495 research outputs found
Exposure to pesticides and risk of amyotrophic lateral sclerosis: a population-based case-control study
A few epidemiologic studies have suggested an association of agricultural work and pesticidesexposure with a severe degenerative disease of the motor neurons, amyotrophic lateral sclerosis(ALS), though conflicting results have also been provided. We investigated through a populationbasedcase-control study the possible relation between overall occupational exposure to pesticidesand ALS risk in the northern Italy municipality of Reggio Emilia. By administering a questionnaire,we investigated occupational history and leisure-time habits of the 41 ALS patients diagnosed in the1995-2006 period, and of 82 age- and sex-matched randomly sampled population controls. Morecases than controls were found to have been exposed to pesticides for at least six months (31.7% vs13.4%, respectively), in all cases within the occupational environment. In a conditional logistic regressionmodel, we found an excess ALS risk associated with exposure to pesticides, with a relativerisk of 3.6 (95% confidence interval 1.2-10.5). Such association persisted after inclusion in the statisticalanalysis of potential confounders. Despite the limited statistical stability of the risk estimates,these results appear to indicate that occupational exposure to pesticides is a risk factor for ALS,suggesting the need to further investigate this issue
Association between cognitive performance and cortical glucose metabolism in patients with mild Alzheimer's disease
Background: Neuronal and synaptic function in Alzheimer's disease (AD) is measured in vivo by glucose metabolism using positron emission tomography (PET). Objective: We hypothesized that neuronal activation as measured by PET is a more sensitive index of neuronal dysfunction than activity during rest. We investigated if the correlations between dementia severity as measured with the Mini Mental State Examination (MMSE) and glucose metabolism are an artifact of brain atrophy. Method: Glucose metabolism was measured using {[}F-18]fluorodeoxyglucose PET during rest and activation due to audiovisual stimulation in 13 mild to moderate AD patients (MMSE score >= 17). PET data were corrected for brain atrophy. Results: In the rest condition, glucose metabolism was correlated with the MMSE score primarily within the posterior cingulate and parietal lobes. For the activation condition, additional correlations were within the primary and association audiovisual areas. Most local maxima remained significant after correcting for brain atrophy. Conclusion: PET activity measured during audiovisual stimulation was more sensitive to functional alterations in glucose metabolism in AD patients compared to the resting PET. The association between glucose metabolism and MMSE score was not dependent on brain atrophy. Copyright (C) 2005 S. Karger AG, Basel
Selective Effects of Cholinergic Modulation on Task Performance during Selective Attention
The cholinergic neurotransmitter system is critically linked to cognitive functions including attention. The current studies were designed to evaluate the effect of a cholinergic agonist and an antagonist on performance during a selective visual attention task where the inherent salience of attended/unattended stimuli was modulated. Two randomized, placebo-controlled, crossover studies were performed, one (n=9) with the anticholinesterase physostigmine (1.0 mg/h), and the other (n=30) with the anticholinergic scopolamine (0.4 mc/kg). During the task, two double-exposure pictures of faces and houses were presented side by side. Subjects were cued to attend to either the face or the house component of the stimuli, and were instructed to perform a matching task with the two exemplars from the attended category. The cue changed every 4–7 trials to instruct subjects to shift attention from one stimulus component to the other. During placebo in both studies, reaction time (RT) associated with the first trial following a cued shift in attention was longer than RT associated with later trials (p<0.05); RT also was significantly longer when attending to houses than to faces (p<0.05). Physostigmine decreased RT relative to placebo preferentially during trials greater than one (p<0.05), with no change during trial one; and decreased RT preferentially during the attention to houses condition (p<0.05) vs attention to faces. Scopolamine increased RT relative to placebo selectively during trials greater than one (p<0.05), and preferentially increased RT during the attention to faces condition (p<0.05). The results suggest that enhancement or impairment of cholinergic activity preferentially influences the maintenance of selective attention (ie trials greater than 1). Moreover, effects of cholinergic manipulation depend on the selective attention condition (ie faces vs houses), which may suggest that cholinergic activity interacts with stimulus salience. The findings are discussed within the context of the role of acetylcholine both in stimulus processing and stimulus salience, and in establishing attention biases through top-down and bottom-up mechanisms of attention
The babyPose dataset
none5noThe database here described contains data relevant to preterm infants' movement acquired in neonatal intensive care units (NICUs). The data consists of 16 depth videos recorded during the actual clinical practice. Each video consists of 1000 frames (i.e., 100s). The dataset was acquired at the NICU of the Salesi Hospital, Ancona (Italy). Each frame was annotated with the limb-joint location. Twelve joints were annotated, i.e., left and right shoul- der, elbow, wrist, hip, knee and ankle. The database is freely accessible at http://doi.org/10.5281/zenodo.3891404. This dataset represents a unique resource for artificial intelligence researchers that want to develop algorithms to provide healthcare professionals working in NICUs with decision support. Hence, the babyPose dataset is the first annotated dataset of depth images relevant to preterm infants' movement analysis.openMigliorelli L.; Moccia S.; Pietrini R.; Carnielli V.P.; Frontoni E.Migliorelli, L.; Moccia, S.; Pietrini, R.; Carnielli, V. P.; Frontoni, E
The Effect of Visual Experience on the Development of Functional Architecture in hMT+
We investigated whether the visual hMT+ cortex plays a role in supramodal representation of sensory flow, not mediated by visual mental imagery. We used functional magnetic resonance imaging to measure neural activity in sighted and congenitally blind individuals during passive perception of optic and tactile flows. Visual motion–responsive cortex, including hMT+, was identified in the lateral occipital and inferior temporal cortices of the sighted subjects by response to optic flow. Tactile flow perception in sighted subjects activated the more anterior part of these cortical regions but deactivated the more posterior part. By contrast, perception of tactile flow in blind subjects activated the full extent, including the more posterior part. These results demonstrate that activation of hMT+ and surrounding cortex by tactile flow is not mediated by visual mental imagery and that the functional organization of hMT+ can develop to subserve tactile flow perception in the absence of any visual experience. Moreover, visual experience leads to a segregation of the motion-responsive occipitotemporal cortex into an anterior subregion involved in the representation of both optic and tactile flows and a posterior subregion that processes optic flow only
"Comets" orbiting a black hole
We use a long (300 ksec), continuous Suzaku X-ray observation of the active
nucleus in NGC1365 to investigate the structure of the circumnuclear BLR clouds
through their occultation of the X-ray source. The variations of the absorbing
column density and of the covering factor indicate that the clouds surrounding
the black hole are far from having a spherical geometry (as sometimes assumed),
instead they have a strongly elongated and cometary shape, with a dense head
(n=10^11 cm^-3) and an expanding, dissolving tail. We infer that the cometary
tails must be longer than a few times 10^13 cm and their opening angle must be
smaller than a few degrees. We suggest that the cometary shape may be a common
feature of BLR clouds in general, but which has been difficult to recognize
observationally so far. The cometary shape may originate from shocks and
hydrodynamical instabilities generated by the supersonic motion of the BLR
clouds into the intracloud medium. As a consequence of the mass loss into their
tail, we infer that the BLR clouds probably have a lifetime of only a few
months, implying that they must be continuously replenished. We also find a
large, puzzling discrepancy (two orders of magnitude) between the mass of the
BLR inferred from the properties of the absorbing clouds and the mass of the
BLR inferred from photoionization models; we discuss the possible solutions to
this discrepancy.Comment: Accepted for publication in A&A. 11 pages, 9 figure
LIN7 regulates the filopodia and neurite promoting activity of IRSp53
The insulin receptor substrate protein of 53\u2005kDa (IRSp53) is critically involved in the formation of filopodia and neurites through mechanisms that have only in part been clarified. Here, we investigated the role of the small scaffold protein LIN7, an interactor of IRSp53. We found that formation of actin-filled protrusions in neuronal NSC34 cells and neurites in neuroblastoma N2A depends on motifs mediating the LIN7:IRSp53 association, as both the coexpression of LIN7 with IRSp53 or the expression of the L27-IRSp53 chimera (a fusion protein between IRSp53 and the LIN7L27 domain for plasma membrane protein complexes association) prevented actin-deficient protrusions induced by overexpressed IRSp53, and enhanced the formation of actin-filled protrusions. The regulatory role of LIN7 in IRSp53-mediated extension of filopodia was demonstrated by live-cell imaging experiments in neuronal N2A cells. Moreover, LIN7 silencing prevented the extension of filopodia and neurites, induced by ectopic expression of IRSp53 or serum starvation, respectively in undifferentiated and differentiated N2A cells. The expression of full length IRSp53 or the LIN7\u394PDZ mutant lacking the domain for association with IRSp53 was unable to restore neuritogenesis in LIN7 silenced cells. Conversely, defective neuritogenesis could be rescued by the expression of RNAi-resistant full length LIN7 or chimeric L27-IRSp53. Finally, LIN7 silencing prevented the recruitment of IRSp53 in Triton X-100 insoluble complexes, otherwise occurring in differentiated cells. Collectively these data indicate that LIN7 is a novel regulator of IRSp53, and that their association is required to promote the formation of actin-dependent filopodia and neurites
Brain imaging and human nutrition: which measures to use in intervention studies?
The present review describes brain imaging technologies that can be used to assess the effects of nutritional interventions in human subjects. Specifically, we summarise the biological relevance of their outcome measures, practical use and feasibility, and recommended use in short- and long-term nutritional studies. The brain imaging technologies described consist of MRI, including diffusion tensor imaging, magnetic resonance spectroscopy and functional MRI, as well as electroencephalography/magnetoencephalography, near-IR spectroscopy, positron emission tomography and single-photon emission computerised tomography. In nutritional interventions and across the lifespan, brain imaging can detect macro- and microstructural, functional, electrophysiological and metabolic changes linked to broader functional outcomes, such as cognition. Imaging markers can be considered as specific for one or several brain processes and as surrogate instrumental endpoints that may provide sensitive measures of short- and long-term effects. For the majority of imaging measures, little information is available regarding their correlation with functional endpoints in healthy subjects; therefore, imaging markers generally cannot replace clinical endpoints that reflect the overall capacity of the brain to behaviourally respond to specific situations and stimuli. The principal added value of brain imaging measures for human nutritional intervention studies is their ability to provide unique in vivo information on the working mechanism of an intervention in hypothesis-driven research. Selection of brain imaging techniques and target markers within a given technique should mainly depend on the hypothesis regarding the mechanism of action of the intervention, level (structural, metabolic or functional) and anticipated timescale of the intervention's effects, target population, availability and costs of the technique
Cell-Sized confinement in microspheres accelerates the reaction of gene expression
Cell-sized water-in-oil droplet covered by a lipid layer was used to understand how lipid membranes affect biochemical systems in living cells. Here, we report a remarkable acceleration of gene expression in a cell-sized water-in-oil droplet entrapping a cell-free translation system to synthesize GFP (green fluorescent protein). The production rate of GFP (VGFP) in each droplet remained almost constant at least for on the order of a day, which implies 0th-order reaction kinetics. Interestingly, VGFP was inversely proportional to radius of droplets (R) when R is under 50 μm, and VGFP in droplets with R ∼ 10 μm was more than 10 times higher than that in the bulk. The acceleration rates of GFP production in cell-sized droplets strongly depended on the lipid types. These results demonstrate that the membrane surface has the significant effect to facilitate protein production, especially when the scale of confinement is on the order of cell-size
Multivoxel Pattern Analysis Reveals Auditory Motion Information in MT+ of Both Congenitally Blind and Sighted Individuals
Cross-modal plasticity refers to the recruitment of cortical regions involved in the processing of one modality (e.g. vision) for processing other modalities (e.g. audition). The principles determining how and where cross-modal plasticity occurs remain poorly understood. Here, we investigate these principles by testing responses to auditory motion in visual motion area MT+ of congenitally blind and sighted individuals. Replicating previous reports, we find that MT+ as a whole shows a strong and selective responses to auditory motion in congenitally blind but not sighted individuals, suggesting that the emergence of this univariate response depends on experience. Importantly, however, multivoxel pattern analyses showed that MT+ contained information about different auditory motion conditions in both blind and sighted individuals. These results were specific to MT+ and not found in early visual cortex. Basic sensitivity to auditory motion in MT+ is thus experience-independent, which may be a basis for the region's strong cross-modal recruitment in congenital blindness
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