A multidimensional statistical study of similarities between 74 notes used in perfumery

From a data bank of 2467 odoriferous products, the similaritiesbetween 74 notes used in perfumery were calculated. The similaritymatrix (74,74) contains – 63% of zero values and showsthat only a few pairs of notes present high similarity coefficients.A fine analysis using ascending hierarchical taxonomy with thecomplete linkage procedure shows that 14 notes are isolatedwhile 60 notes are regrouped in 27 groups containing two tofour notes. The isolated notes correspond to well-defined structuralparticularities. Some pairs of notes or groups present similaritiesin their chemical structures but some groups are built on thebasis of semantic processes. This study shows that the notesare generally independent, with no strict hierarchy among them,and rules out the existence of primary odors.     

Physiological effects of inspiratory resistance on progressive aerobic work

The purpose of this study was to determine the potential effects on progressive aerobic work while breathing through a new military type chemical and biological (CB) respirator loaded with three different types of purifying canisters. Twelve healthy well-motivated male subjects (mean age 23 +/- 3 years) participated in the study. Results indicated that mean maximal oxygen uptake (VO2max), time to exhaustion, respiratory exchange ratio, rate of perceived exertion, respiratory rate and tidal volume at exhaustion, maximal lactate and the 2-min post-exercise lactate were not significantly influenced when breathing with the respirator and the canisters in comparison to a laboratory valve. Mean pulmonary ventilation, however, was reduced by 21% while oxygen and carbon dioxide ventilatory equivalents were significantly lower by 9% and 8% respectively. Review of the stage-by-stage responses to the treadmill test between the laboratory valve and respirator/canister conditions indicated no significant differences (NS) in oxygen uptake but slightly lower heart rates (NS). Ventilation was not influenced by the canisters until 80% of VO2max at which time the mean oxygen ventilatory equivalent became significantly lower. Blood lactate was significantly depressed between 60% and 90% VO2max under the respirator/canister conditions. It was concluded that, although physiological adaptation occurred, breathing with the new CB respirator and each of the three purifying canisters had no detrimental effect on progressive aerobic work to exhaustion. However, prolonged work at intensities greater than 80-85% of VO2max would in all probability be impaired when breathing with the CB mask and the canisters.     

Follicular regulatory T cells produce neuritin to regulate B cells

1. Download : Download high-res image (167KB)
2. Download : Download full-size image

     

Implications phylogenetiques et biogeographiques des dernieres decouvertes de Muridae en Afghanistan,au Pakistan et en Ethiopie

Based on recent discoveries of Murid species in Pakistan and Afghanistan, two Asiatic autochtonous lineagesare proposed. Two forms from the African Pliocene seem to be related to these lineages. On this set of data, a new faunal province can be defined at the Mio-Pliocene boundary.     

Alkaloids of Fumaria vaillantii

The aerial parts of Turkish Fumaria vaillantii yielded 26 isoquinoline alkaloids. Of these, oxysanguinarine, (±)-8-acetonyldihydrosanguinarine, (±)-8-methoxydihydrosanguinarine and fumaramidine are reported for the first time from this plant. New alkaloids for the genus Fumaria are dihydrosanguinarine, norsanguinarine, (+)-isocorydine, (?)-corledine and (+)-juziphine. This is the first occurrence of the isoquinolone N-methylcorydaldine in a member of the Fumariaceae. Spectral data are given for the new compound, E-fumaramine.     

Fantastic Ca2+ “z-waves” fade out quietly

The first report that high speed Ca²⁺ waves travel in a restricted zone around the cell periphery in a clockwise manner and which can only be revealed by very high speed imaging has been quietly retracted. In the original report, a single small region of high Ca²⁺ was seen to spin around the cell periphery and around phagosomes formed within phagocytes in a manner unlike anything reported previously. This consequently caused a lot of interest. Several other papers reporting a similar phenomenon in a variety of cells were also published by the same lab and the phenomenon has been included in high profile reviews such as in Science. However, several groups have failed to reproduce this work and attempts to detect the Ca²⁺ waves or the mechanism for their generation have failed. Now, the original report has been quietly retracted. In this short commentary, we give a brief account of the sorry story of the non-existent circulating Ca²⁺ waves (z-waves) in the hope that the literature can be rectified and that future cell calcium biologists are not misled by these fantastic and spurious Ca²⁺ reports.