A canonical Frobenius structure

We show that it makes sense to speak of THE Frobenius manifold attached to a convenient and nondegenerate Laurent polynomialComment: 24 page

Chirality Selection in Open Flow Systems and in Polymerization

As an attempt to understand the homochirality of organic molecules in life, a chemical reaction model is proposed where the production of chiral monomers from achiral substrate is catalyzed by the polymers of the same enatiomeric type. This system has to be open because in a closed system the enhanced production of chiral monomers by enzymes is compensated by the associated enhancement in back reaction, and the chiral symmetry is conserved. Open flow without cross inhibition is shown to lead to the chirality selection in a general model. In polymerization, the influx of substrate from the ambience and the efflux of chiral products for purposes other than the catalyst production make the system necessarily open. The chiral symmetry is found to be broken if the influx of substrate lies within a finite interval. As the efficiency of the enzyme increases, the maximum value of the enantiomeric excess approaches unity so that the chirality selection becomes complete.Comment: 8 pages, 4 figure

Spontaneous magnetization and structure formation in a spin-1 ferromagnetic Bose-Einstein condensate

Motivated by recent experiments involving the non-destructive imaging of magnetization of a spin-1 87Rb Bose gas (Higbie et al., cond-mat/0502517), we address the question of how the spontaneous magnetization of a ferromagnetic BEC occurs in a spin-conserving system. Due to competition between the ferromagnetic interaction and the total spin conservation, various spin structures such as staggered magnetic domains, and helical and concentric ring structures are formed, depending on the geometry of the trapping potential.Comment: 8 pages, 5 figure

Diagnostics for the ground state phase of a spin-2 Bose-Einstein condensate

We propose a method to determine the singlet-pair energy of a spin-2 Bose-Einstein condensate (BEC). By preparing the initial populations in the magnetic sublevels 0, 2, -2 with appropriate relative phases, we can obtain the coefficient of the spin singlet-pair term from the spin exchange dynamics. This method is suitable for hyperfine states with short lifetimes, since only the initial change in the population of each magnetic sublevel is needed. This method therefore enables the determination of the ground state phase of a spin-2 87Rb BEC at zero magnetic field, which is considered to lie in the immediate vicinity of the boundary between the antiferromagnetic and cyclic phases. We also show that the initial state in which relative phases are controlled can be prepared by Raman processes.Comment: 12 pages, 6 figure

Trust in scientists on climate change and vaccines

On climate change and other topics, conservatives have taken positions at odds with a strong scientific consensus. Claims that this indicates a broad conservative distrust of science have been countered by assertions that while conservatives might oppose the scientific consensus on climate change or evolution, liberals oppose scientists on some other domains such as vaccines. Evidence for disproportionately liberal bias against science on vaccines has been largely anecdotal, however. Here, we test this proposition of opposite biases using 2014 survey data from Oregon and New Hampshire. Across vaccine as well as climate change questions on each of these two surveys, we find that Democrats are most likely to say they trust scientists for information, and Tea Party supporters are least likely, contradicting the proposition of opposite bias. Moreover, partisan divisions tend to widen with education. Theoretical explanations that have been offered for liberal trust or conservative distrust of science in other specific domains such as climate change or environmental protection fit less well with these results on vaccines. Given the much different content of climate change and vaccine issues, the common political pattern appears more consistent with hypotheses of broader ideological divisions on acceptance of science

Agricultural extension for women farmers in Africa

Women are responsible for at least 70 percent of food staple production in Africa. They are also important in other agricultural activities, including food processing and marketing, cash cropping and animal husbandry. Women's involvement is significant not only in terms of their labor input, but also in terms of their decision-making authority. This paper proposes a series of operational guidelines on how to provide agricultural extension services in a cost-effective way to women farmers. All small-scale farmers, regardless of gender, face constraints, but the focus here is on women farmers in order to foster a better understanding of the particular gender-related barriers confronting women and the strategies needed to overcome them. Attention is concentrated on sub-Saharan Africa in view of the crucial role of women in agriculture throughout the sub-continent. This paper addresses the question of why women need help -- the role women have in agriculture and the particular constraints they face in terms of access to resources and information. It examines the information needed to modify extension systems to better reach women farmers, to modify the focus of research to address women's activities and to monitor and evaluate programs. The paper also deals with the transmission of the extension message to women farmers and the formulation of the message to be delivered, and the linkage between extension and agricultural research and technology.Agricultural Research,Health Monitoring&Evaluation,Crops&Crop Management Systems,Primary Education,Agricultural Knowledge&Information Systems

BASIS RISK FOR RICE

The objective of this paper is to develop a cross hedging model for rice that minimizes basis risk and accounts for the existence of the nonstationary nature of basis. Basis is treated as an endogenous variable and model for basis risk are developed.Financial Economics, Risk and Uncertainty,

The impact of Lyman-α\alpha radiative transfer on large-scale clustering in the Illustris simulation

Lyman-$\alpha$ emitters (LAEs) are a promising probe of the large-scale structure at high redshift, $z\gtrsim 2$. In particular, the Hobby-Eberly Telescope Dark Energy Experiment aims at observing LAEs at 1.9 $<z<$ 3.5 to measure the Baryon Acoustic Oscillation (BAO) scale and the Redshift-Space Distortion (RSD). However, Zheng et al. (2011) pointed out that the complicated radiative transfer (RT) of the resonant Lyman-$\alpha$ emission line generates an anisotropic selection bias in the LAE clustering on large scales, $s\gtrsim 10$ Mpc. This effect could potentially induce a systematic error in the BAO and RSD measurements. Also, Croft et al. (2016) claims an observational evidence of the effect in the Lyman-$\alpha$ intensity map, albeit statistically insignificant. We aim at quantifying the impact of the Lyman-$\alpha$ RT on the large-scale galaxy clustering in detail. For this purpose, we study the correlations between the large-scale environment and the ratio of an apparent Lyman-$\alpha$ luminosity to an intrinsic one, which we call the `observed fraction', at $2<z<6$. We apply our Lyman-$\alpha$ RT code by post-processing the full Illustris simulations. We simply assume that the intrinsic luminosity of the Lyman-$\alpha$ emission is proportional to the star formation rate of galaxies in Illustris, yielding a sufficiently large sample of LAEs to measure the anisotropic selection bias. We find little correlations between large-scale environment and the observed fraction induced by the RT, and hence a smaller anisotropic selection bias than what was claimed by Zheng et al. (2011). We argue that the anisotropy was overestimated in the previous work due to the insufficient spatial resolution: it is important to keep the resolution such that it resolves the high density region down to the scale of the interstellar medium, $\sim1$ physical kpc. (abridged)Comment: 11 pages, published in A&