12,555 research outputs found
Curvature Spectra and Nongaussianities in the Roulette Inflation Model
Using the gradient expansion method of Rigopoulos, Shellard and van Tent
which treats cosmological perturbations as gradients on top of a homogeneous
and isotropic FRW background, we study the production of nongaussianities in
the roulette model of inflation. Investigating a number of trajectories within
this two-field model of inflation, we find that while the superhorizon
influence of the isocurvature modes on the curvature bispectrum produces
nonzero contribution to f_NL, the effect is negligible next to the standard
inflationary prediction |f_NL| ~ n_s - 1. This is the case in both the squeezed
and equilateral configurations of the bispectrum, although the former is
slightly larger in the trajectories under consideration.Comment: 23 pages, 6 figures, 3 tables, 1 appendix; Added references, slightly
extended section
Sonar and radar SAR processing for parking lot detection
In this paper, SAR processing algorithms for automotive applications are presented and illustrated on data from non-trivial test scenes. The chosen application is parking lot detection. Laboratory results obtained with a teaching sonar experiment emphasize the resolution improvement introduced with range-Doppler SAR processing. A similar improvement is then confirmed through full scale measurements performed with an automotive radar prototype operating at 77GHz in very close range conditions, typical
of parking lot detection. The collected data allows a performance comparison between different SAR processing algorithms for realistic targets
Environmental Regulation, Market Power and Price Discrimination in the Agricultural Chemical Industry
Chemical companies generally support environmental regulatory segregation Canadian and U.S. agricultural chemical markets, apparently because it enables them to practice third order price discrimination. This study provides new cross section evidence that suggests price discrimination is practiced. We examine the potential implications chemical market desegregation for agricultural chemical prices, farmer welfare, and consumer welfare.price discrimination, agricultural chemicals, economic welfare, Environmental Economics and Policy,
THE FUTURE OF MINNESOTA'S AGRICULTURE UNDER THE FOOD SECURITY ACT OF 1985
Agricultural and Food Policy,
The inhibiting factors that principal investigators experience in leading publicly funded research
Securing public funding to conduct research and leading it by being a principal investigator (PI) is seen as significant career development step. Such a role brings professional prestige but also new responsibilities beyond research leadership to research management. If public funding brings financial and infrastructure support, little is understood about the inhibiting factors that publicly funded PIs face given the research autonomy offered by publicly funded research. Our study finds that there are three key PI inhibiting factors (1) political and environmental, (2) institutional and (3) project based. Traditional knowledge, skills and technical know-how of publicly funded PIs are insufficient to deal with the increasing managerial demands and expectations i.e. growing external bureaucracy of public funding agencies. Public funding is no longer the 'freest form of support' as suggested by Chubin and Hackett (Peerless science: peer review and US science policy. Suny Press, New York, 1990) and the inhibiting factors experienced by publicly funded PIs limits their research autonomy. We also argue that PIs have little influence in overcoming these inhibiting factors despite their central role in conducting publicly funded research
Yeast Bax Inhibitor, Bxi1p, Is an ER-Localized Protein that Links the Unfolded Protein Response and Programmed Cell Death in \u3cem\u3eSaccharomyces cerevisiae\u3c/em\u3e
Bax inhibitor-1 (BI-1) is an anti-apoptotic gene whose expression is upregulated in a wide range of human cancers. Studies in both mammalian and plant cells suggest that the BI-1 protein resides in the endoplasmic reticulum and is involved in the unfolded protein response (UPR) that is triggered by ER stress. It is thought to act via a mechanism involving altered calcium dynamics. In this paper, we provide evidence that the Saccharomyces cerevisiae protein encoded by the open reading frame, YNL305C, is a bona fide homolog for BI-1. First, we confirm that yeast cells from two different strain backgrounds lacking YNL305C, which we have renamed BXI1, are more sensitive to heat-shock induced cell death than wildtype controls even though they have indistinguishable growth rates at 30°C. They are also more susceptible both to ethanol-induced and to glucose-induced programmed cell death. Significantly, we show that Bxi1p-GFP colocalizes with the ER localized protein Sec63p-RFP. We have also discovered that Δbxi1 cells are not only more sensitive to drugs that induce ER stress, but also have a decreased unfolded protein response as measured with a UPRE-lacZ reporter. Finally, we have discovered that deleting BXI1 diminishes the calcium signaling response in response to the accumulation of unfolded proteins in the ER as measured by a calcineurin-dependent CDRE-lacZ reporter. In toto, our data suggests that the Bxi1p, like its metazoan homologs, is an ER-localized protein that links the unfolded protein response and programmed cell death
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