bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose–response meta‐analysis of randomized controlled trials
Authors: Chen Yan , Zhao Ying , Wang Yanjun , Nazary‐Vannani Ali , Clark Cain C. T. , Sedanur Macit Melahat , Khani Vahid , Zhang Yong
Published: March 2020

Studies regarding the influence of green coffee extract (GCE) on blood glucose levels are conflicting. Thus, we sought to conduct a meta‐analysis and systematic review of all available randomized controlled trials (RCTs) to quantify the effects of GCE and CGA intervention on blood glucose and insulin levels. We performed systematic online searches in Scopus, Web of science, and PubMed databases, from inception to July 2019. Data were combined analyzed using a random effects model (Der Simonian‐Laird method) and reported as weighted mean differences (WMD). Ten trials reported the influences of GCE on FBS and insulin and were subsequently entered into the meta‐analysis. Combined results highlighted that FBS was significantly altered after GCE consumption (WMD: −1.791 mg/dl, 95% CI −3.404, −0.177), with no significant heterogeneity among the studies (I2 = 35.0%, p = .128). However, overall results demonstrated that GCE administration did not result in any significant alteration in insulin levels (WMD: −0.925 μU/ml, 95% CI:−1.915, 0.064), with significant heterogeneity found across studies (I2 = 87.9%). In sub‐group analysis, insulin levels were significantly reduced when GCE was supplemented in dosages of ≥400 mg/day (WMD:−1.942 mg/dl, 95% CI:−1.184, −0.975; I2 = 0.0%). The results of present study support the use of GCE for the enhancement of blood glucose, while subgroup analysis highlighted significant improvements in insulin levels when GCE is supplemented in doses ≥400 mg/day.
Decoration of Cube‐Like Ceria Crystals by Well‐Dispersed Au Nanoparticles: Surface Influence
Authors: Małecka Małgorzata A. , Matus Krzysztof , Woźniak Piotr
Published: March 2020

In this paper, the run of the decorating process of the active support, like CeO2, by the gold nanoparticles via deposition‐precipitation method has been studied. Two types of the Au/CeO2 systems with different mean particle size (but the same morphology) of the support have been investigated. It was noted that the decoration process proceeds easily only for large crystals with average size about 67 nm. Three hypotheses were tested in order to explain unsuccessful initial Au nanoparticles decoration of the cube‐like CeO2 crystals with average size about 14 nm as a support. The tests have shown that the ratio of the molar content of the chloroauric acid to the total surface area of the support (MAu/SCeO2) has a significant impact on the decorating process of CeO2 by nano‐Au. If the above ratio is too small, the thin layer of gold instead of the Au nanoparticles is formed on the support surface. In this paper, the calculations of the real surface area (from TEM/HRTEM data) were used to adjust the optimum the MAu/SCeO2 to obtain the Au/CeO2 system with the desired properties.
A Modified Suture Technique for Attaching Radiotransmitters to Northern Bobwhite Chicks
Authors: Terhune Theron M. , Caudill Danny , Terhune V. Heather , Martin James A.
Published: March 2020

Reliable and unbiased information is needed for informing management decisions relevant to all animal life stages. Radiomarking is commonly used for adult birds, but this approach is more challenging for galliform chicks. Following preliminary experimentation of multiple attachment methods, we selected 2 radiotransmitter attachment techniques, gluing and suturing, to test on 11‐day‐old northern bobwhite (Colinus virginianus; hereafter, bobwhite) chicks in an outdoor aviary environment during 1 May 2013 through 30 Sep 2016. In addition, we field‐tested a novel, modified‐suture technique on 11‐ and 12‐day‐old wild bobwhite chicks. We found that suturing was a superior method of transmitter attachment. Glue‐on attachment of transmitters performed poorly with average retention rates <7 days. The probability of retaining a radiotransmitter for the duration of our 8‐week study was 0.76 (±0.08 SE), 0.89 (±0.09 SE), and 0.00 for normal suture, our modified suture, and glue‐on techniques, respectively. Development and growth of suture‐ and patagial‐tagged bobwhite chicks (average mass gain of 41.95 g ± 2.79 SE) was unimpeded compared with a control (patagial‐tagged only, no transmitter) group of birds (average mass gain: 40.89 g ± 2.91 SE). We observed similar tag‐retention rates (0.906 ± 0.07 SE) of transmitters affixed to wild bobwhite chicks in the field using a modified‐suture technique compared with the aviary study. Our modifications to the traditional suture methods include changing the placement of the transmitter to reduce snag rate in vegetation, using a smaller gauge syringe needle to reduce skin‐tearing, applying a surgeon's knot for increased knot‐security and reduced knot slippage while suturing, and applying insta‐set spray to rapidly dry superglue to reduce handling time of chicks. The modified‐suture technique provides improvements in tag‐retention, facilitates shorter handling time of birds in the field, and provides an effective means for tagging and tracking individuals to collect ecological data and demographic vital rates on bobwhite chicks and other birds. Future studies should investigate potential sublethal effects that suture tags may impose on individuals to identify and account for estimable biases of vital rates. © 2020 The Wildlife Society.
Quantum chaos, pole-skipping and hydrodynamics in a holographic system with chiral anomaly
Authors: Abbasi Navid , Tabatabaei Javad
Published: March 2020

Abstract

It is well-known that chiral anomaly can be macroscopically detected through the energy and charge transport, due to the chiral magnetic effect. On the other hand, in a holographic many body system, the chaotic modes might be only associated with the energy conservation. This suggests that, perhaps, one can detect microscopic anomalies through the diagnosis of quantum chaos in such systems. To investigate this idea, we consider a magnetized brane in AdS space time with a Chern-Simons coupling in the bulk. By studying the shock wave geometry in this background, we first compute the corresponding butterfly velocities, in the presence of an external magnetic field B, in μ « T and B « T2 limit. We find that the butterfly propagation in the direction of B has a different velocity than in the opposite direction; the difference is ∆vB = (log(4)−1)∆vsound with ∆vsound being the difference between the velocity of two sound modes propagating in the system. The splitting of butterfly velocities confirms the idea that chiral anomaly can be macroscopically manifested via quantum chaos. We then show that the pole-skipping points of energy density Green’s function of the boundary theory coincide precisely with the chaos points. This might be regarded as the hydrodynamic origin of quantum chaos in an anomalous system. Additionally, by studying the near horizon dynamics of a scalar field on the above background, we find the spectrum of pole-skipping points associated with the two-point function of dual boundary operator. We find that the sum of wavenumbers corresponding to pole-skipping points at a specific Matsubara frequency is a universal quantity, which is independent of the scaling dimension of the dual boundary operator. We then show that this quantity follows from a closed formula and can be regarded as another macroscopic manifestation of the chiral anomaly.
Symmetries in A-type little string theories. Part I. Reduced free energy and paramodular groups
Authors: Bastian Brice , Hohenegger Stefan
Published: March 2020

Abstract

We analyse the symmetries of a class of A-type little string theories that are engineered by N parallel M5-branes with M2-branes stretched between them. This paper deals with the so-called reduced free energy, which only receives contributions from the subset of the BPS states that carry the same charges under all the Cartan generators of the underlying gauge algebra. We argue (and check explicitly in a number of examples) that the former is invariant under the paramodular group ΣN ⊂ Sp(4, ℚ), which gets extended to a subgroup of Sp(4, ℝ) in the Nekrasov-Shatashvili-limit. This extension agrees with the observation made in [18] that these BPS states form a symmetric orbifold CFT. Furthermore, we argue that ΣN (along with other symmetries) places strong constraints on the BPS counting function that governs the intersection between the M5- and M2-branes.
Conformal structure of FLRW cosmology: spinorial representation and the $$ \mathfrak{so} $$ (2, 3) algebra of observables
Authors: Achour Jibril Ben , Livine Etera R.
Published: March 2020

Abstract

It was recently shown that the homogeneous and isotropic cosmology of a massless scalar field coupled to general relativity exhibits a new hidden conformal invariance under Mobius transformation of the proper time, additionally to the invariance under time-reparamterization. The resulting Noether charges form a $$ \mathfrak{sl}\left(2,\mathbb{R}\right) $$
sl

2
ℝ

Lie algebra, which encapsulates the whole kinematics and dynamics of the geometry. This allows to map FLRW cosmology onto conformal mechanics and formulate quantum cosmology in CFT1 terms. Here, we show that this conformal structure is embedded in a larger $$ \mathfrak{so} $$
so
(3, 2) algebra of observables, which allows to present all the Dirac observables for the whole gravity plus matter sectors in a unified picture. Not only this allows one to quantize the system and its whole algebra of observables as a single irreducible representation of $$ \mathfrak{so} $$
so
(3, 2), but this also gives access to a scalar field operator $$ \hat{\phi} $$

ϕ
̂

opening the door to the inclusion of non-trivial potentials for the scalar field. As such, this extended conformal structure might allow to perform a group quantization of inflationary cosmological backgrounds.
Eventually Entanglement Breaking Markovian Dynamics: Structure and Characteristic Times
Authors: Hanson Eric P. , Rouzé Cambyse , Stilck França Daniel
Published: March 2020

We investigate entanglement breaking times of Markovian evolutions in discrete and continuous time. In continuous time, we characterize which Markovian evolutions are eventually entanglement breaking, that is, evolutions for which there is a finite time after which any entanglement initially present has been destroyed by the noisy evolution. In the discrete-time framework, we consider the entanglement breaking index, that is, the number of times a quantum channel has to be composed with itself before it becomes entanglement breaking. The $$\hbox {PPT}^2$$PPT2 conjecture is that every PPT quantum channel has an entanglement breaking index of at most 2; we prove that every faithful PPT quantum channel has a finite entanglement breaking index, and more generally, any faithful PPT CP map whose Hilbert–Schmidt adjoint is also faithful is eventually entanglement breaking. We also provide a method to obtain concrete bounds on this index for any faithful quantum channel. To obtain these estimates, we use a notion of robustness of separability to obtain bounds on the radius of the largest separable ball around faithful product states. We also extend the framework of Poincaré inequalities for non-primitive semigroups to the discrete setting to quantify the convergence of quantum semigroups in discrete time, which is of independent interest.
DKG-Zertifizierung kinderonkologischer Zentren – ein weites Feld …
Authors: Lauten Melchior , Kontny Udo , Nathrath Michaela , Schrappe Martin
Published: March 2020

Die Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH) und die Deutsche Krebsgesellschaft (DKG) haben Kriterien für die DKG-Zertifizierung der Kinderonkologie erarbeitet, nach denen 2017 in Deutschland erstmals pädiatrisch-onkologische Abteilungen zertifiziert wurden. Das Ziel der DKG-Zertifizierung ist „die Vereinheitlichung und die transparente Darstellung der Versorgungsqualität für pädiatrische Patientinnen und Patienten mit hämato-onkologischen Erkrankungen“, wie 2018 in einer Veröffentlichung von Mensah et al. dargestellt. Die Auswahl der Zertifizierungskriterien hat innerhalb der GPOH zu einer intensiven Diskussion darüber geführt, inwieweit die Kriterien für sich genommen einer wissenschaftlichen Überprüfbarkeit standhalten und damit valide Parameter für die Bestimmung der Versorgungsqualität in der Kinderonkologie in Deutschland darstellen.

Wir haben untersucht, ob aus der Arbeit von Mensah et al. valide Folgerungen für das deutsche Gesundheitssystem ableitbar sind. Dabei zeigt sich, dass die momentan definierten DKG-Zertifizierungskriterien für die Kinderonkologie in Deutschland in kritischen Bereichen einer fundierten wissenschaftlichen Grundlage entbehren.

Diese Arbeit stellt Fallzahlen als Maß für Qualität in der Kinderonkologie infrage und regt die Entwicklung alternativer Kriterien für die Überprüfbarkeit von Qualität in der deutschen Kinderonkologie an.
Automated monitoring of delamination factor during up (conventional) and down (climb) milling of melamine-faced MDF using image processing methods
Authors: Śmietańska Katarzyna , Podziewski Piotr , Bator Marcin , Górski Jarosław
Published: March 2020

The main goal of this paper was to examine whether image processing can be an effective tool in automatic quality control systems for furniture manufacturing, at least in cases where delamination is a key problem. Image processing turned out to be a very effective way of delamination factor monitoring. Moreover, the research analyzed the quality effect of up or down milling of melamine-faced MDF. The delamination factor increased significantly with increasing tool wear. However, the increase was not very regular. The experimental data showed that up milling had a significant advantage over down milling.
A quantitative comparison among different types of auxiliary slot, auxiliary tooth, and the slot opening in split-pole Vernier machine
Authors: Mirzaei Alavijeh Mohammad , Shamlou Sadegh
Published: March 2020

The Vernier permanent magnet machine is a high-torque, low-speed system suitable for direct-drive applications such as in-wheel electrical machines and wind generation turbines. In this paper, specific critical parameters of the electrical machine for auxiliary tooth and slot are investigated in different conditions. It should be noted that all the models are fully optimized and compared under the same condition by FEA analysis. The results illustrate that the stator with α ≠ β = θ is the best choice for stator split pole. Also, the concentrated winding is wound around the main stator tooth and the magnets mounted on the rotor surface. Besides, all essential characteristics for an electric machine such as torque, cogging torque, power factor, and efficiency are investigated. Furthermore, many basic formulas for designing a Vernier machine are proposed. This comparison helps designers choose the best combination among α, β, and θ in the split-pole structures. There is a nomenclature to organize this manuscript for the reader. It should be noted that all the figures are baked by ANSYS Electronics Maxwell version 19.0. Moreover, all of them are modified by Origin software to show with high quality.
Cold-Resistant Heterotrophic Ammonium and Nitrite-Removing Bacteria Improve Aquaculture Conditions of Rainbow Trout (Oncorhynchus mykiss)
Authors: Neissi Alireza , Rafiee Gholamreza , Farahmand Hamid , Rahimi Shadi , Mijakovic Ivan
Published: March 2020

The aim of this study was isolation and characterization of heterotrophic bacteria capable of ammonium and nitrite removal at 15 °C (optimal temperature for growing rainbow trout Oncorhynchus mykiss). Environmental isolates were grown in liquid media containing ammonium or nitrite, and best strains in terms of growth and ammonium or nitrite removal were identified via 16S rRNA sequencing. Dyadobacter sp. (no. 68) and Janthinobacterium sp. (no. 100) were selected for optimal adaptation to growth at 15 °C and best ammonium and nitrite removal (P < 0.05), respectively. A heterotrophic ammonium and nitrite removal (HAN) microbial complex, containing selected strains, was prepared and applied in a trout culture system. After 10 days, the effect of microbial HAN complex was investigated in terms of ammonium and nitrite removal, as well as stress and immune indices present in the plasma of cultivated trout. Compared to a standard cultivation setup, addition of the HAN complex had a clear beneficial effect on keeping the un-ionized ammonia and nitrite level below prescribed standards (P < 0.05). This resulted in reduction of stress and immune reactions of cultivated fish (P < 0.05), leading to an augmentation of final weight and survival. Application of the selected microbial complex resulted in a significant improvement of the aquaculture ecosystem.
Evaluation des Trabecular Bone Score (TBS) in der täglichen Praxis bei Patienten mit entzündlich rheumatischen und nichtentzündlichen Erkrankungen
Authors: Buehring B. , Thomas J. , Wittkämper T. , Baraliakos X. , Braun J.
Published: March 2020

Hintergrund

Osteoporosebedingte Frakturen sind bei Patienten mit rheumatoider Arthritis (RA) häufig. Die Messung der Knochenmineraldichte (KDM) mit der Dual-Energie-Röntgenabsorptionsmessung (DXA) allein sagt das Frakturrisiko nur begrenzt voraus. Der Trabecular Bone Score (TBS) ist ein Surrogatmarker für die trabekuläre Mikroarchitektur des Knochens, der das Frakturrisiko unabhängig von der KDM vorhersagen kann.

Ziel

Ermittlung der Prävalenz von KDM, TBS und osteoporotisch bedingten Wirbelkörperbrüchen („vertebral fractures“ [VF]) bei Patienten mit RA im Vergleich zu Kontrollen mit nichtentzündlichen Muskel-Skelett-Erkrankungen (MSK).

Methoden

Die Daten von Patienten mit von Rheumatologen diagnostizierter RA und verfügbaren TBS- und DXA-Messungen, die in unserem Krankenhaus von 2006 bis 2014 erhoben wurden, wurden retrospektiv analysiert. Den RA-Patienten wurden Kontrollen mit nichtentzündlichen MSK zugeordnet. Eine „reduzierte Knochengesundheit“ wurde definiert als ein T‑Score <−1,0 und/oder ein TBS-Wert <−1,31. Statistische Vergleiche wurden mit dem Mann-Whitney- und dem Wilcoxon-Test durchgeführt.

Ergebnisse

Es wurden 143 Patienten mit RA (Alter 72,1 ± 11,1 Jahre, 72 % weiblich) und 106 Kontrollen (Alter 69,6 ± 12,6 Jahre, 75 % weiblich) eingeschlossen. RA-Patienten hatten häufiger eine erniedrigte KDM (n = 102; 71,3 %) und einen erniedrigen TBS-Wert (n = 125; 87,4 %) als die Kontrollen (n = 63; 59,4 % und n = 79; 74,5 %, p = 0,049 und p = 0,009). RA-Patienten hatten mehr VF (n = 52, 36,4 %) als Kontrollen (n = 24, 22,6 %, p = 0,02). Insgesamt hatten 20 Patienten mit VF (26,3 %) eine normale Wirbelsäulen-KDM und 9 (11,8 %) auch eine normale Hüft-KDM. Bei Patienten mit VF war die Kombination eines niedrigen TBS bei normaler WS-KDM häufiger als ein normaler TBS bei niedriger WS-KDM (p = 0,008 für RA, p = 0,025 für Kontrollen).

Diskussion

VF treten bei Patienten mit normaler KDM auf. Bei Patienten mit VF wurde eine niedrige TBS bei normaler Wirbelsäulen-KDM häufiger gefunden als eine normale TBS bei niedriger Wirbelsäulen-KDM. Die Messung des TBS scheint für die Erkennung eines erhöhten Frakturrisikos bei RA-Patienten mit normaler WS-KDM nützlich zu sein.
Preliminary effect of projectile yaw on extremity gunshot wounding in a cadaveric animal model: a serendipitous study
Authors: Stevenson Tom , Carr Debra J , Gibb Iain E , Stapley Sarah A
Published: March 2020

Gunshot wounding (GSW) is capable of causing devastating tissue injuries by delivering kinetic energy (KE) through the contact surface area of a projectile. The contact surface area can be increased by yaw, deformation and fragmentation, all of which may be caused by any intermediate layers struck by the projectile prior to entering its target. This study aims to describe whether projectile yaw occurring before penetration of a cadaveric animal limb model causes greater damage with or without clothing layers present using 5.45 × 39 mm projectiles. In total, 12 fallow deer hind limbs were shot, further divided into 4 with no clothing layers (Cnil), 4 with a single clothing layer (Cmin) and 4 with maximum clothing layers (Cmax) as worn on active duty by UK military personnel. Contrast computed tomography (CT) of limbs was used to measure permanent cavity size and the results were compared using analysis of variance (ANOVA). No significant differences were found among clothing states for each series of measurements taken, with greater cavity sizes noted in all clothing states. This is in contrast to previous work looking at symmetrically flying projectiles in the same model, where a larger permanent cavity was found only with Cmax present. Projectile yaw is therefore likely to be a key variable with regard to causation of damage within this extremity wound model.
On the Tractability of Optimization Problems on H-Graphs
Authors: Fomin Fedor V. , Golovach Petr A. , Raymond Jean-Florent
Published: March 2020

For a graph H, a graph G is an H-graph if it is an intersection graph of connected subgraphs of some subdivision of H. H-graphs naturally generalize several important graph classes like interval graphs or circular-arc graph. This class was introduced in the early 1990s by Bíró, Hujter, and Tuza. Recently, Chaplick et al. initiated the algorithmic study of H-graphs by showing that a number of fundamental optimization problems like Maximum Clique, Maximum Independent Set, or Minimum Dominating Set are solvable in polynomial time on H-graphs. We extend and complement these algorithmic findings in several directions. First we show that for every fixed H, the class of H-graphs is of logarithmically-bounded boolean-width (via mim-width). Pipelined with the plethora of known algorithms on graphs of bounded boolean-width, this describes a large class of problems solvable in polynomial time on H-graphs. We also observe that H-graphs are graphs with polynomially many minimal separators. Combined with the work of Fomin, Todinca and Villanger on algorithmic properties of such classes of graphs, this identify another wide class of problems solvable in polynomial time on H-graphs. The most fundamental optimization problems among the problems solvable in polynomial time on H-graphs are Maximum Clique, Maximum Independent Set, and Minimum Dominating Set. We provide a more refined complexity analysis of these problems from the perspective of parameterized complexity. We show that Maximum Independent Set and Minimum Dominating Set are W[1]-hard being parameterized by the size of H plus the size of the solution. On the other hand, we prove that when H is a tree, then Minimum Dominating Set is fixed-parameter tractable parameterized by the size of H. For Maximum Clique we show that it admits a polynomial kernel parameterized by H and the solution size.
Grid-Resolution Requirements for Large-Eddy Simulations of the Atmospheric Boundary Layer
Authors: Wurps Hauke , Steinfeld Gerald , Heinz Stefan
Published: March 2020

Large-eddy simulations are widely used to study flows in the atmospheric boundary layer. As atmospheric boundary-layer flows of different atmospheric stratification have very different flow characteristics on different length scales, well-resolved simulations of these flows require very different meshes. The Parallelized Large-Eddy Simulation Model combined with a realizable dynamic subgrid model is used to identify the best method for evaluating the resolution requirements for boundary-layer flows simulated by large-eddy simulations. In particular, we consider three atmospheric boundary-layer set-ups with different stratifications (stable, neutral, convective) to investigate how the quality of the simulation changes with the grid resolution. By following the work of Davidson (Int J Heat Fluid Flow 30(5):1016–1025, 2009), the results are examined using criteria such as the convergence of mean profiles, the ratio of modelled and resolved turbulence kinetic energy, and the two-point correlation. We conclude that the two-point correlation is the best measure to evaluate whether the resolution demands for a specific flow are fulfilled.
Preliminary studies of hair follicle regeneration by injections of epidermal stem cells and dermal papilla cells into nude mice
Authors: Zhang Mingsheng , Ye Yan , Zhao Pin , Bai Liming , Li Xinping
Published: March 2020

The ultimate goal of organ regenerative therapy is to reproduce fully functional organs to replace which have been damaged as a result of diseases or injury. Although several studies claimed that using different types of cells in some animal models promote hair follicles regeneration, more researches can be done to develop a sufficient and efficient protocol to induce hair generation from different animal models. In this study, we investigated the therapeutic potentials for hair follicle formation by injecting a mixture of epidermal stem cells and dermal papilla cells. Those cells were isolated and culture-expanded. Then we randomly allocated 8 nude mice into two groups. The experiment group received an injection of a mixture that containing of epidermal stem cells and dermal papilla cells. The control group received injection of keratinocyte serum-free medium. The hair follicles regeneration was observed and the injection area was harvested for HE staining. 14 day later, the regenerated hair shafts were observed and HE staining indicated that the newly hair follicle formed the correct structures in experiment group. Furthermore, the mixture injection induced a regular and multilayered stratified epidermis and the epidermis contained of hair follicle-likes structures. Our data showed that injection of a mixture of epidermal stem cells and dermal papilla cells could induce hair follicles regeneration and well-ordered epidermis formation. This study emphasized that the rearrangement of the interactions during seed cells and the niches of the seed cells is essential and necessary for tissue-engineered construct success.
Variational Networks: An Optimal Control Approach to Early Stopping Variational Methods for Image Restoration
Authors: Effland Alexander , Kobler Erich , Kunisch Karl , Pock Thomas
Published: March 2020

We investigate a well-known phenomenon of variational approaches in image processing, where typically the best image quality is achieved when the gradient flow process is stopped before converging to a stationary point. This paradox originates from a tradeoff between optimization and modeling errors of the underlying variational model and holds true even if deep learning methods are used to learn highly expressive regularizers from data. In this paper, we take advantage of this paradox and introduce an optimal stopping time into the gradient flow process, which in turn is learned from data by means of an optimal control approach. After a time discretization, we obtain variational networks, which can be interpreted as a particular type of recurrent neural networks. The learned variational networks achieve competitive results for image denoising and image deblurring on a standard benchmark data set. One of the key theoretical results is the development of first- and second-order conditions to verify optimal stopping time. A nonlinear spectral analysis of the gradient of the learned regularizer gives enlightening insights into the different regularization properties.
Performance of Adiabatic Melting as a Method to Pursue the Lowest Possible Temperature in $$^{3}\hbox {He}$$ and $$^{3}\hbox {He}$$–$$^{4}\hbox {He}$$ Mixture at the $$^{4}\hbox {He}$$ Crystallization Pressure
Authors: Riekki T. S. , Sebedash A. P. , Tuoriniemi J. T.
Published: March 2020

We studied a novel cooling method, in which $$^{3}\hbox {He}$$3He and $$^{4}\hbox {He}$$4He are mixed at the $$^{4}\hbox {He}$$4He crystallization pressure at temperatures below $$0.5\,\mathrm {mK}$$0.5mK. We describe the experimental setup in detail and present an analysis of its performance under varying isotope contents, temperatures, and operational modes. Further, we developed a computational model of the system, which was required to determine the lowest temperatures obtained, since our mechanical oscillator thermometers already became insensitive at the low end of the temperature range, extending down to $$\left( 90\pm 20\right) \,\upmu {\mathrm {K}}\approx \frac{T_{c}}{\left( 29\pm 5\right) }$$90±20μK≈Tc29±5 ($$T_{c}$$Tc of pure $$^{3}\hbox {He}$$3He). We did not observe any indication of superfluidity of the $$^{3}\hbox {He}$$3He component in the isotope mixture. The performance of the setup was limited by the background heat leak of the order of $$30\,\mathrm {pW}$$30pW at low melting rates, and by the heat leak caused by the flow of $$^{4}\hbox {He}$$4He in the superleak line at high melting rates up to $$500\,\upmu \mathrm {mol/s}$$500μmol/s. The optimal mixing rate between $$^{3}\hbox {He}$$3He and $$^{4}\hbox {He}$$4He, with the heat leak taken into account, was found to be about $$100..150\,\upmu \mathrm {mol/s}$$100..150μmol/s. We suggest improvements to the experimental design to reduce the ultimate achievable temperature further.
On the eigenvalues of spectral gaps of matrix-valued Schrödinger operators
Authors: Aljawi Salma , Marletta Marco
Published: March 2020

This paper presents a method for calculating eigenvalues lying in the gaps of the essential spectrum of matrix-valued Schrödinger operators. The technique of dissipative perturbation allows eigenvalues of interest to move up the real axis in order to achieve approximations free from spectral pollution. Some results of the behaviour of the corresponding eigenvalues are obtained. The effectiveness of this procedure is illustrated by several numerical examples.
Exploring the burden of X-linked hypophosphatemia: a European multi-country qualitative study
Authors: Lo S. H. , Lachmann R. , Williams A. , Piglowska N. , Lloyd A. J.
Published: March 2020

Introduction

X-linked hypophosphatemia (XLH) is a rare, lifelong, progressive disease characterised by renal phosphate wasting and abnormal bone mineralisation. Symptoms begin in early childhood, with the development of rickets and related skeletal deformities and reduced growth, progressing to long-term complications, including pseudofractures and fractures, as well as pain, stiffness and fatigue. The present study was designed to explore the patient experience of pain, stiffness and fatigue and the psychosocial impact of XLH in detail.

Methods

A cross-sectional qualitative study was conducted in the United Kingdom (18), Finland (6), France (4), Germany (1) and Luxembourg (1) with XLH patients aged 26 and over. Interview discussion guides were developed in consultation with clinical experts and patient associations. Data were analysed thematically.

Results

Participants (N = 30) described pain, stiffness and fatigue as frequently experienced symptoms with a significant impact on physical functioning and activities of daily living (ADLs). Some also described the symptoms as impacting their mood/mental health, relationships, social life and leisure activities. Participants described how common symptoms could interact or aggravate other symptoms. Symptoms had often worsened over time, and for many, were associated with concern about the future. Most participants were worried or felt guilty about having children with XLH. The findings confirmed and extended the existing model of the burden of XLH.

Conclusion

The present study is the first to provide an in-depth analysis of pain, stiffness and fatigue, their impact and the interrelatedness of these symptoms among adults with XLH. The study also described the psychosocial impact of XLH as a hereditary, lifelong progressive disease.
Psychometric Network Models from Time-Series and Panel Data
Authors: Epskamp Sacha
Published: March 2020

Researchers in the field of network psychometrics often focus on the estimation of Gaussian graphical models (GGMs)—an undirected network model of partial correlations—between observed variables of cross-sectional data or single-subject time-series data. This assumes that all variables are measured without measurement error, which may be implausible. In addition, cross-sectional data cannot distinguish between within-subject and between-subject effects. This paper provides a general framework that extends GGM modeling with latent variables, including relationships over time. These relationships can be estimated from time-series data or panel data featuring at least three waves of measurement. The model takes the form of a graphical vector-autoregression model between latent variables and is termed the ts-lvgvar when estimated from time-series data and the panel-lvgvar when estimated from panel data. These methods have been implemented in the software package psychonetrics, which is exemplified in two empirical examples, one using time-series data and one using panel data, and evaluated in two large-scale simulation studies. The paper concludes with a discussion on ergodicity and generalizability. Although within-subject effects may in principle be separated from between-subject effects, the interpretation of these results rests on the intensity and the time interval of measurement and on the plausibility of the assumption of stationarity.
Berufliche Belastungen und Burnout-Risiko von Leitungs- und Fachkräften in Werkstätten für Menschen mit Behinderung: Ergebnisse der bundesweiten WeCareOnline-Studie
Authors: Schwangler Julia , Wahl Laura , Neuperdt Laura , Rathmann Katharina
Published: March 2020

Hintergrund

Laut dem aktuellen Fehlzeitenreport liegt für Fachkräfte eine hohe Prävalenz beruflicher Belastungen und psychischer Beanspruchungen wie z. B. Burnout vor. Für die besonders gefährdeten Fachkräfte (d. h. Leitungs- und Fachkräfte) in der Behindertenhilfe existieren für Deutschland keine Untersuchungen zu Arbeitsbelastungen und Burnout in Werkstätten für Menschen mit Behinderung (WfbM).

Ziel der Arbeit

Ziele der WeCareOnline-Studie sind 1) berufliche Belastungen und 2) das Burnout-Risiko von Fachkräften in WfbM in Deutschland zu ermitteln sowie 3) Zusammenhänge zwischen beruflichen Belastungen und dem Burnout-Risiko aufzudecken.

Material und Methoden

Es wurde eine quantitative Querschnittsstudie mittels Online-Befragung in WfbM in Deutschland durchgeführt. Der Fragebogen setzt sich aus bereits validierten Instrumenten (CBI, COPSOQ) zusammen. Mit SPSS erfolgten uni-, bi- sowie multivariate statistische (binär-logistische Regressions‑)Analysen.

Ergebnisse

Von den 396 an der Befragung teilnehmenden Fachkräften in WfbM (männlich = 50,5 %; weiblich = 49,5 %) berichten 60 % (n = 186) über ein hohes Burnout-Risiko. Befragte, die bei der Arbeit eine geringe Vorhersehbarkeit (Odds Ratio [OR]: 2,29; p < 0,05; 95 %-Konfidenzintervall [‑KI]: 1,13–4,64), ein geringes Gemeinschaftsgefühl (OR: 2,87; p < 0,01; 95 %-KI: 1,48–5,58), hohe physische Anforderungen (OR: 2,59; p < 0,01; 95 %-KI: 1,32–5,06) sowie ein niedriges Maß an Wertschätzung (OR: 2,72; p < 0,01; 95 %-KI: 1,32–5,58) angeben, weisen ein erhöhtes Burnout-Risiko auf.

Diskussion

Die Studie verdeutlicht, dass ein Großteil der Fachkräfte ein hohes Burnout-Risiko wahrnimmt und diverse berufliche Belastungen damit assoziiert sind. Zur Risikominimierung sind betriebliche Gesundheitsförderungsmaßnahmen zu empfehlen.
TrimetaziDine as a Performance-enhancING drug in heart failure with preserved ejection fraction (DoPING-HFpEF): rationale and design of a placebo-controlled cross-over intervention study
Authors: van de Bovenkamp A. A. , Bakermans A. J. , Allaart C. P. , Nederveen A. J. , Kok W. E. M. , van Rossum A. C. , Handoko M. L.
Published: March 2020

Background

Currently, no specific treatment exists for heart failure with preserved ejection fraction (HFpEF). Left ventricular (LV) relaxation during diastole is a highly energy-demanding process, while energy homeostasis is known to be compromised in HFpEF. We hypothesise that trimetazidine – a fatty acid β‑oxidation inhibitor – improves LV diastolic function in HFpEF, by altering myocardial substrate use and improving the myocardial energy status.

Objectives

To assess whether trimetazidine improves LV diastolic function by improving myocardial energy metabolism in HFpEF.

Methods

The DoPING-HFpEF trial is a randomised, double-blind, placebo-controlled cross-over intervention trial comparing the efficacy of trimetazidine and placebo in 25 patients with stable HFpEF. The main inclusion criteria are: New York Heart Association functional class II to IV, LV ejection fraction ≥50%, and evidence of LV diastolic dysfunction. Patients are treated with one 20-mg trimetazidine tablet or placebo thrice daily (twice daily in the case of moderate renal dysfunction) for two periods of 3 months separated by a 2-week washout period. The primary endpoint is the change in pulmonary capillary wedge pressure during different intensities of exercise measured by right heart catheterisation. Our key secondary endpoint is the myocardial phosphocreatine (PCr)/ATP ratio measured by phosphorus-31 magnetic resonance spectroscopy and its relation to the primary endpoint. Exploratory endpoints are 6‑min walk distance, N-terminal pro-brain natriuretic peptide levels, and quality of life.

Conclusion

The DoPING-HFpEF is a phase-II trial that evaluates the effect of trimetazidine, a metabolic modulator, on diastolic function and myocardial energy status in HFpEF. [EU Clinical Trial Register: 2018-002170-52; NTR registration: NL7830]
Microstructure modification of Y2O3 stabilized ZrO2 thermal barrier coatings by laser glazing and the effects on the hot corrosion resistance
Authors: Guo Lei , Xin Hui , Zhang Zhao , Zhang Xinmu , Ye Fuxing
Published: March 2020

Y2O3 stabilized ZrO2 (YSZ) thermal barrier coatings (TBCs) are prone to hot corrosion by molten salts. In this study, the microstructure of atmospheric plasma spraying YSZ TBCs is modified by laser glazing in order to improve the corrosion resistance. By optimizing the laser parameters, a ∼18 µm smooth glazed layer with some vertical cracks was produced on the coating surfaces. The as-sprayed and modified coatings were both exposed to hot corrosion tests at 700 and 1000 °C for 4 h in V2O5 molten salt, and the results revealed that the modified one had improved corrosion resistance. After hot corrosion, the glazed layer kept structural integrity, with little evidence of dissolution. However, the vertical cracks in the glazed layer acted as the paths for molten salt penetration, accelerating the corrosion of the non-modified coating. Further optimization of the glazed layer is needed in the future work.
Direct Synthesis of 5A Zeolite From Palygorskite: The Influence of Crystallization Directing Agent on the Separation Performance for Hexane Isomers
Authors: Chen Le , Qian Jun-Yan , Yang Chuang , Xu Ping-Ping , Zhu Dan-Dan , Zhong Jing , He Ming-Yang , Chen Qun , Zhang Zhi-Hui
Published: March 2020

The efficient separation of hexane isomers from the light naphtha fraction is a significant challenge in the petrochemical industry. 5A zeolite adsorbent is used commercially to sieve alkane isomers. In this study, 5A zeolites were synthesized using a low-cost natural clay mineral precursor, i.e. palygorskite (PAL), with the addition of crystallization directing agent (CDA). By varying the mass ratio of CDA/deionized water, 5A zeolites were obtained as CDA-5%, CDA-7.5%, and CDA-10%. All products were submicron particles with an average particle size of 400–800 nm. A sieving test of CDA-induced 5A zeolites was carried out on hexane adsorbates including n-hexane (nHEX), 2-methylpentane (2MP), and 3-methylpentane (3MP). According to vapor-phase batch adsorption experiments, a significant equilibrium amount (0.149 g/g) of nHEX and only 0.0321 g/g 2MP and 0.0416 g/g 3MP were adsorbed on the 5A zeolite product with CDA-5%. The dynamic adsorption performance of 5A zeolite (CDA-5%) was evaluated by breakthrough curves of binary mixtures of nHEX/2MP and nHEX/3MP. Palygorskite 5A (PAL 5A) zeolite achieved maximum dynamic adsorption capacities of nHEX (0.16 g/g in both cases) at 200°C and 1.2 MPa total pressure. This work provided an economic alternative for the synthesis of 5A zeolites using natural clay minerals instead of chemical raw materials.
A Large-Scale Comparison of Canadian Sexual/Gender Minority and Heterosexual, Cisgender Adolescents’ Pornography Use Characteristics
Authors: Bőthe Beáta , Vaillancourt-Morel Marie-Pier , Girouard Alice , Štulhofer Aleksandar , Dion Jacinthe , Bergeron Sophie
Published: March 2020

Background

The ease of access to pornography has made its use common among adolescents. Although sexual and gender minority (SGM) (eg, gay, transgender) adolescents may be more prone to use pornography owing to sexual orientation–related information seeking and/or scarcity of potential romantic or sexual partners, relatively little attention has been paid to their pornography use and to the quantitative examination of the similarities and differences between heterosexual, cisgender (HC) and SGM adolescents’ pornography use characteristics.

Aim

The aim of the present study was to compare SGM and HC adolescents’ pornography use considering potential sex differences.

Methods

We used a sample of 2,846 adolescents (52.5% girls; M  age = 14.5 years, SD = 0.6), which was collected as part of an ongoing longitudinal study on adolescents’ sexual health. Data were analyzed with 5 groups: HC boys; HC girls; SGM boys; SGM girls; and SGM non-binary individuals.

Outcomes

Adolescents completed a self-report questionnaire about sexual and gender minority status and pornography use (ie, lifetime use, age at first exposure, and frequency of use in the past 3 months.)

Results

Results indicated significant differences between all groups: 88.2% of HC boys, 78.2% of SGM boys, 54.2% of SGM girls, 39.4% of HC girls, and 29.4% of SGM non-binary individuals reported having ever viewed pornography by the age of 14 years. SGM girls indicated a significantly younger age at first pornography use than HC girls, but this difference was not significant among boys. SGM boys reported the highest (median: many times per week), whereas HC girls reported the lowest (median: less than once a month) frequency of pornography use.

Clinical Translation

Results suggest that SGM and HC boys' pornography use characteristics are rather similar, whereas SGM and HC girls’ pornography use patterns may be considered different presumably because of the varying underlying motivations (eg, using pornography to confirm sexual orientation).

Strengths & Limitations

Self-report measures and cross-sectional designs have potential biases that should be considered. However, the present study involved a large sample of adolescents including SGM adolescents, a population group that is understudied.

Conclusion

Approximately two-thirds of teenagers had gained their first experience with pornography in the present sample, and 52.2% reported using it once a week or more often in the past 3 months, indicating that pornography use may play an important role in both HC and SGM adolescents’ sexual development. Gender-based differences concerning pornography use seem to be robust regardless of SGM status.
Evaluating the effects of lateral control surfaces failure on the generic transport model: a case study
Authors: Norouzi R. , Kosari A. , Sabour M. Hossein
Published: March 2020

Extensive research in recent years has focused on improving the current loss-of-control prevention systems and developing new strategies for safe path planning of the impaired aircraft. Success in developing such systems requires a comprehensive perception of the influence of damage on the aircraft’s dynamic behaviour and performance, and the effect of various failure degrees on the flight envelope confinement and the remaining safe maneuvers. This paper comprehensively describes the effects of lateral control surface failure on the NASA Generic Transport Model (GTM) flight envelope, defined by a set of attainable steady-state maneuvers herein referred to as trim points. The study utilises a large database of high-fidelity maneuvering flight envelopes computed for the unimpaired case and wide ranges of the aileron and rudder failure cases at different flight conditions. Flight envelope boundary is rigorously investigated, and the key parameters confining the trim points at different boundary sections are identified. Trend analyses of the impaired flight envelopes and the corresponding limiting factors demonstrate the effect of various failure degrees on the remaining feasible trim points. Results can be employed in emergency path planning with potential uses in the development of aircraft resilient control and upset recovery systems.
Formation of sea ice ponds from ice-shelf runoff, adjacent to the McMurdo Ice Shelf, Antarctica
Authors: Macdonald Grant J. , Popović Predrag , Mayer David P.
Published: March 2020

Ponds that form on sea ice can cause it to thin or break-up, which can promote calving from an adjacent ice shelf. Studies of sea ice ponds have predominantly focused on Arctic ponds formed by in situ melting/ponding. Our study documents another mechanism for the formation of sea ice ponds. Using Landsat 8 and Sentinel-2 images from the 2015–16 to 2018–19 austral summers, we analyze the evolution of sea ice ponds that form adjacent to the McMurdo Ice Shelf, Antarctica. We find that each summer, meltwater flows from the ice shelf onto the sea ice and forms large (up to 9 km2) ponds. These ponds decrease the sea ice's albedo, thinning it. We suggest the added mass of runoff causes the ice to flex, potentially promoting sea-ice instability by the ice-shelf front. As surface melting on ice shelves increases, we suggest that ice-shelf surface hydrology will have a greater effect on sea-ice stability.
WOMEN'S ROLE IN THE PRODUCTION AND SALE OF ALCOHOL IN HAN CHINA AS REFLECTED IN TOMB ART FROM SICHUAN
Authors: Elias Hajni
Published: March 2020

Pictorial brick tiles and stone carvings from the Eastern Han period show women engaged in the production of alcohol, and early histories and literary sources provide an insight into women's role in brewing, drinking, and selling alcohol in shops and in the market. Preparation of alcohol for ritual ceremonies, banquets, and daily consumption is listed among the many household duties for which women were responsible. It was women's work (nüshi女事), as was the production of textiles, which assigned women with an economic role but also gave them a moral identity in the social sphere. However, women's mastery of brewing—mentioned but rarely elaborated—upon, did not connote feminine virtues in the same way as weaving. Through a close examination of artistic representations that show women engaged in the making of alcohol on the estate and in a workshop setting in the southwest (present-day Sichuan province), this article aims to examine the role women played in alcohol production and their contribution to the economy of both their household and the region in early Imperial China.
Teachers in the Movement: Pedagogy, Activism, and Freedom
Authors: Alridge Derrick P.
Published: March 2020

In this year's Presidential Address, historian Derrick P. Alridge discusses his current research project, Teachers in the Movement: Pedagogy, Activism, and Freedom. The project builds on recent literature about teachers as activists between 1950 and 1980 and explores how and what secondary and postsecondary teachers taught. Focusing on teachers in Maryland, Virginia, North Carolina, South Carolina, and Georgia, the project investigates teachers’ roles as agents of social change through teaching the ideals of freedom during the most significant social movement in the United States in the twentieth century. Drawing on oral history and archival research, the project plans to produce five hundred videotaped interviews that will generate extensive firsthand knowledge and fresh perspectives about teachers in the civil rights movement. By examining teachers’ pedagogical activism during this period of rapid social change, Alridge hopes to inspire and inform educators teaching in the midst of today's freedom and social justice movements.