. , Breneman A. , Mann I. R. , Peek T. , Chang E. , Blake J. B. , Fennell J. F. , O'Brien T. P. , Looper M. D.
Published: October 2018

Electron flux measurements are an important diagnostic for interactions between ultralow‐frequency (ULF) waves and relativistic (∼1 MeV) electrons. Since measurements are collected by particle detectors with finite energy channel width, they are affected by a phase mixing process that can obscure these interactions. We demonstrate that ultrahigh‐resolution electron measurements from the Magnetic Electron Ion Spectrometer on the Van Allen Probes mission—obtained using a data product that improves the energy resolution by roughly an order of magnitude—are crucial for understanding ULF wave‐particle interactions. In particular, the ultrahigh‐resolution measurements reveal a range of complex dynamics that cannot be resolved by standard measurements. Furthermore, the standard measurements provide estimates for the ULF flux modulation amplitude, period, and phase that may not be representative of true flux modulations, potentially leading to ambiguous conclusions concerning electron dynamics.
Impact of Background Magnetic Field for EMIC Wave‐Driven Electron Precipitation
Authors: Woodger L. A. , Millan R. M. , Li Z. , Sample J. G.
Published: October 2018

Wave‐particle interaction between relativistic electrons and electromagnetic ion cyclotron (EMIC) waves is a highly debated loss process contributing to the dynamics of Earth's radiation belts. Theoretical studies show that EMIC waves can result in strong loss of relativistic electrons in the radiation belts (Summers & Thorne, 2003, https://doi.org/10.1029/2002JA009489). However, many of these studies have not been validated by observations. Li et al. (2014, https://doi.org/10.1002/2014GL062273) modeled the relativistic electron precipitation observed by Balloon Array for Radiation belt Relativistic Electron Losses (BARREL) in a single‐event case study based on a quasi‐linear diffusion model and observations by Van Allen Probes and GOES 13. We expand upon that study to investigate the localization of the precipitation region and the effectiveness of EMIC waves as an electron loss mechanism.The model results of BARREL 1I observations on 17 January 2013 show that as the BARREL balloon drifts in local time to regions that map to lower equatorial magnetic field strength, the flux of precipitating electrons increases and peaks at lower energy. The hypothesis that the energy of the precipitating electrons is controlled by background magnetic field strength is further tested by considering observations from balloon campaigns conducted from 2000 to 2014, including BARREL. Consistent with theory for wave‐particle interaction between relativistic electrons and EMIC waves, we find observationally that stronger equatorial magnetic field strength generally correlates with more energetic electron precipitation and further conclude that magnetic field strength can drive the localization and distribution of precipitating electrons.