bluuebunny/crossref_metadata_2025 huggingface dataset:
A constructive approach to accessible group classes
Authors: de Giovanni Francesco , Trombetti Marco
Published: August 2021

Let $${\mathfrak {X}}$$
X
be a group class. A group G is an opponent of $${\mathfrak {X}}$$
X
if it is not an $${\mathfrak {X}}$$
X
-group, but all its proper subgroups belong to $${\mathfrak {X}}$$
X
. Of course, every opponent of $${\mathfrak {X}}$$
X
is a cohopfian group and the aim of this paper is to describe the smallest group class containing $${\mathfrak {X}}$$
X
and admitting no such a kind of cohopfian groups.
Metallurgical Analysis as a Useful Method for Fire Investigation: the Case of Galvanized Steel Sheets
Authors: Casaroli A. , Boniardi M. , Gerosa R. , Rivolta B.
Published: August 2021

In this work, fire simulations were carried out on zinc-coated steel sheets usually employed for the structural parts of furniture, transformer rooms and aeration pipes. The thermal alteration induced by the fire was simulated by heating samples at 13 different temperatures (from 20° C to 1050° C) and for different exposure times (1 h and 6 h) in a laboratory furnace. The metallurgical investigation concerned the surface coloring by photographic analysis, the morphology and chemical composition of the surface oxides by SEM and EDS and the microstructure modifications as a function of the temperature by LOM. The influence of the different parameters was discussed by a statistical approach. The obtained results allowed to associate the temperature to one or more alteration of the steel microstructure and of the color, the morphology and the chemical composition of the surface oxides.
Plimpton 322: A Study of Rectangles
Authors: Mansfield Daniel F.
Published: August 2021

Plimpton 322 is one of the most sophisticated and interesting mathematical objects from antiquity. It is often regarded as teacher’s list of school problems, however new analysis suggests that it relates to a particular geometric problem in contemporary surveying.
Aqueous extracts characteristics obtained by ultrasound-assisted extraction from Ascophyllum nodosum seaweeds: effect of operation conditions
Authors: Gisbert Mauro , Barcala Manuel , Rosell Cristina M. , Sineiro Jorge , Moreira Ramón
Published: August 2021

Aqueous extracts fromAscophyllum nodosumbrown edible seaweeds were obtained after continuous ultrasound-assisted extraction. The effect of sonication time (from 2 to 6 min), sonication amplitude (from 80 to 100%) and solvent-solid ratio (from 20 to 40 g water g−1dried seaweed) on the extracts features was studied employing a Box-Behnken experimental design. Extracts were characterised by polyphenols, carbohydrate and uronic acid content. Response surface method (by means of a quadratic model) was successfully employed to relate chemical composition of extracts and operation conditions. Optimal experimental conditions were established to obtain maximal polyphenols content and several polyphenols-carbohydrates ratios together with the conditions that minimise energy consumption per extracted polyphenols amount relationship. Antioxidant capacities of extracts were measured employing different methods (DPPH, FRAP and ABTS). Positive linear correlations between antioxidant activity and total polyphenols content were established.
Experiences from Exporting Major Proof Assistant Libraries
Authors: Kohlhase Michael , Rabe Florian
Published: August 2021

The interoperability of proof assistants and the integration of their libraries is a highly valued but elusive goal in the field of theorem proving. As a preparatory step, in previous work, we translated the libraries of multiple proof assistants, specifically the ones of Coq, HOL Light, IMPS, Isabelle, Mizar, and PVS into a universal format: OMDoc/MMT. Each translation presented great theoretical, technical, and social challenges, some universal and some system-specific, some solvable and some still open. In this paper, we survey these challenges and compare and evaluate the solutions we chose. We believe similar library translations will be an essential part of any future system interoperability solution, and our experiences will prove valuable to others undertaking such efforts.
Investigating the effect of nitrogen on the structural and tribo-mechanical behavior of vanadium nitride thin films deposited using R.F. magnetron sputtering
Authors: Aissani Linda , Fellah Mamoun , Chadli Ablel Hakim , Samad Mohammed Abdul , Cheriet Abderrahmane , Salhi Faiza , Nouveau Corinne , Weiß Sabine , Obrosov Aleksei , Alhussein Akram
Published: August 2021

Magnetron sputtering is one of the most commonly used deposition techniques, which has received considerable attention in industrial applications. In particular, owing to its compatibility with conventional fabrication processes, it can produce and fabricate high-quality dense thin films of a wide range of materials. In the present study, nitrogen (N) was combined with pure vanadium in order to form binary nitride to improve its mechanical and tribological performance. To evaluate the influence of nitrogen on the structure of the as-deposited vanadium nitride (VN) coatings, the following techniques were used: XPS, XRD, SEM, AFM and optical profilometry. The residual stresses were determined by the curvature method using Stoney’s formula. The hardness and Young’s modulus were obtained by nanoindentation measurements. The friction behavior and wear characteristics of the films were evaluated by using a ball-on-disk tribometer. The obtained results showed that the N/V ratio increased with increasing the N2 flow rate while the deposition rate decreased. The preferred orientation was changed from (200) to (111) as the N2 flow rate increased with the presence of V–N and V–O binding energies as confirmed by XPS analysis. The nitrogen addition resulted in a columnar morphology and a fine structure with fine surface roughness. The VN thin film containing 49.5 at.% of nitrogen showed the best performance: highest mechanical properties (hardness = 25 GPa), lowest friction coefficient (μ = 0.37) and lowest wear rate (Ws = 2.72 × 10−5 mm3N−1 m−1). A good correlation between the film microstructure, crystallite size, residual stress and mechanical and tribological properties was observed.
Modeling and evaluating beat gestures for social robots
Authors: Zabala Unai , Rodriguez Igor , Martínez-Otzeta José María , Lazkano Elena
Published: August 2021

Natural gestures are a desirable feature for a humanoid robot, as they are presumed to elicit a more comfortable interaction in people. With this aim in mind, we present in this paper a system to develop a natural talking gesture generation behavior. A Generative Adversarial Network (GAN) produces novel beat gestures from the data captured from recordings of human talking. The data is obtained without the need for any kind of wearable, as a motion capture system properly estimates the position of the limbs/joints involved in human expressive talking behavior. After testing in a Pepper robot, it is shown that the system is able to generate natural gestures during large talking periods without becoming repetitive. This approach is computationally more demanding than previous work, therefore a comparison is made in order to evaluate the improvements. This comparison is made by calculating some common measures about the end effectors’ trajectories (jerk and path lengths) and complemented by the Fréchet Gesture Distance (FGD) that aims to measure the fidelity of the generated gestures with respect to the provided ones. Results show that the described system is able to learn natural gestures just by observation and improves the one developed with a simpler motion capture system. The quantitative results are sustained by questionnaire based human evaluation

.
Soft and hard information in equity crowdfunding: network effects in the digitalization of entrepreneurial finance
Authors: Estrin Saul , Khavul Susanna , Wright Mike
Published: August 2021

As a digital financial innovation, equity crowdfunding (ECF) allows investors to exploit the complementarity of information provision and network effects in a reduced transaction cost environment. We build on the underlying distinction between soft and hard information and show that ECF platforms create an environment of greater information pooling that benefits from network externalities. We test our hypotheses using a unique proprietary dataset and find that soft information has a greater impact than hard on the likelihood that a financing pitch will be successful. Moreover, the effects of soft information are amplified by the size of the investor network on the platform and network size also positively moderates the effect of information on the amount invested during each pitch. We conclude that ECF platforms can successfully exploit low transaction costs of the digital environment and bring network externalities to bear on investor decisions. Taken together that these increase the supply of funds to entrepreneurs.
MATTER: A tool for generating end-to-end IoT test scripts
Authors: Olianas Dario , Leotta Maurizio , Ricca Filippo
Published: August 2021

In the last few years, Internet of Things (IoT) systems have drastically increased their relevance in many fundamental sectors. For this reason, assuring their quality is of paramount importance, especially in safety-critical contexts. Unfortunately, few quality assurance proposals for assuring the quality of these complex systems are present in the literature. In this paper, we extended and improved our previous approach for semi-automated model-based generation of executable test scripts. Our proposal is oriented to system-level acceptance testing of IoT systems. We have implemented a prototype tool taking in input a UML model of the system under test and some additional artefacts, and producing in output a test suite that checks if the system’s behaviour is compliant with such a model. We empirically evaluated our tool employing two IoT systems: a mobile health IoT system for diabetic patients and a smart park management system part of a smart city project. Both systems involve sensors or actuators, smartphones, and a remote cloud server. Results show that the test suites generated with our tool have been able to kill 91% of the overall 260 generated mutants (i.e. artificial bugged versions of the two considered systems). Moreover, the optimisation introduced in this novel version of our prototype, based on a minimisation post-processing step, allowed to reduce the time required for executing the entire test suites (about -20/25%) with no adverse effect on the bug-detection capability.
Electroreduction of Carbon Dioxide by Heterogenized Cofacial Porphyrins
Authors: Tian Pengfei , Su Jianjun , Song Yun , Ye Ruquan , Zhu Minghui
Published: August 2021

Great attention has been paid to cofacial porphyrins due to their many unique advantages over their monomeric analogs. However, their synthesis is usually complicated. In this work, a facile impregnation method for preparing heterogenized, cofacially stacked porphyrins is proposed. An anionic porphyrin is introduced as an underlayer for immobilization of cationic cobalt porphyrin via electrostatic force. The metal center of the underlying molecule contributes to the electronic structure of the upper cationic cobalt porphyrin. Screening reveals the anionic iron porphyrin to be the most efficient underlayer molecule, lowering the activation energy barrier of CO2 electroreduction, with an improved turnover frequency by 74% to 8.0 s−1 at − 0.6 V versus RHE.
Tris (2,3-Dibromopropyl) Isocyanurate (TDBP-TAZTO or TBC) Shows Different Toxicity Depending on the Degree of Differentiation of the Human Neuroblastoma (SH-SY5Y) Cell Line
Authors: Szychowski Konrad A. , Skóra Bartosz , Mańdziuk Marzena
Published: August 2021

Tris (2,3-dibromopropyl) isocyanurate (TDBP-TAZTO or TBC) is a heterocyclic hexabromated flame retardant. It is widely used during the production of many synthetic compounds. High concentrations of TDBP-TAZTO were found in river water, surface sediments, soil, earthworms, and carp tissues. Moreover, it has been shown that this compound can cross the blood–brain barrier and accumulate in the gut and brain of carp. The aryl hydrocarbon receptor (AhR) has been characterized as a multifunctional intracellular sensor and receptor. AhR is an activator of cytochrome P450 1A1 and 1A2, which metabolize various toxic compounds. The aim of the study was to explain how/whether TDBP-TAZTO increases the expression and/or activity of the CYP1A1 enzyme and the AhR and TUBB3 expression during SH-SY5Y cell differentiation. SH-SY5Y cells were differentiated for 7 and 14 days using retinoic acid. Cell viability, ethoxyresorufin-O-deethylase (EROD) activity, and mRNA expression of CYP1A1, AhR, and TUBB3 were assessed. Our experiment showed that, during the differentiation process, the ability of TDBP-TAZTO to induce EROD activity in SH-SY5Y cells subsequently decreased, which may have been an effect of cell differentiation into neurons. Moreover, the results suggest that TDBP-TAZTO can affect the differentiation process. Since no CYP2B6 mRNA expression was detected, the CAR receptor may not be involved in the TDBP-TAZTO mechanism of action. However, more research is needed in this field to elucidate this mechanism precisely.
Targeting phytoprotection in the COVID-19-induced lung damage and associated systemic effects—the evidence-based 3PM proposition to mitigate individual risks
Authors: Liskova Alena , Koklesova Lenka , Samec Marek , Abdellatif Basma , Zhai Kevin , Siddiqui Manaal , Šudomová Miroslava , Hassan Sherif T.S. , Kudela Erik , Biringer Kamil , Giordano Frank A. , Büsselberg Dietrich , Golubnitschaja Olga , Kubatka Peter
Published: August 2021

The risks related to the COVID-19 are multi-faceted including but by far not restricted to the following: direct health risks by poorly understood effects of COVID-19 infection, overloaded capacities of healthcare units, restricted and slowed down care of patients with non-communicable disorders such as cancer, neurologic and cardiovascular pathologies, among others; social risks—restricted and broken social contacts, isolation, professional disruption, explosion of aggression in the society, violence in the familial environment; mental risks—loneliness, helplessness, defenceless, depressions; and economic risks—slowed down industrial productivity, broken delivery chains, unemployment, bankrupted SMEs, inflation, decreased capacity of the state to perform socially important programs and to support socio-economically weak subgroups in the population. Directly or indirectly, the above listed risks will get reflected in a healthcare occupation and workload which is a tremendous long-term challenge for the healthcare capacity and robustness. The article does not pretend to provide solutions for all kind of health risks. However, it aims to present the scientific evidence of great clinical utility for primary, secondary, and tertiary care to protect affected individuals in a cost-effective manner. To this end, due to pronounced antimicrobial, antioxidant, anti-inflammatory, and antiviral properties, naturally occurring plant substances are capable to protect affected individuals against COVID-19-associated life-threatening complications such as lung damage. Furthermore, they can be highly effective, if being applied to secondary and tertiary care of noncommunicable diseases under pandemic condition. Thus, the stratification of patients evaluating specific health conditions such as sleep quality, periodontitis, smoking, chronic inflammation and diseases, metabolic disorders and obesity, vascular dysfunction, and cancers would enable effective managemenet of COVID-19-associated complications in primary, secondary, and tertiary care in the context of predictive, preventive, and personalized medicine (3PM).
Phenolic composition of leaf and flower extracts of black cherry (Prunus serotina Ehrh.)
Authors: Brozdowski Jakub , Waliszewska Boguslawa , Gacnik Sasa , Hudina Metka , Veberic Robert , Mikulic-Petkovsek Maja
Published: August 2021

Key Message

The best yields in the extraction of hydroxycinnamic acids, flavanols and total phenolics from black cherry flowers were obtained with 40% ethanol and the poorest with water. A 30% higher content of total phenolics was obtained from leaves by using methanol rather than water.

Context

Black cherry (Prunus serotina Erhr.) is widespread in Europe. Because it is an invasive species, most research has been aimed at trying to find a method to remove this shrub from forests. The incentive for the development of the research was that we were trying to find a possible folk use of black cherry leaves and flowers.

Aims

The aim of this work was to study the detailed phenolic profile of extracts of P. serotina leaves and flowers.

Methods

Three types of extracts of P. serotina were made. The extracts were analysed for differences in phenolics content based on different extraction methods. HPLC-MSn was used to identify the phenolic compounds, and HPLC–DAD was used for their quantification.

Results

The results show that different extraction methods result in differences in the amount of extractables. Flavanols are the main group of identified compounds in both leaves and flowers. A larger extraction efficiency leads to a higher amount of phenolics in the flowers compared to leaves (49.8 vs. 36.5 g/kg dry weight). No difference was detected in the amount of phenolics between water extracts of leaves and flowers. Each extract can be considered rich in phenolics.

Conclusion

This work shows that leaves and flowers of P. serotina are a rich source of phenolic compounds. We provide interesting results that might be of interest in the industrial valuation of several compounds.
Verbale und nonverbale Indikatoren der kognitiven Komponente situational-naturwissenschaftlichen Interesses
Authors: Brandtner Miriam , Hertel Silke
Published: August 2021

Frühkindliche (naturwissenschaftliche) Interessen werden bislang vorrangig anhand von Befragungen erhoben. Wie zuverlässig Kinder bereits im Kindergartenalter über ihre Interessen Auskunft geben können, lässt sich kritisch diskutieren: einerseits, da Befragungen eine adäquate Rekonstruktion vergangener Zustände erfordern; andererseits, da sich Kinder ihrer Umwelt noch überwiegend nonverbal mitteilen. Nichtsdestotrotz ist zur Bestimmung des mentalen Konstrukts Interessensgegenstand die Erhebung von Selbstauskünften unumgänglich. Die vorliegende Studie wählt daher einen Zugang zu frühkindlichen naturwissenschaftlichen Interessen, der spontane Selbstauskünfte und Verhaltensbeobachtungen integriert. Hierfür wurden zehn Kinder in drei Lernsituationen der frühen naturwissenschaftlichen Bildung videografiert. Spontane Äußerungen wurden zur Einschätzung ihres aktuellen Interessensgegenstands herangezogen. Die Aufmerksamkeitsintensität in der nonverbalen Lerngegenstands-Auseinandersetzung diente als Anhaltspunkt für ihre momentane Interessiertheit. Es zeigten sich signifikant-positive Zusammenhänge zwischen der Verbalisierung eines naturwissenschaftlichen Interessensgegenstands und der nonverbalen Interessensausprägung. Dies legt nahe, dass die Kinder vorwiegend situational-naturwissenschaftliche Interessen entwickelt haben. Varianzanalysen wiesen auf bedeutsame Unterschiede in den naturwissenschaftlichen Interessensausprägungen hin, die einerseits von Kind-, andererseits von Lernsituations-Merkmalen beeinflusst wurden. Zeitreihenanalysen zeigten zudem, dass die Kinder meist erst nach mehreren Minuten interessiert-nonverbaler Auseinandersetzung ihr Interesse auch verbal zum Ausdruck brachten. Dies spricht für die Bedeutung schweigender Auseinandersetzungsprozesse in der Entwicklung situationalen Interesses.
Research Progress on Corrosion Resistance of Magnesium Alloys with Bio-inspired Water-repellent Properties: A Review
Authors: Xu Jinkai , Cai Qianqian , Lian Zhongxu , Yu Zhanjiang , Ren Wanfei , Yu Huadong
Published: August 2021

Thanks to its excellent mechanical properties, magnesium alloys have many potential applications in the aerospace and other fields. However, failure to adequately solve corrosion problems of magnesium alloy becomes one of the factors restricting its wide use in many industrial fields. Inspired by nature, researchers designed and fabricated bio-inspired water-repellent (superhydrophobic and slippery liquid-infused porous surface) surfaces with special wetting properties by exploring the surface microstructures of plants and animals such as lotus leaf and nepenthes pitcher, exhibiting excellent corrosion-resistant performance. This article summarizes the research progress on corrosion resistance of magnesium alloys with bio-inspired water-repellent properties in recent years. It mainly introduces the corrosion reasons, types of corrosion of magnesium alloys, and the preparation of magnesium alloys with bio-inspired water-repellent properties to improve corrosion resistance. In particular, it is widely used and effective to construct water-repellent and anti-corrosion coating on the surface of magnesium alloy by surface treatment. It is hoped that the research in this review can broaden the application range of magnesium alloys and provide a powerful reference for the future research on corrosion resistance of magnesium alloys.
Generalized Oppositional Moth Flame Optimization with Crossover Strategy: An Approach for Medical Diagnosis
Authors: Xia Jianfu , Zhang Hongliang , Li Rizeng , Chen Huiling , Turabieh Hamza , Mafarja Majdi , Pan Zhifang
Published: August 2021

In the original Moth-Flame Optimization (MFO), the search behavior of the moth depends on the corresponding flame and the interaction between the moth and its corresponding flame, so it will get stuck in the local optimum easily when facing the multi-dimensional and high-dimensional optimization problems. Therefore, in this work, a generalized oppositional MFO with crossover strategy, named GCMFO, is presented to overcome the mentioned defects. In the proposed GCMFO, GOBL is employed to increase the population diversity and expand the search range in the initialization and iteration jump phase based on the jump rate; crisscross search (CC) is adopted to promote the exploitation and/or exploration ability of MFO. The proposed algorithm’s performance is estimated by organizing a series of experiments; firstly, the CEC2017 benchmark set is adopted to evaluate the performance of GCMFO in tackling high-dimensional and multimodal problems. Secondly, GCMFO is applied to handle multilevel thresholding image segmentation problems. At last, GCMFO is integrated into kernel extreme learning machine classifier to deal with three medical diagnosis cases, including the appendicitis diagnosis, overweight statuses diagnosis, and thyroid cancer diagnosis. Experimental results and discussions show that the proposed approach outperforms the original MFO and other state-of-the-art algorithms on both convergence speed and accuracy. It also indicates that the presented GCMFO has a promising potential for application.
Modeling Colonial Paternalism: GIS and Multispectral Satellite Imagery at Kingstown, British Virgin Islands
Authors: Chenoweth John M. , Bossio Laura M. , Salvatore Mark
Published: August 2021

GIS modeling and analysis of multispectral satellite imagery are applied to a former plantation in the British Virgin Islands (BVI), which, in 1831, became a settlement of free Africans who lived within slavery-based British colonialism. A map of the settlement represents the paternalist British government ideal for this community—an “experiment” for controlling a postemancipation peasantry—and the techniques discussed here allow clearer understanding of the way these ideals would have interacted with the physical and social landscape of the BVI had they been implemented. The residents were certainly aware of their situation, and this study does not mean to imply that they simply adopted the plan they were handed. Instead, our goal is to interrogate the implications of the plan itself. We combine least cost path (LCP), Normalized Difference Vegetation Indexes (NDVI), and other technical analyses to show the interaction of the British plan and the BVI landscape in order to describe the context in which the Kingstown community was built and maintained. Although schematic, this study quantifies at least some of the barriers the community overcame and contributes in a limited way to broader considerations of the place of land and landscape in structures of colonialism.
(Inter)subjectivisation et chaines sémantiques dans les adverbes français en–ment: analyse du passage de l'adverbe intégré à la proposition au marqueur discursif
Authors: Álvarez-Prendes Emma
Published: August 2021

Les adverbes français se terminant en–mentont évolué par un double processus de grammaticalisation. Une première grammaticalisation, d'origine romane, a été responsable de l'émergence de tels adverbes, tandis qu'un second processus (appelé (inter)subjectification) a entrainé des changements syntaxiques et sémantiques spécifiques. Selon Traugott, ces changements répondent aux principaux critères établis pour le processus de grammaticalisation (recatégorisation, amélioration de la portée syntaxique, sens plus abstraits, enrichissement pragmatique et unidirectionalité (Traugott 1995b, 2010; Traugott et Dasher 2002). Afin de prouver cette hypothèse, j'analyse ici une collection de tels adverbes qui ont au moins trois usages différents en français contemporain :sérieusement,honnêtement,franchement,apparemment,carrément,décidément,étonnammentetseulement. Outre l'analyse synchronique et diachronique de ces adverbes, je rapporte des régularités spécifiques (ou chaînes sémantiques, selon Heine et Kuteva (2002) observées au cours de leur évolution.
Ben Sira on the Free Will Problem: A Comparison with Chrysippus
Authors: Li Xi
Published: August 2021

This article deals with the similarities and differences between Ben Sira and Chrysippus regarding their solutions to the tension between free will and determinism. Both Ben Sira and Chrysippus argue for compatibilism, the theory that free will and determinism are compatible. However, Ben Sira and Chrysippus have different understandings of freedom required by moral responsibility. According to Chrysippus, consent is the internal cause of persons’ actions, and, thus, they should be responsible for these actions. By contrast, Ben Sira claims that although being shaped by God’s plan, persons could have done otherwise and, in this sense, are responsible for their sins. The first section of this article examines the texts of Ben Sira and Chrysippus regarding the problem of free will. The second section discusses the positions of Ben Sira and Chrysippus on compatibilism. The last section explains the possible influence of Chrysippus on Ben Sira and the main difference between their understandings of freedom.
Anatomical differences in the psoas muscles in young black
and white men
Authors: HANSON PATRICK , MAGNUSSON S. PETER , SORENSEN HENRIK , SIMONSEN ERIK B.
Published: August 2021

The anatomy of the psoas major muscle (PMA) in young black and white men was studied during routine
autopsies. The forensic autopsies included 44 fresh male cadavers (21 black, 23 white) with an age span of
14 to 25 y. The range for weight was 66–76 kg and for height 169–182 cm. The PMA was initially measured
in its entire length before measuring the diameter and circumference at each segmental level (L1–S1). At
each segmental level, the calculated anatomical cross-sectional area (ACSA) was more than 3 times greater
in the black group compared with the white (P<0.001). The psoas minor muscle (PMI) was absent in 91%
of the black subjects, but only in 13% of the white subjects. These data show that the PMA is markedly
larger in black than white subjects. The marked race specific difference in the size of the PMA may have
implications for hip flexor strength, spine function and race specific incidence in low back pathology, and
warrants further investigation.
Concerning the ultrastructural origin of large-scale swelling in
articular cartilage
Authors: CHEN MIN-HUEY , BROOM NEIL D.
Published: August 2021

The swelling behaviour of the general matrix of both normal and abnormally softened articular cartilage
was investigated in the context of its relationship to the underlying subchondral bone, the articular surface,
and with respect to the primary structural directions represented in its strongly anisotropic collagenous
architecture. Swelling behaviours were compared by subjecting tissue specimens under different modes of
constraint to a high swelling bathing solution of distilled water and comparing structural changes imaged at
the macroscopic, microscopic and ultrastructural levels of resolution. Near zero swelling was observed in the
isolated normal general matrix with minimal structural change. By contrast the similarly isolated softened
general matrix exhibited large-scale swelling in both the transverse and radial directions. This difference in
dimensional stability was attributed to fundamentally different levels of fibril interconnectivity between the 2
matrices. A model of structural transformation is proposed to accommodate fibrillar rearrangements
associated with the large-scale swelling in the radial and transverse directions in the softened general matrix.
Increase in liver pigmentation during natural hibernation
in some amphibians
Authors: BARNI SERGIO , BERTONE VITTORIO , CROCE ANNA CLETA , BOTTIROLI GIOVANNI , BERNINI FRANCO , GERZELI GIUSEPPE
Published: August 2021

The amount/distribution of liver melanin in 3 amphibian species (Rana esculenta, Triturus a. apuanus,
Triturus carnifex) was studied during 2 periods of the annual cycle (summer activity–winter hibernation) by
light and electron microscopy, image analysis and microspectrofluorometry. The increase in liver
pigmentation (melanin content) during winter appeared to be correlated with morphological and functional
modifications in the hepatocytes, which at this period were characterised by a decrease in metabolic activity.
These findings were interpreted according to the functional role (e.g. phagocytosis, cytotoxic substance
inactivation) played by the pigment cell component in the general physiology of the heterothermic vertebrate
liver and, in particular, in relation to a compensatory engagement of these cells against hepatocellular
hypoactivity during the winter period.
Stimulation of the middle meningeal artery leads to
Fos expression in the trigeminocervical nucleus:
a comparative study of monkey and cat
Authors: HOSKIN KAREN L. , ZAGAMI ALESSANDRO S. , GOADSBY PETER J.
Published: August 2021

The pain of a migraine attack is often described as unilateral, with a throbbing or pulsating quality. The
middle meningeal artery (MMA) is the largest artery supplying the dura mater, is paired, and pain-producing in humans. This artery, or its branches, and other large intracranial extracerebral vessels have
been implicated in the pathophysiology of migraine by theories suggesting neurogenic inflammation or
cranial vasodilatation, or both, as explanations for the pain of migraine. Having previously studied in detail
the distribution of the second order neurons that are involved in the transmission of nociceptive signals from
intracranial venous sinuses, we sought to compare the distribution of second order neurons from a pain-producing intracranial artery in both monkey and cat. By electrically stimulating the middle meningeal
artery in these species and using immunohistochemical detection of the proto-oncogene Fos as a marker of
neuronal activation, we have mapped the sites of the central trigeminal neurons which may be involved in
transmission of nociception from intracranial extracerebral arteries. Ten cats and 3 monkeys were
anaesthetised with α-chloralose and the middle meningeal artery was isolated following a temporal
craniotomy. The animals were maintained under stable anaesthesia for 24 h to allow Fos expression due to
the initial surgery to dissipate. Following the rest period, the vessel was carefully lifted onto hook electrodes,
and then left alone in control animals (cat n = 3), or stimulated (cat n = 6, monkey n = 3). Stimulation of
the left middle meningeal artery evoked Fos expression in the trigeminocervical nucleus, consisting of the
dorsal horn of the caudal medulla and upper 2 divisions of the cervical spinal cord, on both the ipsilateral
and contralateral sides. Cats had larger amounts of Fos expressed on the ipsilateral than on the
contralateral side. Fos expression in the caudal nucleus tractus solitarius and its caudal extension in lamina
X of the spinal cord was seen bilaterally in response to middle meningeal artery stimulation. This study
demonstrates a comparable anatomical distribution of Fos activation between cat and monkey and, when
compared with previous studies, between this arterial structure and the superior sagittal sinus. These data
add to the overall picture of the trigeminovascular innervation of the intracranial pain-producing vessels
showing marked anatomical overlap which is consistent with the often poorly localised pain of migraine.
The electron microscope appearance of the subchondral bone
plate in the human femoral head in osteoarthritis and
osteoporosis
Authors: LI BAOHUA , MARSHALL DEBORAH , ROE MARTIN , ASPDEN RICHARD M.
Published: August 2021

The subchondral bone plate supports the articular cartilage in diarthrodial joints. It has a significant
mechanical function in transmitting loads from the cartilage into the underlying cancellous bone and has
been implicated in the destruction of cartilage in osteoarthritis (OA) and its sparing in osteoporosis (OP),
but little is known of its composition, structure or material properties. This study investigated the
microscopic appearance and mineral composition of the subchondral bone plate in femoral heads from
patients with OA or OP to determine how these correspond to changes in composition and stiffness found in
other studies. Freeze-fractured full-depth samples of the subchondral bone plate from the femoral heads of
patients with osteoarthritis, osteoporosis or a matched control group were examined using back scattered
and secondary emission scanning electron microscopy. Other samples were embedded and polished and
examined using back-scattered electron microscopy and electron probe microanalysis. The appearances of
the samples from the normal and osteoporotic patients were very similar, with the subchondral bone plate
overlayed by a layer of calcified cartilage. Osteoporotic samples presented a more uniform fracture surface
and the relative thicknesses of the layers appeared to be different. In contrast, the OA bone plate appeared
to be porous and have a much more textured surface. There were occasional sites of microtrabecular bone
formation between the trabeculae of the underlying cancellous bone, which were not seen in the other
groups, and more numerous osteoclast resorption pits. The calcified cartilage layer was almost absent and
the bone plate was apparently thickened. The appearance of the osteoarthritic subchondral bone plate was,
therefore, considerably different from both the normal and the osteoporotic, strongly indicative of abnormal
cellular activity.
Hippocampal layers on high resolution magnetic resonance
images: real or imaginary?
Authors: WIESHMANN U. C. , SYMMS M. R. , MOTTERSHEAD J. P. , MACMANUS D. G. , BARKER G. J. , TOFTS P. S. , REVESZ T. , STEVENS J. M. , SHORVON S. D.
Published: August 2021

To evaluate whether the lines occasionally detected on clinical magnetic resonance (MR) images are genuine
hippocampal layers, a formalin fixed hippocampal specimen was scanned using T2 weighted sequences at 7
Tesla (voxel dimensions 0.064×0.064×1 mm) and at 1.5 Tesla (voxel dimensions: 0.156×0.156×1 mm) and
compared with the results of histological examination. In addition, a healthy volunteer was scanned with a
T2 weighted sequence at 1.5 Tesla (voxel dimensions: 0.469×0.469×2 mm). On 7 Tesla images
hippocampal layers and the granule cell layer of the dentate were visible. On 1.5 Tesla images of the
specimen, the hippocampal layers were again identified, but the granule cell layer of the dentate was not
detectable. On 1.5 Tesla images of the hippocampus in vivo, 3 layers could be distinguished in the
hippocampus on some slices. These mainly represented the alveus, pyramidal cell layer and stratum
radiatum. A dark line consisting of a few pixels possibly represented the dentate gyrus. Our results show
that the lines occasionally detected on clinical MR images are likely to be real hippocampal layers. However,
the resolution currently used in clinical imaging (typically 0.469×0.469×2 mm or lower) is not sufficient for
the detection of all hippocampal layers. For the reliable detection of all hippocampal layers on MR images
an increase by a factor of approximately 20 would be necessary.
Microvascular features and ossification process in the femoral
head of growing rats
Authors: MORINI SERGIO , PANNARALE LUIGI , FRANCHITTO ANTONIO , DONATI SAARA , GAUDIO EUGENIO
Published: August 2021

In the epiphysis of long bones, different patterns of development of ossification processes have been
described in different species. The development of the vascularisation of the femoral head has not yet been
fully clarified, although its role in the ossification process is obvious. Our aim was to investigate ossification
and vascular proliferation and their relationship, in growing rat femoral heads. Male Wistar rats aged ∼ 1, 5
and 8 wk and 4, 8 and 12 mo were used. Light microscopy frontal sections and vascular corrosion casts
observed by scanning electron microscopy were employed. In the rat proximal femoral epiphysis, ossification
develops from the medullary circulation of the diaphysis, quickly extending to the neck and the base of the
head. Hypertrophic chondrocytes occupy the epiphyseal cartilage, and a physeal plate with regular cell
columns is present. Starting from about the end of the third month one or more points of fibrovascular
outgrowth, above the physeal line, can be observed in each sample. They are often placed centrally or,
sometimes, peripherally. The fibrovascular outgrowths penetrate deeply into the cartilage and extend
laterally. At age 8 mo, large fibro-osseous peduncles connect the epiphysis to the diaphyseal tissue. At
12 mo, the entire epiphysis appears calcified with an almost total absence of residual cartilage islands. This
situation differs in man and in other mammals due both to differing thickness of the cartilage and to the
presence of more extensive sources of blood vessels other than the diaphyseal microcirculation, as supplied
by the teres ligament and Hunter's circle. In young rats, subchondral vessels and the synovial fluid could
play a role in feeding the ossifying cartilage. Later, a loss of resistance of the physis due to marked
degeneration of the cell columns, and extensive chondrocyte hypertrophy permit fibrovascular penetration
starting from diaphyseal vessels rather than neighbouring vascular territories, such as those of the
periosteum and capsule.
Structural abnormalities do not explain the early functional
abnormalities in the peripheral nerves of the streptozotocin
diabetic rat
Authors: WALKER DAVID , CARRINGTON ANNE , CANNAN SUSAN A. , SAWICKI DIANE , SREDY JANET , BOULTON ANDREW J. M. , MALIK RAYAZ A.
Published: August 2021

The streptozotocin (STZ)-diabetic rat, the most commonly employed model of experimental diabetic
neuropathy, is characterised by a reduction in nerve conduction velocity, pain threshold and blood flow.
Whether or not structural abnormalities underlie these functional abnormalities is unclear. 10 adult male
Sprague–Dawley STZ-diabetic rats (diabetes duration 27 d) and 10 age-matched (23 wk) control animals
were studied. Motor nerve conduction velocity (m s−1) was significantly reduced in diabetic
(41.31±0.8) compared with control (46.15±1.5) animals (P<0.001). The concentration of sciatic nerve glucose
(P<0.001), fructose (P<0.001) and sorbitol (P<0.001) was elevated, and myoinositol (P<0.001) was reduced
in diabetic compared with control animals. Detailed morphometric studies demonstrated no significant
difference in fascicular area, myelinated fibre density, fibre and axon areas as well as unmyelinated fibre
density and diameter. Endoneurial capillary density, basement membrane area and endothelial cell profile
number did not differ between diabetic and control animals. However, luminal area (P<0.03) was increased
and endothelial cell area (P<0.08) was decreased in the diabetic rats. We conclude there is no detectable
structural basis for the reduction in nerve conduction velocity, pain threshold or blood flow, observed in the
streptozotocin diabetic rat.
Prevalence and determinants of serum antibodies to SARS-CoV-2 in the general population of the Gardena valley
Authors: Melotti Roberto , Scaggiante Federica , Falciani Michela , Weichenberger Christian X. , Foco Luisa , Lombardo Stefano , De Grandi Alessandro , von Laer Dorothee , Mahlknecht Angelika , Pramstaller Peter P. , Pagani Elisabetta , Meier Horand , Gaertner Timon , Troi Christina , Mascalzoni Deborah , Pattaro Cristian , Mian Michael
Published: August 2021

Estimating the spread of SARS-CoV-2 infection in communities is critical. We surveyed 2244 stratified random sample community members of the Gardena valley, a winter touristic area, amidst the first expansion phase of the COVID-19 pandemic in Europe. We measured agreement between Diasorin and Abbott serum bioassay outputs and the Abbott optimal discriminant threshold of serum neutralisation titres with recursive receiver operating characteristic curve. We analytically adjusted serum antibody tests for unbiased seroprevalence estimate and analysed the determinants of infection with non-response weighted multiple logistic regression. SARS-CoV-2 seroprevalence was 26.9% (95% CI 25.2–28.6) by June 2020. The bioassays had a modest agreement with each other. At a lower threshold than the manufacturer's recommended level, the Abbott assay reflected greater discrimination of serum neutralisation capacity. Seropositivity was associated with place and economic activity, not with sex or age. Symptoms like fever and weakness were age-dependent. SARS-CoV-2 mitigation strategies should account for context in high prevalence areas.
Origin, Accretion, and Reworking of Continents
Authors: Zhu Rixiang , Zhao Guochun , Xiao Wenjiao , Chen Ling , Tang Yanjie
Published: August 2021

The continental crust is unique to the Earth in the solar system, and controversies remain regarding its origin, accretion and reworking of continents. The plate tectonics theory has been significantly challenged in explaining the origin of Archean (especially pre‐3.0 Ga) continents as they rarely preserve hallmarks of plate tectonics. In contrast, growing evidence emerges to support oceanic plateau models that better explain characteristics of Archean continents, including the bimodal volcanics and nearly coeval emplacement of tonalite‐trondjhemite‐granodiorite (TTG) rocks, presence of ∼1600°C komatiites and dominant dome structures, and lack of ultra‐high‐pressure rocks, paired metamorphic belts and ophiolites. On the other hand, the theory of plate tectonics has been successfully applied to interpret the accretion of continents along subduction zones since the late Archean (3.0–2.5 Ga). During subduction processes, the new mafic crust is generated at the base of continents through partial melting of mantle wedge with the addition of H2O‐dominant fluids from subducted oceanic slabs and partial melting of the juvenile mafic crust results in the generation of new felsic crusts. This eventually leads to the outgrowth of continents. Subduction processes also cause softening, thinning, and recycling of continental lithosphere due to the vigorous infiltration of volatile‐rich fluids and melts, especially along weak belts/layers, leading to widespread continental reworking and even craton destruction. Reworking of continents also occurs in continental interiors due to either plate boundary processes or plume‐lithosphere interactions. The effects of plumes have proven to be less significant and cause lower degrees of lithospheric modification than subduction‐induced craton destruction.
Increasing Difference in Interannual Summertime Surface Air Temperature Between Interior East Antarctica and the Antarctic Peninsula Under Future Climate Scenarios
Authors: Mao Rui , Kim Seong‐Joong , Gong Dao‐Yi , Liu Xiaohong , Wen Xinyu , Zhang Liping , Tang Feng , Zong Qi , Xiao Cunde , Ding Minghu , Park Sang‐Jong
Published: August 2021

Plain Language Summary

Melting of the Antarctic ice sheet and shelf in the future will be influenced by interannual changes in the surface air temperature (SAT) in Antarctica. The SAT changes in Antarctica are related to variations in the Southern Hemisphere Annular Mode (SAM) during the austral summer. The SAM is a dominant pattern of atmospheric variability in the Southern Hemisphere and influences the Antarctic SAT with opposite changes between the northern Antarctic Peninsula (AP) and Eastern Antarctica (EA). To project future changes in the Antarctic SAT, we analyzed historical and future simulations from the Climate Model Intercomparison Project 5 models. We found that the degree of opposite interannual SAT changes between EA and the AP increases in the future due to intensified magnitude of the SAM‐related circulation anomalies, and summers of warmer SAT in the northern AP and cooler SAT in EA increase by 4% in the future compared to the historical period. This finding has major consequences for glacier melting in the northern AP in the future because more days of extremely high SAT in the northern AP may occur in the future.
Gas Geochemistry at Grande Comore and Mayotte Volcanic Islands (Comoros Archipelago), Indian Ocean
Authors: Liuzzo Marco , Di Muro Andrea , Rizzo Andrea Luca , Caracausi Antonio , Grassa Fausto , Fournier Nicolas , Shafik Bafakih , Boudoire Guillaume , Coltorti Massimo , Moreira Manuel , Italiano Francesco
Published: August 2021

The Comoros archipelago is an active geodynamic region of intra‐plate volcanism within which the youngest and oldest islands (Grande Comore and Mayotte respectively) are characterized by recent volcanic activity. The frequent eruptions of the large shield volcano Karthala on Grande Comore (last eruption 2007), and the recent birth of a large submarine volcano since 2018 at the submarine base of Mayotte are associated with permanent fumarolic emissions, bubbling gas seeps, and soil gas emissions, which are studied in detail here for the first time. CO2 fluxes and chemical and isotopic gas compositions acquired during two surveys in 2017 and 2020 are integrated with older data sets collected between 2005 and 2016, permitting the identification of a possible influence of the recent volcanic and magmatic activity at Mayotte. At Karthala, high gas fluxes with high temperature, and a marked magmatic signature are concentrated close to the summit crater area, while only weaker emissions with a stronger biogenic signature are found on the volcano flanks. At Mayotte, lower temperature and higher CH4 content are recorded in two main seep areas of CO2‐rich fluid bubbling, while soil emissions on land record a higher proportion of magmatic fluids compared to Karthala. Our preliminary results reveal two quite separate gas emission patterns for each island that are distinct in composition and isotopic signatures, and well correlated with the present state of volcanic activity. This work may potentially provide support for local observation infrastructures and contribute to the improvement in volcanic and environmental monitoring.