601 research outputs found
Household Portfolio Underdiversification and Probability Weighting: Evidence from the Field
We test whether probability weighting affects household portfolio choice in a representative survey. On average, people display inverse-S shaped probability weighting, overweighting low probability events. As theory predicts, probability weighting is positively associated with portfolio underdiversification and significant Sharpe ratio losses. Analyzing respondents’ individual stock holdings, we find higher probability weighting is associated with owning lottery-type stocks and positively-skewed equity portfolios. People with higher probability weighting are less likely to own mutual funds and more likely to either avoid equities or hold individual stocks. We are the first to empirically link individuals’ elicited probability weighting and real-world decisions under risk
Sinteza 2-(1H-indol-3-il)acetil-N-(supstituiranih fenil)hidrazinkarbotioamida i srodnih heterocikličkih spojeva te procjena njihovog antikonvulzivnog djelovanja i toksičnosti
A series of new 5-(1H-indol-3-yl)methyl-4-(substituted aryl)-2,4-dihydro-3H-1,2,4-triazole-3-thiones (4a-g), 5-(1H-indol-3-yl)methyl-N-(substituted aryl)-1,3,4-oxadiazol-2-amines (5a-g) and 5-(1H-indol-3-yl)methyl-N-(substituted aryl)-1,3,4-thiadiazol-2-amines (6a-g) were prepared by treating 2-(1H-indol-3-yl)acetyl-N-(substituted phenyl)hydrazine carbothioamides (3a-g) with suitable reagents. All the newly synthesized compounds were screened for their anticonvulsant activity in the MES model and were compared with the standard drugs phenytoin sodium and carbamazepine. Out of the twenty-one compounds studied, 4b, 4e, 4f, 5b, 5d, 5g, 6b, 6d and 6e showed comparable MES activity to phenytoin and carbamazepine after 0.5 h. Compound 5b showed to be more potent than carbamazepine after 4 h. Compounds 4a, 4c, 4d, 5a, 5c, 5e, 5f, 6f and 6g showed lower neurotoxicity than phenytoin.Reakcijom 2-(1H-indol-3-il)acetil-N-(supstituiranih fenil)hidrazinkarbotioamida (3a-g) s odgovarajućim reaktantom sintetizirana je serija novih 5-(1H-indol-3-il)metil-4-(supstituiranih aril)-2,4-dihidro-3H-1,2,4-triazol-3-tiona (4a-g), 5-(1H-indol-3-yl)metil-N-(supstituiranih aril)-1,3,4-oksadiazol-2-amina (5a-g) i 5-(1H-indol-3-il)metil-N-(supstituiranih aril)-1,3,4-tiadiazol-2-amina (6a-g). Ispitano je antikonvulzivno djelovanje sintetiziranih spojeva na MES modelu i uspoređeno s djelovanjem fenitoin natrija i karbamazepina. Spojevi 4b, 4e, 4f, 5b, 5d, 5g, 6b, 6d i 6e pokazali su MES djelovanje usporedivo s djelovanjem fenitoina i karbamazepina nakon 0,5 h, dok je spoj 5b nakon 4 sata imao snažnije djelovanje od karbamazepina. Osim toga, spojevi 4a, 4c, 4d, 5a, 5c, 5e, 5f, 6f i 6g su manje neurotoksični od fenitoina
Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation
In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magnetospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report on SHFAs surviving the shock crossing into the down-stream region and show that the interaction of SHFAs with the bow shock can lead to the formation of a magnetosheath cavity, previously identified in observations and simulations. We report on the first identification of long-term local weakening and erosion of the bow shock, associated with a region of increased foreshock SHFA and caviton formation, and repeated shock crossings by them. We show that SHFAs are linked to an increase in suprathermal particle pitch-angle spreads. The realistic length scales in our simulation allow us to present a statistical study of global caviton and SHFA size distributions, and their comparable size distributions support the theory that SHFAs are formed from cavitons. Virtual spacecraft observations are shown to be in good agreement with observational studies.Peer reviewe
Biallelic mutations in valyl-tRNA synthetase gene VARS are associated with a progressive neurodevelopmental epileptic encephalopathy.
Aminoacyl-tRNA synthetases (ARSs) function to transfer amino acids to cognate tRNA molecules, which are required for protein translation. To date, biallelic mutations in 31 ARS genes are known to cause recessive, early-onset severe multi-organ diseases. VARS encodes the only known valine cytoplasmic-localized aminoacyl-tRNA synthetase. Here, we report seven patients from five unrelated families with five different biallelic missense variants in VARS. Subjects present with a range of global developmental delay, epileptic encephalopathy and primary or progressive microcephaly. Longitudinal assessment demonstrates progressive cortical atrophy and white matter volume loss. Variants map to the VARS tRNA binding domain and adjacent to the anticodon domain, and disrupt highly conserved residues. Patient primary cells show intact VARS protein but reduced enzymatic activity, suggesting partial loss of function. The implication of VARS in pediatric neurodegeneration broadens the spectrum of human diseases due to mutations in tRNA synthetase genes
Panspermia, Past and Present: Astrophysical and Biophysical Conditions for the Dissemination of Life in Space
Astronomically, there are viable mechanisms for distributing organic material
throughout the Milky Way. Biologically, the destructive effects of ultraviolet
light and cosmic rays means that the majority of organisms arrive broken and
dead on a new world. The likelihood of conventional forms of panspermia must
therefore be considered low. However, the information content of dam-aged
biological molecules might serve to seed new life (necropanspermia).Comment: Accepted for publication in Space Science Review
Electron correlation effects and magnetic ordering at the Gd(0001) surface
Effects of electron correlation on the electronic structure and magnetic
properties of the Gd(0001) surface are investigated using of the full-potential
linearized augmented plane wave implementation of correlated band theory
("LDA+U"). The use of LDA+U instead of LDA (local density approximation) total
energy calculations produces the correct ferromagnetic ground state for both
bulk Gd and the Gd surface. Surface strain relaxation leads to an 90 %
enhancement of the interlayer surface-to-bulk effective exchange coupling.
Application of a Landau-Ginzburg type theory yields a 30 % enhancement of the
Curie temperature at the surface, in very good agreement with the experiment.Comment: revised version: minor typos correcte
Topological crystalline insulator states in Pb(1-x)Sn(x)Se
Topological insulators are a novel class of quantum materials in which
time-reversal symmetry, relativistic (spin-orbit) effects and an inverted band
structure result in electronic metallic states on the surfaces of bulk
crystals. These helical states exhibit a Dirac-like energy dispersion across
the bulk bandgap, and they are topologically protected. Recent theoretical
proposals have suggested the existence of topological crystalline insulators, a
novel class of topological insulators in which crystalline symmetry replaces
the role of time-reversal symmetry in topological protection [1,2]. In this
study, we show that the narrow-gap semiconductor Pb(1-x)Sn(x)Se is a
topological crystalline insulator for x=0.23. Temperature-dependent
magnetotransport measurements and angle-resolved photoelectron spectroscopy
demonstrate that the material undergoes a temperature-driven topological phase
transition from a trivial insulator to a topological crystalline insulator.
These experimental findings add a new class to the family of topological
insulators. We expect these results to be the beginning of both a considerable
body of additional research on topological crystalline insulators as well as
detailed studies of topological phase transitions.Comment: v2: published revised manuscript (6 pages, 3 figures) and
supplementary information (5 pages, 8 figures
Permeating the social justice ideals of equality and equity within the context of Early Years: challenges for leadership in multi-cultural and mono-cultural primary schools
The ideology and commitment of social justice principles is central to Early Years practice, however, the term social justice in education is complex and remains contested. This paper explores the ideology of social justice through links between equality and equity and how it is embedded within Early Years, and what remain the potential challenges for leadership. Interviews in English multi-cultural and mono-cultural primary schools were conducted. Findings showed that the ideology of social justice, equality and equity was interpreted differently. Multi-cultural schools appear to use a greater variety of activities to embed social justice principles that involved their diverse communities more to enrich the curriculum. In mono-cultural schools leadership had to be more creative in promoting equality and equity given the smaller proportion of their diverse pupil and staff population. Tentative conclusions suggest that the vision for permeating equality and equity in Early Years, at best, is at early stages
Exploring Solar-Terrestrial Interactions via Multiple Observers (A White Paper for the Voyage 2050 long-term plan in the ESA Science Programme)
This paper addresses the fundamental science question: "How does solar wind
energy flow through the Earth's magnetosphere, how is it converted and
distributed?". We need to understand how the Sun creates the heliosphere, and
how the planets interact with the solar wind and its magnetic field, not just
as a matter of scientific curiosity, but to address a clear and pressing
practical problem: space weather, which can influence the performance and
reliability of our technological systems, in space and on the ground, and can
endanger human life and health.
Much knowledge has already been acquired over the past decades, but the
infant stage of space weather forecasting demonstrates that we still have a
vast amount of learning to do. We can tackle this issue in two ways: 1) By
using multiple spacecraft measuring conditions in situ in the magnetosphere in
order to make sense of the fundamental small scale processes that enable
transport and coupling, or 2) By taking a global approach to observations of
the conditions that prevail throughout geospace in order to quantify the global
effects of external drivers.
A global approach is now being taken by a number of space missions under
development and the first tantalising results of their exploration will be
available in the next decade. Here we propose the next step-up in the quest for
a complete understanding of how the Sun gives rise to and controls the Earth's
plasma environment: a tomographic imaging approach comprising two spacecraft
which enable global imaging of magnetopause and cusps, auroral regions,
plasmasphere and ring current, alongside in situ measurements. Such a mission
is going to be crucial on the way to achieve scientific closure on the question
of solar-terrestrial interactions
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