Microscopic origin of isotropic non-Heisenberg behavior in highly correlated systems

We have reanalyzed the microscopic origin of the isotropic deviations that are observed from the energy spacings predicted by the HDVV Hamiltonian. Usually, a biquadratic spin operator is added to the HDVV Hamiltonian to account for such deviations. It is shown here that this operator cannot describe the effect of the excited atomic non-Hund states which brought the most important contribution to the deviations. For systems containing more than two magnetic centers, non-Hund states cause additional interactions that are of the same order of magnitude as the biquadratic exchange and should have significant effects on the macroscopic properties of extended systems.Comment: 4 pages, 3 figure

The Netherlands: Childbearing within the context of a "Poldermodel" society

The Netherlands has seen a considerable decline of the period total fertility rate and delayed childbearing, just like all other European countries. The drop in fertility, however, has not been as sharp as in many other regions of Europe. The period total fertility rate in the Netherlands has stabilized since the late 1970s at around 1.6 children per woman, and it has even risen slightly since 1995. In addition, although the Netherlands has one of the oldest first-time mothers, completed fertility is still rather high compared to other European countries, suggesting a strong “catching up†of births by women in their thirties. This chapter provides a comprehensive overview of the main driving forces behind specific fertility trends in the Netherlands. Among other factors, it focuses on changing patterns of home leaving and union formation, declining partnership stability, and the growing acceptability and use of contraception. The chapter also looks at prolonged education, rising labor-force participation of women, economic uncertainties, the growing migrant population, and family policies. Data allowing, and to the extent possible, we examine the effects of these factors on decision-making about parenthood and the timing of childbearing.childbearing, Europe, fertility, Netherlands

Green synthesis of highly functionalized octahydropyrrolo[3,4-c]pyrrole derivatives using subcritical water, and their anti(myco)bacterial and antifungal activity

A series of novel 2-(thiazol-2-yl)-octahydropyrrolo[3,4-c]pyrroles was synthesized by reaction of octahydropyrrolo[3,4-c]pyrrole N-benzoylthiourea derivatives and α-haloketones in subcritical water at 130 °C in 75-91% yield. Both the thiourea intermediates and the end productswere synthesized in subcritical water, which proved a suitable green alternative to acetone by delivering the desired compounds in much shorter reaction times and practically the same yields. The antimicrobial activity of the compounds was determined against five bacterial strains and three fungal strains, and MIC values of 15.62-250 µg/mL were observed. Moreover, the compounds exhibited antimycobacterial activity against M. tuberculosis H37Rv with MIC values of 7.81-62.5 μg/mL

Ab initio study of the CE magnetic phase in half-doped manganites: Purely magnetic versus double exchange description

The leading electronic interactions governing the local physics of the CE phase of half-doped manganites are extracted from correlated ab initio calculations performed on an embedded cluster. The electronic structure of the low-energy states is dominated by double exchange configurations and O-2$p_{\sigma}$ to Mn-3d charge transfer configurations. The model spectra of both a purely magnetic non-symmetric Heisenberg Hamiltonian involving a magnetic oxygen and two non-symmetric double exchange models are compared to the \textit{ab initio} one. While a satisfactory agreement between the Heisenberg spectrum and the calculated one is obtained, the best description is provided by a double exchange model involving excited non-Hund atomic states. This refined model not only perfectly reproduces the spectrum of the embedded cluster in the crystal geometry, but also gives a full description of the local double-well potential energy curve of the ground state (resulting from the interaction of the charge localized electronic configurations) and the local potential energy curves of all excited states ruled by the double exchange mechanism

Antenatal corticosteroids-to-birth interval in preterm birth

Objectives: The purpose of this study was to compare short-term outcomes in children born between 24 and 34 weeks’ gestation, according to observed antenatal corticosteroids (ACS)-to-birth intervals. Research question: ‘Is there a difference in short-term outcomes between observed ACS-to-birth intervals across a range of gestational ages at birth?’ Methods: Cohort study assessing differences in incidence of short-term neonatal outcomes according to the observed interval between the last administration of ACS and birth. Linear, non-weighted GEE models with an independence working correlation structure were fitted to infant level data providing valid point estimates for either incidence or rate differences (binary outcomes) or average differences (continuous outcomes). Results: Of 886 children, 35.9% were born within 2 days after the last administration of ACS, 32.2% within 2 to 7 days, 14.1% within 8 to 14 days, and 17.8% more than 14 days after. Across gestational ages at birth, there were no differences in birth weight between children born at an ACS-to-birth interval of 7 days or less compared to more than 7 days, nor were there differences in respiratory outcomes, cerebral outcomes, or composite outcome. Conclusion: Drawing conclusions on the importance of the ACS-to-birth interval is difficult due to the post-hoc nature of the variable. In the absence of tools to better estimate if and when PTB will occur, it might not have any value in daily practice, regardless of whether there is an optimal ACS-to-birth interval or not

An Introduction to Software Ecosystems

This chapter defines and presents different kinds of software ecosystems. The focus is on the development, tooling and analytics aspects of software ecosystems, i.e., communities of software developers and the interconnected software components (e.g., projects, libraries, packages, repositories, plug-ins, apps) they are developing and maintaining. The technical and social dependencies between these developers and software components form a socio-technical dependency network, and the dynamics of this network change over time. We classify and provide several examples of such ecosystems. The chapter also introduces and clarifies the relevant terms needed to understand and analyse these ecosystems, as well as the techniques and research methods that can be used to analyse different aspects of these ecosystems.Comment: Preprint of chapter "An Introduction to Software Ecosystems" by Tom Mens and Coen De Roover, published in the book "Software Ecosystems: Tooling and Analytics" (eds. T. Mens, C. De Roover, A. Cleve), 2023, ISBN 978-3-031-36059-6, reproduced with permission of Springer. The final authenticated version of the book and this chapter is available online at: https://doi.org/10.1007/978-3-031-36060-

A Framework for Cross-Platform E-Commerce Website Development for Multiple Devices and Browsers

The aim of this study has been to identify Human- Computer Interaction HCI design methods and techniques for the development of cross-platform e-commerce websites that can be used on multiple devices with different screen sizes and web browsers The findings presented here are based on a theoretical framework consisting of three categorizations composition continuity and consistency The framework was implemented with the aid of a case study and a prototype implementation that adapts to the user context The development of the prototype was based on the evaluation of existing e-commerce websites Identified usability issues were readability and the fact that tasks should be dependent on the user context The overall results of this study are presented as a set of usability guidelines for cross-platform e-commerce which highlight the importance of identifying the users needs as well as the context in which they operate by offering a common set of functionality between devices and using device specific input mechanism

The Cu(OTf)2 catalysed microwave assisted synthesis of a new scaffold, 7-aryl-7,8-dihydropyrido[4,3-c]pyridazin-5(6H)-one

The synthesis of novel 7-aryl-7,8-dihydropyrido[4,3-c]pyridazin-5(6H)-ones is described including a one-step Mannich-type reaction followed by intramolecular ring closure of ethyl 3-methylpyridazine-4- carboxylate and aldimines, catalysed by the Lewis acid Cu(OTf)2 under microwave heating. This synthesis opens up possibilities to access this unexplored scaffold for medicinal chemistry