D-term Inflation and Nonperturbative Kahler Potential of Dilaton

We study the $D$-term inflation scenario with a nonperturbative K\"ahler potential of the dilaton field. Although the FI term which leads an inflationary expansion is given by the derivative of the K\"ahler potential with respect to the dilaton in heterotic string models with anomalous U(1), the too large magnitude is problematic for a viable $D$-term inflation. In this paper, we point out that the K\"ahler potential with a nonperturbative term can reduce the magnitude of FI term to desired values while both the dilaton stabilization and $D$-term domination in the potential are realized by nonperturbative superpotential.Comment: 13 pages, latex, 3 figure

Losing sight of Luck: Automatic approach tendencies toward gambling cues in Canadian moderate- to high-risk gamblers – A replication study

Evidence for approach bias tendencies to underly automatic behavioural impulses towards seeking out gambling activities in the presence of appetitive salient cues was first shown by Boffo et al. (2018) in a Dutch sample. Relative to non-problem gamblers, moderate-to-high-risk gamblers demonstrated stronger approach tendencies towards gambling-related stimuli compared with neutral ones. Moreover, gambling approach bias was associated with past-month gambling behaviour and predictive of gambling activity persistence over time. The current study aimed to replicate these findings within a Canadian sample evaluating the concurrent and longitudinal correlates of gambling approach bias. The study was conducted online, available throughout Canada. Twenty-seven non-treatment-seeking moderate-to-high-risk gamblers and 26 non-problem gamblers community-recruited via multiple channels (i.e., internet and newspaper advertisements, land-based flyers, and university recruitment portals). Participants completed two online assessment sessions 6-months apart. Each session included (1) self-report measures of gambling behaviour (frequency, duration, and expenditure), (2) self-report assessment of problem gambling severity (PGSI), and (3) a gambling approach-avoidance task, utilising culturally relevant stimuli tailored to individual gambling habits. However, our study failed to replicate Boffo et al. (2018) findings in a Canadian sample. Relative to non-problem gamblers, moderate-to-high-risk gamblers did not exhibit greater approach bias tendencies towards gambling-related stimuli compared to neutral stimuli. Moreover, gambling approach bias was not predictive of prospective gambling behaviour (frequency, duration, or expenditure) or severity of gambling problems. Reported results do not provide evidence for approach tendencies contributing to problematic gambling behaviour in a Canadian sample of moderate-to-high-risk gamblers compared to non-problematic gambler controls. Further replications on the topic are needed. Future research should evaluate approach tendencies within the gambling context, considering the potential impact of task reliability to assess approach bias in light of individual gambling modality preferences.</p

Electronic Structure and Heavy Fermion Behavior in LiV_2O_4

First principles density functional calculations of the electronic and magnetic properties of spinel-structure LiV$_{2}$O$_{4}$ have been performed using the full potential linearized augmented planewave method. The calculations show that the electronic structure near the Fermi energy consists of a manifold of 12 bands derived from V $t_{2g}$ states, weakly hybridized with O p states. While the total width of this active manifold is approximately 2 eV, it may be roughly decomposed into two groups: high velocity bands and flatter bands, although these mix in density functional calculations. The flat bands, which are the more atomic-like lead to a high density of states and magnetic instability of local moment character. The value of the on-site exchange energy is sensitive to the exact exchange correlation parameterization used in the calculations, but is much larger than the interaction between neighboring spins, reflecting the weak coupling of the magnetic system with the high velocity bands. A scenario for the observed heavy fermion behavior is discussed in which conduction electrons in the dispersive bands are weakly scattered by local moments associated with strongly correlated electrons in the heavy bands.This is analogous to that in conventional Kondo type heavy fermions, but is unusual in that both the local moments and conduction electrons come from the same d-manifold.Comment: 6 Revtex pages, Postscript figs embedded. Revision: figure 4 replaced with a better version, showing the band character explicitel

Exotic Heavy Fermion State in the Filled Skutterudite PrFe4_4P12_{12} Uncovered by the de Haas-van Alphen Effect

We report the de Haas-van Alphen (dHvA) experiment on the filled skutterudite PrFe$_4$P$_{12}$ exhibiting apparent Kondo-like behaviors in the transport and thermal properties. We have found enormously enhanced cyclotron effective mass $m^{\rm \ast}_{\rm c}=81 m_{\rm 0}$ in the high field phase (HFP), which indicates that PrFe$_4$P$_{12}$ is the first Pr-compound in which really heavy mass has been unambiguously confirmed. Also in the low field non-magnetic ordered phase (LOP), we observed the dHvA branch with $m^{\rm \ast}_{\rm c}=10 m_{0}$ that is quite heavy taking into account its small Fermi surface volume (0.15% of the Brillouin zone size). The insensitivity of mass in LOP against the magnetic field suggests that the quadrupolar interaction plays a main role both in the mass renormalization and the LOP formation.Comment: 5 pages, 5 figures, Phys. Rev. B (01 October 2002) in pres

Sex and menopausal status influence human dietary requirements for the nutrient choline

Background: Although humans require dietary choline for methyl donation, membrane function, and neurotransmission, choline can also be derived from the de novo synthesis of phosphatidylcholine, which is up-regulated by estrogen. A recommended Adequate Intake (AI) exists for choline; however, an Estimated Average Requirement has not been set because of a lack of sufficient human data. Objective: The objective of the study was to evaluate the dietary requirements for choline in healthy men and women and to investigate the clinical sequelae of choline deficiency. Design: Fifty-seven adult subjects (26 men, 16 premenopausal women, 15 postmenopausal women) were fed a diet containing 550 mg choline · 70 kg-1 · d-1 for 10 d followed by <50 mg choline · 70 kg-1 · d-1 with or without a folic acid supplement (400 μg/d per randomization) for up to 42 d. Subjects who developed organ dysfunction during this diet had normal organ function restored after incremental amounts of choline were added back to the diet. Blood and urine were monitored for signs of toxicity and metabolite concentrations, and liver fat was assessed by using magnetic resonance imaging. Results: When deprived of dietary choline, 77% of men and 80% of postmenopausal women developed fatty liver or muscle damage, whereas only 44% of premenopausal women developed such signs of organ dysfunction. Moreover, 6 men developed these signs while consuming 550mgcholine · 70 kg-1 · d -1, the AI for choline. Folic acid supplementation did not alter the subjects' response. Conclusion: Subject characteristics (eg, menopausal status) modulated the dietary requirement for choline, and a daily intake at the current AI was not sufficient to prevent organ dysfunction in 19 of the subjects

Two-sided Grassmann-Rayleigh quotient iteration

The two-sided Rayleigh quotient iteration proposed by Ostrowski computes a pair of corresponding left-right eigenvectors of a matrix $C$. We propose a Grassmannian version of this iteration, i.e., its iterates are pairs of $p$-dimensional subspaces instead of one-dimensional subspaces in the classical case. The new iteration generically converges locally cubically to the pairs of left-right $p$-dimensional invariant subspaces of $C$. Moreover, Grassmannian versions of the Rayleigh quotient iteration are given for the generalized Hermitian eigenproblem, the Hamiltonian eigenproblem and the skew-Hamiltonian eigenproblem.Comment: The text is identical to a manuscript that was submitted for publication on 19 April 200

D3/D7 Inflationary Model and M-theory

A proposal is made for a cosmological D3/D7 model with a constant magnetic flux along the D7 world-volume. It describes an N=2 gauge model with Fayet-Iliopoulos terms and the potential of the hybrid P-term inflation. The motion of the D3-brane towards D7 in a phase with spontaneously broken supersymmetry provides a period of slow-roll inflation in the de Sitter valley, the role of the inflaton being played by the distance between D3 and D7-branes. After tachyon condensation a supersymmetric ground state is formed: a D3/D7 bound state corresponding to an Abelian non-linear (non-commutative) instanton. In this model the existence of a non-vanishing cosmological constant is associated with the resolution of the instanton singularity. We discuss a possible embedding of this model into a compactified M-theory setup.Comment: 30 pages, 4 figures, LaTeX; v2, minor typos corrected, one reference adde