A New Metric for Grey-Scale Image Comparison

Error measures can be used to numerically assess the differences between two images. Much work has been done on binary error measures, but little on objective metrics for grey-scale images. In our discussion here we introduce a new grey-scale measure, ^g, aiming to improve upon the most common grey-scale error measure, the root-mean-square error. Our new measure is an extension of the authors' recently developed binary error measure, ^b, not only in structure, but also having both a theoretical and intuitive basis. We consider the similarities between ^b and ^g when tested in practice on binary images, and present results comparing ^g to the root-mean-squared error and the Sobolev norm for various binary and grey-scale images. There are no previous examples where the last of these measures, the Sobolev norm, has been implemented for this purpose.     

Site-directed mutagenesis of Arg60 and Cys271 in ornithine transcarbamylase from rat liver

We have investigated the putative carbamylphosphate- and ornithine-bindingdomains in ornithine transcarbamylase from rat liver using site-directedmutagenesis. Arg60, present in the phosphate-binding motif X-Ser-X-Arg-Xand therefore implicated in the binding of the phosphate moietyof carbamylphosphate has been replaced with a leucine. Thisresults in a dramatic reduction of catalytic activity, althoughthe enzyme is synthesized in cells stably transfected with themutant clone and imported, correctly processed and assembledinto a homotrimer in mitochondria. The sole cysteine residue(Cys271) has been implicated in ornithine binding by the chemicalmodification studies of Marshall and Cohen in 1972 and 1980(J. Biol. Chem., 247, 1654–1668, 1669–1682; 255,7291–7295, 7296–7300). Replacement of this residuewith serine did not eliminate enzyme activity but affected theMichaelis constant for ornithine (K_b, increasing it 5-fold from0.71 to 3.7 mM and reduced the k_cat at pH 8.5 by 20-fold. Thesechanges represent a loss in apparent binding energy for theenzyme - ornithine complex of 2.9 kcal/mol, suggesting thatCys271 is normally involved in hydrogen bonding to the substrate,ornithine. The cysteine to serine substitution also caused thedissociation constant (Kä for the competitive inhibitor,L-norvaline to be increased 10-fold, from 12 to 120 µM.The small loss in binding energy and relatively high residualcatalytic activity of the mutant strongly suggests that a numberof other residues are involved in the binding of ornithine.The effect of replacement of Cys271 with serine was restrictedto the ornithine binding site of the enzyme since both the bindingconstant for carbamyl-phosphate (K_ia) and Michaelis constant(K_a) were not appreciably different for mutant and wild-typeenzymes. The pH optimum of the wild-type enzyme (8.6) is increasedto > 9.6 in the Ser271 mutant.     

Subcortical cognitive impairment in dialysis patients

Given the high burden of atherosclerotic cardiovascular disease in dialysis patients, we hypothesized that cognitive testing would reveal subtle abnormalities in subcortical brain function, a measure frequently associated with cerebrovascular disease. Detailed neurocognitive testing was performed in 25 hemodialysis patients. All patients had Mini-Mental State Examination (MMSE) scores >24 and had no history of cerebrovascular disease. Where appropriate, scores were normalized for age, gender, and education. One-sample t tests were used to compare differences in cognitive function between dialysis patients and normative data. The mean age was 57 years, and the mean MMSE was 27.5. Fourteen subjects (56%) were females, and 15 white (60%). Results of the North American Adult Reading Test, a measure of verbal intelligence, were comparable with the general population. Similarly, measures of cortical function, namely retention and recognition scores from the Word List Learning subtest of the Wechsler Memory Scale-III, were preserved when compared with normative data where reference = 10. Significant deficits were seen on tests assessing subcortical function: scores (mean+/-standard deviation) for block design, and symbol coding subtests of the Wechsler Adult Intelligence Scale-III were 7.0+/-1.7 and 7.7+/-3.1, respectively (p<0.001 for both comparisons with normative data). Similarly, adjusted scores on the trails A and B tests were 40.5+/-8.3 and 41.8+/-11.3, respectively (p<0.001 for both comparisons with normative data where reference= 50). These results suggest that, despite relatively normal MMSE scores, mild cognitive impairment may be prevalent in hemodialysis patients. The pattern of cognitive dysfunction is primarily subcortical in nature.     

Meat color is determined not only by chromatic heme pigments but also by the physical structure and achromatic light scattering properties of the muscle

Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color. Differences in achromatic light scattering between light and dark extremes of meat color are most likely explained by structural attributes within the muscle cell. These differences are proposed to arise from variations in (a) transverse shrinkage of the structural lattice of the myofilaments, myofibrils, and muscles fibers, (b) longitudinal shrinkage of the sarcomere, and (c) different protein composition of the surrounding medium (sarcoplasm and extracellular space). These are discussed at a mechanistic level, in relation to six parameters of the muscle cell: (a) protein surface charge altering the myofilament spacing, (b) protein solubility, (c) sarcoplasmic protein binding to myofilaments and myofibrils, (d) integrity of the cytoskeleton and cell adhesion proteins, (e) sarcomere integrity and myofibrillar proteins, and (f) myosin denaturation and rigor bond modification. New data are presented to support the proposed role of structural elements in muscle causing achromatic light scattering and their contribution to the surface color of meat. In addition, the relationships between lightness and water holding capacity and pH are explored and the economic impact of dark meat for the meat industry is discussed.     

Effect of Heat Processing on IgE Reactivity and Cross‐Reactivity of Tropomyosin and Other Allergens of Asia‐Pacific Mollusc Species: Identification of Novel Sydney Rock Oyster Tropomyosin Sac g 1

1 Scope

Shellfish allergy is an increasing global health priority, frequently affecting adults. Molluscs are an important shellfish group causing food allergy but knowledge of their allergens and cross‐reactivity is limited. Optimal diagnosis of mollusc allergy enabling accurate advice on food avoidance is difficult. Allergens of four frequently ingested Asia‐Pacific molluscs are characterized: Sydney rock oyster (Saccostrea glomerata), blue mussel (Mytilus edulis), saucer scallop (Amusium balloti), and southern calamari (Sepioteuthis australis), examining cross‐reactivity between species and with blue swimmer crab tropomyosin, Por p 1.

2 Methods and results

IgE ELISA showed that cooking increased IgE reactivity of mollusc extracts and basophil activation confirmed biologically relevant IgE reactivity. Immunoblotting demonstrated strong IgE reactivity of several proteins including one corresponding to heat‐stable tropomyosin in all species (37–40 kDa). IgE‐reactive Sydney rock oyster proteins were identified by mass spectrometry, and the novel major oyster tropomyosin allergen was cloned, sequenced, and designated Sac g 1 by the IUIS. Oyster extracts showed highest IgE cross‐reactivity with other molluscs, while mussel cross‐reactivity was weakest. Inhibition immunoblotting demonstrated high cross‐reactivity between tropomyosins of mollusc and crustacean species.

3 Conclusion

These findings inform novel approaches for reliable diagnosis and improved management of mollusc allergy.     

The effect of accuracy motivation on anchoring and adjustment: Do people adjust from provided anchors?

Increasing accuracy motivation (e.g., by providing monetary incentives for accuracy) often fails to increase adjustment away from provided anchors, a result that has led researchers to conclude that people do not effortfully adjust away from such anchors. We challenge this conclusion. First, we show that people are typically uncertain about which way to adjust from provided anchors and that this uncertainty often causes people to believe that they have initially adjusted too far away from such anchors (Studies 1a and 1b). Then, we show that although accuracy motivation fails to increase the gap between anchors and final estimates when people are uncertain about the direction of adjustment, accuracy motivation does increase anchor–estimate gaps when people are certain about the direction of adjustment, and that this is true regardless of whether the anchors are provided or self-generated (Studies 2, 3a, 3b, and 5). These results suggest that people do effortfully adjust away from provided anchors but that uncertainty about the direction of adjustment makes that adjustment harder to detect than previously assumed. This conclusion has important theoretical implications, suggesting that currently emphasized distinctions between anchor types (self-generated vs. provided) are not fundamental and that ostensibly competing theories of anchoring (selective accessibility and anchoring-and-adjustment) are complementary. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposures to transit and other sources of noise among New York City residents

To evaluate the contributions of common noise sources to total annual noise exposures among urban residents and workers, we estimated exposures associated with five common sources (use of mass transit, occupational and nonoccupational activities, MP3 player and stereo use, and time at home and doing other miscellaneous activities) among a sample of over 4500 individuals in New York City (NYC). We then evaluated the contributions of each source to total noise exposure and also compared our estimated exposures to the recommended 70 dBA annual exposure limit. We found that one in ten transit users had noise exposures in excess of the recommended exposure limit from their transit use alone. When we estimated total annual exposures, 90% of NYC transit users and 87% of nonusers exceeded the recommended limit. MP3 player and stereo use, which represented a small fraction of the total annual hours for each subject on average, was the primary source of exposure among the majority of urban dwellers we evaluated. Our results suggest that the vast majority of urban mass transit riders may be at risk of permanent, irreversible noise-induced hearing loss and that, for many individuals, this risk is driven primarily by exposures other than occupational noise.     

Pre-rigor temperature and the relationship between lamb tenderisation,free water production,bound water and dry matter

The M. longissimus from lambs electrically stimulated at 15 min post-mortem were removed after grading, wrapped in polythene film and held at 4 (n = 6), 7 (n = 6), 15 (n = 6, n = 8) and 35 °C (n = 6), until rigor mortis then aged at 15 °C for 0, 4, 24 and 72 h post-rigor. Centrifuged free water increased exponentially, and bound water, dry matter and shear force decreased exponentially over time. Decreases in shear force and increases in free water were closely related (r² = 0.52) and were unaffected by pre-rigor temperatures.     

Gender,Class and Home Ownership: Placing the Connections

This paper contributes to understandings of how gender interacts with the social class implications of home ownership. It is argued that the connections between gender, class and home ownership have only been partially elaborated, and suggested that a more specific focus on identity and the socio-spatial context facilitates a more complex portrayal of these connections. Using material from in-depth, semi-structured interviews with 60 men and women in two neighbourhoods in Vancouver, British Columbia, it will be demonstrated that, contrary to common expectations, home ownership is an important component of both middle-class masculinity and middle-class femininity. However, there is no singular or linear connection between gender, class and home. Instead, there is conflict between familial and status expressions of home, conflict that varies for men and women and according to geographical location.