bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coordinating scaffolds for collaborative inquiry in a game‐based learning environment
Authors: Saleh Asmalina , Yuxin Chen , Hmelo‐Silver Cindy E. , Glazewski Krista D. , Mott Bradford W. , Lester James C. 
Published: September 2020

AbstractCollaborative inquiry learning affords educators a context within which to support understanding of scientific practices, disciplinary core ideas, and crosscutting concepts. One approach to supporting collaborative science inquiry is through problem‐based learning (PBL). However, there are two key challenges in scaffolding collaborative inquiry learning in technology rich environments. First, it is unclear how we might understand the impact of scaffolds that address multiple functions (e.g., to support inquiry and argumentation). Second, scaffolds take different forms, further complicating how to coordinate the forms and functions of scaffolds to support effective collaborative inquiry. To address these issues, we identify two functions that needed to be scaffolded, the PBL inquiry cycle and accountable talk. We then designed predefined hard scaffolds and just‐in‐time soft scaffolds that target the regulation of collaborative inquiry processes and accountable talk. Drawing on a mixed method approach, we examine how middle school students from a rural school engaged with Crystal Island: EcoJourneys for two weeks (N=45). Findings indicate that hard scaffolds targeting the PBL inquiry process and soft scaffolds that targeted accountable talk fostered engagement in these processes. Although the one‐to‐one mapping between form and function generated positive results, additional soft scaffolds were also needed for effective engagement in collaborative inquiry and that these soft scaffolds were often contingent on hard scaffolds. Our findings have implications for how we might design the form of scaffolds across multiple functions in game‐based learning environments.
Flavour anomalies from a split dark sector
Authors: Darmé Luc , Fedele Marco , Kowalska Kamila , Sessolo Enrico Maria 
Published: August 2020

Abstract
We investigate solutions to the flavour anomalies in B decays based on loop diagrams of a “split” dark sector characterised by the simultaneous presence of heavy particles at the TeV scale and light particles around and below the B-meson mass scale. We show that viable parameter space exists for solutions based on penguin diagrams with a vector mediator, while minimal constructions relying on box diagrams are in strong tension with the constraints from the LHC, LEP, and the anomalous magnetic moment of the muon. In particular, we highlight a regime where the mediator lies close to the B-meson mass, naturally realising a resonance structure and a q2-dependent effective coupling. We perform a full fit to the relevant flavour observables and analyse the constraints from intensity frontier experiments. Besides new measurements of the anomalous magnetic moment of the muon, we find that decays of the B meson, Bs-mixing, missing energy searches at Belle-II, and LHC searches for top/bottom partners can robustly test these scenarios in the near future.
Extending low energy effective field theory with a complete set of dimension-7 operators
Authors: Liao Yi , Ma Xiao-Dong , Wang Quan-Yu 
Published: September 2020

Abstract
We present a complete and independent set of dimension-7 operators in the low energy effective field theory (LEFT) where the dynamical degrees of freedom are the standard model five quarks and all of the neutral and charged leptons. All operators are non-Hermitian and are classified according to their baryon (∆B) and lepton (∆L) numbers violated. Including Hermitian-conjugated operators, there are in total 3168, 750, 588, 712 operators with (∆B, ∆L) = (0, 0), (0, ±2), (±1, ∓1), (±1, ±1) respectively. We perform the tree-level matching with the standard model effective field theory (SMEFT) up to dimension-7 (dim-7) operators in both LEFT and SMEFT. As a phenomenological application we study the effective neutrino-photon interactions due to dim-7 lepton number violating operators that are induced and much enhanced at one loop from dim-6 operators that in turn are matched from dim-7 SMEFT operators. We compare various neutrino-photon scattering cross sections with their counterparts in the standard model and highlight the new features. Finally, we illustrate how these effective interactions could arise from ultraviolet completion.
Superexponential stabilizability of evolution equations of parabolic type via bilinear control
Authors: Alabau-Boussouira Fatiha , Cannarsa Piermarco , Urbani Cristina 
Published: August 2020

AbstractWe study the stabilizability of a class of abstract parabolic equations of the form $$\begin{aligned} u'(t)+Au(t)+p(t)Bu(t)=0,\qquad t\ge 0 \end{aligned}$$

u
′

(
t
)

+
A
u

(
t
)

+
p

(
t
)

B
u

(
t
)

=
0
,

t
≥
0

where the control $$p(\cdot )$$

p
(
·
)

is a scalar function, A is a self-adjoint operator on a Hilbert space X that satisfies $$A\ge -\sigma I$$

A
≥
-
σ
I

, with $$\sigma >0$$

σ
>
0

, and B is a bounded linear operator on X. Denoting by $$\{\lambda _k\}_{k\in {\mathbb {N}}^*}$$

{

λ
k

}

k
∈

N

∗

and $$\{\varphi _k\}_{j\in {\mathbb {N}}^*}$$

{

φ
k

}

j
∈

N

∗

the eigenvalues and the eigenfunctions of A, we show that the above system is locally stabilizable to the eigensolutions $$\psi _j={\mathrm{e}}^{-\lambda _j t}\varphi _j$$

ψ
j

=

e

-

λ
j

t

φ
j

with doubly exponential rate of convergence, provided that the associated linearized system is null controllable. Moreover, we give sufficient conditions for the pair $$\{A,B\}$$

{
A
,
B
}

to satisfy such a property, namely a gap condition for A and a rank condition for B in the direction $$\varphi _j$$

φ
j

. We give several applications of our result to different kinds of parabolic equations.
Determination of mono- and diacylglycerols from E 471 food emulsifiers in aerosol whipping cream by high-performance thin-layer chromatography–fluorescence detection
Authors: Oellig Claudia , Blankart Max , Hinrichs Jörg , Schwack Wolfgang , Granvogl Michael 
Published: August 2020

AbstractMono- and diacylglycerol (MAG and DAG) emulsifiers (E 471) are widely applied to regulate techno-functional properties in different food categories, for example, in dairy products. A method for the determination of MAG and DAG in aerosol whipping cream by high-performance thin-layer chromatography with fluorescence detection (HPTLC–FLD) after derivatization with primuline was developed. For sample preparation, aerosol whipping cream was mixed with ethanol, followed by the addition of water and liquid-liquid extraction with tert-butyl methyl ether. The sample extracts were analyzed by HPTLC–FLD on silica gel LiChrospher plates with n-pentane/n-hexane/diethyl ether (22.5:22.5:55, v/v/v) as mobile phase, when interfering matrix like cholesterol and triacylglycerols were successfully separated from the E 471 food additives. For quantitation, an emulsifier with known composition was used as calibration standard and the fluorescent MAG and DAG were scanned at 366/> 400 nm. Limits of detection and quantitation of 4 and 11 mg/100 g aerosol whipping cream were obtained for both monostearin and 1,2-distearin, respectively, and allowed the reliable quantitation of MAG and DAG from E 471 far below commonly applied emulsifier amounts. Recoveries from model aerosol whipping cream with 400 mg E 471/100 g were determined in a calibration range of 200–600 mg E 471/100 g sample and ranged between 86 and 105% with relative standard deviations below 7%. In aerosol whipping creams from the German market, E 471 amounts ranged between 384 and 610 mg/100 g.
Inconsistency evaluation in pairwise comparison using norm-based distances
Authors: Fedrizzi Michele , Civolani Nino , Critch Andrew 
Published: August 2020

AbstractThis paper studies the properties of an inconsistency index of a pairwise comparison matrix under the assumption that the index is defined as a norm-induced distance from the nearest consistent matrix. Under additive representation of preferences, it is proved that an inconsistency index defined in this way is a seminorm in the linear space of skew-symmetric matrices and several relevant properties hold. In particular, this linear space can be partitioned into equivalence classes, where each class is an affine subspace and all the matrices in the same class share a common value of the inconsistency index. The paper extends in a more general framework some results due, respectively, to Crawford and to Barzilai. It is also proved that norm-based inconsistency indices satisfy a set of six characterizing properties previously introduced, as well as an upper bound property for group preference aggregation.
Screening for HIV-Associated Neurocognitive Disorder (HAND) in Adults Aged 50 and Over Attending a Government HIV Clinic in Kilimanjaro, Tanzania. Comparison of the International HIV Dementia Scale (IHDS) and IDEA Six Item Dementia Screen
Authors: Kellett-Wright Johanna , Flatt Aidan , Eaton Patrick , Urasa Sarah , Howlett William , Dekker Marieke , Kisoli Aloyce , Duijinmaijer Ashanti , Thornton Jessica , McCartney Judith , Yarwood Vanessa , Irwin Charley , Mukaetova-ladinska Elizabeta , Akinyemi Rufus , Lwezuala Bingileki , Gray William K. , Walker Richard W. , Dotchin Catherine L. , Makupa Philip , Paddick Stella-Maria 
Published: September 2020

AbstractValidated screening tools for HIV-associated neurocognitive disorders (HAND) are lacking for the newly emergent ageing population of people living with HIV (PLWH) in sub-Saharan Africa (SSA). We aimed to validate and compare diagnostic accuracy of two cognitive screening tools, the International HIV dementia scale (IHDS), and the Identification and Interventions for Dementia in Elderly Africans (IDEA) screen, for identification of HAND in older PLWH in Tanzania. A systematic sample of 253 PLWH aged ≥ 50 attending a Government clinic in Tanzania were screened with the IHDS and IDEA. HAND were diagnosed by consensus American Academy of Neurology (AAN) criteria based on detailed clinical neuropsychological assessment. Strict blinding was maintained between screening and clinical evaluation. Both tools had limited diagnostic accuracy for HAND (area under the receiver operating characteristic (AUROC) curve 0.639–0.667 IHDS, 0.647–0.713 IDEA), which was highly-prevalent (47.0%). Accurate HAND screening tools for older PLWH in SSA are needed.
Persistence codebooks for topological data analysis
Authors: Zieliński Bartosz , Lipiński Michał , Juda Mateusz , Zeppelzauer Matthias , Dłotko Paweł 
Published: September 2020

AbstractPersistent homology is a rigorous mathematical theory that provides a robust descriptor of data in the form of persistence diagrams (PDs) which are 2D multisets of points. Their variable size makes them, however, difficult to combine with typical machine learning workflows. In this paper we introduce persistence codebooks, a novel expressive and discriminative fixed-size vectorized representation of PDs that adapts to the inherent sparsity of persistence diagrams. To this end, we adapt bag-of-words, vectors of locally aggregated descriptors and Fischer vectors for the quantization of PDs. Persistence codebooks represent PDs in a convenient way for machine learning and statistical analysis and have a number of favorable practical and theoretical properties including 1-Wasserstein stability. We evaluate the presented representations on several heterogeneous datasets and show their (high) discriminative power. Our approach yields comparable—and partly even higher—performance in much less time than alternative approaches.
A Systematic Review of Parental Involvement in Cognitive Behavioural Therapy for Adolescent Anxiety Disorders
Authors: Cardy Jessica Louise , Waite Polly , Cocks Francesca , Creswell Cathy 
Published: August 2020

AbstractAnxiety disorders are common among adolescents and lead to poor long-term outcomes. Cognitive Behavioural Therapy (CBT) is an evidenced-based intervention for adolescent anxiety disorders, but little is known about whether and how parents should be involved. This systematic review evaluated how parents have been involved and associated treatment outcomes in studies of CBT for adolescent anxiety disorders. Electronic systematic searches were conducted in PsycINFO, Embase, CINAHL, Medline, AMED databases, to identify studies investigating CBT for adolescent anxiety disorder(s) that included parents in treatment. Twenty-three papers were identified. Parents were involved in treatment in a number of different ways: by attending separate parent sessions, joint parent–adolescent sessions, or both, or through provision of a workbook while attending some adolescent sessions. Content varied but was most typically aimed at the parent developing an understanding of core CBT components and skills to help them manage their adolescent’s anxiety and avoidance. Treatment outcomes indicate that CBT with parental involvement is an effective intervention for adolescent anxiety disorders; however, it is not possible to draw conclusions regarding whether parental involvement (generally or in any particular form) enhances treatment outcomes. Poor reporting and methodological issues also limit the conclusions. Further research is required to identify whether there are particular types of parental involvement in CBT that bring clinical benefits to adolescents with anxiety disorders generally, as well as in particular circumstances.
On the Spherical Quasi-convexity of Quadratic Functions on Spherically Subdual Convex Sets
Authors: Ferreira Orizon Pereira , Németh Sándor Zoltán , Xiao Lianghai 
Published: September 2020

AbstractIn this paper, the spherical quasi-convexity of quadratic functions on spherically subdual convex sets is studied. Sufficient conditions for spherical quasi-convexity on spherically subdual convex sets are presented. A partial characterization of spherical quasi-convexity on spherical Lorentz sets is given, and some examples are provided.
Do Higher Educated People Feel Better in Everyday Life? Insights From a Day Reconstruction Method Study
Authors: Möwisch Dave , Brose Annette , Schmiedek Florian 
Published: September 2020

AbstractPast research has shown a positive association between education and well-being. Much of this research has focused on the cognitive component of well-being (i.e., life satisfaction) as outcome. On the other hand, the affective component, that is, how often and intensively people experience positive affect (PA) and negative affect (NA) in their everyday lives, has received far less attention. Therefore, we examined the association between education and PA and NA in everyday life, with a particular focus on affective experiences at the sub-facet level (based on a structure of NA with multiple factors). We used data from a nationally representative sample (N = 1647) of the German Socioeconomic Panel Innovation Sample (SOEP-IS), employing the Day Reconstruction Method (DRM) to capture affective experiences of everyday activities. Multilevel structural equation models revealed that (1) education was not related to PA, but (2) was positively associated with two sub-facets of NA (mourning/worries and loneliness/boredom); (3) income might in part explain the association between education and NA; (4) education does not particularly seem to serve as a resource in times of unemployment or retirement (i.e., there were no interactions between education and unemployment/retirement regarding well-being) In essence, higher educated people reported fewer negative emotions in everyday life than their lower educated counterparts, but not more positive emotions. The findings underline that different facets of NA, in addition to life satisfaction, are relevant variables related to education and should receive more attention in order to gain a more comprehensive understanding of non-monetary correlates of education.
Example-based learning: should learners receive closed-book or open-book self-explanation prompts?
Authors: Hiller Sara , Rumann Stefan , Berthold Kirsten , Roelle Julian 
Published: September 2020

AbstractIn learning from examples, students are often first provided with basic instructional explanations of new principles and concepts and second with examples thereof. In this sequence, it is important that learners self-explain by generating links between the basic instructional explanations’ content and the examples. Therefore, it is well established that learners receive self-explanation prompts. However, there is hardly any research on whether these prompts should be provided in a closed-book format—in which learners cannot access the basic instructional explanations during self-explaining and thus have to retrieve the main content of the instructional explanations that is needed to explain the examples from memory (i.e., retrieval practice)—or in an open-book format in which learners can access the instructional explanations during self-explaining. In two experiments, we varied whether learners received closed- or open-book self-explanation prompts. We also varied whether learners were prompted to actively process the main content of the basic instructional explanations before they proceeded to the self-explanation prompts. When the learners were not prompted to actively process the basic instructional explanations, closed-book prompts yielded detrimental effects on immediate and delayed (1 week) posttest performance. When the learners were prompted to actively process the basic instructional explanations beforehand, closed-book self-explanation prompts were not less beneficial than open-book prompts regarding performance on a delayed posttest. We conclude that at least when the retention interval does not exceed 1 week, closed-book self-explanation prompts do not entail an added value and can even be harmful in comparison to open-book ones.
Discussing God: The Effect of (Ir)Religious Identities on Topic-Sentiment Polarization in Online Debates
Authors: Grigoropoulou Nikolitsa 
Published: August 2020

Amidst growing societal tensions, social media platforms become hubs of heated intergroup exchanges. According to social identity theory, group membership and the value we assign to it drive the expression of intergroup bias. Within the blooming scholarship on social and political polarization online, little attention has been paid to interreligious deliberations, despite the well-established relationship between religion and intergroup grievances. The present studies are designed to address the void in the scholarship of social identity and online religion by examining how religious identities, or the lack thereof, affect intergroup biases in the form of identity-specific topic preferences and topic-sentiment polarization. Drawing from social identity theory, five hypotheses were tested. The data for the study, a product of a natural experiment, are YouTube commentary sections featuring videos on two cases of interreligious debates between (1) Christian and Muslim or (2) Christian and atheist speakers. Using topic-sentiment analysis, a multistage method of topic modeling with latent semantic analysis and sentiment analysis, 24,179 comments, for the Christian–Muslim debates, and 52,607 comments, for the Christian–atheist debates, were analyzed. The results demonstrate normative content and identity-specific instances of topic-sentiment polarization. In terms of content, Christian–Muslim and Christian–atheist discussions are nearly completely preoccupied with theological or intellectual concepts. While interreligious polarization is robust in both debates, it appears more normative among Christians–Muslims and deeper among Christians–atheists, possibly indicating the higher stakes in the battle for moral authority. Interreligious debates on YouTube serve to uplift and defend the in-group and to delegitimize the outgroup in a broader battle for moral authority. Regardless of group affiliation, these debaters were concerned with ‘big picture’ questions of meaning and how best to address them. Stereotyping and cultural altercations appear mostly as a reaction to challenged identity characteristics, suggesting that issue-based social differences and cultural incompatibilities, often emphasized in self-report research, may be evoked as rationalizations of interreligious prejudice. Last, the successful application of topic-sentiment analysis lends support for the more systematic utilization of this method.
Influence of lubrication, tool steel composition, and topography on the high temperature tribological behaviour of aluminium
Authors: Decrozant-Triquenaux Justine , Pelcastre Leonardo , Prakash Braham , Hardell Jens 
Published: September 2020

AbstractThe use of high strength aluminium alloys, such as 6XXX and 7XXX series, is continuously increasing for automotive applications in view of their good strength-to-weight ratio. Their formability at room temperature is limited and they are thus often formed at high temperatures to enable production of complex geometries. Critical challenges during hot forming of aluminium are the occurrence of severe adhesion and material transfer onto the forming tools. This negatively affects the tool life and the quality of the produced parts. In general, the main mechanisms involved in the occurrence of material transfer of aluminium alloys at high temperature are still not clearly understood. Therefore, this study is focussed on understanding of the friction and wear behaviour during interaction of Al6016 alloy and three different tool steels in as-received and polished state. The tribotests were carried out under dry and lubricated conditions, with two distinct lubricants, using a reciprocating friction and wear tester. The worn surfaces were analysed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results showed a high dependence of friction and wear behaviour on the tool steel roughness as well as on the stability of the lubricant films. Tribolayers were found to develop in the contact zone and their capacity to improve the tribological behaviour is seen to be drastically impacted by the surface roughness of the tool steel. When the tribolayers failed, severe adhesion took place and led to high and unstable friction as well as material transfer to the tool steel.
Investigation of tribological characteristics of nickel alloy-based solid-lubricating composites at elevated temperatures under vacuum
Authors: Zhen Jinming , Cheng Jun , Tan Hui , Sun Qichun , Zhu Shengyu , Yang Jun , Liu Weimin 
Published: September 2020

AbstractThe development of a high-performance solid-lubricating composite with excellent self-lubricity over a broad temperature range in vacuum is significant to solve the frictional problems of spatial mechanisms. In this study, the vacuum tribological behaviors of nickel-matrix/Ag/(Ca, Ba)F2/graphite (0–2 wt%) composites were studied from 25 to 800 °C. The results show that the synergistic effects of solid lubricants can significantly improve the tribological properties of the composites in vacuum, with the graphite content contributing considerably. For 2 wt% graphite, a low friction coefficient (0.14–0.25) and the lowest wear rate ((0.12−4.78)×10−5 mm3·N−1·m−1) were observed in vacuum over the entire testing temperature range. Moreover, the wear mechanisms were clarified via analysis of the chemical composition and morphologies of the sliding surfaces.