2,418 research outputs found
A First Principles Theory of Nuclear Magnetic Resonance J-Coupling in solid-state systems
A method to calculate NMR J-coupling constants from first principles in
extended systems is presented. It is based on density functional theory and is
formulated within a planewave-pseudopotential framework. The all-electron
properties are recovered using the projector augmented wave approach. The
method is validated by comparison with existing quantum chemical calculations
of solution-state systems and with experimental data. The approach has been
applied to verify measured J-coupling in a silicophosphate structure,
Si5O(PO4)6Comment: 9 page
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Reasons for shunting and reasons for revision: a survey based on data from the UK Shunt Registry
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Government ideology and international migration
We provide the first empirical evidence that differences in government ideology play an
important role in the choice of cross-border migration destinations. In absence of first-hand
experience, immigrants rely on information about the political landscape of the origin and host
countries to form expectations about the context of reception in the host society. We use
data on bilateral migration and government ideology for 36 OECD countries between 1990 and
2016. Our analysis shows that bilateral migration flows are higher when the government at the
destination is more left-wing than the government at the origin, especially when we consider
proximate countries
Low attentional engagement makes attention network activity susceptible to emotional interference
The aim of this study was to investigate whether emotion-attention interaction depends on attentional engagement. To investigate emotional modulation of attention network activation, we used a functional MRI paradigm consisting of a visuospatial attention task with either frequent (high-engagement) or infrequent (low-engagement) targets and intermittent emotional or neutral distractors. The attention task recruited a bilateral frontoparietal network with no emotional interference on network activation when the attentional engagement was high. In contrast, when the attentional engagement was low, the unpleasant stimuli interfered with the activation of the frontoparietal attention network, especially in the right hemisphere. This study provides novel evidence for low attentional engagement making attention control network activation susceptible to emotional interference. © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins.Fil: Exposito, Veronica. FundaciĂłn para la Lucha contra las Enfermedades NeurolĂłgicas de la Infancia; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad de Tampere; FinlandiaFil: Pickard, Natasha. California State University; Estados UnidosFil: Solbakk, Anne-Kristin. University of Oslo; NoruegaFil: Ogawa, Keith H.. Saint Mary's College Of California; Estados UnidosFil: Knight, Robert T.. California State University; Estados UnidosFil: Hartikainen, Kaisa M.. Universidad de Tampere; Finlandi
Explaining fiscal decentralization and the role of ethnic diversity
This paper considers the causes of fiscal decentralization with a specific focus on the role of ethnic diversity. To do so, I employ an instrument for ethnic diversity based on the origin of
anatomically modern human life. Using two measures of decentralization that capture decision making autonomy and accounting for the depth of divisions between ethno-linguistic groups using the structure of language trees, I find that ethnic diversity has a positive effect on the degree of decentralization. It is the amount of fractionalization towards the leaves of the trees, where groups are more numerous and less distinct, that drive decentralization
A mailshot in the dark? The impact of the UK government's leaflet on the 2016 EU referendum
In this paper I explore the causal effect of exposure to the UK government’s mailshot on vote preference in the 2016 EU referendum. I find that exposure caused a drop in the probability of voting leave by 3 percentage points. The effect was stronger in individuals who were exposed to few other sources of referendum information. For instance, females and the risk averse were even less likely to vote leave after exposure. The effect was also larger for Conservative party supporters who consumed many other sources of information. The evidence is consistent with voters being liable to persuasion. On the mechanism, I show that exposed individuals experienced a “persuasion-through-knowledge” effect, which changed beliefs on topics of contention
Does Congressional experience in US governors influence state transfers?
This paper examines the relationship between US governors who have previously served as a member of Congress and the federal transfers to their state. I assemble a novel dataset of governors political background and match this to federal transfer data from 1950 to 2008. Governors with Congressional experience have 0.8 percentage points more transfers to their state. I find no evidence of problematic trends or selection issues. Moreover, the result is robust to outliers in the data and many robustness checks
A natural carbohydrate fraction Actigen™ from Saccharomyces cerevisiae cell wall: effects on goblet cells, gut morphology and performance of broiler chickens
A study was conducted to evaluate a natural carbohydrate fraction Actigen™ (NCF), derived from mannanoligosaccharide, in feed on growth performance, intestinal morphology and goblet cell number and area of male broilers'. Dietary treatments included: 1) control diet (antibiotic and NCF free), 2) NCF at 200g/t, 3) NCF at 400g/t, and 4) NCF 800g/t. Two hundred and forty birds were placed into 12 replicate pens per treatment (5 birds/pen), sixty birds per treatment. Body weight and feed intake were recorded weekly up to day 42. At this time a 2.5cm section of jejunum and duodenum were excised post mortem for morphological analysis. Birds fed 200g/t and 800g/t NCF were significantly (P<0.01) heavier from day 14 onwards than the control birds. Feed intake was significantly higher in birds fed 200g/t NCF compared to those fed the control at 21 and 35 days (P<0.05). Diets containing 200g/t and 800g/t of NCF significantly decreased broiler feed conversion ratio (FCR) compared to the control in the first phase (1-14 days) (P<0.01) and levels of NCF decreased FCR (P<0.05) in the second phase (15-28 days). NCF had no significant effect on villus height, villus width, crypt depth or villus to crypt ratio in either duodenum or jejunum. NCF did not significantly affect goblet cell area or goblet cell number in the duodenum, however, in the jejunum, 800g/t NCF significantly (P<0.05) increased goblet cell area over the control. In conclusion, NCF showed a positive effect on broiler performance in the starter and grower phases, and increased goblet cell area in the jejunum, suggesting higher levels of mucin production. This indicated that the performance benefit of NCF could be age-dependent, with younger birds responding more than the older ones. There were no additional benefits to performance when feeding NCF for a longer period (after 28 d of age), however it is postulated that birds fed NCF would have greater defence to pathogenic challenge through increased storage capacity of muci
Introducing fluctuation-driven order into density functional theory using the quantum order-by-disorder framework
Density functional theory in the local or semi-local density approximation is
a powerful tool for materials simulation, yet it struggles in many cases to
describe collective electronic order that is driven by electronic interactions.
In this work it is shown how arbitrary, fluctuation-driven electronic order may
be introduced into density functional theory using the quantum
order-by-disorder framework. This is a method of calculating the free energy
correction due to collective spin and charge fluctuations about a state that
hosts static order, in a self-consistent manner. In practical terms, the
quantum order-by-disorder method is applied to the Kohn-Sham auxiliary system
of density functional theory to give an order-dependent correction to the
exchange-correlation functional. Calculation of fluctuation propagators within
density functional theory renders the result fully first-principles. Two types
of order are considered as examples -- fluctuation-driven superconductivity and
spin nematic order -- and implementation schemes are presented in each case.Comment: 20 pages, 2 figure
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