bluuebunny/crossref_metadata_2025 huggingface dataset:
The Direct and Indirect Role of Migrants’ Networks in Accessing Diverse Labour Market Sectors: An Analysis of the Weak/Strong Ties Continuum
Authors: Ryan Louise
Published: March 2022

Much has been written about how migrants may utilise social networks to access jobs. Nevertheless, gaps remain in our understanding of how skills, labour market sectors, education level, language proficiency, etc. may influence the relationship between network ties and employment opportunities. Moreover, it is important to adopt a temporal perspective to understand change over time (Ryan L, D’Angelo A, Soc Netw 53:148–158, 2018). Strategies adopted to initially access the labour market, in a new destination, may differ from how employment seeking trajectories develop as migrants become more familiar with local contexts and gain relevant work-experience. This chapter draws upon interviews with diverse migrants, in London, across varied public and private sectors jobs. Beyond a simple binary of strong versus weak ties, I build upon my analytical framework (Ryan L, Sociol Rev, 59(4):707–724, 2011; Ryan L, Sociol Rev, 64(4):951–969, 2016), I explore the relationships within ties, the flow of resources and the relative social location of the actors vertically and horizontally. In so doing, this chapter aims to contribute to understanding migrant networks in three key ways. (1) How migrants’ networks operate both directly and indirectly in job seeking strategies and career development. (2) How the role of networks may differ across varied labour market sectors. (3) How weak and strong ties can be conceptualised as a continuum of dynamic relationships.
Social Capital, Immigrants and Their Descendants – The Case of Sweden
Authors: Behtoui Alireza
Published: March 2022

This chapter is about the access to networks with valuable resources (social capital) of individuals with a migrant background. Findings from the empirical studies in this field that I have conducted in Sweden over the last 20 years are the main basis for my arguments here: (i) it is not an individual’s social networks per se but the resources embedded in these social networks which define a person’s social capital; (ii) immigrants have different social and economic backgrounds and positions. An intersectional perspective challenges studies on the social capital of immigrants that lump all immigrants together as one homogenous group; (iii) social capital is a significant device for reproducing the existing hierarchical structure of society and the distinct power positions of various social groups; (iv) although the stratification effect of social capital is the predominant pattern, some groups or individuals from the unprivileged strata of society and other low-status people (like immigrants) have been able to gain access to resources beyond their immediate social networks, through institutional mediation or via membership in civil-society organisations (the “counter stratification” effect of social capital); finally (iv) the outcomes of social capital may differ due to context specificity.
Activating Social Capital: Steep Mobility of Descendants of Turkish Immigrants at the Top of the Corporate Business Sector
Authors: Rezai Sara , Keskiner Elif
Published: March 2022

This qualitative study on steep social mobility is based on interviews with descendants of guest-worker immigrants from Turkey. They currently work in highly prestigious positions in the field of professional business services in the Netherlands. The majority of studies on social capital and career mobility is based on quantitative methods which makes it difficult to gain insight into its mechanisms. In line with Lin (Annu Rev Sociol 25:467–487, 1999) and Smith (Am J Sociol 111:1–57, 2005) the current article makes the distinction between the access to and the activation of social capital. By explaining how the professional characteristics of the social climbers triggered their network connections to become ‘donors’ (Portes A, Annu Rev Sociol 24:1–24, 1998), we attempt to shed light on the mechanisms of social capital activation. For this claim we apply the concepts of ‘likeability’ and ‘reliability’. Furthermore, we categorize two types of donors that have emerged from our data: ‘ambassadors’ and ‘coaches’. By comprehending how the descendants of migrants activated their social capital, this article gives insight into the mechanisms of their steep social mobility, and it deepens our understanding of the relation between social capital and career mobility.
Mitmachmedien. Musenalmanache als literarische Formulare
Authors: Hildebrandt Annika
Published: March 2022

In der deutschen Literatur des 18. Jahrhunderts gibt es wenige Medien, die so fest mit dem Vorwurf der Unoriginalität verknüpft sind wie Musenalmanache. Die auffällige Konventionalität der Almanachpoesie, die sowohl die vertretenen lyrischen Gattungen als auch die einzelnen Gedichte betrifft, ist von der bisherigen Forschung meist aus der Perspektive der Rezipienten reflektiert worden. Dieser Beitrag verfolgt dagegen die Frage, welche Funktion das formularisch vorstrukturierte Medium für die Produzenten besaß. Dadurch richtet sich die Aufmerksamkeit auf die Bedeutung der populären Anthologien für die soziale Öffnung von Autorschaftskonzepten um 1800. Untersucht wird, wie das interaktive Format der Musenalmanache, in dem auch die Leserinnen und Leser zur Publikation eingeladen wurden, durch ein festes Repertoire von Gattungsformularen ausbalanciert wurde.
»…daß der Bürger richtig reagiert«. Die Formularverweigerung der Poesie*
Authors: Landkammer Joachim
Published: March 2022

Formulare sind Leerstellen-Module für asymmetrische Kommunikationen (vgl. Becker 2009, 282, mit Bezugnahme auf Lothar Schilling). Sie führen eine Art schriftliches Verhör: Nach herrschaftsunfreiem patriarchalen Muster „redet“ der das Formular ausfüllende „Dialog“-Partner (hier wie im gesamten Text wird aus Gründen der Einfachheit das generische Maskulinum angewandt) „nur, wenn er gefragt wird“, und nur zu den ihm gestellten Fragen – der manchmal vorgesehene Raum für „Freitext“ (oder die Möglichkeit der Beigabe eines sog. „formlosen“ Anhangs zum Formular) versucht das nachträglich und eher augenwischend zu kompensieren. Die (Staats-)Macht manifestierende Asymmetrie der Formularkommunikation hat auch schon vor Peter Schneiders oben zitiertem exemplarischen 68er-Aufbegehren deren Verweigerung nahelegt, sei es, dass man sie durch eine überbordend-umständliche und pseudo-genaue Beantwortung ad absurdum führte (wie in Ernst Salomons Der Fragebogen von 1951), öffentlich zweckentfremdete (Volkszählungsboykotteure hatten 1987 die Berliner Mauer mit den Erfassungsbögen tapeziert) oder historistisch-ironisch zitierte (die Tagung „Niklas Luhmann am OVG Lüneburg“ im Januar 2017 präsentierte ihre Unterlagen in einer im klassischen Kanzlei-Stil der 50er Jahre designten Mappe, inklusive sauberster Sütterlin-Handschrift) (vgl. auch das Cover der englischen und deutschen Ausgabe Graeber 2017).
»the form of forms«. Zur Poetik bürokratischen Schreibens in David Foster Wallace’ The Pale King
Authors: Pethes Nicolas
Published: March 2022

Der Beitrag geht der Homonymie nach, durch die der Begriff „form“ im Englischen das Konzept der (ästhetischen) Form mit demjenigen des (bürokratischen) Formulars verknüpft: Hegels Feststellung, dass der moderne Roman von der alltäglichen „Prosa der Wirklichkeit“ bestimmt sei, findet seit der zweiten Hälfte des 20. Jahrhunderts ihre Zuspitzung im Genre des Büroromans, der das Erzählen von Verwaltungsakten an die Stelle interessanter Handlungszusammenhänge treten lässt. In David Foster Wallace’ postum veröffentlichtem Romanfragment „The Pale King“ (2011) wird sogar das mediale Format des Formulars selbst zum Prinzip des Erzählens von den Angestellten der US-amerikanischen Steuerbehörde IRS und die „form“ der Bürokratie mithin selbst zur „form“ des Romans.
Ausfüllen/Überfüllen. Wie Ernst von Salomon den ›großen Fragebogen‹ beantwortet
Authors: Balke Friedrich
Published: March 2022

Formulare sind Grenzobjekte. Eine besondere Bedeutung kommt in ihrem Fall der Unterscheidung von (vorgeschriebenem) Text, den auszufüllenden Lücken und ihren Rändern zu. Der lückenhafte Text weist demjenigen, der das Formular ausfüllt, einen präzise ausgemessenen Raum für seine Textergänzungen zu. Aber Formulare gestatten noch einen anderen Typ von Textergänzung, dessen Schauplatz die Ränder sind: Auf ihnen finden sich gelegentlich Inskriptionen, die in den vorgegebenen Lücken, die das Formular lässt, nicht vorgesehen sind und die sich zugleich als Kritik an den Klassifizierungszwängen dieser Textsorte lesen lassen. Vor diesem Hintergrund geht der Aufsatz den literarischen Spielräumen einer Textgattung nach, der es scheinbar allein auf bürokratische Genauigkeit ankommt: Ernst von Salomon orientiert in seinem umstrittenen Nachkriegs-Bestseller „Der Fragebogen“ (1951) seine Lebensgeschichte am Raster des sogenannten „großen Fragebogens“, mit dem das „Military Government of Germany“ das Kriegsziel der Entnazifizierung der deutschen Bevölkerung auf bürokratischem Wege erreichen wollte. Indem er sich weigert, seine Geschichte in die Kategorien der Verwaltung zu transformieren und sie stattdessen in allen anekdotischen Details ausfabuliert, benutzt von Salomon die Möglichkeiten der Literatur, um die Asymmetrie zwischen fragender Behörde und Auskunftsgebenden zu verkehren.
Flavour anomalies and the muon g − 2 from feebly interacting particles
Authors: Darmé Luc , Fedele Marco , Kowalska Kamila , Sessolo Enrico Maria
Published: March 2022

Abstract

We perform a phenomenological analysis of simplified models of light, feebly interacting particles (FIPs) that can provide a combined explanation of the anomalies in b → sl+l− transitions at LHCb and the anomalous magnetic moment of the muon. Different scenarios are categorised according to the explicit momentum dependence of the FIP coupling to the b−s and μ−μ vector currents and they are subject to several constraints from flavour and precision physics. We show that viable combined solutions to the muon g − 2 and flavour anomalies exist with the exchange of a vector FIP with mass larger than 4 GeV. Interestingly, the LHC has the potential to probe this region of the parameter space by increasing the precision of the Z → 4μ cross-section measurement. Conversely, we find that solutions based on the exchange of a lighter vector, in the mV< 1 GeV range, are essentially excluded by a combination of B → K+ invisible and W-decay precision bounds.
Neutrino mass from Affleck-Dine leptogenesis and WIMP dark matter
Authors: Mohapatra Rabindra N. , Okada Nobuchika
Published: March 2022

Abstract

Affleck-Dine (AD) mechanism for leptogenesis involves the cosmological evolution of a complex scalar field (AD field) that carries non-zero lepton number. We show how explicit lepton number breaking terms, which involve the AD field needed to implement this scenario combined with fermionic WIMP dark matter, can generate neutrino mass at the one loop level, thus providing a unified framework for solving four major puzzles of the standard model i.e. inflation, baryogenesis, dark matter and neutrino mass. We discuss some phenomenological implications of this model.
Wahrnehmungen zum Umgang mit Opioiden: Fokus COVID-19
Authors: Peuckmann-Post Vera , Wiese Christoph , Keszei András , Rolke Roman , Elsner Frank
Published: March 2022

Hintergrund

Opioide gehören zum Klinikalltag in Anästhesiologie, Intensivmedizin und Palliativmedizin. Hinsichtlich der Behandlung von Dyspnoe mit Opioiden finden sich in Leitlinien jedoch unterschiedliche Gewichtungen. Dies kann zu Unsicherheiten bezüglich Indikationsstellung und ethischer Implikationen im Umgang mit Opioiden – auch bei COVID-19 – führen.

Ziel der Arbeit

Erfassung der Wahrnehmung bezüglich Umgang mit Morphin/Opioiden (M/O) zur Symptomkontrolle inner- und außerhalb der Palliativmedizin, auch bei COVID-19-Erkrankten.

Material und Methoden

Mittels SurveyMonkey® (Momentive Inc., San Mateo, CA, USA) wurden Mitglieder der Deutschen Gesellschaft für Anästhesiologie (DGAI) und des Berufsverbands Deutscher Anästhesisten (BDA) im Oktober 2020 anonymisiert nach ihrer eigenen Wahrnehmung zum Umgang mit M/O zur Symptomkontrolle befragt.

Ergebnisse und Diskussion

Von N = 1365 teilnehmenden Anästhesist:innen beschrieben 88 % den Umgang mit M/O innerhalb der Palliativmedizin als „sicher und vertraut“ bzw. 85 % als „klar geregelt“, während dies für die Bereiche außerhalb der Palliativmedizin deutlich seltener angegeben wurde (77 %/63 %). Bei der Betreuung COVID-19-Erkrankter wurde der Umgang mit M/O außerhalb der Palliativmedizin noch seltener als „sicher und vertraut“ (40 %) oder „klar geregelt“ (29 %) wahrgenommen. Dyspnoe (95 %/75 %), Erleichterung des Sterbeprozesses (84 %/51 %), Unruhe (59 %/27 %) und Angst/Panik (61 %/33 %) wurden häufiger innerhalb als außerhalb der Palliativmedizin als allgemeine Indikationen genannt. Von den Befragten wünschten sich 85 % die Einbindung eines palliativmedizinischen Konsilteams.

Fazit

Anästhesist:innen nahmen deutliche Unsicherheiten im Umgang mit M/O wahr, insbesondere außerhalb der Palliativmedizin. Einheitliche, interdisziplinäre Leitlinien zur Symptomkontrolle etwa bei Dyspnoe, mehr Lehre und die Einbindung eines palliativmedizinischen Konsilteams sollten zukünftig intensiver bedacht werden.
Körperliche und psychische Folgeerkrankungen bei Diabetes mellitus
Authors: Kulzer Bernhard
Published: March 2022

Trotz Verbesserungen in der Therapie des Diabetes und besseren Versorgungbedingungen weisen die Betroffenen aktuell im Vergleich zur Allgemeinbevölkerung noch immer ein deutlich erhöhtes Risiko für physische wie psychische Folgeerkrankungen sowie eine reduzierte Lebensqualität auf. Etwa 21 % aller Todesfälle sind in Deutschland auf Diabetes und seine Folgeerkrankungen zurückzuführen, das Mortalitätsrisiko ist für Menschen mit Diabetes um mehr als das 1,5-Fache gegenüber Menschen ohne Diabetes erhöht. In dieser Übersicht werden die Verbreitung und die Risikofaktoren für die häufigsten körperlichen und psychischen Folgen des Diabetes beschrieben sowie deren Einflüsse auf die Lebensqualität der Patienten. Zusammenhänge zwischen den Folgeerkrankungen und einer erhöhten Mortalität werden aufgezeigt.

In großen Interventionsstudien konnte die Bedeutung einer guten Glukoseeinstellung – vor allem zu Beginn der Erkrankung – in Hinblick auf eine Senkung der Mortalitätsrate gezeigt werden, weitere wichtige Einflussfaktoren sind z. B. Blutdruck, Blutfette und Rauchen. Weltweite Studienergebnisse deuten auf einen stabilen Trend hinsichtlich einer verbesserten Lebenserwartung von Menschen mit Diabetes in den letzten Jahren hin. Zukünftig könnte der positive Trend durch bessere Versorgungsstrukturen und neue Technologien sowie digitale Anwendungen in der Forschung und Therapie fortgesetzt werden. Mithilfe der Präzisionsmedizin könnten individuelle Risikofaktoren und protektive Faktoren erkannt werden, um der Entstehung von Folgekomplikationen noch besser vorzubeugen.
Pityriasis rubra pilaris nach COVID-19-Impfung: Kausaler Zusammenhang oder Koinzidenz?
Authors: Bramhoff A. C. , Wesselmann U. , Bender S. T. , Berghoff A. V. , Hofmann S. C. , Balakirski G.
Published: March 2022

Seit der Markteinführung der COVID-19-Impfstoffe werden regelmäßig kutane Nebenwirkungen dieser Vakzine beschrieben. Diese beinhalten unter anderem lokale Impfreaktionen (insbesondere den sog. COVID-Arm), urtikarielle, makulopapulöse und pityriasiforme Exantheme oder vorübergehende Exazerbationen einer vorbestehenden chronisch entzündlichen Hauterkrankung. Wir berichten über 3 Fälle einer Pityriasis rubra pilaris, die in engem zeitlichen Zusammenhang mit der Verabreichung eines COVID-19-Impfstoffs erstmals aufgetreten sind.
Color, Scent and Size: Exploring Women's Preferences Around Design Characteristics of Drug-Releasing Vaginal Rings
Authors: Zhao Xinyu , Milford Cecilia , Smit Jenni , Zulu Bongiwe , Boyd Peter , Malcolm R. Karl , Beksinska Mags
Published: March 2022

Steroid-releasing vaginal rings are available for contraception and estrogen replacement therapy, and a new antiretroviral-releasing ring was recently approved for HIV prevention. Marketed rings are white or transparent in appearance, non-scented, and supplied as one-size-fits-all devices with diameters ranging from 54 to 56 mm. In this study, drug-free silicone elastomer rings were manufactured in different sizes, colors and scents, and the opinions/preferences of 16 women (eThekwini District, South Africa; 20–34 years) assessed through focus group discussions and thematic analysis. Opinions varied on ring color and scent, with some women preferring specific colors or scent intensities, while for others these attributes were unimportant. Concerns about color and scent were linked to perceptions around vaginal health and safety related to chemical composition. There was greater agreement on preferred ring size; flexibility and width were considered important factors for insertion and comfort. Greater choice with ring products could facilitate acceptability and overall uptake.
Sustainable fish feeds: potential of emerging protein sources in diets for juvenile turbot (Scophthalmus maximus) in RAS
Authors: Hoerterer Christina , Petereit Jessica , Lannig Gisela , Johansen Johan , Pereira Gabriella V. , Conceição Luis E. C. , Pastres Roberto , Buck Bela H.
Published: March 2022

In Europe, turbot aquaculture has a high potential for sustainable production, but the low tolerance to fishmeal replacement in the diet represents a big issue. Therefore, this study investigated the effects of more sustainable feed formulations on growth and feed performance, as well as nutritional status of juvenile turbot in recirculating aquaculture systems. In a 16-week feeding trial with 20 g juvenile turbot, one control diet containing traditional fishmeal, fish oil and soy products and two experimental diets where 20% of the fishmeal was replaced either with processed animal proteins (PAP) or with terrestrial plant proteins (PLANT) were tested. Irrespective of diets, growth performance was similar between groups, whereas the feed performance was significantly reduced in fish of the PAP group compared to the control. Comparing growth, feed utilisation and biochemical parameters, the results indicate that the fish fed on PAP diet had the lowest performance. Fish fed the PLANT diet had similar feed utilisation compared to the control, whereas parameters of the nutritional status, such as condition factor, hepato-somatic index and glycogen content showed reduced levels after 16 weeks. These effects in biochemical parameters are within the physiological range and therefore not the cause of negative performance. Since growth was unaffected, the lower feed performance of fish that were fed the PAP formulation might be balanced by the cost efficient formulation in comparison to the commercial and the PLANT formulations. Present study highlights the suitability of alternative food formulation for farmed fish.
The Tension between National and Local Concerns in Preparing for Large-Scale Generic Systems in Healthcare
Authors: Ellingsen Gunnar , Hertzum Morten , Melby Line
Published: March 2022

Large-scale generic systems are typically adapted to local practice through configuration. This is especially important in healthcare, which involves a plurality of institutions and users. However, the decision to acquire a generic system in public healthcare is typically founded on regional and national health policy goals, which often are translated into various forms of standardization. As a result, national and regional health policy interests may stand in contrast to interests on the local level. Therefore, we analyze how national and local concerns are weighed against each other in the preparations for implementing large-scale generic systems in healthcare. We explore what role configuration plays and what the prospects are for long-term development. We contribute with insight into how the organizational consequences of generic systems are formed already in the preparation phase and point to how configuration easily results in standardization, thereby basically privileging national and regional health goals at the expense of local needs. Empirically, we focus on the preparations for implementing the Epic electronic health record in Central Norway.
The fiscal response to revenue shocks
Authors: Berset Simon , Huber Martin , Schelker Mark
Published: March 2022

We study the impact of fiscal revenue shocks on local fiscal policy. We focus on the very volatile revenues from the immovable property gains tax in the canton of Zurich, Switzerland, and analyze fiscal behavior following large and rare positive and negative transitory revenue shocks. We apply causal machine learning strategies and implement the post-double-selection LASSO method to identify the effect of revenue shocks on public finances. We find that local policymakers predominantly smooth transitory fiscal shocks.
Effect of high pressure on temperature dependences of the resistivity in the ab-plane of Y0.77Pr0.23Ba2Cu3O7-δ single crystals
Authors: Chroneos A. , Khadzhai G. Ya. , Goulatis I. L. , Mazepulin A. V. , Korobkov M. V. , Vovk R. V.
Published: March 2022

In the present work, we investigated the influence of high hydrostatic pressure up to 11 kbar on the conductivity in the basal ab-plane of medium-doped with praseodymium (x≈0.23) single-crystal Y1-xPrxBa2Cu3O7-δ samples. It was determined that, in contrast to the pure YBa2Cu3O7-δsamples with the optimal oxygen content, the application of high pressure leads to the formation of phase separation in the basal plane of Y0.77Pr0.23Ba2Cu3O7-δ single crystals. Possible mechanisms of the effect of Pr doping and high pressure on the two-step resistive transition to the superconducting state are discussed. It was determined that in the normal state, the conductivity is metallic and is limited by phonons scattering (Bloch-Grüneisen regime) and defects. The fluctuation conductivity is considered within the Lorentz-Doniach model. Hydrostatic pressure, accompanied by a decrease in anisotropy, leads to a decrease in the residual and phonon resistances. Debye temperature and coherence length are independent of pressure. The applicability of the McMillan formula in the presence of significant anisotropy is discussed.
A Group Contingency to Increase Walking Speed At a Residential Summer Camp
Authors: Bloomfield Bradley S.
Published: March 2022

Groups of children often transition between activity spaces in both academic and recreational settings. In schools, children may be asked to walk as a group between the classroom and spaces such as a cafeteria and playground whereas summer camps similarly use different spaces for separate activities throughout a scheduled day. Interdependent group contingencies have previously addressed school-based transitions (e.g., timely transitions game); however, limited research has applied similar interventions to recreational settings such as summer camps. An ABAB design was used to evaluate an interdependent group contingency with visual feedback to increase walking speed between activities across one group of seven 10- to 11-year-old boys at a residential summer camp. The results showed that the intervention was effective to increase the average speed walking, in feet per second, for the group of boys. Further, there were high rates of intervention fidelity, and acceptability among camp counselors.
Inorganic-organic hybrid polymers for printing of optical components: from digital light processing to inkjet 3D-printing
Authors: Klein Matthias , Steenhusen Sönke , Löbmann Peer
Published: March 2022

Solvent-free inorganic-organic hybrid polymers were prepared for digital light processing (DLP) and ink-jet printing. The resins were characterized in terms of viscosity, surface tension, and refractive index. Optical bulk components were prepared with both printing techniques and compared regarding their surface roughness and optical scattering. The haze of DLP-samples can be avoided by inkjet 3D printing. Moreover, different quantum dots (QD) could be incorporated into resins; DLP resulted in complex 3D assemblies.
A Comparison Between Machine Learning and Functional Geostatistics Approaches for Data-Driven Analyses of Sediment Transport in a Pre-Alpine Stream
Authors: Didkovskyi Oleksandr , Ivanov Vladislav , Radice Alessio , Papini Monica , Longoni Laura , Menafoglio Alessandra
Published: March 2022

The problem of providing data-driven models for sediment transport in a pre-Alpine stream in Italy is addressed. This study is based on a large set of measurements collected from real pebbles, traced along the stream through radio-frequency identification tags after precipitation events. Two classes of data-driven models based on machine learning and functional geostatistics approaches are proposed and evaluated to predict the probability of movement of single pebbles within the stream. The first class built upon gradient-boosting decision trees allows one to estimate the probability of movement of a pebble based on the pebbles’ geometrical features, river flow rate, location, and subdomain types. The second class is built upon functional kriging, a recent geostatistical technique that allows one to predict a functional profile—that is, the movement probability of a pebble, as a function of the pebbles’ geometrical features or the stream’s flow rate—at unsampled locations in the study area. Although grounded in different perspectives, both models aim to account for two main sources of uncertainty, namely, (1) the complexity of a river’s morphological structure and (2) the highly nonlinear dependence between probability of movement, pebble size and shape, and the stream’s flow rate. The performance of the two methods is extensively compared in terms of classification accuracy. The analyses show that despite the different perspectives, the overall performance is adequate and consistent, which suggests that both approaches can provide modeling frameworks for sediment transport. These data-driven approaches are also compared with physics-based ones that are classically used in the hydrological literature. Finally, the use of the developed models in a bottom-up strategy, which starts with the prediction/classification of a single pebble and then integrates the results into a forecast of the grain-size distribution of mobilized sediments, is discussed.
Hydrodynamic Green functions: paradoxes in unsteady Stokes conditions and infinite propagation velocity in incompressible viscous models
Authors: Giona Massimiliano , Procopio Giuseppe , Mauri Roberto
Published: March 2022

We present a simple representation of the hydrodynamic Green functions grounded on the free propagation of a vector field without any constraints (such as incompressibility) coupled with a gradient gauge in order to enforce these constraints. This approach involves the solution of two scalar problems: a couple of Poisson equations in the case of the Stokes regime, and a system of diffusion/Poisson equations for unsteady Stokes flows. The explicit and closed-form expression of the Green function for unsteady Stokes flow is developed. The relevance of this approach resides in its conceptual simplicity and it enables us to focus on the intrinsic singularities (Stokesian paradoxes) associated with the propagation of the stresses in incompressible flows under unsteady Stokes conditions, determining the occurrence of power-law tails in the velocity profile arbitrarily far away from the location of the impulsive force.
Energy dissipation in horizontally driven particle dampers of low acceleration intensities
Authors: Meyer Niklas , Seifried Robert
Published: March 2022

The energy dissipation in sinusoidally driven particle dampers is highly dependent on the motion mode of the particle bed. Especially, for applications of low acceleration intensity, i.e., acceleration amplitude below gravitational acceleration, only small energy dissipation rates are obtained so far, due to sticking of particles. Here, a new and more efficient design of particle dampers is introduced for such applications, whereby the focus is on horizontal vibrations. The proposed design makes use of the rolling property of spheres inside particle containers with flat bases. First, a cuboid container shape is studied. Two different motion modes are observed experimentally within this container shape. For low driving amplitudes, the particle bed is showing a scattered behavior resulting in a low damping efficiency. For high driving amplitudes instead, the rolling collect-and-collide state is observed resulting in much higher efficiency. Analytical descriptions for the energy dissipation are derived for both motion modes, being in good agreement with experimental measurements. It is obtained that the optimal working point of such dampers, i.e., the optimal stroke, is only depending on the filling ratio of the damper. Additionally, the optimal working point separates both motion modes. For lower strokes as the optimal one, the scattered state is observed, while for higher strokes the rolling collect-and-collide mode is seen. Sensitivity analyses are performed using the experimental setup and discrete element simulations. It is obtained that especially a low friction coefficient and a high particle radius are beneficial. On the other hand, a small tilt around the container’s longitudinal or pitch axis might significantly decrease the efficiency of the damper. Besides the cuboid container, the effect of a cylindrical container heading against gravity is analyzed. While the particle bed motion modes are only little influenced, the efficiency of the damper becomes independent of the excitation direction in the horizontal plane. Thus, such dampers could be applied to a large field of applications in mechanical and civil engineering.
Eucalyptus grandis AUX/INDOLE-3-ACETIC ACID 13 (EgrIAA13) is a novel transcriptional regulator of xylogenesis
Authors: Karannagoda Nadeeshani , Spokevicius Antanas , Hussey Steven , Cassan-Wang Hua , Grima-Pettenati Jacqueline , Bossinger Gerd
Published: March 2022

Key message

Our Induced Somatic Sector Analysis and protein–protein interaction experiments demonstrate that Eucalyptus grandis IAA13 regulates xylem fibre and vessel development, potentially via EgrIAA13 modules involving ARF2, ARF5, ARF6 and ARF19.

Auxin is a crucial phytohormone regulating multiple aspects of plant growth and differentiation, including regulation of vascular cambium activity, xylogenesis and its responsiveness towards gravitropic stress. Although the regulation of these biological processes greatly depends on auxin and regulators of the auxin signalling pathway, many of their specific functions remain unclear. Therefore, the present study aims to functionally characterise Eucalyptus grandis AUX/INDOLE-3-ACETIC ACID 13 (EgrIAA13), a member of the auxin signalling pathway. In Eucalyptus and Populus, EgrIAA13 and its orthologs are preferentially expressed in the xylogenic tissues and downregulated in tension wood. Therefore, to further investigate EgrIAA13 and its function during xylogenesis, we conducted subcellular localisation and Induced Somatic Sector Analysis experiments using overexpression and RNAi knockdown constructs of EgrIAA13 to create transgenic tissue sectors on growing stems of Eucalyptus and Populus. Since Aux/IAAs interact with Auxin Responsive Factors (ARFs), in silico predictions of IAA13-ARF interactions were explored and experimentally validated via yeast-2-hybrid experiments. Our results demonstrate that EgrIAA13 localises to the nucleus and that downregulation of EgrIAA13 impedes Eucalyptus xylem fibre and vessel development. We also observed that EgrIAA13 interacts with Eucalyptus ARF2, ARF5, ARF6 and ARF19A. Based on these results, we conclude that EgrIAA13 is a regulator of Eucalyptus xylogenesis and postulate that the observed phenotypes are likely to result from alterations in the auxin-responsive transcriptome via IAA13-ARF modules such as EgrIAA13-EgrARF5. Our results provide the first insights into the regulatory role of EgrIAA13 during xylogenesis.
Implementation of three efficient 4-digit fault-tolerant quantum carry lookahead adders
Authors: Orts Francisco , Ortega Gloria , Filatovas Ernestas , M. Garzón Ester
Published: March 2022

Adders are one of the most interesting circuits in quantum computing due to their use in major algorithms that benefit from the special characteristics of this type of computation. Among these algorithms, Shor’s algorithm stands out, which allows decomposing numbers in a time exponentially lower than the time needed to do it with classical computation. In this work, we propose three fault-tolerant carry lookahead adders that improve the cost in terms of quantum gates and qubits with respect to the rest of quantum circuits available in the literature. Their optimal implementation in a real quantum computer is also presented. Finally, the work ends with a rigorous comparison where the advantages and disadvantages of the proposed circuits against the rest of the circuits of the state of the art are exposed. Moreover, the information obtained from such a comparison is summarized in tables that allow a quick consultation to interested researchers.
How preparation-for-learning with a worked versus an open inventing problem affect subsequent learning processes in pre-service teachers
Authors: Glogger-Frey Inga , Treier Anne-Katrin , Renkl Alexander
Published: March 2022

A worked-out or an open inventing problem with contrasting cases can prepare learners for learning from subsequent instruction differently regarding motivation and cognition. In addition, such activities potentially initiate different learning processes during the subsequent (“future”) learning phase. In this experiment (N = 45 pre-service teachers), we aimed to replicate effects of earlier studies on learning outcomes and, on this basis, to analyze respective learning processes during the future-learning phase via think-aloud protocols. The inventing group invented criteria to assess learning strategies in learning journals while the worked-example group studied the same problem in a solved version. Afterwards, the pre-service teachers thought aloud during learning in a computer-based learning environment. We did not find substantial motivational differences (interest, self-efficacy), but the worked-example group clearly outperformed their counterparts in transfer (BF+0 > 313). We found moderate evidence for the hypothesis that their learning processes during the subsequent learning phase was deepened: the example group showed more elaborative processes, more spontaneous application of the canonical, but also of sub-optimal solutions than the inventing group (BFs around 4), and it tended to focus more on the most relevant learning contents. Explorative analyses suggest that applying canonical solutions to examples is one of the processes explaining why working through the solution leads to higher transfer. In conclusion, a worked-out inventing problem seems to prepare future learning more effectively than an open inventing activity by deepening and focusing subsequent learning processes.
The role of geological models and uncertainties in safety assessments
Authors: Bjorge Merle , Kreye Phillip , Heim Elisa , Wellmann Florian , Rühaak Wolfram
Published: March 2022

Safety assessments in nuclear waste management typically include the analysis of thermo-mechanical (TM)-coupled processes. The TM behavior of the host rock is, among other aspects, dependent on the prevalent geological geometry. This study aims to evaluate the impact of uncertainties in geometry on the TM rock behavior. It is one of the very first studies aiming to bring uncertainties of structural geological models and numerical simulations together. To analyze the influence of geological geometries, a simplified model of the region around the Mont Terri rock laboratory was created. A 3D structural geological model was set up and uncertainties of the lithological contacts were quantified by means of stochastic simulations, resulting in an ensemble of 89 model realizations. These realizations were transformed to a 2D numerical model. In this numerical model, TM simulations were computed over a simulation time of 500 years, employing the Finite Element Method. To simulate a heat source of nuclear waste, the lower edge of the model was set to 100 °C. The results of these simulations show mean temperature variations of 90.89 and 92.70 °C after 500 years, with a maximum stress varying between 0.02 and 0.16 MPa of elastic shear energy density and according mean cumulative displacements ranging from 30 to 38 cm. The presented results indicate that different model geometries and differences in material properties lead to noticeable variabilities of the TM behavior of claystone. However, in this case, these variabilities would not significantly affect the integrity of the rock.
Effects of external dynamic disturbances and structural plane on rock fracturing around deep underground cavern
Authors: Feng Fan , Chen Shaojie , Zhao Xingdong , Li Diyuan , Wang Xianlai , Cui Jiqiang
Published: March 2022

The occurrence of disasters in deep mining engineering has been confirmed to be closely related to the external dynamic disturbances and geological discontinuities. Thus, a combined finite-element method was employed to simulate the failure process of an underground cavern, which provided insights into the failure mechanism of deep hard rock affected by factors such as the dynamic stress-wave amplitudes, disturbance direction, and dip angles of the structural plane. The crack-propagation process, stress-field distribution, displacement, velocity of failed rock, and failure zone around the circular cavern were analyzed to identify the dynamic response and failure properties of the underground structures. The simulation results indicate that the dynamic disturbance direction had less influence on the dynamic response for the constant in situ stress state, while the failure intensity and damage range around the cavern always exhibited a monotonically increasing trend with an increase in the dynamic load. The crack distribution around the circular cavern exhibited an asymmetric pattern, possibly owing to the stress-wave reflection behavior and attenuation effect along the propagation route. Geological discontinuities significantly affected the stability of nearby caverns subjected to dynamic disturbances, during which the failure intensity exhibited the pattern of an initial increase followed by a decrease with an increase in the dip angle of the structural plane. Additionally, the dynamic disturbance direction led to variations in the crack distribution for specific structural planes and stress states. These results indicate that the failure behavior should be the integrated response of the excavation unloading effect, geological conditions, and external dynamic disturbances.
The Effect of Giving Credit to Social Enterprises: Evidence From Italy
Authors: Aktaş Koray , Barbetta Gian Paolo
Published: March 2022

We study how receiving credit from a social bank (Banca Prossima), created in 2008, has affected the economic performance of social enterprises in Italy in the following years. Social enterprises are key providers of welfare services in the country, but due to their legal status as not-for-profit organizations they have difficulty raising capital. Consequently, their growth is often very slow. Credit could replace capital, but not-for-profit organizations are often subject to credit constraints. Moreover, given that they cannot choose the optimal combination of credit and capital, the effect of credit on the economic performance of social enterprises is far from clear. We use a proprietary data set and a difference-in-differences approach to compare social enterprises that received credit from the social bank and those that did not receive it. The results suggest that receivers significantly increase their production, fixed assets, properties, and employment when they have access to new credit. The results are robust to several tests and an alternative identification strategy that combines matching and difference-in-differences methods.
The effect of energy density and porosity structure on tensile properties of 316L stainless steel produced by laser powder bed fusion
Authors: Cacace Stefania , Pagani Luca , Colosimo Bianca M. , Semeraro Quirico
Published: March 2022

Understanding the influence of process parameters and defect structure on the properties of parts produced via laser powder bed fusion (L-PBF) is a fundamental step towards the broader use of additive manufacturing technologies in critical applications. Furthermore, the ability to predict mechanical properties by simply considering information on the process parameters and defects observed via X-ray computer tomography (XCT) allows one to avoid expensive destructive testing, provide an in-depth understanding of the process quality and represents a viable solution towards process optimisation. Most of the previous works showed that energy density could be used as an excellent synthetic indicator to predict the mechanical properties of parts produced by L-PBF. This paper explores the effect of different energy density levels on the tensile properties of 316L stainless steel parts produced by L-PBF. Different from previous works in the literature, the same level of energy density is obtained considering various combinations of process parameters (speed, power and hatch distance). While energy density is shown to be a good synthetic indicator for predicting ultimate tensile strength (UTS) and yield strength (YS), a different behaviour is observed for elongation. Elongation shows a significant variability even when samples are produced at the same level of energy density, which contrasts with results obtained for UTS and YS. Synthetic indices representing the porosity structure are shown to be quite significant for predicting elongation even when the optimal energy density is considered. By combining process parameters with porosity structure, we show that almost a full prediction of the tensile properties can be achieved, paving the way for a significant reduction in expensive destructive tests.
Teaching machines to optimizing machining parameters: using independent fuzzy logic controller and image data
Authors: Mamledesai Harshavardhan , Zheng Yufan , Ahmad Rafiq
Published: March 2022

Optimization of machining parameters like cutting speed, feed, and depth of cut is one of the extensively studied fields in the past two decades. While researchers agree optimization of these parameters is essential, there is no conscience as to what the objective of the optimization should be. The studies consider production cost, production time, surface finish, among others, as the objective of parameter optimization, but there are very few studies that consider the manufacturer prescribed tool life as the criteria for parament optimization. Among the methods that do consider tool life as an optimization objective, very few are closed-loop systems and these systems are facing challenges to generalizing when the application changes or the machining material changes or the tool geometry changes. Considering this, a novel image feedback using a convolution neural network-based method combined with principles of fuzzy logic is used to optimize machining parameters. Since the system is based on online feedback from the images of the inserts, it can be used for different materials, and the system is invariant to the different tool geometries and grades as the decisions are based on the wear mechanisms detected. The hybrid system is validated through experimentation for the turning application, but the methodology can be easily adapted for other machining applications.
Evaluation of the National Health System Utilization Status of the Syrian Refugees in Turkey Between 2011 and 2017
Authors: Kinik Kerem , Koçak Hüseyin , Mayadağli Alpaslan
Published: March 2022

Background:

The objective of this study is to evaluate the status of the Syrian refugees (SR) in Turkey in terms of using the National Health System (NHS) between 2011 and 2017.

Methods:

The study is a descriptive and cross-sectional epidemiological research ORACLE SQL Developer program was used for data analysis, and frequency analyzes regarding the person, place, and time characteristics of the health services that SR received between 2011 and 2017 were presented.

Results:

The SRs benefited from NHS hospital services approximately 35 million times (34,973,029). Approximately 40% of the SRs that benefited from the NHS are under the age of 18. The proportion of those under 5 y old is 15.8%; 55.8% of the SRs that benefited from the NHS are women. The utilization status of the SRs from the NHS by region is as follows: 33.4% Mediterranean Region, 29.2% Southeastern Anatolia Region, and 19.0% Marmara Region. The types of health institutions that the SRs used are as follows: 44.0% state hospitals, 15.0% family medicine centers, and 13.3% training and research hospitals. A total of 16,009,524 cases were intervened as part of EMS.

Conclusion:

Syrian refugees in Turkey comprehensively benefited from primary, secondary, and tertiary health services free of charge between 2011 and 2017 in Turkey. It is seen that they have access to private and high-cost health services, such as air ambulance, cancer treatment, and dental treatment.
Delays and declines in seasonal influenza vaccinations due to Hurricane Harvey narrow annual gaps in vaccination by race, income and rurality
Authors: Carrel Margaret A. , Clore Gosia S. , Kim Seungwon , Goto Michihiko , Perencevich Eli N. , Sarrazin Mary Vaughan
Published: March 2022

Objective:

Temporal overlap of the Atlantic hurricane season and seasonal influenza vaccine rollout has the potential to result in delays or disruptions of vaccination campaigns. We documented seasonal influenza vaccination behavior over a 5-year period and explored associations between flooding following Hurricane Harvey and timing and uptake of vaccines, as well as how the impacts of Hurricane Harvey on vaccination vary by race, wealth, and rurality.

Design:

Retrospective cohort analysis.

Setting:

Texas counties affected by Hurricane Harvey.

Patients:

Active users of the Veterans’ Health Administration in 2017.

Methods:

We used geocoded residential address data to assess flood exposure status following Hurricane Harvey. Days to receipt of seasonal influenza vaccines were calculated for each year from 2014 to 2019. Proportional hazards models were used to determine how likelihood of vaccination varied according to flood status as well as the race, wealth, and rural–urban residence of patients.

Results:

The year of Hurricane Harvey was associated with a median delay of 2 weeks to vaccination and lower overall vaccination than in prior years. Residential status in flooded areas was associated with lower hazards of influenza vaccination in all years. White patients had higher proportional hazards of influenza vaccination than non-White patients, though this attenuated to 6.39% (hazard ratio [HR], 1.0639; 95% confidence interval [CI], 1.034–1.095) in the hurricane. year.

Conclusions:

Receipt of seasonal influenza vaccination following regional exposure to the effects of Hurricane Harvey was delayed among US veterans. White, non–low-income, and rural patients had higher likelihood of vaccination in all years of the study, but these gaps narrowed during the hurricane year.