bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of highly soluble wholly aromatic polyamides containing both furanyl and phenyl units
Authors: Yu Zuolong , Deng Ru , Rao Guiwei , Lu Yanyu , Wei Yunxiao , Fu Changchun , Yan Xiaoping , Cao Fei , Zhang Deyong 
Published: July 2020

AbstractThis paper presents the synthesis and characterization of two series of polymeric compounds comprising eight furan‐based polyamides prepared via melt polycondensation at low temperatures using various combinations of five aromatic raw materials. The chemical and physical structures and thermal stabilities of the obtained polyamides were investigated by various characterization methods. In addition, the polyamides were subjected to solubility testing in five common organic solvents. The results showed that the proposed furan‐based polyamides possessed thermal stabilities similar to those of conventional high‐performance aromatic polyamides, but with greatly improved solubility. Accordingly, the introduction of furan groups increased the solubility of the polyamides with respect to the solubility of their individual precursors, which is highly advantageous for subsequent polyamide processing and expanding their range of potential applications.
Minimality and identifiability of discrete‐time switched autoregressive exogenous systems
Authors: Petreczky M. , Bako L. , Lecoeuche S. , Motchon K. M. D. 
Published: July 2020

SummaryThis article studies the problem of minimality and identifiability for switched autoregressive exogenous (SARX) systems. We propose formal definitions of the concepts of identifiability and minimality for SARX models. Based on these formalizations, we derive conditions for minimality and identifiability of SARX systems. In particular, we show that polynomially parameterized SARX systems are generically identifiable.
Analysis of robustness of homogeneous systems with time delays using Lyapunov‐Krasovskii functionals
Authors: Efimov D. , Aleksandrov A. 
Published: July 2020

SummaryThis article is devoted to stability analysis of homogeneous time‐delay systems applying the Lyapunov‐Krasovskii theory, and a generic structure of the functional is given that suits for any homogeneous system of nonzero degree (and can also be used for any dynamics admitting a homogeneous approximation). The obtained stability conditions are utilized to evaluate the domain of attraction for the delayed twisting control algorithm.
Comparing publicly available databases to evaluate soil organic carbon in Maine, USA
Authors: Bai Xue , Fernandez Ivan J. 
Published: July 2020

AbstractElevated greenhouse gas (GHG) emissions have resulted in growing societal interest in natural climate solutions that include enhancing soil organic carbon (SOC). This study evaluated SOC from three USDA soil databases for Maine, a state that is nearly 90% forested. These databases were: (1) Forest Inventory and Analysis (FIA), (2) NRCS Soil Survey Geographic (SSURGO), and (3) Rapid Carbon Assessment (RaCA). We compared estimates of SOC density and concentration among databases and analyzed relationships between key soil properties and SOC densities and concentrations. Estimates of SOC density to a 20 cm depth which allows comparison among all three databases were 77 ± 1.2 Mg ha−1, 95 ± 0.3 Mg ha−1, and 39 ± 2.2 Mg ha−1 for SSURGO, RaCA, and FIA, respectively. Significant differences existed among databases in SOC density at shallow depth increments, and marked differences existed among databases in the soil depths measured. Analysis of the influence of soil texture and drainage class on SOC highlighted the importance of silt and clay in SOC retention. A hypothetical increase in forest and agricultural SOC was compared to reported Maine GHG emissions to illustrate potential policy implications in the use of soil databases. We conclude that all three databases are valuable but not interchangeable. The database should be carefully chosen to match the objectives of the user.
Factors that foster and deter STEM professional development among teachers
Authors: Affouneh Saida , Salha Soheil , Burgos Daniel , Khlaif Zuheir N. , Saifi Abdel G. , Mater Naela , Odeh Ahmed 
Published: July 2020

AbstractThe present study seeks to identify teachers' perceptions regarding STEM teaching professional development and to identify the factors that facilitate or hinder the success of teachers' professional development. The participants of the study were 35 teachers. A qualitative approach was used for data collection by conducting semistructured interviews with 11 teachers out of 35. All the participants were involved in the three focus group sessions. The findings of the study revealed that teachers have various perceptions toward the STEM professional development based on their experience, knowledge, and skills. Moreover, the study revealed different factors influencing STEM professional development among teachers including personal characteristics and internal factors including attitudes and beliefs toward STEM professional development activities, and teachers' capacity. Also, external factors such as design of the training program, availability of training material, and timing of training. The findings of the study could benefit the decision‐makers to be aware about these factors that influence professional development and the teachers' needs.
Sensitivity analysis of treatment effect to unmeasured confounding in observational studies with survival and competing risks outcomes
Authors: Huang Rong , Xu Ronghui , Dulai Parambir S. 
Published: July 2020

No unmeasured confounding is often assumed in estimating treatment effects in observational data, whether using classical regression models or approaches such as propensity scores and inverse probability weighting. However, in many such studies collection of confounders cannot possibly be exhaustive in practice, and it is crucial to examine the extent to which the resulting estimate is sensitive to the unmeasured confounders. We consider this problem for survival and competing risks data. Due to the complexity of models for such data, we adapt the simulated potential confounder approach of Carnegie et al (2016), which provides a general tool for sensitivity analysis due to unmeasured confounding. More specifically, we specify one sensitivity parameter to quantify the association between an unmeasured confounder and the exposure or treatment received, and another set of parameters to quantify the association between the confounder and the time‐to‐event outcomes. By varying the magnitudes of the sensitivity parameters, we estimate the treatment effect of interest using the stochastic expectation‐maximization (EM) and the EM algorithms. We demonstrate the performance of our methods on simulated data, and apply them to a comparative effectiveness study in inflammatory bowel disease. An R package “survSens” is available on CRAN that implements the proposed methodology.
Conductive Metal–Organic Frameworks: Design, Synthesis, and Applications
Authors: Meng Haibing , Han Ying , Zhou Chenhui , Jiang Qinyuan , Shi Xiaofei , Zhan Chenhao , Zhang Rufan 
Published: July 2020

AbstractMetal–organic frameworks (MOFs) have aroused worldwide interest over the last two decades due to their various excellent properties, such as porosity, modifiability, stability, etc. Based on these unique features, they have been widely exploited for applications from electrocatalysis to electrochemical devices. However, most MOFs are inherently insulated due to the lack of free charge carriers and low‐energy barriers for charge transfer, which largely restricts their further electrochemical applications. By imparting MOFs with electrical conductivity, their electrochemical process and catalysis efficiency can be effectively improved. Similarly, their applications in sensors, secondary batteries, electrochemical devices, etc., can be well developed. Over the past few years, many conductive MOFs have been constructed by formatting composite, postsynthesized modification, introducing guest molecules, etc. Meanwhile, their electrochemical applications depending on their good conductivity have been investigated detailedly. However, it remains a challenge to endow most MOFs with high conductivity due to the tedious synthesis process and weak charge transfer properties of MOFs. In this review, the latest designs and synthesis strategies of conductive MOFs as well as their conductive mechanisms are summarized. The direct/postsynthesis methods are mainly focused for constructing conductive MOFs. In addition, their applications in sensors, energy conversion, electronics, etc., are also introduced.
Isatidis Folium alleviates acetaminophen‐induced liver injury in mice by enhancing the endogenous antioxidant system
Authors: Ding Chuan‐Hua , Zhu He 
Published: July 2020

AbstractIsatidis Folium (IF) has been clinically combined with acetaminophen (APAP), but the rationality of combinational therapy is still ambiguous. In the present study, the protective effect and related mechanism of IF on APAP‐induced hepatotoxicity were evaluated. Hepatic histopathology and blood biochemistry investigations clearly demonstrated that IF could restore APAP‐induced hepatotoxicity. Liver distribution study indicated that the hepatoprotective effect of IF on APAP is attributed to the reduction of N‐acetyl‐p‐benzoquinone imine (NAPQI) in liver, which is a known hepatotoxic metabolite of APAP. Further study suggested the reduction is not via decreasing the generation of NAPQI through inhibiting the enzyme activities of CYP 1A2, 2E1, and 3A4 but via accelerating the transformation of NAPQI to NAPQI‐GSH by promoting GSH and decreasing GSSG contents in liver. Furthermore, IF significantly enhanced the hepatic activities of GSH‐associated enzymes in APAP‐treated mice. In summary, IF could alleviate APAP‐induced hepatotoxicity by reducing the content of NAPQI via enhancing the level of GSH and the followed generation of NAPQI‐GSH which might be ascribed to the upregulation of GSH‐associated enzymes.
Multimodel validation of single wakes in neutral and stratified atmospheric conditions
Authors: Doubrawa Paula , Quon Eliot W. , Martinez‐Tossas Luis A. , Shaler Kelsey , Debnath Mithu , Hamilton Nicholas , Herges Thomas G. , Maniaci Dave , Kelley Christopher L. , Hsieh Alan S. , Blaylock Myra L. , van der Laan Paul , Andersen Søren Juhl , Krueger Sonja , Cathelain Marie , Schlez Wolfgang , Jonkman Jason , Branlard Emmanuel , Steinfeld Gerald , Schmidt Sascha , Blondel Frédéric , Lukassen Laura J. , Moriarty Patrick 
Published: July 2020

AbstractPrevious research has revealed the need for a validation study that considers several wake quantities and code types so that decisions on the trade‐off between accuracy and computational cost can be well informed and appropriate to the intended application. In addition to guiding code choice and setup, rigorous model validation exercises are needed to identify weaknesses and strengths of specific models and guide future improvements. Here, we consider 13 approaches to simulating wakes observed with a nacelle‐mounted lidar at the Scaled Wind Technology Facility (SWiFT) under varying atmospheric conditions. We find that some of the main challenges in wind turbine wake modeling are related to simulating the inflow. In the neutral benchmark, model performance tracked as expected with model fidelity, with large‐eddy simulations performing the best. In the more challenging stable case, steady‐state Reynolds‐averaged Navier–Stokes simulations were found to outperform other model alternatives because they provide the ability to more easily prescribe noncanonical inflows and their low cost allows for simulations to be repeated as needed. Dynamic measurements were only available for the unstable benchmark at a single downstream distance. These dynamic analyses revealed that differences in the performance of time‐stepping models come largely from differences in wake meandering. This highlights the need for more validation exercises that take into account wake dynamics and are able to identify where these differences come from: mesh setup, inflow, turbulence models, or wake‐meandering parameterizations. In addition to model validation findings, we summarize lessons learned and provide recommendations for future benchmark exercises.
Word problems for finite nilpotent groups
Authors: Camina Rachel D. , Iñiguez Ainhoa , Thillaisundaram Anitha 
Published: July 2020

AbstractLet w be a word in k variables. For a finite nilpotent group G, a conjecture of Amit states that $$N_w(1)\ge |G|^{k-1}$$

N
w

(
1
)

≥

|
G
|

k
-
1

, where for $$g\in G$$

g
∈
G

, the quantity $$N_w(g)$$

N
w

(
g
)

is the number of k-tuples $$(g_1,\ldots ,g_k)\in G^{(k)}$$

(

g
1

,
…
,

g
k

)

∈

G

(
k
)

such that $$w(g_1,\ldots ,g_k)={g}$$

w
(

g
1

,
…
,

g
k

)
=
g

. Currently, this conjecture is known to be true for groups of nilpotency class 2. Here we consider a generalized version of Amit’s conjecture, which states that $$N_w(g)\ge |G|^{k-1}$$

N
w

(
g
)

≥

|
G
|

k
-
1

for g a w-value in G, and prove that $$N_w(g)\ge |G|^{k-2}$$

N
w

(
g
)

≥

|
G
|

k
-
2

for finite groups G of odd order and nilpotency class 2. If w is a word in two variables, we further show that the generalized Amit conjecture holds for finite groups G of nilpotency class 2. In addition, we use character theory techniques to confirm the generalized Amit conjecture for finite p-groups (p a prime) with two distinct irreducible character degrees and a particular family of words. Finally, we discuss the related group properties of being rational and chiral, and show that every finite group of nilpotency class 2 is rational.
Ethnic variations in duration of untreated psychosis: report from the CRIS-FEP study
Authors: Oduola Sherifat , Craig Tom K. J. , Morgan Craig 
Published: July 2020

Abstract
Objectives
There is inconsistent evidence on the influence of ethnicity on duration of untreated psychosis (DUP). We investigated ethnic differences in DUP in a large epidemiological dataset of first episode psychosis patients in an inner city area of south London, UK.

Methods
We analysed data on 558 first episode psychosis patients at the South London and Maudsley NHS Trust, between 2010 and 2012. We performed multivariable logistic regression to estimate the odds of a short DUP (≤ 6 months) by ethnic group, controlling for confounders.

Results
There was no evidence that ethnicity is associated with duration of untreated psychosis. However, we found evidence that a short DUP was strongly associated with age, living circumstances, and pathways to care variables (involuntary admission, out of office hour contact, accident and emergency referral, criminal justice agency referral and family involvement in help-seeking). Conversely, a long DUP was associated with report of social isolation, living alone, being single and General Practitioner referral.

Conclusion
Our findings suggest that indicators of social isolation were associated with long DUP. Our data also show that pathways into care characteristics play significant role in DUP. Thus, the challenge of tackling the issue of timely access to EI under the new Access and Waiting Time standard for psychosis requires a multilevel approach, including joint working with communities, public awareness of psychosis, less restrictive referral pathways and adequate resourcing of early intervention for psychosis services. These will go a long way in addressing patients’ needs rather than be determined by service structures.
Pericentromere clustering in Tradescantia section Rhoeo involves self-associations of AT- and GC-rich heterochromatin fractions, is developmentally regulated, and increases during differentiation
Authors: Golczyk Hieronim , Limanówka Arleta , Uchman-Książek Anna 
Published: July 2020

AbstractA spectacular but poorly recognized nuclear repatterning is the association of heterochromatic domains during interphase. Using base-specific fluorescence and extended-depth-of-focus imaging, we show that the association of heterochromatic pericentromeres composed of AT- and GC-rich chromatin occurs on a large scale in cycling meiotic and somatic cells and during development in ring- and bivalent-forming Tradescantia spathacea (section Rhoeo) varieties. The mean number of pericentromere AT-rich domains per root meristem nucleus was ca. half the expected diploid number in both varieties, suggesting chromosome pairing via (peri)centromeric regions. Indeed, regular pairing of AT-rich domains was observed. The AT- and GC-rich associations in differentiated cells contributed to a significant reduction of the mean number of the corresponding foci per nucleus in relation to root meristem. Within the first 10 mm of the root, the pericentromere attraction was in progress, as if it was an active process and involved both AT- and GC-rich associations. Complying with Rabl arrangement, the pericentromeres preferentially located on one nuclear pole, clustered into diverse configurations. Among them, a strikingly regular one with 5–7 ring-arranged pericentromeric AT-rich domains may be potentially engaged in chromosome positioning during mitosis. The fluorescent pattern of pachytene meiocytes and somatic nuclei suggests the existence of a highly prescribed ring/chain type of chromocenter architecture with side-by-side arranged pericentromeric regions. The dynamics of pericentromere associations together with their non-random location within nuclei was compared with nuclear architecture in other organisms, including the widely explored Arabidopsis model.
Detrital zircon provenance of Carboniferous sandstones of the Variscan Externides (SW Poland) – record of the eastern Variscides exhumation
Authors: Zagórska Urszula , Kowalska Sylwia , Sláma Jiří , Dziubińska Beata , Wolański Krzysztof 
Published: July 2020

AbstractThe Variscan Externides in the area of south-western Poland (the basement of the Fore-Sudetic Monocline), are considered an extension of the Rheno-Hercynian Zone of the Variscan Orogen. The Externides are made of Carboniferous siliciclastic sediments, the exact stratigraphic age and provenance of which are not known in detail. To constrain the sedimentary evolution and detritus provenance of the Variscan external belt, eight sandstone samples from boreholes located in the area of SW Poland were selected for petrography, whole rock geochemistry and detrital zircon U–Pb dating. The results show abrupt change in detrital zircon U–Pb provenance, between strata that have been classified as Mississippian (L. Carboniferous) and Pennsylvanian (U. Carboniferous) based on previously published miospore zonation. The Pennsylvanian rocks (from the boreholes of Września-IG1 and Siciny IG1) bear a significant population of zircon grains with Lower Carboniferous ages (350–330 Ma), while such a zircon population is absent in Lower Carboniferous rocks (from the boreholes of Paproć-29 and Kobylin 1). The absence of Moscovian to Asselian zircons that are otherwise known from the adjacent areas with zircon-bearing volcanic activity, suggests that the studied Pennsylvanian sediments represent the lower part of Upper Carboniferous. The presented data indicate abrupt provenance change that occurred in the source areas at the Mississippian—Pennsylvanian turn, and that was probably caused by changes in the tectonic architecture of the Variscan Orogen. This tectonic changeover resulted in exhumation and erosion of the Lower Carboniferous rock complexes and manifested itself by recycling of the Lower Carboniferous zircon into Upper Carboniferous strata.
The Leland–Toft optimal capital structure model under Poisson observations
Authors: Palmowski Zbigniew , Pérez José Luis , Surya Budhi Arta , Yamazaki Kazutoshi 
Published: July 2020

AbstractThis paper revisits the optimal capital structure model with endogenous bankruptcy, first studied by Leland (J. Finance 49:1213–1252, 1994) and Leland and Toft (J. Finance 51:987–1019, 1996). Unlike in the standard case where shareholders continuously observe the asset value and bankruptcy is executed instantaneously without delay, the information of the asset value is assumed to be updated periodically at the jump times of an independent Poisson process. Under a spectrally negative Lévy model, we obtain the optimal bankruptcy strategy and the corresponding capital structure. A series of numerical studies provide an analysis of the sensitivity, with respect to the observation frequency, of the optimal strategies, optimal leverage and credit spreads.
The effectiveness of conservative interventions for the management of syndromic hypermobility: a systematic literature review
Authors: Palmer Shea , Davey Indi , Oliver Laura , Preece Amara , Sowerby Laura , House Sophie 
Published: July 2020

AbstractIntroduction‘Syndromic hypermobility’ encompasses heritable connective tissue disorders such as hypermobile Ehlers-Danlos syndrome and hypermobility spectrum disorders which are characterised by excessive joint range of motion and pain. Conservative interventions such as exercise are the cornerstone of management, yet their effectiveness is unclear.AimTo systematically appraise the effectiveness of conservative management for people with syndromic hypermobility.MethodA systematic online database search was conducted (AMED, BND, CINAHL Plus, MEDLINE, PEDro, PsychINFO and SportDiscus). Potential articles were assessed for eligibility by two researchers against the following criteria: adults and children with a hEDS/HSD diagnosis (or equivalent diagnosis using specific criteria); non-pharmacological or non-surgical interventions; outcomes related to pain, physical function, psychological well-being or quality of life. Controlled trials and cohort studies were included. Critical Appraisal Skills Programme checklists were used to assess methodological quality.ResultsEleven studies were included, comprising eight controlled trials and three cohort studies. All studies investigated interventions that had exercise as the primary component. Three small controlled studies demonstrated superior effects of conservative management relative to a control group. However, those studies only focused on a single area of the body, only recruited women, and had no long-term follow-up. All studies reported improvements in a wide range of outcomes over time.ConclusionControlled trial evidence for the superiority of conservative management over comparators is weak. There is some evidence that people improve over time. Robust randomised controlled trial research of the long-term effectiveness of ‘whole-body’ (rather than individual joints or body areas) conservative management is required.Key Points• Conservative management is the cornerstone of management of syndromic hypermobility.• The review found that evidence for the effectiveness of conservative management relative to no treatment or other conservative comparators was weak.• However, there was consistent evidence for effectiveness from pre- to post-treatment.• Further robust randomised controlled trial evidence is required.