bluuebunny/crossref_metadata_2025 huggingface dataset:
Incorporation of Extracted Mucor indicus Fungus Chitin Nanofibers into Starch Biopolymer: Morphological, Physical, and Mechanical Evaluation
Authors: Bahrami Bahador , Behzad Tayebeh , Salehinik Fatemeh , Zamani Akram , Heidarian Pejman
Published: April 2021

Bio‐nanocomposites based on starch are reinforced by different percentages of chitin nanofibers (ChNFs) and compatibilized by glycerol. Nanofibers are extracted from Mucor indicus fungus through different chemo‐mechanical pretreatments. The mechnical, chemo‐physical, and morphological properties of the nanocomposite starch films were evaluated and compared with the unfilled thermoplastic starch (TPS) film. Based on the obtained results, Young's modulus of the film at 5 wt.% ChNFs indicated 239% enhancement compared to the TPS film due to the existence of good interactions between starch and ChNFs. Moreover, the ultimate strength of the reinforced film at 5 wt.% ChNFs and the unreinforced counterpart are found to be 5.5 and 1.74 MPa, indicating 216% improvement; however, the elongation at break of the films decreases from 59.3% to 19.3% by adding 5 wt.% ChNFs. In addition, the moisture absorption of the film decreases after the incorporation of ChNFs. Based on the morphological study, ChNFs increase the roughness of the starch matrix with a homogenous morphology revealing the good dispersion of nanofibers in the TPS film. Finally, the nanocomposite film with 5 wt.% ChNFs show the best properties to employ for bio‐film applications.
Optimization of combined mixture and process variables for the pyrolysis oil yield from co‐pyrolysis of polymeric wastes
Authors: Oladunni Atilade Amos , Odejobi Oludare Johnson , Sanda Olayinka , Sonibare Jacob Ademola
Published: April 2021

The combined mixture process variable approach for optimization and prediction of oil yield in co‐pyrolysis of polymeric wastes was investigated in this study using I‐optimal design. The components mixture investigated were low‐density polyethylene (LDPE), polystyrene (PS), and polyethylene terephthalate (PET), whereas the process variables were temperature and residence time. Thirty experimental runs were developed using the I‐optimality criterion to investigate the effect of interaction between the mixture and process parameters on oil recovery from co‐pyrolysis of the polymeric wastes. The data obtained were used to generate a model equation, and analysis of variance was used to estimate the significance of the model. The model was significant with aPvalue < 0.0001, theR2value of 0.9980, adjustedR2of 0.9949, and predictedR2of 0.9201. Optimized oil yield showed close match between actual and predicted responses with a desirability factor of 0.999. The predicted mixture compositions and operating parameters for the optimum oil yield were 52.86% for LDPE, 47.15% for PS, and 0% for PET at 471.07°C and 115.25 minutes. The chemical compositions of the pyrolysis oil at the optimum conditions were hydrocarbons in the carbon range between C6and C25, with physical properties comparable to conventional diesel.
The occurrence of selected endocrine‐disrupting chemicals in water and sediments from an urban lagoon in Southern Italy
Authors: Russo Giacomo , Laneri Sonia , Di Lorenzo Ritamaria , Ferrara Luciano , Grumetto Lucia
Published: April 2021

Endocrine‐disrupting chemicals (EDCs) are agents able to exert perturbation toward the endocrine system via a broad array of signalling pathways. Some EDCs are released into the environment as a result of antropogenic activities. Analytical surveillance plays a critical role in investigating the prevalence of such chemicals in environmental samples. A study was carried out in a lagoon in Southern Italy, a water basin relates to the sea through a mouth channel, making this water body a “dynamic environment”. The screening of fourteen EDCs in surface waters and sediments, includes a fast and cost‐effective sample preparation, based on a solid–liquid (sediments) and liquid–liquid (surface waters) extraction and a chromatographic analysis by liquid chromatography tandem UV and fluorescence detection. Only four chemicals out the fourteen investigated EDCs were detected in both matrices with a frequency higher than 60%. The average concentrations of the single EDC were higher in sediments (730–155.000 ng kg−1 dw) than in surface waters (132–28.000 ng L−1). Limited to the assayed EDCs, the ecosystem has a low risk regarding to the conservation of biodiversity of the animal species living thereby, since the total estrogenic activity does not exceed 1 ng L−1.

Practitioner points

Occurrence of selected EDCs was investigated in an Italian lagoon in Southern Italy.

BPAF, BADGE, and BPA were the most frequently and highly detected compounds in both waters and sediments.

Concentration levels were greater in the sediment than in water samples.

Low risk for the ecosystem biodiversity concerning investigated EDCs.
Usability Study of Learning-Based Pose Estimation of Industrial Objects from Synthetic Depth Data
Authors: Thalhammer Stefan , Patten Timothy , Vincze Markus
Published: April 2021

For visual assistance systems deployed in an industrial setting, precise object pose estimation is an important task in order to support scene understanding and to enable subsequent grasping and manipulation. Industrial environments are especially challenging since mesh-models are usually available while physical objects are not or are expensive to model. Manufactured objects are often similar in appearance, have limited to no textural cues and exhibit symmetries. Thus, these are especially challenging for recognizers that are meant to provide detection, classification and pose estimation on instance level. A usability study of a recent synthetically trained learning-based recognizer for these particular challenges is conducted. Experiments are performed on the challenging T-LESS dataset due to its relevance for industry.
Safety as Bad Cop of Physical Assistance Systems?
Authors: Rathmair Michael , Brandstötter Mathias
Published: April 2021

Constantly increasing variety of products and customer-specific requirements lead to more complex assembly lines in the shop floors. These new demands require novel systems and technologies such as flexible assembly lines, track and trace systems or assistive systems. In this paper, supporting systems on the physical level are analyzed and in particular robot assistance systems with respect to their safety aspects are discussed. Moreover, the current standards and guidelines in the field of robot safety and their development focus are presented. It is intended to provide a comprehensive overview of what role safety actually plays with assistance systems and how ongoing research may affect it in future.
Erratum zu: Selbststudium im digitalen Wandel
Authors: Küstermann Roland , Kunkel Matthias , Mersch André , Schreiber Anne
Published: April 2021

Erratum zu:

R. Küstermann et al. (Hrsg.),Selbststudium im digitalen Wandel,10.1007/978-3-658-31279-4

Die Affiliations der Autoren der folgenden Kapitel wurden geändert. Sie werden nun aktualisiert.
Dark Matter production from relativistic bubble walls
Authors: Azatov Aleksandr , Vanvlasselaer Miguel , Yin Wen
Published: April 2021

Abstract

In this paper we present a novel mechanism for producing the observed Dark Matter (DM) relic abundance during the First Order Phase Transition (FOPT) in the early universe. We show that the bubble expansion with ultra-relativistic velocities can lead to the abundance of DM particles with masses much larger than the scale of the transition. We study this non-thermal production mechanism in the context of a generic phase transition and the electroweak phase transition. The application of the mechanism to the Higgs portal DM as well as the signal in the Stochastic Gravitational Background are discussed.
Notes on AdS-Schwarzschild eikonal phase
Authors: Parnachev Andrei , Sen Kallol
Published: April 2021

Abstract

We consider the eikonal phase associated with the gravitational scattering of a highly energetic light particle off a very heavy object in AdS spacetime. A simple expression for this phase follows from the WKB approximation to the scattering amplitude and has been computed to all orders in the ratio of the impact parameter to the Schwarzschild radius of the heavy particle. The eikonal phase is related to the deflection angle by the usual stationary phase relation. We consider the flat space limit and observe that for sufficiently small impact parameters (or angular momenta) the eikonal phase develops a large imaginary part; the inelastic cross-section is exactly the classical absorption cross-section of the black hole. We also consider a double scaling limit where the momentum becomes null simultaneously with the asymptotically AdS black hole becoming very large. In the dual CFT this limit retains contributions from all leading twist multi stress tensor operators, which are universal with respect to the addition of higher derivative terms to the gravitational lagrangian. We compute the eikonal phase and the associated Lyapunov exponent in the double scaling limit.
ThickBrick: optimal event selection and categorization in high energy physics. Part I. Signal discovery
Authors: Matchev Konstantin T. , Shyamsundar Prasanth
Published: April 2021

Abstract

We provide a prescription called ThickBrick to train optimal machine-learning-based event selectors and categorizers that maximize the statistical significance of a potential signal excess in high energy physics (HEP) experiments, as quantified by any of six different performance measures. For analyses where the signal search is performed in the distribution of some event variables, our prescription ensures that only the information complementary to those event variables is used in event selection and categorization. This eliminates a major misalignment with the physics goals of the analysis (maximizing the significance of an excess) that exists in the training of typical ML-based event selectors and categorizers. In addition, this decorrelation of event selectors from the relevant event variables prevents the background distribution from becoming peaked in the signal region as a result of event selection, thereby ameliorating the challenges imposed on signal searches by systematic uncertainties. Our event selectors (categorizers) use the output of machine-learning-based classifiers as input and apply optimal selection cutoffs (categorization thresholds) that are functions of the event variables being analyzed, as opposed to flat cutoffs (thresholds). These optimal cutoffs and thresholds are learned iteratively, using a novel approach with connections to Lloyd’s k-means clustering algorithm. We provide a public, Python implementation of our prescription, also called ThickBrick, along with usage examples.
Algebraic singularities of scattering amplitudes from tropical geometry
Authors: Drummond James , Foster Jack , Gürdoğan Ömer , Kalousios Chrysostomos
Published: April 2021

Abstract

We address the appearance of algebraic singularities in the symbol alphabet of scattering amplitudes in the context of planar $$ \mathcal{N} $$
N
= 4 super Yang-Mills theory. We argue that connections between cluster algebras and tropical geometry provide a natural language for postulating a finite alphabet for scattering amplitudes beyond six and seven points where the corresponding Grassmannian cluster algebras are finite. As well as generating natural finite sets of letters, the tropical fans we discuss provide letters containing square roots. Remarkably, the minimal fan we consider provides all the square root letters recently discovered in an explicit two-loop eight-point NMHV calculation.
On genus-one string amplitudes on AdS5 × S5
Authors: Alday Luis F.
Published: April 2021

Abstract

We study non-planar correlators in $$ \mathcal{N} $$
N
= 4 super-Yang-Mills in Mellin space. We focus in the stress tensor four-point correlator to order 1/N4 and in a strong coupling expansion. This can be regarded as the genus-one four-point graviton amplitude of type IIB string theory on AdS5× S5 in a low energy expansion. Both the loop supergravity result as well as the tower of stringy corrections have a remarkable simple structure in Mellin space, making manifest important properties such as the correct flat space limit and the structure of UV divergences.
Production of nonulosonic acids in the extracellular polymeric substances of “Candidatus Accumulibacter phosphatis”
Authors: Tomás-Martínez Sergio , Kleikamp Hugo B.C. , Neu Thomas R. , Pabst Martin , Weissbrodt David G. , van Loosdrecht Mark C.M. , Lin Yuemei
Published: April 2021

Nonulosonic acids (NulOs) are a family of acidic carbohydrates with a nine-carbon backbone, which include different related structures, such as sialic acids. They have mainly been studied for their relevance in animal cells and pathogenic bacteria. Recently, sialic acids have been discovered as an important compound in the extracellular matrix of virtually all microbial life and in “CandidatusAccumulibacter phosphatis”, a well-studied polyphosphate-accumulating organism, in particular. Here, bioaggregates highly enriched with these bacteria (approx. 95% based on proteomic data) were used to study the production of NulOs in an enrichment of this microorganism. Fluorescence lectin-binding analysis, enzymatic quantification, and mass spectrometry were used to analyze the different NulOs present, showing a wide distribution and variety of these carbohydrates, such as sialic acids and bacterial NulOs, in the bioaggregates. Phylogenetic analysis confirmed the potential of “Ca. Accumulibacter” to produce different types of NulOs. Proteomic analysis showed the ability of “Ca. Accumulibacter” to reutilize and reincorporate these carbohydrates. This investigation points out the importance of diverse NulOs in non-pathogenic bacteria, which are normally overlooked. Sialic acids and other NulOs should be further investigated for their role in the ecology of “Ca. Accumulibacter” in particular, and biofilms in general.

Key Points

•“Ca. Accumulibacter” has the potential to produce a range of nonulosonic acids.

•Mass spectrometry and lectin binding can reveal the presence and location of nonulosonic acids.

•The role of nonulosonic acid in non-pathogenic bacteria needs to be studied in detail.
Modification of the Thermal Spread by the Blade Shape of an Ultrasonically Activated Device
Authors: Kajiwara Shuhei , Noshiro Hirokazu , Kitagawa Hiroshi , Tanaka Tomokazu , Kai Keita
Published: April 2021

Background

Few studies have focused on the spread of thermal damage from different blade shapes of ultrasonically activated devices (USADs) used during minimally invasive surgery.

Methods

In vivo experiments using pig arteries, nerves, and mesentery were used to compare the thermal spread of two different blade types of USADs, non‐tapered and tapered, under the same conditions. The tissue temperatures were monitored using a high‐resolution infrared thermographic camera and calculated using an image analysis program. The spread of heat denaturation was measured histologically.

Results

The temperature was greater at the sides with greater curvature when non‐tapered USADs were activated (artery, 1 s, 2 mm: − 0.92 ± 0.5 °C vs. − 0.44 ± 0.5 °C, P = 0.022). This effect was more prominent in the tapered type (artery, 1 s, 0/1/2 mm: 9.14 ± 3.7 °C vs. 28.3 ± 16.2 °C/0.5 ± 1.4 °C vs. 9.76 ± 6.2 °C/ − 0.12 ± 0.9 °C vs. 1.44 ± 1.9 °C, P = 0.044/0.016/0.038, respectively). The temperatures in the tapered USAD were significantly higher at some time‐ and distance‐points than those in a non‐tapered USAD (artery, 1 s, 0 mm, Less/1 s, 1 mm, Gre: 4.2 ± 2.9 °C vs. 9.14 ± 3.7 °C /0.36 ± 0.5 °C vs. 9.76 ± 6.2 °C, P = 0.047/0.027; nerve, 2 s, 0 mm, Gre: 6.54 ± 3.9 °C vs. 17.66 ± 6.2 °C, P = 0.012). A three‐directional study revealed the thermal spread of the mesentery was greatest at the tip side of the non‐tapered type USAD (4.55 ± 2.53 °C vs. 12.43 ± 4.03 °C/12.43 ± 4.03 °C vs. 5.04 ± 1.91 °C, P = 0.003/0.005).

Conclusions

The thermal spread changed according to the blade shape of the USAD. This knowledge can be applied to more meticulous and complicated procedures, reducing surgical morbidity.
Strong for Surgery: Association Between Bundled Risk Factors and Outcomes After Major Elective Surgery in the VA Population
Authors: Liou Douglas Z. , Patel Deven C. , Bhandari Prasha , Wren Sherry M. , Marshall Nell J. , Harris Alex HS. , Shrager Joseph B. , Berry Mark F. , Lui Natalie S. , Backhus Leah M.
Published: April 2021

Background

Strong for Surgery (S4S) is a public health campaign focused on optimizing patient health prior to surgery by identifying evidence‐based modifiable risk factors. The potential impact of S4S bundled risk factors on outcomes after major surgery has not been previously studied. This study tested the hypothesis that a higher number of S4S risk factors is associated with an escalating risk of complications and mortality after major elective surgery in the VA population.

Methods

The Veterans Affairs Surgical Quality Improvement Program (VASQIP) database was queried for patients who underwent major non‐emergent general, thoracic, vascular, urologic, and orthopedic surgeries between the years 2008 and 2015. Patients with complete data pertaining to S4S risk factors, specifically preoperative smoking status, HbA1c level, and serum albumin level, were stratified by number of positive risk factors, and perioperative outcomes were compared.

Results

A total of 31,285 patients comprised the study group, with 16,630 (53.2%) patients having no S4S risk factors (S4S0), 12,323 (39.4%) having one (S4S1), 2,186 (7.0%) having two (S4S2), and 146 (0.5%) having three (S4S3). In the S4S1 group, 60.3% were actively smoking, 35.2% had HbA1c > 7, and 4.4% had serum albumin < 3. In the S4S2 group, 87.8% were smokers, 84.8% had HbA1c > 7, and 27.4% had albumin < 3. Major complications, reoperations, length of stay, and 30‐day mortality increased progressively from S4S0 to S4S3 groups. S4S3 had the greatest adjusted mortality risk (adjusted odds radio [AOR] 2.56, p = 0.04) followed by S4S2 (AOR 1.58, p = 0.02) and S4S1 (AOR 1.34, p = 0.02).

Conclusion

In the VA population, patients who had all three S4S risk factors, namely active smoking, suboptimal nutritional status, and poor glycemic control, had the greatest risk of postoperative mortality compared to patients with fewer S4S risk factors.
MRI index lesion radiomics and machine learning for detection of extraprostatic extension of disease: a multicenter study
Authors: Cuocolo Renato , Stanzione Arnaldo , Faletti Riccardo , Gatti Marco , Calleris Giorgio , Fornari Alberto , Gentile Francesco , Motta Aurelio , Dell’Aversana Serena , Creta Massimiliano , Longo Nicola , Gontero Paolo , Cirillo Stefano , Fonio Paolo , Imbriaco Massimo
Published: April 2021

Objectives

To build a machine learning (ML) model to detect extraprostatic extension (EPE) of prostate cancer (PCa), based on radiomics features extracted from prostate MRI index lesions.

Methods

Consecutive MRI exams of patients undergoing radical prostatectomy for PCa were retrospectively collected from three institutions. Axial T2-weighted and apparent diffusion coefficient map images were annotated to obtain index lesion volumes of interest for radiomics feature extraction. Data from one institution was used for training, feature selection (using reproducibility, variance and pairwise correlation analyses, and a correlation-based subset evaluator), and tuning of a support vector machine (SVM) algorithm, with stratified 10-fold cross-validation. The model was tested on the two remaining institutions’ data and compared with a baseline reference and expert radiologist assessment of EPE.

Results

In total, 193 patients were included. From an initial dataset of 2436 features, 2287 were excluded due to either poor stability, low variance, or high collinearity. Among the remaining, 14 features were used to train the ML model, which reached an overall accuracy of 83% in the training set. In the two external test sets, the SVM achieved an accuracy of 79% and 74% respectively, not statistically different from that of the radiologist (81–83%, p = 0.39–1) and outperforming the baseline reference (p = 0.001–0.02).

Conclusions

A ML model solely based on radiomics features demonstrated high accuracy for EPE detection and good generalizability in a multicenter setting. Paired to qualitative EPE assessment, this approach could aid radiologists in this challenging task.

Key Points

• Predicting the presence of EPE in prostate cancer patients is a challenging task for radiologists.

• A support vector machine algorithm achieved high diagnostic accuracy for EPE detection, with good generalizability when tested on multiple external datasets.

• The performance of the algorithm was not significantly different from that of an experienced radiologist.
Personality traits, sex and food abundance shape space use in an arboreal mammal
Authors: Wauters Lucas A. , Mazzamuto Maria Vittoria , Santicchia Francesca , Martinoli Adriano , Preatoni Damiano G. , Lurz Peter W. W. , Bertolino Sandro , Romeo Claudia
Published: April 2021

Animal space use is affected by spatio-temporal variation in food availability and/or population density and varies among individuals. This inter-individual variation in spacing behaviour can be further influenced by sex, body condition, social dominance, and by the animal’s personality. We used capture-mark-recapture and radio-tracking to examine the relationship between space use and personality in Eurasian red squirrels (Sciurus vulgaris) in three conifer forests in the Italian Alps. We further explored to what extent this was influenced by changes in food abundance and/or population density. Measures of an individual’s trappability and trap diversity had high repeatability and were used in a Principal Component Analysis to obtain a single personality score representing a boldness-exploration tendency. Males increased home-range size with low food abundance and low female density, independent of their personality. However, bolder males used larger core-areas that overlapped less with other males than shy ones, suggesting different resource (food, partners) utilization strategies among personality types. For females, space use-personality relationships varied with food abundance, and bolder females used larger home ranges than shy ones at low female density, but the trend was opposite at high female density. Females’ intrasexual core-area overlap was negatively related to body mass, with no effect of personality. We conclude that relationships between personality traits and space use in free-ranging squirrels varied with sex, and were further influenced by spatio-temporal fluctuations in food availability. Moreover, different personality types (bold-explorative vs. shy) seemed to adopt different space-use strategies to increase access to food and/or partners.
Kurze Ketten im Lebensmittelbereich
Authors: Tuitjer Gesine
Published: April 2021

Short Food Supply Chains (SFSC), also kurze Wertschöpfungsketten im Lebensmittelbereich, sind ein verbreiteter Ansatz in der Regionalentwicklung – im ländlichen wie auch im städtischen Kontext. Aufgrund der Breite des Konzeptes sind empirische Belege für die regionalen Auswirkungen von kurzen Ketten jedoch uneindeutig und ihrem konkreten Aufbau stehen teilweise große Herausforderungen gegenüber. Im vorliegenden Text werden Direktvermarktung, Regionalvermarktungsinitiativen und regionalisierte vertikale Wertschöpfungsketten behandelt. Der Text fasst Ergebnisse einzelner Fallstudien zusammen, die zwischen 2015 und 2019 in 6 ländlichen Kreisen durchgeführt wurden. Im Text werden Herausforderungen für die Entwicklung dieser kurzen Ketten skizziert und mögliche Chancen aufgezeigt. Der Ausbau von alternativen Vermarktungswegen kann beispielsweise durch Infrastruktur im Bereich der Lagerung und Logistik unterstützt werden. Ein weiteres zentrales Ergebnis stellt die Notwendigkeit von Netzwerkvermittlern dar, die Kooperationen zwischen Produzenten innerhalb einer Region entlang vertikaler Wertschöpfungsketten begleiten bzw. initiieren.
Adaptive time-step control for a monolithic multirate scheme coupling the heat and wave equation
Authors: Soszyńska Martyna , Richter Thomas
Published: April 2021

We study the dynamics of a parabolic and a hyperbolic equation coupled on a common interface. We develop time-stepping schemes that can use different time-step sizes for each of the subproblems. The problem is formulated in a strongly coupled (monolithic) space-time framework. Coupling two different step sizes monolithically gives rise to large algebraic systems of equations. There, multiple states of the subproblems must be solved at once. For efficiently solving these algebraic systems, we inherit ideas from the partitioned regime. Therefore we present two decoupling methods, namely a partitioned relaxation scheme and a shooting method. Furthermore, we develop an a posteriori error estimator serving as a mean for an adaptive time-stepping procedure. The goal is to optimally balance the time-step sizes of the two subproblems. The error estimator is based on the dual weighted residual method and relies on the space-time Galerkin formulation of the coupled problem. As an example, we take a linear set-up with the heat equation coupled to the wave equation. We formulate the problem in a monolithic manner using the space-time framework. In numerical test cases, we demonstrate the efficiency of the solution process and we also validate the accuracy of the a posteriori error estimator and its use for controlling the time-step sizes.
A New Conceptual ‘Cylinder’ Framework for Sustainable Bioeconomy Systems and Their Actors
Authors: de Vries Hugo , Donner Mechthild , Axelos Monique
Published: April 2021

Concepts for sustainable bioeconomy systems are gradually replacing the ones on linear product chains. The reason is that continuously expanding linear chain activities are considered to contribute to climate change, reduced biodiversity, over-exploitation of resources, food insecurity, and the double burden of disease. Are sustainable bioeconomy systems a guarantee for a healthy planet? If yes, why, when, and how? In literature, different sustainability indicators have been presented to shed light on this complicated question. Due to high degrees of complexity and interactions of actors in bioeconomy systems, trade-offs and non-linear outcomes became apparent. This fueled the debates about the normative dimensions of the bioeconomy. In particular, the behavior of actors and the utilization of products do not seem to be harmonized according to the environmental, social, and economic pillars of sustainability. Potential conflicts require a new conceptual framework that is here introduced. It consists of a ‘sustainability’ cylinder captured between an inner-cylinder, representing order, and an outer-cylinder for chaos, based on the laws of physics and complex adaptive systems. Such a framework permits (bioeconomy) systems to propagate in the sustainability zone only if they follow helical pathways serving as the new norms. Helices are a combination of two sinusoidal patterns. The first represents here the sustainable behavior of interacting actors and the second the balanced usage of resources and products. The latter counteracts current growth discourses. The applicability of the conceptual cylinder framework is positively verified via 9 cases in Europe, which encompass social-organizational and product-technological innovations. –
Valuing life and evaluating suffering in infants with life-limiting illness
Authors: Wilkinson Dominic , Zayegh Amir
Published: April 2021

In this paper, we explore three separate questions that are relevant to assessing the prudential value of life in infants with severe life-limiting illness. First, what is the value or disvalue of a short life? Is it in the interests of a child to save her life if she will nevertheless die in infancy or very early childhood? Second, how does profound cognitive impairment affect the balance of positives and negatives in a child’s future life? Third, if the life of a child with life-limiting illness is prolonged, how much suffering will she experience and can any of it be alleviated? Is there a risk that negative experiences for such a child (suffering) will remain despite the provision of palliative care? We argue that both the subjective and objective components of well-being for children could be greatly reduced if they are anticipated to have a short life that is affected by profound cognitive impairment. This does not mean that their overall well-being will be negative, but rather that there may be a higher risk of negative overall well-being if they are expected to experience pain, discomfort, or distress. Furthermore, we point to some of the practical limitations of therapies aimed at relieving suffering, such that there is a risk that suffering will go partially or completely unrelieved. Taken together, these considerations imply that some life-prolonging treatments are not in the best interests of infants with severe life-limiting illness.
Subjektive Belastung der Eltern durch die Beschulung ihrer Kinder zu Hause zu Zeiten des Corona-bedingten Lockdowns im Frühjahr 2020
Authors: Zinn Sabine , Bayer Michael
Published: April 2021

Die Corona-bedingten Schulschließungen sowie die Schließung von Kinderbetreuungseinrichtungen im April und Mai 2020 haben viele Eltern vor eine immense Herausforderung gestellt. Plötzlich mussten Kinder ganztags Zuhause betreut und beschult werden. In diesem Beitrag beschäftigen wir uns mit der Frage nach der subjektiven Belastung, der sich Eltern durch die Beschulung ihrer Kinder Zuhause ausgesetzt sahen. Hierbei legen wir ein besonderes Augenmerk auf die individuelle Ressourcenausstattung der Eltern sowie auf ihre familiäre Situation und ihr Erwerbsleben. Insbesondere untersuchen wir das subjektive Belastungsempfinden alleinerziehender Eltern. Für unsere Analysen nutzen wir die Daten der SOEP-CoV Studie, einer Sonderbefragung an Panelteilnehmern des Sozio-Oekonomischen Panels (SOEP) zum Thema Corona. Insgesamt konnten wir bei allen befragten Eltern (N = 1508, davonN = 243 alleinerziehend) eine mäßige Belastung durch die Anforderungen der Beschulung ihrer Kinder Zuhause ausmachen. Besonders belastet fühlten sich jedoch Eltern mit einem niedrigen Bildungsabschluss und alleinerziehende Eltern, insbesondere wenn sie zur Zeit der Schulschließungen erwerbstätig waren. Unsere Analysen legen nahe, dass gerade diese Elterngruppen Probleme hatten, den Anforderungen, die eine Beschulung Zuhause mit sich bringt, unter den gegebenen Umständen umfassend nachzukommen.
The Toxicological Risk Assessment of Lead and Cadmium in Valeriana officinalis L., radix (Valerian root) as Herbal Medicinal Product for the Relief of Mild Nervous Tension and Sleep Disorders Available in Polish Pharmacies
Authors: Jurowski Kamil , Fołta Maria , Tatar Barbara , Berkoz Mehmet , Krośniak Mirosław
Published: April 2021

Studies related to the toxicological risk assessment (TRA) of heavy metal impurities (HMIs) in pharmaceuticals are an important issue but there is a lack of refereed literature around the safety of Valeriana officinalis L., radix (Valerian root) as herbal medicinal product (HMP) for the relief of mild nervous tension and sleep disorders according to lead and cadmium impurities. The aim of the study was to estimate the TRA of lead and cadmium in Valeriana officinalis L., radix (Valerian root) as HMP (n = 5) available in Polish pharmacies. In the case of herbal pharmaceuticals, it is particularly important to control the level of HMIs accumulated during the plant’s growth. Perhaps, the exposure for a single dose is not relevant; however, justification of our studies is a fact that herbal therapies are usually long term. Therefore, even small HMI doses as present in particular plant may accumulate in patient body over a long period of time. Levels of lead and cadmium were measured by electrothermal atomization atomic absorption spectrometry. The levels of lead and cadmium as HMIs (independently of the producer and declared composition) are quite similar. Our results are satisfactory, confirming the safety of Valeriana officinalis L., radix (Valerian root) as herbal medicinal product for the relief of mild nervous tension and sleep disorders available in Polish pharmacies according to ICH guideline Q3D. To the best of our knowledge, this paper is the first study about lead and cadmium content as HMIs in HMP containing Valeriana officinalis L., radix (Valerian root).
Malnutrition and cancer, diagnosis and treatment
Authors: Beirer Angelika
Published: April 2021

Background

The prevalence of malnutrition in cancer patients ranges from about 20% to more than 70%. However, 10–20% of cancer patients’ deaths are related to malnutrition, not the malignancy itself. To reverse the pattern of weight loss, improve the patients’ quality of life, reduce the treatment toxicity, the psychological stress and the risk of mortality, the diagnosis of malnutrition should be made as early as possible to facilitate the best possible treatment.

Methods

A systematic literature search was conducted following guidelines of ESPEN (European Society for Clinical Nutrition), DGEM (German Society for Nutritional Medicine) and ASPEN (American Society for Parenteral and Enteral Nutrition).

Results and conclusion

To assess the risk of malnutrition, all cancer patients should be screened regularly with a valid screening tool (e.g., MUST [Malnutrition Universal Screening Tool], NRS [Nutritional Risk Screening] or PG-SGA [Scored Patient-Generated Subjective Global Assessment]). If risk of malnutrition is present, adequate nutritional therapy is recommended to stop involuntary weight loss. Patients should engage in exercise to maintain and improve muscle mass, strength and function. They should be offered regular dietetic counselling, and their muscle depletion should be monitored by determining fat-free mass. As cachectic patients in particular are at risk, the presence of cachexia should also be recognized at an early stage. Three consensus-based definitions are widely accepted: Fearon et al. and the EPCRC (European Palliative Care Research Collaborative) propose definitions specifically for cancer cachexia, while Evans et al. put forward a definition for cachexia associated with all types of underlying chronic diseases. However, if there is a cancer cachexia diagnosis, additional pharmacological and psychological treatment should be considered.
Improvement the InAs, InSb, GaAs and GaSb surface state by nanoscale wet etching
Authors: Levchenko Iryna , Tomashyk Vasyl , Malanych Galyna , Stratiychuk Iryna , Korchovyi Andrii
Published: April 2021

Various experimental approaches of the wet nanoscale treatment have been proposed to account for features of the InAs, InSb and GaAs, GaSb semiconductor dissolution process in the (NH4)2Cr2O7–HBr–EG etching solution. Etching kinetics data showed that a crystal dissolution has diffusion-determined nature. The lowering of the solvent concentration from 80 to 0 vol.% in the solution was accompanied by a significant increase in the semiconductor etching speed. Depending on the solution composition, we have studied two types of crystal surface morphology, polished and passivated by the film, which was formed after chemical-dynamic (CDP) and/or chemical-mechanic polishing (CMP) in the solution, saturated by solvent and by oxidant, accordingly. It was found that in the polished etchants both CDP and CMP procedures lead to the formation of the mirror-like and super-smooth surface with nanoscale roughness less than 1 nm. The obtained results of surface state indicate that the (NH4)2Cr2O7–HBr–EG etchants could be used successfully for controllable CDP and CMP treatment of III–V semiconductors and formation of super-smooth surface.
Review of Femtosecond-Laser-Inscribed Fiber Bragg Gratings: Fabrication Technologies and Sensing Applications
Authors: He Jun , Xu Baijie , Xu Xizhen , Liao Changrui , Wang Yiping
Published: April 2021

Fiber Bragg grating (FBG) is the most widely used optical fiber sensor due to its compact size, high sensitivity, and easiness for multiplexing. Conventional FBGs fabricated by using an ultraviolet (UV) laser phase-mask method require the sensitization of the optical fiber and could not be used at high temperatures. Recently, the fabrication of FBGs by using a femtosecond laser has attracted extensive interests due to its excellent flexibility in creating FBGs array or special FBGs with complex spectra. The femtosecond laser could also be used for inscribing various FBGs on almost all fiber types, even fibers without any photosensitivity. Such femtosecond-laser-induced FBGs exhibit excellent thermal stability, which is suitable for sensing in harsh environment. In this review, we present the historical developments and recent advances in the fabrication technologies and sensing applications of femtosecond-laser-inscribed FBGs. Firstly, the mechanism of femtosecond-laser-induced material modification is introduced. And then, three different fabrication technologies, i.e., femtosecond laser phase mask technology, femtosecond laser holographic interferometry, and femtosecond laser direct writing technology, are discussed. Finally, the advances in high-temperature sensing applications and vector bending sensing applications of various femtosecond-laser-inscribed FBGs are summarized. Such femtosecond-laser-inscribed FBGs are promising in many industrial areas, such as aerospace vehicles, nuclear plants, oil and gas explorations, and advanced robotics in harsh environments.
Mathematics in Engineering Education: a Review of the Recent Literature with a View towards Innovative Practices
Authors: Pepin Birgit , Biehler Rolf , Gueudet Ghislaine
Published: April 2021

The aim of the special issue is to bring together important current international research on innovative teaching and learning practices in mathematics in engineering education, and to develop deeper understandings of the characteristics of current teaching and learning practices that can inform the design and implementation of future innovative practice. The focus of this review paper is to provide a state-of-the-art overview of this emerging field at the cross-roads between mathematics and engineering education, in addition to introducing the papers of this special issue. To guide this paper, we posed three review questions: (1) How can current (teaching/learning/study) practices of mathematics in engineering education be characterized with a view towards innovation?; (2) What are the ‘resources’ (cognitive, material, digital, social) used, and what are those that appear also well suited for innovative courses?; (3) What are promising innovative practices in mathematics in engineering education, and what are the implications for curriculum reform? Looking back across the studies we summarized in the review, we conclude that they are lagging behind the more fundamental changes that are happening in engineering education, whilst addressing selected aspects of innovative changes within the current system of engineering education. At the same time, the nine papers of this special issue contribute new perspectives for innovative practices in mathematics in engineering education, for a better understanding of current practices and for future research.
cPCN-Regulated SnO2 Composites Enables Perovskite Solar Cell with Efficiency Beyond 23%
Authors: Li Zicheng , Gao Yifeng , Zhang Zhihao , Xiong Qiu , Deng Longhui , Li Xiaochun , Zhou Qin , Fang Yuanxing , Gao Peng
Published: April 2021

Efficient electron transport layers (ETLs) not only play a crucial role in promoting carrier separation and electron extraction in perovskite solar cells (PSCs) but also significantly affect the process of nucleation and growth of the perovskite layer. Herein, crystalline polymeric carbon nitrides (cPCN) are introduced to regulate the electronic properties of SnO2 nanocrystals, resulting in cPCN-composited SnO2 (SnO2-cPCN) ETLs with enhanced charge transport and perovskite layers with decreased grain boundaries. Firstly, SnO2-cPCN ETLs show three times higher electron mobility than pristine SnO2 while offering better energy level alignment with the perovskite layer. The SnO2-cPCN ETLs with decreased wettability endow the perovskite films with higher crystallinity by retarding the crystallization rate. In the end, the power conversion efficiency (PCE) of planar PSCs can be boosted to 23.17% with negligible hysteresis and a steady-state efficiency output of 21.98%, which is one of the highest PCEs for PSCs with modified SnO2 ETLs. SnO2-cPCN based devices also showed higher stability than pristine SnO2, maintaining 88% of the initial PCE after 2000 h of storage in the ambient environment (with controlled RH of 30% ± 5%) without encapsulation.
Design Optimization of a Composite Rail Vehicle Anchor Bracket
Authors: Lang Daniel , Radford Donald W.
Published: April 2021

The rail transportation sector is currently seeking to decrease greenhouse gas emissions by incorporating composite materials that can reduce the mass of vehicles. During early adoption of composites in the rail transportation industry, these materials have predominantly been applied to simple design geometries and lightly loaded structures, have been optimized only through modification of composite thickness and composite layer shape, and have only been constrained with respect to a single mechanical performance metric. This study investigates the use of finite element analysis software in the simulation of fiber-reinforced composite materials applied to, and optimized for, a complex and heavily loaded rail vehicle anchor bracket. The research assesses the applicability of optimization methodologies to a complex and heavily loaded structure and advances established practices by constraining the solution with respect to multiple design requirements: manufacturing, compliance, and failure criterion. The optimization process successfully developed a composite structure with a predicted mass reduction of 33% compared to an existing steel design, and simultaneously met compliance, manufacturing, and failure criteria constraints.
Optimizing facility siting for probabilistic collection and distribution of information in support of urban transportation
Authors: Matisziw Timothy C. , Gholamialam Ashkan
Published: April 2021

Collecting and receiving information about the state of a transportation system is essential to effective planning for intelligent transportation systems, whether it be on the part of individual users or managers of the system. However, efforts to collect or convey information about a system’s status often require considerable investment in infrastructure/technology. Moreover, given variations in the development and use of transportation systems over time, uncertainties exist as to where and when demand for such services may be needed. To address these problems, a model for minimizing the cost of siting and/or collecting information while ensuring specified levels of demand are served at an acceptable level of reliability is proposed. To demonstrate the characteristics of the proposed formulation, it is coupled with another planning objective and applied to identify optimal sites for information provision/collection in a transportation system. Model solutions are then derived for multiple scenarios of system flow to explore how variations in the use of a transportation system can impact siting configurations.
Engineering geology and geotechnical characterization of Tabriz Metro Line 2, Iran
Authors: Alizadeh Ali , Buzari Souheila , Sattarzadeh Yousef , Pourkermani Mohsen
Published: April 2021

The present study was performed in order to determine the engineering geology and geotechnical details of soils and rocks along Tabriz Metro Line 2(TML2) by using the information and raw data which were acquired by borehole drilling and all field and laboratory tests in the study area. The minimum and maximum depths of the boreholes were 15 and 40 m, respectively. The results of their analysis revealed that geologically, the areas of metro route, mainly formed by alternating layers of claystone, siltstone, marl, and conglomerate, covered mainly by the alluvial deposits and in addition to older, dextral, strike-slip North Tabriz Fault (NTF) which is a major and most important geological structure of Tabriz area, there are also many minor and generally young and seismically active faults. The results of investigation on the groundwater depth in boreholes of TML2 also indicated that the groundwater depth varies between 1.5 and 30 m, along the route of metro. Eventually, based on the standard penetration test values (N-SPT), it was revealed that soils of the western parts of TML2 are in the group of dense to very dense, the central parts are in the group of very dense (Bazaar area) and dense (Fahmideh area), and the eastern parts are very dense. And finally the results achieved from determining groundwater sulfate values according to Concrete Code of Iran (CCI) indicated that the amount of soluble sulfate in the soil is mild to extremely high. Accordingly, the amount of sulfate increases from the western to the eastern parts. So that, this value is between 200 and 26,500 ppm. Based on these studies, the average of sulfate in the western, central and eastern parts is, respectively, 1118, 1275 and 4840 ppm. Thus, the groundwater in the east part is highly aggressive, and deterioration of concrete lining of the tunnel is expected in the near future.
The Impossible Office?
Authors: Seldon Anthony , Meakin Jonathan , Thoms Illias
Published: April 2021

Marking the third centenary of the office of Prime Minister, this book tells its extraordinary story, explaining how and why it has endured longer than any other democratic political office in world history. Sir Anthony Seldon, historian of Number 10 Downing Street, explores the lives and careers, loves and scandals, successes and failures, of all our great Prime Ministers. From Robert Walpole and William Pitt the Younger, to Clement Attlee and Margaret Thatcher, Seldon discusses which of our Prime Ministers have been most effective and why. He reveals the changing relationship between the Monarchy and the office of the Prime Minister in intimate detail, describing how the increasing power of the Prime Minister in becoming leader of Britain coincided with the steadily falling influence of the Monarchy. This book celebrates the humanity and frailty, work and achievement, of these 55 remarkable individuals, who averted revolution and civil war, leading the country through times of peace, crisis and war.
Modern Impact and Penetration Mechanics
Authors: Walker James
Published: April 2021

This graduate text is indispensable for those wanting to see and understand the mechanics of extreme dynamic events. It describes in detail the mechanics and material models used in understanding impact and penetration events. Covers continuum mechanics, the Hugoniot jump conditions, plasticity theory, damage and failure theory, shock and wave propagation in both Eulerian and Lagrangian frameworks, and the high pressure and high-rate response of materials. Nonlinearity in response of materials and systems is a common theme, showing itself in interesting and surprising ways. Materials are studied through damage to failure, since in armor and protection applications materials are utilized all the way through failure. Continuum and constitutive modelling topics required for modern large-scale numerical simulation techniques are clearly described. Extensive exercises ensure comprehension and explore new topics. This text is appropriate for a variety of graduate courses, including Continuum Mechanics, Advanced Solid Mechanics, and Plasticity and Inelasticity Theory.