No abstract

Image quality assessment plays an important role in various image processing applications. A great deal of effort has been made in recent years to develop objective image quality metrics that correlate with perceived quality measurement. Unfortunately, only limited success has been achieved. In this paper, we provide some insights on why image quality assessment is so difficult by pointing out the weaknesses of the error sensitivity based framework, which has been used by most image quality assessment approaches in the literature.Furthermore, we propose a new philosophy in designing image quality metrics: The main function of the human eyes is to extract structural information from the viewing field, and the human visual system is highly adapted for this purpose. Therefore, a measurement of structural distortion should be a good approximation of perceived image distortion. Based on the new philosophy, we implemented a simple but effective image quality indexing algorithm, which is very promising as shown by our current results.

Soybean consumption may be protective for breast cancer, possibly due in part to the presence of the isoflavones daidzein and genistein, which are weakly estrogenic. The metabolism and disposition of these phytoestrogens during chronic soya exposure were studied on a metabolic unit. Six healthy 22- to 29-year-old women consumed an unrestricted hospital diet for most of the study and ingested 12 oz of soymilk with each meal for one month. At two-week intervals, excretion of isoflavones in urine was studied, during which time the subjects consumed a constant basal diet for three to four days, ingested the full daily 36-oz portion of soymilk within 30 minutes each day for one to two days, and collected urine continuously. Urinary recovery of genistein [initially 23.9 +/- 17.3% (SD) of ingested genistin + genistein], daidzein (initially 66.2 +/- 23.5% of ingested daidzin + daidzein), and equol (initially 28% of the ingested precursors daidzin + daidzein in 1 subject and < 1% in 5 subjects) decreased progressively over four weeks of daily soya ingestion by 42% for genistein (p < 0.05) and 31% for daidzein (p < 0.01) but increased by 3- to 100-fold for equol (4 subjects, p < 0.05). Total amounts excreted and peak levels were similarly affected. The absorption half-lives (t 1/2) for genistein and daidzein were initially 2.7 +/- 0.8 and 1.6 +/- 0.5 hours, respectively, and during four weeks of soymilk ingestion decreased to 2.0 +/- 0.6 (p = 0.04) and 1.4 +/- 0.2 hours (p = 0.06), respectively, suggesting more rapid absorption. The appearance t 1/2 of equol can be estimated for only one subject initially (2.9 hrs), but during four weeks of soya ingestion it could be estimated for three more subjects (4.7 +/- 2.3 hrs). The excretion t 1/2 values for genistein and daidzein were initially 6.7 +/- 0.8 and 4.4 +/- 0.7 hours, respectively, and during four weeks of soymilk ingestion decreased to 4.2 +/- 1.2 (p = 0.005) and 3.2 +/- 1.1 hours (p = 0.005), respectively, suggesting more rapid excretion. For equol, the excretion t 1/2 was initially 9.1 hours (1 subject), and after two and four weeks of soymilk ingestion it was 13.4 +/- 9.7 and 5.5 +/- 1.6 hours (4 subjects, p = 0.046, 2 wks vs. 4 wks), respectively. These results indicate that metabolism and disposition of ingested isoflavones are altered during chronic soya ingestion in women, perhaps from increased metabolic degradation to formation of nonisoflavone metabolites. Increased production of the longer- and stronger-acting estrogenic equol in some women during chronic soymilk ingestion may alter the estrogenic potency of dietary soya isoflavones.

The human visual system (HVS) is highly non-uniform in sampling, coding, processing and understanding. The spatial resolution of the HVS is highest around the point of fixation (foveation point) and decreases rapidly with increasing eccentricity. Currently, most image quality measurement methods are designed for uniform resolution images. These methods do not correlate well with the perceived foveated image quality. Wavelet analysis delivers a convenient way to simultaneously examine localized spatial as well as frequency information. We developed a new image quality metric called foveated wavelet image quality index (FWQI) in the wavelet transform domain. FWQI considers multiple factors of the HVS, including the space variance of the contrast sensitivity function, the spatial variance of the local visual cutoff frequency, the variance of human visual sensitivity in different wavelet subbands, and the influence of the viewing distance on the display resolution and the HVS features. FWQI can be employed for foveated region of interest (ROI) image coding and quality enhancement. We show its effectiveness by using it as a guide for optimal bit assignment of an embedded foveated image coding system. The coding system demonstrates very good coding performance and scalability in terms of foveated objective as well as subjective quality measurement.

The novel genistein (G) derivative, 6-carboxymethyl genistein (CG) was evaluated for its biological properties in comparison with G. Both compounds showed oestrogenic activity in vitro and in vivo. On the other hand G and CG differed in the following parameters: (i) only CG displayed mixed agonist-antagonist activity for oestrogen receptor (ER) in transactivation assays and (ii) only CG was capable of attenuating oestrogen (E 2 )-induced proliferation in vascular smooth muscle cells and of inhibiting oestrogen-induced creatine kinase (CK) specific activity in rat tissues. On the other hand only G enhanced the stimulatory effect on CK specific activity in the uterus. In comparison to the selective oestrogen receptor modulator (SERM) raloxifene (RAL), CG showed the same selectivity profile as RAL in blocking the CK response to E 2 in tissues derived from both immature and ovariectomized female rats. Molecular modelling of CG bound to the ligand binding domain (LBD) of ER predicts that the 6-carboxymethyl group of CG almost fits the binding cavity. On the other hand, molecular modelling of CG bound to the LBD of ER suggests that the carboxyl group of CG may perturb the end of Helix 11, eliciting a severe backbone change for Leu 525, and consequently induces a conformational change which could position Helix 12 in an antagonist conformation. This model supports the experimental findings that CG can act as a mixed agonist-antagonist when E 2 is bound to its receptors. Collectively, our findings suggest that CG can be considered a novel SERM with unique effects on the vasculature, bone and uterus.