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Space-number and space-time associations have been a timely topic in the cognitive sciences for years, but evidence from developmental populations is still scarce. In particular, it remains to be established whether space-number and space-time mappings are anchored onto the same spatial frame of reference across development. To explore this issue, we manipulated visual and proprioceptive feedback in a Number Comparison task (Experiment 1) and a Time Comparison task (Expriment 2), in which 6- and 10-year-old children had to classify numerical and temporal words by means of a lateralised response with or without a blindfold (visual manipulation), and with hands uncrossed or crossed over the body midline (proprioceptive manipulation). Results revealed that 10-year-old children were more efficient in associating smaller numbers and past events with the left key, and larger numbers and future events with the right key, irrespective of the visual and proprioceptive manipulations. On the contrary, younger children did so only in the Time Comparison task, but not in the Number Comparison task. In the latter task, 6-year-olds associated small/large numbers with the left/right side of space only in the presence of visual feedback, but not when blindfolded. Taken together, our findings unveil that in school-aged children the spatial representation of number and time develop on different spatial frames of reference: while space-time associations exclusively rely on external coordinates at age 6, space-number associations shift from mixed internal and external coordinates at age 6 to more adult-like external coordinates by age 10.

Studies to determine the population fluctuation of Diaphorina citri, vector of Candidatus Liberibacter sp., have been carried out mainly in commercial plantations, whereas less have focused in urban areas and their synchrony. The objectives of this work were to monitor D. citri adult populations in Murraya paniculata (OJ) in urban areas and in Persian lime (LM) orchards, to estimate the effect of some environmental factors and to evaluate the synchronization between these populations. Sampling was performed from September 2012 to August 2014 in Veracruz, Mexico. Five urban areas and five commercial Persian lime plots close to each other were selected. Adult D. citri catches were made monthly with yellow traps. Vegetative shoots, temperature and relative humidity were measured throughout the sampling period. Adults of Diaphorina citri were captured in all the sampling sites throughout the two-years sampling period and the populations were more abundant in summer. Significant factors affecting trap catches were the presence of new shoots and temperature. Temperature and relative humidity enclosed a comfort zone between 26 and 28 °C and 75 to 85% respectively. Cross-correlation values were positive across hosts within the same locations and between locations, regardless of the distance, thus suggesting a spatial synchronization in trap catches. This spatial relationship represents a risk of infestation between host species because of the potential movement and dispersal.

Infants' attention is captured by the redundancy of amodal stimulation in multimodal objects and events. Evidence from this study demonstrates that intersensory redundancy can facilitate discrimination of rhythm changes presented in the visual modality alone in visually impaired infants, suggesting that multisensory rehabilitation strategies could prove helpful in this population.

We assessed sound localisation abilities of late-implanted adults fitted with a single cochlear implant (CI) and examined whether these abilities are affected by the duration of implant use. Ten prelingually and four postlingually deafened adults who received a unilateral CI were tested in a sound-source identification task. Above chance performance was observed in those prelingual CI recipients who had worn their implant for longer time (9 years on average), revealing some monaural sound localisation abilities in this population but only after extensive CI use. On the contrary, the four postlingual recipients performed equal or better with respect to the best prelingual participants despite shorter experience with the monaural implant (11 months on average). Our findings reveal that some sound localisation ability can emerge in prelingually deafened adults fitted with a single implant, at least in a controlled laboratory setting. This ability, however, appears to emerge only after several years of CI use. Furthermore, the results of four postlingually deafened adults suggest that early experience with auditory cues may result in more rapid acquisition of spatial hearing with a single CI. © 2009 Elsevier B.V. All rights reserved.

Purified cytochrome oxidase was compared to the oxidase on submitochondrial particles with respect to reactions with added soluble cytochrome c. The reactions studied were the spectrophotometric assay of the oxidation of ferrocytochrome c, and the polarographic measurement of the rate of O2 uptake in the presence of N,N,N′,N′-tetramethylphenyl-enediamine plus ascorbate and cytochrome c. The oxidase activity of the preparations expressed in terms of their concentration of cytochrome aa3 was lower with the purified preparation than with the membrane-bound preparation. Apparent KM values for low concentrations of cytochrome c (0.05 to 0.25 μ m ) derived from plots of v S versus v are similar for the two types of preparation when obtained either by the spectrophotometric or polarographic assays. The apparent KM values for higher concentrations of cytochrome c (0.5 to 5.0 μM) are similar in the spectrophotometric assays but different in the polarographic determinations. At pH 7.8 in buffers with nonbinding ions, the rates of O2 uptake measured polarographically were greater than the rates of O2 uptake calculated from the spectrophotometric measurements of the rates of oxidation of ferrocytochrome c ( L. Smith, H. C. Davies, and M. E., Nava (1979) Biochemistry 18, 3140–3146 ). The O2 uptake observed in the polarographic method in excess of that corresponding to the oxidation of ferrocytochrome c is much greater with the membrane-bound (30-fold) than with the purified oxidase (three- to four-fold difference). This implies a decreased ability of the purified preparation to form a complex with a high turnover rate which can be repeatedly reduced by the N,N,N′,N′-tetramethylphenylenediamine plus ascorbate. The extent of cytochrome c which remains oxidized during the aerobic steady state in the presence of the reducing agents is less for the purified than for the particulate preparation, suggesting that the reactive complex of cytochrome c and cytochrome oxidase is not as readily formed with the purified preparation as with the SMP.