bluuebunny/crossref_metadata_2025 huggingface dataset:
Terrain‐aided navigation for long‐range AUVs in dynamic under‐mapped environments
Authors: Salavasidis Georgios , Munafò Andrea , Fenucci Davide , Harris Catherine A. , Prampart Thomas , Templeton Robert , Smart Michael , Roper Daniel T. , Pebody Miles , Abrahamsen E. Povl , McPhail Stephen D. , Rogers Eric , Phillips Alexander B.
Published: November 2020

Deploying long‐range autonomous underwater vehicles (AUVs) mid‐water column in the deep ocean is one of the most challenging applications for these submersibles. Without external support and speed over the ground measurements, dead‐reckoning (DR) navigation inevitably experiences an error proportional to the mission range and the speed of the water currents. In response to this problem, a computationally feasible and low‐power terrain‐aided navigation (TAN) system is developed. A Rao‐Blackwellized Particle Filter robust to estimation divergence is designed to estimate the vehicle's position and the speed of water currents. To evaluate performance, field data from multiday AUV deployments in the Southern Ocean are used. These form a unique test case for assessing the TAN performance under extremely challenging conditions. Despite the use of a small number of low‐power sensors and a Doppler velocity log to enable TAN, the algorithm limits the localisation error to within a few hundreds of metres, as opposed to a DR error of 40 km, given a 50 m resolution bathymetric map. To evaluate further the effectiveness of the system under a varying map quality, grids of 100, 200, and 400 m resolution are generated by subsampling the original 50 m resolution map. Despite the high complexity of the navigation problem, the filter exhibits robust and relatively accurate behaviour. Given the current aim of the oceanographic community to develop maps of similar resolution, the results of this study suggest that TAN can enable AUV operations of the order of months using global bathymetric models.
Coping with Antarctic demands: Psychological implications of isolation and confinement
Authors: Tortello Camila , Folgueira Agustín , Nicolas Michel , Cuiuli Juan Manuel , Cairoli Germán , Crippa Valeria , Barbarito Marta , Abulafia Carolina , Golombek Diego Andrés , Vigo Daniel Eduardo , Plano Santiago Andrés
Published: November 2020

Working in extreme environments requires a wide range of cognitive, psychological and social competences. Antarctica represents one of the most challenging habitats to work in due to its aridity, extremely cold weather, and isolated conditions. This study aimed to assess mood variations and coping strategies, as well as their possible modulation by group dynamics in a crew at the Belgrano II Argentine Antarctic Station throughout 1 year of confinement. Thirteen members of the Argentine Army completed emotional, coping and social dynamics questionnaires bimonthly in March, May, July, September and November. Results showed a significant decline in social dynamics scales, evidenced by decreases in perceived peer and hierarchical support. Additionally, coping strategies displayed a drop in mature defence throughout the expedition. A positive correlation was found between social support and recovery from stress. Our results highlight the importance of interpersonal relationships in psychological adjustment to isolation and extreme environments.
Magic‐Sized Stoichiometric II–VI Nanoclusters
Authors: Bootharaju Megalamane S. , Baek Woonhyuk , Lee Sanghwa , Chang Hogeun , Kim Junhee , Hyeon Taeghwan
Published: November 2020

Metal chalcogenide nanomaterials have gained widespread interest in the past two decades for their potential optoelectronic, energy, and catalytic applications. The colloidal growth of various forms of these materials, such as nanowires, platelets, and lamellar assemblies, proceeds through certain thermodynamically stable, ultrasmall (<2 nm) intermediates called magic‐sized nanoclusters (MSCs). Due to quantum confinement and its resultant intriguing properties, isolation or direct synthesis of MSCs and their structure characterization, which is very much challenging, are current topics of fundamental and applied scientific research. By comprehensive understanding of the structure–activity relationships in MSCs, the nucleation and growth processes can be manipulated, resulting in the synthesis of novel metal chalcogenide materials for various applications. This review focuses on recent advances in the chemical synthesis, characterization, and theoretical calculations of CdSe and its related II–VI nanoclusters. It highlights the studies of photophysical and magneto‐optical properties as well as heteroatom doping of MSCs followed by their chemical transformation to high‐dimensional nanostructures. At the end of the review, future directions and possible ways to overcome the challenges in the research of semiconductor MSCs are also presented.
Borneol protects against cerulein‐induced oxidative stress and inflammation in acute pancreatitis mice model
Authors: Bansod Sapana , Chilvery Shrilekha , Saifi Mohd Aslam , Das Tridip Jyoti , Tag Hui , Godugu Chandraiah
Published: November 2020

Borneol is a commonly used flavouring substance in traditional Chinese medicine, which possesses several pharmacological activities including analgesic, antiinflammatory, and antioxidant properties. The aim of this study was to investigate the effects of borneol on cerulein‐induced acute pancreatitis (AP) model. Swiss albino mice were pretreated with borneol (100 and 300 mg/kg) daily for 7 days, before six consecutive injections of cerulein (50 μg/kg/hr, intraperitoneally). The protective effect of borneol was studied by biochemical, enzyme linked immunosorbent assay, histological, immunoblotting, and immunohistochemical analysis. Oral administration of borneol significantly attenuated pancreatic damage by reducing amylase, lipase levels and histological changes. Borneol attenuated cerulein‐induced oxidative‐nitrosative stress by decreasing malondialdehyde, nitrite levels, and elevating reduced glutathione levels. Pancreatic inflammation was ameliorated by inhibiting myeloperoxidase activity and pro‐inflammatory cytokine (Interleukins and TNF‐α) levels. Furthermore, borneol administration significantly increased nuclear factor E2‐related factor 2 (Nrf2), superoxide dismutase (SOD1) expression and reduced phospho‐NF‐κB p65 expression. Treatment with borneol significantly inhibited TNF‐α, IL‐1β, IL‐6, and inducible nitric oxide synthase expression in cerulein‐induced AP mouse model. Together, these results indicate that borneol which is currently used as US‐FDA approved food adjuvant has the potential to attenuate cerulein‐induced AP possibly by reducing the oxidative damage and pancreatic inflammation by modulating Nrf2/NF‐κB pathway.
Monitoring schistosomiasis and sanitation interventions—The potential of environmental DNA
Authors: Champion Teteh S. , Connelly Stephanie , Smith Cindy J. , Lamberton Poppy H. L.
Published: November 2020

Transmission of schistosomiasis, a human parasitic disease, is intrinsically linked to inadequate water, sanitation, and hygiene (WASH) facilities and/or their use. The mainstay of control is population‐based chemotherapy. Globally, each year, 240 million people are estimated to require this preventative treatment. However, for long‐term, sustainable control of this disease, supplementary WASH improvements are required to prevent (re)infection of humans (provision of safe water) and transmission from humans to the environment (improved sanitation). While there is established methodology for monitoring transmission in human populations, presently methods for monitoring the impact of WASH interventions, in particular sanitation, on environmental transmission are lacking. Development of such becomes paramount as integrated control programs combine drug treatments with enhanced WASH facilities and behavior change interventions, with uptake likely correlated to a reduction in fecal matter, and schistosome eggs, in the environment but any impact on infection levels in humans taking longer to become apparent. This article reports and critiques the methods currently used to monitor schistosomiasis in freshwater and soil environments and explores how environmental DNA could be used to better understand and monitor environmental contamination in relation to sanitation. Stronger evidence is required to understand how different sanitation interventions serve to limit the environmental transmission of the parasite and their relative effectiveness in preventing disease.

This article is categorized under:

Engineering Water > Methods
Advancements in protein nanoparticle vaccine platforms to combat infectious disease
Authors: Butkovich Nina , Li Enya , Ramirez Aaron , Burkhardt Amanda M. , Wang Szu‐Wen
Published: November 2020

Infectious diseases are a major threat to global human health, yet prophylactic treatment options can be limited, as safe and efficacious vaccines exist only for a fraction of all diseases. Notably, devastating diseases such as acquired immunodeficiency syndrome (AIDS) and coronavirus disease of 2019 (COVID‐19) currently do not have vaccine therapies. Conventional vaccine platforms, such as live attenuated vaccines and whole inactivated vaccines, can be difficult to manufacture, may cause severe side effects, and can potentially induce severe infection. Subunit vaccines carry far fewer safety concerns due to their inability to cause vaccine‐based infections. The applicability of protein nanoparticles (NPs) as vaccine scaffolds is promising to prevent infectious diseases, and they have been explored for a number of viral, bacterial, fungal, and parasitic diseases. Many types of protein NPs exist, including self‐assembling NPs, bacteriophage‐derived NPs, plant virus‐derived NPs, and human virus‐based vectors, and these particular categories will be covered in this review. These vaccines can elicit strong humoral and cellular immune responses against specific pathogens, as well as provide protection against infection in a number of animal models. Furthermore, published clinical trials demonstrate the promise of applying these NP vaccine platforms, which include bacteriophage‐derived NPs, in addition to multiple viral vectors that are currently used in the clinic. The continued investigations of protein NP vaccine platforms are critical to generate safer alternatives to current vaccines, advance vaccines for diseases that currently lack effective prophylactic therapies, and prepare for the rapid development of new vaccines against emerging infectious diseases.

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

Biology‐Inspired Nanomaterials > Protein and Virus‐Based Structures
Conclusions: Differing Contexts, Converging Experiences, Transnational Solidarity
Authors: Zschache Ulrike , Lahusen Christian
Published: November 2020

The concluding chapter shifts attention to the diverging socio-economic and political contexts of transnational solidarity organisations from eight European countries, ranging from a severe impact of the Eurozone and migration policy crisis to experiences less affected by recent crises but more vigorously shaped by policy-driven aggravations due to austerity measures, welfare retrenchments and immigration restrictions. The conclusions also underline the considerable number of similarities between solidarity activities and discourses since activists everywhere are concerned about increasing grievances and social problems nurtured by recent crises and/or long-standing public policy transformations. In particular, they highlight salient parallels between most of the countries with regard to politicisation and contentiousness, cooperation and transnationalism and social learning and innovation, while also raising awareness for field-specific differences and particularities.
Transnational Solidarity Organisations in Contemporary Greek Civil Society: Vibrant, Multifarious and Politicised
Authors: Kanellopoulos Kostas , Karakioulafi Christina , Alexandropoulou Pinelopi , Soros Giorgos
Published: November 2020

Based on interviews conducted with groups working in the fields of migration, disabilities and unemployment, this chapter offers insights into Greek civil society as it has emerged and developed during the economic and refugee crises. The findings of these interviews also testify to a vibrant pre-crises Greek civil society, which has become even more multifarious and politicised. The newly imposed grievances as the backdrop of a deteriorating political framework led to the growth of the organisational field (more volunteers and new groups) and more voices in regard to issues and demands. It seems that active participation in solidarity activities beyond the provision of help to beneficiaries has become a means in itself for one part of Greek society in its efforts to overcome and recover from the dual economic and migration crisis.
Civil Society Activism in Italy Across Different Fields: A Multifaceted Picture of Solidarity in Hard Times
Authors: Maggini Nicola , Federico Veronica
Published: November 2020

Over the last years, Italian civil society organisations have been working on a daily basis to mitigate the impact of both the global economic crisis and the refugee crisis, which have increased social vulnerabilities. Relying on the data gathered through 30 in-depth interviews with transnational solidarity organisations’ representatives, this chapter analyses solidarity practices in three fields of activity: disability, unemployment and migration. Results show that solidarity attitudes, practices and discourses are strongly influenced by the policy domain in which the organisations are active. Furthermore, the crisis led organisations to search for new strategies and approaches, even though it has been an ineffective vector of transnationalisation due to lack of resources, and the necessity to cope with pressing needs at national and local level/s.
The Danish Welfare State and Transnational Solidarity in Times of Crisis
Authors: Duru Deniz N. , Trenz Hans-Jörg , Sejersen Thomas Spejlborg
Published: November 2020

This chapter investigates transnational solidarity action across the fields of unemployment, disability and immigration in Denmark. It discusses how solidarity is manifested and organised by civil society, focusing on 30 qualitative interviews conducted with the so-called transnational solidarity organisations (TSOs). The chapter explores solidarity challenges that Danish TSOs were facing in the context of the welfare retrenchment and the structural reform in 2007, as well as the 2008 financial crisis and the migration crisis of 2015. Our interviews confirm that the effects of the financial crisis, austerity measures and the migration crisis were not easy to separate from the welfare retrenchment in the Danish system. These recent changes to the welfare state have been experienced as dramatic as they have loosened the traditionally close ties between the Danish civil society and municipalities in providing welfare services. The voluntary sector has, in response, become more political, not only providing services to affected groups but also increasingly seeking to defend their social rights, as well as entering into conflict with the government.
Modular invariance in superstring theory from $$ \mathcal{N} $$ = 4 super-Yang-Mills
Authors: Chester Shai M. , Green Michael B. , Pufu Silviu S. , Wang Yifan , Wen Congkao
Published: November 2020

Abstract

We study the four-point function of the lowest-lying half-BPS operators in the $$ \mathcal{N} $$
N
= 4 SU(N) super-Yang-Mills theory and its relation to the flat-space four-graviton amplitude in type IIB superstring theory. We work in a large-N expansion in which the complexified Yang-Mills coupling τ is fixed. In this expansion, non-perturbative instanton contributions are present, and the SL(2, ℤ) duality invariance of correlation functions is manifest. Our results are based on a detailed analysis of the sphere partition function of the mass-deformed SYM theory, which was previously computed using supersymmetric localization. This partition function determines a certain integrated correlator in the undeformed $$ \mathcal{N} $$
N
= 4 SYM theory, which in turn constrains the four-point correlator at separated points. In a normalization where the two-point functions are proportional to N2− 1 and are independent of τ and $$ \overline{\tau} $$

τ
¯

, we find that the terms of order $$ \sqrt{N} $$

N

and $$ 1/\sqrt{N} $$
1
/

N

in the large N expansion of the four-point correlator are proportional to the non-holomorphic Eisenstein series $$ E\left(\frac{3}{2},\tau, \overline{\tau}\right) $$
E

3
2

τ

τ
¯

and $$ E\left(\frac{5}{2},\tau, \overline{\tau}\right) $$
E

5
2

τ

τ
¯

, respectively. In the flat space limit, these terms match the corresponding terms in the type IIB S-matrix arising from R4 and D4R4 contact inter-actions, which, for the R4 case, represents a check of AdS/CFT at finite string coupling. Furthermore, we present striking evidence that these results generalize so that, at order $$ {N}^{\frac{1}{2}-m} $$

N

1
2

−
m

with integer m ≥ 0, the expansion of the integrated correlator we study is a linear sum of non-holomorphic Eisenstein series with half-integer index, which are manifestly SL(2, ℤ) invariant.
Solidity without inhomogeneity: perfectly homogeneous, weakly coupled, UV-complete solids
Authors: Esposito Angelo , Krichevsky Rafael , Nicolis Alberto
Published: November 2020

Abstract

Solid-like behavior at low energies and long distances is usually associated with the spontaneous breaking of spatial translations at microscopic scales, as in the case of a lattice of atoms. We exhibit three quantum field theories that are renormalizable, Poincaré invariant, and weakly coupled, and that admit states that on the one hand are perfectly homogeneous down to arbitrarily short scales, and on the other hand have the same infrared dynamics as isotropic solids. All three examples presented here lead to the same peculiar solid at low energies, featuring very constrained interactions and transverse phonons that always propagate at the speed of light. In particular, they violate the well known $$ {c}_L^2>\frac{4}{3}{c}_T^2 $$

c
L
2

>

4
3

c
T
2

bound, thus showing that it is possible to have a healthy renormalizable theory that at low energies exhibits a negative bulk modulus (we discuss how the associated instabilities are absent in the presence of suitable boundary conditions). We do not know whether such peculiarities are unavoidable features of large scale solid-like behavior in the absence of short scale inhomogeneities, or whether they simply reflect the limits of our imagination.
Updates to the Regional Seismic Travel Time (RSTT) Model: 1. Tomography
Authors: Begnaud Michael L. , Myers Stephen C. , Young Brian , Hipp James R. , Dodge Doug , Phillips W. Scott
Published: November 2020

A function of global monitoring of nuclear explosions is the development of Earth models for predicting seismic travel times for more accurate calculation of event locations. Most monitoring agencies rely on fast, distance-dependent one-dimensional (1D) Earth models to calculate seismic event locations quickly and in near real-time. RSTT (Regional Seismic Travel Time) is a seismic velocity model and computer software package that captures the major effects of three-dimensional crust and upper mantle structure on regional seismic travel times, while still allowing for fast prediction speed (milliseconds). We describe updates to the RSTT model using a refined data set of regional phases (i.e., Pn, Pg, Sn, Lg) using theBayeslocrelative relocation algorithm. The tomographic inversion shown here acts to refine the previous RSTT public model (rstt201404um) and displays significant features related to areas of global tectonic complexity as well as further reduction in arrival residual values. Validation of the updated RSTT model demonstrates significant reduction in median epicenter mislocation (15.3 km) using all regional phases compared to theiasp911D model (22.1 km) as well as to the current station correction approach used at the Comprehensive Nuclear-Test-Ban Treaty Organization International Data Centre (18.9 km).
Impact of melamine and its derivatives on the properties of poly(vinyl acetate)-based composite wood adhesive
Authors: Góral Zuzanna , Mastalska-Popławska Joanna , Izak Piotr , Rutkowski Paweł , Gnyla Joanna , Majka Tomasz M. , Pielichowski Krzysztof
Published: November 2020

A fire retardant composite adhesive for bonding wood and wood-based elements has been developed and characterized. To obtain the enhanced fire-proof properties of the wood adhesive dispersion based on the poly(vinyl acetate) (PVAc), ceramic fillers (17.5 wt% total)—alumina, silica, kaolin and glass fibers were applied. Moreover, fire retardants such as melamine, melamine phosphate and melamine polyphosphate (up to 7 wt%) were also used. Thermal analysis (TG-DSC), strength tests, rheology, pH and flammability measurements (PCFC) were performed. The best properties of the adhesive were achieved for ceramic additives supported by melamine phosphate. A slight improvement of shear strength, shift of the last decomposition step of PVAc (residue degradation) towards higher temperatures by about 50 °C, reduction in mass loss from 100 wt% to less than 70 wt% and about 30–40% improvement of flammability parameters such as heat release capacity, total heat release or peak heat release rate were found compared to the pure poly(vinyl acetate) adhesive.
Laminar air flow reduces particle load in TKA—even outside the LAF panel: a prospective, randomized cohort study
Authors: Kirschbaum Stephanie , Hommel Hagen , Strache Peggy , Horn Roland , Falk Roman , Perka Carsten
Published: November 2020

Purpose

Released particles are a major risk of airborne contamination during surgery. The present prospective study investigated the quantitative and qualitative particle load in the operating room (OR) depending on location, time of surgery and use of laminar air flow (LAF) system.

Methods

The particle load/m3 was measured during the implantation of 12 total knee arthroplasties (6 × LAF, 6 × Non-LAF) by using the Met One HHPC 6 + device (Beckmann Coulter GmbH, Germany). Measurement was based on the absorption and scattering of (laser) light by particles and was performed at three different time-points [empty OR, setting up, ongoing operation) at 3 fixed measurement points [OR table (central LAF area), anaesthesia tower (marginal LAF area), surgical image amplifier (outside LAF area)].

Results

Independent of time and location, all measurements showed a significantly higher particle load in the Non-LAF group (p < 0.01). With ongoing surgical procedure both groups showed increasing particle load. While there was a major increase of fine particles (size < 1 µm) with advancing activity in the LAF group, the Non-LAF group showed higher particle gain with increasing particle size. The lowest particle load in the LAF group was measured at the operating column, increasing with greater distance from the operating table. The Non-LAF group presented a significantly higher particle load than the LAF group at all locations.

Conclusion

The use of a LAF system significantly reduces the particle load and therefore potential bacterial contamination regardless of the time or place of measurement and therefore seems to be a useful tool for infection prevention. As LAF leads to a significant decrease of respirable particles, it appears to be a protective factor for the health of the surgical team regardless of its use in infection prevention.

Level of evidence

I.
On the synergy of matrix-isolation infrared spectroscopy and vibrational configuration interaction computations
Authors: Dinu Dennis F. , Podewitz Maren , Grothe Hinrich , Loerting Thomas , Liedl Klaus R.
Published: November 2020

The key feature of matrix-isolation infrared (MI-IR) spectroscopy is the isolation of single guest molecules in a host system at cryogenic conditions. The matrix mostly hinders rotation of the guest molecule, providing access to pure vibrational features. Vibrational self-consistent field (VSCF) and configuration interaction computations (VCI) on ab initio multimode potential energy surfaces (PES) give rise to anharmonic vibrational spectra. In a single-sourced combination of these experimental and computational approaches, we have established an iterative spectroscopic characterization procedure. The present article reviews the scope of this procedure by highlighting the strengths and limitations based on the examples of water, carbon dioxide, methane, methanol, and fluoroethane. An assessment of setups for the construction of the multimode PES on the example of methanol demonstrates that CCSD(T)-F12 level of theory is preferable to compute (a) accurate vibrational frequencies and (b) equilibrium or vibrationally averaged structural parameters. Our procedure has allowed us to uniquely assign unknown or disputed bands and enabled us to clarify problematic spectral regions that are crowded with combination bands and overtones. Besides spectroscopic assignment, the excellent agreement between theory and experiment paves the way to tackle questions of rather fundamental nature as to whether or not matrix effects are systematic, and it shows the limits of conventional notations used by spectroscopists.
Insight into the effects of moisture and layer build-up on the formation of lead soaps using micro-ATR-FTIR spectroscopic imaging of complex painted stratigraphies
Authors: Possenti Elena , Colombo Chiara , Realini Marco , Song Cai Li , Kazarian Sergei G.
Published: November 2020

Metal soaps are formed in paint layers thorough the reaction of metal ions of pigments and fatty acids of organic binders. In this study, micro-ATR-FTIR spectroscopic imaging was used to analyse the formation of lead soaps in oil-based paint layers in relation to their exposure to moisture sources. The investigations were carried out on authentic samples of complex stratigraphies from cold painted terracotta statues (Sacred Mount, Varallo, UNESCO) and different IR-active lead white pigments, organic materials, and lead soaps were discriminated. The saponification of selected paint layers was correlated to the conservation history, the manufacturing technique, and the build-up of layers. The presence of hydrophilic layers within the stratigraphy and their role as a further water source are discussed. Furthermore, the modifications experienced by lead-based pigments from the core of an intact grain of pigment towards the newly formed decay phases were investigated via a novel approach based on shift of the peak for the corresponding spectral bands and their integrated absorbance in the ATR-FTIR spectra. Qualitative information on the spatial distribution from the chemical images was combined with quantitative information on the peak shift to evaluate the different manufacture (lead carbonate, basic lead carbonate) or the extent of decay undergone by the lead-based pigments as a function of their grain size, contiguous layers, and moisture source. Similar results, having a high impact on heritage science and analytical chemistry, allow developing up-to-date conservation strategies by connecting an advanced knowledge of the materials to the social and conservation history of artefacts.
Lone Atrial Flutter in Children and Adolescents: Is It Really “Lone”?
Authors: Dieks Jana-K. , Backhoff David , Schneider Heike E. , Müller Matthias J. , Krause Ulrich , Paul Thomas
Published: November 2020

Atrial flutter (AFL) in children and adolescents beyond the neonatal period in the absence of any underlying myocardial disease (“lone AFL”) is rare and data is limited. Our study aims to present clinical and electrophysiological data of presumed “lone AFL” in pediatric patients and discuss the role of endomyocardial biopsy (EMB) and further follow-up. Since July 2005, eight consecutive patients at a median age of 12.7 (range 10.4–16.7) years presenting with presumed “lone AFL” after negative non-invasive diagnostic work-up had electrophysiological study (EPS) and induction of cavotricuspid isthmus (CTI) conduction block by radiofrequency (RF) current application. In 6/8 patients EMB could be taken. Induction of CTI conduction block was achieved in all patients. Histopathological examination of EMB from the right ventricular septum exhibited myocarditis or cardiomyopathy in 4/6 patients, respectively. During follow-up, 4/8 patients had recurrent arrhythmia (AFL n = 2, wide QRS complex tachycardia n = 1, monomorphic premature ventricular contractions n = 1) after the ablation procedure. 3/4 patients with recurrent arrhythmia had pathological EMB results. The remaining patient with recurrent arrhythmia had a negative EMB but was diagnosed with Brugada syndrome during further follow-up. Taking together results of EMB and further clinical course, only 3/8 patients finally turned out to have true “lone AFL”. Our study demonstrates that true “lone AFL” in children and adolescents is rare. EMB and clinical course revealed an underlying cardiac pathology in the majority of the individuals studied. EMB was very helpful in order to timely establish the diagnosis of myocarditis or cardiomyopathy.
High-temperature creep of magnetite and ilmenite single crystals
Authors: Till J. L. , Rybacki E.
Published: November 2020

We performed deformation experiments on dry natural single crystals of magnetite and ilmenite to determine the rheological behavior of these oxide minerals as a function of temperature, orientation, and oxygen fugacity. Samples were deformed at temperatures of 825–1150 $$\,^{\circ }$$

∘

C to axial strains of up to 15–24% under approximately constant stress conditions up to 120 MPa in a dead-load-type creep rig at ambient pressure in a controlled gas atmosphere. Oxygen fugacity ranged from 10$$^{-9.4}$$

-
9.4

to 10$$^{-4}$$

-
4

atm. Ilmenite creep was insensitive to oxygen fugacity, while magnetite displayed a strong, non-monotonic oxygen fugacity dependence, with creep rates varying as $$f_{O_{2}}^{-0.7}$$

f

O
2

-
0.7

and $$f_{O_{2}}^{0.4}$$

f

O
2

0.4

at more reducing and more oxidizing conditions, respectively. Dislocation creep rates of magnetite single crystals were weakly dependent on crystallographic orientation with stress exponents that varied between 2.8 and 4.3 (mean 3.5 ± 0.4). Magnetite compressed parallel to <100>, <110>, and <111> axes exhibited apparent activation energies of 315±5, 345±30, and 290±5 kJ/mol, respectively. We estimated $${f_O}_2$$

f
O

2

-independent magnetite activation energies of 715 ± 150, 725 ± 145, and 690 ± 150 kJ/mol for <100>, <110>, and <111> orientations, respectively, in the region of negative $${f_O}_2$$

f
O

2

-dependence. Ilmenite single crystals were compressed parallel, normal, and inclined to the c-axis. Stress exponents of 3.4, 4.3, and 3.9 indicate dislocation creep with activation energies of 420 ± 35, 345 ± 30, and 360 ± 40 kJ/mol, respectively, for these orientations. Mechanical anisotropy in ilmenite is notably higher than in magnetite, as expected from its lower crystal symmetry. Constitutive equations were formulated for ilmenite and magnetite creep.
Autoimmunological serum parameters and bone mass density in premature ovarian insufficiency: a retrospective cohort study
Authors: Beitl Klara , Rosta Klara , Poetsch Nina , Seifried Manuel , Mayrhofer Daniel , Soliman Barbara , Marculescu Rodrig , Ott Johannes
Published: November 2020

Purpose

It is still not clear whether to screen women with primary premature ovarian insufficiency for autoimmunity. Moreover, a possible association of autoimmunity with decreased bone mass density in premature ovarian insufficiency patients has not been evaluated. Thus, the objectives of this study were to review our experience with the use of an autoimmune screening panel in premature ovarian insufficiency women and to focus on bone mass density.

Methods

In a retrospective cohort study, 76 chromosomally normal women with primary premature ovarian insufficiency were included. The main outcome parameters were the results of an autoimmune screening panel and of dual-energy X-ray absorptiometry.

Results

Median age was 33 years. Sixty percent of premature ovarian insufficiency patients revealed abnormal dual-energy X-ray absorptiometry results (minimal T-score < −1.0). Any signs of autoimmunity were found in 21 women (36.2%). The most frequent abnormal results were increased thyroperoxidase antibodies (24.1%) and thyroglobulin antibodies (20.7%). A longer duration of amenorrhea (β = −0.015; p = 0.007), any abnormality during autoimmune screening (β = −0.940; p = 0.010), and a lower body mass index (β = −0.057; p = 0.036) were associated with a lower minimal T-score.

Conclusion

In chromosomally normal women with primary premature ovarian insufficiency, the prevalence of autoimmunity and decreased bone mass density seem high. Our data highlight the association between autoimmune abnormalities and decreased dual-energy X-ray absorptiometry results.
Phase field simulation of fatigue crack propagation under complex load situations
Authors: Schreiber Christoph , Müller Ralf , Kuhn Charlotte
Published: November 2020

Within this work, we utilize the framework of phase field modeling for fracture in order to handle a very crucial issue in terms of designing technical structures, namely the phenomenon of fatigue crack growth. So far, phase field fracture models were applied to a number of problems in the field of fracture mechanics and were proven to yield reliable results even for complex crack problems. For crack growth due to cyclic fatigue, our basic approach considers an additional energy contribution entering the regularized energy density function accounting for crack driving forces associated with fatigue damage. With other words, the crack surface energy is not solely in competition with the time-dependent elastic strain energy but also with a contribution consisting of accumulated energies, which enables crack extension even for small maximum loads. The load time function applied to a certain structure has an essential effect on its fatigue life. Besides the pure magnitude of a certain load cycle, it is highly decisive at which point of the fatigue life a certain load cycle is applied. Furthermore, the level of the mean load has a significant effect. We show that the model developed within this study is able to predict realistic fatigue crack growth behavior in terms of accurate growth rates and also to account for mean stress effects and different stress ratios. These are important properties that must be treated accurately in order to yield an accurate model for arbitrary load sequences, where various amplitude loading occurs.
Evolution of the stiffness tetrad in fiber-reinforced materials under large plastic strain
Authors: Weber Martin , Glüge Rainer , Altenbach Holm
Published: November 2020

The main aim of this work is to track the evolution of the stiffness tetrad during large plastic strain. Therefore, the framework of a general finite plasticity theory is developed. Some special cases are examined, and the case of a material plasticity theory is considered more closely. Its main feature is that the elasticity law changes during plastic deformations, for which we develop an approach. As sample materials, we use three types of fiber-reinforced composites. For numerical experiments and verification of the model’s predictions, finite element simulations of representative volume elements for uni-, bi- and tri-directional reinforced materials with periodic boundary conditions are used. From these, we extract the stiffness tetrads before and after large deformations of the material. We quantify the change of the stiffness tetrads due to the fiber reorientation. Finally, we propose an analytical evolution with three parameters that account reasonably well for the evolution of the stiffness tetrad.
Networking of glucagon-like peptide-1 axons with GnRH neurons in the basal forebrain of male mice revealed by 3DISCO-based immunocytochemistry and optogenetics
Authors: Vastagh Csaba , Farkas Imre , Scott Michael M. , Liposits Zsolt
Published: November 2020

Glucagon-like peptide-1 (GLP-1) regulates reproduction centrally, although, the neuroanatomical basis of the process is unknown. Therefore, the putative networking of the central GLP-1 and gonadotropin-releasing hormone (GnRH) systems was addressed in male mice using whole mount immunocytochemistry and optogenetics. Enhanced antibody penetration and optical clearing procedures applied to 500–1000 µm thick basal forebrain slices allowed the simultaneous visualization of the two distinct systems in the basal forebrain. Beaded GLP-1-IR axons innervated about a quarter of GnRH neurons (23.2 ± 1.4%) forming either single or multiple contacts. GnRH dendrites received a more intense GLP-1 innervation (64.6 ± 0.03%) than perikarya (35.4 ± 0.03%). The physiological significance of the innervation was examined by optogenetic activation of channelrhodopsin-2 (ChR2)-expressing axons of preproglucagon (GCG) neurons upon the firing of GnRH neurons by patch clamp electrophysiology in acute brain slices of triple transgenic mice (Gcg-cre/ChR2/GFP-GnRH). High-frequency laser beam stimulation (20 Hz, 10 ms pulse width, 3 mW laser power) of ChR2-expressing GCG axons in the mPOA increased the firing rate of GnRH neurons (by 75 ± 17.3%, p = 0.0007). Application of the GLP-1 receptor antagonist, Exendin-3-(9-39) (1 μM), prior to the photo-stimulation, abolished the facilitatory effect. In contrast, low-frequency trains of laser pulses (0.2 Hz, 60 pulses) had no effect on the spontaneous postsynaptic currents of GnRH neurons. The findings indicate a direct wiring of GLP-1 neurons with GnRH cells which route is excitatory for the GnRH system. The pathway may relay metabolic signals to GnRH neurons and synchronize metabolism with reproduction.
Low-power integrated transmitter design using frequency multiplication techniques
Authors: Stadelmayer Markus , Schumacher Tim , Faseth Thomas , Pretl Harald
Published: November 2020

This paper proposes an approach to employ frequency multiplication techniques like edge-combining and third harmonic extraction in ultra-low-power integrated transmitter design. The overall power demand of the transmitter is reduced by keeping operating frequency of its components low. For that reason, edge-combining and third harmonic extraction are integrated directly into a switched mode power amplifier. Hence, the radio frequency signal is generated just before it is fed to the antenna. This leads to a reduced power demand of the overall transmitter in comparison to conventional designs where the oscillator and other components are operated directly at the radio frequency.

Within this paper we propose an amplifier that generates a 2.4 GHz carrier frequency from a ring oscillator running at a low 200 MHz resulting in a frequency multiplication factor of twelve. The exemplary design is targeted to be used in ultra-low-power short range applications. Hence, our simulations using extracted layout models show that the amplifier provides an output power of approximately -12 dBm at a supply voltage of 0.6 V while consuming 2.4 mW of power fully integrated in a 180 nm 1P6M CMOS process.

This demonstrates that the proposed techniques are especially suitable for ultra-low-power transmitter in short range applications. That includes medical and body area network applications.
Clinical characteristics of 172 children and adolescents with body dysmorphic disorder
Authors: Rautio Daniel , Jassi Amita , Krebs Georgina , Andrén Per , Monzani Benedetta , Gumpert Martina , Lewis Angela , Peile Lauren , Sevilla-Cermeño Laura , Jansson-Fröjmark Markus , Lundgren Tobias , Hillborg Maria , Silverberg-Morse Maria , Clark Bruce , Fernández de la Cruz Lorena , Mataix-Cols David
Published: November 2020

Body dysmorphic disorder (BDD) often starts in childhood, with most cases developing symptoms before age 18. Yet, BDD research has primarily focused on adults. We report the clinical characteristics of the world’s largest cohort of carefully diagnosed youths with BDD and focus on previously unexplored sex and age differences. We systematically collected clinical data from 172 young people with BDD consecutively referred to 2 specialist pediatric obsessive–compulsive and related disorders outpatient clinics in Stockholm, Sweden and in London, England. A series of clinician-, self-, and parent-reported measures were administered. The cohort consisted of 136 girls, 32 boys, and 4 transgender individuals (age range 10–19 years). The mean severity of BDD symptoms was in the moderate to severe range, with more than one third presenting with severe symptoms and more than half showing poor or absent insight/delusional beliefs. We observed high rates of current psychiatric comorbidity (71.5%), past or current self-harm (52.1%), suicide attempts (11.0%), current desire for cosmetic procedures (53.7%), and complete school dropout (32.4%). Compared to boys, girls had significantly more severe self-reported BDD symptoms, depression, suicidal thoughts, and self-harm. Compared to the younger participants (14 or younger), older participants had significantly more severe compulsions and were more likely to report a desire for conducting cosmetic procedures. Adolescent BDD can be a severe and disabling disorder associated with significant risks and substantial functional impairment. The clinical presentation of the disorder is largely similar across sexes and age groups, indicating the importance of early detection and treatment. More research is needed specifically focusing on boys and pre-pubertal individuals with BDD.
Coordinating large distributed relational process structures
Authors: Steinau Sebastian , Andrews Kevin , Reichert Manfred
Published: November 2020

Representing a business process as a collaboration of interacting processes has become feasible with the emergence of data-centric business process management paradigms. Usually, these interacting processes have relations and, thereby, form a complex relational process structure. The interactions of processes within this relational process structure need to be coordinated to arrive at a meaningful overall business goal. However, relational process structures may become arbitrarily large. With the use of cloud technology, they may additionally be distributed over multiple nodes, allowing for scalability. Coordination processes have been proposed to coordinate relational process structures, where processes may have one-to-many and many-to-many relations at run-time. This paper shows how multiple coordination processes can be used in a decentralized fashion to more efficiently coordinate large, distributed process structures. The main challenge of using multiple coordination processes is to effectively realize the coordination responsibility of each coordination process. Key components of the solution are the subsidiary principle and the hierarchy of the relational process structure. Finally, an implementation of the coordination process concept based on microservices was developed, which allows for fast and concurrent enactment of multiple, decentralized coordination processes in large, distributed process structures.
Smart urban governance: an alternative to technocratic “smartness”
Authors: Jiang Huaxiong , Geertman Stan , Witte Patrick
Published: November 2020

This paper argues for a specific urban planning perspective on smart governance that we call “smart urban governance,” which represents a move away from the technocratic way of governing cities often found in smart cities. A framework on smart urban governance is proposed on the basis of three intertwined key components, namely spatial, institutional, and technological components. To test the applicability of the framework, we conducted an international questionnaire survey on smart city projects. We then identified and discursively analyzed two smart city projects—Smart Nation Singapore and Helsinki Smart City—to illustrate how this framework works in practice. The questionnaire survey revealed that smart urban governance varies remarkably: As urban issues differ in different contexts, the governance modes and relevant ICT functionalities applied also differ considerably. Moreover, the case analysis indicates that a focus on substantive urban challenges helps to define appropriate modes of governance and develop dedicated technologies that can contribute to solving specific smart city challenges. The analyses of both cases highlight the importance of context (cultural, political, economic, etc.) in analyzing interactions between the components. In this, smart urban governance promotes a sociotechnical way of governing cities in the “smart” era by starting with the urban issue at stake, promoting demand-driven governance modes, and shaping technological intelligence more socially, given the specific context.
Algorithmic Skeletons and Parallel Design Patterns in Mainstream Parallel Programming
Authors: Danelutto Marco , Mencagli Gabriele , Torquati Massimo , González–Vélez Horacio , Kilpatrick Peter
Published: November 2020

This paper discusses the impact of structured parallel programming methodologies in state-of-the-art industrial and research parallel programming frameworks. We first recap the main ideas underpinning structured parallel programming models and then present the concepts of algorithmic skeletons and parallel design patterns. We then discuss how such concepts have permeated the wider parallel programming community. Finally, we give our personal overview—as researchers active for more than two decades in the parallel programming models and frameworks area—of the process that led to the adoption of these concepts in state-of-the-art industrial and research parallel programming frameworks, and the perspectives they open in relation to the exploitation of forthcoming massively-parallel (both general and special-purpose) architectures.
Plant uptake, translocation and metabolism of PBDEs in plants of food and feed industry: A review
Authors: Dobslaw Daniel , Woiski Christine , Kiel Martina , Kuch Bertram , Breuer Jörn
Published: November 2020

Polybrominated diphenyl ethers (PBDEs) have widely been used for decades as flame retardants in a variety of products like plastics for building insulation, upholstered furniture, electrical appliances, vehicles, aircrafts, polyurethane foams, textiles, cable insulation, appliance plugs and various technical plastics in concentrations of 5–30%. However, PBDEs also act as endocrine disrupters, neurotoxins, and negatively affect fertility. In 2001, worldwide consumption of technically relevant penta-BDEs was still estimated at 7500 tons, octa-BDEs at 3790 tons, and deca-BDE at 56,100 tons, but 50–60% of this total volume are discharged into the environment via sewage sludge and its agricultural use alone. In addition, soils are ubiquitously contaminated by the gaseous or particle-bound transport of PBDEs, which today has its main source in highly contaminated electronic waste recycling sites. The emitted PBDEs enter the food chain via uptake by the plants’ roots and shoots. However, uptake and intrinsic transport behaviour strongly depend on crop specifics and various soil parameters. The relevant exposure and transformation pathways, transport-relevant soil and plant characteristics and both root concentration factors (RCF) and transfer factors (TF) as derivable parameters are addressed and quantified in this review. Finally, a simple predictive model for quantification of RCF and TF based on log KOW values and the organic content of the soil/lipid content of the plants is also presented.
Constrained Lipschitzian Error Bounds and Noncritical Solutions of Constrained Equations
Authors: Fischer A. , Izmailov A. F. , Jelitte M.
Published: November 2020

For many years, local Lipschitzian error bounds for systems of equations have been successfully used for the design and analysis of Newton-type methods. There are characterizations of those error bounds by means of first-order derivatives like a recent result by Izmailov, Kurennoy, and Solodov on critical solutions of nonlinear equations. We aim at extending this result in two directions which shall enable, to some extent, to include additional constraints and to consider mappings with reduced smoothness requirements. This leads to new necessary as well as sufficient conditions for the existence of error bounds.