bluuebunny/crossref_metadata_2025 huggingface dataset:
Global properties of the conformal manifold for S-fold backgrounds
Authors: Giambrone Alfredo , Malek Emanuel , Samtleben Henning , Trigiante Mario
Published: June 2021

Abstract

We study a one-parameter family of $$ \mathcal{N} $$
N
= 2 anti-de Sitter vacua with U(1)2 symmetry of gauged four-dimensional maximal supergravity, with dyonic gauge group [SO(6) × SO(1, 1)] ⋉ ℝ12. These backgrounds are known to correspond to Type IIB S-fold solutions with internal manifold of topology S1 × S5. The family of AdS4 vacua is parametrized by a modulus χ. Although χ appears non-compact in the four-dimensional supergravity, we show that this is just an artefact of the four-dimensional description. We give the 10-dimensional geometric interpretation of the modulus and show that it actually has periodicity of $$ \frac{2\pi }{T} $$

2
π

T

, which is the inverse radius of S1. We deduce this by providing the explicit D = 10 uplift of the family of vacua as well as computing the entire modulus-dependent Kaluza-Klein spectrum as a function of χ. At the special values χ = 0 and χ = $$ \frac{\pi }{T} $$

π
T

, the symmetry enhances according to U(1)2 → U(2), giving rise however to inequivalent Kaluza-Klein spectra. At χ = $$ \frac{\pi }{T} $$

π
T

, this realizes a bosonic version of the “space invaders” scenario with additional massless vector fields arising from formerly massive fields at higher Kaluza-Klein levels.
Chiral anomaly in SU(2)R-axion inflation and the new prediction for particle cosmology
Authors: Maleknejad Azadeh
Published: June 2021

Abstract

Upon embedding the axion-inflation in the minimal left-right symmetric gauge extension of the SM with gauge group SU(2)L× SU(2)R× U(1)B−L, [1] proposed a new particle physics model for inflation. In this work, we present a more detailed analysis. As a compelling consequence, this setup provides a new mechanism for simultaneous baryogenesis and right-handed neutrino creation by the chiral anomaly ofWRin inflation. The lightest right-handed neutrino is the dark matter candidate. This setup has two unknown fundamental scales, i.e., the scale of inflation and left-right symmetry breaking SU(2)R× U(1)B−L→U(1)Y. Sufficient matter creation demands the left-right symmetry breaking scale happens shortly after the end of inflation. Interestingly, it prefers left-right symmetry breaking scales above 1010GeV, which is in the range suggested by the non-supersymmetric SO(10) Grand Unified Theory with an intermediate left-right symmetry scale. AlthoughWRgauge field generates equal amounts of right-handed baryons and leptons in inflation, i.e. B−L = 0, in the Standard Model sub-sector B−LSM≠ 0. A key aspect of this setup is that SU(2)Rsphalerons are never in equilibrium, and the primordial B−LSMis conserved by the Standard Model interactions. This setup yields a deep connection between CP violation in physics of inflation and matter creation (visible and dark); hence it can naturally explain the observed coincidences among cosmological parameters, i.e.,ηB≃ 0.3Pζand ΩDM≃ 5ΩB. The new mechanism does not rely on the largeness of the unconstrained CP-violating phases in the neutrino sector nor fine-tuned masses for the heaviest right-handed neutrinos. The SU(2)R-axion inflation comes with a cosmological smoking gun; chiral, non-Gaussian, and blue-tilted gravitational wave background, which can be probed by future CMB missions and laser interferometer detectors.
On ambiguities and divergences in perturbative renormalization group functions
Authors: Herren Florian , Thomsen Anders Eller
Published: June 2021

Abstract

There is an ambiguity in choosing field-strength renormalization factors in the $$ \overline{\mathrm{MS}} $$

MS
¯

scheme starting from the 3-loop order in perturbation theory. More concerning, trivially choosing Hermitian factors has been shown to produce divergent renormalization group functions, which are commonly understood to be finite quantities. We demonstrate that the divergences of the RG functions are such that they vanish in the RG equation due to the Ward identity associated with the flavor symmetry. It turns out that any such divergences can be removed using the renormalization ambiguity and that the use of the flavor-improved β-function is preferred. We show how our observations resolve the issue of divergences appearing in previous calculations of the 3-loop SM Yukawa β-functions and provide the first calculation of the flavor-improved 3-loop SM β-functions in the gaugeless limit.
Matrix integrals & finite holography
Authors: Anninos Dionysios , Mühlmann Beatrix
Published: June 2021

Abstract

We explore the conjectured duality between a class of large N matrix integrals, known as multicritical matrix integrals (MMI), and the series (2m − 1, 2) of non-unitary minimal models on a fluctuating background. We match the critical exponents of the leading order planar expansion of MMI, to those of the continuum theory on an S2 topology. From the MMI perspective this is done both through a multi-vertex diagrammatic expansion, thereby revealing novel combinatorial expressions, as well as through a systematic saddle point evaluation of the matrix integral as a function of its parameters. From the continuum point of view the corresponding critical exponents are obtained upon computing the partition function in the presence of a given conformal primary. Further to this, we elaborate on a Hilbert space of the continuum theory, and the putative finiteness thereof, on both an S2 and a T2 topology using BRST cohomology considerations. Matrix integrals support this finiteness.
Rank 2 local systems and abelian varieties
Authors: Krishnamoorthy Raju , Pál Ambrus
Published: June 2021

Let $$X/\mathbb {F}_{q}$$

X
/

F
q

be a smooth, geometrically connected variety. For X projective, we prove a Lefschetz-style theorem for abelian schemes of $$\text {GL}_2$$

GL
2

-type on X, modeled after a theorem of Simpson. Inspired by work of Corlette-Simpson over $$\mathbb {C}$$
C
, we formulate a conjecture that absolutely irreducible rank 2 local systems with infinite monodromy on X come from families of abelian varieties. We have the following application of our main result. If one assumes a strong form of Deligne’s (p-adic) companions conjecture from Weil II, then our conjecture for projective varieties reduces to the conjecture for projective curves. We also answer affirmitavely a question of Grothendieck on extending abelian schemes via their p-divisible groups.
A qualitative study exploring personal recovery meaning and the potential influence of clinical recovery status on this meaning 20 years after a first-episode psychosis
Authors: O’Keeffe Donal , Sheridan Ann , Kelly Aine , Doyle Roisin , Madigan Kevin , Lawlor Elizabeth , Clarke Mary
Published: June 2021

Purpose

Long-term data on recovery conceptualisation in psychotic illness are needed to support mental health services to organise themselves according to recovery-oriented frameworks. To our knowledge, no previous research has investigated how first-episode psychosis (FEP) service users (sampled across psychotic illness type) perceive recovery beyond 5 years after diagnosis. We aimed to explore personal recovery meaning with individuals 20 years after their FEP and examine the potential influence of clinical recovery status on how they defined recovery (i.e. personal recovery).

Methods

Twenty participants were purposefully sampled from an epidemiologically representative FEP incidence cohort. At 20-year follow-up, semi-structured interviews were conducted with 10 cohort members who met full ‘functional recovery criteria’ (Clinically Recovered Group) and 10 who did not (Not Clinically Recovered Group). A thematic analysis was performed to develop shared themes and group-specific sub-themes to capture agreement and divergence between groups.

Results

Five shared themes were produced: pursuing balance in conflict, generating meaning in life, experiencing a dynamic personal relationship with time, redressing inequality while managing added challenges/vulnerability, and directing life from resilience to flourishing. The five group-specific sub-themes developed illuminate differences in the meaning ascribed to personal recovery by each group.

Conclusion

Findings emphasise the role of time in how personal recovery is conceptualised by service users and identify ways clinical recovery may influence personal recovery meaning in FEP at mid-later life. Mental health services failing to consider temporal changes in meaning-making and discounting clinical recovery risk ignoring key factors affecting personal recovery.
Accurate prediction of machining feedrate and cycle times considering interpolator dynamics
Authors: Ward Rob , Sencer Burak , Jones Bryn , Ozturk Erdem
Published: June 2021

This paper presents an accurate machining feedrate prediction technique by modelling the trajectory generation behaviour of modern CNC machine tools. Typically, CAM systems simulate machines’ motion based on the commanded feedrate and the path geometry. Such approach does not consider the feed planning and interpolation strategy of the machine’s numerical control (NC) system. In this study, trajectory generation behaviour of the NC system is modelled and accurate cycle time prediction for complex machining toolpaths is realised. NC system’s linear interpolation dynamics and commanded axis kinematic profiles are predicted by using finite impulse response (FIR)–based low-pass filters. The corner blending behaviour during non-stop interpolation of linear segments is modelled, and for the first time, the minimum cornering feedrate that satisfies both the tolerance and machining constraints has been calculated analytically for 3-axis toolpaths of any geometry. The proposed method is applied to 4 different case studies including complex machining toolpaths. Experimental validations show actual cycle times can be estimated with > 90% accuracy, greatly outperforming CAM-based predictions. It is expected that the proposed approach will help improve the accuracy of virtual machining models and support businesses’ decision-making when costing machining processes.
Fatal hemorrhage after tonsillectomy
Authors: Feld Katharina , Mellin W. , Melzer B. , Rothschild Markus A. , Fries Jochen
Published: June 2021

This is the first report of a segmental mediolysis occurring in arterioles, affecting the neck/tonsillar region and leading to a fatal hemorrhage after a tonsillectomy in a 20-year-old woman. Arteriolar mediolysis could be observed in tissue layers about 2 cm distant from the tonsillectomy region. Reparative changes were observed in the carotid and small neck arteries as well as in only one intramyocardial arteriole; however, no other vascular regions typically reported in segmental mediolysis arteriopathy were affected and aneurysm formation was not observed. No family history of vascular disease or hypertension was known. Pathophysiologically, previously reported reasons for post-tonsillectomy bleeding could be excluded. Segmental mediolysis may represent a wider spectrum of affected arteriolar vessels besides the reported small and medium sized arteries leading to aneurysms, which impedes radiographic diagnosis.
Carbon isotope ratios of endogenous steroids found in human serum—method development, validation, and reference population-derived thresholds
Authors: Piper Thomas , Geyer Hans , Nieschlag Eberhard , Bally Lia , Thevis Mario
Published: June 2021

In order to detect the misuse of testosterone (T), urinary steroid concentrations and concentration ratios are quantified and monitored in a longitudinal manner to enable the identification of samples exhibiting atypical test results. These suspicious samples are then forwarded to isotope ratio mass spectrometry (IRMS)–based methods for confirmation. Especially concentration ratios like T over epitestosterone (E) or 5α-androstanediol over E proved to be valuable markers. Unfortunately, depending on the UGT2B17 genotype and/or the gender of the athlete, these markers may fail to provide evidence for T administrations when focusing exclusively on urine samples. In recent years, the potential of plasma steroids has been investigated and were found to be suitable to detect T administrations especially in female volunteers. A current drawback of this approach is the missing possibility to confirm that elevated steroid concentrations are solely derived from an administration of T and cannot be attributed to confounding factors. Therefore, an IRMS method for plasma steroids was developed and validated taking into account the comparably limited sample volume. As endogenous reference compounds, unconjugated cholesterol and dehydroepiandrosterone sulfate were found suitable, while androsterone and epiandrosterone (both sulfo-conjugated) were chosen as target analytes. The developed method is based on multi-dimensional gas chromatography coupled to IRMS in order to optimize the overall assay sensitivity. The approach was validated, and a reference population encompassing n = 65 males and females was investigated to calculate population-based thresholds. As proof-of-concept, samples from volunteers receiving T replacement therapies and excretion study samples were investigated.

Graphical abstract
Development and validation of a method for quantification of common wheat, durum wheat, rye and barley by droplet digital PCR
Authors: Schulze Christian , Geuthner Anne-Catrin , Mäde Dietrich
Published: June 2021

Food fraud is becoming a prominent topic in the food industry. Thus, valid methods for detecting potential adulterations are necessary to identify instances of food fraud in cereal products, a significant component of human diet. In this work, primer–probe systems for real-time PCR and droplet digital PCR (ddPCR) for the detection of these cereal species: bread wheat (together with spelt), durum wheat, rye and barley for real-time PCR and ddPCR were established, optimized and validated. In addition, it was projected to validate a molecular system for differentiation of bread wheat and spelt; however, attempts for molecular differentiation between common wheat and spelt based on the gene GAG56D failed because of the genetic variability of the molecular target. Primer–probe systems were further developed and optimized on the basis of alignments of DNA sequences, as well as already developed PCR systems. The specificity of each system was demonstrated on 10 (spelt), 11 (durum wheat and rye) and 12 (bread wheat) reference samples. Specificity of the barley system was already proved in previous work. The calculated limits of detection (LOD95%) were between 2.43 and 4.07 single genome copies in real-time PCR. Based on the “three droplet rule”, the LOD95%in ddPCR was calculated to be 9.07–13.26 single genome copies. The systems were tested in mixtures of flours (rye and common wheat) and of semolina (durum and common wheat). The methods proved to be robust with regard to the tested conditions in the ddPCR. The developed primer–probe systems for ddPCR proved to be effective in quantitatively detecting the investigated cereal species rye and common wheat in mixtures by taking into account the haploid genome weight and the degree of milling of a flour. This method can correctly detect proportions of 50%, 60% and 90% wholemeal rye flour in a mixture of wholemeal common wheat flour. Quantitative results depend on the DNA content, on ploidy of cereal species and are also influenced by comminution. Hence, the proportion of less processed rye is overestimated in higher processed bread wheat and adulteration of durum wheat by common wheat by 1–5% resulted in underestimation of common wheat.
A multilevel investigation supported by multivariate analysis for tomato product formulation
Authors: Boukid Fatma , Curti Elena , Diantom Agoura , Carini Eleonora , Vittadini Elena
Published: June 2021

Industrial processing of tomato includes its cutting and mincing, thermal treatments, and the addition of ingredients, which might induce changes in physicochemical properties of the final products. In this frame, the impact of texturing/thickening [xanthan gum (X) or potato fiber (F)] on the macroscopic, mesoscopic and molecular properties of tomato double concentrate (TDC) was investigated to determine if F can efficiently substitute X, in association with small solutes (sugar and salt) and thermal treatment (cold and hot). At a macroscopic level, multivariate statistics (MANOVA) underlined that color change (ΔE) was increased by X and F addition contrary to heating and the addition of salt and sugar. MANOVA revealed that texture was greatly enhanced through the use of F over X. 1H NMR molecular mobility changes were more controlled by texturing agents (F and X) than thermal treatment and small solutes. Particularly F increased the more rigid population indicating stronger interaction with water molecules resulting in shear-thinning flow. However, adding X contributed into the increase of the dynamic and mobile populations. Therefore, F can be a valid “clean label” substitute of X in modulating tomato products properties.
In-air hearing in Hawaiian monk seals: implications for understanding the auditory biology of Monachinae seals
Authors: Ruscher Brandi , Sills Jillian M. , Richter Beau P. , Reichmuth Colleen
Published: June 2021

The auditory biology of Monachinae seals is poorly understood. Limited audiometric data and certain anatomical features suggest that these seals may have reduced sensitivity to airborne sounds compared to related species. Here, we describe the in-air hearing abilities of a Hawaiian monk seal (Neomonachus schauinslandi) trained to participate in a psychophysical paradigm. We report absolute (unmasked) thresholds for narrowband signals measured in quiet conditions across the range of hearing and masked thresholds measured in the presence of octave-band noise at two frequencies. The behavioral audiogram indicates a functional hearing range from 0.1 to 33 kHz and poor sensitivity, with detection thresholds above 40 dB re 20 µPa. Critical ratio measurements are elevated compared to those of other seals. The apparently reduced terrestrial hearing ability of this individual—considered with available auditory data for a northern elephant seal (Mirounga angustirostris)—suggests that hearing in Monachinae seals differs from that of the highly sensitive Phocinae seals. Exploration of phylogenetic relationships and anatomical traits support this claim. This work advances understanding of the evolution of hearing in amphibious marine mammals and provides updated information that can be used for management and conservation of endangered Hawaiian monk seals.
High-quality imaging of endolymphatic hydrops acquired in 7 minutes using sensitive hT2W–3D–FLAIR reconstructed with magnitude and zero-filled interpolation
Authors: Zou Jing , Chen Luguang , Li Hongbin , Zhang Guoping , Pyykkö Ilmari , Lu Jianping
Published: June 2021

Background

It is still challenging to detect endolymphatic hydrops (EH) in patients with Meniere’s disease (MD) using MRI. The aim of the present study was to optimize a sensitive technique generating strong contrast enhancement from minimum gadolinium–diethylenetriamine pentaacetic acid (Gd–DTPA) while reliably detecting EH in the inner ear, including the apex.

Materials and methods

All imaging was performed using a 3.0 T MR system 24 h after intratympanic injection of low-dose Gd–DTPA. Heavily T2-weighted 3-dimensional fluid-attenuated inversion recovery reconstructed with magnitude and zero-filled interpolation (hT2W–FLAIR–ZFI) was optimized and validated in phantom studies and compared with medium inversion time inversion recovery imaging with magnitude reconstruction (MIIRMR). The following parameters were used in hT2W–FLAIR–ZFI: repetition time 14,000 ms, echo time 663 ms, inversion time 2900 ms, flip angle 120°, echo train length 271, and field of view 166 × 196 mm2.

Results

MRI obtained using hT2W–FLAIR–MZFI yielded high-quality images with sharper and smoother borders between the endolymph and perilymph and a higher signal intensity ratio and more homogenous perilymph enhancement than those generated with MIIRMR (p < 0.01). There were predominantly grade II EHs in the cochleae and grade III EHs in the vestibule in definite MD. EH was detected in the apex of 11/16 ipsilateral ears, 3/16 contralateral ears in unilateral definite MD and 3/6 ears in bilateral MD.

Conclusions

The novel hT2W–FLAIR–MZFI technique is sensitive and demonstrates strong and homogenous enhancement by minimum Gd–DTPA in the inner ear, including the apex, and yields high-quality images with sharp borders between the endolymph and perilymph.
National record-linkage study of hospital admissions for schizophrenia in childhood and adolescence in England
Authors: Seminog Olena , Hoang Uy , Goldacre Michael , James Anthony
Published: June 2021

Background

There is a lack of information on changes in hospital admission rates for childhood-onset schizophrenia (COS), or on patient characteristics, to inform clinical research and health service provision.

Aims

To report age- and sex-specific incidence rates of hospital admissions and day patient care for schizophrenia (ICD-10 F20) and non-affective psychosis (ICD-10 F20-29), by year of occurrence and age, in childhood and adolescence.

Methods

Population-based study using person-linked data for England (available 2001–2016); time-periods in single years and 4-year groups.

Results

Hospitalised incidence for schizophrenia increased with increasing age, from 0.03 (95% confidence interval (CI) 0.02–0.05) and 0.01 (0–0.01) per 100,000 in, respectively, males and females aged 5–12 years, to 3.67 (3.44–3.91) in males and 1.58 (1.43–1.75) in females aged 13–17 years. There was no gender difference in hospitalised incidence rates in children aged 5–12, but in 13–17 years old, there was a male excess. Rates for schizophrenia were stable over time in 5–12 years old. In ages 13–17, rates for schizophrenia decreased between 2001–2004 and 2013–2016 in males, from 6.65 (6.04–7.31) down to 1.40 (1.13–1.73), and in females from 2.42 (2.05–2.83) to 1.18 (0.92–1.48). The hospitalisation rates for schizophrenia and non-affective psychosis, combined, in 13–17 years old decreased in males from 14.20 (13.30–15.14) in 2001–2004 to 10.77 (9.97–11.60) in 2013–2016, but increased in females from 7.49 (6.83–8.20) to 10.16 (9.38–11.00).

Conclusions

The study confirms that childhood-onset schizophrenia is extremely rare, with only 32 cases identified over a 15-year period in the whole of England. The incidence of schizophrenia and non-affective psychosis increased substantially in adolescence; however, the marked reduction in the proportion of those diagnosed with schizophrenia in this age group suggests a possible change in diagnostic practice.
Numerical Approximation of Poisson Problems in Long Domains
Authors: Chipot Michel , Hackbusch Wolfgang , Sauter Stefan , Veit Alexander
Published: June 2021

In this paper, we consider the Poisson equation on a “long” domain which is the Cartesian product of a one-dimensional long interval with a (d − 1)-dimensional domain. The right-hand side is assumed to have a rank-1 tensor structure. We will present and compare methods to construct approximations of the solution which have tensor structure and the computational effort is governed by only solving elliptic problems on lower-dimensional domains. A zero-th order tensor approximation is derived by using tools from asymptotic analysis (method 1). The resulting approximation is an elementary tensor and, hence has a fixed error which turns out to be very close to the best possible approximation of zero-th order. This approximation can be used as a starting guess for the derivation of higher-order tensor approximations by a greedy-type method (method 2). Numerical experiments show that this method is converging towards the exact solution. Method 3 is based on the derivation of a tensor approximation via exponential sums applied to discretized differential operators and their inverses. It can be proved that this method converges exponentially with respect to the tensor rank. We present numerical experiments which compare the performance and sensitivity of these three methods.
Numerical Accuracy of Ladder Schemes for Parallel Transport on Manifolds
Authors: Guigui Nicolas , Pennec Xavier
Published: June 2021

Parallel transport is a fundamental tool to perform statistics on Riemannian manifolds. Since closed formulae do not exist in general, practitioners often have to resort to numerical schemes. Ladder methods are a popular class of algorithms that rely on iterative constructions of geodesic parallelograms. And yet, the literature lacks a clear analysis of their convergence performance. In this work, we give Taylor approximations of the elementary constructions of Schild’s ladder and the pole ladder with respect to the Riemann curvature of the underlying space. We then prove that these methods can be iterated to converge with quadratic speed, even when geodesics are approximated by numerical schemes. We also contribute a new link between Schild’s ladder and the Fanning scheme which explains why the latter naturally converges only linearly. The extra computational cost of ladder methods is thus easily compensated by a drastic reduction of the number of steps needed to achieve the requested accuracy. Illustrations on the 2-sphere, the space of symmetric positive definite matrices and the special Euclidean group show that the theoretical errors we have established are measured with a high accuracy in practice. The special Euclidean group with an anisotropic left-invariant metric is of particular interest as it is a tractable example of a non-symmetric space in general, which reduces to a Riemannian symmetric space in a particular case. As a secondary contribution, we compute the covariant derivative of the curvature in this space.
Safer Solvent Blends for Food, Dye, and Environmental Analyses Using Reversed-Phase High Performance Liquid Chromatography
Authors: Nallar Melisa , Tenaglia Nicholas , Morose Gregory , Wong Hsi-Wu
Published: June 2021

Liquid chromatography (LC) is a technique widely used to identify and quantify organic compounds in a complex mixture. Typical operations of high-performance liquid chromatography (HPLC) involve continuous use of harmful solvents. Replacing these harmful solvents with safer alternatives will provide significant environmental, health, and safety benefits. In this work, a systematic approach for searching safer solvent blends to replace acetonitrile for reversed-phase (RP) HPLC operations is presented. GreenScreen® for Safer Chemicals was used as the first filter to down-select safer solvent candidates from thousands of chemicals based on their safety ratings. A list of LC operation parameters was then employed to determine final solvent candidates. Finally, Hansen Solubility Parameters in Practice (HSPiP) software was utilized to identify the most probable compositions of blends from these solvents for actual LC testing. It was found that a blend of 75% ethanol and 25% methyl acetate by volume provided the chromatograms with the best performance, which had similar response factors and column efficiency compared to acetonitrile when surrogate food additives, dyes, and water pollutants were tested, suggesting that this solvent blend is a potential safer alternative to replace acetonitrile for certain LC applications.
The Jew Is to Be Burned: A Turning Point in the Communist Approach to the “Jewish Question” on the Eve of Catastrophe
Authors: Navon Tom
Published: June 2021

Otto Heller, the Austrian-Czech-German communist intellectual of Jewish origin, was known almost exclusively for his 1931 orthodox Marxist book, Der Untergang des Judentums (The Decline of Judaism). A recently rediscovered unpublished manuscript of a second book on the “Jewish Question,” written by Heller in 1939 and entitled Der Jude wird verbrannt (The Jew Is to Be Burned), sheds new light on the man and his work. Furthermore, the unknown manuscript, as one of the longest communist accounts of the Jewish Question and antisemitism from that period, reveals a substantial turning point in the history of the communist discussion on those issues. Existing scholarship has identified novel political stances among communists, such as recognizing the Jews as a nation and as unique victims of Nazism only from 1942 onwards. Although Heller did not express such far-reaching political views in this lost manuscript, he did introduce an original theoretical approach to the Jewish Question. This article analyzes Heller’s theoretical innovations as early intellectual precursors of later dramatic developments in the communist political discourse.
High-resolution imaging of depth filter structures using X-ray computed tomography
Authors: Johnson T. F. , Iacoviello F. , Welsh J. H. , Shearing P. R. , Bracewell D. G.
Published: June 2021

A multiple length scale approach to the imaging and measurement of depth filters using X-ray computed tomography is described. Three different filter grades of varying nominal retention ratings were visualized in 3D and compared quantitatively based on porosity, pore size and tortuosity. Positional based analysis within the filters revealed greater voidage and average pore sizes in the upstream quartile before reducing progressively through the filter from the center to the downstream quartile, with these results visually supported by voidage distance maps in each case. Flow simulation to display tortuous paths that flow may take through internal voidage were examined.

Digital reconstructions were capable of identifying individual constituents of voidage, cellulose and perlite inside each depth filter grade, with elemental analysis on upstream and downstream surfaces confirming perlite presence. Achieving an appropriate pixel size was of particular importance when optimizing imaging conditions for all grades examined. A 3 µm pixel size was capable of representing internal macropores of each filter structure; however, for the finest grade, an improvement to a 1 µm pixel size was required in order to resolve micropores and small perlite shards. Enhancing the pixel size resulted in average porosity measurements of 70% to 80% for all grades.

Graphical abstract
Refugee and Immigrant Community Health Champions: a Qualitative Study of Perceived Barriers to Service Access and Utilisation of the National Health Service (NHS) in the West Midlands, UK
Authors: Mudyarabikwa Oliver , Regmi Krishna , Ouillon Sinead , Simmonds Raymond
Published: June 2021

There has been much discussion recently that better healthcare systems lead to increased service access and utilisation. However, there are still concerns raised among the refugee and immigrant communities about barriers to access and utilisation of primary healthcare services in the UK. This study aimed to explore with refugee and immigrant community health champions (CHCs) their perceptions about such barriers based on feedback in their own discussions with fellow refugees, asylum-seekers and immigrants in the West Midlands, UK. A total of 42 refugees and immigrants were recruited. Qualitative design-focused group discussions were conducted among purposively selected participants. These discussions were conducted between May and September 2019, and data were analysed using thematic analysis. The barriers to service access and utilisation are categorised into four themes: (i) knowledge about health issues that most affected refugees and immigrants; (ii) community indications of factors that obstructed service access; (iii) challenges in identifying local teams involved in service provision; and (iv) accurate knowledge about the different teams and their roles in facilitating access. This study higlighted that the levels of service access and utilisation would depend on the competence and effectiveness of the health system. Urgency and seriousness of individuals’ healthcare needs were the factors that were perceived to strongly influence refugees and immigrants to seek and utilise local services. We identified a number of potential barriers and challenges to service access and utilisation that should be overcome if primary healthcare service is to be planned and delivered effectively, efficiently and equitably in the West Midlands.
Causal coupling inference from multivariate time series based on ordinal partition transition networks
Authors: Subramaniyam Narayan Puthanmadam , Donner Reik V. , Caron Davide , Panuccio Gabriella , Hyttinen Jari
Published: June 2021

Identifying causal relationships is a challenging yet crucial problem in many fields of science like epidemiology, climatology, ecology, genomics, economics and neuroscience, to mention only a few. Recent studies have demonstrated that ordinal partition transition networks (OPTNs) allow inferring the coupling direction between two dynamical systems. In this work, we generalize this concept to the study of the interactions among multiple dynamical systems and we propose a new method to detect causality in multivariate observational data. By applying this method to numerical simulations of coupled linear stochastic processes as well as two examples of interacting nonlinear dynamical systems (coupled Lorenz systems and a network of neural mass models), we demonstrate that our approach can reliably identify the direction of interactions and the associated coupling delays. Finally, we study real-world observational microelectrode array electrophysiology data from rodent brain slices to identify the causal coupling structures underlying epileptiform activity. Our results, both from simulations and real-world data, suggest that OPTNs can provide a complementary and robust approach to infer causal effect networks from multivariate observational data.
Experimental practices and objectivity in the social sciences: re-embedding construct validity in the internal–external validity distinction
Authors: Jiménez-Buedo María , Russo Federica
Published: June 2021

The experimental revolution in the social sciences is one of the most significant methodological shifts undergone by the field since the ‘quantitative revolution’ in the nineteenth century. One of the often valued features of social science experimentation is precisely the fact that there are (alleged) clear methodological rules regarding hypothesis testing that come from the methods of the natural sciences and from the methodology of RCTs in the biomedical sciences, and that allow for the adjudication among contentious causal claims. We examine critically this claim and argue that some current understandings of the practices that surround social science experimentation overestimate the degree to which experiments can actually fulfil this role as “objective” adjudicators, by neglecting the importance of shared background knowledge or assumptions and of consensus regarding the validity of the constructs involved in an experiment. We take issue with the way the distinction between internal and external validity is often used to comment on the inferential import of experiments, used both among practitioners and among philosophers of science. We describe the ways in which the more common (dichotomous) use of the internal/external distinction differs from Cook and Campbell’s original methodological project, in which construct validity and the four-fold validity typology were all important in assessing the inferential import of experiments. We argue that the current uses of the labels internal and external, as applied to experimental validity, help to encroach a simplistic view on the inferential import of experiments that, in turn, misrepresents their capacity to provide objective knowledge about the causal relations between variables.
Multitasking NPOs: An Analysis of the Relationship Between Funding Intentions and Nonprofit Capacities
Authors: Stühlinger Sara , Hersberger-Langloh Sophie E.
Published: June 2021

Nonprofit organizations (NPOs) often find themselves under pressure to invest all of their available income in mission-related activities rather than in capacity building. We investigate one factor that can influence the decision to invest in such capacity-building tasks: funding sources pursued by an organization. Drawing on the benefits theory of nonprofit finance, we take these funding sources as predetermined by an organization’s mission and propose an extension of the theory by linking it to economic multitasking theory, which states that organizations prioritize tasks that offer greater and more measurable rewards. Through regression analyses of survey data from Swiss nonprofits, we analyze the extent to which funding sources sought affect the amount of effort invested in three areas of capacity building: public relations, impact focus, and resource attraction parameters. The results support the predictions of multitasking theory by showing that the effort invested in certain capacity-building tasks is affected considerably by seeking a specific funding source. The effects are stronger for resource attraction-related tasks than for tasks closer to the service delivery of NPOs. The results indicate that an organization’s mission affects not only the available funding sources but also the extent to which an organization invests in its capacities, which can lead to a ‘lock-in’ status for organizations.
A case of periosteal fasciitis located in the mandible in a child
Authors: Eida Sato , Hotokezaka Yuka , Sasaki Miho , Hotokezaka Hitoshi , Fujita Shuichi , Katayama Ikuo , Takagi Yukinori , Sumi Misa
Published: June 2021

Periosteal fasciitis (PF), a subtype of nodular fasciitis, is an uncommon benign soft-tissue mass that originates from the periosteum or tissues adjacent to bones. PF has rarely seen in children, especially involving in the mandible. This case report presents a rare case of PF originating from the periosteum of the mandible in an 11-year-old girl. She was referred to our hospital with fast-growing painless swelling in her left mandible. Computed tomography revealed an exophytic juxtacortical mass eroding the lower part of the left mandible and lower mandibular cortex with a periosteal reaction. The mass showed low signal intensity on T1-weighted magnetic resonance imaging (MRI) and high signal intensity on T2-weighted MRI. The apparent diffusion coefficient (ADC) of the lesion found to be moderate. Dynamic contrast-enhanced MRI revealed a gradual increment pattern in the central region of the mass. On 18F-fluorodeoxyglucose (FDG) positron-emission tomography/computed tomography (PET/CT), relatively high 18F-FDG uptake was observed on the early scan and the 18F-FDG uptake was declined on the delayed scan. The clinical and conventional radiological findings of the mass were suggestive of malignancy. However, the findings of ADC and dynamic MRI and dual-time-point FDG-PET/CT favored benign etiology over malignant etiology. Histological and immunohistochemical findings along with reactive ossification of the periosteum confirmed the diagnosis of PF. Currently, comprehensive examinations, such as clinical, imaging, and histopathological examinations, are recommended for the definitive diagnosis of PF, while MRI and dual-time-point FDG-PET/CT could have a potential usefulness to differentiate from malignancy.
An investigation of qualitative variations of groundwater resources under municipal wastewater recharge using numerical and laboratory models, Nazarabad plain, Iran
Authors: Amiri Nezhla , Nakhaei Mohammad
Published: June 2021

Municipal wastewater irrigation induces elevated concentrations of heavy metals in the soil which their further leaching leads to groundwater contamination in the long run. In this study, both column experiment and 5-year prediction modeling using HYDRUS-1D were conducted to investigate the probable adsorption and transport of 10 different metals including As, Ba, Cr, Cu, Mo, Ni, Pb, Rb, Sr, and Zn in an alkaline soil from Nazarabad plain in Iran which has been irrigated with treated urban wastewater for several years. The obtained results revealed that reaching the equilibrium rate for the mentioned elements during 1825 days (= 5 years) was as follows: Mo > Cr > Rb > Zn > Ni > Ba> Sr > Pb > As> Cu. The finding implies that molybdenum (Mo) and copper (Cu) are the most mobile and the most adsorbent heavy metals in the soil, respectively. Higher mobility poses the greater potential risk of leaching into groundwater resources. Overall, experimental and numerical modelings had good accordance and were capable of describing the actual condition.
Ex situ phytoremediation trial of Sardinian mine waste using a pioneer plant species
Authors: Boi Maria Enrica , Cappai Giovanna , De Giudici Giovanni , Medas Daniela , Piredda Martina , Porceddu Marco , Bacchetta Gianluigi
Published: June 2021

The mitigation of metals contamination is currently a crucial issue for the reclamation of mine sites. Indeed, mine wastes are often disposed in open dumps and consequently pollutants are subjected to dispersion in the surrounding areas. In this study, the potential use ofHelichrysum microphyllumsubsp.tyrrhenicumfor phytostabilization was evaluated in ex situ conditions. Ninety specimens were randomly selected and were planted in three substrates (reference substrate, mine waste materials, and mine wastes with compost). Mineralogical compositions of substrates, rhizosphere, and roots were assessed through X-ray diffraction (XRD). Zn, Pb, and Cd concentrations of substrates, rhizosphere, soil pore waters, and plant tissues were determined. The phytostabilization potential was determined through the application of biological accumulation coefficient (BAC), biological concentration factor (BCF), and translocation factor (TF). Moreover, survival and biometric parameters were assessed on plant specimens. The polluted substrates and related rhizosphere materials were mainly composed of dolomite, quartz, pyrite, and phyllosilicate. Zn was the most abundant metal in substrates, rhizosphere, and soil pore waters. XRD analysis on roots showed the presence of amorphous cellulose and quartz and Zn was the most abundant metal in plant tissues.H. microphyllumsubsp.tyrrhenicumrestricts the accumulation of the metals into roots limiting their translocation in aereal parts, indicating its potential use as phytostabilizer (BCF, BAC, TF < 1). Survival and growth data showed a great adaptability to different substrates, with an evident positive effect of the implementation of compost which increased the plant survival and decreased the metals uptake into roots.
Wenn die Kamera dunkel bleibt – Psychodramatische Überlegungen zur Rolle digitaler Medien beim Lehren und Lernen.
Authors: Krauskopf Karsten
Published: June 2021

Dieser Beitrag der Zeitschrift für Psychodrama und Soziometrie (ZPS) entwickelt aus psychodramatischer Perspektive die These, digitale Medien nicht nur als Lernwerkzeuge auf einer kognitiven, sozialen und handlungsnahen Ebene zu verstehen, sondern auch ihren Einfluss auf Begrenzung und Ermöglichung soziometrischer Wahlen in Lehr-Lern-Settings zu betrachten. Ausgehend von einem Einblick in aktuelle Konzepte der pädagogisch-psychologischen Forschung wird das Konzept des Aufforderungscharakters – Affordanzen – digitaler Medien eingeführt. Anhand einer Vignette aus dem hochschuldidaktischen Kontext werden mögliche „Verführungen“ durch Medien im Hinblick auf soziometrisches Handeln rekonstruiert und vor dem Hintergrund von Rollenerwartungen und Morenos Konzept der Begegnung diskutiert.
A taxonomic revision of Acanthaceae tribe Barlerieae in Angola and Namibia. Part 2
Authors: Darbyshire Iain , Manzitto-Tripp Erin A. , Chase Frances M.
Published: June 2021

The second part of a taxonomic revision of the tribe Barlerieae (Acanthaceae) in Angola and Namibia coversBarleriasects.SomaliaandStellatohirta. Thirty-one taxa including 27 accepted species are treated. Four new species (Barleria eburnea,B. imatensis,B. louiseanaandB. thunbergiiflora), one new subspecies (B. kacondensissubsp.glabrescens) and one new variety (B. violascensvar.humpatana) are described. In addition,B. taitensisS.Moore var.occidentalisS.Moore is elevated to subspecies status andB. newtoniiLindau is resurrected as a distinct species endemic to the Lubango Highlands of Angola. Full descriptions, citations of types and representative specimens, and notes on their habitat(s), ecology and biogeography are provided for each taxon. Thirteen names inBarleriaare lectotypified and a neotype is selected forB. newtonii. A preliminary assessment of the conservation status and extinction risk is provided for each taxon. Of the 31 taxa enumerated, five are assessed as Endangered, two as Vulnerable, two as Near Threatened, and 13 are of Least Concern, whilst nine are currently considered to be Data Deficient. This contribution completes our revision ofBarleriain Angola and Namibia, with 59 accepted species, four additional subspecies, four additional varieties and two incompletely known taxa documented in total. A remarkable 75% of the taxa are endemic or near-endemic to Angola and Namibia.
Thief-zone plugging mechanism and application of calcite particles in fractured formations
Authors: Li Jiaxue , Li Shuanggui , Pan Lijuan , Gao Wei , Sun Jie , Qin Meng
Published: June 2021

Lost circulation in fractured strata during drilling incurs additional costs and leads to difficulties in promoting drilling safety and efficiency. Plugging-while-drilling is a feasible means to address lost circulation in fractured formations. The particle size distribution (PSD) of plugging particles is determined empirically; therefore, it is often not matched with the fracture sealing requirement. This study investigates the lost circulation mechanism of fractured strata and identifies a calcite particle-based material as the preferred plugging agent. The plugging mechanism and the design of PSD and particle concentration are demonstrated. Based on the concentration, a plugging-while-drilling technique was developed for fractured strata. The results show that calcite particles tend to form the filling layer at the fracture inlet, which cuts off the leakage of the drilling fluid into the fracture, eliminating the drilling fluid pressure applied on the fracture surface. Thus, a stable sealing for the fractured formation is achieved, and the pressure-bearing capacity of the borehole wall is increased. The result also reveals the optimal mixing and concentration models for calcite particles with various diameters. The plugging technique based on calcite particles for fractured formations is applied in a field experiment. The results confirm that the technique can improve the chance of lost circulation prevention and thief-zone plugging in fractured strata and remarkably reduce both the event quantity of lost circulation and the volume of circulation loss. The findings of this research lay a theoretical basis to address lost circulation in fractured formations and, thus, have important practical significance.