bluuebunny/crossref_metadata_2025 huggingface dataset:
Gravitational instantons with conformally coupled scalar fields
Authors: Barrientos José , Cisterna Adolfo , Corral Cristóbal , Oyarzo Marcelo
Published: May 2022

Abstract

We present novel regular Euclidean solutions to General Relativity in presence of Maxwell and conformally coupled scalar fields. In particular, we consider metrics of the Eguchi-Hanson and Taub-NUT families to solve the field equations analytically. The solutions have nontrivial topology labeled by the Hirzebruch signature and Euler characteristic that we compute explicitly. We find that, although the solutions are locally inequivalent with the original (anti-)self-dual Eguchi-Hanson metric, they have the same global properties in the flat limit. We revisit the Taub-NUT solution previously found in the literature, analyze their nuts and bolts structure, and obtain the renormalized Euclidean on-shell action as well as their topological invariants. Additionally, we discuss how the solutions get modified in presence of higher-curvature corrections that respect conformal invariance. In the conformally invariant case, we obtain novel Eguchi-Hanson and Taub-NUT solutions and demonstrate that both Euclidean on-shell action and Noether-Wald charges are finite without any reference to intrinsic boundary counterterms.
Entanglement of the 3-state Potts model via form factor bootstrap: total and symmetry resolved entropies
Authors: Capizzi Luca , Horváth Dávid X. , Calabrese Pasquale , Castro-Alvaredo Olalla A.
Published: May 2022

Abstract

In this paper, we apply the form factor bootstrap approach to branch point twist fields in the q-state Potts model for q ≤ 3. For q = 3 this is an integrable interacting quantum field theory with an internal discrete ℤ3 symmetry and therefore provides an ideal starting point for the investigation of the symmetry resolved entanglement entropies. However, more generally, for q ≤ 3 the standard Rényi and entanglement entropies are also accessible through the bootstrap programme. In our work we present form factor solutions both for the standard branch point twist field with q ≤ 3 and for the composite (or symmetry resolved) branch point twist field with q = 3. In both cases, the form factor equations are solved for two particles and the solutions are carefully checked via the ∆-sum rule. Using our analytic predictions, we compute the leading finite-size corrections to the entanglement entropy and entanglement equipartition for a single interval in the ground state.
The Triticum ispahanicum elongated glume locus P2 maps to chromosome 6A and is associated with the ectopic expression of SVP-A1
Authors: Chen Yi , Liu Yinqi , Zhang Junli , Torrance Adam , Watanabe Nobuyoshi , Adamski Nikolai M. , Uauy Cristobal
Published: May 2022

Key message

We propose the MADS-box transcription factor SVP-A1 as a promising candidate gene for the elongated glume locus P2, which maps to chromosome 6A instead of the previously proposed chromosome 7B.

In rice and wheat, glume and floral organ length are positively correlated with grain size, making them an important target to increase grain size and potentially yield. The wheat subspecies Triticum ispahanicum is known to develop elongated glumes and floral organs as well as long grains. These multiple phenotypic effects are controlled by the P2 locus, which was previously mapped to wheat chromosome 7B. Using three mapping populations, we show that the long glume locus P2 does not map to chromosome 7B, but instead maps to a 1.68 Mbp interval on chromosome 6A. Within this interval, we identified SVP-A1, a MADS box transcription factor which is the direct ortholog of the maize gene underlying the ‘pod corn’ Tunicate locus and is a paralog to the T. polonicum elongated glume P1 gene. In T. ispahanicum, we identified a unique allele which has a 482-bp deletion in the SVP-A1 promoter and is associated with ectopic and higher expression of SVP-A1 in the elongated glumes and floral organs. We used near-isogenic lines (NILs) to show that P2 has a consistent positive effect on the length of glume, lemma, palea, spike and grain. Based on the mapping data, natural variation, biological function of SVP genes in cereals and expression analyses, we propose the MADS-box transcription factor SVP-A1 as a promising candidate for P2.
Potential Causes for Cracking of a Laser Powder Bed Fused Carbon-free FeCoMo Alloy
Authors: Platl Jan , Rainer Daniel , Leitner Harald , Turk Christoph , Galbusera Francesco , Demir Ali Gökhan , Previtali Barbara , Schnitzer Ronald
Published: May 2022

Compared to hot isostatic pressing or casting, laser-based powder bed fusion (LPBF) facilitates a near-net-shape fabrication of geometrically complex tools leading to a strongly reduced post-processing time and effort and consequently lower costs. Conventional tool steels are, however, prone to cracking during LPBF due to their high carbon equivalent numbers. In contrast, carbon-free maraging steels promise an enhanced processability due to the formation of a soft martensite, which is subsequently hardened by the precipitation of intermetallic phases.

A novel maraging steel for cutting applications (Fe25Co15Mo (wt%)) has been developed in recent years, and the present contribution deals with the processability of this novel alloy as a candidate for LPBF. However, severe cracking has been observed despite its low carbon content. The scanning electron microscopy revealed transcrystalline cleavage fracture plains on the crack surfaces. It is assumed that silicon oxide inclusions, which were verified by energy dispersive X‑ray spectroscopy, are responsible for the brittle failure. The electron backscatter diffraction analysis revealed coarse elongated grains, which may also contribute to cracking. The differential scanning calorimetry could not confirm an influence of brittle ordered FeCo domains that are potentially formed during cooling. In conclusion, solution approaches for the fabrication of crack-free parts are presented.
The Role of Pillars in Raise Caving
Authors: Gams Patrick , Ladinig Tobias
Published: May 2022

Mining advances to greater depth, where the control of rock pressure is central for a successful operation. To handle the increasing rock pressure at LKAB’s Kiruna iron ore mine, LKAB and Montanuniversität Leoben develop a novel mining method called “raise caving”. Raise caving is based on an active stress management approach. De-stressing slots, which are separated by substantial pillars, are developed first and provide stress shadows for stope development and subsequent large-scale mineral extraction. At an advanced stage of extraction, these pillars are extracted, too. The pillars are decisive for the success of the raise caving method. They are responsible for the control of stresses, the stability of the hanging wall, and the control of seismic energy release. Hence, studies on pillars have a high importance. This contribution investigates the effect of pillar behavior on the overall extraction system by means of numerical simulations. Two different types for pillar behavior are examined, namely infinitely strong pillars and pillars which yield or crush in the process of extraction. In the second case, pillar stress strain curves are created and replicated numerically. The investigated behavior of pillars is based on available studies on the pillar stress strain behavior. Results show the importance of intact (not overloaded) pillars in the initial de-stressing phase in raise caving. These pillars are essential for controlling the stress levels at the position of the raise bore holes for the initial slot development. Pillar overloading results not only in an increase of the spatial extent of the stress shadow but also in a growth of stresses in the abutment areas and neighboring not yet overloaded pillars. It has been found that this instance can endanger the mining activities in the de-stressing phase. Furthermore, it has been found that the layout of the slot-pillar system together with the extraction sequence is decisive for ensuring that pillars are not overloaded in the de-stressing phase.
The incidence and prevalence, diagnosis, and treatment of multiple sclerosis in China: a narrative review
Authors: Jia Dongmei , Zhang Yu , Yang Chunsheng
Published: May 2022

In 2018, the first list of rare diseases was published by the National Health Council of China, and multiple sclerosis (MS) was included in this list. Since then, the Chinese government and neurologists have made efforts to improve the clinical outcomes of patients with MS. During last few years, the incidence of MS in China was also investigated. The early and accurate diagnosis of MS was improved due to the application and promotion of magnetic resonance imaging and new diagnosis criteria. The market for and medical insurance access to disease-modifying therapies (DMTs) has been greatly accelerated, which has provided more treatment options and improved clinical outcomes for patients with MS, as well as reduced treatment cost. The pattern of MS in China is gradually changing, from delayed to early diagnosis, and from no treatment to treatment with DMTs during remission. This narrative review aimed to summarize an update to the status of MS in China, including incidence and prevalence, diagnosis, and available treatments. This would help to better understand the diagnosis and treatment gap between mainland China and other Asian regions, demonstrating the necessity of accurate diagnosis and optimized treatment of MS in China.
The distribution of power within the EU: perspectives on a Ukrainian accession and a Turkish accession
Authors: Kirsch Werner
Published: May 2022

On February 28th, 2022, Ukraine submitted an application concerning accession to the European Union. As Ukraine is already linked to the European Union through an Association Agreement and the Deep and Comprehensive Free Trade Agreement—signed in 2014—there might be a chance for the Ukraine to join the EU within the next decade. With about 41 million inhabitants, Ukraine is a rather large country and the 65% majority requirement under the EU’s Qualified Majority Voting rules would give Ukraine some significant power in a future EU28. Herein, it is shown how relative political power indices—as measured by the Banzhaf index—would change in the case of an EU enlargement to allow accession by Ukraine: The large economies would lose power and, surprisingly, many small countries would gain political power. Such perspectives might lead one to reconsider the voting procedures of the Council of the European Union at the EU level in the course of future negotiations on amendments to the Lisbon Treaty. The case of Turkey’s accession is also considered as is the case of Montenegro joining the European Union.
Experimental Effects of Institutionalizing Co-determination by a Procedurally Fair Bidding Rule
Authors: Alberti Federica , Güth Werner , Tsutsui Kei
Published: May 2022

From an institutional perspective we contribute to corporate governance of firms by (1) proposing a procedurally fair mechanism that is ethically desirable, and (2) experimentally testing whether procedural fairness crowds-in ethical behavior of managers (on behalf of shareholders) and workers. The experiment sees one ‘manager’ and three ‘workers’ (possibly representing three sections of the firm) co-determining an efficiency-enhancing investment which could harm some workers. Firstly, the manager claims a share of the investment surplus, then workers ‘bid’ for the investment to express their willingness to satisfy the manager’s claim in case the investment is implemented. If the sum of workers’ bids is less than the manager’s claim, the investment is not implementable, which means its surplus will be lost. Workers’ behavior is ‘ethical’ when they veto unfair managerial claims, because the workers have to sacrifice own earnings. Hence, a manager’s fair claim is the ethical response to the threat of workers’ veto. If the manager claims fairly, workers’ ethical behavior is to ‘truthfully’ bid their investment evaluations; by all doing so, they equally share whatever surplus the manager has left for them. The experimental results show ethical behavior of managers in the form of fair claims. Despite these fair claims, workers behave less ethically by strategically underbidding. So the procedurally fair mechanism only partially crowds-in ethical behavior. This study should interest theorists of stakeholder management, especially those engaged in designing the rules of corporate governance.
The role of human-induced climate change in heavy rainfall events such as the one associated with Typhoon Hagibis
Authors: Li Sihan , Otto Friederike E. L.
Published: May 2022

Around October 12, 2019, torrential rainfall from Typhoon Hagibis caused large-scale flooding in a large area around the metropole region of Tokyo leading to large-scale destruction including losses of lives, livelihoods, and economic losses of well over $10 bn US dollars. In this paper we use a multi-method probabilistic event attribution framework to assess the role of human-induced climate change in the heavy rainfall event responsible for a large proportion of the damages. Combining different observational datasets and various climate model simulations, we find an increase in the likelihood of such an event to occur of 15–150%. We use this assessment and the calculated fraction of attributable risk (FAR) to further estimate the economic costs attributable to anthropogenic climate change based on the insured economic losses. Our conservative estimate is that ~$4bn of the damages due to the extreme heavy rainfall associated with Typhoon Hagibis are due to human-induced climate change.
Propositions as Made of Words
Authors: Kemp Gary
Published: May 2022

I argue that the principal roles standardly envisaged for abstract propositions can be discharged to the sentences themselves (and similarly for the meanings or senses of words). I discuss: (1) Cognitive Value: Hesperus-Phosphorus; (2) Indirect Sense and Propositional Attitudes; (3) the Paradox of Analysis; (4) the Picture Theory of the Tractatus; (5) Syntactical Diagrams and Meaning; (6) Quantifying-in. (7) Patterns of Use. I end with comparisons with related views of the territory.
Characterising a Representation Construction Pedagogy for Integrating Science and Mathematics in the Primary School
Authors: Tytler Russell , Prain Vaughan , Kirk Melinda , Mulligan Joanne , Nielsen Chris , Speldewinde Chris , White Peta , Xu Lihua
Published: May 2022

Growing research evidence indicates student learning gains from guided representation construction/invention in school science and mathematics. In this inquiry approach, students address challenges around what features of a phenomenon/problem to attend to, what data to collect, how and why, and make collective judgments about multimodal accounts of phenomena. However, researchers to date have tended to focus on student learning rather than on the teacher’s role in guiding various phases of inquiry. In this paper we report on (a) analysis of Grade 1 students’ engagement in interdisciplinary mathematics and science inquiry practices in a classroom sequence in ecology; (b) the teacher’s role in guiding such inquiry; and (c) interpretation of these practices in terms of support of student transduction (connecting and remaking meanings across representations in different modes). Data from our study included video capture of two case study teachers’ guidance of tasks and classroom discussion and student artefacts. We examine the classroom processes through which the teachers used students’ invention and revision of data displays to teach the concepts of living things, diversity, distribution and adaptive features related to habitat in science. Mathematical processes included constructing and interpreting mapping, measurement and data modelling, sampling and using a scale. The analysis offers fresh insights into how teachers support student learning in these two subjects, through discrete stages of orienting, representation challenge, building consensus and applying and extending representational systems.
Low power memristive gas sensor architectures with improved sensing accuracy
Authors: Khandelwal Saurabh , Ottavi Marco , Martinelli Eugenio , Jabir Abusaleh
Published: May 2022

Memristive devices, traditionally considered for memory, logic, and neuromorphic systems, are exhibiting many interesting properties for applications in a variety of areas, such as in sensing chemicals. However, any realistic approach based on these devices must take into account their susceptibility to process and parametric variations. When used for sensing purposes this, together with wire resistance, can significantly degrade their sensing accuracy. To this end, we propose novel memristive gas sensor architectures that can significantly reduce these effects in a predictable manner, while improving accuracy and overall power consumption. Additionally, we show that in the absence of gasses this architecture can also be configured to realize multifunction logic operations as well as Complementary Resistive Switch with low hardware overhead, thereby enhancing resource reusability. We also present a method for further improving power consumption and measurability by manipulating a device’s internal barrier. Our results show that the proposed architecture is significantly immune to process and parametric variations compared to a single sensor and almost unaffected by wire resistance, while offering much higher accuracy and much lower power consumption compared to existing techniques.
Serine-Arginine Protein Kinase 1 (SRPK1): a systematic review of its multimodal role in oncogenesis
Authors: Duggan William P. , O’Connell Emer , Prehn Jochen H. M. , Burke John P.
Published: May 2022

Alternative splicing is implicated in each of the hallmarks of cancer, and is mechanised by various splicing factors. Serine-Arginine Protein Kinase 1 (SRPK1) is an enzyme which moderates the activity of splicing factors rich in serine/arginine domains. Here we review SRPK1’s relationship with various cancers by performing a systematic review of all relevant published data. Elevated SRPK1 expression correlates with advanced disease stage and poor survival in many epithelial derived cancers. Numerous pre-clinical studies investigating a host of different tumour types; have found increased SRPK1 expression to be associated with proliferation, invasion, migration and apoptosis in vitro as well as tumour growth, tumourigenicity and metastasis in vivo. Aberrant SRPK1 expression is implicated in various signalling pathways associated with oncogenesis, a number of which, such as the PI3K/AKT, NF-КB and TGF-Beta pathway, are implicated in multiple different cancers. SRPK1-targeting micro RNAs have been identified in a number of studies and shown to have an important role in regulating SRPK1 activity. SRPK1 expression is also closely related to the response of various tumours to platinum-based chemotherapeutic agents. Future clinical applications will likely focus on the role of SRPK1 as a biomarker of treatment resistance and the potential role of its inhibition.
Umbilical cord-derived mesenchymal stem cell conditioned medium reverses neuronal oxidative injury by inhibition of TRPM2 activation and the JNK signaling pathway
Authors: Wang Yan , Liu Jiaxin , Yu Baocong , Jin Yiran , Li Jiahui , Ma Xiaona , Yu Jianqiang , Niu Jianguo , Liang Xueyun
Published: May 2022

Background

The mechanism by which MSC-CM protects neuronal cells against ischemic injury remains to be elucidated. In this study, we aimed to clarify the protective effect of umbilical cord-derived mesenchymal stem cell conditioned medium (UC-MSC-CM) on neuronal oxidative injury and its potential mechanism.

Methods and Results

Neuronal oxidative damage was mimicked by H2O2 treatment of the HT22 cell line. The numbers of cleaved-Caspase-3-positive cells and protein expression of Caspase-9 induced by H2O2 treatment were decreased by UC-MSC-CM treatment. Furthermore, SOD protein expression was increased in the MSC-CM group compared with that in the H2O2 group. The H2O2-induced TRPM2-like currents in HT22 cells were attenuated by MSC-CM treatment. In addition, H2O2 treatment downregulated the expression of p-JNK protein in HT22 cells, and this the downward trend was reversed by incubation with MSC-CM.

Conclusions

UC-MSC-CM protects neurons against oxidative injury, possibly by inhibiting activation of TRPM2 and the JNK signaling pathway.
‘Should We Be Doing It, Should We Not Be Doing It, Who Could Be Harmed?’
Authors: Garrecht Carola , Czinczel Berrit , Kretschmann Marek , Reiss Michael J.
Published: May 2022

Many science educators have argued in favour of including socioscientific issues (SSI) in general, and ethical issues in particular, in school science. However, there have been a number of objections to this proposal, and it is widely acknowledged that such teaching places additional demands on science teachers. This study examined the curricula, textbooks and views of both student teachers and established teachers in England and in Germany regarding the teaching of ethical issues in secondary school science, particularly the ethical issues surrounding animal tests. Analysis of the curriculum documents for secondary or upper secondary school science showed that in both countries, ethical considerations feature strongly. However, in both countries, the overall treatments in the school textbooks of the ethical issues of animal testing were generally ‘thin’, and little opportunity was given for students to consider different ethical frameworks. The teacher and student teacher interviews revealed that interviewees generally gave ethical issues less emphasis than fundamental science. A number of interviewees referred to a lack of appropriate teaching material, and many of them also had concerns that such teaching could give rise to classroom management issues or that they might be accused of indoctrinating their students. Given the increasing acknowledgement of the need for school science to address so-called wicked socioscientific problems, these findings are a concern. We end with recommendations for curricula, for textbooks and for teacher education.
Atorvastatin can delay arterial stiffness progression in hemodialysis patients
Authors: Elsayed Mohamed Mamdouh , Ayman Elhassan Mohamed
Published: May 2022

Purpose

Arterial stiffness is one of the vascular pathologies in hemodialysis (HD) patients with increased cardiovascular mortality and morbidity. Few approaches have been tested to reduce arterial stiffness in patients with chronic kidney disease (CKD). We aimed to assess effects of atorvastatin on arterial stiffness in hemodialysis patients.

Methods

This research is a double-blinded, placebo-controlled, randomized clinical trial which included 50 patients maintained on regular HD. Patients were allocated to receive 10 mg atorvastatin or placebo for 24 weeks. Aortic pulse wave velocity (PWV) as an index of large artery stiffness and augmentation index (AIx) as an index of wave reflections were assessed at baseline and after 6 months in both groups.

Results

In atorvastatin group at study end, there was no significant difference from baseline findings in aortic PWV (7.86 ± 2.5 vs 7.88 ± 2.6 m/sec; p = 0.136), AIx (26.04 ± 8.5 vs 26.0 ± 8.6%; p = 0.714) and central pulse pressure (PP) (p = 1.0). On the other hand, in placebo group after 24 weeks, aortic PWV (7.80 ± 2.16 vs 7.63 ± 2.1 m/sec; p < 0.001), AIx (25.88 ± 9.4 vs 25.04 ± 9.4%; p < 0.001) increased significantly from baseline measurements but central pulse pressure (PP) (p = 0.870) did not. Also, the change (Δ) in aortic PWV and AIx was significantly higher than the change in the atorvastatin group with p value of < 0.001 and < 0.001, respectively.

Conclusions

Arterial stiffness parameters remained stable in atorvastatin group but increased significantly in placebo-treated patients suggesting a potential role for atorvastatin to delay arterial stiffness progression in HD patients. Larger randomized clinical trials are needed to confirm these findings.

Clinical Trials registration

ClinicalTrials.gov NCT04472637.
Mechanical analysis of the wide-hipped titanosaur Savannasaurus elliottorum
Authors: Preuschoft Holger
Published: May 2022

Fossil material of the wide-hipped titanosaurian sauropod Savannasaurus elliottorum from the Winton Formation has been described precisely. The authors, Poropat et al. (2020), reconstruct the original owner of the bones and draw well-founded conclusions about the evolution of Savannasaurus by connecting its body shape with its environment. These conclusions are in the sense of Bock and von Wahlert (in Evolution, 19, 269–299, 1965), on the level of the ultimate “Biological Role”. In fact there are also arguments on the level of the more proximate “Mechanical Function” to strengthen this view. The investigation of the mechanical conditions leads to a confirmation of the conclusions drawn by the authors of the study, now on the proximate level of “Function”. Like each functional analysis it bridges the gap between the morphological trait and the use made of it during lifetime. The mechanical stresses (or internal forces) evoked by forces acting on it from outside (or the external forces) are the immediate causes which dictate its shape; in the case of fossils, the shapes of skeletal elements.
On local isometries between algebras of C(Y)-valued differentiable maps
Authors: Hosseini Maliheh , Jiménez-Vargas A. , Ramírez María Isabel
Published: May 2022

Let K be either the real unit interval [0, 1] or the complex unit circle $${\mathbb {T}}$$
T
and let C(Y) be the space of all complex-valued continuous functions on a compact Hausdorff space Y. We prove that the isometry group of the algebra $$C^1(K,C(Y))$$

C
1

(
K
,
C

(
Y
)

)

of all C(Y)-valued continuously differentiable maps on K, equipped with the $$\Sigma $$
Σ
-norm, is topologically reflexive and 2-topologically reflexive whenever the isometry group of C(Y) is topologically reflexive.
The ‘good’ of extending fertility: ontology and moral reasoning in a biotemporal regime of reproduction
Authors: Bühler Nolwenn
Published: May 2022

Since the emergence of in-vitro fertilization (IVF), a specific set of technologies has been developed to address the problem of the ‘biological clock’. The medical extension of fertility time is accompanied by promissory narratives to help women synchronize conflicting biological and social temporalities. This possibility also has a transgressive potential by blurring one of the biological landmarks – the menopause – by which reproductive lives are organized and governed. These new ways of managing, measuring and controlling reproductive time have renewed debates on the age limits of motherhood and the moral legitimacy of medical intervention into age-related fertility decline. Building on Amir’s feminist concept of biotemporality, this paper questions what happens when the ontological foundations of age-limited motherhood are disrupted by technologies which allow fertility to be extended. It discusses the reconfigurations of the ontological boundaries of the facts of life in the light of literature on reproductive technologies and temporality. Through the Swiss experience, the paper shows how medical experts are drawn into negotiating the ontological boundaries of age-limited motherhood along the binaries of the normal/pathological and the biological/social. Questioning the purpose of medical interventions in what are seen as facts of life, they produce different configurations of moral reasoning where what is natural undergoes shifts which both reinforce the normative order and subvert it.
Das ›Schweißtuch der Veronika‹. Zur Ästhetik liturgischer Referenzen bei Gertrud von le Fort
Authors: Bölling Jörg , Heilmann Gesa
Published: May 2022

Kirchengeschichtliche und liturgiehistorische Forschungen wenden sich seit einiger Zeit wieder vermehrt dem Mittelalter und der Frühen Neuzeit zu. Besonderes Interesse finden dabei liturgische Rituale und Zeremonien, die einen fruchtbaren Austausch zu mediävistischen Fragestellungen zwischen der Theologie, Philologie, Musikgeschichte, Kunstgeschichte und Geschichte versprechen. In diesem Zusammenhang ist vor allem die im Mittelalter aufgekommene Präsentation des sog. ›Schweißtuches der Veronika‹ von Bedeutung – einem Phänomen, dem im Magdalene College der Universität Cambridge jüngst eine ganze Tagung gewidmet worden ist. Wenig Beachtung hat bisher jedoch die literarische Bearbeitung dieses im Kern mittelalterlichen Gegenstandes im gleichnamig suggestiv betitelten modernen Roman der Autorin Gertrud von le Fort (1876–1971) gefunden. Dieser Beitrag sucht im ersten Teil die zugrunde liegenden historischen, dem Ursprung nach mittelalterlichen Prätexte mit ihrer immanent liturgischen Ästhetik aufzuspüren (Jörg Bölling), um diese dann mit der literarischen Ästhetik der Autorin selbst zu vergleichen (Gesa Heilmann) sowie in einem abschließenden Fazit zu würdigen (Jörg Bölling und Gesa Heilmann).
The evolution of turbulent micro-vortices and their effect on convection heat transfer in porous media
Authors: Huang Ching-Wei , Srikanth Vishal , Kuznetsov Andrey V.
Published: May 2022

New insight into the contribution of the microscale vortex evolution to convection heat transfer in porous media is presented in this paper. The objective is to determine how the microscale vortices influence convection heat transfer in turbulent flow inside porous media. The microscale temperature distribution is analysed using flow visualization in two dimensions using streamlines and in three dimensions using the Q-criterion. The pertinent observations are supplemented with a comparison of surface skin friction and heat transfer using: (i) surface skin-friction lines and (ii) the joint probability density function of the pressure and skin-friction coefficients, along with the Nusselt number. The microscale flow phenomena observed are corroborated with the features of the frequency spectra of the drag coefficient and macroscale Nusselt number. The large eddy simulation technique is used in this study to investigate the flow field inside a periodic porous medium. The Reynolds numbers of the flow are 300 and 500. The porous medium consists of solid obstacles in the shape of square and circular cylinders. Two distinct flow regimes are represented by using the porosities of 0.50 and 0.87. The results show that the surface Nusselt number distribution is dependent on whether the micro-vortices are attached to or detached from the surface of the obstacle. The spectra of the macroscale Nusselt number and the pressure drag are similar, signifying a correlation between the dynamics of heat transfer and the microscale turbulent structures. Both vortex shedding and secondary flow instabilities are observed that significantly influence the Nusselt number. The fundamental insight gained in this paper can inform the development of more robust macroscale models of convection heat transfer in turbulent flow in porous media.
Minimal energy thresholds for sustained turbulent bands in channel flow
Authors: Parente E. , Robinet J.-Ch. , De Palma P. , Cherubini S.
Published: May 2022

In this work, nonlinear variational optimization is used for obtaining minimal seeds for the formation of turbulent bands in channel flow. Using nonlinear optimization together with energy bisection, we have found that the minimal energy threshold for obtaining spatially patterned turbulence scales with$Re^{-8.5}$for$Re>1000$. The minimal seed, which is different to that found in a much smaller domain, is characterized by a spot-like structure surrounded by a low-amplitude large-scale quadrupolar flow filling the whole domain. This minimal-energy perturbation of the laminar flow has dominant wavelengths close to$4$in the streamwise direction and$1$in the spanwise direction, and is characterized by a spatial localization increasing with the Reynolds number. At$Re \lesssim 1200$, the minimal seed evolves in time, creating an isolated oblique band, whereas for$Re\gtrsim 1200$, a quasi-spanwise-symmetric evolution is observed, giving rise to two distinct bands. A similar evolution is found also at low$Re$for non-minimal optimal perturbations. This highlights two different mechanisms of formation of turbulent bands in channel flow, depending on the Reynolds number and initial energy of the perturbation. The selection of one of these two mechanisms appears to be dependent on the probability of decay of the newly created stripe, which increases with time, but decreases with the Reynolds number.
NEW GENERALISATIONS OF VAN HAMME’S (G.2) SUPERCONGRUENCE
Authors: TANG NA
Published: May 2022

Swisher [‘On the supercongruence conjectures of van Hamme’, Res. Math. Sci.2 (2015), Article no. 18] and He [‘Supercongruences on truncated hypergeometric series’, Results Math.72 (2017), 303–317] independently proved that Van Hamme’s (G.2) supercongruence holds modulo
$p^4$
for any prime
$p\equiv 1\pmod {4}$
. Swisher also obtained an extension of Van Hamme’s (G.2) supercongruence for
$p\equiv 3 \pmod 4$
and
$p>3$
. In this note, we give new one-parameter generalisations of Van Hamme’s (G.2) supercongruence modulo
$p^3$
for any odd prime p. Our proof uses the method of ‘creative microscoping’ introduced by Guo and Zudilin [‘A q-microscope for supercongruences’, Adv. Math.346 (2019), 329–358].
Attitude towards negotiating safer sexual relations: Exploring power dynamics among married couples in India
Authors: Vishwakarma Deepanjali , Sharma Santosh Kumar , Kukreti Shikha , Singh S.K.
Published: May 2022

The study primarily focuses on analyzing married women’s attitudes towards negotiating safer sex in two contexts. The first context is when a woman refuses to have sex with husband if she knows her husband has a sexually transmitted disease (STD) and the second is when she does so if she knows he has sex with other women. The study examined predictors of Indian women’s attitude towards negotiating safer-sex using data on 92,306 ever married women from the state module of the 2015-16, National Family Health Survey 4. Descriptive and multilevel logistic regression was used to understand the interplay between the attitude towards negotiation of safer sexual relationships with husband and the selected background characteristics with a primary focus on controlling behaviour and power relations. About 17% of women did not believe in negotiating safer sexual relations with the husband. An approximately equal proportion of ever-married women (79% each) believed in doing so under the two specific conditions, that is, if they knew the husband had an STD and they knew he had sex with other women. Multilevel regression analysis showed that women who had household decision-making power [AOR=0.71; p<0.01] and those whose husbands displayed low control towards them [AOR=0.91; p<0.05] were more likely to believe in negotiating safer-sex. Our findings suggest that women who have controlling partners or those who live under the umbrella of the husband’s authority lack the power to negotiate for safer sex. Interventions promoting sexual well-being must deal with negative male perceptions and expectations that perpetuate unhealthy sexual habits and marriage ties.
Size-related, seasonal and interdecadal changes in the diet of the Patagonian longfin squid Doryteuthis gahi in the South-western Atlantic
Authors: Büring Tobias , Schroeder Paul , Jones Jessica B. , Pierce Graham , Rocha Francisco , Arkhipkin Alexander I.
Published: May 2022

The Patagonian longfin squid Doryteuthis gahi has an annual life cycle with two seasonal cohorts (autumn and spring spawners). Earlier studies on the Patagonian shelf found a predominance of Euphausiacea in the D. gahi diet, but no studies to date have investigated differences between feeding spectra of the two cohorts or decadal diet shifts. The present study investigated differences in diet of D. gahi on the Patagonian shelf sampled two decades apart, and differences between seasonal cohorts. Classical stomach content analysis and generalized additive models were used to investigate and model the influence of mantle length, sampling period and spawning cohort on the diet. Results revealed an ontogenetic diet change from ~70% Frequency of Occurrence of Euphausiacea in small squid to more than 60% FO of fish and Cephalopoda at larger sizes. Cannibalism was also frequently observed. Euphausiacea were ingested more frequently and in higher amounts during the austral summer and therefore were consumed more by the autumn spawning cohort, whereas fish was more frequently fed upon during austral winter and also by the spring spawning cohort. Cannibalism was also recorded more in austral winter months but, contrary to feeding on fish, was more prevalent in the autumn spawning cohort. Increased predation of Munida gregaria was observed in 2020 compared with 2001. This study is an important step towards improving the knowledge of D. gahi's two seasonal cohorts, providing data that can be used for future ecosystem modelling.
Towards a Burma-inclusive South Asian Studies: A Roundtable
Authors: Emmrich Christoph , McQuade Joseph , Aiyar Sana , d'Hubert Thibaut
Published: May 2022

Burma, or Myanmar as it was renamed in 1989, is largely ignored within the discipline of South Asian Studies, despite its cultural, religious, economic, and strategic significance for the wider worlds of Asia. Burma is often studied either in isolation or alongside Southeast Asian countries such as Thailand, Vietnam, and Malaysia, despite its equally important historical and cultural connections to communities, states, and networks across what is now India, Bangladesh, Sri Lanka, or Nepal. In this Roundtable, four scholars of South Asia discuss Burma's erasure within the discipline, the origins and limitations of traditional area studies frameworks, and the possibilities afforded by Burma's inclusion within a more expansive conception of South Asia.
Depressive symptoms among Mexican adolescent girls in relation to iron status, anaemia, body weight and pubertal status: results from a latent class analysis
Authors: Zarate-Ortiz Arli Guadalupe , Verhoef Hans , Melse-Boonstra Alida , Woods Bo-Jane , Lee-Bazaldúa Elida Estefania , Feskens Edith JM , Quiroga-Garza Angelica , Cepeda-Lopez Ana Carla
Published: May 2022

Objective:

The study examined the association between depressive symptoms and iron status, anaemia, body weight and pubertal status among Mexican adolescent girls.

Design:

In this cross-sectional study, depressive symptoms were assessed by the 6-item Kutcher Adolescent Depression Scale, and latent class analysis (LCA) was used to identify and characterise groups of girls based on depressive symptoms. Iron status and inflammation were assessed using ferritin and soluble transferrin receptor, C-reactive protein and alpha-1-acid glycoprotein, respectively. Multiple logistic and linear regressions were applied to model class membership as a function of iron status, anaemia, body weight and pubertal status.

Participants:

We collected data from 408 girls aged 12–20 years.

Setting:

Public schools in northern Mexico.

Results:

LCA yielded three classes of depressive symptoms: 44·4 % of the adolescents were ‘unlikely to be depressed’, 41·5 % were ‘likely to be depressed’ and 14·1 % were ‘highly likely to be depressed’. Our analyses demonstrated that iron-deficient girls had greater odds of being ‘likely depressed’ (OR 2·01, 95 % CI 1·01, 3·00) or ‘highly likely depressed’ (OR 2·80, 95 % CI 1·76, 3·84). Linear regression analyses revealed that lower Hb concentrations and higher body weight increased the probability of being ‘likely depressed’. There was no evidence that depressive symptoms were associated with age at menarche and years since menstruation.

Conclusions:

This study shows that iron-deficient adolescent girls are more likely to suffer from depressive symptoms and that lower concentrations of Hb and higher body weight increased the probability of experiencing depressive symptoms.
Cosmopolitan Connections: Yevgeny Onegin as realist drame lyrique in Nice
Authors: Alexander Tamsin
Published: May 2022

In the build-up to the French premiere of Tchaikovsky's Yevgeny Onegin in Nice in 1895, critics, speakers and writers on music were declaring the opera a masterpiece of psychological realism. Such a reading seems to resonate more with recent assessments of the opera; but in 1890s France, a combination of interest in the Russian realist novel and new trends in realist opera had led critics to make the literary link already. With the Franco-Russian Alliance recently finalized and hostility towards the Triplice mounting, many even suggested that the opera might form the lyric equivalent of the Russian realist novel and, in so doing, offer a morally and politically superior alternative to the so-called verismo operas of the new Italian school.

The optimism surrounding Onegin, I'd like to show, was part of a broader move in late nineteenth-century France to celebrate cosmopolitanism, if not in the sense one might expect. Tchaikovsky and Onegin were very much deemed representatively Russian. What was cosmopolitan, and in turn modern, was the act of cultural transfer – exploiting international personal networks – and the opera's realism: its evocations of ordinary life and of the contemporary psychological condition. As such, a Russian opera like this could be applauded not for its revelations of an exotic or disconnected country, but for the potential it posed to integrate with and revitalize French culture.
Mass Statistical Analysis of Early VLF Events
Authors: Pailoor N. A. , Cohen M. B.
Published: May 2022

The analysis of very low frequency (VLF, 3–30 kHz) radio scattering can be used to measure the impact of lightning on the D region of the ionosphere (60–90 km). Early/fast events are prompt and rapid changes to the D‐region ionosphere associated with certain lightning flashes, causing heating, ionization, and attachment. Previous work has observed the behavior of early/fast events and their connection to specific types of lightning flashes through VLF remote sensing and lightning geolocation, but the unique nature of each event makes it difficult to broadly infer the interactions between lightning and the ionosphere using a small number of case studies. We assembled a massive database of VLF amplitude samples for cases when high‐intensity lightning occurs near a transmitter‐receiver path. We constructed an artificial neural network to detect and label early/fast events. With a large volume of events compiled, we charted detailed statistics of event occurrences and behavior. We find a correlation between lightning current magnitude and event likelihood, as well as inverse correlation between event likelihood and distance to transmitter‐receiver path. We further confirm the asymmetry of the peak current trends, with positive‐current strokes being significantly more likely to produce an event. We find that increased distance of the lightning to the transmitter, and to a lesser extent to the receiver, decreases the probability of an ionospheric disturbance. We find that recovery time is largely not a function of the peak current. We do not find evidence that long‐recovery events are a distinct class of Early/Fast events.
Large Geomagnetically Induced Currents at Equator Caused by an Interplanetary Magnetic Cloud
Authors: Nilam B. , Tulasi Ram S.
Published: May 2022

Here, we report a rare observation of an extremely large and rapid change of geomagnetic field (dB/dt), a proxy for the geomagnetically induced currents (GICs), at the equator caused by a sudden drop in solar wind density at the front boundary of a magnetic cloud (MC) during the great 31 March 2001 storm. The horizontal component at the Indian equatorial station, Tirunelveli, recorded a sharp decline of ∼350 nT in just 5 min with a peak dB/dt exhibiting a concerning value of 136 nT/min, a possible GIC risk to the electric power systems. The responsible physical mechanisms were examined through magneto‐hydrodynamic model simulations and found that a prompt penetration of strong westward‐overshielding electric fields and ionospheric currents at the equator play a dominant role. This study provides some new insights into the extent of extreme geomagnetic field changes that can occur at the equatorial region due to solar wind density reduction at MC, which can have potential impacts on the electric power grid systems.
Top-down regulation of motivated behaviors via lateral septum sub-circuits
Authors: Besnard Antoine , Leroy Felix
Published: May 2022

How does cognition regulate innate behaviors? While the cognitive functions of the cortex have been extensively studied, we know much less about how cognition can regulate innate motivated behaviors to fulfill physiological, safety and social needs. Selection of appropriate motivated behaviors depends on external stimuli and past experiences that helps to scale priorities. With its abundant inputs from neocortical and allocortical regions, the lateral septum (LS) is ideally positioned to integrate perception and experience signals in order to regulate the activity of hypothalamic and midbrain nuclei that control motivated behaviors. In addition, LS receives numerous subcortical modulatory inputs, which represent the animal internal states and also participate in this regulation. In this perspective, we argue that LS sub-circuits regulate distinct motivated behaviors by integrating neural activity from neocortical, allocortical and neuromodulatory inputs. In addition, we propose that lateral inhibition between LS sub-circuits may allow the emergence of functional units that orchestrates competing motivated behaviors.
Macrophage migration inhibitory factor (MIF) acetylation protects neurons from ischemic injury
Authors: Hu Jin-Xia , Ma Wei-Jing , He Li-Ying , Zhang Cong-Hui , Zhang Cheng , Wang Yan , Chen Chao-Nan , Shen Da-Yong , Gao Hui-Min , Guo Rui-Ru , Ning Qian-Qian , Ye Xin-Chun , Cui Gui-Yun , Li Lei
Published: May 2022

Ischemia-induced neuronal death leads to serious lifelong neurological deficits in ischemic stroke patients. Histone deacetylase 6 (HDAC6) is a promising target for neuroprotection in many neurological disorders, including ischemic stroke. However, the mechanism by which HDAC6 inhibition protects neurons after ischemic stroke remains unclear. Here, we discovered that genetic ablation or pharmacological inhibition of HDAC6 reduced brain injury after ischemic stroke by increasing macrophage migration inhibitory factor (MIF) acetylation. Mass spectrum analysis and biochemical results revealed that HDAC6 inhibitor or aspirin treatment promoted MIF acetylation on the K78 residue. MIF K78 acetylation suppressed the interaction between MIF and AIF, which impaired MIF translocation to the nucleus in ischemic cortical neurons. Moreover, neuronal DNA fragmentation and neuronal death were impaired in the cortex after ischemia in MIF K78Q mutant mice. Our results indicate that the neuroprotective effect of HDAC6 inhibition and aspirin treatment results from MIF K78 acetylation; thus, MIF K78 acetylation may be a therapeutic target for ischemic stroke and other neurological diseases.
Rectification and confinement of photokinetic bacteria in an optical feedback loop
Authors: Massana-Cid Helena , Maggi Claudio , Frangipane Giacomo , Di Leonardo Roberto
Published: May 2022

Active particles can self-propel by exploiting locally available energy resources. When powered by light, these resources can be distributed with high resolution allowing spatio-temporal modulation of motility. Here we show that the random walks of light-driven bacteria are rectified when they swim in a structured light field that is obtained by a simple geometric transformation of a previous system snapshot. The obtained currents achieve an optimal value that we establish by general theoretical arguments. This optical feedback is used to gather and confine bacteria in high-density and high-activity regions that can be dynamically relocated and reconfigured. Moving away from the boundaries of these optically confined states, the density decays to zero in a few tens of micrometers, exhibiting steep exponential tails that suppress cell escape and ensure long-term stability. Our method is general and scalable, providing a versatile tool to produce localized and tunable active baths for microengineering applications and systematic studies of non-equilibrium phenomena in active systems.