bluuebunny/crossref_metadata_2025 huggingface dataset:
Comprehensive Cell Surface Antigen Analysis Identifies Transferrin Receptor Protein-1 (CD71) as a Negative Selection Marker for Human Neuronal Cells
Authors: Menon Vishal , Thomas Ria , Elgueta Claudio , Horl Marcus , Osborn Teresia , Hallett Penny J. , Bartos Marlene , Isacson Ole , Pruszak Jan
Published: August 2019

Cell state-, developmental stage-, and lineage-specific combinatorial expression of cluster of differentiation (CD) molecules enables the identification of cellular subsets via multicolor flow cytometry. We describe an exhaustive characterization of neural cell types by surface antigens, exploiting human pluripotent stem cell-derived neural cell systems. Using multiwell screening approaches followed by detailed validation of expression patterns and dynamics, we exemplify a strategy for resolving cellular heterogeneity in stem cell paradigms. In addition to providing a catalog of surface antigens expressed in the neural lineage, we identified the transferrin receptor-1 (CD71) to be differentially expressed in neural stem cells and differentiated neurons. In this context, we describe a role for N-Myc proto-oncogene (MYCN) in maintaining CD71 expression in proliferating neural cells. We report that in vitro human stem cell-derived neurons lack CD71 surface expression and that the observed differential expression can be used to identify and enrich CD71− neuronal derivatives from heterogeneous cultures. Stem Cells  2019;37:1293–1306
Engineered stem cells targeting multiple cell surface receptors in tumors
Authors: Kavari Sanam L. , Shah Khalid
Published: August 2019

Multiple stem cell types exhibit inherent tropism for cancer, and engineered stem cells have been used as therapeutic agents to specifically target cancer cells. Recently, stem cells have been engineered to target multiple surface receptors on tumor cells, as well as endothelial and immune cells in the tumor microenvironment. In this review, we discuss the rationales and strategies for developing multiple receptor-targeted stem cells, their mechanisms of action, and the promises and challenges they hold as cancer therapeutics.
MiR‐20b‐5p relieves neuropathic pain by targeting Akt3 in a chronic constriction injury rat model
Authors: You Haiping , Zhang Lihong , Chen Zhiyuan , Liu Weifeng , Wang Honggeng , He Hefan
Published: August 2019

Neuropathic pain is caused by somatosensory nervous system disorder which happens in patients with different diseases. Akt3 regulates innate immune function and plays a role in neuropathic pain pathogenesis in rats. MiR‐20b‐5p is a microRNA which has been suggested to inhibit Akt3 expression through directly targeting Akt3 mRNA. This research focused on miR‐20b‐5p function in neuropathic pain by Akt3 expression inhibition. Chronic constriction injury (CCI) was employed to induce neuropathic pain in rats. Paw withdrawal thresholds and paw withdrawal latency were examined to show neuropathic pain development. Expression levels of relative genes or microRNA were checked using qRT‐PCR and western blot. Inflammation cytokine levels were measured by enzyme‐linked immunosorbent assay kits. In CCI rat model, miR‐20b‐5p level was declined and Akt3 mRNA level was upregulated. MiR‐20b‐5p mimics suppressed the enhanced neuropathic pain, neuroinflammation, and Akt3 expression. MiR‐20b‐5p directly targeted Akt3 mRNA and downregulated the Akt3 expression in rat primary microglial cells. MiR‐20b‐5p inhibitory function in neuropathic pain was suppressed by the upregulation of Akt3 expression. This research illustrated that miR‐20b‐5p alleviated neuropathic pain through the inhibition of Akt3 expression in CCI rat model.
Associations among Fish Length, Dam Passage History, and Survival to Adulthood in Two At‐Risk Species of Pacific Salmon
Authors: Faulkner James R. , Bellerud Blane L. , Widener Daniel L. , Zabel Richard W.
Published: August 2019

Threatened or endangered salmon and steelhead originating in the Snake River basin must pass through a series of eight major hydroelectric dams during their seaward migration. Understanding the effects of specific dam passage routes on lifetime survival for these stocks is essential for successful management. Juvenile fish may pass these dams via three primary routes: (1) spillways, (2) turbines, or (3) juvenile bypass systems, which divert fish away from turbines and route them downstream. Bypass systems may expose fish to trauma, increased stress, or disease. However, numerous studies have indicated that direct survival through bypass systems is comparable to and often higher than that through spillways. Some researchers have suggested that the route of dam passage affects mortality in the estuary or ocean, but this is complicated by studies finding that fish size affects the route of passage. We tested whether passage through bypass systems was associated with the probability of adult return after accounting for fish length and other covariates for two species of concern. We also investigated the association between fish length and the probability of bypass at dams and how this relationship could lead to spurious conclusions regarding effects of bypass systems on survival if length is ignored. We found that (1) larger fish had lower bypass probabilities at six of seven dams; (2) larger fish had a higher probability of surviving to adulthood; (3) bypass history had little association with adult return after accounting for fish length; and (4) simulations indicated that spurious effects of bypass on survival may arise when no true bypass effect exists, especially in models without length. Our results suggest that after fish leave the hydropower system, bypass passage history has little effect on mortality. Our findings underscore the importance of accounting for fish size in studies of dam passage or survival.
Lie–Poisson Methods for Isospectral Flows
Authors: Modin Klas , Viviani Milo
Published: August 2019

The theory of isospectral flows comprises a large class of continuous dynamical systems, particularly integrable systems and Lie–Poisson systems. Their discretization is a classical problem in numerical analysis. Preserving the spectrum in the discrete flow requires the conservation of high order polynomials, which is hard to come by. Existing methods achieving this are complicated and usually fail to preserve the underlying Lie–Poisson structure. Here, we present a class of numerical methods of arbitrary order for Hamiltonian and non-Hamiltonian isospectral flows, which preserve both the spectra and the Lie–Poisson structure. The methods are surprisingly simple and avoid the use of constraints or exponential maps. Furthermore, due to preservation of the Lie–Poisson structure, they exhibit near conservation of the Hamiltonian function. As an illustration, we apply the methods to several classical isospectral flows.
The Sentiment Analysis of Tweets as a New Tool to Measure Public Perception of Male Erectile and Ejaculatory Dysfunctions
Authors: Sansone Andrea , Cignarelli Angelo , Ciocca Giacomo , Pozza Carlotta , Giorgino Francesco , Romanelli Francesco , Jannini Emmanuele A.
Published: August 2019

Introduction

Twitter is a social network based on “tweets,” short messages of up to 280 characters. Social media has been investigated in health care research to ascertain positive or negative feelings associated with several conditions but never in sexual medicine.

Aim

To assess perceptions related to erectile dysfunction (ED) and premature ejaculation (PE) among Twitter users.

Methods

Data collection was performed on a daily basis between May 24–October 9, 2018 (138 days) via an automated script. Data collection was then performed after data cleaning. The statistical software R and the rtweet packages were used in both phases.

Results

We collected 11,000 unique tweets for PE and 30,546 unique tweets for ED. After data cleaning, we analyzed 7,020 tweets on PE and 22,648 tweets on ED by analyzing the most recurring words and the clusters describing word associations. The most popular words for ED were “Treatment,” “Health,” and “Viagra,” whereas “Sex,” “Sexual,” and “Cure” were the top 3 for PE. Word clusters suggest the presence of some recurring themes, such as medical terms being grouped together. Additionally, tweets reflect the general feelings triggered by specific events, such as pieces of news pertaining to sexual dysfunctions.

Clinical Implications

Tweets on sexual dysfunctions are posted every day, with more tweets on ED than on PE. Treatment is among the chief topics discussed for both conditions, although health concerns differ between PE and DE tweets.

Strength and Limitations

This is the first analysis conducted on Tweets in the field of andrology and sexual medicine. A significant number of tweets were collected and analyzed. However, quantitative assessment of the sentiment was not feasible.

Conclusion

Sexual dysfunctions are openly discussed on social media, and Twitter analysis could help understand the needs and interests of the general population on these themes.
UF membrane technology from inge takes drinking water from nature to the customer's tap
Authors: Atkinson Simon
Published: August 2019

This article shows how fresh water from local watershed creeks in the mountains around the town of Los Gatos in California, USA, makes its way to customers’ taps in the greater San Jose area. It highlights the important role that Multibore® membranes from Germany's inge GmbH – a wholly owned subsidiary of BASF – are playing in supplying this water to residents living, and businesses operating, in the area.
An experimental-numerical method for transient infrared measurement of film cooling effectiveness and heat transfer coefficient in a single test
Authors: Holgate Nicholas E. , Ireland Peter T. , Romero Eduardo
Published: August 2019

An experimental technique for assessing film cooling performance is proposed which can determine both film effectiveness and heat transfer coefficient distributions from a single infrared experiment. First, the film effectiveness is determined in the experiment’s steady-state phase on a series of film-cooled nozzle guide vane leading edge geometries made of a low thermal conductivity foam. Then, the effectiveness is used to calculate the distribution of the transient phase driving gas temperatures, which is applied to a finite element conduction model. Heat transfer coefficients are guessed and iteratively refined until the surface temperature histories predicted by the finite element model match those which were experimentally observed. Unlike conventional methods based on one-dimensional analytical heat transfer solutions, this approach does not require assumptions about the material thickness underlying the test surface or the uniformity with depth of its initial temperature distribution. This relieves certain experimental constraints and reduces uncertainty in results.
What Should We Ask Reputation to Do?
Authors: Stephan Paul B.
Published: August 2019

Kristina Daugirdas's important new article prompts two kinds of responses. By providing a sophisticated analysis of the role of reputation in influencing the behavior of international actors, it invites further thoughts about what we might think reputation is and does. By taking a moral position—the UN should do more to reduce sexual abuse by UN-sponsored peacekeepers in conflict zones—she provokes us to consider how to optimize institutional design in light of particular goals. In this essay, I don't quarrel with anything she says. Rather, I will respond to her prompting. I will discuss methodological issues first, then normative ones.
The open-endedness of macroprudential policy. Endogenous risks as an obstacle to countercyclical financial regulation
Authors: Stellinga Bart
Published: August 2019

After the global financial crisis of 2007–9, policymakers hailed macroprudential policy as the solution to financial markets’ boom-bust patterns. Financial regulations would have to operate countercyclically, increasing in stringency during a boom while becoming lenient in a bust. Simultaneously, the procyclical effects of pre-crisis rules would have to be eliminated. Actual reforms, however, do not live up to these high hopes. In addition to the countercyclical policy framework's limited scope and ambition, its open-endedness is particularly striking. As policymakers have not specified when supervisors should (de)activate what instruments and how firms should measure risk, there is an inbuilt indeterminacy at macroprudential policy's core. I argue that obstacles inherent to the nature of systemic risk are key to understanding this policy outcome. As the financial system is reflexive, adaptive, and complex, there are hard limits to supervisors’ ability to “read” the financial cycle. Furthermore, as macroprudential policy itself becomes “part of financial markets,” countercyclical interventions may have systemically significant unintended consequences. This article empirically shows how policymakers at the global and EU level, confronted with these measurement and mitigation problems, ultimately opted for a limited and open-ended policy framework.
Pope Francis on Conscience, Gradualness, and Discernment: Adapting Amoris Laetitia for Business Ethics
Authors: Bernacchio Caleb
Published: August 2019

Experience often manifests a gap between moral principles that are both rationally defensible and widely accepted, and the actual practice of business. In this article, I adapt Pope Francis’s discussion of conscience, gradualness, and discernment, inAmoris Laetitia, for the philosophical context of business ethics in order to better conceptualize and to identify means of narrowing the gap between objective moral principles and business practice. Specifically, right conscience allows for a better understanding of the scope and boundary conditions of moral principles, gradualness highlights the need to identify ways that moral principles can be properly implemented within organizations, and discernment draws attention to the importance of solidarity, in order to avoid one-sided, self-serving action descriptions. In these ways, Francis’s discussion contributes to the narrowing of the gap between objective moral principles and business practice. I conclude by discussing ways that Francis’s framework can inform business ethics courses.
Barriers to Psychologists’ Adherence to Evidence-Based Practice Guidelines for Treating Musculoskeletal Injuries Within the State Insurance Regulatory Authority Compensation Schemes
Authors: Haider Tahira , Dunstan Debra A.
Published: August 2019

Objectives:

The use of evidence-based practice (EBP) guidelines by psychologists working within the State Insurance Regulatory Authority (SIRA) compensation schemes for treating musculoskeletal injuries has been found to vary. The aim of this study was to qualitatively explore psychologists’ perceived barriers to adhering with EBP guidelines implemented by the New South Wales (NSW) SIRA.

Methods:

Registered psychologists (n= 20) working within the NSW SIRA compensation schemes participated in four focus groups conducted face-to-face (F2F) and online. Participants’ responses were audiotaped, transcribed verbatim and entered into NVivo 11 software. Text data were analysed to identify recurrent themes within and across groups (metropolitan, regional and rural).

Results:

Thematic analysis revealed three key issues: (a) a lack of trust in the validity of the recommended EBP guidelines; (b) lack of knowledge of the psychologist’s role in this context and insufficient skills to fully apply the guidelines, protocols and procedures; and (c) a poor fit between EBP guidelines, client presentations and circumstances, and the SIRA compensation schemes.

Conclusion

The findings showed that both individual practitioner variables and contextual barriers influenced adherence to EBP. Practical implications for future research include generating recommendations to overcome the identified barriers using a collaborative approach between policymakers, researchers and practitioners.
When Wurst comes to Wurscht: Variation and koiné formation in Texas German
Authors: Lindemann Luke
Published: August 2019

Texas German is a new world language variety that shows some evidence of koiné development but also presents with substantial variation at many levels of structure. I present a case study on the variant pronunciation of sibilants in Texas German consonant clusters. This feature is fairly frequent and found throughout the regions of German settlement in Central Texas. After a discussion of the presence of this feature in the donor dialects, I investigate the factors that correlate with variation in the modern language. From an analysis of local and global spatial autocorrelation, I argue that variation is not significantly associated with particular geographic regions and is compatible with stable and homogenous variation. This provides insight into our understanding of new dialect emergence and the mechanisms by which dialect features are leveled over multiple generations.
Understanding node-link and matrix visualizations of networks: A large-scale online experiment
Authors: Ren Donghao , Marusich Laura R. , O’Donovan John , Bakdash Jonathan Z. , Schaffer James A. , Cassenti Daniel N. , Kase Sue E. , Roy Heather E. , Lin Wan-yi (Sabrina) , Höllerer Tobias
Published: August 2019

We investigated human understanding of different network visualizations in a large-scale online experiment. Three types of network visualizations were examined: node-link and two different sorting variants of matrix representations on a representative social network of either 20 or 50 nodes. Understanding of the network was quantified using task time and accuracy metrics on questions that were derived from an established task taxonomy. The sample size in our experiment was more than an order of magnitude larger (N = 600) than in previous research, leading to high statistical power and thus more precise estimation of detailed effects. Specifically, high statistical power allowed us to consider modern interaction capabilities as part of the evaluated visualizations, and to evaluate overall learning rates as well as ambient (implicit) learning. Findings indicate that participant understanding was best for the node-link visualization, with higher accuracy and faster task times than the two matrix visualizations. Analysis of participant learning indicated a large initial difference in task time between the node-link and matrix visualizations, with matrix performance steadily approaching that of the node-link visualization over the course of the experiment. This research is reproducible as the web-based module and results have been made available at: https://osf.io/qct84/.
Effect of temperature on post-diapause reproductive development in Listronotus maculicollis (Coleoptera: curculionidae)
Authors: Wu S. , Kostromytska O.S. , Koppenhöfer A.M.
Published: August 2019

The annual bluegrass weevil Listronotus maculicollis requires chilling exposure to terminate reproductive diapause during overwintering, but the effects of temperature on its post-diapause development in spring remain unclear. To explore this effect, overwintering adults were transferred from cold conditions (6°C/4°C, L:D 10:14) to different warm-up temperatures at L:D 12:12. When weevils were transferred to 7, 14 and 21°C in December and late January, the sizes of male and female reproductive organs were significantly smaller at 7°C than at 14 and 21°C. When weevils were transferred to 7, 9, 11, 13 and 15°C in late January, higher temperatures facilitated the post-diapause development. In both sexes, the sizes of reproductive organs and developmental rate increased with temperature. Reproductive organs did not grow significantly at 7°C in males and at 7–9°C in females, at which the percentage of developing weevils remained low. The time required for 50% of individuals to resume development was 44, 18, 13 and 8 days at 9, 11, 13 and 15°C, respectively, in males and 19, 14 and 8 days at 11, 13 and 15°C, respectively, in females. The threshold temperature for post-diapause development was 7.8°C in males, based on which 61.7 degree-days coincided with 50% of individuals developing. Under field conditions, the percentage of male and female maturity and insemination rate were low until early March, but all reached 100% by late March.
The Presence of the Dead among U.S. Protestants, 1800–1848
Authors: Seeman Erik R.
Published: August 2019

Historians have long known that antebellum American Protestants were fascinated by death, but they have overlooked Protestant relationships with the dead. Long before the advent of séance Spiritualism in 1848, many mourners began to believe—contrary to mainstream Protestant theology—that the souls of the dead turned into angels, that the dead could return to earth as guardian angels, and that in graveyards one could experience communion with the spirits of the departed. The version of Protestantism these mourners developed was therefore, to use Robert Orsi's term, a religion of “presence,” a religion in which suprahuman beings—in addition to God—played an important role. Based on diaries and popular sentimental literature written mostly by women, this article brings to light an unexplored facet of antebellum Protestant lived religion: that the dead were “present with us tho’ invisible,” as one young woman wrote about her deceased sister.
The Puzzling Path of a Recondite Text: The Composition, Circulation, and Reception of theNotícias Recônditasin Eighteenth-Century England
Authors: Vieira Carla
Published: August 2019

The so-calledNotícias Recônditas, an anonymous account written in the context of the negotiations that led to the suspension of Inquisition-related actions in Portugal between 1674 and 1681, has been approached by historiography principally from the points of view of its controversial authorship, its compositional framework, and even the accuracy of its contents. This article proposes a different perspective, focusing on its circulation and reception in the eighteenth-century England. Comparing different handwritten and printed versions of this text reveals numerous additions, transformations, and adaptations of its contents and structure, from its moment of composition until its publication and even afterwards. Eighteenth-century London, where anti-Catholic polemical literature was flourishing, is the place of publication of the first editions. There,Notíciaswas also appropriated by Anglican polemists with one main purpose in mind: attacking the Catholic Church. This, however, did not suit the text's original goals of making contributions to reforms to the Inquisition in Portugal and raising awareness for the New Christian cause. Therefore, identifying and analyzing the discrepancies among the different versions of the text give way to new questions concerning the intervention of copyists, translators, compilers, and publishers in order to achieve specific objectives and to reach target audiences.
A Homosocial Priesthood of All Believers: Laity and Gender in Interwar Sweden
Authors: Nykvist Martin
Published: August 2019

Around the turn of the twentieth century, there was a growing concern within the Church of Sweden that the church was, to a too large extent, managed by the clergy alone. In an attempt to give the laity a more active and influential role in the Church of Sweden, the Brethren of the Church was established in 1918. Since it was only possible for men to become members, the organization simultaneously addressed a different issue: the view that women had become a much too salient group in church life. This process was described by the Brethren and similar groups as a “feminization” of the church, a phrasing which later came to be used by historians and theologians to explain changes in Western Christianity in the nineteenth century. In other words, the Brethren considered questions of gender vital to their endeavor to create a church in which the laity held a more prominent position. This article analyzes how the perceived feminization and its assumed connection to secularization caused enhanced attempts to uphold and strengthen gender differentiation in the Church of Sweden in the early twentieth century. By analyzing an all-male lay organization, the importance of homosociality in the construction of Christian masculinities will also be discussed.
Automatic landmark discovery for learning agents under partial observability
Authors: Demіr Alper , Çіlden Erkіn , Polat Faruk
Published: August 2019

In the reinforcement learning context, a landmark is a compact information which uniquely couples a state, for problems with hidden states. Landmarks are shown to support finding good memoryless policies for Partially Observable Markov Decision Processes (POMDP) which contain at least one landmark. SarsaLandmark, as an adaptation of Sarsa(λ), is known to promise a better learning performance with the assumption that all landmarks of the problem are known in advance.

In this paper, we propose a framework built upon SarsaLandmark, which is able to automatically identify landmarks within the problem during learning without sacrificing quality, and requiring no prior information about the problem structure. For this purpose, the framework fuses SarsaLandmark with a well-known multiple-instance learning algorithm, namely Diverse Density (DD). By further experimentation, we also provide a deeper insight into our concept filtering heuristic to accelerate DD, abbreviated as DDCF (Diverse Density with Concept Filtering), which proves itself to be suitable for POMDPs with landmarks. DDCF outperforms its antecedent in terms of computation speed and solution quality without loss of generality.

The methods are empirically shown to be effective via extensive experimentation on a number of known and newly introduced problems with hidden state, and the results are discussed.
Temporal and spatial distribution of anthrax outbreaks among Kenyan wildlife, 1999–2017
Authors: Gachohi J. M. , Gakuya F. , Lekolool I. , Osoro E. , Nderitu L. , Munyua P. , Ngere I. , Kemunto N. , Bett B. , Otieno F. , Muturi M. , Mwatondo A. , Widdowson M. A. , Njenga M. Kariuki
Published: August 2019

The burden of anthrax in wildlife is demonstrated through high numbers of sudden mortalities among herbivore species, including endangered animal species. East Africa is home of multiple species of faunal wildlife numbering in the millions but there are limited disease surveillance programmes, resulting in a paucity of information on the role of anthrax and other infectious diseases on declining wildlife populations in the region. We reviewed historical data on anthrax outbreaks from Kenya Wildlife Service (KWS) spanning from 1999 to 2017 in Kenya to determine the burden, characteristics and spatial distribution of anthrax outbreaks. A total of 51 anthrax outbreaks associated with 1014 animal deaths were reported across 20 of 60 wildlife conservation areas located in six of the seven agro-ecological zones. Overall, 67% of the outbreaks were reported during the dry seasons, affecting 24 different wildlife species. Over 90% (22 of 24) of the affected species were herbivore, including 12 grazers, five browsers and five mixed grazers and browsers. Buffaloes (23.5%), black rhinos (21.6%) and elephants (17.6%) were the most frequently affected species. Our findings demonstrate the extensive geographic distribution of wildlife anthrax in the country, making it one of the important infectious diseases that threaten wildlife conservation.
Language and categorization in monolinguals and bilinguals
Authors: Fairchild Sarah , Papafragou Anna
Published: August 2019

People assume that objects labelled alike belong to the same category. Here we asked whether the role of labels in categorization depends on individuals' language experience, linguistic abilities, and/or cognitive abilities. We compared monolinguals' and bilinguals' use of phonologically licit words (zeg), illicit words (gsz), and non-linguistic frames (in addition to a baseline condition with no additional cues) in forming novel categories. For both groups, licit words affected categorization more than frames, especially in the absence of perceptual evidence for category boundaries; illicit words also shifted categorization preferences compared to frames. Furthermore, linguistic abilities predicted reliance on both licit and illicit words, and bilingualism predicted reliance on illicit words in categorization. Thus, in both monolinguals and bilinguals, novel (and even unconventional) linguistic labels act as unique category markers but their use in categorization depends on individual language processing skills (and, in some cases, exposure to a second language).
Measurement of the photon and thermal neutron doses of contralateral breast surface in breast cancer radiotherapy
Authors: Bagheri Hamed , Abedi Firouzjah Razzagh , Farhood Bagher
Published: August 2019

Introduction and purpose:

During the radiation therapy of tumoral breast, the contralateral breast (CB) will receive scattered doses. In the present study, the photon and thermal neutron dose values received by CB surface during breast cancer radiation therapy were measured.

Materials and methods:

The right breast region of RANDO phantom was considered as CB, and the measurements of photon and thermal neutron dose values were carried out on this region surface. The phantom was irradiated with 18 MV photon beams, and the dose values were measured with thermoluminescent dosimeter (TLD-600 and TLD-700) chips for 11 × 13, 11 × 17 and 11 × 21 cm2field sizes in the presence of physical and dynamic wedges.

Results:

The total dose values (photon + thermal neutron) received by the CB surface in the presence of physical wedge were 12·06%, 15·75% and 33·40% of the prescribed dose, respectively, for 11 × 13, 11 × 17 and 11 × 21 cm2field sizes. The corresponding dose values for dynamic wedge were 9·18%, 12·92% and 29·26% of the prescribed dose, respectively. Moreover, the results showed that treatment field size and wedge type affect the received photon and thermal neutron doses at CB surface.

Conclusion:

According to our results, the total dose values received at CB surface during breast cancer radiotherapy with high-energy photon beams are remarkable. In addition, the dose values received at CB surface when using a physical wedge were greater than when using a dynamic wedge, especially for medial tangential fields.
Hoch motiviert, engagiert und kompetent: Eine profilanalytische Untersuchung zur Studien- und Berufswahlmotivation von Lehramtsstudierenden
Authors: Biermann Antje , Dörrenbächer-Ulrich Laura , Grassmé Isabelle , Perels Franziska , Gläser-Zikuda Michaela , Brünken Roland
Published: August 2019

Zusammenfassung. Die Motivation zur Wahl des Lehramtsstudiums bzw. des Lehrerberufs und dabei besonders intrinsische Motive sind von großer Bedeutung für die Entwicklung professioneller Kompetenzen und das Handeln im Beruf. Mit Hilfe von personenzentrierten Ansätzen können Motivkombinationen identifiziert werden, die sich als (un-)günstig in Hinblick auf professionelle Kompetenzen (z. B. Professionswissen, Einstellungen und Überzeugungen, motivationale Merkmale wie Selbstwirksamkeitserwartungen und selbstreguliertes Lernen) erwiesen haben. In der vorliegenden Studie werden die Ergebnisse bisheriger Studien erweitert um den Einbezug handlungsbezogener Merkmale. In einer ersten Studie ( N = 801 Lehramtsstudierende) wurden drei Profile der Studien- und Berufswahlmotivation identifiziert. Es zeigen sich erwartungskonforme Unterschiede in Hinblick auf die Nutzung schulpraktischer Lerngelegenheiten sowie die Einschätzung des professionellen Verhaltens zugunsten der beiden Profile mit hohen Ausprägungen in den intrinsischen Aspekten im Vergleich zum Profil mit lediglich hohen Ausprägungen auf den extrinsischen Dimensionen. In der zweiten Studie wurden N = 89 Lehramtsstudierende den in Studie 1 identifizierten Profilen zugewiesen und hinsichtlich der videobasiert erfassten Unterrichtsqualität im ersten Schulpraktikum verglichen. Hier zeigen sich ebenfalls Vorteile für die intrinsisch motivierten Gruppen in den Dimensionen Klarheit und Strukturiertheit sowie Lernunterstützung. Die Ergebnisse aus profilanalytischen Studien können insbesondere für die Studieneingangs- und Verlaufsberatung genutzt werden.
Qualitätsmerkmale von Ganztagsangeboten aus der Perspektive der Schülerinnen und Schüler – Entwicklung und Validierung eines Fragebogens
Authors: Nowak Dennis , Ennigkeit Fabienne , Heim Christopher
Published: August 2019

Zusammenfassung. Wie Schülerinnen und Schüler die Qualität von Ganztagsangeboten (AGs) beurteilen, wurde bislang mithilfe von Merkmalen erfasst, die aus der empirischen Unterrichtsforschung bzw. der Sozialpädagogik abgeleitet sind. Dabei standen vornehmlich unterrichtsnahe Angebote im Mittelpunkt, wodurch die deutlich stärker nachgefragten freizeitbezogenen Angebote (z. B. aus dem Bereich Sport oder Musik) kaum berücksichtigt wurden. Im Rahmen des vorliegenden Beitrags wird mit der Skala zur Erfassung AG-spezifischer Qualitätsmerkmale (GAINS-AG-Skala) ein Instrument vorgestellt, mit dem die Qualität aller Angebotstypen im Rahmen des Ganztags erfasst werden kann. Die Ergebnisse aus insgesamt drei Studien ergeben, dass die 28 Items des Fragebogens die vier Faktoren Lernförderlichkeit, Interesse, pädagogische Unterstützung und Lerngemeinschaft abbilden, die sich auch an einer unabhängigen Stichprobe replizieren lassen. Zudem sprechen die Ergebnisse für Konstruktvalidität und Test-Retest-Reliabilität der Skala. Mit dem vorliegenden Beitrag wird nicht nur eine Anschlussfähigkeit an die aktuelle Debatte um Qualitätsmerkmale ganztägiger Angebote hergestellt, sondern mit den Subskalen Interesse und Lerngemeinschaft erfolgt auch eine Erweiterung des bisherigen Qualitätsverständnisses um zwei wesentliche Aspekte.
Modeling of a New Electron Acceleration Mechanism Ahead of Streamers
Authors: Ihaddadene Kevin M. A. , Dwyer Joseph R. , Liu Ningyu , Celestin Sebastien , Shi Feng
Published: August 2019

Head‐on collisions between negative and positive streamers have been proposed as a mechanism behind X‐ray emissions by laboratory spark discharges. Recent simulations using plasma fluid and particle in cell models of a single head‐on collision of two streamers of opposite polarities in ground pressure air predicted an insignificant number of thermal runaway electrons >1 keV and hence weak undetectable X‐ray emissions. Because the current available models of a single streamer collision failed to explain the observations, we first use a Monte Carlo model coupled with multiple static dielectric ellipsoids immersed in a subbreakdown ambient electric field as a description of multiple streamer environment and we investigate the ability of multiple streamer‐streamer head‐on collisions to accelerate runaway electrons >1 keV up to energies ∼200–300 keV instead of just one single head‐on collision. The results of simulations show that the streamer head‐on collision mechanism fails to accelerate electrons; instead, they decelerate in the positive streamer channel. In a second part, we use a streamer plasma fluid model to simulate a new streamer‐electron acceleration mechanism based on a collision of a large negative streamer with a small neutral plasma patch in different Laplacian electric fields |E0|= (35, 40, 45) kV/cm, respectively. We observe the formation of a secondary short propagating negative streamer with a strong peak electric field >250 up to 378 kV/cm over a time duration of ∼0.16 ns at the moment of the collision. The mechanism produces up to 106 runaway electrons with an upper energy limit of 24 keV.
An Experimental Study on Effect of Boundary Condition on Particle Damage in Shear Zone of Crushed Sand
Authors: Vafaei Nasrin , Fakharian Kazem , Sadrekarimi Abouzar
Published: August 2019

Various factors influence particle breakage in the shear zone of silica sands, including particle shape characteristics, loading path, shear displacement, normal load, initial density, and boundary conditions. The present study focuses on particle breakage occurring in the shear zone of a crushed silica sand under shear loading. Several ring shear tests were conducted to measure shear stress‐displacement response of a sand. Grain‐size distribution curves of the original sand (prior to shearing) and the sheared sand from the shear zone are then compared. The mechanism of particle breakage is determined by a thorough examination of particle damage under “constant normal load” and “constant volume” tests, considering both loose and dense samples. The results show that void ratio is the dominant factor in particle breakage. On the other hand, it is observed that particle breakage resulting from particle shape properties accrues within the initial loading stages. It is observed that the boundary condition also affects the magnitude of particle breakage; that is, particle damage under “constant normal load” boundary condition is found to be significantly higher than that under “constant volume” condition for the same initial normal stress and void ratio.
Offshore Spreading of Mississippi Waters: Pathways and Vertical Structure Under Eddy Influence
Authors: Androulidakis Yannis , Kourafalou Vassiliki , Le Hénaff Matthieu , Kang HeeSook , Sutton Tracey , Chen Shuangling , Hu Chuanmin , Ntaganou Nektaria
Published: August 2019

The three‐dimensional structure of the offshore export of Mississippi River (MR) waters is documented for the first time with in situ data. Numerical simulations and satellite data in the Gulf of Mexico (GoM) are also employed to study two pathways that were detected in summer of 2015, along the eastern and western sides of the Loop Current (LC). The initial formation of offshore branches was primarily due to the interaction of the anticyclonic LC and LC Eddy (which were close to the MR Delta and the Louisiana‐Texas shelf‐slope, respectively) with riverine waters that had been advected eastward by westerly winds (which reduced the westward buoyancy‐driven currents). The interaction of anticyclonic circulation patterns with cyclones (LC Frontal Eddies) was found to influence the dynamics and structure of the branches. Thickness variability and other vertical characteristics of the brackish plumes were investigated from their origin in the northern GoM through their extension in the Straits of Florida. In particular, offshore branch thickness increased near the LC and LC Frontal Eddy fronts. The two types of pathways revealed different factors contributing to the low‐salinity waters. Besides the MR input, precipitation contributed to the eastern pathway, while waters from additional northern GoM rivers contributed to the western pathway. The study offers new insights on the processes that control the formation and the offshore (southward) advection of low‐salinity waters. These processes have implications on the properties of waters hundreds of kilometers from the northern river sources, extending to the southern Gulf and the Straits of Florida.
Climate Response to Pulse Versus Sustained Stratospheric Aerosol Forcing
Authors: Duan Lei , Cao Long , Bala Govindasamy , Caldeira Ken
Published: August 2019

Solar geoengineering has been suggested as a potential means to counteract anthropogenic warming. Major volcanic eruptions have been used as natural analogues to large‐scale deployments of stratospheric aerosol geoengineering, yet difference in climate responses to these forcings remains unclear. Using the National Center for Atmospheric Research Community Earth System Model, we compare climate responses to two highly idealized stratospheric aerosol forcings that have different durations: a short‐term pulse representative of volcanic eruptions and a long‐term sustained forcing representative of geoengineering. For the same amount of global mean cooling, decreases in land temperature, precipitation, and runoff in the pulse case are much larger than that in the sustained case. The spatial pattern changes differ substantially between these two cases. Thus, direct extrapolations from volcanic eruption observations provide limited insight into impacts of potential stratospheric aerosol geoengineering. However, simulations of volcanic eruptions can be useful to test process representations in models that are used to simulate geoengineering deployments.
Different Sources of 10‐ to 30‐day Intraseasonal Variations of Autumn Snow over Western and Eastern Tibetan Plateau
Authors: Song Lei , Wu Renguang , An Lu
Published: August 2019

Using the latest daily Moderate Resolution Imaging Spectroradiometer satellite snow cover data, the present study reveals distinctly different sources of 10‐ to 30‐day intraseasonal snow cover variations over the western and eastern Tibetan Plateau (TP) during September–December. The intraseasonal snow variation over the western TP is related to a midlatitude wave train associated with the Arctic Oscillation and that over the eastern TP is related to a subtropical wave train triggered by the North Atlantic Oscillation. The Rossby wave train in both cases leads to anomalous water vapor convergence and ascending motion, which contributes to snow accumulation and positive snow cover anomalies. For the western TP snow events, the moisture comes from the Caspian Sea. During the eastern TP snow events, the moisture originates from the Bay of Bengal.
Choice of Irrigation Water Management Practice Affects Indian Summer Monsoon Rainfall and Its Extremes
Authors: Devanand Anjana , Huang Maoyi , Ashfaq Moetasim , Barik Beas , Ghosh Subimal
Published: August 2019

There is an emerging understanding toward the importance of land‐atmosphere interactions in the monsoon system, but the effects of specific land and water management practices remain unclear. Here, using regional process‐based experiments, we demonstrate that monsoon precipitation is sensitive to the choice of irrigation practices in South Asia. Experiments with realistic representation of unmanaged irrigation and paddy cultivation over north‐northwest India exhibit an increase in the late season terrestrial monsoon precipitation and intensification of widespread extreme events over Central India, consistent with changes in observations. Such precipitation changes exhibit substantially different spatial patterns in experiments with a well‐managed irrigation system, indicating that increase in unmanaged irrigation might be a factor driving the observed changes in the intraseasonal monsoon characteristics. Our findings stress the need for accurate representation of irrigation practices to improve the reliability of earth system modeling over South Asia.
All‐Sky Imaging Observations and Modeling of Bright 630‐nm Airglow Structures Associated With MSTIDs
Authors: Martinis C. , Yokoyama T. , Nishioka M.
Published: August 2019

An all‐sky imager at El Leoncito Observatory (−31.8°, 69.3°W, 18.2° magnetic latitude) is used to study 630.0‐nm airglow emissions related to medium‐scale traveling ionospheric disturbances (MSTIDs). On the night of 6 December 2007 an unusual event consisting of bright bands propagating northwestward was observed. Enhancements in total electron content from ground‐based Global Positioning System receivers were observed collocated with the bright airglow bands. A regional Global Positioning System‐derived total electron content map matches the direction of motion, scale size, and location of these bright bands. Model results including F region coupling with E region structures reproduce the characteristics of the bright bands. Specific conditions in the E region must exist in order to observe these unusual MSTIDs consisting of propagating bright bands only.
How Accurately Can We Model Magma Reservoir Failure With Uncertainties in Host Rock Rheology?
Authors: Zhan Y. , Gregg P. M.
Published: August 2019

Forecasting the onset of a volcanic eruption from a closed system requires understanding its stress state and failure potential, which can be investigated through numerical modeling. However, the lack of constraints on model parameters, especially rheology, may substantially impair the accuracy of failure forecasts. Therefore, it is essential to know whether large variations and uncertainties in rock properties will preclude the ability of models to predict reservoir failure. A series of two‐dimensional, axisymmetric models are used to investigate sensitivities of brittle failure initiation to assumed rock properties. The numerical experiments indicate that the deformation and overpressure at failure onset simulated by elastic models will be much lower than the viscoelastic models, when the timescale of pressurization exceeds the viscoelastic relaxation time of the host rock. Poisson's ratio and internal friction angle have much less effect on failure forecasts than Young's modulus. Variations in Young's modulus significantly affect the prediction of surface deformation before failure onset when Young's modulus is < 40 GPa. Longer precursory volcano‐tectonic events may occur in weak host rock (E < 40 GPa) due to well‐developed Coulomb failure prior to dike propagation. Thus, combining surface deformation with seismicity may enhance the accuracy of eruption forecast in these situations. Compared to large and oblate magma systems, small and prolate systems create far less surface uplift prior to failure initiation, suggesting that more frequent measurements are necessary.
Parametric Controls on Vegetation Responses to Biogeochemical Forcing in the CLM5
Authors: Fisher Rosie A. , Wieder William R. , Sanderson Benjamin M. , Koven Charles D. , Oleson Keith W. , Xu Chonggang , Fisher Joshua B. , Shi Mingjie , Walker Anthony P. , Lawrence David M.
Published: August 2019

Future projections of land carbon uptake in Earth System Models are affected by land surface model responses to both CO2 and nitrogen fertilization. The Community Land Model, Version 5 (CLM5), contains a suite of modifications to carbon and nitrogen cycle representation. Globally, the CLM5 has a larger CO2 response and smaller nitrogen response than its predecessors. To improve our understanding of the controls over the fertilization responses of the new model, we assess sensitivity to eight parameters pertinent to the cycling of carbon and nitrogen by vegetation, both under present‐day conditions and with CO2 and nitrogen fertilization. The impact of fertilization varies with both model parameters and with the balance of limiting factors (water, temperature, nutrients, and light) in the pre‐fertilization model state. The model parameters that impact the pre‐fertilization state are in general not the same as those that control fertilization responses, meaning that goodness of fit to present‐day conditions does not necessarily imply a constraint on future transient projections. Where pre‐fertilization state has low leaf area, fertilization‐induced increases in leaf production amplify the model response to the initial fertilization via further increases in photosynthesis. Model responses to CO2 and N fertilization are strongly impacted by how much plant communities can increase their rates of nitrogen fixation and also directly affected by costs of N extraction from soil and stoichiometric flexibility. Illustration of how parametric flexibility impacts model outputs should help inform the interpretation of carbon‐climate feedbacks estimated by in fully coupled Earth system model simulations.