Anti-Oxidative Effects of Rubus coreanum Miquel Extract on Hepatic Injury Induced by Lipopolysaccharide

Kim, In-Deok; Kang, Kum-Suk; Kwon, Ryun-Hee; Ha, Bae-Jin

doi:10.5487/tr.2007.23.4.347

Cited by 4 publications

(7 citation statements)

References 14 publications

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“…In Appendix B we show that for a Gaussian distributed likelihood function, the linear bias in a parameter, which we shall call δθ i , due to a bias in a fixed model parameter (i.e. one whose value we have assumed and is not being measured), which we shall call δψ j , is given by (see also Kim et al 2004)…”

Section: Bias In the Photometric Redshiftsmentioning

confidence: 99%

“…The effective magnitude uncertainty in a given bin at a particular redshift, taking into account luminosity evolution, gravitational lensing and dust and the effect of peculiar velocity uncertainty is given by (Kim et al 2004)…”

Section: Combining With Snia Experimentsmentioning

confidence: 99%

“…one whose value we have assumed and is not being measured), which we shall call δψ j , is given by (e.g. Knox, Scoccimarro & Dodelson 1998;Kim et al 2004)…”

Section: A P P E N D I X B : B I a S I N A S S U M E D Pa R A M E T Ementioning

confidence: 99%

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Probing dark energy with the shear-ratio geometric test

Taylor

Kitching

Bacon

et al. 2007

Monthly Notices of the Royal Astronomical Society

122

206

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We adapt the Jain--Taylor (2003) shear-ratio geometric lensing method to measure the dark energy equation of state, and its time derivative from dark matter haloes in cosmologies with arbitrary spatial curvature. The full shear-ratio covariance matrix is calculated for lensed sources, including the intervening large-scale structure and photometric redshift errors as additional sources of noise, and a maximum likelihood method for applying the test is presented. Combining with the expected results from the CMB we design an optimal survey for probing dark energy. A targeted survey imaging 60 of the largest clusters in a hemisphere with 5-band optical photometric redshifts to a median galaxy depth of zm=0.9 could measure w0 to a marginal 1-sigma error of $\Delta$w0=0.5. We marginalize over all other parameters including wa, where the equation of state is parameterized in terms of scale factor a as w(a)=w0+wa(1-a). For higher accuracy a large-scale photometric redshift survey is required. Such a near-future 5-band survey covering 10,000 square degrees to z_m=0.7 could measure w0 to $\Delta$w0=0.075 and $\Delta$wa=0.33. A stronger combined constraint is measured at a pivot redshift zp=0.27 of $\Delta$w(zp)=0.0298. We compare and combine the geometric test with the cosmological and dark energy parameters measured from planned Baryon Acoustic Oscillation (BAO) and supernova Type Ia experiments, and find that the geometric test results combine with a significant reduction in errors due to different degeneracies. A combination of geometric lensing, CMB and BAO experiments could achieve a pivot redshift constraint of $\Delta$w(zp)=0.020 at zp=0.62. Simple relations are presented that show how our lensing results can be scaled to other telescope classes and survey parameters.Comment: 30 pages, 29 figures. Accepted to MNRAS. Figures now grayscale. Scaling between SIS and NFW profiles is now mass, redshift and cosmology dependant. Further discussion on photometric redshifts and outlier

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Section: Bias In the Photometric Redshiftsmentioning

confidence: 99%

Section: Combining With Snia Experimentsmentioning

confidence: 99%

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Probing dark energy with the shear-ratio geometric test

Taylor

Kitching

Bacon

et al. 2007

Monthly Notices of the Royal Astronomical Society

122

206

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show abstract

“…Due to the Cramér-Rao inequality this is a lower bound on the error. To assess the effect of the systematic, we also calculate the bias on every parameter by means of the bias formalism (Kim et al 2004;Huterer & Takada 2005;Huterer et al 2006;Taylor et al 2007;Kitching et al 2008). Assuming a systematic P GI that is subdominant with respect to the signal and causes only small systematic errors, the bias b on a parameter p µ can be calculated by…”

Section: Fisher Matrix Formalismmentioning

confidence: 99%

The removal of shear-ellipticity correlations from the cosmic shear signal via nulling techniques

Joachimi¹,

Schneider²

2008

A&A

125

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Aims. To render cosmic shear an astronomical tool of high precision, it is essential to eliminate systematic effects upon its signal, one of the most significant ones being the intrinsic alignment of galaxies. The alignment in tidal fields that are created by the surrounding matter structure induces correlations between the intrinsic ellipticities of source galaxies, as well as correlations between the gravitational shear and the intrinsic ellipticity. While the former effect is restricted to physically close galaxy pairs and thus relatively easy to control, shear-ellipticity correlations occur for pairs at large separations. Because of the crudeness of current models of intrinsic alignment, we have developed a model-independent, purely geometrical method for removing the contamination of the cosmic shear signal by shear-ellipticity correlations. Methods. We remove the contributions to a tomographic cosmic shear signal that may be subject to contamination by shear-ellipticity correlations, making use of the characteristic dependence of these correlations on redshift. By introducing an appropriately chosen weight function to the lensing efficiency that nulls signals stemming from certain distances, new second-order measures of cosmic shear can be constructed that are free from intrinsic alignment. We present three approaches to determining such weight functions, optimized with respect to the amount of information the weighting preserves. After generalizing the construction of weight functions, the loss of information induced by this nulling technique and the subsequent degradation of constraints on cosmological parameters is quantified in a likelihood analysis. Results. For constructing optimal weight functions, good agreement is achieved between all approaches considered. In particular, a simplified analytical ansatz is shown to approximate the numerical results closely, significantly lowering computational efforts. For a survey divided into 20 redshift bins, we find that the area of credible regions increases by 20% up to about 50% after the application of nulling, depending on the cosmological parameters considered. We demonstrate that, due to the optimization of the weight functions, nearly all information is contained in a small subset of the new second-order measures. The use of a significantly smaller number of redshift bins than 20 for the nulling considerably degrades parameter constraints under conservative assumptions, emphasizing the need for detailed redshift information.

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“…The estimate of the parameter values will now be biased but the marginal error on the parameters will remain the same (the caveat here that this is only the case when the systematic is smaller than the signal). It can be shown (Kim et al 2004;Taylor et al 2007;Amara & Refregier 2008) that, with the assumption of Gaussian likelihoods, the predicted bias in a parameter due to an uncorrected systematic is given by…”

Section: The Bias Formalismmentioning

confidence: 99%

Cosmological systematics beyond nuisance parameters: form-filling functions

Kitching

Amara

Abdalla

et al. 2009

Monthly Notices of the Royal Astronomical Society

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In the absence of any compelling physical model, cosmological systematics are often misrepresented as statistical effects and the approach of marginalizing over extra nuisance systematic parameters is used to gauge the effect of the systematic. In this article, we argue that such an approach is risky at best since the key choice of function can have a large effect on the resultant cosmological errors. As an alternative we present a functional form‐filling technique in which an unknown, residual, systematic is treated as such. Since the underlying function is unknown, we evaluate the effect of every functional form allowed by the information available (either a hard boundary or some data). Using a simple toy model, we introduce the formalism of functional form filling. We show that parameter errors can be dramatically affected by the choice of function in the case of marginalizing over a systematic, but that in contrast the functional form‐filling approach is independent of the choice of basis set. We then apply the technique to cosmic shear shape measurement systematics and show that a shear calibration bias of |m(z)| ≲ 10−3 (1 +z)0.7 is required for a future all‐sky photometric survey to yield unbiased cosmological parameter constraints to per cent accuracy. A module associated with the work in this paper is available through the open source icosmo code available at http://www.icosmo.org.

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Anti-Oxidative Effects of Rubus coreanum Miquel Extract on Hepatic Injury Induced by Lipopolysaccharide

Cited by 4 publications

References 14 publications

Probing dark energy with the shear-ratio geometric test

Probing dark energy with the shear-ratio geometric test

The removal of shear-ellipticity correlations from the cosmic shear signal via nulling techniques

Cosmological systematics beyond nuisance parameters: form-filling functions

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