Superior Orthonasal but Not Retronasal Olfactory Skills in Congenital Blindness

Sight is undoubtedly important for finding and appreciating food, and cooking. Blind individuals are strongly impaired in finding food, limiting the variety of flavours they are exposed to. We have shown before that compared to sighted controls, congenitally blind individuals have enhanced olfactory but reduced taste perception. In this study we tested the hypothesis that congenitally blind subjects have enhanced orthonasal but not retronasal olfactory skills. Twelve congenitally blind and 14 sighted control subjects, matched in age, gender and body mass index, were asked to identify odours using grocery-available food powders. Results showed that blind subjects were significantly faster and tended to be better at identifying odours presented orthonasally. This was not the case when odorants were presented retronasally. We also found a significant group x route interaction, showing that although both groups performed better for retronasally compared to orthonasally presented odours, this gain was less pronounced for blind subjects. Finally, our data revealed that blind subjects were more familiar with the orthonasal odorants and used the retronasal odorants less often for cooking than their sighted counterparts. These results confirm that orthonasal but not retronasal olfactory perception is enhanced in congenital blindness, a result that is concordant with the reduced food variety exposure in this group.     

Development of an Accelerometer-Linked Online Intervention System to Promote Physical Activity in Adolescents

Most adolescents do not achieve the recommended levels of moderate-to-vigorous physical activity (MVPA), placing them at increased risk for a diverse array of chronic diseases in adulthood. There is a great need for scalable and effective interventions that can increase MVPA in adolescents. Here we report the results of a measurement validation study and a preliminary proof-of-concept experiment testing the impact of Zamzee, an accelerometer-linked online intervention system that combines proximal performance feedback and incentive motivation features to promote MVPA. In a calibration study that parametrically varied levels of physical activity in 31 12-14 year-old children, the Zamzee activity meter was shown to provide a valid measure of MVPA (sensitivity in detecting MVPA = 85.9%, specificity = 97.5%, and r = .94 correspondence with the benchmark RT3 accelerometer system; all p < .0001). In a subsequent randomized controlled multi-site experiment involving 182 middle school-aged children assessed for MVPA over 6 wks, intent-to-treat analyses found that those who received access to the Zamzee intervention had average MVPA levels 54% greater than those of a passive control group (p < 0.0001) and 68% greater than those of an active control group that received access to a commercially available active videogame (p < .0001). Zamzee’s effects on MVPA did not diminish significantly over the course of the 6-wk study period, and were statistically significant in both females and males, and in normal- vs. high-BMI subgroups. These results provide promising initial indications that combining the Zamzee activity meter with online proximal performance feedback and incentive motivation features can positively impact MVPA levels in adolescents.     

Indication of dynamic neurovascular coupling from inconsistency between EEG and fMRI indices across sleep–wake states

Sleep and Biological Rhythms - Neurovascular coupling (NVC), the transient regional hyperemia following the evoked neuronal responses, is the basis of blood oxygenation level-dependent techniques...     

Comparing the use of leaf and cambium tissue in a single genetic study of tropical trees

Amplified fragment length polymorphisms (AFLPs) are a useful molecular tool for studying species with little available genetic information; however, since universal primers are used contaminant DNA from non-target organisms may also be amplified. Cambium tissue may contain fewer biotic contaminants or plant defense chemicals, than the more commonly used leaf tissue, and therefore be more suitable for use as a source of DNA when using universal primers. On the other hand, cambium tissue can be difficult to identify, yields low DNA and requires the bark of the tree to be damaged, thereby increasing the risk of introducing disease. We show that within two tropical tree species, there are few differences between AFLP profiles obtained from either cambium or leaf tissue from the same tree. We studied 50 Brosimum alicastrum individuals at 119 AFLP loci and 40 Swietenia macrophylla individuals at 112 AFLP loci. The matrix of S?rensen similarity indices between individual AFLP profiles for cambium samples was strongly correlated to the matrix for leaf samples in each species (Mantel test; B. alicastrum r = 0.815, P < 0.001; S. macrophylla r = 0.895, P < 0.001). The phylogenetic relationship between the trees studied did not differ dependent on tissue type used and therefore shows that both tissues can be used within a single study without introducing substantial error.     

Inhibition of yeast binding to mouse peritoneal macrophages by wheat germ agglutinin: a novel effect of the lectin on phagocytic cells

The ability of wheat germ agglutinin (WGA) to enhance the binding of bacteria and tumor cells to phagocytic cells, and to induce the killing of tumor cells by macrophages and monocytes, is well established. We observed, however, that WGA inhibits the binding to and phagocytosis of yeast cells by thioglycolate-elicited murine peritoneal macrophages. In order to follow these processes rapidly, the yeasts were labeled with Congo-red and their binding to the macrophages was measured spectrophotometrically after treatment with sodium dodecylsulfate. Phagocytosis was also followed by light microscopy. Binding of the yeasts was inhibited by about 80% after pretreating the macrophages with 150 micrograms/ml of WGA. This effect was reversed by subsequent incubation with N-acetyl-D-glucosamine, chitobiose or chitotriose, but was unaffected by methyl alpha-D-mannoside, N-acetyl-D-mannosamine, D-mannose or D-galactose. Pretreatment of the Congo-red yeasts with WGA did not inhibit their binding by the macrophages. Of a variety of lectins tested, only WGA and Datura stramonium lectin had this effect. Pretreating the macrophages with sialidase prevented the inhibition induced by WGA. Our findings suggest the presence on the macrophages of a class of WGA receptors not previously reported.     

Crystallization and preliminary X-ray diffraction studies of the lectin from Erythrina corallodendron

The lectin from Erythrina corallodendron, specific for N-acetyllactosamine, crystallizes in the hexagonal space group P6(1) (P6(5)) with unit cell dimensions a = b = 136.3 A, c = 83.2 A and one dimer of Mr 60,000 in the asymmetric unit. The crystals are suitable for high-resolution work.