158 research outputs found
Rapid, energy-efficient synthesis of the layered carbide, Al<sub>4</sub>C<sub>3</sub>
The phase-pure binary aluminium carbide, Al4C3 can be synthesised in vacuo from the elements in 30 minutes via microwave heating in a multimode cavity reactor. The success of the reaction is dependent on the use of finely divided aluminium and graphite starting materials, both of which couple effectively to the microwave field. The yellow-brown powder product was characterised by powder X-ray diffraction, scanning electron microscopy/energy dispersive X-ray spectroscopy thermogravimetric-differential thermal analysis and Raman spectroscopy. Powders were composed of hexagonal single crystallites tens of microns in diameter (rhombohedral space group R[3 with combining macron]m; Z = 3; a = 3.33813(5) Å, c = 25.0021(4) Å) and were stable to 1000 °C in air, argon and nitrogen. Equivalent microwave reactions of the elements in air led to the formation of the oxycarbide phases Al2OC and Al4O4C
A comprehensive score reflecting memory-related fMRI activations and deactivations as potential biomarker for neurocognitive aging
Older adults and particularly those at risk for developing dementia typically show a
decline in episodic memory performance, which has been associated with altered
memory network activity detectable via functional magnetic resonance imaging
(fMRI). To quantify the degree of these alterations, a score has been developed as a
putative imaging biomarker for successful aging in memory for older adults (Functional Activity Deviations during Encoding, FADE; Düzel et al., Hippocampus, 2011; 21:
803–814). Here, we introduce and validate a more comprehensive version of the
FADE score, termed FADE-SAME (Similarity of Activations during Memory Encoding),
which differs from the original FADE score by considering not only activations but
also deactivations in fMRI contrasts of stimulus novelty and successful encoding, and
by taking into account the variance of young adults' activations. We computed both
scores for novelty and subsequent memory contrasts in a cohort of 217 healthy
adults, including 106 young and 111 older participants, as well as a replication cohort
of 117 young subjects. We further tested the stability and generalizability of both
scores by controlling for different MR scanners and gender, as well as by using different data sets of young adults as reference samples. Both scores showed robust agegroup-related differences for the subsequent memory contrast, and the FADE-SAME
score additionally exhibited age-group-related differences for the novelty contrast.
Furthermore, both scores correlate with behavioral measures of cognitive aging,
namely memory performance. Taken together, our results suggest that single-value
scores of memory-related fMRI responses may constitute promising biomarkers for
quantifying neurocognitive aging
A comprehensive score reflecting memory-related fMRI activations and deactivations as potential biomarker for neurocognitive aging
Older adults and particularly those at risk for developing dementia typically show a
decline in episodic memory performance, which has been associated with altered
memory network activity detectable via functional magnetic resonance imaging
(fMRI). To quantify the degree of these alterations, a score has been developed as a
putative imaging biomarker for successful aging in memory for older adults (Functional Activity Deviations during Encoding, FADE; Düzel et al., Hippocampus, 2011; 21:
803–814). Here, we introduce and validate a more comprehensive version of the
FADE score, termed FADE-SAME (Similarity of Activations during Memory Encoding),
which differs from the original FADE score by considering not only activations but
also deactivations in fMRI contrasts of stimulus novelty and successful encoding, and
by taking into account the variance of young adults' activations. We computed both
scores for novelty and subsequent memory contrasts in a cohort of 217 healthy
adults, including 106 young and 111 older participants, as well as a replication cohort
of 117 young subjects. We further tested the stability and generalizability of both
scores by controlling for different MR scanners and gender, as well as by using different data sets of young adults as reference samples. Both scores showed robust agegroup-related differences for the subsequent memory contrast, and the FADE-SAME
score additionally exhibited age-group-related differences for the novelty contrast.
Furthermore, both scores correlate with behavioral measures of cognitive aging,
namely memory performance. Taken together, our results suggest that single-value
scores of memory-related fMRI responses may constitute promising biomarkers for
quantifying neurocognitive aging
Complex networks for climate model evaluation with application to statistical versus dynamical modeling of South American climate
Acknowledgments: This paper was developed within the scope of the IRTG 1740/TRP 2011/50151-0, funded by the DFG/FAPESP. Furthermore, this work has been financially supported by the Leibniz Society (project ECONS), and the Stordalen Foundation (JFD). For certain calculations, the software packages pyunicorn (Donges et al. 2013a) and igraph (Csa´rdi and Nepusz 2006) were used. The authors would like to thank Manoel F. Cardoso, Niklas Boers, and the reviewers for helpful comments on the manuscript. Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.Peer reviewedPostprin
Roadmap for Sustainable Mixed Ionic‐Electronic Conducting Membranes
Mixed ionic‐electronic conducting (MIEC) membranes have gained growing interest recently for various promising environmental and energy applications, such as H₂ and O₂ production, CO₂ reduction, O₂ and H₂ separation, CO₂ separation, membrane reactors for production of chemicals, cathode development for solid oxide fuel cells, solar‐driven evaporation and energy‐saving regeneration as well as electrolyzer cells for power‐to‐X technologies. The purpose of this roadmap, written by international specialists in their fields, is to present a snapshot of the state‐of‐the‐art, and provide opinions on the future challenges and opportunities in this complex multidisciplinary research field. As the fundamentals of using MIEC membranes for various applications become increasingly challenging tasks, particularly in view of the growing interdisciplinary nature of this field, a better understanding of the underlying physical and chemical processes is also crucial to enable the career advancement of the next generation of researchers. As an integrated and combined article, it is hoped that this roadmap, covering all these aspects, will be informative to support further progress in academics as well as in the industry‐oriented research toward commercialization of MIEC membranes for different applications
Does microfinance have an impact on borrower's consumption patterns and women's empowerment?
This paper conducts a thorough data analysis using cross-sectional data from a study carried out in Mexico including over 16,500 observations. In the study, clusters were selected in areas Compartamos Banco, a Microfinance institution (MFI), has not lent in before. The clusters were randomly assigned to either the treatment or the control group. The analysis suggests that Microfinance has a significant positive effect on school and food expenditure but no apparent effect on entrepreneurship. Using regression analysis, a significant positive effect on women's empowerment and its positive effect on total consumption is found.Diese Forschungsarbeit analysiert Querschnittsdaten aus einer in Mexiko durchgeführten Studie mit über 16.500 Beobachtungen. In dieser Studie wurden Cluster in Gebieten ausgewählt, in denen Compartamos Banco, eine Mikrofinanzinstitution (MFI), zuvor noch keine Kredite vergeben hatte. Die Cluster wurden zufällig entweder der Behandlungs- oder der Kontrollgruppe zugeordnet. Die Analyse deutet darauf hin, dass Mikrofinanz sich signifikant positiv auf die Schul- und Nahrungsmittelausgaben auswirkt, aber offensichtlich Unternehmertum nicht fördert. Unter Verwendung eines Regressionsansatzes wird aber ein signifikant positiver Effekt auf die Frauenförderung und ihre positive Wirkung auf den Gesamtkonsum festgestellt
The child penalty: Implications of parenthood on labour market outcomes for men and women in Germany
Whilst gender inequality has been falling in the developed world, child-related gender inequality in pay has stayed constant. In this paper I use German panel data spanning across 33 years from 1984 until 2017 including over 50,000 individuals. The main contribution of this paper is the analysis of the effect of parenthood on women's and men's earnings using propensity score matching. I estimate the annual average treatment effect of parenthood over the 20 years following the birth of the first child to be -10500€ for women and +6800€ for men. When comparing the percentage loss of potential earnings, I find that women suffer a long-run child penalty of 63% compared to men. I then examine the relationship between the treatment effect and gender norms, willingness to take on risk for your career and priorities regarding job characteristics. There exists evidence which suggests that all of these factors are associated with changes in the individual treatment effects
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