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Pre-saccadic perception: separate time courses for enhancement and spatial pooling at the saccade target
We interact with complex scenes using eye movements to select targets of interest. Studies have shown that the future target of a saccadic eye movement is processed differently by the visual system. A number of effects have been reported, including a benefit for perceptual performance at the target (“enhancement”), reduced influences of backward masking (“unmasking”), reduced crowding (“un-crowding”) and spatial compression towards the saccade target. We investigated the time course of these effects by measuring orientation discrimination for targets that were spatially crowded or temporally masked. In four experiments, we varied the target-flanker distance, the presence of forward/backward masks, the orientation of the flankers and whether participants made a saccade. Masking and randomizing flanker orientation reduced performance in both fixation and saccade trials. We found a small improvement in performance on saccade trials, compared to fixation trials, with a time course that was consistent with a general enhancement at the saccade target. In addition, a decrement in performance (reporting the average flanker orientation, rather than the target) was found in the time bins nearest saccade onset when random oriented flankers were used, consistent with spatial pooling around the saccade target. We did not find strong evidence for un-crowding. Overall, our pattern of results was consistent with both an early, general enhancement at the saccade target and a later, peri-saccadic compression/pooling towards the saccade target
Longitudinal analysis of the developing rhesus monkey brain using magnetic resonance imaging: birth to adulthood.
We have longitudinally assessed normative brain growth patterns in naturalistically reared Macaca mulatta monkeys. Postnatal to early adulthood brain development in two cohorts of rhesus monkeys was analyzed using magnetic resonance imaging. Cohort A consisted of 24 rhesus monkeys (12 male, 12 female) and cohort B of 21 monkeys (11 male, 10 female). All subjects were scanned at 1, 4, 8, 13, 26, 39, and 52 weeks; cohort A had additional scans at 156 weeks (3 years) and 260 weeks (5 years). Age-specific segmentation templates were developed for automated volumetric analyses of the T1-weighted magnetic resonance imaging scans. Trajectories of total brain size as well as cerebral and subcortical subdivisions were evaluated over this period. Total brain volume was about 64 % of adult estimates in the 1-week-old monkey. Brain volume of the male subjects was always, on average, larger than the female subjects. While brain volume generally increased between any two imaging time points, there was a transient plateau of brain growth between 26 and 39 weeks in both cohorts of monkeys. The trajectory of enlargement differed across cortical regions with the occipital cortex demonstrating the most idiosyncratic pattern of maturation and the frontal and temporal lobes showing the greatest and most protracted growth. A variety of allometric measurements were also acquired and body weight gain was most closely associated with the rate of brain growth. These findings provide a valuable baseline for the effects of fetal and early postnatal manipulations on the pattern of abnormal brain growth related to neurodevelopmental disorders
Isolation of anaerobic, extremely thermophilic, sulphur metabolising archaebacteria from New Zealand hot springs
Enrichments of New Zealand geo-thermal samples, initiated in anaerobic sulphur-containing media and incubated at temperatures above 85°C, yielded rod and coccal shaped organisms which possessed archaebacterial characteristics. Pure cultures were isolated and characterised. Five of the seven isolates, which were rod-shaped organisms and did not have an obligate requirement for sulphur respiration, were similar to Ther-moproteus sp. but had more neutral pH optima for growth. Three of these five Thermoproteus sp. were obligate heterotrophs, which has not previously been reported. The two coccal isolates had an obligate requirement for sulphur as an electron acceptor and were similar to Desulfurococcus sp. but again with more neutral pH optima for growth
A genomic atlas of human adrenal and gonad development [version 2; referees: 4 approved]
BACKGROUND: In humans, the adrenal glands and gonads undergo distinct
biological events between 6-10 weeks post conception (wpc), such as testis
determination, the onset of steroidogenesis and primordial germ cell
development. However, relatively little is currently known about the genetic
mechanisms underlying these processes. We therefore aimed to generate a
detailed genomic atlas of adrenal and gonad development across these critical
stages of human embryonic and fetal development.
METHODS: RNA was extracted from 53 tissue samples between 6-10 wpc
(adrenal, testis, ovary and control). Affymetrix array analysis was performed
and differential gene expression was analysed using Bioconductor. A
mathematical model was constructed to investigate time-series changes across
the dataset. Pathway analysis was performed using ClueGo and cellular
localisation of novel factors confirmed using immunohistochemistry.
RESULTS: Using this approach, we have identified novel components of adrenal
development (e.g. ASB4, NPR3) and confirmed the role of SRY as the main
human testis-determining gene. By mathematical modelling time-series data
we have found new genes up-regulated with SOX9 in the testis (e.g. CITED1),
which may represent components of the testis development pathway. We have
shown that testicular steroidogenesis has a distinct onset at around 8 wpc and
identified potential novel components in adrenal and testicular steroidogenesis
(e.g. MGARP, FOXO4, MAP3K15, GRAMD1B, RMND2), as well as testis
biomarkers (e.g. SCUBE1). We have also shown that the developing human
ovary expresses distinct subsets of genes (e.g. OR10G9, OR4D5), but
enrichment for established biological pathways is limited.
CONCLUSION: This genomic atlas is revealing important novel aspects of human
development and new candidate genes for adrenal and reproductive disorders
A genomic atlas of human adrenal and gonad development [version 1; referees: awaiting peer review]
Background: In humans, the adrenal glands and gonads undergo distinct biological events between 6-10 weeks post conception (wpc), such as testis determination, the onset of steroidogenesis and primordial germ cell development. However, relatively little is currently known about the genetic mechanisms underlying these processes. We therefore aimed to generate a detailed genomic atlas of adrenal and gonad development across these critical stages of human embryonic and fetal development. / Methods: RNA was extracted from 53 tissue samples between 6-10 wpc (adrenal, testis, ovary and control). Affymetrix array analysis was performed and differential gene expression was analysed using Bioconductor. A mathematical model was constructed to investigate time-series changes across the dataset. Pathway analysis was performed using ClueGo and cellular localisation of novel factors confirmed using immunohistochemistry. / Results: Using this approach, we have identified novel components of adrenal development (e.g. ASB4, NPR3) and confirmed the role of SRY as the main human testis-determining gene. By mathematical modelling time-series data we have found new genes up-regulated with SOX9 in the testis (e.g. CITED1), which may represent components of the testis development pathway. We have shown that testicular steroidogenesis has a distinct onset at around 8 wpc and identified potential novel components in adrenal and testicular steroidogenesis (e.g. MGARP, FOXO4, MAP3K15, GRAMD1B, RMND2), as well as testis biomarkers (e.g. SCUBE1). We have also shown that the developing human ovary expresses distinct subsets of genes (e.g. OR10G9, OR4D5), but enrichment for established biological pathways is limited. / Conclusion: This genomic atlas is revealing important novel aspects of human development and new candidate genes for adrenal and reproductive disorders
Characterization of cDNA clones of the family of trypsin/α-amylase inhibitors (CM-proteins) in barley (Hordeum vulgare L.)
Recombinants encoding members of the trypsin/-amylase inhibitors family (also designated CM-proteins) were selected from a cDNA library prepared from developing barley endosperm. Inserts in two of the clones, pUP-13 and pUP-38, were sequenced and found to encode proteins which clearly belong to this family, as judged from the extensive homology of the deduced sequences with that of the barley trypsin inhibitor CMe, the only member of the group for which a complete amino acid sequence has been obtained by direct protein sequencing. These results, together with previously obtained N-terminal sequences of purified CM-proteins, imply that there are at least six different members of this dispersed gene family in barley. The relationship of this protein family to the B-3 hordein and to reserve prolamins from related species is discussed in terms of their genome structure and evolution
Time-dependent inhibition of covert shifts of attention
Buonocore A, Dietze N, McIntosh RD. Time-dependent inhibition of covert shifts of attention. Experimental brain research. 2021.Visual transients can interrupt overt orienting by abolishing the execution of a planned eye movement due about 90ms later, a phenomenon known as saccadic inhibition (SI). It is not known if the same inhibitory process might influence covert orienting in the absence of saccades, and consequently alter visual perception. In Experiment 1 (n=14), we measured orientation discrimination during a covert orienting task in which an uninformative exogenous visual cue preceded the onset of an oriented probe by 140-290ms. In half of the trials, the onset of the probe was accompanied by a brief irrelevant flash, a visual transient that would normally induce SI. We report a time-dependent inhibition of covert orienting in which the irrelevant flash impaired orientation discrimination accuracy when the probe followed the cue by 190 and 240ms. The interference was more pronounced when the cue was incongruent with the probe location, suggesting an impact on the reorienting component of the attentional shift. In Experiment 2 (n=12), we tested whether the inhibitory effect of the flash could occur within an earlier time range, or only within the later, reorienting range. We presented probes at congruent cue locations in a time window between 50 and 200ms. Similar to Experiment 1, discrimination performance was altered at 200ms after the cue. We suggest that covert attention may be susceptible to similar inhibitory mechanisms that generate SI, especially in later stages of attentional shifting (>200ms after a cue), typically associated with reorienting
Structural, Electronic and Vibrational Properties of B24N24 Nanocapsules: Novel Anodes for Magnesium Batteries
We report on DFT-TDDFT studies of the structural, electronic and vibrational properties of (Formula presented.) nanocapsules and the effect of encapsulation of homonuclear diatomic halogens ((Formula presented.), (Formula presented.) and (Formula presented.)) and chalcogens ((Formula presented.) and (Formula presented.)) on the interaction of the (Formula presented.) nanocapsules with the divalent magnesium cation. In particular, to foretell whether these BN nanostructures could be proper negative electrodes for magnesium-ion batteries, the structural, vibrational and electronic properties, as well as the interaction energy and the cell voltage, which is important for applications, have been computed for each system, highlighting their differences and similarities. The encapsulation of halogen and chalcogen diatomic molecules increases the cell voltage, with an effect enhanced down groups 16 and 17 of the periodic table, leading to better performing anodes and fulfilling a remarkable cell voltage of 3.61 V for the iodine-encapsulated system
Pictorial depth cues always influence reaching distance
We report five experiments to test the influence of pictorial depth on reaching. Our core method is to project a wide-field background of linear perspective and/or texture gradient onto a tabletop, and to measure the amplitude of reaches made to targets within it. In 63 healthy participants performing immediate open-loop reaches across Experiments 1–4, we observed a clear effect of pictorial depth. This effect was driven specifically by the convergence of the background pattern at the target position: for each additional degree of pictorial convergence, reaching distance increased by half a millimetre. In the individual experiments, we applied manipulations that might be expected to modify the influence of pictorial depth. We found no evidence that the effect was modified with monocular viewing, or when participants responded with the left hand, or if a memory delay was inserted before the response. Nor did participants become less susceptible to pictorial depth when visual feedback of terminal reaching errors was provided, although visual feedback during the reach did mitigate the influence of pictorial depth. Finally, the visual form agnosic patient DF showed an entirely normal effect of pictorial depth cues, which leads us to question the idea that this effect emanates from visual analyses of size and shape in the ventral stream, rather than from the dorsal stream, or from earlier stages of visual processing
Targeted emission reductions from global super-polluting power plant units
There are more than 30,000 biomass- and fossil-fuel-burning power plants now operating worldwide, reflecting a tremendously diverse infrastructure, which ranges in capacity from less than a megawatt to more than a gigawatt. In 2010, 68.7% of electricity generated globally came from these power plants, compared with 64.2% in 1990. Although the electricity generated by this infrastructure is vital to economic activity worldwide, it also produces more CO2 and air pollutant emissions than infrastructure from any other industrial sector. Here, we assess fuel- and region-specific opportunities for reducing undesirable air pollutant emissions using a newly developed emission dataset at the level of individual generating units. For example, we find that retiring or installing emission control technologies on units representing 0.8% of the global coal-fired power plant capacity could reduce levels of PM2.5 emissions by 7.7–14.2%. In India and China, retiring coal-fired plants representing 1.8% and 0.8% of total capacity can reduce total PM2.5 emissions from coal-fired plants by 13.2% and 16.0%, respectively. Our results therefore suggest that policies targeting a relatively small number of ‘super-polluting’ units could substantially reduce pollutant emissions and thus the related impacts on both human health and global climate
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