bluuebunny/crossref_metadata_2025_split huggingface dataset:
A fractional model for population dynamics of two interacting species by using spectral and Hermite wavelets methods
Authors: Kumar Sunil , Ghosh Surath , Kumar Ranbir , Jleli Mohamed 
Published: October 2020

AbstractThe Lotka‐Volterra model is a very famous model and frequently used to describe the dynamics of ecological systems in which two species interact, one a predator and one its prey. In this present work, a comparative study is presented for solving Lotka‐Volterra model which has an important role in Biological sciences. The Lotka‐Volterra equations are solved by spectral collocation method (SCM) by using shifted Chebyshev polynomials of first kind. Then, a numerical example with two different cases is presented to demonstrate the accuracy and effectiveness of the numerical schemes. Using spectral method, we get a system of nonlinear algebraic equations which are solved by Newton's iteration method. Also the achieved solutions are compared with another solutions obtained by the Hermite wavelets method (HWM). Further, this work reflects that the integer order Lotka‐Volterra model and the fractional order one have close relationship where integer order model is a special case of fractional order. The behaviors study of predator and prey populations due to presence of fractional derivative are the key features of the present work. Our numerical and graphical results indicate that the proposed methods are simple, powerful and fully compatible for treatment of the Lotka‐Volterra model of fractional order.
‘On a nos mots à dire’: Kanak Women's Experience of Bridewealth in Lifou
Authors: Paini Anna 
Published: October 2020

ABSTRACTBridewealth in Lifou cannot be discussed on its own; rather it should be considered within the plurality of ceremonial acts which are needed to legitimize a marriage as customary. What do these transactions mean? Where does women's agency lie? Through a longitudinal analysis of ethnographic materials from my fieldwork in Lifou, Loyalty Islands, I consider how Kanak women are engaged in and perceive these ceremonial and cultural processes through a declared women's perspective that highlights their ability to make autonomous choices in an open ended historical context. I argue that it is a case of ‘positive agency’. I emphasize that local categories (june hmala and wenehleng) which define specific moments in this process can be subsumed under the anthropological term ‘bridewealth’. Further, I examine the meaning of money in bridewealth and the fact that the monetary contribution keeps increasing, raising local concerns about the need to regulate the amount circulating in marriage exchanges and its dispersion. Furthermore in Lifou there is no indication that the assembling of the bridewealth by the grooms implies a commoditization and (later) exploitation of women.
Thiophene‐based polyphosphazenes with tunable optoelectronic properties
Authors: Ogueri Kennedy S. , Ogueri Kenneth S. , Laurencin Cato T. , Allcock Harry R. 
Published: October 2020

AbstractThe polyphosphazene backbone provides a versatile platform to explore numerous synthesis and structure–property relationships for many technological applications. In this study, a new class of polyphosphazene semiconducting materials was synthesized via macromolecular substitution, which integrates a PN backbone with thiophene‐based side groups. The synthesized thiophene‐based polymers were subjected to chemical oxidation (oxidative coupling) to optimize their optoelectronic properties through side‐chain chemistry. Both the spectroscopic and electronic analyses revealed that optical and electronic properties, as well as glass transition temperatures could be modulated by chemical oxidation of the polymers. The suitability of the polymers as potential semiconductors was further evaluated using their steady‐state fluorescence quenching behavior in the presence of four different dopants (PC70BM, PC60BM, F4TCNQ, and TCNQ). It was found that the addition of dopant as a quencher to the polymer solutions does not form a complex in the ground state, and its excited state shows an efficient decrease in fluorescence intensity without altering the shape and peak position of the fluorescence band. The overall results demonstrate that the utilization of chemical oxidation via side‐chain chemistry of polyphosphazenes offers an adaptable toolbox that can be used to make new and potentially useful polymeric semiconductors for applications in organic electronics.
The nature of ammonium nitrate decomposition and explosions
Authors: Willey Ronald J. 
Published: October 2020

AbstractAmmonium nitrate explosions can cause significant destruction as shown with examples in West, Texas (2013) and Tianjin, China (2015). Yet, ammonium nitrate is available in nearly every garden center, and serves as one of the major fertilizers used throughout the world. Why is it safe to store in a garden center, and yet not safe when stored in wooden framed buildings? This presentation explores the nature of ammonium nitrate decomposition steps using a process simulator where adiabatic, constant pressure, and constant volume scenarios are evaluated. Answers are simple, yet complex. The first decomposition step is endothermic. In other words, there is a natural barrier that needs to be overcome before further decomposition. Further explanations are offered within the paper.
Polycentric development and local fertility in metropolitan regions: An empirical analysis for Barcelona, Spain
Authors: López‐Gay Antonio , Salvati Luca 
Published: October 2020

AbstractThe present study verifies if spatial variability in local fertility reflects the shift from a monocentric dense settlement model towards a polycentric metropolis organised in central cores and subcentral locations. The spatial distribution of a crude birth rate in Barcelona's province was investigated for a long time span (1975–2018), identifying distinctive trends within five concentric rings around Barcelona at four subperiods (1975–1985, 1986–1996, 1997–2007 and 2008–2018). Using multivariate exploratory statistics, local fertility rates were correlated with background indicators delineating the socio‐economic profile of each municipality in the study area. Fertility rates decreased with the distance from downward Barcelona and with population density. In the first time interval (1975–1985), fertility levels—higher in subcentral municipalities and peri‐urban locations than in downtown Barcelona—were positively associated with urban growth. In the following two subperiods (1986–1996 and 1997–2007), the contribution of local fertility to urban growth decreased significantly, reaching the lowest‐low figures at the end of the 1980s. In the most recent time interval (2008–2018), a moderate (and spatially heterogeneous) recovery of fertility rates was observed in subcentral locations. Demographic processes underlying Barcelona's expansion provide evidence in favour of a positive relationship between polycentric development and local fertility. Our article finally debates on the use of fertility indicators in the assessment of monocentric versus polycentric (metropolitan) growth in advanced economies.
Adaptive sequential predictive maintenance policy with nonperiodic inspection for hard failures
Authors: Wu Lang , Zhou Qiang 
Published: October 2020

AbstractThis paper proposes a novel adaptive maintenance policy for degrading systems subject to hard failure. Compared with traditional condition‐based maintenance policies, the proposed predictive maintenance policy makes maintenance decisions adaptively based on model prognostic results. The prognostic model is continuously updated based on newly inspected data. The inspection times and preventive maintenance activities are scheduled online in a sequential manner based on the most current prediction of system reliability. A computationally efficient optimization scheme is proposed for obtaining optimal maintenance parameters. The proposed policy is demonstrated and its performance is evaluated through extensive simulations.
Does the timing of integrating new skills affect start‐up growth?
Authors: Grillitsch Markus , Schubert Torben 
Published: October 2020

AbstractResearch SummaryGrowth often requires start‐ups to recruit new skills not present in the founding team. We analyze if the relationship between integrating new skills and growth depends on timing. Should new skills be recruited as early as possible, or can start‐ups add them as needed along the way? Using a unique panel dataset covering Sweden's population of start‐ups from 1997 to 2012, our analysis shows that (a) start‐ups' growth rate is positively correlated with integrating novel skills early in their life, while adding novel skills later is associated with lower growth and (b) corporate spin‐offs profit less from recruiting novel skills than de novo start‐ups. We mirror our results against existing theories and develop theoretical perspectives for future research.Managerial SummaryEntrepreneurs and managers of start‐ups need to develop the competences of their company as it matures. For this, they typically need to hire qualified personnel. But when is the best time to do so? In this paper, we show that the costs of integrating new skills from recruitment increase over time. We show that in order to achieve high firm growth there is a window of opportunity for successful recruitment covering the first 3–4 years after the founding of the company. Recruiting novel skills after this period is associated with reduced firm growth. Our results are thus in favor of a hiring strategy, where needed skills are recruited as early as possible.
Selection signatures across seven decades of hard winter wheat breeding in the Great Plains of the United States
Authors: Ayalew Habtamu , Sorrells Mark E. , Carver Brett F. , Baenziger P. Stephen , Ma Xue‐Feng 
Published: October 2020

AbstractClassical plant breeding has been instrumental in changing the genetic makeup of crop plants for better ecological adaptation and improved quality. This paper provides insights of the genomic changes effected in hard winter wheat (Triticum aestivum L.) through decades of breeding and selection in the Great Plains of the United States. Population structure and differentiation analyses were conducted on 185 wheat cultivars released from 1943 to 2013. Cultivars were grouped into four distinct clusters using discriminant analysis of principal components (DAPC). One of the clusters was unique in that 15 out of the 18 individuals were recent releases (2000–2010), while 12 of the 18 shared the cultivar ‘Jagger’ in their genetic background. Jagger carries a 2NS/2AS translocation segment from Aegilops ventricosa, an important segment for resistance to several foliar diseases. Using the outlier approach, Wright's population fixation index (Fst) identified 450 loci that were directionally selected. The largest signature of selection was found on chromosome 2A. Genetic diversity was high while the inbreeding coefficient was low, indicating extensive hybridization and germplasm exchange among breeding programs within the region. Foliar disease pressure and selection for resistance helped shape the microevolution of wheat in the southern Great Plains. The results showed that high genetic diversity remains in hard winter wheat cultivars adapted to the Great Plains of the USA, and modern plant breeding did not cause any sizable reduction in genetic diversity of the crop in this region.
Echocardiographic evaluation in Dorper ovine fetuses: Applications and limitations
Authors: Cruz‐Aleixo Amanda Sarita , Lima Mayra de Castro Ferreira , Albuquerque Ana Luísa Holanda de , Teixeira Raphael Tortorelli , Paula Renata Alves de , Grandi Marina Cecília , Ferreira Danilo Otávio Laurenti , Tsunemi Miriam Harumi , Chiacchio Simone Biagio , Lourenço Maria Lucia Gomes 
Published: October 2020

AbstractIn this study we aim to show the application of ultrasound evaluation of the fetal heart in the ovine species, as well as its limitations in the field. Ten Dorper sheep, without any sedation, were evaluated starting from the second month of pregnancy through transabdominal ultrasound with an ultrasound device equipped with a convex transducer. Images of the fetal heart were obtained through maternal abdominal ultrasound by identifying the position of the fetus and conducting the following measurements: length and diameter of the heart, dimensions of the right and left ventricles and dimensions of the right and left atria. The measurements could only be conducted with acceptable precision starting from the third month of pregnancy. There was a significant difference only for left ventricle diameter, which was larger in the fifth month of pregnancy. The echocardiographic evaluation of the fetus enables monitoring the heart development identifying early fetal viability, assessing inadequate events that could put the pregnancy at risk, especially for production animals. For the experimental design of research employing production animals, it is important to consider, among other factors, the limitations of the evaluation on the field, such as restraining the animals, the stress caused by handling and environmental conditions, temperature, luminosity, facilities available and the qualifications of the team.
Three-dimensional Maxwellian extended Newtonian gravity and flat limit
Authors: Concha Patrick , Ravera Lucrezia , Rodríguez Evelyn , Rubio Gustavo 
Published: October 2020

Abstract
In the present work we find novel Newtonian gravity models in three space-time dimensions. We first present a Maxwellian version of the extended Newtonian gravity, which is obtained as the non-relativistic limit of a particular U(1)-enlargement of an enhanced Maxwell Chern-Simons gravity. We show that the extended Newtonian gravity appears as a particular sub-case. Then, the introduction of a cosmological constant to the Maxwellian extended Newtonian theory is also explored. To this purpose, we consider the non-relativistic limit of an enlarged symmetry. An alternative method to obtain our results is presented by applying the semigroup expansion method to the enhanced Nappi-Witten algebra. The advantages of considering the Lie algebra expansion procedure is also discussed.
Magnetic catalysis and the chiral condensate in holographic QCD
Authors: Ballon-Bayona Alfonso , Shock Jonathan P. , Zoakos Dimitrios 
Published: October 2020

Abstract
We investigate the effect of a non-zero magnetic field on the chiral condensate using a holographic QCD approach. We extend the model proposed by Iatrakis, Kiritsis and Paredes in [1] that realises chiral symmetry breaking dynamically from 5d tachyon condensation. We calculate the chiral condensate, magnetisation and susceptibilities for the confined and deconfined phases. The model leads, in the probe approximation, to magnetic catalysis of chiral symmetry breaking in both confined and deconfined phases. In the chiral limit, mq = 0, we find that in the deconfined phase a sufficiently strong magnetic field leads to a second order phase transition from the chirally restored phase to a chirally broken phase. The transition becomes a crossover as the quark mass increases. Due to a scaling in the temperature, the chiral transition will also be interpreted as a transition in the temperature for fixed magnetic field. We elaborate on the relationship between the chiral condensate, magnetisation and the (magnetic) free energy density. We compare our results at low and moderate temperatures with lattice QCD results.
Odd and Even Major Indices and One-Dimensional Characters for Classical Weyl Groups
Authors: Brenti Francesco , Sentinelli Paolo 
Published: October 2020

Abstract
We define and study odd and even analogues of the major index statistics for the classical Weyl groups. More precisely, we show that the generating functions of these statistics, twisted by the one-dimensional characters of the corresponding groups, always factor in an explicit way. In particular, we obtain odd and even analogues of Carlitz’s identity, of the Gessel–Simion Theorem, and a parabolic extension, and refinement, of a result of Wachs.
The effects of caffeine on olfactory function and mood: an exploratory study
Authors: Stafford Lorenzo D. , Orgill Kaylee 
Published: October 2020

AbstractCaffeine has been demonstrated to enhance olfactory function in rodents, but to date, the sparse research in humans has not shown any equivalent effects. However, due to the methodological nature of those human studies, a number of questions remain unanswered, which the present study aimed to investigate. Using a double-blind experimental design, participants (n = 40) completed baseline mood measures, standardised threshold and identification tests and were then randomly allocated to receive a capsule containing either 100 mg of caffeine or placebo, followed by the same olfactory tests and mood measures. Results revealed that despite a trend toward elevated arousal following caffeine for habitual caffeine consumers, there were no changes in odour function. In contrast, for non-caffeine consumers, caffeine acted to enhance odour (threshold) sensitivity but reduce odour identification. Overall, these findings demonstrate a complex profile of effects of caffeine on odour function and, given the evidence from the wider caffeine literature, it is proposed that the effects of caffeine might be limited to older populations.
Adduct annotation in liquid chromatography/high-resolution mass spectrometry to enhance compound identification
Authors: Stricker Thomas , Bonner Ron , Lisacek Frédérique , Hopfgartner Gérard 
Published: October 2020

AbstractAnnotation and interpretation of full scan electrospray mass spectra of metabolites is complicated by the presence of a wide variety of ions. Not only protonated, deprotonated, and neutral loss ions but also sodium, potassium, and ammonium adducts as well as oligomers are frequently observed. This diversity challenges automatic annotation and is often poorly addressed by current annotation tools. In many cases, annotation is integrated in metabolomics workflows and is based on specific chromatographic peak-picking tools. We introduce mzAdan, a nonchromatography-based multipurpose standalone application that was developed for the annotation and exploration of convolved high-resolution ESI-MS spectra. The tool annotates single or multiple accurate mass spectra using a customizable adduct annotation list and outputs a list of [M+H]+ candidates. MzAdan was first tested with a collection of 408 analytes acquired with flow injection analysis. This resulted in 402 correct [M+H]+ identifications and, with combinations of sodium, ammonium, and potassium adducts and water and ammonia losses within a tolerance of 10 mmu, explained close to 50% of the total ion current. False positives were monitored with mass accuracy and bias as well as chromatographic behavior which led to the identification of adducts with calcium instead of the expected potassium. MzAdan was then integrated in a workflow with XCMS for the untargeted LC-MS data analysis of a 52 metabolite standard mix and a human urine sample. The results were benchmarked against three other annotation tools, CAMERA, findMAIN, and CliqueMS: findMAIN and mzAdan consistently produced higher numbers of [M+H]+ candidates compared with CliqueMS and CAMERA, especially with co-eluting metabolites. Detection of low-intensity ions and correct grouping were found to be essential for annotation performance.
Diffusion magnetic resonance imaging assessment of regional white matter maturation in preterm neonates
Authors: Kimpton J. A. , Batalle D. , Barnett M. L. , Hughes E. J. , Chew A. T. M. , Falconer S. , Tournier J. D. , Alexander D. , Zhang H. , Edwards A. D. , Counsell S. J. 
Published: October 2020

Abstract
Purpose
Diffusion magnetic resonance imaging (dMRI) studies report altered white matter (WM) development in preterm infants. Neurite orientation dispersion and density imaging (NODDI) metrics provide more realistic estimations of neurite architecture in vivo compared with standard diffusion tensor imaging (DTI) metrics. This study investigated microstructural maturation of WM in preterm neonates scanned between 25 and 45 weeks postmenstrual age (PMA) with normal neurodevelopmental outcomes at 2 years using DTI and NODDI metrics.

Methods
Thirty-one neonates (n = 17 male) with median (range) gestational age (GA) 32+1 weeks (24+2–36+4) underwent 3 T brain MRI at median (range) post menstrual age (PMA) 35+2 weeks (25+3–43+1). WM tracts (cingulum, fornix, corticospinal tract (CST), inferior longitudinal fasciculus (ILF), optic radiations) were delineated using constrained spherical deconvolution and probabilistic tractography in MRtrix3. DTI and NODDI metrics were extracted for the whole tract and cross-sections along each tract to assess regional development.

Results
PMA at scan positively correlated with fractional anisotropy (FA) in the CST, fornix and optic radiations and neurite density index (NDI) in the cingulum, CST and fornix and negatively correlated with mean diffusivity (MD) in all tracts. A multilinear regression model demonstrated PMA at scan influenced all diffusion measures, GA and GAxPMA at scan influenced FA, MD and NDI and gender affected NDI. Cross-sectional analyses revealed asynchronous WM maturation within and between WM tracts.).

Conclusion
We describe normal WM maturation in preterm neonates with normal neurodevelopmental outcomes. NODDI can enhance our understanding of WM maturation compared with standard DTI metrics alone.
BnSIP1-1 Involves in Light Response and Regulation of Endogenous Hormones and Flowering Time of Brassica Napus
Authors: Luo Junling , Jiang Weihua , Tang Shaohua , Mei Fengling , Yan Xiaohong , Zeng Xinhua , Wu Gang 
Published: October 2020

AbstractBnSIP1-1 is a trihelix transcription factor family gene which functions in abiotic stress response and abscisic acid (ABA) signaling during seed germination and seedling growth of Brassica napus. In the present study, further sequence analysis and phenotype identification indicated that this gene had roles in light regulation and flowering of reproductive growth stage. Many phytohormones responsive cis-acting elements, including TC-rich repeats, GARE-motif, and TCA and TGA elements, were identified in the promoter sequence of BnSIP1-1. The expression of BnSIP1-1 was regulated by light period and remarkable higher expression level of BnSIP1-1 was detected in roots than in leaves. Overexpression of BnSIP1-1 in Arabidopsis delayed flowering time for 3–5 days in transgenic plants. In addition, we also found BnSIP1-1 can respond to abiotic and ABA stress (treated with 200 mM NaCl, 300 mM mannitol or 50 μM ABA for 0, 1, 6, and 24 h) in B. napus through adjusting not only ABA but also other endogenous hormones, including indole-3-acetic acid and salicylic acid. Moreover, jasmonates (JA) signaling pathway was found not involving in the pathway of BnSIP1-1 responding to abiotic stresses.
Global value chains and technology transfer: new evidence from developing countries
Authors: Rigo Davide 
Published: October 2020

AbstractInternational trade has long been considered a channel of technology transfer. This paper draws from the World Bank’s Enterprise Surveys to provide a sample of 18 developing and emerging economies to investigate whether global value chains (GVCs) are a vehicle for the transfer of technology. It focuses on one specific channel for technology transfer, namely, the licensing of foreign technology. To control for the possible endogeneity of technology licensing, propensity score matching is combined with a difference-in-differences approach. The results show a positive effect of being involved in two-way trading on the licensing of foreign technology. Firms that become two-way traders are significantly more likely to use foreign-licensed technology than firms starting to export or import. This evidence suggests that the complexity associated with the mode of internationalisation determines the licensing of foreign technology. GVC participation also appears to foster firms’ performance, reflecting my findings that the acquisition of foreign technology leads to significant productivity improvements.