2,344 research outputs found
Nematic Fluctuations in Iron-Oxychalcogenide Mott Insulators
Nematic fluctuations occur in a wide range of physical systems from liquid
crystals to biological molecules to solids such as exotic magnets, cuprates and
iron-based high- superconductors. Nematic fluctuations are thought to be
closely linked to the formation of Cooper-pairs in iron-based superconductors.
It is unclear whether the anisotropy inherent in this nematicity arises from
electronic spin or orbital degrees of freedom. We have studied the iron-based
Mott insulators LaOFeO = (S, Se) which are
structurally similar to the iron pnictide superconductors. They are also in
close electronic phase diagram proximity to the iron pnictides. Nuclear
magnetic resonance (NMR) revealed a critical slowing down of nematic
fluctuations as observed by the spin-lattice relaxation rate (). This is
complemented by the observation of a change of electrical field gradient over a
similar temperature range using M\"ossbauer spectroscopy. The neutron pair
distribution function technique applied to the nuclear structure reveals the
presence of local nematic fluctuations over a wide temperature range
while neutron diffraction indicates that global symmetry is preserved.
Theoretical modeling of a geometrically frustrated spin- Heisenberg model
with biquadratic and single-ion anisotropic terms provides the interpretation
of magnetic fluctuations in terms of hidden quadrupolar spin fluctuations.
Nematicity is closely linked to geometrically frustrated magnetism, which
emerges from orbital selectivity. The results highlight orbital order and spin
fluctuations in the emergence of nematicity in Fe-based oxychalcogenides. The
detection of nematic fluctuation within these Mott insulator expands the group
of iron-based materials that show short-range symmetry-breaking
Claimed Co-ethnics and Kin-State Citizenship in Southeastern Europe
The paper introduces the often neglected concept of 'claimed co-ethnics' in the analysis of citizenship policies. It argues that this is an interstitial category that further complicates the triadic nexus between national minorities, nationalising states and kin-states. The 'claimed co-ethnics' are defined as people who are recognised by the citizenship (or ethnizenship) conferring state as belonging to its main ethnic group, although they themselves do not embrace that definition. In addition to bringing the issue of claimed co-ethnics into focus, the paper elucidates how citizenship policies can affect groups that challenge the exact fit between ethnicity and nation, showing how national governments through particular citizenship policies and categorisation practices engage in the construction of these groups. The paper shows that the triadic nexus framework, which has had a strong influence on citizenship and minorities scholarship, needs to be revised to include unidirectional relations between the elements of the triadic nexus. The paper is based on the comparison between the cases of ethnic Vlachs (in the context of Albania and Greece) and Bunjevci (in the context of Serbia and Croatia).European Commission - Seventh Framework Programme (FP7
The contribution of financial entities to the sustainable development through the reporting of corporate social responsibility information
This paper aims at examining the relationship between board composition and corporate
social responsibility (CSR) of a sample of listed financial entities, discussing the driving
reasons of these entities to disclose CSR information. We hypothesize that there is a positive
association between outside (institutional and independent directors) and female directors and
CSR disclosure and a negative relationship between inside directors and CSR reporting. Our
findings provide evidence that the proportions of independent directors and female directors
on boards encourage CSR disclosure. Moreover, the results also show that the proportions of
inside directors and institutional directors on boards do not have influence on CSR reporting.
Thus, our evidence suggests that board attributes such as independent and female directors
encourage financial entities to report CSR matters, showing the effectiveness of these two
corporate governance mechanisms. The paper shed light on the influence of board structure of
financial entities on CSR disclosure. Therefore, this study contributes to past research by
providing an index to measure CSR disclosure of financial entities and the importance of the
distinction between outside and inside directors
Sex differences in colon cancer metabolism reveal a novel subphenotype
Women have a lower incidence of colorectal cancer (CRC) than men, however, they have a higher incidence of right-sided colon cancer (RCC). This is of concern as patients with RCC have the poorest clinical outcomes among all CRC patients. Aberrant metabolism is a known hallmark and therapeutic target for cancer. We propose that metabolic subphenotypes exist between CRCs due to intertumoral molecular and genomic variation, and differences in environmental milieu of the colon which vary between the sexes. Metabolomics analysis of patient colon tumors (n = 197) and normal tissues (n = 39) revealed sex-specific metabolic subphenotypes dependent on anatomic location. Tumors from women with RCC were nutrient-deplete, showing enhanced energy production to fuel asparagine synthesis and amino acid uptake. The clinical importance of our findings were further investigated in an independent data set from The Cancer Genomic Atlas, and demonstrated that high asparagine synthetase (ASNS) expression correlated with poorer survival for women. This is the first study to show a unique, nutrient-deplete metabolic subphenotype in women with RCC, with implications for tumor progression and outcomes in CRC patients
Exogenously applied ZnO nanoparticles induced salt tolerance in potentially high yielding modern wheat (Triticum aestivum L.) cultivars
Salinity stress is one of the potential threats that adversely affect the productivity of many cereal crops worldwide. Spraying plants with nano-Zn particles may lessen effectively such negative impacts on plants; yet its mode of action is still not well explored. This study was performed to evaluate the effects of spraying nano-Zn particles with varying concentrations (0, 20, 50 and 80 mg L-1) on two wheat cultivars irrigated with saline water (EC = 6.3 dS m-1) versus a non-saline one. The key results revealed that root and shoot weights decreased significantly under salinity stress conditions, while improved considerably with nano-Zn-particles foliar application up to 50 mg nanoZn L-1; thereafter significant reductions occurred. Also, shoot and root lengths as well as plant leaf area index improved considerably owing to this foliar application. Clearly, roots and shoots weights of wheat plants sprayed with nano-Zn particles under salinity stress conditions exhibited higher values than the corresponding ones that was grown under non-saline conditions without nano-Zn-particles applications. Unexpectedly, this foliar spray led to significant reductions in plant pigments and also in enzymatic and non-enzymatic antioxidants in plants. Yet, this foliar spray enhanced formation of total soluble sugars and proline, and raised significantly Ca contents in wheat roots and shoots, and to some extent K contents. In conclusion, the foliar application of nano-Zn particles increased plant growth under salty stress conditions via two parallel processes, i.e., stimulating formation of osmolytes and stimulating nutrient uptake which may, in turn, increase plant metabolism. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CCPeer reviewe
Multiple agency perspective, family control, and private information abuse in an emerging economy
Using a comprehensive sample of listed companies in Hong Kong this paper investigates how family control affects private information abuses and firm performance in emerging economies. We combine research on stock market microstructure with more recent studies of multiple agency perspectives and argue that family ownership and control over the board increases the risk of private information abuse. This, in turn, has a negative impact on stock market performance. Family control is associated with an incentive to distort information disclosure to minority shareholders and obtain private benefits of control. However, the multiple agency roles of controlling families may have different governance properties in terms of investors’ perceptions of private information abuse. These findings contribute to our understanding of the conflicting evidence on the governance role of family control within a multiple agency perspectiv
Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study
This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions
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