bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of micro‐ and nanofiller hybrids on the dynamic mechanical properties of glass reinforced epoxy composites
Authors: Bommegowda Kabbala Basavarajappa , Renukappa Nijagal Marulaiah , Rajan Jagannathan Sundara
Published: February 2021

Reinforcement of epoxy glass fabric composites with nano‐ and micro‐fillers has resulted in the development of polymer composites with good electrical, thermal, and mechanical properties. The present work attempts to estimate the impact of hybrid fillers on dynamic‐mechanical properties of the epoxy composites with a different filler. The dynamic mechanical parameters such as storage modulus, loss modulus, and damping factor over a temperature of 25°C–250°C have been investigated. The viscoelastic properties of composites are also confirmed with a Cole‐Cole plot. From the results, the storage modulus of the composites is observed to lie in the range of 8000 to 12,500 MPa, and the epoxy composite with silicon carbide filler shows the highest storage modulus. Composite with 5 wt% of alumina shows the maximum loss modulus of 2100 MPa. The glass transition temperature of the base epoxy composite is 135°C and it increases to 137°C with the incorporation of hybrid cenosphere and molybdenum sulfide fillers. The storage modulus shows only marginal differences as compared to their counterparts with nanofillers but is higher by about 10–15% in comparison to the micron filler‐based composites. However, the differences in the loss modulus of the nanocomposites, hybrid composites, and the composites with micron‐sized filler are not significant.
Effect of silane concentration on the properties of crosslinked linear low density polyethylene‐montmorillonite nanocomposite
Authors: Yussuf Abdirahman A. , Al‐Saleh Mohammad A. , Al‐Enezi Salah T. , Abraham Gils
Published: February 2021

In this study, linear low density polyethylene (LLDPE) was grafted and crosslinked by reactive extrusion melt compounding using different silane concentration with and without the presence of montmorillonite (MMT) nanoclay. The effects of different silane concentration and the addition of nanoclay filler on the degree of crosslinking, mechanical, thermal, rheological, and morphological properties were investigated and reported. Gel content results for all crosslinked samples were found to increase with increasing silane concentration. Tensile strength and Young's modulus of crosslinked LLDPE samples increased with increasing silane concentration compared to neat LLDPE; while the crosslinked LLDPE samples containing nanoclay have achieved higher tensile strength and Young's modulus, indicating strong interfacial interaction between silane grafted LLDPE matrix and nanoclay. However, the decrease of elongation at break for all crosslinked samples were observed compared to neat LLDPE. A reduction in the degree of crystallinity for crosslinked samples, particularly crosslinked samples containing nanoclay, was shown by thermal analysis results; whereas the melting temperature did not change significantly with increased silane concentration and subsequent addition of nanoclay. Thermogravimetric analysis results have revealed significant thermal stability improvement for neat LLDPE with increased silane concentration. Furthermore, crosslinked samples containing nanoclay have achieved better thermal stability compared to crosslinked samples without nanoclay. At lower frequency, it was found that viscosity, and storage modulus of neat LLDPE increased with increased silane concentration due to crosslinking and further addition of nanoclay into crosslinked LLDPE. The transmission electron microscopy results confirmed the intercalated structure of the nanocomposite for the crosslinked samples containing nanoclay.
Additives to prevent the formation of surface defects during poly(vinyl chloride) calendering
Authors: Jamarani Roya , Halloran Matthew W. , Panchal Kushal , Garcia‐Valdez Omar , Mafi Roozbeh , Nicell James A. , Leask Richard L. , Marić Milan
Published: February 2021

Gas checks are visible fleck‐shaped defects that occur on the surface of poly(vinyl chloride) (PVC) films during industrial calendering. Films containing these surface defects often do not meet minimum product specifications and therefore must be disposed of or recycled, resulting in increased cost and material waste. Currently, gas checks are controlled by keeping film gauge low and through trial‐and‐error modifications of processing parameters by calender operators. In this work, our group developed a series of chemical additives that can be blended with PVC to prevent the formation of gas check defects. We found that a series of poly(caprolactone) (PCL)‐based compounds with diester linkers and alkyl chain cappers were all effective at preventing the formation of gas checks during calendering, with additive concentrations as low as 8 phr producing films with no gas checks. We found that the blends produced with our additives had higher melt viscosities than those produced with additives that do not remove gas checks, suggesting that viscosity plays an important role in preventing gas check defects.
About the Azido Derivatives of Pentaerythritol Tetranitrate
Authors: Lenz Tobias , Klapötke Thomas M. , Mühlemann Moritz , Stierstorfer Jörg
Published: February 2021

With the first ever synthesis of monoazidopentaerythritol trinitrate, a comparative study of the properties of all azidonitrate derivatives from pentaerythritol tetranitrate (PETN) to tetraazidopentaerythritol (TAPE) was possible. The azides were prepared by halogen azide exchange and the remaining alcohols were then converted into the organic nitrate esters using acetyl nitrate. The resulting compounds pentaerythritol tetranitrate (PETN), monoazidopentaerythritol mononitrate (MAPETN), diazidopentaerythritol dinitrate (DAPEDN), triazidopentaerythritol mononitrate (TAPEMN), tetraazidopentaerythritol (TAPE) were analyzed for their chemical (XRD, NMR, EA, IR) and energetic properties (DTA/DSC, impact and friction sensitivity) and presented for comparison. An interesting trend of decreasing melting points from PETN to the triazide was observed, with the monoazide found to meet the thermal requirements for a melt‐castable explosive. The mechanical sensitivities were successfully explained by Hirshfeld analysis. The energetic properties were calculated with the EXPLO5 code and show a decreasing performance towards the highly sensitive tetraazido derivative. Furthermore, PETN was successfully initiated with its tetraazido derivative TAPE.
Promising influences ofScutellaria baicalensisand its two active constituents, baicalin, and baicalein, against metabolic syndrome: A review
Authors: Baradaran Rahimi Vafa , Askari Vahid Reza , Hosseinzadeh Hossein
Published: February 2021

Metabolic syndrome is known as a group of metabolic abnormalities with features including central obesity, insulin resistance, hypercholesterolemia, hypertriglyceridemia, and hypertension as well as low level of high‐density lipoprotein (HDL)‐cholesterol. Previous studies showed the ameliorating effects ofScutellaria baicalensison metabolic syndrome parameters, including antidiabetic, anti‐hyperlipidemic, anti‐obesity, and antihypertensive. In this review, we deeply and mechanistically evaluated different studies on the effect ofS. baicalensisand its two major bioactive constituents, baicalin, and baicalein, on the critical components of metabolic syndrome, including diabetes, hyperlipidemia, obesity, hypertension, and atherosclerosis. Scientific databases, including PubMed, Scopus, and Google Scholar were searched in the English language until the end of June 2020. Accordingly,S. baicalensis,and its two major bioactive constituents, baicalin and baicalein, represent promising effects on the control of metabolic syndrome and its related disorders such as obesity, hyperlipidemia, atherosclerosis, diabetes, and their following complications. In summary, our findings show thatS. baicalensisand its active constituents, baicalin and baicalein, by activation and upregulation of AMPK and PPAR‐γ as the main signaling in the hemostasis of glucose and lipid metabolisms may be favorable candidates for the prevention and treatment of the metabolic syndrome.
Template‐Free Synthesis of Zinc Cobalt Oxides/Phosphides (Co2P/CoO/ZnCo2O4) Hollow Sub‐Micron Boxes as Hydrogen Evolution Reaction Catalysts
Authors: Zhang Chunlei , Pan Yexin , Ouyang Chong , Li Xiaoyu , Quan Xinyao , Hong Zhanglian , Zhi Mingjia
Published: February 2021

In this work, we report the template‐free synthesis of zinc cobalt oxides/phosphides (Co2P/CoO/ZnCo2O4) hollow sub‐micron boxes as electrocatalysts for HER (hydrogen evolution reaction). The synthesis of such sub‐micron box starts with the preparation of the hollow oxide sub‐micron box and is followed by a phosphorization process. It is proven that the selective etching induces by cation exchange (Zn2+ and Co2+) was the key to the formation of the hollow structure. The analysis of chemical states and electrochemical activity further reveals Zn enhanced the intrinsic activity of catalysts by increasing the electron density of Co in final products. The optimized ZnCo‐OP hollow sub‐micron box exhibits good HER activity with overpotentials of 112 mV at 10 mA/cm2 and 197 mV at 250 mA/cm2.
MXenes: Synthesis, Optical Properties, and Applications in Ultrafast Photonics
Authors: Fu Bo , Sun Jingxuan , Wang Cong , Shang Ce , Xu Lijun , Li Jiebo , Zhang Han
Published: February 2021

Recently, 2D materials are in great demand for various applications such as optical devices, supercapacitors, sensors, and biomedicine. MXenes as a kind of novel 2D material have attracted considerable research interest due to their outstanding mechanical, thermal, electrical, and optical properties. Especially, the excellent nonlinear optical response enables them to be potential candidates for the applications in ultrafast photonics. Here, a review of MXenes synthesis, optical properties, and applications in ultrafast lasers is presented. First, aqueous acid etching and chemical vapor deposition methods for preparing MXenes are introduced, in which the storage stability and challenges of the existing synthesis techniques are also discussed. Then, the optical properties of MXenes are discussed specifically, including plasmonic properties, optical detection, photothermal effects, and ultrafast dynamics. Furthermore, the typical ultrafast pulsed lasers enabled by MXene‐based saturable absorbers operated at different wavelength regions are summarized. Finally, a summary and outlook on the development of MXenes is presented in the perspectives section.
Grain Boundary Passivation with Dion–Jacobson Phase Perovskites for High‐Performance Pb–Sn Mixed Narrow‐Bandgap Perovskite Solar Cells
Authors: Zhang Lei , Kang Qiao , Song Yanping , Chi Dan , Huang Shihua , He Gang
Published: February 2021

The mixed Pb–Sn perovskites have the ideal bandgap of ≈1.2 eV for photovoltaic application. However, the undesirable p‐doping introduced by Sn2+ oxidation restrains the device's power conversion efficiency (PCE) and stability. Herein, an additive strategy with p‐phenyl dimethylammonium iodide (PhDMADI) is proposed, which has a bulky divalent organic cation and facilitates the formation of Dion–Jacobson phase‐based quasi‐2D perovskites at the grain boundaries. It is found that this unique 2D/3D bulk heterojunction structure is beneficial to suppress the oxidation of Sn2+ and isolate the moisture and oxygen, resulting in a good stability of the solar cell. Moreover, the quasi‐2D perovskites can passivate defects effectively. The trap density of the perovskite film has decreased by one order of magnitude, thus the carrier lifetime is increased more than twice. These enhanced properties enable us to fabricate a device of 20.5% PCE with great stability.
Potential Role of Kesterites in Development of Earth‐Abundant Elements‐Based Next Generation Technology
Authors: Gour Kuldeep Singh , Karade Vijay , Babar Pravin , Park Jongsung , Lee Dong Min , Singh Vidya Nand , Kim Jin Hyeok
Published: February 2021

Recently, Cu2ZnSn(S,Se)4 (CZTSSe)‐based kesterite thin films have received growing attention in a wide variety of fields due to their suitable physico‐chemical asset nano‐ and micro‐scale. The low elemental cost, earth abundance, and environment‐friendly nature have widened the scope and made it a potential material for developing next‐generation technology. The kesterite thin films have already shown their potential in thin‐film photovoltaics (PVs) with a record efficiency of nearly 12.6%. Apart from solar cells, they have also demonstrated their widespread applicability in the field of photodetectors, gas sensors, thermoelectrics, solar water splitting, energy storage, humidity sensors, antibacterial activities, and many more. This review aims to present an overview of the advancement in the CZTSSe‐based kesterite thin films in terms of synthesis, material properties, and their use in various applications. A comprehensive review of each device application contains ongoing progress, device fabrication, and related issues. Furthermore, this review emphasizes kesterite materials and possible solutions to proposed pitfalls, thus strengthening kesterite's perspective.
Effect of steel fiber on the shear behavior of reinforced recycled aggregate concrete beams
Authors: Ibrahim Yasser E. , Fawzy Khaled , Farouk Mohamed A.
Published: February 2021

In this research, the influence of using steel fibers on the shear action of reinforced concrete beams, made of recycled concrete aggregate (RCA), was investigated through experiment and finite element analysis (FEA). First, 12 reinforced concrete beams were tested with varying amounts of steel fibers. These beams contained normal concrete aggregate (NCA) as reference beams besides RCA beams. All beam models had the same 150 mm x 250 mm cross‐section and 2000 mm length. The beams had three bars of 16 mm reinforcement and two bars of 12 mm reinforcement at its bottom and top, respectively. Three replacement ratios of recycled aggregate (RA) were considered; 0%, 30%, and 70%. Moreover, steel fibers were introduced in the beams at 0%, 0.5%, 1%, and 1.5% content by volume. The beams were evaluated under a four‐point bending test while the load‐deflection diagram and failure load for all beams were considered as the criteria for comparing the shear response of different beams. A thorough FEA was carried out using ANSYS to model these beams. The FEA results were compared with the outcomes of the experimental tests, and a clear agreement was obtained. The results showed that using steel fibers improved the shear strength of the beams by 2.94%, 15.88%, and 34.71% for NAC beams, 1.39%, 11.11%, and 16.67% for 30% RCA beams, and 24.53%, 40.57%, and 59.44% for 70% RCA beams, respectively by using steel fibers with ratios of 0.5%, 1%, and 1.5%, respectively.
Haemophagocytic histiocytic sarcoma with presumed involvement of the skeletal musculature in a greyhound
Authors: Cruzado Perez Judith , Beck Samuel , Di Bella Andrea , Kelly Darren
Published: February 2021

An 11‐year‐old male neutered Greyhound was evaluated for severe generalized pain of one‐week duration. Lameness, hyporexia, acute diarrhoea and pyrexia were also listed symptoms. Computerized tomography of thorax and abdomen revealed splenomegaly with multiple nodules, mediastinal, tracheobronchial and hepatic lymphadenomegaly, and multiple irregular and hypoattenuating skeletal muscular lesions. Ultrasound‐guided aspirates of the spleen, hepatic lymph nodes and muscular lesions were performed followed by splenectomy, hepatic biopsy and excision of multiple intra‐abdominal lymph nodes. The final diagnosis after histopathology and immunohistochemistry was haemophagocytic histiocytic sarcoma with presumed involvement of skeletal musculature. The patient was euthanised due to clinical deterioration and grave prognosis.
5D BPS quivers and KK towers
Authors: Duan Zhihao , Ghim Dongwook , Yi Piljin
Published: February 2021

Abstract

We explore BPS quivers for D = 5 theories, compactified on a circle and geometrically engineered over local Calabi-Yau 3-folds, for which many of known machineries leading to (refined) indices fail due to the fine-tuning of the superpotential. For Abelian quivers, the counting reduces to a geometric one, but the technically challenging L2 cohomology proved to be essential for sensible BPS spectra. We offer a mathematical theorem to remedy the difficulty, but for non-Abelian quivers, the cohomology approach itself fails because the relevant wavefunctions are inherently gauge-theoretical. For the Cartan part of gauge multiplets, which suffers no wall-crossing, we resort to the D0 picture and reconstruct entire KK towers. We also perform numerical checks using a multi-center Coulombic routine, with a simple hypothesis on the quiver invariants, and extend this to electric BPS states in the weak coupling chamber. We close with a comment on known Donaldson-Thomas invariants and on how L2 index might be read off from these.
CP violating effects in 210Fr and prospects for new physics beyond the Standard Model
Authors: Shitara Nanako , Yamanaka Nodoka , Sahoo Bijaya Kumar , Watanabe Toshio , Das Bhanu Pratap
Published: February 2021

Abstract

We report theoretical results of the electric dipole moment (EDM) of 210Fr which arises from the interaction of the EDM of an electron with the internal electric field in an atom and the scalar-pseudoscalar electron-nucleus interaction; the two dominant sources of CP violation in this atom. Employing the relativistic coupled-cluster theory, we evaluate the enhancement factors for these two CP violating interactions to an accuracy of about 3% and analyze the contributions of the many-body effects. These two quantities in combination with the projected sensitivity of the 210Fr EDM experiment provide constraints on new physics beyond the Standard Model. Particularly, we demonstrate that their precise values are necessary to account for the effect of the bottom quark in models in which the Higgs sector is augmented by nonstandard Yukawa interactions such as the two-Higgs doublet model.
Three-loop soft function for energetic electroweak boson production at hadron colliders
Authors: Liu Ze Long , Stahlhofen Maximilian
Published: February 2021

Abstract

We calculate the three-loop soft function for the production of an electroweak boson (Higgs, γ, W±, Z) with large transverse momentum at a hadron collider. It is the first time a soft function for a three-parton process is computed at next-to-next-to-next-to-leading order (N3LO). As a technical novelty, we perform the calculation in terms of forward-scattering-type loop diagrams rather than evaluating phase space integrals. Our three-loop result contains color-tripole contributions and explicitly confirms predictions on the universal infrared structure of QCD scattering amplitudes with three massless parton legs. The soft function is a central ingredient in the factorized cross section for electroweak boson production near the kinematic endpoint (threshold), where the invariant mass of the recoiling hadronic radiation is small compared to its transverse momentum. Our result is required for predictions of the near-threshold cross sections at N3LO and for the resummation of threshold logarithms at primed next-to-next-to-next-to-leading logarithmic (N3LL′) accuracy.
The time-dependent angular analysis of Bd → KSℓℓ, a new benchmark for new physics
Authors: Descotes-Genon Sébastien , Novoa-Brunet Martín , Vos K. Keri
Published: February 2021

Abstract

We consider the time-dependent analysis of Bd→ KSℓℓ taking into account the time-evolution of the Bd meson and its mixing into $$ {\overline{B}}_d $$

B
¯

d

. We discuss the angular conventions required to define the angular observables in a transparent way with respect to CP conjugation. The inclusion of time evolution allows us to identify six new observables, out of which three could be accessed from a time-dependent tagged analysis. We also show that these observables could be obtained by time-integrated measurements in a hadronic environment if flavour tagging is available. We provide simple and precise predictions for these observables in the SM and in NP models with real contributions to SM and chirally flipped operators, which are independent of form factors and charm-loop contributions. As such, these observables provide robust and powerful cross-checks of the New Physics scenarios currently favoured by global fits to b → sℓℓ data. In addition, we discuss the sensitivity of these observables with respect to NP scenarios involving scalar and tensor operators, or CP-violating phases. We illustrate how these new observables can provide a benchmark to discriminate among the various NP scenarios in b → sμμ. We discuss the extension of these results for Bs decays into f0, η or η′.
Black hole interactions at large D: brane blobology
Authors: Suzuki Ryotaku
Published: February 2021

Abstract

In the large dimension (D) limit, Einstein’s equation reduces to an effective theory on the horizon surface, drastically simplifying the black hole analysis. Especially, the effective theory on the black brane has been successful in describing the non-linear dynamics not only of black branes, but also of compact black objects which are encoded as solitary Gaussian-shaped lumps, blobs. For a rigidly rotating ansatz, in addition to axisymmetric deformed branches, various non-axisymmetric solutions have been found, such as black bars, which only stay stationary in the large D limit.

In this article, we demonstrate the blob approximation has a wider range of applicability by formulating the interaction between blobs and subsequent dynamics. We identify that this interaction occurs via thin necks connecting blobs. Especially, black strings are well captured in this approximation sufficiently away from the perturbative regime. Highly deformed black dumbbells and ripples are also found to be tractable in the approximation. By defining the local quantities, the effective force acting on distant blobs are evaluated as well. These results reveal that the large D effective theory is capable of describing not only individual black holes but also the gravitational interactions between them, as a full dynamical theory of interactive blobs, which we call brane blobology.
Two-loop superstring five-point amplitudes. Part II. Low energy expansion and S-duality
Authors: D’Hoker Eric , Mafra Carlos R. , Pioline Boris , Schlotterer Oliver
Published: February 2021

Abstract

In an earlier paper, we constructed the genus-two amplitudes for five external massless states in Type II and Heterotic string theory, and showed that the α′ expansion of the Type II amplitude reproduces the corresponding supergravity amplitude to leading order. In this paper, we analyze the effective interactions induced by Type IIB superstrings beyond supergravity, both for U(1)R-preserving amplitudes such as for five gravitons, and for U(1)R-violating amplitudes such as for one dilaton and four gravitons. At each order in α′, the coefficients of the effective interactions are given by integrals over moduli space of genus-two modular graph functions, generalizing those already encountered for four external massless states. To leading and sub-leading orders, the coefficients of the effective interactions D2ℛ5 and D4ℛ5 are found to match those of D4ℛ4 and D6ℛ4, respectively, as required by non-linear supersymmetry. To the next order, a D6ℛ5 effective interaction arises, which is independent of the supersymmetric completion of D8ℛ4, and already arose at genus one. A novel identity on genus-two modular graph functions, which we prove, ensures that up to order D6ℛ5, the five-point amplitudes require only a single new modular graph function in addition to those needed for the four-point amplitude. We check that the supergravity limit of U(1)R-violating amplitudes is free of UV divergences to this order, consistently with the known structure of divergences in Type IIB supergravity. Our results give strong consistency tests on the full five-point amplitude, and pave the way for understanding S-duality beyond the BPS-protected sector.
Algebra of quantum $$ \mathcal{C} $$-polynomials
Authors: Mironov Andrei , Morozov Alexei
Published: February 2021

Abstract

Knot polynomials colored with symmetric representations of SLq(N) satisfy difference equations as functions of representation parameter, which look like quantization of classical $$ \mathcal{A} $$
A
-polynomials. However, they are quite difficult to derive and investigate. Much simpler should be the equations for coefficients of differential expansion nicknamed quantum $$ \mathcal{C} $$
C
-polynomials. It turns out that, for each knot, one can actually derive two difference equations of a finite order for these coefficients, those with shifts in spin n of the representation and in A = qN. Thus, the $$ \mathcal{C} $$
C
-polynomials are much richer and form an entire ring. We demonstrate this with the examples of various defect zero knots, mostly discussing the entire twist family.
A note on letters of Yangian invariants
Authors: He Song , Li Zhenjie
Published: February 2021

Abstract

Motivated by reformulating Yangian invariants in planar $$ \mathcal{N} $$
N
= 4 SYM directly as d log forms on momentum-twistor space, we propose a purely algebraic problem of determining the arguments of the d log’s, which we call “letters”, for any Yangian invariant. These are functions of momentum twistors Z ’s, given by the positive coordinates α’s of parametrizations of the matrix C(α), evaluated on the support of polynomial equations C(α) · Z = 0. We provide evidence that the letters of Yangian invariants are related to the cluster algebra of Grassmannian G(4, n), which is relevant for the symbol alphabet of n-point scattering amplitudes. For n = 6, 7, the collection of letters for all Yangian invariants contains the cluster $$ \mathcal{A} $$
A
coordinates of G(4, n). We determine algebraic letters of Yangian invariant associated with any “four-mass” box, which for n = 8 reproduce the 18 multiplicative-independent, algebraic symbol letters discovered recently for two-loop amplitudes.
Baryonic Higgs and dark matter
Authors: Pérez Pavel Fileviez , Murgui Clara , Plascencia Alexis D.
Published: February 2021

Abstract

We discuss the correlation between dark matter and Higgs decays in gauge theories where the dark matter is predicted from anomaly cancellation. In these theories, the Higgs responsible for the breaking of the gauge symmetry generates the mass for the dark matter candidate. We investigate the Higgs decays in the minimal gauge theory for Baryon number. After imposing the dark matter density and direct detection constraints, we find that the new Higgs can have a large branching ratio into two photons or into dark matter. Furthermore, we discuss the production channels and the unique signatures at the Large Hadron Collider.
G. Czédli’s tolerance factor lattice construction and weak ordered relations
Authors: Radeleczki Sándor
Published: February 2021

G. Czédli proved that the blocks of any compatible tolerance T of a lattice L can be ordered in such a way that they form a lattice L/T called the factor lattice of L modulo T. Here we show that the Dedekind–MacNeille completion of the lattice L/T is isomorphic to the concept lattice of the context (L, L, R), where R stands for the reflexive weak ordered relation $$ \mathord {\le } \circ T$$

≤
∘
T

. Weak ordered relations constitute the generalization of the ordered relations introduced by S. Valentini. Reflexive weak ordered relations can be characterized as compatible reflexive relations $$R\subseteq L^{2}$$

R
⊆

L
2

satisfying $$R=\ \mathord {\le } \circ R\circ \mathord {\le } $$

R
=

≤
∘
R
∘
≤

.
Changes in chemical cues of Melissococcus plutonius infected honey bee larvae
Authors: Kathe Elisa , Seidelmann Karsten , Lewkowski Oleg , Le Conte Yves , Erler Silvio
Published: February 2021

European foulbrood (EFB), caused by Melissococcus plutonius, is a globally distributed bacterial brood disease affecting Apis mellifera larvae. There is some evidence, even if under debate, that spreading of the disease within the colony is prevented by worker bees performing hygienic behaviour, including detection and removal of infected larvae. Olfactory cues (brood pheromones, signature mixtures, diagnostic substances) emitted by infected individuals may play a central role for hygienic bees to initiate the disease-specific behaviour. However, the mechanisms of cue detection and brood removal, causing hygienic behaviour in EFB affected colonies, are poorly understood. Here, coupled gas chromatography-mass spectrometry (GC–MS) was used to detect disease-specific substances, changes in cuticular hydrocarbon (CHC) profiles, and brood ester pheromones (BEPs) of honey bee larvae artificially infected with M. plutonius. Although no diagnostic substances were found in significant quantities, discriminant analysis revealed specific differences in CHC and BEP profiles of infected and healthy larvae. β-Ocimene, a volatile brood pheromone related to starvation and hygienic behaviour, was present in all larvae with highest quantities in healthy young larvae; whereas oleic acid, a non-volatile necromone, was present only in old infected larvae. Furthermore, γ-octalactone (newly discovered in A. mellifera in this study) was detectable in trace amounts only in infected larvae. We propose that the deviation from the olfactory profile of healthy brood is supposed to trigger hygienic behaviour in worker bees. To confirm the relevance of change in the chemical bouquet (CHCs, BEPs, γ-octalactone, etc.), a field colony bioassay is needed, using healthy brood and hygienic bees to determine if bouquet changes elicit hygienic behaviour.
Der deutsche Sydney Swallow Questionnaire
Authors: Bohlender J. E. , Frick S. , Colotto U. , Hotzenköcherle S. , Brockmann-Bauser M.
Published: February 2021

Hintergrund

Der Sydney Swallow Questionnaire (SSQ) ist ein patientenbasierter Fragebogen zur Erhebung von subjektiven Beschwerden oropharyngealer Schluckstörungen unterschiedlicher Ursachen, mit starker inhalts-, konstrukt-, diskriminativer und prädiktiver Validität.

Ziel der Arbeit/Fragestellung

Ziel dieser Arbeit war die Überprüfung der Reliabilität und Validität der deutschen Fassung des Sydney Swallow Questionnaire (SSQ-G).

Material und Methode

In einer Kreuzvalidierungsstudie füllten 48 erwachsene deutschsprachige Patienten (12 Frauen/36 Männer) mit neurogen (n = 16), strukturell (n = 16) und funktionell (n = 16) bedingten Schluckstörungen den deutschen SSQ‑G und MD Anderson Dysphagia Inventory (MDADI) aus. Die Reliabilität des SSQ‑G wurde anhand der internen Konsistenz mittels Cronbach‑α berechnet. Die Überprüfung der Kriterien- und der Konstruktvalidität erfolgte durch eine Kreuzvalidierung mittels Spearman-Korrelationskoeffizient.

Ergebnisse

Die interne Konsistenz des SSQ‑G war mit Cronbach-α = 0,94 exzellent. Die SSQ-G-Fragen 1 und 17 wiesen mit MDADI-Frage 1 einen moderat signifikanten bzw. hochsignifikanten Korrelationskoeffizienten von −0,43 und −0,45 auf (p < 0,5; p < 0,001). Zwischen Fragen 8, 11 und 12 des SSQ‑G und Fragen 7, 13 und 10 des MDADI lag mit Korrelationen von −0,48 bis −0,55 ein mittlerer bis starker hochsignifikanter Zusammenhang vor (p < 0,001). Somit wurden die Reliabilität, die Kriteriums- und Konstruktvalidität statistisch bestätigt.

Schlussfolgerung

Mit der deutschen Version des SSQ (SSQ-G) können funktionsspezifische Schluckbeschwerden reliabel und valide erfasst werden. In Kombination mit Fragenbögen zur symptomspezifischen Lebensqualität wie dem MDADI ist somit eine differenziertere klinische Analyse von Schluckbeschwerden möglich.
The association of migration and ethnicity with use of the Improving Access to Psychological Treatment (IAPT) programme: a general population cohort study
Authors: Bhavsar Vishal , Jannesari Sohail , McGuire Philip , MacCabe James H. , Das-Munshi Jayati , Bhugra Dinesh , Dorrington Sarah , Brown June S. L. , Hotopf Matthew H. , Hatch Stephani L.
Published: February 2021

Background

Common mental disorders (CMD), such as depression and anxiety, are an important cause of morbidity, economic burden and public mental health need. The UK Improving Access to Psychological Therapies (IAPT) programme is a national effort to reduce the burden and impact of CMD, available since 2008.

Aims

To examine ethnic and migration-related differences in use of IAPT-based psychological treatment using a novel epidemiological dataset with linkage to de-identified IAPT records.

Method

Data from a psychiatric morbidity survey of two South East London boroughs (2008–2010) were individually-linked to data on IAPT services serving those boroughs. We used Poisson regression to estimate association between ethnicity and migration status (including years of UK residence), with rate of subsequent use of psychological treatment.

Results

The rate of psychological treatment use was 14.4 cases per thousand person years [cases/1000 pyrs, 95% confidence intervals (95% CI) 12.4, 16.7]. There was strong statistical evidence that compared to non-migrants, migrants residing in the UK for less than 10 years were less likely to use psychological treatment after adjustment for probable sociodemographic predictors of need, life adversity, and physical/psychiatric morbidity at baseline [rate ratio (RR) 0.4 (95% CI 0.20, 0.75]. This difference was not explained by migration for asylum/political reasons, or English language proficiency, and was evident for both self- and GP referrals.

Conclusions

Lower use of IAPT among recent migrants is unexplained by sociodemographics, adversity, and baseline morbidity. Further research should focus on other individual-level and societal barriers to psychological treatment use among recent migrants to the UK, including in categories of intersecting migration and ethnicity.
Developing and testing a principle-based fidelity index for peer support in mental health services
Authors: Gillard S. , Banach N. , Barlow E. , Byrne J. , Foster R. , Goldsmith L. , Marks J. , McWilliam C. , Morshead R. , Stepanian K. , Turner R. , Verey A. , White S.
Published: February 2021

Purpose

Evidence suggests that the distinctive relational qualities of peer support—compared to clinical-patient relationships—can be eroded in regulated healthcare environments. Measurement of fidelity in trials of peer support is lacking. This paper reports the development and testing of a fidelity index for one-to-one peer support in mental health services, designed to assess fidelity to principles that characterise the distinctiveness of peer support.

Methods

A draft index was developed using expert panels of service user researchers and people doing peer support, informed by an evidence-based, peer support principles framework. Two rounds of testing took place in 24 mental health services providing peer support in a range of settings. Fidelity was assessed through interviews with peer workers, their supervisors and people receiving peer support. Responses were tested for spread and internal consistency, independently double rated for inter-rater reliability, with feedback from interviewees and service user researchers used to refine the index.

Results

A fidelity index for one-to-one peer support in mental health services was produced with good psychometric properties. Fidelity is assessed in four principle-based domains; building trusting relationships based on shared lived experience; reciprocity and mutuality; leadership, choice and control; building strengths and making connections to community.

Conclusions

The index offers potential to improve the evidence base for peer support in mental health services, enabling future trials to assess fidelity of interventions to peer support principles, and service providers a means of ensuring that peer support retains its distinctive qualities as it is introduced into mental health services.
Numerical simulation of dual-phase steel based on real and virtual three-dimensional microstructures
Authors: Scherff Frederik , Gola Jessica , Scholl Sebastian , Srivastava Kinshuk , Staudt Thorsten , Britz Dominik , Mücklich Frank , Diebels Stefan
Published: February 2021

Dual-phase steel shows a strong connection between its microstructure and its mechanical properties. This structure–property correlation is caused by the composition of the microstructure of a soft ferritic matrix with embedded hard martensite areas, leading to a simultaneous increase in strength and ductility. As a result, dual-phase steels are widely used especially for strength-relevant and energy-absorbing sheet metal structures. However, their use as heavy plate steel is also desirable. Therefore, a better understanding of the structure–property correlation is of great interest. Microstructure-based simulation is essential for a realistic simulation of the mechanical properties of dual-phase steel. This paper describes the entire process route of such a simulation, from the extraction of the microstructure by 3D tomography and the determination of the properties of the individual phases by nanoindentation, to the implementation of a simulation model and its validation by experiments. In addition to simulations based on real microstructures, simulations based on virtual microstructures are also of great importance. Thus, a model for the generation of virtual microstructures is presented, allowing for the same statistical properties as real microstructures. With the help of these structures and the aforementioned simulation model, it is then possible to predict the mechanical properties of a dual-phase steel, whose three-dimensional (3D) microstructure is not yet known with high accuracy. This will enable future investigations of new dual-phase steel microstructures within a virtual laboratory even before their production.
Utilizing a contralateral hamstring autograft facilitates earlier isokinetic and isometric strength recovery after anterior cruciate ligament reconstruction: a randomised controlled trial
Authors: von Essen Christoffer , Hallgren Alexander , Barenius Björn , Eriksson Karl
Published: February 2021

Purpose

To compare muscle strength and patient reported outcomes following ACLR using a semitendinosus (ST) graft from the ipsilateral (IL) leg compared to a graft from the contralateral (CL) leg.

Methods

One-hundred and forty patients with an ACL injury were randomized to IL or CL ACLR. Patients were assessed at 6, 12 and 24 months with isokinetic and isometric muscle strength measured using Biodex. Patient-reported outcomes and manual stability measurements were also recorded.

Results

Patient-related outcomes improved over time for both groups with no significant differences between groups at any time point. No differences between groups in objective knee assessment scores or rerupture rates were found. The IL group was significantly weaker in knee flexion strength at all time points compared to the CL group, additionally the IL group did not recover flexor strength within 2 years.

Conclusion

This study demonstrated that utilizing an ST graft harvested from the uninjured limb for ACLR facilitates early isokinetic and isometric strength recovery, with no significant adverse outcomes demonstrated in other measurements and therefore be performed to reduce the risk of long-term strength deficits in the injured leg

Level of evidence

II.
Diving behaviour of albatrosses: implications for foraging ecology and bycatch susceptibility
Authors: Bentley L. K. , Kato A. , Ropert-Coudert Y. , Manica A. , Phillips R. A.
Published: February 2021

Diving is an ecologically important behaviour that provides air-breathing predators with opportunities to capture prey, but that also increases their exposure to incidental mortality (bycatch) in commercial fisheries. In this study, we characterised the diving behaviour of 26 individuals of three species, the black-browed albatross Thalassarche melanophris, grey-headed albatross T. chrysostoma and light-mantled albatross Phoebetria palpebrata, breeding at Bird Island, South Georgia. Individuals were tracked using Global Location Sensor (GLS)-immersion loggers and time-depth recorders (TDRs) and, for two species, Global Positioning System (GPS) loggers. Although the TDRs recorded 589 dives (defined in this paper as submersion > 1 m), average dive depths and durations were just 1.30–1.49 m and 2.5–3.3 s, respectively, for the three species. In addition, many individuals (22% of black-browed, 20% of grey-headed, and 57% of light-mantled albatrosses; total n = 9, 10 and 7 individuals, respectively) did not dive at all. Most dives occurred at the distal end of foraging trips and were rare during the commuting phase. No dives took place in darkness, despite long periods spent on water at night. The limited and shallow dive activity contrasts with impressions from a previous study using capillary-tube depth gauges (which are less accurate than TDRs) and has implications for the susceptibility of albatrosses to bycatch on longlines. This study provides further support for regulations requiring night setting and increased sink rates of baited hooks to help mitigate albatross bycatch.
Governance Challenges at the Interface of Food Security and Biodiversity Conservation: A Multi-Level Case Study from Ethiopia
Authors: Jiren Tolera Senbeto , Leventon Julia , Jager Nicolas W. , Dorresteijn Ine , Schultner Jannik , Senbeta Feyera , Bergsten Arvid , Fischer Joern
Published: February 2021

Ensuring food security while also protecting biodiversity requires a governance system that can address intra- and intersectoral complexity. In this paper, we sought to explore the governance challenges surrounding food security and biodiversity conservation through an empirical study in Jimma zone, southwestern Ethiopia. We used bottom-up snowball sampling to identify stakeholders and then held semi-structured interviews with 177 stakeholders across multiple levels of governance. We also conducted 24 focus group discussions with local people. Data were transcribed and thematically analyzed for its contents. Challenges in the structure of institutions and policy incoherence were the key challenges identified for the governance of food security and biodiversity conservation. The challenges around institutional structure included incompatibilities of the nature of governing institutions with the complexity inherent within and between the two sectors examined. Incoherences in policy goals, instruments, and contradictions of policy output relative to the actual problems of food security and biodiversity further hampered effective governance of food security and biodiversity conservation. Notably, many of the challenges that influenced an individual sector also posed a challenge for the integrated governance of food security and biodiversity conservation, often in a more pronounced way. Based on our findings, we argue that governance in our case study area requires a more integrated and collaborative approach that pays attention to institutional interplay in order to ensure institutional fit and consistency across policy goals.
Die Affektphobietherapie
Authors: Michal Matthias , Osborn Kristin
Published: February 2021

Hintergrund

Ein zentraler Faktor psychischer Gesundheit ist die Fähigkeit, Affekte wahrnehmen und adaptiv regulieren zu können. Die Verbesserung dieser Fähigkeit ist ein Ziel der psychodynamischen Psychotherapie. Psychodynamische Behandlungsmodelle, die sich aus der gut validierten Tradition der „short-term dynamic psychotherapy“ (STDP) ableiten und die heute unter dem Dach der International Experiential Dynamic Therapy Association (https://iedta.net/) versammelt sind, legen auf besondere Weise den Behandlungsfokus auf das emotionale Erleben. Ein derartiges psychodynamisches transdiagnostisches Behandlungsmodell ist die Affektphobietherapie (APT).

Ziel der Arbeit (Fragestellung)

Ziel der Übersicht ist es, den Leser mit dem Behandlungsrational und der Evidenz der APT vertraut zu machen.

Material und Methoden

Es werden die theoretischen Grundlagen der APT, typische Interventionen und Prozessinstrumente beschrieben. Die Evidenz des APT-Modells wird als narrative Übersicht der Studienlage dargestellt.

Ergebnisse und Schlussfolgerung

Die APT ist ein evidenzbasiertes psychodynamisches Behandlungsmodell. Das Rational ist schulenübergreifend. Ein Selbsthilfeprogramm auf der Basis der APT wird von Patienten gut aufgenommen. Manualisierung, Fertigkeitenorientierung und Prozessinstrumente machen es zu einem vielversprechenden Modell für die Aus- und Fortbildung.
Complete Characterization of Incorrect Orthology Assignments in Best Match Graphs
Authors: Schaller David , Geiß Manuela , Stadler Peter F. , Hellmuth Marc
Published: February 2021

Genome-scale orthology assignments are usually based on reciprocal best matches. In the absence of horizontal gene transfer (HGT), every pair of orthologs forms a reciprocal best match. Incorrect orthology assignments therefore are always false positives in the reciprocal best match graph. We consider duplication/loss scenarios and characterize unambiguous false-positive (u-fp) orthology assignments, that is, edges in the best match graphs (BMGs) that cannot correspond to orthologs for any gene tree that explains the BMG. Moreover, we provide a polynomial-time algorithm to identify allu-fporthology assignments in a BMG. Simulations show that at least$$75\%$$75%of all incorrect orthology assignments can be detected in this manner. All results rely only on the structure of the BMGs andnoton anya prioriknowledge about underlying gene or species trees.
Coping with the cold and fighting the heat: thermal homeostasis of a superorganism, the honeybee colony
Authors: Stabentheiner Anton , Kovac Helmut , Mandl Monika , Käfer Helmut
Published: February 2021

The worldwide distribution of honeybees and their fast propagation to new areas rests on their ability to keep up optimal ‘tropical conditions’ in their brood nest both in the cold and in the heat. Honeybee colonies behave like ‘superorganisms’ where individuals work together to promote reproduction of the colony. Social cooperation has developed strongly in thermal homeostasis, which guarantees a fast and constant development of the brood. We here report on the cooperation of individuals in reaction to environmental variation to achieve thermal constancy of 34–36 °C. The measurement of body temperature together with bee density and in-hive microclimate showed that behaviours for hive heating or cooling are strongly interlaced and differ in their start values. When environmental temperature changes, heat production is adjusted both by regulation of bee density due to migration activity and by the degree of endothermy. Overheating of the brood is prevented by cooling with water droplets and increased fanning, which start already at moderate temperatures where heat production and bee density are still at an increased level. This interlaced change and onset of different thermoregulatory behaviours guarantees a graded adaptation of individual behaviour to stabilise the temperature of the brood.