Neural correlates of counting large numerosity

The mastery of counting numerosities larger than those correctly estimated by infants or non-human species is an important foundation for the development of higher level calculation skills. The cognitive processes involved in counting are related to spatial attention, language, and number processing. However, the respective involvement of language- and/or visuo-spatial-based brain systems during counting is still under debate. In the present functional magnetic resonance imaging study, we asked 27 right-handed participants to perform an enumeration task on visual arrays of bars that varied in numerosity. Each enumeration condition was contrasted to a color-detection condition that was numerically and spatially matched to the counting condition. The results showed a behavioral discontinuity in response time slopes between large (6–10) and small (1–5) numerosities during enumeration, suggesting that during large enumeration, participants engaged counting processes. Comparing brain regional activity during the enumeration of large numerosity to the enumeration of smaller numerosity, we found increased activation in the bilateral fronto-parietal attentional network, the inferior parietal gyri/intraparietal sulci, and the left ventral premotor and left inferior temporal areas. These results indicated that in adults who master enumeration, counting more than five items requires the strong involvement of spatial attention and eye movements, as well as numerical magnitude processes. Counting large numerosity also recruited verbal working memory areas, subtending a subvocal articulatory code and a visual representation of numbers.     

Aqueous phase transfer hydrogenation of aryl ketones catalysed by achiral ruthenium(II) and rhodium(III) complexes and their papain conjugates

Several ruthenium and rhodium complexes including 2,2′‐dipyridylamine ligands substituted at the central N atom by an alkyl chain terminated by a maleimide functional group were tested along with a newly synthesized Rh(III) complex of unsubstituted 2,2′‐dipyridylamine as catalysts in the transfer hydrogenation of aryl ketones in neat water with formate as hydrogen donor. All of them except one led to the secondary alcohol products with conversion rates depending on the metal complex. Site‐specific anchoring of the N‐maleimide complexes to the single free cysteine residue of the cysteine endoproteinase papain endowed this protein with transfer hydrogenase properties towards 2,2,2‐trifluoroacetophenone. Quantitative conversions were reached with the Rh‐based biocatalysts, while modest enantioselectivities were obtained in certain reactional conditions. Copyright © 2012 John Wiley & Sons, Ltd.     

On permanental processes

Permanental processes can be viewed as a generalization of squared centered Gaussian processes. We analyze the connections of these processes with the local time process of general Markov processes. The obtained results are related to the notion of infinite divisibility.     

New acorane sesquiterpenes isolated from the endophytic fungus Colletotrichum gloeosporioides SNB-GSS07

Looking for new anti-glycation compounds, four new acorane sesquiterpenes together with seven known molecules were isolated from Colletrotrichum gloeosporioides, an endophytic fungus of Sabicea cinerea. Their structures were established based on mass spectrometry and NMR, together with circular dichroism for their absolute configurations.     

A new crystalline phase of nitric acid dihydrate

The crystal structure of a new high-temperature phase of nitric acid dihydrate, HNO₃·2H₂O, has been determined at 225 K by single-crystal X-ray diffraction. The H atom of the nitric acid is delocalized to one water mol­ecule, leading to an association of equimolar NO₃⁻ and H₅O₂⁺ ionic groups. The asymmetric unit contains two mol­ecules of HNO₃·2H₂O. The two independent mol­ecules are related by a pseudo-twofold c axis, by a translation of 0.54 (approximately ½) along b , with a mean atomic distance difference of 0.3 Å, except for one H atom of the water mol­ecules (1.5 Å), because of their different orientations in the two mol­ecules. The two independent mol­ecules, linked by strong hydrogen bonds, are arranged in layers. These layers are linked by weaker hydrogen bonds oriented approximately along the c axis. A three-dimensional hydrogen-bond network is observed.