bluuebunny/crossref_metadata_2025 huggingface dataset:
How to build a time machine for public affairs executives
Authors: Fleisher Craig S. , Voiovich Jason T.
Published: January 2020

Temporal factors such as time and timing are so self‐evident in public affairs that they are rarely mentioned and even less frequently researched. Time is seen as the independent variable—a scaffold that underpins a calendar of communication events, legislative and regulatory processes, or issue lifecycles. However, time is a more complex and essential variable to contemplate than public affairs (and most other) executives give it credit for. This paper explores 16 unique ways to think about time, applying those dimensions to the Amazon HQ2 (second headquarters) selection process to illustrate how public affairs executives could use them to illuminate aspects of strategy and behavior they might otherwise not consider. Strategically, understanding interconnected dimensions of time improves clarity in the choice‐making process, allowing public affairs executives to exploit ideal timing as they execute their strategies.
Development of cashew nut shell carbon reinforced thiourea based biophenolic benzoxazine‐epoxy composites: High performance biobased coating materials
Authors: Vaithilingam Selvaraj , ThangavelRavivarman Raghavarshini , Muthukaruppan Alagar
Published: January 2020

The research work focused on the preparation of biobased eugenol benzoxazine (EUBz) using thiourea as amine resource and their conversion into EUBz‐epoxy (EUBz‐EP) blend matrix and EUBz‐EP blend composites. In the present work, thiourea‐based eugenol‐benzoxazine monomer was synthesized using eugenol as phenolic compound, thiourea as amine resource and paraformaldehyde. The molecular structure of monomer was confirmed by FTIR, NMR, and Maldi mass studies. The thiourea‐based EUBz properties were enhanced by the blending of EP resin and reinforced with varying weight percentages of amine functionalized cashew nut shell carbon (f‐CSC). The thermally cured f‐CSC/EUBz‐EP composites possesses a higher glass transition temperature of 202.9°C when compared to that of the EUBz matrix (104.2°C), which might arise due to the higher crosslinking density resulted from the reinforcement of EP resin with f‐CSC. In addition, the hydrophobic behavior of the prepared composite materials is improved by blending the EUBz with EP resin and reinforcing with f‐CSC. The enhancement of the value of contact angle from 80.3° to 105.9° infers the improvement of hydrophobic behavior of f‐CSC reinforced EUBz‐EP blend composites. The corrosion rate and protection efficiency of 5 wt% f‐CSC/EUBz‐EP composites exhibits 0.814 (mm/year) and 99.97%, respectively. Data obtained from different studies suggested that the f‐CSC reinforced EUBz‐EP blended composites can be used in the form of sealants, encapsulants, adhesives, and coatings for different industrial and engineering applications.
High‐resolution analysis of the human placental DNA methylome in early gestation
Authors: Shridhar Varsha , Chu Tianjiao , Simhan Hyagriv , Shaw Patricia A. , Peters David G.
Published: January 2020

Background/Objective

We communicate high‐read‐depth bisulfite sequencing analysis of the chorionic villus (CV) DNA methylome from samples obtained between 11 and 13 weeks gestation and samples of gestationally age‐matched maternal blood cells (MBC).

Methods

This was achieved through solution‐phase targeted region capture (84 Mb) of bisulfite converted human DNA.

Results

We identified biphasic distribution of methylation in CV and MBC genomes. We found greater numbers of intermediate methylated sites (20%‐80% methylated) in CV and greater number of high methylation sites in MBC and investigated distributions of these in promoters, introns, exons, CpG islands, CpG islands shores, and enhancers. We identified differentially methylated sites distinguishing CV and MBC. These are less likely to occur in CpG islands (CGIs), particularly those that exist outside promoters, exons, and introns. We found that gene promoter and gene body methylation patterns are associated with mRNA transcriptional profiles in CV. Despite the relative hypomethylation of CV genomes, we found that these contain DM regions that are more likely to be hypermethylated in CV relative to MBC.

Conclusions

Our data provide novel insight into the structure and organization of the CV epigenome, which may inform future studies of placental biology and noninvasive prenatal phenotyping.
The Effect of Intravenous Acetaminophen on Patient Outcomes within a Large Integrated Delivery Network
Authors: Mattern Henry P. , Reichert James C. , McConnell Karen J.
Published: January 2020

Objective

To evaluate the impact of intravenous acetaminophen on patient outcomes.

Methods

In this retrospective observational analysis, 54,742 patients were identified from 19 Catholic Health Initiatives hospitals during a 12‐month period. Charges were used to identify patients who received intravenous acetaminophen during their encounter. The control group included patients who did not receive intravenous acetaminophen. Five outcomes were measured: total length of stay, intensive care unit (ICU) length of stay, total narcotic use (in morphine milligram equivalents [MME]), likelihood of receiving a narcotic prescription at discharge, and 30‐day readmission rate. Patients undergoing five procedures were evaluated: total knee replacements, total hip replacements, cesarean section, coronary artery bypass graft (CABG), and gallbladder resection. These patients were also evaluated in a combined group.

Results

After matching, population imbalances for patient characteristics were addressed. Combined with the five outcomes, 25 populations had a sufficient number of matched pairs for analysis. Six of the 25 tests showed a significant difference favoring the control group. Total length of stay was shorter for the control group in the combined population (−0.18 days [4 hours], 95% confidence interval (CI) −0.26 to −0.11). Total narcotic use was lower for the control group in the caesarean section (−10 MME, 95% CI −16 to −5), CABG (−26 MME, 95% CI −41 to −12), and combined (−13 MME, 95% CI −16 to −11) populations. The control group was less likely to be discharged with a narcotic prescription for the caesarean section (odds ratio (OR) −1.39, 95% CI −1.00 to −1.92) and combined (OR −1.14, 95% CI −1.04 to −1.24) populations.

Conclusions

Intravenous acetaminophen was not associated with improvement in the following patient outcomes: total length of stay, ICU length of stay, total narcotic use, likelihood of receiving a discharge narcotic prescription, and 30‐day readmission rate. Based on these findings, clinicians may reconsider the routine use of intravenous acetaminophen.
23.83% efficient mono‐PERC incorporating advanced hydrogenation
Authors: Chen Ran , Tong Hongbo , Zhu Haitao , Ding Chao , Li Hua , Chen Daniel , Hallam Brett , Chong Chee Mun , Wenham Stuart , Ciesla Alison
Published: January 2020

LONGi Solar Energy Technology Co. Ltd. has achieved 23.83% for a commercial p‐type Cz PERC cell. From a batch of over 40 000 cells, the average line efficiency achieved was 22.5%. R&D studies investigating hydrogenation and degradation show the importance of hydrogenation processes for efficiency improvements and controlling the hydrogen to prevent light‐induced degradation. Such degradation is shown to appear very differently under different illumination and temperature conditions. This degradation impacts VOC, ISC, and especially fill factor. Current injection and thermal anneal can be used to recover the degradation, but the recovery may not be stable. Reducing the hydrogen content within the cell is shown to minimise degradation without sacrificing performance, provided that enough hydrogen is retained to passivate boron‐oxygen defects.
High ability students with coexisting disabilities: Implications for school psychological practice
Authors: Foley‐Nicpon Megan , Assouline Susan G.
Published: January 2020

School psychologists are well‐positioned to change the educational landscape for twice‐exceptional students, or those who possess high ability in one or more talent domains along with one or more disabilities. Better understanding of the nuanced cognitive and psychosocial assessment patterns within this population may increase well‐needed participation in gifted education opportunities and the likelihood of receiving accommodations, as well as decrease missed diagnoses. Based on our review of the empirical literature within domains of twice‐exceptionality (e.g., attention deficit hyperactivity disorder, autism spectrum disorder, and specific learning disability), we provide recommendations for how school psychologists can interpret formative and summative assessments taken by twice‐exceptional students and subsequently help design educational plans that will meet their unique needs.
DFT investigations of the unusual reactivity of 2‐pyridinecarboxaldehyde in base‐catalyzed aldol reactions with acetophenone
Authors: Wachter Nanette M. , Rani Neha , Zolfaghari Arghavan , Tarbox Haley , Mazumder Shivnath
Published: January 2020

The aldol reaction is recognized as an archetypal method to form carbon‐carbon bonds. Base‐catalyzed aldol reactions of aryl aldehydes with aryl methyl ketones typically produce condensation products (chalcones). However, 2‐pyridinecarboxaldehye, 2‐quinolinecarboxaldehyde, and 2‐ and 3‐fluorobenzaldehyde undergo tandem aldol‐Michael reactions with aryl enolates to yield conjugate addition products. To elucidate the different reactivities of aldol products formed in the reactions of benzaldehyde and 2‐pyridinecarboxaldehyde with the sodium enolate of acetophenone, density functional theory (DFT) calculations were performed to compare the energies of conformational isomers of the intermediates formed in the reaction, the energies of the corresponding condensation products, and the kinetic barriers to dehydration and conjugate addition. Computational results support the formation of the trans isomer of the condensation product in base‐catalyzed aldol reactions of either benzaldehyde or 2‐pyridinecarboxaldehyde with acetophenone. The susceptibility of the condensation product to conjugate addition is determined to result from the lower LUMO energy of trans‐1‐phenyl‐3‐(2‐pyridinyl)‐2‐propen‐1‐one. Consequently, the kinetic barrier for conjugate addition of a second equivalent of enolate with the condensation product of 2‐pyridinecarboxaldehyde is found to be significantly lower. Similar results were obtained for the reactions of fluorobenzaldehydes with aryl enolates.
Structural and functional characterization of the dominant negative P‐loop lysine mutation in the dynamin superfamily protein Vps1
Authors: Tornabene Bryan A. , Varlakhanova Natalia V. , Hosford Christopher J. , Chappie Joshua S. , Ford Marijn G. J.
Published: January 2020

Dynamin‐superfamily proteins (DSPs) are large self‐assembling mechanochemical GTPases that harness GTP hydrolysis to drive membrane remodeling events needed for many cellular processes. Mutation to alanine of a fully conserved lysine within the P‐loop of the DSP GTPase domain results in abrogation of GTPase activity. This mutant has been widely used in the context of several DSPs as a dominant‐negative to impair DSP‐dependent processes. However, the precise deficit of the P‐loop K to A mutation remains an open question. Here, we use biophysical, biochemical and structural approaches to characterize this mutant in the context of the endosomal DSP Vps1. We show that the Vps1 P‐loop K to A mutant binds nucleotide with an affinity similar to wild type but exhibits defects in the organization of the GTPase active site that explain the lack of hydrolysis. In cells, Vps1 and Dnm1 bearing the P‐loop K to A mutation are defective in disassembly. These mutants become trapped in assemblies at the typical site of action of the DSP. This work provides mechanistic insight into the widely‐used DSP P‐loop K to A mutation and the basis of its dominant‐negative effects in the cell.
RNA interference of tyrosine hydroxylase caused rapid mortality by impairing cuticle formation in Nilaparvata lugens (Hemiptera: Delphacidae)
Authors: Liu Shu H , Yang Bao J , Wang Ai Y , Luo Ju , Tang Jian
Published: January 2020

BACKGROUND

The application of RNA interference (RNAi) technique in controlling agricultural insect pests has been receiving much attention since the discovery of RNAi. The brown planthopper (BPH) Nilaparvata lugens, a notorious pest of rice, has evolved a high level of resistance to many kinds of insecticides. Tyrosine hydroxylase (Th) is an indispensable survival gene in holometabolous insects, playing key roles in cuticle tanning and immunity. In this study, we investigated whether Th could be used as a potential target in controlling N. lugens.

RESULTS

Here, we demonstrated that NlTh had a periodical expression pattern during molting with the highest level observed in epidermis. Dysfunction of NlTH by dsNlTh microinjection or 3‐IT feeding similarly caused rapid death of N. lugens. Compared with dsGFP control BPHs, dsNlTh injected BPHs (i) had cuticle pigmentation and sclerotizaton defects; (ii) had less endocuticle lamella in tergum integument; (iii) showed higher mortality during the molting process as a result of defective cuticle shedding; (iv) showed feeding disorders indicated by a low number of probe wound dots on rice; (v) had more vulnerable cuticle.

CONCLUSION

This study demonstrated that TH orthologues play a conservative and crucial role for exocuticle tanning in both holometabolous and hemimetabolous insects, and NlTh could be targeted for RNAi‐mediated BPH control. The rapid lethal phenotype of NlTH dysfunction BPHs partly induced by cuticle formation defects. © 2020 Society of Chemical Industry
Using gyroplane for application of Trichogramma spp. against the European corn borer in maize
Authors: Bzowska‐Bakalarz Małgorzata , Bulak Piotr , Bereś Paweł K. , Czarnigowska Agata , Czarnigowski Jacek , Karamon Bartłomiej , Pniak Michał , Bieganowski Andrzej
Published: January 2020

BACKGROUND

Achieving sustainability of agricultural production is one of the key challenges for humanity. Minimizing the use of chemicals and replacing them with biological plant protection is, firstly, fully in line with the agriculture's development strategy and, secondly, confirmed to be achievable in practice. For instance, many researchers point to the potential of using Trichogramma spp. to control Ostrinia nubilalis in maize. However, the application methods for preparations containing Trichogramma spp. are still at the stage of development. So far, ground application proved time and energy consuming. Aerial application using ultralight aircraft is a new option.

RESULTS

The present study presents the results of tests on the effectiveness of applying Trichogramma spp. from the board of an ultralight gyroplane. A 6‐year experiment was conducted on a maize monoculture located in south‐western Poland. The results indicate that the low‐height aerial application allows precise dosing and satisfactory distribution of the biopesticide. The efficacy of 60–85% (depending on the year) of the gyroplane‐based spraying operations was comparable with that observed for ground application.

CONCLUSION

Considering the speed and high efficiency of the treatment, using a gyroplane as a carrier of the biopesticide application system is a good alternative to the other methods. © 2020 Society of Chemical Industry
Optical Response of Epitaxial ZnO Films Grown by Atomic Layer Deposition and Coimplanted with Dy and Yb
Authors: Guziewicz Elżbieta , Kobyakov Serhiy , Ratajczak Renata , Wierzbicka Aleksandra , Wozniak Wojciech , Kaminska Agata
Published: January 2020

In this study, structural and optical properties of ZnO:Dy, ZnO:Yb, and ZnO:(Dy,Yb) films are investigated. Epitaxial ZnO films are grown by atomic layer deposition at 300 °C and implanted with Yb and Dy ions to the fluence of 5 × 1014 cm−2. The effects of Dy and Yb implantation, Dy/Yb coimplantation, and postgrowth annealing are studied by channeling Rutherford backscattering spectrometry (RBS/c) and room‐temperature photoluminescence (RT PL). The damage built up after implantation is found to be similar for Dy and Yb ions, but crystal structure recovery after annealing is more efficient for ZnO:Yb than for ZnO:Dy, when similar annealing conditions are applied. Colorimetric analysis of the RT PL spectra shows that (Dy,Yb) coimplantation allows shifting the optical response of ZnO:Dy films toward white color light. The correlated color temperature can be tuned in this way from 2500 to 3200 K, which makes these films attractive for indoor applications.
Surface Stress and Lattice Dynamics in Oxide Ultrathin Films
Authors: Premper Jörg , Schumann Florian O. , Dhaka Anita , Polzin Sebastian , Kostov Krassimir L. , Goian Veronica , Sander Dirk , Widdra Wolf
Published: January 2020

The lattice misfit between the substrate and an epitaxial film leads in general to static forces, which define the interface stress, and dynamic responses that modify the thin‐film lattice dynamics. Although these are both fundamental concepts that are important for film growth and thin‐film properties, they have not been investigated in a combined way so far. Therefore, herein, surface stress experiments in combination with surface phonon studies for three different, cubic oxide ultrathin film systems are reviewed. Within the class of binary oxides, NiO(001) grown on Ag(001) is chosen, which exhibits a −2.2% lattice mismatch, and BaO(001) on Pt(001), a system with a negligible lattice mismatch. For the ternary oxides, perovskite thin films of BaTiO3 grown epitaxially on Pt(001) with a lattice mismatch of −2.3% are focused upon. The surface stress experiments are conducted with an optical two‐beam curvature technique under in situ growth conditions. Surface and thin‐film phonons are determined by high‐resolution electron energy loss spectroscopy. Surface stress and lattice dynamics are discussed in the range from the oxide monolayer to thin films of about 20 unit cell in thickness.
Unique continuation for the magnetic Schrödinger equation
Authors: Laestadius Andre , Benedicks Michael , Penz Markus
Published: January 2020

The unique‐continuation property from sets of positive measure is here proven for the many‐body magnetic Schrödinger equation. This property guarantees that if a solution of the Schrödinger equation vanishes on a set of positive measure, then it is identically zero. We explicitly consider potentials written as sums of either one‐body or two‐body functions, typical for Hamiltonians in many‐body quantum mechanics. As a special case, we are able to treat atomic and molecular Hamiltonians. The unique‐continuation property plays an important role in density‐functional theories, which underpins its relevance in quantum chemistry.
A rapid throughput technique to isolate pyrogenic carbon by hydrogen pyrolysis for stable isotope and radiocarbon analysis
Authors: Haig Jordahna , Ascough Philippa L. , Wurster Christopher M. , Bird Michael I.
Published: January 2020

Rationale

Rapid, reliable isolation of pyrogenic carbon (PyC; also known as char, soot, black carbon, or biochar) for the determination of stable carbon isotope (δ13C) composition and radiocarbon (14C) dating is needed across multiple fields of research in geoscience, environmental science and archaeology. Many current techniques do not provide reliable isolation from contaminating organics and/or are relatively time‐consuming. Hydrogen pyrolysis (HyPy) does provide reliable isolation of PyC, but the current methodology is time consuming.

Methods

We explored the potential for subjecting multiple samples to HyPy analysis by placing up to nine individual samples in custom‐designed borosilicate sample vessels in a single reactor run. We tested for cross‐contamination between samples in the same run using materials with highly divergent radiocarbon activities (~0.04–116.3 pMC), δ13C values (−11.9 to −26.5‰) and labile carbon content. We determined 14C/13C using accelerator mass spectrometry and δ13C values using an elemental analyser coupled to a continuous flow isotope ratio mass spectrometer.

Results

Very small but measurable transfer between samples of highly divergent isotope composition was detectable. For samples having a similar composition, this cross‐contamination is considered negligible with respect to measurement uncertainty. For samples having divergent composition, we found that placing a sample vessel loaded with silica mesh adsorbent between samples eliminated measurable cross‐contamination in all cases for both 14C/13C and δ13C values.

Conclusions

It is possible to subject up to seven samples to HyPy in the same reactor run for the determination of radiocarbon content and δ13C value without diminishing the precision or accuracy of the results. This approach enables an increase in sample throughput of 300–600%. HyPy process background values are consistently lower than the nominal laboratory process background for quartz tube combustion in the NERC Radiocarbon Laboratory, indicating that HyPy may also be advantageous as a relatively ‘clean’ radiocarbon pre‐treatment method.
Phosphine detection in veterinary samples using headspace gas chromatography/tandem mass spectrometry with multiple reaction monitoring
Authors: Lehner Andreas F. , Johnson Margaret , Buchweitz John P.
Published: January 2020

Rationale

Determination of phosphine exposure from zinc or aluminum phosphide fumigants continues to be a routine analytical requirement in veterinary forensic toxicology. There is a need for a more reliable and specific method than simple gas chromatography/mass spectrometry (GC/MS) analysis of sample solvent extracts, as GC/MS of extracts on capillary columns used for general screens involves significant interference from air peaks.

Methods

GC/MS/MS headspace analysis of acid‐generated phosphine gas enabled study of the feasibility of devising multiple reaction monitoring (MRM) approaches to the determination of phosphine with greater specificity.

Results

Collision‐induced dissociation in GC/MS/MS showed that phosphine generated m/z 34 → 31, 32 and 33 ion transitions by sequential proton release as well as minor transitions m/z 34 → 47, 34 → 63 and 63 → 31.5 by intermolecular collisions and double charging. Study of the formation of these product ions enabled development of MRM settings for a highly useful headspace method for phosphine detection.

Conclusions

The method was validated over a working range of 5–100 ppm of phosphide generating phosphine gas which enabled retention of regular screen capillary columns without necessitating separation from air components. The method should have adequate sensitivity and reliability for veterinary toxicology laboratories confronting specimens from animals poisoned by crop fumigants.
Restrictive ventilatory impairment and thrombosis due to a giant liver cyst
Authors: Nakamoto Keitaro , Miyaoka Chika , Hirata Aya , Nakamura Yasuhiro , Nakazato Tetsuya , Takizawa Hajime
Published: January 2020

Most patients with liver cysts are asymptomatic and require no treatment. In this patient with symptoms and restrictive ventilatory impairment, percutaneous needle aspiration with injection of minocycline hydrochloride was effective.
Hybrid dynamic learning mechanism for multivariate time series segmentation
Authors: Wang Ling , Li Kang , Ma Qian , Lu YanRong
Published: January 2020

To improve the efficiency of segmentation methods for multivariate time series, a hybrid dynamic learning mechanism for such series' segmentation is proposed. First, an incremental clustering algorithm is used to automatically cluster variables of multivariate time series. Second, common factors are extracted from every cluster by a dynamic factor model as an ensemble description of the system. Third, this common factor series is segmented by dynamic programming. The proposed method can potentially segment multivariate time series and not only performs segmentation better on multivariate time series with a large number of variables but also improves the running accuracy and efficiency of the algorithm, especially when analyzing complex datasets.
Peculiarities of fullerenes and carbon onions application for reinforcing the aluminum matrix in the metal matrix composites
Authors: Popov Vladimir A. , Borunova Anna B. , Senatulin Boris R. , Shelekhov Evgeny V. , Kirichenko Alexey N.
Published: January 2020

Aluminum matrix composites with fullerenes and carbon onions as reinforcing nanoparticles were studied by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). Composites were produced by mechanical alloying. It is demonstrated that aluminum carbide formation (the reaction proceeds between aluminum and carbon nanoparticles) starts at 300 to 370°C, which is much lower compared with the starting temperature of the reaction between aluminum and carbon macromaterials.
Determination of haematological and biochemical parameters of Calf Saiga antelope (Saiga tatarica) living in the Gansu Endangered Animals Research Center
Authors: Du Xiaohua , Liu Xia , Mawolo James Blackar , Wang Haifang , Mi Xiaoyu , Dong Jianying , Li Qiao , Wen Yongqiang
Published: January 2020

Background

The Saiga antelope (Saiga tatarica) is native to Eurasia and is a member of the family Bovidae. Prior to 1920, the antelope had been extensively hunted for its horns, which were used in traditional Chinese medicine. Since 1920, the Saiga antelope has been protected because of this extensive hunting, which nearly led to its extinction.

Objective

The study evaluated haematological and biochemical parameters to provide references for the Calf Saiga antelope (S. tatarica). The study also sought to explore the mechanisms affecting these parameters in both genders of the Calf Saiga antelope.

Methods

Haematological and biochemical parameters were collected from the Calf Saiga antelope. Haematological and biochemical parameters were analysed by the Coulter counter and Automatic analyser, respectively.

Results

The average concentrations of female triglyceride levels showed significantly higher values than the significant concentrations of male. Female red blood cells and platelets concentrations were statistically significant than the significant concentrations of males. Magnesium female concentrations were also significantly higher than male values. Other parameters showed differences between males and females.

Conclusion

The reported results show that haematological and biochemical characteristics varied among Calf Saiga antelope and other animals. The study results suggest that regardless of the factors, breed, the breeding environment, and climatic variables, haematological and biochemical variations can be triggered that can result in a reduction in the heat production needed for maintenance of homeothermy.
Gynaecological diagnosis by ultrasound and the measurement of urinary sex steroid hormones in female orangutans
Authors: Kinoshita Kodzue , Nakamura Tomoyuki , Kimura Koichi , Shimizu Mika , Kuze Noko , Ozaki Yasuhiko
Published: January 2020

Gynaecological diagnoses were carried in three adult female orangutans (Pongo spp.) using ultrasound, and their estrous states were estimated by measuring urinary sex steroid hormone concentrations using enzyme immunoassay. Ultrasound diagnosis revealed that the endometrial thickness and follicle size were correlated with the oestrogen‐3‐glucuronide concentrations in the follicular phase. In addition, administration of the ovulation inducer human chorionic gonadotropin (hCG) had the strongest effect on the pregnanediol‐3‐glucuronide (PdG) concentration when the follicle size was 22.3 mm, suggesting that the follicle reaches this size before ovulation. The similarity between this and the maximum ovarian follicle size in humans (approximately 20 mm) indicates that the ancestral reproductive characteristics may have been retained in these species.
Analytical and numerical studies for slip flows of a generalised Phan‐Thien–Tanner fluid
Authors: Ribau A. M. , Ferrás L. L. , Morgado M. L. , Rebelo M. , Afonso A. M.
Published: January 2020

This work presents analytical and numerical studies for pure Couette and combined Poiseuille‐Couette flows under slip. The fluid behaviour is described by the recently proposed viscoelastic model, known as the generalised simplified Phan‐Thien‐Tanner constitutive equation, that considers the Mittag‐Leffler function instead of the classical linear and exponential functions of the trace of the stress tensor, and provides one or two new fitting constants in order to achieve additional fitting flexibility. The solutions derived in this work allow a better understanding of the model and its influence on the slippery behaviour of some complex fluids, contributing in this way to improve the modeling of complex fluids.
On generalized Macdonald polynomials
Authors: Mironov A. , Morozov A.
Published: January 2020

Abstract

Generalized Macdonald polynomials (GMP) are eigenfunctions of specifically­deformed Ruijsenaars Hamiltonians and are built as triangular polylinear combinations of Macdonald polynomials. They are orthogonal with respect to a modified scalar product, which could be constructed with the help of an increasingly important triangular perturbation theory, showing up in a variety of applications. A peculiar feature of GMP is that denominators in this expansion are fully factorized, which is a consequence of a hidden symmetry resulting from the special choice of the Hamiltonian deformation. We introduce also a simplified but deformed version of GMP, which we call generalized Schur functions. Our basic examples are bilinear in Macdonald polynomials.
Modular A4 invariance and leptogenesis
Authors: Asaka Takehiko , Heo Yongtae , Tatsuishi Takuya H. , Yoshida Takahiro
Published: January 2020

Abstract

We consider a model with three right-handed neutrinos in which Yukawa coupling constants and Majorana masses are obtained by requiring the modular A
4 symmetry. It has been shown that the model can explain mass hierarchies and mixing patterns of charged leptons and neutrinos with the seesaw mechanism. In this article we investigate the leptogenesis by decays of right-handed neutrinos in this model. It is shown that masses of right-handed neutrinos are about 1013 GeV in order to account for the observed baryon asymmetry of the universe. Furthermore, the positive sign of the baryon asymmetry is obtained only for the limited ranges of mixing angles and CP violation phases of active neutrinos, which can be tested by future neutrino experiments.
Off-shell unimodular N = 1, d = 4 supergravity
Authors: Anero Jesus , Martin Carmelo P. , Santos-Garcia Raquel
Published: January 2020

Abstract

We formulate a unimodular N = 1, d = 4 supergravity theory off shell. We see that the infinitesimal Grassmann parameters defining the unimodular supergravity trans- formations are constrained and show that the conmutator of two infinitesinal unimodular supergravity transformations closes on transverse diffeomorphisms, Lorentz transforma- tions and unimodular supergravity transformations. Along the way, we also show that the linearized theory is a supersymmetric theory of gravitons and gravitinos. We see that de Sitter and anti-de Sitter spacetimes are non-supersymmetric vacua of our unimodular supergravity theory.
BPS states, conserved charges and centres of symmetric group algebras
Authors: Kemp Garreth , Ramgoolam Sanjaye
Published: January 2020

Abstract

In

$$ \mathcal{N} $$

N

= 4 SYM with U(N) gauge symmetry, the multiplicity of half-BPS states with fixed dimension can be labelled by Young diagrams and can be distinguished using conserved charges corresponding to Casimirs of U(N). The information theoretic study of LLM geometries and superstars in the dual AdS
5
× S
5 background has raised a number of questions about the distinguishability of Young diagrams when a finite set of Casimirs are known. Using Schur-Weyl duality relations between unitary groups and symmetric groups, these questions translate into structural questions about the centres of symmetric group algebras. We obtain algebraic and computational results about these structural properties and related Shannon entropies, and generate associated number sequences. A characterization of Young diagrams in terms of content distribution functions relates these number sequences to diophantine equations. These content distribution functions can be visualized as connected, segmented, open strings in content space.
Generalised power series expansions for the elliptic planar families of Higgs + jet production at two loops
Authors: Moriello F.
Published: January 2020

Abstract

We obtain generalised power series expansions for a family of planar two-loop master integrals relevant for the QCD corrections to Higgs + jet production, with phys- ical heavy-quark mass. This is achieved by defining differential equations along contours connecting two fixed points, and by solving them in terms of one-dimensional generalised power series. The procedure is efficient, and can be repeated in order to reach any point of the kinematic regions. The analytic continuation of the series is straightforward, and we present new results below and above the physical thresholds. The method we use allows to compute the integrals in all kinematic regions with high precision. For example, per- forming a series expansion on a typical contour above the heavy-quark threshold takes on average O(1 second) per integral with worst relative error of O(10
−32), on a single CPU core. After the series is found, the numerical evaluation of the integrals in any point of the contour is virtually instant. Our approach is general, and can be applied to Feynman integrals provided that a set of differential equations is available.
Isolated zeros destroy Fermi surface in holographic models with a lattice
Authors: Balm Floris , Krikun Alexander , Romero-Bermúdez Aurelio , Schalm Koenraad , Zaanen Jan
Published: January 2020

Abstract

We study the fermionic spectral density in a strongly correlated quantum system described by a gravity dual. In the presence of periodically modulated chemical potential, which models the effect of the ionic lattice, we explore the shapes of the corresponding Fermi surfaces, defined by the location of peaks in the spectral density at the Fermi level. We find that at strong lattice potentials sectors of the Fermi surface are unexpectedly destroyed and the Fermi surface becomes an arc-like disconnected manifold. We explain this phenomenon in terms of a collision of the Fermi surface pole with zeros of the fermionic Green’s function, which are explicitly computable in the holographic dual.
4d $$ \mathcal{N} $$ = 1 from 6d D-type $$ \mathcal{N} $$ = (1, 0)
Authors: Chen Jin , Haghighat Babak , Liu Shuwei , Sperling Marcus
Published: January 2020

Abstract

Compactifications of 6d

$$ \mathcal{N} $$

N

= (1, 0) SCFTs give rise to new 4d

$$ \mathcal{N} $$

N

= 1 SCFTs and shed light on interesting dualities between such theories. In this paper we continue exploring this line of research by extending the class of compactified 6d theories to the D- type case. The simplest such 6d theory arises from D5 branes probing D-type singularities. Equivalently, this theory can be obtained from an F-theory compactification using −2- curves intersecting according to a D-type quiver. Our approach is two-fold. We start by compactifying the 6d SCFT on a Riemann surface and compute the central charges of the resulting 4d theory by integrating the 6d anomaly polynomial over the Riemann surface. As a second step, in order to find candidate 4d UV Lagrangians, there is an intermediate 5d theory that serves to construct 4d domain walls. These can be used as building blocks to obtain torus compactifications. In contrast to the A-type case, the vanishing of anomalies in the 4d theory turns out to be very restrictive and constraints the choices of gauge nodes and matter content severely. As a consequence, in this paper one has to resort to non- maximal boundary conditions for the 4d domain walls. However, the comparison to the 6d theory compactified on the Riemann surface becomes less tractable.
From bulk loops to boundary large-N expansion
Authors: Ponomarev Dmitry
Published: January 2020

Abstract

We study the analytic structure of loop Witten diagrams in Euclidean AdS represented by their conformal partial wave expansions. We show that, as in flat space, amplitude’s singularities are associated with non-trivial cuts of the diagram and factorize into products of the coefficient functions for the subdiagrams resulting from these cuts. We consider an example of a one-loop four-point diagram in detail and then briefly discuss how the procedure can be extended to more general diagrams. Finally, we show that this analysis reproduces simple relations that follow from the large-N considerations on the boundary.
Gravitational corner conditions in holography
Authors: Horowitz Gary T. , Wang Diandian
Published: January 2020

Abstract

Contrary to popular belief, asymptotically anti-de Sitter solutions of gravitational theories cannot be obtained by taking initial data (satisfying the constraints) on a spacelike surface, and choosing an arbitrary conformal metric on the timelike boundary at infinity. There are an infinite number of corner conditions that also must be satisfied where the initial data surface hits the boundary. These are well known to mathematical relativists, but to make them more widely known we give a simple explanation of why these conditions exist and discuss some of their consequences. An example is given which illustrates their power. Some implications for holography are also mentioned.
The Higgs mechanism — Hasse diagrams for symplectic singularities
Authors: Bourget Antoine , Cabrera Santiago , Grimminger Julius F. , Hanany Amihay , Sperling Marcus , Zajac Anton , Zhong Zhenghao
Published: January 2020

Abstract

We explore the geometrical structure of Higgs branches of quantum field theories with 8 supercharges in 3, 4, 5 and 6 dimensions. They are symplectic singularities, and as such admit a decomposition (or foliation ) into so-called symplectic leaves, which are related to each other by transverse slices. We identify this foliation with the pattern of partial Higgs mechanism of the theory and, using brane systems and recently introduced notions of magnetic quivers and quiver subtraction, we formalise the rules to obtain the Hasse diagram which encodes the structure of the foliation. While the unbroken gauge symmetry and the number of flat directions are obtainable by classical field theory analysis for Lagrangian theories, our approach allows us to characterise the geometry of the Higgs branch by a Hasse diagram with symplectic leaves and transverse slices, thus refining the analysis and extending it to non-Lagrangian theories. Most of the Hasse diagrams we obtain extend beyond the cases of nilpotent orbit closures known in the mathematics literature. The geometric analysis developed in this paper is applied to Higgs branches of several Lagrangian gauge theories, Argyres-Douglas theories, five dimensional SQCD theories at the conformal fixed point, and six dimensional SCFTs.
ACL reconstruction combined with lateral monoloop tenodesis can restore intact knee laxity
Authors: Lagae Koen C. , Robberecht Joris , Athwal Kiron K. , Verdonk Peter C. M. , Amis Andrew A.
Published: January 2020

Purpose

An anterior cruciate ligament (ACL) injury is often combined with injury to the lateral extra-articular structures, which may cause a combined anterior and rotational laxity. It was hypothesised that addition of a ‘monoloop’ lateral extra-articular tenodesis (mLET) to an ACL reconstruction would restore anteroposterior, internal rotation and pivot-shift laxities better than isolated ACL reconstruction in combined injuries.

Method

Twelve cadaveric knees were tested, using an optical tracking system to record the kinematics through 0°–100° of knee flexion with no load, anterior and posterior translational forces (90 N), internal and external rotational torques (5 Nm), and a combination of an anterior translational (90 N) plus internal rotational load (5 Nm). They were tested intact, after sectioning the ACL, sectioning anterolateral ligament (ALL), iliotibial band (ITB) graft harvest, releasing deep ITB fibres, hamstrings tendon ACL reconstruction, mLET combined with ACL reconstruction, and isolated mLET. Two-way repeated-measures ANOVA compared laxity data across knee states and flexion angles. When differences were found, paired t tests with Bonferroni correction were performed.

Results

In the ACL-deficient knee, cutting the ALL significantly increased anterior laxity only at 20°–30°, and only significantly increased internal rotation at 50°. Additional deep ITB release significantly increased anterior laxity at 40°–90° and caused a large increase of internal rotation at 20°–100°. Isolated ACL reconstruction restored anterior drawer, but significant differences remained in internal rotation at 30°–100°. After adding an mLET there were no remaining differences with anterior translation or internal rotation compared to the intact knee. With the combined injury, isolated mLET allowed abnormal anterior translation and rotation to persist.

Conclusions

Cutting the deep fibres of the ITB caused large increases in tibial internal rotation laxity across the range of knee flexion, while cutting the ALL alone did not. With ACL deficiency combined with anterolateral deficiency, ACL reconstruction alone was insufficient to restore native knee rotational laxity. However, combining a ‘monoloop’ lateral extra-articular tenodesis with ACL reconstruction did restore native knee laxity.
Statistical properties of estimators for the log-optimal portfolio
Authors: Frahm Gabriel
Published: January 2020

The best constant re-balanced portfolio represents the standard estimator for the log-optimal portfolio. It is shown that a quadratic approximation of log-returns works very well on a daily basis and a mean-variance estimator is proposed as an alternative to the best constant re-balanced portfolio. It can easily be computed and the numerical algorithm is very fast even if the number of dimensions is high. Some small-sample and the basic large-sample properties of the estimators are derived. The asymptotic results can be used for constructing hypothesis tests and for computing confidence regions. For this purpose, one should apply a finite-sample correction, which substantially improves the large-sample approximation. However, it is shown that the impact of estimation errors concerning the expected asset returns is serious. The given results confirm a general rule, which has become folklore during the last decades, namely that portfolio optimization typically fails on estimating expected asset returns.
Fruiting bodies of selected edible mushrooms as a potential source of lovastatin
Authors: Kała Katarzyna , Kryczyk-Poprawa Agata , Rzewińska Aleksandra , Muszyńska Bożena
Published: January 2020

Agaricus bisporus, Cantharellus cibarius, Imleria badia, and Lentinula edodes are among the most popular species of edible mushrooms in Poland. These edible mushrooms are an important source of biologically active substances exhibiting beneficial (e.g., antioxidant, antitumor, antimicrobial, anti-inflammatory) effects on the human body. The fruiting bodies of edible mushrooms are also a valuable source of lovastatin, which belongs to a group of compounds, called statins, commonly used as cholesterol-lowering drugs. Due to the presence of lovastatin, edible mushrooms can be useful in the prevention of hypercholesterolemia. Therefore, the aim of this study was to determine the content of lovastatin in the selected species of edible mushrooms and to evaluate its release into artificial digestive juices. This study was the first to determine the release of lovastatin into digestive juices after the extraction of materials obtained from edible mushrooms. The largest amount of lovastatin was found in the fruiting bodies of C. cibarius (67.89 mg/100 g d.w.), and the smallest in those of L. edodes (0.95 mg/100 g d.w.). The amount of lovastatin released from the extracts of the examined species into digestive juices was found to be relatively low. The highest content after incubation in artificial gastric juice was detected for the fruiting bodies of L. edodes (0.02 mg/100 g d.w.) and after incubation in the intestinal juice for the mycelium from the in vitro cultures of L. edodes (0.51 mg/100 g d.w.). Thus, the results of the present study showed that due to its ability to accumulate lovastatin from culture medium, L. edodes mycelium can be used to obtain a product with increased hypolipidemic activity.
Asymptotic Optimality of a First-Order Approximate Strategy for an Exponential Utility Maximization Problem with a Small Coefficient of Wealth-Dependent Risk Aversion
Authors: Delong Łukasz
Published: January 2020

In Delong [8] we investigate an exponential utility maximization problem for an insurer who faces a stream of non-hedgeable claims. We assume that the insurer’s risk aversion coefficient consists of a constant risk aversion and a small amount of wealth-dependent risk aversion. We apply perturbation theory and expand the equilibrium value function of the optimization problem on the parameter $$\epsilon $$
ϵ
controlling the degree of the insurer’s risk aversion depending on wealth. We derive a candidate for the first-order approximation to the equilibrium investment strategy. In this paper we formally show that the zeroth-order investment strategy $$\pi _0^*$$

π
0
∗

postulated by Delong (Math Methods Oper Res 89:73–113, 2019) performs better than any strategy $$\pi _0$$

π
0

when we compare the asymptotic expansions of the objective functions up to order $${\mathcal {O}}(1)$$

O
(
1
)

as $$\epsilon \rightarrow 0$$

ϵ
→
0

, and the first-order investment strategy $$\pi _0^*+\pi _1^*\epsilon $$

π
0
∗

+

π
1
∗

ϵ

postulated by Delong (Math Methods Oper Res 89:73–113, 2019) is the equilibrium strategy in the class of strategies $$\pi ^*_0+\pi _1\epsilon $$

π
0
∗

+

π
1

ϵ

when we compare the asymptotic expansions of the objective functions up to order $${\mathcal {O}}(\epsilon ^2)$$

O
(

ϵ
2

)

as $$\epsilon \rightarrow 0$$

ϵ
→
0

, where $$\epsilon $$
ϵ
denotes the parameter controlling the degree of the insurer’s risk aversion depending on wealth.
Suppressive activity of Vδ2+ γδ T cells on αβ T cells is licensed by TCR signaling and correlates with signal strength
Authors: Schilbach Karin , Krickeberg Naomi , Kaißer Carlotta , Mingram Simon , Kind Janika , Siegers Gabrielle M. , Hashimoto Hisayoshi
Published: January 2020

Despite recent progress in the understanding of γδ T cells’ roles and functions, their interaction with αβ T cells still remains to be elucidated. In this study, we sought to clarify what precisely endows peripheral Vδ2+T cells with immunosuppressive function on autologous αβ T cells. We found that negatively freshly isolated Vδ2+T cells do not exhibit suppressive behavior, even after stimulation with IL-12/IL-18/IL-15 or the sheer contact with butyrophilin-3A1-expressing tumor cell lines (U251 or SK-Mel-28). On the other hand, Vδ2+T cells positively isolated through TCR crosslinking or after prolonged stimulation with isopentenyl pyrophosphate (IPP) mediate strong inhibitory effects on αβ T cell proliferation. Stimulation with IPP in the presence of IL-15 induces the most robust suppressive phenotype of Vδ2+T cells. This indicates that Vδ2+T cells’ suppressive activity is dependent on a TCR signal and that the degree of suppression correlates with its strength. Vδ2+T cell immunosuppression does not correlate with their Foxp3 expression but rather with their PD-L1 protein expression, evidenced by the massive reduction of suppressive activity when using a blocking antibody. In conclusion, pharmacologic stimulation of Vδ2+T cells via the Vδ2 TCR for activation and expansion induces Vδ2+T cells' potent killer activity while simultaneously licensing them to suppress αβ T cell responses. Taken together, the study is a further step to understand—in more detail—the suppressive activity of Vδ2+γδ T cells.